Models for the use of commercial TCAD in the analysis of silicon-based integrated biosensors

•We extend commercial TCAD for semiconductors to simulate electronic biosensors.•Screening at high electrolyte concentration strongly reduces their DC sensitivity.•We analyze the relevance of steric and polarization effects in nano-electrodes sensors.

We present a simple approach to describe electrolytes in TCAD simulators for the modeling of nano-biosensors. The method exploits the similarity between the transport equations for electrons and holes in semiconductors and the ones for charged ions in a solution. We describe a few workarounds to improve the model accuracy in spite of the limitations of commercial TCAD. Applications to the simulations of silicon nanowire and nano-electrode biosensors are reported as relevant examples.