JP2009029656A - METHOD FOR PRODUCING SiC EPITAXIAL FILM AND METHOD FOR FORMING SPACER - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a single crystal SiC epitaxial film which is less in micropipe defects and high in reproducibility and uniformity of film thickness. <P>SOLUTION: In the method for producing the single crystal SiC epitaxial film, by which a single crystal SiC substrate 11 and a carbon raw material supply plate 24 are arranged facing each other through a spacer 23 and a heat treatment is performed in such a state that a metallic Si melt layer 27 is interposed in a space formed between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 to epitaxially grow SiC on the single crystal SiC substrate 11, a spacer, formed by applying a photoresist on the surface of a carbon raw material supply plate 24 and curing the photoresist, is used as the spacer 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an SiC epitaxial film manufacturing method for forming an SiC epitaxial film by epitaxially growing SiC on a single crystal SiC substrate, and a spacer forming method used for forming the SiC epitaxial film.

  SiC (silicon carbide; silicon carbide) is (i) excellent in heat resistance and mechanical strength, (ii) resistant to radiation, and (iii) valence electron control of electrons and holes is easy by addition of impurities. It is expected to be a semiconductor material for next-generation power devices and high-frequency devices because it has such characteristics as (iv) wide forbidden bandwidth.

  However, single crystal SiC has a problem in that crystal defects such as basal plane dislocations, screw dislocations, and micropipes tend to be inherent due to the influence of heat, and crystal grain boundaries due to nucleation are likely to occur.

Therefore, as a technique for suppressing the generation of micropipes, for example, in Patent Documents 1 and 2, heat treatment is performed with an ultrathin metal silicon melt interposed between a single crystal SiC substrate and a carbon raw material supply plate. A liquid phase epitaxial technique (hereinafter referred to as an MSE (Metastable Solvent Epitaxy) method) in which SiC is epitaxially grown by performing is disclosed.
Japanese Patent Laying-Open No. 2005-126248 (Publication date: May 19, 2005) JP 2005-126249 A (Publication date: May 19, 2005)

  However, in the techniques disclosed in Patent Documents 1 and 2, the film thickness of the SiC epitaxial film is likely to vary, and the film thickness reproducibility of the SiC epitaxial film is low. Therefore, the reproducibility of the characteristics of the device using the SiC epitaxial film is low. There was a problem of low.

  That is, in the techniques of Patent Documents 1 and 2, a spacer provided by machining on at least one of the two substrates between the single crystal SiC substrate and the carbon raw material supply plate, or a solid phase on at least one of the two substrates. By disposing spacers bonded by reaction, the distance between the two substrates is controlled, thereby controlling the thickness of the ultrathin metal Si melt interposed between the two substrates. However, in the conventional machining technique, the processing accuracy of the spacer thickness is limited to the order of 30 μm (target thickness ± 15 μm). Further, the minimum value of the spacer thickness (target thickness) that can be processed by the conventional machining technique is about 20 μm, and if it is made thinner than that, the strength of the spacer is insufficient and it is damaged during handling. Even when spacers are bonded by solid phase reaction, the processing accuracy of the spacers is limited to the same extent when the spacers before bonding are prepared by machining.

  For this reason, in the techniques of Patent Documents 1 and 2, the thickness of the ultrathin metal Si melt (the thickness in the direction perpendicular to the substrate surfaces of the single crystal SiC substrate and the carbon raw material supply plate) is likely to vary, Since the reproducibility of the thickness of the thin metal Si melt is low, it is difficult to accurately control the thickness of the SiC epitaxial film with respect to the target value and to make it uniform. Therefore, the film thickness uniformity within the same substrate and the film thickness uniformity between a plurality of substrates (film thickness reproducibility) were low.

  The present invention has been made in view of the above-mentioned problems, and its object is to produce a single crystal SiC epitaxial film with few micropipe defects and high reproducibility and uniformity of film thickness, and this production method. It is in providing the formation method of the spacer used for.

  In order to solve the above-described problem, the spacer forming method of the present invention makes a single crystal SiC substrate and a carbon raw material supply plate face each other with a spacer interposed between the single crystal SiC substrate and the carbon raw material supply plate. A method of forming the spacer used in the process of epitaxially growing SiC on the single-crystal SiC substrate by producing a SiC epitaxial film by performing a heat treatment with a metal Si melt interposed in a space generated in It includes an application step of applying a curable resin serving as the spacer to at least one surface of the single crystal SiC substrate and the carbon raw material supply plate, and a curing step of curing the curable resin. . The curable resin may be a resin that can be cured by a predetermined method. As an example, a thermosetting resin that is cured by heating, a photocurable resin (photosensitive resin) that is cured by irradiation with light, or the like can be used.

  According to said method, the formation precision of the thickness of a spacer can be improved significantly rather than the formation method of the conventional spacer. Therefore, by epitaxially growing SiC using the spacer generated by the above method, the film thickness of the SiC epitaxial film can be controlled with high accuracy and the film thickness uniformity can be improved. Thereby, the SiC epitaxial film excellent in the film thickness uniformity in the same substrate can be generated with a high reproducibility on a plurality of substrates.

  That is, when the control accuracy of the spacer thickness is poor, the distance between the single crystal SiC substrate and the carbon raw material supply plate cannot be made constant, and the thickness of the metal Si melt layer is a region on the single crystal SiC substrate. Therefore, the growth rate of the SiC epitaxial film varies from region to region, and the film thickness uniformity within the same substrate decreases. In addition, when the thickness of the formed spacer is different from the target thickness (design value) (when reproducibility with respect to the target thickness is low), the growth rate of the single crystal SiC epitaxial film is assumed to be the assumed rate (design rate). Since the desired film thickness cannot be obtained, the thickness of the SiC epitaxial film varies from substrate to substrate when the SiC epitaxial film is generated on each of the plurality of substrates. On the other hand, according to the spacer forming method described above, the formation accuracy of the spacer thickness can be significantly improved as compared with the spacer formed by conventional machining. Therefore, compared with the case where a SiC epitaxial film is generated using a spacer formed by conventional machining, the film thickness control accuracy and film thickness uniformity can be improved. In addition, film thickness uniformity between different substrates can be improved.

  In order to solve the above-described problem, the spacer forming method of the present invention makes a single crystal SiC substrate and a carbon raw material supply plate face each other with a spacer interposed between the single crystal SiC substrate and the carbon raw material supply plate. The spacer is formed by epitaxially growing SiC on the single crystal SiC substrate by performing a heat treatment in a state in which a metal Si melt is interposed in a space generated in the method, and forming the SiC epitaxial film, wherein the single crystal SiC is formed. A mask placement step of placing a mask having an opening corresponding to the position and shape of the spacer on at least one surface of the substrate and the carbon raw material supply plate; and on the at least one surface through the opening. A vapor deposition step of vapor-depositing the spacer material. In addition, said vapor deposition method is not specifically limited, For example, PVD methods, such as a vacuum evaporation method, an ion plating method, sputtering method, or CVD method etc. can be used.

  According to said method, the formation precision of the thickness of a spacer can be improved significantly rather than the formation method of the conventional spacer. Therefore, by epitaxially growing SiC using the spacer generated by the above method, the film thickness of the SiC epitaxial film can be controlled with high accuracy and the film thickness uniformity can be improved. Thereby, the SiC epitaxial film excellent in the film thickness uniformity in the same substrate can be generated with a high reproducibility on a plurality of substrates.

  In order to solve the above problems, a method for producing an SiC epitaxial film according to the present invention is a method for producing an SiC epitaxial film, which is formed on at least one surface of a single crystal SiC substrate and a carbon raw material supply plate. A step of forming a spacer using the above method, a step of making the single crystal SiC substrate and the carbon raw material supply plate face each other via the spacer, and between the single crystal SiC substrate and the carbon raw material supply plate And a step of epitaxially growing SiC on the single crystal SiC substrate by performing a heat treatment in a state where a metal Si melt is interposed therebetween.

  According to the above method, since the formation accuracy of the spacer thickness can be greatly improved as compared with the conventional formation method of the spacer, the thickness of the SiC epitaxial film formed on the single crystal SiC substrate is highly accurate. And the uniformity of the thickness of the SiC epitaxial film can be improved. Thereby, the SiC epitaxial film excellent in the film thickness uniformity in the same substrate can be generated with a high reproducibility on a plurality of substrates.

  As described above, the spacer forming method of the present invention includes an application step of applying a curable resin serving as the spacer to the surface of at least one of the single crystal SiC substrate and the carbon raw material supply plate, and this curable property. Curing step of curing the resin. Alternatively, a mask placement step of placing a mask having an opening corresponding to the position and shape of the spacer on the surface of at least one of the single crystal SiC substrate and the carbon raw material supply plate, and through the opening A vapor deposition step of vapor-depositing a material to be the spacer on the at least one surface.

  Therefore, the formation accuracy of the spacer thickness can be greatly improved as compared with the conventional spacer formation method. Therefore, by epitaxially growing SiC using the spacer generated by the above method, the film thickness of the SiC epitaxial film can be controlled with high accuracy and the film thickness uniformity can be improved. Thereby, the SiC epitaxial film excellent in the film thickness uniformity in the same substrate can be generated with a high reproducibility on a plurality of substrates.

  The SiC epitaxial film manufacturing method of the present invention includes a step of forming a spacer on at least one surface of a single crystal SiC substrate and a carbon raw material supply plate using any of the methods described above, and a single crystal SiC substrate. On the single crystal SiC substrate by performing a heat treatment with a metal Si melt interposed between the single crystal SiC substrate and the carbon raw material supply plate. And epitaxially growing SiC.

  Therefore, the film thickness of the SiC epitaxial film can be controlled with high accuracy and the film thickness uniformity can be improved. Thereby, the SiC epitaxial film excellent in the film thickness uniformity in the same substrate can be generated with a high reproducibility on a plurality of substrates.

  An embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing a configuration of a SiC epitaxial substrate 1 according to the present embodiment.

  As shown in FIG. 1, SiC epitaxial substrate 1 includes single crystal SiC substrate 11 and SiC epitaxial film 12 formed on single crystal SiC substrate 11.

  As the single crystal SiC substrate 11, a conventionally known single crystal SiC substrate (for example, a commercially available single crystal SiC substrate) can be used. In this embodiment, a 4H—SiC substrate having an 8 ° off angle in the <11-20> direction is used. Further, in this embodiment, before the SiC epitaxial film 12 is formed, the surface of the single crystal SiC substrate 11 on the side on which the SiC epitaxial film 12 is formed is planarized by a CMP method (chemical mechanical polishing method), and a polishing mark is formed. Etc. were removed.

  The SiC epitaxial film 12 is produced by the MSE method described above.

  FIG. 2 is an explanatory diagram for explaining a production process of the SiC epitaxial film 12. As shown in this figure, the support substrate 22, the single crystal SiC substrate 11, the carbon raw material supply plate 24, the Si substrate 25, and the weight 26 are arranged in an overlapping manner from the bottom to the top in a sealed container (not shown). As shown in FIG. 2, a spacer 23 is formed in advance on the surface of the carbon raw material supply plate 24 by a method described later, and the surface of the carbon raw material supply plate 24 provided with the spacer 23 is formed on the single crystal SiC substrate 11. Arranged to face each other. FIG. 2 shows a state in which heat treatment for epitaxially growing SiC on the single crystal SiC substrate 11 is performed, and a metal Si melt layer is provided between the single crystal SiC substrate 11 and the carbon raw material supply plate 24. 27 is interposed. Thus, in the present embodiment, the distance between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 is defined by the thickness of the spacer 23, thereby controlling the thickness of the metal Si melt layer 27. Yes. Details of the formation method of the spacer 23 and the heat treatment step will be described later.

  The support substrate 22 is a substrate for supporting the single crystal SiC substrate 11, the carbon raw material supply plate 24, the Si substrate 25, and the weight stone 26. Support substrate 22 has a function of preventing adverse effects from the sealed container, and contributes to improving the quality of the SiC epitaxial film epitaxially grown on single crystal SiC substrate 11. The material of the support substrate 22 is not particularly limited, but for example, the same material as the carbon raw material supply plate 24 can be used. In the present embodiment, the support substrate 22 is obtained by polishing the surface of a polycrystalline SiC substrate into a mirror surface and removing oils, oxide films, metals, etc. adhering to the surface by washing or the like.

  As described above, the single crystal SiC substrate 11 is subjected to a planarization process by a CMP method (chemical mechanical polishing method) on a 4H-SiC substrate provided with an off angle of 8 ° in the <11-20> direction. What was done was used.

  The carbon raw material supply plate 24 is for supplying carbon onto the single crystal SiC substrate 11 through the metal Si melt layer 27 during heat treatment. The material of the carbon raw material supply plate 24 is not particularly limited as long as carbon can be supplied onto the single crystal SiC substrate 11. For example, a polycrystalline SiC substrate, a carbon substrate, a porous SiC substrate, and sintered SiC are used. A substrate, an amorphous SiC substrate, or the like can be used. In the present embodiment, like the support substrate 22, the surface of the polycrystalline SiC substrate is polished into a mirror surface, and oils, oxide films, metals, etc. adhering to the surface are removed by washing or the like.

  The spacer 23 defines the distance between the single crystal SiC substrate 11 and the carbon raw material supply plate 24, thereby the thickness of the metal Si melt layer 27 (perpendicular to the substrate surfaces of the single crystal SiC substrate 11 and the carbon raw material supply plate 24. Thickness in a specific direction). Thereby, the thickness of the growth film (single crystal SiC epitaxial film) can be made uniform over the entire growth surface. A method for forming the spacer 23 will be described later.

  Next, a heat treatment process for forming SiC epitaxial film 12 will be described.

First, after the inside of the closed container is depressurized to a pressure of 1 × 10 ⁻² Pa or less (after evacuation), this pressure state is maintained and the temperature in the container is set to a predetermined growth temperature (in this embodiment). 1800 ° C.) at a rate of 20 ° C./min. And after reaching a predetermined growth temperature, this temperature state was maintained for 10 minutes. After 10 minutes, the temperature in the container was lowered to 500 ° C. at 20 ° C./min. It cooled naturally from 500 degreeC to room temperature. As a result, a SiC epitaxial film (4H—SiC epitaxial film) 12 was formed on the single crystal SiC substrate 11.

  In the present embodiment, the time for maintaining the growth temperature is 10 minutes. However, the time is not limited to this, and may be set as appropriate according to the required film thickness of the SiC epitaxial film 12. The predetermined growth temperature is not particularly limited as long as it is 1420 ° C. or higher, which is the melting point of Si, but 1500 ° C. or higher and 2300 ° C. or lower in order to grow the SiC epitaxial film efficiently and stably. It is preferable to be within the range.

  Next, a method for forming the spacer 23 will be described. In the present embodiment, the spacer 23 is formed by the following two methods (Example 1 and Example 2). In addition, when the SiC epitaxial film 12 is formed using the spacer 23 formed by these two methods, the SiC epitaxial film 12 is formed using a spacer (Comparative Example 1) formed by conventional machining. The film thickness of the SiC epitaxial film after film formation and the growth rate of the SiC epitaxial film were compared with each other. In any of Example 1, Example 2, and Comparative Example 1, spacers were formed with a target thickness of 20 μm. This is because the conventional machining method has low spacer formation accuracy, so the lower limit of the target thickness for forming a spacer having the minimum strength required for use in the SiC epitaxial film formation process is This is because it is about 20 μm. In addition, according to the method of Example 1 and Example 2, even when it is a case where the film thickness thinner than 20 micrometers (for example, about several micrometers) is made into a target thickness, it is necessary for using it at the formation process of a SiC epitaxial film. A spacer having a sufficient strength can be formed.

Example 1
Photoresist (photo-curing resin) was applied to the entire surface of the carbon raw material supply plate 24 facing the single crystal SiC substrate 11 with a spin coater, and prebaking was performed by heating to a temperature of 120 ° C. for 5 minutes. A commercially available product was used as the photoresist.

  Then, until the photoresist film thickness reaches a desired film thickness (in this embodiment, the photoresist film thickness is 50 μm so that the spacer 23 finally formed has a thickness of 20 μm). The application and the pre-bake treatment were repeated.

  Thereafter, the position of the spacers 23 formed on the photoresist (two peripheral portions of the carbon raw material supply plate 24 facing the single crystal SiC substrate 11) and the shape (in this embodiment, on the substrate surface of the carbon raw material supply plate 24) A photomask having an opening corresponding to a square having a parallel cross section of 1 mm × 1 mm is formed, and an exposed portion of the photoresist (a portion exposed through the opening) is exposed through the photomask. The portion that becomes the spacer 23 was cured. Then, after rinsing the carbon raw material supply plate 24 to remove unnecessary portions of the photoresist, the photoresist remaining on the carbon raw material supply plate 24 is carbonized by heating to 800 ° C. in an inert gas atmosphere. Thus, a spacer 23 was formed. Thereby, square spacers 23 having a cross section of 1 mm × 1 mm parallel to the substrate surface of the carbon raw material supply plate 24 were formed at two locations.

(Example 2)
The position of the spacer 23 to be formed on the carbon raw material supply plate 24 (two peripheral edge portions of the carbon raw material supply plate 24 facing the single crystal SiC substrate 11) and the shape (in this embodiment, the substrate of the carbon raw material supply plate 24) A mask having an opening corresponding to a square having a cross section parallel to the surface of 1 mm × 1 mm was attached.

  Thereafter, the carbon raw material supply plate 24 with the mask attached is placed on the sample holder of the vacuum vapor deposition apparatus, and vacuum deposition is performed using carbon as a vapor deposition source, thereby exposing the exposed portion of the carbon raw material supply plate 24 (exposed through the opening). The spacers 23 were formed by continuously performing the process of depositing carbon on the portion where the film was formed until a desired film thickness (in this embodiment, 20 μm) was obtained.

(Comparative Example 1)
Spacers 23 were formed by machining at predetermined positions on the carbon raw material supply plate 24 (two peripheral portions of the carbon raw material supply plate 24 facing the single crystal SiC substrate 11). When the spacer is formed by machining, the target thickness is limited to 20 μm. If the target thickness is further reduced, the mechanical strength of the spacer is insufficient at the time of handling, resulting in a failure. For this reason, in Comparative Example 1, the spacer was formed with a target thickness of 20 μm.

  Table 1 shows the dimensional accuracy (processing accuracy of spacer height) of spacers formed by the methods of Example 1, Example 2, and Comparative Example 1, and conditions other than the spacers using these spacers (film formation method, temperature). Uniformity of SiC epitaxial film (uniformity of film thickness on the same substrate and multiple different substrates) when a SiC epitaxial film is formed on a single crystal SiC substrate by the MSE method with the same control method and film formation time) (Thickness uniformity between batches)). As a method for measuring the film thickness, the peripheral portion of the substrate on which the SiC epitaxial film is formed by the above-described methods is cut, and the sample is prepared so that the substrate surface has a square shape of 20 mm × 20 mm as shown in FIG. The film thickness of the SiC epitaxial film was measured by cutting out and observing the cross section of the predetermined location in each sample with a microscope. In addition, the said predetermined location was made into 5 points | pieces about each sample produced and cut out by each method as shown in FIG.

  Regarding the film thickness uniformity on the same substrate, the maximum value with respect to the average value of the maximum value max and the minimum value min when the maximum value in the measurement result of 5 points is max and the minimum value is min, and the minimum value Evaluation was made based on the ratio Ra of min. That is, the ratio Ra is expressed by the following formula.

Ra = {max− (max + min) / 2} / {(max + min) / 2}
= {(Max + min) / 2-min} / {(max + min) / 2}
= (Max-min) / (max + min)
As for film thickness uniformity between different substrates, the maximum value of the average value of the film thickness measurement results on different substrates formed by the same forming method is Amax, and the minimum value is Amin. Evaluation was made based on the ratio Rb of the maximum value Amax and the minimum value Amin to the average value of the maximum value Amax and the minimum value Amin. That is, the ratio Rb is expressed by the following equation.

Rb = {Amax− (Amax + Amin) / 2} / {(Amax + Amin) / 2}
= {(Amax + Amin) / 2-Amin} / {(Amax + Amin) / 2}
= (Amax-Amin) / (Amax + Amin)

  As shown in this table, in the method of Comparative Example 1, the dimensional accuracy of the spacer was 20.8 μm ± 15.2 μm, whereas in the method of Example 1, 20.5 μm ± 3.8 μm, Example 2 In this method, the spacer could be formed with a dimensional accuracy of 20.3 μm ± 1.5 μm. In addition, about the formation precision of the spacer, it computed based on the thickness measurement result of the two spacers formed on the same board | substrate.

  As shown in Table 1, in the method of Comparative Example 1, the film thickness uniformity (the value of Ra above) in the same substrate of the SiC epitaxial film is 33.3%, and between different substrates (between batches). The film thickness uniformity (the value of Rb above) was 30.8%. On the other hand, in the method of Example 1, the film thickness uniformity within the same substrate of the SiC epitaxial film is 9.6%, and the film thickness uniformity between a plurality of different substrates (between batches) is 5.2%. Met. Moreover, in the method of Example 1, the film thickness uniformity within the same substrate of the SiC epitaxial film was 5.7%, and the film thickness uniformity between different substrates (between batches) was 4.9%. .

  As described above, in Example 1 of the present embodiment, the spacer 23 is formed by applying a curable resin to a predetermined position on the carbon raw material supply plate 24 and curing the curable resin. In Example 2 of the present embodiment, the spacer 23 is formed by vapor-depositing a material to be the spacer 23 at a predetermined position on the carbon raw material supply plate 24. A metal is formed in a space generated between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 by making the single crystal SiC substrate 11 and the carbon raw material supply plate 24 face each other through the spacer 23 formed by any method. A heat treatment is performed with the Si melt interposed, and SiC is epitaxially grown on the single crystal SiC substrate 11 to generate a SiC epitaxial film 12.

  By forming the spacers 23 by the above method, the formation accuracy of the spacers 23 can be improved to the order of several μm (target thickness ± within several μm). Thereby, the film thickness of SiC epitaxial film 12 formed on single crystal SiC substrate 11 can be controlled with high accuracy and the film thickness uniformity can be improved. That is, the film thickness uniformity within the same substrate and the film thickness uniformity between different substrates can be improved.

  That is, when the control accuracy of the thickness of the spacer 23 is poor, the distance between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 cannot be made constant, and the thickness of the metal Si melt layer 27 is single crystal SiC. Since it differs for every area | region on the board | substrate 11, the growth rate of a SiC epitaxial film changes for every area | region, and the film thickness uniformity in the same board | substrate will fall. Further, when the thickness of the formed spacer 23 is different from the target thickness, the growth rate of the SiC epitaxial film deviates from the assumed rate, and a desired film thickness cannot be obtained. Therefore, when the reproducibility of the thickness of the spacer 23 is low, the film thickness uniformity (film thickness reproducibility) between the substrates decreases.

  On the other hand, according to the spacer forming method of the present embodiment (Example 1 and Example 2), the control accuracy of the spacer thickness by conventional machining is limited to the order of 30 μm (target thickness ± 15 μm). However, the formation accuracy of the spacer 23 can be improved to the order of several μm (target thickness ± within several μm). Therefore, it is possible to improve the film thickness uniformity within the same substrate and the film thickness uniformity among a plurality of different substrates, compared to the case where a SiC epitaxial film is generated using a spacer by conventional machining.

  The formation method of the spacer 23 is not limited to the method of the first and second embodiments, and any method can be used as long as the thickness of the spacer 23 can be controlled more accurately than the conventional machining method. An effect substantially similar to that of the form can be obtained. It is more preferable that the control accuracy of the thickness of the spacer 23 be within a target thickness of ± 4 μm.

  For example, the spacer 23 may be formed by applying a thermosetting resin to a predetermined position on the carbon raw material supply plate 24 and curing the thermosetting resin by heating. In this case, a thermosetting resin may be applied through a mask corresponding to the shape of the spacer 23 to be formed, and only the portion that becomes the spacer 23 may be cured. Moreover, you may heat only the part used as the spacer 23 in a thermosetting resin. Further, after the thermosetting resin is cured, the spacer 23 may be formed by removing unnecessary portions by etching or the like.

  Further, the material to be the spacer 23 may be deposited at a predetermined position on the carbon raw material supply plate 24 by another deposition method different from the vacuum deposition. As the vapor deposition method, in addition to the vacuum vapor deposition method, for example, other PVD methods such as an ion plating method and a sputtering method, or a CVD method can be used. Moreover, the material to be vapor-deposited is not particularly limited as long as it has an appropriate strength for keeping the interval between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 at a predetermined interval.

  In the present embodiment, the spacers 23 are formed on the carbon raw material supply plate 24, but the present invention is not limited to this, and the spacers 23 may be provided on the single crystal SiC substrate 11.

  In addition, the arrangement position and the number of the spacers 23 are not limited to the above-described examples, and the positions and the numbers can appropriately define the interval between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 over the entire substrate surface. I just need it. However, in order to keep the distance between the single crystal SiC substrate 11 and the carbon material supply plate 24 appropriately over the entire surface of the substrate, it is preferable to arrange at least two locations.

Further, the shape of the spacer 23 is not limited to the above-described example, and may be any shape as long as the distance between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 can be appropriately defined over the entire substrate surface. For example, the cross-sectional shape parallel to the carbon raw material supply plate 24 may be a rectangular shape, a polygonal shape, an elliptical shape, a circular shape, or the like. In order to keep the distance between the single crystal SiC substrate 11 and the carbon raw material supply plate 24 appropriately over the entire substrate surface, the cross-sectional area of the cross section of the spacer 23 parallel to the carbon raw material supply plate 24 is 0.5 mm in diameter. It is preferable to make it larger than the area of the circle (0.196 mm ² ). Moreover, when making circular shape, it is preferable to make a diameter into 0.5 mm or more, and when making cross-sectional shape into a rectangular shape, it is preferable to make 1 side into 0.5 mm or more.

  The thickness of the spacer 23 is not particularly limited as long as the carbon supplied from the carbon raw material supply plate 24 can be transported to the surface of the single crystal SiC substrate 11 through the metal Si melt layer 27. Although not intended, in order to appropriately transport the carbon dissolved from the carbon raw material supply plate 24 to the surface of the single crystal SiC substrate, the thickness of the spacer 23 is preferably 1 μm or more and 50 μm or less.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The present invention can be applied to a method for manufacturing a SiC epitaxial film in which a SiC epitaxial film is formed on a single crystal SiC substrate. Further, the SiC epitaxial film manufactured by the method of the present invention has few crystal defects and the like, and has high reproducibility and uniformity of film thickness. Therefore, it can be suitably used for light emitting diodes, various semiconductor diodes, and electronic devices.

It is sectional drawing of the single-crystal SiC epitaxial substrate provided with the single-crystal SiC epitaxial film concerning one Embodiment of this invention. It is explanatory drawing which shows the manufacturing method of the single crystal SiC epitaxial film concerning one Embodiment of this invention. It is a top view which shows the film thickness measurement position of a SiC epitaxial film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Single crystal SiC epitaxial substrate 11 Single crystal SiC substrate 12 Active layer (2nd single crystal SiC epitaxial film)
22 Support substrate 23 Spacer 24 Carbon raw material supply plate 25 Si substrate 26 Weight stone 27 Metal Si melt layer

Claims (3)

The single crystal SiC substrate and the carbon raw material supply plate are opposed to each other through a spacer, and the heat treatment is performed in a state where the metal Si melt is interposed in the space formed between the single crystal SiC substrate and the carbon raw material supply plate. The method of forming the spacer used in the step of epitaxially growing SiC on the single crystal SiC substrate to manufacture a SiC epitaxial film,
It includes an application step of applying a curable resin serving as the spacer to the surface of at least one of the single crystal SiC substrate and the carbon raw material supply plate, and a curing step of curing the curable resin. Spacer formation method. The single crystal SiC substrate and the carbon raw material supply plate are opposed to each other through a spacer, and the heat treatment is performed in a state where the metal Si melt is interposed in the space formed between the single crystal SiC substrate and the carbon raw material supply plate. The method of forming the spacer used in the step of epitaxially growing SiC on the single crystal SiC substrate to manufacture a SiC epitaxial film,
A mask placement step of placing a mask having an opening corresponding to the position and shape of the spacer on the surface of at least one of the single crystal SiC substrate and the carbon raw material supply plate; and at least the above through the opening. A method of forming a spacer, comprising: a vapor deposition step of vapor-depositing a material to be the spacer on one surface. A method for producing a single crystal SiC epitaxial film, comprising:
Forming a spacer on the surface of at least one of the single-crystal SiC substrate and the carbon raw material supply plate using the method according to claim 1 or 2,
The step of facing the single crystal SiC substrate and the carbon raw material supply plate through the spacer;
And a step of epitaxially growing SiC on the single crystal SiC substrate by performing a heat treatment in a state where a metal Si melt is interposed between the single crystal SiC substrate and the carbon raw material supply plate. Manufacturing method of SiC epitaxial film.

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