JP2023033153A - Method and apparatus for manufacturing single crystal, and crucible lid - Google Patents

Abstract

To improve the quality of a silicon carbide single crystal.SOLUTION: A method for manufacturing a single crystal comprises the steps of: (a) contacting the bottom surface of a seed crystal to the surface of a solution including carbon and silicon and stored in a crucible by moving a shaft having the seed crystal attached to the tip downward; and (b) growing a single crystal consisting of silicon carbide on the bottom surface of the seed crystal. The shaft has a fin structure attached so as to intersect the extending direction of the shaft; the lid attached to the crucible includes a cylindrical member and a connection member connected to the cylindrical member; in the (a) step, the fin structure is arranged at a first position facing the inner wall of the cylindrical member when contacting the bottom surface of the seed crystal to the surface of the solution; and in the (b) step, the fin structure is arranged at a second position facing the inner wall of the cylindrical member when moving or stopping the shaft.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD The present invention relates to a technology for manufacturing a single crystal made of silicon carbide, a single crystal manufacturing apparatus, and a crucible lid, and relates to a technology that is effectively applied to a technology for manufacturing a single crystal by a solution method, for example.

In Japanese Patent No. 5964094 (Patent Document 1), Japanese Patent No. 6068603 (Patent Document 2) and Japanese Patent No. 6174013 (Patent Document 3), when a single crystal made of silicon carbide is grown by a solution method, the Techniques for suppressing crystal growth are described.

Japanese Patent No. 5964094 Japanese Patent No. 6068603 Japanese Patent No. 6174013

For example, inverter circuits are used as circuits for controlling motors included in automobiles, home appliances, and the like. Power semiconductor elements typified by power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors) are used in this inverter circuit.

Such power semiconductor devices are required to have, for example, low on-resistance and low switching loss in addition to high withstand voltage. Here, the current mainstream of power semiconductor devices is a field effect transistor formed on a semiconductor substrate whose main component is silicon, but this power semiconductor device is approaching its theoretical performance limit.

In this regard, a semiconductor device (hereinafter referred to as a wide bandgap power semiconductor device) including a field effect transistor formed on a semiconductor substrate whose main component is a semiconductor material having a bandgap larger than that of silicon has attracted attention.

This is because a large bandgap means high dielectric breakdown strength, which makes it easier to achieve a high withstand voltage.

If the semiconductor material itself has a high dielectric breakdown strength, the breakdown voltage can be ensured even if the drift layer that maintains the breakdown voltage is thin. , the on-resistance of the power semiconductor element can be reduced.

That is, the wide bandgap power semiconductor device is excellent in that it can achieve both an improvement in breakdown voltage and a reduction in on-resistance, which are in a trade-off relationship. Therefore, wide bandgap power semiconductor devices are expected as semiconductor devices capable of achieving high performance.

Examples of semiconductor materials having a bandgap larger than that of silicon include silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), and diamond. In the following, description will be made focusing on silicon carbide.

A single crystal made of silicon carbide (hereinafter referred to as a silicon carbide single crystal) is manufactured by using, for example, a solution method. In the solution method, a seed crystal attached to the tip of a shaft is brought into contact with a solution containing carbon and silicon contained in a crucible, thereby growing a silicon carbide single crystal on the seed crystal and pulling up the shaft. , a method for growing a silicon carbide single crystal.

Here, in the solution method, it is important to suppress the evaporation of the solution contained in the crucible. This is because when the amount of evaporation of the solution increases, the temperature of the solution changes, and the composition of the solution also changes, which makes it difficult to produce silicon carbide single crystals of excellent quality. Therefore, when a silicon carbide single crystal is produced by the solution method, it is desired to devise a method for suppressing evaporation from the solution contained in the crucible.

In one embodiment of the method for producing a single crystal, (a) a shaft having a seed crystal attached to its tip portion is moved downward to displace the lower surface of the seed crystal into a solution containing carbon and silicon contained in a crucible. and (b) growing a single crystal made of silicon carbide on the lower surface of the seed crystal.

Here, the shaft has a fin structure attached so as to intersect the extending direction of the shaft, the crucible is attached with a lid, and the lid is connected to the tubular member and the tubular member. and a connection member to be connected. Then, in the step (a), when the lower surface of the seed crystal is brought into contact with the surface of the solution, the fin structure is arranged at the first position facing the inner wall of the tubular member, and in the step (b), the shaft When moved or stopped, the fin structure is arranged at a second position facing the inner wall of the tubular member.

A single crystal manufacturing apparatus according to one embodiment includes a shaft on which a crucible with a lid having a tubular member can be placed, a seed crystal can be attached to the tip, a controller for vertically moving the shaft, Prepare. Here, the shaft has a fin structure attached so as to intersect with the extending direction of the shaft, and the controller moves the shaft having the fin structure vertically through the interior of the tubular member. to control the axis.

The crucible lid in one embodiment is a shaft that can be attached to a crucible containing a solution containing carbon and silicon, has a seed crystal attached to the tip, and is arranged to intersect the extending direction of the shaft. It has a tubular member through which the shaft with the fin structure attached is passed.

According to one embodiment, the quality of silicon carbide single crystal can be improved.

It is a figure explaining the importance of suppressing evaporation in a single-crystal manufacturing apparatus. It is a figure which shows the structure of the single-crystal manufacturing apparatus in related technology. In related art, it is a figure which shows the state after crystal growth progresses. It is a figure which shows the structure of the single-crystal manufacturing apparatus in embodiment. FIG. 4 is a diagram showing a state in which a silicon carbide single crystal is grown on the lower surface of the seed crystal; 4 is a flow chart for explaining the operation of the single crystal manufacturing apparatus; 3 is a diagram showing the configuration of a single-crystal manufacturing apparatus in Modification 1. FIG. FIG. 4 is a diagram showing a state in which a silicon carbide single crystal is grown on the lower surface of the seed crystal; FIG. 10 is a diagram showing the configuration of a single-crystal manufacturing apparatus in modification 2; FIG. 10 is a diagram showing the configuration of a single-crystal manufacturing apparatus in modification 3;

In principle, the same members are denoted by the same reference numerals throughout the drawings for describing the embodiments, and repeated description thereof will be omitted. In order to make the drawing easier to understand, even a plan view may be hatched.

<Importance of suppressing evaporation>
FIG. 1 is a diagram explaining the importance of suppressing evaporation in a single crystal manufacturing apparatus 100. FIG.

In FIG. 1 , a single crystal manufacturing apparatus 100 has a container 10 . The internal space of the container 10 is filled with, for example, argon gas, and a horizontally rotatable pedestal 11 is arranged. A crucible 12 is arranged on the pedestal 11 .

The crucible 12 is made of, for example, graphite, and contains a high-temperature solution 20 containing silicon (Si). A coil 14 through which a high-frequency current flows is provided on the outer periphery of the container 10 of the single-crystal manufacturing apparatus 100, and the crucible 12 is heated by induction heating based on the high-frequency current flowing through the coil 14. . As a result, the solution 20 contained in the crucible 12 is at a high temperature, and the graphite (C) that constitutes the crucible 12 is dissolved, so that the solution 20 contains carbon and silicon.

Single-crystal manufacturing apparatus 100 is provided with shaft 13 that can move vertically, and seed crystal 30 made of silicon carbide is attached to the tip of shaft 13 . Then, by moving downward the shaft 13 having the seed crystal 30 attached to the tip thereof, the lower surface of the seed crystal 30 is brought into contact with the surface of the solution 20 contained in the crucible 12 . Thereafter, a single crystal made of silicon carbide is grown on the lower surface of seed crystal 30 while moving shaft 13 upward, for example. Thus, single-crystal manufacturing apparatus 100 can manufacture a silicon carbide single crystal. It should be noted that a configuration in which a single crystal made of silicon carbide can be grown on the lower surface of the seed crystal by moving the shaft 13 upward is an example. A single crystal made of silicon carbide may be grown on the lower surface of the seed crystal in this state, or a single crystal made of silicon carbide may be grown on the lower surface of the seed crystal by moving the shaft 13 downward. It can also be configured to allow This configuration takes into account that, for example, evaporation of the solution 20 may lower the surface of the solution 20 . That is, when the surface of the solution 20 recedes due to the evaporation of the solution 20, the single crystal can be reliably grown on the seed crystal by growing the single crystal while moving the shaft 13 downward.

Here, for example, as shown in FIG. 1, the solution 20 contained in the crucible 12 is in a high temperature state, and the solution 20 evaporates.

In this regard, as shown in FIG. 1, the evaporation of the solution 20 from the crucible 12 cannot be suppressed if no measures are taken for the crucible 12 . When the amount of evaporation of solution 20 increases, the temperature of solution 20 changes, and the composition of solution 20 also changes. As a result, it becomes difficult to manufacture silicon carbide single crystals of excellent quality.

Further, in the manufacturing process of the silicon carbide single crystal, for example, when the temperature difference inside the growing (growing) silicon carbide single crystal is 10° C. or more, the silicon carbide single crystal breaks due to thermal stress. For this reason, it is important to have a uniform temperature distribution inside the silicon carbide single crystal. In the process of manufacturing a silicon carbide single crystal by the solution method, the crystal is grown under a high temperature condition of about 1800° C. or higher and about 2100° C. or lower. Therefore, heat is removed from shaft 13 by the influence of heat radiation from solution 20 and the convection of vapor originating from solution 20, and as a result, the temperature gradient inside the silicon carbide single crystal tends to increase. Furthermore, if the vapor evaporated from the solution 20 spreads widely inside the container 10, it causes deterioration of expensive furnace materials, such as carbon molded heat insulating material.

From the above, diffusion of vapor from the solution 20 is suppressed not only from the viewpoint of manufacturing a silicon carbide single crystal of good quality but also from the viewpoint of extending the life of the furnace material constituting the single crystal manufacturing apparatus 100. is very important.

Regarding this point, the following related techniques exist as techniques for suppressing the diffusion of vapor generated from the solution 20 . Therefore, this related technology will be described.

<Description of related technology>
The term "related art" as used in this specification means a technology that is not a publicly known technology, but has a problem found by the inventor of the present application, and is a technology that is a premise of the present invention.

FIG. 2 is a schematic diagram showing a single crystal manufacturing apparatus 100R in related art.

Unlike the single crystal manufacturing apparatus 100 shown in FIG. 1, the single crystal manufacturing apparatus 100R shown in FIG. 2 is different from the single crystal manufacturing apparatus 100 shown in FIG. The difference is that Due to this difference, in the single crystal manufacturing apparatus 100R, diffusion of vapor generated from the solution 20 can be suppressed by the protrusion 12a and the collar 13a. That is, in the related art, provision of protrusion 12a and flange 13a can suppress diffusion of vapor generated from solution 20, so that silicon carbide single crystals of good quality can be manufactured, and single crystal manufacturing apparatus 100R can be configured. It is considered that the service life of the furnace material can be extended.

<Room for Improvement in Related Technologies>
However, as a result of the inventor's investigation, it became clear that there is room for improvement in the related art, so this point will be described below.

As described above, it is important to suppress the diffusion of the vapor generated from the solution 20 in order to be able to manufacture silicon carbide single crystals of good quality and to extend the life of the furnace material constituting the single crystal manufacturing apparatus 100R. is. At this time, it is important not only to suppress the diffusion of the vapor generated from the solution 20 in the initial stage of crystal growth, but also to suppress the diffusion of the vapor generated from the solution 20 from the initial stage to the final stage of crystal growth. .

In this regard, the related art is effective from the viewpoint of suppressing diffusion of vapor generated from the solution 20 in the initial stage of crystal growth (see FIG. 2). On the other hand, in the related art, the diffusion of the vapor generated from the solution 20 cannot be sufficiently suppressed in the stage after the crystal growth has progressed. In other words, in the related art, it is difficult to sufficiently suppress the diffusion of the vapor generated from the solution 20 from the initial stage of crystal growth to the stage after the crystal growth progresses.

Specifically, FIG. 3 is a diagram showing a state after crystal growth has progressed in the related art.

As shown in FIG. 3, after the crystal growth progresses, the shaft 13 is moved or stopped to grow the silicon carbide single crystal 40, resulting in a large gap between the protrusion 12a and the collar 13a. . Therefore, the vapor generated from the solution 20 leaks through this gap and diffuses into the container 10 . Thus, it can be seen that in the related art, it is difficult to sufficiently suppress the diffusion of the vapor generated from the solution 20 from the initial stage of crystal growth to the stage after the crystal growth progresses. In other words, in the related art, there is room for improvement from the viewpoint of suppressing the diffusion of the vapor generated from the solution 20 from the initial stage of crystal growth to the stage after the crystal growth progresses.

Therefore, in the present embodiment, contrivances are made to overcome the room for improvement that exists in the related art. In the following, the technical idea of this embodiment with this ingenuity will be described.

<Configuration of Single Crystal Manufacturing Apparatus>
FIG. 4 is a diagram showing the configuration of a single-crystal manufacturing apparatus 100A according to this embodiment.

In FIG. 4, a single crystal manufacturing apparatus 100A has a container 10. As shown in FIG. The internal space of the container 10 is filled with, for example, argon gas, and a horizontally rotatable pedestal 11 is arranged. A crucible 12 is arranged on the pedestal 11 .

The crucible 12 is made of, for example, graphite, and contains a high-temperature solution 20 containing silicon (Si). A coil 14 through which a high-frequency current flows is provided on the outer periphery of the container 10 of the single-crystal manufacturing apparatus 100, and the crucible 12 is heated by induction heating based on the high-frequency current flowing through the coil 14. . As a result, the solution 20 contained in the crucible 12 is at a high temperature, and the graphite (C) that constitutes the crucible 12 is dissolved, so that the solution 20 contains carbon and silicon. A crucible lid 15 is attached to the crucible 12. The crucible lid 15 has a tubular member 15a and a connecting member 15b connected to the tubular member 15a. The connecting member 15b has a function of fixing and supporting the cylindrical member 15a, and is configured to be able to contact with the crucible 12, for example.

Next, the single-crystal manufacturing apparatus 100A is provided with a vertically movable shaft 16, and a seed crystal 30 made of silicon carbide is attached to the tip of the shaft 16. As shown in FIG. Further, the shaft 16 has a fin structure 16a attached so as to intersect the extending direction of the shaft 16. As shown in FIG. Furthermore, the inside of the shaft 16 has a hollow structure, and a thermocouple 17 for measuring the temperature near the seed crystal 30 is inserted inside the shaft 16 . Temperature measurement in the vicinity of the seed crystal 30 can also be performed by arranging a radiation thermometer having a measurement diameter smaller than the inner diameter of the shaft 16 at the upper end of the shaft 16 instead of inserting the thermocouple 17 .

The single-crystal manufacturing apparatus 100A has a control unit 50 that controls the vertical movement of the shaft 16 having the fin structure 16a. The control unit 50 is configured to control the shaft 16 having the fin structure 16a so as to move vertically through the interior of the tubular member 15a. The control unit 50 is configured to bring the lower surface of the seed crystal 30 into contact with the surface of the solution 20 contained in the crucible 12 by moving downward the shaft 16 having the seed crystal 30 attached to the tip thereof. At the same time, after bringing the lower surface of seed crystal 30 into contact with the surface of solution 20, by moving or stopping shaft 16, a single crystal made of silicon carbide can be grown on the lower surface of seed crystal 30. It is configured.

FIG. 4 shows a state in which the lower surface of seed crystal 30 is in contact with the surface of solution 20 . In this case, as shown in FIG. 4, the fin structure 16a attached to the shaft 16 is arranged at a first position P1 facing the inner wall of the cylindrical member 15a provided on the crucible lid 15. As shown in FIG.

On the other hand, FIG. 5 shows a state in which a silicon carbide single crystal 40 is grown on the lower surface of the seed crystal. In this case, as shown in FIG. 5, the fin structure 16a attached to the shaft 16 is arranged at a second position P2 facing the inner wall of the cylindrical member 15a provided on the crucible lid 15. As shown in FIG.

4 and 5, the gap between the fin structure 16a and the inner wall of the tubular member 15a when the shaft 16 having the fin structure 16a passes through the inside of the tubular member 15a is It is smaller than the distance between 16 a and the inner wall of crucible 12 .

In plan view, the tubular member 15a is included in the crucible 12, and in plan view, the fin structure 16a is included in the tubular member 15a.

The single crystal manufacturing apparatus 100A is configured as described above.

<Operation of Single Crystal Manufacturing Apparatus (Single Crystal Manufacturing Method)>
Next, the operation of the single crystal manufacturing apparatus 100A will be explained.

FIG. 6 is a flow chart for explaining the operation of the single crystal manufacturing apparatus 100A.

In FIG. 6, first, the controller 50 lowers the shaft 16 with the seed crystal 30 attached to the tip (S101). As a result, the seed crystal 30 attached to the shaft 16 contacts the surface of the solution 20 containing carbon and silicon accommodated in the crucible 12 after passing through the cylindrical member 15a provided in the crucible lid 15. (S102). At this time, the fin structure 16a attached to the shaft 16 is arranged at the first position P1 facing the inner wall of the tubular member 15a (see FIG. 4).

Next, the controller 50 slowly raises the shaft 16 (S103). Thereby, silicon carbide single crystal 40 grows on the lower surface of seed crystal 30 that is pulled up. At this time, the fin structure 16a attached to the shaft 16 moves while maintaining facing the inner wall of the tubular member 15a.

After that, when crystal growth is to be continued (S104), the process of step S103 is continued. On the other hand, when terminating the crystal growth (S104), the controller 50 stops raising the shaft 16 (S105). This completes the growth of silicon carbide single crystal 40 . At this time, the fin structure 16a attached to the shaft 16 is finally arranged at the second position P2 facing the inner wall of the tubular member 15a (see FIG. 5). As described above, a silicon carbide single crystal can be manufactured by operating single crystal manufacturing apparatus 100A.

<Features of the embodiment>
Next, feature points in this embodiment will be described.

A first feature of the present embodiment is that, as shown in FIGS. 4 and 5, for example, a crucible lid 15 is provided with a tubular member 15a, and a fin structure 16a capable of passing through the tubular member 15a is provided. is provided on the shaft 16. Based on this premise configuration, the first characteristic point is from the initial stage of crystal growth in which the lower surface of the seed crystal 30 is brought into contact with the surface of the solution 20 to the final stage in which the shaft 16 is slowly raised to complete the crystal growth. , the fin structure 16a is maintained facing the inner wall of the cylindrical member 15a. Specifically, in the initial stage of crystal growth shown in FIG. 4, the fin structure 16a is arranged at the first position P1 facing the inner wall of the cylindrical member 15a. On the other hand, at the final stage of crystal growth shown in FIG. 5, the fin structure 16a is arranged at the second position P2 facing the inner wall of the cylindrical member 15a. Therefore, from the initial stage of crystal growth shown in FIG. 4 to the final stage of crystal growth shown in FIG.

As a result, according to the present embodiment, for example, as is apparent from FIGS. can suppress the diffusion of vapor generated from the solution 20 by the presence of . That is, according to the first characteristic point of the present embodiment, as in the related art described above, the Diffusion of vapor can be suppressed. Thus, according to the present embodiment, it is possible to suppress changes in solution temperature and solution composition caused by evaporation of solution 20. As a result, silicon carbide single crystals of good quality can be manufactured, and As a result of being able to suppress the deterioration of the furnace material, which constitutes the single-crystal manufacturing apparatus 100A, the service life of the furnace material can be extended. That is, it can be seen that the first characteristic point in the present embodiment has a very useful technical significance from the viewpoint of improving the quality of silicon carbide single crystals and extending the life of furnace materials.

In particular, as shown in FIGS. 4 and 5, the gap between the fin structure 16a and the inner wall of the tubular member 15a when the shaft 16 having the fin structure 16a passes through the inside of the tubular member 15a is It is smaller than the distance between the structure 16 a and the inner wall of the crucible 12 . Therefore, the vapor generated from the solution 20 is less likely to pass through the gap between the fin structure 16a and the inner wall of the cylindrical member 15a. diffusion can be effectively suppressed.

Furthermore, according to the first characteristic point of the present embodiment, the diffusion of the vapor generated from the solution 20 can be suppressed, which also means that the heat dissipation effect of the vapor can be suppressed. It can also be said to be easier to maintain. For example, if there is a temperature difference of 10° C. or more inside the silicon carbide single crystal during growth (during growth), the silicon carbide single crystal will break due to thermal stress. Distribution is important. Therefore, the first feature that the crystal temperature can be easily maintained is also useful from the viewpoint of suppressing breakage of the silicon carbide single crystal due to thermal stress.

Moreover, the first characteristic point of the present embodiment is excellent in that the above advantages can be easily obtained even when the silicon carbide single crystal is elongated. Specifically, by changing the length of the cylindrical member 15a provided in the crucible lid 15 in accordance with the lengthening of the silicon carbide single crystal, the fin can be formed from the initial stage of crystal growth to the final stage of crystal growth. The structure 16a can be arranged to face the inner wall of the tubular member 15a. This means that diffusion of vapor generated from solution 20 can be suppressed even when the silicon carbide single crystal is elongated. That is, according to the first characteristic point of the present embodiment, it is possible to flexibly cope with the lengthening of the silicon carbide single crystal, to manufacture a silicon carbide single crystal of good quality, and to manufacture the single crystal manufacturing apparatus 100A. It is also possible to extend the life of the furnace material that constitutes the. Furthermore, according to the first characteristic point, even if the silicon carbide single crystal is lengthened, by correspondingly changing the length of the cylindrical member 15a, a configuration that facilitates maintaining the crystal temperature can be easily realized. can do. From this, it can be said that even when the length of the silicon carbide single crystal is lengthened, it is also very excellent in that breakage of the silicon carbide single crystal due to thermal stress can be suppressed.

Next, a second characteristic point of the present embodiment is that, as shown in FIGS. The difference lies in that the lid 15 is provided with a cylindrical member 15a. Thereby, the cylindrical member 15a for suppressing the diffusion of vapor generated from the solution 20 can be attached from the initial stage of crystal growth to the final stage of crystal growth without complicating the structure of the crucible 12 itself. For example, crucible 12 itself needs to be replaced each time a silicon carbide single crystal is manufactured. Therefore, when the cylindrical member 15a is attached to the crucible 12 itself, not only does the structure of the crucible 12 itself become complicated, but also the weight of the crucible 12 itself increases, and the work load for attaching the crucible 12 increases. Furthermore, when the cylindrical member 15a is attached to the crucible 12 itself, the cylindrical member 15a is used because not only the crucible 12 but also the cylindrical member 15a is replaced each time the silicon carbide single crystal is manufactured. The cost of doing so will also increase.

On the other hand, when the cylindrical member 15a is provided on the crucible lid 15 that can be attached to the crucible 12, the structure of the crucible 12 itself is simplified and the weight is reduced. Furthermore, unlike the crucible 12, the crucible lid 15 itself does not need to be replaced each time a silicon carbide single crystal is manufactured. The cost of using 15a can be suppressed. As described above, the second feature of the present embodiment is that the structure of crucible 12 itself, which must be replaced each time a silicon carbide single crystal is manufactured, can be simplified and reduced in weight, and cylindrical member 15a can be reused. As a result, the cost of using the tubular member 15a can be reduced, which is very useful.

<Modification 1>
FIG. 7 is a diagram showing the configuration of a single-crystal manufacturing apparatus 100B in Modification 1. As shown in FIG.

In FIG. 7, single-crystal manufacturing apparatus 100B has a plurality of fin structures 16a attached so as to intersect the extending direction of shaft 16. As shown in FIG. As shown in FIG. 7, in the single crystal manufacturing apparatus 100B, a plurality of fin structures 16a (three fin structures 16a in FIG. 7) are arranged at positions facing the inner wall of the cylindrical member 15a. . Thus, according to Modification 1, diffusion of vapor generated from the solution 20 can be effectively suppressed.

Here, FIG. 7 shows a state in which the lower surface of the seed crystal 30 is in contact with the surface of the solution 20 (initial stage of crystal growth). In this case, three fin structures 16a are arranged at positions facing the inner wall of the tubular member 15a. On the other hand, FIG. 8 shows a state in which a silicon carbide single crystal 40 is grown on the lower surface of the seed crystal (at the end of crystal growth). Also in this case, three fin structures 16a are arranged at positions facing the inner wall of the tubular member 15a.

That is, in Modification 1, for example, the shaft 16 is raised such that the three fin structures 16a are always arranged at positions facing the inner wall of the tubular member 15a. In other words, conceptually speaking, in Modification 1, the number of fin structures 16a arranged at positions facing the inner wall of the cylindrical member 15a is the same from the initial stage of crystal growth to the final stage of crystal growth. As shown, the shaft 16 is pulled up. Thus, according to Modification 1, the same positional relationship between the cylindrical member 15a and the plurality of fin structures 16a can be maintained from the initial stage of crystal growth to the final stage of crystal growth. This means that the structure that suppresses diffusion of vapor generated from the solution 20 can be made uniform from the initial stage of crystal growth to the final stage of crystal growth. As a result, according to Modification 1, it is possible to obtain the same vapor diffusion suppression effect from the initial stage of crystal growth to the final stage of crystal growth.

In addition, in Modification 1, as shown in FIGS. 7 and 8, a connecting portion C1 between the connecting member 15b and the tubular member 15a is provided at a lower portion on the side surface of the tubular member 15a. Thus, according to Modification 1, even when the length of the silicon carbide single crystal is increased, the vapor generated from the solution 20 is uniformly diffused from the initial stage of crystal growth to the final stage of crystal growth. It has the advantage of being able to be suppressed to That is, in the case of lengthening the silicon carbide single crystal, from the viewpoint of uniformly suppressing the diffusion of the vapor generated from the solution 20 from the initial stage of crystal growth to the final stage of crystal growth, the connection member 15b and the cylindrical member It is desirable to provide the connecting portion C1 with the cylindrical member 15a at a lower portion on the side surface of the cylindrical member 15a.

<Modification 2>
FIG. 9 is a diagram showing the configuration of a single-crystal manufacturing apparatus 100C in Modification 2. As shown in FIG.

In FIG. 9, in the single-crystal manufacturing apparatus 100C, the connecting portion C2 between the connecting member 15b and the tubular member 15a is provided at the upper portion of the side surface of the tubular member 15a. Thus, according to Modification 2, the facing portion between the inner wall of the cylindrical member 15a and the fin structure 16a can be brought closer to the surface of the solution 20. FIG. As a result, according to Modification 2, the effect of suppressing diffusion of vapor generated from the solution 20 can be enhanced. Furthermore, by arranging the fin structure 16a close to the surface of the solution 20, it is possible to suppress the heat dissipation effect of the steam, so that it is possible to obtain the advantage that the crystal temperature can be easily maintained.

<Modification 3>
FIG. 10 is a diagram showing the configuration of a single-crystal manufacturing apparatus 100D in Modification 3. As shown in FIG.

In FIG. 10, in single crystal manufacturing apparatus 100D, wall member 18 is attached to the side wall of crucible 12, and wall member 18 is provided with opening lid 18a having opening 19. As shown in FIG. Thus, in the single-crystal manufacturing apparatus 100D, the control unit 50 can vertically move the shaft 16 having the fin structure 16a so that the shaft 16 passes through the opening 19 and the cylindrical member 15a. is configured to

According to Modification 3 configured in this way, by attaching the wall member 18 to the side wall of the crucible 12, the wall thickness of the crucible 12 itself can be reduced, and as a result, the weight of the crucible 12 can be further reduced. can do. Further, according to Modification 3, the crucible 12 can be surrounded by the wall member 18 to which the opening lid 18a is attached. Since the heat radiation effect can also be suppressed, it is possible to obtain the advantage that the crystal temperature can be easily maintained.

Although the invention made by the present inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and can be variously modified without departing from the gist of the invention. Needless to say.

Reference Signs List 10 container 11 pedestal 12 crucible 12a projection 13 shaft 13a flange 14 coil 15 crucible lid 15a cylindrical member 16 shaft 16a fin structure 17 thermocouple 18 wall member 18a opening lid 19 opening 20 solution 30 seed crystal 40 silicon carbide Single crystal 50 Control unit 100 Single crystal manufacturing apparatus 100R Single crystal manufacturing apparatus 100A Single crystal manufacturing apparatus 100B Single crystal manufacturing apparatus 100C Single crystal manufacturing apparatus 100D Single crystal manufacturing apparatus C1 Connection part C2 Connection part P1 First position P2 Second position

Claims (10)

(a) bringing the lower surface of the seed crystal into contact with the surface of the solution containing carbon and silicon contained in the crucible by moving downward a shaft having a seed crystal attached to the tip;
(b) growing a single crystal made of silicon carbide on the lower surface of the seed crystal;
A single crystal manufacturing method comprising
the shaft has a fin structure attached so as to intersect the extending direction of the shaft;
A lid is attached to the crucible,
The lid has a tubular member and a connection member connected to the tubular member,
In the step (a), when the lower surface of the seed crystal is brought into contact with the surface of the solution, the fin structure is arranged at a first position facing the inner wall of the tubular member,
In the step (b), the fin structure is arranged at a second position facing the inner wall of the cylindrical member when the shaft is moved or stopped. In the single crystal manufacturing method according to claim 1,
The gap between the fin structure and the inner wall of the tubular member when the shaft having the fin structure passes through the tubular member is the gap between the fin structure and the inner wall of the crucible. A single crystal manufacturing method that is smaller than the distance. In the single crystal manufacturing method according to claim 1 or 2,
The method for producing a single crystal, wherein the cylindrical member is enclosed in the crucible in plan view. In the single crystal manufacturing method according to any one of claims 1 to 3,
The method for manufacturing a single crystal, wherein the fin structure is included in the cylindrical member in plan view. In the single crystal manufacturing method according to any one of claims 1 to 4,
The method for manufacturing a single crystal, wherein the connecting portion between the connecting member and the tubular member is provided at a lower portion on the side surface of the tubular member. In the single crystal manufacturing method according to any one of claims 1 to 4,
The method for manufacturing a single crystal, wherein the connecting portion between the connecting member and the tubular member is provided at an upper portion on the side surface of the tubular member. In the single crystal manufacturing method according to any one of claims 1 to 6,
a side wall of the crucible is attached to a wall member;
An opening lid having an opening is attached to the wall member,
In plan view, the fin structure is included in the opening,
In the step (a), the shaft having the fin structure moves downward so that the shaft passes through the opening and the cylindrical member;
In the step (b), the single crystal manufacturing method moves or stops the shaft having the fin structure so that the shaft passes through the inside of the tubular member and the opening. In the single crystal production method according to any one of claims 1 to 7,
the shaft has a plurality of fin structures arranged in the extending direction of the shaft;
In step (a), the number of fin structures arranged at positions facing the inner wall of the tubular member is equal to the number of fin structures arranged at positions facing the inner wall of the tubular member in step (b). a single crystal manufacturing method, wherein the number of the fin structures is equal to the number of the fin structures. A single crystal manufacturing apparatus capable of disposing a crucible having a lid having a cylindrical member,
The single crystal manufacturing apparatus is
a shaft to which a seed crystal can be attached at the tip;
a control unit for vertically moving the shaft;
with
the shaft has a fin structure attached so as to intersect the extending direction of the shaft;
The single-crystal manufacturing apparatus, wherein the controller controls the shaft having the fin structure so that the shaft moves vertically through the interior of the tubular member. A crucible lid attachable to a crucible containing a solution containing carbon and silicon,
The crucible lid has a shaft having a seed crystal attached to the tip thereof, and has a cylindrical member having a fin structure attached so as to intersect with the extending direction of the shaft, through which the shaft passes. lid.

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