TEM analysis of epitaxial semiconductor layers with high stacking fault densities considering artifacts induced by the cross-section geometry

Epitaxial semiconductor layers, in particular II-VI compound semiconductors with the component Se deposited on III-V semiconductor substrates like GaA s or InAs, can contain high densities of stacking faults. CdxMg1-xSe layers with Cd-concentrations x of 93% and 57% on InAs(0 0 1) substrates were inv estigated as typical representatives of this class of heterostructures. The defect structure of the layers is dominated by a high density of stacking fault (SF) pairs bound by Shockley partial dislocations with Burgers vector s b = 1/6[112] and a stair-rod dislocation with b = 1/6[110] at the interse ction line of the pairs. Plan-view transmission electron microscopy (TEM) i s generally applied to obtain information about the type, density and arran gement of the stacking faults in thin epilayers up to moderate SF densities . Cross-section TEM is more frequently carried out for thick layers and at high SF densities. It will be demonstrated by a detailed analysis of cross- section images that a careful interpretation of the observed SF morphologie s is necessary due to artifacts induced by the cross-section geometry. (C) 2000 Elsevier Science B.V. All rights reserved.