Research/Monolithic Integration of Microactuators with High Voltage Driver Circuits

2019-02-18 (月) 00:15:30 (243d)

High Voltage Driver Circuits as a Platform for MEMS Actuators



Performace of microactuators such as fast response and large displacement is often determined by driving voltages, and high volatages (over several tens of volts) are usually used for MEMS actuators of lab-level development. From a practical point of view of MEMS, however, high-voltage drive circuitry such as operation-amplifiers is a costly solution. In addition to this, a highly integrated MEMS would suffer from the jam of electrical interconnection to and from the chip. In this work, we present an ASIC (Application Specific Integrated Circuit)-like post-processing and designing solution for integrating arbitrary MEMS actuators with pre-fabricated high-voltage analog and digital circuits by collaborating with TOSHIBA Corp.

CMOS-First & MEMS-Last 型集積化
CMOS-First & MEMS-Last Integration


耐圧40Vの高電圧ドライバ回路のチップを,内部に将来MEMSアクチュエータなどを作り込む空き地 (7 mm x 6 mm)を残したまま製作します.MEMSの構造となるのは,厚さ8umのSOI層で,これはシリコンDRIEによって加工します.もし必要であれば,厚さ625umの基板を裏側から同様にDRIEによって加工することも可能です.高電圧ドライバ回路と低電圧ロジック回路は,チップの周辺部分に配置されています.4組あるうちの1区画には,16ビットのデマルチプレクサ1個,12ビットのデジタル/アナログコンバータ1個,オペアンプ4個が含まれており,オペアンプの出力はサンプル・ホールド回路で電圧維持しています.MEMS部分と回路出力段の接続は,MEMS設計時に自由に決定可能です.

The high-voltage IC chip (max 40 Vdc) is made with a blank field inside (7 mm x 6 mm), where MEMS actuators are to be post-fabricated. The structural layer for the MEMS is an 8-um-thick SOI (silicon on insulator) layer, which could be dry-etched by silicon DRIE (deep reactive ion etching). The carrier substrate (626 um thick) can be etched from the backside, if needed. High-voltage analog driver circuits and low-voltage digital circuits are made near the edges of chip; one of four segments contains a 16-bit-demultiplexer, four operational amplifiers are pre-fabricated. DC leves of the amps are fixed by the sample&hold. Connection to the MEMS actuators (or sensors) can be designed by MEMS users.

Test Run: Electrostatic Comb-Drive Actuators Integrated with Driver Circuits



For demonstration, we have monolithically integrated an array of electrostatic comb-drive actuators with the driver circuits, and successfully observed driving operation on the chip. The amplifier was found to have a gain of approximately 50x for maximum 60 Vdc output.

Contact Investigator


  1. K. Takahashi, H. N. Kwon, M. Mita, H. Fujita, H. Toshiyoshi, K. Suzuki, H. Funaki, "Monolithic Integration of High Voltage Driver Circuits and MEMS Actuators by ASIC-like postprocess," Proc. 13th Int. Conf. on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS '05), June 5 - 9, 2005, Seoul, Korea.