Fabrication of nanodevices for magneto-transport measurements through nanoparticles

Abstract

We are developing nanoelectrodes for investigation of magneto-transport mechanisms through a single or a few nanoparticles. In this work, we present two different ways for patterning these nanodevices, based on high resolution electron beam lithography (HREBL). The first method consists in defining electrode shape patterns in a positive PMMA resist layer by HREBL and then lifting-off a metallic or ferromagnetic film deposited by ion beam assisted evaporation. The second method consists in etching a continuous metallic or ferromagnetic thin layer deposited by sputtering, using as etching mask a negative PMMA resist previously patterned by HREBL. The entire processes are described in detail and the geometrical quality and resolution of the nanoelectrodes obtained in each case are analysed and compared by scanning electron microscopy.