Sensors (Apr 2022)

Two High-Precision Proximity Capacitance CMOS Image Sensors with Large Format and High Resolution

  • Yuki Sugama,
  • Yoshiaki Watanabe,
  • Rihito Kuroda,
  • Masahiro Yamamoto,
  • Tetsuya Goto,
  • Toshiro Yasuda,
  • Hiroshi Hamori,
  • Naoya Kuriyama,
  • Shigetoshi Sugawa

DOI
https://doi.org/10.3390/s22072770
Journal volume & issue
Vol. 22, no. 7
p. 2770

Abstract

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This paper presents newly developed two high-precision CMOS proximity capacitance image sensors: Chip A with 12 μm pitch pixels with a large detection area of 1.68 cm2; Chip B with 2.8 μm pitch 1.8 M pixels for a higher resolution. Both fabricated chips achieved a capacitance detection precision of less than 100 zF (10−19 F) at an input voltage of 20 V and less than 10 zF (10−20 F) at 300 V due to the noise cancelling technique. Furthermore, by using multiple input pulse amplitudes, a capacitance detection dynamic range of up to 123 dB was achieved. The spatial resolution improvement was confirmed by the experimentally obtained modulation transfer function for Chip B with various line and space pattens. The examples of capacitance imaging using the fabricated chips were also demonstrated.

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