EFFECTS OF LOW-DOSE SILICON, CARBON, AND OXYGEN IMPLANTATION DAMAGE ON DIFFUSION OF PHOSPHORUS IN SILICON

As device dimensions shrink to submicron levels, good design of ultrashallow junctions has become increasingly important. It is in this context that the use of carbon/oxygen as a possible diffusion-suppressing agent for phosphorus has been suggested. To study this complex phenomenon, this experimental study looks at the effects of low dose silicon, carbon, and oxygen implantation damage on the diffusion of lightly doped phosphorus layers. The effects of a silicon and carbon coimplant on the diffusion of phosphorus are studied as part of a second experiment. Finally, lightly doped drain structure is annealed in the presence of a carbon implant. Carbon is the most effective diffusion-suppressing agent among the three species. Results from the second experiment suggest that carbon strongly affects the interstitial profile, and thereby the final phosphorus profile.