JP2005093892A - Manufacturing apparatus for semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent depositions from sticking on a gate valve communicating with a processing chamber of a plasma etching apparatus, etc., and prevent valve leakage and the generation of particles. <P>SOLUTION: The gate valve for opening/closing an exhausting port 11 communicating with the inside of a treatment chamber 1 has a first valve plate 54 capable of abutting against the sealing surface of the periphery of the exhausting port 11, a second valve plate 55 capable of covering the sealing surface when the plate 55 is positioned oppositely to the exhausting port 11, and a purging means 56 for covering with an inert gas the surface of the first valve plate 54 and the sealing surface in the state of the first valve plate 54 opening the exhausting port 11. Since the surface of the first valve plate 54 and the sealing surface are purged by the inert gas in a valve chamber 52, the treatment gas flowing out of the exhausting port 11 is so not contacted with these surfaces as to prevent depositions from sticking on these surfaces and as to prevent particles from being generated on these surfaces. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a configuration of a gate valve provided in a semiconductor manufacturing apparatus including a vacuum processing chamber such as a dry etching apparatus.

  As an example of a dry etching apparatus, a plasma etching apparatus, for example, evacuates the inside of the processing chamber 1 with a vacuum pump 2 and introduces a required processing gas into the processing chamber 1 from the gas supply pipe 3 as shown in FIG. The interior is set to a required gas pressure, and a high frequency power is applied to an RF coil (high frequency coil) 4 disposed facing the processing chamber 1 to generate an electric field in the processing chamber 1 to generate plasma, thereby generating a product. Etching is performed on the semiconductor wafer W. In such an apparatus, an exhaust port 11 connected to an exhaust path 10 that communicates the processing chamber 1 and the vacuum pump 2 is provided with a gate valve 5 that is opened during vacuuming and closed during processing.

  FIG. 4 is a cross-sectional view of an example of a conventional gate valve 5A. A gate valve body 51 is disposed between a processing chamber 1 indicated by a one-dot chain line in the drawing and a turbo molecular pump (hereinafter referred to as TMP) 2 as a vacuum pump. The gate valve body 51 includes a valve chamber 52 that extends in a direction orthogonal to the exhaust passage 11, and a valve plate 59 is housed in the valve chamber 52. The valve plate 59 can be moved in a direction perpendicular to the exhaust passage 10 in the valve chamber 51 by a drive mechanism not shown in the drawing, and moved to a position facing the exhaust port 11 as indicated by a two-dot chain line in the figure. When this is done, the exhaust port 11 is closed, and as indicated by the solid line, the exhaust port 11 is opened when the exhaust port 11 is retracted from the position. Further, at the time of closing, the O-ring 53 arranged along the periphery of the exhaust port 11 is brought into elastic contact with the surface of the valve plate 59 to seal the exhaust port 11.

  In such a conventional gate valve 5 </ b> A, when the valve plate 59 opens the exhaust port 11, the valve chamber 52 is in communication with the inside of the processing chamber 1. Therefore, substances contained in the exhaust gas flowing out from the processing chamber 1 through the exhaust port 11 adhere to the inner surface of the valve chamber 52, the surface of the O-ring 53, and further the surface of the valve plate 59 as indicated by x in the figure. A depot occurs. When this deposit is deposited around the exhaust port 11 on the inner wall surface of the O-ring 53 or the valve chamber 52, that is, on the seal surface or the surface of the valve plate 59 facing the seal surface, the thickness of the deposit increases. The close contact between 59 and the O-ring 53 is reduced to cause a valve leak or cause foreign matter (particles) due to deposit peeling.

  In a dry etching apparatus, deposition of aluminum chloride (boiling point: 182.7 ° C atmospheric pressure) can be suppressed even at a relatively low temperature, but aluminum or ceramic is used in the process kit in the processing chamber, and If F-based plasma is used, high-melting aluminum fluoride (melting point: 1291 ° C.) is generated, and it is difficult to suppress deposition. When the processing chamber or valve chamber is opened to the atmosphere in order to remove this deposit film by cleaning, aluminum fluoride reacts with moisture in the atmosphere and a wide range of deposits begin to peel off. In particular, in the valve chamber, the deposit attached to the surface of the valve plate easily peels off due to the movement of the valve plate accompanying the opening and closing operation of the gate valve, and the peeled object is sucked up to the TMP, and energy is obtained by the TMP blades. Return to the processing chamber to become particles. In addition, the aluminum fluoride-based deposit attached to the TMP blades reacts with moisture in the atmosphere, and suddenly peels off to form a large number of particles. In order to prevent this, the TMP was frequently overhauled.

In order to prevent deposition of deposits due to exhaust gas outside the processing chamber, the technique proposed in Patent Document 1 exhausts the transfer chamber connected to the processing chamber, closes the exhaust valve, and sets the transfer chamber to the transfer chamber. Nitrogen gas is purged to maintain the required pressure. Therefore, the gate valve connected to the processing chamber is opened, and the nitrogen gas flowing in the transfer chamber is set to a large flow rate to prevent the gas flow from the processing chamber to the transfer chamber, thereby preventing the deposit in the transfer chamber. Has been proposed.
Japanese Patent Laid-Open No. 2000-233201

  As described above, in the gate valve 5A shown in FIG. 4, deposits are deposited on the surface of the O-ring 53 and the seal surface and the surface of the valve plate 59 that are important for the valve function. There is a problem that the downtime due to this cleaning is increased, and the TMP overhaul is necessary, resulting in a high maintenance cost. Further, when the purge technique of Patent Document 1 is simply applied to the gate valve having the configuration shown in FIG. 4, nitrogen gas or the like is purged into the valve chamber 52 to prevent deposition. When the flow rate of the gas purged into the chamber is increased, a substantial exhaust speed in TMP 2 is reduced during evacuation when setting the inside of the processing chamber 1 to a predetermined gas pressure, or nitrogen gas flows into the processing chamber 1. The diffusion affects the gas atmosphere in the processing chamber 1 and causes a problem of processing efficiency that it takes time to set the required gas atmosphere.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor manufacturing apparatus that prevents deposits on a gate valve connected to a processing chamber, prevents valve leakage and partying, and improves the processing efficiency of products.

  The present invention provides a semiconductor manufacturing apparatus including a processing chamber and a gate valve for opening and closing an opening connected to the inside of the processing chamber. The gate valve includes a valve chamber communicating with the opening, an interior of the valve chamber, and the opening. A first valve plate whose surface abuts against the seal surface around the surface and closes the opening; and a second valve plate which is housed in the valve chamber and is positioned opposite the opening while opening the opening and covering the seal surface And a purge means for covering the surface of the first valve plate and the sealing surface with an inert gas when the opening of the first valve plate is open.

  Here, the first valve plate and the second valve plate can move in conjunction with or integrally with each other in the valve chamber, and when one valve plate is moved to a position facing the opening, the other valve plate Is configured to be retracted to a position adjacent to the opening.

  According to the present invention, when the opening of the first valve plate is open, the surface of the first valve plate is purged with the inert gas in the valve chamber, and at the same time, the sealing surface of the opening is covered with the second valve plate. The gas is purged by the inert gas, and the contact of the processing gas flowing out from the processing chamber through the opening to the surfaces is prevented, the deposition of deposits is prevented, and further the generation of particles is prevented. .

  In the present invention, the means for defining the first purge space opened to the valve chamber through the minute gap between the first valve plate and the inner wall surface of the valve chamber, the seal surface and the second plate It is preferable to include a means for defining a second purge space that is opened to the valve chamber through a minute gap therebetween, and a means for introducing an inert gas into each of the first and second purge spaces. . For example, the inner wall surface of the valve chamber is provided with a recess for defining a first purge space between the first valve plate and the surface of the first valve plate when the opening of the first valve plate is open. The surface of the second valve plate is provided with a recess for forming a second purge space between the second valve plate and the seal surface when the second valve plate is positioned opposite the opening.

  In addition, a first spacer for forming a minute gap between the inner surface of the valve chamber is provided on the surface of the first valve plate, and a minute gap between the second valve plate and the seal surface is provided on the surface of the second valve plate. It is preferable to include a second spacer for forming. Further, an elastic seal member surrounding the opening and contacting the surface of the first valve plate is disposed on the seal surface, and the second valve plate is disposed between the seal surface including the elastic seal member and the second seal plate. It is preferable that the purge space be defined.

  2 is a cross-sectional view of the gate valve 5 according to the first embodiment of the present invention in a closed state, showing a configuration example disposed between the processing chamber 1 and the TMP 2 of the dry etching apparatus shown in FIG. ing. FIG. 3 is a sectional view showing a state in which the gate valve 5 is opened. In FIG. 2, the exhaust port 11 of the processing chamber 1 is connected to a TMP 2 partially indicated by a one-dot chain line through an exhaust path 10, and the inside of the processing chamber 1 is evacuated by this TMP 2. . The gate valve 5 is provided to open and close the exhaust port 11, and includes a valve body 51 having a flat valve chamber 52 extending in a direction orthogonal to the extending direction of the exhaust passage 10. The valve chamber 52 includes a valve plate 54 as a first valve plate and a donut-shaped valve plate (hereinafter referred to as a donut-shaped plate) 55 as a second valve plate. The valve plate 54 and the donut-shaped plate 55 are linked to each other in the valve chamber 52 by a drive mechanism that does not appear in the drawing, and in the first embodiment, both are moved integrally. The exhaust port 11 has a circular cross section. Correspondingly, the valve plate 54 is formed in a circular plate shape slightly larger in diameter than the exhaust port 11 and moved to a position facing the exhaust port 11. The exhaust port 11 is sometimes closed. The donut-shaped plate 55 is formed to have a larger diameter than that, and is formed in an annular plate shape having a communication port 551 connected to the exhaust port 11 at the center thereof.

  The valve chamber 52 is configured as a seal surface in a region surrounding the exhaust port 11 on the inner wall surface on the processing chamber side, more precisely, a region where the valve plate 54 abuts when closing the exhaust port. An O-ring 53 as an elastic seal member is attached to a part of the seal surface so as to surround the exhaust port 11. The O-ring 53 is for elastically contacting the surface of the valve plate 54 to improve the sealing performance. In addition, the inner wall surface of the outer region of the valve chamber 52 adjacent to the seal surface has inert gas such as nitrogen gas introduced into the valve chamber and has a gas inlet opening for purging. Purge means 56 is provided, and is connected to an inert gas source not shown in the drawing via a gas passage 563 and an inert gas valve 564. Here, two gas introduction ports are provided, and the first gas introduction port 561 is located at a first position separated from the O-ring 53 toward the outer region by a distance substantially close to the diameter of the valve plate 54. The second gas inlet 562 is opened at a second position close to the O-ring 53. The annular wall 521 has a diameter slightly smaller than the diameter of the valve plate 54 and substantially equal to the diameter of the O-ring 53 so that the inner wall surface of the valve chamber 52 includes the first gas inlet 561. And a purge recess 522 for forming a first purge space with the surface of the valve plate 54 is defined.

  On the other hand, the valve plate 54 is integrally formed with a resin spacer 541 protruding toward the inner wall surface at a substantially central position on the surface thereof. As shown in FIG. 3, when the resin spacer 541 is moved to a position retracted from the exhaust port 11, the resin spacer 541 comes into contact with the inner wall surface and is interposed between the surface of the valve plate 54 and the annular wall 521. The valve plate 54 is formed to project at a height that forms a minute gap in the thickness direction.

  Further, the surface of the donut-shaped plate 55 includes the O-ring 53 when the donut-shaped plate 55 is located at a position facing the exhaust port 11, and at the same time includes the second gas introduction port 562. Thus, an annular recess 552 for forming an annular second purge space is formed between the sealing surface and the sealing surface. Further, a resin spacer 553 having an annular shape with a small gap in the thickness direction is formed between the surface of the donut-shaped plate 55 and the seal surface at the inner peripheral position of the annular recess 552. Has been.

  The operation of the gate valve 5 having the above configuration will be described. When a product is processed in the processing chamber 1 or when the processing chamber 1 is evacuated while not processing, the valve plate 54 and the donut-shaped plate 55 are shown in FIG. In this state, the valve plate 54 is opposed to the annular wall 521, and the donut-shaped plate 55 is opposed to the exhaust port 11. Since the exhaust port 11 communicates with the TMP 2 through the central communication port 551 of the donut-shaped plate 55, the inside of the processing chamber 1 is evacuated by the TMP 2.

  On the other hand, as shown in FIG. 2, when the product is processed in the processing chamber 1 and the valve plate 54 and the donut-shaped plate 55 are moved rightward by the drive mechanism, the valve plate 54 faces the exhaust port 11. Then, the donut-shaped plate 55 is moved backward in the region on the right side of the exhaust port 11. In this state, the surface of the valve plate 54 is elastically deformed by elastic contact with the O-ring 53 and is further brought into contact with the seal surface. As a result, the exhaust port 11 is blocked by the valve plate 54, and the inside of the processing chamber 1 is kept airtight.

  It should be noted that when the valve plate 54 and the donut-shaped plate 55 move to the left and right, the resin spacers 541 and 553 provided on the valve plate 54 and the donut-shaped plate 55 do not interfere with the annular wall 521 and the O-ring 53 in FIG. As indicated by the arrow, it is moved to the left and right after being slightly moved in the downward direction, and then moved to the respective positions in FIG. 2 and FIG. become.

  When the exhaust port 11 is opened and closed by the valve plate 54 and the doughnut-shaped plate 55 described above, the processing flowed from the processing chamber 1 to the valve chamber 52 through the exhaust port 11 when the exhaust port 11 is opened. Depots are attached to the exposed surfaces of the inner wall surface of the valve chamber 52, the valve plate 54, and the doughnut-shaped plate 55 by the gas, as indicated by x. At this time, a purge chamber comprising a purge recess 522 is defined between the upper surface of the valve plate 54 and the annular wall 521. The purge chamber communicates with the first gas inlet 561, and at the same time, the resin spacer 541 abuts against the inner wall surface of the valve chamber 52, so that a minute gap is secured between the surface of the valve plate 54 and the annular wall. The On the other hand, the donut-shaped plate 55 is in a state in which the annular recess 552 surrounds the O-ring 53, and this annular recess 522 communicates with the second gas inlet 562, and at the same time, the resin spacer 553 is connected to the inner wall surface (seal A small gap is ensured between the sealing surface and the surface of the donut-shaped plate 55.

  When the exhaust port 11 is thus opened to process the product in the processing chamber 1, the inert gas is supplied from the inert gas source to the valve chamber 52 from the first and second gas introduction ports 561 and 562. , A part of the inert gas is supplied from the first gas introduction port 561 into the purge recess 522 of the valve plate 54, fills the purge recess 522, and then the surface of the valve plate 54 and the annular wall. It flows out little by little from the gap between 521. Therefore, the surfaces of the valve plate 54 facing the purge recess 522 are purged with the inert gas, and the processing gas from the exhaust port 11 does not reach these surfaces, and does not reach these surfaces. Depots are prevented from sticking. The other part of the inert gas is supplied from the second gas introduction port 562 into the annular recess 552 of the doughnut-shaped plate 55, fills the annular recess 552, and seals the surface of the donut-shaped plate 55. It flows out little by little from the gap between the surfaces. Therefore, the surfaces of the O-ring 53 covered by the annular recess 522 and the seal surface around the exhaust port 11 are purged by the inert gas, and the processing gas from the exhaust port 11 reaches these surfaces. And deposition of deposits is prevented.

  In this way, the deposit on the surface of the valve plate 54 and the sealing surface including the O-ring 53 is prevented by purging with an inert gas, but the inert gas to be purged is introduced into the purge recess 522 and the annular recess 552. After that, the flow of the inert gas can be minimized because only the small gaps secured by the resin spacers 541 and 553 flow out into the valve chamber 52 little by little. It is possible to improve the quality of the manufactured product by suppressing the influence on the internal atmosphere of the processing chamber 1 due to the decrease in the exhaust speed and the diffusion of the inert gas.

  Even if deposits adhere to the surface side of the valve plate 54 or the sealing surface including the O-ring 53, the resin spacers 541 and 553 provided on the valve plate 54 and the doughnut-shaped plate 55 can prevent these deposits. Since the plate is brought into contact with the inner wall surface of the valve chamber 52 only at the resin spacer, it is possible to suppress the attached deposits from being peeled off from the surfaces and inner wall surfaces of the plates 54 and 55. In particular, when only the O-ring 53 is present and the resin spacer is not present, the clearance is gradually reduced due to the compression set of the O-ring 53, and the contact easily occurs. it can. As a result, it is possible to prevent the generation of particles in the valve chamber 52 and the leakage caused by deposits attached to the surface of each plate and the inner wall surface. In addition, an effect of preventing generation of particles due to depot winding in TMP2 can be obtained.

  In the first embodiment, the gate valve according to the present invention is configured as a gate valve that opens and closes the exhaust port of the processing chamber connected to the TMP. However, the gate that opens and closes the transfer port that connects the processing chamber and the product transfer chamber. The present invention can also be applied to a valve.

  In the first embodiment, the configuration example in which the valve plate and the donut-shaped plate are moved to the left and right is shown. However, both plates are rotated in the direction along the plate plane so that the positions of both plates are exchanged. In this case, the area (volume) of the valve chamber can be reduced and the gate valve can be reduced.

  The resin spacer is not limited to the configuration of the first embodiment as long as a predetermined space can be secured between the valve plate and the donut-shaped plate and the inner wall surface.

1 is a schematic configuration diagram of a dry etching apparatus to which the present invention is applied. It is sectional drawing of the state which closed the exhaust port with the gate valve. It is sectional drawing in the state where the gate valve opened the exhaust port. It is sectional drawing of an example of the conventional gate valve.

Explanation of symbols

1 Processing chamber 2 Vacuum pump (TMP)
3 Gas introduction port 4 RF coil 10 Exhaust path 11 Exhaust port 5, 5A Gate valve 51 Valve body 52 Valve chamber 53 O-ring 54 Valve plate 55 Donut-shaped plate 56 Purge means 521 Annular wall 522 Purge chamber 541 Resin spacer 552 Annular recess 553 Resin spacer

Claims (7)

  In a semiconductor manufacturing apparatus including a processing chamber and a gate valve for opening and closing an opening connected to the inside of the processing chamber, the gate valve is provided in the valve chamber, the valve chamber communicated with the opening, and the opening. A first valve plate whose surface is in contact with a sealing surface around the opening and closes the opening; and when the valve is placed in the valve chamber and opposed to the opening, the opening is opened while the seal is closed. A second valve plate that covers the surface, and purge means that covers the surface of the first valve plate and the seal surface with an inert gas when the first valve plate is in a state of opening the opening. A semiconductor manufacturing apparatus comprising:   The first valve plate and the second valve plate are movable in conjunction with or integrally with each other in the valve chamber. When one valve plate is moved to a position facing the opening, the other valve plate is moved. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the plate is retracted to a position adjacent to the opening.   Means for defining a first purge space opened to the valve chamber through a minute gap between the first valve plate and the inner wall surface of the valve chamber; and the seal surface and the second plate And a means for defining a second purge space opened to the valve chamber through a minute gap therebetween, and a means for introducing an inert gas into each of the first and second purge spaces. The semiconductor manufacturing apparatus according to claim 1 or 2.   A recess for defining a first purge space is provided between the inner wall surface of the valve chamber and the surface of the first valve plate when the first valve plate opens the opening. And a second purge space is formed on the surface of the second valve plate with the seal surface including the O-ring when the second valve plate is positioned opposite the opening. The semiconductor manufacturing apparatus according to claim 3, wherein a recess is provided.   A first spacer for forming a minute gap between the inner surface of the valve chamber and the inner surface of the valve chamber is provided on the surface of the first valve plate, and a minute amount between the surface of the second valve plate and the seal surface is provided. The semiconductor manufacturing apparatus according to claim 4, further comprising a second spacer for forming a gap.   An elastic seal member that surrounds the opening and contacts the surface of the first valve plate is disposed on the seal surface, and the second valve plate is disposed between the seal surface and the seal surface including the elastic seal member. The semiconductor manufacturing apparatus according to claim 3, wherein the second purge space is defined. 7. A semiconductor manufacturing apparatus according to claim 1, wherein said valve chamber is connected to a vacuum pump.

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