Journal of Chromatography & Separation Techniques
Open Access

High strength Au film fabricated by advanced electrochemical technique in supercritical CO2 emulsified electrolyte for MEMS accelerometers

2^nd International Conference and Expo on Separation Techniques

September 26-28, 2016 Valencia, Spain

Chun Yi Chen, Masaharu Yoshiba, Haochun Tang, Tso Fu Mark Chang, Daisuke Yamane, Katsuyuki Machida, Kazuya Masu and Masato Sone

Tokyo Institute of Technology, Japan
Japan Science and Technology Agency, Japan
NTT Advanced Technology Corporation, Japan

Scientific Tracks Abstracts: J Chromatogr Sep Tech

Abstract :

In recent years, Au has become promising material used as the movable structures and proof mass in micro-electricalmechanical system (MEMS) accelerometers, because the density of Au is about 10 times higher than that of silicon and the sensitivity of the MEMS accelerometer can be improved with a reduction in the density. However, Au is known to be a soft material and the mechanical strength becomes a concern in miniaturization of the MEMS device. One of the approaches is to decrease the grain size of the Au material to increase the mechanical properties according to the Hall-Petch relation. Pulse plating has been reported to be effective to fabricate metal films with finer grain, higher uniformity and lower porosity. On the other hand, application of supercritical carbon dioxide (Sc-CO2) in electroplating of metal film has also received recent research interests. Physical and transport properties such as density, viscosity, diffusivity and reactant solubility in Sc-CO2 can be adjusted through control of pressure and temperature. Sc-CO2 is often used as a substitute or additive to control overall physical and transport properties of the reaction medium. Surface tension and viscosity of Sc-CO2 are much lower than those of aqueous solution. In this work, grain refinement, surface smoothening and compressive strength enhancement of Au films were achieved by an electroplating using Sc-CO2 emulsified electrolyte.

Biography :

Chun Yi Chen has completed her PhD from Tokyo Institute of Technology, Japan. She was a Research Assistant Professor for next generation battery project in Waseda University from 2012 to 2015. She is currently a Research Assistant Professor of Precision and Intelligence Laboratory in Tokyo Institute of Technology, focusing on advanced electrochemical technique for biomedical materials and devices. She has published many papers in reputed journals and received 6 awards from the international conferences.

Email: chen.c.ac@m.titech.ac.jp