Texas Instruments Corporation

Charles E Stanford

James F Belcher

Robert A Owen

Steven N Frank

Robert J Kyle

This is a system and method of forming an electrical contact to the optical coating of an infrared detector. The method may comprise: forming thermal isolation trenches 22 and contact vias 23 in a substrate 20; depositing a bias contact metal 32 into the vias 23 forming biasing contact areas around a periphery of the substrate 20; depositing a first trench filler 24 in the trenches 22 and vias 23; replanarizing; depositing a common electrode layer 25 over the thermal isolation trenches and the biasing contact areas; mechanically thinning the substrate 20 to expose the biasing contact area 32 and the trench filler 24; depositing a contact metal 34 on the backside of the substrate 20, the exposed trench filler 24 and the exposed bias contact area; and etching the contact metal 34 and the trench filler 24 to form pixel mesas of the contact metal 34 and the substrate 20. The thermal isolation trenches 22 and the bias contact vias 23 may be formed by ion milling or laser vaporization. Alternately, the bias contact areas 23 may be formed by performing laser vaporization on the substrate 20 to produce conductive 23 areas within the substrate.

Method for forming electrical contact to the optical coating of an

This is a system and method of forming an electrical contact to the optical coating of an infrared detector. The method may comprise: forming thermal isolation trenches 22 in a substrate 20; depositing a trench filler 24 in the thermal isolation trenches 22; depositing a common electrode layer 31 over the thermal isolation trenches 22; depositing an optical coating 26 above the common electrode layer 31; mechanically thinning the substrate to expose the trench filler 24; etching to remove the trench filler 24 in the bias contact area; depositing a contact metal 34 on the backside of the substrate 20, wherein the contact metal 34 connects to the common electrode layer 31 at bias contact areas 34 around a periphery of the thermal isolation trenches; and etching the contact metal 34 and the trench filler 24 to form pixel mesas of the contact metal 34 and the substrate 20. Bias contact vias 23 may be formed in the bias contact areas and then filled with bias contact metal 49. Alternately, the bias contact vias may also be filled with the contact metal 34. The thermal isolation trenches may be formed by laser vaporization, ion milling or other equivalent methods. In addition, an elevation layer may be formed between the optical coating and the substrate to provide greater tolerances for ion milling. The elevation layer may be filled with a trench filler and then removed after milling. Alternately, the elevation layer may be filled with a metal 49 to connect the bias contact metal to the common electrode in the bias contact areas.

Infrared sensing device

This is a system and method of forming an electrical contact to the optical coating of an infrared detector using conductive epoxy. The method may comprise: forming thermal isolation trenches 22 and bias contact vias 23 in a substrate 20; depositing a trench filler 24 in the thermal isolation trenches 22; depositing conductive epoxy 50 into the bias contact vias 23; replanarizing; depositing a common electrode layer 31 over the thermal isolation trenches 22 and vias 23; depositing an optical coating 26 above the common electrode layer 31; mechanically polishing a backside of the substrate 20 to expose the trench filler 24 and conductive epoxy 50; depositing a contact metal 34 on the backside of the substrate 20; etching the contact metal 34 and the trench filler 24 to form pixel mesas of the contact metal 34 and the substrate 20.

A system for infrared sensing has thermally sensitive picture elements within a substrate; bias contact areas within the substrate and around a periphery of the thermally sensitive picture elements; a common electrode on a front side of the thermally sensitive picture elements and the bias contact areas; an optical coating on top of the common electrode; a first electrical contact metal on a backside of the thermally sensitive picture elements; and a second electrical contact metal connected to the bias contact areas on a backside of the bias contact areas and electrically connected to the common electrode. The bias contact areas may include a conductive substrate area. In addition, the device may be connected to an integrated circuit by an ohmic connection to the first and/or the second electrical contact metal.

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Plano, TX, United States of America

Charles E Stanford