Papatzacos Phillip H, Akram M Nadeem, Hector Olivier, Lemarquis Frédéric, Moreau Antonin, Lumeau Julien, Ohlckers Per
Department of MicroSystems, University of South-Eastern Norway, Borre, Norway.
Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France.
Heliyon. 2023 Apr 27;9(5):e15888. doi: 10.1016/j.heliyon.2023.e15888. eCollection 2023 May.
A micromachined Silicon lid, sealed by CuSn solid liquid interdiffusion bonding is a promising approach for hermetic sealing of microbolometers for use in low-cost thermal cameras. However, since ∼30% of long-wave infrared light is reflected at an uncoated single Si-air interface, anti-reflective treatments are required. Traditional anti-reflective coatings are inapplicable since CuSn solid liquid interdiffusion bonding requires heating to about 270 °C and these multi-layer coatings fail due to differing coefficients of thermal expansion for the different layers and the substrate. For this purpose, an anti-reflective coating that maintains its anti-reflective properties after being heat-cycled to 300 °C has been developed. This coating was developed using a simple 2-layer structure composed of ZnS and YF and deposited at 100 °C. The development process that led to the successful coating has also been described in this paper. The final sample shows a 30% average increase in transmission in the 8-12 μm wavelength range as compared to an uncoated wafer.
一种通过铜锡固液扩散键合密封的微机械硅盖，是用于低成本热成像相机的微测辐射热计气密密封的一种很有前景的方法。然而，由于在未镀膜的单一硅 - 空气界面处约30%的长波红外光会被反射，因此需要进行抗反射处理。传统的抗反射涂层不适用，因为铜锡固液扩散键合需要加热到约270°C，并且这些多层涂层会因不同层与基底的热膨胀系数不同而失效。为此，已经开发出一种在热循环至300°C后仍能保持其抗反射性能的抗反射涂层。该涂层采用由硫化锌（ZnS）和氟化钇（YF）组成的简单双层结构，并在100°C下沉积而成。本文还描述了成功制备该涂层的开发过程。最终样品在8 - 12μm波长范围内的透过率与未镀膜晶圆相比平均提高了30%。
