November 11, 2011 -- Backside-illuminated CMOS image sensors
(BSI) capture light directly on the silicon light-sensitive
layer. They have a higher sensitivity in a broader spectrum than
the mainstream frontside-illuminated imagers (FSI). And in the
field of high-end and specialty imagers, they have started to
compete with established charged-coupled device (CCD)
technology. BSIs, however, are more difficult to fabricate than
FSIs. They require advanced wafer thinning, surface passivation
techniques to maximize sensitivity, and careful substrate
engineering to minimize crosstalk. Using the possibilities of
BSI technology, imager researchers are also looking at
alternative architectures, producing pixels and readout
electronics as separate dies and stacking those using high-
density microbumps and TSVs. Detecting and capturing light with
image sensors: CCD versus CMOS Silicon is an ideal material to
make image capturing sensors, for use in digital cameras and
other products. It absorbs that part of the electroma