GaAs thin film grown on Si substrate, and preparation method for GaAs thin film grown on Si substrate

A preparation method for a GaAs thin film grown on a Si substrate, characterized in that the method comprises the following steps:

• (1) cleaning a Si substrate;
• (2) preprocessing the Si substrate;
• (3) removing the oxide film from the Si substrate;
• (4) growing a first InxGa1-xAs buffer layer:
• decreasing the temperature of the substrate to 350˜500° C., and growing an InxGa1-xAs buffer layer with a thickness of 2˜20 nm under the conditions of a reaction chamber pressure of 3.0×10−5˜2.5×10−8 Pa, a V/III value of 20˜30, and a growth rate of 0.1˜0.5 ML/s, wherein 0.05<x<0.10;
• (5) in situ annealing the first InxGa1-xAs buffer layer:
• increasing the substrate temperature to 500˜540° C. and annealing for 10˜20 min, and the pressure of the reaction chamber being 3.0×10−5˜2.5×10−8 Pa;
• (6) growing a GaAs the buffer layer:
• decreasing the temperature of the substrate temperature to 350˜500° C., and growing a GaAs buffer layer with a thickness of 2˜20 nm under the conditions of a reaction chamber pressure of 3.0×10−5˜2.5×10−8 Pa, a V/III value of 20˜30, and a growth rate of 0.1˜0.5 ML/s;
• (7) in situ annealing the GaAs buffer layer:
• increasing the substrate temperature to 500˜540° C. and annealing for 10˜20 min, the pressure of the reaction chamber being 3.0×10−5˜2.5×10−8 Pa;
• (8) growing a second InxGa1-xAs buffer layer:
• decreasing the temperature of the substrate to 350˜500° C. and growing a second InxGa1-xAs buffer layer with a thickness of 2˜20 nm under the conditions of a reaction chamber pressure of 3.0×10−5˜2.5×10−8 Pa, a V/III value of 20˜30, and a growth rate of 0.1˜0.5 ML/s, wherein 0.01<x<0.05;
• (9) in situ annealing the second InxGa1-xAs buffer layer:
• increasing the temperature of the substrate to 500˜540° C. for 10˜20 min, the pressure of the reaction chamber being 3.0×10−5˜2.5×10−8 Pa;
• (10) growing a GaAs epitaxial film:
• increasing the substrate temperature to 500˜580° C. and growing a GaAs epitaxial film with a thickness of 100 nm˜1000 nm under the conditions of a reaction chamber vacuum degree of 4.0×10−5˜2.7×10−8 Pa, a V/III value of 40˜60, and a growth rate of 0.6˜1 ML/s.