Realizing Efficient Volume Depletion in SOI Junctionless FETs

In this paper, we provide a simple and effective solution to realize efficient volume depletion and therefore, significantly reduce the OFF-state leakage current of a junctionless FET (JLFET) by replacing the SiO₂ by HfO₂ in the buried oxide (BOX). Using calibrated 2-D simulations, we show that the JLFET with a high-k BOX (HB JLFET) exhibits a considerably high I_ON/I_OFF ratio of ~10⁶ even for a channel length of 20 nm. Further, we demonstrate that the use of a high-k BOX leads to a reduction in both gate capacitance C_g and gate-to-drain feedback (Miller) capacitance C_gd.