Image sensor for mitigating dark current

Patent metadata

Field	Value
Publication number	US-9147702-B2
Application number	US-201313769421-A
Country	US
Kind code	B2
Filing date	Feb 18, 2013
Priority date	Feb 18, 2013
Publication date	Sep 29, 2015
Grant date	Sep 29, 2015

Abstract

One or more embodiments of techniques or systems for mitigating dark current of an image sensor are provided herein. Generally, a silicon interface, such as an edge of a dielectric region or an edge between a back side interface (BSI) region and a pass region, is a source of electrons or holes which cause dark current. In some embodiments, the image sensor includes a surface protect region. For example, the surface protect region is doped with a first doping type and a photo-diode of the image sensor is doped with the same first doping type. In this manner, the surface protect region acts as an electron magnet or a hole magnet for electrons or holes from the silicon interface, thus mitigating electrons or holes from the silicon interface from being collected by the photo-diode, for example.

First claim

What is claimed is:

1. An image sensor for mitigating dark current, comprising:
a first region comprising a first doping type;
a second region comprising a second doping type, the second doping type opposite of the first doping type, the first region surrounded by the second region;
a first surface protect region above the second region and comprising the first doping type;
a first silicon interface comprising an edge between the first surface protect region and a dielectric…

Assignees

• Taiwan Semiconductor Mfg

Inventors

• Hung Feng-Chi
• Yaung Dun-Nian
• Liu Jen-Cheng
• Tsai Shu-Ting
• Tsai Shuang-Ji

Classifications

• H10F39/8037

  Electricity · mapped topic

• H10F39/18

  Electricity · mapped topic

• H10F39/014

  Electricity · mapped topic

• H10F39/8033

  Electricity · mapped topic

• H10F39/80 Primary

  Electricity · mapped topic