Seagate Technology Incorporated

Wei C Hsie

Nathan Curland

Michael M Collver

Uri Cohen

Timothy A Madsen

Timothy A Masaden

A magnetoresistive sensor includes a track width oxide layer which overlies a magnetoresistive element. Etch stop layers lie on opposite sides of the magnetoresistive element adjacent a magnetoresistive element. Contact/boundary control layers overlie the etch stop layer and lie adjacent the track width oxide layer. A separate loft oxide layer overlies the contact/boundary control layers and the track width oxide layer. The magnetoresistive sensor is formed by depositing a track width oxide to a thickness of the contact/boundary control layers.

Planarized magnetoresistive sensor

Method of manufacturing a planarized magnetoresistive sensor

A thin film magnetic read/write head deposited upon a magnetic substrate and including a shallow top pole take-off angle reduces leading and trailing undershoots in an isolated pulse signal. The undershoots are reduced by minimizing the magnetic discontinuities across the recording surface of the head, except for the recording gap.

Method of making a thin film head on ferrite substrate with inclined top

Thin film head on ferrite substrate with inclined top pole

An etchant for etching iron-silicon-aluminum trialloys comprises a one liter aqueous solution of ammonium bifluoride and nitric acid in the range of about 0.03 to 0.1 Moles of ammonium bifluoride and 3.5 to 10 Moles of nitric acid with the remainder being water. The etch is applied directly to the iron-silicon-aluminum trially at room temperature in an isotropic and isothermal process.

Process of etching iron-silicon-aluminum trialloys and etchant solutions

The seed-layer, or metallization layer, used to form the coil winding in a thin film head (TFH) by electrodeposition, is removed from between individual winding turns by selective etching with an etchant which preferentially, or selectively, attacks the seed-layer while leaving the coil winding, insulation, and gap materials essentially intact. A suitable combination of compatible materials which can be used as the seed-layer, coil winding, and etchant, respectively, in practicing this invention comprises nickel-iron Permalloy, copper, and a mixture of nitric acid and phosphoric acid diluted in pure water. Other combinations of materials and types of etching processes suitable for this invention are also disclosed.

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Eden Prairie, MN, United States of America

Wei C Hsie