TCAD-based evaluations of a high-performance, low-power dielectric modulated BioTFET with dopingless tunneling junctions

Abstract

This article introduces a biosensor that utilizes a dopingless Ge/Si heterostructure for more efficient detecting the intended biomolecules. In order to convert the intrinsic germanium-based semiconductor within our bioTFET (biological tunneling field-effect transistor) into a P⁺ region, we have surrounded the source with two heavily-doped silicon layers. This addresses challenges such as silicide formation and parasitic metal-to-source tunneling, which are commonly found in charge plasma-based devices. In the drain region, we have incorporated N⁺ doping instead of using inductive metal, resulting in improved AC performance. To verify our findings, we have used a calibrated device simulator and proposed a detailed fabrication process for our bioTFET. In order to assess the functionality of our biosensor, we have executed a series of simulations to quantify its performance metrics, including the sensitivity of drain current and subthreshold swing. Due to our device's optimal design, we achieved ideal parameters such as $S_{I_D}$ = 6.15 × 10⁶,and $S_{{SS}_{avg}}$ = 0.92 at V_GS = 0.7 V.