Demonstrating antiphase domain boundary-free GaAs buffer layer on zero off-cut Si (001) substrate for interfacial misfit dislocation GaSb film by metalorganic chemical vapor deposition

Abstract

High quality 40 nm GaSb thin film was grown on the zero off-cut Si (001)-oriented substrate using metalorganic chemical vapor deposition with the temperature-graded GaAs buffer layer. The growth time of the GaAs nucleation layer, which was deposited at a low temperature of 490 degrees C, is systematically investigated in this paper. Cross-sections of the high resolution transmission electron microscopy images indicate that the GaAs compound formed 3D-islands first before to quasi-2D islands, and finally formed uniform GaAs layer. The optimum thickness of the 490 degrees C-GaAs layer was found to be 10 nm to suppress the formation of antiphase domain boundaries (APDs). The thin GaAs nucleation layer had a root-mean-square surface roughness of 0.483 nm. This allows the continued high temperature GaAs buffer layer to be achieved with low threading dislocation density of around 7.1 x 10(6) cm(-2) and almost invisible APDs. Finally, a fully relaxed GaSb film was grown on the top of the GaAs/Si heterostructure using interfacial misfit dislocation growth mode. These results indicate that the GaSb epitaxial layer can be grown on Si substrate with GaAs buffer layer for future p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) applications.