Double silicon-on-insulator device and method therefor

Abstract

An integrated circuit chip wherein one or more semiconductor devices are completely isolated from bulk effects of other semiconductor devices in the same circuit and a method of making the integrated circuit chip. The devices may be passive devices such as resistors, or active devices such as diodes, bipolar transistors or field effect transistors (FETs). A multi-layer semiconductor body is formed of, preferably silicon and silicon dioxide. A conducting region or channel is formed in one or more of the layers. For the FET, silicon above and below the channel region provides controllable gates with vertically symmetrical device characteristics. Buried insulator layers may be added to isolate the lower gate of individual devices from each other and to create multiple vertically stacked isolated devices. Both PFET and NFET devices can be made with independent doping profiles in both depletion and accumulation modes.