Analytical model for subthreshold current and subthreshold swing of short-channel double-material-gate MOSFETs with strained-silicon channel on silicon—germanium substrates

Abstract

The present work gives some insight into the subthreshold behaviour of short-channel double-material-gate strained-silicon on silicon—germanium MOSFETs in terms of subthreshold swing and off-current. The formulation of subthreshold current and, thereupon, the subthreshold swing have been done by exploiting the expression of potential distribution in the channel region of the device. The dependence of the subthreshold characteristics on the device parameters, such as Ge mole fraction, gate length ratio, work function of control gate metal and gate length, has been tested in detail. The analytical models have been validated by the numerical simulation results that were obtained from the device simulation software ATLAS™ by Silvaco Inc.

Development of Tri‐Layered s‐Si/s‐SiGe/s‐Si Channel Heterostructure‐on‐Insulator MOSFET for Enhanced Drive Current

“…For shallow source/drain, doping needs to be increased to keep the sheet resistance constant otherwise, increased series resistance would be encountered, which induces difficulty in accessing the channel, hence vitiates the device performance radically . Therefore, the concept of strain engineering to develop new heterostructure devices have been explored to some extent and has become a crucial feature in present CMOS technology since it enhances the drain current without further gate length scaling, which seemed to be a promising solution for further improvement in device performances …”