P-channel I-MOS transistor featuring silicon nano-wire with multiple-gates, strained Si1-yCy I-region, in situ doped Si 1-yCy source, and sub-5 mV/decade subthreshold swing

Abstract

We realized Impact Ionization Nanowire Multiple-gate Field-Effect Transistors (I-MuGFETs or I-FinFETs) having a multiplegate/nanowire-channel architecture to exploit the superior gate-to-channel coupling for reduced breakdown voltage VBD and enhanced device performance. The first p-channel Impact Ionization MOS transistor (I-MOS) having in situ doped source was also demonstrated. An in situ phosphorus-doped Si source with improved dopant activation and very abrupt junction profile reduces VBD and enhances the on-state current Ion. A further improvement was also made by incorporating strained Si1-yCy, impact-ionization region (I-region) and in situ doped Si1-yCy source, leading to further reduction in VBD and enhancement in I on. This is due to strain-induced reduction of the impact-ionization threshold energy Eth. In addition, excellent subthreshold swing of below 5 mV/decade at room temperature was achieved for all devices. © 2008 IEEE.