Deep levels in neutron-transmutation-doped and thermally annealed semi-insulating GaAs

A thermally stimulated current (TSC) technique has been carried out in order to investigate deep trap properties such as the activation energy and the capture cross section in a neutron-transmutation-doped and thermally annealed GaAs bulk. Two peaks are found near 125 and 185 K in the TSC curve. The trap activation energies and the capture cross sections are 0.23 eV and 9.0 × 10−15 cm2 for the 125 K peak and 0.37 eV and 3.5 × 10−13 cm2 for the 185 K peak, respectively. The values of the activation energy and the capture cross section for the 125 K are in reasonable agreement with those for the EL 14 level obtained from deep-level transient spectroscopy.