Institute of Experimental Physics, TU Bergakademie Freiberg, Silbermannstr. 1, Freiberg, 09599, Germany
Freiberger Compound Materials GmbH, Am Junger Löwe Brunnen 5, Freiberg, 09599, Germany
The EL2 as the most important intrinsic defect in semi-insulating GaAs was already deeply studied in the past. All investigation methods applied so far to semi-insulating GaAs explore the entire depth of the sample and are therefore not suitable to analyse e.g. influences of surface treatments. In this work the detection of EL2 in the surface of samples by the application of microwave detected photo induced current transient spectroscopy will be presented. A correlation between height and sign of the signals and the concentration of acceptors, furthermore of the compensation ratio of the EL2, the position of the Fermi level as well as the specific resistivity was found. The results can be simulated by solving rate equations for the measurement process.
(Received September 9 2003)
(Accepted January 28 2004)
(Online publication July 15 2004)