CMOS image sensors serve as the “eyes” of machines in sensing applications for automotive and machine vision fields, and the demand for their further high performance continues to grow.
Research team led by Graduate student Kohei Takizawa (Graduate School of Engineering), Professor Masato Kuroda (NICHe / Graduate School of Engineering) et.al., have developed a horizontal overflow storage capacitor (LOFIC) that accumulates overflowing photocurrent from a photodiode (PD) during the exposure period. have developed a horizontal overflow storage capacitor (LOFIC) that accumulates excess photoelectric charges overflowing from the photodiode (PD) during the exposure period. By implementing two stages of LOFIC per pixel, they expanded the dynamic range and achieved a light-adaptive signal selection function that reads out the appropriate signal according to the light intensity. Furthermore, by applying 3D stacking technology to the image sensor chip, they achieved an unprecedented saturation electron count per unit area (276.8 ke-/μm²). Saturation electron count is an indicator linked to wide dynamic range and high signal-to-noise ratio (SNR). Using these technologies, they developed a CMOS image sensor with a dynamic range of 120dB.
This achievement is expected to contribute to the high performance, miniaturization, and low power consumption of CMOS image sensors.
Details of the development technology were announced on December 10, 2025, at the International Electron Devices Meeting (IEDM2025), an international conference held in San Francisco, USA.
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