NiMnGa nanostructures open up an unforeseen variety of opportunities for the development of novel nanomachines, which may be controlled by local heating and a magnetic field. Nanoindentation experiments on conventional shape memory alloys have already demonstrated the scalability of the shape memory effect to nanometer-sized depths. The purpose of this study is to explore the technologies of electron beam lithography and Ar ion-etching for fabrication of NiMnGa structures with critical dimensions in the sub-micrometer range.

One micron thick films of Ni₂MnGa are deposited on a PVA substrate by RF magnetron sputtering at 200 W. The sputtering target of nominal composition Ni₅₂Mn₂₄Ga₂₄ is fabricated by hot pressing. During sputtering the substrate temperature is kept at 50 °C. An Argon gas flow is maintained at 230 mm³s^-1. After release from the substrate the films are heat-treated at 800 °C for 36 ks.

Electron beam lithography is used to generate a primary pattern in a PMMA resist layer, which has been deposited on the Ni₂MnGa thin film. Its thickness is adjusted in the range of 1-3 µm by varying the spin-coating parameters. During the subsequent ion-etching process the resist is used as a protective layer for the functional structures. Therefore, the minimum resist thickness is given by the ablation rates of resist and thin film. The anisotropic behavior of the ion-etching process enables aspect ratios larger than 1, and thus, lateral structures with sub-micrometer dimensions. The process steps of lithography, pattern transfer and electrical contacting are performed on an auxiliary substrate with an adhesive bonding layer in-between, which is removed finally to obtain freely movable structures.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/11600 must be provided.

1. Nanofabrication - direct write and replication patterning technologies in EUMINAfab
2. Nanofabrication - direct write and replication patterning technologies in EUMINAfab
3. Transfer Bonding Technologies for Batch Fabrication of SMA Microactuators
4. Integration Technologies for Single-Crystalline NiMnGa Films
5. A Magnetization- and Strain-Dependent Free Energy Model for FEM Simulation of Magnetic Shape Memory Alloys
6. Residual stress in Ni-Mn-Ga thin films deposited on different substrates
7. A Free Energy model for Magneto-Mechanically Coupled NiMnGa Single Crystals
8. Texture and Stress in Ni-Mn-Ga Thin Films Deposited on Alumina
9. Properties of martensitic Ni-Mn-Ga thin films deposited on Mo foils
10. MAGNETORESISTANCE OF Ni-Mn-Ga THIN FILMS IN THE VICINITY OF MAGNETOSTRUCTURAL TRANSFORMATION
11. Magnetomechanical Properties of Polycrystalline Ni-Mn-Ga Thin Film Actuators
12. Ferromagnetic Shape Memory Microscanner with Large Deflection Angles
13. PROPERTIES OF SPUTTER-DEPOSITED Ni-Mn-Ga THIN FILMS
14. DEPENDENCE OF THE MAGNETIC ANISOTROPY ON THE THICKNESS AND ANNEALING OF SPUTTER-DEPOSITED Ni-Mn-Ga THIN FILMS
15. Coupled simulation of the thermo-magneto-mechanical properties of a Ni-Mn-Ga actuator
16. Ferromagnetic Shape Memory Microscanner System for Automotive Applications