Sensitivity Controllable CMOS Image Sensor Pixel Using Control Gate Overlaid on Photodiode

Author

Chae, Youngcheol ; Choe, Kunil ; Kim, Bokyung ; Han, Gunhee

Author_Institution

Yonsei Univ., Seoul

Volume

28

Issue

6

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

495

Lastpage

498

Abstract

A new sensitivity controllable pixel structure is proposed for CMOS active-pixel image sensor. The proposed pixel structure has a sensitivity control gate overlaid on the photodiode. The sensitivity of the pixel is controlled by the bias voltage of the control gate that forms a variable accumulation-mode MOS capacitor. The prototype sensor is fabricated with a 0.35-mum CMOS process and consists of 60 times 240 pixels with 5.6-mum pixel pitch. Measurement results show that the sensitivity of the photodiode can be controlled by a factor of 4.

Keywords

CMOS image sensors; MOS capacitors; photodiodes; sensitivity; CMOS active-pixel image sensor; accumulation-mode MOS capacitor; control gate; photodiode; sensitivity controllable CMOS image sensor pixel; sensitivity controllable pixel structure; size 0.35 mum; CMOS image sensors; CMOS process; Capacitance; Charge coupled devices; Image sensors; MOS capacitors; Photodiodes; Signal processing; Smart pixels; Voltage control; Accumulation-mode MOS capacitor; CMOSactive-pixel image sensor; control gate; photodiode; sensitivitycontrollable pixel;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2007.897459

Filename

4212166