JP3543963B2 - Heat treatment equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat treatment apparatus.
[0002]
[Prior art]
2. Description of the Related Art In a semiconductor device manufacturing process, a heat treatment apparatus is used for subjecting an object to be processed, for example, a semiconductor wafer to a heat treatment such as a CVD (Chemical Vapor Deposition). This heat treatment apparatus includes a heat treatment furnace for accommodating the object to be processed, a gas supply system for supplying a gas such as a processing gas into the furnace, and an exhaust system for depressurizing and exhausting the inside of the furnace. This exhaust system is, for example, first vacuum-replaced in the furnace, performs slow vacuum so as not to wind up particles at that time, and then performs pressure control such that the inside of the furnace is set to a predetermined processing pressure as follows. Configuration is adopted.
[0003]
As shown in FIG. 6, the exhaust system 12 has a pipe 13 having a predetermined pipe diameter of, for example, 3 inches. The pipe 13 has a main valve (main open / close valve) 18 composed of, for example, an angle valve and a main valve composed of a butterfly valve. A pressure control valve 19 and a pressure reducing pump 17 are provided in order (not shown). A small pipe diameter, for example, a 1/4 inch bypass pipe 60 that bypasses the main valve 18 is connected to the pipe 13, and a first auxiliary valve 61 and a second auxiliary valve 62 are connected in parallel to the bypass pipe 60. And a needle valve 63 for adjusting the flow rate is provided in series on the second auxiliary valve 62 side.
[0004]
When the pressure in the furnace is reduced from the atmospheric pressure to a predetermined processing pressure, first, the main valve 18 and the first auxiliary valve 61 are closed, the second auxiliary valve 62 is opened, and the needle valve is opened to perform slow vacuum. Vacuum evacuation is started at the minute flow rate set at 63, and then the first auxiliary valve 62 and the main valve 61 are opened in order to evacuate to the target final pressure.
[0005]
[Problems to be solved by the invention]
However, in the conventional heat treatment apparatus, since the bypass pipe 60 is connected to the exhaust system 12 and the first and second auxiliary valves 61 and 62 are provided, not only the large space Sa is required but also the piping 13 There has been a problem that the surroundings are complicated and maintenance workability is poor. Further, in order to fix the main valve 18, it is necessary to fix the pipes before and after the main valve 18 to the frame 14 of the apparatus via the fixing bracket 70, which not only makes the piping area more complicated, but also increases the heating. In the case of piping, there is a problem in that heat escapes from the fixture 70 and reaction by-products are generated in the piping.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat treatment apparatus that can simplify the piping around an exhaust system and improve maintenance workability. Another object of the present invention is to provide a heat treatment apparatus in which the main valve can be directly fixed to the frame of the apparatus, and the area around the piping can be further simplified.
[0007]
[Means for Solving the Problems]
Among the present invention, the invention of claim 1 provides a main valve, a first auxiliary valve, and a second auxiliary valve in a piping of an exhaust system of a heat treatment furnace which is provided with a heat treatment furnace inside a skeleton and which is piped from the skeleton to outside the skeleton. A heat treatment apparatus provided with a valve in parallel, wherein two bypass passages communicating an inlet side and an outlet side are formed in a main body forming an outer shell of the main valve, and one bypass passage is opened and closed in the main valve body. And a second auxiliary valve for opening and closing the other bypass passage. A main body of the main valve is provided with a self-standing fixing plate, and a main body of the main valve is provided via the fixing plate. Are fixed to the frame .
[0008]
According to a second aspect of the present invention, in the heat treatment apparatus according to the first aspect, the second auxiliary valve is configured to be capable of adjusting a flow rate.
[0009]
According to a third aspect of the present invention, in the heat treatment apparatus according to the first aspect , a bracket is attached to the frame, and the fixing plate is fixed to the bracket .
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0011]
In FIG. 1 which shows a schematic configuration of a heat treatment apparatus, reference numeral 1 denotes a heat treatment furnace which accommodates an object to be processed, for example, a semiconductor wafer w, and performs a predetermined heat treatment, for example, a CVD process. Has been adopted. The heat treatment furnace 1 includes a processing vessel (reaction tube) 2 made of quartz, and a cylindrical heater 3 provided around the processing vessel 2 so as to surround the processing vessel 2.
[0012]
Although the processing vessel 2 has a double pipe structure of the inner pipe 2a and the outer pipe 2b in the illustrated example, it may have a single pipe structure. A lower end of the processing vessel 2 is opened, and a gas introduction pipe section 4 for introducing a gas such as a processing gas into the processing vessel 2 and an exhaust pipe section 5 for exhausting an atmosphere in the processing vessel 2 are provided at a lower end of the processing vessel 2. An annular manifold 6 having an airtight connection is hermetically connected. The lower end of the manifold 6 is opened as a furnace port 7, and a lid 8 for hermetically closing the furnace port 7 is provided below the furnace port 7 via an elevating mechanism 9 so as to be freely opened and closed.
[0013]
On the lid 8, a quartz boat 10, which is a holder for mounting and holding a large number of, for example, about 150 wafers w at predetermined intervals in a vertical direction, is provided via a furnace port heat insulating means, for example, a heat retaining cylinder 11. It is placed. The boat 10 is loaded (unloaded) and unloaded (unloaded) into the furnace 1, that is, into the processing vessel 2, by the lifting mechanism 9.
[0014]
A gas supply pipe (not shown) leading to a gas supply source is connected to the gas introduction pipe 4, and a pipe (also referred to as an exhaust pipe) 13 of an exhaust system 12 is connected to the exhaust pipe 5. The heat treatment furnace 1 is installed in a frame (also referred to as a housing) 14 that forms an outer shell of the heat treatment apparatus (see FIG. 5). A base plate 15 having an opening through which the processing vessel 2 can be inserted from below is provided in the frame 14, and the manifold 6 is mounted on the base plate 15 via a mounting bracket, and the heater 3 is mounted on the base plate 15. . Further, below the base plate 15, a loading area 16 which is a work area for unloading the boat 10 is provided.
[0015]
The pipe 13 of the exhaust system 12 is piped from the inside of the frame 14 to the outside of the frame 14, and is connected to a pressure reducing pump 17 below. In the pipe 13 of the exhaust system 12, a main valve 18 composed of, for example, an angle valve, a pressure control valve 19 composed of, for example, a butterfly valve, and a trap 20 for trapping by-products are provided in this order from the upstream side. Therefore, the exhaust system 12 includes a pipe 13 and a main valve 18, a pressure control valve 19, a pressure reducing pump 17, and a trap 20 provided in the pipe 13.
[0016]
2 is a perspective view of the main valve, FIG. 3 is a sectional view of a main part of the main valve, and FIG. 4 is an enlarged sectional view of the second auxiliary valve. The main valve 18 has a main body 21 which is a body (also referred to as a valve box) forming an outer shell thereof, and a valve body 26 provided inside the main body 21. Openings 22 and 23 for connection are formed, and one opening 22 serves as, for example, a fluid inlet, and the other opening 23 serves as an outlet. These inlets and outlets may be reversed as in FIG. In the main body 21, a flow path 24 communicating between the openings 22 and 23 is formed, and a valve seat 25 is provided on the lower opening 23 side of the flow path 24, and a valve body 26 is provided for the valve seat 25. It is seated and closed.
[0017]
An actuator (drive unit) 28 for opening and closing the main valve 18 by moving the valve body 26 upward or downward via a valve rod 27 is provided at an upper portion of the main body 21. A bellows 29 is provided between the valve body 21 and the main body 21 so as to surround the valve rod 27. Generally, the main valve 18, the first auxiliary valve 30, and the second auxiliary valve 31 are connected in parallel to the exhaust system 12, but in the present embodiment, one opening is formed in the main body 21 of the main valve 18. Two bypass passages 32 and 33 are formed to communicate between the (inlet) 22 side and the other opening (outlet) 23 side, and a first auxiliary valve 30 that opens and closes one of the bypass passages 32 is formed on the side of the main body 21. And a second auxiliary valve 31 that opens and closes the other bypass passage 33.
[0018]
The first and second bypass passages 32 and 33 are formed so as to open to the sides of the main body 21, respectively, and the open ends thereof are formed as valve seats 34 and 35. The first auxiliary valve 30 has a valve box 36 provided on a side portion of the main body 21 so as to communicate with the valve seat 34, and a valve closing direction (in the valve seat direction) provided by a spring (not shown) provided in the valve box 36. A valve body 37 urged in a seating direction) to drive the valve body 37 in a valve opening direction (a direction away from the valve seat) against the urging force of a spring. A pipe 38 of an air pressure supply system for supplying compressed air is connected.
[0019]
When the air pressure is not supplied, the first auxiliary valve 30 is in a closed state in which the valve body 37 is seated (abutted) on the valve seat 34 and the first bypass passage 32 is shut off. The valve body 37 is separated from the valve seat 34 to be in an open state in which the first bypass passage 32 is opened. The first auxiliary valve 30 is a so-called fixed flow valve.
[0020]
The second auxiliary valve 31 has a valve box 39 provided on a side portion of the main body 21 so as to communicate with the valve seat 35, and a valve closing direction (seated on the valve seat) by a spring 40 provided in the valve box 39. The valve body 41 is urged in the valve opening direction (the direction away from the valve seat) against the urging force of the spring 40. A pipe 42 of an air pressure supply system for supplying air is connected. That is, a piston 44 is connected to the valve element 41 via the valve rod 43, and the piston 44 is slidably fitted into a cylinder 45 formed in the valve box 39. At one end in the cylinder chamber 45, the spring 40 for biasing the piston 44 in the valve closing direction is incorporated, and at the other end in the cylinder chamber 45, a pressure chamber for driving the piston 44 in the valve opening direction by compressed air. 46 are formed. In the valve box 39 and the piston 44, an introduction passage 47 for introducing compressed air from the piping 42 of the air pressure supply system into the pressure chamber 46 is formed substantially along the axis. This configuration is the same for the first auxiliary valve (not shown).
[0021]
Like the first auxiliary valve 30, the second auxiliary valve 31 closes the second bypass passage 33 when the air pressure is not supplied by seating (contacting) the valve body 41 on the valve seat 35. In this state, when the compressed air is supplied, the valve body 41 is separated from the valve seat 35 to be in an open state in which the second bypass passage 33 is opened. The second auxiliary valve 31 is different from the first auxiliary valve 30 in that a flow rate can be adjusted, specifically, a minute flow rate can be adjusted, and the second auxiliary valve 31 is a variable flow rate adjustment valve.
[0022]
That is, a variable flow handle 48 is provided at the rear end of the valve box 39 of the second auxiliary valve 31. The variable flow rate handle 48 is formed in a blind screw shape, and is screwed into a male screw portion 49 formed at the rear end of the valve box 39. Further, a sleeve 50 for regulating the moving range (ie, the lift amount of the valve body) d of the piston 44 is provided on the variable flow handle 48 along the axis thereof. The inserted shaft portion 51 is slidably fitted.
[0023]
Therefore, when the variable flow handle 48 is rotated in the tightening direction, the lift amount d of the valve body 41 decreases, and when the variable flow handle 48 is rotated in the loosening direction, the lift amount d of the valve body 41 increases. By rotating the variable flow rate handle 48, the flow rate of the fluid flowing through the second bypass passage 33, for example, the flow rate of the exhaust gas from the heat treatment furnace 1 can be adjusted. A pressure sensor 52 for detecting the pressure in the pipe 13 is provided upstream of the main valve 18 in the pipe 13 of the exhaust system 12, and a detection signal is input to a controller 53. The opening and closing control of the main valve 18, the pressure control valve 19, and the first and second auxiliary valves 30, 31 is performed in order to control the pressure of the exhaust system 12 based on the above.
[0024]
On the other hand, a self-standing fixing plate 54 is provided on the main body 21 of the main valve 18, and the main body 21 of the main valve 18 is fixed to the frame 14 of the apparatus via the fixing plate 54. The fixing plate 54 is attached to the main body 21 of the main valve 18 with, for example, a screw 55. The fixing plate 54 is provided with a hole 56 for connecting the fixing plate 54 to a bracket or the like with a bolt and a nut, for example. For example, as shown in FIG. 5, a bracket 57 may be attached to the frame 14 of the apparatus, and the fixing plate 54 of the main body 21 of the main valve 18 may be fixed to the bracket 57 with bolts and nuts. The valve 18 can be securely fixed.
[0025]
Next, the operation of the heat treatment apparatus having the above configuration will be described. When the pressure in the heat treatment furnace 1 is reduced from the atmospheric pressure to a predetermined processing pressure, the pressure is first reduced in order to prevent the reaction by-product in the processing vessel 2 from rising and the semiconductor wafer w from being displaced on the boat 10. The main valve 18 and the first auxiliary valve 30 are closed and the second auxiliary valve 31 is opened in order to drive the pump 17 and perform slow vacuum. Start pulling. The atmosphere in the furnace passes through the exhaust pipe section 5 and the pipe 13 of the exhaust system 12, and is further exhausted at a very small flow rate through the second bypass passage 33 of the main valve 18.
[0026]
When the pre-programmed first stage pressure has been reached in the furnace, the first auxiliary valve 30 is then opened and a vacuum is drawn through the first and second bypass passages 32, 33 at a higher flow rate. When the pressure in the furnace reaches the pre-programmed second stage pressure, the main valve 18 is opened, and the evacuation is performed at a large flow rate through the first and second bypass passages 32 and 33 and the flow passage 24 of the main valve 18. Then, vacuum may be drawn to the target final pressure.
[0027]
As described above, according to the heat treatment apparatus, the main body 21 of the main valve 18 provided in the exhaust system 12 of the heat treatment furnace 1 is formed with two bypass passages 32 and 33 communicating the inlet 22 side and the outlet 23 side. Since the main body 21 is provided with the first auxiliary valve 30 that opens and closes one bypass passage 32 and the second auxiliary valve 31 that opens and closes the other bypass passage 33, the area around the pipe 13 of the exhaust system 12 is simplified. Thus, space saving Sb and maintenance workability can be improved. Since the second auxiliary valve 31 has a flow rate adjusting function, the necessity of a separate needle valve or the like is not required, and the circumference of the pipe can be further simplified.
[0028]
The main body 21 of the main valve 18 is provided with a self-standing fixing plate 54. The main body 21 of the main valve 18 is fixed to the frame 14 of the apparatus via the fixing plate 54. It can be fixed to the frame 14 of the device, and there is no need to fix the pipes before and after the main valve 18 with fixing fittings, so that the area around the pipes can be further simplified. Since the fixture for the pipe 13 is not used, even in the case of a heated pipe, heat does not escape, and the generation of reaction by-products in the pipe 13 can be suppressed.
[0029]
As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to the above embodiments, and various design changes and the like can be made without departing from the gist of the present invention. is there. For example, the heat treatment furnace is not limited to a vertical type and may be a horizontal type, and is not limited to a batch type and may be a single wafer type. The heat treatment may be oxidation, diffusion, annealing, or the like, in addition to CVD. The object to be processed may be, for example, a glass substrate or an LCD substrate other than the semiconductor wafer.
[0030]
【The invention's effect】
In short, according to the present invention, the following effects can be obtained.
[0031]
(1) According to the first aspect of the present invention, a main valve, a first auxiliary valve, and a second auxiliary valve are provided in an exhaust system pipe of a heat treatment furnace in which a heat treatment furnace is installed in a skeleton and is piped from the skeleton to outside the skeleton. Wherein two bypass passages communicating the inlet side and the outlet side are formed in a main body forming an outer shell of the main valve, and one of the bypass passages is opened and closed in the main valve main body. Since the first auxiliary valve and the second auxiliary valve that opens and closes the other bypass passage are provided, the area around the exhaust system piping can be simplified, and maintenance workability can be improved. In addition, the main valve body is provided with a self-standing fixing plate, and the main valve main body is fixed to the skeleton through the fixing plate. Since the surroundings can be further simplified and no fixture for the pipe is used, even in the case of a heated pipe, heat does not escape from the fixture for the pipe, and the generation of reaction by-products in the pipe can be suppressed.
[0032]
(2) According to the second aspect of the present invention, since the second auxiliary valve is configured to be capable of adjusting the flow rate, the necessity of a separate needle valve is eliminated, and the circumference of the pipe can be further simplified.
[0033]
(3) According to the third aspect of the present invention, since the bracket is attached to the frame and the fixing plate is fixed to the bracket, the main valve can be securely fixed to the frame .
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a heat treatment apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view of a main valve.
FIG. 3 is a sectional view of a main part of a main valve.
FIG. 4 is an enlarged sectional view of a second auxiliary valve.
5A and 5B are diagrams showing a mounting structure of a main valve, wherein FIG. 5A is a side view and FIG. 5B is a plan view.
6A and 6B are diagrams showing a conventional main valve mounting structure, in which FIG. 6A is a side view and FIG. 6B is a plan view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat treatment furnace 12 Exhaust system 13 Exhaust system piping 14 Body 18 Main valve 21 Main body 22 Opening (inlet)
23 opening (exit)
30 first auxiliary valve 31 second auxiliary valve 32, 33 bypass passage 54 fixing plate

Claims (3)

A heat treatment apparatus in which a heat treatment furnace is installed in a skeleton , and a main valve, a first auxiliary valve, and a second auxiliary valve are provided in parallel in a pipe of an exhaust system of the heat treatment furnace which is piped from the skeleton to outside the skeleton , A first auxiliary valve that opens and closes one bypass passage in a main body of the main valve, wherein two bypass passages communicating an inlet side and an outlet side are formed in a main body forming an outer shell of the main valve; A main body of the main valve is provided with a self-standing fixing plate, and the main valve main body is fixed to the frame via the fixing plate. Heat treatment equipment. The heat treatment apparatus according to claim 1, wherein the second auxiliary valve is configured to be capable of adjusting a flow rate. The heat treatment apparatus according to claim 1 , wherein a bracket is attached to the frame, and the fixing plate is fixed to the bracket .

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