TCAD-ASSISTED TECHNIQUE FOR DETERMINING THE PARAMETERS OF
MICROLENSES USED IN PHOTOSENSITIVE CCD VLSI
In this paper we introduce the simulation technique for photosensitive cell with CCD VLSI microlens with interline transfer. A microlens enhances the photosensitivity of the cell and reduces image blur. The technique is based on the calculation and comparison of the volumetric photogeneration rate integrals of different areas of the photocell, where generated charge carriers are collected and transferred. This technique does not require simulation of the full frame accumulation cycle of the cell, significantly reducing the time of simulation and enabling the evaluation of many design options for microlenses. The technique is implemented in the Sentaurus TCAD (by Synopsys). In the paper we present the results of simulation made for cells with various microlenses. The proposed technique can also be used for the optimization of microlenses of CMOS photodiode VLSI photocells.