TW202318600A - Temperature control component with variable thermal conductivity, method, system and plasma processing apparatus capable of adjusting thermal conductivity of the temperature control components - Google Patents

Abstract

The present invention provides a temperature control component with variable thermal conductivity, which is applied to a plasma processing apparatus, and is arranged between a first component and a second component. The first component and the second component have a temperature difference when the plasma processing apparatus is working. The temperature control component is used to adjust the heat conduction between the first component and the second component, including: an airtight cavity, which includes a first side and a second side opposite to the first side, wherein the first side faces the first component, and the second side faces the second component. The airtight cavity is used to introduce or extract heat transfer fluid to adjust the thermal conductivity of the temperature control component. Correspondingly, a temperature control method, system and plasma processing apparatus are also provided.

Description

Variable thermal conductivity temperature control component, method, system and plasma processing device

The invention relates to the technical field of semiconductors, in particular to a variable thermal conductivity temperature control component, method, system and plasma processing device.

In recent years, with the development of semiconductor manufacturing process, plasma treatment process has been widely used in the process of semiconductor components. The above processes, such as deposition and etching processes, are generally performed in a plasma processing device. In order to meet the process requirements, some structures in the plasma processing device need to be precisely temperature-controlled, such as electrostatic chuck (ESC), gas shower head and other temperature-controlled structures. The commonly used temperature control structure is to install a heater on a substrate with a refrigerant flow and a cooling function. By controlling the heating power of the heater and the cooling power of the refrigerant, the temperature-controlled structure is at the required temperature point. reach temperature equilibrium.

Due to the limitation of the heat capacity of the refrigerant, the length of the pipeline and the heat capacity of the cooling base of the temperature-controlled component, the response time of the change of the cooling power is much slower than the change of the heating power of the heater. Therefore, the usual temperature control method is to choose to change the power of the heater. Achieve temperature control. However, in this scenario, a large part of the heat generated by the heater will be taken away by the refrigerant, so that the upper limit of temperature control is not high enough. It is necessary to install an insulation layer between the heater and the cooling substrate to reduce this part of energy loss. However, the addition of an insulating layer will slow down the cooling process and affect the temperature control rate when the temperature control point is switched. Therefore, a structure that can adjust the thermal conductivity online according to the demand is required to reduce the temperature when the temperature needs to be controlled at a high temperature point. The thermal conductivity forms a thermal insulation layer, and when the temperature needs to be lowered, the thermal conductivity is improved to accelerate the heat transfer to achieve rapid cooling.

The purpose of the present invention is to provide a variable thermal conductivity temperature control component, method, system and plasma processing device, which can change the thermal conductivity according to the demand and adjust the heat conduction between two components with temperature difference.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

A temperature control component with variable thermal conductivity is used in a plasma processing device, which is arranged between a first component and a second component, and the first component and the second component have a temperature difference when the plasma processing device is working, The temperature control component is used to adjust the heat conduction between the first component and the second component, including:

an airtight cavity comprising a first side and a second side facing the first side, the first side is opposite to the first component, and the second side is opposite to the second component;

a supporting frame, arranged in the airtight cavity, supported between the first side and the second side;

The airtight cavity is used for introducing or withdrawing heat transfer fluid to adjust the thermal conductivity of the temperature control component.

Further, the supporting frame is made of a material with a thermal conductivity of 0.01-1 W/m·K.

Further, the material of the supporting frame is a polymer material.

Further, the heat transfer fluid is a heat transfer gas or a heat transfer liquid.

Further, when the heat transfer fluid is a heat transfer gas, the thermal conductivity of the temperature control component is changed by changing the pressure of the heat transfer gas in the airtight cavity.

Further, the heat conduction gas is selected from helium.

Further, when the heat transfer fluid is a heat transfer liquid, the thermal conductivity of the temperature control component is changed by passing the heat transfer liquid into or out of the airtight cavity.

Further, the temperature control component has a thickness in the range of 200-2000 microns.

Further, an airtight casing is also included for forming the airtight cavity, and the airtight casing is provided with a fluid inlet and outlet.

Further, the airtight cavity is formed between the first component and the second component, and the support frame is in contact with the first component and the second component.

Further, the number of the airtight cavities is multiple, and each of the airtight cavities is individually controlled to pass in or draw out heat transfer fluid, so as to adjust the heat in the area where the different airtight cavities are located in the temperature control assembly. Conductivity.

Further, the plasma processing device includes a base and an electrostatic chuck, the electrostatic chuck is arranged on the base, and a first heater is arranged under the electrostatic chuck for providing heat to the electrostatic chuck, the A first cooling channel is provided in the base for circulating cooling liquid to cool the electrostatic chuck;

One of the first component and the second component is the first heater, and the other is the base.

Further, the plasma processing device includes a mounting seat and a gas shower head, the gas shower head is arranged under the mounting seat, and a second heating device is provided between the mounting seat and the gas shower head. device, or the second heater is arranged above the mounting base for providing heat to the gas shower head, and the mounting base is provided with a second cooling channel for circulating cooling liquid to spray the gas cooling of the head;

One of the first component and the second component is the second heater, and the other is the mounting seat.

A temperature control method, comprising:

providing a temperature control assembly as described above;

The heat conduction fluid is passed into or withdrawn from the airtight cavity to change the thermal conductivity of the temperature control component.

Further, when the airtight cavity is vacuum, the temperature control component acts as a heat insulating layer; when the airtight cavity is filled with the heat transfer fluid, the temperature control component acts as a heat conduction layer.

A temperature control system, comprising a high temperature component, a low temperature component and a temperature control component with variable thermal conductivity as described above, the temperature control component is arranged between the high temperature component and the low temperature component.

A plasma processing device is characterized in that it is equipped with the above-mentioned temperature control system.

Compared with prior art, the present invention has following advantage:

The mechanical strength can be improved by setting the support frame in the airtight cavity of the temperature control component, and the thermal conductivity can be changed by passing in or out of the heat transfer fluid in the cavity; integrating the temperature control component into the temperature control structure can improve the thermal conductivity by adjusting the thermal conductivity. The temperature control dynamic range of the temperature control structure.

The solution proposed by the present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and all use imprecise scales, which are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention. In order to make the objects, features and advantages of the present invention more comprehensible, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. shown in the drawings attached to this specification are only used to match the content disclosed in the specification, for those who are familiar with this technology to understand and read, and are not used to limit the implementation of the present invention. Conditions, so it has no technical substantive meaning, any modification of structure, change of proportional relationship or adjustment of size shall still fall within the scope of the present invention without affecting the effect and purpose of the present invention. within the scope covered by the disclosed technical content.

Figure 1 shows a schematic diagram of the structure of a capacitively coupled plasma (CCP) processing equipment. The capacitively coupled plasma processing equipment is a kind of plasma generated in the reaction chamber by the radio frequency power applied to the plate through capacitive coupling and used for Etched equipment. It includes a vacuum reaction chamber 100. The vacuum reaction chamber 100 includes a substantially cylindrical reaction chamber side wall 101 made of metal material, and an opening 102 is provided on the reaction chamber side wall for accommodating the entry and exit of wafers. A gas shower head 120 and a pedestal 110 opposite to the gas shower head are arranged in the vacuum reaction chamber 100, and the gas shower head 120 is connected with a gas supply device 125 for supplying gas to the vacuum reaction chamber 100. Convey reaction gas, and serve as the upper electrode of the vacuum reaction chamber 100 at the same time, an electrostatic chuck 112 is arranged above the base, and serve as the lower electrode of the vacuum reaction chamber 100 at the same time, a reaction area is formed between the upper electrode and the lower electrode . An electrostatic electrode 113 is disposed inside the electrostatic chuck 112 for generating electrostatic attraction to support and fix the wafer W to be processed during the manufacturing process. At least one radio frequency power source 150 is applied to one of the upper electrode or the lower electrode through the matching network 152, and a radio frequency electric field is generated between the upper electrode and the lower electrode to dissociate the reaction gas into plasma, and the plasma Contains a large number of active particles such as electrons, ions, excited atoms, molecules, and free radicals. The above-mentioned active particles can undergo various physical and chemical reactions with the surface of the wafer W to be processed, so that the morphology of the wafer surface changes. That is, the etching process is completed.

Wherein, the temperature of the gas shower head 120 and the electrostatic chuck 112 needs to be precisely controlled during the process. Taking the electrostatic chuck 112 as an example to illustrate its temperature control method, a first heater 114 is arranged under the electrostatic chuck 112 to provide heat to the electrostatic chuck 112, and a first heater 114 is arranged in the base 110. The cooling channel is used for circulating cooling liquid to cool the electrostatic chuck 112 . The temperature control component with variable thermal conductivity provided by the present invention can be used to adjust the thermal conductivity between the first heater 114 and the base 110 to achieve precise temperature control of the electrostatic chuck 112 . Taking the gas shower head 120 as an example to illustrate its temperature control method, the gas shower head 120 is installed under the mounting seat 122, and a second A heater, usually a second cooling channel is provided in the mounting base 122, through which a cooling fluid is introduced, which controls the temperature of the gas shower head 120 together with the second heater, and the variable thermal conductivity provided by the present invention A high-rate temperature control component is disposed between the mounting base 122 and the second heater for adjusting the thermal conductivity between the two. In other embodiments, the second heater can also be arranged above the installation base 122, and the variable thermal conductivity temperature control component provided by the present invention is arranged between the installation base 122 and the second heater. between heaters.

FIG. 2 shows a variable thermal conductivity temperature control assembly 200 according to the first embodiment of the present invention, which can be used in a plasma processing device, and it is arranged between a first assembly and a second assembly, and the first assembly and the second assembly The two components have a temperature difference when the plasma processing device is working, and the temperature control component 200 is used to adjust the heat conduction between the first component and the second component. Specifically, when controlling the temperature of the electrostatic chuck 112 in the plasma processing apparatus as shown in FIG. 1 , the first component is, for example, the first heater 114 , and the second component is correspondingly the base 110 . In other embodiments, when controlling the temperature of the gas shower head 120 in the plasma processing apparatus shown in FIG. 1 , the first component is, for example, a second heater, and the second component is correspondingly mount 122.

The temperature control assembly 200 includes: an airtight cavity 210, which includes a first side and a second side opposite to the first side, the first side is opposite to the first assembly, and the second side is opposite to the first side. The second component is opposite; the support frame 220 is arranged in the airtight cavity 210, supported between the first side and the second side, and maintains the overall structure of the airtight cavity 210 from collapsing, Make the first side and the second side have good contact with the first component and the second component, avoid uneven heat transfer, and enable the electrostatic chuck to have sufficient flatness on the substrate; the airtight cavity 210 is used to feed in or draw out heat transfer fluid to adjust the thermal conductivity of the temperature control assembly 200 . That is, when controlling the temperature of the electrostatic chuck 112, the temperature control assembly 200 is installed between the first heater 114 and the base 110, its first side is close to the first heater 114, and its second side is close to the first heater 114. The side is close to the base 110, the airtight cavity 210 is passed into a heat transfer fluid, which can increase the heat conduction between the first heater 114 and the base 110, when the airtight cavity 210 is pulled out After the heat transfer fluid inside, the heat conduction between the first heater 114 and the susceptor 110 is reduced, so the amount of the heat transfer fluid introduced into or extracted from the airtight cavity 210 can be controlled according to the actual process requirements, To adjust the heat conduction between the first heater 114 and the base 110 . It can be seen that by integrating the temperature control component 200 between the base 11 and the first heater 114 in the temperature control structure of the electrostatic chuck 112, the effect of the temperature control structure on the electrostatic chuck 112 can be greatly improved by adjusting its thermal conductivity. The temperature control dynamic range.

The heat transfer fluid may be a heat transfer gas, such as helium. There is a corresponding change relationship between the thermal conductivity of the gas and the air pressure, and by changing the pressure of the heat-conducting gas in the airtight cavity 210 , the thermal conductivity of the temperature control component 200 is changed. That is, when the airtight cavity 210 is filled with heat-conducting gas, as the pressure of the gas increases, the thermal conductivity of the temperature control component 200 increases, and the heat transfer speeds up. The temperature control component 200 can be used as a heat-conducting layer, when the heat-conducting gas in the airtight cavity 210 is pumped out, the thermal conductivity of the temperature control component 200 decreases, and the heat transfer decreases, and it can be used as a heat-insulating layer when it is evacuated to a near vacuum.

It can be understood that, when the airtight cavity 210 is close to vacuum, the thermal conductivity of the temperature control assembly 200 is related to the support frame 220 . The thermal conductivity reference values of common substances are shown in Table 1. Since the thermal conductivity of solid substances is relatively fixed when the structure and material are fixed, in order to reduce the thermal conductivity of the supporting skeleton 220, the The supporting frame 220 is made of materials with a thermal conductivity of 0.01-1 W/m·K, such as Vespel, Kapton polyimide, PTFE polytetrafluoroethylene and other polymer materials.

Table 1 substance Thermal conductivityW/m·K copper 383 aluminum 204 Stainless steel 17 Vespel 0.35 Polyimide film (Kapton) 0.25 PTFE 0.25 Vacuum Insulation Panel 0.004 vacuum 0 (radiative thermal conductivity 5.67E-8 W/m ² ·K ⁴ )

In addition, the thickness of the temperature control component 200 may be in the range of 200-2000 microns. The support frame 220 disposed in the airtight cavity 210 can be used to enhance the mechanical strength of the airtight cavity 210 during vacuuming.

The heat-conducting fluid can also be selected as a heat-conducting liquid, and the thermal conductivity of the temperature control component 200 can be changed by passing the heat-conducting liquid into or out of the airtight cavity 210, so as to realize two kinds of heat-conducting liquids with or without heat-conducting liquid. Switching between thermal conductivity: when the airtight cavity 210 is emptied of heat-conducting liquid, the temperature control component 200 acts as a thermal insulation layer to reduce heat conduction; when the airtight cavity 210 is filled with heat-conducting liquid, the temperature control The component 200 acts as a heat conduction layer to enhance heat conduction.

As shown in FIG. 2, in order to ensure airtightness, the temperature control assembly 200 further includes an airtight casing 230 for forming the airtight cavity 210, and the airtight casing 230 covers the support frame 220, The airtight shell is provided with a fluid inlet and outlet 231 , through which the heat transfer fluid is passed into or drawn out from the airtight cavity 220 . The material of the airtight casing 230 can be the same as or different from that of the support frame 220 .

Fig. 3 shows a variable thermal conductivity temperature control assembly 300 according to the second embodiment of the present invention, the airtight cavity 310 is formed between the first assembly A and the second assembly B, the support The frame 320 is in contact with the first component A and the second component B. As shown in FIG. That is, the heat transfer fluid in the airtight cavity 310 can directly contact the first component A and the second component B.

The difference between this embodiment and the first embodiment is that the temperature control assembly 300 does not include an airtight casing. For example, when controlling the temperature of the electrostatic chuck 112 in the plasma processing apparatus as shown in FIG. In between, the surfaces of the base 110 and the first heater 114 can be directly used as an airtight enclosure.

Fig. 4 shows a variable thermal conductivity temperature control assembly 400 according to the third embodiment of the present invention, the number of the airtight cavities 410 is multiple, and each of the airtight cavities 410 is individually controlled to pass in or out The heat conducting fluid is used to adjust the thermal conductivity of different regions where the airtight cavity 410 is located in the temperature control assembly 400 . This enables zoned temperature control. Each airtight cavity 410 in the temperature control assembly 400 of this embodiment can adopt the structure shown in the first embodiment or the second embodiment.

The difference between this embodiment and the first and second embodiments is that the temperature control assembly 400 is divided into internal zones, so as to regulate the thermal conductivity in zones. For example, when controlling the temperature of the electrostatic chuck 112 in the plasma processing apparatus as shown in FIG. control, or used in conjunction with the dynamic electrostatic chuck temperature control design, to control the heat transfer from the first heater 114 to the base 110 .

The temperature control component with variable thermal conductivity and its temperature control principle provided by the present invention are described in detail above by taking the electrostatic chuck 112 as an example. Those with ordinary knowledge in the technical field to which this case belongs can understand that in other temperature control structures such as the temperature control structure of the gas shower head 120, the arrangement and temperature control of the temperature control components with variable thermal conductivity provided by the present invention The principles are basically similar, and will not be repeated here.

Based on the same inventive concept, the present invention also provides a temperature control system, which includes a high temperature component, a low temperature component, and a temperature control component with variable thermal conductivity as described in the above three embodiments, and the temperature control component is arranged on the Between the high temperature component and the low temperature component, used to adjust the heat conduction between the high temperature component and the low temperature component. For example, the temperature control system can be used to control the temperature of an electrostatic chuck or a gas shower head.

The present invention also provides a plasma processing device, which is characterized in that it is equipped with the aforementioned temperature control system. The plasma processing device may be a capacitively coupled plasma (CCP) processing device shown in FIG. 1 , or may be an inductively coupled plasma (ICP) processing device.

The present invention also provides a temperature control method, as shown in Figure 5, comprising:

Step S100, providing the above-mentioned temperature control component;

Step S200, introducing or withdrawing heat transfer fluid into the airtight cavity to change the thermal conductivity of the temperature control component.

Specifically, the temperature control component is installed between the first component and the second component, and the first component and the second component have a temperature difference during operation.

When it is necessary to reduce the heat conduction between the first component and the second component, for example, it is desired to increase the heating range of the heating component to the first component and reduce the cooling effect of the second component on the first component, from the airtight chamber The body draws the heat transfer fluid to vacuum, reduces the thermal conductivity of the temperature control component, and forms a heat insulating layer between the first component and the second component. When it is necessary to speed up the heat conduction between the first component and the second component, for example, to increase the cooling rate of the second component to the first component, so that the temperature of the first component drops rapidly, the airtight cavity is filled with heat conduction The fluid improves the thermal conductivity of the temperature control component and serves as a heat conduction layer between the first component and the second component to accelerate heat transfer.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those having ordinary skill in the art of the present invention after reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended patent application scope.

100: vacuum reaction chamber 101: side wall of reaction chamber 102: opening 110: Base 112: Electrostatic chuck 113: Electrostatic electrode 114: The first heater 120: Gas sprinkler head 122: Mounting seat 125: gas supply device 150: RF power supply 152:Matching network 200: temperature control components 210: airtight cavity 220: Support skeleton 230: Airtight enclosure 231: Fluid import and export 300: temperature control components 310: airtight cavity 320: Support skeleton 400: temperature control components 410: airtight cavity A: The first component B: Second component W: wafer to be processed S100~S200: Steps

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings that need to be used in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are an embodiment of the present invention. Those with ordinary knowledge can also obtain other drawings based on these drawings without paying creative work: Fig. 1 is a structural schematic diagram of a capacitively coupled plasma processing device; Fig. 2 is a schematic structural diagram of a variable thermal conductivity temperature control component provided by the first embodiment of the present invention; 3 is a schematic structural diagram of a variable thermal conductivity temperature control component provided by the second embodiment of the present invention; Fig. 4 is a schematic structural diagram of a variable thermal conductivity temperature control component provided by the third embodiment of the present invention; Fig. 5 is a schematic flowchart of a temperature control method provided by an embodiment of the present invention.

200: temperature control components

210: airtight cavity

220: Support skeleton

230: Airtight enclosure

231: Fluid import and export

Claims (17)

A temperature control component with variable thermal conductivity, used in a plasma processing device, is arranged between a first component and a second component, and the first component and the second component have a temperature when the plasma processing device is working difference, the temperature control component is used to adjust the heat conduction between the first component and the second component, including: An airtight cavity, which includes a first side and a second side opposite to the first side, the first side is opposite to the first component, and the second side is opposite to the second component; a supporting frame, arranged in the airtight cavity, supported between the first side and the second side; The airtight cavity is used for introducing or extracting heat-conducting fluid to adjust the thermal conductivity of the temperature control component. The temperature control component with variable thermal conductivity as described in Claim 1, wherein the support frame is made of a material with a thermal conductivity of 0.01~1W/m·K. The temperature control component with variable thermal conductivity as claimed in claim 2, wherein the supporting frame is made of polymer material. The variable thermal conductivity temperature control component according to claim 1, wherein the heat transfer fluid is a heat transfer gas or a heat transfer liquid. The temperature control component with variable thermal conductivity according to claim 4, wherein when the heat transfer fluid is heat transfer gas, the thermal conductivity of the temperature control component is changed by changing the pressure of the heat transfer gas in the airtight cavity. The temperature control component with variable thermal conductivity as described in Claim 4, wherein helium is selected as the heat conducting gas. The temperature control component with variable thermal conductivity as described in Claim 4, wherein when the heat transfer fluid is a heat transfer liquid, the thermal conductivity of the temperature control component is changed by passing the heat transfer liquid into or out of the airtight cavity . The temperature control component with variable thermal conductivity as described in Claim 1, wherein the thickness of the temperature control component is in the range of 200-2000 microns. The temperature control assembly with variable thermal conductivity according to Claim 1, further comprising an airtight casing for forming the airtight cavity, and the airtight casing is provided with a fluid inlet and outlet. The temperature control component with variable thermal conductivity according to claim 1, wherein the airtight cavity is formed between the first component and the second component, and the supporting frame is connected with the first component and the second component touch. The variable thermal conductivity temperature control component as described in any one of claims 1 to 10, wherein the number of the airtight cavities is multiple, and each of the airtight cavities is individually controlled to pass in or out of the heat transfer fluid, In order to adjust the thermal conductivity of different regions where the airtight cavity is located in the temperature control component. The temperature control assembly with variable thermal conductivity as described in Claim 1, wherein the plasma processing device includes a base and an electrostatic chuck, the electrostatic chuck is arranged on the base, and a first A heater is used to provide heat to the electrostatic chuck, and a first cooling channel is provided in the base to circulate cooling liquid to cool the electrostatic chuck; One of the first component and the second component is the first heater, and the other is the base. The temperature control assembly with variable thermal conductivity as described in claim 1, wherein the plasma processing device includes a mounting base and a gas shower head, the gas shower head is arranged under the mounting base, and the mounting base A second heater is provided between the gas shower head, or the second heater is provided above the mounting base to provide heat to the gas shower head, and a second cooling channel is provided in the mounting base for use in Cooling the gas shower head by circulating cooling liquid; One of the first component and the second component is the second heater, and the other is the mounting base. A temperature control method, comprising: Provide a temperature control component as described in any one of claim items 1 to 13; The heat conduction fluid is passed into or withdrawn from the airtight cavity to change the thermal conductivity of the temperature control component. The temperature control method according to claim 14, wherein when the airtight cavity is vacuum, the temperature control component acts as a heat insulating layer; when the airtight cavity is filled with a heat transfer fluid, the temperature control component acts as a heat conduction layer. A temperature control system, including a high temperature component, a low temperature component and a variable thermal conductivity temperature control component as described in any one of claims 1 to 13, the temperature control component is arranged between the high temperature component and the between cryogenic components. A plasma processing device, wherein a temperature control system as described in claim 16 is configured.

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