Fabrication of ferromagnetic nanoconstrictions by electron beam lithography using LOR/PMMA bilayer technique
Chen Y., Lu Z., Wang X., Cui Z., Pan G., Zhou Y., Muñoz M., Hao C., Yonghua L., Garcia N.
This paper reports nanofabrications of in-plane nanoconstrictions in ferromagnetic films by electron beam lithography (EBL). In this process a LOR/PMMA bilayer technique was applied to create a clear undercut for subsequent metalisation and lift-off processes. Monte Carlo simulation was applied to investigate the resist profiles in PMMA layer with various thicknesses. The simulation result was used to decide the layer thicknesses in the design of the bilayer stack. With this technique the constrictions as small as 20-30 nm for spintronic devices in ferromagnetic films have been achieved and magneto resistance was measured. This is the first time to apply LOR/PMMA bilayer technique for nanodevices fabrication. © 2007 Elsevier B.V. All rights reserved.