Mechanical effects of galvanic corrosion of thin film polysilicon

Conference Paper

Mechanical, and electrical effects generated by the galvanic corrosion of polysilicon immersed in various hydrofluoric acid (HF)-based solutions are described. Micromachined test structures consisting of phosphorus-doped polysilicon in contact with a gold metallization layer are utilized. A suite of otherwise identical test (metal added) and reference (no metal) structures were used to investigate changes in key performance parameters. Corroded test structures demonstrate an increase in through-thickness strain gradient, a decrease in the characteristic frequency of mechanical resonance, no change in in-plane strain, greatly increased electrical resistance, a decrease in hardness, and a decrease in elastic modulus. Noteworthy results were observed for aqueous- hydrochloric acid, ethanol, water, ammonium fluoride (found in buffered oxide etchant), Triton-X-100, as well as vapor-HF based chemistries. This first systematic study validates preliminary experiments and demonstrates the impact of corrosion on miniaturized structures, indicating a potential influence upon the material properties, design, performance, fatigue, tribology (friction/ wear), manufacture, and packaging of micro- and nano-scale devices. Copyright © 2005 by ASME.

Full Text

Duke Authors

Cited Authors

  • Miller, DC; Gall, K; Stoldt, CR

Published Date

  • December 1, 2005

Published In

Volume / Issue

  • 7 MEMS /

Start / End Page

  • 325 - 334

International Standard Serial Number (ISSN)

  • 1096-665X

International Standard Book Number 10 (ISBN-10)

  • 079184224X

International Standard Book Number 13 (ISBN-13)

  • 9780791842249

Digital Object Identifier (DOI)

  • 10.1115/IMECE2005-79295

Citation Source

  • Scopus