Patent ID: 9064982
Filing Date: 2015-06-23
Classification: G01J,H01L

Abstract:
1. A method of fabricating a bolometer infrared sensor, the method comprising: depositing a first sacrificial layer on a surface of a substrate over a sensor region of the substrate; forming an absorber structure for the infrared sensor on top of the first sacrificial layer; depositing a second sacrificial layer on top of the absorber structure; forming a trench through the first sacrificial layer and the second sacrificial layer, the trench surrounding the sensor region; depositing an encapsulating layer on top of the second sacrificial layer to form an encapsulating thin film and into the trench to form a perimeter wall around the sensing region; forming vent holes in the encapsulating thin film; using the vent holes to remove the first and the second sacrificial layers 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, the cavity being surrounded by the perimeter wall, the encapsulating thin film being suspended over the cavity and the absorber structure by the perimeter wall; and closing the vent holes in a vacuum environment to seal the absorber structure within the cavity.