Suppression of reverse short channel effect by nitrogen implantation and its implications on nitrogen as a dopant species for applications in 0.25 /spl mu/m technology

Abstract

Nitrogen implantation into the channel region was used for the reduction of the "Reverse Short Channel Effect(RSCE)". This approach was found to be very effective in reducing the RSCE without adverse effects on the short channel behavior. The reduction of the RSCE is believed to be due to the implanted nitrogen ions. These implanted nitrogen ions retards the redistribution of the channel boron concentration, which is believed to be the cause of the RSCE. Threshold voltage shifts were observed in both n- and p-ch MOSFETs. We propose that these threshold voltage shifts are due to the partial activation of the nitrogen atoms that have taken up substitutional sites in the silicon lattice and thus behave as a dopant species for silicon.