This paper describes a free-standing microthermopile infrared detector. The device consists of micron-sized copper-constantan free-standing wires which overlap to form the hot junctions of the thermocouples, while the cold junctions are made from larger metal strips which are attached to the substrate. Incident radiation absorbed by the device causes the temperature of the free-standing hot junction to rise relative to the cold junction thereby resulting in a thermovoltage. These detectors were found to exhibit a response time of ∼10 μs. The spectral response of the detectors was found to be 3 times higher at a wavelength of 10 μm compared to that at 1 μm and this difference is thought to be due to antenna effects. The antenna behavior of free-standing microthermocouples has been studied and the results from these experiments are also presented. The device is fabricated using standard silicon microfabrication techniques and can be integrated with active electronic circuits to result in a smart sensor.
|Original language||English (US)|
|Number of pages||10|
|Journal||Sensors and Materials|
|State||Published - Dec 1 1996|
All Science Journal Classification (ASJC) codes
- Materials Science(all)