I was given TowerJazz presentation at Image Sensor Europe in March 2010 titled:
Foundry business for CMOS Image Sensors
Dr. Avi Strum, VP & GM Specialty BU
Below are few slides from the presentation talking about the company's approach and technology achievements:
A slide showing stitching quality for large sensors:
BSI becomes an option for TowerJazz customers:
Lightpipe is another available option:
All in all, it seems that access to a lot of advanced technologies is now available to the smaller players on the image sensor market.