GaN evaporation and enhanced diffusion of Ar during high-temperature ion implantation

Abstract

GaN films were implanted with 150 keV Ar+ at temperatures up to 1100 °C to a dose of 3×1015 cm−2. Concentration profiles of Ar were measured by secondary ion mass spectroscopy and depth distributions of ion-induced damage were estimated from Rutherford backscattering/channeling spectra. No redistribution of Ar atoms was detected up to 700 °C. At 1000 °C a deep penetrating diffusion tail and a shift of the Ar peak to the surface were observed. At temperatures higher than 800 °C shift of the damage peak to the surface was also observed. We attributed the shift of the Ar peak and the damage peaks to evaporation of thin layer of GaN during high-temperature implantation and estimated its temperature dependence.