Dielectrically modulated hetero‐material double gate tunnel field‐effect transistor for label free biosensing

Abstract

This work proposes a novel double gate hetero‐material tunnel field effect transistor for label free biosensing applications. The device consists of III‐V semiconductor gallium arsenide (GaAs) which serves as a substrate. Source and drain regions made of Germanium are used due to its compatibility with GaAs. Cavities of 15 × 1.5 nm are created near source‐channel junctions for the biomolecules to be placed in. The ION sensitivity of 2.23 × 106 for neutral biomolecules has been obtained from 2D simulations using ATLAS TCAD software. Furthermore, transconductance sensitivity of 2.27 × 106, ION/IOFF sensitivity of 2.46 × 105, subthreshold swing (SS) sensitivity of 28.6 mV/decade and threshold voltage sensitivity of 1.2 mV for neutral biomolecules is obtained. The ION sensitivity of 3.93 × 106 and 1.42 × 106 for positively and negatively charged biomolecules respectively has been obtained. Also, SS sensitivity of 28.3 and 28.8 mV/decade for positively and negatively charged biomolecules respectively has been observed. ION sensitivity shows that the proposed device is 1000× better than the conventional one.