P-Channel I-MOS Transistor featuring Silicon Nano-Wire with Multiple-Gates, Strained Si1-yCy I-region, in situ doped Si1-yCy Source, and Sub-5 mV/decade Subthreshold Swing

We realized Impact Ionization Nanowire Multiple-gate Field- Effect Transistors (I-MuGFETs or I-FinFETs) having a multiple- gate/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 V_BD and enhances the on-state current I_on. A further improvement was also made by incorporating strained Si_1-yC_y impact-ionization region (I-region) and in situ doped Si_1-yC_y 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 E_th. In addition, excellent subthreshold swing of below 5 mV/decade at room temperature was achieved for all devices.