Research/NEXT Overview

2019-02-18 (月) 00:20:53 (243d)

日本学術振興会 最先端・次世代研究開発支援プログラム(平成22~25年度)
Funding Program for Next Generation World-Leading Researchers~



Integrated MEMS Technology for Multi-functional Low Power Electronics



MEMS (Micro Electromechanical Systems) is expected to be an enabling technology to deliver the More-than-Moore type values to the next generation electronics. Unlike CMOS technology, however, MEMS has not yet seen a standard technique for integrated designing or fabrication. Within the framework of JSPS NEXT Program from February 2011 to March 2014, we aim to develop a handy toolbox of multi-physics analysis and post-processing for integrated MEMS.




Integration of microelectromechanical components with miroelectronics was very difficult to achieve when the MEMS technology was called "silicon miromachining" more than twenty years ago, due to the poor process compatibility between them. The difficulty has been almost removed today thanks to the R&D of MEMS processes transferred from the CMOS-compatible ones, which attracts more attentions of LSI design engineers who would like to integrate micromechanical flavor in their circuits. Nonetheless, the hurdle to step into the MEMS fields is high to clear for them plausibly because a handy tool for multi-physics simulation or CAD tool for integrated MEMS is still missing; furthermore, MEMS urges them to comprehensively understand the material science, fabrication process, and actuation principle of micromechanical components. In this work, we deliver technologies to lower such hurdle to make the LSI-MEMS more straightforward to try for LSI engineers.

Multi-Physics Simulation Tool for MEMS


回路設計者にMEMSを扱って貰えるように、電気回路シミュレータ(Qucs, LTSpice, Cadence) をベースにしたMEMSアクチュエータ・センサの統合解析手法を開発しました。この原理は、機械系の運動方程式を解くアナログコンピュータをPC上の等価回路モデルで置き換えたものです。このため、MEMSの機械的な挙動と、それを駆動・検出する電気回路系の挙動を統合的に解析することが可能です。


We have newly developed a user-friendly multi-physics simulation platform for MEMS based on electrical circuit simulator such as Qucs, LTspice, and Cadence Virtuoso. Unlike typical FEM- and HDL-based macro model, we use an equivalent circuit for the mechanical equation of motion implemented in the circuit simulator to handle both mechanical and electrical behavior of MEMS.

Post-Process Development for Integrated MEMS



Various types of post-processing methods have been reported to integrate micromechanical structures onto an LSI wafer, including our own approach of micro patterning the surface of silicon after LSI development. The most important feature of such process is the scalability toward larger wafer sizes coming in future. In our R&D activities, we have installed a new machine to laminate a dry film onto an LSI wafer of large scale, and to use the film as a part of micro patterns or a packaging seal. A MEMS power-gating switch is under development by using such post-CMOS processing technique.

Expected Output



All the PIs (principal investigators) in the JSPS NEXT program were requested to visually show the expected output after the program in terms of either Green-Innovation or Life-Innovation. In our project, we proposed a use of integrated MEMS technology to realize power-gating switch on LSI to regulate the power dissipation at minimum loss, a robust control system for a MEMS resonator array, and tunable MEMS capacitor for reconfigurable microwave circuit; such devices will not be realized by the conventional solid-state technology but as micromechanical structure of MEMS. We are also integrating "intelligent control system" in the MEMS to improve the performance of micromechanical devices.