Rewarming: facts and myths from the neurological perspectives

Abstract

Single-crystal semiconductor layers can be grown with large coherency strains. This review covers their standard elasticitytheory and methods of measuring the strain. High-quality strained layers are thermodynamically stable up to a critical thickness,and both theoretical and experimental determinations of critical thickness are considered. Above critical thickness thereis a metastable regime, with thicknesses of a few tens of nanometres for a typical misfit ε0∼1%. A relaxation critical thicknessis identified, above which compressive strain produces plastic relaxation so the strain in a layer is less than its misfit (tensile layers commonly experience cracking instead of plastic relaxation). Relaxing layers may have a misfit ε0∼1%, andthicknesses of a few hundred nanometres. In the high-mismatch regime, any strain severely perturbs the crystal growth; thisoccurs typically for misfits of 2% upwards. The review concludes with some unresolved questions about multilayer structures.