Properties of metastable hydrogen-related defects in n-type GaAs studied by isothermal deep-level transient spectroscopy

Metastable hydrogen-related defects (M3/M4) in n-GaAs were studied in detail by using isothermal deep-level transient spectroscopy. In order to clarify the electric-field dependence of the electron-emission process, the double-correlation technique was applied to both M3 and M4 defects. It was clearly shown that with increasing electric field, the M4 level observed around 140 K split into two discrete components labeled M4(1) and M4(2). The result supports the recent finding that the M4 defect consists of two different configurations. On the other hand, the M3 defect gave a single peak in the double-correlation spectra around 230 K. The electric field dependence of the emission rates suggests that the M3 and M4(1) defects have a donor-like nature, while the M4(2) defect is acceptor-like. It was speculated that the metastable defect coupling with the M3 level is only M4(2) out of two components of the M4 defect. (C) 2000 American Institute of Physics. [S0021- 8979(00)06416-1].