Stress analyses of GaN film manufactured by ECR plasma-enhanced chemical vapor deposition

► GaN film grown on (0001) α-Al2O3 substrate at 450-500 °C by ECR-PECVD. ► A low level of compressive stress from −0.46 GPa to −1.03 GPa. ► Compressive stress leads to a blue shift in PL spectra. ► Low temperature and high N2:TMG ratio is favorable for weakening stress. ► Fine smoothness and uniform surface in AFM morphology as GaN grown by ECR-PECVD.