Process for fabricating silicon-on-nothing MOSFETs

摘要

A semiconductor device includes a gate stack; an air-gap under the gate stack; a semiconductor layer vertically between the gate stack and the air-gap; and a first dielectric layer underlying and adjoining the semiconductor layer. The first dielectric layer is exposed to the air-gap.

主权项

1. A method of forming a semiconductor device, the method comprising:
providing a semiconductor substrate; forming a semiconductor layer over the semiconductor substrate; forming an air-gap between the semiconductor substrate and the semiconductor layer; forming a gate dielectric over the semiconductor layer; forming a gate electrode over the gate dielectric; forming a first oxide layer vertically between the semiconductor layer and the air-gap; forming a second oxide layer vertically between the semiconductor substrate and the air-gap; and removing non-air-gap portions of the first oxide layer and the second oxide layer, and during the step of removing non-air-gap portions of the first oxide layer and the second oxide layer, keeping top surfaces of air-gap portions of the first oxide layer and the second oxide layer exposed to the air-gap.