Method for forming shallow junctions with a low resistivity silicide layer

摘要

A method for forming a shallow junction (56) with a relatively thick metal silicide (52) thereover is provided. A first relatively thin layer (38) of a metal is deposited over the surface of a semiconductor substrate. An impurity (40) is then implanted (42) into or through the first layer (38). A relatively thick second layer (48) of metal is deposited over the first layer (38). An anneal process (50) is then performed to out-diffuse the impurities (40) from the first layer (38) into the substrate (32). The anneal also forms a combined metal silicide (52) from the first layer (38) and the second layer (48). The junction (56) thus formed has less surface damage, reduced spiking and reduced implant straggle than junctions formed according to the prior art. An alternate technique is also disclosed wherein an implant into or through a silicide layer is utilized.