Preface

The history of metallic materials is thought to have begun about 11,000 years ago because of their brilliant beautiful features. The noble metals, especially gold, are often used as components in electronic devices because of their high electrical conductivity, chemical stability, corrosion resistance, and high density.

In the field of microelectromechanical system (MEMS) devices, continuous miniaturization, while maintaining high sensitivity, is always a challenge. Especially for MEMS accelerometers, sensitivity is highly affected by Brownian noise, and structures with sufficient mass in the device are needed to suppress this noise. Because of the requirement of overall mass of the components, it is difficult to reduce the dimensions of components to allow further miniaturization of the MEMS device.

This book presents recent progress in noble metal electrodeposition and the application of gold materials in the realization of highly sensitive complementary metal-oxide semiconductor-microelectromechanical systems (CMOS-MEMS) accelerometers. A feature of the CMOS-MEMS accelerometer is the use of gold proofmass. The high density of gold enables sensitivity enhancement by reducing thermomechanical noise, which is inversely proportional to overall mass of the proofmass. The developed CMOS-MEMS multiphysics design environment is also presented. An equivalent circuit of a MEMS accelerometer has been designed to simultaneously clarify both mechanical and electrical behaviors. One of the potential applications of the highly sensitive accelerometer is also discussed by focusing on early-stage diagnosis of Parkinson's disease.

**II**

**Chapter 7 111**

**Chapter 8 133**

Electrodeposition of High-Functional Metal Oxide on Noble Metal for

Multi-Physics Simulation Platform and Multi-Layer Metal Technology

*by Katsuyuki Machida,Toshifumi Konishi, Daisuke Yamane, Hiroshi Toshiyoshi* 

for CMOS-MEMS Accelerometer with Gold Proof Mass

*by Wan-Ting Chiu, Chun-Yi Chen, Tso-Fu Mark Chang, Tomoko Hashimoto* 

MEMS Devices

*and Hiroyuki Ito*

*and Hiromichi Kurosu*

**Dr. Masato Sone and Dr. Kazuya Masu** Tokyo Institute of Technology, Japan

**1**

Section 1

Evaluation Method of

Electrodeposited Metal

Section 1
