Rajeev R. Pillai fabricated lithographically patterned cobalt microstructures and characterized their properties. He used DC magnetron sputtering to deposit a thin film of cobalt on a silicon substrate, then direct laser beam writing and ion beam etching to pattern the cobalt film. Atomic force microscopy and magnetic resistance measurements were used to characterize the structural and magnetic properties of the cobalt microstructures. The resistance was found to vary with the angle between the magnetic field and current, showing the anisotropic magnetoresistance effect.

1. LITHOGRAPHICALLY PATTERNED COBALT MICROSTRUCTURES AND ITS CHARACTERISTICS RAJEEV R. PILLAI Register No: 071605100010 M.Tech Nano Technology Biotechnology Centre, Department of Nano Technology Anna University

5. Thin Film deposition process

7. Desired Microstructure

13. Sputtering Unit at IIsc

20. Ion Beam etching Base Pressure 3.6E-6mbar (250 Hz) Pressure with Argon = 2.6E-4mbar (183 Hz) Cathode filament current 3.19A Beam Voltage 400V Acceleration Voltage 200V Neutraliser filament current 2.79A Discharge Voltage 38V Discharge current = 0.16A Neutraliser emission current 16mA Beam current = 9mA Acceleration current 1mA

32. RESULTS: Co target - before & after sputtering

33. Cobalt microstructure Cobalt microstructure

39. Thank You