JP4125110B2 - Exhaust flow channel structure of semiconductor manufacturing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the structure of piping, valves and other exhaust passages of various semiconductor manufacturing apparatuses such as vacuum processing apparatuses.
[0002]
[Prior art]
In the manufacturing process of semiconductor wafers, various vacuum processes such as film formation, etching, and ashing are performed. When such vacuum processing is performed, for example, reaction by-products are formed in the film formation process, and processing gas is used in the etching process. Products from the surface of the wafer and the components scraped from the wafer surface are discharged from the exhaust port of the vacuum chamber through the exhaust path, and if the exhaust path is not heated to a predetermined temperature, they will adhere to the inner wall of the exhaust path .
[0003]
For this reason, in Patent Document 1, in a vacuum processing apparatus for processing a wafer by introducing a processing gas into a processing chamber having an airtight structure to which a vacuum pump is connected via an exhaust path, an exhaust is provided in at least a part of the exhaust path. A tape heater is provided to heat the inner surface of the passage so that it becomes equal to or higher than the sublimation temperature of the exhaust according to the pressure in the exhaust passage, and this tape heater causes the temperature gradient in the length direction of the exhaust passage toward the vacuum pump side. It has been proposed to set the temperature to be low.
[0004]
[Problems to be solved by the invention]
However, in this prior art, since the tape heater is wound around the outer surface of the pipe of the exhaust passage, it is difficult to maintain the temperature of the inner surface of the pipe at the target temperature, and heat is taken away from the pipe and the surroundings. Energy loss is also great.
[0005]
Furthermore, when maintaining the exhaust pipe, the work load is heavy because it is necessary to remove the tape heater, and since the tape heater is wound around the pipe, the diameter of the pipe becomes large and there is a problem in handling. In addition, since the tape heater is exposed, it is necessary to take measures to prevent the operator from touching it by mistake.
[0006]
[Patent Document 1]
Patent No. 3204866 publication [0007]
[Means for Solving the Problems]
An object of this invention is to provide piping with high utilization efficiency of energy and excellent maintenance workability and safety.
[0008]
(1) In order to achieve the above-mentioned object, according to the present invention, the reaction by-product generated in the exhaust passage when the processing gas is introduced into the processing chamber having an airtight structure and the object to be processed is processed. In an exhaust channel structure of a semiconductor manufacturing apparatus for preventing adhesion, a channel body constituting the exhaust channel, a planar heating sheet detachably provided on the entire inner surface of the channel body, and the channel body And a heat insulator having a continuous gap portion along the longitudinal direction of the flow path, and an exhaust flow path structure for a semiconductor manufacturing apparatus.
[0009]
In the present invention, since the sheet heating sheet is provided on the inner surface of the flow path main body constituting the exhaust path for the processing gas, the temperature of the gas passing through the exhaust channel is directly controlled by the sheet heating sheet. be able to. Thereby, the heat by the sheet heating sheet is efficiently utilized without being taken away by surrounding members, and energy loss can be reduced. In addition, as a result of efficiently using the heat generation energy, the target temperature arrival time at start-up is shortened, and the target temperature return time at operation is also shortened.
[0010]
Furthermore, as a result of appropriately controlling the temperature of the gas passing through the exhaust passage, it is possible to prevent reaction by-products from adhering to the inside of the passage main body, so that the maintenance frequency of the exhaust passage can be reduced, Maintenance costs can be reduced.
[0011]
Further, since the sheet heating sheet is provided on the inner surface of the flow path body, the pipe diameter can be reduced and handling workability is improved.
[0012]
Furthermore, in the present invention, since a heat insulator having a gap is provided on the outer surface of the flow path body, the heat of the flow path body is blocked by the gap, and as a result, the outer surface of the exhaust flow path becomes a low temperature. If you touch the exhaust passage, you will not be burned.
[0015]
(2) In this invention, a cylinder can also be provided in the outer surface of the said heat insulating body. By doing so, the heat insulating property and the strength of the exhaust passage are further improved.
[0016]
(3) In this invention, it is more preferable to maintain the space | gap part of a heat insulating body in a vacuum, or to fill this space | gap part with the gas which has the heat conductivity below the heat conductivity of air.
[0017]
Since thermal conductivity is a physical property value that varies depending on temperature and pressure, the thermal conductivity can be reduced by lowering the pressure. Therefore, the heat insulation effect can be further enhanced by maintaining the space of the heat insulator at a vacuum lower than the atmospheric pressure. The vacuum according to the present invention does not mean an absolute vacuum but a broad concept that means a pressure state lower than the atmospheric pressure.
[0018]
In addition to maintaining the space of the heat insulator in a vacuum, it is possible to further enhance the heat insulation effect of the heat insulator by filling it with a gas having a thermal conductivity equal to or lower than that of air. it can. Since the thermal conductivity of air is 18.1 mW / mK at 200 ° C., preferred gases to be filled in the gaps of the heat insulator include argon gas (thermal conductivity is 12.6 mW at 200 ° C.). / MK), nitrogen gas (thermal conductivity is 18.3 mW / mK at 200 ° C.), carbon dioxide gas (thermal conductivity is 12.9 mW / mK at 250 ° C.), and a mixed gas thereof.
[0019]
(4) In the present invention, it is more preferable that the heat insulator provided with the continuous voids is constituted by a honeycomb structure. The honeycomb structure has a small contact area with the flow channel body and contributes to a heat insulating effect, and also functions as a strength reinforcement for the flow channel body.
[0020]
(5) In the present invention, it is more preferable that the heat insulator having the voids is made of foam metal, foam ceramic or foam elastomer. A heat insulating body made of a foam metal, a foam ceramic or a foam elastomer has a very high porosity and, as a result, has a large specific surface area, so that the heat insulation effect is further enhanced.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a perspective view showing a pipe according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the pipe according to an embodiment of the present invention, and FIG. 3 is a perspective view showing a sheet heating sheet according to the embodiment of the present invention. FIG. 4 is a block diagram showing an example of a semiconductor manufacturing apparatus to which the pipe of the present invention is applied.
[0022]
First, an example of a semiconductor device to which the pipe of the present invention is applied will be described with reference to FIG. In this example, the present invention is applied to an exhaust pipe of an aluminum dry etching apparatus (corresponding to a semiconductor manufacturing apparatus according to the present invention).
[0023]
As shown in the figure, the dry etching apparatus 100 includes an etching chamber 101, a turbomolecular pump 102, a heat insulating valve 103, a trap apparatus 104, a dry pump 105, and an abatement treatment apparatus 106. A semiconductor wafer W, which is an object to be processed, is set at a predetermined position in the etching chamber 101, and the etching chamber 101 is evacuated with a vacuum pump including a turbomolecular pump 102 and a dry pump 105. A reaction gas such as boron trichloride (BCl ₃ ) is supplied from the supply unit 107. As a result, the semiconductor wafer W is etched with a desired pattern of aluminum. At this time, the exhaust gas discharged from the dry pump 105 is purified by the detoxification gas processing device 106 and then exhausted.
[0024]
The turbomolecular pump 102 and the heat insulation valve 103 shown in the figure are connected by a pipe 108, the heat insulation valve 103 and the trap device 104 are connected by a pipe 109, and the trap device 104 and the dry pump 105 are connected to a pipe 110. The dry pump 105 and the removal gas treatment device 106 are connected by a pipe 111.
[0025]
In this aluminum etching apparatus, as shown by the sublimation curve in FIG. 5, aluminum chloride, which is a reaction by-product, becomes solid and easily adheres to the inner surface of a pipe or the like when the temperature falls below about 100 ° C. at atmospheric pressure. . For this reason, in order to prevent reaction by-products from adhering to the gas flow path from the etching chamber 101 to the detoxification gas processing device 106, particularly the inner surfaces of the pipes 108, 109, 110, 111, these pipes 108, The piping 1 of this embodiment is used for 109,110,111.
[0026]
As shown in FIGS. 1 and 2, the pipe 1 of the present embodiment has a flow path body 11 and is made of, for example, stainless steel having an inner diameter of 46.1 mm and a plate thickness of 1.0 mm. On the inner surface 11a of the flow path main body 11, a roll of a sheet heating sheet 14 having a thickness of, for example, 0.1 mm to 1.0 mm as shown in FIG.
[0027]
The sheet heating sheet 14 is obtained by embedding a heating resistor 14b made of a material such as tungsten, cobalt, or stainless steel in an insulating sheet 14a made of polyimide resin or the like, and controls the current flowing through the heating resistor 14b. By doing so, the exothermic temperature is adjusted.
[0028]
In particular, in the sheet heating sheet 14 according to the present embodiment, as shown in FIG. 3A, a material having rigidity such as tungsten, cobalt, stainless steel or the like is rolled with respect to the insulating sheet 14a. Since it is meandering and embedded in X, if it is rounded as shown in FIG. 4B, a buckling force is generated in the entire sheet-like heat generating sheet 14, and thereby the flow path body 11 without using an adhesive or the like. It can be made to adhere and hold to the inner surface of the. Further, since the sheet heating sheet 14 is held on the inner surface of the flow path body 11 only by the self-buckling force, it can be detached with a little force, and maintenance such as replacement of the sheet heating sheet 14 is performed. Workability is improved.
[0029]
Further, since the sheet heating sheet 14 is provided on the inner surface 11a of the flow path main body 11, the inner surface of the sheet heating sheet 14 is in contact with the exhaust gas flow path. That is, in this example, the exhaust gas containing the reaction by-product flows down in direct contact with the sheet heating sheet 14, so that the reaction by-product is solid if the temperature control of the sheet heating sheet 14 is appropriately performed. There is no risk of becoming attached. Even if the reaction by-product is solidified, it adheres to the sheet heating sheet 14, so that only the sheet heating sheet 14 needs to be replaced. Therefore, the flow path main body 11 and the first cylinder 15 and the second cylinder 16 described later can be used as they are.
[0030]
The control temperature of the sheet heating sheet 14 is appropriately selected according to the physical properties of reaction by-products contained in the exhaust gas of the semiconductor manufacturing apparatus to be applied. For example, in the aluminum etching apparatus of this example, since aluminum chloride becomes a reaction byproduct, the temperature is controlled to an appropriate temperature using the sublimation curve shown in FIG. Also, as shown in the figure, ammonium chloride is a reaction by-product in the LPCVD equipment nitride film process, and various ammonium compounds are reaction by-products in the PECVD equipment nitride film process, so refer to the sublimation curves of each substance. Control to an appropriate temperature.
[0031]
Returning to FIGS. 1 and 2, the entire outer surface 11 b of the flow path body 11 is provided with a first heat insulator 15 made of foam metal, foam ceramic, or foam elastomer. As shown in FIG. 6, the first heat insulator 15 is obtained by joining the same stainless steel foil 15 c formed in a corrugated shape to the surface of a stainless steel core foil 15 b of 30 μm to 100 μm by brazing or welding. A wave-shaped honeycomb structure is formed so as to form a plurality of continuous voids 15a along the longitudinal direction. The first heat insulator 15 can be fixed to the outer surface of the flow path body 11 by using fastening means such as welding, but instead, the tape-shaped first heat insulation body 15 is attached to the flow path body 11. The outer surface may be spirally wound.
[0032]
For example, a stainless steel first cylindrical body 12 having a thickness of 0.5 mm is provided on the outer side of the first heat insulating body 15, and the first heat insulating body 15 described above is located on the inner surface thereof. In this way, the first heat insulator 15 having the honeycomb structure is interposed between the flow path main body 11 and the first cylindrical body 12, so that first, the heat insulation effect is exhibited due to the presence of the gap portion 15a of the heat insulator 15. In addition, the heat insulation effect can be further enhanced by configuring the first heat insulator 15 with a material having a large specific surface area such as foam metal, foam ceramic, or foam elastomer.
[0033]
The pipe 1 of this example is further configured as follows. That is, on the outer surface 12b of the first tubular body 12, the second heat insulating body 16 having the same honeycomb structure as that of the first heat insulating body 15 described above, which is made of the same metal foam, ceramic foam or foamed elastomer as the first heat insulating body 15 described above. Is provided. The second heat insulator 16 is also formed in a wave-shaped honeycomb structure so that a plurality of continuous voids 16a are formed along the longitudinal direction of the pipe 1 as shown in FIG. The second heat insulator 16 can also be fixed to the outer surface of the first cylinder 12 by using fastening means such as welding. Instead, the tape-like second heat insulator 16 is attached to the first cylinder. The outer surface of the body 12 may be wound spirally.
[0034]
Furthermore, a stainless steel second cylinder 13 having a thickness of 0.5 mm, for example, is provided outside the second heat insulator 16, and the second heat insulator 16 described above is located on the inner surface thereof. In this way, the second heat insulating body 16 having the honeycomb structure is interposed between the first cylindrical body 12 and the second cylindrical body 13, so that first, the heat insulating effect is exhibited due to the presence of the gap portion 16a of the heat insulating body 16. In addition, the heat insulation effect can be further enhanced by configuring the second heat insulator 16 with a material having a large specific surface area such as foam metal, foam ceramic, or foam elastomer.
[0035]
Next, the operation will be described.
The pipe 1 according to this embodiment described above is applied to the pipes 108, 109, 110, and 111 of the dry etching apparatus 100 shown in FIG. 4, and is further provided in each of the first heat insulator 15 and the second heat insulator 16 of each pipe. A vacuum pump or the like is connected to each of the gaps 15a and 16a, and the gaps 15a and 16a are maintained in vacuum. Alternatively, when the pipe 1 is manufactured, the gaps 15a and 16a may be evacuated and sealed. The vacuum in this case is not a narrowly-defined vacuum that means an absolute vacuum, and it is only necessary to maintain a lower pressure than atmospheric pressure. As shown in FIG. 5, the lower the pressure, the lower the sublimation temperature of the reaction by-product, thereby lowering the set temperature of the sheet heating sheet 14 and the sheet heating sheet of the reaction by-product. This is because it is difficult to adhere to the inner surface 14a.
[0036]
Further, instead of maintaining the inside of the gaps 15a, 16a provided in the first heat insulator 15 and the second heat insulator 16 of each pipe in a vacuum, air or air in the gaps 15a, 16a is provided. A gas having a thermal conductivity equal to or lower than the thermal conductivity may be filled. Since the thermal conductivity of air is 18.1 mW / mK at 200 ° C., a preferable gas to be filled in the gaps 15a and 16a of the first and second heat insulators 15 and 16 is as long as safety is considered. In addition to air itself, argon gas, nitrogen gas, carbon dioxide gas, and a mixed gas thereof.
[0037]
Further, the temperature of the sheet heating sheet 14 is controlled to an appropriate temperature according to the pressure of the gas passing through the inside. For example, according to the sublimation curve shown in FIG. 5, the reaction by-product aluminum chloride sublimates at about 100 ° C. when the gas pressure is 1 Torr, but when the gas pressure increases, the sublimation temperature also increases. As the gas pressure decreases, the sublimation temperature decreases. Therefore, the sheet heating sheet 14 is controlled to a temperature at which aluminum chloride as a reaction by-product is sublimated and does not solidify according to the gas pressure passing through the pipes 108 to 111 of the dry etching apparatus 100.
[0038]
As described above, when the pipe 1 of this example is employed in the pipes 108 to 111 (at least one of the pipes 108 to 111) of the dry etching apparatus 100 shown in FIG. 4, the temperature of the gas passing through the pipe is changed by the planar heating sheet 14. It can be controlled directly. Thereby, the heat by the sheet-like heat generating sheet 14 is efficiently utilized without being taken away by surrounding members, and energy loss can be reduced. In addition, as a result of efficiently using the heat generation energy, the target temperature arrival time at start-up is shortened, and the target temperature return time at operation is also shortened.
[0039]
Further, as a result of appropriately controlling the temperature of the gas passing through the pipe, reaction by-products are prevented from adhering to the inner surfaces of the pipes 108 to 111, so the maintenance frequency of the exhaust path of the semiconductor manufacturing apparatus 100 is reduced. Maintenance costs can be reduced.
[0040]
Moreover, since the sheet-like heat generating sheet 14 is provided on the inner surfaces of the pipes 108 to 111 by using the self-buckle force, the attachment / detachment workability is excellent, the piping system can be reduced, and the handling workability is improved.
[0041]
Furthermore, in this embodiment, between the flow path main body 11 and the 1st cylinder 15 of the piping 1, and between the 1st cylinder 12 and the 2nd cylinder 13, respectively, it is the space | gap part 15a, 16a which continued to the whole, respectively. Since the first heat insulator 15 and the second heat insulator 16 are provided, the outer surface of the second cylinder 13 which is the outermost surface of the pipe is sufficiently low in temperature, and even if the operator touches the pipe, burns etc. There is no burden.
[0042]
In this example, the gaps 15a and 16a of the first heat insulator 15 and the second heat insulator 16 are maintained in vacuum, or the gaps 15a and 16a have a thermal conductivity equal to or lower than the thermal conductivity of air. Since the gas is filled, the thermal conductivity can be reduced, and the heat insulation effect becomes higher.
[0043]
Further, since the first heat insulating body 15 and the second heat insulating body 16 have a corrugated honeycomb structure, in addition to contributing to the heat insulating effect, a strong reinforcing body between the flow path main body 11 and the cylindrical bodies 12 and 13 of the piping. Can also increase the strength of the piping itself.
[0044]
Further, since the first heat insulator 15 and the second heat insulator 16 are made of foam metal, foam ceramic, or foam elastomer, the porosity is extremely large and, as a result, the specific surface area is large, so that the heat insulation effect is further enhanced. .
[0045]
The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0046]
For example, in the above-described embodiment, two cylinders, that is, the first cylinder 12 and the second cylinder 13 are provided as the cylinders of the pipe 1, and between the flow path body 11 and the first cylinder 12. Although the 1st heat insulation 15 was provided and the 2nd heat insulation 16 was provided between the 1st cylinder 12 and the 2nd cylinder 13, among these, the 1st cylinder 12, the 2nd cylinder 13, and the 2nd The heat insulator 16 can be omitted.
[0047]
That is, by a pipe having a flow path body 11, a sheet heating sheet 14 that is detachably provided on the inner surface 11 a of the flow path body 11, and a first heat insulator 15 provided on the outer side of the flow path body 11. In addition, the various effects described above are exhibited.
[0048]
Moreover, although only the example applied to piping was given in embodiment mentioned above, the basic structure of this invention is applicable also to various valves, such as a vacuum shut-off valve and a vacuum pressure control valve, and a trap besides piping. it can.
[0049]
For example, FIG. 7 shows an example in which the exhaust passage structure of the present invention is applied to the heat insulating valve 103 shown in FIG. An inlet 103b and an outlet 103c are formed in the valve body 103a, and a valve body 103e formed at the tip of the bellows 103d opens and closes the valve seat 103g by an actuator 103f. In this example, the sheet heating sheet 14 is provided on the inner surface of the valve body 103a, and the honeycomb structure heat insulator 15 is provided on the outer surface of the valve body 103a.
[0050]
When the sheet heating sheet 14 is provided on the inner surface of the valve body 103a, the self-buckling force of the sheet heating sheet 14 is used to hold the sheet heating sheet 14 without using an adhesive or the like, as in the example of the pipe 1 described above. Can do. Further, the heat insulator 15 having the same structure as the first heat insulator 15 and the second heat insulator described above is provided on the outer surface of the valve main body 103a, and the gap 15a is maintained in a vacuum, or air, argon gas, Nitrogen gas, carbon dioxide gas and a mixed gas thereof may be flowed.
[0051]
【The invention's effect】
(1) According to the first aspect of the present invention, the heat generated by the planar heat generating sheet is efficiently utilized without being taken away by surrounding members, and energy loss can be reduced. In addition, as a result of efficiently using the heat generation energy, the target temperature arrival time at start-up is shortened, and the target temperature return time at operation is also shortened.
[0052]
In addition, the temperature of the gas passing through the exhaust passage can be controlled appropriately, preventing reaction by-products from adhering to the piping, reducing the maintenance frequency of the exhaust passage and reducing maintenance costs. can do.
[0053]
In addition, the piping system can be reduced, and handling workability is improved. Furthermore, the outer surface of the exhaust passage becomes low temperature, and even if an operator touches the piping, there is no burn.
[0054]
Moreover, since the detachable planar heating sheet is provided , maintenance workability such as replacement of the planar heating sheet is improved.
[0055]
(2) According to the inventions of claims 2 to 4 , the heat insulation effect can be further enhanced.
[0056]
(3) According to the invention described in claim 5, in addition to contributing to the heat insulation effect, it also functions as a strength reinforcing body of the flow path main body of the exhaust flow path, so that the strength of the exhaust flow path itself can be increased.
[0057]
(4) According to the invention described in claim 6 , the heat insulating body made of the foam metal, the foam ceramic or the foam elastomer has a very high porosity and, as a result, has a large specific surface area, so that the heat insulation effect is further enhanced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a pipe according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a pipe according to an embodiment of the present invention.
FIG. 3 is a perspective view showing a sheet heating sheet according to an embodiment of the present invention.
FIG. 4 is a block diagram showing an example of a semiconductor manufacturing apparatus to which the present invention is applied.
FIG. 5 is a graph showing a sublimation curve of a reaction by-product.
FIG. 6 is a partial perspective view showing an example of a heat insulator according to the present invention.
FIG. 7 is a cross-sectional view showing a heat insulation valve according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Piping 11 ... Channel body 11a ... Inner surface of channel body, 11b ... Outer surface 12 of channel body ... First cylinder 12a ... Inner surface of first cylinder 12b ... Outer surface 13 of first cylinder ... Second Cylindrical body 13a: inner surface of second cylindrical body, 13b: outer surface 14 of second cylindrical body ... sheet-like heat generating sheet 15 ... first heat insulating body 15a ... void 16 of first heat insulating body ... second heat insulating body 16a ... second Cavity 100 of heat insulator ... Dry etching apparatus (semiconductor manufacturing apparatus)
101 ... Etching chamber (processing room)
DESCRIPTION OF SYMBOLS 102 ... Turbo molecular pump 103 ... Thermal insulation valve 104 ... Trap apparatus 105 ... Dry pump 106 ... Detoxification gas processing apparatus 107 ... Gas supply part 108,109,110,111 ... Piping

Claims (6)

In the exhaust flow channel structure of a semiconductor manufacturing apparatus for introducing a processing gas into a processing chamber having an airtight structure and preventing adhesion of reaction by-products generated in the exhaust flow channel when processing an object to be processed,
A flow path body constituting the exhaust flow path, a planar heating sheet detachably provided on the entire inner surface of the flow path body, and a plurality of continuous heat flow sheets provided on the outer surface of the flow path body in the longitudinal direction of the flow path An exhaust passage structure of a semiconductor manufacturing apparatus, comprising: The exhaust channel structure for a semiconductor manufacturing apparatus according to claim 1, wherein a cylindrical body is provided on an outer surface of the heat insulator. The exhaust passage structure of a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the space of the heat insulator is maintained in a vacuum. 3. The exhaust flow path structure of a semiconductor manufacturing apparatus according to claim 1 , wherein a gas having a thermal conductivity equal to or lower than a thermal conductivity of air is filled in a gap portion of the heat insulator. The exhaust passage structure for a semiconductor manufacturing apparatus according to any one of claims 1 to 4 , wherein the heat insulator has a honeycomb structure. 6. The exhaust channel structure of a semiconductor manufacturing apparatus according to claim 1 , wherein the heat insulator is made of foam metal, foam ceramic, or foam elastomer.

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