Device drive current degradation observed with retrograde channel profiles

Abstract

Super steep retrograde channel profiles have been widely known to produce improved short channel characteristics in sub-0.35 /spl mu/m CMOS technologies. In this paper, an attempt is made to leverage this improved short channel behaviour and thereby improve transistor performance (as measured by the current drive). Whereas significant improvements in short channel effects measured by DIBL and /spl Delta/Vt/sub sat/ are obtained with retrograde channels, it is observed that for a fixed gate length and equal threshold voltage, transistors with retrograde channel profiles typically exhibit lower drive currents than equivalent transistors fabricated with conventional doping profiles. Potential trade offs in device design resulting from this observation are discussed.