Fabrication of Patterned Media at Manchester

The magnetic films chosen for the fabrication of patterned media are Pt/Co multilayer thin films (1nm Pt seed layer + 15 [0.4nm Co/1nm Pt] bi-layer) due to their large perpendicular anisotropy and square hysteresis loops. The films were produced by vacuum deposition using an electron beam source at a average pressure of 4-5x10-7 mbar, and a substrate temperature of 200 C in order to achieve adequate {111} texture in the Pt seed layer and to induce high perpendicular anisotropy. In addition, we have developed a process for fabricating such multilayer structures on a thick (100nm) Permalloy (Ni81 Fe19 alloy) soft underlayer (SUL). These films have been characterised using both alternating gradient field magnetometer (AGFM) and magneto-optical Kerr effect (MOKE) techniques and have been shown to exhibit the desired characteristics of square hysteresis loops and high coercivity (2-4kOe - unpatterned, bulk film).

Patterned films were produced using electron beam lithography using the LEO 1530 Gemini FEG SEM with Raith Elphy Plus Lithography System with Laser Interferometer Stage available in Manchester Centre for Mesoscience and Nanotechnology.

Under development ...

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Created by Paul Nutter