Split-gate dielectrically modulated TFET for ultrasensitive and label-free breast cancer cell detection

This paper shows the design and simulation of highly sensitive label-free biosensor using Split Source Dual Gate Dielectric Modulated Tunnel Field-Effect Transistor (SSDG-DMTFET) to detect the early stage of breast cancer. The biosensor is designed with a nanocavity close to the source-channel junction that permits dielectric modulation during immobilizing a variety of breast cell lines, both healthy (MCF-10A) and cancerous (Hs 578T, MDA-MB-231, MCF-7, T-47D). Under simulation with SILVACO ATLAS TCAD, the proposed breast cancer detector demonstrates great improvement in electrical characteristics such as ON current, subthreshold swing, and transconductance of the sensor, owing to effective band-to-band tunneling enabled by high-k dielectric biomolecules. It is verified that the proposed structure works with uniform and non-uniform distributions of the biomolecules and spatial profiles like increasing, decreasing, convex and concave geometries are tested. The robustness of the biosensor is also determined in the presence of a mix cell condition based on the effective medium Bruggeman theory and shows the precision in detecting when low volumes fraction of the cell is present (as low as 10% of the malignant cells). The sensitivity analysis shows impeccable detection abilities with sensitivity improvement of maximum three orders in $I_{ON}/I_{OFF}$ ratio and 72% in threshold voltage between healthy and cancerous cells. The presented SSDG-DMTFET has the potential to significantly surpass a number of state-of-the-art biosensors in sensitivity, and thus constitutes a viable, compact and CMOS-compatible option for breast cancer detection.