Noise immune dielectric modulated dual trench transparent gate engineered MOSFET as a label free biosensor: proposal and investigation

We propose and investigate a biosensor based on a transparent dielectric-modulated dual-trench gate-engineered metal–oxide–semiconductor field-effect transistor (DM DT GE-MOSFET) for label-free detection of biomolecules with enhanced sensitivity and efficiency. Various sensing parameters such as the I_ON/I_OFF ratio and the threshold voltage shift are evaluated as metrics to validate the proposed sensing device. Additionally, S_Vth (the V_th sensitivity) is also analyzed, considering both positively and negatively charged biomolecules. In addition, radiofrequency (RF) sensing parameters such as the transconductance gain and the cutoff frequency are taken into account to provide further insight into the sensitivity of the proposed device. Furthermore, the linearity, distortion, and noise immunity of the device are evaluated to confirm the overall performance of the biosensor at high (GHz) frequency. The results indicate that the proposed biosensor exhibits a S_Vth value of 0.68 for positively charged biomolecules at a very low drain bias of 0.2 V. The proposed device can thus be used as an alternative to conventional FET-based biosensors.