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CN-121046929-B - Low-defect gallium oxide single crystal pulling growth equipment and method based on double-cavity atmosphere regulation and control

CN121046929BCN 121046929 BCN121046929 BCN 121046929BCN-121046929-B

Abstract

The application relates to the technical field of semiconductor material growth, and aims to solve the technical problems that service life of a heating element is reduced and quality of more crystal defects is difficult to guarantee due to single atmosphere sharing, and single crystal production cost is high but production efficiency is low in the prior art. The application discloses a single crystal growth device which is characterized by comprising a furnace body, a first chamber, a second chamber, a heating component, a growth component, an atmosphere isolation and heat conduction component, an atmosphere management system and a central control system, wherein the atmosphere isolation and heat conduction component is used for separating the furnace body into a first chamber and a second chamber which are isolated in an airtight manner and transferring heat efficiently. By adopting the scheme, the application can realize atmosphere structure separation and combined crucible design, effectively prolong the service life of the heating element and obviously reduce the operation cost while ensuring the high quality and high purity of the crystal.

Inventors

  • Gong xueyuan
  • LI LONG

Assignees

  • 北京镓创半导体装备有限公司

Dates

Publication Date
20260505
Application Date
20250829

Claims (12)

  1. 1. A growth apparatus for low-defect single crystals for growing low-defect gallium oxide single crystals by a pulling method or a guided mode method, comprising: The furnace body is internally provided with a cylindrical atmosphere separation and heat conduction assembly, and the atmosphere separation and heat conduction assembly physically separates the inner space of the furnace body into a first chamber and a second chamber which are mutually isolated and coaxially arranged; a protective heating system, wherein the heating system comprises a heating element arranged in the first cavity, and a protective coating is arranged on the surface of the heating element; An atmosphere control system comprising a first atmosphere management unit in communication with the first chamber for supplying and maintaining a protective atmosphere to the first chamber, and a second atmosphere management unit in communication with the second chamber for supplying and maintaining an oxygen-containing atmosphere to the second chamber; The temperature control system comprises a first temperature management unit, a second temperature management unit and a control unit, wherein the first temperature management unit is communicated with the first chamber and is used for regulating and controlling the temperature of the first chamber; A central control system including a temperature sensor, a pressure sensor, an oxygen partial pressure sensor and a central processor, and The crystal growth system comprises a combined crucible arranged in the second cavity, the combined crucible comprises a crucible with a first inner diameter and a crucible support with a second inner diameter, the wall thickness of the crucible is 0.1-0.8 mm, the crucible and the crucible support are coaxially arranged, the second inner diameter is 1-3 mm larger than the first inner diameter, an annular gap is formed between the outer wall of the crucible and the inner wall of the crucible support, an adaptive pressure compensation layer arranged coaxially is arranged in the annular gap, and the adaptive pressure compensation layer is selected from nickel-titanium shape memory alloy fiber felt or ceramic fiber.
  2. 2. The low defect monocrystalline growth device according to claim 1, wherein the atmosphere separation and thermal conduction assembly is integrally formed of a high temperature resistant transparent ceramic having a wall thickness of 5 mm to 15: 15 mm, the high temperature resistant transparent ceramic being selected from zirconia transparent ceramic, magnesia-alumina spinel transparent ceramic or sapphire.
  3. 3. The low defect monocrystalline growth device according to claim 1, wherein the heating element body is selected from graphite, honeycomb graphite, molybdenum disilicide or tungsten alloy, the protective coating comprises at least one layer, the heating element comprises at least one group.
  4. 4. The apparatus for growing a low defect single crystal according to claim 1, wherein the crucible is made of an oxidation-resistant material having a wall thickness of 0.1 to 0.8 mm for heating and/or maintaining a melt at a high temperature, which is detachably supported on the crucible support, the oxidation-resistant material including iridium, platinum iridium, platinum rhodium, composite iridium, aluminum oxide, magnesium oxide, zirconium oxide, the crucible support is made of a heat-resistant material having a bottom thickness of 2 to 3 times the thickness of a side wall and a second inner diameter of 30 to 50 times the thickness of a side wall, the heat-resistant material including magnesium oxide, aluminum oxide, or zirconium oxide, and the adaptive pressure compensating layer may include cerium oxide nanoparticles.
  5. 5. The low defect single crystal growing apparatus according to claim 1, wherein the first atmosphere management unit comprises a first gas pressure detection module for monitoring the pressure in the first chamber in real time; the second atmosphere management unit comprises a multi-gas source module and a gas pressure detection module, wherein the multi-gas source module comprises an inert gas source and an oxygen-containing gas source, and the gas pressure detection module comprises a pressure sensor arranged in the second chamber and is used for monitoring the pressure and the oxygen partial pressure in the second chamber in real time.
  6. 6. The low defect single crystal growing apparatus according to claim 1, further comprising: the integrated temperature monitoring system comprises an infrared thermometer, an infrared thermal imaging feedback unit and a high-resolution infrared camera, wherein the infrared thermometer is used for measuring the temperature inside a crucible in the crystal growth system in a non-contact mode through an optical window arranged on the furnace body, the infrared thermal imaging feedback unit comprises a high-resolution infrared camera and is arranged on the outer side of an observation window on the side wall of the furnace body, and temperature distribution images of the surface of a melt and a solid-liquid interface are acquired in real time through the atmosphere separation and heat conduction assembly.
  7. 7. The apparatus for growing a low defect single crystal according to claim 6, wherein the integrated temperature monitoring system further comprises a thermocouple provided on the atmosphere separation and heat conduction assembly in the first chamber for monitoring the temperature in the first chamber in real time.
  8. 8. The apparatus according to claim 1, wherein the central control system is electrically connected to and in data communication with the protective heating system, the driving mechanism of the crystal growth system, the atmosphere control system, and the integrated temperature detection system, and wherein a differential pressure control algorithm is built in the central control system to control the heating power of the protective heating system, the displacement speed of the driving mechanism of the crystal growth system, the gas flow rate and oxygen partial pressure of the atmosphere control system, and the temperature in the furnace in real time based on the acquired data.
  9. 9. A method for growing a gallium oxide single crystal with low defects based on the apparatus of claims 1 to 8, comprising the steps of: s1, charging, namely charging a high-purity gallium oxide raw material into a crucible and placing the crucible in the center of a second chamber; S2, initializing the chamber atmosphere, namely filling inert gas into the first chamber to normal pressure or micro-positive pressure, and filling oxygen-containing gas into the second chamber to enable the oxygen partial pressure to reach a preset value; s3, preparing a melt, namely starting a protective heating system, and heating the melt for a certain time through a heating element to completely melt the gallium oxide raw material; S4, crystal growth, namely, in the step, dynamic atmosphere adjustment is carried out, the oxygen ratio in the oxygen-containing gas is regulated in real time according to the feedback of a temperature monitoring system and an air pressure detection module, in the seeding stage, the crystal grows at a first temperature, the oxygen volume ratio is maintained at 0-10%, in the crystal growth stage, the crystal grows at a second temperature, the oxygen volume ratio is maintained at 15-25%, and after the crystal growth is completed, the temperature is gradually reduced to a third temperature, and the oxygen volume ratio is gradually reduced from 10% to 0; S5, cooling and depressurization regulation of the first chamber, wherein after the second chamber is started to cool for a certain time, the first chamber starts to cool, the cooling rate is equal to or lower than that of the second chamber, and the temperature difference between the first chamber and the second chamber is kept within 30 ℃, when the temperature in the first chamber is lower than the oxidation critical temperature of the heating element, the flow rate of inert gas is gradually reduced, and when the temperature difference between the first chamber and the outside atmospheric temperature is lower than 200 ℃ and the pressure of the first chamber is equal to the outside atmospheric pressure, the inert gas is closed; S6, taking out the crystal after the crystal is cooled to room temperature.
  10. 10. The growth method according to claim 9, wherein in step S2, the pressure difference between the first chamber and the second chamber is maintained below 10 KPa; in step S4, the second temperature is equal to or lower than the first temperature, and the third temperature is lower than the second temperature; in step S4, when the apparatus is used for growing a gallium oxide single crystal by a Czochralski method, the product of the pulling speed and the rotation speed of the driving mechanism of the crystal growth system is in the range of 1-10 mm rpm/h; In the crystal growth process of the steps S3 to S5, the temperature distribution of the solid-liquid interface is monitored in real time by utilizing an infrared thermal imaging feedback unit, and the central control system optimizes the oxygen-argon ratio and the heating power according to the temperature, partial pressure change and pulling speed parameters, so that the axial temperature gradient in the furnace body is stabilized to be 5-8 ℃ per cm, and the radial temperature gradient is stabilized to be within 1-5 ℃.
  11. 11. The growth method according to claim 10, wherein in step S2, the pressure difference between the first chamber and the second chamber is maintained at 5 KPa or less.
  12. 12. Gallium oxide single crystal obtainable by the growth process according to claims 9-11, characterized in that it is crack-free, transparent and has a crystal defect density of at least <5 x 10 3 cm -2 .

Description

Low-defect gallium oxide single crystal pulling growth equipment and method based on double-cavity atmosphere regulation and control Technical Field The invention relates to the technical field of preparation of ultra-wide band-gap semiconductor materials, in particular to equipment and a method for manufacturing low-defect gallium oxide single crystals. Background Gallium oxide (Ga 2O3) is used as an ultra-wide band gap semiconductor material, has the outstanding advantages of large band gap (about 4.9 eV), high breakdown electric field strength (about 8 MV/cm) and the like, and the Baliga's figure of merit and BFOM of the ultra-wide band gap semiconductor material is obviously superior to the traditional semiconductor material, so that the ultra-wide band gap semiconductor material has wide application prospect in the fields of high-power electronic devices, solar blind ultraviolet light electric devices and the like. In addition, unlike silicon carbide, gallium nitride, diamond and other wide band gap/ultra wide band gap semiconductors, which are generally prepared by a vapor phase method with a Growth rate of only about 0.1mm/h, gallium oxide single crystals can be prepared by melt methods such as the Czochralski method, the vertical Bridgman method (Vertical Bridgman, VB), the Edge-DEFINED FILM-fed Growth (EFG), the casting method, and the like, and the Growth rate can reach as high as 10mm/h, thereby greatly improving the production efficiency and reducing the production cost. Gallium oxide is therefore considered by the industry as the most likely ultra-wideband semiconductor material for which large-scale commercialization is being pursued. However, the large-size, high-quality growth of gallium oxide single crystals still faces many challenges. Firstly, the gallium oxide melt is extremely easy to decompose and volatilize at high temperature (the melting point is about 1790-1810 ℃). To suppress decomposition, a certain partial pressure of oxygen is required to be maintained in the growth environment. If the oxygen partial pressure is insufficient, gallium metal generated by melt decomposition can corrode the crucible, and meanwhile, decomposition products can form floaters, so that the seeding and pulling processes are interfered. In addition, insufficient oxygen partial pressure may also cause higher concentration of oxygen vacancy defects in the crystal, degrading the crystal quality and electrical properties of the crystal. At present, the common melt method (such as a Czochralski method and a guided mode method) mostly adopts gases such as carbon dioxide to control the atmosphere and maintain the oxygen partial pressure within 4 percent, but practice shows that the method still cannot completely avoid the decomposition of gallium oxide melt, so that the crystal growth yield and quality are limited. Second, existing gallium oxide crystal growth equipment is costly. The conventional gallium oxide single crystal growth method generally uses a large amount of noble metal (such as iridium) as a heating element and as a crucible and a die, the thickness of the iridium crucible is generally more than 2mm, one single crystal growth furnace generally needs several kilograms of iridium, the manufacturing cost is high, and the structures of a thermal field and a lifting system are complex, so that the manufacturing cost of equipment is high. Meanwhile, when the crucible is operated at high temperature in an oxygen-containing atmosphere, the crucible materials such as iridium are inevitably oxidized and corroded, and the production cost is further increased. Some of the inventions replace the noble metal iridium crucible with an oxide crucible which can resist oxidation, such as zirconia, alumina, etc., so that the use of the iridium crucible can be eliminated to reduce the production cost, and the oxygen partial pressure is increased to reduce the oxygen vacancy defect when the gallium oxide single crystal grows, but the gallium oxide and other oxides can generate unavoidable chemical reactions to generate intermediate compounds, which can cause excessive impurity elements to be doped in the gallium oxide single crystal, and even generate a second phase which can not obtain the gallium oxide single crystal. Disclosure of Invention In order to solve at least one of the problems, the invention provides gallium oxide single crystal manufacturing equipment and a manufacturing method thereof, which realize the technical effects of improving the crystal growth yield and the crystal quality, reducing the consumption of noble metal crucible materials, prolonging the service life of a heating system and reducing the production cost. According to an aspect of the present invention, there is provided a gallium oxide single crystal manufacturing apparatus, which is particularly suitable for growing a low-defect gallium oxide single crystal by a pulling method or a guided-mode method, characterized by comprising: The f