NOVEL METAL SILICIDE MATERIALS FOR NANOMETER SCALE CMOS TECHNOLOGY

摘要

Nanometer scale CMOS requires renovation of the metal silicide technology. The current mature TiSi_2 and CoSi_2 silicide technology encountered unavoidable difficulties for CMOS device below 90 nm. The NiSi salicide technology is under intensive development for 65nm and below. For further scaled CMOS the low Schottky barrier height silicide technology has to be developed. Recently the rare earth metal silicides, such as Yb-silicide, become subject of great interest. Their low barrier height on n-Si is attractive for both lowering the contact resistance and developing novel SBD-CMOS. However, there is a series of problems, such as metal oxidation and pinhole formation, which impede the formation of uniform film of rare earth metal silicide. In this paper, some material and process issues of NiSi, and the oxidation suppression during Yb-silicide formation are discussed.