Design strategy of localized halo profile for achieving sub-50 nm bulk MOSFET

摘要

This paper presents a design strategy to optimize short-channel effects with localized halo profile for achieving sub-50 nm bulk MOSFET devices. With the optimal choice of the location of heavily doped halo, it can be simultaneously accomplished to improve the roll-off of threshold voltage and to relieve drain leakage current without raising the low threshold voltage. To reduce the impact of heavy halo doping concentration on the threshold voltage, it is essential to have a deep and short enough halo doping profile. The halo-to-extension spacing is the most effective design parameter to control the band-to-band leakage current and the threshold-voltage roll-off. With adequate halo-to-extension spacing, a much heavier halo doping concentration can be used to suppress the roll-off of threshold voltage without raising the drain leakage current. The sidewall oxide of the insulated shallow extension structure demonstrates the feasibility of the precise control of the halo-to-extension spacing to achieve a sub-50 nm bulk MOSFET with fully CMOS compatible process.