Repeatability and Mechanisms of Threading Dislocation Reduction in InN Film Grown with In Situ Surface Modification by Radical Beam Irradiation

Abstract

The objective of this study was to investigate the repeatability of in situ surface modification by radical beam irradiation to reduce threading dislocation density in InN film. The growth of InN template and N radical irradiation processes were repeated twice in situ in the radio-frequency plasma-excited molecular beam epitaxy chamber before the regrowth of InN film on the N radical irradiated template. Transmission electron microscopy was applied to study dislocation behaviors of the InN film grown. In this letter, we show cross-sectional-view transmission electron microscopy evidence of the threading dislocation reduction from ~2.8×10¹⁰ cm^-2 in the first irradiated InN layer to ~2.0×10¹⁰ cm^-2 in the second irradiated InN layer, and to ~1.3×10¹⁰ cm^-2 in the top regrown InN layer. The mechanisms of threading dislocation reduction were also studied.