IMPROVEMENT OF THE CRYSTALLINITY AND PASSIVATION OF THE DEFECT COMPLEX CENTER OF NEUTRON-TRANSMUTATION-DOPED GAAS BY ANNEALING AND HYDROGENATION

Photoluminescence measurements are carried out in order to investigate the effects on the defect levels of neutron-transmutation-doped (NTD) GaAs due to annealing and hydrogenation. The peak intensity correspon ding to the transition from the conduction band to the Ge acceptor [Ge (B-A)] increases at an annealing temperature of 600-degrees-C, and the n decreases remarkably around a temperature of 650-degrees-C; on the o ther hand, the peak intensity of the defect complex peak increases at 600-degrees-C. After annealing and subsequent hydrogenation, the peak of the transitions between the band and the carbon acceptors [C(B-A)] is resolved clearly into the C(B-A) and Ge(B-A) peaks, and the intensi ty of the peak corresponding to the As vacancy and carbon complex cent er on Al sites decreases remarkably. These results indicate that the c rystallinity of the NTD GaAs is improved by annealing and hydrogenatio n and that the defect complex center is passivated by thermal treatmen t and hydrogenation.