New signal readout method for ultrahigh-sensitivity CMOS image sensor

Author

Watabe, Toshihisa ; Goto, Masahide ; Ohtake, Hiroshi ; Maruyama, Hirotaka ; Abe, Masahide ; Tanioka, Kenkichi ; Egami, Norifumi

Author_Institution

NHK Sci. & Tech. Res. Labs., Tokyo, Japan

Volume

50

Issue

1

fYear

2003

fDate

1/1/2003 12:00:00 AM

Firstpage

63

Lastpage

69

Abstract

We propose a new signal readout method that uses a charge-transfer circuit. Its application is to an ultrahigh-sensitivity CMOS image sensor on which an avalanche-mode photoconductive film is overlaid. The charge-transfer circuit makes it possible to obtain high signal-to-noise ratio features by transferring signal charges accumulated in each photodiode to a parasitic capacitance that is small compared with the photodiode capacitance. A 138 × 138 passive-pixel prototype sensor that had the charge-transfer circuit in each column was fabricated and tested. The prototype´s column-to-column fixed-pattern noise and random noise were, respectively, 56.7 and 58.4 dB below the saturation signal level, which demonstrated its potential as a signal readout circuit for a next-generation ultrahigh-sensitivity CMOS image sensor.

Keywords

CMOS image sensors; capacitance; integrated circuit noise; photodiodes; readout electronics; sensitivity; 138 pixel; 19044 pixel; CMOS image sensor; avalanche-mode photoconductive film; charge-transfer circuit; column-to-column fixed-pattern noise; high SNR features; parasitic capacitance; photodiode capacitance; random noise; signal readout method; signal-to-noise ratio; solid-state HARP image sensor; ultrahigh-sensitivity image sensor; CMOS image sensors; Circuit noise; FETs; Image sensors; Photoconductivity; Photodiodes; Prototypes; Sensor phenomena and characterization; Signal to noise ratio; Solid state circuits;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2002.806472

Filename

1185164