The value of the world image sensors market is expected to rise to $11.7 billion by 2012, according to a report from Global Industry Analysts Inc. of San Jose, Calif. Titled “Image Sensors: A Global Strategic Business Report,” it concludes that the market is dominated by Japan, the US and the Asia-Pacific region, which collectively held an estimated 79.5 percent share in 2008. It predicts that the market will reach a value of $695 million in Japan by 2012, and that it could experience a compound annual growth rate of more than 10 percent from 2011 through 2015 in the Asia-Pacific region and Latin America. The report analyzes the specific product segments of complementary metal oxide semiconductor (CMOS) and charge-coupled device (CCD) image sensors. It maintains that the CMOS market could experience double-digit growth rates, with global sales rising by $4.3 billion between 2008 and 2012. CMOS sensors are expected to find expansive market opportunities in the video-enabled cell-phone end-use market and in other consumer electronics and mobile applications.Demand for CCD image sensors is predicted to decline, and the market value for this segment is projected to fall by $369.9 million between 2008 and 2012. Japan and the Asia-Pacific region are expected to see the sharpest fall in sales during this period.However, technological advances will help strengthen their position in high-end industrial, medical and scientific imaging applications. CCD sensors will continue to play a significant role in medical, scientific and industrial cameras; x-ray crystallography, for example, requires large-pixel devices with high dynamic range that only CCD sensors can provide.An expanding marketOverall, image sensors have expanding applications in consumer electronics, such as camcorders, security and computer cameras and portable communications devices, and in the industrial and business sector, in areas such as biometrics, machine vision, broadcasting, film cameras and medicine. Developments in digital imaging and high-sensitivity image sensor technologies are expected to contribute to market growth, especially in developing countries. In the automotive industry, there is increased demand for angular rate, occupancy seat and cruise control sensors, lane deviation systems and rear-view cameras.Shown is a comparison of traditional front-side illumination (FSI) and OmniVision Technologies’ OmniBSI back-side illumination (BSI) pixel architectures for image sensors. The latter involves turning the image sensor upside down and applying the color filters and microlenses to the back side of the pixels so that the sensor can collect light through it. This approach effectively reverses the arrangement of layers so that metal and dielectric layers reside below the sensor array, providing the most direct path for light to travel into the pixel. Courtesy of OmniVision Technologies Inc.Bruce Weyer, vice president of marketing at OmniVision Technologies Inc. in Santa Clara, Calif., noted that, although the company sells only CMOS image sensors, its representatives agree with the assessment of industry analysts that the CCD market will continue to decline, particularly in the areas in which it has been traditionally strong – security, surveillance and digital still cameras – along with the automotive industry, which also is using CMOS devices predominantly. He added that CCDs will continue to be used in higher-end digital (single-lens reflex) cameras and camcorders as well as in other high-performance applications where size and system cost are less important; for example, in the military and aerospace sectors. Weyer said that CMOS sensors have reached performance levels equal to or higher than those of CCD sensors, while offering additional benefits such as on-chip image processing, further miniaturization, lower system device count and cost. Their pixel architectures have evolved to the point where they are now comparable to those of CCD image sensors, he said, adding that CMOS sensors are showing huge growth potential in automotive and medical applications as well as in integrated notebook cameras.A key driverThe mobile phone market has been one of the key drivers for the explosive growth and rapid development of CMOS image sensors, Weyer said. Consumer demand for quality cameras in cell phones has fueled the growth of the market, resulting in better and smaller cameras at ever-lower cost levels. The cost-effectiveness of lower-end resolution devices is enabling handset manufacturers to incorporate cameras in all phones, even the low-end models, he added. This trend is expected to keep driving the growth of the CMOS sensor markets, particularly in new growth markets such as Latin America, India, Russia and China.The continued miniaturization and pixel performance race has come up against some scientific hurdles. At the 1.4-μm pixel node, the laws of physics are hindering further shrinkage of the pixel in its current state, Weyer said. He noted that OmniVision has developed a pixel architecture using backside illumination technology, or OmniBSI technology, that will allow image sensors to shrink down to 0.9 μm or smaller. Optimizing light absorption, the approach enables the company to build a 1.4-μm backside illumination pixel that surpasses the performance metrics of 1.4-μm or even 1.75-μm front-side illumination pixels. With innovations such as OmniBSI, CMOS image sensors are beginning to offer lower light sensitivity and higher image quality and levels of integration in comparison with their CCD technology counterparts, Weyer said. CMOS-based camera systems also typically use just one-tenth the power of CCD devices – a critical differentiator in the power-sensitive wireless devices market, he added.