As the pixel size of CMOS image sensors (CIS) shrink, problems associated with crosstalk become more severe for devices built using mainstream CMOS processing. This high crosstalk increases the amount of noise added to the final image (via an increase of the off-diagonal terms in the color correction matrix (CCM)) and degrades the modulation transfer function (MTF). Reducing dark current has also been challenging for such CIS imagers. At present, the solution to these problems has been to switch to n-type substrates since they have been used for interline charge-coupled devices (CCDs) for decades.
Published in:
Solid-State Circuits Conference, 2008. ISSCC 2008. Digest of Technical Papers. IEEE International
Date of Conference: 3-7 Feb. 2008