Advances in Atom Probe Specimen Fabrication from Planar Multilayer Thin Film Structures

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Atom probe tomography (APT) requires precisely shaped specimens for high-resolution analysis.
• Analyzing multilayer thin films presents challenges in resolving interfaces at the atomic scale.

Purpose of the Study:

• To develop a reliable sample preparation method for atom probe analysis of multilayer thin films.
• To enable atomic-layer spatial resolution of composition profiles across interfaces.

Main Methods:

• Fabrication of sharp needle-shaped specimens from multilayer thin films on silicon substrates.
• Utilizing standard silicon etching techniques and focused ion-beam milling.
• Orienting specimens for layer normals parallel to the needle axis for compositional profiling.

Main Results:

• Successful fabrication of specimens suitable for atom probe analysis.
• Demonstration of atomic-layer spatial resolution across interfaces in a NiFe/CoFe/Cu/CoFe thin film structure.
• Validation of the technique's feasibility and utility for complex multilayer systems.

Conclusions:

• The developed method provides a pathway for high-resolution interfacial analysis in multilayer thin films using atom probe tomography.
• This technique is crucial for understanding the structure-property relationships in advanced materials.
• The approach is applicable to various multilayer thin film systems requiring atomic-scale compositional characterization.