Inverted field-effect device with polycrystalline silicon/germanium channel

摘要

A CMOS device architecture which includes substrate-gated inverted PMOS transistors, as well as bulk NMOS. The inverted-PMOS channels are formed in a different layer from the NMOS gates, and these layers may even have different compositions. Moreover, the NMOS and inverted-PMOS devices have different gate oxide layers, so the thicknesses can be independently optimized. The drain underlap of the inverted device is defined by a patterning step, so it can be increased for high-voltage operation if desired.