TSMC proposes to use deep trench isolation to reduce crosstalk between BSI pixels. Its patent application US20120025199 covers two cases of deep trench isolation in BSI sensor. One goes through the whole BSI wafer thickness, thus completely isolating pixels one from another:
In the other version the deep trench starts from the backside, but stops before reaching the front surface:
Omnivision patent application US20120019695 proposes a process to create dark sidewalls 445 between color filters to reduce optical crosstalk:
i thought STMicro had already got a patent for the FSI pixel.
ReplyDeletewell, the old photodiode array using MEZA etching can be also considered as isolation trench !
ReplyDeleteIt appears that this e2v patent application deals similarly with optimized crosstalk for the BSI pixel: US2010038740 - 'COLOR IMAGE SENSOR WITH IMPROVED OPTICAL CROSSTALK'
ReplyDelete