Focused-ion-beam milling based nanostencil mask fabrication for spin transfer torque studies

TL;DR

This paper presents a focused-ion-beam milling technique to create nanostencil masks for precise magnetic nanostructure fabrication, enabling detailed studies of spin transfer torque effects in nanoscale devices.

Contribution

It introduces a novel nanostencil mask fabrication method using focused-ion-beam milling tailored for spin transfer torque research applications.

Findings

Successfully fabricated Co/Cu/Co nanopillars with the method.

Demonstrated current-induced magnetization dynamics in the structures.

Provided a versatile approach for magnetic nanostructure patterning.

Abstract

Focused-ion-beam milling is used to fabricate nanostencil masks suitable for the fabrication of magnetic nanostructures relevant for spin transfer torque studies. Nanostencil masks are used to define the device dimensions prior to the growth of the thin film stack. They consist of a wet etch resistant top layer and an insulator on top of a pre-patterned bottom electrode. The insulator supports a hard mask and gives rise to an undercut by its selective etching. The approach is demonstrated by fabricating current perpendicular to the plane Co/Cu/Co nanopillar junctions, which exhibit current-induced magnetization dynamics.