Comparison of raised and Schottky source/drain MOSFETs using a novel tunneling contact model

We present, for the first time, a physical contact tunneling model that is critical for studying the increasingly important contact behaviour in future scaled CMOS. The tunneling processes are self-consistently treated with all current transport in the semiconductor. With this new model, we compared the performance of raised S/D and Schottky S/D MOSFETs. Both raised S/D and Schottky S/D MOSFETs can be designed to give good short-channel characteristics. Our analyses show that despite the lower sheet resistance of the Schottky S/D MOSFETs, contact resistance could be large due to finite Schottky barrier height. A lower barrier height contact material should be used to minimize the contact resistance.