Patent ID: 9024240
Filing Date: 2015-05-05
Classification: H01L

Abstract:
1. An image sensor comprising: a plurality of pixel zones formed in a substrate; a plurality of isolation trenches delimiting the pixel zones and separating the pixel zones from each other; a plurality of photodiodes respectively positioned in the pixel zones; a plurality of sensing nodes associated with the pixel zones; a plurality of transfer gates respectively associated with said pixel zones, each transfer gate being arranged to transfer charge from said photodiode of the associated pixel zone to one of the sensing nodes; and a read circuit for reading a voltage at the one of the sensing nodes, the read circuit including a plurality of transistors including at least one transistor that is positioned at least partially over a first pixel zone of said plurality of pixel zones, wherein said isolation trenches delimiting said pixel zones are deep trench isolations, wherein said deep trench isolations and said substrate are of equal depth and wherein said at least one transistor has a channel region bounded on at least one side by a shallow trench isolation of less depth than the deep trench isolations, wherein each transfer gate comprises a conductive column formed in an opening in the isolation trench delimiting the pixel zone associated with the transfer gate, wherein the one of the sensing nodes is also formed in said opening, adjacent to said conductive column.