Influence of HALO and drain-extension doping gradients on transistor performance

For achieving a physical gate length lower than 50 nm and keeping at the same time good transistor performance, a careful design of drain-extension and channel doping profiles is required. For this we investigate the influence of drain-extension and HALO doping gradients at the drain-extension channel junction (DECJ). It is found that the influence of the drain extension doping gradient on the threshold voltage roll-off behavior is small for steep profiles when keeping saturation current and overlap capacitance constant. On the other hand, the shape of the HALO profile influences the threshold voltage roll-off characteristics and allows to adjust the roll-off behavior without degrading the saturation current dramatically. The effect of process parameters like HALO implantation angle and energy on the transistor performance is studied. (C) 2004 Published by Elsevier B.V.