Infrared sensing device

US5623158A · kind A · utility

Assignee

• TEXAS INSTRUMENTS INCORPORATED · US

Inventors

• Steven N. Frank · McKinney, US
• James F. Belcher · Plano, US
• Charles E. Stanford · Plano, US
• Robert A. Owen · Faringdon, GB
• Robert J. S. Kyle · Battle Creek, US

Key dates

• Filing date: Jun 7, 1995
• Grant date: Apr 22, 1997
• Expiry date: Jun 7, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/977

Abstract

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 elevati…