I am using TSMC 180 to design a CMOS imager. I wonder if I need to manually add a passivation opening to let light to shine on my photodiode. Thanks a lot.
Depends on wavelength of interest; anything blue or longer
ought to not be bothered by nitride or oxide passivation layers.
Metal shadowing is a big concern in unit cell design.
There are some backside illuminated imager technologies,
like the ON Semi "star tracker" 110nm flow (Gresham
foundry), which eliminate this as a concern altogether
(but what concerns may roll on, I do not know).
Thanks for reply. It's a single color imager only sensing the light intensity, so I guess blue and longer wavelength is fine for me, which mean no special maneuver is needed right?