为了测量脉冲激光沉积法制备的小面积薄膜的残余应力, 并解决Stoney公式在特定情况下误差较大的问题, 本文提出了一种基于悬臂梁结构和数值计算的薄膜残余应力测量方法。该方法以初始曲率为零的原子力显微镜探针作为衬底梁, 在衬底梁上使用脉冲激光沉积方法沉积被测薄膜, 并记录衬底梁在薄膜沉积前后的翘曲形貌变化, 再结合薄膜厚度、衬底梁几何尺寸、所涉及材料的杨氏模量与泊松比等其他参数, 借助数值计算对实验数据进行分析, 得出被测薄膜的残余应力。使用该方法测出: 基于脉冲激光沉积法在高温环境下制备的二氧化钒薄膜的残余应力为-340 MPa, 与文献报道的结果相符。本文提出的基于悬臂梁结构和数值计算的薄膜残余应力测量方法具有适用范围广、准确度好、实验成本低的优点。

To measure the residual stresses in thin films with limited area prepared by pulsed laser deposition, as well as to solve the problem of the relatively large error introduced by the Stoney equation under certain circumstances, a measurement method for residual stresses in thin films based on cantilever structures and numerical calculation was proposed in this article. In this method, atomic force microscopy probes with zero initial curvature were used as substrate cantilevers, and thin films were deposited on the substrate cantilevers using pulsed laser deposition. The bending profiles of the substrate cantilevers before and after thin film deposition were recorded and used in numerical calculation, together with other parameters including the thin film thicknesses, the geometries of the substrate cantilevers, and the Young’s moduli and the Poisson’s ratios of the involved materials, to analyze the experimental data and obtain the residual stresses in the thin films. By using this method, the residual stress in vanadium dioxide thin films, prepared by pulsed laser deposition in a high-temperature environment, is measured to be -340 MPa, corresponding to the value reported in the literature. The measurement method for residual stresses in thin films proposed in this article, which is based on cantilever structures and numerical calculation, has the advantages of wide versatility, good accuracy, and low costs.