Silicon-on-insulator-with-active-substrate (SOIAS) technology

SOIAS (SOI with Active Substrate) is a novel, SOI-based technology which enables the integration in the third dimension of gates and interconnects by utilizing buried under-layers. The fabrication of SOIAS substrates takes full advantage of the existing technologies of Chemical Mechanical Polishing (CMP) and wafer bonding. The active buried under-layers can be pre-patterned isolated gates or interconnects using high temperature refractory metals such as tungsten, or blanket insulating or semi-insulating films of polysilicon which can be rendered conductive by masking and selective doping. SOIAS substrate preparation and materials characterization are described.