Mechanisms of Implantation Damage Formation in AlxGa1–xN Compounds

Abstract

AlxGa1–xN alloys, covering the entire compositional range (0 ≤ x ≤ 1), were implanted at room temperature with 200 keV argon (Ar) ions to fluences ranging from 1 × 1013 to 2 × 1016 Ar/cm2. The damage formation mechanisms and radiation resistance of AlxGa1–xN alloys were investigated combining in situ Rutherford backscattering spectrometry/channeling (RBS/C) and ex situ X-ray diffraction (XRD) in order to assess the damage profiles and the elastic response of the material to radiation. For all compounds, damage buildup proceeds in four stages revealing a saturation of the defect level for high fluences without any sign of amorphization. Surprisingly, in this high fluence regime, RBS/C reveals higher defect levels in samples with high AlN concentrations in contrast to the common believe that AlN is more radiation resistant than GaN. A model is proposed ascribing this behavior to a lower defect recombination cross section at room temperature combined with the formation of stable extended defects. The process...