Modeling the effect of source/drain sidewall spacer process on boron ultra shallow junctions

Abstract

A novel model is developed to explain the effect of the source/drain sidewall spacer process on boron drain extension formation. A diffusion model for hydrogen in the source/drain sidewall spacer is developed and combined with a model for boron diffusion in oxides. The model is first calibrated to hydrogen out-diffusion data from Nuclear Reaction Analysis (NRA) and then to boron diffusion data from Secondary Ion Mass Spectroscopy (SIMS). Seemingly anomalous changes in boron junction depths with variation in sidewall spacer deposition conditions are explained by this model. The model is applied to TCAD process/device simulations to understand the effect of sidewall spacer on CMOS device performance.