Direct measurements of lattice parameter variations and relaxation kinetics in strained Si1−xGex/Si heterostructures

Abstract

Lattice parameter variations in strained Si1−xGex/Ge (x<0.23) induced by high-temperature annealing in the range 700–1000 °C, were determined by x-ray high-resolution reciprocal lattice mapping of the crystal structure. In the range 700–800 °C, the strain relaxation was found to increase by one order of magnitude owing to glide propagation of misfit dislocations, with an activation energy of 2.3 eV. In the range 850–1000 °C, relaxation was still high but the increase with the temperature was limited by dislocation interactions.