Eric Fossum on Omnivision's BSI Announcement

Eric Fossum posted his opinion on Omnivision BSI announcement in dpreview forums:

"While backside illumination has been around a long time for CCDs, and has been investigated for CMOS image sensors, the key aspect of this announcement is that the process has been developed for volume manufacturing for consumer application. This has never been done before and is a major achievement by TSMC in Taiwan - the foundry for Omnivision. The trick is to get the process under such stringent control that the yield is high and the cost is low.

Backside illumination will have benefits at all pixel sizes, but is most important for smaller pixels. Improved QE (SNR) and CRA are two of the main benefits. The high volume of camera phones, and to a less extent, compact DSCs, will make the R&D investment pay off.

I would consider this announcement as REAL and NEAR FUTURE. All major sensor suppliers are working on backside illumination and Omnivision has fired the first salvo in this PR game.

Additional problems remain for pixel size shrinkage (e.g. dynamic range and SNR) and there remain fundamental problems with backside illumination such as instability under UV exposure and bias control, but perhaps Omnivision has made progress on these issues as well."