New SOI devices transferred onto fused silica by direct wafer bonding

SOI technologies allow interesting improvements of devices performances. For RF applications, a further enhancement of SOI circuits' performances is to use high resistivity silicon substrates. Another alternative is to replace the initial silicon substrate after devices processing, by an insulating substrate such as fused silica, which presents a high intrinsic resistivity. In this paper, the transfer of SOI devices layer onto fused silica based on direct wafer bonding and thinning down processes is described. Electrical characteristics of components after transfer are evaluated and compared to initial SOI ones. The transfer onto fused silica preserves the electrical properties of active transistors, and significantly improves the RF characteristics of passive elements.