Integration scheme for fully silicided gate

Abstract

To form a semiconductor device, a silicon (e.g., polysilicon) gate layer is formed over a gate dielectric and a sacrificial layer (preferably titanium nitride) is formed over the silicon gate layer. The silicon gate layer and the sacrificial layer are patterned to form a gate structure. A spacer, such as an oxide sidewall spacer and a nitride sidewall spacer, is formed adjacent the sidewall of the gate structure. The semiconductor body is then doped to form a source region and a drain region that are self-aligned to the spacers. The sacrificial layer can then be removed selectively with respect to the oxide sidewall spacer, the nitride sidewall spacer and the silicon gate. A metal layer (e.g., nickel) is formed over the source region, the drain region and the silicon gate and reacted with these regions to form a silicided source contact, a silicided drain contact and a silicided gate.