摘要 |
In a micro-bridge structure in which a temperature detecting portion 14 (diaphragm) including a bolometer thin film 7 is supported by a supporting portion 13 in a state floated from a circuit substrate 2, a reflective film 3 reflecting a THz wave is formed on the circuit substrate 2, an absorbing film 11 absorbing the THz wave is formed on the temperature detecting portion 14, and an optical resonance structure is formed by the reflective film 3 and the temperature detecting portion 14. And a gap between the reflective film 3 and the temperature detecting portion 14 is set approximately ¼ of a wavelength of an infrared ray on the basis of the wavelength of the infrared ray (in a range of approximately 1.5 to 2.5 μm, for example), and a sheet resistance of the temperature detecting portion 14 is set in a range in which an absorptance of the THz wave becomes a predetermined value or above on the basis of the THz wave (in a range of approximately 10 to 100 &OHgr;/sq.). By this arrangement, the absorptance of the THz wave is drastically improved while using the structure and manufacturing technique of a bolometer-type infrared detector.
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