Optical metrology for MR heads

The volume production of magnetoresistive heads requires fast and precise measurement of many critical material parameters such as film thickness and roughness. Optical metrology is ideally suited to perform these measurements. We review and demonstrate the application of Ellipsometry and Scatterometry for MR head metrology. We report results for NiFe film thickness measurements and Sendust surface roughness measurements with sub-Angstrom precision and repeatability.