Semi-insulating gallium arsenide single crystal, preparation method and growth device therefor

A preparation method of a semi-insulating gallium arsenide single crystal, comprising the follow steps:

• Step 1:
• adding GaAs polycrystals, a crystal seed and boron oxide to a pyrolytic boron nitride (PBN) crucible, and transferring the PBN crucible to a quartz crucible;
• and adding graphite to a quartz cap, and connecting the quartz cap to the quartz crucible hermetically;
• Step 2:
• loading the hermetically connected quartz cap and quartz crucible in Step 1 into a vertical gradient freeze (VGF) single crystal furnace, wherein the quartz cap and the quartz crucible are located in different temperature zones within the VGF single crystal furnace;
• Step 3:
• controlling a temperature in a temperature zone in which the quartz crucible is located at 1238° C. for material melting, while controlling a temperature in a temperature zone in which the quartz cap is located at 1000±50° C.:
• Step 4:
• after the temperature zone in which the quartz crucible is located reaches the temperature of 1238° C. for material melting, preserving the temperature at 1238° C. for the material melting, controlling the temperature in the temperature zone in which the quartz cap is located at 1200±50° C. and preserving the temperature at 1200±50° C. for 4 to 50 h to produce CO for atmosphere doping;
• Step 5:
• after the material melting is completed, lowering a temperature in the temperature zone in which the quartz cap is located to 1000±50° C. and preserving the temperature at 1000±50° C. to allow atmosphere doping and crystal growth to obtain the semi-insulating gallium arsenide single crystal;
• and
• Step 6:
• cooling and discharging the semi-insulating gallium arsenide single crystal.