OmniVision’s R&D team has continued to refine its novel silicon semiconductor architectures and processes to achieve new records in quantum efficiency (QE). Nyxel 2 can now achieve 50% QE at 940nm and 70% QE at the 850nm NIR wavelength, providing a 25% improvement in the invisible 940nm NIR light spectrum and a 17% bump at the barely visible 850nm NIR wavelength. These sensitivity improvements enable image sensors to see even better and farther under the same amount of light, further extending the image detection range. Nyxel 2-based camera systems also require fewer LED lights, thus reducing overall power consumption and extending battery life. These added benefits make Nyxel 2 an ideal technology for surveillance systems, automotive in-cabin driving monitoring systems and the burgeoning under-display sensors in mobile devices.
Competing CMOS approaches for NIR image sensing continue to rely solely on thick silicon to improve NIR sensitivity. However, this results in cross-talk 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. With Nyxel 2, OmniVision has further refined its approach to NIR imaging that combines thick-silicon pixel architectures with careful management of wafer surface texture to improve QE, along with extended DTI to retain the MTF levels of the first generation without affecting the sensor’s dark current.
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