JP2011219293A - Single crystal production apparatus and method for producing silicon carbide single crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single crystal production apparatus which prevents the occurrence of structural defects such as cracks in a seed crystal and produces a high quality single crystal, in the production of the single crystal by a sublimation recrystallization method, and to provide a method for producing a silicon carbide single crystal using the single crystal production apparatus.SOLUTION: The single crystal production apparatus 1 includes a seed crystal 10 serving as a base for the growth of a single crystal, and a crucible 100 which holds a raw material for sublimation used for the growth of the single crystal. The crucible 100 has an opening part 111 and includes a reaction vessel 110 for holding the raw material 20 for sublimation, a lid body 120 attached to the opening part 111, and a holding part 130 for holding the seed crystal 10. The holding part 130 has a contact face 133 brought into contact with only a portion on the opposite side (lower surface 10B) from the lid body 120 side (upper surface 10A) of the seed crystal 10. The thickness of the seed crystal 10 is ≥1 mm. The seed crystal 10 is closely brought into contact with the lid body 120. The whole surface of the seed crystal 10 is exposed.

Description

  The present invention relates to a single crystal manufacturing apparatus provided with a crucible containing a sublimation raw material used for the growth of the single crystal using the single crystal for growth as a seed crystal, and a silicon carbide single crystal using the single crystal manufacturing apparatus It relates to the manufacturing method.

  Conventionally, a method of manufacturing a silicon carbide single crystal (hereinafter, appropriately abbreviated as a single crystal) by a sublimation recrystallization method using a crucible containing a seed crystal formed of silicon carbide and a sublimation raw material is known. ing. In this method, the seed crystal is fixed to the crucible lid (seed crystal base) through an adhesive layer such as a resin material. On the seed crystal fixed to the lid, the gas obtained by sublimating the sublimation raw material is recrystallized (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-225710 (page 7, FIG. 1)

  However, the conventional method described above has the following problems. That is, when the temperature inside the crucible becomes high, the resin material constituting the adhesive layer contracts, and thus a crack may occur at the interface between the seed crystal and the adhesive layer. Moreover, even if the resin material between the seed crystal and the lid is made uniform, the seed crystal is sublimated from the contact surface between the seed crystal and the adhesive layer, and a structural defect may occur. Further, the resin material component constituting the adhesive layer may be mixed into the single crystal as an impurity.

  As described above, in the method of Patent Document 1, the quality of the single crystal may be deteriorated due to the occurrence of structural defects such as cracks or the incorporation of impurities.

  Therefore, the present invention provides a single crystal manufacturing apparatus and a single crystal manufacturing apparatus capable of manufacturing a high quality single crystal by preventing the occurrence of structural defects such as cracks in the seed crystal in the production of a single crystal by a sublimation recrystallization method. It aims at providing the manufacturing method of the silicon carbide single crystal using this.

  In order to solve the above-described problems, the present invention has the following features. First, a first feature of the present invention is that a crucible containing a sublimation raw material (sublimation raw material 20) used for the growth of the single crystal as a seed crystal (seed crystal 10) as a base for the growth of the single crystal ( A single crystal production apparatus (single crystal production apparatus 1) including a crucible 100), wherein the crucible has an opening (opening 111) and a reaction vessel (reaction vessel 110) containing the raw material for sublimation; A lid body (lid body 120) attached to the opening, and a holding portion (holding portion 130) for holding the seed crystal, the holding portion with respect to the lid body side (upper surface 10A) of the seed crystal It has a contact portion (contact surface 133, contact surface 143) in contact with only a part of the opposite side (lower surface 10B), the seed crystal has a thickness of 1 mm or more, and the seed crystal and the lid body have a gap The entire surface of the seed crystal is exposed. The gist of the Rukoto.

  According to this feature, the holding portion has a contact portion that contacts only a part of the seed crystal opposite to the lid side, and the entire surface of the seed crystal is exposed. According to this, the seed crystal can be held in the reaction vessel without using an adhesive layer. For this reason, even if the inside of the crucible reaches a high temperature, the occurrence of cracks due to the shrinkage of the resin material or the like constituting the adhesive layer can be reliably prevented. In addition, it is not necessary to uniformly apply the resin material constituting the adhesive layer uniformly, and it is possible to prevent the components of the resin material from being mixed into the single crystal as impurities.

  Further, the thickness of the seed crystal is 1 mm or more, and the seed crystal and the lid are in contact with each other without a gap. By setting the thickness of the seed crystal to 1 mm or more, warping of the seed crystal can be suppressed. For this reason, the seed crystal and the lid are in contact with each other without generating a gap between the seed crystal and the lid. This can prevent the occurrence of structural defects due to the gap between the seed crystal and the lid.

  Further, the contact portion is in contact with only a part of the seed crystal opposite to the lid side. That is, the contact portion does not contact the peripheral surface (side surface) of the seed crystal. According to this, it is not necessary to process the seed crystal, and for example, it is not necessary to process the peripheral surface of the seed crystal into a circular shape or the like. For this reason, the process of processing the seed crystal becomes unnecessary, and the manufacturing cost of the single crystal can be reduced.

  In this way, in the production of a single crystal by the sublimation recrystallization method, it is possible to suppress the occurrence of structural defects such as cracks and the deterioration of the quality of the single crystal due to the incorporation of impurities. Moreover, the manufacturing cost of the single crystal can be reduced.

  Another feature of the present invention is that the seed crystal has a first surface portion (upper surface 10A) provided on the lid body side and a second surface portion (lower surface 10B) provided on the sublimation raw material side opposite to the first surface portion. ), The warp of the seed crystal is warped toward the lid body, and the holding portion is in contact with the end portion of the second surface portion.

  Another feature of the present invention is that the second surface portion protrudes toward the sublimation raw material side.

  Another feature of the present invention is that the seed crystal is formed by cutting an end surface of a single crystal, and the end surface is the second surface portion.

  Another feature of the present invention is that the seed crystal has a side surface portion connecting the first surface portion and the second surface portion, and the seed crystal is formed by cutting an end surface of a single crystal, The gist is that the end surface is the side surface portion.

  Another feature of the present invention is that the holding portion is configured by a guide member that is disposed inside the crucible and regulates a growth range of the silicon carbide single crystal grown based on the seed crystal. And

  Another feature of the present invention is summarized in that the contact portion is in contact with the second surface portion of the seed crystal.

  Other features of the present invention include a preparation step of preparing a seed crystal made of silicon carbide, a raw material placement step of placing a sublimation raw material in a crucible, a seed crystal placement step of placing the seed crystal in the crucible, A method of manufacturing a silicon carbide single crystal comprising a single crystal growth step of growing a silicon carbide single crystal on the seed crystal by sublimating a raw material for sublimation, wherein the crucible has an opening and is used for the sublimation A seed vessel having a reaction vessel containing raw materials, a lid attached to the opening, and a holding portion for holding the seed crystal is prepared, and the seed crystal has a thickness of 1 mm or more in the preparation step The whole surface of the seed crystal is exposed, and in the seed crystal arranging step, the holding portion has a contact portion that contacts only a part of the seed crystal opposite to the lid body side, The seed crystal whose surface is exposed is referred to as the seed crystal. And gist placing without leaving a gap between Kifutatai.

  Another feature of the present invention is that in the seed crystal arranging step, the seed crystal is arranged so that the warp of the seed crystal is warped toward the lid, and the contact portion is an end of the seed crystal. It is a summary.

  According to the features of the present invention, in the production of a single crystal by the sublimation recrystallization method, the occurrence of structural defects such as cracks in the seed crystal can be prevented, and a single crystal production apparatus capable of producing a high-quality single crystal A method for producing a silicon carbide single crystal using a production apparatus can be provided.

FIG. 1 is a cross-sectional view showing a single crystal manufacturing apparatus 1 (a state before growth of a single crystal) according to the present embodiment. FIG. 2 is a perspective view showing the holding unit 130 according to the present embodiment. FIG. 3A is a cross-sectional view showing a part of the holding unit 130 according to the present embodiment. FIG. 3B is a plan view showing the holding unit 130 according to the present embodiment. FIG. 4 is a flowchart showing a method for manufacturing a silicon carbide single crystal according to the present embodiment. FIG. 5A is a cross-sectional view showing a part of the holding unit 140 according to the modified example. FIG. 5B is a plan view showing the holding unit 140 according to the modified example (No. 1). FIG. 6 is a plan view showing the holding unit 140 according to the modified example (No. 2). FIG. 7 is a plan view showing the holding unit 140 according to the modification (part 3).

  Next, an embodiment of a single crystal manufacturing apparatus according to the present invention will be described with reference to the drawings. Specifically, (1) configuration of single crystal manufacturing apparatus, (2) configuration of holding part, (3) manufacturing method of silicon carbide single crystal, (4) action / effect, (5) modification example, (6) Other embodiments will be described.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. It should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings may be contained.

(1) Configuration of Single Crystal Manufacturing Apparatus First, a single crystal manufacturing apparatus 1 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a single crystal manufacturing apparatus 1 (a state before growth of a single crystal) according to the present embodiment. In the present embodiment, the single crystal is a silicon carbide single crystal.

  As shown in FIG. 1, a single crystal manufacturing apparatus 1 includes a seed crystal that is a base for growing a single crystal, and a cylindrical graphite crucible (hereinafter referred to as a crucible 100). The crucible 100 accommodates a sublimation raw material 20 used for the growth of a single crystal using a growth single crystal having a predetermined crystal orientation as a seed crystal 10. The sublimation raw material 20 is a silicon carbide raw material containing silicon carbide.

  The crucible 100 includes a reaction vessel 110, a lid 120, and a holding unit 130. The reaction vessel 110 has an opening 111 and accommodates the sublimation raw material 20. The lid 120 is attached to the opening 111. The space formed by the reaction vessel 110 and the lid 120 is filled with an inert gas such as argon to form an inert atmosphere. The holding unit 130 holds the seed crystal 10 in a state where the seed crystal 10 is in contact with the lid 120. Details of the holding unit 130 will be described later.

  Here, the seed crystal 10 is disposed on the inner surface 121 of the lid 120 at a position substantially opposite to the sublimation raw material 20. The seed crystal 10 is formed by cutting an end face of a single crystal (for example, an end face of a single crystal that is no longer necessary after growth).

  Specifically, the seed crystal 10 is formed in a circular shape (see FIG. 2) in the plan view of the seed crystal 10. The seed crystal 10 has an upper surface 10A (first surface portion), a lower surface 10B (second surface portion), and a side surface 10C. The upper surface 10A is provided on the lid 120 side. The upper surface 10A is formed in a planar shape. The upper surface 10A and the lid 120 are in contact with each other without a gap. On the other hand, the lower surface 10B faces the upper surface 10A and is provided on the sublimation raw material 20 side. The lower surface 10B protrudes toward the sublimation raw material 20 side. In the present embodiment, the shape of the lower surface 10B protrudes in a hemispherical shape toward the sublimation raw material 20 side in a cross-sectional view of the single crystal manufacturing apparatus. The side surface 10C connects the upper surface 10A and the lower surface 10B.

  The entire surface of the seed crystal 10 is exposed. Therefore, the surface of the seed crystal 10 is not covered with an adhesive layer for fixing the seed crystal. The surface of the seed crystal 10 is not covered with a protective layer that protects the seed crystal 10. Moreover, the thickness of the seed crystal 10 is 1 mm or more. Thereby, the warp of the seed crystal 10 can be suppressed.

  Such a crucible 100 is covered with a heat insulating material (not shown). The crucible 100 is fixed inside the quartz tube 60 via the support rod 50. On the outer periphery of the quartz tube 60, a dielectric heating coil 70 for heating the crucible 100 (that is, the reaction vessel 110 and the lid 120) is provided. When the inside of the crucible 100 becomes a predetermined temperature condition and pressure condition, the sublimation raw material 20 sublimates and recrystallizes on the seed crystal 10 to form a silicon carbide single crystal. Note that the pressure and temperature inside the reaction vessel 110 can be changed by the heating temperature of the dielectric heating coil 70.

(2) Configuration of Holding Unit Next, the configuration of the holding unit 130 described above will be described with reference to FIGS. FIG. 2 is a perspective view showing the holding unit 130 according to the present embodiment. FIG. 3A is a cross-sectional view showing a part of the holding unit 130 according to the present embodiment. FIG. 3B is a plan view showing the holding unit 130 according to the present embodiment.

  As shown in FIG. 1, the holding unit 130 is disposed inside the crucible 100 (that is, the reaction vessel 110). In the present embodiment, the holding unit 130 is configured by a guide member that regulates the growth range of a single crystal that grows based on the seed crystal 10.

  The holding unit 130 covers the space above the sublimation raw material 20 and blocks the sublimation raw material 20 and the inner surface 121 of the lid 120. The holding unit 130 includes a guiding unit 131 that guides the sublimation gas of the sublimation raw material 20 toward the surface of the seed crystal 10.

  Specifically, as shown in FIGS. 2 and 3, a circular opening 132 is formed in the guide portion 131. The opening 132 has an upper end opening 132A and a lower end opening 132B.

  The upper end opening 132A opens near the lid 120. On the other hand, the lower end opening 132B opens on the sublimation raw material 20 side and is supported by the inner wall of the reaction vessel 110. Such a holding part 130 (induction part 131) has a tapered shape that gradually expands from the seed crystal 10 side toward the sublimation raw material 20 side.

  Here, the upper end opening 132A is provided with a contact surface 133 (contact portion) that contacts only a part of the opposite side (lower surface 10B) of the seed crystal 10 with respect to the lid 120 side (upper surface 10A). Here, contacting with only part of the opposite side (lower surface 10B) means contacting with a part that does not inhibit recrystallization of silicon carbide.

  The contact surface 133 is preferably in contact with the lower surface 10B of the seed crystal 10 at the surface. The diameter of the contact surface 133 is smaller than the diameter of the surface of the seed crystal 10 on the sublimation raw material 20 side. That is, the diameter of the upper end opening 132A is smaller than the diameter of the lower surface 10B of the seed crystal 10. The lower surface 10 </ b> B of the seed crystal 10 is preferably in contact with the entire contact surface 133.

(3) Manufacturing method of silicon carbide single crystal The manufacturing method of the silicon carbide single crystal which concerns on embodiment of this invention is demonstrated, referring FIG.1 and FIG.4. FIG. 4 is a flowchart showing a method for manufacturing a silicon carbide single crystal according to the present embodiment. As shown in FIG. 4, the method for manufacturing a silicon carbide single crystal includes steps S1 to S4.

(3.1) Preparation step S1
Step S1 is a preparation step for preparing seed crystal 10 made of silicon carbide. The grown silicon carbide single crystal is cut out to prepare a seed crystal 10. The silicon carbide single crystal is cut so that the thickness of seed crystal 10 is 1 mm or more. It is preferable to cut out the seed crystal so that the surface of the prepared seed crystal 10 includes the surface (end face) of the grown silicon carbide single crystal. Since the surface of the grown silicon carbide single crystal is a growth surface, it is not necessary to process the surface. The surface of the silicon carbide single crystal is made to be the lower surface 10B or the side surface 10C. More preferably, lower surface 10B and side surface 10C are the surface of a silicon carbide single crystal. The entire surface of the seed crystal 10 is left exposed. That is, no adhesive layer or protective layer is applied to the seed crystal 10.

(3.2) Raw material placement step S2
Step S <b> 2 is a raw material arranging step of arranging the sublimation raw material 20 in the crucible 100. Specifically, as shown in FIG. 1, the sublimation raw material 20 is placed in a reaction vessel 110. Sublimation raw material 20 is a silicon carbide raw material containing silicon carbide. The sublimation raw material 20 may be prepared by any manufacturing method. For example, silicon carbide produced by chemical vapor deposition (CVD) may be used as the sublimation raw material 20, or a silicon carbide precursor is produced from a silicon-containing raw material and a carbon-containing raw material, and the produced silicon carbide precursor is produced. Silicon carbide obtained by firing the body may be used as the sublimation raw material 20.

(3.3) Seed crystal arrangement step S3
Step S <b> 3 is a seed crystal placement step for placing the seed crystal 10 in the crucible 100. As shown in FIG. 4, the seed crystal placement step S3 includes a holding portion attachment step S31, a seed crystal placement step S32, and a lid attachment step S33.

  In holding part attachment process S31, the holding part 130 mentioned above is attached to the inner wall of the reaction vessel 110.

  In the seed crystal placement step S <b> 32, the seed crystal 10 is placed on the contact surface 133 of the holding unit 130. The seed crystal 10 is arranged such that the holding unit 130 has a contact portion that contacts only a part of the seed crystal 10 opposite to the lid 120 side. That is, the seed crystal 10 is placed so that the lower surface 10B faces the sublimation raw material 20. Since the seed crystal 10 is not fixed with an adhesive, the entire surface of the seed crystal 10 remains exposed.

  The thickness of the seed crystal 10 is 1 mm or more. For this reason, the warp of the seed crystal 10 is suppressed. Thus, the seed crystal 10 and the lid 120 are in contact with each other without generating a gap between the upper surface 10A and the lid 120. That is, the seed crystal 10 whose entire surface is exposed is arranged without leaving a gap between the seed crystal 10 and the lid 120. Therefore, it is possible to prevent the occurrence of structural defects due to the gap between the seed crystal 10 and the lid 120.

  When the seed crystal 10 protrudes in a hemispherical shape, the hemispherical lower surface 10 </ b> B is inserted into the upper end opening 132 </ b> A of the holding unit 130. Thus, the seed crystal 10 is held by the holding unit 130 in a state where the hemispherical lower surface 10B is inserted into the upper end opening 132A of the holding unit 130. For this reason, the seed crystal 10 is stably held without generating a gap between the upper end opening 132A and the seed crystal 10.

  In the lid attaching step S33, the lid 120 is attached (screwed) to the opening 111 of the reaction vessel 110. Thereby, the seed crystal 10 is held by the holding unit 130.

  Step S3 is not necessarily performed after step S2. Step S3 may be performed before step S2.

(3.3) Single crystal growth step S4
Step S4 is a single crystal growth step in which the sublimation raw material 20 is sublimated to grow a silicon carbide single crystal on the seed crystal 10. A current is passed through the heating coil to heat the sublimation raw material 20. Generally, the heating temperature is 2000 ° C to 2500 ° C. It is preferable to heat the seed crystal 10 so that the temperature of the seed crystal 10 is slightly lower than that of the sublimation raw material 20. The sublimation raw material 20 thus heated sublimates. The sublimated raw material 20 is recrystallized into the seed crystal 10 by the holding unit 130 (guide member). The silicon carbide single crystal grows starting from the seed crystal 10. The silicon carbide single crystal grows along holding portion 130 (guide member). In this way, a silicon carbide single crystal is manufactured.

  Since the entire surface of the seed crystal 10 is exposed, a single crystal also grows from the upper surface 10A of the seed crystal 10. By this growth, the lid 120 and the seed crystal 10 are bonded by the grown single crystal. That is, the single crystal grown from the upper surface 10 </ b> A serves as an adhesive that bonds the seed crystal 10 and the lid 120. Thereby, the burden on the holding part 130 can be reduced by the growth of the single crystal.

(4) Action / Effect In the embodiment, the holding unit 130 has a contact surface 133 that contacts only a part of the opposite side (lower surface 10B) of the seed crystal 10 to the lid 120 side (upper surface 10A). The entire surface of is exposed. According to this, the seed crystal 10 can be held in the reaction vessel 110 without using an adhesive layer. For this reason, even if the inside of the crucible 100 reaches a high temperature, generation of cracks due to shrinkage of the resin material or the like constituting the adhesive layer can be reliably prevented. In addition, it is not necessary to uniformly apply the resin material constituting the adhesive layer uniformly, and it is possible to prevent the components of the resin material from being mixed into the single crystal as impurities.

  The thickness of the seed crystal 10 is 1 mm or more, and the seed crystal 10 and the lid 120 are in contact with each other without a gap. By setting the thickness of the seed crystal 10 to 1 mm or more, warping of the seed crystal 10 can be suppressed. For this reason, the seed crystal 10 and the lid 120 are in contact with each other without generating a gap between the seed crystal 10 and the lid 120. As a result, the occurrence of structural defects due to the gap between the seed crystal 10 and the lid 120 can be prevented.

  Further, the contact surface 133 is in contact with only a part of the lower surface 10B. That is, the contact surface 133 does not contact the peripheral surface (side surface 10 </ b> C) of the seed crystal 10. Therefore, it is not necessary to process the seed crystal 10 on a disk or a cylinder. For this reason, the process which processes the seed crystal 10 becomes unnecessary, and the reduction of the manufacturing cost of a single crystal can also be aimed at.

  In this way, in the production of a single crystal by the sublimation recrystallization method, it is possible to suppress the occurrence of structural defects such as cracks and the deterioration of the quality of the single crystal due to the incorporation of impurities. Moreover, the manufacturing cost of the single crystal can be reduced.

  In the embodiment, the lower surface 10B protrudes in a hemispherical shape toward the sublimation raw material 20 side. According to this, the seed crystal 10 is held by the holding unit 130 in a state where the hemispherical lower surface 10 </ b> B is inserted into the upper end opening 132 </ b> A of the holding unit 130. For this reason, the seed crystal 10 is stably held without generating a gap between the upper end opening 132A and the seed crystal 10.

  In the embodiment, in the seed crystal 10, the end surface of the single crystal for growth is cut, and the end surface of the single crystal becomes the lower surface 10B or the side surface 10C. According to this, the process of processing the seed crystal 10 becomes unnecessary, and the manufacturing cost of the single crystal can be reduced. Since the end surface of the single crystal is a growth surface, and the lower surface 10B or the side surface 10C is not a cut surface, no surface defects are caused by cutting. Therefore, a high quality single crystal can be manufactured.

  In the embodiment, the holding unit 130 is configured by a guide member. According to this, a general guide member can be used without newly providing the holding part 130 in the crucible 100. For this reason, the cost of the single crystal manufacturing apparatus 1 itself can be reduced.

  In the embodiment, the holding unit 130 holds the seed crystal 10 in a state where the seed crystal 10 is in contact with the lid 120. According to this, since the seed crystal 10 and the lid 120 are in contact with each other, heat necessary for the growth of the single crystal can be efficiently transmitted to the seed crystal 10. Therefore, the manufacturing time can be shortened, and the manufacturing cost of the single crystal can be reduced.

  In the embodiment, the contact surface 133 is preferably in contact with the lower surface 10 </ b> B of the seed crystal 10 at the surface. That is, the holding unit 130 is preferably in surface contact with the seed crystal 10. According to this, compared with the case where the contact surface 133 is an edge (that is, line contact), the weight of the seed crystal 10 does not concentrate on a part of the seed crystal 10. For this reason, generation | occurrence | production of the structural defect of a single crystal can be prevented further reliably.

  In the embodiment, the diameter of the contact surface 133 is smaller than the diameter of the surface of the seed crystal 10 on the sublimation raw material 20 side. In particular, the contact area between the contact surface 133 and the surface of the seed crystal 10 on the sublimation raw material 20 side is preferably as small as possible. According to this, it is possible to prevent the occurrence of structural defects in the single crystal without disturbing the enlargement of the diameter of the single crystal during the growth of the single crystal.

(5) Modification Example Next, a modification example of the single crystal manufacturing apparatus 1 according to the above-described embodiment will be described with reference to the drawings. FIG. 5A is a cross-sectional view showing a part of the holding unit 140 according to the modified example. FIG. 5B is a plan view showing the holding unit 140 according to the modified example. The same parts as those in the single crystal manufacturing apparatus 1 according to the embodiment described above are denoted by the same reference numerals, and different parts will be mainly described.

  Here, in the above-described embodiment, the holding unit 130 is configured by a guide member. On the other hand, in the modified example, the holding unit 140 is configured to only hold the seed crystal 10 instead of the guide member. In the modified example, the single crystal manufacturing apparatus 1 is not provided with a guide member.

  Specifically, as illustrated in FIG. 5, the holding unit 140 includes a disc-shaped holding unit main body 141 in a plan view of the holding unit 140. A circular opening 142 is formed in the holding part main body 141. Similar to the upper end opening 132A described in the embodiment, the opening 142 is provided with a contact surface 143 (contact portion) that contacts only a part of the lower surface 10B of the seed crystal 10. The holding part main body 141 is fixed in the reaction vessel 110 by a plurality of (three in the drawing) support parts 144.

  Here, the holding unit main body 141 may have such a size that the gap 145 between the holding unit main body 141 and the reaction vessel 110 is small as shown in FIG. 5B. As shown in FIG. The gap 145 between the part main body 141 and the reaction vessel 110 may be large.

  Further, the holding portion 140 does not necessarily have the holding portion main body 141, and is configured by only a plurality of (three in the drawing) support portions 144 having the contact surface 143 as shown in FIG. Also good. In this case, it is preferable that the lower surface 10 </ b> B of the seed crystal 10 is in uniform contact with the entire surface of each contact surface 143. In addition to the holding unit 140 described above, the single crystal manufacturing apparatus 1 may further include a guide member that regulates the growth range of the single crystal without contacting the seed crystal 10.

(6) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows. Specifically, the configuration of the single crystal manufacturing apparatus 1 is not limited to that described in the embodiment, and can be appropriately set according to the purpose. That is, the configuration of the holding unit is not limited to that described in the embodiment or the modified example, and can be appropriately selected according to the purpose.

  Further, the single crystal and the sublimation raw material 20 do not necessarily contain silicon carbide. That is, the polymorphism, amount used, purity, production method, etc. of the single crystal or the sublimation raw material 20 can be selected as appropriate. Furthermore, it is needless to say that the configuration and shape of the seed crystal can be selected as appropriate.

  Further, in the above-described embodiment, the warp is suppressed by setting the thickness of the seed crystal 10 to 1 mm or more. However, the warp is suppressed by setting the thickness of the seed crystal 10 to 1 mm or more. 10 may be slightly warped. In such a case, the seed crystal 10 is arranged so that the warp of the seed crystal 10 is warped toward the lid 120, and the holding unit 130 is in contact with the end of the seed crystal 10. That is, the warp of the seed crystal 10 is warped toward the lid 120 side, and the holding portion 130 is in contact with the end portion of the lower surface 10B that is the second surface portion. Here, the end means an end on the outer side of the lower surface 10B of the seed crystal 10. Therefore, the lower surface 10B on the side surface 10C side is meant. Even if the seed crystal 10 is slightly warped, the holding portion 130 is in contact with the end portion of the lower surface 10B, and thus the seed crystal 10 and the lid are formed without generating a gap between the upper surface 10A and the lid body 120. The body 120 is in contact. Thereby, even if the seed crystal 10 is slightly warped, it is possible to prevent the occurrence of structural defects due to the gap between the seed crystal 10 and the lid 120. In other words, when the warp of the seed crystal 10 is warped toward the sublimation raw material 20 side, not the end of the seed crystal 10 but the vicinity of the center of the lower surface 10B and the holding portion 130 are not in contact with each other. A gap is generated between the upper surface 10A and the lid 120. With such a configuration, the holding unit 130 limits the growth surface of the seed crystal 10 and makes it difficult to produce a single crystal having a large diameter. Therefore, it is preferable that the seed crystal 10 is disposed so that the warp of the seed crystal 10 is warped toward the lid 120, and the holding portion 130 is in contact with the end portion of the seed crystal 10.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is determined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  DESCRIPTION OF SYMBOLS 1 ... Single crystal manufacturing apparatus, 10 ... Seed crystal, 10A ... Upper surface (1st surface part), 10B ... Lower surface (2nd surface part), 20 ... Raw material for sublimation, 50 ... Support rod, 60 ... Quartz tube, 70 ... Dielectric heating Coil, 100 ... crucible, 110 ... reaction vessel, 111 ... opening, 120 ... lid, 121 ... inner surface, 130 ... holding part, 131 ... induction part, 132 ... opening, 132A ... upper end opening, 132B ... lower end Opening part, 133 ... contact surface, 140 ... holding part, 141 ... holding body, 142 ... opening part, 143 ... contact surface, 144 ... support part, 145 ... gap

Claims (9)

A single crystal production apparatus comprising a seed crystal that is a base for growth of a single crystal and a crucible containing a raw material for sublimation used for the growth of the single crystal,
The crucible is
A reaction vessel having an opening and containing the sublimation raw material;
A lid attached to the opening;
A holding part for holding the seed crystal,
The holding portion has a contact portion that contacts only a part of the seed crystal opposite to the lid side,
The seed crystal has a thickness of 1 mm or more,
The seed crystal and the lid are in contact with each other without a gap,
The single crystal manufacturing apparatus in which the entire surface of the seed crystal is exposed. The seed crystal is
A first surface provided on the lid side;
It has at least a second surface portion facing the first surface portion and provided on the sublimation raw material side,
The warp of the seed crystal is warped on the lid side,
The single crystal manufacturing apparatus according to claim 1, wherein the holding portion is in contact with an end portion of the second surface portion.   The single crystal manufacturing apparatus according to claim 1, wherein the second surface portion protrudes toward the sublimation raw material side.   The single crystal manufacturing apparatus according to claim 2, wherein the seed crystal is formed by cutting an end surface of the single crystal, and the end surface is the second surface portion. The seed crystal has a side portion that connects the first surface portion and the second surface portion,
The single crystal manufacturing apparatus according to claim 2, wherein the seed crystal is formed by cutting an end surface of the single crystal, and the end surface is the side surface portion. The holding part is
The single crystal production according to any one of claims 1 to 5, wherein the single crystal production is configured by a guide member that is disposed inside the crucible and regulates a growth range of the silicon carbide single crystal that grows based on the seed crystal. apparatus.   The single crystal manufacturing apparatus according to claim 2, wherein the contact portion is in contact with the second surface portion of the seed crystal. A preparation step of preparing a seed crystal made of silicon carbide, a raw material arrangement step of arranging a sublimation raw material in a crucible, a seed crystal arrangement step of arranging the seed crystal in the crucible, and sublimating the sublimation raw material to A method for producing a silicon carbide single crystal comprising a growth step of growing a silicon carbide single crystal on a seed crystal,
The crucible has an opening, and includes a reaction container that contains the raw material for sublimation, a lid attached to the opening, and a holding part that holds the seed crystal.
In the preparation step,
Preparing a seed crystal having a thickness of 1 mm or more,
Leaving the entire surface of the seed crystal exposed;
In the seed crystal arrangement step,
The holding portion has a contact portion that contacts only a part of the seed crystal opposite to the lid side,
A method for producing a silicon carbide single crystal, wherein the seed crystal with the entire surface exposed is arranged without leaving a gap between the seed crystal and the lid. In the seed crystal arrangement step,
The seed crystal is arranged so that the warp of the seed crystal is warped toward the lid body side,
The method for producing a silicon carbide single crystal according to claim 8, wherein the contact portion is located at an end of the seed crystal.

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