CMOS on bonded wafers fabricated using a novel Si-Ge etch stop

The bond-and-etchback silicon-on-insulator (BESOI) substrates utilize a novel silicon-germanium etch-stop fabrication method to produce a device-film which is thin, defect-free, and highly resistive. Other features of these BESOI substrates include a high-quality thermal oxide at all silicon/insulator interfaces and a buried isolation layer which is fabricated using a radiation-hardened process. Results are presented for CMOS devices and circuits fabricated on these BESOI substrates for which the device-films are 0.25- mu m thick. Test results indicate that circuit performance is improved by more than 30% over the bulk controls and is not adversely affected by incorporating buried layers, and gate and field oxides optimized for radiation environments in the BESOI process.<
>