Fabrication of Freestanding Metallic Ni-Mo-W Microcantilever Beams with High Dimensional Stability

Gianna M. Valentino, Pralav P. Shetty, Jessica A. Krogstad, Kevin J. Hemker

Research output: Contribution to journalArticlepeer-review


Recent studies have elucidated a promising balance of physical and mechanical properties of sputter deposited nickel-molybdenum-tungsten (Ni-Mo-W) films that have a unique nanotwinned microstructure and promising potential for use in high temperature microelectromechanical systems (MEMS). The current study was undertaken to establish the feasibility of making nanotwinned Ni-Mo-W microcantilevers with standard microfabrication processing, to assess their dimensional stability, and to demonstrate the possibility of using nanotwinned Ni-Mo-W in metal MEMS devices. Deposition of Ni-Mo-W films in commercial sputtering chambers revealed a wide processing window for the formation of the requisite nanotwinned microstructure. Conventional photolithography and etchants were employed to shape blanket Ni-Mo-W films into freestanding microcantilever beams. Monitoring microcantilever deflections via interferometry provided a direct measure of residual stresses and overall dimensional stability. Heat treatments of 200°C and 400°C were used to mimic wafer bonding temperatures. At 400°C, microcantilevers exhibited modest stress relaxation, yielding beam deflection profiles on the nanometer scale and portending dimensional stability and control for future metal MEMS devices.

Original languageEnglish (US)
Article number9036093
Pages (from-to)329-337
Number of pages9
JournalJournal of Microelectromechanical Systems
Issue number3
StatePublished - Jun 2020


  • Microcantilevers
  • microelectromechanical systems (MEMS)
  • microfabrication
  • nickel alloys
  • sputter deposition

ASJC Scopus subject areas

  • Mechanical Engineering
  • Electrical and Electronic Engineering


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