The weak-beam contrast of overlapping stacking faults

Abstract

Thin (< 80 nm) layers of ZnSe grown on (001)-oriented GaAs contain a variety of both partially and fully pyramidal configurations of triangular {111} stacking faults whose apices are at, or close to, the interface. It was found that one format of these fault groupings exhibited extrinsic-type strong-beam characteristics but two distinct classes of contrast when examined under specific weak-beam conditions. The contrast behaviour is described and discussed in relation to the contrast expected for different model structures of the overlapping groupings suggested by their high-resolution edge-on examination.