Silicide gate transistors and method of manufacture

摘要

A method in which a gate and raised source/drain (S/D) regions are fully silicided in separate steps to avoid degrading the resistance or junction leakage is described. A gate dielectric layer, gate, and spacers are formed over a semiconductor layer that is preferably Si, SiGe, or SiGeC on a buried insulator. Raised S/D regions are formed by selective epitaxy between spacers and isolation regions. The gate is protected with a mask while the raised S/D regions are covered with a first metal layer. A first anneal affords fully silicided S/D regions. A dielectric stack is deposited on the substrate and planarized to be coplanar with the top of the spacers. The mask is removed and a second metal layer is deposited. A second anneal yields a fully silicided gate electrode. The invention is also an SOI transistor with silicided raised S/D regions and a fully silicided and optionally recessed gate.