Ions (50keV) of S were implanted into semi-insulating wafers to a dose of 1015/cm2. The implanted wafer was then annealed (650 to 1000C, 0.25h). Deep levels were measured in regions having carrier concentrations that were lower than 3 x 1017cm3 when layers of various thickness were removed from the wafer surface. The predominant defects, in samples that were annealed below 850C, were EL2 and EL6. Samples which were annealed at 1000C exhibited isolated EL2 and EL3 defects. Isolated EL2 defects were observed in regions having carrier concentrations that were lower than 1017/cm3, and EL3 defects were observed in regions having carrier concentrations above 2 x 1017/cm3.

EL2, EL3 and EL6 Defects in GaAs Highly Implanted with Sulfur. K.Yokota, H.Kuchii, K.Nakamura, M.Sakaguchi, H.Takano, Y.Ando: Journal of Applied Physics, 2000, 88[9], 5017-21