Defects and strain relaxation in silicon-germanium-on-insulator formed by high-temperature oxidation

Abstract

SiGe layers were grown on silicon-on-insulator substrates and oxidized at temperatures from 1200 to 1300 °C to form silicon-germanium-on-insualtor (SGOI) layers. Strain relaxation of the SGOI film is shown to be dislocation mediated and the residual strain scaled with the final SGOI thickness in a manner consistent with equilibrium theory. Stacking faults (SF) are observed in the relaxed SGOI layer and their density increases exponentially with decreasing film thickness. In films below ∼500 Å, the SF density becomes comparable with the dislocation density which may be responsible for differences between equilibrium and measured residual strain in thin SGOI layers. © 2004 American Institute of Physics.