Method of fabricating an NMOS transistor

摘要

A SiC region and a source/drain region are formed such that the SiC region includes a first portion overlapping the source/drain region and a second portion protruding from the source/drain region to a position beneath the LDD region. The concentration of crystalline SiC in the second portion is higher than the concentration of crystalline SiC in the first portion. The SiC region may be formed through a normal implantation before the second spacer is formed, or the SiC region may be formed through a tilt implantation or deposition epitaxially in a recess having a sigma-shape like sidewall after the second spacer is formed.