A new physically based circuit simulation model for finger photodiodes has been proposed. The approach is based on the solution of transport and continuity equation for generated carriers within the two-dimensional structure. As an example we present results of a diode consisting of N+-fingers located in a P-well on top of a N-type buried layer integrated in a P-type silicon substrate (N+/PW/ NBL/Psub finger photodiode). The model is capable to predict the sensitivity of the diode in a wide spectral range very accurately. The structure under consideration was fabricated in an industrial 0.6 mu m BiCMOS process. The good agreement of simulated sensitivity data with results of measurements and numerical simulations demonstrate the high quality of our model. (c) 2007 Elsevier Ltd. All rights reserved.