Ti和TiN薄膜的制备以及残余应力的测试方法研究

Preparation of Ti and TiN Films and Investigation of the Residual Stress Measuring Method

基底曲率半径法是一种测量薄膜残余应力的常用方法,其中的光杠杆法应用最为广泛。文章在SUS304基底上使用电弧离子镀法制备了不同厚度的钛(Ti)和氮化钛(TiN)薄膜,研究了薄膜的形貌、密度以及物相,基于光杠杆原理分别从正面(正测法)和反面(背测法)对两种薄膜样品镀膜前后基底的曲率半径进行了测量,采用Stoney公式计算薄膜残余应力。通过对比正测法和反测法的测试结果,结合薄膜形貌、密度以及晶体结构表征分析,对背测法的测试误差和适用范围进行了分析。研究结果表明,背测法测得的应力值低于正测法的测量结果,薄膜残余应力水平越高,背测法的测量结果与正测法越接近:当薄膜残余应力水平较高(>1 GPa)时,背测法结果可以如实反映薄膜的应力水平;但当薄膜应力水平较低(<1 GPa)时,背测法结果存在较大误差。

The optical lever method is one of the substrate curvature-based instrumentations, which has been widely used to measure the residual stress of thin films. In this work, the Ti and TiN films were prepared based on SUS304 substrate by arc with different thicknesses, and the morphology, density and phase of two films were studied. Curvature radius of the substrate before and after coating was measured by the optical lever method from the front side（positive test method） and the opposite side（negative test method）. The residual stresses of films were calculated via Stoney method. The test error and the applicable scope of the negative test method were studied by comparing the results of the positive and negative test methods and the morphology, density, and crystal structure of the films. The results show that the measurement value of residual stress by the negative test method is lower than the positive test method. The higher of the residual stress, the closer of the measurement result to the positive test method. When the residual stress is high（1 GPa）, the results measured by negative test method can reflect true level of the residual stress. However, when the residual stress is low（1 GPa）, measurement accuracy of the negative test method is usually decreased.