A novel bi-layer cobalt silicide process with nitrogen implantation for sub-50 nm CMOS and beyond

We propose the "bi-layer" CoSi/sub 2/ structure with smaller grain size, which realizes low sheet resistance for 35 nm gate length as well as low junction leakage current for 100 nm junction depth for the first time. The formation of the bi-layer CoSi/sub 2/ structure is successfully controlled by the N/sub 2/ ion implantation with low energy and high dosage, and enables us to manufacture sub-50 nm CMOS devices.