Closed-form and explicit analytical model for crosstalk in CMOS photodiodes

A closed-form and explicit 2D analytical model for crosstalk (CTK) effects in p-n+ CMOS photodiodes for pixel design optimization has been developed in this work. This model complements and extends a previous development describing the photocurrent due to the active area illumination along with the lateral depletion region and lateral components owing to the diffused photocarriers from the surroundings of the junction. The model has very few fitting parameters since it is physically-based. In this way, it can be of great use for CMOS image sensors designers, especially to fulfill high resolution and small area requirements by pixel size reduction. The model was validated extensively through device simulations with ATLAS and experimental data, and describes the CTK dependencies on light conditions and physical, geometrical and process parameters.

keywords: CMOS photodiodes, crosstalk, modeling, simulation