Sensitivity Analysis of Biosensors Based on a Dielectric-Modulated L-Shaped Gate Field-Effect Transistor

Label-free biomolecular sensors have been widely studied due to their simple operation. L-shaped tunneling field-effect transistors (LTFETs) are used in biosensors due to their low subthreshold swing, off-state current, and power consumption. In a dielectric-modulated LTFET (DM-LTFET), a cavity is trenched under the gate electrode in the vertical direction and filled with biomolecules to realize the function of the sensor. A 2D simulator was utilized to study the sensitivity of a DM-LTFET sensor. The simulation results show that the current sensitivity of the proposed structure could be as high as 2321, the threshold voltage sensitivity could reach 0.4, and the subthreshold swing sensitivity could reach 0.7. This shows that the DM-LTFET sensor is suitable for a high-sensitivity, low-power-consumption sensor field.