Backside-illuminated lateral PIN photodiode for CMOS image sensor on SOS substrate

Author

Xu, Chen ; Shen, Chao ; Wu, Wen ; Chan, Mansun

Author_Institution

Micron Technol. Inc. Imaging Group, Boise, ID, USA

Volume

52

Issue

6

fYear

2005

fDate

6/1/2005 12:00:00 AM

Firstpage

1110

Lastpage

1115

Abstract

In this paper, we propose a method to design charge-sensing elements for CMOS image sensor pixels on a silicon-on-sapphire (SOS) substrate. To address the low quantum efficiency problem due to very thin active film used, a backside illuminated lateral PIN photodiode on an SOS substrate is proposed and developed. It has the advantages of higher photo response with a PIN structure and improved optical transmission with a backside illumination through a transparent sapphire substrate. An active pixel sensor (APS) based on the PIN and backside illumination has been implemented in a commercially available SOS CMOS process. Acceptable sensitivity in optical conversion from the APS can be achieved, even with the ultrathin silicon film. The APS is demonstrated to function at 1.2 V, giving a dynamic range of 51 dB.

Keywords

CMOS image sensors; p-i-n photodiodes; silicon-on-insulator; substrates; 1.2 V; CMOS image sensor; SOS substrate; Si; active film; active pixel sensor; backside-illuminated PIN photodiode; charge-sensing elements; improved optical transmission; lateral PIN photodiode; optical conversion; photoresponse; quantum efficiency problem; sapphire substrate; silicon-on-sapphire; ultrathin silicon film; CMOS image sensors; CMOS process; Design methodology; Lighting; Optical films; Optical sensors; PIN photodiodes; Pixel; Silicon; Substrates; Active pixel sensor (APS); backside illuminated; lateral PIN photodiode; quantum efficiency; silicon-on-sapphire (SOS);

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2005.848106

Filename

1433103