CN100397577C - Valve device and heat treatment device - Google Patents

Abstract

The invention relates to a valve device and a heat treatment device, two bypasses are formed on the valve housing (21) of the main valve (18) installed on the piping (13) of the exhaust system (12) of the heat treatment furnace (1) (32, 33). Each bypass (32, 33) is opened and closed by an auxiliary valve (30, 31) installed on the valve casing (21). One of the auxiliary valves (31) has a flow regulating structure. The main valve (18) uses a fixing plate (54) arranged on the main valve, and is fixed on the casing (14) of the heat treatment device by bolts and nuts. The invention can simplify the revolving piping of the exhaust system and improve the maintenance operability of the heat treatment device.

Description

Valve device and heat treatment device

technical field

The invention relates to a heat treatment device, in particular to a valve device suitable for the exhaust system of the heat treatment device, and a heat treatment device with the valve device.

Background technique

In the manufacturing process of a semiconductor device, a heat treatment apparatus is often used to perform heat treatment such as CVD (Vapor Phase Chemical Growth) on an object to be processed such as a semiconductor substrate. The heat treatment apparatus includes a heat treatment furnace in which the substrate is placed, a gas supply system for supplying gas such as a processing gas into the heat treatment furnace, and an exhaust system for depressurizing and exhausting the heat treatment furnace.

When the heat treatment device is evacuated in the furnace, in order not to raise dust, the extraction flow rate is reduced at the beginning of evacuation, that is, the vacuum is decelerated. For this purpose, the exhaust system has the structure shown in FIG. 6 . The exhaust system 12 has a pipe 13 with a limited pipe diameter such as 3 inches. This pipe 13 is equipped with a main valve (main on-off valve) 18 composed of an angle valve and a main pressure control valve (main pressure control valve) composed of a butterfly valve in sequence. not shown) and decompression pump (not shown). The pipe 13 is connected to a small-diameter bypass pipe 60 of about 1/4 inch that bypasses the main valve 18 . The first auxiliary valve 61 and the second auxiliary valve 62 are arranged in parallel on the bypass pipe 60 . In the bypass pipe 60 , a needle valve 63 for flow rate adjustment is provided in series with the second auxiliary valve 62 .

When depressurizing the furnace from atmospheric pressure to the set processing pressure, in order to decelerate and evacuate at first, close the main valve 18 and the first auxiliary valve 61, open the second auxiliary valve 62, and start to set the pressure in the needle valve 63. A certain small flow rate is used to extract vacuum. Then, the first auxiliary valve 62 and the main valve 61 are sequentially opened, and vacuum is evacuated up to the set processing pressure in this state.

However, in the above-mentioned conventional heat treatment apparatus, the bypass pipe 60 is connected to the pipe 13, and the first and second auxiliary valves 61, 62, etc. are provided, so not only the wide distance Sa [see FIG. 6(b) ], and the structure surrounding the piping 13 is complicated, causing the problem that it is difficult to carry out maintenance operations.

In addition, in order to fix the main valve 18 at a predetermined position, the piping 13 on the upstream side or the downstream side of the main valve 18 needs to be fixed on the box body 14 of the heat treatment device by means of the fixing fitting 70, which makes the structure around the piping 13 more complicated. . Furthermore, when the piping 13 is heated, heat is lost from the fixing fitting 70 , so there is a problem that side reaction products are generated in the piping 13 .

Contents of the invention

An object of the present invention is to integrate the auxiliary valve and the bypass with the main valve in consideration of the above-mentioned problems, and to constitute a compact valve device. Another object of the present invention is to simplify the structure around the piping of the exhaust system of the heat treatment apparatus by applying the compact valve device.

To achieve the above object, the heat treatment device provided by the present invention includes a heat treatment furnace; an exhaust pipe connected to the heat treatment furnace and used to exhaust the heat treatment furnace; and a main valve installed on the above exhaust pipe, The main valve has: a valve casing formed with an inlet hole and an outlet hole and a main passage communicating with the inlet hole and the outlet hole; and a valve body provided on the valve casing and opening and closing the main passage, characterized in that , On the valve casing of the above-mentioned main valve, a first bypass and a second bypass communicating with the above-mentioned inlet hole and the outlet hole are formed in parallel; The first auxiliary valve for the bypass and the second auxiliary valve for opening and closing the second bypass.

In a preferred embodiment, the first bypass and the second bypass are holes formed in the wall of the valve casing.

Furthermore, in a preferred embodiment, the second auxiliary valve has a flow rate adjustable structure.

Furthermore, in a preferred embodiment, a fixing part is provided on the valve casing of the main valve, and the main valve is fixed on the box body of the heat treatment device by means of the fixing part.

A second aspect of the present invention provides a valve device having a valve casing forming an inlet hole and an outlet hole, and a main passage communicating with the inlet hole and the outlet hole; The passage valve body is characterized in that it also has: a first bypass formed in the above-mentioned valve housing, bypassing the above-mentioned valve body and communicating with the above-mentioned inlet hole and outlet hole; and forming in parallel with the above-mentioned first bypass. In the above-mentioned valve casing, the second bypass bypasses the above-mentioned valve body and can communicate with the above-mentioned inlet hole and outlet hole; the first auxiliary valve for opening and closing the first bypass and the second bypass for opening and closing the second bypass 2 auxiliary valves.

Please refer to the attached drawings for other features and advantages of the present invention, and illustrate them with the following implementation manners.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of an embodiment of the heat treatment device of the present invention.

Fig. 2 is a perspective view of the main valve shown in Fig. 1 .

Fig. 3 is a sectional view of main parts of the main valve shown in Fig. 2 .

FIG. 4 is an enlarged sectional view of the second auxiliary valve shown in FIG. 2 , that is, a sectional view taken along line IV-IV in FIG. 3 .

Figure 5 is a diagram showing the arrangement of components around the main valve, Figure 5(a) is a side view, and Figure 5(b) is a plan view.

Fig. 6 is a diagram showing the arrangement of components around the main valve in the prior art, Fig. 6(a) is a side view, and Fig. 6(b) is a plan view.

Detailed ways

Embodiments are described in detail below with reference to the accompanying drawings.

The overall structure of the heat treatment device is schematically shown in Figure 1 , and reference numeral 1 is a heat treatment furnace for accommodating a semiconductor substrate W and performing prescribed heat treatment such as CVD treatment. In the illustrated embodiment, the heat treatment furnace 1 is a batch type vertical furnace. The heat treatment furnace 1 is provided with a processing container (reaction tube) 2 made of quartz, and a cylindrical heater 3 provided around the processing container 2 and around the processing container 2 .

In the illustrated embodiment, the processing container 2 has a double-layer structure of an inner tube 2a and an outer tube 2b, but a single-layer tube may also be used, and the lower end of the processing container 2 is open. The lower end of the processing container 2 is airtightly connected with an annular manifold 6, which has a gas introduction part 4 for introducing gas such as processing gas into the processing container 2, and an exhaust part for discharging the gas in the processing container 2. 5. The lower end of the manifold 6 is an open furnace mouth 7 . Below the furnace mouth 7, a cover 8 that airtightly seals the furnace mouth 7 is provided. The lid 8 is raised and lowered by the lifting mechanism 9 to open and close the furnace mouth 7 . On the cover 8 , a quartz substrate mounting member 10 (substrate holder) capable of mounting a plurality of, for example, 150 semiconductor substrates W at predetermined intervals in the vertical direction is mounted via a thermal insulation cylinder 11 . The mounting member 10 can be carried in and out in the processing container 2 by the elevating mechanism 9 .

Pipes of a gas supply system not shown in the figure are connected to the gas introduction part 4 and communicate with a gas supply source, and the exhaust part 5 communicates with a pipe 13 of an exhaust system 12 (also referred to as an exhaust pipe). The heat treatment furnace 1 is installed in a housing 14 of the heat treatment apparatus (see FIG. 5 ). A bottom plate 15 having an opening into which the processing container 2 can be inserted from below is provided in the box body 14 . The manifold 6 is installed on the bottom plate 15 by means of fittings (not shown), and the heater 3 is arranged on the bottom plate 15 . Below the bottom plate 15 is provided a load area as an operation area for loading and unloading the substrate mounting part 10 .

The piping 13 of the exhaust system 12 is drawn from the inside of the casing 14 to the outside of the casing 14, and a decompression pump 17 is connected to the lower side thereof. On the piping 13 of the exhaust system 12, a main valve 18 consisting of an angle valve, a pressure control valve 19 consisting of a butterfly valve, and a trap 20 for trapping by-products are provided in this order from upstream. The exhaust system 12 is composed of a pipe 13 and a main valve 18 provided on the pipe 13 , a pressure control valve 19 , a decompression pump 17 and a trap 20 .

Referring to Fig. 2 to Fig. 4, the main valve 18 and its auxiliary mechanism will be described in detail below. The main valve 18 has a valve casing 21 (valve body) and a valve body 26 provided inside the valve casing 21 . An inlet hole 22 and an outlet hole 23 that can be flanged are respectively provided on the side and the bottom of the valve housing 21 . As shown in FIG. 3 , a main passage 24 communicating with the two holes 22 , 23 is formed in the valve housing 21 . A valve seat 25 is provided in the main passage 24, and when the main valve 18 is closed, the valve body 26 falls on the valve seat 25.

An actuator 28 is provided on the upper portion of the valve housing 21 to move the valve body 26 vertically through the valve stem 27 and to open and close the main valve 18 . The valve stem 27 is surrounded by a bellows 29 , the upper end of the bellows 29 is connected to the valve casing 21 , and the lower end of the bellows 29 is connected to the top of the valve body 26 . The bellows 29 protects the transmission 28 from corrosive gases.

The valve housing 21 of the main valve 18 is provided with a first bypass 32 and a second bypass 33 which communicate with the inlet hole 22 and the outlet hole 23 and are separated and independent from each other. The bypasses 32 , 33 are holes formed in the valve wall of the valve housing 21 . On a side surface of the valve housing 21, a first auxiliary valve 30 for opening and closing the first bypass passage 32 and a second auxiliary valve 31 for opening and closing the second bypass passage 33 are provided. The first and second bypasses 32 and 33 allow the fluid to flow from the inlet hole 22 to the outlet hole 23 without passing the fluid through the portion between the valve seat 25 and the valve body 26 of the main passage 24 .

As shown in FIG. 3 , the first bypass 32 is opened on the side surface of the valve case 21 along its way. The side surface of the valve case 21 around the opening end of the first bypass 32 is a valve seat 34 . The first auxiliary valve 30 has a valve casing 36 installed on the side of the valve casing 21, and a valve body provided in the valve casing 36 and pressed against the valve closing direction (the direction falling on the valve seat 34) by a spring not shown. 37. In order to enable the valve body 37 to be driven in the valve opening direction (the direction away from the valve seat) against the elastic force of the spring, a piping 38 of an air pressure supply system for supplying compressed air is communicated to the valve housing 36 . The valve body 37 of the first auxiliary valve 30 leans against the valve seat 34 to block the first bypass passage 32 when no air pressure is supplied, and leaves the valve seat 34 to open the first bypass passage 32 when compressed air is supplied.

As shown in FIG. 4 , the second bypass 33 has an opening on the side surface of the valve casing 21 in its middle. A valve seat 35 is formed on the side surface of the valve casing 21 around the opening end of the first bypass 33 . The second auxiliary valve 31 has a valve casing 39 attached to the side of the valve casing 21, and a valve body 41 provided in the valve casing 39 and pressed in the valve closing direction (the direction of falling on the valve seat 35) by the spring 40. In order to drive the valve body 41 in the valve opening direction (direction away from the valve seat 35 ) against the elastic force of the spring 40 , a pipe 42 of an air supply system for supplying compressed air is connected to the valve case 39 . The valve body 41 of the second auxiliary valve 31 is close to the valve seat 35 when there is no air supply, blocking the second bypass 33, and once the compressed air is supplied, it is separated from the valve seat 35 to open the second bypass 33.

Connected to the valve body 41 via a valve rod 43 is a piston 44 which is slidably engaged in a cylinder 45 formed in the valve housing 39 . One end in the cylinder 45 is embedded with a spring 40 that makes the piston 44 press against the valve closing direction, and the other end in the cylinder 45 forms a pressure chamber 46 that drives the piston 44 in the valve opening direction by compressed air. An introduction passage 47 through which compressed air can be introduced into the pressure chamber 46 from the piping 42 of the air pressure supply system is formed in the piston 44 . The introduction passage 47 extends along the axis of the piston 44 and opens to the pressure chamber 46 .

A flow rate adjustment knob 48 is provided at the front end portion of the valve case 39 of the second auxiliary valve 31 . The flow rate adjustment knob 48 has threads formed on its inner peripheral surface, and is screwed with a male threaded portion 49 formed on the outer peripheral surface of the front end portion of the valve case 39 . The flow regulating knob 48 is provided with a sleeve 50 that limits the moving range of the piston 44 (ie, the lifting amount of the valve body) d. The sleeve 50 is coaxial with the piston 44 , and a slidable shaft portion 51 provided at the front end of the piston 44 is inserted into the sleeve 50 . By turning the flow rate adjustment knob 48, the lifting amount d of the valve body 41 can be changed, and the flow rate of the fluid flowing through the second bypass 33 can be adjusted.

The second auxiliary valve 31 is different from the first auxiliary valve 30 of the fixed flow type in that the flow rate can be adjusted, that is, the first auxiliary valve 30 can be formed by removing the components having the flow adjustment function of the second auxiliary valve 31 .

Referring again to FIG. 1 , on the upstream side of the main valve 18 of the piping 13 of the exhaust system 12 , a pressure sensing element 52 for detecting the pressure inside the piping 13 is provided. The detection signal of the pressure sensor element 52 is input to the controller 53 . The controller 53 controls the opening and closing of the main valve 18, the pressure control valve 19 and the first and second auxiliary valves 30 and 31 by referring to a preset control program, and adjusts the pressure in the exhaust system 12 and the heat treatment furnace 1 .

The valve casing 21 of the main valve 18 is provided with a fixing plate 54 , by means of the fixing plate 54 , the valve casing 21 of the main valve 18 is fixed on the box body 14 of the device. The fixing plate 54 is installed on the valve casing 21 of the main valve 18 by using suitable fixing parts such as bolts 55 . Holes 56 are provided in the fixing plate 54 for bolting the fixing plate 54 to a suitable support member. For example, as shown in Figure 5, by installing a support frame 57 on the casing 14 of the heat treatment device, the fixing plate 54 is fixed by bolts and nuts on the support frame 57, so that the main valve 18 can be firmly fixed on the heat treatment device. Box 14.

Next, the operation of the heat treatment apparatus when the inside of the heat treatment furnace 1 is decompressed from atmospheric pressure to a predetermined treatment pressure will be described. If rapid decompression (that is, depressurization at a large flow rate) is performed, the reaction by-products in the processing container 2 may fly and the semiconductor substrate W on the mounting member 10 may be misaligned. Therefore, at first the main valve 18 and the first auxiliary valve 30 should be closed, the second auxiliary valve 31 should be opened, the decompression pump 17 should be driven, and the vacuum pumping (deceleration vacuum) should be started with a small flow rate. Set an appropriate value. The gas in the heat treatment furnace 1 is discharged through the exhaust pipe provided in the exhaust part 5 of the manifold 6 and the pipe 13 of the exhaust system 12 , and then through the second bypass 33 of the main valve 18 .

After the heat treatment furnace 1 reaches the specified first decompression requirement, the first auxiliary valve 30 is opened, and the flow rate is increased through the first and second bypasses 32 and 33 for vacuuming operation. After reaching the specified second decompression requirement in the heat treatment furnace 1, the main valve 18 is opened, and a large-flow vacuum is carried out through the first and second bypasses 32, 33 and the main passage 24 of the main valve 18 until the target final pressure is reached. .

In the above-described embodiment, since the passage for bypassing the main valve 18 is incorporated into the valve case 21 of the main valve 18 , it is not necessary to separately provide a bypass pipe with respect to the pipe 13 . Therefore, the piping system of the exhaust system 12 is simplified, which has the advantages of saving space and facilitating maintenance. Please refer to Sb in Fig. 5(b) and Sa in Fig. 6(b) for space saving. In addition, since the second auxiliary valve 31 has a flow regulating function, there is no need to additionally provide a valve having a flow regulating function, such as a needle valve. Therefore, the structure of the exhaust system 12 is further simplified.

In addition, since the valve housing 21 of the main valve 18 is fixed on the casing 14 of the device by the fixing plate 54, it is not necessary to fix the piping 13 before and after the main valve 18 with fixing fittings. Therefore, the structure of the piping 13 and its vicinity can be further simplified. Since no fixing fittings for the piping 13 are used, even if the piping 13 is a heating piping, heat will not be lost, and at the same time, reaction by-products in the piping 13 can be suppressed. From this point of view, it is more preferable that the fixing plate 54 is provided at a position separated from the main passage 24 in the valve housing 21 . In the illustrated embodiment, the fixed plate 54 is disposed proximately on the actuator 28 away from the main passageway 24 .

The embodiments of the present invention have been described in detail above with reference to the drawings, but the present invention cannot be limited by the above examples, and various design changes can be made within the scope of the claims of the present invention. For example, the heat treatment furnace is not limited to a vertical type, but a horizontal type may be used; it is not limited to a batch type, and a single-wafer type may be used. As heat treatment, oxidation, diffusion, annealing, etc. may be used other than CVD. The object to be processed may be a glass substrate, an LCD substrate, or the like in addition to a semiconductor substrate.

Claims (6)

1. A heat treatment device, comprising a heat treatment furnace; an exhaust pipe connected to the heat treatment furnace and used for exhausting the heat treatment furnace; and a main valve installed on the exhaust pipe; the main valve having: a valve casing formed with an inlet hole and an outlet hole and a main passage communicating with the inlet hole and the outlet hole; and a valve body provided in the valve casing and opening and closing the main passage, On the valve casing of the main valve, a first bypass and a second bypass communicating with the inlet hole and the outlet hole are formed in parallel, A first auxiliary valve for opening and closing the first bypass and a second auxiliary valve for opening and closing the second bypass are provided on the valve casing of the main valve, wherein The second auxiliary valve has a flow rate adjustable structure. 2 . The heat treatment device according to claim 1 , wherein the first and second bypasses are holes formed on the wall of the valve housing. 3 . 3 . The heat treatment device according to claim 1 , wherein a fixing part is provided on the valve casing of the main valve, and the main valve is fixed on the box body of the heat treatment device by means of the fixing part. 4 . 4. A valve device having a valve casing forming an inlet hole and an outlet hole, and a main passage communicated with the inlet hole and the outlet hole; and a valve provided in the valve casing and opening and closing the main passage body, It also has: a first bypass formed in the valve casing, bypassing the valve body and communicating with the inlet hole and the outlet hole; A second bypass is formed in the valve housing in parallel with the first bypass, bypasses the valve body, and communicates with the inlet hole and the outlet hole; opening and closing the first auxiliary valve of the first bypass; The second auxiliary valve that opens and closes the second bypass is characterized in that, The second auxiliary valve has a flow rate adjustable structure. 5. The valve device according to claim 4, wherein the first and second bypasses are holes formed in the wall of the valve housing. 6. A heat treatment device, characterized in that it has a heat treatment furnace; an exhaust pipe connected to the heat treatment furnace and used to exhaust the heat treatment furnace; and installed on the exhaust pipe, as claimed in The valve device described in 4 or 5 is required.

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