Recent innovations in CMOS image sensors

The trend in semiconductor manufacturing over the last decade has been an accelerated rate for both materials integration and wafer fabrication process development. While the cutting edge of semiconductor technology is driven by digital logic and memory applications, several other technology sectors benefit from innovation by the leaders. Of these technology sectors, image sensor manufacturers have realized many benefits from the selective use of developments within advanced technology node manufacturing. The motivations for the imaging industry to pursue Moore´s Law type of scaling are comparable to that of the broader semiconductor industry. Additionally, image sensor companies seek a reduction of camera module form factor, an increase in pixel resolution, and an increase in pixel array performance. Today, semi-professional grade digital single-lens reflex (DSLR) pixels have scaled down to the size of what were state-of-the-art “small pixel” consumer grade camera phone sensors just a few years ago. The pixel size of recent camera phones has shrunk to 1.12 μm. The resolution for recent camera phones has reached 16.4 Mp. Beyond silicon foundry processes, imaging companies must also concern themselves with the optical systems and packaging solutions required to integrate their silicon devices with the consumer electronics supply chain. Chipworks, as a supplier of competitive intelligence to the semiconductor and electronics industries, monitors the evolution of image sensor technologies as they come into production. Chipworks has obtained charge-coupled devices (CCD) and CMOS image sensor (CIS) chips from leading manufacturers and performed structural, compositional, and design analyses to benchmark the technology of the market leaders.