EXTENDED RAISED SOURCE/DRAIN STRUCTURE FOR ENHANCED CONTACT AREA AND METHOD FOR FORMING EXTENDED RAISED SOURCE/DRAIN STRUCTURE

摘要

A semiconductor device comprises a gate electrode stack having sidewalls and a top surface with a gate dielectric layer and the gate electrode, and LDD/LDS regions in the substrate aligned with the stack. Conformal L-shaped etch-stop layers with a thickness from about 50 Å to about 200 Å are formed with a vertical leg on the sidewalls of the stack and a horizontal leg reaching over the LDD/LDS regions next to the stack. RSD regions are formed in contact with the substrate aside from the etch-stop layers. The RSD regions cover the horizontal leg of the etch-stop layer and cover at least a portion of the vertical leg of the etch-stop layer on the sidewall of the gate electrode.