Deep levels in Sb-doped ZnSe fabricated by metalorganic vapor-phase epitaxy

Sb-doped ZnSe samples were deposited on the (001)GaAs substrate by metalorganic vapor-phase epitaxy (MOVPE). Isothermal capacitance transient spectroscopy (ICTS) and spectral analysis of deep-level transient spectroscopy (SADLTS) were used to characterize deep levels of Sb-doped ZnSe. The p-type sample grown by MOVPE at 490 degreesC in the darkness shows three ICTS peaks. Three deep levels were observed in the N-doped ZnSe deposited by MOVPE. Using the SADLTS. we can estimate the activation energy and the capture-cross section distributions of that hole traps. We also examined samples that were photoassist-deposited at lower temperature. The non-doped ZnSe thin films were also measured to check the effects of Light irradiation during the deposition. We could get only n-type samples and the light irradiation generates the new level of the electron traps. Sb doping generates other new levels. The levels that correspond to trap E1 in the light-irradiated Sb-doped samples are constructed from two adjacent levels in SADLTS, and one new level near trap E1 can be observed in SADLTS. (C) 2000 Elsevier Science B.V. All rights reserved.