CHARACTERIZATION OF DEEP TRAPS IN SEMIINSULATING GALLIUM-ARSENIDE

In this paper a number of deep traps, which play a crucial role in many macroscopic properties of semi-insulating GaAs have been characterized and analyzed. The main trap parameters (activation energy and capture cross section) were deduced by several experimental methods, based on thermally stimulated current and isothermal current transients. Results were compared with other studies of deep traps in SI GaAs performed with these and other methods as well as studes of deep levels in conductive GaAs. To enable these comparisons an analysis of the methods and usually employed calculation procedures was given as well as suggestions for the presentation of the trap parameters. It was also concluded that the observed traps are complex defects which correspond to deep traps observed by other authors in a variety of other SI GaAs materials. Some of them seem to include, as a part of the defect, a well known defect EL2 but there are also strong indications for involvement of other structural defects and/or common impurities.