GaN thick films growth on Si(111) by hydride vapour phase epitaxy

C-plane GaN thick films have been successfully grown on Si(111) substrates with AlN as buffer layers by hydride vapour phase epitaxy(HVPE) system.Raman scattering,X-ray diffraction(XRD),and photoluminescence(PL) measurements are used to analyze the structure and properties of the GaN films.The results indicated that the structure of the film is hexagonal wurtzite,the biaxial stress of film is tensile and the value is 0.17GPa,the band edge emission of the GaN thick film is at 363.7nm and no yellow luminescence bands are observed.The AlN buffer layers can effectively block the additional reaction between Si substrate and reactive gas during the GaN growth,and reduce the residual stress of the GaN thick film.