Image sensor pixel cell with switched deep trench isolation structure

US9496304B2 · 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
• Dyson H. Tai · San Jose, US

Key dates

• Filing date: May 5, 2015
• Grant date: Nov 15, 2016
• Expiry date: May 5, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/8037

Abstract

A pixel cell includes a photodiode disposed in an epitaxial layer in a first region of semiconductor material to accumulate image charge. A floating diffusion is disposed in a well region disposed in the epitaxial layer in the first region. A transfer transistor is coupled to selectively transfer the image charge from the photodiode to the floating diffusion. A deep trench isolation (DTI) structure disposed in the semiconductor material. The DTI structure isolates the first region of the semiconductor material on one side of the DTI structure from a second region of the semiconductor material on an other side of the DTI structure. The DTI structure includes a doped semiconductor material disposed inside the DTI structure that 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.