Transient Simulation of Field-Effect Biosensors : How to Avoid Charge Screening Effect

Abstract

We developed a numerical simulator to model the operation of a bio-FET in transient state. The simulator takes a realistic device structure as a simulation domain, and it employs the drift-diffusion equation for ion / channel transport, and the Ramo-Shockley theorem for accurate calculation of nonfaradaic current. For efficient transient simulation, the implicit time integration scheme is employed where the solution at each time step is obtained from the coupled Nevvton-Raphson method. Using the simulator, we found that the sensitivity of bio-FET can be improved with transient measurement by redistribution of the mobile ions by an external electric field.