阅读说明：本技术 一种碳化硅的结晶界面控制结构、生长设备和制备方法 (Silicon carbide crystallization interface control structure, growth equipment and preparation method ) 是由 潘尧波 薛卫明 马远 于 2021-08-04 设计创作，主要内容包括：本发明提供一种碳化硅的结晶界面控制结构、生长设备及制备方法,其中,所述结晶界面控制结构包括石墨托盘、分布在所述石墨托盘上的多个石墨杆、与所述多个石墨杆对应连接的多个换热管及多个电信号接收器,所述换热管内设有进气管,所述进气管内有冷媒气体流通；所述电信号接收器的一端通过连接导线与所述换热管相连,另一端通过连接导线与所述石墨杆相连；所述石墨杆与所述换热管及所述电信号接收器构成热电偶测温系统,通过所述电信号接收器可判断所述石墨杆的温度；通过调节所述冷媒气体的流量可调节所述石墨托盘的温度分布,进而实现结晶界面的控制。采用包含本发明的结晶界面控制结构的生长设备可获得的低密度缺陷的碳化硅单晶衬底。(The invention provides a silicon carbide crystal interface control structure, growth equipment and a preparation method, wherein the crystal interface control structure comprises a graphite tray, a plurality of graphite rods distributed on the graphite tray, a plurality of heat exchange tubes correspondingly connected with the graphite rods and a plurality of electric signal receivers, wherein air inlet tubes are arranged in the heat exchange tubes, and refrigerant gas flows in the air inlet tubes; one end of the electric signal receiver is connected with the heat exchange tube through a connecting wire, and the other end of the electric signal receiver is connected with the graphite rod through a connecting wire; the graphite rod, the heat exchange tube and the electric signal receiver form a thermocouple temperature measuring system, and the temperature of the graphite rod can be judged through the electric signal receiver; the temperature distribution of the graphite tray can be adjusted by adjusting the flow of the refrigerant gas, so that the control of a crystallization interface is realized. A low-density defect silicon carbide single crystal substrate obtainable by a growth apparatus comprising the crystalline interface control structure of the present invention.)

1. A crystalline interface control structure, comprising:

the graphite tray is used for placing seed crystals;

a plurality of graphite rods are distributed on one surface of the graphite tray, which is far away from the seed crystal;

the heat exchange tubes are respectively and correspondingly connected with the graphite rods, air inlet tubes are arranged in the heat exchange tubes, and refrigerant gas flows in the air inlet tubes; and

the plurality of electric signal receivers are arranged corresponding to the plurality of heat exchange tubes, one ends of the electric signal receivers are connected with the heat exchange tubes through connecting wires, and the other ends of the electric signal receivers are connected with the graphite rods through connecting wires;

the graphite rod, the heat exchange tube and the electric signal receiver form a thermocouple temperature measuring system, and the temperature of the graphite rod can be judged through the electric signal receiver;

the temperature distribution of the graphite tray can be adjusted by adjusting the flow of the refrigerant gas, so that the control of a crystallization interface is realized.

2. The crystalline interface control structure of claim 1, wherein the heat exchange tube is made of a high temperature resistant material, the high temperature resistant material being any one of tantalum, tantalum carbide, tungsten, molybdenum, rhenium, or a ceramic material.

3. The crystalline interface control structure of claim 1, wherein the plurality of graphite rods are uniformly distributed on the graphite tray.

4. The crystallization interface control structure according to claim 3, wherein the plurality of graphite rods and the graphite tray are of an integral structure, and one end of each graphite rod, which is away from the graphite tray, is connected with the plurality of heat exchange tubes in a one-to-one correspondence manner.

5. The crystal interface control structure according to claim 4, wherein the graphite rod is a hollow structure, the air outlet of the air inlet pipe corresponds to the inside of the graphite rod, and the refrigerant gas enters the graphite rod through the air inlet pipe to cool the graphite rod and is discharged through the heat exchange pipe.

6. The crystal interface control structure of claim 1, wherein the graphite rod and the graphite tray are made of a high density graphite material, and the density of the graphite tray is 1.6-1.8 g/cm³The thermal conductivity is 80-150 Wm^{- 1}K^-1。

7. The crystal interface control structure of claim 1, wherein the coolant gas is selected from any one of hydrogen, helium and argon.

8. An apparatus for growing silicon carbide, comprising the crystalline interface control structure of any one of claims 1 to 7.

9. A preparation method for controlling defects of a silicon carbide single crystal substrate is characterized by comprising the following steps:

providing a silicon carbide growth apparatus according to claim 8;

fixing a seed crystal on a graphite tray of the silicon carbide growth equipment;

raising the temperature of the silicon carbide growth equipment to 1600-2500 ℃, and controlling the pressure to be 0.1-100 mbar;

adjusting the flow of refrigerant gas according to the temperature distribution of the graphite tray and the defect distribution in the seed crystal so as to enable the graphite tray to obtain expected temperature distribution, wherein the growth interface of the seed crystal is in an expected shape;

adjusting the flow of the refrigerant gas to ensure that the specific crystalline phase of the silicon carbide is preferentially crystallized, and repairing the defects;

adjusting the flow of the refrigerant gas to enable the temperature of each position of the graphite tray to reach a stable growth temperature;

after the stable growth is finished, cooling and taking out;

and processing the cooled silicon carbide crystal to obtain the silicon carbide single crystal substrate with low-density defects.

10. A producing method according to claim 9, wherein the intended shape of the growth interface of the seed crystal is stepped.

Technical Field

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

Background

As a representative of third-generation semiconductor single crystal materials, silicon carbide (SiC) has the characteristics of wide band gap, high critical breakdown electric field, high thermal conductivity, high carrier saturation drift velocity, excellent chemical stability and the like, and these excellent properties make silicon carbide crystal widely used in the fields of power electronics, radio frequency devices, optoelectronic devices and the like, and have an important influence on the development of future electronic information industry technologies.

The silicon carbide wafer is used as a semiconductor substrate material, can be made into a silicon carbide-based power device and a microwave radio frequency device through links such as epitaxial growth, device manufacturing and the like, and is an important basic material for the development of the third-generation semiconductor industry. The silicon carbide single crystal substrate is generally a substrate slice obtained by growing a bulk crystal by a Physical Vapor Transport (PVT) method or a Liquid Phase Epitaxy (LPE) method and then machining, so that the quality of the bulk crystal directly determines the quality of the silicon carbide single crystal substrate, and the order of magnitude of basic defects of the silicon carbide single crystal substrate is determined by defects on the bulk crystal.

At present, the methods for controlling the defects of the silicon carbide single crystal mainly comprise: after the patterning treatment of the crystal, the defects are repaired by utilizing the lateral growth of the crystal, such as CN111958070B and JP 2006052097A; adding special atmosphere or adjusting the structure of seed crystal tray in growth environment, such as CN112160028A or CN106435734A and US7501022B 2; the purity of the raw material is improved by improving the PVT gas phase transportation process so as to avoid defects caused by impurities, such as CN110983434A and US8741413B 2; and more so, Chemical Vapor Deposition (CVD) processes are used to improve defects such as CN1926266A and CN 111051581A. However, the above solution has many disadvantages, such as patterned seed crystal, or special structure of seed crystal holder, in which the shape of crystal growth interface is only changed in the initial stage during the growth process, and the crystal interface is not controlled during most of the crystal growth process; improvements in gas phase transport processes may have some improvements in micropipe or carbon encapsulation, but not in Stacking Faults (SF), threading dislocations (TSD) or Basal Plane Dislocations (BPD). The CVD process can improve the number of defects on the substrate wafer to some extent, but the TSD is not repaired or only replaced by SF defects during the epitaxy process. In view of the above, a novel method for controlling defects of a silicon carbide single crystal substrate has yet to be proposed.

Disclosure of Invention

Aiming at the defects and defects in the prior art, the invention provides a silicon carbide crystallization interface control structure, growth equipment and a preparation method, which are used for controlling the crystallization interface of silicon carbide so as to improve the defects in a silicon carbide single crystal substrate.

In order to achieve the above and other related objects, the present invention provides a crystal interface control structure of silicon carbide, comprising a graphite tray, a plurality of graphite rods, a plurality of heat exchange tubes and a plurality of electrical signal receivers, wherein the graphite tray is used for accommodating a silicon carbide seed crystal, and the plurality of graphite rods are mounted on a surface of the graphite tray away from the seed crystal; the heat exchange tubes are respectively and correspondingly connected with the graphite rods, air inlet tubes are arranged in the heat exchange tubes, and refrigerant gas flows in the air inlet tubes; the plurality of electric signal receivers are arranged corresponding to the plurality of heat exchange tubes, one ends of the electric signal receivers are connected with the heat exchange tubes through connecting wires, and the other ends of the electric signal receivers are connected with the graphite rods through connecting wires; the graphite rod, the heat exchange tube and the electric signal receiver form a thermocouple temperature measuring system, and the temperature of the graphite rod can be judged through the electric signal receiver; the crystallization interface control device adjusts the temperature distribution of the graphite tray by adjusting the flow of the refrigerant gas, thereby realizing the control of the crystallization interface.

In an embodiment of the present invention, the heat exchange tube is made of a high temperature resistant material, and the high temperature resistant material is any one of tantalum (Ta), tantalum carbide (TaC), tungsten (W), molybdenum (Mo), rhenium (Re), or a ceramic material.

In an embodiment of the present invention, the plurality of graphite rods are uniformly distributed on the graphite tray.

In an embodiment of the present invention, the plurality of graphite rods and the graphite tray are of an integrated structure, and one end of each of the plurality of graphite rods, which is away from the graphite tray, is connected to the plurality of heat exchange tubes in a one-to-one correspondence manner.

In an embodiment of the present invention, the graphite rod is a hollow structure, the air outlet of the air inlet pipe corresponds to the inside of the graphite rod, and the refrigerant gas enters the graphite rod through the air inlet pipe to cool the graphite rod and is discharged through the heat exchange pipe.

In an embodiment of the present invention, the graphite rod and the graphite tray are made of a high-density graphite material, and the density of the high-density graphite material is 1.6-1.8 g/cm³The thermal conductivity is 80-150 Wm^-1K^-1。

In one embodiment of the present invention, the coolant gas is selected from hydrogen (H)₂) Helium (He) or argon (Ar).

In a second aspect of the invention, there is provided a silicon carbide growth apparatus comprising a crystalline interface control structure of the invention.

The third aspect of the present invention provides a method for preparing a silicon carbide single crystal substrate with controlled defects, comprising the steps of:

providing a silicon carbide growth apparatus comprising the crystalline interface control structure of the present invention;

fixing a seed crystal on a graphite tray of the silicon carbide growth equipment;

raising the temperature of the silicon carbide growth equipment to 1600-2500 ℃, and controlling the pressure to be 0.1-100 mbar;

adjusting the flow of refrigerant gas according to the temperature distribution of the graphite tray and the defect distribution in the seed crystal so as to enable the graphite tray to obtain expected temperature distribution and enable the growth interface of the seed crystal to be in an expected shape;

adjusting the flow of the refrigerant gas to ensure that the specific crystalline phase of the silicon carbide is preferentially crystallized, and repairing the defects;

adjusting the flow of the refrigerant gas to enable the temperature of each position of the graphite tray to reach a stable growth temperature;

after the stable growth is finished, cooling and taking out;

and processing the cooled silicon carbide crystal to obtain the silicon carbide single crystal substrate with low defect density.

In one embodiment of the present invention, the desired shape of the growth interface of the seed crystal is stepped.

As described above, the present invention provides a crystal interface control structure, wherein a plurality of graphite rods and heat exchange tubes connected with the graphite rods are arranged on a graphite tray, and an air inlet tube through which a refrigerant gas flows is arranged in each heat exchange tube, wherein the graphite rods, the graphite tray and an electrical signal receiver form a thermocouple temperature measurement system, and the temperature of the graphite rods at different positions can be obtained through the electrical signal receiver, so as to obtain the temperature distribution of the graphite tray; the temperature of the graphite rod can be adjusted and controlled by adjusting the flow of the refrigerant gas, so that the temperature distribution of the graphite tray reaches the expected distribution to achieve the aim of controlling a crystallization interface; the crystal interface control structure is arranged in the growth equipment, the temperature distribution of the graphite tray can be adjusted by adjusting the flow of the refrigerant gas by utilizing the growth equipment, so that the specific crystal phase of the silicon carbide preferentially grows, the defects in different directions can be eliminated or converged into a defect after meeting, and the temperature distribution of the graphite tray can be adjusted again according to the requirement of the product grade until a growth interface with low defect density is obtained. The invention also provides a method for controlling the defects of the silicon carbide single crystal substrate, which can control the defects of the silicon carbide single crystal substrate and obtain the silicon carbide single crystal substrate with low-density defects.

Drawings

The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:

fig. 1 is a schematic structural diagram of a crystal interface control structure according to an embodiment of the present invention.

Fig. 2 is an enlarged view, partially in section, of the area i in fig. 1.

FIG. 3 is a flow chart showing a method for controlling defects of a silicon carbide single crystal substrate according to the present invention.

FIG. 4 is a schematic diagram showing the distribution of defects in the seed crystal selected in step S2 of FIG. 3.

Fig. 5 is a schematic diagram illustrating the development direction of each defect corresponding to step S4 in fig. 3.

Fig. 6 is a schematic structural diagram of the repaired defect corresponding to step S5 in fig. 3.

FIG. 7 is a schematic diagram showing the structure of the silicon carbide crystal after being stably grown, corresponding to step S6 in FIG. 3.

FIG. 8 is a schematic view of defect elimination during the growth of silicon carbide with a step-like growth interface in one embodiment of the present invention.

Reference numerals

1. A graphite tray; 2. a graphite rod; 3. a heat exchange pipe; 4. an electrical signal receiver; 5. seed crystal; 6. an air inlet pipe; 501. a preferential growth region; 502. a base surface; 503. the surface of the seed crystal; 504. defects perpendicular to the basal plane; 505. defects perpendicular to the surface of the seed crystal; 506. defects parallel to the basal plane; 7. a crystal plane direction; 8. a defect; 9. a low defect growth interface; 10. Seed crystal defects; 101. top defects; 11. a silicon carbide growth interface; 1101. sidewall defects.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The invention is capable of other and different embodiments and its several details are capable of modifications and various changes in detail without departing from the spirit of the invention.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

In the present invention, it should be noted that, as the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, their indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the present application and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first" and "second," if any, are used for descriptive and distinguishing purposes only and are not to be construed as indicating or implying relative importance.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice of the present invention, the preferred methods, devices, and materials are described below.

The invention provides a crystallization interface control structure of silicon carbide, growth equipment and a preparation method, which can control a crystallization interface by controlling the temperature distribution of a graphite tray so as to achieve the purpose of controlling a silicon carbide single crystal substrate.

Referring to fig. 1 and 2, the present invention provides a crystallization interface control structure, including a graphite tray 1, a plurality of graphite rods 2, a plurality of heat exchange tubes 3 and a plurality of electrical signal receivers 4, wherein the graphite tray 1 is used for placing seed crystals 5, and the plurality of graphite rods 2 are installed on a surface of the graphite tray 1 departing from the seed crystals 5; the plurality of heat exchange tubes 3 are respectively and correspondingly connected with the plurality of graphite rods 2, air inlet tubes 6 are arranged in the heat exchange tubes 3, and refrigerant gas circulates in the air inlet tubes 6; the plurality of electric signal receivers 4 are arranged corresponding to the plurality of heat exchange tubes 3, one ends of the electric signal receivers 4 are connected with the heat exchange tubes 3 through connecting wires, and the other ends of the electric signal receivers are connected with the graphite rods 2 through connecting wires; the graphite rod 2, the heat exchange tube 3 and the electric signal receiver 4 form a closed loop through connecting wires to form a thermocouple temperature measuring system, one end of the heat exchange tube 3, which is tightly contacted with the graphite rod 2, generates thermoelectromotive force at high temperature, and is received by the electric signal receiver 4, and the temperature of the graphite tray 1 at the position can be obtained according to the electric signal received by the electric signal receiver 4; the crystallization interface control device adjusts the temperature distribution of the graphite tray 1 by adjusting the flow of the refrigerant gas, thereby realizing the control of the crystallization interface.

Referring to fig. 1 and 2, the heat exchange tube 3, the graphite rod 2 and the electrical signal receiver 4 form a thermocouple temperature measuring system, which satisfies the requirement that the heat exchange tube 3 and the graphite rod 2 are made of different materials, and the heat exchange tube 3 is made of a high temperature resistant conductor or semiconductor material, for example, the heat exchange tube 3 is made of Ta, TaC, W, Mo, Re or a high purity dense ceramic material. One end of the heat exchange tube 3, which is in close contact with the graphite rod 2, is a hot end of a thermocouple temperature measuring system, and one end of the heat exchange tube, which is connected with the electric signal receiver 4, is a cold end, in the crystal growth process, the cold end is in a constant temperature state, the temperature of the hot end can change along with the flow change of refrigerant gas, the closed loop of the thermocouple can generate thermoelectromotive force and the thermoelectromotive force is presented in the electric signal receiver 4, and the temperature of the graphite tray 1 at the point can be judged according to the electromotive force in the electric signal receiver 4.

Referring to fig. 1 and 2, as an example, a plurality of graphite rods 2, for example, 3 or more than 3 graphite rods 2 are uniformly distributed on a surface of the graphite tray 1 away from the seed crystal 5, the graphite rods 2 and the graphite tray 1 are of an integral structure, and both are made of the same material, for example, the graphite rods 2 and the graphite tray 1 have a density of 1.6-1.8 g/cm³The thermal conductivity is 80-150 Wm^-1K^-1The temperature of the graphite rod 2 is equal to the temperature of the connecting position of the graphite tray 1 and the graphite rod 2, so that the temperature of the graphite rod 2 which is adjusted to be different through the refrigerant gas is also equal to the temperature distribution of the graphite tray 1.

Referring to fig. 1 and 2, in an embodiment, the graphite rod 2 is a hollow structure, the heat exchange tube 3 is correspondingly connected with the graphite rod 2 and the interiors of the two are communicated, an air inlet of an air inlet tube 6 inside the heat exchange tube 3 is connected with a refrigerant air source, an air outlet of the air inlet tube corresponds to the interior of the graphite rod 2, and the refrigerant air enters the graphite rod 2 from the air inlet tube 6 to cool the graphite rod and is discharged through the heat exchange tube 3. Wherein the refrigerant gas is selected from H₂He, Ar or other inert gas.

Referring to fig. 1 to 3, the present invention further provides a method for controlling defects of a silicon carbide single crystal substrate, comprising the steps of:

s1, providing a silicon carbide growth device comprising the crystal interface control structure;

s2, fixing a seed crystal 5 on a graphite tray 1 of the silicon carbide growth equipment;

s3, raising the temperature of the silicon carbide growth equipment to 1600-2500 ℃, and controlling the pressure to be 0.1-100 mbar;

s4, adjusting the flow of the refrigerant gas according to the temperature distribution of the graphite tray 1 and the defect distribution in the seed crystal 5 to enable the graphite tray 1 to obtain the expected temperature distribution and the growth interface of the seed crystal 5 to reach the expected shape;

s5, adjusting the flow of the refrigerant gas to ensure that the specific crystalline phase of the silicon carbide is preferentially crystallized, and repairing the defects;

s6, adjusting the flow of the refrigerant gas to ensure that the temperature of each position of the graphite tray 1 is stabilized to the growth temperature of the silicon carbide;

s7, cooling and taking out after the stable growth is finished;

and S8, processing the cooled silicon carbide crystal to obtain the silicon carbide single crystal substrate with low defect density.

Specifically, the silicon carbide growth apparatus in step S1 includes a crucible and a crystal interface control structure mounted on the crucible, wherein the crystal interface control structure is a crystal interface control structure of the present invention, and the structure is plugged at the top of the crucible. Other undisclosed structures of the silicon carbide growth apparatus are conventional in the art and will not be described in detail herein.

Referring to fig. 1, 3 and 4, the seed crystal 5 in step S2 is attached to the graphite tray 1, the defect distribution in the seed crystal 5 is known, and in one embodiment, the seed crystal 5 is selected such that the seed crystal surface 503 and the basal plane 502 have an angle θ of 4 °, and the seed crystal 5 has a defect 504 perpendicular to the basal plane, a defect 505 perpendicular to the seed crystal surface and a defect 506 parallel to the basal plane.

Referring to fig. 3, in step S3, the temperature of the silicon carbide growth apparatus is raised to 1600-2500 ℃, and the pressure is controlled to 0.1-100 mbar, for example, the temperature of the silicon carbide growth apparatus is raised to 2300 ℃ at a heating rate of 200 ℃/h, the pressure in the apparatus is controlled to 100mbar before the temperature in the apparatus reaches 2300 ℃, and the pressure in the apparatus is reduced to 30mbar when the temperature approaches 2300 ℃.

Referring to fig. 2, 3 and 5, in step S4, the temperature distribution of the graphite tray 1The defect distribution in the seed crystal 5 can be obtained by detection before the seed crystal 5 is installed through the electric signal receiver 4 corresponding to each position; firstly, the flow rate of the refrigerant gas in the heat exchange tubes 3 is adjusted according to the temperature distribution of the graphite tray 1, and the refrigerant gas can be selected from H for example₂Any one of He, Ar or other inert gases, so that the local preferential growth of the seed crystal 5 obtains a preferential growth area 501; and then, according to the temperature distribution in the graphite tray 1 and the defect distribution in the seed crystal 5, the flow rate of the refrigerant gas in the heat exchange tube 3 around the defect is adjusted, so that the temperature around the defect is lower than that of the defect, for example, the temperature around the defect is adjusted to be more than 5 ℃ lower than that of the defect, and the silicon carbide preferentially grows at the defect to obtain a desired crystal interface.

Referring to fig. 3, 5 and 6, in step S5, [0001 ] of silicon carbide]Directional growth rate of less thanThe direction and the central heat dissipation function, the defect 504 vertical to the basal plane, the defect 505 vertical to the surface of the seed crystal and the defect 506 parallel to the basal plane all develop towards the center, and the development direction of the defects is not completely vertical to the direction 7 of the crystal plane. When the defects meet, the defects are eliminated or are converged together to form a converged defect 8, the temperature at the defect 9 is adjusted again according to the grade requirement of the product, and the steps S4 and S5 are repeated to obtain a growth interface 9 with low defect density.

Referring to fig. 3 and 6, in step S6, the temperature of each point on the graphite tray 1 is raised to the growth temperature of silicon carbide by adjusting the flow rate of the cooling medium gas corresponding to each position of the graphite tray 1, and the silicon carbide crystal is stably grown for a period of time, for example, for 80 hours.

Referring to fig. 3, after the stable growth is completed in step S7, the flow rate of the cooling medium gas is adjusted to make the temperature of the graphite tray 1 in the uniform temperature state, and then the crystal temperature is decreased from 2300 ℃ to room temperature and taken out.

The processing of the silicon carbide crystal in step S8 to obtain a silicon carbide single crystal substrate is a conventional technical operation and will not be described in detail herein.

Referring to fig. 8, in an embodiment, a seed crystal 5 is provided, in which a plurality of seed crystal defects 10 are randomly distributed, and a step-shaped growth interface is obtained by adjusting the flow rate of a coolant gas corresponding to each position of a graphite tray 1 at the initial stage of crystal growth (corresponding to step S4) by using the method for controlling defects of a silicon carbide single crystal substrate according to the present invention; then regulating the flow of refrigerant gas to make the crystal grow along the direction of lower step, and extending partial defect along the normal direction of crystal growth interface, but because the growth speed of step bottom is slow, the growth speed of step top is fast, and [ 0001%]Growth rate of growthSlow growth rate, so that the defect extension rate of the bottom step is slower than the growth rate of the top step crystal, the top crystal covers the bottom defect, and the top defect edgeLateral defects 1101 are formed extending towards the crystal sidewalls, and eventually the crystal retains only a portion of the top defect 101 at the top of the step. And in the subsequent processing process, the defect part is ground, and the high-quality silicon carbide single crystal substrate can be obtained.

The crystallization interface control structure can also be used in chemical vapor phase epitaxy equipment, and the defects of the silicon carbide single crystal substrate can be further reduced by the crystallization interface control structure and the CVD epitaxy process.

In summary, the present invention provides a crystal interface control structure of silicon carbide, a growing apparatus and a preparation method thereof, the crystal interface control structure regulates the temperature distribution of a graphite tray by adjusting the flow rate of a coolant gas to achieve the purpose of controlling the crystal interface, and a silicon carbide crystal grown by the growing apparatus comprising the crystal interface control structure of the present invention can obtain a silicon carbide single crystal substrate with high quality. Therefore, the invention effectively overcomes some practical problems in the prior art, thereby having high utilization value and use significance.

The foregoing embodiments are merely illustrative of the principles of this invention and its efficacy, rather than limiting it, and various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention, which is defined in the appended claims.