Photoluminescence studies of 4He- and 9Be-implanted semi-insulating InP

Abstract

Low‐temperature (5 °K) photoluminescence data on the annealing characteristics of both unimplanted and implanted (⁴He, ⁹Be) semi‐insulating, Fe‐doped (100) InP are presented. A rf plasma‐deposited Si₃N₄ was used as the encapsulant during anneals. Annealing with this cap results in the appearance of a new spectral feature at 1.378 eV. For all samples examined here, high temperature (T?750 °C) anneals result in band‐edge integrated intensities greater than in virgin material. This phenomenon is correlated with the appearance of the 1.378‐eV peak. In samples implanted with 100 keV ⁹Be the band‐edge peak is observed to shift to lower energies with increasing dose. Also, a new emission peak at 1.382 eV is shown to be associated with Be acceptors. The ionization energy of Be is estimated to be 41.3±3 meV. For 30‐min anneals, maximum Be activation appears to occur for all doses at ∼750 °C. At this temperature, Be activation appears to saturate between 30 and 60 min.