Steep slope p-type 2D WSe 2 field-effect transistors with van der waals contact and negative capacitance

Abstract

Steep-slope p-type 2D WSe 2 back-gated field-effect transistors (FETs) are realized by using van der Waals Pt-WSe 2 contact and HfZrO 2 / Al 2 O 3 as the dielectric layer. The van der Waals Pt-WSe 2 contact is free from disorder and Fermi level pinning and decreases the subthreshold slope. The WSe 2 NCFET with van der Waals contact shows low subthreshold slope for both forward and reverse gate voltage sweep (the minimum SS forward =18.2 mV dec and SS reverse =44.1 mV dec) with a hysteresis as small as 20 mV at subthreshold region.