Infrared detector with high-efficiency resonant cavity and preparation method thereof

Abstract

The present invention discloses an infrared detector with a high-efficiency resonant cavity and a preparation method thereof. In order to improve the integration degree of the chip, the resonant cavity of the detector is arranged inside the silicon wafer, and compared with the conventional infrared detecting device, the vacuum chamber of the sensitive film is only a few micrometers in height, thecavity space is greatly reduced, a high vacuum is formed and maintained in an easier manner, and the heat loss of the sensitive layer caused by air convection can be avoided. The sensitive layer filmis arranged in the middle of the resonant cavity, and the upper reflective layer is a thin metal layer which is half-transflected on the back surface of the upper substrate; and the lower reflective layer is a thick metal layer which is totally reflected on the upper surface of the lower substrate, and the light reflects in a round trip in the resonant cavity to pass through the sensitive layer film for two times, so that the number of times of passing through the sensitive layer film is increased, and the light absorption rate is increased. The preparation method for the resonant cavity reflective layer is a conventional photolithography, coating and etching process, the process is simple and easy to implement, the metal pillars are respectively fabricated on the two substrates and finally assembled into a resonant cavity by flip chip bonding, and a skillful process, a low cost and high precision are achieved.

Description

【Technical field】 [0001] The invention belongs to the technical field of photoelectric detection, and in particular relates to an infrared detector with a high-efficiency resonant cavity and a preparation method thereof. 【Background technique】 [0002] The infrared imaging system is a system that relies on the thermal radiation of the target and the background to generate a scene image. It can work 24 hours a day, and can detect hidden thermal targets through camouflage. The infrared detector is the core component of the infrared imaging system, which can convert the incident infrared signal into an electrical signal output by the photoelectric effect and pyroelectric effect. However, in order to further improve device integration, when other silicon-based detection structures are superimposed on the infrared detector, the infrared signal received by the infrared sensitive film is weakened due to the inevitable absorption of infrared light in the process of penetrating the u...

AI Technical Summary

Problems solved by technology

However, in order to further improve device integration, when other silicon-based detection structures are superimposed on the infrared detector, the infrared signal received by the infrared sensitive film is weakened due to the inevitable absorption of infrared light in the process of penetrating the upper material, thus affecting The detection efficiency of the detector

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