Epitaxial extension CMOS transistor

摘要

A pair of horizontal-step-including trenches are formed in a semiconductor layer by forming a pair of first trenches having a first depth d 1 around a gate structure on the semiconductor layer, forming a disposable spacer 58 around the gate structure to cover proximal portions of the first trenches, and by forming a pair of second trenches to a second depth d2 greater than the first depth d1. The disposable spacer is removed, and selective epitaxy is performed to form an integrated epitaxial source and source extension region 16 and an integrated epitaxial drain and drain extension region 18. A replacement gate structure can be formed after deposition and of a planarization dielectric layer 70 and subsequent removal of the gate structure and laterally expand the gate cavity 59 over expitaxial source 16 and drain extension regions 18. Alternately, a contact-level dielectric layer can be deposited directly on the integrated epitaxial regions and contact via structures can be formed therein.