It was recalled that the concentration of the intrinsic mid-gap donor, EL2, in semi-insulating GaAs depended upon the melt composition during crystal growth and upon the post-growth heat-treatment. A detailed analysis of data which resulted from monitoring the production of state-of-the-art GaAs substrates revealed discrepancies with the compensation model. By using a combination of methods for quantitative point defect analysis, it was shown that the EL2 concentration also depended upon the compensation ratio or the position of the Fermi level.

Influence of Compensation Level on EL2 Concentration in Semi-Insulating Gallium Arsenide. U.Kretzer, H.C.Alt: Physica Status Solidi C, 2003, 0[3], 845-9