Wurtzite GaN epitaxial growth on a Si(001) substrate using γ-Al2O3 as an intermediate layer

Abstract

Wurtzite GaN films have been grown on (001) Si substrates using γ-Al2O3 as an intermediate layer by low pressure (∼76 Torr) metalorganic chemical vapor deposition. Reflection high energy electron diffraction and double crystal x-ray diffraction measurements revealed that the thin γ-Al2O3 layer of “compliant” character was an effective intermediate layer for the GaN film grown epitaxially on Si. The narrowest linewidth of the x-ray rocking curve for (0002) diffraction of the 1.3 μm GaN sample was 54 arcmin. The orientation relationship of GaN/γ-Al2O3/Si was (0001) GaN‖(001) γ-Al2O3‖(001) Si, [11–20] GaN‖[110] γ-Al2O3‖[110] Si. The photoluminescence measurement for GaN at room temperature exhibited a near band-edge peak of 365 nm (3.4 eV).