A high sensitivity biosensor based on fin-type electron-hole bilayer TFET

Abstract

A novel biosensor is proposed based on the fin-type electron-hole bilayer tunnel field-effect transistor, and its sensitivity is investigated in detail using numerical simulation. Single vertical nanocavity in this biosensor facilitates the injection and filling of biomolecules and simplifies the fabrication process. This biosensor’s operation depends on the line-tunneling occurring between electron-hole bilayer, making it more sensitive to biomolecules. By investigating effects of neutral and charged biomolecules, biomolecules’ irregular distribution, probe position, and device structure on this biosensor, it follows that it is more sensitive to positively charged biomolecules with higher dielectric constant and charge density. Furthermore, it has higher sensitivity when biomolecules show an increasing distribution and the probe is located in the lower half of the nanocavity and has high filling rate. Calculation shows that at a low operating voltage of 0.5 V, its threshold voltage sensitivity, on-state current sensitivity, and subthreshold swing sensitivity are as high as 740 mV, 6.0 × 10³, and 0.92, respectively.