| dc.description.abstract | Metal-organic chemical vapor deposition(MOCVD) and molecular beam epitaxy(MBE) have been applied to deposit epitaxial gallium nitride(GaN) thin films in the industry. The process temperatures on MOCVD and MBE were approached to or than 1000˚C. Considering the thermal expansion coefficient in between the substrate and the GaN film, the higher process temperature the more cause cracks and warpage happened on the epitaxial film. Beside, MOCVD and MBE have the problems of using toxic gas and low depositing rate when fabricating the GaN films.
In this study, a high power impulse magnetron sputtering(HiPIMS) has been useds to fabricate epitaxial GaN films on Si substrate without toxic substances during the sputtering and high depositing rate. The high-energy and high-density plasma during the HiPIMS process, decrease the process temperature and increas the depositing rate without the toxic gases.
The process temperature was fixed at 500˚C, the on-time, duty cycle, gas flow, and bias voltage were varied. X-ray diffractometer(XRD) has been applied to analyze crystalline strength and lattice peak full-width at half-width(FWHM), scanning electron microscope(SEM) to analyze film thickness and surface growth conditions, atomic-force microscopy(AFM) to analyze the surface roughness, photoelectron spectroscopy(XPS) to analyze the elemental composition of the films, transmission electron microscopy(TEM) to analyze the crystallinity grid arrangement and defects. Finally, the epitaxial GaN thin films have been fabricated on the Si substrate by using HiPIMS with low process temperature successfully. | en_US |