Performance Analysis of Feedback Field-Effect Transistor-Based Biosensor

To speed up the performance of the device with scaling down the physical size, steep switching has become the major concern for reduction in subthreshold slope. In this paper, in order to achieve steep switching, the subthreshold slope has been obtained similar to 5mV/decade by introducing the feedback field-effect transistor (FBFET) based biosensor which utilizes the positive feedback mechanism in the device. The reduction in the subthrshold slope of the proposed biosensor leads to detection of biomolecules such as biotin, and biotin-streptavidin at the rapid response with higher sensitivity. This detection of biomolecules has been carried out by creating the cavity at the source end. With the immobilization of biotin-streptavidin in the cavity about 75% of the sensitivity has been achieved. In addition to this, we have also studied the impact of cavity parameter modulation on the drive current and on its sensitivity. Further, we have compared the transfer charcteristics and the sensitivity of conventional dielectric modulated FET with the proposed device at different dielectric constant and the negative charge density of biomolecules which shows that proposed FBFET has higher sensitivity than conventional DM-FET. Furthermore, the fabrication process of the proposed device has been included which shows that it can be fabricated with simple steps without any complexity and at lower cost.