CN216192879U

CN216192879U - Gallium nitride single crystal growth device

Info

Publication number: CN216192879U
Application number: CN202122740145.3U
Authority: CN
Inventors: 张华芹; 程佳彪; 李广敏
Original assignee: Shanghai Rhyme New Energy Technology Co ltd
Current assignee: Shanghai Rhyme New Energy Technology Co ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-04-05
Anticipated expiration: 2031-11-10

Abstract

The utility model discloses a gallium nitride single crystal growth device, which comprises a reaction furnace body with a reaction cavity, a temperature control system and a pressurizing system, and is characterized in that a buffer layer is arranged in the reaction cavity, the buffer layer divides the reaction cavity into a first reaction space and a second reaction space, and a reactant can be transferred from the first reaction space to the second reaction space through the buffer layer, the temperature control system comprises a first heater arranged outside the first reaction space, a second heater arranged outside the second reaction space and a thermocouple arranged in the whole reaction cavity, the temperatures of the two reaction spaces can be independently regulated, and the pressurizing system comprises a pressurizing device and a pressure sensor arranged in the reaction cavity. According to the gallium nitride single crystal growth device provided by the utility model, the temperature of the two reaction spaces is independently regulated and controlled, and the mass transfer flow and direction are controlled by the buffer layer, so that the balanced growth of the gallium nitride single crystal is realized, the dislocation density is effectively reduced, and the yield is improved.

Description

Gallium nitride single crystal growth device

Technical Field

The utility model relates to the technical field of single crystal growth devices, in particular to a gallium nitride single crystal growth device.

Background

Gallium nitride (GaN) is the most important third-generation semiconductor material for developing microelectronic and optoelectronic devices, and has the advantages of wide direct band gap (3.4eV), good chemical stability, excellent heat conductivity, and high breakdown voltage (breakdown electric field ≈ 5 × 10)⁶V cm^-1) Low dielectric constant (8.9), and has great application potential.

The current GaN single crystal substrate growth methods mainly include a hydride vapor phase epitaxy method (HVPE method), an Ammonothermal method (ammothermal method), and a Na Flux method (Na-Flux method). The GaN substrate material produced by the current method has high dislocation density (10)⁴～10⁸cm^-2)。

The most significant advantage of the Na flux method is that it can grow at 700-900 deg.C and 2-10MPa nitrogen pressure, the growth condition is mild, and the operation is easy. However, the method has the technical problems of poor growth repeatability, strong anisotropy in growth, slow growth rate and the like, is in need of solving, is easy to perform supersaturation and crystallization, and can perform spontaneous nucleation to interfere with the directional growth of the seed crystal, thereby having great influence on the growth of the GaN large-size crystal.

Therefore, providing a gallium nitride single crystal growth apparatus, creating excellent conditions for the growth process of gallium nitride, has been the direction of effort in the photovoltaic single crystal manufacturing industry.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned shortcomings, the present invention provides a gallium nitride single crystal growth apparatus, which divides a reaction chamber into a first reaction space and a second reaction space through a buffer layer, and then realizes the balanced growth of the gallium nitride single crystal through a precisely controlled temperature control system and a precisely controlled pressurization system, thereby effectively reducing the dislocation density, improving the growth efficiency of the gallium nitride, and improving the quality of the crystal.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides a gallium nitride single crystal growth device, is including reaction furnace body, temperature control system and the pressurization system that has the reaction chamber, its characterized in that, be equipped with the buffer layer in the reaction chamber, the buffer layer is divided into first reaction space and second reaction space with the reaction chamber to accessible buffer layer shifts the reactant from first reaction space to second reaction space, temperature control system is including setting up the first heater in the first reaction space outside, setting up the second heater in the second reaction space outside and setting up the thermocouple in whole reaction chamber, temperature control system control makes the temperature in first reaction space and second reaction space inequality, pressurization system includes pressurization device and the pressure sensor of setting in the reaction chamber.

According to one aspect of the utility model, the reaction chamber has a pressurizing port at one end, and the pressurizing device is connected with a pressure sensor in the reaction chamber through the pressurizing port.

According to an aspect of the utility model, the heater is connected to the pressurization system through a pressurization port.

According to an aspect of the utility model, the shape and the opening of the buffer layer are adjustable.

In accordance with an aspect of the present invention, the buffer layer is a separator having an opening.

According to an aspect of the present invention, a seed holder on which a seed crystal is mounted is provided in the second reaction space.

According to one aspect of the utility model, the reaction furnace body is a crucible.

According to one aspect of the utility model, the reaction vessel body is placed in an autoclave, which is made of a special steel material resistant to high temperatures and pressures.

In accordance with one aspect of the utility model, the autoclave is made of a nickel-based superalloy.

In accordance with one aspect of the utility model, the autoclave is externally provided with an insulation layer.

The implementation of the utility model has the advantages that: divide into first reaction space and second reaction space through the buffer layer to the reaction chamber, rethread precision control's temperature control system and pressurization system, control first reaction space and second reaction space be different temperatures, form first reaction space and be the high temperature region, the second reaction space is the low temperature region, the temperature of two reaction spaces can be adjusted and optimize mutually supporting simultaneously, when letting the solution volume receive the influence of system temperature and pressure, the solution filling degree keeps in 60-100% scope, can prevent that spontaneous nucleation from appearing in the gallium nitride growth process. Meanwhile, the buffer layer controls the mass transfer flow and direction in the growth process of the gallium nitride single crystal by adjusting the shape and the aperture opening ratio. Through reasonable design of the internal structure of the reaction cavity, the balanced growth of the gallium nitride single crystal is realized, the dislocation density is effectively reduced, the growth efficiency of the gallium nitride is improved, and the quality of the crystal is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic cross-sectional view of a gallium nitride single crystal growth apparatus according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in FIG. 1, an apparatus for growing a gallium nitride single crystal comprises an autoclave 2, and the autoclave 2 is made of a special steel material resistant to high temperature and high pressure. The alloy can bear complicated stress for a long time and reliably in oxidation and fuel gas corrosion atmosphere at 600-1000 ℃, and can be made of various nickel-based high-temperature alloys (generally containing 50-80% of nickel and 20% of chromium), such as Inconel alloy 625 and other types of alloy materials. The outside of the autoclave 2 is provided with a heat preservation layer which can be rock wool. The autoclave 2 comprises an autoclave body and an autoclave cover, wherein the autoclave body and the autoclave cover are hermetically connected through a fastening device, such as a hinge, and a reaction cavity is formed inside the autoclave body. A reaction furnace body is placed in the reaction cavity, and the reaction furnace body is a crucible. The crucible is made of high-temperature and high-pressure resistant materials, such as boron nitride, and has the function of preventing the corrosion of a mineralizer. A buffer layer 8 is arranged in the reaction chamber, said buffer layer having openings, such as partitions, of adjustable shape and size. The partition board is provided with a cylindrical channel. The buffer layer 8 divides the reaction chamber into a first reaction space 9 and a second reaction space 6, and reactants can be transferred from the first reaction space 9 to the second reaction space 6 through the buffer layer 8. The first reaction space 9 is in the lower part of the reaction chamber and the second reaction space 6 is in the upper part of the reaction chamber, and the ratio of the first reaction space 9 to the second reaction space 6 may be 4: 6. Meanwhile, the second reaction space is preset with seed crystals. The seed crystal may be suspended in the space above the buffer layer 8 by a silver wire. Other means, such as clamping, gluing, etc., may be used to attach the cushion layer 8 to the upper space. The seed crystal can also be designed into seed crystal splicing for large-size single crystal growth. In this embodiment, a seed crystal frame 5 may be further disposed in the second reaction space 6, the seed crystal frame 5 may be a plurality of seed crystals arranged uniformly, and the seed crystals are mounted on the seed crystal frame 5. In the whole device, the buffer layer 8 and the seed crystal frame 5 which are in contact with reactants are structurally provided with other noble metal anti-corrosion layers.

The reaction device also comprises a temperature control system and a pressurization system. The temperature control system comprises a heater 7 arranged outside the reaction chamber and a thermocouple 12 arranged in the whole reaction chamber. The heater may be a thermal resistor. In the present embodiment, a first heater is disposed outside the first reaction space 9, which is disposed around the first reaction space 9, and a second heater is disposed outside the second reaction space 6, which is disposed at both sides of the second reaction space 6. Thermocouples 12 are uniformly arranged in the first reaction space 9 and the second reaction space 6, respectively. The temperature control system controls the temperature of the first reaction space 9 and the second reaction space 6 to be different, and the pressurizing system comprises a pressurizing device and a pressure sensor arranged in the reaction cavity. One end of the reaction cavity is provided with a pressurizing port 1, the pressurizing device is connected with a pressure sensor in the reaction cavity through the pressurizing port 1, and the pressure sensor is connected to the pressurizing port 1 of the pressurizing system. The heater 7 is connected with a pressurizing system through a pressurizing port 1.

In this embodiment, the temperature of the first reaction space 9 and the temperature of the second reaction space 6 are controlled to be different by a precisely controlled temperature control system and a precisely controlled pressurization system, so that the first reaction space 9 is a high temperature region and the second reaction space 6 is a low temperature region. In the growth process of the gallium nitride single crystal, most of the inside of the reaction cavity is heated, the temperature which can be reached is generally not more than 900 ℃, the pressure in the reaction cavity is uniform, and the measurement and control are carried out by a thermocouple and a temperature control system. The temperature of the two reaction spaces can be adjusted and mutually matched and optimized, when the volume of the solution is influenced by the temperature and the pressure of the system, the filling degree of the solution is kept within the range of 60-100 percent, spontaneous nucleation and crystallization in the growth process of the gallium nitride can be prevented, the stable growth speed is ensured, the dissolution and crystallization are carried out according to the balanced growth process, the growth system of the gallium nitride single crystal is kept at the optimal process condition, and the growth efficiency of the gallium nitride single crystal and the quality of the single crystal are further improved.

In this embodiment, the seed crystal shelf 5 is disposed in the second reaction space, which can reduce the cost, maximize the yield of gallium nitride, and optimize the quality.

For the experiment, a solvent 10 and a solute 11 were placed in a reaction chamber. The gallium nitride reaction device has reasonable internal structure design, can reasonably control the temperature and the pressure of a gallium nitride growth system, and realizes the optimal process design conditions.

The implementation of the utility model has the advantages that: the reaction cavity is divided into a first reaction space 9 and a second reaction space 6 through a buffer layer 8, then the first reaction space 9 and the second reaction space 6 are controlled to be at different temperatures through a temperature control system and a pressurization system which are precisely controlled, the first reaction space 9 is a high-temperature area, the second reaction space 6 is a low-temperature area, and meanwhile, the temperatures of the two reaction spaces can be adjusted and optimized in a matched mode, so that when the volume of the solution is influenced by the temperature and the pressure of the system, the filling degree of the solution is kept in a range of 60-100%, and spontaneous nucleation and precipitation in the growth process of gallium nitride can be prevented. Meanwhile, the buffer layer 8 controls the mass transfer flow and direction in the growth process of the gallium nitride single crystal by adjusting the shape and the opening size. Through reasonable design of the internal structure of the reaction cavity, the balanced growth of the gallium nitride single crystal is realized, the dislocation density is effectively reduced, the growth efficiency of the gallium nitride is improved, and the quality of the crystal is improved.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention disclosed herein are intended to be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. The utility model provides a gallium nitride single crystal growth device, is including reaction furnace body, temperature control system and the pressurization system that has the reaction chamber, its characterized in that, be equipped with the buffer layer in the reaction chamber, the buffer layer is divided into first reaction space and second reaction space with the reaction chamber to accessible buffer layer shifts the reactant from first reaction space to second reaction space, temperature control system is including setting up the first heater in the first reaction space outside, setting up the second heater in the second reaction space outside and setting up the thermocouple in whole reaction chamber, temperature control system control makes the temperature in first reaction space and second reaction space inequality, pressurization system includes pressurization device and the pressure sensor of setting in the reaction chamber.

2. A single crystal growing apparatus of gallium nitride according to claim 1, wherein the reaction chamber has a pressure port at one end, and said pressure device is connected to a pressure sensor in the reaction chamber through the pressure port.

3. A gallium nitride single crystal growth apparatus according to claim 1, wherein said heater is connected to a pressurizing system through a pressurizing port.

4. A gallium nitride single crystal growth apparatus according to claim 1, wherein the shape and opening of the buffer layer are adjustable.

5. A gallium nitride single crystal growth apparatus according to claim 1, wherein the buffer layer is a partition plate having an opening.

6. A gallium nitride single crystal growth apparatus according to claim 1, wherein a seed holder is provided in the second reaction space, and the seed crystal is mounted on said seed holder.

7. A gallium nitride single crystal growth apparatus according to claim 1, wherein the reaction furnace is a crucible.

8. A gallium nitride single crystal growth apparatus according to claim 1, wherein the reaction furnace body is placed in an autoclave, said autoclave being made of a special steel material resistant to high temperature and high pressure.

9. A gallium nitride single crystal growth apparatus according to claim 1, wherein the autoclave is made of nickel-based superalloy.

10. A gallium nitride single crystal growth apparatus according to claim 1, wherein the autoclave is externally provided with a heat insulating layer.