Method for growing gallium oxide single crystal by casting and semiconductor device containing gallium oxide single crystal

A method for growing a gallium oxide single crystal by casting, comprising the following steps:

• 1) Heating a solid gallium oxide to complete melting, cooling to a melting point of the gallium oxide, and maintaining a melt state for at least 30 min;
• and
• 2) conducting gradient cooling on a gallium oxide melt obtained in step 1) until a solid gallium oxide single crystal is obtained, wherein the gradient cooling is to cool the gallium oxide melt obtained in step 1) to a first temperature according to a first gradient, and then continue cooling to a room temperature according to a second gradient to obtain the gallium oxide single crystal, and
• in step 1), since the solid gallium oxide is heated to the first temperature, oxygen with a volume fraction of 2-10% is present in a growth atmosphere;
• and the growth atmosphere comprises an inert gas;
• wherein:
• a cooling rate of the first gradient is 10-20° C./h;
• a cooling rate of the second gradient is 30-60° C./h;
• the first temperature is 1,500-1,700° C.;
• and
• the method does not use a single crystal seed.