Samples of N-doped heterostructures which had been grown at 150 or 250C were studied by means of transmission electron microscopy. The density of threading dislocations, and the interfacial dislocation structure were related to the N concentration. In addition, in situ transmission electron microscopy heating studies showed that the Frank partial dislocations which formed below a critical thickness were sources for the nucleation of a regular array of misfit dislocations at the ZnSe/GaAs interface. It was noted that 60 misfit dislocations formed via the dissociation of the Frank partial dislocations and by interaction reactions between dislocations. The Frank partial dislocations bounded stacking faults which usually formed in pairs at the film/substrate interface. The density of stacking faults increased with increasing N concentration. Thus, at high N-levels, the dislocation nucleation sources were close together and not all of the Frank partial dislocations dissociated; so that a high density of threading dislocations appeared in samples with high N concentrations. A high density of threading dislocations in the ZnSe film was associated with a reduction or saturation of the net carrier density.

L.H.Kuo, L.Salamanca-Riba, J.M.Depuydt, H.Cheng, J.Qiu: Journal of Electronic Materials, 1994, 23[3], 275-81