The complexing of silicon impurities with point defects in plastically deformed and annealed GaAs

Si-doped GaAs crystals grown by the horizontal Bridgman method were plastically deformed at 450 °C and then annealed at various temperatures up to 800 °C. Localized vibrational mode (LVM) absorption due to Si-related defects was investigated using infrared Fourier-transform spectroscopy with the samples at liquid He temperature. Two LVM lines near 367 cm−1 due to a complex labeled Si-Y increased in strength in deformed samples which were subsequently annealed around 650–700 °C for 1 h. A new result was the observation of an LVM line from Si-Y superposed on the absorption from SiAs. Thus three separate lines occur at 366.8, 367.5, and 397.8 cm−1. It is proposed that the Si-Y center is a SiGa−VGa complex.