Study On The Crystalline Properties Of GaN Films Deposited On Graphite And Stainless Steel Substrates At Low-temperature

Gallium nitride (GaN) is a direct wide-band gap semiconductor material with a band-gap of3.39eV at room temperature. Since the band gap can be tuned from0.7eV to6.2eV and covers the extensive spectrum range between near infrared to ultraviolet, GaN has been attracted increasing attention in the field of photoelectric devices, such as light-emitting diode (LED), laser diode (LD), the detector and so on. In addition, GaN posssess some superior characteristics including high temperature resistant, high heat conductivity, high hardness and so on, so GaN-based semiconductor materials have important application value for manufacturing high-frequency, high-temperature and high-power microelectronic.The growth of GaN is basically prepared by heterostructure at present, the epitaxial layer of GaN usually adopts chemical methods mainly including metal organic chemical vapor deposition (MOCVD), molecule beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE) and so on. In these methods, the method of MOCVD has high technical level, simple experimental parameters, high purity and production capacity, with the continuous improvement of the reaction chamber of MOCVD, MOCVD turns in come from behind epitaxy technique. However, to gain high-quality epitaxial growth, it needs to find a suitable lattice-matched substrate. So far, the substrates with suitable for crystal growth mainly include sapphire (α-Al2O3), silicon carbide (SiC), In addition the silicon (Si), gallium arsenide (GaAs), zinc oxide (ZnO) and so on, moreover the epitaxial wafer with the α-Al2O3substrate growth was bonded to other substates by laser lift-off technique(LLO), such as Cu, Si. Currently the substrate materials are not satisfied, for example, the intrinsic drawback of α-Al2O3includes expensive price, difficult cleavage and so on; the substrate meterial of SiC is also very expensive; the peeling technology requires high technology and the final rate of finished product is quite low.Recently, Japan’s Matsushita Company has issued a report about growth of high-quality GaN films on the graphite substrate, and graphite is an excellent choice of electrodes. But high temperature growth will exacerbates easily unintentionally doped carbon impurities diffusion to the films, thus it is necessary to adopt a low-temperature growth method, and there has been little research on GaN films deposited on graphite substrate, GaN thin film is tried to deposite at the low-temperature on graphite substrate in the paper. In addition, Stainless steel with cheap and readily available has good corrosion...