Local strain relaxation in Si0.7Ge0.3 on Si(001) induced by Ga+ irradiation

Abstract
A strained pseudomorphic Si0.7Ge0.3 film grown by gas-source molecular-beam epitaxy on Si(001) was irradiated at room temperature with 25 keV Ga+ ions. The gradual strain relaxation of the metastable Si0.7Ge0.3 film was monitored using in situ x-ray diffraction as a function of dose. Based on a dimensional argument, the ion-induced damage scales as extended defects. The Hendricks-Teller model was successfully applied to explain the shifting and broadening of the additional diffuse scattering.