E-beam lithography patterning of Co/Pd multilayer pillars below 50 nm in diameter

Co/Pd multilayer superlattice structures are among the most popular thin film systems for use in future bit patterned media. Multilayer Ta(9 nm)/Pd(7)/{\{}Co(0.3)/Pd(0.3){\}}x15 films were deposited on a Si(111) substrate by combined RF and DC magnetron sputtering. The films were characterized by x-ray reflectivity, x-ray diffraction, and a vibrating-sample magnetometer and found to exhibit perpendicular anisotropy. Additional films were made with a 30 nm sputtered nanocrystalline Si capping layer which serves as an etch stop [1]. These films were patterned into pillars with diameters of less than 50 nm using e-beam lithography. We present results of the lithographic process and analysis of the Co/Pd nanopillars which are formed. \\[4pt] [1] Jung-Sub Wi, et al. ``Electron beam lithography of Co/Pd multilayer with hydrogen silsesquioxane and amorphous Si intermediate layer.'' J. Vac. Sci. Technol. B, 24(6), 2616, Nov/Dec 2006.