Patent ID: 7544561

Claim:
A method for forming semiconductor structure comprising: providing a semiconductor substrate comprising silicon; forming a PMOS device comprising: forming a first gate dielectric on the semiconductor substrate; forming a first gate electrode on the first gate dielectric; and forming a first gate spacer on sidewalls of the first gate electrode and the first gate dielectric, wherein the PMOS device is free from a nitrided polysilicon re-oxidation material between the first gate spacer and a respective sidewall of the first gate electrode; and forming an NMOS device comprising: forming a second gate dielectric on the semiconductor substrate; forming a second gate electrode on the second gate dielectric; forming a nitrided polysilicon re-oxidation layer having a vertical portion and a horizontal portion, wherein the vertical portion is on sidewalls of the second gate electrode and the second gate dielectric, and wherein the horizontal portion is on the semiconductor substrate; and forming a second gate spacer on sidewalls of the second gate electrode and the second gate dielectric, wherein the second gate spacer is on the horizontal portion of the nitrided polysilicon re-oxidation layer.