[15a-PB3-1~12] 13.4 Si processing /Si based thin film / MEMS / Equipment technology

▲ [15a-PB3-4] Electrodeposited High Strength Au-TiO₂ Nano Composite Film for MEMS Devices

〇(M2)Yuan Chien¹, Tso-Fu Mark Chang¹, Chun-Yi Chen¹, Daisuke Yamane¹, Hiroyuki Ito¹, Katsuyuki Machida¹, Kazuya Masu¹, Masato Sone¹ (1.Tokyo Tech)

Keywords:Metal matrix composites, electrodeposition, Au-TiO2

In this study, high strength Au-based composited films was achieved through TiO₂ nanoparticles (NPs) reinforcement. The Au-TiO₂ composite film was electrodeposited onto a copper plate with a 1 cm² surface area using galvanostatic method. Different surface morphologies of composite films with different TiO₂ contents were observed through scanning electron microscope (SE4300, Hitachi). The surfaces were found to be composed of particles, and a decrease in the particle size was observed with an increase in amounts of TiO₂ in the film from 0 to 2.72 wt%. Broadened XRD peaks of the Au-TiO₂ composite film containing 2.72 wt% TiO₂ indicated grain refinement caused by co-deposition with the NPs. The primary characteristic peak of TiO₂ at 2θ = 25.1° also appeared in the XRD patterns of the Au-TiO₂ composite film containing 2.72 wt% TiO₂ NPs. The scanning ion microscope (SIM, FB-2100, Hitachi) images and a stress-strain curve of a micro-pillar fabricated from the composite film containing 2.72 wt% TiO₂ NPs showed that yield strength of the pillar was 0.84 GPa, which was much higher than that of pure gold electroplated through conventional method.