Ion beam synthesis of strain-relieved Si1-xGex layers on SIMOX

Abstract

High dose 74 Ge ion implantation into the Si surface layer of SIMOX substrates has been used to form strain relieved Si 1-x Ge x layers. Two different approaches were investigated: One series of samples was implanted at elevated temperatures (350°C – 450°C) to retain crystallinity followed by rapid thermal annealing (RTA) to redistribute the implanted Ge and to improve the crystalline quality. A second series of samples was implanted at room temperature with lower energies to retain a thin, undamaged Si seed layer on the amorphous SiO 2 , which allows epitaxial regrowth during subsequent annealing. Ion implantation with an energy of 100 keV and doses of 1×10 17 to 3×10 17 cm -2 at 450°C followed by RTA above 1150°C resulted in homogeneous, single crystalline Si 1-x Ge x layers. Rutherford backscattering spectrometry, He + ion channeling and transmission electron microscopy were used to characterize the Ge depth profile and crystalline quality of the samples.