Electrical properties and thermal stability of semi-insulating InP crystals with different iron content

Results of electrical measurements carried out on different InP:Fe crystals are discussed. The Hall mobility of high-resistivity Fe-doped InP wafers is shown to vary over a wide range. On the basis of their mobility, the high-resistivity samples are classified into three groups. The results of electrical measurements on annealed InP and the correlation between the electrical characteristics of as-grown and annealed InP are also discussed. Semi-insulating InP is shown to exhibit different compensation regimes and electrical characteristics, according to the concentration of Fe incorporated and residual shallow levels. It is also shown that as-grown InP, with a compensation ratio N _FE/(N_d-N_a) in the 1.2 to 2.5 range, has the highest mobility and resistivity. An acceptable thermal stability is found in samples where N_Fe> N_d>N_a