JP2010141221A - Method of manufacturing silicon substrate with oxide film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a silicon substrate with an oxide film, which has the oxide film of high quality free from tool marks on the mirror finish surface of the silicon substrate, and to provide a thermal processing apparatus for use in manufacturing the silicon substrate with the oxide film. <P>SOLUTION: In the method of manufacturing the silicon substrate with an oxide film, which is subjected to edge chamfering is held by a holder including at least side plates facing each other and a plurality of support rods connected between the side plates and having grooves and is subjected to heat treatment in an oxidizing atmosphere to form the oxide film on the surface. In this method, the silicon substrate is held by only bringing the grooves of support rods provided to the holder into contact with at least one of the outermost peripheral end part and the chamfered part of the silicon substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a silicon substrate with an oxide film having a silicon oxide film having a thickness of 5 μm or more and having substantially no convex portion on a mirror-finished surface.

  A silicon substrate having an oxide film made of silicon oxide is manufactured by a thermal oxidation method or a CVD method and widely used in the semiconductor field. In the semiconductor field, since this oxide film uses the function as an insulating film, the oxide film thickness is comparatively thin, and several hundred angstroms are used.

  On the other hand, silicon substrates with oxide films are also used in optical waveguide devices for optical communication and MEMS (Micro Electro Mechanical System). An oxide film having a thickness of 5 μm or more and sometimes about 20 μm is required.

  In the thermal oxidation method widely used in the semiconductor field, a dense and high-quality oxide film can be formed on both the front and back surfaces of a silicon substrate by a simple operation. In this method, it is known that the progress of oxidation follows the diffusion rule of oxygen atoms and has a relationship in which the square of the oxide film thickness is proportional to the oxidation time. That is, the thicker the oxide film thickness, the greater the time required for oxidation.

  As a fast oxidation method, a method of thermally oxidizing polysilicon (see, for example, Patent Documents 1 and 2) has been reported. The manufacturing method is a method in which a process of “depositing polysilicon on a substrate and oxidizing the polysilicon layer by oxidizing the substrate to oxidize the polysilicon layer” is repeated until a desired oxide film thickness is reached. For this reason, a process becomes complicated and substantial manufacturing efficiency is hard to be improved. In addition, since the surface of the oxide film is rough and a thick oxide film is formed only on one side of the silicon substrate, there is a quality problem that the substrate is likely to warp due to non-uniform thermal stress distribution in the subsequent process.

  As a high-speed oxidation method different from the above, there is a method in which an atmosphere containing water vapor is used as an oxidizing atmosphere in a pressurized container, and the time for producing an oxide film having a thickness of 15 μm at an oxidation temperature of 1000 ° C. is about 150 hours. It is excellent in terms of efficiency.

  When a relatively thin oxide film having a thickness of, for example, about 2 μm is formed by a thermal oxidation method, a method of heating polysilicon, or a thermal oxidation method using water vapor, since the oxidation time is short, the silicon substrate and the jig for holding it The height of the convex portion generated on the contact surface is about 0.05 μm at most, and if this height is reached, there is no problem in forming a circuit for producing a device.

  However, in the case of a silicon substrate with a thick oxide film having an oxide film thickness of 5 μm or more, in the case of the thermal oxidation method, the oxidation time becomes longer in proportion to the square of the film thickness, so the contact time between the silicon substrate and the jig For example, when an oxide film of 5 μm is formed, a convex portion of about 0.4 μm is formed on the mirror-finished surface around the jig, and as a result, there is a problem that the characteristics of the optical waveguide device deteriorate at this portion. Arise.

JP 2002-148462 A JP 2003-192328 A

  The present invention has been made in view of the above problems, and provides a method of manufacturing a silicon substrate with an oxide film having a high-quality oxide film having no jig trace on the mirror-finished surface of the silicon substrate that is to be a pattern forming surface. The purpose is to do.

  In order to solve the above-mentioned problems, the present invention holds a silicon substrate subjected to edge chamfering processing in a holder including at least opposing side plates and a plurality of support bars having grooves connected between the side plates. In the method of manufacturing a silicon substrate with an oxide film, in which an oxide film is formed on the surface by heat treatment in an oxidizing atmosphere, the silicon substrate is held by the groove of the support rod provided in the holder, and the silicon Provided is a method of manufacturing a silicon substrate with an oxide film, which is performed only by bringing at least one of the outermost peripheral end portion and the chamfered portion of the substrate into contact with each other.

  As described above, the silicon substrate is held by bringing the groove of the support rod provided in the holder holding the silicon substrate into contact with only the chamfered portion from the outermost peripheral end of the silicon substrate. Then, the held silicon substrate is heat-treated to form an oxide film on the surface of the silicon substrate, thereby forming an oxide film free from jig marks by the holder that holds the silicon substrate on the mirror-finished surface of the silicon substrate. be able to. Therefore, a silicon substrate with an oxide film having a high-quality oxide film on the mirror-finished surface of the silicon substrate can be obtained, and pattern formation that does not cause deterioration of characteristics when the silicon substrate with an oxide film is used in an optical waveguide device A silicon substrate with an oxide film having a surface can be manufactured.

In this case, the depth h of the groove of the support rod provided in the holder for holding the silicon substrate can be made smaller than the length W of the chamfered portion of the silicon substrate.
Thus, in the present invention, the holder is provided with only the chamfered portion from the outermost peripheral end portion of the silicon substrate by making the depth h of the groove of the support rod smaller than the length W of the chamfered portion of the silicon substrate. The mirror processing part (the main surface of the silicon substrate) is in contact with the groove of the support rod, and can hold the silicon substrate without contacting the holder. Therefore, it is possible to form an oxide film free from jig marks by the holder that holds the silicon substrate on the mirror-finished surface of the silicon substrate.

Further, in this case, the depth h of the groove of the support rod provided in the holder for holding the silicon substrate is larger than the length W of the chamfered portion of the silicon substrate, and the opening angle α of the groove is the chamfered portion of the chamfered portion. It can be made larger than the formed angle (Claim 3).
Thus, in the present invention, the depth h of the groove of the support rod is made larger than the length W of the chamfered portion of the silicon substrate, and the opening angle α of the groove is made larger than the angle formed by the chamfered surface. Only the chamfered portion is in contact with the groove of the support rod provided in the holder from the outermost peripheral end portion of the substrate, and the mirror-finished portion can hold the silicon substrate without being in contact with the holder. Therefore, it is possible to form an oxide film free from jig marks by the holder that holds the silicon substrate on the mirror-finished surface of the silicon substrate.

Furthermore, in this case, the thickness of the oxide film to be formed can be 5 μm or more.
As described above, in the present invention, even when the thickness of the oxide film formed on the silicon substrate is as thick as 5 μm or more, the oxide film is free from jig marks by the holder that holds the silicon substrate on the mirror-finished surface of the silicon substrate. Can be formed. Therefore, according to the conventional method, it is possible to manufacture a silicon substrate with an oxide film that solves the problem of circuit formation that has occurred when producing an optical waveguide device.

In the production method of the present invention, the oxidizing atmosphere may contain water vapor (Claim 5).
Thus, when the oxidizing atmosphere contains water vapor, for example, the time for producing an oxide film having a thickness of 15 μm at an oxidation temperature of 1000 ° C. is about 150 hours, and thus a silicon substrate with an oxide film can be produced efficiently. it can. Therefore, it is possible to manufacture a silicon substrate with an oxide film that solves the problem of circuit formation that has occurred when an optical waveguide device is produced by the conventional method.

  As described above, in the method for manufacturing a silicon substrate with an oxide film according to the present invention, the silicon substrate is held by chamfering from the groove of the support rod provided in the holder for holding the silicon substrate and the outermost peripheral edge of the silicon substrate. This is done by contacting only the processed part. Then, the held silicon substrate is heat-treated to form an oxide film on the surface of the silicon substrate, thereby forming an oxide film without a jig trace of the holder that holds the silicon substrate on the mirror-finished surface of the silicon substrate. be able to. Therefore, when used for an optical waveguide device, a silicon substrate with an oxide film having a high-quality oxide film can be manufactured on the mirror-finished surface of the silicon substrate that serves as a pattern formation surface.

Hereinafter, the present invention will be described more specifically.
As described above, as a problem when manufacturing this thick oxide film, there is a quality of the oxide film surface, and there is a problem that the characteristics deteriorate when used in an optical waveguide device.

The problem of the quality of the oxide film surface is that, for example, when an oxide film having a film thickness of 5 μm is formed, a convex portion having a height of about 0.4 μm is formed on the mirror-finished surface of the silicon substrate. It is considered that the characteristics of the optical waveguide device are deteriorated because the portion propagates to the core layer serving as the functional portion of the optical waveguide device and the shape of the core layer is destroyed.
In addition, when a relatively thin oxide film with an oxide film of about 2 μm is formed, the height of this convex part is about 0.05 μm, and this height causes a problem in circuit formation for manufacturing a device. I knew it was n’t there.

  Accordingly, the present inventors have conceived that a thick oxide film is formed on a silicon substrate without forming convex portions that cause deterioration of the quality of the oxide film surface. The support rod groove provided in the holder to be held is brought into contact with only the chamfered portion from the outermost peripheral end of the silicon substrate, and the held silicon substrate is heat-treated to form an oxide film on the surface of the silicon substrate. In this way, an attempt was made to form a thick oxide film free from jig marks by a holder for holding the silicon substrate on the mirror-finished surface of the silicon substrate.

  As a result, it is possible to form a thick oxide film without a jig trace by a holder that holds the silicon substrate on the mirror-finished surface of the silicon substrate, and when used for an optical waveguide device, the mirror-finishing of the silicon substrate that becomes the pattern formation surface A silicon substrate with an oxide film having a high quality oxide film on the surface could be obtained.

The present invention has been completed based on the above findings, and the present invention will be described in more detail below with reference to the drawings. However, the present invention is not limited to these.
Here, FIG. 1 is a diagram schematically showing a configuration example of the heat treatment apparatus of the present invention.

  The heat treatment apparatus 10 includes a cylindrical cantal heater 4 for heating the silicon substrate 1 and a quartz furnace core tube 3 disposed coaxially inside the heater 4. The heater 4 is divided into three equal parts, and the inside of the core tube 3 can be soaked within ± 1 ° C. Nozzles 7 to 9 are inserted in the tail portion of the core tube 3, and hydrogen, oxygen, and nitrogen as a carrier gas are supplied from the nozzles 7 to 9. Further, an exhaust pipe 6 is provided at the lower part of the core tube 3 opposite to the nozzles 7 to 9, and the core tube 3 can be closed with a cap 5 made of silicon carbide.

  Further, a quartz holder 2 having a side plate 16 facing each other as shown in FIG. 2A and a plurality of support rods 11 having grooves 14 connected between the side plates for holding the silicon substrate 1 is a core. The silicon substrate 1 is held at equal intervals by the holder 2 disposed in the tube 3. Here, FIG. 2 (b) is a cross-sectional view of the principal part showing the silicon substrate held by the support rod provided in the holder in the heat treatment apparatus of the present invention, and FIGS. 3 and 5 show grooves in the heat treatment apparatus of the present invention. It is a figure which shows typically the silicon substrate hold | maintained at the holder from which depth differs. Moreover, the shape of the groove | channel of the support rod with which the holder in the heat processing apparatus of this invention was equipped at this time is shown in FIG. 4 and FIG.

  As shown in FIG. 2, the silicon substrate 1 is held by a plurality of support rods 11 provided in the holder 2, so that the silicon substrate 1 is held in a state where there are few contact points between the silicon substrate 1 and the holder 2. In this case, the number of support bars 11 is not three, but may be two or four or more.

  As shown in FIG. 3, the depth h of the groove 14 of the support rod 11 provided in the holder 2 is made smaller than the length W of the chamfered portion 13, thereby chamfering from the outermost peripheral end portion 12 of the silicon substrate 1. Only the processing portion 13 is in contact with the groove 14 of the support bar 11 provided in the holder 2, and the silicon substrate 1 is held in a state where the mirror processing surface 15 is not in contact with the holder 2. The shape of the groove 14 of the support rod 11 provided in the holder 2 is such that only the chamfered portion 13 contacts the groove 14 of the support rod 11 provided in the holder 2 from the outermost peripheral end portion 12 of the silicon substrate 1. There is no limitation as long as it is present, and the shape shown in FIG. 4 or 6 may be used.

Further, as shown in FIG. 5, the depth h of the groove 14 of the support bar 11 provided in the holder 2 is made larger than the length W of the chamfered portion 13, and the support bar 11 provided in the holder 2 is provided. By making the opening angle α of the groove 14 larger than the angle β formed by the chamfered surface of the substrate chamfered portion, only the chamfered portion 13 from the outermost peripheral end portion 12 of the silicon substrate 1 is formed on the support rod 11 provided in the holder 2. The silicon substrate 1 is held in contact with the groove 14 and the mirror-finished surface 15 not in contact with the holder 2.
In addition, as for the support point of a board | substrate, the support from a lower side is 1 or 2 places, the support from 2 places from a horizontal side, and a total of 3 to 4 places support is desirable.

  As shown in FIG. 3 or FIG. 5, an oxide film without a jig mark by the holder that holds the silicon substrate can be formed on the mirror-finished surface 15 of the silicon substrate by holding and heat-treating the silicon substrate. It can be set as the heat processing apparatus. Therefore, when used in an optical waveguide device, a silicon substrate with an oxide film having a high-quality oxide film can be obtained on the mirror-finished surface of the silicon substrate that is the pattern formation surface, resulting in deterioration of characteristics in the optical waveguide device. A heat treatment apparatus capable of forming a non-oxide film can be obtained.

  Next, although an example of the manufacturing method of the silicon substrate with an oxide film of this invention is demonstrated in detail, referring drawings, this invention is not necessarily limited to these.

  First, the silicon substrate 1 subjected to edge chamfering is set in the groove 14 of the support bar 11 provided in the holder 2 as shown in FIG. 4 or FIG. Then, the holder 2 holding the silicon substrate 1 is inserted into the core tube 3 of the heat treatment apparatus as shown in FIG. 1, and the core tube 3 is closed with the cap 5.

  Next, hydrogen is supplied from the nozzle 7, oxygen is supplied from the nozzle 8, and nitrogen as a carrier gas is supplied from the nozzle 9 to cause a thermal reaction, thereby generating water vapor in the core tube 3 to create an atmosphere containing water vapor. Further, the inside of the furnace core tube 3 is soaked by the heater 4 within a heat treatment temperature ± 1 ° C., and the silicon substrate 1 is heated to form an oxide film having a desired film thickness on the surface of the silicon substrate 1. The method for forming the oxide film may be a thermal oxidation method, and atmospheric pressure oxidation or pressure oxidation can be selected depending on the device used and the convenience of the oxide film thickness to be formed.

  As described above, the method of manufacturing the silicon substrate with an oxide film according to the present invention is chamfered from the groove 14 of the support rod 11 provided in the holder 2 and the outermost peripheral end 12 of the silicon substrate 1 as shown in FIG. The silicon substrate 1 is held by bringing only the processed portion 13 into contact, and the held silicon substrate 1 is heat-treated in an atmosphere containing water vapor to form an oxide film on the surface of the silicon substrate 1. Thereby, an oxide film without a jig trace by the holder holding the silicon substrate can be formed on the mirror-finished surface of the silicon substrate. Therefore, a silicon substrate with an oxide film having a high-quality oxide film on the mirror-finished surface of the silicon substrate can be obtained, and pattern formation that does not cause deterioration of characteristics when the silicon substrate with an oxide film is used in an optical waveguide device A silicon substrate with an oxide film having a surface can be manufactured.

Moreover, in the manufacturing method of the silicon substrate with an oxide film of this invention, the thickness of the oxide film to form can be 5 micrometers or more.
In the present invention, even if the thickness of the oxide film formed on the silicon substrate is as thick as 5 μm or more, an oxide film without a jig trace by the holder that holds the silicon substrate is formed on the mirror-finished surface of the silicon substrate. be able to. Therefore, in the conventional method, when producing an optical waveguide device, the convex portion generated as a jig trace affects the surface of the oxide film, and the oxide film that can solve the problem of circuit formation on the pattern forming surface that has occurred An attached silicon substrate can be manufactured.

Next, the present invention will be described more specifically with reference to Examples and Comparative Examples of the present invention, but the present invention is not limited to these.
Example 1
An oxide film having a thickness of 10 μm was formed on a silicon substrate having a diameter of 100 mm. At this time, a heat treatment apparatus as shown in FIG. 1 was used for heat treatment of the silicon substrate. The procedure for forming an oxide film using this heat treatment apparatus is as follows.

  First, a quartz core tube 3 having a diameter of 350 mm and a length of 2000 mm is set coaxially in a cylindrical cantal heater 4 having a diameter of 400 mm and a length of 2500 mm as shown in FIG. The inside of the furnace core tube 3 is soaked with the heater 4 within 1000 ° C. ± 1 ° C. Three nozzles 7 to 9 having a diameter of 10 mm and a length of 200 mm are inserted into the tail portion of the reactor core tube 3, hydrogen 3.6 L / min, oxygen 2.0 L / min, and nitrogen 25 L / min as a carrier gas from each nozzle. Supply each. And by making it heat-react, water vapor | steam is produced | generated within the core tube 3, and the atmosphere containing water vapor | steam is produced. The silicon substrate 1 is set at equal intervals in the groove 14 of the support rod 11 provided in the quartz holder 2, inserted into the core tube 3, closed with the silicon carbide cap 5, and the heat treatment is performed by setting the oxidation conditions. Then, an oxide film is formed on the surface of the silicon substrate 1.

  At this time, the support rod 11 provided in the holder 2 for holding the silicon substrate 1 has a groove having a shape as shown in FIG. 6, the depth h of the groove is 2.0 mm, and the upper width is 2 mm. 0.0 mm and the groove angle α processed to 30 degrees were used. The silicon substrate used had a diameter of 200 mm, a thickness of 725 μm, an edge chamfering angle of 25 degrees, and a chamfered portion length W of 0.6 mm. This silicon substrate was held by contacting only the chamfered portion from the outermost peripheral portion with a holder having a support rod having a groove shaped as shown in FIG. As oxidation conditions, as high-pressure oxidation conditions, oxidation was performed for 70 hours at a heater set temperature of 1000 ° C. and a pressure in the furnace core tube of 5 atm.

  As a result, an oxide film having an average film thickness of 10.7 μm was grown, and 50 oxide-coated silicon substrates having no jig trace on the mirror-finished surface could be obtained. In addition, as a result of observing the outer peripheral surface of the silicon substrate, a cloudy region was observed as a jig trace in the chamfered portion of the silicon substrate in contact with the groove of the support rod provided in the holder. There was no abnormality and no jig trace was observed.

(Example 2)
In the same procedure as in Example 1, the silicon substrate was heat-treated using a heat treatment apparatus as shown in FIG. 1 to form an oxide film.
At this time, the support rod 11 provided in the holder 2 holding the silicon substrate 1 has a groove having a shape as shown in FIG. 4, the width of the groove is 1.0 mm, and the depth h is 0. What was processed into 5 mm was used. The silicon substrate used had a diameter of 200 mm, a thickness of 725 μm, and the edge chamfered portion length W was 0.6 mm. This silicon substrate was held in contact with only the chamfered portion from the outermost peripheral portion by a holder having a support rod having a groove shaped as shown in FIG. As the oxidation conditions, oxidation was performed for 70 hours at a heater set temperature of 1000 ° C. and a reactor core pressure of 5 atm as high-pressure oxidation conditions as in Example 1.

  As a result, an oxide film having an average film thickness of 10.5 μm was grown, and 50 oxide-coated silicon substrates having no jig traces on the mirror-finished surface could be obtained. In addition, as a result of observing the outer peripheral surface of the silicon substrate, a cloudy region was observed as a jig trace in the chamfered portion of the silicon substrate in contact with the groove of the support rod provided in the holder. There was no abnormality and no jig trace was observed.

(Comparative example)
In the same procedure as in Example 1, the silicon substrate was heat treated using a conventional heat treatment apparatus to form an oxide film.
At this time, the support rod 11 provided in the holder 2 for holding the silicon substrate 1 has a groove having a shape as shown in FIG. 7, the width of the groove is 1.0 mm, and the depth h is 2. What was processed into 0 mm was used. The silicon substrate used had a diameter of 200 mm, a thickness of 725 μm, and the edge chamfered portion length W was 0.6 mm. This silicon substrate was held in contact with not only the chamfered portion but also the mirror-finished surface from the outermost peripheral portion by a holder having a support rod having a groove shaped as shown in FIG. As the oxidation conditions, oxidation was performed for 70 hours at a heater set temperature of 1000 ° C. and a reactor core pressure of 5 atm as high-pressure oxidation conditions as in Example 1.
In addition, since the depth of the groove | channel of the support bar with which the holder of the comparative example was equipped is deeper than the thing of an Example, the thickness A of a holder is made thinner than an Example.

As a result, 50 silicon substrates on which an oxide film having an average film thickness of 10.6 μm was grown could be obtained. However, as a result of observing the vicinity of the outer periphery of the silicon substrate after the silicon substrate was taken out, a cloudiness region having a size of about 2 mm ² was observed on the oxide film on 37 mirror-finished surfaces of the 50 silicon substrates. It was. As a result of measuring the height of this region with HRP (manufactured by KLA Tencor), the height was 2.8 μm. In addition, as a result of elemental analysis by SEM-EDX, silicon and oxygen elements were observed. Thus, it was found that the silicon oxide film was formed preferentially in the vicinity of the contact surface between the silicon substrate and the groove of the support rod provided in the holder, and this was a convex portion.

  From the above, Example 1 and Example 2 were able to form an oxide film without a jig trace by a holder that holds the silicon substrate on the mirror-finished surface of the silicon substrate. Convex portions were formed on the mirror-finished surface of the substrate, and a high-quality oxide film could not be obtained.

  Thus, according to the manufacturing method of the silicon substrate with an oxide film of the present invention, an oxide film without a jig trace by the holder holding the silicon substrate can be formed on the mirror-finished surface of the silicon substrate. Therefore, a silicon substrate with an oxide film having a high-quality oxide film on the mirror-finished surface of the silicon substrate can be obtained, and pattern formation that does not cause deterioration of characteristics when the silicon substrate with an oxide film is used in an optical waveguide device A silicon substrate with an oxide film having a surface can be manufactured.

  Further, the heat treatment apparatus of the present invention can form an oxide film without a jig trace by a holder for holding a silicon substrate on the mirror-finished surface of the silicon substrate, and when used for an optical waveguide device, it becomes a pattern formation surface. A high-quality oxide film can be formed on the mirror-finished surface of the silicon substrate. Therefore, a heat treatment apparatus capable of forming an oxide film that does not cause a problem in circuit formation in the optical waveguide device can be obtained.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

It is a figure which shows typically the structural example of the heat processing apparatus of this invention. (A) It is an example of a holder. (B) It is principal part sectional drawing which shows the silicon substrate hold | maintained by the support rod with which the holder of the heat processing apparatus of this invention was equipped. It is a figure which shows typically the silicon substrate hold | maintained at the groove | channel of the support bar with which the holder was equipped in the heat processing apparatus of this invention. It is a figure which shows the shape of the groove | channel of the support bar with which the holder in the heat processing apparatus of this invention was equipped. It is a figure which shows typically the silicon substrate hold | maintained at the groove | channel of the support bar with which the other holder was equipped in the heat processing apparatus of this invention. It is a figure which shows the shape of the groove | channel of the support bar with which the other holder in the heat processing apparatus of this invention was equipped. It is a figure which shows the shape of the groove | channel of the support bar with which the holder in the heat processing apparatus of the comparative example was equipped.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Silicon substrate, 2 ... Holder, 3 ... Core tube, 4 ... Heater, 5 ... Cap, 6 ... Exhaust pipe, 7 ... Nozzle, 8 ... Nozzle, 9 ... Nozzle, 10 ... Heat treatment apparatus, 11 ... Support rod, 12 ... outermost peripheral edge part, 13 ... chamfered part, 14 ... groove, 15 ... mirror-finished surface, 16 ... side plate.

Claims (5)

  Holding the edge chamfered silicon substrate in a holder having at least side plates facing each other and a plurality of support rods having grooves connected between the side plates, and heat-treating them in an oxidizing atmosphere. In the manufacturing method of the silicon substrate with an oxide film that forms an oxide film on the surface, the silicon substrate is held by the groove of the support rod provided in the holder, the outermost peripheral end portion of the silicon substrate, and the chamfered portion. A method for producing a silicon substrate with an oxide film, characterized in that it is performed only by contacting at least one of them.   2. The oxide film according to claim 1, wherein a depth h of a groove of the support rod provided in the holder for holding the silicon substrate is smaller than a length W of a chamfered portion of the silicon substrate. A method for manufacturing a silicon substrate.   The depth h of the groove of the support rod provided in the holder for holding the silicon substrate is larger than the length W of the chamfered portion of the silicon substrate, and the opening angle α of the groove is chamfered of the silicon substrate. 2. The method of manufacturing a silicon substrate with an oxide film according to claim 1, wherein the angle is larger than an angle formed by a chamfered surface of the processed portion.   4. The method for manufacturing a silicon substrate with an oxide film according to claim 1, wherein a thickness of the oxide film to be formed is 5 μm or more. 5.   The said oxidizing atmosphere contains water vapor | steam, The manufacturing method of the silicon substrate with an oxide film of any one of Claims 1-4 characterized by the above-mentioned.

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