Investigation On The Epitaxial Growth Of GaN On Si Substrate

The technology of epitaxy growth GaN/Si (111) with high temperature AIN buffer was investigated. The state of strain and crystalline quality of GaN epitaxial layer on Si(111) substrate was investigated by High resolution X-ray double crystal diffraction(HRXRD). The influence of the high temperature AIN buffer thickness on the surface morphologies of GaN films was characterized by the atomic force microscopy(AFM). The experimental results show that the A1pre-treatment time and the thickness of AIN buffer have a big influence on the crystalline quality、 state of strain and surface morphology of GaN. The optimal Al pre-treatment time is10s, and the thickness of AIN buffer is40nm. The good surface morphologies of GaN epitaxial layer was obtained with the full wide half maximum(FWHM) of GaN (0002) of452arcsec, and (10-12) of722arcsec by X-ray double crystal diffraction.Under the optimal conditions of the Al pre-treatment time and the thickness of AIN buffer, with the analysis of the formation mechanism of the dislocation during the material epitaxial process, respectively, the growth rate of the nucleation layer and the combined layer of the GaN epitaxial layer were studied.The crystal quality of GaN epitaxial layer has been grately improved, witch plays a guiding role for the epitaxy of the device structures.