Fabrication of GaAs on Si Heterostuctures by Helium Implantation and Direct Wafer Bonding

Abstract

Transfer of GaAs layers onto Si by helium ion implantation at room temperature and direct wafer bonding was investigated. The in uence of the ion energy (100 keV and 500 keV), the ion uence and the subsequent annealing condition on exfoliation and/or blistering was studied by using optical microscopy, Rutherford backscattering and channeling spectrometry (RBS/C), X-ray di raction (XRD) and cross-sectional transmission electron microscopy (XTEM) analysis and the optimum conditions for achieving thin layer exfoliation only after post-implantation annealing were experimentally determined. Our results suggest that the optimum uence for the GaAs ion-cut is in the range of (2 { 5) 1017 He+/cm2. Thin 400 GaAs layers were successfully transferred onto silicon after bonding of helium-implanted GaAs and Si wafers via a silicon-oxide intermediate layer and subsequent low-temperature splitting annealing at less than 220 C. Field emission scanning electron microscopy (FE-SEM) showed that a uniform transfer of the GaAs layer onto Si was obtained with no detectable defects at the GaAs/SiO2/Si bonding interfaces. XTEM observations of the as-split GaAs layers revealed that the relatively undamaged layer close to the intermediate layer could be extended by appropriate choices of the bonding process and/or implanted ion energy.