JP2006216586A - Substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve yield of substrate processing by improving the efficiency of preprocessing of a substrate, preventing contamination of the substrate in a process of shifting from the preprocessing to the substrate processing and enabling forming a high-quality film. <P>SOLUTION: This apparatus is provided with a processing chamber 71 for housing the substrate 36 and forming a desired film on the substrate, a gas feeding means 93 for feeding a desired gas to the processing chamber, and a gas discharging means 77 for discharging the gas from the processing chamber. This apparatus is configured so that the gas feeding means supplies a reducing gas prior to film forming processing to perform preprocessing of removing a natural oxide film, and the feeding flow rate of the reducing gas may be larger than the feeding flow rate of the film forming gas. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substrate processing apparatus that performs processing such as generation of a thin film such as an oxide film, diffusion of impurities, etching, and annealing on a substrate such as a silicon wafer.

  As a substrate processing apparatus for processing a thin film such as an oxide film, diffusion of impurities, etching, annealing, etc. on a substrate such as a silicon wafer (hereinafter referred to as a wafer), a single wafer type substrate that processes each wafer one by one There are processing apparatuses or batch-type substrate processing apparatuses that process a predetermined number of sheets at a time. Furthermore, there is a vertical substrate processing apparatus including a vertical processing furnace as one of batch type substrate processing apparatuses.

  In substrate processing that requires a high-quality film, removal of substances that adversely affect film quality such as natural oxide film and impurities on the wafer surface is performed (hereinafter referred to as pre-processing) before the film forming process.

  With reference to FIG. 6, the pretreatment performed in the vertical processing furnace of the conventional substrate processing apparatus and the conventional substrate processing apparatus will be described.

  The processing furnace 1 includes a reaction tube 3 inside a heater 2, and the reaction tube 3 is erected in an airtight manner on a manifold 5 via a sealing material 4 such as an O-ring. The manifold 5 is airtightly installed in the load lock chamber 7 concentrically with the reaction tube 3 through a sealing material 6, and a furnace 7 concentrically with the manifold 5 is provided on the top plate 7 a of the load lock chamber 7 as an airtight chamber. A mouth 8 is formed. The reaction tube 3 and the manifold 5 define a processing chamber 9.

  A boat 10 as a substrate holder holds wafers 11 in a multi-stage in a horizontal posture. The boat 10 is supported by a seal cap 13 via a boat shaft 12, and a boat rotation mechanism 14 is provided on the lower surface of the seal cap 13. The boat shaft 12 is rotated by the boat rotation mechanism 14. The boat 10 is inserted into the processing furnace 1 by a boat elevator (not shown), and the seal cap 13 closes the processing furnace 1 in an airtight manner via a sealing material 15.

  A gas exhaust pipe 16 and a gas supply pipe 17 are communicated with the manifold 5. The gas exhaust pipe 16 is connected to an exhaust device (not shown), and the gas supply pipe 17 is connected to a gas nozzle 18 and a gas supply source (not shown). The gas nozzle 18 extends upward along the inner wall of the reaction tube 3 and opens to the upper part of the processing chamber 9 so that gas is supplied and diffused from the upper part of the processing chamber 9.

  Next, the operation of the vertical processing furnace will be described.

  When the boat 10 holding unprocessed wafers 11 is loaded into the processing furnace 1 and the processing furnace 1 is hermetically closed by the seal cap 13, the natural oxide film and impurities on the surface of the wafer 11 are removed. Pre-processing is performed. The processing chamber 9 is exhausted by the exhaust device, and a reducing gas for removing the natural oxide film is supplied from the gas nozzle 18 to the processing chamber 9, and the processing chamber 9 is maintained at a predetermined pressure. The processing chamber 9 and the wafer 11 are heated to a predetermined temperature by the heater 2.

  As the reducing gas, for example, H2 gas is used. The supply flow rate per unit time of the reducing gas was set to the same amount as the flow rate per unit time of the film formation process gas supplied during the subsequent film formation process.

  The natural oxide film on the surface of the wafer 11 is reduced by the pretreatment, and impurities are exhausted from the gas exhaust pipe 16 together with exhaust gas. After the pre-process for a predetermined time, the reducing gas is replaced with a film forming process gas, and the process proceeds from the pre-process to the film forming process.

  After the film forming process or the subsequent required process is completed, an inert gas is supplied to the processing chamber 9 and the gas is purged to make the processing chamber 9 have the same pressure as the load lock chamber 7. After the pressure equalization, the boat 10 is pulled out of the processing furnace 1, and after cooling, the processed wafer 11 is discharged by a transfer means (not shown).

  In the conventional pretreatment, the interfacial oxygen concentration of the wafer 11 is still high, and the reaction product adhering to the gas downstream portion of the processing chamber 9, for example, the vacuum seal member around the seal cap 13, the gas exhaust pipe 16, etc. Contaminants from organic substances such as sealing members may be diffused back toward the upper side of the processing chamber 9, contaminating the wafer 11 before film formation, and increasing the contamination level at the interface between the substrate and the growth film. There was sex.

  In view of such circumstances, the present invention enhances the effect of substrate pretreatment, prevents contamination of the substrate in the process of transition from pretreatment to substrate processing, enables high-quality film formation, and yields in substrate processing. It is intended to improve.

  The present invention includes a processing chamber that accommodates a substrate and generates a desired film on the substrate, a gas supply unit that supplies a desired gas to the processing chamber, and a gas discharge unit that exhausts the processing chamber. The substrate is configured to supply a reducing gas by the gas supply means before the film forming process to perform a pretreatment for removing the natural oxide film, and to make the supply flow rate of the reducing gas larger than the supply flow rate of the film forming process gas. This relates to a processing apparatus.

  According to the present invention, a processing chamber for accommodating a substrate and generating a desired film on the substrate, a gas supply means for supplying a desired gas to the processing chamber, and a gas discharging means for exhausting the processing chamber, And a pretreatment for removing a natural oxide film by supplying a reducing gas by the gas supply means before the film forming process, and the supply flow rate of the reducing gas is made larger than the supply flow rate of the film forming process gas. Therefore, while improving the pretreatment effect, it prevents the contamination of the substrate during the transition from the pretreatment to the substrate processing, enables the production of a high quality film, and improves the substrate processing yield. Demonstrate.

  1 to 4, a vertical substrate processing apparatus which is an example of a substrate processing apparatus in which the present invention is implemented will be described.

  A cassette stage 20 as a storage container exchanging section is provided on the front side inside the housing 19, and exchanges a cassette 21 as a substrate storage container with an external transfer device (not shown). A cassette elevator 22 as lifting means is provided on the rear side of the cassette stage 20, and a cassette transport machine 23 as a transport means is attached to the cassette elevator 22. On the rear side of the cassette elevator 22, a cassette shelf 24 is provided as a storage means for the cassette 21, and the cassette shelf 24 is provided on a slide stage 25 so as to be able to traverse.

  Above the cassette shelf 24, a buffer cassette shelf 26 as a means for storing the cassette 21 is provided. Further, a clean unit 27 is provided on the rear side of the buffer cassette shelf 26, and the clean unit 27 is configured to circulate clean air inside the housing 19.

  A processing furnace 28 is provided above the rear portion of the casing 19, and a load lock chamber 29 as an airtight chamber is connected to the lower side of the processing furnace 28, and the cassette is disposed in front of the load lock chamber 29. A substrate transfer port 30 is formed at a position facing the shelf 24, and the substrate transfer port 30 is closed by a load lock door 31 as a partitioning means.

  A boat elevator 32 (described later) is provided on the rear side of the processing furnace 28 as an elevating means. The boat elevator 32 extends from the elevating shaft 33 that passes through the load lock chamber 29 in an airtight manner and the elevating shaft 33. An elevating substrate 34 is provided. A boat 35 serving as a substrate holder is accommodated in the load lock chamber 29. The boat 35 holds wafers 36 in a multi-stage in a horizontal posture, is lifted and lowered by the boat elevator 32, and is loaded into the processing furnace 28. It can be withdrawn.

  An exhaust line 37 and a gas supply line 38 are communicated with the load lock chamber 29, the inside of the load lock chamber 29 is evacuated, and an inert gas such as nitrogen gas can be supplied for the purpose of gas purging or the like. .

  A transfer elevator (not shown) is provided between the load lock chamber 29 and the cassette shelf 24, and a wafer transfer device 39 as a substrate transfer means is attached to the transfer elevator. .

  A furnace port 41 is formed in the top plate 40 of the load lock chamber 29, and the processing furnace 28 is erected on the top plate 40 concentrically with the furnace port 41. The furnace port 41 can be airtightly closed by a furnace port gate valve 43 through a seal ring 42 and can be airtightly closed by an elevator seat 44 described later.

  The boat elevator 32 will be described with reference to FIGS.

  A lower substrate 45 is provided on the outer surface of the load lock chamber 29, an upper substrate 47 is provided on the upper end of a guide shaft 46 erected on the lower substrate 45, and is passed between the lower substrate 45 and the upper substrate 47. A ball screw 48 is rotatably provided. The ball screw 48 is rotated by an elevating motor 49 provided on the upper substrate 47. An elevator base 50 is fitted to the guide shaft 46 so as to be movable up and down, and the elevator base 50 is screwed into the ball screw 48.

  The hollow lifting shaft 33 is vertically suspended from the lifting platform 50, and constitutes the boat elevator 32 together with the lower substrate 45, the guide shaft 46, the upper substrate 47, the ball screw 48, the lifting motor 49, and the lifting platform 50. The support part for the elevator 50 and the elevator shaft 33 is airtight. The elevating shaft 33 penetrates the top plate 40 of the load lock chamber 29 and reaches near the bottom surface of the load lock chamber 29. The penetrating portion of the elevating shaft 33 has a sufficient margin so that it does not come into contact with the elevating movement of the elevating shaft 33, and the elevating shaft 33 is between the load lock chamber 29 and the elevating platform 50. A bellows 51 is provided in an airtight manner to cover the protruding portion of the bellows 51. The bellows 51 has a sufficient expansion / contraction amount that can correspond to the lifting / lowering amount of the lifting platform 50. The bellows 51 is sufficiently large so that it does not come into contact with the expansion and contraction.

  The elevating board 34 is fixed horizontally to the lower end of the elevating shaft 33. A drive unit cover 52 is attached to the lower surface of the elevating board 34 to form a drive unit storage case 53. A sealing material 54 such as an O-ring is provided at the joint between the elevating substrate 34 and the drive unit cover 52, and the inside of the drive unit storage case 53 has an airtight structure with respect to the load lock chamber 29.

  A boat rotation motor 55 is provided on the lower surface of the elevating board 34, an output shaft 56 is provided concentrically with the furnace port 41, and a boat cradle 57 is provided at the upper end of the output shaft 56. Is provided. The bearing portion 58 of the output shaft 56 is hermetically sealed by a magnetic fluid seal or the like, and a bearing cooler 59 is fitted on the bearing portion 58.

  The elevating seat 44 is airtightly attached to the upper surface of the elevating substrate 34 via a seal material 60, the elevating seat 44 is concentric with the output shaft 56, and the output shaft 56 passes through the elevating seat 44. is doing.

  A power supply cable 61 is led from the upper end of the elevating shaft 33 through the hollow portion of the elevating shaft 33 to the boat rotation motor 55 and connected thereto. Further, cooling passages 62 and 63 are formed in the bearing cooler 59 and the lift seat 44, respectively, and cooling water pipes 64 and 65 are connected to the cooling passages 62 and 63, respectively.

  The cooling water pipe 64 is guided through the hollow portion of the elevating shaft 33 and connected to the bearing cooler 59, and the cooling water pipe 65 is guided through the hollow portion of the elevating shaft 33 and further the elevating substrate 34. And is connected to the elevating seat 44. The portion of the cooling water pipe 65 penetrating the elevating board 34 is hermetically sealed by a pipe joint 66.

  The processing furnace 28 will be described with reference to FIG.

  The processing furnace 28 includes a heater 67 and a reaction tube 68 provided inside the heater 67. The reaction tube 68 is heat resistant material such as quartz and does not contaminate the wafer 36, and the lower end is opened. It has a celestial tube shape. The reaction tube 68 is erected in an airtight manner on the manifold 70 through a sealing material 69 such as an O-ring. A processing chamber 71 is defined by the reaction tube 68 and the manifold 70.

  The manifold 70 is erected on the top plate 40 of the load lock chamber 29 through a sealing material 72 so as to be concentric with the furnace port 41.

  A gas exhaust pipe 73 and a gas supply pipe 74 are communicated with the manifold 70. The exhaust pipe 73 is provided with an exhaust valve 75 and an exhaust device 76 such as a vacuum pump. The gas exhaust pipe 73, the exhaust valve 75 and the exhaust device 76 constitute a gas exhaust means 77.

  The exhaust valve 75 and the exhaust device 76 are connected to a control device 78, and the exhaust processing is controlled by the control device 78.

  A gas nozzle 79 is provided at an end of the gas supply pipe 74, the gas nozzle 79 extends along the inner wall of the reaction pipe 68 and above the processing chamber 71, and an upper end is opened above the processing chamber 71. Yes. The gas supply pipe 74 is provided with an air supply valve 80, and a first branch pipe 81, a second branch pipe 82, and a third branch pipe 83 are connected to the upstream end of the gas supply pipe 74. Has been.

  The first branch pipe 81 is connected to a first gas supply source 84. The first branch pipe 81 is provided with a first valve 85 and a first mass flow controller (MFC) 86 for adjusting the gas flow rate. Yes. Similarly, the second branch pipe 82 is connected to a second gas supply source 87, the second branch pipe 82 is provided with a second valve 88 and a second mass flow controller 89, and the third branch pipe 83 is a third gas pipe. A third valve 91 and a third mass flow controller 92 are provided in the third branch pipe 83 connected to the gas supply source 90. The gas nozzle 79, gas supply pipe 74, first branch pipe 81, second branch pipe 82, third branch pipe 83, first valve 85, second valve 88, third valve 91, first mass flow controller 86, second The mass flow controller 89, the third mass flow controller 92, the first gas supply source 84, the second gas supply source 87 and the third gas supply source 90 constitute a gas supply means 93.

  The first mass flow controller 86, the second mass flow controller 89, and the third mass flow controller 92 are connected to the control device 78, and the gas flow rate is independently controlled by the control device 78. The first valve 85, the second valve 88, and the third valve 91 are connected to the control device 78, and the control device 78 controls the opening and closing independently of each other. Further, the air supply valve 80 is connected to the control device 78, and the control device 78 controls the opening and closing thereof so that the gas supply amount to the processing chamber 71 is controlled.

  For example, in the case of the resistance heating method, the heater 67 is constituted by a heater wire and a heat insulating member. The heater 67 is connected to the control device 78, and the temperature of the processing chamber 71 is controlled by the control device 78. . The boat rotation motor 55 is driven and controlled by the controller 78, and the rotation of the boat 35 is controlled.

  Hereinafter, the operation of the substrate processing apparatus will be described.

  The cassette 21 transported from an external transport device (not shown) is placed on the cassette stage 20, and the posture of the cassette 21 is changed by 90 ° on the cassette stage 20, and the cassette elevator 22 is moved up and down, traversed, and The cassette is transported to the cassette shelf 24 or the buffer cassette shelf 26 in cooperation with the advance / retreat operation of the cassette transporter 23.

  The wafer transfer device 39 transfers the wafer 36 from the cassette shelf 24 to the boat 35. In preparation for transferring the wafer 36, the boat 35 is lowered into the load lock chamber 29 by the boat elevator 32, the processing furnace 28 is closed by the furnace port gate valve 43, and the load lock chamber 29 is further closed. A purge gas such as nitrogen gas is introduced into the interior of the gas supply line 38. After the load lock chamber 29 is restored to atmospheric pressure, the load lock door 31 is opened.

  The slide stage 25 moves the cassette shelf 24 horizontally and positions the cassette 21 to be transferred so as to face the wafer transfer device 39. The wafer transfer device 39 transfers the wafer 36 from the cassette 21 to the boat 35 by cooperation of lifting and rotating operations. The wafers 36 are transferred to several cassettes 21, and after the transfer of a predetermined number of wafers to the boat 35 is completed, the load lock door 31 is closed, and the exhaust line 37 The atmosphere in the load lock chamber 29 is exhausted, and the load lock chamber 29 is evacuated. After the evacuation is completed, gas is introduced from the gas supply line 38, and the inside of the load lock chamber 29 is made to have the same pressure as the inside of the processing chamber 71. By making the inside of the load lock chamber 29 a vacuum atmosphere or an inert gas atmosphere such as nitrogen gas, natural generation of the wafer 36 is suppressed.

  When the furnace port gate valve 43 is opened, the lift motor 49 is driven, and the ball screw 48 is rotated to raise the drive unit storage case 53 via the lift 50 and the lift shaft 33. As the drive unit storage case 53 is raised, the boat 35 is raised through the lift seat 44 and is loaded into the processing chamber 71, and the lift seat 44 closes the processing furnace 28.

  Next, pre-processing is performed prior to film formation.

  The exhaust valve 75 is opened, and the atmosphere of the processing chamber 71 is exhausted through the gas exhaust pipe 73 by the exhaust device 76, and the processing chamber 71 is depressurized to a predetermined pressure (0.1 Pa to 1000 Pa). The processing chamber 71 is heated by the heater 67, and the wafer 36 is heated to 600 ° C. to 900 ° C. The pressure and temperature settings of the processing chamber 71 are selected depending on the processing content.

  H2 gas as a reducing gas is supplied from the first gas supply source 84. The flow rate of H2 gas is adjusted by the first mass flow controller 86. The flow rate per minute of the H2 gas is set to be higher (up to 50 L / min) than the flow rate per minute (5 L / min) of the film forming process gas (the mixed gas of the film forming raw material gas and the dilution gas).

  By opening the first valve 85, the H2 gas flows into the gas supply pipe 74, and further by opening the air supply valve 80, the H2 gas passes from the upper portion of the processing chamber 71 through the gas nozzle 79 to the wafer 36. Supplied to the surface.

  Compared with the case where the flow rate of H2 gas per minute is the same as the flow rate of film formation processing gas per minute, the reduction reaction on the surface of the wafer 36 proceeds more and more oxide films are removed, The reaction product is exhausted from the gas exhaust pipe 73 together with H2 gas. Further, contaminants generated or staying in the gas downstream portion of the processing chamber 71, for example, around the gas exhaust pipe 73 or around the furnace port 41, are diffused back to the upper side of the processing chamber 71, and the wafer 36 is formed. Contamination is suppressed and the pretreatment effect is enhanced.

  When the preprocessing is started, the boat rotation motor 55 is driven and the boat 35 is rotated.

  Cooling water is circulated through the cooling flow path 62 and the cooling flow path 63 via the cooling water pipe 64 and the cooling water pipe 65, the bearing portion 58 is cooled via the bearing cooler 59, and the lifting seat 44. Cool down. Further, when the processing furnace 28 is closed, the seal ring 42 is cooled by cooling water via the lift seat 44.

  By cooling the seal ring 42, the reaction between the material on the surface of the seal ring 42 and the gas supplied to the processing chamber 71 is suppressed, the corrosion of the seal ring 42 is prevented, and the corrosion of the seal ring 42 is caused. Contaminants can be prevented from diffusing into the processing chamber 71.

  The boat rotation motor 55, the guide shaft 46, the power supply cable 61, and the like are isolated from the atmosphere of the load lock chamber 29, and contamination of the wafer 36 by these members is suppressed.

  After the oxide film removal process is continued for a predetermined time (5 minutes to 120 minutes), the flow rate of H2 gas per minute is adjusted by the first mass flow controller 86 and gradually or continuously decreased. The flow rate per minute (5 L / min) of the film processing gas can be approached.

  For example, SiH 4 gas or Si 2 H 6 gas is supplied from the second gas supply source 87 as a film forming source gas, and the flow rate of the film forming source gas is adjusted by the second mass flow controller 89. A dilution gas (inert gas such as nitrogen gas) is supplied from the third gas supply source 90, and the flow rate of the dilution gas is adjusted by the third mass flow controller 92. The ratio between the flow rate of the film forming raw material gas and the flow rate of the dilution gas is set to a predetermined value.

  When the flow rate of H2 gas per minute reaches 5 L / min, the first valve 85 is closed and the supply of H2 gas is stopped. The second valve 88 and the third valve 91 are opened, and a mixed gas of a film forming raw material gas and a dilution gas flows into the gas supply pipe 74 as a film forming process gas, and passes through the gas nozzle 79 to the upper part of the processing chamber 71. Supplied from The flow rate per minute of the film forming process gas is set to 5 L / min.

  When shifting from the pretreatment to the film formation process after the replacement of the H2 gas and the film formation process gas, the flow rate per minute of the H2 gas is decreased stepwise or continuously, By approaching the flow rate per minute, the occurrence of pressure fluctuations in the processing chamber 71 is suppressed, and contaminants generated or staying in the gas downstream portion of the processing chamber 71 are diffused back to the upper side of the processing chamber 71. The wafer 36 is prevented from being contaminated. In the epitaxial process, the diluting gas for the film forming process is H2, and the process shifts from the reduction process to the film forming process with H2 kept flowing. In the transition process, the total gas flow rate is kept constant or substantially constant and switched.

  The processing chamber 71 is heated and maintained at a predetermined pressure and a predetermined temperature, and a film forming process is performed. When the film forming process for the wafer 36 is completed, an inert gas such as nitrogen gas is supplied to the processing chamber 71, the processing chamber 71 is purged, and the pressure in the load lock chamber 29 is equalized. Further, the rotation of the boat 35 is stopped, the lifting motor 49 is driven, and the boat 35 is lowered.

  The boat 35 is drawn into the load lock chamber 29 in a nitrogen gas atmosphere, and the furnace gate valve 43 is closed. After the wafer 36 heated by processing such as film formation is cooled to a required temperature (for example, 100 ° C.), the load lock door 31 is opened. By making the load lock chamber 29 a nitrogen gas atmosphere, natural generation of the processed wafer 36 is suppressed.

  The processed wafer 36 is transferred from the boat 35 to the cassette 21 of the cassette shelf 24 by the wafer transfer device 39, and the cassette 21 loaded with the processed wafer 36 is further loaded by the cassette transfer device 23. The cassette 21 is transported to the cassette stage 20 and is unloaded by an external transport device (not shown).

  The operations of the cassette transfer device 23, the wafer transfer device 39, and the like are controlled by transfer control means 94.

  FIG. 5 shows a comparison of the oxygen concentration at the interface between the wafer and the growth film when the flow rate per minute of H2 gas supplied as a reducing gas during pretreatment is 5 L / min and 20 L / min. In the above vertical substrate processing apparatus, the processing chamber 71 is heated to 750 ° C., pre-treated for 30 minutes with the processing chamber 71 in an H 2 atmosphere, and then the temperature of the processing chamber 71 is adjusted to 600 ° C. Si was epitaxially grown on the wafer 36, and the interfacial oxygen concentration was measured by secondary ion mass spectrometry. The film forming treatment gas was a mixed gas of a film forming raw material gas (SiH4 gas) and a dilution gas (nitrogen gas), and the flow rate per minute was 5 L / min.

When the flow rate of H2 gas per minute was 5 L / min, 1.9E12 oxygen atoms per cm ² were detected from the wafer / film interface. Also, when the flow rate of H2 gas per minute is 20 L / min, the interfacial oxygen concentration is lower than when the flow rate of H2 gas is 5 L / min, which is measured by secondary ion mass spectrometry. It was impossible. When the flow rate of H2 gas per minute was 20 L / min, the flow rate of H2 gas was gradually decreased when moving from the pretreatment to the film forming process so as to approach 5 L / min.

When the temperature of the processing chamber 71 was heated to 800 ° C. and the flow rate of H 2 gas was 1 L / min, it was 2E13 atoms / cm ² .

  In the embodiment of the present invention, the flow rate per unit time of the reducing gas is increased by making the flow rate per unit time of the reducing gas supplied during the pretreatment larger than the flow rate per unit time of the film forming process gas. Compared to the case where the flow rate of deposition process gas is the same as the flow rate per unit time, more oxide film is removed from the wafer to enhance the pretreatment effect and the substrate in the process of transition from pretreatment to substrate treatment. Contamination can be prevented, a high quality film can be formed, and the yield of substrate processing can be improved.

  The heater 67 may be a lamp heating system, and the present invention can be implemented in a single wafer type substrate processing apparatus.

1 is a perspective view of a substrate processing apparatus in which the present invention is implemented. It is sectional drawing which shows the processing furnace and load lock chamber in embodiment of this invention, and is a figure which shows the retreat state of a boat. It is sectional drawing which shows the processing furnace and load lock chamber in embodiment of this invention, and is a figure which shows the charging condition of a boat. It is sectional drawing of the processing furnace in embodiment of this invention. It is a figure which shows the oxygen concentration of the interface of a reducing gas flow volume and a growth film. It is sectional drawing of the processing furnace of the conventional substrate processing apparatus.

Explanation of symbols

36 Wafer 68 Reaction tube 70 Manifold 71 Processing chamber 73 Gas exhaust tube 74 Gas supply tube 75 Exhaust valve 76 Exhaust device 77 Gas exhaust means 78 Control device 79 Gas nozzle 80 Supply valve 81 First branch tube 82 Second branch tube 83 3rd Branch pipe 84 First gas supply source 85 First valve 86 First mass flow controller 87 Second gas supply source 88 Second valve 89 Second mass flow controller 90 Third gas supply source 91 Third valve 92 Third mass flow controller 93 Gas supply means

Claims (1)

  A process chamber for accommodating a substrate and generating a desired film on the substrate, a gas supply means for supplying a desired gas to the process chamber, and a gas discharge means for exhausting the process chamber are provided to form a film. Before the process, the reducing gas is supplied by the gas supply means to perform a pretreatment for removing the natural oxide film, and the supply flow rate of the reducing gas is made larger than the supply flow rate of the film forming process gas. Substrate processing equipment.

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