Papers by Author: J.H. Zhao

Abstract: Material properties of GaN thin films grown on 3C-SiC/semiconductor-on-insulator (SOI) substrate, by metalorganic chemical vapor deposition technology, are studied by X-ray diffraction, photoluminescence and Raman scattering, with data indicating the high quality of GaN films. Our results have shown that SiC/SOI structures obtained by carbonization have the potential to serve as useful substrates for GaN growth.

Abstract: The polytype structural variations of a set of SiC bulk wafers with different Nitrogen (N) doping levels, prepared by Physical Vapore Deposition (PVD), are studied. The initial growth conditions were used to produce 6H-polytype SiC, which has been approved for the undoped and lightly doped materials. However, when extreme high N-dopants were applied, the obtained wafer was found with 4H- and 15R-polytype features. Our experimental results of HR-TEM and Raman scattering have revealed clearly the polytype transformation, indicating that the inducement of N in the reactor leads to the polytype transformation of the resulted SiC crystal.