Semiconductor contact silicide/nitride process with control for silicide thickness

Claim 1

In the fabrication of an integrated circuit, a process for establishing an electrical contact at a contact opening in an insulative material to an underlying silicon region of said integrated circuit and for forming a metallurgic barrier over said contact comprising the steps of: establishing a relatively thin control region in said contact opening over said underlying silicon region, said control region comprising a compound including silicon oxygen and nitrogen; then establishing a first layer comprising a transition metal over said insulative material and said control region; and then thermally cycling the integrated circuit to convert at least part of said transition metal layer into a metallurgic barrier and to establish a low resistance silicide contact region below said barrier in said underlying silicon region previously exposed by said contact opening, said control region retarding the development of said silicide contact region in said contact opening, said control region being replaced during said thermally cycling step by said silicide region, said control region thereby permitting the thickness of said silicide contact region relative to said metallurgic barrier to be controlled.