CBED measurement of lattice mismatch for sub-micron quaternary structures grown on indium phosphide substrates

Abstract

The positions of HOLZ lines in CBED zone axis patterns, taken from heteroeptaxial thin films, are influenced by both dynamical diffraction and strain effects. Rather than relying on a priori calculations for extracting the lattice mismatch from HOLZ line positions for sub-micron quaternary (InGaAsP) structures grown on InP, however, we have chosen to calibrate HOLZ line positions using X-ray lattice parameter measurements which were obtained from planar quaternary layers grown on InP substrates. For the active quaternary region of an electro-optical device structure, it is shown that this approach may be sensitive to a relative change in the lattice parameter as small as ±2 parts in 10 4 .