CN115679441B - Method and apparatus for growing III-V compound single crystals by hydride vapor phase epitaxy - Google Patents

Abstract

Translated fromChinese

本发明公开了一种氢化物气相外延法生长III‑V族化合物单晶的方法及设备。所述方法包括：将III元素源、氮源与载气输入HVPE反应腔室内，并依次经过所述反应腔室内的第一区域、第二区域、第三区域，分别将所述反应腔室第一区域、第二区域和第三区域的调节至第一温度、第二温度和第三温度，使所述III元素源与氮源于所述第一区域发生反应而形成III氮化物单晶，使III元素源与氢气于第二区域发生反应而形成III元素单质，使氮源与卤素氢化物于第三区域发生反应而形成铵盐。本发明实施例提供的一种氢化物气相外延法生长III族氮化物单晶的方法，提高了III族氮化物单晶的产量和纯度，并能回收III族元素单质，降低了III族氮化物单晶的制备成本。

The present invention discloses a method and apparatus for growing a III-V compound single crystal by hydride vapor phase epitaxy. The method comprises: introducing a III element source, a nitrogen source, and a carrier gas into a HVPE reaction chamber, and sequentially passing through a first region, a second region, and a third region of the reaction chamber, adjusting the first region, the second region, and the third region of the reaction chamber to a first temperature, a second temperature, and a third temperature, respectively, causing the III element source and the nitrogen source to react in the first region to form a III nitride single crystal, causing the III element source and hydrogen to react in the second region to form a III element element, and causing the nitrogen source and a halogen hydride to react in the third region to form an ammonium salt. An embodiment of the present invention provides a method for growing a III nitride single crystal by hydride vapor phase epitaxy, which improves the yield and purity of the III nitride single crystal, can recover the III element element element, and reduces the preparation cost of the III nitride single crystal.

Description

Method and apparatus for growing III-V group compound single crystal by hydride vapor phase epitaxy

Technical Field

The invention relates to hydride vapor phase epitaxy equipment, in particular to a method and equipment for growing III-V compound single crystals by a hydride vapor phase epitaxy method, and belongs to the technical field of semiconductor epitaxy equipment.

Background

The third generation semiconductor material is a wide bandgap semiconductor material represented by III-V group compounds (such as gallium nitride GaN), silicon carbide (SiC), diamond and zinc oxide, the bandgap energy of the wide bandgap semiconductor material can reach 3.3-5.5 eV, and compared with the traditional first generation semiconductor materials of silicon (Si) and germanium (Ge), the second generation semiconductor materials of gallium arsenide (GaAs), indium phosphide (InP) and the like, the third generation semiconductor material has the unique properties of large bandgap width, high breakdown electric field, large thermal conductivity, high electron saturation drift velocity, small dielectric constant and the like, so that the wide bandgap semiconductor material has huge application potential in the aspects of optoelectronic devices, power electronics, radio frequency microwave devices, lasers, detectors and the like, and is a hot spot for research in semiconductor fields of all countries of the world.

The growth methods of III-V group compound single crystals (such as gallium nitride single crystals) include hydride vapor phase epitaxy (Hydride Vapor Phase Epitaxy, HVPE), high pressure nitrogen solution method, ammonothermal method, na flux method, etc., but the single crystal growth technology is not mature at present and has not yet been widely used. Among the above methods, the ammonothermal method is easy to obtain larger-sized single crystals, and has the potential to mass-produce single crystals of group III-V compounds.

Taking hydride vapor phase epitaxy for gallium nitride growth as an example, the reaction principle is ①Ga+HCl→GaCl+H₂、②GaCl+NH₃ to GaN (single crystal) +HCl+H₂, and a large amount of byproducts are ③GaCl+NH₃ to GaN (polycrystal) +HCl+H₂、④2GaCl+H₂→Ga+2HCl、⑤NH₃+HCl→NH₄ Cl generated in the HVPE growth process.

Fig. 1 is a schematic diagram showing the structure of an HVPE growth system in the prior art and the deposition of byproducts in a reaction chamber during gallium nitride single crystal growth. In the existing HVPE growth system, besides gallium nitride is deposited on a substrate sheet, a plurality of other parasitic products such as gallium nitride polycrystal, gallium metal, ammonium chloride and the like are also arranged in a reaction chamber, the main material of the reaction chamber of the HVPE growth system is quartz, polycrystal GaN is deposited on the quartz, a large amount of deposition can cause quartz pipeline blockage to influence growth, a large amount of deposition can also cause quartz cracking, the blockage and cracking enable the system to work for a short time, frequent replacement of quartz accessories can also cause poor production stability, ammonium chloride is a main deposit in an HVPE tail gas system, in conventional HVPE, ammonium chloride is deposited in the reaction chamber and the tail gas system, a plurality of places are deposited to cause cleaning difficulty, and ammonium chloride deposited in the reaction chamber also causes particle pollution in the reaction chamber to influence growth.

Therefore, various parasites in the existing HVPE growth system can be mixed in the reaction chamber, so that the atmosphere in the reaction chamber can be changed, the effective reaction time of the reaction chamber is influenced, the cleanliness of the reaction chamber is influenced, and the problems of difficult waste treatment, low utilization rate of reaction sources and the like are caused by mixing various different substances.

Disclosure of Invention

The invention mainly aims to provide a method and equipment for growing III-V compound single crystals by a hydride vapor phase epitaxy method, which overcome the defects in the prior art.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention comprises the following steps:

The embodiment of the invention provides a method for growing III-V compound single crystals by a hydride vapor phase epitaxy method, which comprises the steps of inputting a first source substance and a second source substance into a reaction chamber, wherein the first source substance comprises a III element, the second source substance comprises a V element, enabling the first source substance and the second source substance to react in the first area of the reaction chamber to generate the III-V compound single crystals and first byproducts by setting the first area, the second area and the third area in the reaction chamber to be different in temperature respectively, enabling at least part of the first byproducts and unreacted first source substance to react in the second area to generate recoverable III element simple substances and second byproducts, and enabling at least part of the first byproducts and/or at least part of the second byproducts to react with unreacted second source substance in the third area to generate recoverable products.

The embodiment of the invention also provides a method for growing III-nitride single crystals by a hydride vapor phase epitaxy method, which comprises the following steps:

Inputting a group III element source, a nitrogen source and a carrier gas into an HVPE reaction chamber, and sequentially passing through a first region, a second region and a third region in the reaction chamber, wherein the first region comprises a group III nitride single crystal growth region and a peripheral region which radially surrounds the group III nitride single crystal growth region, a substrate is distributed in the group III nitride single crystal growth region, the group III element source comprises halide of a group III element, and the nitrogen source comprises NH₃;

Setting the temperature of the group III nitride single crystal growth region to a first temperature to cause a first reaction of a group III element source and a nitrogen source within the group III nitride single crystal growth region to produce a group III nitride single crystal, hydrogen gas, and a halogen hydride, and to cause the group III nitride single crystal to be deposited on a substrate, and setting the temperature of the peripheral region to a second temperature, the first temperature being a temperature suitable for producing a group III nitride single crystal, the second temperature being greater than the first temperature;

Setting the temperature of the second region to be a third temperature, so that at least hydrogen generated by the first reaction and a III group element source perform a second reaction in the second region to generate a III group element simple substance and a halogen hydride, wherein the third temperature is higher than the formation temperature of ammonium salt and lower than the cracking temperature of halide of the III group element;

setting the temperature of the third region to a fourth temperature, so that at least the halogen hydride generated by the first reaction and/or the second reaction and the nitrogen source perform a third reaction in the third region to generate ammonium salt, wherein the fourth temperature is not higher than the decomposition temperature of the ammonium salt.

The embodiment of the invention also provides equipment for growing III-nitride single crystals by a hydride vapor phase epitaxy method, which comprises the following steps:

The HVPE reaction chamber is provided with a first area, a second area and a third area which are sequentially communicated in a preset direction, wherein the first area comprises a III-nitride single crystal growth area and a peripheral area which radially surrounds the III-nitride single crystal growth area, a substrate is distributed in the III-nitride single crystal growth area, the III-nitride single crystal growth area at least can be used for enabling a III-element source to react with a nitrogen source to generate a III-nitride single crystal, hydrogen and halogen hydride, and the III-nitride single crystal is deposited on the substrate;

Heating means for at least bringing the temperatures of the group III nitride single crystal growth region, the peripheral region, the second region, and the third region to a first temperature, a second temperature, a third temperature, and a fourth temperature, respectively;

And a nitrogen source and group III element source supply mechanism connected to the HVPE reaction chamber and configured to supply at least a nitrogen source and a group III element source for performing group III nitride single crystal growth into the HVPE reaction chamber.

Compared with the prior art, the invention has the advantages that:

1) The hydride vapor phase epitaxy equipment for growing the III-nitride single crystal has a simple structure, and can reduce deposition of reaction byproducts and realize classified recovery of the reaction byproducts only by simply modifying the reaction chamber;

2) The method for growing the III nitride monocrystal by using the III nitride hydride vapor phase epitaxy method provided by the embodiment of the invention improves the yield and purity of the III nitride monocrystal, reduces the formation of III nitride polycrystal by precisely regulating and controlling the multi-section area (temperature and length), assisting the diluent gas and locally heating, simultaneously realizes high-purity concentrated recovery of byproducts such as III element simple substance, ammonium salt and the like, reduces the cost of III element simple substance recovery, and reduces the maintenance frequency of equipment;

3) According to the hydride vapor phase epitaxy equipment for growing the III-nitride single crystal, provided by the embodiment of the invention, the temperatures in the unused areas in the reaction chamber are distributed in a gradient manner by adjusting the temperatures in different chambers, and the air flow dilution is increased, so that the decomposition of redundant ammonium salt is realized, and the yield of the III-nitride single substance is increased;

4) According to the hydride vapor phase epitaxy equipment for growing the III nitride single crystal, provided by the embodiment of the invention, the temperature of the recovery area (the recovery area comprises the second area and the third area) in the reaction chamber is lower than the cracking temperature of the halide of the III element and higher than the formation temperature of the ammonium salt, so that the decomposition of the halide of the superfluous III element is promoted.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to the drawings without inventive effort to those skilled in the art.

FIG. 1 is a schematic diagram of the structure of an HVPE growth system in the prior art and the deposition of byproducts in a reaction chamber during gallium nitride single crystal growth;

fig. 2 is a schematic structural view of a reaction chamber in a hydride vapor phase epitaxy apparatus for growing gallium nitride single crystal and a schematic deposition of by-products in the reaction chamber when growing gallium nitride single crystal according to an exemplary embodiment of the invention.

Detailed Description

In view of the shortcomings in the prior art, the inventor of the present invention has long studied and practiced in a large number of ways to propose the technical scheme of the present invention. The technical scheme, the implementation process, the principle and the like are further explained as follows.

The reaction principle of gallium nitride growth by hydride vapor phase epitaxy is ①Ga+HCl→GaCl+H₂、②GaCl+NH₃ - & gt GaN (single crystal) +HCl+H₂, and a large amount of byproducts are produced in the HVPE growth process, namely ③GaCl+NH₃ - & gt GaN (polycrystal) +HCl+H₂、④2GaCl+H₂→Ga+2HCl、⑤NH₃+HCl→NH₄ Cl. The reaction ② is the main reaction and is also the target of the HVPE system, namely, the GaN single crystal is obtained as much as possible, while the proportion of GaCl formed into single crystal GaN in the reaction ② in the conventional HVPE reaction system is only 5-30%, most of GaCl is finally converted into reaction byproducts, and the reaction byproducts exist in various forms, such as GaN polycrystal, ga and Ga-NH₄Cl、GaCl*NH₄ Cl, so that the utilization rate of Ga is low, thereby improving the growth cost of the GaN single crystal, and the byproducts have the highest purity of metal Ga and the lowest purification difficulty, and if the reaction byproducts can be converted into metal Ga as much as possible, the purification cost can be reduced, and the comprehensive preparation cost of the GaN single crystal is reduced.

The embodiment of the invention provides a method for growing III-V compound single crystals by a hydride vapor phase epitaxy method, which comprises the steps of inputting a first source substance and a second source substance into a reaction chamber, wherein the first source substance comprises a III element, the second source substance comprises a V element, enabling the first source substance and the second source substance to react in the first area of the reaction chamber to generate the III-V compound single crystals and first byproducts by setting the first area, the second area and the third area in the reaction chamber to be different in temperature respectively, enabling at least part of the first byproducts and unreacted first source substance to react in the second area to generate recoverable III element simple substances and second byproducts, and enabling at least part of the first byproducts and/or at least part of the second byproducts to react with unreacted second source substance in the third area to generate recoverable products.

Further, the first region includes a III-V compound single crystal growth region and a peripheral region radially surrounding the III-V compound single crystal growth region, the III-V compound single crystal growth region being set to a temperature suitable for producing a III-V compound single crystal, the peripheral region having a temperature higher than that of the III-V compound single crystal growth region.

Further, the method includes inputting a dilution gas into the peripheral region to reduce the concentration of the first source material and the second source material in the peripheral region, thereby preventing the first source material and the second source material from reacting in the peripheral region to form a group III-V compound polycrystal.

Further, at least a portion of the diluent gas is capable of reacting with unreacted first source material in the second region to form the elemental group III element.

Further, at least a portion of the diluent gas can be reacted with unreacted second source material in a third zone to produce the recoverable product.

Further, the temperature of the second zone is set to be higher than the formation temperature of the recoverable product and lower than the decomposition temperature of the first source material, and the temperature of the third zone is set to be not higher than the decomposition temperature of the recoverable product.

Further, the method further comprises disposing an operation region for placing a growth substrate of a III-V compound single crystal into or out of the first region between the second region and the third region, and setting a temperature of the operation region to be higher than a generation temperature of the recoverable product.

The embodiment of the invention also provides a method for growing III-nitride single crystals by a hydride vapor phase epitaxy method, which comprises the following steps:

Inputting a group III element source, a nitrogen source and a carrier gas into an HVPE reaction chamber, and sequentially passing through a first region, a second region and a third region in the reaction chamber, wherein the first region comprises a group III nitride single crystal growth region and a peripheral region which radially surrounds the group III nitride single crystal growth region, a substrate is distributed in the group III nitride single crystal growth region, the group III element source comprises halide of a group III element, and the nitrogen source comprises NH₃;

Setting the temperature of the group III nitride single crystal growth region to a first temperature to cause a first reaction of a group III element source and a nitrogen source within the group III nitride single crystal growth region to produce a group III nitride single crystal, hydrogen gas, and a halogen hydride, and to cause the group III nitride single crystal to be deposited on a substrate, and setting the temperature of the peripheral region to a second temperature, the first temperature being a temperature suitable for producing a group III nitride single crystal, the second temperature being greater than the first temperature;

Setting the temperature of the second region to be a third temperature, so that at least hydrogen generated by the first reaction and a III group element source perform a second reaction in the second region to generate a III group element simple substance and a halogen hydride, wherein the third temperature is higher than the formation temperature of ammonium salt and lower than the cracking temperature of halide of the III group element;

setting the temperature of the third region to a fourth temperature, so that at least the halogen hydride generated by the first reaction and/or the second reaction and the nitrogen source perform a third reaction in the third region to generate ammonium salt, wherein the fourth temperature is not higher than the decomposition temperature of the ammonium salt.

Further, the peripheral region is a region near the tube wall of the HVPE reaction chamber.

Further, the method specifically comprises the steps of enabling the temperature of the peripheral area to reach the second temperature by adjusting the heating power of the HVPE reaction equipment on the peripheral area, or enabling the temperature of the peripheral area to reach the second temperature by arranging an auxiliary heating device on the peripheral area.

Further, the method includes inputting a dilution gas into the peripheral zone to reduce the concentration of the group III element source and the nitrogen source in the peripheral zone.

Further, the diluent gas comprises hydrogen, and hydrogen derived from the diluent gas also participates in the second reaction.

Further, the input flow rate of the hydrogen is 0.5-50slm.

Further, the diluent gas comprises a halogen hydride, and the halogen hydride derived from the diluent gas also participates in the third reaction.

Further, the input flow rate of the halogen hydride is smaller than the generation rate of the halogen hydride in the first reaction.

Further, the input flow rate of the halogen hydride is 0.05-1slm.

Further, the method comprises maintaining the hydrogen concentration in the HVPE reaction chamber at 20% -80% and the halogen hydride concentration at 1% -10%.

Further, the nitrogen source input to the HVPE reaction chamber is excessive.

Further, the HVPE reaction chamber further includes an operating zone disposed between the second zone and the third zone, the operating zone being set at a temperature greater than a formation temperature of the ammonium salt.

Further, the method also comprises the step of arranging a group III element simple substance collection mechanism in the second area.

Further, the group III element simple substance collection mechanism comprises a group III element simple substance collection flat plate.

Further, the group III element source comprises GaM_x、InM_x、AlM_x or BM_x, x is 1-3, and M comprises Cl, br or I.

The embodiment of the invention also provides equipment for growing III-nitride single crystals by a hydride vapor phase epitaxy method, which comprises the following steps:

The HVPE reaction chamber is provided with a first area, a second area and a third area which are sequentially communicated in a preset direction, wherein the first area comprises a III-nitride single crystal growth area and a peripheral area which radially surrounds the III-nitride single crystal growth area, a substrate is distributed in the III-nitride single crystal growth area, the III-nitride single crystal growth area at least can be used for enabling a III-element source to react with a nitrogen source to generate a III-nitride single crystal, hydrogen and halogen hydride, and the III-nitride single crystal is deposited on the substrate;

Heating means for at least bringing the temperatures of the group III nitride single crystal growth region, the peripheral region, the second region, and the third region to a first temperature, a second temperature, a third temperature, and a fourth temperature, respectively;

And a nitrogen source and group III element source supply mechanism connected to the HVPE reaction chamber and configured to supply at least a nitrogen source and a group III element source for performing group III nitride single crystal growth into the HVPE reaction chamber.

Further, the apparatus for growing a group III nitride single crystal by hydride vapor phase epitaxy further comprises:

A diluent gas supply mechanism connected to the HVPE reaction chamber and configured to supply a diluent gas to at least the peripheral region, the peripheral region being a region near a tube wall of the HVPE reaction chamber, the diluent gas supply mechanism being configured to reduce concentrations of a group III element source and a nitrogen source in the peripheral region;

And/or, setting a group III element simple substance collection mechanism in the second area.

Further, the group III element simple substance collection mechanism comprises a group III element simple substance collection flat plate.

Further, the HVPE reaction chamber further comprises an operation area distributed in the second area and the third area, wherein the operation area is provided with an operation opening, and an operation cover plate capable of being opened and closed is arranged at the operation opening.

Further, the ratio of the lengths of the first region, the second region and the third region is 1:2:2-1:10:4.

Further, the device also comprises a tail gas treatment mechanism, and the tail gas treatment mechanism is connected with a tail gas outlet of the HVPE reaction chamber.

The technical solution, the implementation process, the principle and the like will be further explained below with reference to the accompanying drawings, and the gallium nitride growth source supply mechanism, the dilution gas supply mechanism, the tail gas treatment mechanism and the like in the hydride vapor phase epitaxy apparatus for gallium nitride single crystal growth according to the embodiments of the present invention may be known to those skilled in the art, unless otherwise specified, and are not specifically limited herein.

Referring to fig. 2, an apparatus for growing gallium nitride single crystal by hydride vapor phase epitaxy comprises:

The HVPE reaction chamber is provided with a first area, a second area, an operation area and a third area which are sequentially communicated in a preset direction, wherein the first area comprises a gallium nitride single crystal growth area and a peripheral area which radially surrounds the gallium nitride single crystal growth area, a substrate is distributed in the gallium nitride single crystal growth area, at least a gallium source and a nitrogen source can react to generate a gallium nitride single crystal, hydrogen and hydrogen chloride, and the gallium nitride single crystal is deposited on the substrate;

Heating means for at least bringing the temperatures of the gallium nitride single crystal growth region, the peripheral region, the second region, and the third region to a first temperature, a second temperature, a third temperature, and a fourth temperature, respectively;

A nitrogen source and gallium source supply mechanism connected to the HVPE reaction chamber and at least for inputting a nitrogen source and a gallium source for growing gallium nitride single crystal into the HVPE reaction chamber;

A dilution gas supply mechanism connected to the HVPE reaction chamber and at least configured to supply a dilution gas to the peripheral region, the peripheral region being a region near a tube wall of the HVPE reaction chamber, to reduce concentrations of a gallium source and a nitrogen source in the peripheral region;

And the tail gas treatment mechanism is connected with a tail gas outlet of the HVPE reaction chamber.

Specifically, a gallium metal collecting mechanism is arranged in the second area, for example, the gallium metal collecting mechanism comprises a gallium metal collecting flat plate, an operation opening is formed in the operation area, and an operation cover plate capable of being opened and closed is arranged at the operation opening.

Specifically, the ratio of the lengths of the first region, the second region and the third region is 1:2:2-1:10:4.

Example 1

A method for growing gallium nitride single crystals by hydride vapor phase epitaxy, comprising:

providing a device for growing gallium nitride single crystals by a hydride vapor phase epitaxy method as shown in fig. 2, and respectively adjusting the growth area, the peripheral area, the second area and the third area of the gallium nitride single crystals of the reaction chamber to a first temperature, a second temperature, a third temperature and a third temperature;

Inputting a gallium source, a nitrogen source and a carrier gas into an HVPE reaction chamber, and sequentially passing through a first region, a second region and a third region in the reaction chamber, wherein the first region comprises a gallium nitride single crystal growth region and a peripheral region which radially surrounds the gallium nitride single crystal growth region, a substrate is distributed in the gallium nitride single crystal growth region, the gallium source comprises GaCl, and the nitrogen source comprises NH₃;

Setting the temperature of the gallium nitride single crystal growth area to be a first temperature, so that a gallium source and a nitrogen source perform a first reaction in the gallium nitride single crystal growth area to generate a gallium nitride single crystal, hydrogen and hydrogen chloride, the gallium nitride single crystal is deposited on a substrate, and setting the temperature of the peripheral area to be a second temperature, wherein the first temperature is a temperature suitable for generating the gallium nitride single crystal, and the second temperature is higher than the first temperature;

setting the temperature of the second region to be a third temperature, so that at least hydrogen generated by the first reaction and a gallium source perform a second reaction in the second region to generate metallic gallium and hydrogen chloride, wherein the third temperature is higher than the formation temperature of ammonium chloride and lower than the cracking temperature of gallium chloride;

setting the temperature of the third region to a fourth temperature, so that at least hydrogen chloride generated by the first reaction and/or the second reaction and a nitrogen source undergo a third reaction in the third region to generate ammonium chloride, wherein the fourth temperature is not higher than the decomposition temperature of the ammonium chloride, and

Inputting a diluent gas into the reaction chamber to purge the first region, and purging part of the gallium source, the nitrogen source and part of H₂ and HCl generated by the reaction to a second region and a third region, wherein the first reaction, the second reaction and the third reaction are respectively shown in the formula 1), the formula 2) and the formula 3);

GaCl+NH₃→GaN+HCl+H₂ 1)

GaCl+H₂→Ga+HCl 2)

NH₃+HCl→NH₄Cl 3)。

Specifically, the first temperature is 1000-1090 ℃, the second temperature is above 1090 ℃, the third temperature is 350-800 ℃, the temperature of the operation area is 25-350 ℃, and the fourth temperature is more than or equal to 350 ℃.

Specifically, the method comprises the steps of inputting diluent gas into a peripheral area of the reaction chamber along the inner wall of the reaction chamber so as to adjust the concentration of H₂ in the HVPE reaction chamber to 20% -80% and the concentration of HCl to 1% -10%, wherein the diluent gas comprises any one or more than two of N₂、H₂ and HCl, the input flow rate of any one of N₂ and H₂ is 0.5-50slm, and the input flow rate of HCl is smaller than the generation rate of HCl in the first reaction, for example, the input flow rate of HCl is 0.05-0.1sccm.

Specifically, the reaction of forming gallium nitride polycrystal in the gallium nitride single crystal growth zone is GaCl+NH₃ - & gtGaN (polycrystal) +HCL+H2₂, and the inventor researches that when the temperature is raised, the positive reaction is restrained, the reverse reaction is promoted, so that the GaN synthesis efficiency is reduced, the temperature is raised, the polycrystal GaN generation is restrained (the formation temperature of single crystal and polycrystal is the same, the formation state is different on different substrates, the single crystal is formed on the substrate, the polycrystal is formed on quartz), and when the concentration of HCl and H₂ in the reaction chamber is higher than 30%, the reverse reaction is promoted, the polycrystal GaN synthesis is reduced, and therefore, when the total flow rate in the reaction chamber is higher than 20slm, the relative concentration of source gas is reduced to 20%, and the efficiency of forming gallium nitride polycrystal by the reaction is also reduced.

The inventor also researches and discovers that gallium nitride polycrystal is deposited on the cavity wall of the reaction chamber, so that the dilution gas is input into the reaction chamber along the inner wall of the reaction chamber, the gallium nitride polycrystal can be effectively prevented from being deposited on the cavity wall of the reaction chamber, and the peripheral area of the HVPE reaction chamber is locally heated, so that the temperature of the peripheral area reaches above 1090 ℃, and the reaction formation and deposition of the gallium nitride polycrystal are restrained.

The implementation principle of the method for growing gallium nitride monocrystal by using the hydride vapor phase epitaxy method provided by the embodiment of the invention at least comprises the following steps:

①Ga+HCl→GaCl+H₂、②GaCl+NH₃ GaN (single crystal) +hcl+h₂, and a large amount of byproducts ③GaCl+NH₃ →gan (polycrystal) +hcl+h₂、④2GaCl+H₂→Ga+2HCl、⑤NH₃+HCl→NH₄ Cl are generated during HVPE growth;

The gallium source GaCl, the nitrogen source NH₃ and the doping source gas are input into an HVPE reaction chamber through carrier gas, so that the gallium source reacts with the nitrogen source in the gallium nitride single crystal growth zone to form gallium nitride single crystals, the temperature in the gallium nitride single crystal growth zone is suitable for gallium nitride single crystal growth and unsuitable for gallium nitride polycrystal growth, therefore, the formation of gallium nitride polycrystal can be reduced, dilution gas is input into the reaction chamber along the inner wall of the reaction chamber, part of the gallium source, the nitrogen source and part of H₂ and HCl generated by the reaction are purged to a second zone and a third zone, and because hydrogen serving as the dilution gas does not participate in the reaction in the first zone, part of hydrogen is purged to the second zone, and reaction GaCl+H2₂ - & Ga+HCl occurs in the second zone to form metallic gallium, the third temperature is higher than the formation temperature of ammonium chloride but lower than the cracking temperature of gallium chloride, and the improvement of the flow rate of the hydrogen in the second zone can promote the yield of the metallic gallium;

Because the fourth temperature of the third region is lower than that of the second region and the gallium nitride single crystal growth region, and the fourth temperature is the temperature at which the reaction NH₃+HCl→NH₄ Cl can occur, the reaction forming ammonium chloride hardly occurs in the first region and the second region, and because the input NH₃ is in large excess, and NH₃ only participates in the GaN generation reaction and does not participate in other reactions, the excess ammonia can flow into the third region, and HCl is the product of the reaction forming GaN, and the excess HCl can be introduced when the generation of polycrystalline GaN is reduced, and the side reaction ④ generates HCl when gallium is generated, and the partial HCl does not participate in other reactions and flows into the third region.

Specifically, the equipment for growing the gallium nitride single crystal by the hydride vapor phase epitaxy method shown in the figures 1 and 2 is provided respectively, and the epitaxial growth of the gallium nitride single crystal is carried out by the hydride vapor phase epitaxy equipment and the corresponding process respectively;

According to measurement and calculation, when gallium nitride single crystals are prepared by using equipment shown in fig. 1 and the existing technology (see the background art part), each 1000g of gallium nitride single crystals are consumed, 62.5g of generated gallium nitride single crystals, 960.8g of gallium nitride polycrystal, 30g of gallium metal, 956.1g of ammonium chloride and gallium chloride mixture are measured, the content of gallium in the ammonium chloride and gallium chloride mixture is 12%, a large amount of ammonium chloride is deposited on the cavity wall of a wafer loading and unloading area, the macroscopic defect density of the surface of the prepared gallium nitride single crystals due to particles such as chamber byproducts is 2 pieces/cm², and each growth of a reaction chamber is required to be cleaned.

When gallium nitride single crystal is prepared by the equipment shown in figure 2 and the method provided by the invention, each 1000g of metal gallium is consumed, the generated gallium nitride single crystal is 77.2g, gallium nitride polycrystal is 360.3g, metal gallium is 550g, the mixture of ammonium chloride and gallium chloride is 1127.8g, the content of gallium in the mixture of ammonium chloride and gallium chloride is 6% after measurement, and the method provided by the invention has almost no ammonium chloride deposition on the cavity wall of a chip loading area, the macroscopic defect density of the surface of the gallium nitride single crystal obtained by the preparation due to particles such as a cavity byproduct is 0.3/cm², and the reaction cavity is cleaned once every 5 times.

By calculation and comparison, the method for growing gallium nitride single crystals by using the hydride vapor phase epitaxy method provided by the embodiment improves the proportion of converting metal gallium into gallium nitride single crystals from 5.2% (by adopting equipment shown in fig. 1and the prior art) to 6.4%, reduces the proportion of converting the metal gallium into polycrystalline gallium from 80% to 30%, improves the proportion of converting the metal gallium into 55%, reduces the gallium content in ammonium chloride from 12% to 6%, greatly improves the cleanliness of a loading and unloading operation area, reduces the macroscopic defect density caused by particle pollution by one order of magnitude, and reduces the cleaning frequency of a reaction chamber to 1/5 of the original frequency.

Example 2

According to the embodiment, alCl_x (x takes 1-3) and ammonia gas are used as an aluminum source and a nitrogen source respectively, and the AlN single crystal is grown by using the equipment shown in fig. 1 and 2 and a matched process, so that the result shows that compared with the equipment shown in fig. 1, the AlN single crystal is grown by using the equipment shown in fig. 2, the proportion of aluminum effectively converted into aluminum nitride single crystal is increased from 7.2% to 8.1%, the proportion of aluminum effectively converted into polycrystalline aluminum nitride is reduced from 70% to 40%, the recovery proportion of metal aluminum is increased from 2% to 29%, the equipment cleaning maintenance frequency is also reduced to 1/4, and the yield and quality (mainly the surface defect density) of the AlN single crystal grown by using the equipment shown in fig. 2 and the matched process are obviously better than those of the AlN single crystal grown by using the equipment shown in fig. 1 and the matched process, and the recovery proportion of the metal aluminum is also obviously improved.

The method for growing the III-V compound single crystal by hydride vapor phase epitaxy improves the yield and purity of the III-V compound single crystal, reduces the formation of the III-V compound polycrystal by precise regulation and control (temperature and length) of a multi-section area, the assistance of diluent gas and local heating, simultaneously realizes high-purity concentrated recovery of various valuable byproducts, reduces recovery cost and reduces maintenance frequency of equipment.

It should be understood that the above embodiments are merely for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the present invention and implement the same according to the present invention without limiting the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.

Claims (26)

1. A method for growing a single crystal of a group III-V compound by hydride vapor phase epitaxy, comprising: inputting a first source substance and a second source substance into a reaction chamber, wherein the first source substance comprises a group III element, the second source substance comprises a group V element, the first region, the second region and the third region in the reaction chamber are respectively set to different temperatures, the first source substance and the second source substance react in the first region of the reaction chamber to generate a III-V compound single crystal and a first byproduct, at least part of the first byproduct reacts with the unreacted first source substance in the second region to generate a recoverable group III element simple substance and a second subsidiary product, at least part of the first byproduct and/or at least part of the second subsidiary product reacts with the unreacted second source substance in the third region to generate a recoverable product, the first region comprises a III-V compound single crystal growth region and a peripheral region which radially surrounds the III-V compound single crystal growth region, the temperature of the III-V compound single crystal is set to be suitable for generating the III-V compound single crystal, the peripheral region is higher than the temperature of the III-V compound single crystal, the temperature is set to be higher than the temperature of the III-V compound single crystal, and the temperature of the recovered single crystal is set to be higher than the temperature of the first region and the recovered product is set to be higher than the temperature of the first material.

2. The method of claim 1, further comprising introducing a dilution gas into the peripheral zone to reduce the concentration of the first source and the second source in the peripheral zone, thereby preventing the first source from reacting with the second source in the peripheral zone to form a group III-V compound polycrystal.

3. The method of claim 2, wherein at least a portion of the diluent gas is capable of reacting with unreacted first source material in a second zone to produce elemental group III elements and/or at least a portion of the diluent gas is capable of reacting with unreacted second source material in a third zone to produce the recoverable product.

4. The method according to claim 1, further comprising providing an operation region for placing a growth substrate of a III-V compound single crystal into or out of the first region between the second region and the third region, and setting a temperature of the operation region to be higher than a production temperature of the recoverable product.

5. A method for growing a group III nitride single crystal by hydride vapor phase epitaxy, comprising:

Inputting a group III element source, a nitrogen source and a carrier gas into an HVPE reaction chamber, and sequentially passing through a first region, a second region and a third region in the reaction chamber, wherein the first region comprises a group III nitride single crystal growth region and a peripheral region which radially surrounds the group III nitride single crystal growth region, a substrate is distributed in the group III nitride single crystal growth region, the group III element source comprises halide of a group III element, and the nitrogen source comprises NH₃;

Setting the temperature of the group III nitride single crystal growth region to a first temperature to cause a first reaction of a group III element source and a nitrogen source within the group III nitride single crystal growth region to produce a group III nitride single crystal, hydrogen gas, and a halogen hydride, and to cause the group III nitride single crystal to be deposited on a substrate, and setting the temperature of the peripheral region to a second temperature, the first temperature being a temperature suitable for producing a group III nitride single crystal, the second temperature being greater than the first temperature;

Setting the temperature of the second region to be a third temperature, so that at least hydrogen generated by the first reaction and a III group element source perform a second reaction in the second region to generate a III group element simple substance and a halogen hydride, wherein the third temperature is higher than the formation temperature of ammonium salt and lower than the cracking temperature of halide of the III group element;

setting the temperature of the third region to a fourth temperature, so that at least the halogen hydride generated by the first reaction and/or the second reaction and the nitrogen source perform a third reaction in the third region to generate ammonium salt, wherein the fourth temperature is not higher than the decomposition temperature of the ammonium salt.

6. The method of claim 5, wherein the peripheral region is a region near a wall of the HVPE reaction chamber.

7. The method according to claim 5, comprising adjusting heating power of the HVPE reaction device to the peripheral area so as to enable the temperature of the peripheral area to reach the second temperature, or arranging an auxiliary heating device in the peripheral area so as to enable the temperature of the peripheral area to reach the second temperature.

8. The method of claim 5, further comprising inputting a dilution gas into the peripheral zone to reduce the concentration of the source of group III element and the source of nitrogen in the peripheral zone.

9. The method of claim 8, wherein the diluent gas comprises hydrogen and hydrogen derived from the diluent gas also participates in the second reaction.

10. The method of claim 9, wherein the hydrogen gas is introduced at a flow rate of 0.5 to 50slm.

11. The method of claim 9, wherein the diluent gas comprises a halogen hydride and the halogen hydride derived from the diluent gas also participates in the third reaction.

12. The method of claim 11, wherein the input flow rate of the halogen hydride is less than the rate of formation of the halogen hydride in the first reaction.

13. The method of claim 12, wherein the input flow rate of the halogen hydride is 0.05-1slm.

14. The method of claim 11, comprising maintaining a hydrogen concentration in the HVPE reaction chamber in the range of 20% to 80% and a halogen hydride concentration in the range of 1% to 10%.

15. The method of claim 5, wherein the nitrogen source input to the HVPE reaction chamber is excessive.

16. The method of claim 5, wherein the HVPE reaction chamber further comprises an operating zone disposed between the second zone and the third zone, wherein the operating zone is set at a temperature greater than a formation temperature of the ammonium salt.

17. The method of claim 5, further comprising disposing a group III element simple substance collection mechanism within the second region.

18. The method of claim 17, wherein the elemental III-element collection mechanism comprises a elemental III-element collection plate.

19. The method of claim 5, wherein the source of group III elements comprises GaM_x、InM_x、AlM_x or BM_x, x is 1 to 3, and M comprises Cl, br or I.

20. An apparatus for growing a group III nitride single crystal by hydride vapor phase epitaxy, comprising:

The HVPE reaction chamber is provided with a first area, a second area and a third area which are sequentially communicated and arranged along a preset direction, wherein the first area comprises a III-nitride single crystal growth area and a peripheral area which radially surrounds the III-nitride single crystal growth area, the III-nitride single crystal growth area at least can be used for enabling a III-element source to react with a nitrogen source to generate a III-nitride single crystal, hydrogen and halogen hydride, a III-element simple substance collecting mechanism is arranged in the second area, and can be used for enabling the III-element source to react with the hydrogen to generate a III-element simple substance and the halogen hydride, and the third area can be used for enabling the nitrogen source to react with the halogen hydride to generate ammonium salt;

and a heating device for at least bringing the temperatures of the group III nitride single crystal growth region, the peripheral region, the second region, and the third region to a first temperature, a second temperature, a third temperature, and a fourth temperature, respectively.

21. The apparatus for growing a group III nitride single crystal by hydride vapor phase epitaxy as claimed in claim 20, characterized by further comprising:

and the diluent gas supply mechanism is connected with the HVPE reaction chamber and is at least used for inputting diluent gas into the peripheral area so as to reduce the concentration of the III-group element source and the nitrogen source in the peripheral area, wherein the peripheral area is an area near the pipe wall of the HVPE reaction chamber.

22. The apparatus for growing a single crystal of a group III nitride by a hydride vapor phase epitaxy method according to claim 20 or 21, characterized in that a group III element simple substance collecting mechanism is provided in said second region.

23. The apparatus for growing a single crystal of a group III nitride by a hydride vapor phase epitaxy method of claim 22, wherein said group III element simple substance collection means comprises a group III element simple substance collection plate.

24. The apparatus for growing a group III nitride single crystal by a hydride vapor phase epitaxy method according to claim 20 or 21, wherein the HVPE reaction chamber further comprises an operation region distributed in the second region and the third region, the operation region is provided with an operation port, and an operation cover plate capable of being opened and closed is arranged at the operation port.

25. The apparatus for growing a group III nitride single crystal by a hydride vapor phase epitaxy method according to claim 20 or 21, wherein the ratio of the lengths of said first region, second region and third region is 1:2:2 to 1:10:4.

26. The apparatus for growing a group III nitride single crystal by a hydride vapor phase epitaxy method according to claim 20 or 21, further comprising a tail gas treatment mechanism connected to a tail gas outlet of said HVPE reaction chamber.