Smart Sensor Systems: Emerging Technologies and Applications

Chapter 7CMOS Image Sensors

Albert Theuwissen

Electronic Instrumentation Laboratory, Harvest Imaging, Bree, Belgium and Delft University of Technology, Delft, The Netherlands

Over the last decade, CMOS image-sensor technology made huge progress. Not only was the imagers' performance drastically improved, but also their commercial success boomed after the introduction of mobile phones with an on-board camera. Many scientists and marketing specialists predicted 15 years ago that CMOS image sensors were going to completely take over from CCD imagers, in the same way as CCD imagers did in the mid 1980s when they took over the imaging business from tubes [1].

Although CMOS has a strong position in imaging today, it did not rule out the business of CCDs. On the other hand, the CMOS-push drastically increased the overall imaging market due to the fact that CMOS image sensors created new applications areas and they boosted the performance of CCD imagers as well.

This chapter describes the state-of-the-art of CMOS image sensors.

7.1 Impact of CMOS Scaling on Image Sensors

It is common knowledge that the scaling effects in CMOS technology allow the semiconductor industry to make smaller devices. This rule holds for CMOS imaging applications as well.

Figure 7.1 gives an overview of CMOS imager data published at IEDM and ISSCC of the last 15 years [2]. The bottom curve illustrates the CMOS scaling effects over the years, as described by the ITRS roadmap [3]. The second curve shows the ...