1/4-inch 2-mpixel MOS image sensor with 1.75 transistors/pixel

Author

Mori, Mitsuyoshi ; Katsuno, Motonari ; Kasuga, Shigetaka ; Murata, Takahiko ; Yamaguchi, Takumi

Author_Institution

Semicond. Devices Res. Center, Semicond. Co., Nagaokakyo, Japan

Volume

39

Issue

12

fYear

2004

Firstpage

2426

Lastpage

2430

Abstract

This paper presents new MOS image sensor technologies that realize ultra-small pixel size, i.e., 2.25×2.25 μm², with high sensitivity and low supply voltage. A 1/4-inch 2-Mpixel MOS image sensor has been developed by a new pixel configuration and by a new pixel design with a 0.25-μm CMOS process. In the new pixel configuration, a unit pixel consists of one photodiode (PD), one transfer transistor, and an amplifier circuit with three transistors which are shared by four pixels. As a result, the unit pixel has 1.75 transistors. High sensitivity has been achieved by a high aperture ratio of 25%. In the new pixel design, the low supply voltage of 2.5 V has been realized by optimizing both the potential profile in the PD and the gate length of the transfer transistor.

Keywords

CMOS image sensors; photodiodes; transistors; 0.25 microns; 2.5 V; CMOS; MOS image sensor; amplifier circuit; optical format; photodiode; pixel configuration; pixel design; transfer transistor; ultra-small pixel size; Apertures; CMOS process; CMOS technology; Circuits; Design optimization; Image sensors; Low voltage; MOSFETs; Photodiodes; Pixel; 65; MOS image sensor; optical format; pixel configuration; pixel design; pixel size; sensitivity; supply voltage;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2004.837028

Filename

1362852