Infrared detector with microbridge structure and its manufacturing method

Abstract

The invention provides an infrared detector of a microbridge structure and a method for manufacturing the infrared detector of the microbridge structure. The detector comprises a reading circuit substrate, a microbridge leg, a heat sensitive layer, an infrared reflection layer and an infrared absorption layer. The infrared absorption layer is supported by and arranged above the heat sensitive layer, a resonant cavity for incoming infrared light is formed by the infrared absorption layer and the infrared reflection layer, and the microbridge leg is arranged below the infrared reflection layer and electrically connected with the reading circuit substrate. Through the structure, the infrared absorptivity of the device can be improved while thermal conductance of the device can be reduced, the filling rate of the device is improved, the defects of the resonant cavity are overcome, and thus the thermal isolation effect and the responsivity of the device are improved and the performance of the device is optimized.

Description

technical field [0001] The invention belongs to the field of micro-electromechanical technology, and in particular relates to a multi-layer micro-bridge structure infrared detector and a manufacturing method thereof. Background technique [0002] Infrared detectors in the prior art use a MEMS microbridge structure integrated on a CMOS circuit, and use a sensitive material detection layer (usually amorphous silicon or vanadium oxide) to absorb infrared rays and convert them into electrical signals, thereby realizing thermal Imaging function. At present, the main development direction of infrared detectors is to reduce the size of the pixel structure and increase the size of the array, improve the image resolution of the detector, and expand the application range of infrared detectors. The level of its MEMS manufacturing process has become the main factor restricting product performance. factor. The microbridge structure of the infrared detector has shrunk from the early 100...

AI Technical Summary

Problems solved by technology

The focus of the double-layer structure design is to completely separate the infrared reflection layer 21 from the plane where the heat-insulating bridge legs 23 are located, so that they no longer affect each other, but this structure also has defects, that is, the large-area infrared absorption layer 25 and the infrared reflection layer The bridge leg 23 is sandwiched in the resonant cavity 24 formed by 21, and the bridge leg 23 will affect the resonance effect of the infrared incident light wave and reduce the infrared absorption efficiency

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