The Study and Analysis of Using CMY Color Filter Arrays for 0.8 um CMOS Image Sensors

Digital color cameras detect scenes through color filterarrays (CFAs). In VisEra, we fabricated 0.8 um pixel pitch CIS with both RGB and CMY CFAs, followed by testing and comparing them under various simulated light sources. It is found that, at low light conditions, the SNR of CMY CFA is higher than that of RGB CFA by around 40% as a result of reduced light loss through color filters, which is particularly important for light constraining small pixels. Although, CMY color filters are generally believed to suffer from lower color fidelity than their counterpart RGB filters, VisEra has been working on next generation CMY filters that have a similar color performance to RGB filters under a proper de-mosaic and color correction algorithm. Our efforts toward finding the suitable color filter materials and renovating pixel designs will improve image sensor performance for low light conditions for astrophotography, low photo-toxicity bio-imaging, as well as general photography during dawn and dusk.