Plastic relaxation and relaxed buffer layers for semiconductor epitaxy

Abstract

We present a critical review of the strategies used in the fabrication of mismatched semiconductor heterostructures. By using simple concepts derived from the Matthews model of misfit relief, we show how the relaxation of single layers and complex structures may be analysed and predicted. These techniques allow a broad view of the processes that take place in the relaxation of strained layers. This is followed by a discussion of how the relative misfits and thicknesses of different layers in a heterostructure may influence the behaviour and distribution of dislocations in the structure. Finally, we describe the historical development and status of the experimental work and development that has been carried out in this area.