Eliminating metal-rich silicides using an amorphous Ni alloy silicide structure

摘要

The present invention provides a method for producing thin nickel (Ni) monosilicide or NiSi films (having a thickness on the order of about 30 nm or less), as contacts in CMOS devices wherein an amorphous Ni alloy silicide layer is formed during annealing which eliminates (i.e., completely by-passing) the formation of metal-rich silicide layers. By eliminating the formation of the metal-rich silicide layers, the resultant NiSi film formed has improved surface roughness as compared to a NiSi film formed from a metal-rich silicide phase. The method of the present invention also forms Ni monosilicide films without experiencing any dependence of the dopant type concentration within the Si-containing substrate that exists with the prior art NiSi films.