Patent ID: 7176096

Claim:
A method of forming a local interconnect on a semiconductor integrated circuit, the method comprising: forming a gate stack on a substrate, the gate stack having at least one conductive layer and a source layer of a first thickness positioned on top of the at least one conductive layer so that the at least one conductive layer directly-contacts the source layer and at an uppermost surface of the gate stack, the source layer providing a rich source of silicon; exhuming a first layer of the gate stack so as to expose a portion of the source layer above at least a portion of the gate stack so as to define a first circuit node; depositing a refractory material so that the refractory material contacts the exposed uppermost portion of the source layer of the gate stack with the source layer substantially maintaining the first thickness and so that the refractory material is also positioned to contact a second circuit node of the integrated circuit having a rich source of the silicon; forming a masking layer over the refractory material; etching the masking layer so as to define an extent of the local interconnect; selectively transforming the refractory material in a nitrogen containing ambient such that the refractory material underneath the etched masking layer and at least adjacent the exposed portion of the source layer and the second circuit node is transformed into low resistance contacts comprising refractory material silicide such that electrical contact between the refractory metal and the at least one conductive level occurs through the source layer and wherein the source layer provides silicon to the portion of the refractory material positioned adjacent the exposed uppermost portion of the source layer and wherein the refractory material beyond the extent of the local interconnect is transformed to comprise refractory material nitride; and performing a selective removal process such that the refractory material nitride and remaining refractory material beyond the extent of the local interconnect is preferentially removed and wherein the contacts comprising refractory material silicide are preferentially unresponsive to the selective removal process.