期刊
MEASUREMENT SCIENCE AND TECHNOLOGY
卷 14, 期 10, 页码 1807-1814出版社
IOP PUBLISHING LTD
DOI: 10.1088/0957-0233/14/10/310
关键词
surface profiling; mechanical properties; interferometry; optical profiling; MEMS; microsystems; micromachining
As microelectromechanical systems (MEMS) move rapidly towards commercialization, the issue of mechanical characterization has emerged as a major consideration in device design and fabrication. It is now common to include a set of test structures on a MEMS wafer for extraction of thin film material properties (in particular, residual stress, stress gradient and Young's modulus), and for process and device monitoring. These structures usually consist of micromachined beams and strain gauges. Measurement techniques include tensile testing, scanning electron microscopy (SEM) imaging, atomic force microscopy (AFM) analysis, surface profiling and Raman spectroscopy. However, these tests are often destructive and may be difficult to carry out at the wafer scale. Instead of these methods, this paper uses white-light interferometry surface profiling for material characterization and device inspection. Interferometry is quick, non-destructive, non-contact, and can offer a high density lateral resolution with extremely high sensitivities to the surface in the z-direction-all essential requirements for high volume manufacturing. A range of devices is employed to illustrate the capabilities of white-light interferometry as a measurement and process characterization tool. It is shown that residual stress may be determined by using electrostatic actuation to pull fixed-fixed beams towards the substrate, and interferometry to record the beam deflection profile. Finite-element simulation software is employed to model this deflection, and to estimate the material properties which minimize the difference between the measured and simulated profiles. The results agree well with blanket film measurements.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据