Structural instability of the ion beam-mixed Au/Si(1 1 1) systems at elevated temperatures

Abstract

The Au/Si(1 1 1) system is irradiated at elevated temperatures using Ar + ions. The structural study is carried out using grazing incidence X-ray diffraction (GIXRD) and Rutherford backscattering spectrometry (RBS). The surface morphology of the sample is determined using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The formation of Au 5Si 2 crystalline phase is observed when the sample is irradiated at 150°C. The mixture of Au and Si is only found when the sample is irradiated at 250°C. The formation of a new phase occurs when the sample is irradiated at 363°C (the eutectic temperature of Au–Si system). The instability of the surface morphology is seen when the sample is irradiated at different temperatures. The formation of fractal and the isolateral triangles is also observed when the sample is irradiated at the eutectic temperature of Au–Si system. The fractal growth and triangle growth may be the effect of thermal annealing.