Fabrication of cobalt trifluoride (CoF3) phase from metallic cobalt by XeF2-assisted Focused Electron Beam Induced Processing

Abstract

Focused Electron Beam Induced Processing (FEBIP) using XeF2 gas injection is routinely applied in circuit editing, mask repair and nanolithography to etch semiconducting or metallic materials. Here, we report the use of XeF2-assisted FEBIP for a novel application: the formation of a metal fluoride from a metal layer in the area scanned by the electron beam. Our study focuses on the reaction of cobalt into cobalt trifluoride (CoF3). The objective of the present study is to locally obtain the CoF3 compound out of a cobalt nanostructure. The CoF3 phase has been reported in the past to show antiferromagnetic properties at room temperature, thus ferromagnetic/antiferromagnetic (Co/CoF3) bilayer structures with magnetic exchange bias phenomena could be engineered at the micro/nano scale. Electron Energy Loss Spectroscopy studies presented here demonstrate that CoF3 is efficiently obtained out of Co by means of XeF2-assisted FEBIP, opening the route for future Co/CoF3-based devices.