Effects of annealing temperature on amorphous GaN films formed on Si(111) by pulsed laser deposition

摘要

GaN thin films were grown on Si(111) substrates using a pulsed KrF excimer laser-depositionrnsystem, and post-annealing was examined to improve the films' quality. In order to investigaternthe effect of thermal annealing temperature on the crystalline quality, optical properties andrnsurface morphology of the samples, after deposition, the samples were subsequently annealedrnat different temperatures in ammonia (NH_3) ambience for 15 min. The annealed films wererncharacterized by x-ray diffraction (XRD), atomic force microscopy (AFM), Fourier transformrninfrared spectroscopy (FTIR), Raman spectra and photoluminescence spectra. The measuredrnresults show that annealing temperature plays an important role in improving the quality ofrnGaN films, polycrystalline wurtzite structure GaN thin films with c-axis preferred orientationrnwere successfully obtained by annealing, and the optimum annealing temperature is 1100℃.