Study of Bulge Test, Nano Tensile Tester, and Nanoindentation System for Mechanical Properties Measurement of Thin Films

• Main Authors: Wu, Chung Lin, 吳忠霖
• Other Authors: Yip, Ming-Chuen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/35286258751227527601

博士 === 國立清華大學 === 動力機械工程學系 === 97 === The bulge test is a convenient approach to determine the thin film mechanical properties. This study presents a fabrication process to prepare the circular membrane made of metal as well as dielectric films for bulge test. The process successfully combines the dry etching of DRIE and XeF2 to release the test metal films. The Si3N4 film is used to protect the metal layers during the release process. By changing the recipe of XeF2 etching, the circular Si3N4 test membrane can also be fabricated. In applications, the circular membranes of Al, Au, and Si3N4 films were successfully prepared using the present approach. By using these specimens, the bulge test designed in this work was used to determine the thin film Young's modulus. The results by the bulge test show the similar trend with the results obtained by nanoindentation test. To find out the measurement ability of force and displacement of nano tensile tester and nanoindentation system, we adopted the method suggested in ISO GUN to calculate the uncertainty of this system. The standard weights are used to calibrate the force of the testing system. In addition, an optical method is adopted to evaluate the displacement uncertainty of the system. This research can be used as the basis for calculating measurement uncertainty in performing material tests. Moreover, this study is to investigate the static and dynamic mechanical properties of polydimethylsiloxane (PDMS) and the mixture of PDMS and carbon nanotubes. The PDMS/CNTs nanocomposites were stirred by an ultrasonic instrument to prevent agglomerations. A calibrated nano tensile tester was adopted in this testing system with maximum load of 500 mN and crosshead extension of 150 mm. The dynamic properties of PDMS/CNTs nanocomposites such as storage and loss modulus can be obtained by this system. The storage modulus increased with the CNTs content and also with the higher frequencies. Finally, the nanoindentation measurement system was employed to characterize the mechanical properties of PDMS and PDMS/CNTs. The increase of Young’s modulus by nanoindentation test has the similar trend with the results obtained by the tensile test method.