JP2007064619A - Semiconductor element manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent adhesion of LMCS onto a wafer, and to remove LMCS adhering to the wafer. <P>SOLUTION: (1) A fluorine-based sealing material is used as a sealing material used for a clean room wherein a semiconductor element is manufactured. (2) A silicon sealing material is used for the sealing material, and the surface of the sealing material exposed in the clean room is coated with a material having an electrical insulating property, mechanical stability, aging resistance, excellent processability and excellent adhesiveness. (3) Fine particles are generated in a high energy state from a material of LMCS generated in the atmosphere for performing a process for generating LMCS and then removed, and each process other than the process is performed in an atmosphere separated from the atmosphere for performing the process for generating LMCS. (4) A chemical filter using activated carbon is provided on an outside air suction port into a device for manufacturing the semiconductor element. (5) A spare buffer chamber filled with inert gas is provided in the semiconductor element manufacturing device, and a member for the semiconductor element contaminated with LMCS is subjected to heating treatment in the chamber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for suppressing adsorption of low-molecular siloxane to a semiconductor element member during the manufacture of a semiconductor element.

  In recent years, a technique for removing particles that cause contamination of a wafer in an environment in a clean room for manufacturing a semiconductor element has been established. However, on the other hand, the atmosphere in the clean room contains various gases, and some gases contaminate the wafer surface. One of the pollutant gases is low molecular siloxane (LMCS) which is an organic gas.

  This low molecular siloxane (LMCS) is generated in the clean room by degassing from a seal material containing a large amount of silicon used as a seal material in the clean room (hereinafter referred to as a silicon seal material).

  Of the semiconductor element manufacturing processes, hexamethylene disilazane (HMDS) is often used in the photolithography process to improve the adhesion between the resist and the base on which the resist is provided. This HMDS is easily trimethylated by hydrolysis. Decomposes into silanol and ammonia gas. This trimethylsilanol is a material for LMCS.

  Further, it is known that a silicon compound, which is an organic SOG material used in a multilayer wiring process, also becomes an LMCS material.

  The LMCS gas generated as described above exists in the clean room and the semiconductor element manufacturing apparatus. Here, for example, when a gate oxide film is formed on the wafer surface, the wafer is first subjected to wet cleaning before the oxide film is formed. Thereafter, the wafer is transferred to an oxide film forming furnace while being exposed to a clean room atmosphere. Then, an oxide film is formed in the oxide film forming furnace. Since the oxide film forming furnace also takes in the gas in the clean room, it is considered that LMCS gas is also present inside the furnace. Thus, since the wafer before forming the oxide film is exposed to the atmosphere containing the LMCS gas, the LMCS is easily adsorbed to the wafer. When a gate oxide film is formed on the surface of a wafer on which LMCS is adsorbed, there is a possibility that voids (defects) are generated in the film or the film is locally thinned to cause gate breakdown voltage failure.

The capacitor insulating film on the wafer surface, for example even in the case of attempting to form a Si ₃ N ₄ film, the thickness of the Si ₃ N ₄ film LMCS is formed on the wafer adsorbed partially become nonuniform End up.

  Furthermore, since the wafer in the portion where the LMCS is adsorbed becomes hydrophobic, the wettability of the wafer is deteriorated, for example, when a wet etching is performed, a portion that is difficult to be etched is generated.

Here, since the organic gas is oxidized by active oxygen and decomposed into carbon dioxide and water, it is considered that this gas can be removed if UV / O ₃ treatment or the like is performed before each step. Since LMCS contains Si, the methyl group, which is an organic group, is oxidatively decomposed and volatilized, but the Si—O bond, which is the main chain, remains on the adsorption surface and may bind more strongly. .

In addition, it is known that LMCS gas particles when encountering high energy fields such as discharge, plasma, and radiation. For this reason, for example, when dry etching using plasma is performed in a wiring forming process, LMCS forms SiO ₂ particles, which causes a problem of wiring short-circuiting.

  For this reason, the advent of a method for preventing adsorption of LMCS to the wafer and a method for removing LMCS adsorbed on the wafer has been desired.

  Therefore, as a means for realizing the above method, the inventor has intensively researched paying attention to the following four means to arrive at the present invention.

(1) A clean room that does not generate LMCS,
(2) LMCS coping method in semiconductor device manufacturing method and semiconductor device manufacturing process chamber used therefor,
(3) a semiconductor device manufacturing apparatus having processing means for LMCS, and
(4) A method for cleaning a member for a semiconductor element contaminated by LMCS.

  Therefore, according to the clean room of the present invention, a fluorine-based seal material is used as a seal material used for components of the clean room itself for manufacturing semiconductor elements.

  Thereby, since there is no possibility that LMCS will degas, a fluorine-type sealing material can suppress generation | occurrence | production of LMCS derived from the sealing material used for a clean room.

  In addition, according to the present invention, when the same silicon sealing material as the conventional one is used as the sealing material, the surface of the silicon sealing material exposed in the clean room has electrical insulation and is mechanically stable. Thus, the coating is made of a material having aging resistance, excellent workability, and excellent adhesion.

  Since the portion of the silicon sealing material that may degas LMCS that is exposed in the clean room is covered with the material as described above, there is no possibility that LMCS will occur. As a coating method, the coating may be performed so as to cover the exposed surface of the silicon sealing material. Moreover, you may affix so that an exposed part may be covered with the tape-shaped member formed with said material.

  Moreover, as a material to coat, preferably, polyurethane or epoxy resin can be used.

  Further, in the method of manufacturing a semiconductor device including the step of generating LMCS, the LMCS material generated in the atmosphere in which the step of generating LMCS is performed is granulated under a high energy state and then removed to remove the LMCS. Steps other than this step may be performed in an atmosphere isolated from the atmosphere in which the generated steps are performed.

  Among the processes for manufacturing semiconductor elements, there is a process in which the material used in the process becomes a material for LMCS. For this reason, after the LMCS material generated in the atmosphere in which such a process is performed is granulated under a high energy state, the particles are removed by means such as local exhaust. Thereby, it can avoid that LMCS adsorb | sucks to members for semiconductor elements, such as a wafer. Further, the LMCS is not suspended in the atmosphere. Thereafter, if the subsequent steps are performed in an atmosphere isolated from the atmosphere in which the process of generating LMCS is performed, LMCS will not be present in the atmosphere in which these processes are performed. Therefore, since it is not contaminated by LMCS, a preferable semiconductor element can be manufactured.

  The process for generating LMCS is, for example, a photolithography process.

  In the photolithography process, HMDS (hexamethyldisilazane) is used in order to improve the adhesion between the resist and the base on which the resist is provided. Is generated.

  Moreover, as a process which generate | occur | produces LMCS, a multilayer wiring process can be mentioned, for example. In this step, organic SOG (spin-on-glass) is used. This organic SOG solution contains a silicon compound, and the silicon compound is dehydrated and condensed to become LMCS.

  As described above, examples of the material for LMCS include HMDS (hexamethyldisilazane) and silicon compounds that are organic SOG raw materials.

  LMCS is easily synthesized from these materials and floats in the atmosphere in which the semiconductor element manufacturing process is performed. However, these materials and LMCS are particleized under high energy conditions, and therefore, using means such as local exhaust. If the particles are removed, contamination of the atmosphere by LMCS can be sufficiently reduced. Further, by performing the subsequent process after the process of generating the LMCS in an atmosphere isolated from the atmosphere in which the process of generating the LMCS is performed, there is no fear of being affected by the LMCS in the subsequent process.

  Preferably, an energy field forming apparatus for forming an energy field for atomizing the material of LMCS contained in the processing chamber and a means for removing particles in a processing chamber for manufacturing a semiconductor element that performs a process of generating LMCS. It is good to have.

  By providing such a processing chamber, LMCS generated in the processing chamber can be made into particles using an energy field forming device and further removed by means for removing the particles.

  Preferably, the energy field forming device is a device that generates a discharge, a device that generates plasma, or a device that generates radiation. An energy field can be generated by these devices. For this reason, the material of LMCS and LMCS can be granulated under a high energy state.

  Moreover, in the apparatus for manufacturing a semiconductor element, it is preferable that a chemical filter using activated carbon is provided at an outside air inlet in the apparatus.

  This device is installed in a clean room and sucks gas in the clean room. For this reason, if LMCS exists in the clean room, the surface of this member is exposed to the atmosphere in the apparatus when the semiconductor element member such as a wafer is transported in the apparatus. End up. Therefore, if a chemical filter using activated carbon is provided at the outside air intake port in the apparatus as described above, LMCS can be adsorbed by this filter, so that inflow into the apparatus can be prevented. In addition, a filter using activated carbon is inexpensive, has a small pressure loss of the filter, and is excellent in organic substance carrying ability.

  Preferably, in this semiconductor device manufacturing apparatus, the device is stored in a position where the surface of the cover of the storage device storing the member for the semiconductor device is perpendicular to the direction of the air flow in the atmosphere in the device. Goods should be placed.

  The surface of the member for semiconductor elements is stored in the storage tool in a state parallel to the surface of the cover of the storage tool. If the storage device is disposed at a position where the surface of the lid portion is perpendicular to the direction of the airflow in the atmosphere in the apparatus, the airflow does not directly pass through the surface of the member for the semiconductor element because the airflow once hits the lid portion. For this reason, even if there is LMCS that passes through the chemical filter, it can be made difficult to adsorb to the surface of the member for the semiconductor element.

  Further, it is preferable that the semiconductor element member is a wafer before the gate oxide film is formed, and the storage tool is a carrier for carrying the wafer.

  If this semiconductor element manufacturing apparatus is a gate oxide film forming apparatus, for example, a commonly used vertical diffusion furnace, LMCS is adsorbed to the exposed wafer surface while the wafer is transported to the film forming furnace in the apparatus. It wo n’t let you. For this reason, a preferable gate oxide film free from voids or the like can be obtained.

  Further, in the method for cleaning a semiconductor element member contaminated with LMCS, a spare buffer chamber filled with an inert gas is provided in the semiconductor element manufacturing apparatus, and the semiconductor element member is heat-treated in the spare buffer chamber. It is good.

As the inert gas, for example, He (helium) gas, Ar (argon), or N ₂ (nitrogen) gas can be used. LMCS adsorbed on the surface of the semiconductor element member can be easily desorbed by heat-treating the semiconductor element member at a temperature of about 700 to 800 ° C. in the spare buffer chamber filled with these gases. . Here, the inert gas is used because an oxidizing gas may remain on the surface where the Si—O bond of LMCS is adsorbed and may be bonded more firmly. The heating temperature is set to 700 to 800 ° C. to prevent self diffusion of impurities in the semiconductor element member.

  The semiconductor element member is preferably a wafer before forming a gate oxide film, for example. As a result, LMCS adsorbed on the surface of the wafer can be removed, so that a preferable gate oxide film free from voids can be formed on the wafer surface.

  Further, a vacuum preliminary chamber may be provided in the semiconductor element manufacturing apparatus, and the semiconductor element member may be heat-treated in the vacuum preliminary chamber.

  When a semiconductor element member is heat-treated in a vacuum state, not only LMCS is physically adsorbed on the surface of this member (adsorption by van der Waals force), but also by chemical adsorption (adsorption by chemical bond with the member surface). It is considered that LMCS adsorbed on the metal can also be desorbed.

  Further, in cleaning the semiconductor element member using the semiconductor element manufacturing apparatus having the vacuum preparatory chamber as described above, the semiconductor element member is preferably a wafer before the gate oxide film is formed.

  Further, the above-described reserve buffer chamber or vacuum reserve chamber may be formed in the apparatus using, for example, the film forming furnace itself. In this way, it is not necessary to newly provide a space for the spare buffer chamber or the vacuum spare chamber and the device in the device.

  According to the clean room for manufacturing the semiconductor element of the present invention, since the fluorine-based sealing material is used as the sealing material used in the clean room, the LMCS is degassed in the clean room, and the atmosphere in the clean room is contaminated with LMCS. Never happen.

  Further, in the case where the same silicon sealing material as the conventional one is used as the sealing material, the degassing of LMCS into the clean room can be prevented by covering the surface of the silicon sealing material exposed in the clean room. it can.

  For this reason, in the clean room of this invention, LMCS is not adsorbed on the surface of a semiconductor element member such as a wafer, and a preferable semiconductor element can be manufactured.

  In addition, in a method for manufacturing a semiconductor device including a process for generating LMCS (for example, a photolithography process, a multilayer wiring process), the LMCS material generated in the atmosphere in which the process for generating LMCS is performed is atomized in a high energy state. To do. For example, a high energy field can be formed by corona discharge using an ionizer. High energy states can also be created by plasma and radiation. After removing the particles generated in this way, in an atmosphere isolated from the atmosphere in which the process of generating LMCS is further performed, other processes than this process, for example, formation of a gate oxide film that is adversely affected by LMCS, A capacitor insulating film is formed.

  Thereby, the following process can be performed without adsorbing LMCS also to the member for semiconductor elements that has undergone the process of generating LMCS.

  In addition, in a semiconductor element manufacturing apparatus (film forming apparatus) used for forming a gate oxide film or a capacitor insulating film, a chemical filter using activated carbon is provided at the outside air inlet of the apparatus. As a result, LMCS in the outside air (air in the clean room) is adsorbed by the chemical filter and does not flow into the atmosphere in the apparatus, so that LMCS is not adsorbed by the wafer. Therefore, a uniform film free from voids can be formed on the wafer surface.

  Further, the carrier is arranged at a position where the surface of the lid of the carrier in which the wafer is stored is perpendicular to the direction of the airflow in the atmosphere in the apparatus. As a result, even if there is LMCS that passes through the chemical filter, the airflow does not become laminar with respect to the wafer in the carrier. For this reason, it is considered that LMCS is less likely to be adsorbed on the surface of the wafer. Therefore, when such an apparatus is used, formation of a preferable film can be expected.

  In order to form a gate oxide film on the wafer after LMCS has been removed from the wafer on which LMCS has already been adsorbed, a spare buffer chamber filled with an inert gas is provided in the film forming apparatus. The wafer is heated in the buffer chamber. LMCS is easily detached from the wafer by heat treatment in an inert gas that is not oxidizing. Therefore, after that, if a gate oxide film is formed on this wafer, a preferable film can be obtained.

  Further, a vacuum preliminary chamber may be provided in the film forming apparatus instead of the preliminary buffer chamber. By heat-treating the wafer on which LMCS is adsorbed in a vacuum state, not only LMCS that is physically adsorbed on the wafer surface but also chemically adsorbed LMCS that is firmly bonded to the wafer surface is desorbed from the wafer. It is considered possible. Therefore, a more uniform film can be expected on the surface of the wafer.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Each figure is only schematically shown to the extent that the invention can be understood, and therefore the invention is not limited to the illustrated examples. Further, in the drawing, hatching (hatched lines) showing a cross section is omitted except for a part for easy understanding of the drawing.

<First Embodiment>
As a first embodiment, an example in which a fluorine-based sealing material is used as a sealing material used in a clean room for manufacturing a semiconductor element will be described.

  FIG. 1A is a schematic cross-sectional view for explaining the structure of a clean room. FIG. 1B is a schematic enlarged view of a portion surrounded by a dotted line in the clean room of FIG.

  First, reference is made to FIG. Here, the clean room 11 is assumed to be of the down flow type (vertical laminar flow type). A high-efficiency particulate air-filter (HEPA filter) 15 is installed on the entire ceiling 13a of the clean room space 13, and this filter 15 serves as a blowout port and the entire floor 13b serves as a suction port. Structure. As the filter 15, an ULPA filter (ultra low penetrating air-filter) that can remove particles having a smaller particle diameter may be used.

  The air flow blown into the clean room 11 by the fan 12 flows vertically from the ceiling 13a to the floor surface 13b as indicated by arrows. The floor is a grating floor having a sawtooth structure. For this reason, the airflow which reached the floor surface 13b is discharged | emitted out of the clean room 11 from the exhaust part 16 through the return chamber 14 located under it from the floor surface 13b. A plenum chamber 17 is provided on the opposite side of the HEPA filter 15 from the clean room space 13 side. The plenum chamber 17 is a space for controlling the pressure of the air sent to the clean room space 13 (FIG. 1A).

  In this embodiment, for example, a HEPA filter 15 is interposed between the plenum chamber 17 and the clean room space 13. The clean room space and the plenum chamber 17 must be isolated. For this purpose, it is necessary to completely seal the gap between the HEPA filter 15 and the wall surface of the clean room 11. As this sealing material for isolation, a fluorine-based sealing material 18 is used.

  Here, reference is made to FIG. FIG. 1B is an enlarged view of a portion sealed with a sealing material. With this sealing material 18, the plenum chamber 17 and the clean room space 13 can be isolated by interposing the HEPA filter 15. Therefore, the airflow flowing from the plenum chamber 17 into the clean room space 13 passes through the filter 15 and is preferably dedusted.

  Here, for example, a fluorine-based sealing material made of a polymer or copolymer such as vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, and perfluoromethyl vinyl ether is used.

  As a result, this fluorine-based sealing material has an excellent sealing effect similar to a silicon sealing material that has been used as a conventional sealing material. Further, low molecular siloxane (LMCS) that becomes a pollutant gas of the semiconductor element in manufacturing the semiconductor element is not generated. For this reason, if a semiconductor element is manufactured in such a clean room, LMCS will not be adsorbed to the member for the semiconductor element. For example, when forming a film such as a gate oxide film or a capacitor insulating film on the wafer, there is no void. A uniform film can be obtained.

<Second Embodiment>
As a second embodiment, an example in which the same silicon seal material as that in the conventional case is used in a downflow clean room of the same type as the first embodiment will be described with reference to FIG. FIG. 2 is a schematic enlarged view of a portion of a clean room that is sealed using a sealing material.

  Hereinafter, differences from the first embodiment will be described, and detailed description of points similar to those of the first embodiment will be omitted.

  In this embodiment, the same silicon seal material 19, for example, an oxime condensation type silicon sealant as the conventional one, is used as a seal material for isolating the plenum chamber 17 and the clean room space 13 from each other.

  Here, after the sealing process by the silicon sealing material 19 is completed, the surface 19a of the silicon sealing material 19 exposed in the clean room is painted. The material 20 to be painted must have properties suitable for a clean room for manufacturing semiconductor elements. For this reason, the necessary conditions for the coating material 20 include, for example, electrical insulation, mechanical strength and stability, excellent aging resistance, workability and The adhesiveness is good. As a material satisfying such conditions, for example, polyurethane and epoxy resin are preferable.

  By coating the exposed surface 19a of the silicon sealing material 19, LMCS degassing from the surface 19a can be suppressed. Therefore, since LMCS contamination in the clean room space 13 can be avoided, a preferable semiconductor element can be obtained.

  Further, the exposed surface 19a of the silicon sealing material 19 may be sealed with a tape-shaped member made of the above-described polyurethane or epoxy resin.

<Third Embodiment>
A third embodiment will be described with reference to FIG. 3 as an example of preventing adsorption of LMCS generated in a semiconductor element manufacturing process to the semiconductor element. FIG. 3 is a schematic view of a clean room in which an atmosphere for performing a process that may cause LMCS is isolated.

  In this example, the LMCS material generated in the atmosphere in which the process of generating LMCS is performed is granulated under a high energy state and then removed, and the atmosphere isolated from the atmosphere in which the process of generating LMCS is performed In the process other than this process.

  Of the semiconductor element manufacturing processes, a process that may generate LMCS is, for example, a photolithography process. In this photolithography process, hexamethyldisilazane (HMDS) is often used to improve the adhesion between the resist and the substrate on which the resist is provided. This HMDS is easily decomposed into trimethylsilanol and ammonia gas by hydrolysis. . This trimethylsilanol is a material for LMCS.

  A multilayer wiring process can also be cited as a process for generating LMCS. In this step, organic SOG (spin-on-glass) is used. This organic SOG solution contains a silicon compound, and the silicon compound becomes LMCS by dehydration condensation.

  Here, among the semiconductor manufacturing processes, the processes that are adversely affected by the LMCS are the gate oxide film forming process and the capacitor insulating film forming process.

  For this reason, processes other than this are performed in the atmosphere isolated from the process which may generate LMCS.

  Here, the atmosphere in which the photolithography process and the multilayer wiring process are performed is blocked from the atmosphere in which the gate oxide film forming process and the capacitor insulating film forming process are performed. Specifically, as shown in FIG. 3, the clean room 21 is partitioned by a partition wall 23 or the like and divided into at least two processing chambers, for example, a processing chamber A25 and a processing chamber B27.

  In addition, in the processing chamber A25 for performing a process (photolithographic process and multilayer wiring process) that may generate LMCS, an energy field forming device 29 that forms an energy field for atomizing the material of LMCS and dust generated are removed. Means 31.

  In this embodiment, an ionizer 29 is attached to the wall surface 25x of the processing chamber A25 as an energy field forming device. As a means 31 for removing particles, a local exhaust device 31 for dust removal is newly provided in the processing chamber A25.

As a result, trimethylsilanol generated in the photolithography process, silicon compound used in the multilayer wiring process, and LMCS are converted into SiO ₂ particles by corona discharge of the ionizer, and the particles are locally exhausted to obtain wafers and the like. LMCS can be prevented from adsorbing to the semiconductor element member. Further, after these steps are completed, the semiconductor element member is transferred from the processing chamber A25 to the processing chamber B27 by using the door 33 attached to the partition wall 23 in order to form a gate oxide film or a capacitor insulating film. In some cases, LMCS will not flow out of process chamber A. Therefore, since LMCS does not exist in the processing chamber B in which the film is formed, a uniform and preferable film (a gate oxide film or a capacitor insulating film) free from voids can be formed.

  The energy field forming device 29 may be a device that generates plasma, such as a CVD device or an etching device. Moreover, it is good also as an apparatus which generate | occur | produces radiations, such as a fluorescent X ray, for example, an ion implantation apparatus.

  Further, the means 31 for removing particles may be a HEPA filter.

<Fourth embodiment>
As a fourth embodiment, an example in which LMCS is not present in the atmosphere in an apparatus for manufacturing a semiconductor element will be described with reference to FIG. FIG. 4 is a schematic view for explaining the structure of the film forming apparatus.

  In this embodiment, the semiconductor element manufacturing apparatus 41 installed in the clean room is a film forming apparatus including a film forming furnace 43. The film forming apparatus 41 includes at least a workpiece transport unit 45 and a processing unit 47, and the workpiece transport unit 45 is provided with an outside air inlet 49. The processing unit 47 is provided with a film forming furnace 43.

  Here, a chemical filter 51 using activated carbon is attached to an outside air inlet 49 into the apparatus 41. Thereby, the LMCS floating in the atmosphere in the clean room is not mixed in the film forming apparatus 41, and the adsorption of the LMCS to the workpiece 53 such as a wafer before film formation can be suppressed.

  Further, the lid portion 55a of the storage tool 55 in which the object to be processed 53 is stored in the direction 54 of the air flow sucked into the device 41 from the outside air inlet 49 (indicated by a thin arrow in FIG. 4). The storage device 55 is arranged at a position that is vertical. Here, the workpiece 53 is a wafer before the gate oxide film is formed, and the container 55 is a carrier for carrying the wafer. The carrier 55 has a lid portion 55 a, and a plurality of wafers 53 are set on the carrier 55 so that the surface of the wafer 53 is parallel to the surface of the lid portion 55 a of the carrier 55.

  Reference is now made to FIG. FIG. 5 is a diagram showing the arrangement position of the carrier with respect to the direction of airflow. As shown in FIG. 5B, when the carrier is disposed at a position where the surface of the lid 55a of the carrier 55 is perpendicular to the direction 54 of the airflow that has passed through the chemical filter 51, the outside air inlet 49 Even if there is LMCS that has passed through the chemical filter 51, the airflow first hits the surface of the lid 55a of the carrier 55 directly. For this reason, the air flow does not become a laminar flow with respect to the wafer 53 in the carrier 55, that is, the air flow does not directly pass through the surface of the wafer 53, so that it is considered that the LMCS contamination of the wafer can be further reduced.

  FIG. 5A shows the arrangement position of the conventional carrier 55, and it can be seen that the airflow is laminar with respect to the wafer 53 in this arrangement.

<Fifth embodiment>
As a fifth embodiment, an example of manufacturing a semiconductor element by cleaning a member for a semiconductor element contaminated with LMCS will be described with reference to FIG. FIG. 6 is a schematic view of a film forming apparatus.

  Here, contamination refers to a state where LMCS is adsorbed, and cleaning refers to removal of adsorbed LMCS from the adsorbed portion.

  In this embodiment, the semiconductor element member is a wafer before the gate oxide film is formed.

  Here, a film forming apparatus 61 is taken as an example of a semiconductor element manufacturing apparatus, and a method for cleaning a wafer in this apparatus will be described.

  The workpiece transfer section 63 of the film forming apparatus 61 is provided with a reserve buffer chamber 65 filled with an inert gas 67. In the spare buffer chamber 65, at least a heater 69 and an inert gas introduction means 71 are provided. Further, the atmosphere in the spare buffer chamber 65 is replaced with an inert gas 67 in advance. Then, the wafer 75 stored in the carrier 73 is transferred to the spare buffer chamber 65 and heat-treated at a temperature of 700 to 800 ° C. Thereby, the LMCS adsorbed on the wafer 75 is desorbed, that is, the wafer 75 can be cleaned. The cleaned wafer 75 is transferred to a film formation furnace 79 (oxidation furnace) in the processing unit 77, and then a gate oxide film is formed on the surface.

  As a result, a uniform gate oxide film having no voids can be formed on the surface of the wafer 75.

Further, the inert gas 67 introduced into the spare buffer chamber 65 is preferably, for example, He gas, Ar gas, or N ₂ gas.

  Further, instead of newly providing the spare buffer chamber 65 in the workpiece transfer section 63, the film forming furnace 79 itself may be used as the spare buffer chamber. At this time, after the inert gas 67 is sealed in the film forming furnace 79, heat treatment is performed to desorb LMCS from the surface of the wafer 75. Thereafter, the LMCS is removed from the film forming furnace 79 by exhaust, and then film formation is performed.

  If the film forming furnace 79 itself is used as a spare buffer chamber, there is no need to newly provide a space and equipment for the spare buffer chamber in the semiconductor element manufacturing apparatus 61.

<Sixth Embodiment>
As a sixth embodiment, an example of manufacturing a semiconductor element by cleaning a member for a semiconductor element contaminated with LMCS as in the fifth embodiment will be described with reference to FIG. FIG. 7 is a schematic view of a film forming apparatus.

  Hereinafter, differences from the fifth embodiment will be described, and detailed description of points similar to those of the fifth embodiment will be omitted.

  Here, a vacuum preliminary chamber 81 is provided instead of the preliminary buffer chamber in the workpiece transfer section 63 in the film forming apparatus 61. After the LMCS adsorbed wafer 75 is introduced into the vacuum preliminary chamber 81, the vacuum preliminary chamber 81 is evacuated and heat-treated. Thereby, it is considered that not only the LMCS physically adsorbed on the surface of the wafer 75 but also the LMCS that is firmly adsorbed by the chemical bond with the surface of the wafer 75 can be removed. Thereafter, the inert gas 67 is introduced into the vacuum preliminary chamber 81 to return to normal pressure. Then, the LMCS in the vacuum preliminary chamber 81 is removed by exhausting.

  Since the cleaning effect of the wafer 75 can be further improved by performing the heat treatment in a vacuum state, the film formed on the wafer 75 thereafter is expected to be a more uniform and preferable film.

  Also in this embodiment, the vacuum preliminary chamber may be constituted by the film forming furnace 79 itself. In this case, after the wafer 75 is transferred into the film forming furnace 79, the inside of the furnace 79 is evacuated and heat-treated. Thereafter, an inert gas 67 is introduced into the vacuum preliminary chamber (film formation furnace) 79, and the chamber is returned to normal pressure and exhausted. Thereby, the desorbed LMCS can be removed from the film forming furnace 79. Thereafter, a film is formed on the surface of the wafer 75 using the film forming furnace 79. Thereby, it is not necessary to newly provide a facility for the vacuum preliminary chamber in the film forming apparatus 61.

(A) is the schematic of the clean room with which description of 1st Embodiment is provided, (B) is a schematic principal part enlarged view of a clean room. It is a schematic principal part enlarged view of the clean room with which it uses for description of 2nd Embodiment. It is the schematic where it uses for description of 3rd Embodiment. It is the schematic where it uses for description of 4th Embodiment. (A) is a figure which shows the arrangement position of the carrier with respect to the direction of the conventional airflow, (B) is a figure which shows the arrangement position of the carrier of 4th Embodiment. It is the schematic of the film forming apparatus with which it uses for description of 5th Embodiment. It is the schematic of the film forming apparatus with which it uses for description of 6th Embodiment.

Explanation of symbols

11, 21: Clean room 12: Fan 13: Clean room space 13a: Ceiling 13b: Floor 14: Return chamber
15: HEPA filter, filter 16: Exhaust part 17: Plenum chamber 18: Fluorine-based seal material (seal material)
19: Silicone sealing material 19a: Exposed surface (surface)
20: Coating material 23: Partition 25: Processing chamber A
25x: Wall surface 27: Processing chamber B
29: Energy field generator (ionizer)
31: Means for removing particles (local exhaust system)
33: Door 41: Semiconductor element manufacturing apparatus, film forming apparatus 43, 79: Film forming furnace 45, 63: Object transfer section 47, 77: Processing section 49: Outside air inlet 51: Chemical filter using activated carbon 53: Object to be processed (wafer) 54: Direction of air flow 55: Storage tool (carrier) 55b: Lid 61: Film forming device 65: Preliminary buffer chamber 67: Inert gas 69: Heater 71: Inert gas introduction means 73: Carrier 75: Wafer 81: Vacuum prechamber

Claims (3)

A semiconductor element manufacturing apparatus, wherein a chemical filter using activated carbon is provided at an outside air inlet into an apparatus for manufacturing a semiconductor element. In the semiconductor element manufacturing apparatus according to claim 1,
The storage tool is disposed at a position where the surface of the cover of the storage tool in which the member for the semiconductor element is stored is perpendicular to the direction of the airflow of the atmosphere in the apparatus. A semiconductor device manufacturing apparatus. The semiconductor element manufacturing apparatus according to claim 2,
The member for the semiconductor element is a wafer before forming a gate oxide film,
A semiconductor element manufacturing apparatus, wherein the storage tool is a carrier for transporting the wafer.

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