Microfabrication Approaches on Magnetic Shape Memory Films

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Satyakam Kar - , Chair of Metallic Materials and Metal Physics, Leibniz Institute for Solid State and Materials Research Dresden, Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Author)
  • Kornelius Nielsch - , Chair of Metallic Materials and Metal Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Sebastian Fähler - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Author)
  • Heiko Reith - , Leibniz Institute for Solid State and Materials Research Dresden (Author)

Abstract

Magnetic shape memory alloys are emerging multifunctional materials that enable applications like high-stroke actuation, solid-state refrigeration, and energy harvesting of waste heat. Thin films of these alloys promise integration in microsystems to exploit their multifunctional properties at the microscale. However, the microfabrication process of these Heusler alloys is difficult. Herein, different etching techniques are investigated for the microfabrication of epitaxial Ni-Mn-Ga films, the encountered challenges are explained, and ways to overcome them are demonstrated. The results show that wet chemical etching is suitable for large patterned structures, while reactive ion etching of Ni-Mn-Ga films is unsuitable due to redeposition. For patterning structures below 10 μm with clean and sharp edges, the best results are obtained by ion beam etching with adjusted sample-stage tilt. Finally, a microfabrication process using Si microtechnology to fabricate partially freestanding structures is demonstrated. These findings give guidelines for the fabrication and integration of these smart materials in Si-based microsystems.

Details

Original languageEnglish
Article number2301133
JournalAdvanced engineering materials
Volume25
Issue number22
Publication statusPublished - Nov 2023
Peer-reviewedYes

Keywords

Keywords

  • epitaxial films, freestanding structures, ion-beam etching, magnetic shape memory alloys, microfabrication, redeposition