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.