JP2010138006A - Production method of silicon carbide single crystal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of a silicon carbide single crystal, by which crystal defects such as screw dislocation can be further suppressed while continuously sublimating a raw material for sublimation in a given amount. <P>SOLUTION: The production method of a silicon carbide single crystal is carried out by using a seed crystal 70 containing silicon carbide, a graphite crucible 10 disposed below the seed crystal 70 and housing a raw material 80 for sublimation to be used for growing the seed crystal 70, and a heating unit 30 disposed around the side part of the graphite crucible 10 and heating the graphite crucible 10 by use of an induction heating coil 30a; and the method includes a step of heating the graphite crucible 10 by using the heating unit 30 with a substantially constant output power, and a step of inserting a heat insulating member 12 inbetween the heating unit 30 and the graphite crucible 10 while the raw material 80 for sublimation housed in the graphite crucible 10 is successively sublimated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a silicon carbide single crystal using a crucible containing a seed crystal and a sublimation raw material, and a heating unit for heating the crucible using an induction heating coil.

  2. Description of the Related Art Conventionally, a silicon carbide single crystal production apparatus for producing a silicon carbide single crystal (hereinafter abbreviated as “single crystal” as appropriate) using a crucible containing a seed crystal formed of silicon carbide and a sublimation raw material has been widely used. It is used. In such a silicon carbide single crystal manufacturing apparatus, a powdery sublimation raw material is placed on the bottom of the crucible, and a single crystal seed crystal is placed on the top of the crucible. An induction heating coil for heating the crucible is disposed around the outer periphery of the crucible.

  In the silicon carbide single crystal manufacturing apparatus having such a structure, the growth of seed crystals is inhibited by the precipitation of polycrystalline silicon carbide on the surface of the sublimation raw material while continuously sublimating a certain amount of the sublimation raw material. In order to suppress this, a method of controlling the induction heating coil so that the temperature of the surface portion of the sublimation raw material is higher than the temperature of the bottom portion of the sublimation raw material is known (for example, Patent Document 1).

Specifically, as the sublimation raw material is sublimated, the position where the induction heating coil is heated is gradually lowered. According to such a method, it is possible to suppress the growth inhibition of the seed crystal while continuously sublimating a certain amount of the sublimation raw material according to the amount of the sublimation raw material remaining at the bottom in the crucible.
JP 2006-321678 A (pages 7-8, FIG. 1)

  However, the conventional silicon carbide single crystal manufacturing apparatus described above has the following problems. That is, if the position where the induction heating coil is heated is changed, the temperature distribution on the silicon carbide single crystal on which the seed crystal is grown changes, which causes crystal defects such as a decrease in crystallinity and screw dislocations. It was.

  Further, as a method of continuously sublimating a certain amount of sublimation raw material, it is conceivable to change the output of the induction heating coil in accordance with the amount of remaining sublimation raw material. However, this method still has a problem that the temperature distribution on the silicon carbide single crystal changes.

  Therefore, the present invention has been made in view of such a situation, and it is possible to further suppress the occurrence of crystal defects such as a decrease in crystallinity and screw dislocation while continuously sublimating a certain amount of the sublimation raw material. It aims at providing the manufacturing method of a silicon carbide single crystal.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a seed crystal containing silicon carbide (seed crystal 70) and a sublimation material (sublimation material 80) disposed under the seed crystal and used for seed crystal growth are provided. Carbonization using a crucible (graphite crucible 10) to be accommodated and a heating unit (heating unit 30) disposed around the side of the crucible and heating the crucible using an induction heating coil (induction heating coil 30a) A method for producing a silicon single crystal, in which a crucible is heated at a substantially constant output using a heating unit, and while a sublimation raw material contained in the crucible is sequentially sublimated, a heat insulating member (heat insulating member 12). ) Is inserted between the heating unit and the crucible.

  According to such a method for producing a silicon carbide single crystal, the sublimation raw material housed in the crucible is heated by the heating unit disposed around the side of the crucible, and thus is located closer to the outside of the crucible. Sublimation starts from the sublimation raw material.

  Further, the heat insulating member is inserted between the heating unit and the crucible while the sublimation raw materials housed in the crucible are sequentially sublimated. For this reason, the manufacturing apparatus of a silicon carbide single crystal can suppress the temperature fall inside the crucible heated by the heating part, and can raise the temperature inside the crucible gradually.

  Along with this, the sublimation raw material sequentially sublimates from the sublimation raw material located closer to the crucible outer side, and finally the sublimation raw material located in the center of the crucible is sublimated. That is, the silicon carbide single crystal manufacturing apparatus continuously sublimates a certain amount of sublimation raw material.

  Since the heating unit can heat the crucible containing the seed crystal with a substantially constant output without changing the position, the temperature distribution on the silicon carbide single crystal on which the seed crystal has grown does not change. For this reason, the manufacturing apparatus of a silicon carbide single crystal can further suppress generation | occurrence | production of crystal defects, such as a crystallinity fall and a screw dislocation.

  Therefore, according to such a method of manufacturing a silicon carbide single crystal, the silicon carbide single crystal manufacturing apparatus continuously sublimates a certain amount of sublimation raw material while reducing crystallinity and crystal defects such as screw dislocations. Can be further suppressed.

  The second feature of the present invention relates to the first feature of the present invention, and in the step of inserting the heat insulating member, in the side view of the crucible, a position corresponding to the disposition position of the sublimation raw material accommodated in the crucible. The gist is to insert a heat insulating member.

  A third feature of the present invention relates to the first or second feature of the present invention, and in the step of inserting the heat insulating member, the heat insulating member is inserted between the heating unit and the crucible from the bottom (bottom 51) side of the crucible. The gist is to do.

  A fourth feature of the present invention relates to any one of the first to third features of the present invention, and in the step of inserting the heat insulating member, the step is inserted between the heating unit and the crucible as the seed crystal grows. The gist is to increase the portion of the heat insulating member.

  A fifth feature of the present invention relates to any one of the first to fourth features of the present invention. In the step of inserting the heat insulating member, sublimation of the sublimation raw material disposed on the inner surface portion of the crucible is performed. The gist is to insert a heat insulating member before completion.

  A sixth feature of the present invention relates to any one of the first to fifth features of the present invention, and is summarized in that the crucible is covered with a heat insulating member (heat insulating member 11).

  According to the feature of the present invention, there is provided a silicon carbide single crystal manufacturing apparatus capable of further suppressing generation of crystal defects such as a decrease in crystallinity and screw dislocation while continuously sublimating a certain amount of sublimation raw material. Can do.

  Next, first to second embodiments according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[First Embodiment]
In the present embodiment, (1) a schematic configuration of a silicon carbide single crystal manufacturing apparatus, (2) a silicon carbide single crystal manufacturing method, and (3) actions and effects will be described.

(1) Schematic Configuration of Silicon Carbide Single Crystal Manufacturing Device FIG. 1 is a configuration diagram illustrating an overview of a silicon carbide single crystal manufacturing device 1 according to the first embodiment of the present invention.

  As shown in FIG. 1, the silicon carbide single crystal manufacturing apparatus 1 includes a graphite crucible 10, a quartz tube 20, a heating unit 30, and a heat insulating member 12.

  Each part which comprises the manufacturing apparatus 1 of a silicon carbide single crystal is demonstrated. Specifically, (1.1) graphite crucible 10, (1.2) quartz tube 20, (1.3) heating unit 30, and (1.4) heat insulating member 12 will be described.

(1.1) Graphite crucible 10
The graphite crucible 10 is disposed under the seed crystal 70 containing silicon carbide and the seed crystal 70, and accommodates a sublimation raw material 80 used for the growth of the seed crystal 70. The graphite crucible 10 is fixed inside the quartz tube 20 by a support rod 40. The graphite crucible 10 includes a reaction vessel main body 50 and a lid portion 60.

  The reaction vessel main body 50 is cylindrical at least inside. A seed crystal 70 is disposed inside the reaction vessel main body 50. Specifically, the seed crystal 70 is bonded to the inner surface 61 of the lid 60.

  The inside of the reaction vessel main body 50 is filled with an inert gas such as argon to form an inert atmosphere. The pressure and temperature inside the reaction vessel main body 50 can be changed.

  The lid 60 is detachably provided on the reaction vessel main body 50 by screwing.

  A seed crystal 70 and a sublimation raw material 80 are accommodated in the reaction vessel main body 50.

  Sublimation raw material 80 is a silicon carbide raw material containing silicon carbide. When the inside of graphite crucible 10 reaches predetermined temperature conditions and pressure conditions, sublimation raw material 80 sublimates and recrystallizes on seed crystal 70 to form silicon carbide single crystal 100.

  As the growth proceeds, silicon carbide single crystal 100 forms convex surface 100a and eventually grows according to the conditions inside reaction vessel body 50.

(1.2) Quartz tube 20
In the present embodiment, the quartz tube 20 covers at least the side surface of the graphite crucible 10. The inside of the quartz tube 20 is filled with an inert gas such as argon to form an inert atmosphere.

(1.3) Heating unit 30
The heating unit 30 is disposed around the side of the graphite crucible 10 and heats the graphite crucible 10 using the induction heating coil 30a. The heating unit 30 is disposed on the outer periphery of the quartz tube 20.

(1.4) Thermal insulation member 12
The heat insulating member 12 will be further described with reference to FIGS.

  FIG. 2 is a perspective view for explaining the positional relationship between the heat insulating member 12 and the sublimation raw material 80 disposed in the silicon carbide single crystal manufacturing apparatus 1.

  As shown in FIG. 2, the heat insulating member 12 is formed in a cylindrical shape. The heat insulating member 12 is inserted between the graphite crucible 10 and the heating unit 30.

  Specifically, the heat insulating member 12 is inserted between the reaction vessel main body 50 constituting the graphite crucible 10 and the quartz tube 20 and is in close contact with the side portion of the reaction vessel main body 50. At this time, the heat insulating member 12 is inserted from the bottom 51 side of the graphite crucible 10 to at least the upper surface s of the sublimation raw material 80.

  The heat insulating member 12 has a lower thermal conductivity than the graphite crucible 10. Specifically, the thermal conductivity of the heat insulating member 12 is preferably 0.06 W / m · k or less.

  The heat insulating member 12 is formed of, for example, porous carbon or a carbon felt in which a plurality of holes are formed. The thickness d of the heat insulating member 12 is 15 millimeters or more.

(2) Manufacturing method of silicon carbide single crystal Next, the manufacturing method of the silicon carbide single crystal which concerns on this embodiment is demonstrated using FIG. FIG. 3 is a flowchart showing a method for manufacturing a silicon carbide single crystal according to the present embodiment.

  Specifically, the method for producing a silicon carbide single crystal includes (2.1) a raw material preparation step, (2.2) an arrangement step, (2.3) a crucible heating step, (2.4) a heat insulating member insertion step, (2.5) a single crystal growth step, (2.6) a peripheral grinding step, and (2.7) a slicing step.

(2.1) Raw material preparation process In the raw material preparation process of step S1, the sublimation raw material 80 is prepared.

(2.2) Arrangement Step In the arrangement step of Step S2, the sublimation raw material 80, the seed crystal 70, etc. are arranged in the silicon carbide single crystal manufacturing apparatus 1.

  In the arrangement step of step S <b> 2, the heat insulating member 12 is not inserted between the reaction vessel main body 50 and the quartz tube 20. Specifically, the heat insulating member 12 is disposed closer to the support rod 40 than the bottom 51 of the reaction vessel main body 50.

(2.3) Crucible Heating Step In the crucible heating step of step S3, the graphite crucible 10 is heated with a substantially constant output using the heating unit 30. Specifically, the heating unit 30 energizes the induction heating coil 30a to heat the graphite crucible 10 with a substantially constant output. The heating unit 30 heats the graphite crucible 10 and sublimates the sublimation raw material 80.

(2.4) Thermal insulation member insertion process In the thermal insulation member insertion process of step S4, while the sublimation raw material 80 accommodated in the graphite crucible 10 is sequentially sublimated, the thermal insulation member 12 is replaced with the heating unit 30 and the graphite crucible. Insert between 10 and 10.

  In the heat insulating member insertion step of step S4, the heat insulating member 12 is inserted to a position corresponding to the position where the sublimation raw material 80 accommodated in the graphite crucible 10 is disposed in a side view of the graphite crucible 10. Specifically, the heat insulating member 12 is inserted between the heating unit 30 and the graphite crucible 10 from the bottom 51 side of the graphite crucible 10.

  In the heat insulating member inserting step of step S4, as the seed crystal 70 grows, the portion of the heat insulating member 12 inserted between the heating unit 30 and the graphite crucible 10 is increased.

  Further, in the heat insulating member insertion step of step S4, the heat insulating member 12 is inserted before the sublimation of the sublimation raw material 80 disposed on the inner side surface portion of the graphite crucible 10 is completed.

(2.5) Single Crystal Growth Step In the single crystal growth step of step S5, a silicon carbide single crystal is grown based on the seed crystal 70.

  Specifically, in the single crystal growth step of step S <b> 5, the sublimated raw material 80 is recrystallized on the seed crystal 70 disposed on the inner surface 61 of the lid 60.

  That is, the raw material gas sublimated from the sublimation raw material 80 grows the silicon carbide single crystal 100 on the seed crystal 70.

  Thereby, a silicon carbide single crystal (hereinafter referred to as a single crystal ingot) grows in the radial direction of the reaction vessel main body 50 with time. A single crystal ingot is obtained by performing steps S1 to S4 described above.

(2.6) Outer peripheral grinding step In the outer peripheral grinding step of step S6, outer peripheral grinding or the like is performed on the single crystal ingot grown to a desired size. For example, orientation flat forming processing may be performed in which an orientation flat (orientation flat) indicating a crystal orientation (Si plane, C plane, etc.) is formed on a single crystal ingot.

(2.7) Slicing Step In the slicing step of step S7, a semiconductor wafer is cut out from the single crystal ingot.

  In addition, a semiconductor wafer can be manufactured by performing the above-mentioned steps S1-S7.

  As described above, according to the manufacturing method shown in FIG. 3, the raw material gas is sublimated from the heating position of the heated sublimation raw material 80, recrystallized on seed crystal 70, and silicon carbide single crystal 100 is formed on seed crystal 70. grow up.

(3) Actions / Effects As described above, according to the present embodiment, the sublimation raw material 80 accommodated in the graphite crucible 10 is heated around the side portion of the graphite crucible 10. Therefore, the material is sublimated sequentially from the sublimation raw material 80 located near the outside of the graphite crucible 10.

  Further, the heat insulating member 12 is inserted between the heating unit 30 and the graphite crucible 10 while the sublimation raw material 80 accommodated in the graphite crucible 10 is sublimating sequentially. For this reason, the silicon carbide single crystal manufacturing apparatus 1 suppresses the temperature drop inside the graphite crucible 10 heated by the heating unit 30 and gradually raises the temperature inside the graphite crucible 10.

  Along with this, the sublimation raw material 80 sequentially sublimates from the sublimation raw material 80 located closer to the outside of the graphite crucible 10, and finally the sublimation raw material 80 located in the center of the graphite crucible 10 sublimates. That is, the silicon carbide single crystal manufacturing apparatus 1 continuously sublimates a certain amount of the sublimation raw material 80.

  Since the heating unit 30 can heat the graphite crucible 10 containing the seed crystal 70 with a substantially constant output without changing the position, the temperature distribution on the silicon carbide single crystal on which the seed crystal 70 has grown is ,It does not change. For this reason, the silicon carbide single crystal manufacturing apparatus 1 can further suppress the occurrence of crystal defects such as a decrease in crystallinity and screw dislocations.

  Therefore, according to such a method for manufacturing a silicon carbide single crystal, the silicon carbide single crystal manufacturing apparatus 1 continuously sublimates a certain amount of the sublimation raw material 80, while reducing crystallinity, screw dislocation, and the like. Generation of crystal defects can be further suppressed.

  In the present embodiment, since the heat insulating member 12 is inserted to the position corresponding to the position where the raw material for sublimation 80 accommodated in the graphite crucible 10 is disposed in the heat insulating member inserting step of Step S4, the silicon carbide single crystal is manufactured. The apparatus 1 further suppresses at least the temperature drop around the sublimation raw material 80 inside the graphite crucible 10 and gradually raises the temperature inside the graphite crucible 10. In other words, since silicon carbide single crystal manufacturing apparatus 1 can maintain an appropriate sublimation atmosphere in the single crystal growth step of step S5, high-quality silicon carbide single crystal 100 can be grown on seed crystal 70. .

  In this embodiment, since the heat insulating member 12 is inserted between the heating unit 30 and the graphite crucible 10 from the bottom 51 side of the graphite crucible 10 in the heat insulating member inserting step of step S4, the silicon carbide single crystal manufacturing apparatus 1 further suppresses the temperature drop around the sublimation raw material 80 disposed below the seed crystal 70 and gradually raises the temperature inside the graphite crucible 10. That is, the silicon carbide single crystal manufacturing apparatus 1 can maintain a more appropriate sublimation atmosphere in the single crystal growth step of step S5.

  In the present embodiment, in the heat insulating member insertion step of step S4, as the seed crystal 70 grows, the portion of the heat insulating member 12 inserted between the heating unit 30 and the graphite crucible 10 is increased. The crystal manufacturing apparatus 1 can gradually sublimate from the sublimation raw material 80 around the heat insulating member 12 to be inserted. That is, since the silicon carbide single crystal manufacturing apparatus 1 can supply a constant sublimation amount of source gas to the seed crystal 70 side in the single crystal growth step of step S5, it can maintain a more appropriate sublimation atmosphere.

  In this embodiment, in order to insert the heat insulating member 12 before the sublimation of the raw material for sublimation 80 disposed on the inner surface portion of the graphite crucible 10 is completed in the heat insulating member insertion step of Step S4, The sublimation raw material 80 disposed inside the crucible 10 is continuously sublimated. That is, in the single crystal growth step of step S5, the sublimation gas generated from the sublimation raw material 80 is supplied to the seed crystal 70 side without interruption. Therefore, since the silicon carbide single crystal manufacturing apparatus 1 can supply a high-quality sublimation source gas to the seed crystal 70 side, a more appropriate sublimation atmosphere can be maintained.

[Second Embodiment]
In 1st Embodiment mentioned above, since the heat insulation member 12 is inserted between the graphite crucible 10 and the heating part 30 in the silicon carbide single crystal manufacturing apparatus 1, the silicon carbide single crystal manufacturing apparatus 1 includes: A temperature drop inside the graphite crucible 10 heated by the heating unit 30 is suppressed.

  In 2nd Embodiment, the structure provided with the heat insulation member 11 in advance between the graphite crucible 10 and the heating part 30 is demonstrated using FIG.4 and FIG.5.

  FIG. 4 is a configuration diagram illustrating an outline of the silicon carbide single crystal manufacturing apparatus 2 according to the second embodiment of the present invention. FIG. 5 is a perspective view for explaining the positional relationship between the heat insulating member 11 and the heat insulating member 12 disposed in the silicon carbide single crystal manufacturing apparatus 2.

  Note that, in the following second embodiment, differences from the first embodiment will be mainly described, and overlapping descriptions will be omitted.

In the present embodiment, (1) a schematic configuration of a silicon carbide single crystal manufacturing apparatus, (2) a silicon carbide single crystal manufacturing method, (3) comparative evaluation, and (4) actions and effects will be described.

(1) Schematic Configuration of Silicon Carbide Single Crystal Manufacturing Device As shown in FIGS. 4 and 5, the silicon carbide single crystal manufacturing device 2 includes a graphite crucible 10, a quartz tube 20, a heating unit 30, and a heat insulating member. 12 and a heat insulating member 11.

  The graphite crucible 10 is covered with a heat insulating member 11. Specifically, the heat insulating member 11 is in close contact with the side portion, the upper surface, and the lower surface of the reaction vessel main body 50 constituting the graphite crucible 10.

  The heat insulating member 11 is formed of the same material as the heat insulating member 12. The heat insulating member 11 is formed of, for example, porous carbon or a carbon felt in which a plurality of holes are formed. The thickness d2 of the heat insulating member 11 is 15 millimeters or more.

  The heat insulating member 11 is made thin at a position corresponding to the position where the raw material for sublimation 80 accommodated in the graphite crucible 10 is disposed. Specifically, on the side surface of the heat insulating member 11 covering the side portion of the reaction vessel main body 50, the thickness of the heat insulating member 11 corresponds to the position where the sublimation raw material 80 accommodated in the graphite crucible 10 is disposed. Thus, the graphite crucible 10 is thinly formed on the inner side in the radial direction.

  The heat insulating member 12 is inserted between the heat insulating member 11 covering the side portion of the reaction vessel main body 50 and the quartz tube 20, and is in close contact with the side portion of the heat insulating member 11. At this time, the heat insulating member 12 is inserted from the bottom 51 of the graphite crucible 10 to at least the upper surface s of the sublimation raw material 80. The heat insulating member 12 is inserted into a portion where the thickness is formed thin on the side portion of the heat insulating member 11.

(2) Manufacturing Method of Silicon Carbide Single Crystal Next, the manufacturing method of the silicon carbide single crystal according to the present embodiment will be described mainly with respect to differences from the first embodiment.

  In the arrangement step of step S2, the heat insulating member 11 is in close contact with the side, upper surface, and lower surface of the reaction vessel main body 50 constituting the graphite crucible 10.

  In the arrangement step of step S <b> 2, the heat insulating member 12 is not inserted between the heat insulating member 11 and the reaction vessel main body 50. Specifically, the heat insulating member 12 is disposed on the support rod 40 side (downward) from the bottom of the heat insulating member 11.

  In the heat insulating member insertion step of step S4, the heat insulating member 12 is inserted between the heating unit 30 and the graphite crucible 10 while the sublimation raw material 80 accommodated in the graphite crucible 10 is sequentially sublimated. Specifically, the heat insulating member 12 is inserted between the heat insulating member 11 and the quartz tube 20 from the bottom 51 side of the graphite crucible 10.

(3) Comparative Evaluation Next, in order to further clarify the effects of the present invention, comparative evaluation performed using the silicon carbide single crystal manufacturing apparatus according to the following comparative examples and examples will be described. Specifically, (3.1) Evaluation method and (3.2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(3.1) Evaluation Method A silicon carbide single crystal was manufactured using three types of silicon carbide single crystal manufacturing apparatuses. The silicon carbide single crystal manufacturing apparatus and evaluation method according to Comparative Examples 1 and 2 and Example 1 used for comparative evaluation will be described.

(3.1.1) Silicon carbide single crystal manufacturing apparatus according to Example 1 A silicon carbide single crystal manufacturing apparatus according to Example 1 is a silicon carbide single crystal manufacturing apparatus 2 according to the second embodiment of the present invention. Was used. Hereinafter, the characteristic site | part of the manufacturing apparatus of the silicon carbide single crystal which concerns on Example 1 is demonstrated.

  The thickness of the heat insulating member 11 was 25 mm. In the heat insulating member 11, only the thickness of the side surface portion of the sublimation raw material 80 was set to 10 mm. Moreover, the thickness of the heat insulation member 12 was 15 mm.

(3.1.2) Method for Producing Silicon Carbide Single Crystal According to Example 1 The seed crystal 70 was placed in the graphite crucible 10 and heated at 2200 ° C. for 40 hours to sublimate the sublimation raw material 80.

  Next, the heat insulating member 12 was gradually inserted from below the sublimation raw material 80. Specifically, after 40 hours, the heat insulating member 12 was inserted so that the upper end of the heat insulating member 12 reached the upper end of the sublimation raw material 80. The central portion of the sublimation raw material 80 was continuously sublimated.

(3.1.3) Silicon carbide single crystal manufacturing apparatus according to Comparative Example 1 The silicon carbide single crystal manufacturing apparatus according to Comparative Example 1 is insulated from the silicon carbide single crystal manufacturing apparatus according to Example 1. The difference is that the thickness of the member 11 is uniformly 25 mm. Other parts are the same as those of the silicon carbide single crystal manufacturing apparatus according to the first embodiment.

(3.1.4) Method for producing silicon carbide single crystal according to Comparative Example 1 The seed crystal 70 was placed in the graphite crucible 10 and heated from 2200 ° C. to 2350 ° C. for 80 hours to sublimate the sublimation raw material 80. .

(3.1.5) Silicon carbide single crystal manufacturing apparatus according to Comparative Example 2 The silicon carbide single crystal manufacturing apparatus according to Comparative Example 2 is insulated from the silicon carbide single crystal manufacturing apparatus according to Example 1. The difference is that the thickness of the member 11 is uniformly 25 mm. Other parts are the same as those of the silicon carbide single crystal manufacturing apparatus according to the first embodiment.

(3.1.6) Method for Producing Silicon Carbide Single Crystal According to Comparative Example 2 The seed crystal 70 was placed in the graphite crucible 10 and heated at 2200 ° C. for 80 hours to sublimate the sublimation raw material 80. In addition, the center position along the up-down direction of the heating unit 30 was disposed at the upper end of the sublimation raw material 80 at the start of heating, and was moved to the bottom of the sublimation raw material 80 with heating.

(3.2) Evaluation Results A semiconductor wafer was cut out from the silicon carbide single crystal manufactured by the silicon carbide single crystal manufacturing apparatus according to Comparative Examples 1 and 2 and Example 1, and the half width was measured with an X-ray diffractometer. . The measurement results are shown in Table 1.

  As shown in Table 1, the silicon carbide single crystal manufactured by the silicon carbide single crystal manufacturing apparatus according to Example 1 is the same as the silicon carbide single crystal manufactured by the silicon carbide single crystal manufacturing apparatus according to Comparative Examples 1 and 2. It was found that the half width was narrow and the crystallinity was excellent as compared with the crystal.

(4.1) Actions / Effects As described above, according to the present embodiment, the graphite crucible 10 is covered with the heat insulating member 11, so that the silicon carbide single crystal manufacturing apparatus 2 is heated. The temperature inside the graphite crucible 10 heated by the part 30 is further suppressed, and the temperature inside the graphite crucible 10 is gradually increased.

  According to this embodiment, the thickness of the heat insulating member 11 is thinly formed on the radially inner side of the graphite crucible 10 at a position corresponding to the position where the raw material for sublimation 80 accommodated in the graphite crucible 10 is disposed. Therefore, the sublimation raw material 80 is easily heated by the heating unit 30. Accordingly, the silicon carbide single crystal manufacturing apparatus 2 promotes sublimation of the sublimation raw material 80.

  According to the present embodiment, the heat insulating member 12 includes the heat insulating member 11 that covers the side portion of the reaction vessel main body 50 and the quartz tube 20 while the sublimation raw material 80 accommodated in the graphite crucible 10 is sequentially sublimated. Inserted between. For this reason, the silicon carbide single crystal manufacturing apparatus 2 further suppresses the temperature drop inside the graphite crucible 10 heated by the heating unit 30 and gradually raises the temperature inside the graphite crucible 10.

[Other Embodiments]
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. 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. In the above-described embodiment, the heat insulating member 12 is inserted up to the position corresponding to the position where the sublimation raw material 80 is disposed, but the graphite crucible 10 other than the position corresponding to the position where the seed crystal 70 is disposed. You may insert to the position which covers a side part.

  The heat insulating member 12 has been described as a porous carbon felt in which a plurality of holes are formed, but any material having a lower thermal conductivity than the graphite crucible 10 may be used. In addition, the thickness of the heat insulating member 12 is at least 15 millimeters. However, when a heat insulating member different from carbon felt is used, the lower limit value is not necessarily 15 mm. The thickness can be appropriately changed according to the heat insulating effect of the material.

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

It is a lineblock diagram explaining the outline of silicon carbide single crystal manufacturing device 1 concerning a 1st embodiment of the present invention. It is a perspective view explaining the positional relationship of the heat insulation member 12 arrange | positioned inside the manufacturing apparatus 1 of the silicon carbide single crystal which concerns on 1st Embodiment of this invention, and the raw material 80 for sublimation. It is a flowchart which shows the manufacturing method of the silicon carbide single crystal which concerns on 1st Embodiment of this invention. It is a block diagram explaining the outline of the manufacturing apparatus 2 of the silicon carbide single crystal which concerns on 2nd Embodiment of this invention. It is a perspective view explaining the positional relationship of the heat insulation member 11 and the heat insulation member 12 which are arrange | positioned inside the manufacturing apparatus 2 of the silicon carbide single crystal which concerns on 2nd Embodiment of this invention.

Explanation of symbols

s ... upper surface, 1 ... manufacturing apparatus, 2 ... manufacturing apparatus, 10 ... graphite crucible, 11 ... heat insulating member,
12 ... Thermal insulation member, 20 ... Quartz tube, 30 ... Heating part, 30a ... Induction heating coil,
40 ... support rod, 50 ... reaction vessel main body, 51 ... bottom, 60 ... lid, 61 ... inner surface,
70 ... Seed crystal, 80 ... Raw material for sublimation, 100 ... Silicon carbide single crystal, 100a ... Convex surface

Claims (6)

A crucible containing a seed crystal containing silicon carbide, and a sublimation raw material disposed under the seed crystal and used for growing the seed crystal;
A method for producing a silicon carbide single crystal using a heating unit disposed around a side portion of the crucible and heating the crucible using an induction heating coil,
Heating the crucible at a substantially constant output using the heating unit;
A method for producing a silicon carbide single crystal, comprising: inserting a heat insulating member between the heating unit and the crucible while the sublimation raw materials housed in the crucible are sequentially sublimated.
2. The silicon carbide according to claim 1, wherein in the step of inserting the heat insulating member, the heat insulating member is inserted to a position corresponding to a position where the raw material for sublimation accommodated in the crucible is disposed in a side view of the crucible. A method for producing a single crystal.
3. The method for producing a silicon carbide single crystal according to claim 1, wherein in the step of inserting the heat insulating member, the heat insulating member is inserted between the heating unit and the crucible from the bottom side of the crucible.
The step of inserting the heat insulating member increases the portion of the heat insulating member inserted between the heating unit and the crucible as the seed crystal grows. A method for producing a silicon carbide single crystal.
5. The step of inserting the heat insulating member according to claim 1, wherein the heat insulating member is inserted before the sublimation of the sublimation raw material disposed on the inner surface portion of the crucible is completed. The manufacturing method of the silicon carbide single crystal of description.
  The said crucible is the manufacturing method of the silicon carbide single crystal as described in any one of Claims 1 thru | or 5 covered using the heat insulation member.

Images