Zhou Zai-Fa, Meng Mu-Zi, Sun Chao, Huang Qing-An
Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096, China.
Micromachines (Basel). 2019 Oct 2;10(10):669. doi: 10.3390/mi10100669.
Various multilayered thin films are extensively used as the basic component of some micro-electro-mechanical systems, requiring an efficient measurement method for material parameters, such as Young's modulus, residual stress, etc. This paper developed a novel measurement method to extract the Young's moduli and residual stresses for individual layers in multilayered thin films, based on the first resonance frequency measurements of both cantilever beams and doubly-clamped beams. The fabrication process of the test structure, the corresponding modeling and the material parameter extraction process are introduced. To verify this method, the test structures with gold/polysilicon bilayer beams are fabricated and tested. The obtained Young's moduli of polysilicon films are from 151.38 GPa to 154.93GPa, and the obtained Young's moduli of gold films are from 70.72 GPa to 75.34GPa. The obtained residual stresses of polysilicon films are from -14.86 MPa to -13.11 MPa (compressive stress), and the obtained residual stresses of gold films are from 16.27 to 23.95 MPa (tensile stress). The extracted parameters are within the reasonable ranges, compared with the available results or the results obtained by other test methods.
各种多层薄膜被广泛用作一些微机电系统的基本组件，这就需要一种有效的材料参数测量方法，如杨氏模量、残余应力等。本文基于悬臂梁和双端固支梁的一阶共振频率测量，开发了一种新颖的测量方法来提取多层薄膜中各层的杨氏模量和残余应力。介绍了测试结构的制作工艺、相应的建模以及材料参数提取过程。为验证该方法，制作并测试了具有金/多晶硅双层梁的测试结构。所得到的多晶硅薄膜的杨氏模量为151.38吉帕至154.93吉帕，金薄膜的杨氏模量为70.72吉帕至75.34吉帕。所得到的多晶硅薄膜的残余应力为-14.86兆帕至-13.11兆帕（压应力），金薄膜的残余应力为16.27至23.95兆帕（拉应力）。与现有结果或通过其他测试方法得到的结果相比，所提取的参数在合理范围内。
