The Structure of Intrinsic Stacking Faults in GaAs

• Main Authors: Beckman, S P, Chrzan, D C
• Format: Conference Proceeding
• Language: English
• ISSN: 0094-243X
• DOI: 10.1063/1.1994035

The structure and electronic properties of dislocations in GaAs and other zincblende semiconductors are not well understood. The broken bonds at the cores of the dislocations are believed to reconstruct to reduce the number of deep level defects, but the properties of the reconstruction are not easily studied directly. Computational methods are frequently limited by the accuracy of the applied methods and the geometrical necessity to convolve multiple dislocations. Microscopy methods are advancing rapidly and definitive information regarding the properties of the cores is beginning to be revealed. A high resolution electron microscopy (HREM) image of 30 deg partial in bulk GaAs has been qualitatively compared to a simulated image of the same structure [1]. Recent quantitative analysis reveals a systematic mismatch between the two images at the stacking fault and localized EELS measurements indicate Be and Ga enrichment at the stacking fault [2]. The effect of Be and Ga segregation to an intrinsic stacking fault has been studied with ab initio methods and the results will be presented here.