Low-resistance N-type gallium oxide crystal and growth method thereof

Abstract

The invention discloses a low-resistance N-type gallium oxide crystal and a growth method thereof. The growth method comprises the following steps: pretreatment of raw materials: sintering a doped gallium oxide material block formed by mixing gallium oxide powder and doped raw material powder; crystal growth: heating the iraurita crucible to melt the doped gallium oxide material block, increasing the power of the medium-frequency induction coil to raise the temperature of the gallium oxide melt, keeping the temperature, cooling to the melting point of gallium oxide, keeping the melt state, firstly reducing the power of the medium-frequency induction coil to spontaneously nucleate at the cold core of the upper surface of the melt and realize the transverse growth of the nucleated crystal; reducing the power of the lower medium-frequency induction coil to enable the gallium oxide melt to grow from top to bottom until the gallium oxide melt completely grows into crystals; after crystal growth is finished, the temperature is reduced to 1200-1400 DEG C, heat preservation is conducted, cooling is conducted to the room temperature, and the low-resistance N-type gallium oxide crystals are obtained.The growth method is simple in process, the crystal growth speed is conveniently controlled, the crystal forming rate is increased, and large-scale mass production is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of gallium oxide crystal growth, and particularly relates to a low-resistance N-type gallium oxide crystal and a growth method thereof. Background Art

[0002] Gallium oxide (β-Ga2O3) crystal is a kind of ultra-wide bandgap semiconductor material, with a bandgap width of about 4.8 eV and a breakdown electric field strength as high as 8 MV / cm, far higher than that of semiconductor materials such as silicon (1.1 eV, 0.3 MV / cm), gallium arsenide (1.4 eV, 0.4 MV / cm), silicon carbide (3.3 eV, 2.5 MV / cm), gallium nitride (3.4 eV, 3.3 MV / cm), etc., and is known as the "fourth-generation semiconductor material". Gallium oxide crystals can be grown by the melt method, greatly reducing the crystal growth cost. Therefore, gallium oxide has become a preferred material for semiconductor devices such as ultra-high voltage, ultra-high power chips, and optoelectronic devices. In recent years, the application of gallium oxide crystal materials and devices has become a research hotspot in countries such as Japan, Germany, and the United States. Usually, pure gallium oxide crystals exhibit weak N-type conductivity and relatively weak conductivity, mainly due to oxygen vacancies formed during the growth process and some unintentionally doped impurity elements. Therefore, it is very important to achieve controllable adjustment of low-resistance N-type gallium oxide crystals, enabling them to play an important role in high-voltage withstand, low-loss power devices, and deep-ultraviolet optoelectronic devices.

[0003] At present, low-resistance N-type gallium oxide crystals mainly achieve the regulation of carrier concentration through doping, and the growth methods are mainly the Czochralski method and the edge-defined film-fed growth (EFG) method. However, both of these methods have certain disadvantages, affecting subsequent large-scale industrialization. In the Czochralski method, due to the greatly increased carrier concentration of low-resistance N-type gallium oxide crystals, there is an absorption peak in the infrared band, resulting in the inversion of the growth solid-liquid interface to form a concave interface, and it is extremely easy to generate spiral growth phenomena during the crystal growth process, making it difficult to obtain large-sized regular crystals. In the EFG method, due to the extremely easy dissociation property of gallium oxide crystals and the limitation of the mold, there is only a limitation in growing specific crystal planes. Only the main growth crystal plane of the entire crystal can obtain a single crystal of more than 1 inch, which is not conducive to batch growth of gallium oxide substrates with specific crystal planes. In addition, after N-type doping, the greatly increased carrier concentration of gallium oxide crystals enhances the absorption of radiant heat in the infrared band, resulting in the crystal being extremely easy to crack along the dissociation planes (100) and (001) during the subsequent cooling process, ultimately leading to the failure of crystal growth.

[0004] Therefore, it is of extremely important application value and prospect to invent a method for growing low-resistance N-type gallium oxide crystals with relatively simple technology, effective doping, and low cost. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems in the background art and propose a low-resistance N-type gallium oxide crystal and a growth method thereof.

[0006] To achieve the above object, the present invention provides a method for growing a low-resistance N-type gallium oxide crystal, comprising the following steps:

[0007] Pretreatment of raw materials: Mix and extrude gallium oxide powder and doping raw material powder to obtain a doped gallium oxide compact, and sinter the doped gallium oxide compact;

[0008] Crystal growth: Heat an iridium crucible through an intermediate-frequency induction coil to completely melt the sintered doped gallium oxide compact to obtain a gallium oxide melt. Increase the power of the intermediate-frequency induction coil to raise the temperature of the gallium oxide melt by 5°C to 10°C and keep it warm for more than 1 h to achieve uniform distribution of dopant elements in the gallium oxide melt. Cool down to the melting point of gallium oxide and keep the melt state for more than 30 minutes. First, reduce the power of the upper intermediate-frequency induction coil to cause spontaneous nucleation at the cold center on the upper surface of the gallium oxide melt and achieve lateral growth of the nucleated crystal. Then, reduce the power of the lower intermediate-frequency induction coil to cause the gallium oxide melt to grow from top to bottom until the gallium oxide melt completely grows into a crystal;

[0009] Post-treatment of crystal growth: After crystal growth is completed, cool down to 1200°C to 1400°C, keep it warm for 2 h to 6 h, perform stress relief annealing, and cool to room temperature to obtain a low-resistance N-type gallium oxide crystal;

[0010] Wherein, the doping raw material powder is an oxide powder of a Group IV element or an oxide powder of a transition metal element or a co-doping of an oxide powder of a Group IV element and an oxide powder of a Group III element.

[0011] Preferably, the post-treatment step of crystal growth is specifically: After crystal growth is completed, cool down to 1200°C to 1400°C, keep it warm for 2 h to 6 h, perform stress relief annealing, and cool to room temperature to obtain a low-resistance N-type gallium oxide crystal. During the cooling process, the power of the upper intermediate-frequency induction coil is 50 W to 200 W higher than that of the lower intermediate-frequency induction coil.

[0012] Preferably, the doping raw material powder is an oxide powder of a Group IV element, and the doping concentration of the Group IV element is controlled at 0.01 to 10% of the molar ratio of the Ga element. Preferably, the Group IV element is at least one of Si, Ge, and Sn.

[0013] Preferably, the doping raw material powder is an oxide powder of a transition metal element, and the doping concentration of the transition metal element is controlled at 0.01 to 8% of the molar ratio of the Ga element. Preferably, the transition metal element is at least one of Nb, Ta, Hf, V, Zr, and Mn.

[0014] Preferably, the doped raw material powder is co-doped with an oxide powder of a Group-IV element and an oxide powder of a Group-III element. The Group-IV element is at least one of Si, Ge, and Sn. The Group-III element is Al or In. The doping concentration of the Group-III element is controlled to be 0.01-15% of the molar ratio of the Ga element, and the doping concentration of the Group-IV element is controlled to be 0.01-10% of the molar ratio of the Ga element.

[0015] Preferably, the sintering temperature is 1200-1500 °C, and the sintering time is not less than 8 h.

[0016] Preferably, the sintering temperature is 1300 °C, and the sintering time is 8 h.

[0017] Preferably, the sintered doped gallium oxide ingot is placed in an iridium crucible. The iridium crucible is placed in a crystal growth furnace. Before heating the iridium crucible, the inside of the crystal growth furnace is evacuated and filled with a protective gas. The protective gas is carbon dioxide gas or an inert gas. After introducing the protective gas, the air pressure inside the crystal growth furnace is 1-1.2 atmospheres. The inert gas includes argon and helium.

[0018] Preferably, after the gallium oxide powder and the doped raw material powder are mixed, they are pressed into a columnar doped gallium oxide ingot by a hydraulic device. The purity of the doped raw material powder is not less than 99.9%, and the gallium oxide powder is of 4N or 5N grade.

[0019] The present invention also provides a low-resistance N-type gallium oxide crystal grown by the growth method of the above low-resistance N-type gallium oxide crystal. The resistivity of the low-resistance N-type gallium oxide crystal is less than 200 Ω·cm, and the carrier concentration is 10 14 ~10 21 / cm 3 , and the low-resistance N-type gallium oxide crystal is a single crystal.

[0020] Advantages of the present invention:

[0021] 1. This growth method does not require the use of a single crystal seed crystal. The crystal growth process is relatively simple, which is convenient for the industrialization of subsequent crystal growth. Large-size and high-quality low-resistance N-type gallium oxide crystals (crystal plane size greater than 2 inches) can be grown by this method. By processing to obtain large-size single crystal substrates with different crystal planes, different crystal planes can be obtained by cutting the crystal horizontally, obliquely, or longitudinally as needed.

[0022] 2. This growth method can effectively control the crystal growth rate by using a multi-coil thermal field structure and an in-situ thermal field treatment process. At the same time, the generation of hetero-crystals and cracks in the crystal during the directional solidification process is avoided, greatly improving the crystal formation rate, and large-scale mass production can be achieved.

[0023] 3. This growth method is applicable to the effective doping of different doping elements, effectively reducing the carrier concentration of the crystal. The crystal has high crystallization quality. The resistivity of the low-resistance N-type gallium oxide single crystal substrate is less than 200 Ω·cm, and the carrier concentration is in the range of 10 14 ~10 21 / cm 3 , greatly expanding the applications of gallium oxide in high-voltage withstand, low-loss power devices and deep ultraviolet optoelectronic devices.

[0024] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. Description of the Drawings

[0025] Figure 1 is a process flow chart of the method for growing a low-resistance N-type gallium oxide crystal of the present invention.

[0026] Figure 2 is a schematic structural diagram of the crystal growth furnace of the present invention.

[0027] In the figure: 1 - furnace body, 2 - thermal insulation material, 3 - iridium crucible, 4 - upper intermediate frequency induction coil, 5 - support connecting rod, 6 - lower intermediate frequency induction coil, 7 - heat insulation pad. Detailed Embodiments

[0028] The method for growing a low-resistance N-type gallium oxide crystal of the present invention is carried out in a crystal growth furnace with the following structure. Refer to Figure 2 , the crystal growth furnace includes a furnace body 1, a thermal insulation material 2, an iridium crucible 3 and an intermediate frequency induction heating device arranged inside the furnace body 1. The intermediate frequency induction heating device includes an intermediate frequency induction coil, and the intermediate frequency induction coil includes an upper intermediate frequency induction coil 4 and a lower intermediate frequency induction coil 6. The upper intermediate frequency induction coil 4 and the lower intermediate frequency induction coil 6 are separated by a heat insulation pad 7 to form two independently controlled temperature zones. The iridium crucible 3, the thermal insulation material 2 and the intermediate frequency induction coil are arranged in sequence from the inside out and are concentrically installed. The iridium crucible 3 is located at the center of the thermal field. The thermal insulation material 2 is made of zirconia fiber bricks. The bottom of the thermal insulation material 2 is installed in the furnace body 1 by a support connecting rod 5. The intermediate frequency induction coil is sleeved outside the thermal insulation material 2. During the heating process of the iridium crucible 3, the temperature of the iridium crucible 3 and the materials inside the crucible is monitored by an infrared thermometer. An opening is provided at the upper end of the thermal insulation material 2, and the power of the upper intermediate frequency induction coil 4 and the lower intermediate frequency induction coil 6 is regulated by a control system.

[0029] The following further illustrates the present invention through specific embodiments. The following embodiments are only used to illustrate the present invention and do not limit the present invention:

[0030] Embodiment 1

[0031] Refer to Figure 1 , the present invention provides a method for growing a low-resistance N-type gallium oxide crystal, including the following steps:

[0032] S01. Pretreatment of raw materials: Gallium oxide powder with a concentration of 5N and SiO2 powder with a concentration of 4N are put into a planetary ball mill for thorough mixing for 24 hours. The mixed raw materials are placed in a specific mold and pressed into columnar doped gallium oxide blocks by a hydraulic press. The doped gallium oxide blocks are sintered at 1300 °C for 10 hours to obtain Si-doped gallium oxide polycrystalline blocks. Among them, the doping concentration of Si in the doped gallium oxide blocks is controlled at 0.6% of the molar ratio of Ga element;

[0033] S02. Crystal growth: The Si-doped gallium oxide polycrystalline blocks are put into an iridium crucible, the furnace door of the crystal growth furnace is closed, and the mechanical pump is used to evacuate to a vacuum degree of 1×10 -3 Pa, and then a protective atmosphere is filled to make the furnace pressure one atmospheric pressure, and the circulating cooling water device is turned on; the intermediate frequency induction heating device is turned on, and at the same time, the upper intermediate frequency induction coil and the lower intermediate frequency induction coil are turned on and heated at the same power to melt the Si-doped gallium oxide polycrystalline blocks in the iridium crucible. The temperature of the crucible and the blocks is monitored by an infrared thermometer. When the power is increased to completely melt the Si-doped gallium oxide polycrystalline blocks, the melt temperature is 10 °C higher than the melting point of gallium oxide and maintained for 2 hours, and then the heating power is reduced to cool the melt to the melting point of gallium oxide and maintained for 1 hour;

[0034] First, reduce the power of the upper intermediate frequency induction coil to make the melt nucleate and grow at the cold center position of the upper surface center of the crucible, and gradually grow directionally by controlling the temperature gradient to form a gallium oxide crystal. During the crystal growth process, keep the slightly positive pressure state in the furnace, and realize the lateral growth of the nucleated crystal by further reducing the power of the upper intermediate frequency induction coil. Observe until the crystal area is sufficient, then reduce the power of the lower intermediate frequency induction coil to make the crystal start to grow from top to bottom until the crystal grows to the bottom of the crucible and the gallium oxide melt is completely grown into a crystal;

[0035] S03. Post-treatment after crystal growth: After the crystal growth is completed, the temperature is reduced to 1400 °C and held for 4 hours. During the temperature reduction and holding process, the power of the upper intermediate frequency induction coil is always 100W more than the power of the lower intermediate frequency induction coil. Stress relief annealing is carried out on the grown crystal to avoid the generation of crystal cracks caused by thermal stress concentration. Cool to room temperature, open the crystal growth furnace and take out the iridium crucible, and completely take out the whole doped Si low-resistance N-type gallium oxide crystal.

[0036] Observe the doped Si low-resistance N-type gallium oxide crystal. The crystal has no obvious cracks and bubbles, and a single crystal substrate can be obtained through processing such as cutting, grinding, and polishing.

[0037] Example 2

[0038] Refer to Figure 1 , the present invention provides a method for growing a low-resistance N-type gallium oxide crystal, including the following steps:

[0039] S01. Pretreatment of raw materials: Gallium oxide powder with a concentration of 5N and GeO2 powder with a concentration of 4N are put into a planetary ball mill for thorough mixing for 24 hours. The mixed raw materials are placed in a specific mold and pressed into columnar doped gallium oxide blocks by a hydraulic press. The doped gallium oxide blocks are sintered at 1300 °C for 10 hours to obtain Ge-doped gallium oxide polycrystalline blocks. Among them, the doping concentration of Ge in the doped gallium oxide blocks is controlled at 0.6% of the molar ratio of Ga element;

[0040] S02. Crystal growth: The Si-doped gallium oxide polycrystalline blocks are put into an iridium crucible, the furnace door of the crystal growth furnace is closed, and the mechanical pump is used to evacuate to a vacuum degree of 1×10 -3 Pa, and then a protective atmosphere is filled to make the furnace pressure one atmospheric pressure, and the circulating cooling water device is turned on; the intermediate frequency induction heating device is turned on, and at the same time, the upper intermediate frequency induction coil and the lower intermediate frequency induction coil are turned on and heated with the same power to melt the Ge-doped gallium oxide polycrystalline blocks in the iridium crucible. The temperature of the crucible and the blocks is monitored by an infrared thermometer. When the power is increased until the Ge-doped gallium oxide polycrystalline blocks are completely melted, the melt temperature is 10 °C higher than the melting point of gallium oxide and kept for 2 hours, then the heating power is reduced to cool the melt to the melting point of gallium oxide and kept for 1 hour;

[0041] First, reduce the power of the upper intermediate frequency induction coil to make the melt nucleate and grow at the center of the cold spot on the upper surface of the crucible, and gradually grow directionally by controlling the temperature gradient to form gallium oxide crystals. During the crystal growth process, keep the slightly positive pressure state in the furnace, and realize the lateral growth of the nucleated crystals by further reducing the power of the upper intermediate frequency induction coil. Observe until the crystal area is sufficient, then reduce the power of the lower intermediate frequency induction coil to make the crystal start to grow from top to bottom until the crystal grows to the bottom of the crucible and the gallium oxide melt is completely grown into crystals;

[0042] S03. Post-treatment after crystal growth: After crystal growth is completed, cool down to 1300 °C and keep it warm for 4 hours. During the cooling and heat preservation process, the power of the upper intermediate frequency induction coil is always 100W more than that of the lower intermediate frequency induction coil. Stress relief annealing is carried out on the grown crystal to avoid the generation of crystal cracks caused by thermal stress concentration. Cool to room temperature, open the crystal growth furnace and take out the iridium crucible, and completely take out the whole doped Ge low-resistance N-type gallium oxide crystal.

[0043] Observe the doped Ge low-resistance N-type gallium oxide crystal. There are no obvious cracks and bubbles in the crystal, and a single crystal substrate can be obtained through processing such as cutting, grinding, and polishing.

[0044] Example 3

[0045] Refer to Figure 1 , the present invention provides a method for growing a low-resistance N-type gallium oxide crystal, including the following steps:

[0046] S01. Pretreatment of raw materials: Gallium oxide powder with a concentration of 5N, SiO2 powder with a concentration of 4N, and In2O3 powder are put into a planetary ball mill for thorough mixing for 24 hours. The mixed raw materials are placed in a specific mold and pressed into columnar doped gallium oxide blocks by a hydraulic press. The doped gallium oxide blocks are sintered at 1300 °C for 10 hours to obtain In- and Si-codoped gallium oxide polycrystalline blocks. Among them, the doping concentration of Si in the doped gallium oxide blocks is controlled at 0.5% of the molar ratio of Ga element, and the doping concentration of In is controlled at 1% of the molar ratio of Ga element;

[0047] S02. Crystal growth: The In- and Si-codoped gallium oxide polycrystalline blocks are put into an iridium crucible. The furnace door of the crystal growth furnace is closed, and the mechanical pump is used to evacuate to a vacuum degree of 1×10 -3 Pa, and then a protective atmosphere is filled to make the furnace pressure one atmospheric pressure. The circulating cooling water device is turned on; the intermediate frequency induction heating device is turned on, and at the same time, the upper intermediate frequency induction coil and the lower intermediate frequency induction coil are turned on and heated with the same power to melt the In- and Si-codoped gallium oxide polycrystalline blocks in the iridium crucible. The infrared thermometer is used to monitor the temperature of the crucible and the blocks. When the power is increased until the In- and Si-codoped gallium oxide polycrystalline blocks are completely melted, the melt temperature is 10 °C higher than the melting point of gallium oxide and maintained for 2 hours. Then the heating power is reduced to cool the melt to the melting point of gallium oxide and maintained for 1 hour;

[0048] First, the power of the upper intermediate frequency induction coil is reduced to make the melt nucleate and grow at the cold center position of the upper surface center of the crucible, and gradually grow directionally by controlling the temperature gradient to form a gallium oxide crystal. During the crystal growth process, the slightly positive pressure state in the furnace is maintained, and the lateral growth of the nucleated crystal is realized by further reducing the power of the upper intermediate frequency induction coil. When observing until the crystal area is sufficient, the power of the lower intermediate frequency induction coil is reduced to make the crystal start to grow from top to bottom until the crystal grows to the bottom of the crucible and the gallium oxide melt is completely grown into a crystal;

[0049] S03. Post-treatment after crystal growth: After the crystal growth is completed, the temperature is lowered to 1300 °C and held for 4 hours. During the temperature reduction and holding process, the power of the upper intermediate frequency induction coil is always 100W more than that of the lower intermediate frequency induction coil. Stress relief annealing is carried out on the grown crystal to avoid the generation of crystal cracks caused by thermal stress concentration. It is cooled to room temperature, the furnace door of the crystal growth furnace is opened, and the iridium crucible is taken out, and the whole doped In- and Si low-resistance N-type gallium oxide crystal is taken out intact.

[0050] Observe the doped In- and Si low-resistance N-type gallium oxide crystal. The crystal has no obvious cracks and bubbles, and a single crystal substrate can be obtained through processing such as cutting, grinding, and polishing.

[0051] The above embodiments are illustrative of the present invention and not restrictive thereof. Any solution obtained by simply transforming the present invention falls within the protection scope of the present invention.

Claims

1. A method for growing a low-resistance N-type gallium oxide crystal, characterized in that: It includes the following steps: Pretreatment of raw materials: Mix gallium oxide powder and doping raw material powder and extrude them to obtain a doped gallium oxide ingot, and sinter the doped gallium oxide ingot. Crystal growth: Heat the iridium crucible through an intermediate frequency induction coil to completely melt the sintered doped gallium oxide ingot to obtain a gallium oxide melt. Increase the power of the intermediate frequency induction coil to raise the temperature of the gallium oxide melt by 5°C to 10°C and keep it for more than 1 h. Cool down to the melting point of gallium oxide and keep the melt state for more than 30 minutes. First, reduce the power of the upper intermediate frequency induction coil to make spontaneous nucleation occur at the cold center on the upper surface of the gallium oxide melt and achieve the lateral growth of the nucleated crystal. Then, reduce the power of the lower intermediate frequency induction coil to make the gallium oxide melt grow from top to bottom until the gallium oxide melt completely grows into a crystal. Post-treatment of crystal growth: After crystal growth is completed, cool down to 1200°C to 1400°C, keep it for 2 h to 6 h, perform stress relief annealing, and obtain a low-resistance N-type gallium oxide crystal after cooling to room temperature. Among them, the doping raw material powder is an oxide powder of a Group IV element or an oxide powder of a transition metal element or a co-doping of an oxide powder of a Group IV element and an oxide powder of a Group III element.

2. The growth method of the low-resistance N-type gallium oxide crystal according to claim 1, characterized in that: The specific steps of the post-treatment of crystal growth are: After crystal growth is completed, cool down to 1200°C to 1400°C, keep it for 2 h to 6 h, perform stress relief annealing, and obtain a low-resistance N-type gallium oxide crystal after cooling to room temperature. During the cooling process, the power of the upper intermediate frequency induction coil is 50 W to 200 W higher than that of the lower intermediate frequency induction coil.

3. The growth method of the low-resistance N-type gallium oxide crystal according to claim 1, characterized in that: The doping raw material powder is an oxide powder of a Group IV element, and the doping concentration of the Group IV element is controlled at 0.01% to 10% of the molar ratio of the Ga element.

4. The growth method of the low-resistance N-type gallium oxide crystal according to claim 1, characterized in that: The doping raw material powder is an oxide powder of a transition metal element, and the doping concentration of the transition metal element is controlled at 0.01% to 8% of the molar ratio of the Ga element.

5. The growth method of the low-resistance N-type gallium oxide crystal according to claim 1, characterized in that: The doping raw material powder is composed of a co-doping of an oxide powder of a Group IV element and an oxide powder of a Group III element. The Group IV element is at least one of Si, Ge, and Sn. The Group III element is Al or In. The doping concentration of the Group III element is controlled at 0.01% to 15% of the molar ratio of the Ga element, and the doping concentration of the Group IV element is controlled at 0.01% to 10% of the molar ratio of the Ga element.

6. The growth method of the low-resistance N-type gallium oxide crystal according to claim 1, characterized in that: The sintering temperature is 1200 to 1500°C, and the sintering time is not less than 8 h.

7. The growth method of the low-resistance N-type gallium oxide crystal according to claim 6, characterized in that: The sintering temperature is 1300°C, and the sintering time is 8 h.

8. The growth method of the low-resistance N-type gallium oxide crystal according to claim 1, characterized in that: Put the sintered doped gallium oxide ingot into an iridium crucible. Place the iridium crucible in a crystal growth furnace. Before heating the iridium crucible, evacuate the crystal growth furnace and fill it with a protective gas. The protective gas is carbon dioxide gas or an inert gas. After introducing the protective gas, the air pressure in the crystal growth furnace is 1 to 1.2 atmospheres. The inert gas includes argon and helium.

9. The growth method of the low-resistance N-type gallium oxide crystal according to claim 1, characterized in that: The gallium oxide powder and the doping raw material powder are mixed and then pressed into a columnar doped gallium oxide ingot by a hydraulic device. The purity of the doping raw material powder is not less than 99.9%, and the gallium oxide powder is selected as 4N or 5N grade.

10. A low-resistance N-type gallium oxide crystal grown by the method for growing a low-resistance N-type gallium oxide crystal according to any one of claims 1 to 9, characterized in that: The resistivity of the low-resistance N-type gallium oxide crystal is less than 200 Ω·cm, and the carrier concentration is 10 14 ~10 21 / cm 3 .

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