Preparation Of <111>-3C-SiC Film By Laser Chemical Vapor Deposition

3C-SiC is widely applied as high temperature,corrosion resistant coating and semiconductor devices because of its excellent properties such as high temperature resistant?3000 K?,high hardness?moray rigidity 9.5?,high electron mobility(1000cm^-2·?V·s?^-1)and high saturated drift velocity?2.7×10⁷ cm²?.Besides,<111>-3C-SiC has great potential as a substrate for the growth of grapheme,AlN,GaN epitaxial layer.At present,the traditional preparations of SiC films have shortages including low deposition rate,low safety and extremely high cost.In this research,the<111>-3C-SiC films were prepared with high deposition rate and high safety by Laser Chemical Deposition?LCVD?technique and using Hexamethyldisilane as precursor.The phase structure and out-plane orientation of the films were studied by X-Ray Diffraction?XRD?in?-2?mode.The epitaxial relationship between film and substrate was analyzed by Pole Figure.The microstructure and deposition rate was observed by Scanning Electron Microscope?SEM?.The crystalline defects in films were observed by Transmission Electron and Microscope?TEM?;observe single phase domain and grain boundary by Electron Back-Scattered Diffraction?EBSD?.Polycrystalline<111>-3C-SiC films were prepared at deposition temperature?Tdep?in the range of 1330¹420 K and pressure?Ptot?in the range of 200⁴00 Pa.,The maximum of deposition rate of 200?m/h was obtained at T_dep=1420 K,P_tot=200Pa,which was 10 to 10³ times higher than these of traditional CVDs.The orientation of films transferred from<111>to random,to<110>with increasing of Tdep from1330 to 1605 K,and P_depep from 200 to 600 Pa.The angle of grain boundaries decreased and the single phase domains increase with increasing of Pdep,which was observed by EBSD analysis.The films exhibited 2kinds of surfacial morphology,including pyramids-like and needle-like.The growth mechanisms of films with different surfacial morphologies have also been investigated via crystal Wulff shape theory,competition growth theory.Epitaxial<111>-3C-SiC films were prepared on Si?111?at deposition temperature?Tdep?in the range of 1273¹573 K and pressure?Ptot?in the range of200¹000 Pa.The films without double position boundary?DPB?defect at Tdep=1273 K and Ptot=200⁶00 Pa.The formation mechanism of DPB was analysised by two dimensional crystal nucleus formation theory.