Mole Fraction-Based Approach for Sensitivity Analysis of Dual Material Control Gate Polarity Controlled Tunnel Field Effect Transistor for Applications in Biomedical Engineering
Authors: Shreyanshi Maturkar , Sangeedh  , Nigam Kaushal Kumar , Raghuvanshi Ajay Singh , Dharmender  
Published: January 2024

The fabrication complexity and cost associated with nanoscale devices are major concerns. Therefore, to address these challenges, we have introduced a mole fraction-based approach for the sensitivity analysis of a dual material control gate cavity on a source electrically doped polarity-controlled tunnel field effect transistor (DMCG-CS-ED-PC-TFET)-based biosensor for label-free detection of biomolecule species. For this purpose, a polarity bias (electrically doped) of PG-[Formula: see text] V and PG-[Formula: see text] V is applied for the formation of n+ drain and p+ source regions, respectively, over the thin silicon body. The proposed device structure overcomes the random dopant fluctuation issues, thereby avoiding thermal budget and fabrication complexity as compared to the conventional TFET. Moreover, the nanogap cavity is created by etching the appropriate portion at the source side oxide layer. Furthermore, we have applied a dual metal work function (M1 and M2) at the gate electrode along with hetero material [Formula: see text] at the source side region to improve the sensitivity of the device by varying the mole fraction value (X). The performance of the proposed device has been evaluated in terms of variations in carrier concentration profile, electric field variation, energy band diagram, transfer ([Formula: see text]) characteristics and the sensitivity in terms of drain current (I[Formula: see text]), ON-state current (I[Formula: see text]) and switching ratio (I[Formula: see text]/I[Formula: see text]). Furthermore, the sensitivity of the proposed device biosensor has been investigated by considering nanocavity dimensions, practical challenges such as various fill factors, and various step profiles generated from steric hindrance. For this purpose, different neutral biomolecules such as Biotin ([Formula: see text]), APTES ([Formula: see text]), Keratin ([Formula: see text]), Ferrocytochrome C ([Formula: see text]) and Gelatin ([Formula: see text]) have been considered in the etched nanocavity region. Additionally, charged biomolecules with positive (negative) charge densities at the oxide semiconductor interface below the nanocavity region have been incorporated to assess the performance of the proposed device using the Silvaco ATLAS device simulator. In this analysis, the proposed biosensor achieves a drain current sensitivity of [Formula: see text] for neutral biomolecules ([Formula: see text]), [Formula: see text] for [Formula: see text] = [Formula: see text] cm[Formula: see text] with [Formula: see text] and [Formula: see text] for [Formula: see text] = [Formula: see text] cm[Formula: see text] and [Formula: see text]. Finally, the performance of the proposed biosensor, DMCG-CS-ED-PC-TFET, exhibits higher sensitivity compared to various existing TFET-based biosensors. Hence, the proposed biosensor exhibits the potential candidate for the development of future sensing bio-equipment.