Micro and nano indentation studies and atomic force microscopy analysis of epitaxially grown GaN InGaN and SiC

Abstract

Gallium nitride(GaN) bulk and epitaxial thin films have received much attention in rccent years for their proven and potential ability in optoelectronic and optical detectors. The large band gap,strong inter- atomic bonding and associated high thermal conductivity are the main features making it an ideal material for high-temperature, high-power optoelectronic device applications. Consequently, majority of research on this compound has been focused on exploring its optoelectronic characteristics. However, due to the ubiquitously existent lattice mismatch-induced stress between GaN thin films and the available substrates, the resultant defects have been found to significantly affect the threshld power density in stimulated emission of GaN optoclectronic devices. Therefore, it is be-coming increasingly evident that research on the mechanical characterization of GaN thin films is equally important in order to harvest the most out of this fascinating material. Silicon carbide (SIC) films have attracted growing interest because of their various excellent properties. SIC is a wide bandgap semiconductor that possesses extremely high thermal, chemical, and mechanical stability. It is an excellent material for thin film temperature sensors for the measurement of the surface temperature of gas turbine engine components operated at very high temperature. newline newline newline