Effects of the remnant polarization on the electrical characteristics of steeper sub-threshold swing Fe-GeFinFET

Abstract

In this article, a ferroelectric material is used in the gate stack of germanium FinFET to enhance the electrical performance of transistor, viz. subthreshold swing (SS), switching ratio (ION/IOFF), threshold voltage (Vth), transconductance (gm), and improve the short channel effects (SCEs). The extent of the improvement depends on the capacitance matching between the ferroelectric (FE) capacitance (Cferro) and baseline FinFET capacitance (Cmos). The variation of ferroelectric parameters like ferrothickness (tferro) and remnant polarization (Pr) on electrical characteristics of ferro-germanium FinFET (Fe-GeFinFET) have been investigated. The non-linear relationship between Cferro and Cmos over a voltage range circumvents the acceptable capacitance congruence between the two capacitances. With the incorporation of FE layer, the SS has been obtained as 8 mV/decade and the ION enhanced by 12 %. The device yields a transconductance (gm) of 20 mS at Vgs = Vds = 0.7 V. The results have been investigated using Sentaurus 3-D TCAD simulations.