The Study Of GaN And InN Deposition On Glass Substrate

As members ofⅢ/Ⅴnitrides family, GaN(Gallium Nitride) and InN(Indium Nitride) have direct room-temperature bandgaps of 3.4eV and 0.7eV. InN alloyed with GaN and A1N may span a continuous range of direct bandgap energies through much of the visible spectrum well into the UV(Ultraviolet) wavelengths, which makes it attractive for optoelectronic device applications, such as blue-green-UV LED(light-emitting diodes), LD(laser diodes) and solar-blind UV detector and so on. In addition, the potential of InxGa1-xN alloys on the fabrication of high efficiency solar cell has attracted much attention.Nowadays the widely used methods in the deposition of III-nitides Include:Molecular Beam Epitaxy (MBE),Metal Organic Chemical Vapor Deposition (MOCVD),Hydride Vapor Phase Epitaxy (HVPE)and so on. Becuse of its easy contral,relatively high quality of the epitaxy film a, MOCVD is more suitable for large-scale production.The conventional substrates used for GaN and InN deposition like Sapphire (α-Al2O3) and Carborundum (SiC) are expensive and difficult to make large surface area. In this work we use conventional glass as substrate, which greatly decrease the cost of experiment without considering the ara of substrates. With TMGa and TMIn as metal organic (MO) sources, high purity Hydrogen (H2) as carrier gas and high purity Nitrogen (N2) as N source, highly c-axis orientation GaN and InN were prepared by Electron Cyclotron Resonance-Plasma Enhanced MOCVD (ECR-PEMOCVD) system at low temperature. The deposition of GaN and InN film were monitored with in situ RHEED system.The X-Ray diffraction(XRD), RHEED, Atomic Force Microscope (AFM), Ttransmission Spectrum, and Hall measurements wered used to study the films deposited at various condition. And the results find out that:The substrate nitride time would affect the the quality of GaN film, the film deposited with substrate nitrided for 5 min is of high c-axis preferred orientation and highly crystallined, with the Full Width at Half Maximum (FWHM) of (002) reflection only 0.19°; as the Trimethyl-gallium (TMGa) flow increase, at first the crystallization of GaN film improve with the flow of 1.4sccm the best, futher increase the TMGa flow, the film would degrade; varied the InN deposition temperature, the results show GaN deposited at 450℃is of the best qualiy, and no metal In phase on XRD spectrum were inspected.