September 10, 2012 - United Microelectronics Corp. (UMC) and STMicroelectronics say they are collaborating on 65nm CMOS image sensor (CIS) technology using backside illumination (BSI), following completion of a frontside illumination (FSI) process at UMC's 300mm Fab 12i in Singapore.

The 1.1μm pixel 65nm BSI process, also developed at UMC's Fab 12i, will be available through a licensing agreement with ST as an open platform for future smartphone designs that require high resolution and >10MP picture quality. Targeted applications include smartphones, tablets, high-end surveillance, and DSC/DSLR; UMC adds that it expects the technology to see use in automotive and industrial applications "in the coming years."

Backside-illuminated CMOS image sensors (BSI) are an evolution from FSI image-sensor technology. They help manage noise issues seen in FSI, and capture light directly on the silicon light-sensitive layer, giving them higher sensitivity and better picture quality in low-light conditions. BSI CIS are more difficult to fabricate, though, requiring wafer thinning, surface passivation techniques, and careful substrate engineering.

"This agreement is consistent with UMC's open collaboration strategy to deliver customer-driven foundry solutions to address ever evolving market requirements," stated Po-Wen Yen, SVP of 12-inch operations at UMC.

"ST's previous successes in imaging technologies with UMC gives us great confidence in the development of this next-generation image-sensor process technology with UMC," added Eric Aussedat, corporate VP of imaging, Bi-CMOS, ASIC, and silicon photonics group at ST. "Our joint experience will enable ST to offer a state-of-the-art back-side illumination process to support all the applications and markets that we want to address."

UMC also has been working with Singapore’s A*STAR Institute of Microelectronics (IME) touted an expanded collaboration to use through-silicon vias (TSV) for BSI CMOS image sensors, leveraging IME's 300mm TSV line. The foundry also offers CIS for both 200mm and 300mm manufacturing Earlier this year Sony touted its own denser, smaller-formfactor BSI CIS technology.