SGER: High Performance MEMS Metals Developed by Solidification Processing of Composite Coatings and Embedded Layers

Tufts University, Medford MA

Investigators

Abstract

This SGER focuses on an innovative process and materials that can solve (1) reliability problems due to surface effects, (2) high-temperature post-processing, and (3) packaging in multi-layer devices. The materials are high performance Ni-Al and Ti-Al thin films that can coat surfaces or be embedded in structures. Here we propose to initiate a reaction to create either Ni-Al or Ti-Al intermetallics in-situ with minimal intervention to the fabrication process/equipment. These materials have good corrosion resistance, high temperature strength, and, in the case of Ti-Al, good biocompatibility with potential applications in BioMEMS. The proposed research will involve both thermal modeling and experimental validation. The largest challenge is in optimization of the Ni-Al and Ti-Al deposition thickness and laser and infrared heating parameters to trigger the reaction without harming the rest of the silicon structures. The team will adapt and use a transient melting/solidification model, which will ultimately be expanded to include reaction kinetics and the possibility of atomic level deposition. This SGER will result in the development of high performance intermetallics for interlayer/interconnects in multi-layer and multi-chip MEMS devices, utilizing an innovative, realistic thermal process that can be added to standard microfabrication lines. In addition, an advanced thermal model of intermetallic solidification processing will be created. The graduate students in this project will benefit from strong, interdisciplinary collaboration between two universities, as well as the opportunity to create exciting demonstrations for undergraduate courses