纳米薄膜屈曲模式的实验研究

Experimental Study of Nano-Film Buckling Mode

薄膜/基底系统在信息科学以及微电子机械系统中有着十分重要的地位。薄膜中常会有压或拉的残余应力,因此薄膜/基底结构通常是工作在残余应力以及外加应力的联合作用下。根据结构的功用不同,其载荷方式也有不同,从而也导致了不同的破坏模式。压缩载荷下的脱粘屈曲是薄膜基底结构主要的破坏形式之一。本文使用磁控溅射镀膜技术,制作了压缩薄膜试件。选用表面抛光的有机玻璃作为基底,制作了厚度为150nm的铝薄膜和150nm的钛薄膜。在实验中,使用一台光学显微镜观测膜层表面的形貌及其变化。考虑了薄膜在残余应力、外加轴向压应力共同作用下的屈曲破坏模式,并对屈曲的力学行为进行了分析。

Film/substrate system plays a very important role in information science and microelectromechanical system （MEMS）. Film/substrate structure works commonly under the combination of applied stress and residual stress due to the regular existence of residual stress in film. The load is different due to the different functions of film, which leads different damage modes of film. Buckling under compressive loading is one of the main damage mode of film/substrate structure. This paper focuses on the buckling process of compressed thin titanium film （150nm） and aluminium film （150nm） deposited on an organic glass substrate by using magnetron sputtering technology. In order to simulate film working and to produce regular buckle mode, external uniaxial compression was exerted to specimen. Under the condition of combination effect of axial compressive stress and residual stress, whole process from delamination to bulking was investigated. Mechanism of straight-sided bulking, the propagation of bulking driven delamintaion and the conversion from straight side bucklings to telephone cord buckling were analyzed.