Planar thermopile infrared microsensor

US8853632B2 · kind B2 · utility

Assignee

• TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. · TW

Inventors

• Mohamed Boutchich · Auxerre, FR
• Benoit Bataillou · Evergem, BE

Key dates

• Filing date: Sep 7, 2009
• Grant date: Oct 7, 2014
• Expiry date: Dec 24, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J5/0853
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An IR sensor comprises a heat sink substrate (10) having portions (12) of relatively high thermal conductivity and portions (14) of relatively low thermal conductivity and a planar thermocouple layer (16) having a hot junction (18) and a cold junction (20), with the hot junction (18) located on a portion (14) of the heat sink substrate with relatively low thermal conductivity. A low thermal conductivity dielectric layer (22) is provided over the thermocouple layer (16), and has a via (24) leading to the hot junction (18). An IR reflector layer (26) covers the low thermal conductivity dielectric layer (22) and the side walls of the via (24). An IR absorber (30; 30′) is within the via. This structure forms a planar IR microsensor which uses a structured substrate and a dielectric layer to avoid the need for any specific packaging. This design provides a higher sensitivity by providing a focus on the thermocouple, and also gives better immunity to gas conduction and convection.