Thin-film encapsulated infrared sensor

US9064982B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Fabian Purkl · Gerlingen, DE
• Gary Yama · Mountain View, US
• Ando Feyh · Palo Alto, US
• Andrew Graham · Redwood City, US
• Ashwin Samarao · Sunnyvale, US
• Gary O'Brien · Palo Alto, US

Key dates

• Filing date: Dec 17, 2013
• Grant date: Jun 23, 2015
• Expiry date: Dec 17, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F71/00
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method of fabricating a bolometer infrared sensor includes depositing a first sacrificial layer on a surface of a substrate over a sensor region, and forming an absorber structure for the infrared sensor on top of the first sacrificial layer. A second sacrificial layer is deposited on top of the absorber structure. An encapsulating thin film is then deposited on top of the second sacrificial layer. Vent holes are formed in the encapsulating thin film. The first and the second sacrificial layers are removed below the encapsulating thin film to release the absorber structure and form a cavity above the sensing region that extends down to the substrate in which the absorber structure is located via the vent holes. The vent holes are then closed in a vacuum environment to seal the absorber structure within the cavity.