Thermal properties are critical to the performance of micromachined silicon bolometers. In order to verify thermal models of the device, a means of measuring the local temperature distribution over the element is required, as it is heated by passing current through a thin film titanium meander. Because of the very low thermal mass of the membrane a non-contact method of temperature measurement is needed. Most conventional thermal imaging systems operate in the wavelength range 5-15 μm and offer poor spatial resolution but in this work an infrared microscope, operating at shorter wavelengths, was used. The microscope comprises an objective lens which focuses radiation onto a cooled (77K) cadmium mercury telluride focal plane array sensitive over the range 800 nm to 2500nm. For this application a bandpass filter centered at 2150 nm was used. Good agreement was obtained between finite element modeling of the temperature distribution, using ANSYS, and the measured data.
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