辐射致冷用氮化硅薄膜的微观结构和光学性质

MICROSTRUCTURE AND OPTICAL PROPERTIES OF SILICON NITRIDE THIN FILMS AS RADIATIVE COOLING MATERIALS

采用射频等离子体化学气相沉积 (PECVD)法制备了SiNx 薄膜。用X 射线荧光光谱、红外吸收光谱、红外反射光谱以及扫描电镜对薄膜的成分、结构、表面形貌和光学性质进行了初步研究。X 射线荧光分析表明SiNx 薄膜的组成为SiN0 .3 5。从红外透过光谱可见 ,氮参加了反应并生成Si N键 ,薄膜中有少量的Si H键和N H键。红外反射光谱表明SiN0 .3 5薄膜是非常好的窗口材料 ,在 8～ 13μm波段内具有很低的反射率 ,8～ 13μm波段外反射率高 ,适合制备辐射制冷体。

SiNx thin films were prepared by RF plasma enhanced chemical vapor deposition. Composition, structure, surface morphology and optical properties of the films were analyzed by X-ray fluorescence, IR transmittance, IR reflectance and SEM. The analysis shows that the main composition of the films is SiN0.35. The nitrogen atom takes part in reaction with the silicon atom and Si-N bond is formed, while there are also some Si-H and N-H bonds in the films. The films have very low IR reflectance across the full 8-13 μm bond and high reflectance elsewhere. Then the growth mechanism of the films was explained by SEM observation.