Raised Source/Drain Germanium Junctionless MOSFET for Subthermal OFF-to-ON Transition

Abstract

This paper reports the significance of device architecture to enhance impact ionization (I.I.) resulting in steep increase in the current from OFF- to ON-state. Recognizing that the area over which I.I. occurs is a key factor governing impact generated power per unit volume in the semiconductor film, we use raised source/drain (RSD) architecture to achieve sub-60-mV/decade subthreshold swing (S-swing) in germanium (Ge) junctionless (JL) devices at drain bias ( ${V}_{\text {ds}}$ ) of 0.9 V. The performance of RSD Ge JL device is compared with double-gate Ge JL transistor to highlight the occurrence of subthermal S-swing $({N}_{\text {ch}}) \ge {5}\times {10}^{18}$ cm−3 to facilitate sharp current transition.