Short channel characteristics of Si MOSFET with extremely shallow source and drain regions formed by inversion layers

摘要

The influence of extremely shallow source and drain junctions on the short channel effects of Si MOSFET's are experimentally investigated. These extremely shallow junctions are realized in MOSFET's with a triple-gate structure. Two subgates formed as side-wall spacers of a main gate induce inversion layers which work as the virtual source and drain. Significant improvement in threshold voltage roll-off and punchthrough characteristics are obtained in comparison with conventional MOSFET's whose junctions are formed by ion implantation: threshold voltage roll off is suppressed down to a physical gate length of 0.1 /spl mu/m while punchthrough is suppressed down to 0.07 /spl mu/m, the minimum pattern size delineated. It is also demonstrated experimentally that the carrier concentrations in the source and drain do not have any influence on the short channel effects.