Complete set of deep traps in semi-insulating GaAs

Reevaluation and recalculation of thermally stimulated current (TSC) data f rom semi-insulating (SI) GaAs, published by many different authors over a p eriod of three decades were done by means of the new analytical method, sim ultaneous multiple peak analysis (SIMPA). The SIMPA procedure clearly resol ved contributions from various overlapping TSC peaks and enabled the precis e determination of signatures (activation energy, E-a and capture cross sec tion, sigma) of all observed deep traps. The analyzed TSC spectra refer to SI GaAs samples that have been grown/treated in quite different ways (vario us growth techniques, growth under As or Ga rich conditions, different anne aling procedures, irradiation with neutrons, gamma rays, etc.). Although th e SIMPA procedure was applied to apparently quite different TSC spectra, in all cases excellent fits were achieved, with the unique set (or subset fro m it) of eleven different deep traps, the only difference being in relative and absolute concentrations of traps. Despite a broad variety of samples a nalyzed in this article, the set of deep traps obtained is the same as the one being previously seen in the narrow range of SI GaAs samples. This find ing suggests that this set of traps is a finite and complete set of all def ects with deep levels in SI GaAs. It was also concluded that these defects are primarily complexes containing simple native defects. (C) 2000 American Institute of Physics. [S0021- 8979(00)05820-5].