Silicon-based MEMS infrared light source and preparation method thereof

Abstract

The invention discloses a silicon-based MEMS infrared light source and a preparation method thereof.The silicon-based MEMS infrared light source comprises a substrate, a blocking supporting layer, a blocking layer, a heating electrode supporting layer, a heating electrode layer, an insulation protection layer, an electrode layer and a radiation layer, the blocking supporting layer is arranged on the substrate, the blocking layer is arranged on the surface of the blocking supporting layer, and the heating electrode supporting layer is arranged on the surface of the insulation protection layer; a heating electrode supporting layer and an electrode layer which are connected in sequence are arranged above the barrier layer in a suspension manner, and a heating electrode layer, an insulating protection layer and a radiation layer are arranged on the barrier layer in sequence. The metal heating material and the radiation layer material are adaptively matched, the cost is low, the working temperature is higher and stable, the double-suspension-film structure can effectively enhance the infrared emission efficiency, the infrared reflection enhancement layer does not make contact with the substrate, the heat loss is low, and heat radiation can be effectively enhanced.

Description

technical field [0001] The invention belongs to the technical field of infrared light sources, in particular to a silicon-based MEMS infrared light source and a preparation method thereof. Background technique [0002] In the fields of NDIR infrared gas sensors, infrared security detection, infrared medical imaging, etc., specific infrared bands are used as specific detection methods, which can effectively distinguish and test specific targets. As the infrared emitter in the whole test system, the MEMS infrared light source has its own selectivity and stability, which can greatly improve the work efficiency of the test system. [0003] The micro-electromechanical system (MEMS) infrared light source prepared by micromachining technology realizes high-temperature radiation of infrared light by heating the suspended thin-film resistive layer. and suitable for mass production. At present, most of the infrared gas sensors at home and abroad combine MEMS technology to develop ME...

AI Technical Summary

Problems solved by technology

[0006] The existing design of MEMS infrared light sources mostly uses metal Pt or polysilicon as the heating resistance material of MEMS infrared light sources. The overall working temperature is below 600°C, and the infrared radiation efficiency is low; The preparation of silver black or nano-black silicon, etc., has problems such as high cost of process preparation or contradictions in process preparation, which greatly limits the working efficiency of MEMS infrared light source

[0007] All MEMS infrared light sources are structurally suspended film structures. Although they can ensure the independence of the device layer and the substrate and high infrared radiation, there is no structure or device that can effectively block the infrared back radiation, resulting in infrared radiation. low utilization

[0008] Although the Chinese patent CN106629577A and the Chinese patent CN206014406U have also proposed the scheme of releasing part of the silicon cavity to realize the radiation barrier on the back of the suspended film, although they can also enhance the effect of radiation, there is still heat radiation after contacting the silicon in the cavity. The thermal conductivity is strong, resulting in a large dissipation of thermal radiation energy, which greatly reduces the efficiency of thermal radiation

[0010] 1) In the selection of materials for the heating resistance layer, the working temperature of polysilicon is low, limited to below 600°C, and the working efficiency is low;

[0011] 2) High-temperature heat treatment annealing of metal Pt has high requirements on the annealing environment, and oxygen-free annealing must be done;

[0012] 3) Metal Pt is a precious metal, and there are many polysilicon process procedures, all of which have the problem of high cost;

[0013] 4) The choice of black gold, platinum, silver black and other materials for the radiation layer is expensive and cannot be commercialized at low cost;

[0014] 5) Polysilicon is selected as the material of the radiation layer to etch nano-black silicon. If the previous process contains metal, polysilicon cannot be deposited, and there is a contradiction in the process.

[0015] 6) The existing structure has low utilization rate of infrared radiation and high heat loss

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