Robert L. Wood

MEMS 2D matrix switch

Microelectromechanical systems, or MEMS, are among several promising technical approaches to implementing all-optical switching in telecom and data networks. At the core of MEMS switches is an array of micromirrors capable of redirecting light either in free space or within a waveguide framework. The 2D switch architecture as shown in figure I employs one mirror for every possible switched node in a matrix switch, and thus requires N/sup 2/ mirrors for an NXN array. 2D mirror arrays are characterized by two-state mirror positioning. One state is inactive and requires only that the mirror can be parked out of the optical path.

MEMS reliability, process monitoring, and quality assurance

The reliability of a MEMS-based system depends on the producibility and environmental stability of the MEMS components as well as other components within the system. This article will focus on MEMS components in a sacrificial LIGA MEMS-based Safety & Arming (S&A) system. The process monitoring and quality assurance methods under development for LIGA MEMS S&A components are presented. These methods include techniques to study: (1) process bias, (2) material microstructure and mechanical properties, (3) mechanical response of spring-supported structures, and (4) actuator performance. Characterization of the as-produced components and materials serve as the starting point for future studies of reliability of LIGA MEMS components and systems. The utilization of several process monitoring and quality assurance methods in future reliability studies is discussed.

Metrology study of structural transfer accuracy in fabrication of high-aspect-ratio microelectromechanical systems: From optical mask to polished electroplated parts

This article focuses on some fabrication issues and characterization at various steps of the LIGA [German acronym for Lithorgraphy, Galvanoplasty, and molding (Abformung)] process, in particular on the acuity of pattern transfer through the various steps of the process, from the optical mask to planarized electroplated parts for basic LIGA processing (single level). Metrology data on the accuracy of the LIGA process as currently applied in the high-aspect-ratio microelectromechanical systems (HI-MEMS) Alliance at various stages of the process are presented and the sources of process biases are investigated. Some potential areas for improvement with respect to dimensional control will also be highlighted.

Planarization of metallic parts for single- and multilevel (S)LIGA

The quality of surface finish and precise height of LIGA components produced by electroplating has been studied. Planarization is often required to meet specifications for both basic LIGA processing (single level) and extended LIGA processing (multi-level). The HI-MEMS Alliance has successfully developed such a planarization process.