Strained ultra-thin SOI transistor formed by replacement gate

摘要

A semiconductor structure is described. The structure includes a transistor formed in a semiconductor substrate, the semiconductor substrate having a semiconductor-on-insulator (SOI) layer; a channel associated with the transistor and formed on a first portion of the SOI layer; and a source/drain region associated with the transistor and formed in a second portion of the SOI layer and in a recess at each end of the channel, where the second portion of the SOI layer is substantially thicker than the first portion of the SOI layer. A method of fabricating the semiconductor structure is also described. The method includes forming a dummy gate in a semiconductor substrate; performing a SIMOX process to form a SOI layer such that a first portion of the SOI layer under the dummy gate is substantially thinner than a second portion of the SOI layer; forming a source/drain extension in the SOI layer; and recessing the source/drain extension for forming a source/drain region; epitaxially growing the second portion of the SOI layer; forming an insulating layer over the epitaxial growth; removing the dummy gate for forming a gate opening; and filling the gate opening with a gate dielectric material and a gate conductor material.