Local structure determination in strained-layer semiconductors

The theory of elasticity accurately describes the deformations of macroscopic bodies under the action of applied stress [1]. In this review, we examine the internal mechanisms of elasticity for strained-layer semiconductor heterostructures. In particular, we present extended x-ray-absorption fine structure (EXAFS) and x-ray diffraction (XRD) measurements to show how the bond lengths and bond angles in semiconductor thin-alloy films change with strain when they are grown coherently on substrates with different lattice constants. The structural distortions measured by experiment are compared to valence-force field (VFF) calculations and other theoretical models. Atomic switching and interfacial strain at buried interfaces are also discussed.