WO2025205180A1 - Plasma processing apparatus and processing method - Google Patents

Abstract

This plasma processing apparatus includes: a processing container configured to be capable of decompression; a support part provided in the processing container and configured to support a workpiece; a heat-transfer-layer-forming part configured to form a deformable heat transfer layer for the workpiece, the heat transfer layer made from at least one of a liquid layer and a solid layer, on a placement surface of the support part on which the workpiece is placed; an exhaust line configured to perform exhaust from a processing space in the processing container; and a bypass line for bypassing the exhaust line. The bypass line is provided with a trap configured to collect the gaseous heat transfer layer included in the exhaust from the processing space.

Description

Plasma processing apparatus and processing method

This disclosure relates to a plasma processing apparatus and processing method.

Patent Document 1 discloses a substrate processing apparatus that includes a mounting table having a mounting surface on which a substrate is placed and a gas supply pipe for supplying a heat transfer gas into the gap between the substrate and the mounting surface.

Japanese Patent Application Laid-Open No. 2020-120081

The technology disclosed herein efficiently regulates the temperature of a workpiece during plasma processing.

One aspect of the present disclosure is a plasma processing apparatus comprising: a processing vessel configured to be depressurized; a support section provided within the processing vessel for supporting a workpiece; a heat transfer layer forming section configured to form a deformable heat transfer layer for the workpiece, the heat transfer layer being composed of at least one of a liquid layer and a solid layer, on a mounting surface of the support section on which the workpiece is placed; an exhaust line for exhausting air from the processing space within the processing vessel; and a bypass line that bypasses the exhaust line, the bypass line having a trap interposed therein for collecting gaseous heat transfer layer contained in the exhaust air from the processing space.

According to the present disclosure, the temperature of a workpiece can be efficiently adjusted during plasma processing.

1 is a vertical cross-sectional view showing an outline of a configuration of a plasma processing apparatus according to a first embodiment. 2 is a flowchart for explaining an example of wafer processing performed using the plasma processing apparatus of FIG. 1 . 2 is a diagram showing a state of the plasma processing apparatus shown in FIG. 1 during wafer processing performed using the plasma processing apparatus; 2 is a diagram showing a state of the plasma processing apparatus shown in FIG. 1 during wafer processing performed using the plasma processing apparatus; 2 is a diagram showing a state of the plasma processing apparatus shown in FIG. 1 during wafer processing performed using the plasma processing apparatus; 2 is a diagram showing a state of the plasma processing apparatus shown in FIG. 1 during wafer processing performed using the plasma processing apparatus; FIG. 2 is a diagram showing vapor pressure curves of constituent materials of a heat transfer layer. 2 is a diagram showing a state of the plasma processing apparatus shown in FIG. 1 during wafer processing performed using the plasma processing apparatus; 2 is a diagram showing a state of the plasma processing apparatus shown in FIG. 1 during wafer processing performed using the plasma processing apparatus; FIG. 2 is a partially enlarged cross-sectional view of a wafer placement surface. FIG. 2 is a partially enlarged cross-sectional view of a wafer placement surface. FIG. 10 is a diagram for explaining another example of the bypass line. 10A and 10B are diagrams for explaining another example of a form in which the source gas of the heat transfer layer is condensed on the surface of the wafer support table. 10A and 10B are diagrams for explaining another example of a form in which the source gas of the heat transfer layer is condensed on the surface of the wafer support table. 10A and 10B are diagrams for explaining another example of a form in which the source gas of the heat transfer layer is condensed on the surface of the wafer support table. FIG. 10 is a diagram showing a first modified example of a gas supply unit for a heat transfer layer forming gas. FIG. 10 is a diagram showing another example of the raw material of the heat transfer layer. FIG. 10 is a plan view schematically showing a modified example of an electrode of an electrostatic chuck. FIG. 10 is a cross-sectional view schematically showing a modified example of an electrode of an electrostatic chuck. FIG. 10 is a cross-sectional view schematically showing a modified example of an electrode of an electrostatic chuck. FIG. 10 is a cross-sectional view schematically showing a modified example of an electrode of an electrostatic chuck. FIG. 10 is a plan view schematically showing a modified example of an electrode of an electrostatic chuck. FIG. 10 is a diagram showing an example of a heat transfer layer on a wafer placement surface. FIG. 10 is a diagram showing an example in which the central portion of the electrostatic chuck is formed to have a diameter larger than the diameter of the wafer. 10A and 10B are diagrams showing other examples of the manner in which a wafer is placed on a wafer placement surface.

In the manufacturing process of semiconductor devices, etc., plasma processing such as etching and film formation is performed on semiconductor wafers (hereinafter referred to as "wafers") as workpieces using plasma. Plasma processing is performed with the substrate supported on a substrate support table inside a reduced-pressure processing chamber.

Incidentally, since the results of plasma processing depend on the temperature of the substrate, the temperature of the substrate support table is adjusted during plasma processing, and the temperature of the substrate is adjusted via this substrate support table.
Conventionally, a heat transfer gas such as He gas is supplied between the substrate support table and the substrate so that the temperature of the substrate can be efficiently adjusted via the substrate support table.

However, in cases where the heat input from the plasma to the substrate during plasma processing is large, the temperature of the substrate may not be sufficiently adjusted even if the heat transfer gas is used as described above.
Furthermore, the temperature of an object other than the substrate may be adjusted via the substrate support table.

The technology disclosed herein efficiently adjusts the temperature of a workpiece, such as a substrate, via a support stand during plasma processing.

The plasma processing apparatus and processing method according to this embodiment will be described below with reference to the drawings. Note that in this specification and drawings, elements having substantially the same functional configuration will be assigned the same reference numerals, and redundant explanations will be omitted.

(First embodiment)
<Plasma processing apparatus 1>
FIG. 1 is a vertical cross-sectional view showing an outline of the configuration of a plasma processing apparatus 1 according to the first embodiment.
1 performs a desired process on a wafer W under a reduced pressure atmosphere (vacuum atmosphere). Specifically, the plasma processing apparatus 1 performs plasma processes on the wafer W, such as etching and film formation.

The plasma processing apparatus 1 includes a plasma processing chamber 100 as a processing vessel, gas supply units 120 and 130, an RF (Radio Frequency) power supply unit 140, and an exhaust system 150. Furthermore, the plasma processing apparatus 1 includes a wafer support table 101 and an upper electrode 102 as support units.

The wafer support pedestal 101 is disposed in the lower region of the plasma processing space 100s within the plasma processing chamber 100, the interior of which can be depressurized. The upper electrode 102 is disposed above the wafer support pedestal 101. The upper electrode 102 can also function as part of a wall defining the plasma processing space 100s, and more specifically, can function as part of the ceiling of the plasma processing chamber 100.

The wafer support pedestal 101 is configured to support a wafer W in the plasma processing space 100s. In one embodiment, the wafer support pedestal 101 includes a lower electrode 103, an electrostatic chuck 104, an insulator 105, and legs 106, and is provided with a lifter 107. The wafer support pedestal 101 also includes a temperature adjustment unit configured to adjust the temperature of the electrostatic chuck 104 (e.g., the temperature of the upper surface _104-1 at the center thereof), etc. The temperature adjustment unit includes, for example, a heater, a flow path, or a combination thereof. A temperature-controlling fluid such as a coolant or a heat transfer gas flows through the flow path.

The lower electrode 103 is formed of a conductive material such as aluminum and is fixed to the insulator 105. In one embodiment, a flow path 108 for the temperature control fluid is formed inside the lower electrode 103, constituting part of the temperature control unit. The temperature control fluid is supplied to the flow path 108 from, for example, a chiller unit (not shown) provided outside the plasma processing chamber 100. The temperature control fluid supplied to the flow path 108 returns to the chiller unit. For example, by circulating low-temperature brine as the temperature control fluid through the flow path 108, the electrostatic chuck 104 and the wafer W and edge ring E placed on the electrostatic chuck 104 can be cooled to a predetermined temperature. Furthermore, for example, by circulating high-temperature brine as the temperature control fluid through the flow path 108, the electrostatic chuck 104 and the wafer W and edge ring E placed on the electrostatic chuck 104 can be heated to a predetermined temperature.

The electrostatic chuck 104 is a member configured to attract and hold the wafer W by electrostatic force, and is provided on the lower electrode 103. In one embodiment, the electrostatic chuck 104 is formed such that the upper surface of the central portion is higher than the upper surface of the peripheral portion. The upper surface _104-1 of the central portion of the electrostatic chuck 104 serves as a wafer mounting surface on which the wafer W is mounted, and the upper surface _104-2 of the peripheral portion of the electrostatic chuck 104 serves as a ring mounting surface on which an edge ring E is mounted. The edge ring E is an annular member in a plan view that surrounds the wafer W mounted on the upper surface _104-1 of the central portion of the electrostatic chuck 104 and is disposed adjacent to the wafer W.

The electrostatic chuck 104 is an example of a fixing portion that fixes the wafer W to an upper surface ₁₀₄₁ , i.e., a wafer mounting surface, at the center of the electrostatic chuck 104. An electrode 109 is provided at the center of the electrostatic chuck 104.

A DC voltage is applied from a DC power supply (not shown) to the electrode 109. The resulting electrostatic force attracts and holds the wafer W onto the upper surface ₁₀₄₁ at the center of the electrostatic chuck 104.
In one embodiment, the electrostatic chuck 104 is configured to be able to attract and hold the edge ring E by electrostatic force, and is provided with an electrode (not shown) for holding the edge ring E to the wafer support table 101 by electrostatic attraction.
In one embodiment, gas supply holes (not shown) are formed in the upper surface ₁₀₄₂ of the peripheral portion of the electrostatic chuck 104 to supply a heat transfer gas, such as He gas, to the back surface _of the edge ring E placed on the upper surface 1042. The heat transfer gas is supplied from a gas supply unit (not shown) through the gas supply holes. The gas supply unit may include one or more gas sources and one or more pressure controllers. In one embodiment, the gas supply unit is configured to supply the heat transfer gas from the gas source to the gas supply holes via the pressure controller, for example.

Furthermore, the central portion of the electrostatic chuck 104 is formed, for example, with a diameter smaller than the diameter of the wafer W, so that when the wafer W is placed on the upper surface (hereinafter referred to as the wafer placement surface) _104-1 of the central portion of the electrostatic chuck 104, the peripheral portion of the wafer W protrudes beyond the central portion of the electrostatic chuck 104.
The edge ring E has, for example, a step formed on its upper portion, such that the upper surface of the outer periphery is higher than the upper surface of the inner periphery. The inner periphery of the edge ring E is formed to be recessed under the peripheral edge of the wafer W that protrudes from the center of the electrostatic chuck 104.

A heater (specifically, a resistance heating element) constituting a part of the temperature adjustment unit may be provided inside the electrostatic chuck 104. By passing electricity through the heater, the electrostatic chuck 104 and the wafer W placed on the electrostatic chuck 104 can be heated to a predetermined temperature. In this case, the electrostatic chuck 104 has a configuration in which, for example, an electrode 109 for attracting a wafer and an electrode for attracting an edge ring are sandwiched between insulating materials made of an insulating material, and the heater is embedded therein.
The central portion of the electrostatic chuck 104, on which the electrode 109 for attracting the wafer is provided, and the peripheral portion of the electrostatic chuck 104, on which the electrode for attracting the edge ring is provided, may be formed integrally or separately.

The insulator 105 is a disk-shaped member made of ceramic or the like, to which the lower electrode 103 is fixed. The insulator 105 is formed to have the same diameter as the lower electrode 103, for example.

The legs 106 are cylindrical members made of ceramic or the like, and support the electrostatic chuck 104 via the lower electrode 103 and the insulator 105. The legs 106 are formed, for example, to have an outer diameter equal to the outer diameter of the insulator 105, and support the peripheral edge of the insulator 105.

The lifter 107 is a lifting member that moves up and down relative to the wafer mounting surface _104-1 of the electrostatic chuck 104, and is formed, for example, in a columnar shape. When the lifter 107 is raised, its upper end protrudes from the wafer mounting surface _104-1 , enabling it to support the wafer W. The lifter 107 allows the wafer W to be transferred between the electrostatic chuck 104 and the transfer arm 71 of the transfer mechanism 70.
Three or more lifters 107 are provided at intervals from one another and extend in the vertical direction.

Each lifter 107 is connected to a support member 110 that supports the lifter 107. The support member 110 is also connected to a drive unit 111 that generates a driving force to raise and lower the support member 110 and raise and lower the multiple lifters 107. The drive unit 111 has, for example, an actuator (not shown) as a driving source that generates the driving force.

The lifter 107 is inserted into an insertion hole 112 whose upper end opens to the wafer mounting surface _104-1 of the electrostatic chuck 104. The insertion hole 112 is formed so as to penetrate, for example, the central portion of the electrostatic chuck 104, the lower electrode 103, and the insulator 105.
The lifter 107 , the support member 110 and the drive unit 111 constitute a lifting mechanism that lifts and lowers the wafer W relative to the wafer placement surface 104 _-1 .

The upper electrode 102 also functions as a shower head that supplies various gases from the gas supply unit 120 to the plasma processing space 100s. In one embodiment, the upper electrode 102 has a gas inlet 102a, a gas diffusion chamber 102b, and multiple gas inlets 102c. The gas inlet 102a is fluidly connected to, for example, the gas supply unit 120 and the gas diffusion chamber 102b. The multiple gas inlets 102c are fluidly connected to the gas diffusion chamber 102b and the plasma processing space 100s. In one embodiment, the upper electrode 102 is configured to supply various gases from the gas inlet 102a to the plasma processing space 100s via the gas diffusion chamber 102b and the multiple gas inlets 102c.

The gas supply unit 120 may include one or more gas sources 121 and one or more flow controllers 122. In one embodiment, the gas supply unit 120 is configured to supply, for example, one or more process gases from the corresponding gas sources 121 to the gas inlet 102a via the corresponding flow controllers 122. Each flow controller 122 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 120 may include one or more flow modulation devices that modulate or pulse the flow rate of one or more process gases. In one embodiment, the gas supply unit 120 also functions as an inert gas supply unit that supplies an inert gas, such as _N2 gas, to the plasma processing space 100s.

Furthermore, in one embodiment, a gas containing a raw material gas that will be the raw material for the heat transfer layer D (described below), i.e., a heat transfer layer forming gas, is supplied from the gas supply unit 130 to the plasma processing space 100s through the sidewall of the plasma processing chamber 100. In this case, for example, a gas inlet 100k that is fluidly connected to the plasma processing space 100s and to the gas supply unit 130 is provided in the sidewall of the plasma processing chamber 100, and the heat transfer layer forming gas from the gas supply unit 130 is supplied to the plasma processing space 100s via the sidewall (specifically, the gas inlet 100k).

The gas supply unit 130 may include one or more gas sources 131 and one or more flow rate controllers 132. In one embodiment, the gas supply unit 130 is configured to supply, for example, a heat transfer layer forming gas from the gas source 131 to the gas inlet 100k via the flow rate controller 132.
The gas source 131 includes, for example, a tank 131a that stores a raw material liquid for the heat transfer layer D, and a vaporizer 131b that vaporizes the raw material liquid to generate a raw material gas. The gas source 131 may also be connected to a supply path (not shown) for an inert gas as a carrier gas. In this case, for example, a mixed gas of a raw material gas and a carrier gas is supplied from the gas source 131 as a gas for forming the heat transfer layer.
Each flow controller 132 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply section 130 may include one or more flow modulation devices that modulate or pulse the flow rate of one or more heat transfer layer forming gases.
A liquid heat transfer layer D is formed on, for example, the wafer mounting surface _104-1 of the wafer support table 101 from the heat transfer layer forming gas containing the source gas supplied from the gas supply unit 130. Therefore, the gas supply unit 130 can function as at least a part of the heat transfer layer forming unit configured to form the heat transfer layer D on the wafer mounting surface _104-1 .

The RF power supply unit 140 is configured to supply RF power, e.g., one or more RF signals, to one or more electrodes, such as the lower electrode 103, the upper electrode 102, or both the lower electrode 103 and the upper electrode 102. Instead of the lower electrode 103, it may be configured to supply RF power to the electrode 109 provided in the electrostatic chuck 104. This generates plasma from one or more process gases supplied to the plasma processing space 100s. Therefore, the RF power supply unit 140 can function as at least a part of a plasma generation unit configured to generate plasma from one or more process gases in the plasma processing chamber 100.

The RF power supply unit 140 includes, for example, two RF generating units 141a and 141b and two matching circuits 142a and 142b. In one embodiment, the RF power supply unit 140 is configured to supply a first RF signal from the first RF generating unit 141a to the lower electrode 103 via the first matching circuit 142a. For example, the first RF signal may have a frequency in the range of 27 MHz to 100 MHz.

In one embodiment, the RF power supply unit 140 is configured to supply a second RF signal from the second RF generation unit 141b to the lower electrode 103 via the second matching circuit 142b. For example, the second RF signal may have a frequency in the range of 400 kHz to 13.56 MHz. A voltage pulse other than RF may be supplied instead of the second RF signal. The voltage pulse may be a negative DC voltage. In another example, the voltage pulse may be a triangular wave or an impulse.

Furthermore, although not shown, other embodiments are contemplated in the present disclosure. For example, in an alternative embodiment, the RF power supply 140 may be configured to supply a first RF signal from an RF generator to the lower electrode 103, a second RF signal from another RF generator to the lower electrode 103, and a third RF signal from yet another RF generator to the lower electrode 103. Additionally, in another alternative embodiment, a DC voltage may be applied to the upper electrode 102.

Furthermore, in various embodiments, the amplitude of one or more RF signals (i.e., the first RF signal, the second RF signal, etc.) may be pulsed or modulated. Amplitude modulation may include pulsing the RF signal amplitude between an on state and an off state, or between two or more different on states.

The exhaust system 150 has an exhaust line 160 that exhausts air from the plasma processing space 100s and a bypass line 170 that bypasses the exhaust line 160.

The upstream end of the exhaust line 160 is connected to, for example, an exhaust port 100e provided at the bottom of the plasma processing chamber 100. Pumps are provided in the exhaust line 160, and more specifically, for example, a turbo molecular pump 161 as a first exhaust pump and a dry pump 162 as a second exhaust pump are provided in this order from the upstream side.
In one embodiment, an automatic pressure control (APC) valve 163 is provided upstream of the turbomolecular pump 161 in the exhaust line 160, and an on-off valve 164 is provided between the turbomolecular pump 161 and the dry pump 162 in the exhaust line 160. The automatic pressure control valve 163 has, for example, an automatic pressure adjustment function and also a shutoff function.

As described above, the bypass line 170 bypasses the exhaust line 160. Specifically, the bypass line 170 bypasses the upstream side of the exhaust line 160, and more specifically, bypasses the portion of the exhaust line 160 where the turbomolecular pump 161 is provided. The upstream end of the bypass line 170 is connected, for example, to the upstream side of the turbomolecular pump 161 in the exhaust line 160, and specifically, to the upstream side of the automatic pressure control valve 163 in the exhaust line 160. The downstream end of the bypass line 170 is connected, for example, between the turbomolecular pump 161 and the dry pump 162 in the exhaust line 160, and specifically, between the on-off valve 164 and the dry pump 162 in the exhaust line 160. This configuration makes it possible to exhaust air from the plasma processing space 100s via the bypass line 170.

Furthermore, a trap 171 for collecting the gaseous heat transfer layer D contained in the exhaust gas from the plasma processing space 100s is provided in the bypass line 170. The gaseous heat transfer layer D collected in the trap 171 is at least either the source gas of the heat transfer layer D or the vaporized product of the heat transfer layer D.
In one embodiment, an on-off valve 172 is provided upstream of the trap 171 in the bypass line 170, and a pressure adjustment valve 173 and an on-off valve 174 are provided downstream of the bypass line 170 in this order from the upstream side.

The plasma processing apparatus 1 further includes a control unit 200. In one embodiment, the control unit 200 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various steps described in this disclosure. The control unit 200 may be configured to control each of the other elements of the plasma processing apparatus 1 to perform the various steps described herein. In one embodiment, part or all of the control unit 200 may be included in the plasma processing apparatus 1. The control unit 200 may include a processing unit 211, a memory unit 212, and a communication interface 213. The control unit 200 is realized, for example, by a computer 210. The processing unit 211 may be configured to perform various control operations by reading a program from the memory unit 212 and executing the read program. This program may be stored in the memory unit 212 in advance, or may be acquired via a medium when needed. The acquired program is stored in the memory unit 212 and read from the memory unit 212 by the processing unit 211 for execution. The medium may be any of various storage media readable by the computer 210, or may be a communication line connected to the communication interface. The processing unit 211 may be a CPU (Central Processing Unit) or one or more circuits. The storage unit 212 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 213 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

<Wafer Processing in Plasma Processing Apparatus 1>
Next, an example of wafer processing performed using the plasma processing apparatus 1 will be described with reference to FIGS. 2 to 9. FIG. 2 is a flowchart for explaining this example of wafer processing. FIGS. 3 to 6, 8, and 9 are diagrams showing the state of the plasma processing apparatus 1 during the wafer processing. In FIGS. 3 to 6, 8, and 9, open valves are shown in white, closed valves are shown in black, and pipes such as exhaust lines through which liquids and gases flow are shown in bold lines. FIG. 7 is a diagram showing vapor pressure curves of the constituent materials of the heat transfer layer D.

The following wafer processing is performed under the control of the control unit 200. During wafer processing, the temperature Tt of the trap 171 (specifically, the temperature of the space where the gas is liquefied and collected) is maintained at a temperature at which the gaseous heat transfer layer D is likely to liquefy, for example, a predetermined set temperature in the range of −100° C. to 25° C. Furthermore, during wafer processing, the temperature Ts of the wafer support table 101 (specifically, the temperature of the wafer mounting surface _104-1 ) is maintained at a temperature during plasma processing, for example, a predetermined set temperature in the range of −80° C. to 80° C. Furthermore, during wafer processing, the sidewall and upper electrode 102 of the plasma processing chamber (hereinafter referred to as the processing chamber) 100 that define the plasma processing space (hereinafter referred to as the processing space) 100s are maintained at a temperature at which the gaseous heat transfer layer D is unlikely to liquefy, for example, a predetermined set temperature in the range of 25° C. to 150° C.

(Step S1: Forming the heat transfer layer)
For example, first, as shown in FIG. 2, a heat transfer layer D is formed on the wafer mounting surface _104-1 of the wafer support table 101.

In this embodiment, the constituent material of the heat transfer layer D is a material that is liquid at a temperature T1 and a pressure P2, and is gaseous at a pressure P1, as shown in Fig. 7. A suitable material for practical use is one that satisfies the conditions of the temperature T1 in the range of -80°C to 80°C, the pressure P2 in the range of 0.01 Torr to 10 Torr, and the pressure P1 in the range of less than 0.01 Torr, as the constituent material of the heat transfer layer D. An example of such a constituent material is methyl benzolate.
Furthermore, as will be described later, in this embodiment, the wafer W is placed on the wafer placement surface _104-1 via the heat transfer layer D, and therefore the heat transfer layer D has a high surface tension in a liquid state so that the heat transfer layer D, which is in a liquid state when placed, does not flow around onto the surface, i.e., the upper surface, of the wafer W. Note that the term "liquid" also includes sols and gels that use a liquid as a dispersion medium.

Furthermore, the raw material gas for the heat transfer layer D contains, for example, at least one of B (boron) or C (carbon), which are constituent atoms of the heat transfer layer D, and at least one of H (hydrogen), N (nitrogen), or O (oxygen), which constitute the gas components. Furthermore, it is preferable that the raw material gas for the heat transfer layer D is composed of components that do not interfere with plasma processing.

Specifically, in forming the heat transfer layer D, first, the interior of the processing chamber 100, that is, the processing space 100s, is evacuated.
3, in a state where the processing gas is not supplied from the gas supply unit 120 and the heat transfer layer forming gas is not supplied from the gas supply unit 130, the automatic pressure control valve 163 of the exhaust line 160 is fully opened and the on-off valve 164 is opened. As a result, the turbo molecular pump 161 and the dry pump 162 exhaust air from the inside of the processing chamber 100, i.e., the processing space 100s, and the inside of the processing chamber 100 is depressurized to, for example, an achievable vacuum level.
At this time, the on-off valve 172, the pressure adjustment valve 173, and the on-off valve 174 provided in the bypass line 170 are closed. That is, the processing space 100s is not evacuated via the bypass line 170.

Next, the wafer W is loaded into the processing chamber 100 .
4 , the automatic pressure control valve 163 and the on-off valve 164 of the exhaust line 160 are switched to a closed state, for example, so that exhaust of the processing space 100s via the exhaust line 160 is stopped. Also, the on-off valves 172 and 174 of the bypass line 170 are opened, and the pressure control valve 173 is fully opened. That is, exhaust of the processing space 100s via the bypass line 170 is started.
Thereafter, the wafer W is carried into the processing chamber 100 by a transfer mechanism (not shown) external to the plasma processing apparatus 1, and is transferred to the raised lifter 107. After the transfer, the transfer mechanism is retracted from the processing chamber 100.

Subsequently, the source gas for the heat transfer layer D is supplied into the processing chamber 100 .
Specifically, as shown in FIG. 5 , for example, in a state where the wafer W is supported by the lifter 107 and separated from the wafer mounting surface _104-1 of the wafer support pedestal 101, and the processing space 100s is evacuated via the bypass line 170, a heat-transfer layer forming gas containing a source gas is supplied from the gas supply unit 130. In this case, in the illustrated example, no processing gas is supplied from the gas supply unit 120. The supply of the heat-transfer layer forming gas replaces the atmosphere in the processing space 100s with the heat-transfer layer forming gas. During this replacement, the pressure value in the processing space 100s is set to P1, and the temperature Ts of the wafer support pedestal 101 (specifically, the temperature of the wafer mounting surface _104-1 ) is set to T1. The pressure value P1 is a pressure value at which the source gas for the heat-transfer layer D becomes less than the saturated vapor pressure at the temperature T1. For example, the temperature T1 is −80° C. to 80° C., and P1 is less than 0.01 Torr. The temperature Ts of the wafer support table 101 is set by the temperature adjustment unit of the wafer support table 101, and the pressure in the processing space 100s is set by adjusting at least one of the flow rate of the heat transfer layer forming gas or the exhaust rate via the bypass line 170 (specifically, the opening degree of the pressure adjustment valve 173).

During the above-mentioned replacement, the raw material gas for the heat transfer layer D in the heat transfer layer forming gas that has reached the bypass line 170 is condensed and recovered by the trap 171 .
The temperature of the trap 171 is set to Tt so that the source gas in the heat transfer layer D is condensed by the trap 171. The temperature Tt is lower than the temperature at which the source gas liquefies at the pressure P1 and is lower than the temperature T1 (Ts).

Thereafter, the pressure inside the processing chamber 100 is increased, and a liquid heat transfer layer D is formed on the wafer mounting surface ₁₀₄₁ of the wafer support table 101.
6 , for example, in a state where the wafer W is supported by the lifter 107 and separated from the wafer mounting surface _104-1 of the wafer support pedestal 101, and a heat-transfer-layer-forming gas is being supplied from the gas supply unit 130, the on-off valves 172 and 174 of the bypass line 170 are switched to a closed state. This stops exhaust from the processing space 100s, including exhaust via the bypass line 170, and increases the pressure value within the processing space 100s to P2. The pressure value P2 is a pressure value higher than the saturated vapor pressure of the source gas for the heat-transfer layer D at the temperature Ts of the wafer support pedestal 101, and is, for example, 0.01 to 10 Torr. As a result of the pressure increase, the source gas for the heat-transfer layer D condenses on the surface of the wafer support pedestal 101, forming a liquid heat-transfer layer D at least on the wafer mounting surface _104-1 . After the heat-transfer layer D is formed, the supply of the heat-transfer-layer-forming gas from the gas supply unit 130 is stopped.

Note that the temperature of the region other than the wafer mounting surface _104-1 may be set to Tw in order to prevent the formation of the heat transfer layer D in the region other than the wafer mounting surface _104-1 . For example, heaters may be provided on the sidewalls and upper electrode 102 of the plasma processing chamber 100, and the temperatures of the sidewalls and upper electrode 102 of the plasma processing chamber 100 may be adjusted to Tw. The temperature Tw is higher than the temperature at which the source gas liquefies at the pressure value P2, and is higher than the temperature T1 (Ts).

(Step S2: Wafer placement)
Next, the wafer W is placed on the wafer placement surface ₁₀₄₁ of the wafer support table 101 .

Specifically, for example, first, the lifter 107 is lowered, and the wafer W is placed on the wafer placement surface ₁₀₄₁ of the electrostatic chuck 104 with the liquid heat transfer layer D interposed therebetween, as shown in FIG.
Next, the heat transfer layer D formed on the portions of the wafer support table 101 other than the wafer mounting surface _104-1 is removed. Specifically, the on-off valves 172 and 174 of the bypass line 170 are switched to an open state, for example, so that the processing space 100s is evacuated via the bypass line 170. By evacuating the processing space 100s via the bypass line 170, the pressure in the processing space 100s is made less than the saturated vapor pressure of the source gas of the heat transfer layer D relative to the set temperature of the wafer mounting surface 104-1 of the wafer support table _101. For example, while maintaining the temperature Ts of the wafer mounting surface _104-1 at T1, the pressure value of the processing space 100s is set to the aforementioned _P1 . As a result, the heat transfer layer D formed on the portions other than the wafer mounting surface _104-1 is exposed to a reduced-pressure atmosphere, and as a result, is vaporized and removed. In this case, the wafer W may be fixed to the wafer mounting surface _104-1 to suppress vaporization of the heat transfer layer D formed on the wafer mounting surface 104-1. Specifically, a DC voltage may be applied to the electrode 109 of the electrostatic chuck 104 so that the wafer W is electrostatically attracted to the electrostatic chuck 104 by electrostatic force.

When the heat transfer layer D is removed, the vaporized product of the heat transfer layer D that reaches the bypass line 170 is condensed and collected by the trap 171 .
The temperature of the trap 171 is set to Tt so that the vaporized matter in the heat transfer layer D is condensed by the trap 171. The temperature Tt is lower than the temperature at which the source gas liquefies at the pressure P1 and is lower than the temperature T1 (Ts).

(Step S3: Plasma treatment)
Thereafter, the wafer W on the wafer mounting surface ₁₀₄₁ on which the heat transfer layer D is formed is subjected to plasma processing such as etching and film formation.

Specifically, first, as shown in FIG. 9 , exhaust of the processing space 100s via the bypass line 170 is stopped, and then the on-off valves 172 and 174 of the bypass line 170 are switched to an open state, and the on-off valve 164 of the exhaust line 160 is switched to an open state so that exhaust of the processing space 100s via the exhaust line 160 is started.
Next, a processing gas is supplied from the gas supply unit 120 to the processing space 100s via the upper electrode 102, and high-frequency power HF for plasma generation is supplied from the RF power supply unit 140 to the lower electrode 103. This excites the processing gas and generates plasma P. At this time, high-frequency power LF for ion attraction may also be supplied from the RF power supply unit 140. Then, plasma processing is performed on the wafer W by the action of the generated plasma P.

During plasma processing, the wafer mounting surface ₁₀₄₁ is regulated to a predetermined temperature by a temperature-regulating fluid flowing through the flow path 108 to regulate the temperature of the wafer W. During plasma processing, the wafer W is mounted on the wafer mounting surface ₁₀₄₁ via a liquid heat-transfer layer D, and because the heat-transfer layer D is made of a deformable liquid, the lower surface, i.e., the back surface, of the wafer W is in close contact with the heat-transfer layer D. Because the heat-transfer layer D is liquid, it has higher thermal conductivity than a heat-transfer gas such as He. Therefore, when the liquid heat-transfer layer D is used, the temperature of the wafer W can be more efficiently regulated via the wafer mounting surface ₁₀₄₁ than in the conventional case where a heat-transfer gas such as He is flowed between the wafer mounting surface ₁₀₄₁ and the back surface of the wafer W. Specifically, even if a large amount of heat is input from the plasma P to the wafer W during plasma processing, the temperature of the wafer W can be maintained constant by regulating the temperature of the wafer mounting surface ₁₀₄₁ .

During plasma processing, the wafer W may be held or fixed to the wafer support table 101 (specifically, the wafer mounting surface 104 ₁ ) in order to bring the heat transfer layer D and the lower surface of the wafer W into closer contact with each other. For example, the wafer W may be attracted and held to the wafer mounting surface 104 ₁ by electrostatic force generated by the electrostatic chuck 104. More specifically, a DC voltage may be applied to the electrode 109 of the electrostatic chuck 104, so that the wafer W is electrostatically attracted to the electrostatic chuck 104 by electrostatic force. By holding the wafer W in the above manner, the temperature of the wafer W can be adjusted more efficiently.
In addition, when the wafer W is held on the wafer support table 101 by electrostatic force, the degree of adhesion of the wafer W to the wafer support table 101 may be controlled by electrostatic force, and heat removal from the wafer W by the wafer support table 101 may be controlled.

Similarly, during plasma processing, the edge ring E may be held or fixed to the wafer support table 101. For example, a DC voltage may be applied to an electrode (not shown) for attracting the edge ring provided on the electrostatic chuck 104, so that the edge ring E is electrostatically attracted to the electrostatic chuck 104 by electrostatic force.
During plasma processing, a heat transfer gas may be supplied to the rear surface of the edge ring E from gas supply holes (not shown) formed in the upper surface ₁₀₄₂ of the peripheral portion of the electrostatic chuck 104.

When plasma processing is terminated, the supply of high-frequency power HF from the RF power supply unit 140 and the supply of processing gas from the gas supply unit 130 are stopped. If high-frequency power LF was being supplied during plasma processing, the supply of that high-frequency power LF is also stopped. Furthermore, if the wafer W was being attracted and held by the electrostatic chuck 104 during plasma processing, this attraction and holding is also stopped. Furthermore, if the edge ring E was being attracted and held by the electrostatic chuck 104 and a heat transfer gas was being supplied to the back surface of the edge ring E during plasma processing, at least one of these may be stopped.

(Step S4: Wafer Separation)
After the plasma processing, the wafer W is separated from the wafer mounting surface ₁₀₄₁ .

Specifically, for example, as shown in FIG. 4, the wafer W is lifted by the lifter 107 and separated from the heat transfer layer D on the wafer placement surface ₁₀₄₁ .
Furthermore, the automatic pressure control valve 163 and the on-off valve 164 of the exhaust line 160 are switched to a closed state so as to stop exhausting the processing space 100s via the exhaust line 160. Furthermore, the on-off valves 172 and 174 of the bypass line 170 are switched to an open state so as to start exhausting the processing space 100s via the bypass line 170.

(Step S5: Removal of heat transfer layer)
Then, the heat transfer layer D is removed from the wafer mounting surface ₁₀₄₁ (step S6).

Specifically, the processing space 100s continues to be evacuated via the bypass line 170, and the pressure in the processing space 100s is made less than the saturated vapor pressure of the source gas of the heat transfer layer D at the temperature Ts of the wafer support table 101. As a result, the heat transfer layer D formed on the wafer mounting surface _104-1 is exposed to a reduced pressure atmosphere, and as a result, is vaporized and removed.
During the removal of the heat transfer layer D, the vaporized product of the heat transfer layer D that reaches the bypass line 170 is condensed and collected by the trap 171 .
In order to condense the vaporized material in the heat transfer layer D by the trap 171, the following adjustment is made: That is, the exhaust rate through the bypass line 170 is adjusted so that the pressure in the trap 171 exceeds the saturated vapor pressure of the source gas at the temperature Tt of the trap 171, specifically, exceeds 0.01 Torr.

When the heat-transfer layer D is removed from the wafer mounting surface _104-1 , the edge ring E may be held, i.e., fixed, to the wafer support table 101. For example, a DC voltage may be applied to an electrode (not shown) for attracting the edge ring provided on the electrostatic chuck 104, so that the edge ring E is electrostatically attracted to the electrostatic chuck 104 by electrostatic force.
Furthermore, when removing the heat transfer layer D from the wafer mounting surface _104-1 , a heat transfer gas may be supplied to the back surface of the edge ring E from a gas supply hole (not shown) formed in the upper surface _104-2 of the peripheral portion of the electrostatic chuck 104.

(Step S6: Unloading the wafer)
The wafer W is then unloaded from the processing chamber 100 .
Specifically, for example, while the processing space 100s continues to be evacuated via the bypass line 170, the wafer W is transferred via the lifter 107 to a transport mechanism (not shown) outside the plasma processing apparatus 1, and then transported out of the processing chamber 100 by the transport mechanism.
Thereafter, the process returns to step S1, where the processing space 100s is evacuated via the exhaust line 160, and the inside of the processing chamber 100 is depressurized to an achievable vacuum level, for example.
In this way, the series of wafer processing steps is completed.

<Another example of heat transfer layer D>
In the above example, the heat transfer layer D is formed as a liquid by condensing (liquefying) the source gas of the heat transfer layer D. However, the heat transfer layer D may be a solid layer as long as it is deformable. That is, the source gas of the heat transfer layer D may be sublimated (solidified) to form a deformable solid heat transfer layer D. Here, "deformable" means, for example, that the heat transfer layer D is deformable due to the weight of the wafer W. Furthermore, in the case where the wafer W is electrostatically attracted by the electrostatic chuck 104, "deformable" may also mean that the heat transfer layer D is deformable when an electrostatic attracting force acts on the wafer W.
Furthermore, the heat transfer layer D may be a combination of a liquid layer and a solid layer, provided that it is deformable.

In other words, the heat transfer layer D is a layer composed of at least one of a liquid layer and a solid layer, and is a deformable layer. It is also possible for the heat transfer layer D to have a top layer that comes into contact with the backside of the wafer W, which is composed of a liquid layer, a solid layer, or a combination of these and is deformable, and the other parts being solid layers that do not deform.

The solid that constitutes the heat transfer layer D may have an elastic modulus that allows it to deform freely due to the weight of the wafer W, or may have an elastic modulus that allows it to deform freely when an electrostatic adsorption force acts on the wafer W. More specifically, the solid that constitutes the heat transfer layer D may be, for example, an elastic polymeric substance, i.e., an elastomer.

<Effects, etc.>
As described above, in this embodiment, a deformable heat transfer layer D composed of at least one of a liquid layer and a solid layer is formed on the wafer mounting surface _104-1 of the wafer support table 101, and plasma processing is performed on the wafer W on the wafer mounting surface _104-1 on which the heat transfer layer D is formed. Because the heat transfer layer D is composed of at least one of a liquid layer and a solid layer, it has a higher thermal conductivity than a heat transfer layer composed of a heat transfer gas, i.e., a gas. Furthermore, because the heat transfer layer D is deformable, it can be closely attached to the underside of the wafer W. Therefore, according to this embodiment, heat can be efficiently exchanged between the wafer W and the wafer mounting surface _104-1 via _the heat transfer layer D. Therefore, during plasma processing, the temperature of the wafer W can be efficiently adjusted via the wafer mounting surface _104-1 . Specifically, during plasma processing, the wafer mounting surface 104-1 can efficiently absorb heat from the wafer W via the heat transfer layer D, and the wafer mounting surface _104-1 can efficiently heat the wafer W via the heat transfer layer D.
Furthermore, in this embodiment, a bypass line 170 is provided that bypasses the exhaust line 160 that exhausts air from the processing space 100s, and this bypass line 170 is provided with a trap 171 that collects the gaseous heat transfer layer D contained in the exhaust air from the processing space 100s. This prevents the gaseous heat transfer layer D from reaching the pump in the exhaust line 160. This prevents the gaseous heat transfer layer from adversely affecting the pump in the exhaust line 160. Furthermore, compared to when the bypass line 170 is not provided, the frequency of cleaning the pump in the exhaust line 160 can be reduced, thereby improving throughput.

<Specific Example of Wafer Mounting Surface _104-1 >
10 and 11 are enlarged partial cross-sectional views of the wafer mounting surface _1041. FIG.
The wafer mounting surface 104 ₁ is formed flat over its entire surface, as shown in FIG. 10 . Alternatively, the wafer mounting surface 104 ₁ may be roughened as shown in FIG. 11 . In this case, the roughening treatment is performed, for example, on the entire wafer mounting surface 104 ₁ , and the roughened portion has an arithmetic mean roughness Ra of 1 μm to 10 μm, for example. The roughened portion has an increased surface area, and heat from the wafer mounting surface 104 ₁ is transferred to the wafer W more efficiently via the heat transfer layer D. Therefore, the temperature of the wafer W can be adjusted more efficiently via the wafer mounting surface 104 ₁ and the heat transfer layer D.
The roughening treatment is carried out by, for example, shot blasting or laser processing.

As described below, the heat transfer layer D may be formed from a heat transfer medium composed of at least one of a liquid medium and a fluid solid medium. In this case, an annular convex portion concentric with the wafer mounting surface ₁₀₄₁ may be provided along the peripheral edge of the wafer mounting surface ₁₀₄₁ to prevent the heat transfer medium from leaking from the _wafer mounting surface _1041. In this embodiment, the roughening treatment may be performed only on the portion of the wafer mounting surface 1041 excluding the peripheral edge where the annular convex portion is formed, i.e., the portion where the heat transfer layer D is formed. Even if the annular convex portion is not provided, the wafer mounting surface ₁₀₄₁ may have roughened and unroughened portions. For example, the center of the wafer mounting surface ₁₀₄₁ may be an unroughened region, and its peripheral region may be a roughened region. This allows a temperature difference to be created between the center and peripheral portions of the wafer.

<Another example of the bypass line 170>
FIG. 12 is a diagram for explaining another example of the bypass line 170. In FIG.
12 , a return line 180 may be connected to the bypass line 170. The return line 180 is configured to return the raw material gas for the heat-transfer layer D recovered in the trap 171 to the gas supply unit 130. Specifically, the return line 180 is configured to return the raw material liquid for the heat-transfer layer D, which is produced by condensing the raw material gas for the heat-transfer layer D in the trap 171, to the tank 131a of the gas supply unit 130. The return line 180 may be provided with a pump 181 that sucks the raw material liquid for the heat-transfer layer D in the trap 171 and pumps it to the tank 131a of the gas supply unit 130. The return line 180 may also be provided with a filter 182 that removes foreign matter from the raw material liquid for the heat-transfer layer D.

The raw material liquid for the heat transfer layer D is returned from the trap 171 to the tank 131a when the trap 171 is not in communication with the processing space 100s. This timing occurs, for example, when the plasma processing apparatus 1 is idling or during plasma processing.

By providing the return line 180 as described above, the recovered raw gas from heat transfer layer D can be effectively utilized.

<Modification of the form of condensing the source gas>
13 to 15 are diagrams for explaining other examples of the manner in which the source gas in the heat transfer layer D is condensed on the surface of the wafer support table 101. In FIG.
In the above example, after the atmosphere in the processing space 100s is replaced with the heat-transfer-layer-forming gas, exhaust from the processing space 100s, including exhaust via the bypass line 170, is stopped, and the supply of the processing gas from the gas supply unit 120 is stopped, and the heat-transfer-layer-forming gas is supplied from the gas supply unit 130. This increases the pressure in the processing space 100s, causing the source gas for the heat-transfer layer D to condense on the surface of the wafer support table 101. In this configuration, the heat-transfer-layer-forming gas is not exhausted from the processing space 100s during the formation of the heat-transfer layer D, so that the heat-transfer layer D can be efficiently formed from the source gas for the heat-transfer layer D supplied into the processing space 100s.

The manner in which the source gas for the heat transfer layer D is condensed on the surface of the wafer support pedestal 101 is not limited to this. For example, as shown in FIG. 13 , when forming the heat transfer layer D, exhaust from the processing space 100s, including exhaust via the bypass line 170, may be stopped, and in addition to the supply of the heat transfer layer forming gas from the gas supply unit 130, an inert gas (e.g., _N gas) may be supplied from the gas supply unit 120. Even in this manner, the pressure within the processing space 100s can be increased to condense the source gas for the heat transfer layer D on the surface of the wafer support pedestal 101. Specifically, even in this manner, the pressure within the processing space 100s can be increased to exceed the saturated vapor pressure of the source gas for the heat transfer layer D at the temperature Ts of the wafer support pedestal 101, thereby condensing the source gas for the heat transfer layer D on the surface of the wafer support pedestal 101, and forming the liquid heat transfer layer D at least on the wafer mounting surface _104-1 . Also in this embodiment, the heat transfer layer D can be efficiently formed from the source gas for the heat transfer layer D supplied to the processing space 100s.

14 , after the atmosphere in the processing space 100s is replaced with the heat-transfer-layer-forming gas, both the inert gas from the gas supply unit 120 and the heat-transfer-layer-forming gas from the gas supply unit 130 may be supplied to the processing space 100s while the processing space 100s is being exhausted via the bypass line 170 without being exhausted via the exhaust line 160. In this configuration, the pressure in the processing space 100s can be increased to condense the source gas for the heat-transfer layer D on the surface of the wafer support pedestal 101. Specifically, in this configuration, the pressure in the processing space 100s can be increased to exceed the saturated vapor pressure of the source gas for the heat-transfer layer D at the temperature Ts of the wafer support pedestal 101, thereby condensing the source gas for the heat-transfer layer D on the surface of the wafer support pedestal 101 and forming a liquid heat-transfer layer D at least on the wafer mounting surface _104-1 .
Furthermore, in this configuration, even if the pressure in the processing space 100s increases, the pressure in the supply path connecting the gas supply section 130 and the processing chamber 100 is unlikely to increase, so condensation of the raw material gas in the heat transfer layer D on the inner wall surface of the supply path can be suppressed.

15 , after the atmosphere in the processing space 100s is replaced with the heat-transfer-layer-forming gas, only the inert gas from the gas supply unit 120 may be supplied to the processing space 100s while exhausting the processing space 100s through the bypass line 170 without exhausting the processing space 100s through the exhaust line 160. In this configuration, the pressure in the processing space 100s can be increased to condense the source gas for the heat transfer layer D on the surface of the wafer support pedestal 101. Specifically, in this configuration, the pressure in the processing space 100s can be increased to exceed the saturated vapor pressure of the source gas for the heat transfer layer D at the temperature Ts of the wafer support pedestal 101, thereby condensing the source gas for the heat transfer layer D on the surface of the wafer support pedestal 101 and forming a liquid heat transfer layer D at least on the wafer mounting surface _104-1 .
Furthermore, in this configuration, the pressure in the processing space 100s can be adjusted not only by the aperture of the pressure adjustment valve 173 downstream of the trap 171, but also by the flow rate of the inert gas from the gas supply unit 120, i.e., the flow rate of the inert gas from the upper electrode 102. Furthermore, since the upper electrode 102 is closer to the processing space 100s than the pressure adjustment valve 173, this configuration can improve the responsiveness of the pressure adjustment in the processing space 100s.
Furthermore, in this configuration, when the pressure in the processing space 100s increases, the supply path connecting the gas supply unit 130 and the processing chamber 100 is separated from the processing space 100s. Therefore, when the pressure in the processing space 100s increases, condensation of the source gas in the heat transfer layer D on the inner wall surface of the supply path can be suppressed.

Alternatively, a thin heater (not shown) with a small heat capacity may be provided in the vicinity of the wafer mounting surface ₁₀₄₁ of the wafer support table 101, for example, in the electrostatic chuck 104, and the following may be performed.
That is, when the atmosphere in the processing space 100s is replaced with the heat-transfer layer-forming gas, the electrostatic chuck 104 is cooled as a whole by low-temperature brine circulating through the flow path 108, while the wafer mounting surface _104-1 is heated by the thin heater. At the stage of forming the heat-transfer layer D, the heating by the thin heater may be stopped while the cooling of the entire electrostatic chuck 104 is maintained. This instantaneously lowers the temperature of the wafer mounting surface _104-1 , allowing the source gas for the heat-transfer layer D to condense on the wafer mounting surface _104-1 , thereby forming the heat-transfer layer D. In this configuration, when the wafer W is mounted on the wafer mounting surface _104-1 via the heat-transfer layer D and plasma processing is performed, heating by the thin heater is resumed, and the wafer mounting surface _104-1 is adjusted to a temperature suitable for plasma processing.

<Modification 1 of the gas supply unit for heat transfer layer formation gas>
FIG. 16 is a diagram showing a first modification of the gas supply unit for the heat transfer layer forming gas.
As described above, the gas supply unit 130 for the heat-transfer-layer forming gas may include a flow rate controller 132. Alternatively, the gas supply unit for the heat-transfer-layer forming gas may include an automatic pressure control (APC) valve 133 as a pressure control valve instead of the flow rate controller 132, as in the gas supply unit 130A of FIG. 16 . This automatic pressure control valve 133 has, for example, an automatic pressure control function as well as a shut-off function. By including the flow rate controller 132 or the automatic pressure control valve 133 in the gas supply unit for the heat-transfer-layer forming gas, it is possible to control the amount of source gas contained in the heat-transfer-layer forming gas supplied into the processing chamber 100.

<Modification 2 of the gas supply unit for heat transfer layer formation gas>
In the above example, a mixed gas of a source gas and a carrier gas is supplied as the heat-transfer-layer-forming gas from a gas source 131 having a tank 131a storing a source liquid for the heat-transfer layer D in a gas supply unit for the heat-transfer-layer-forming gas. That is, a carrier gas is used to introduce the source gas into the processing chamber 100. However, the source gas may be introduced into the processing chamber 100 without using a carrier gas. In this case, for example, after the source liquid is vaporized in the tank 131a by reducing the pressure or the like to generate the source gas, a valve (e.g., automatic pressure regulating valve 133) separating the tank 131a and the processing chamber 100 is opened, and the source gas is introduced from the tank 131a into the processing chamber 100 due to the pressure difference between the tank 131a and the processing chamber 100. Furthermore, during this introduction, exhaust from within the processing chamber 100 may be stopped (i.e., both the automatic pressure control valve 163 and the on-off valve 172 may be closed) or may be performed (i.e., of the automatic pressure control valve 163 and the on-off valve 172, only the on-off valve 172 may be closed).

<Modification of Source Gas Supply Form>
In the above example, the source gas is supplied to the processing space 100s through the sidewall of the processing chamber 100. However, the source gas may be supplied through a wall defining the processing space 100s other than the sidewall of the processing chamber 100. For example, the heat transfer layer forming gas containing the source gas may be supplied through the upper electrode 102 that is also used to supply the processing gas. In this case, the gas outlet of the upper electrode 102 used to supply the processing gas and the gas outlet used to supply the heat transfer layer forming gas may be different or the same.

Furthermore, the source gas may be supplied to the processing space 100s via a wafer support table that supports the wafer W or a lifter that raises and lowers the wafer W.

<Modification of Formation of Heat Transfer Layer D from Raw Material Gas>
In the above example, the heat transfer layer D is formed by at least one of liquefaction and solidification (i.e., condensation or sublimation) of the source gas, but the form of forming the heat transfer layer D from the source gas is not limited to this. For example, the heat transfer layer D may be formed from the source gas using plasma.

Furthermore, the source gas in the plasma processing space 100s may be irradiated with light to cause at least one of liquefaction and solidification of the source gas, thereby forming the heat transfer layer D.

<Modification of the form of removing the heat transfer layer D formed on a surface other than the wafer mounting surface _104-1 >
In the above example, the heat transfer layer D formed on areas other than the wafer mounting surface ₁₀₄₁ is removed by exposing it to a reduced pressure atmosphere, but the removal method is not limited to this.

For example, plasma may be used to remove the heat transfer layer D formed on the portion other than the wafer mounting surface 104 _1. Alternatively, light may be irradiated onto the heat transfer layer D formed on the portion other than the wafer mounting surface 104 ₁ to vaporize and selectively remove the heat transfer layer D.

<Modification of the form of removing the heat transfer layer D formed on the wafer mounting surface _104-1 >
In the above example, the heat transfer layer D formed on the wafer mounting surface ₁₀₄₁ is removed by exposing it to a reduced pressure atmosphere, but the removal method is not limited to this.

For example, the heat transfer layer D formed on the wafer mounting surface 104 ₁ may be removed using plasma. Alternatively, the heat transfer layer D formed on the wafer mounting surface 104 ₁ may be vaporized and selectively removed by irradiating the heat transfer layer D with light. Furthermore, the heat transfer layer D may be vaporized and selectively removed by using the thin heater described above.
The heat transfer layer D formed on the wafer mounting surface ₁₀₄₁ may be vaporized and removed by raising the temperature of the wafer mounting surface 1041.

<Another Example of the State Inside the Processing Chamber 100 When Forming the Heat Transfer Layer D>
In the above example, when the heat transfer layer D is formed, the wafer W is located inside the processing chamber 100 , but it does not have to be located inside the processing chamber 100 .

<Other Examples of Raw Materials for Heat Transfer Layer D>
In the above example, the raw material for the heat transfer layer D supplied to the wafer mounting surface _104-1 is gas, but it may also be a heat transfer medium composed of at least one of a liquid medium and a solid medium having fluidity.

17, the heat transfer medium is supplied to the wafer mounting surface _104B1 (via the wafer support table 101B). Specifically, the heat transfer medium is supplied to the center of the wafer mounting surface _104B1 via a supply port 300 formed in the wafer mounting surface _104B1 . A plurality of supply ports 300 may be provided in the wafer mounting surface _104B1 .

In this case, a flow path 310 is provided inside the wafer support table 101B, one end of which is fluidly connected to the supply port 300. The other end of the flow path 310 is fluidly connected to, for example, a gas supply unit 130B. The end of the flow path 310 on the wafer mounting surface _104B1 side (specifically, the portion located within the electrostatic chuck 104B) is narrowed, for example, so that the heat transfer medium in the flow path 310 is supplied to the wafer mounting surface _104B1 through the supply port 300 by capillary action. The flow path 310 is formed to span, for example, the electrostatic chuck 104B, the lower electrode 103B, and the insulator 105B.

The gas supply unit 130B may include one or more gas sources 131B and one or more flow controllers 132B. In one embodiment, the gas supply unit 130EB is configured to supply, for example, one or more gases for generating the heat transfer medium described above (hereinafter, heat transfer medium generating gases) to the wafer support table 101B from the corresponding gas sources 131B via the corresponding flow controllers 132B. Each flow controller 132B may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 130B may include one or more flow modulation devices that modulate or pulse the flow rates of the one or more heat transfer medium generating gases.

The heat transfer medium generating gas supplied from the gas supply unit 130B is cooled in the flow path 310, for example, by the lower electrode 103B cooled by a temperature-controlling fluid, and is liquefied or solidified to become a heat transfer medium composed of at least one of a liquid medium and a fluid solid medium. As described above, this heat transfer medium is supplied to the wafer mounting surface _104B1 through the supply port 300 by, for example, capillary action, and forms the heat transfer layer D. Therefore, the gas supply unit 130B can function as at least a part of a heat transfer layer forming unit configured to form the heat transfer layer D on the wafer mounting surface _104B1 .

Furthermore, in this example, for example, with the wafer W supported on the wafer support table 101B, a heat transfer medium is supplied to the wafer mounting surface _104B1 , and a deformable heat transfer layer D consisting of at least one of a liquid layer and a solid layer is formed on the wafer mounting surface _104B1 .

Specifically, for example, with the wafer W supported on the wafer support table 101B, a heat transfer medium generating gas is supplied from the gas supply unit 130B to the flow path 310 of the wafer support table 101B. The heat transfer medium generating gas supplied to the flow path 310 is cooled within the flow path 310 and becomes a heat transfer medium composed of at least one of a liquid medium and a solid medium having fluidity. This heat transfer medium is then supplied to the wafer mounting surface _104B1 through the supply port 300 by, for example, capillary action.
After a predetermined amount of heat transfer medium is supplied to the wafer mounting surface 104B- ₁ , a DC voltage is applied to the electrode 109 of the electrostatic chuck 104B. As a result, the wafer W is electrostatically attracted to the electrostatic chuck 104B by electrostatic force. At the same time, the heat transfer medium sandwiched between the wafer W and the electrostatic chuck 104B spreads along the wafer mounting surface 104B- ₁ , forming a heat transfer layer D.

<Modification of Heat Transfer Medium Supply Form>
In the above example, the heat transfer medium generating gas is supplied to the wafer support table 101B from the outside and converted into a heat transfer medium within the wafer support table 101B, but the heat transfer medium may also be supplied directly to the wafer support table 101B from the outside.

In the above example, the heat transfer medium in the wafer support table 101B is supplied to the wafer mounting surface _104B1 by capillary action. Alternatively, the heat transfer medium in the wafer support table 101B may be supplied to the wafer mounting surface _104B1 by the supply pressure of a heat transfer medium generating gas to the wafer support table 101B from the outside or the supply pressure of the heat transfer medium to the wafer support table 101B from the outside.

<Modification of the Electrode of the Electrostatic Chuck and the Method of Spreading the Heat Transfer Medium>
18 and 19 are a plan view and a cross-sectional view, respectively, that schematically show modified examples of the electrodes of the electrostatic chuck.
In the above examples, the electrostatic chuck 104 is provided with a single electrode 109 that is provided across the central portion and the outer periphery of the electrostatic chuck 104. Alternatively, as in the electrostatic chuck 104C in Figures 18 and 19, multiple (three in the examples shown) electrodes 109C that are annular in plan view may be arranged concentrically with respect to the center of the electrostatic chuck 104C. Note that, hereinafter, the three electrodes 109C shown in the figures may be referred to as electrode 109C1, electrode 109C2, and electrode 109C3, in that order from the center of the electrostatic chuck 104C.

Among the multiple electrodes 109C, the electrode 109C provided in the central portion of the electrostatic chuck 104C may be closer to the wafer mounting surface _104B1 than the electrodes 109C provided in the outer periphery of the electrostatic chuck 104C. In the example shown in the figure, the electrode 109C1 is closer to the wafer mounting surface _104B1 , while the electrodes 109C2 and 109C3 are closer to the wafer mounting surface _104B1 .
In the illustrated example, a common DC power supply (not shown) is provided for the three electrodes 109C, and switches 320 and 321 are provided to switch the destination of the voltage from the DC power supply. When switch 320 is turned OFF, the voltage from the DC power supply is applied only to electrode 109C1. When switch 320 is turned ON and switch 321 is turned OFF, the voltage from the DC power supply is applied to electrodes 109C1 and 109C2. When both switches 320 and 321 are turned ON, the voltage from the DC power supply is applied to electrodes 109C1, 109C2, and 109C3.

When the distance from the electrode 109C to the wafer mounting surface _104B1 is smaller at the center of the electrostatic chuck 104 than at the outer periphery, when forming the heat transfer layer D, for example, a voltage from a DC power supply is first applied only to the electrode 109C provided at the center of the electrostatic chuck 104. As a result, the central portion of the wafer W is attracted to the center of the electrostatic chuck 104 by a large electrostatic force, and the heat transfer medium supplied to the central portion of the wafer mounting surface _104B1 spreads to the outer periphery of the wafer mounting surface _104B1 . Then, a voltage from a DC power supply is also applied to the electrode 109C provided at the outer periphery of the electrostatic chuck 104. As a result, the heat transfer medium that has spread to the outer periphery of the wafer mounting surface _104B1 spreads outward from the wafer mounting surface _104B1 by a small electrostatic force. Because the heat transfer medium spreads in this manner, it is possible to prevent the heat transfer medium from remaining at the center of the wafer mounting surface _104B1 . The heat transfer medium that has spread beyond the wafer placement surface _104B1 is vaporized.

In the case of the electrostatic chuck 104C shown in Figures 18 and 19, when forming the heat transfer layer D, the number of electrodes 109C to which voltage is applied from the DC power supply may be increased in sequence from the center of the electrostatic chuck 104C.

When the distance from the electrode 109C to the wafer placement surface _104B1 is smaller at the center of the electrostatic chuck 104 than at the periphery, the heat transfer layer D may be formed as follows.
A voltage may be applied simultaneously to all of the electrodes 109C in a state in which the heat transfer medium is present only in the center of the wafer mounting surface _104B1 , i.e., a large electrostatic force may be applied simultaneously between the _center of the wafer mounting surface _104B1 and the wafer W, and a small electrostatic force may be applied simultaneously between the outer periphery of the wafer mounting surface 104B1 and the wafer _W. This also causes the heat transfer medium supplied to the center of the wafer mounting surface 104B1 to spread to the outer periphery of the wafer mounting surface _104B1 due to the large electrostatic force, and to spread outward from the wafer mounting surface _104B1 due to the small electrostatic force.

Alternatively, when multiple annular electrodes 109C are arranged concentrically with respect to the center of the electrostatic chuck C, the electrodes 109C may be equally spaced from _{each other} and each electrode 109C may be individually connected to a DC power supply. In this configuration, a high voltage is first applied only to the electrode 109C provided in the center of the electrostatic chuck 104. As a result, the central portion of the wafer W is attracted to the central portion of the electrostatic chuck 104 by a large electrostatic force, and the heat transfer medium supplied to the central portion of the wafer transfer surface _104B1 spreads to the outer periphery of the wafer transfer surface _104B1 . Then, a low voltage is applied to the electrode 109C provided in the outer periphery of the electrostatic chuck 104. As a result, the heat transfer medium that has spread to the outer periphery of the wafer transfer surface _104B1 spreads outward from the wafer transfer surface _104B1 by a small electrostatic force.
In a configuration in which the distances to the wafer mounting surface _104B1 between the electrodes 109C are equal and a DC power supply is individually connected to each electrode 109C, the following may be performed: That is, when forming the heat-transfer layer D, a strong voltage may be applied to the electrode 109C provided in the central portion of the electrostatic chuck ₁₀₄ , and a low voltage may be applied to the electrode 109C provided in the outer periphery of the electrostatic chuck 104, starting from a state in which the heat transfer medium is present only in the central portion of the wafer mounting surface 104B1.

20 and 21 are cross-sectional views and a plan view, respectively, schematically illustrating modified examples of the electrodes of the electrostatic chuck. FIG. 22 is a plan view, respectively, schematically illustrating modified examples of the electrodes of the electrostatic chuck.
20 includes a single electrode 109 extending across the central and peripheral portions of the electrostatic chuck 104D. The electrostatic chuck 104D has a wafer mounting surface _104D1 formed as a concave surface recessed downward, and the electrode 109 formed as a horizontal plate. Therefore, the dielectric layer constituting the electrostatic chuck 104D is thinner in the central portion of the electrostatic chuck 104D than in the peripheral portion of the electrostatic chuck 104D. When a voltage is applied to the electrode 109, the electrostatic chuck 104D simultaneously generates a large electrostatic force between the central portion of the wafer mounting surface _104D1 and the wafer W, and a small electrostatic force between the peripheral portion of the wafer mounting surface _104D1 and the wafer W. Therefore, in the electrostatic chuck 104D, when a voltage is applied to the electrode 109, the heat transfer medium supplied to the center of the wafer mounting surface _104B1 spreads to the outer periphery of the wafer mounting surface _104B1 due to a large electrostatic force, and also spreads outward from the wafer mounting surface _104B1 due to a small electrostatic force.

20 , the electrostatic chuck 104E of FIG. 21 also has a single electrode 109E that straddles the central and outer periphery of the electrostatic chuck 104E. However, unlike the electrostatic chuck 104D, the electrostatic chuck 104E has a wafer mounting surface _104B1 formed as a horizontal plane, and the cross-sectional shape of the electrode 109E is formed as a triangle that protrudes toward the central portion of the wafer mounting surface _104B1 . As a result, the dielectric layer constituting the electrostatic chuck 104E is thinner in the central portion of the electrostatic chuck 104E than in the outer periphery of the electrostatic chuck 104E. When a voltage is applied to the electrode 109E of the electrostatic chuck 104E, a large electrostatic force acts between the central portion of the wafer mounting surface _104B1 and the wafer W, and a small electrostatic force acts between the outer periphery of the wafer mounting surface _104B1 and the wafer W simultaneously. Therefore, in the electrostatic chuck 104E, when a voltage is applied to the electrode 109E, the heat transfer medium supplied to the center of the wafer mounting surface _104B1 spreads to the outer periphery of the wafer mounting surface _104B1 due to a large electrostatic force, and also spreads outward from the wafer mounting surface _104B1 due to a small electrostatic force.
The cross-sectional shape of the electrode 109E does not have to be triangular, as long as it protrudes toward the center of the wafer placement surface _104B1 .

20, the electrostatic chuck 104F of Fig. 22 is provided with a single electrode 109F that straddles the central and outer periphery of the electrostatic chuck 104E. However, unlike the electrostatic chuck 104F, the electrostatic chuck 104F has a wafer mounting surface _104B1 formed as a horizontal plane, and the density of the electrodes 109F is higher in the central portion of the electrostatic chuck 104F than in the outer periphery of the electrostatic chuck 104F. Therefore, in the electrostatic chuck 104F, when a voltage is applied to the electrode 109F, a large electrostatic force acts between the central portion of the wafer mounting surface _104B1 and the wafer W, and a small electrostatic force acts between the outer periphery of the wafer mounting surface _104B1 and the wafer W simultaneously. Therefore, in the electrostatic chuck 104F, when a voltage is applied to the electrode 109F, the heat transfer medium supplied to the center of the wafer mounting surface _104B1 spreads to the outer periphery of the wafer mounting surface _104B1 due to a large electrostatic force, and also spreads outward from the wafer mounting surface _104B1 due to a small electrostatic force.
The shape of the electrode 109F in plan view is not limited to the shape shown in FIG. 22, as long as the density of the electrode 109F is higher at the outer periphery of the electrostatic chuck 104F than at the center of the electrostatic chuck 104F.

When a single electrode is provided across the center and outer periphery of the electrostatic chuck and the wafer mounting surface is formed as a horizontal plane, the dielectric constant of the electrostatic chuck may vary within the surface, with the dielectric constant being higher in the center of the electrostatic chuck than in the outer periphery. With this electrostatic chuck, when a voltage is applied to the electrode, a large electrostatic force acts simultaneously between the center of the wafer mounting surface and the wafer W, and a small electrostatic force acts simultaneously between the outer periphery of the wafer mounting surface and the wafer W.

Methods for varying the dielectric constant within the surface of an electrostatic chuck include, for example, using different dielectric materials in the central and peripheral portions of the electrostatic chuck, and varying the concentration of the dielectric material in the electrostatic chuck's constituent materials within the surface of the electrostatic chuck.

<Example of Heat Transfer Layer D on Wafer Mounting Surface 104 ₁ >
23 is a diagram showing an example of the heat transfer layer D on the wafer mounting surface _1041. Note that the flow path 108 is not shown in FIG.
The heat transfer layer D is formed over the entire wafer mounting surface 104 ₁ , for example, including the central region and peripheral region of the wafer mounting surface 104 _1. However, the heat transfer layer D may be formed only in a partial region of the wafer mounting surface 104 _1. For example, when it is necessary to actively absorb or heat the peripheral portion of the wafer W, the heat transfer layer D may be formed only in the peripheral region of the wafer mounting surface 104 ₁ that faces the peripheral portion of the wafer W, as shown in FIG. 16 . Furthermore, when it is necessary to actively absorb or heat the central portion of the wafer W, the heat transfer layer D may be formed only in the central region of the wafer mounting surface 104 ₁ that faces the central portion of the wafer W.

The method for forming the heat transfer layer D only on a part of the wafer mounting surface 104 ₁ is, for example, as follows: That is, when the raw material of the heat transfer layer D is a gas, the wafer mounting surface 104 ₁ is made to have both a lipophilic portion and an lipophobic portion, so that the heat transfer layer D can be formed only on either the lipophilic portion or the lipophobic portion.
The wafer-mounting surface ₁₀₄₁ having both a lipophilic portion and a lipophobic portion can be formed, for example, as follows. That is, for example, a lipophilic treatment is applied to a portion of the wafer-mounting surface ₁₀₄₁ , and an lipophobic treatment is applied to the other portion. The lipophilic treatment is, for example, a treatment of coating with a substance having a hydrocarbon group or a treatment of forming a predetermined nano-order shape on the surface. The lipophobic treatment is a treatment of coating with a silicone resin, a fluorine-based material, a hydrophilic inorganic substance, or the like.

Furthermore, when the raw material of the heat transfer layer D is the aforementioned heat transfer medium composed of a liquid medium or the like, for example, by forming grooves only in a part of the wafer mounting surface _104-1 , such as the peripheral region, the heat transfer layer D can be formed only in that part of the region.

23 , when the heat-transfer layer D is formed only in a partial region of the wafer mounting surface _104-1 , the wafer support table 101 may be provided with a supply path 190 for supplying a heat-transfer gas such as He gas to a portion of the wafer mounting surface _104-1 between the portion where the heat-transfer layer D is not formed and the wafer W. This allows the temperature control capability of the wafer W by the wafer support table 101 to vary within the wafer mounting surface _104-1 , that is, allows the temperature control capability of the wafer W by the wafer support table 101 to have a distribution.

The method of providing a distribution in the temperature control capability of the wafer W is not limited to this. For example, if the raw material of the heat transfer layer D is the aforementioned heat transfer medium composed of a liquid medium or the like, by forming grooves in each region and supplying a heat transfer medium with a different thermal conductivity to each region, it is possible to provide a distribution in the temperature control capability of the wafer W by the wafer support table 101.

Furthermore, by providing thick and thin portions of the heat transfer layer D on the wafer mounting surface ₁₀₄₁ , the temperature control capability of the wafer W by the wafer support table 101 may be distributed.

Furthermore, by providing the wafer mounting surface 104 ₁ with portions having large surface areas and portions having small surface areas and forming the heat transfer layer D over the entire wafer mounting surface 104 ₁ , it is possible to provide a distribution in the temperature control ability of the wafer W by the wafer support table 101 (specifically, the temperature control ability of the wafer W via _the wafer mounting surface 104 ₁ and the heat transfer layer D). Note that, for example, by performing a surface roughening process on the wafer mounting surface 104 ₁ , it is possible to form both portions having large surface areas and portions having small surface areas on the wafer mounting surface 104 1.

(Other Modifications)
In the above example, the target of temperature adjustment via the wafer support table 101 and the deformable heat transfer layer D is the wafer W, but instead of or in addition to this, the target may be the edge ring E. That is, in the present disclosure, the workpiece whose temperature is to be adjusted is at least one of the wafer W and the edge ring E.
The above-described methods for removing the heat transfer layer formed on each portion may be combined. For example, when removing the heat transfer layer formed on a portion other than the wafer mounting surface, two or more of the method for reducing the pressure inside the processing chamber 100, the method for using plasma, and the method for irradiating light may be combined.

In the above example, the central portion of the electrostatic chuck 104 on which the wafer W is placed is formed to have a diameter smaller than the diameter of the wafer W, but it may also be formed to have a diameter larger than the diameter of the wafer W. Also, in the above example, the central portion of the electrostatic chuck 104, which has a diameter smaller than the diameter of the wafer W, is formed to be higher than the upper surface of the peripheral portion, but they may also be the same height. Figure 24 is a diagram showing an example in which the central portion of the electrostatic chuck 104 is formed to have a diameter larger than the diameter of the wafer W. Note that in the example shown in Figure 24, the central portion of the electrostatic chuck 104, which has a diameter larger than the diameter of the wafer W, and the peripheral portion are formed to be the same height, but the upper surface of the central portion may be formed to be higher than the upper surface of the peripheral portion, as in Figure 1.

24 , the central portion of the electrostatic chuck 104 (i.e., the wafer mounting surface 104 ₁ ) is formed with a diameter larger than the diameter of the wafer W. Therefore, the peripheral portion of the wafer W does not protrude from the central portion of the electrostatic chuck 104, and is mounted on the wafer mounting surface 104 ₁ via the heat transfer layer D. This improves the temperature uniformity of the wafer W. Furthermore, since the heat transfer layer D is also formed in the edge region of the wafer mounting surface 104 ₁ where the wafer W is not mounted, the electrostatic chuck 104 is not exposed to the processing space 100s even in the edge region where the wafer W is not mounted. Therefore, the electrostatic chuck 104 can be protected from plasma in the edge region of the wafer mounting surface 104 ₁ where the wafer W is not mounted.

25, a tray T on which a wafer W is placed and a heat transfer layer D is formed between the wafer W and the tray T may be placed on the wafer placement surface ₁₀₄₁ .
In this example, under the control of the control unit 200, the tray T is placed on the wafer placement surface _104-1 of the wafer support table 101 via the lifter 107, and a heat-transfer layer D is formed on the wafer placement surface _104-1 via the tray T. Therefore, in this embodiment, the mechanism for lifting and lowering the wafer W (or the tray T on which the wafer W is placed), including the control unit 200 and the lifter 107, can function as a part of the heat-transfer layer forming unit that forms the heat-transfer layer D on the wafer placement surface _104-1 .

The tray T is held by the electrostatic chuck 104 by electrostatic attraction. A heat transfer layer D is formed in the center of the tray T, and the wafer W is placed on top of the heat transfer layer D. An edge ring E is also placed on the periphery of the tray T, and by loading and unloading the tray, not only the wafer W but also the edge ring E can be replaced. A heat transfer layer D may also be formed between the edge ring E and the tray T.

In the example shown in Figure 25, the peripheral edge of the wafer W is also placed on the tray T via the heat transfer layer D. This improves the temperature uniformity of the wafer W. In addition, the heat transfer layer D is also formed on the upper surface of the tray T on which the wafer W and edge ring E are not placed. Therefore, even in areas where the wafer W or edge ring E is not placed, the upper surface of the tray T is not exposed to the processing space 100s, and the tray T can be protected from plasma.

A heat transfer layer D may also be formed between the tray T and the electrostatic chuck 104. Alternatively, only the wafer W may be placed on the tray T, and the edge ring E may be placed on the electrostatic chuck 104. In this case, the mounting surface of the edge ring E on the periphery of the electrostatic chuck 104 may be formed at the same height as the center of the electrostatic chuck 104 (the mounting surface of the tray T) as shown in Figure 24, or may be formed lower than the center (the mounting surface of the tray T) as shown in Figure 1.

In the above examples, plasma etching was used as the plasma processing, but the technology disclosed herein can also be applied to plasma processing other than etching (e.g., film formation).

The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the spirit and scope of the appended claims. For example, the components of the above-described embodiments may be combined in any manner. Such combinations will naturally produce the functions and effects of each of the components involved in the combination, as well as other functions and effects that will be apparent to those skilled in the art from the description herein.

Furthermore, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology disclosed herein may achieve other effects in addition to or in place of the above-mentioned effects that would be apparent to those skilled in the art from the description herein.

Note that the following configuration examples also fall within the technical scope of the present disclosure.
(1) A plasma processing apparatus,
a processing container configured to be decompressible;
a support provided in the processing vessel and configured to support a workpiece;
a heat transfer layer forming unit that forms a deformable heat transfer layer for the workpiece, the heat transfer layer being formed of at least one of a liquid layer and a solid layer, on a mounting surface of the support unit on which the workpiece is mounted;
an exhaust line for exhausting the processing space in the processing chamber;
a bypass line that bypasses the exhaust line,
The plasma processing apparatus, wherein the bypass line is provided with a trap for recovering the gaseous heat transfer layer contained in the exhaust gas from the processing space.
(2) the heat transfer layer forming unit supplies a source gas serving as a source material for the heat transfer layer to the processing space in the processing vessel;
The plasma processing apparatus according to (1), wherein the gaseous heat transfer layer recovered in the trap is the source gas.
(3) The plasma processing apparatus according to (2), wherein the trap also collects vaporized material of the heat transfer layer formed on the mounting surface as the gaseous heat transfer layer.
(4) The plasma processing apparatus according to (2) or (3), further comprising a return line for returning the source gas of the heat transfer layer recovered in the trap to the heat transfer layer forming section.
(5) A plasma processing apparatus according to any one of (2) to (4), wherein the mounting surface has a portion exhibiting lipophilicity and a portion exhibiting lipophobicity, and the heat transfer layer is formed on only one of the portions.
(6) The plasma processing apparatus according to (5), wherein the support portion has a supply path for supplying a heat transfer gas between the portion of the mounting surface on which the heat transfer layer is not formed and the workpiece.
(7) The plasma processing apparatus according to any one of (1) to (6), wherein the mounting surface has a portion with a large surface area and a portion with a small surface area.
(8) The plasma processing apparatus according to any one of (1) to (7), wherein the mounting surface is roughened.
(9) an inert gas supply unit that supplies an inert gas to the processing space in the processing vessel;
a control unit,
The plasma processing apparatus according to any one of (2) to (6), wherein the control unit executes a step of supplying both the raw material gas and the inert gas to the processing space to form the heat transfer layer while exhausting the processing space through the exhaust line but not through the bypass line.
(10) further comprising a control unit;
The control unit
supplying the source gas into the processing space while exhausting the processing space through the bypass line without exhausting the processing space through the exhaust line;
Thereafter, the supply of the source gas to the processing space is continued in a state where exhaust from the processing space, including exhaust via the bypass line, is not being performed, thereby forming the heat transfer layer.
(11) An inert gas supply unit that supplies an inert gas to the processing space in the processing container is further provided.
The plasma processing apparatus according to (10), wherein the step of forming the heat transfer layer also includes supplying the inert gas to the processing space.
(12) an inert gas supply unit that supplies an inert gas to the processing space in the processing vessel;
a control unit,
supplying the source gas into the processing space in a state where the processing space is not evacuated through the exhaust line but is evacuated through the bypass line;
Thereafter, in a state in which the processing space is not evacuated through the exhaust line but is evacuated through the bypass line, the inert gas is supplied to the processing space instead of the raw material gas, thereby forming the heat transfer layer.
(13) A first exhaust pump and a second exhaust pump are provided in the exhaust line in this order from the upstream side,
The plasma processing apparatus according to any one of (1) to (12), wherein a downstream end of the bypass line is connected to the exhaust line between the first exhaust pump and the second exhaust pump.
(14) The plasma processing apparatus according to (13), wherein a pressure adjustment valve is connected to the bypass line downstream of the trap.
(15) An open/close valve is provided in the bypass line on the upstream side of the trap and on the downstream side of the pressure regulating valve,
The plasma processing apparatus according to (14), wherein an open/close valve is provided between the first exhaust pump and a portion of the exhaust line to which the downstream end of the bypass line is connected.
(16) A processing method for performing plasma processing on a substrate, comprising:
(A) forming a deformable heat transfer layer for a workpiece, the heat transfer layer being composed of at least one of a liquid layer and a solid layer, on a mounting surface of a support part in a processing vessel configured to be depressurized;
(B) placing a substrate on the heat transfer layer formed on the placement surface of the support;
(C) performing a plasma treatment on the substrate;
(D) separating the substrate from the heat transfer layer and removing the heat transfer layer formed on the mounting surface;
(E) recovering the gaseous heat transfer layer contained in the exhaust from the processing space with a trap provided in a bypass line that bypasses an exhaust line that exhausts the processing space in the processing vessel.
(17) Before the step (A),
closing a valve provided in the exhaust line;
opening a valve provided in the bypass line and evacuating the processing space in the processing vessel through the bypass line;
The processing method according to (16), further comprising the step of supplying a raw material gas serving as a raw material for the heat transfer layer to the processing space.
(18) Between the step (B) and the step (C),
closing a valve provided in the bypass line;
The processing method according to (16) or (17), further comprising the step of opening a valve provided in the exhaust line and exhausting the processing space in the processing vessel through the exhaust line.
(19) The processing method according to any one of (16) to (18), wherein the step (A) includes a step of increasing the pressure in the processing container or a step of decreasing the temperature of the placement surface.

REFERENCE SIGNS LIST 1 Plasma processing apparatus 100 Plasma processing chamber 100s Plasma processing space 101 Wafer support table 130 Gas supply unit 160 Exhaust line 170 Bypass line 171 Trap 104 ₁ Wafer mounting surface 104 ₂ Upper surface of peripheral portion of electrostatic chuck D Heat transfer layer E Edge ring W Wafer

Claims (19)

A plasma processing apparatus,
a processing container configured to be decompressible;
a support provided in the processing vessel and configured to support a workpiece;
a heat transfer layer forming unit that forms a deformable heat transfer layer for the workpiece, the heat transfer layer being formed of at least one of a liquid layer and a solid layer, on a mounting surface of the support unit on which the workpiece is mounted;
an exhaust line for exhausting the processing space in the processing chamber;
a bypass line that bypasses the exhaust line,
The plasma processing apparatus, wherein the bypass line is provided with a trap for recovering the gaseous heat transfer layer contained in the exhaust gas from the processing space. the heat transfer layer forming unit supplies a source gas serving as a source material for the heat transfer layer to a processing space in the processing vessel;
The plasma processing apparatus according to claim 1 , wherein the gaseous heat transfer layer collected in the trap is the source gas. The plasma processing apparatus of claim 2, wherein the trap also collects vaporized material of the heat transfer layer formed on the placement surface as the gaseous heat transfer layer. The plasma processing apparatus of claim 2, further comprising a return line that returns the source gas of the heat transfer layer recovered in the trap to the heat transfer layer forming section. The plasma processing apparatus of claim 2, wherein the mounting surface has a lipophilic portion and a lipophobic portion, and the heat transfer layer is formed on only one of the portions. The plasma processing apparatus of claim 5, wherein the support portion has a supply path for supplying heat transfer gas between the portion of the mounting surface on which the heat transfer layer is not formed and the workpiece. The plasma processing apparatus of claim 1, wherein the mounting surface has a portion with a large surface area and a portion with a small surface area. The plasma processing apparatus of any one of claims 1 to 7, wherein the mounting surface is roughened. an inert gas supply unit that supplies an inert gas to the processing space in the processing vessel;
a control unit,
7. The plasma processing apparatus according to claim 2, wherein the control unit executes a step of supplying both the raw material gas and the inert gas to the processing space to form the heat transfer layer while the processing space is not being evacuated through the exhaust line but is being evacuated through the bypass line. Further comprising a control unit,
The control unit
supplying the source gas into the processing space while exhausting the processing space through the bypass line without exhausting the processing space through the exhaust line;
7. The plasma processing apparatus according to claim 2, further comprising: a step of: subsequently continuing to supply the source gas to the processing space while exhausting air from the processing space, including exhausting air via the bypass line, to form the heat transfer layer. an inert gas supply unit that supplies an inert gas to the processing space in the processing vessel;
The plasma processing apparatus according to claim 10 , wherein the step of forming the heat transfer layer also includes supplying the inert gas into the processing space. an inert gas supply unit that supplies an inert gas to the processing space in the processing vessel;
a control unit,
supplying the source gas into the processing space in a state where the processing space is not evacuated through the exhaust line but is evacuated through the bypass line;
7. The plasma processing apparatus according to claim 2, further comprising: a step of supplying the inert gas, instead of the source gas, into the processing space in a state in which the processing space is not evacuated through the exhaust line but is evacuated through the bypass line, thereby forming the heat transfer layer. a first exhaust pump and a second exhaust pump are interposed in this order from the upstream side in the exhaust line;
8. The plasma processing apparatus according to claim 1, wherein a downstream end of the bypass line is connected to the exhaust line between the first exhaust pump and the second exhaust pump. The plasma processing apparatus of claim 13, wherein a pressure adjustment valve is connected to the bypass line downstream of the trap. an on-off valve is provided in the bypass line on the upstream side of the trap and on the downstream side of the pressure regulating valve;
15. The plasma processing apparatus according to claim 14, further comprising an on-off valve provided between the first exhaust pump and a portion of the exhaust line to which the downstream end of the bypass line is connected. A processing method for performing plasma processing on a substrate, comprising:
(A) forming a deformable heat transfer layer for a workpiece, the heat transfer layer being composed of at least one of a liquid layer and a solid layer, on a mounting surface of a support part in a processing vessel configured to be depressurized;
(B) placing a substrate on the heat transfer layer formed on the placement surface of the support;
(C) performing a plasma treatment on the substrate;
(D) separating the substrate from the heat transfer layer and removing the heat transfer layer formed on the mounting surface;
(E) recovering the gaseous heat transfer layer contained in the exhaust from the processing space with a trap provided in a bypass line that bypasses an exhaust line that exhausts the processing space in the processing vessel. Before the step (A),
closing a valve provided in the exhaust line;
opening a valve provided in the bypass line and evacuating the processing space in the processing vessel through the bypass line;
The processing method according to claim 16 , further comprising the step of supplying a source gas serving as a source material for the heat transfer layer to the processing space. Between the step (B) and the step (C),
closing a valve provided in the bypass line;
18. The processing method according to claim 17, further comprising the step of opening a valve provided in the exhaust line and evacuating the processing space in the processing vessel through the exhaust line. The processing method according to claim 16 , wherein the step (A) includes a step of increasing the pressure in the processing container or a step of decreasing the temperature of the placement surface.