A Novel hetero-metal gate-all-around TFET biosensors based on polarization effect

This paper proposes a dielectric-modulated hetero-metal gate-all-around TFET biosensor based on polarization effects for label-free detection of biomolecules. Using calibrated TCAD simulation, we investigate the sensor's ability to detect both neutral and charged biomolecules. The results indicate that, when detecting gelatin biomolecules (with a relative dielectric constant of 12), the biosensor demonstrates a drain current sensitivity approaching 10¹¹, markedly outperforming currently reported TFET-based biosensing technologies. Additionally, the effects of the relative positioning of the hetero-gate and sensing nanocavity, as well as the length of the sensing nanocavity are also analyzed. The results show that biosensor's performance is optimized when the tunneling gate is precisely aligned with the nanocavity, and increasing the nanocavity length can enhance the biosensor's sensitivity. Furthermore, our study suggests that, in addition to achieving a low SS, a noticeable difference in turn-on voltages between pre- and post-detection is also crucial to further improve sensitivity by maximizing the benefits of a low subthreshold swing.