STRUCTURAL CHARACTERIZATION OF UNDOPED AND DOPED GaAs: A COMPARATIVE STUDY OF FOUR TECHNIQUES

Dislocations, striations and microprecipitates have been imaged in undoped and doped GaAs single crystals using four different techniques: chemical photoetching, synchrotron radiation topography, photoluminescence microscopy and electron microscopy. A comparison of the features observed by these techniques is presented. Photoetching was found to be the most sensitive technique to reveal electrically active structural defects specifically in cases where these defects do not produce significant lattice strain or do not act as recombination centers. 23 refs., 11 figs., 24 tabs.