JP4924676B2 - Gas port structure and processing apparatus - Google Patents

Description

  The present invention relates to a processing apparatus and a gas port structure for performing a heat treatment such as a film forming process on an object to be processed such as a semiconductor wafer.

Generally, in order to manufacture a semiconductor integrated circuit, various processes such as a film formation process, an etching process, an oxidation process, a diffusion process, a modification process, and a natural oxide film removal process are performed on a semiconductor wafer made of a silicon substrate or the like. Is done. In the case where these processes are performed by a vertical type so-called batch type processing apparatus disclosed in Patent Documents 1 to 3, first, in the wafer transfer chamber in the N ₂ atmosphere located below the processing container. The semiconductor wafer is transferred from a cassette capable of accommodating a plurality of, for example, about 25 semiconductor wafers to a vertical wafer boat and supported in multiple stages.

  This wafer boat can place about 30 to 150 wafers, for example, depending on the wafer size. The wafer boat is loaded (loaded) from the wafer transfer chamber below the processing vessel preheated to a temperature of several hundreds of degrees Celsius, and the inside of the processing vessel is kept airtight. Then, a predetermined heat treatment is performed while controlling various process conditions such as the flow rate of process gas, process pressure, and process temperature.

  Here, immediately after the wafer is carried into the processing container, a leak check is performed for each batch process to check whether the source gas or the like leaks out of the processing container. This leak check is performed as follows. That is, after the wafer is carried into the processing container and the inside of the processing container is sealed, the inside of the processing container is evacuated to the base pressure with a vacuum pump in a state where supply of all gases is stopped. After that, the pressure trend in the processing vessel is monitored for several minutes in a state where the on-off valve of the vacuum exhaust system is completely closed and the inside of the processing vessel is isolated. The base pressure refers to the highest degree of vacuum that can be reached in the processing vessel by the exhaust capability of the vacuum pump.

  In this leak check, gas attached to the inner wall surface of the processing vessel and the surface of the internal structure is gradually desorbed, so the pressure in the processing vessel rises little by little. In this case, since it is safe, the process proceeds to an actual heat treatment such as a next film forming process.

Japanese Patent Laid-Open No. 06-151312 JP-A-11-135448 Japanese Patent Laid-Open No. 2004-006801

  Incidentally, gas pipes such as a gas introduction system and a gas exhaust system connected to the processing vessel are connected to the processing vessel via a sealing member such as an O-ring in order to maintain airtightness in the processing vessel. The sealing performance of this sealing member gradually deteriorates due to aging, etc., and it is inevitable that leaks will occur even though it is very slight. At the time of the above-described leak check, the pressure in the processing container is the lowest, so that the slight gas leak amount that enters the processing container from the outside tends to be the largest.

  In this case, there is no particular problem as long as the wafer surface condition is durable against the air entering due to leakage, but the wafer surface condition is easy with air, for example, oxygen or moisture contained in the air. In the case where the wafer is easily reacted, there has been a problem that the material of the wafer surface reacts with the leaked oxygen, moisture, etc. to deteriorate the film quality characteristics. For example, when the tungsten film is exposed on the surface of the wafer, the tungsten film does not cause any particular problem even if it is in contact with air when the temperature is as low as room temperature. When the temperature is about several hundred degrees Celsius, there is a problem that the film quality characteristics are deteriorated by reacting with slight air leaking into the processing vessel, that is, oxygen. This deterioration of the film quality characteristic has a problem that it occurs even with a small amount of air leak that passes the leak check described above.

  In this case, the temperature of the processing container at the time of carrying in the wafer may be lowered to near room temperature, which is a temperature at which oxygen and the tungsten film do not react with each other. However, this is excessive for the temperature raising operation up to the subsequent processing temperature. It takes time and decreases the throughput, which is not realistic.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. The present invention provides a gas port structure capable of preventing air from leaking into a processing vessel from a sealing portion of a gas pipe even when the pressure in the processing vessel is reduced to a base pressure during a leak check, and A processing device is provided.

According to a first aspect of the present invention, there is provided a gas port structure for exhausting a gas from the inside of a processing container that can be evacuated in order to perform a predetermined process on an object to be processed, provided at an end of the processing container. A gas exhaust port having a flange portion, a gas exhaust pipe having a flange portion connected to the gas exhaust port, and a pressure between the flange portion of the gas exhaust port and the flange portion of the gas exhaust pipe a seal member is interposed in a state of being, a covering member provided to cover with a space on the outer peripheral side of the seal member, and an inert gas supply means for supplying an inert gas into said space The inert gas supply means includes an inert gas passage communicated with the space, a flow rate controller interposed in the middle of the inert gas passage, and the processing container in a sealed state. Inside the container A gas port structure characterized by having a gas control unit for instructing the gas flow rate to the flow rate controller while supplying the inert gas into the space when performing a leak check to scan pressure.

In this way, have you the gas port structure for discharging gas from the vacuum exhaust capable made a processing vessel in order to perform a predetermined process on the target object, the pressure base pressure in the processing vessel at the leak check Even if it is lowered to the above, it is possible to prevent air from leaking into the processing container from the sealing portion of the gas pipe.

According to a sixth aspect of the present invention, there is provided a gas port structure for introducing a gas into a processing container that can be evacuated in order to perform a predetermined processing on an object to be processed. The gas port structure is provided at an end of the processing container. A gas introduction port in which a nozzle insertion hole for inserting a gas nozzle for introducing gas is formed and a gas inlet side which is an end portion of the gas nozzle inserted in the nozzle insertion hole are inserted into the end portion and connected. A gas introduction pipe, a seal member interposed between an end of the gas introduction pipe and the gas introduction port, and a cover provided to cover the outer peripheral side of the seal member with a space therebetween, supplying a pressing member, an inert gas into said space to press said seal member said gas inlet tube for biasing the said gas inlet port side to seal the connection portion between the gas introduction tube and the gas nozzle Not to do A sexual gas supply means, the inert gas supply means, and an inert gas passage communicating with the said space, wherein the flow controller which is interposed in the middle of the inert gas passage, the processing vessel A gas control unit for instructing a gas flow rate to the flow rate controller while supplying the inert gas to the space when performing a leak check to make the inside of the processing vessel a base pressure in a sealed state. This is a gas port structure.

Thus, based on the pressure in the evacuation Oite the gas port structure for introducing a gas into the capable made a processing vessel, the processing vessel upon leakage check in order to perform a predetermined process on the target object Even if the pressure is reduced, it is possible to prevent air from leaking into the processing container from the sealing portion of the gas pipe.

According to a twelfth aspect of the present invention, in a processing apparatus for performing a predetermined process on an object to be processed, a cylindrical processing container and a plurality of the objects to be processed are held and inserted into and removed from the processing container. Holding means; heating means provided on the outside of the processing container for heating the object to be processed; gas supply system for supplying necessary gas into the processing container; and exhausting the atmosphere in the processing container a vacuum exhaust system which, further comprising a gas port structure according to any one of claims 1 gas port structure according to any one of乃optimum 5 and / or the claims 6 to 11 Is a processing apparatus characterized by

According to the gas port structure and the processing apparatus according to the present invention, the following excellent operational effects can be exhibited.
According to the invention of claim 1 and claim reference thereto, Te gas port structure odors for discharging gas from the vacuum exhaust capable made a processing vessel in order to perform a predetermined process on the target object, Even when the pressure in the processing container is reduced to the base pressure at the time of the leak check, it is possible to prevent air from leaking into the processing container from the seal portion of the gas pipe.

According to the invention of claim 6 and claim citing this, have you the gas port structure for introducing a gas into the vacuum evacuation can be made a processing vessel in order to perform a predetermined process on the target object Even when the pressure in the processing container is reduced to the base pressure during the leak check , it is possible to prevent air from leaking into the processing container from the seal portion of the gas pipe.

It is a block diagram which shows an example of the processing apparatus which has the gas port structure which concerns on this invention. It is an expanded sectional view showing the gas port structure on the gas exhaust side. It is an expanded sectional view showing the gas port structure on the gas introduction side. It is an exploded view of the gas port structure on the gas introduction side. It is a graph which shows an example of the change of the temperature and pressure in a processing container when the processing apparatus of this invention is operated. It is a graph which shows an example of the change in the pressure in a processing container, and an oxygen index in the processing device of the present invention, and the conventional processing device.

  Hereinafter, an embodiment of a gas port structure and a processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing an example of a processing apparatus having a gas port structure according to the present invention, FIG. 2 is an enlarged sectional view showing a gas port structure on the gas exhaust side, and FIG. 3 is an enlarged view showing a gas port structure on the gas introduction side. FIG. 4 is an exploded view of the gas port structure on the gas introduction side.

  As shown in the figure, the processing apparatus 2 includes a processing container 4 that accommodates a semiconductor wafer W as an object to be processed. Here, the processing container 4 is formed by a container body 6 having an exhaust port on a ceiling formed in a cylindrical shape with heat-resistant quartz, and stands vertically as a vertical processing container 4. It is configured. For example, when the diameter of the wafer W to be processed is 300 mm, the diameter of the processing container body 6 is set in a range of about 350 to 450 mm.

  The lower end portion of the quartz container body 6 is opened so that the wafer W can be loaded and unloaded as described later. The side wall of the lower end portion of the container body 6 is formed thick and slightly extends radially outward to form a ring-shaped container flange portion 8. A gas port structure 10 on the gas introduction side for introducing a necessary gas into the processing container 4 is provided in a container flange portion 8 which is an end portion of the container main body 6. The gas port structure 10 is provided so as to pass through a gas nozzle 12 made of quartz, and gas is introduced from the outside.

  A gas supply system 14 is provided to supply gas to the gas nozzle 12. The gas supply system 14 has a gas introduction pipe 16 made of metal, for example, stainless steel, communicated with the gas nozzle 12, and a flow rate controller 18 such as a mass flow controller and the like are provided in the middle of the gas introduction pipe 16. An on-off valve 20 is sequentially provided so that the processing gas can be supplied while controlling the flow rate. Other necessary process gases are also supplied through a similarly configured gas port structure 10. Although only one gas port structure 10 is shown in the illustrated example, actually, a plurality of gas port structures 10 are provided, for example, about 5 to 6 according to the type of gas required. The gas port structure 10 will be described later.

  The peripheral portion of the container flange portion 8 of the container main body 6 is supported by a base plate 22 formed of, for example, stainless steel, and the base plate 22 supports the load of the container main body 6. Below the base plate 22 is a wafer transfer chamber 24 having a wafer transfer mechanism (not shown), which is in a nitrogen gas atmosphere at a substantially atmospheric pressure. Above the base plate 22 is an atmosphere of clean air in a normal clean room. A quartz wafer boat 26 is accommodated in the container body 6 as holding means for holding a plurality of wafers W at a predetermined pitch in multiple stages.

  The wafer boat 26 is mounted on a table 30 via a quartz heat insulating cylinder 28, and the table 30 has a rotating shaft 34 that passes through a lid portion 32 that opens and closes the lower end opening of the container body 6. It is supported by the upper end part. For example, a magnetic fluid seal 36 is interposed in the penetrating portion of the rotating shaft 34 and supports the rotating shaft 34 so as to be rotatable while hermetically sealing. Further, a sealing member 38 made of, for example, an O-ring is interposed between the peripheral portion of the lid portion 32 and the lower end portion of the container body 6 to maintain the sealing performance in the processing container 4.

  The rotating shaft 34 is attached to the tip of an arm 42 supported by a lifting mechanism 40 such as a boat elevator, for example, so that the wafer boat 26 and the lid 32 can be lifted and lowered integrally. The table 30 may be fixedly provided on the lid portion 32 side and the wafer W may be processed without rotating the wafer boat 26.

  In addition, an open exhaust port 44 is provided at the ceiling, which is an end portion of the container body 6, and a gas port structure 46 on the gas exhaust side is provided at the exhaust port 44. The configuration of the gas port structure 46 will be described later. The gas port structure 46 is connected to a vacuum exhaust system 48 that exhausts the atmosphere in the processing container 4. Specifically, the vacuum exhaust system 48 has a metal gas exhaust pipe 50 made of, for example, stainless steel, connected to the gas port structure 46. The inner diameter of the gas exhaust pipe 50 is, for example, about 110 mm. In the middle of the gas exhaust pipe 50, an on-off valve 52, a pressure adjustment valve 54 such as a butterfly valve, and a vacuum pump 56 are sequentially provided so that the atmosphere in the processing container 4 can be evacuated while adjusting the pressure. It can be done.

  And the heating means 58 which consists of a heater made from the carbon wire described in Unexamined-Japanese-Patent No. 2003-209063 etc. is provided in the side part of the said processing container 4 so that this may be surrounded, and it is located inside this The semiconductor wafer W can be heated. Further, a heat insulating material 60 is provided on the outer periphery of the heating means 58 so as to ensure this thermal stability.

  The gas port structure 46 on the gas discharge side has a gas discharge port 62 made of a quartz tube that extends from the exhaust port 44 and is bent in an L shape in a lateral direction at a right angle, for example. The inner diameter of the gas exhaust port 62 is set to be the same as the inner diameter of the gas exhaust pipe 50, and is about 110 mm, for example. As shown in FIG. 2, an enlarged ring-shaped flange portion 64 is formed at the tip of the gas exhaust port 62. A flange 66 having a diameter slightly larger than that of the flange 64 is formed at the end of the metal gas exhaust pipe 50. For example, an O-ring is provided between the flanges 64 and 66. A sealing member 68 is interposed in a pressed state to seal this portion.

  A cover 72 is provided on the outer peripheral side of the seal member 68 so as to cover the space 70 with a space therebetween. This space 70 is a very small and slightly ring-shaped space. The cover 72 includes a ring-shaped plate 72A made of metal such as stainless steel, which is in contact with the side surface of the flange portion 64 on the gas exhaust port 62 side, and the plate 72A and the gas exhaust pipe 50 side. For example, a metal annular collar member 72B such as stainless steel interposed between the peripheral portion of the flange portion 66, and the flange portion 66, the collar member 72B, and the plate 72A are arranged in the circular direction. A plurality of screws 74 provided at predetermined intervals along the line are fastened and fixed.

  In this case, a buffer member 76 made of, for example, Teflon (registered trademark) is interposed between the quartz flange portion 64 on the gas exhaust port 62 side and the metal cover 72. As a result, the space 70 is loosely sealed. Here, the loosely sealed state means that the joint portion provided with the seal member 68 made of an O-ring has high sealing performance, but the sealability of each joint portion between the flange portions 64 and 66, the plate 72A, and the collar member 72B is as described above. The air tightness is lower than the sealing performance of the joint portion of the sealing member 68 and allows air permeability to some extent with the outside.

  Then, in order to supply the inert gas to the minute space 70 in the loosely sealed state, an inert gas supply means 78 which is a feature of the present invention on the gas discharge side is provided. Specifically, the inert gas supply means 78 has an inert gas passage 80 communicating with the minute space 70. The inert gas passage 80 is made of, for example, a stainless steel pipe, and the tip thereof is connected to a gas flow hole 82 formed in, for example, the flange portion 66 and communicated with the space 70.

In the middle of the inert gas passage 80, an on-off valve 84 and a flow rate controller 86 such as a mass flow controller are sequentially provided so that the inert gas can be supplied while controlling the flow rate including stopping the supply. It has become. Here, N ₂ gas is used as the inert gas. However, the present invention is not limited to this, and a rare gas such as Ar or He may be used. The flow rate of the inert gas and the start and stop of the supply are instructed by a gas control unit 88 (see FIG. 1) comprising a computer.

  Further, as shown in FIGS. 3 and 4, the gas port structure 10 on the gas introduction side provided at the lower end of the container body 6 penetrates the thick quartz container flange 8 in the horizontal direction. A gas introduction port 92 having a nozzle insertion hole 90 formed therein. The base end portion of the quartz gas nozzle 12 bent into an L-shape is inserted into the nozzle insertion hole 90 in a loosely fitted state, and the base end portion on the gas inlet side. Is provided so as to protrude outward from the container flange portion 8 by a length slightly shorter than the nozzle insertion hole 90. The inner diameter of the nozzle insertion hole 90 is, for example, about 10 mm.

  Here, the distal end portion of the metal gas introduction pipe 16 for supplying the processing gas is an enlarged socket portion 94 whose inner diameter and outer diameter are slightly enlarged. An inner diameter H1 of the enlarged socket portion 94 is set to be slightly larger than an outer diameter H2 of the proximal end portion of the gas nozzle 12 (see FIG. 4), and the proximal end portion of the gas nozzle 90 is placed in the enlarged socket portion 94. They are inserted and connected to each other.

  The distal end surface of the enlarged socket portion 94 is formed as a tapered surface inclined inward in the axial direction of the enlarged socket portion 94, and a distal end pressing surface 96 is provided here. A seal receiving step portion 98 is formed in a ring shape at the inlet of the gas introduction port 92 of the container flange portion 8 facing the tip pressing surface 96, and the seal receiving step portion 98 of the gas introduction port 92 and the expansion socket are formed. A seal member 100 such as an O-ring is interposed between the tip pressing surface 96 of the portion 94.

  A cover 104 is provided on the outer peripheral side of the seal member 100 so as to cover the space 102 with a space 102 therebetween. The cover 104 includes a circular ring-shaped upper pressing plate 104A extending along the circumferential direction of the container flange portion 8, a lower pressing plate 104B that is also formed in a circular ring shape, and between the pressing plates 104A, 104B. And a central auxiliary plate 106 interposed therebetween, which are formed of a metal such as stainless steel. Further, the central auxiliary plate 106 is formed with an opening 108 (see FIG. 4) large enough to allow the enlarged socket portion 94 to be inserted therethrough, and the enlarged socket portion 94 is inserted therethrough. Then, the upper presser plate 104A and the lower presser plate 104B are not shown in the figure with the central auxiliary plate 106 and the container flange portion 8 sandwiched between the upper presser plate 104A and the lower presser plate 104B. The central auxiliary plate 106 is fixed by tightening with, for example.

  In this case, thin circular ring-shaped buffer members 110A and 110B made of, for example, Teflon (registered trademark) are provided between the quartz container flange portion 8 and the upper and lower pressing plates 104A and 104B. Is intervened. In order to seal the connecting portion between the gas nozzle 12 and the gas introduction pipe 16, a pressing member 112 that urges the gas introduction pipe 16 toward the gas introduction port and presses the seal member 100 is provided. ing. Specifically, the pressing member 112 is made of a metal such as stainless steel, for example, and can insert the female screw block 112 </ b> A having an opening 114 having a size through which the enlarged socket portion 94 can be inserted, and the gas introduction pipe 16. And a male screw block 112B having an opening 116 having a size.

  A screw thread 118 is formed on the inner wall of the opening 114 of the female screw block 112A to form a female screw. The female screw block 112A is attached and fixed to the central auxiliary plate 106 by a bolt 120 or the like. The tip of the male screw block 112B is expanded in diameter, and a screw thread 122 is formed on the outer periphery of the main body portion to form a male screw so as to be screwed into the screw thread 118 of the female screw block 112A. It has become. In this case, the outer diameter H3 of the enlarged socket portion 94 is set to be slightly larger than the inner diameter H4 of the opening 116 of the male screw block 112B. It contacts the stepped base end of the socket 94 and presses it. As a result, the sealing member 100 is pressed between the tip pressing surface 96 of the enlarged socket portion 94, the seal receiving step portion 98, and the outer peripheral surface of the gas nozzle 12, and this portion is hermetically sealed.

  As a result, the space 102 is loosely sealed. Here, the loosely sealed state means that the joint portion provided with the seal member 100 made of an O-ring has high sealing performance, but the joint portion between the pressing plates 104A and 104B and the flange portion with container 8 and the pressing plates 104A and 104B. The sealing performance of the joint portion between the central auxiliary plate 106, the fitting clearance between the central auxiliary plate 106 and the enlarged socket portion 94, and the sealing performance of the joint portion between the central auxiliary plate 106 and the pressing member 112 are as follows. The airtightness is such that the air permeability is allowed to some extent between the outside and the outside.

  Then, in order to supply the inert gas to the minute space 102 in the loosely sealed state, an inert gas supply means 124 which is a feature of the present invention on the gas introduction side is provided. Specifically, the inert gas supply means 124 has an inert gas passage 126 communicating with the minute space 102. The inert gas passage 126 is made of, for example, a stainless steel tube, and the tip thereof is connected to the gas flow hole 128 formed in the lower pressing plate 104B, for example, and communicates with the space 102. The gas flow hole 128 may be provided in the upper holding plate 102A or the central auxiliary plate 106.

In the middle of the inert gas passage 126, an on-off valve 130 and a flow rate controller 132 such as a mass flow controller are sequentially provided so that the inert gas can be supplied while controlling the flow rate including stopping the supply. It has become. Here, N ₂ gas is used as the inert gas. However, the present invention is not limited to this, and a rare gas such as Ar or He may be used. The flow rate of the inert gas and the start and stop of the supply are instructed by a gas control unit 88 (see FIG. 1) comprising a computer.

  The gas port structure 10 on the gas introduction side as described above is similarly configured for the gas port structure for other processing gas systems. Here, the gas control unit 88 is used in common for the gas port structure 46 on the gas discharge side and the gas port structure 10 on the gas introduction side. However, the present invention is not limited to this. 88 may be provided individually.

  Returning to FIG. 1, an apparatus control unit 134 composed of, for example, a computer is provided in order to control the overall operation of the processing apparatus. The apparatus control unit 134 has a storage medium 136 for storing a program used when controlling the operation of the processing apparatus 2. As the storage medium 136, for example, a flexible disk, a CD (Compact Disc), a hard disk, a flash memory, or a DVD can be used. The gas control unit 88 operates under the control of the device control unit 134.

  Next, the operation of the processing apparatus 2 configured as described above will be described. FIG. 5 is a graph showing an example of changes in temperature and pressure in the processing container when the processing apparatus of the present invention is operated, and FIG. 6 is a graph showing pressure and oxygen in the processing container in the processing apparatus of the present invention and the conventional processing apparatus. It is a graph which shows an example of a change with an index.

  First, a series of flows will be described. In a wafer transfer chamber 24 in a nitrogen gas atmosphere below the base plate 22, a large number of unprocessed wafers are unloaded on the wafer boat 26 that has been unloaded and lowered. The semiconductor wafer W is transferred using a transfer mechanism (not shown) and is supported in multiple stages. The pressure in the wafer transfer chamber 24 is set to about atmospheric pressure. In this case, the surface of the wafer W is exposed to a metal, for example, a tungsten film, which easily reacts with oxygen at a temperature of about 350 ° C. or more to cause film quality degradation.

  When the transfer of the wafer is completed, the wafer boat 26 supporting a large number of wafers W is lifted and loaded into the processing container 4, and the lower end opening of the processing container 4 is loaded. Is sealed by the lid 32. Here, the processing container 4 is preheated to a temperature somewhat lower than the process temperature, for example, about 600 ° C., although it depends on the process temperature in order to improve the throughput. Further, supply of all the gas into the processing container 4 is stopped.

  If the inside of the processing container 4 is sealed, the atmosphere in the processing container 4 is evacuated by the vacuum exhaust system 48 to reduce the pressure in the processing container 4 to the base pressure. The vacuum pump 56 is always driven to rotate. This base pressure is, for example, about 0.0004 Pa.

  In this way, when the pressure in the processing container 4 reaches the base pressure, the closed state of the on-off valve 20 of the gas supply system 14 is maintained and the supply of all the gas into the processing container 4 is stopped. Thus, the on-off valve 52 of the evacuation system 48 is also closed to completely isolate the inside of the processing vessel 4 and perform a leak check to check whether a large gas leak has occurred. During the leak check, the temperature of the wafer W is raised and heated to a process temperature, for example, about 630 to 680 ° C. Then, after a leak check is performed for a predetermined time and the leak check is completed, a necessary process gas is supplied, and a predetermined process such as a film forming process is performed while maintaining the process temperature and the process pressure. . For example, when a silicon nitride film is formed as a film forming process, dichlorosilane, ammonia, or the like is used as a processing gas.

When the predetermined processing is completed, the temperature of the processing vessel 4 is lowered to a preheating temperature at which unloading is possible, and the supply of the processing gas is stopped and the purge gas is flowed to increase the pressure in the processing vessel 4. Return to atmospheric pressure. Note that N ₂ gas is generally used as the purge gas. When the pressure in the processing container 4 returns to the atmospheric pressure in this way, the wafer boat 26 is lowered to unload the wafer W from the processing container 4 and the processing is completed.

  By the way, in the above series of operations, when performing a leak check, the atmosphere in the processing container 4 is reduced to the base pressure, so that the pressure difference inside and outside the processing container 4 is maximized. In this case, if the seal member 68 provided in the gas port structure 46 on the gas discharge side or the seal member 100 provided on the gas port structure 10 on the gas introduction side is deteriorated due to secular change or the like, the sealability of this part is inferior. There is a risk that the outside clean air slightly enters the processing container 4 and reacts with the tungsten film exposed on the surface of the wafer W.

However, in the case of the present invention, N ₂ gas is supplied as an inert gas from the inert gas supply means 124 and 78 provided in the gas port structures 10 and 46, respectively, so that the outer atmosphere of the seal members 100 and 60 is maintained. Since the N ₂ atmosphere is used, it is possible to prevent oxygen from entering the processing container 4 even if the sealing members 100 and 60 deteriorate as described above. That is, in the gas port structure 46 on the gas discharge side, the N ₂ gas whose flow rate is controlled from the inert gas passage 80 of the inert gas supply means 78 is a small space 70 on the outer peripheral side of the seal member 68 as shown in FIG. Being supplied inside. Therefore, since the N ₂ gas atmosphere is mainly in the small space 70, even if a leak check is performed to make the inside of the processing container 4 a base pressure with the seal member 68 deteriorated, the processing container 4, only the N ₂ gas in the space 70 enters, and oxygen and moisture in the atmosphere can be prevented from entering.

Further, in this case, the small space 70 is in a loosely sealed state, and unlike the structure of Japanese Patent Laid-Open No. 6-151312, the N ₂ gas exhaust port is not actively provided. Therefore, the amount of N ₂ gas leaking outside the space 70 is very small, and as a result, the N ₂ gas to be used can be largely eliminated.

Further, in the gas port structure 10 on the gas introduction side, as shown in FIG. 3, the N ₂ gas whose flow rate is controlled from the inert gas passage 126 of the inert gas supply means 124 is a small space 102 on the outer peripheral side of the seal member 100. Being supplied inside. Accordingly, since the N ₂ gas atmosphere is mainly in the small space 102, the processing container 4 is not affected even if a leak check is performed to make the inside of the processing container 4 the base pressure while the seal member 100 is deteriorated. 4, only the N ₂ gas in the space 102 enters, and oxygen and moisture in the atmosphere can be prevented from entering.

Further, in this case, like the gas port structure 46 on the gas discharge side, the small space 102 is in a loosely sealed state, which is different from the structure of Japanese Patent Laid-Open No. 6-151312 of Patent Document 1. Since the N ₂ gas discharge port is not actively provided, the amount of N ₂ gas that leaks outside the space 102 is very small, and as a result, the N ₂ gas to be used can be largely eliminated.

If the above, the may be the each space 70,102 to always supplied with N ₂ gas, but the N ₂ gas _is supplied from the time of starting the pressure reduction in the processing vessel 4 in order to perform at least leak check The supply of N ₂ gas may be stopped when the film forming process is started. Thus, if the supply time of N ₂ gas is limited, the amount of N ₂ gas used can be reduced. Further, if N ₂ gas is supplied so that the oxygen concentration in each of the spaces 70 and 102 is 1% or less, the atmosphere in the spaces 70 and 102 leaks into the processing container 4 by any chance. Even if it penetrates, the tungsten film is not adversely affected. More preferably, N ₂ gas is supplied so that the oxygen concentration is 0.2% or less.

As described above, in order to set the oxygen concentration in the spaces 70 and 102 to be 1% or less, the gas port structure 10 on the gas introduction side has an N of 3 slm or more with respect to one gas port structure. _Two gases may be flowed, and N ₂ gas of 3.0 slm or more may be flowed to the gas port structure 46 on the gas discharge side.

  As described above, according to the present invention, in the gas port structure for introducing the gas into the processing container that can be evacuated in order to perform the predetermined processing on the object to be processed, the gas port structure is provided at the end of the processing container. The gas nozzle is inserted into the gas introduction port in which the nozzle insertion hole for inserting the gas nozzle to be introduced is formed, and the end of the gas introduction pipe is inserted and connected to the gas inlet side which is this end, A seal member is interposed between the end of the gas introduction pipe and the gas introduction port, a cover is provided on the outer peripheral side of the seal member so as to cover the space, and a connection portion between the gas nozzle and the gas introduction pipe is provided. In order to seal, the gas introduction pipe is urged toward the gas introduction port to press the seal member, and the inert gas is supplied to the space by the inert gas supply means. When checking Also decreases the pressure in the processing container to a base pressure, the air into the processing vessel from the sealing portion of the gas pipe it is possible to prevent the entering leaking.

  Further, in a gas port structure for discharging a gas from the inside of a processing container that can be evacuated in order to perform a predetermined process on the object to be processed, a gas discharge having a flange portion provided at an end of the processing container. A seal member is interposed between the port and the gas exhaust pipe having a flange portion and connected to the gas exhaust port in a state of being pressed between the flange portion of the gas exhaust port and the flange portion of the gas exhaust pipe. Since the cover member is provided on the outer peripheral side of the seal member so as to cover the space, the inert gas is supplied to the space by the inert gas supply means. Even if the pressure is reduced to the base pressure, it is possible to prevent air from leaking into the processing container from the sealing portion of the gas pipe.

[Evaluation Experiment of the Present Invention]
Next, since the evaluation experiment of the processing apparatus of this invention was conducted, the evaluation result is demonstrated. FIG. 6 is a graph showing the pressure in the processing container and the oxygen index when an evaluation experiment of the processing apparatus is performed. 6A shows the case of the conventional processing apparatus, and FIG. 6B shows the case of the processing apparatus of the present invention. Both processing apparatuses use an O-ring that deteriorates to such an extent that it does not become NG (no good) at the time of seal check and causes leakage.

Here, the oxygen index on the right vertical axis is synonymous with oxygen concentration. The pressure in the processing vessel changes from atmospheric pressure (760 Torr) to base pressure by evacuation. In the processing apparatus of the present invention, ₂ slm N ₂ gas is supplied to one gas port structure. Note that the large initial amplitude of the oxygen index is a value when the operation of the measuring instrument is unstable.

As shown in FIG. 6A, in the case of the conventional processing apparatus, when the inside of the processing vessel is set to the base pressure, the oxygen index reaches about 1200 to 1400, and a considerable amount of O ₂ has entered due to leakage. I understand that. On the other hand, in the case of the apparatus of the present invention shown in FIG. 6B, the oxygen index is 500 or less even when the inside of the processing container is at the base pressure, and even if a leak occurs, O ₂ enters the processing container. It can be seen that good results are obtained with almost no penetration.

  As another evaluation experiment, in a conventional processing apparatus, a new O-ring without deterioration is used to prevent leakage at the seal portion, and 2 sccm of air is intentionally introduced into the processing container at the time of leak check. As a result of causing the same phenomenon as the leak, the result of the leak check did not become NG, but the tungsten film on the wafer surface was oxidized and the film characteristics were deteriorated.

On the other hand, as described above with reference to FIG. 6B, in the processing apparatus of the present invention using the O-ring whose sealing performance has deteriorated to some extent, 2 slm is applied to one gas port structure at the time of leak check. When N ₂ gas was allowed to flow at a flow rate, the tungsten film on the wafer surface was not oxidized, and the effectiveness of the present invention could be confirmed.

  In addition, in the said Example, although the case where the whole processing container 4 was formed with the quartz container main body 6 was demonstrated as an example, it is not limited to this, A gas nozzle attachment for the lower end part of the container main body 6 is carried out. For example, the present invention can be applied to the processing container 4 provided with a metal manifold such as stainless steel. Further, here, the vertical processing apparatus provided with the processing container 4 standing upright has been described as an example, but the present invention is not limited to this, and the present invention is also applied to a horizontal processing apparatus in which the processing container is installed in the horizontal direction. The invention can be applied.

  Furthermore, although the case where a tungsten film is formed has been described as an example here, the present invention is not limited to this, and the present invention can also be applied to the case where other film types are formed. The present invention can be applied to other processes such as annealing, oxidative diffusion, and modification.

  Although the semiconductor wafer is described as an example of the object to be processed here, the semiconductor wafer includes a silicon substrate and a compound semiconductor substrate such as GaAs, SiC, GaN, and the like, and is not limited to these substrates. The present invention can also be applied to glass substrates, ceramic substrates, and the like used in display devices.

2 Processing equipment 4 Processing container 6 Container body 10 Gas port structure (gas introduction side)
12 Gas nozzle 14 Gas supply system 16 Gas introduction pipe 18 Flow rate controller 20 On-off valve 26 Wafer boat (holding means)
46 Gas port structure (gas exhaust side)
48 Vacuum exhaust system 58 Heating means 62 Gas exhaust port 70 Space 72 Cover 78, 124 Inert gas supply means 80, 126 Inert gas passage 84, 130 On-off valve 86, 132 Flow controller 88 Gas control unit 102 Space 104A Upper side Holding plate 104B Lower holding plate 106 Central auxiliary plate 112 Pressing member 112A Female screw block 112B Male screw block W Semiconductor wafer (object to be processed)

Claims (12)

In the gas port structure for discharging the gas from the inside of the processing vessel that can be evacuated in order to perform a predetermined process on the object to be processed,
A gas exhaust port provided at an end of the processing vessel and having a flange;
A gas exhaust pipe having a flange portion and connected to the gas exhaust port;
A seal member interposed between the flange portion of the gas exhaust port and the flange portion of the gas exhaust pipe;
A cover provided on the outer peripheral side of the seal member so as to cover the space with a space therebetween ;
An inert gas supply means for supplying an inert gas to the space ;
The inert gas supply means includes an inert gas passage communicated with the space, a flow rate controller interposed in the middle of the inert gas passage, and the inside of the processing container in a sealed state. A gas port structure comprising: a gas control unit for instructing a gas flow rate to the flow rate controller while supplying the inert gas to the space when performing a leak check using a base pressure . Wherein the middle of the inert gas passage opening and closing valve is interposed, said gas control unit gas port structure according to claim 1 Symbol placement and controls the opening and closing of the on-off valve. Between the covering body and the flange portion, the gas port structure according to claim 1 or 2, wherein the buffer member is characterized in that it is interposed. The sealing member, the gas port structure according to any one of claims 1 to 3, characterized in that an O-ring. Gas port structure according to any one of claims 1乃optimum 4, characterized in that the surface of the workpiece to be loaded into the processing chamber are exposed tungsten film. In a gas port structure for introducing gas into a processing vessel that can be evacuated in order to perform a predetermined process on an object to be processed,
A gas introduction port formed with a nozzle insertion hole for inserting a gas nozzle for introducing gas provided at an end of the processing container;
A gas introduction pipe connected by inserting a gas inlet side which is an end portion of the gas nozzle inserted through the nozzle insertion hole into the end portion;
A seal member interposed between an end of the gas introduction pipe and the gas introduction port;
A cover provided on the outer peripheral side of the seal member so as to cover the space with a space therebetween;
A pressing member for pressing said sealing member the gas inlet pipe and urges to the gas inlet port side to seal the connection portion between the gas introduction tube and the gas nozzle,
An inert gas supply means for supplying an inert gas to the space ;
The inert gas supply means includes an inert gas passage communicated with the space, a flow rate controller interposed in the middle of the inert gas passage, and the inside of the processing container in a sealed state. A gas port structure comprising: a gas control unit for instructing a gas flow rate to the flow rate controller while supplying the inert gas to the space when performing a leak check using a base pressure . Wherein the middle of the inert gas passage opening and closing valve is interposed, said gas control unit gas port structure according to claim 6 Symbol mounting and controlling the opening and closing of the on-off valve. Wherein between the flange portion and the cover member, according to claim 6 or 7 SL placing the gas port structure cushioning member is characterized in that it is interposed. The gas port structure according to any one of claims 6 to 8, wherein the seal member is an O-ring. The gas port structure according to any one of claims 6 to 9, wherein a tungsten film is exposed on a surface of the object to be processed carried into the processing container. 6. distal end surface in contact with said seal member comprising an end portion of the gas inlet pipe, characterized in that it is formed as a tapered surface which is inclined inwardly toward the axial direction of the gas inlet tube The gas port structure as described in any one of thru | or 10 . In a processing apparatus that performs a predetermined process on an object to be processed,
A cylindrical processing container;
Holding means configured to hold a plurality of the objects to be processed and to be inserted into and removed from the processing container;
A heating means provided on the outside of the processing container for heating the object to be processed;
A gas supply system for supplying a necessary gas into the processing container;
An evacuation system for evacuating the atmosphere in the processing vessel;
And a gas port structure according to any one of claims 1乃optimum 5 of any one gas port structure and / or 6 to claimed in 11,
A processing apparatus comprising:

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