A FoM for Investigation of SB TFET Biosensor Considering Non-Ideality

Abstract

A new FoM to investigate a carefully engineered Schottky barrier (SB) TFET by accounting for dc power consumption, and silicon area,which are the key consideration for energy efficiency and cost of the biosensors, is reported in this paper. The SB TFETutilizes source overlap, drain underlap, and nano-cavity near the source region to detect biomolecules by accounting non-ideality, i.e., steric hindrance (SH). The sensitivity due to drain current ID, ON-OFF ratio ION/IOFF, average subthreshold swing AVSS, threshold voltage VTH transconductance gm are thoroughly investigated. The proposed FoM is utilized, and impact analysis is carried out by considering neutral biomoleculesmainly due to changes in their dielectric constants, SH step profiles, and variation in the pocket length.After the detailed analysis by considering the case ofAPTES (k=3.57) biomolecules in different step profiles, the concave profile realized an optimized FoM of 30nW-1nm-1. However, when k is varied, and when Bacteriophage T7 (k=6.3), Keratin (k=8), and Gelatin (k=12) biomolecules with k>5 were used, the FoM was realized nearly 26nW-1nm-1. The improvement in FoM is observed around 67% when pocket length of 5 nm is used as compared to when it is not used. Comparisons with the published papers having similar dimensions TFETs biosensors by mainly targeting ION sensitivity and corresponding FoM are presented, and the proposed nano SB TFET was found to achieve significantly higher results.