Epitaxial extension cmos transistor

Abstract

A pair of horizontal-step-including trenches are formed in a semiconductor layer by forming a pair of first trenches having a first depth around a gate structure on the semiconductor layer, forming a disposable spacer around the gate structure to cover proximal portions of the first trenches, and by forming a pair of second trenches to a second depth greater than the first depth. The disposable spacer is removed, and selective epitaxy is performed to form an integrated epitaxial source and source extension region and an integrated epitaxial drain and drain extension region. A replacement gate structure can be formed after deposition and planarization of a planarization dielectric layer and subsequent removal of the gate structure and laterally expand the gate cavity over expitaxial source and drain extension regions. Alternately, a contact-level dielectric layer can be deposited directly on the integrated epitaxial regions and contact via structures can be formed therein.

Dependencies are inferred from the claim text.