Formation of unstrained Si 1− xGe x. layers by high-dose 74Ge ion implantation in SIMOX

Abstract

Single crystalline, strain relieved Si 1− x Ge x layers were fabricated on buried, amorphous SiO 2 by high-dose 74Ge ion implantation into the Si surface layer of SIMOX structures followed by thermal treatment. Ion implantation was performed with energies between 80 and 160 keV and ion doses between 1.5 × 10 17 and 3 × 10 17 cm −2. Rutherford backscattering spectrometry, He + ion channeling and transmission electron microscopy were employed to characterize layer thickness, stoichiometry and crystalline quality of the newly formed Si 1− x Ge x . layers. The Ge concentration x of the resulting Si 1− x Ge x layer can be chosen by using an appropriate implantation dose. Depending on implantation dose and energy, homogeneous Si 1− x Ge x layers with Ge concentrations between x = 0.13 and 0.29 were obtained. Strain measurements by ion channeling confirmed complete strain relaxation of the Si 1− x Ge x layer after annealing.