A new pocket-doped NCFET for low power applications: Impact of ferroelectric and oxide thickness on its performance

Abstract

Negative capacitance field-effect transistor (NCFET) is a potential device that has exhibited an immense prospective to outplace conventional FETs because of their steep switching characteristics driven by ferroelectric gate stack. The negative capacitance in ferroelectrics yields a voltage step-up action that curtails the sub-threshold swing (SS) below 60 mV/decade. In this work, a device based on single gate NCFET (SG-NCFET) and a highly doped double pocket double gate (HDDP-DG-NCFET) with n++ pocket at the edge of source and drain channel junction are proposed to investigate the impact of the morphological modification on electrical parameters of NCFET. In addition, the effect of incorporating pocket in HfO2 based single gate and double gate NCFET is investigated that delivers steep SS and enhances the switching ratio. The device architecture is designed systematically to boost ION/IOFF ratio by optimizing the pocket thickness and ferroelectric parameters. Various scaling parameters are optimized to achieve an OFF current of 1.9 × 10−11 A/μm, 2.65 × 10−13 A/μm, ON-OFF current ratio of 108, 1010 and SS of 36.2 mV/decade, 25.5 mV/decade for SG-NCFET and HDDP-DG-NCFET, respectively. Finally, the proposed NCFET characteristics are compared to those of prevailing NCFET designs and the HDDP-DG-NCFET design emerges out to be a better solution for low-power applications.