OmniVision Technologies, Inc., a leading developer of advanced digital imaging solutions, today introduced Nyxel™, a revolutionary near-infrared (NIR) technology that leverages novel silicon semiconductor architectures and processes to tackle challenges that plague existing approaches to NIR detection in image sensors. The result is an increase in quantum efficiency (QE), of up to 3x at 850nm and 5x at 940nm, when compared with our legacy NIR-capable sensors. These improvements in NIR sensitivity enable the image sensor to see better and farther under the same amount of light, extending the image detection range. Conversely, to match the performance of existing systems, Nyxel technology-based camera systems require fewer LED lights, thus reducing overall power consumption. Due to these benefits, Nyxel technology is well-suited for a wide variety of applications, including: surveillance, machine-vision, and automotive applications.
Today’s machine- and night-vision camera applications rely on NIR technology because NIR light illuminates objects outside of the visible light spectrum, avoiding any interference with the surrounding environment. Additionally, because the night sky contains more NIR photons than visible photons, NIR technology allows for higher-resolution image capture with fewer power-hungry LEDs, making it an ideal solution for night-vision and battery-powered security camera applications. Prior approaches to NIR detection, however, have fallen short of the higher-performance requirements of next-generation mobile and AR/VR products with embedded machine-vision applications, and automotive and security camera applications that require higher NIR sensitivity. Nyxel technology delivers the performance advancements over existing NIR technology to address the more stringent requirements of these next-generation applications.
“Conventional approaches to NIR rely solely on thick silicon to improve NIR image-sensor sensitivity. However, this results in crosstalk and reduces the modulation transfer function (MTF). Attempts to overcome this by introducing deep trench isolation (DTI) often lead to defects that corrupt the dark area of the image,” explained Lindsay Grant, vice president of process engineering at OmniVision. “We have worked to overcome these challenges in an exclusive engagement with our foundry partner, leveraging technologies in its 300mm wafer fab. Initial results are very promising, and have generated a great deal of interest with our OEM customers.”
OmniVision’s approach to NIR imaging combines thick-silicon pixel architectures with careful management of wafer surface texture to improve QE, and extended DTI to help retain MTF without affecting the sensor’s dark current. The result is a 3x QE improvement for 850nm sensitivity and a 5x QE improvement for 940nm sensitivity when compared with OmniVision’s legacy NIR capabilities, while maintaining all other image-quality metrics. These NIR image-sensitivity improvements deliver unrivaled image quality, extended image-detection range and a reduced light-source requirement, leading to lower power consumption.
