Effects of titanium salicide process on MOSFET characteristics

The effects of the titanium-salicide (self-aligned silicide) process with different postmetallization anneals on the performance of very thin gate oxide MOSFETs are discussed. Compared to the conventional polycrystalline-silicon (poly-Si) gate process, a titanium-salicide process without enough annealing in hydrogen-containing ambients degrades MOSFET characteristics. However, after hydrogen anneal (but not a nitrogen anneal), the electrical characteristics of the salicided MOSFETs become comparable to those of poly-Si gate MOSFETs. The device degradation has been correlated with interface-state generation through an interface-state density study.< >