Investigation of strain-relaxed SiGe thin film grown on ion-implanted Si compliant substrate

Abstract

Si1−xGex thin films on the Ar+ ion-implanted Si substrates with different implantation energy (30keV, 40keV and 60keV) at the same implantation fluence (3×1015cm−2) were grown by ultra high vacuum chemical vapor deposition (UHVCVD). Various characterization technologies were used to characterize these Si1−xGex films. Investigations by Rutherford backscattering spectroscopy/channeling (RBS/C) demonstrate that thin Si0.81Ge0.19 films could be epitaxially grown on the ion-implanted Si substrates, although there existed obvious crystal defects. These relaxation extents of Si0.81Ge0.19 films on the Ar+ implanted Si substrates are larger than that in the un-implanted case, which were determined by Raman spectra. Atomic force microscopy was used to determine the surface morphology of Si0.81Ge0.19 films. The microstructures of these SiGe/Si hetero-epitaxial materials were investigated by transmission electron microscopy (TEM). All the experimental results demonstrated that a highly relaxed (relaxation extent of 82.3%) Si0.81Ge0.19 thin film (50nm) growing on the 30keV Ar+ ion-implanted Si substrate is optimal, which is compared to those SiGe films grown on the ion-implanted Si substrate under other implantation condition.