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

Abstract

The residual stress in GaN film grown on (0001) α-Al2O3 substrate at 450–500 °C by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR–PECVD) is investigated. Macro deformation analysis reveals a low level of compressive stress, from −0.46 GPa to −1.03 GPa in GaN/Sapphire. Low growth temperature and high N2:TMG flow ratio contributes to decreasing of residual stress. A blue shift for the edge peak in photoluminescence analysis (PL) is related to compressive stress. Roughness statistics and AFM morphology of GaN film show a fine smoothness and uniform surface. All results demonstrate that ECR-PECVD process is favorable for depositing GaN films at low temperature.