Phenomenological description of strain relief in step-graded metamorphic buffer layers based on In x Al1 − x As ternary solutions

Abstract

Spatial distributions of the residual elastic strains in layers of step-graded metamorphic buffers of two different designs, grown via molecular beam epitaxy on the basis of In x Al1 − x As ternary solutions, are obtained by means of reciprocal space mapping. It is shown that with allowance for work hardening, which affects strain relief in buffer layers and increases the strain in dislocation-free layers, the mechanism of strain relief in the final buffer steps, and the residual elastic strain in a buffer dislocation-free layer, are governed by the same phenomenological law as in a single-layer heterostructure.