WORKSHOP PAPER
A Twisted Charge Transfer Structure for All-directional Autofocus CMOS Image Sensor
Daiki Shirahige1,2, Koichi Fukuda3, Hajime Ikeda1, Yusuke Onuki1, Ginjiro Toyoguchi1, Kohei Okamoto3, Shunichi Wakashima3, Hiroshi Sekine1, Shuhei Hayashi1, Ryo Yoshida1, Junji Iwata1, Yasushi Matsuno1, Katsuhito Sakurai1, Hiroshi Yuzurihara1, Takeshi Ichikawa1
1Device Technology Development Headquarters, Canon Inc., Kanagawa, Japan
2Graduate School of Engineering, Tohoku University, Sendai, Japan
3Imaging Business Operations, Canon Inc., Tokyo, Japan

Abstract

We propose a CMOS image sensor with twisted photodiode (PD) for all-directional autofocus (AF) to achieve high speed and high precision AF. The newly developed 3D-stacked back side illuminated (BSI) sensor features a twisted PD that enables vertical phase detection, achieving AF for all pixels and in all directions. In this paper, we introduce the structure of the twisted PD, which enables all-directional AF, and describe the results of our investigation on charge transport in this structure.
Year: 2025
Workshop: IISW
URL: https://doi.org/10.60928/vr4q-4zbq
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Keywords

CMOS image sensor, autofocus, charge transfer, twisted photodiode, phase detection,

References

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