Atomistic Modeling of Pocket Dopant Deactivation and Its Impact on Variation in Scaled Si Planar Devices Using an Atomistic Kinetic Monte Carlo Approach

An analysis of pocket dopant deactivation and its impact on V_th variation for scaled Si devices using an atomistic kinetic Monte Carlo approach are shown in this paper. B 5 keV, 5 × 10¹³/cm² + As 1 keV, 1 × 10¹⁵/cm² implants were used for B pocket deactivation study. An effect of laser annealing (LA) before spike-Rapid Thermal Annealing (RTA) was investigated. In case of B pocket implant, a stable B cluster configuration is changed from B₃I (>1020 °C) to BI₂ at spike-RTA temperature ~1020 °C. BI₂ is a source of B pocket deactivation with lower temperature than 1020 °C. LA before low-temperature spike-RTA (<;1020 °C) is useful to improve B pocket activation. The V_th mismatch figure of merit extracted from Pelgrom plot (Avt) degradation in nFET is shown as spike-RTA temperature is reduced. LA before spike-RTA shows a better short channel effect with lower drain-induced barrier lowering in nFET. LA + spike-RTA at 1000 °C shows better Avt than spike-RTA-only. The difference of pocket deactivation is one of possible important reasons for the higher V_th mismatch for nFET than for pFET.