Electronic shutter with photogenerated charge extinguishment capability for back-illuminated image sensors

US8536625B2 · kind B2 · utility

Assignee

• Massachusetts Institute of Technology · US

Inventor

• Barry E. Burke · Spring, US

Key dates

• Filing date: Sep 9, 2010
• Grant date: Sep 17, 2013
• Expiry date: Jun 18, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/156

Abstract

An electronic image sensor includes a semiconductor substrate having a first surface configured for accepting illumination to a pixel array disposed in the substrate. An electrically-doped channel region for each pixel is disposed at a second substrate surface opposite the first substrate surface. The channel regions are for collecting photogenerated charge in the substrate. An electrically-doped channel stop region is at the second substrate surface between each channel region. An electrically-doped shutter buried layer, disposed in the substrate at a depth from the second substrate surface that is greater than that of the pixel channel regions, extends across the pixel array. An electrically-doped photogenerated-charge-extinguishment layer, at the first substrate surface, extends across the pixel array. A substrate bulk region between the shutter buried layer and the photogenerated-charge-extinguishment layer is characterized by an electrical resistivity enabling independent electrical bias of the photogenerated-charge-extinguishment layer from electrically-doped regions of the substrate.