CN115726028A - Silicon carbide crystal growth device and control method - Google Patents

Abstract

The invention discloses a silicon carbide crystal growth device and a control method, wherein the silicon carbide crystal growth device comprises: a quartz cover; the device comprises a first crucible and a second crucible, wherein the first crucible is provided with a growth cavity with an open end, a graphite support for placing seed crystals is arranged in the growth cavity, the seed crystals and the graphite support divide the growth cavity into a first cavity and a second cavity, a protection assembly is arranged in the first cavity, and the second crucible is provided with a third cavity with an open top; the driving module is used for driving the first crucible to rotate around a preset straight line K between a first position and a second position, in the first position, the second chamber is positioned right above the first chamber, and the silicon surface of the seed crystal is arranged opposite to the circular through hole and faces downwards; in the second position, the second chamber is in butt-joint communication with the third chamber, and the carbon surface of the seed crystal faces downwards. According to the silicon carbide crystal growing device, self-sticking of the seed crystals can be realized, and simultaneously, continuous growth of four-inch silicon carbide crystals and six-inch silicon carbide crystals can be realized.

Description

Silicon carbide crystal growth device and control method

Technical Field

The invention relates to the field of crystal growth, in particular to a silicon carbide crystal growth device and a control method.

Background

Silicon carbide is a third-generation semiconductor material developed after a first-generation semiconductor material, namely silicon and a second-generation semiconductor material, namely gallium arsenide, and compared with the traditional semiconductor material represented by silicon and gallium arsenide, the silicon carbide has the characteristics of wide band gap, high critical breakdown electric field, high thermal conductivity, low dielectric constant, high carrier saturation concentration and the like, and can be applied to the fields of aviation and aerospace detection, nuclear energy detection and development, high temperature and radiation resistance of satellites, automobile engines and the like. However, the problems of slow crystal growth speed, low productivity and the like exist in any preparation method of the silicon carbide crystal, so that the price of the silicon carbide crystal is extremely high, and therefore, how to improve the production efficiency of the silicon carbide crystal is the key to reduce the production cost.

In addition, in the related art, the seed crystal and the graphite cover are generally realized by curing and sintering the carbon binder and the carbon-containing organic matter, the problem of uneven gluing is easy to occur, the sticking efficiency of the seed crystal is low, and the growth quality and the production efficiency of the crystal are influenced.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a silicon carbide crystal growing device which can realize self-adhesion of seed crystals and can realize continuous growth of four-inch silicon carbide crystals and six-inch silicon carbide crystals.

The invention also provides a control method of the silicon carbide crystal growth device.

A silicon carbide crystal growing apparatus according to an embodiment of the present invention includes: a quartz cover defining an accommodating space; the first crucible and the second crucible are both located in the accommodating space, the first crucible is located above the second crucible, the first crucible is provided with a growth cavity with an open end, a graphite support for placing seed crystals is arranged in the growth cavity, the graphite support is formed into a ring shape, a circular through hole is defined in the middle of the graphite support, a plurality of vent holes are formed in the corresponding parts of the graphite support and the seed crystals in the vertical direction, the seed crystals and the graphite support divide the growth cavity into a first cavity and a second cavity, a protection assembly is arranged in the first cavity, the protection assembly divides the first cavity into a first sub-cavity and a second sub-cavity, the protection assembly is only suitable for gas to pass through, the second sub-cavity is located on the side, away from the seed crystals, of the first cavity, first silicon carbide powder is arranged in the second sub-cavity, the second crucible is provided with a third cavity with an open top, and second silicon carbide powder is arranged in the third cavity; the driving module is connected with the first crucible and used for driving the first crucible to rotate around a preset straight line K between a first position and a second position, in the first position, the second chamber is positioned right above the first chamber, the silicon surface of the seed crystal is opposite to the circular through hole and faces downwards, and the carbon surface of the seed crystal faces upwards; in the second position, the second chamber is positioned right below the first chamber, the second chamber is in butt joint communication with the third chamber, the carbon surface of the seed crystal faces downwards, and the silicon surface of the seed crystal faces upwards.

According to the silicon carbide crystal growing device provided by the embodiment of the invention, the first crucible and the second crucible are arranged in the quartz cover, the driving module is suitable for driving the first crucible to rotate between the first position and the second position around the preset straight line K, before crystal growth, the first crucible can be controlled to rotate to the first position through the driving module, then the seed crystal is placed on the graphite support of the first crucible, the first crucible can be controlled to be kept at the first position, the first crucible is heated for the first preset time to grow the four-inch silicon carbide crystal on the silicon surface of the seed crystal, in the crystal growth process, part of silicon carbide gas can be condensed between the seed crystal and the graphite support through the vent hole to realize fixation between the seed crystal and the graphite support, so that self-adhesion between the seed crystal and the graphite support is realized, defects caused by a gluing method and a mechanical fixing method can be effectively avoided, then the first crucible is controlled to rotate to the second position through the first position, the second crucible is heated for the second preset time to grow the six-inch silicon carbide crystal on the carbon surface of the seed crystal, meanwhile, the first crucible assembly is arranged in the first crucible, the first crucible assembly, the second crucible is controlled to rotate to prevent the fourth-inch silicon carbide crystal from being polluted by the first crucible, the second crucible assembly, the silicon carbide crystal growth efficiency of the first crucible is improved, and the silicon carbide crystal is favorably, and the silicon carbide crystal growth process, and the silicon carbide crystal growth efficiency of the fourth-silicon carbide crystal is improved, and the silicon carbide crystal growth process, and the silicon carbide crystal is favorable for the silicon carbide crystal growth process, and the silicon is realized, and the silicon carbide crystal growth efficiency of the silicon carbide crystal is improved, and the silicon carbide crystal growth process, and the silicon is improved.

In some embodiments of the invention, the guard assembly comprises: the protection plate is connected with the inner peripheral wall of the first chamber and provided with a plurality of through hole groups, the through hole groups are uniformly arranged on the protection plate, each through hole group comprises a first through hole and a plurality of second through holes, and the second through holes are arranged around the first through holes; the material blocking part comprises a first blocking part, a connecting rod and a second blocking part, the first blocking part and the second blocking part are respectively arranged at two ends of the connecting rod, the connecting rod penetrates through the first through hole and can move up and down relative to the protection plate, the cross sectional area of the first blocking part and the cross sectional area of the second blocking part are larger than that of the first through hole, the first blocking part is provided with a third through hole, the third through hole and at least one second through hole are oppositely arranged in the vertical direction, the first blocking part is matched with the protection plate in a blocking mode at the first position, and the second blocking part is located right below the first blocking part; in the second position, the second stopping portion is matched with the protection plate in a stopping manner, and the first stopping portion is located right below the second stopping portion.

In some embodiments of the present invention, the shielding assembly includes a striker plate, the striker plate has a plurality of air flow channels, each air flow channel penetrates through the striker plate in a thickness direction of the striker plate, and the air flow channel includes a straight section and a bent section.

In some embodiments of the invention, the graphite tray comprises: the outer graphite support is formed into a ring shape and is connected with the first crucible; the inner graphite support is connected with the outer graphite support, the circular through holes and the plurality of vent holes are formed in the inner graphite support, and the seed crystal is arranged on the top wall of the inner graphite support at the first position.

In some embodiments of the invention, the inner graphite support comprises: the graphite rings are sequentially sleeved and arranged at intervals, the central axes of the graphite rings are on the same straight line, and two adjacent graphite rings are spaced to define the annular vent holes; the graphite rod is connected between a plurality of graphite rings to be fixed, the graphite rod is a plurality of, and is a plurality of the graphite rod is in the internal graphite holds in the palm upwards interval the arranging in circumference of holding in the palm.

In some embodiments of the invention, the gap between two adjacent graphite rings is 0.5mm to 1.5mm.

In some embodiments of the present invention, the silicon carbide crystal growing apparatus further comprises: a perforated plate disposed within the third chamber, the perforated plate configured to be suitable for only gas to pass through, the perforated plate located above the second silicon carbide powder.

In some embodiments of the present invention, the silicon carbide crystal growing apparatus further includes a first induction coil, a second induction coil and a third induction coil sequentially arranged in an up-down direction, the first induction coil, the second induction coil and the third induction coil all surround the quartz cover, the second induction coil is movable in the up-down direction between a third position and a fourth position, in the third position, a distance between the second induction coil and the bottom of the second sub-chamber is L1, and L1 satisfies: l1 is more than or equal to 20mm and less than or equal to 50mm, and in the fourth position, the distance between the second induction coil and the third induction coil is L2, and L2 satisfies the following conditions: l2 is more than or equal to 2mm and less than or equal to 10mm.

The control method of the silicon carbide crystal growing device comprises the following steps: in a first crystal growth stage, controlling the first crucible to be kept at the first position, and heating the first crucible for a first preset time to grow a four-inch silicon carbide crystal on the silicon surface of the seed crystal; a transition stage, controlling the first crucible to rotate from the first position to the second position; and in a second crystal growth stage, controlling the first crucible to be kept at the second position, and heating the second crucible for a second preset time to grow a six-inch silicon carbide crystal on the carbon surface of the seed crystal, wherein the first preset time is shorter than the second preset time.

According to the control method of the silicon carbide crystal growth device provided by the embodiment of the invention, before crystal growth, the first crucible can be controlled to rotate to the first position through the driving module, then the seed crystal is placed on the graphite support of the first crucible, the first crucible can be controlled to be kept at the first position, the first crucible is heated for the first preset time to grow the four-inch silicon carbide crystal on the silicon surface of the seed crystal, and part of silicon carbide gas can be condensed between the seed crystal and the graphite support through the vent hole to realize fixation between the seed crystal and the graphite support, so that self-adhesion between the seed crystal and the graphite support is realized, defects caused by a gluing method and a mechanical fixation method can be effectively avoided, then the first crucible is controlled to rotate to the second position from the first position, and the second crucible is heated for the second preset time to grow the six-inch silicon carbide crystal on the carbon surface of the seed crystal, and therefore, continuous growth of the four-inch silicon carbide crystal and the six-inch silicon carbide crystal can be realized, and the crystal growth efficiency can be improved.

In some embodiments of the present invention, the silicon carbide crystal growing apparatus is the above silicon carbide crystal growing apparatus, and in the first crystal growth stage, the second induction coil is controlled to be in the third position, the first induction coil and the second induction coil are operated, and the third induction coil is not operated; controlling the second induction coil to move from the third position to the fourth position during the transition phase; and in the second crystal growth stage, controlling the second induction coil to be in a fourth position, enabling the first induction coil not to work, and enabling the second induction coil and the third induction coil to work.

In some embodiments of the invention, the control method further comprises: and in the annealing stage, the first crucible is controlled to be kept at the second position, the second induction coil is controlled to be located at the third position, the first induction coil and the second induction coil work, and the third induction coil does not work.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

FIG. 1 is a schematic view of a silicon carbide crystal growing apparatus according to a first embodiment of the present invention, wherein the first crucible is in a first position and the second induction coil is in a third position;

FIG. 2 is a schematic illustration of a silicon carbide crystal growing apparatus according to a first embodiment of the present invention, with the first crucible in the second position and the second induction coil in the fourth position;

FIG. 3 is a schematic view of a silicon carbide crystal growing apparatus according to a second embodiment of the present invention, wherein the first crucible is in a first position and the second induction coil is in a third position;

FIG. 4 is a schematic view of a silicon carbide crystal growing apparatus according to a second embodiment of the present invention, wherein the first crucible is in a second position and the second induction coil is in a fourth position;

FIG. 5 is a schematic view of a silicon carbide crystal growing apparatus according to a second embodiment of the present invention, wherein the first crucible is in a second position and the second induction coil is in a third position;

FIG. 6 is a schematic view of a fender assembly according to a second embodiment of the invention, wherein the first stop portion is engaged with the fender stop;

FIG. 7 is a schematic view of a fender assembly according to a second embodiment of the invention, wherein the second stop portion is engaged with the fender stop;

FIG. 8 is a schematic plan view showing the structure of a guard plate according to a second embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a material blocking member according to a second embodiment of the invention;

FIG. 10 is a schematic structural diagram of a material blocking member according to a third embodiment of the invention;

FIG. 11 is a schematic view of a shield assembly according to a fourth embodiment of the present invention;

FIG. 12 is a schematic structural view of a graphite holder according to a second embodiment of the present invention;

fig. 13 is a schematic structural view of an inner graphite support according to a second embodiment of the present invention;

fig. 14 is a schematic structural view of an outer graphite support according to a second embodiment of the present invention;

figure 15 is a schematic diagram of a method of controlling a silicon carbide crystal growing apparatus according to an embodiment of the invention.

Reference numerals:

a silicon carbide crystal growing apparatus 100;

a quartz cover 10; an accommodation space 11;

a first crucible 20; a first chamber 21; the first sub-chamber 211; second subchamber 212; a first silicon carbide powder 213; a second chamber 22;

a graphite holder 30; an outer graphite holder 31; a connection hole 311; an inner graphite carrier 32; a graphite ring 321; a graphite rod 322; a circular through hole 33; a vent hole 34;

a seed crystal 40; a silicon surface 41; a carbon face 42;

a second crucible 50; a third chamber 51; second silicon carbide powder 52; a perforated plate 53;

a shield assembly 60; a shielding plate 61; a group of through holes 611; a first through hole 612; a second through-hole 613; a material blocking member 62; a first stopper 621; a third through hole 6211; a connecting rod 622; a threaded segment 6221; a second stopper 623; an annular plate 624; a connecting plate 625;

a striker plate 63; an air flow channel 631; a straight line segment 632; a bending section 633;

a drive module 70;

a first induction coil 81; a second induction coil 82; a third induction coil 83;

a four inch silicon carbide crystal 91; six inch silicon carbide crystal 92.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize the applicability of other processes and/or the use of other materials.

An apparatus 100 for growing a silicon carbide crystal and a method of controlling the same according to embodiments of the present invention are described below with reference to figures 1-15.

Referring to fig. 1 and 2, a silicon carbide crystal growing apparatus 100 according to an embodiment of the present invention may include: a quartz cover 10, a first crucible 20, a second crucible 50, a shield assembly 60 and a driving module 70.

Referring to fig. 1, a quartz cover 10 defines a containing space 11, a first crucible 20 and a second crucible 50 are both located in the containing space 11, the first crucible 20 is located above the second crucible 50, the first crucible 20 has a growth chamber with one end open, a graphite holder 30 for placing a seed crystal 40 is arranged in the growth chamber, the graphite holder 30 is formed in a ring shape and the middle portion defines a circular through hole 33 (with reference to fig. 1 and 12), and a plurality of vent holes 34 are arranged at corresponding portions of the graphite holder 30 and the seed crystal 40 in the up-down direction. In general, referring to fig. 5 and 12, the two end surfaces of the seed crystal 40 in the thickness direction are a silicon surface 41 and a carbon surface 42, respectively, the silicon surface 41 being suitable for growing a four-inch silicon carbide crystal 91, and the carbon surface 42 being suitable for growing a six-inch silicon carbide crystal 92.

For example, referring to FIG. 1, the susceptor 30 is formed in a generally circular ring shape, the plurality of vents 34 are evenly spaced apart on the susceptor 30, the first crucible 20 is in a first position in which the seed crystal 40 is placed on the top wall of the susceptor 30, the silicon surface 41 of the seed crystal 40 faces downward, the carbon surface 42 of the seed crystal 40 faces upward, and silicon carbide gas can pass through the vents 34 from bottom to top and condense between the susceptor 30 and the silicon surface 41 of the seed crystal 40 to hold the seed crystal 40 under the influence of a temperature gradient.

Referring to fig. 1, the seed crystal 40 and the graphite holder 30 divide the growth chamber into a first chamber 21 and a second chamber 22, the first chamber 21 is provided with a shield assembly 60, the shield assembly 60 divides the first chamber 21 into a first sub-chamber 211 and a second sub-chamber 212, and the shield assembly 60 is configured to be only suitable for gas to pass through, for example, the shield assembly 60 is provided with a plurality of gas flow channels, each gas flow channel penetrates through the shield assembly 60 in the thickness direction of the shield assembly 60, each gas flow channel may have a diameter of 30 μm to 100 μm, and the first silicon carbide powder 213 may have a particle size of 300um to 1000um, so that the shield assembly 60 can be only suitable for gas to pass through by making the diameter of the gas flow channel 631 smaller than the diameter of the first silicon carbide powder 213. It is understood that the first silicon carbide powder 213 is prevented from flowing through the shield assembly 60 toward the four-inch silicon carbide crystal 91 during the rotation of the first crucible 20 from the first position (see fig. 1) to the second position (see fig. 2), in other words, the shield assembly 60 prevents the first silicon carbide powder 213 from contaminating the four-inch silicon carbide crystal 91 during the rotation of the first crucible 20 from the first position to the second position.

Referring to fig. 1, second sub-chamber 212 is located on a side of first sub-chamber 211 facing away from seed crystal 40, e.g., second sub-chamber 212 is located on a lower side of first sub-chamber 211 (as shown in fig. 1), first silicon carbide powder 213 is disposed in second sub-chamber 212, second crucible 50 has a third chamber 51 with an open top, and second silicon carbide powder 52 is disposed in third chamber 51, wherein first silicon carbide powder 213 and second silicon carbide powder 52 may be the same in composition and particle size.

Referring to fig. 1, a driving module 70 is connected to the first crucible 20, the driving module 70 is located outside the quartz cover 10, an output shaft of the driving module 70 passes through the quartz cover 10 and is connected to the first crucible 20, the driving module 70 is used for driving the first crucible 20 to rotate around a preset straight line K between a first position (refer to fig. 1) and a second position (refer to fig. 2), as shown in fig. 1, in the first position, the second chamber 22 is located right above the first chamber 21, the silicon surface 41 of the seed crystal 40 is opposite to and downward from the circular through hole 33, and the carbon surface 42 of the seed crystal 40 is upward; in the second position, shown in fig. 2, the second chamber 22 is directly below the first chamber 21, the second chamber 22 is in abutting communication with the third chamber 51, the carbon face 42 of the seed crystal 40 is facing downward, and the silicon face 41 of the seed crystal 40 is facing upward. Wherein a predetermined straight line K extends in the horizontal direction and passes through the center of the first crucible 20.

It is understood that the first crucible 20 may be controlled to rotate to the first position by the driving module 70 before the silicon growth (refer to fig. 1), then the seed crystal 40 is placed on the graphite support 30 of the first crucible 20, the first crucible 20 may be controlled to remain at the first position during the silicon growth, the first crucible 20 is heated for a first preset time to grow a four-inch silicon carbide crystal 91 on the silicon surface 41 of the seed crystal 40, and a part of the silicon carbide gas may be condensed between the silicon surface 41 of the seed crystal 40 and the graphite support 30 through the vent holes 34 to achieve fixation between the seed crystal 40 and the graphite support 30, thereby achieving self-adhesion between the seed crystal 40 and the graphite support 30, effectively avoiding defects caused by the adhesion method and the mechanical fixation method, and then the first crucible 20 is controlled to rotate from the first position to the second position (refer to fig. 2), the second crucible 50 is heated for a second preset time to grow a six-inch silicon carbide crystal 92 (refer to fig. 2) on the carbon surface 42 of the seed crystal 40, thereby achieving continuous silicon growth of four inches 91 and six-inches 92, and improving the silicon carbide crystal growth efficiency.

In view of this, according to the silicon carbide crystal growth apparatus 100 of the embodiment of the present invention, by disposing the first crucible 20 and the second crucible 50 in the quartz housing 10, and the driving module 70 is adapted to drive the first crucible 20 to rotate about the predetermined straight line K between the first position and the second position, before the growth of the crystal, the first crucible 20 may be controlled to rotate to the first position by the driving module 70, and then the seed crystal 40 may be placed on the graphite holder 30 of the first crucible 20, during the growth process, the first crucible 20 may be controlled to be held at the first position, the first crucible 20 may be heated for a first predetermined time to grow four inches of silicon carbide 91 on the silicon surface 41 of the seed crystal 40, and a portion of the silicon carbide gas may be condensed between the seed crystal 40 and the graphite holder 30 through the vent 34 to achieve fixation between the seed crystal 40 and the graphite holder 30, thereby achieving a self-bonding between the first crucible 20 and the graphite holder 30 for a time, defects caused by the adhesive and mechanical fixation methods may be effectively avoided, then controlling the first crucible 20 to rotate from the first position to the second position, heating the second crucible 50 to the second crucible 20 to the graphite holder 30, thereby preventing the second crucible 20 from being continuously contaminated by the silicon carbide powder 92, and preventing the first crucible 20 and preventing the second crucible 20 from being disposed in the silicon carbide assembly 20, and preventing the second crucible 20 from being rotated to the second crucible 20, and preventing the silicon carbide powder from being contaminated by the silicon carbide powder, thereby facilitating the silicon carbide powder 92, and preventing the silicon carbide powder from being disposed in the silicon carbide assembly, and preventing the silicon carbide assembly from being disposed in the silicon carbide assembly 92, and preventing the silicon carbide assembly from being continuously growing the silicon carbide assembly, and preventing the silicon carbide assembly from being disposed in the silicon carbide assembly from being disposed in the silicon carbide assembly 20.

In some embodiments of the present invention, referring to fig. 3, 6 and 7, the shield assembly 60 includes a shield plate 61 and a material blocking member 62, the shield plate 61 is connected to the inner peripheral wall of the first chamber 21, the shield plate 61 is provided with a plurality of through hole groups 611, the plurality of through hole groups 611 are uniformly arranged on the shield plate 61, each through hole group 611 includes a first through hole 612 and a plurality of second through holes 613, the plurality of second through holes 613 are arranged around the first through hole 612, for example, as shown in fig. 8, the shield plate 61 and the material blocking member 62 are both graphite members, the shield plate 61 is a circular plate, the plurality of through hole groups 611 are uniformly arranged in an annular array on the shield plate 61, each through hole group 611 includes a first through hole 612 and twelve second through holes 613, the diameter of the first through hole 612 is greater than that of the second through hole 613, and the twelve second through holes 613 are arranged in two circles, four second through holes 613 are located in an inner circle, and eight second through holes 613 are located in an outer circle.

Referring to fig. 9, the blocking member 62 includes a first blocking portion 621, a connecting rod 622 and a second blocking portion 623, the first blocking portion 621 and the second blocking portion 623 are respectively disposed at two ends of the connecting rod 622, the connecting rod 622 is disposed through the first through hole 612 and can move up and down relative to the protection plate 61 (see fig. 6 and 7), cross-sectional areas of the first blocking portion 621 and the second blocking portion 623 are larger than that of the first through hole 612, the first blocking portion 621 is provided with a third through hole 6211, the third through hole 6211 and the at least one second through hole 613 are disposed in an up-down direction, and referring to fig. 3 and 6, in a first position, the first blocking portion 621 cooperates with the protection plate 61, and the second blocking portion 623 is located right below the first blocking portion 621; referring to fig. 4 and 7, in the second position, the second stopping portion 623 is in stopping fit with the protection plate 61, and the first stopping portion 621 is located right below the second stopping portion 623.

It can be understood that, by making the protection assembly 60 include the protection plate 61 and the material blocking member 62, in the first position, the first stopping portion 621 cooperates with the protection plate 61 under the action of gravity, the second stopping portion 623 is located under the first stopping portion 621, at this time, the second through hole 613 and at least a portion of the third through hole 6211 are disposed opposite to each other, during the growth process of the four-inch silicon carbide crystal 91, silicon carbide gas can flow to the seed crystal 40 through the second through hole 613 and the third through hole 6211 from bottom to top under the action of a temperature gradient, which is beneficial to ensuring the normal growth of the four-inch silicon carbide crystal 91, and meanwhile, during the rotation of the first crucible 20 from the first position to the second position, under the action of gravity, the second stopping portion 623 cooperates gradually with the protection plate 61 to block the first through hole 612 and the second through hole 613, so that the first silicon carbide powder 213 can be prevented from contaminating the four-inch silicon carbide crystal 91, which is beneficial to ensuring the final growth quality of the four-inch silicon carbide crystal 91.

Referring to fig. 6, the first stopping portion 621 is provided with a plurality of third through holes 6211, the plurality of third through holes 6211 are uniformly spaced on the first stopping portion 621, and the cross-sectional area of each third through hole 6211 is smaller than the cross-sectional area of each second through hole 613, so that in the growth process of the four-inch silicon carbide crystal 91, when silicon carbide gas sequentially passes through the second through holes 613 and the third through holes 6211 from bottom to top and flows to the seed crystal 40, the second through holes 613 and the third through holes 6211 can also play a role in filtering large-particle impurities, which is favorable for further ensuring the growth quality of the four-inch silicon carbide crystal 91. Of course, referring to fig. 10, the first stopper 621 can also be formed by splicing a circular plate 624 and a plurality of connecting plates 625, wherein the circular plate 624 and the plurality of connecting plates 625 define a plurality of third through holes 6211 therebetween, for example, as shown in fig. 10, four third through holes 6211 are defined between the circular plate 624 and four connecting plates 625.

Alternatively, as shown in fig. 9, the upper end and the lower end of the connecting rod 622 are respectively provided with a threaded section 6221, and the threaded section 6221 of the connecting rod 622 is respectively in threaded connection with the first stopping portion 621 and the second stopping portion 623 through the threaded section 6221, thereby facilitating the installation and the removal of the blocking member 62 on the protection plate 61.

In other embodiments of the present invention, referring to fig. 11, the shielding assembly 60 includes a baffle plate 63, the baffle plate 63 has a plurality of air flow channels 631, each air flow channel 631 penetrates the baffle plate 63 in a thickness direction of the baffle plate 63, the air flow channels 631 include a straight line segment 632 and a bent segment 633, for example, in a first position, as shown in fig. 1 and 11, one end of the straight line segment 632 is communicated with the first sub-chamber 211, the other end of the straight line segment 632 extends toward a direction close to the second sub-chamber 212, one end of the bent segment 633 is communicated with the other end of the straight line segment 632, and the other end of the bent segment 633 is communicated with the second sub-chamber 212. It is understood that by providing the gas passages with the bent sections 633, the minute first silicon carbide powder 213 flowing into the gas flow passages 631 can accumulate in the bent sections 633 during the rotation of the first crucible 20 from the first position to the second position, thereby facilitating further prevention of contamination of the four inch silicon carbide crystal 91 with the first silicon carbide powder 213.

In some embodiments of the present invention, and as illustrated with reference to fig. 1, 12-13, the graphite tray 30 includes: an outer graphite holder 31 and an inner graphite holder 32, the outer graphite holder 31 being formed in a ring shape, the outer graphite holder 31 being connected to the first crucible 20, the inner graphite holder 32 being connected to the outer graphite holder 31, a circular through hole 33 and a plurality of vent holes 34 being provided in the inner graphite holder 32, and a seed crystal 40 being provided on a top wall of the inner graphite holder 32 in a first position. It can be understood that, by making the graphite support 30 include the split type inner graphite support 32 and the split type outer graphite support 31, the respective structures of the inner graphite support 32 and the outer graphite support 31 are simple, which is beneficial to reducing the processing difficulty of the graphite support 30 and improving the production efficiency of the graphite support 30. For example, referring to fig. 14, the outer graphite holder 31 is provided with two connecting holes 311, and two graphite bolts are connected to the inner graphite holder 32 through the two connecting holes 311 in a one-to-one correspondence, so that the structure is simple and reliable connection between the outer graphite holder 31 and the inner graphite holder 32 can be achieved.

In some embodiments of the present invention, as shown with reference to fig. 12 and 13, the inner graphite bracket 32 includes: a plurality of graphite rings 321 and graphite pole 322, a plurality of graphite rings 321 overlap in proper order and establish and interval apart and arrange, the central axis of a plurality of graphite rings 321 is on same straight line, two adjacent graphite rings 321 interval apart in order to inject annular air vent 34, graphite pole 322 is connected between a plurality of graphite rings 321 with fixed graphite ring 321, graphite pole 322 is a plurality of, a plurality of graphite poles 322 are including graphite holds in the palm 32 the interval is arranged in circumference. Therefore, the structure is simple, and the processing and molding of the inner graphite support 32 are convenient. For example, as shown in fig. 13, the number of the graphite rods 322 is four, and four graphite rods 322 are uniformly spaced apart in the circumferential direction of the inner graphite holder 32.

In some alternative embodiments of the present invention, as shown in fig. 13, the gap between two adjacent graphite rings 321 is 0.5mm to 1.5mm. In other words, the gap W between two adjacent graphite rings 321 may be set to any value of 0.5mm to 1.5mm. For example, the gap W between two adjacent graphite rings 321 may be 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.2mm, 1.5mm, or the like. It can be understood that, by making the gap between two adjacent graphite rings 321 be 0.5mm-1.5mm, on one hand, the gap between two adjacent graphite rings 321 is not too small, so that the amount of silicon carbide condensed between the inner graphite support 32 and the silicon surface 41 of the seed crystal 40 can be ensured, which is beneficial to ensuring the reliable connection between the graphite support 30 and the seed crystal 40, and on the other hand, the gap between two adjacent graphite rings 321 is not too large, which is beneficial to ensuring the structural strength of the inner graphite support 32, thereby ensuring the reliability of the work of the inner graphite support 32.

In some embodiments of the present invention, and as illustrated with reference to FIGS. 1-2, silicon carbide crystal growing apparatus 100 further comprises: a porous plate 53, the porous plate 53 being provided in the third chamber 51, the porous plate 53 being configured to be suitable for only gas to pass through, the porous plate 53 being located above the second silicon carbide powder 52. For example, the diameter of the through-holes on the porous plate 53 is 30 μm to 100 μm, and the diameter of the second silicon carbide powder 52 is 300um to 1000um. It is understood that during the growth of six-inch silicon carbide crystal 92, perforated plates 53 may filter silicon carbide gases flowing from bottom to top, which may be beneficial to improving the growth quality of six-inch silicon carbide crystal 92.

In some embodiments of the present invention, referring to fig. 1-2, silicon carbide crystal growth apparatus 100 further comprises first induction coil 81, second induction coil 82, and third induction coil 83 arranged in series in the up-down direction, for example, as shown in fig. 1 and 2, first induction coil 81 may comprise two sets of induction coils, second induction coil 82 may comprise three sets of induction coils, and third induction coil 83 may comprise four sets of induction coils.

Referring to fig. 1-2, the first induction coil 81, the second induction coil 82 and the third induction coil 83 all surround the quartz cover 10, the second induction coil 82 is movable in the up-down direction between a third position and a fourth position, in the third position, the distance between the second induction coil 82 and the bottom of the second sub-chamber 212 is L1, and L1 satisfies: l1 is more than or equal to 20mm and less than or equal to 50mm, in other words, L1 can take any value of 20mm-50mm, it can be understood that, in the process of growing the four-inch silicon carbide crystal 91, the first induction coil 81 and the second induction coil 82 are operated, the third induction coil 83 is not operated, and by controlling L1 within a proper range, the inside of the first chamber 21 can be controlled within a preset range, which is beneficial to ensuring the growth quality of the four-inch silicon carbide crystal 91.

Referring to fig. 2, in the fourth position, the distance between the second induction coil 82 and the third induction coil 83 is L2, and L2 satisfies: l2 is greater than or equal to 2mm and less than or equal to 10mm, in other words, L2 can be any value from 2mm to 10mm, and it can be understood that, in the growth process of the six-inch silicon carbide crystal 92, the second induction coil 82 and the third induction coil 83 are used as main heat sources, and the first induction coil 81 plays an auxiliary role of temperature gradient, so that by controlling L2 within a preset range, sufficient heat can be provided for the third chamber 51, and the growth quality of the six-inch silicon carbide crystal 92 can be ensured.

Referring to fig. 15, a method for controlling a silicon carbide crystal growing apparatus 100 according to an embodiment of the present invention includes: controlling the first crucible 20 to be kept at the first position (refer to fig. 1) in the first crystal growth stage, and heating the first crucible 20 for a first preset time to grow a four-inch silicon carbide crystal 91 on the silicon surface 41 of the seed crystal 40; a transition stage, controlling the first crucible 20 to rotate from the first position to the second position (refer to fig. 2); in the second growth phase, the first crucible 20 is controlled to remain in the second position and the second crucible 50 is heated for a second predetermined length of time to grow a six inch silicon carbide crystal 92 on the carbon face 42 of the seed crystal 40, the first predetermined length of time being less than the second predetermined length of time. For example, the first preset time period is 75h-80h, and the second preset time period is 140h-160h.

According to the control method of the silicon carbide crystal growth device 100 provided by the embodiment of the invention, before crystal growth, the first crucible 20 can be controlled to rotate to the first position through the driving module 70, then the seed crystal 40 is placed on the graphite support 30 of the first crucible 20, during the crystal growth, the first crucible 20 can be controlled to be kept at the first position, the first crucible 20 is heated for the first preset time to grow the four-inch silicon carbide crystal 91 on the silicon surface 41 of the seed crystal 40, and part of silicon carbide gas can be condensed between the seed crystal 40 and the graphite support 30 through the vent hole 34 to realize fixation between the seed crystal 40 and the graphite support 30, so that self-adhesion between the seed crystal 40 and the graphite support 30 is realized, defects caused by an adhesion method and a mechanical fixation method can be effectively avoided, then the first crucible 20 is controlled to rotate to the second position from the first position, and the second crucible 50 is heated for the second preset time to grow the six-inch silicon carbide crystal 92 on the carbon surface 42 of the seed crystal 40, so that continuous growth of the four-inch silicon carbide crystal 91 and the six-inch silicon carbide crystal 92 can be realized, and the continuous growth efficiency of the silicon crystal 92 can be improved.

In some embodiments of the present invention, the silicon carbide crystal growth apparatus 100 is the silicon carbide crystal growth apparatus 100 according to the above-mentioned embodiments of the present invention, and referring to fig. 3, in the first crystal growth stage, the second induction coil 82 is controlled to be in the third position, the first induction coil 81 and the second induction coil 82 are operated, and the third induction coil 83 is not operated, which is beneficial to realize effective control of the temperature in the first chamber 21 and is beneficial to ensure the quality of the four-inch silicon carbide crystal 91 grown on the silicon surface 41 of the seed crystal 40.

In the transition phase, the second induction coil 82 is controlled to move from the third position (refer to fig. 3) to the fourth position (refer to fig. 4), for example, the first crucible 20 can be controlled to rotate from the first position to the second position, and then the second induction coil 82 is controlled to move from the third position to the fourth position, and the transition phase can last for 5min to 10min;

referring to fig. 4, in the second crystal growth stage, the first crucible 20 is controlled to be in the second position, the second induction coil 82 is controlled to be in the fourth position, the first induction coil 81 is not operated, and both the second induction coil 82 and the third induction coil 83 are operated. It will be appreciated that during the second growth phase, second induction coil 82 and third induction coil 83 provide a heat source for heating second silicon carbide powder 52, thereby facilitating effective control of the temperature within the chamber into which second chamber 22 and second chamber 22 are spliced, and facilitating quality assurance of a six-inch silicon carbide crystal 92 grown on carbon face 42 of seed crystal 40.

In some embodiments of the present invention, as shown with reference to fig. 5, the control method further includes: and an annealing stage, wherein the first crucible 20 is controlled to be kept at the second position, the annealing stage is controlled to be positioned after the second crystal growth stage, in the annealing stage, the second induction coil 82 is positioned at the third position, the first induction coil 81 and the second induction coil 82 are operated, and the third induction coil 83 is not operated. It can be appreciated that annealing four-inch silicon carbide crystal 91 and six-inch silicon carbide crystal 92 is beneficial to relieving stress in four-inch silicon carbide crystal 91 and six-inch silicon carbide crystal 92 and preventing crystal cracking, and simultaneously annealing four-inch silicon carbide crystal 91 and six-inch silicon carbide crystal 92 can realize efficient utilization of energy and reduce cost.

For example, referring to fig. 3 to 5, in a specific example of the present invention, the first silicon carbide powder 213 has a particle size of 8 mesh to 40 mesh and a total weight of 3.5kg to 4.5kg, the second silicon carbide powder 52 has a particle size of 8 mesh to 40 mesh and a total weight of 6.5kg to 7kg, the polarity of the seed crystal 40 is selected to be 4 °, the growing crystal form of the silicon surface 41 of the seed crystal 40 is a 6H-SiC single crystal, the growing crystal form of the carbon surface 42 of the seed crystal 40 is a 4H-SiC single crystal, and the control method of the silicon carbide crystal growing apparatus 100 specifically includes the following steps:

in the first crystal growth stage, the first crucible 20 is controlled to be kept at the first position, the first crucible 20 is heated for a first preset time length to grow a four-inch silicon carbide crystal 91 (6H-SiC) on the silicon surface 41 of the seed crystal 40, specifically, as shown in FIG. 1, the outer edge part of the seed crystal 40 is lifted by the inner graphite support 32, the inner graphite support 32 limits a crystal growth surface with the size of 102mm-105 mbar on the silicon surface 41 at the lower end of the seed crystal 40, specifically, the second induction coil 82 is controlled to be at the third position, the first induction coil 81 and the second induction coil 82 are operated, the third induction coil 83 is not operated, in the process, the total power of the first induction coil 81 and the second induction coil 82 can be 9.5kw-11.5kw, the corresponding temperature is 2250-2300 ℃, the crystal growth time is 75H-80H, the power control is controlled in three-stage, the crystal growth pressure is controlled to be 1H-20% (9.5 kw-11.5 kw), 2H-50% (9.5 kw), and 1.5-5H-5.5 w) of the total power is controlled to 1.5-5 kw. In the process, referring to fig. 3, under the action of gravity, a first stopping portion 621 of the material blocking member 62 is matched with the protection plate 61 in a stopping manner, a second stopping portion 623 is located right below the first stopping portion 621, at the moment, the second through hole 613 and the third through hole 6211 are oppositely arranged, silicon carbide gas can flow to the seed crystal 40 from bottom to top through the second through hole 613 and the third through hole 6211, so that the normal growth of a four-inch silicon carbide crystal 91 is ensured, meanwhile, part of the silicon carbide gas can be condensed between the seed crystal 40 and the graphite holder 30 through the vent holes 34 to fix the seed crystal 40 and the graphite holder 30, so that the self-adhesion between the seed crystal 40 and the graphite holder 30 is realized, and the defects caused by an adhesive method and a mechanical fixing method can be effectively avoided;

referring to fig. 4, in the transition stage, the first crucible 20 is controlled to rotate from the first position to the second position, and then the second induction coil 82 is controlled to move from the third position to the fourth position, wherein the total time is 5min to 10min, and in the process of rotating the first crucible 20 from the first position to the second position, under the action of gravity, the second stopping portion 623 is gradually matched with the protection plate 61 in a stopping manner, so that the first silicon carbide powder 213 can be prevented from polluting the four-inch silicon carbide crystal 91, and the final growth quality of the four-inch silicon carbide crystal 91 can be ensured;

referring to FIG. 4, in the second crystal growth stage, the first crucible 20 is controlled to be in the second position, the second induction coil 82 is controlled to be in the fourth position, the first induction coil 81 is not operated, and the second induction coil 82 and the third induction coil 83 are both operated, at this time, the second induction coil 82 and the third induction coil 83 provide a heat source for heating the second silicon carbide powder 52, specifically, the size of the crystal growth surface of the carbon surface 42 of the seed crystal 40 can be 155mm to 165mm, the total power of the second induction coil 82 and the third induction coil 83 can be 11kw to 12kw, corresponding to a temperature of 2100 ℃ to 2150 ℃, and the crystal growth time is 150H, so that a six-inch silicon carbide crystal 92 (4H-SiC) is grown on the carbon surface 42 of the seed crystal 40.

Referring to fig. 5, in the annealing stage, the first crucible 20 is controlled to be in the second position, the second induction coil 82 is moved to the third position, the first induction coil 81 and the second induction coil 82 are operated, the third induction coil 83 is not operated, the total power of the first induction coil 81 and the second induction coil 82 is increased to 11kw-12kw, after 5 hours of maintenance, the annealing is performed for 7H-50% (11 kw-12 kw), 15H-10% (11 kw-12 kw), and then the power is reduced to 0, and then the annealing treatment is performed for the four-inch silicon carbide crystal 91 (6H-SiC) and the six-inch silicon carbide crystal 92 (6H-SiC) at the same time, so that the efficient use of energy can be realized, and the cost can be reduced.

Other configurations and operations of silicon carbide crystal growing apparatus 100 according to embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (11)

1. An apparatus for growing a silicon carbide crystal, comprising:

a quartz cover defining an accommodating space;

the first crucible and the second crucible are both located in the containing space, the first crucible is located above the second crucible, the first crucible is provided with a growth cavity with an open end, a graphite support for placing seed crystals is arranged in the growth cavity, the graphite support is formed into a ring shape, a circular through hole is defined in the middle of the graphite support, a plurality of vent holes are formed in the corresponding parts of the graphite support and the seed crystals in the vertical direction, the seed crystals and the graphite support divide the growth cavity into a first cavity and a second cavity, a protection assembly is arranged in the first cavity, the protection assembly divides the first cavity into a first sub-cavity and a second sub-cavity, the protection assembly is only suitable for gas to pass through, the second sub-cavity is located on the side of the first sub-cavity, which is far away from the seed crystals, first silicon carbide powder is arranged in the second sub-cavity, the second crucible is provided with a third cavity with an open top, and second silicon carbide powder is arranged in the third cavity;

the driving module is connected with the first crucible and used for driving the first crucible to rotate around a preset straight line K between a first position and a second position, in the first position, the second chamber is positioned right above the first chamber, the silicon surface of the seed crystal is opposite to the circular through hole and faces downwards, and the carbon surface of the seed crystal faces upwards; in the second position, the second chamber is positioned right below the first chamber, the second chamber is in butt joint communication with the third chamber, the carbon surface of the seed crystal faces downwards, and the silicon surface of the seed crystal faces upwards.

2. The silicon carbide crystal growing apparatus of claim 1 wherein the guard assembly comprises:

the protection plate is connected with the inner peripheral wall of the first chamber and provided with a plurality of through hole groups, the through hole groups are uniformly arranged on the protection plate, each through hole group comprises a first through hole and a plurality of second through holes, and the second through holes are arranged around the first through holes;

the material blocking part comprises a first blocking part, a connecting rod and a second blocking part, the first blocking part and the second blocking part are respectively arranged at two ends of the connecting rod, the connecting rod penetrates through the first through hole and can move up and down relative to the protection plate, the cross sectional area of the first blocking part and the cross sectional area of the second blocking part are larger than that of the first through hole, the first blocking part is provided with a third through hole, the third through hole and at least one second through hole are oppositely arranged in the vertical direction, the first blocking part is matched with the protection plate in a blocking mode at the first position, and the second blocking part is located right below the first blocking part; in the second position, the second stopping portion is matched with the protection plate in a stopping manner, and the first stopping portion is located right below the second stopping portion.

3. The silicon carbide crystal growth device of claim 1 wherein the guard assembly comprises a baffle plate having a plurality of gas flow channels, each gas flow channel extending through the baffle plate in the thickness direction of the baffle plate, the gas flow channels comprising straight segments and bent segments.

4. The silicon carbide crystal growth apparatus of claim 1 wherein the graphite tray comprises:

the outer graphite support is formed into a ring shape and is connected with the first crucible;

the inner graphite support is connected with the outer graphite support, the circular through holes and the plurality of vent holes are formed in the inner graphite support, and the seed crystal is arranged on the top wall of the inner graphite support at the first position.

5. The silicon carbide crystal growth apparatus of claim 4 wherein the inner graphite support comprises:

the graphite rings are sequentially sleeved and arranged at intervals, the central axes of the graphite rings are on the same straight line, and two adjacent graphite rings are spaced to limit the vent holes;

the graphite rod is connected between a plurality of graphite rings to be fixed, the graphite rod is a plurality of, and is a plurality of the graphite rod is in the internal graphite holds in the palm upwards interval the arranging in circumference of holding in the palm.

6. The silicon carbide crystal growth apparatus of claim 5 wherein the gap between adjacent graphite rings is 0.5mm to 1.5mm.

7. The silicon carbide crystal growth apparatus of claim 1 further comprising:

a porous plate disposed within the third chamber, the porous plate configured to be suitable for passage of only gas therethrough, the porous plate being located above the second silicon carbide powder.

8. The silicon carbide crystal growth apparatus of any one of claims 1-7, further comprising a first induction coil, a second induction coil and a third induction coil sequentially arranged in a vertical direction, wherein the first induction coil, the second induction coil and the third induction coil all surround the quartz shield, the second induction coil is movable in the vertical direction between a third position and a fourth position, and in the third position, the distance between the second induction coil and the bottom of the second sub-chamber is L1, and L1 satisfies: l1 is more than or equal to 20mm and less than or equal to 50mm, and in the fourth position, the distance between the second induction coil and the third induction coil is L2, and L2 satisfies the following conditions: l2 is more than or equal to 2mm and less than or equal to 10mm.

9. A method of controlling a silicon carbide crystal growing apparatus according to claim 1, comprising:

a first crystal growth stage, wherein the first crucible is controlled to be kept at the first position, and the first crucible is heated for a first preset time length so as to grow a four-inch silicon carbide crystal on the silicon surface of the seed crystal;

a transition stage, controlling the first crucible to rotate from the first position to the second position;

and in the second crystal growth stage, the first crucible is controlled to be kept at the second position, the second crucible is heated for a second preset time length so as to grow six-inch silicon carbide crystals on the carbon surface of the seed crystals, and the first preset time length is shorter than the second preset time length.

10. The method of controlling a silicon carbide crystal growing apparatus according to claim 9 wherein the silicon carbide crystal growing apparatus is a silicon carbide crystal growing apparatus according to claim 8,

in the first crystal growth stage, the second induction coil is controlled to be in the third position, the first induction coil and the second induction coil work, and the third induction coil does not work;

controlling the second induction coil to move from the third position to the fourth position during the transition phase;

and in the second crystal growth stage, the second induction coil is controlled to be in the fourth position, the first induction coil does not work, and the second induction coil and the third induction coil work.

11. The method of controlling a silicon carbide crystal growth apparatus according to claim 10, further comprising:

and in the annealing stage, the first crucible is controlled to be kept at the second position, the second induction coil is controlled to move to the third position, the first induction coil and the second induction coil work, and the third induction coil does not work.

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