Strain and surface roughness control of SiGe layer deposited by ion beam sputtering

Strain-relaxed SiGe layer toward the preparation of strain Si layer was prepared by using ion-beam sputtering technique. Samples prepared at acceleration voltage of 300 V show high relaxation regardless of the film thickness and growth temperature, while the surface roughness increases largely with increasing thickness. As for the case of 500 V, although the relaxation and roughness increase with increasing the thickness and growth temperature, samples with small roughness and high relaxation are obtained at 500°C. This phenomenon is related to the recoil Ar. It is found that the strain and surface roughness can be controlled by selecting preparation parameters deliberately. About 200 nm SiGe film with roughness of ~2 nm was obtained at the growth temperature of 500°C with the acceleration voltage of 500 V.