| US 7,601,556 B2 | ||
| Front side electrical contact for photodetector array and method of making same | ||
| Robin Wilson, Belfast (United Kingdom); Conor Brogan, Belfast (United Kingdom); Hugh J. Griffin, Newtownabbery (United Kingdom); and Cormac MacNamara, Belfast (United Kingdom) | ||
| Assigned to Icemos Technology Ltd., Belfast, Northern Ireland (United Kingdom) | ||
| Filed on May 07, 2008, as Appl. No. 12/116,638. | ||
| Application 12/116638 is a division of application No. 11/681543, filed on Mar. 02, 2007, granted, now 7,489,014. | ||
| Claims priority of provisional application 60/778481, filed on Mar. 02, 2006. | ||
| Prior Publication US 2008/0248608 A1, Oct. 09, 2008 | ||
| Int. Cl. H01L 21/00 (2006.01) | ||
| U.S. Cl. 438—57 [257/E27.129] | 8 Claims |
| 1. A method of manufacturing a photodiode, the method comprising:
providing a semiconductor having a front surface and a backside surface and including:
a first active layer having a first conductivity,
a second active layer having a second conductivity opposite the first conductivity, and
an intrinsic layer separating the first and second active layers;
forming a plurality of isolation trenches having a depth extending through the second active layer and the intrinsic layer
into the first active layer, the isolation trenches being arranged to divide the photodiode into a plurality of cells, and
the isolation trenches being arranged to form a central trench region in electrical communication with the first active layer
beneath each of the plurality of cells;
doping at least a portion of sidewalls of the isolation trenches with a dopant of the first conductivity to form a sidewall
active diffusion region extending the isolation trench depth along each isolation trench sidewall;
filling the isolation trenches with a conductive material;
forming a first electrical contact in electrical communication with the first active layer beneath each of the plurality of
cells via the central trench region; and
forming a plurality of second electrical contacts each in electrical communication with the second active layer of one of
the plurality of cells, the first electrical contact and the plurality of second electrical contacts being formed on the front
surface of the photodiode.
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