Image sensor pixel cell with switched deep trench isolation structure

US9054007B2 · kind B2 · utility

Assignee

• OmniVision Technologies, Inc. · US

Inventors

• Sing-Chung Hu · San Jose, US
• Rongsheng Yang · Boise, US
• Gang Chen · San Jose, US
• Howard E. Rhodes · Boise, US
• Sohei Manabe · San Jose, US
• Hsin-Chih Tai · San Jose, US

Key dates

• Filing date: Aug 15, 2013
• Grant date: Jun 9, 2015
• Expiry date: Nov 23, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/807

Abstract

A pixel cell includes a photodiode disposed in an epitaxial layer in a first region of semiconductor material. A floating diffusion is disposed in a well region disposed in the epitaxial layer in the first region. A transfer transistor is disposed in the first region and coupled between the photodiode and the floating diffusion to selectively transfer image charge from the photodiode to the floating diffusion. A deep trench isolation (DTI) structure lined with a dielectric layer inside the DTI structure is disposed in the semiconductor material isolates the first region on one side of the DTI structure from a second region of the semiconductor material on an other side of the DTI structure. Doped semiconductor material inside the DTI structure is selectively coupled to a readout pulse voltage in response to the transfer transistor selectively transferring the image charge from the photodiode to the floating diffusion.