JP2000068260A - Heat-treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent condensation of treating gas by incorporating a treating gas supply system in a thermostat held at a predetermined temperature without condensation of the gas, thereby uniformly heating an overall site of the system. SOLUTION: A heat-treating furnace 1 is constituted of a quartz reaction tube 2 having a long longitudinal cylindrical state blocked at its upper end and opened at its lower end and a heat resistance. The tube 2 is gastightly blocked at its lower end opening opened as a furnace port by a cover 3. A wafer boat 4 for supporting many semiconductor wafers W at intervals in a vertical direction in a horizontal state in multi-stage is placed on the cover 3 via a heat insulation cylinder 5. Further, a gas supply system 6 and an exhaust system 7 are connected to a lower side of the tube 2. The system 6 is contained in a thermostat 16 of a container 11 for holding an inner atmosphere at a predetermined temperature for not bringing about the coagulation of the gas, and a vacuum pump for evacuating the tube 2 is provided in the system 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a heat treatment apparatus.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, for example, various heat treatment apparatuses are used to perform heat treatment such as CVD (Chemical Vapor Deposition), diffusion, oxidation and annealing on a semiconductor wafer to be processed. ing. For example, MO
In a heat treatment apparatus used for CVD (chemical vapor deposition of metal oxide) or the like, as shown in FIG. 4, there is provided a vaporizing section 8 for vaporizing a liquid material or a fixed material to generate a processing gas. . The processing gas generated in the vaporizing section 8 is converted into a heat treatment furnace 1 by a carrier gas, for example, an inert gas such as nitrogen (N ₂ ) gas or a raw material gas via a gas supply system 6.
And the semiconductor wafer W is subjected to a predetermined heat treatment, for example, an MO-CVD process in the heat treatment furnace 1. The gas supply system 6 is composed of a pipe 9 connecting the vaporizing section 8 and the heat treatment furnace 1 and members such as a valve 10 provided in the pipe 9.

By the way, when the processing gas used in the MO / CVD processing or the like falls below a predetermined temperature, coagulation occurs and it becomes difficult to supply the gas stably. For this reason, by winding a ribbon-shaped heater 25 for heating these members such as the pipe 9 and the valve 10 of the gas supply system 6 or covering the member with a heat insulating material from above, the processing gas of the processing gas is removed. Prevents condensation.

[0004]

However, in the above-mentioned heat treatment apparatus, it is difficult to keep all the parts of the members such as pipes and valves at a constant temperature only by winding a ribbon-shaped heater. There is a case where the temperature is locally reduced, for example, a portion having a large heat capacity is not sufficiently heated. In this case, condensation (liquefaction or solidification) of the processing gas tends to occur at a low temperature portion, and it may be difficult to stably supply the processing gas. Further, the ribbon-shaped heater has a limitation in a heating temperature (about 150 to 200 ° C.), and thus has a drawback of poor durability.

Accordingly, the present invention has been made to solve the above-described problems, and can uniformly prevent the processing gas from condensing by uniformly heating all portions of the gas supply system, thereby stabilizing the processing gas. It is an object of the present invention to provide a heat treatment apparatus that can supply the heat.

[0006]

Means for Solving the Problems In the present invention, claim 1 is provided.
The invention according to the present invention is directed to a heat treatment apparatus for performing a predetermined heat treatment by supplying a processing gas from a gas supply system into a heat treatment furnace accommodating an object to be processed, wherein the processing gas supply system has a predetermined temperature at which no condensation of the processing gas occurs. Characterized in that it is housed in a thermostat held in a thermostat.

According to a second aspect of the present invention, there is provided a vaporizing section for vaporizing a liquid material or a fixed material to generate a processing gas, and supplying a processing gas from the vaporizing section by a gas supply system to a predetermined heat treatment on the object to be processed. Wherein the gas supply system is housed in a container having an internal atmosphere maintained at a predetermined temperature at which the processing gas does not condense.

According to a third aspect of the present invention, in the heat treatment apparatus of the second aspect, a vaporizer is also housed in the container.

The invention according to claim 4 is the invention according to claim 2 or 3
The heat treatment apparatus according to the above, wherein the container comprises a heat insulating material that insulates the inside, a heating unit that heats the internal atmosphere, a temperature control unit, and a thermostat having a stirring unit that stirs the internal atmosphere, I do.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing a heat treatment apparatus according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view of the constant temperature bath shown in FIG. 1, and FIG. It is a perspective view.

In FIG. 1, reference numeral 1 denotes a semiconductor wafer W which is an object to be processed, and a processing gas is supplied at 850 ° C.
A vertical, batch-type heat treatment furnace that performs a predetermined heat treatment, for example, MO / CVD treatment, at a high temperature of the order of magnitude. This heat treatment furnace 1 is a vertically long cylindrical heat-resistant material, such as quartz, having a closed upper end and an open lower end. It is constituted by a reaction tube 2.

The reaction tube 2 has a highly airtight heat treatment furnace 1 with its lower end opening, which is opened as a furnace port, hermetically closed by a lid 3. On the lid 3, for example, a wafer boat 4 made of, for example, quartz, which is a substrate support for supporting a large number of, for example, about 150 semiconductor wafers W in a horizontal state at intervals in the vertical direction, is provided with a heat retaining cylinder 5. Has been placed through.

The lid 3 is configured to load (load) and unload (unload) the wafer boat 4 into the heat treatment furnace 1 and open and close the furnace port by a lifting mechanism (not shown). A heater H is provided around the reaction tube 2 so that the inside of the furnace can be controlled to be heated to a predetermined temperature, for example, 300 to 1000 ° C.

A gas supply system 6 for supplying a processing gas into the reaction tube 2 and an exhaust system 7 for exhausting the inside of the reaction tube 2 are connected to a lower portion of the reaction tube 2. The exhaust system 7 includes a reaction tube 2
A vacuum pump (not shown) capable of reducing the pressure inside the chamber to, for example, about 10 ⁻³ Torr is provided.

An evaporator 8 is provided upstream of the gas supply system 6 for evaporating a liquid material or a solid material to generate a processing gas. The processing gas generated in the evaporator 8 is converted into a carrier gas such as nitrogen (N _2). ) The gas is supplied from the vaporizing section 8 into the reaction tube 2 via the gas supply system 6 by an inert gas such as a gas or a raw material gas.

As the liquid material, for example, in the case of a BSTO process, barium (Ba), strontium (S
r) and titanium (Ti) dissolved in alcohol are used. As the solid material, for example, in the case of a ruthenium-based process, metal powder chemically containing ruthenium (Ru) is used. The vaporizing section 8 is provided with a heating means (heater) for heating the liquid material or the solid material to vaporize (not shown).

The gas supply system 6 includes a pipe 9 connecting the vaporizing section 8 and the heat treatment furnace 1 and members (not shown) such as a valve 10 provided in the pipe 9. Here, the valve 10 includes, for example, a manual valve, an air operated valve, a needle valve, and the like. The member includes, for example, a joint, a filter, and the like. The gas supply system 6 has a predetermined temperature, for example, 100 to 25, at which the processing gas does not condense.
It is housed in a container 11 whose internal atmosphere is maintained at about 0 ° C. The ambient temperature in the container 11 is, for example, about 250 ° C. for the BSTO process, about 150 ° C. for the tantalum process, and about 100 ° C. for the TEOS process.

As shown in FIG. 2, the container 11 has a heat insulating material 12 for insulating the inside, a heating unit 13 for heating the internal atmosphere, a temperature control unit (automatic temperature control unit) 14, and a stirring unit for the internal atmosphere. It is preferable to comprise a thermostatic chamber 16 having a stirring section 15 for performing the heating. A heating chamber 17 partitioned by a metal plate such as stainless steel is provided inside a thermostat 16 partitioned by the heat insulating material 12, and a large number of ventilation holes 18 are provided on both side walls of the heating chamber 17. ing.

Between the heating chamber 17 and the heat insulating material 12, a ventilation path 19 for circulating an internal atmosphere, for example, air so as to pass through the heating chamber 17, is provided.
The heating unit 13 comprising a resistance heating element, and an electric motor 20
And a stirrer 15 comprising a fan which is rotated and driven to stir and circulate the atmosphere. In the heating chamber 17, members such as a pipe 9 and a valve 10 which constitute a gas supply system 6 between the vaporizing section 8 and the heat treatment furnace 1 are accommodated. Note that, in the present embodiment, the thermostatic bath 16
The vaporizing section 8 is provided outside the device.

FIG. 3 is a perspective view showing an example of installation of a thermostat in the heat treatment apparatus. The heat treatment apparatus has a casing 21 forming an outer shell, and a loading / unloading port 22 for loading / unloading a carrier (cassette) accommodating a plurality of, for example, about 25 semiconductor wafers, is provided at the front of the casing 21. The heat treatment furnace 1 is provided above the rear part in the housing 21. A gas box 23 for supplying a processing gas or the like is provided on one side of the housing 21, and the thermostat 16 is installed in the gas box 23.

The thermostatic chamber 16 accommodates all the members such as the valve 10 having heat capacity, and then supplies the processing gas to the heat treatment furnace 1 only by a straight pipe. In addition, it is preferable that a ribbon-shaped heater is wound around an exposed portion of the straight pipe (a part of the pipe 9) exposed between the thermostat 16 and the heat treatment furnace 1, and is covered with a heat insulating material.

According to the heat treatment apparatus configured as described above, the vaporizing section 8 that vaporizes the liquid material or the fixed material to generate the processing gas, and supplies the processing gas from the vaporizing section 8 by the gas supply system 6. In a heat treatment apparatus provided with a heat treatment furnace 1 for subjecting the semiconductor wafer W to a predetermined heat treatment, for example, MO / CVD treatment, the gas supply system 6 is maintained at a predetermined temperature at which the processing gas does not condense. Container 1
Since the gas supply system 1 is housed in the gas supply system 1, the gas supply system 6 including members such as the valve 10 can be uniformly heated to a state where there is no local temperature decrease, and the process gas in the gas supply system 6 can be sufficiently condensed. And a stable supply of the processing gas becomes possible.

That is, instead of directly heating the parts with a ribbon-shaped heater as in the conventional heat treatment apparatus, the atmosphere in which the parts are housed is heated so that stable heating without a local temperature decrease is achieved. It can be realized, and the condensation of the processing gas can be sufficiently prevented. Thereby, a stable supply of the processing gas to the heat treatment furnace 1 becomes possible, and the reproducibility and quality of the heat treatment can be improved. The container 11 includes a heat insulating material 12 for insulating the inside and a heating unit 1 for heating the internal atmosphere.
3, a temperature control unit 14, and a thermostatic chamber 16 having a stirring unit 15 for stirring the internal atmosphere.
Can be easily heated to a constant temperature.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the present invention is not limited to the above embodiment, and various design changes and the like can be made without departing from the gist of the present invention. Is possible. For example, in the above-described embodiment, an example is shown in which the vaporizing section is provided outside the thermostat, but the vaporizer may be housed in the thermostat. According to this, since the vaporization unit can be heated by the constant temperature bath, it is not necessary to provide a dedicated heating unit in the vaporization unit,
The structure can be simplified.

Although the present invention is suitably applied to a heat treatment apparatus having a vaporizing section, it is of course applicable to a heat treatment apparatus having no vaporizing section. The heat treatment furnace may be a single wafer type or a horizontal type. As the object to be processed,
Other than the semiconductor wafer, for example, a glass substrate or an LCD substrate may be used.

[0026]

In summary, according to the present invention, the following effects can be obtained.

(1) According to the first aspect of the present invention, in the heat treatment apparatus for performing a predetermined heat treatment by supplying a processing gas from a gas supply system into a heat treatment furnace accommodating an object to be processed, the processing gas supply system Is stored in a constant temperature bath maintained at a predetermined temperature that does not cause condensation of the processing gas, so that the gas supply system can be uniformly heated to a state without a local temperature decrease. Condensation of the processing gas can be sufficiently prevented, and a stable supply of the processing gas can be achieved.

(2) According to the second aspect of the invention, the vaporizing section for vaporizing the liquid material or the fixed material to generate the processing gas, and supplying the processing gas from the vaporizing section by the gas supply system to be processed. A heat treatment apparatus comprising a heat treatment furnace for subjecting the body to a predetermined heat treatment, wherein the gas supply system is housed in a container having an internal atmosphere maintained at a predetermined temperature at which the processing gas does not condense. The supply system can be uniformly heated to a state where there is no local temperature drop, and condensing of the processing gas in the gas supply system of the heat treatment device equipped with a vaporizing unit can be sufficiently prevented, and stable supply of the processing gas is possible. Become.

(3) According to the third aspect of the present invention, since the vaporizing section is also housed in the container, it is not necessary to provide a dedicated heating means in the vaporizing section, and the structure can be simplified.

(4) According to the invention according to claim 4, the container comprises a heat insulating material for insulating the inside, a heating unit for heating the internal atmosphere, a temperature control unit, and a stirring unit for stirring the internal atmosphere. It is possible to easily heat all parts of the gas supply system to a constant temperature, and to uniformly heat the gas supply system to a state where there is no local temperature drop. Condensation of the gas can be sufficiently prevented, and the processing gas can be supplied stably.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of the constant temperature bath shown in FIG.

FIG. 3 is a perspective view showing an installation example of a thermostat in the heat treatment apparatus.

FIG. 4 is a view schematically showing an example of a conventional heat treatment apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat treatment furnace W Semiconductor wafer (object to be processed) 6 Gas supply system 8 Vaporization unit 11 Container 12 Heat insulating material 13 Heating unit 14 Temperature control unit 15 Stirring unit 16 Constant temperature bath

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K030 AA11 CA04 EA01 GA02 KA25 KA41 KA45 LA15 5F045 AA04 AD12 AE15 DP19 EC09 EE02

Claims (4)

[Claims] In a heat treatment apparatus for performing a predetermined heat treatment by supplying a processing gas from a gas supply system into a heat treatment furnace accommodating an object to be processed, the processing gas supply system is set to a predetermined temperature at which no condensation of the processing gas occurs. A heat treatment apparatus, wherein the heat treatment apparatus is housed in a thermostat held in a thermostat. 2. A vaporizing section for vaporizing a liquid material or a fixed material to generate a processing gas, and a heat treatment furnace for supplying a processing gas from the vaporizing section by a gas supply system and performing a predetermined heat treatment on the object to be processed. In the heat treatment apparatus provided, the gas supply system is housed in a container having an internal atmosphere maintained at a predetermined temperature at which the processing gas does not condense. 3. The heat treatment apparatus according to claim 2, wherein a vaporizer is also housed in the container. 4. The container, wherein: a heat insulating material for insulating the inside;
4. The heat treatment apparatus according to claim 2, comprising a constant temperature bath having a heating unit for heating the internal atmosphere, a temperature control unit, and a stirring unit for stirring the internal atmosphere.