Silicon germanium and polysilicon gate structure for strained silicon transistors

Abstract

An integrated circuit semiconductor device, e.g., MOS, CMOS. The device has a semiconductor substrate. The device also has a dielectric layer overlying the semiconductor substrate and a gate structure overlying the dielectric layer. A dielectric layer forms sidewall spacers on edges of the gate structure. A recessed region is within a portion of the gate structure within the sidewall spacer structures. An epitaxial fill material is within the recessed region. The device has a source recessed region and a drain recessed region within the semiconductor substrate and coupled to the gate structure. The device has an epitaxial fill material within the source recessed region and within the drain recessed region. A channel region is between the source region and the drain region is in a strain characteristic from at least the fill material formed in the source region and the drain region. Depending upon the embodiment, the fill material can be any suitable species such as silicon germanium, silicon carbide, and others.