Toward Designing Back-Illuminated Cmos Image Sensor Based On 3d Modeling

Three-dimensional (3D) modeling is reported for CMOS active pixel image sensors particularly by comparing front-surface and back-surface illumination. The opto-electronic responses are presented versus various power intensity and illumination wavelength. The optical efficiency and quantum efficiency from FDTD modeling are also presented. For appropriately designed sensor structure, it is shown that back-surface illumination pixel could achieve improved sensitivity within certain wavelength range. The presented results demonstrate a methodological and technical capability for 3D modeling optimization of complex CMOS image sensor.