A comment in here, about a colour filter sounds a bit like Foveon.

http://www.physorg.com/news5184.html

IBM announced a CMOS image sensor development and manufacturing
collaboration with Kodak in September, 2004, which included the
license of Kodak CMOS image sensor fabrication intellectual property
to IBM. Kodak this week announced new three- and five-megapixel CMOS
image sensors qualified and manufactured for Kodak by IBM's
semiconductor facility in Burlington, Vermont, that utilize this
process.

IBM's foundry offering is based on IBM's 0.18-micron copper CMOS
manufacturing process, available at its Burlington facility, that
features an integrated design kit, including a 4-transistor, 3-micron
pixel with pinned diode, and access to IBM's image sensor circuit
library.

IBM's CMOS technology delivers image sensors with one of the
industry's best "dark current" performance, or the ability to capture
photos in low-light situations, a key feature for consumer
applications such as camera cell phones.

Image quality can also be improved through IBM's ability to produce
sensors featuring an ultra-thin, 2.5-micron copper stack incorporating
an on-chip color filter and microlens. The copper stack is
approximately 30 percent thinner than standard aluminum-based
processes, which can result in significant improvements in light
collection efficiency (quantum efficiency) for improved picture
quality in low light. In addition, IBM's angle response performance --
important when using lenses with wider apertures -- delivers superior
photo resolution and sharpness.

Currently, IBM is the only foundry supplier producing image sensors
based on 0.18-micron copper process technology. IBM was the first
semiconductor manufacturer to introduce copper technology and foundry
clients can benefit from the company's successful copper production
track record. In addition, IBM offers access to industry-recognized
design kits and a comprehensive circuit library.

"IBM is bringing its extensive copper semiconductor process experience
to bear on the CMOS image sensor market, offering clients what we
believe is the best foundry technology available today," said Tom
Reeves, vice president, semiconductor products for IBM Systems &
Technology Group. "Our innovative technology produces sensors with
excellent color accuracy, low noise and very competitive low-light
performance that can help clients differentiate their products in this
competitive and growing consumer market."

"We are pleased to see Kodak's image sensor technology at the heart of
IBM's new foundry offering," said Chris McNiffe, General Manager of
Kodak's Image Sensor solutions business. "Our collaboration with IBM
has been extremely successful thus far, leveraging our respective
strengths in imaging and semiconductor manufacturing."

Image sensor market growth is shifting from charged coupled devices
(CCDs) to CMOS-based sensors. CCDs have been the predominant
technology used in digital imaging products due to improved picture
quality, but CMOS technology benefits can include low power, high
integration and low production costs compared to CCDs, all important
benefits for consumer applications. IBM's foundry technology roadmap
will enable CMOS-based image sensors that approach the size and
performance of CCD pixels offered today.