Control of Source and Drain Extension Phosphorus Profile by Using Carbon Co-Implant

Carbon and fluorine co-implantation have shown encouraging junction formation improvement, especially for P-type junctions. Nevertheless, no obvious improvement is found for arsenic implants. In this paper, phosphorous with different co-implants shows that C co-implant can effectively suppress phosphorous diffusion. With C co-implant, the junction depth decreased 42% at low temperature RTP combined with laser annealing. We implemented L18 DOE experiment with germanium, carbon, phosphorous and RTP splits, and the result shows that the dominant factors are phosphorous dosage and RTP temperature. The best Rs*Xj performance can meet 45 nm requirement.