Predictability of plastic relaxation in metamorphic epitaxy

Abstract

Theoretical models and experimental data on plastic relaxation are reviewed. It is concluded that neither equilibrium nor kinetic effects are responsible for the relaxation observed under conditions of high growth quality in III-V epitaxy; instead dislocation multiplication mechanisms and the space they require to operate constitute the determining factor. Residual strain is then given by ɛ(h)= (0·8;amp;#x00B1; 0·1 nm)/h for a layer of thickness h. Deviationsfrom this rule are indicative of poor crystallinity. Silicon–germanium and II-VI materials are briefly discussed.