Sensors (Jan 2020)

A Stacked Back Side-Illuminated Voltage Domain Global Shutter CMOS Image Sensor with a 4.0 μm Multiple Gain Readout Pixel

  • Ken Miyauchi,
  • Kazuya Mori,
  • Toshinori Otaka,
  • Toshiyuki Isozaki,
  • Naoto Yasuda,
  • Alex Tsai,
  • Yusuke Sawai,
  • Hideki Owada,
  • Isao Takayanagi,
  • Junichi Nakamura

DOI
https://doi.org/10.3390/s20020486
Journal volume & issue
Vol. 20, no. 2
p. 486

Abstract

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A backside-illuminated complementary metal-oxide-semiconductor (CMOS) image sensor with 4.0 μm voltage domain global shutter (GS) pixels has been fabricated in a 45 nm/65 nm stacked CMOS process as a proof-of-concept vehicle. The pixel components for the photon-to-voltage conversion are formed on the top substrate (the first layer). Each voltage signal from the first layer pixel is stored in the sample-and-hold capacitors on the bottom substrate (the second layer) via micro-bump interconnection to achieve a voltage domain GS function. The two sets of voltage domain storage capacitor per pixel enable a multiple gain readout to realize single exposure high dynamic range (SEHDR) in the GS operation. As a result, an 80dB SEHDR GS operation without rolling shutter distortions and motion artifacts has been achieved. Additionally, less than −140dB parasitic light sensitivity, small noise floor, high sensitivity and good angular response have been achieved.

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