Patent ID: 7611938

Claim:
A method comprising: forming a first semiconductor device in a substrate, the first semiconductor device comprises: a gate structure; a spacer disposed on sidewalls of the gate structure, the spacer having a first thickness; raised source and drain regions disposed on either side of the gate structure; forming a second semiconductor device in the substrate and electrically isolated from the first semiconductor device, the second semiconductor device comprises: a gate structure; a spacer disposed on sidewalls of the gate structure, the spacer having a second thickness less than the first thickness of the spacer of the first semiconductor device; recessed source and drain regions disposed on either side of the gate structure; wherein forming the first and second semiconductor devices further comprises: forming a dummy spacer on either side of at least one of the gate structures of the first and second semiconductor devices; and after forming the dummy spacer on either side of the at least one gate structure, etching a portion of the substrate on either side of the gate structure to form a recess, wherein a portion of the recess extends underneath the dummy spacer.