Emerald Group Publishing Limited
Copyright © 2004, Emerald Group Publishing Limited
Applicant: Raytheon Company, USAPatent number: US6,690,014Publication date: 10 February 2004Title: Microbolometer and method for forming
Keywords: Sensors, Patents, Forming technologies
This invention relates to infrared detectors and more particularly to a method for forming microbolometers. Conventional microbolometers measure the change in resistance of a detector element after the microbolometer is exposed to thermal radiation. To maximize the sensitivity of microbolometers, the temperature coefficient of resistance of the detector element should be as high as possible.
The patent describes a microbolometer that includes an absorber element that changes temperature in response to absorbing infrared radiation. An amorphous silicon detector is thermally coupled to the absorber element and is suspended above a silicon substrate at a height of one-quarter wavelength of the infrared radiation to be detected. The amorphous silicon detector changes electrical resistance in response to the absorber element changing temperatures. The microbolometer further comprises electrode arms coupled to the silicon substrate providing structural support for the amorphous silicon detector and electrical connectivity for the microbolometer.
Advantages of such devices include increased operating frequency and increased sensitivity. They have applications in gas detectors, night vision, and many other situations.