Front side electrical contact for photodetector array and method of making same

US7601556B2 · kind B2 · utility

Assignee

• IceMos Technology Limited · GB

Inventors

• Robin Wilson · Holywood, GB
• Conor Brogan · Belfast, GB
• Hugh J. Griffin · Newtownabbey, GB
• Cormac MacNamara · Belfast, GB

Key dates

• Filing date: May 7, 2008
• Grant date: Oct 13, 2009
• Expiry date: May 7, 2028

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/548

Abstract

A photodiode includes a semiconductor having front and backside surfaces and first and second active layers of opposite conductivity, separated by an intrinsic layer. A plurality of isolation trenches filled with conductive material extend into the first active layer, dividing the photodiode into a plurality of cells and forming a central trench region in electrical communication with the first active layer beneath each of the cells. Sidewall active diffusion regions extend the trench depth along each sidewall and are formed by doping at least a portion of the sidewalls with a dopant of first conductivity. A first contact electrically communicates with the first active layer beneath each of the cells via the central trench region. A plurality of second contacts each electrically communicate with the second active layer of one of the plurality of cells. The first and second contacts are formed on the front surface of the photodiode.