SiAlN_x薄膜的应力释放模式及力学性能研究

Stress Release Mechanisms and Mechanical Properties of SiAlN_x Coatings

利用低辐射镀膜玻璃专用的镀膜生产线,在6 mm白玻衬底上制备出SiAlNx薄膜,研究了薄膜在退火之后的内应力释放模式及其力学性能。结果表明:退火后的SiAlNx薄膜存在较大的残余压应力,伴随着压应力的释放,薄膜中出现电话线形屈曲结构;屈曲结构从薄膜边缘产生,并逐渐往样品中心区域扩展;在电话线屈曲的传播过程中,屈曲的各结构参量(包括波长、振幅、宽度等)均发生了明显演化。基于连续弹性理论,对电话线屈曲的结构特征和生长演化进行了分析,并估算了薄膜的内应力和膜基结合能。

The SiAlNxcoatings were deposited by ac magnetron sputtering on window-glass substrates,6 mm thick and 600 mm × 900 mm in size. The influence of the coating conditions,including the sputtering power,substrate temperature,ratio of gas flow rates,and annealing temperature,on the mechanical properties and stress release mode was investigated. The microstructures of the SiAlNxcoatings were characterized with atomic force microscopy and ultraviolet visible spectroscopy. The results show that in cooling down from 700℃ to room temperature after annealing,a fairly high compressive stress existed,which was slowly released,resulting in formation of distinct continuous ripples in the SiAlNxcoatings. Starting from the edges of the coating,the ripples,resembling telephone cord buckles,gradually propagated towards the central area,with a distinctive evolution of its structural characteristics, such as wavelength,amplitude,and width. The possible mechanisms responsible for the release of the compressive stress were tentatively discussed in continuum elastic theory. The internal stress and interfacial adhesion energy were also estimated.