Patent ID: 6030753
Filing Date: 2000-02-29
Classification: B82Y,G01R,G11B,Y10T

Abstract:
A method for fabricating a longitudinal bias layer and conductor leads at end regions of magnetoresistive sensor elements, said magnetoresistive sensor elements having an upper magnetoresistive sensor thin film layer, to form a sensor region between said end regions, comprising the steps of:depositing a uniform longitudinal bias thin film layer overlaying the entirety of said upper magnetoresistive sensor thin film layer, said uniform layer having a thickness greater than a bias critical thickness, said bias critical thickness comprising the thickness required to maintain a longitudinal bias field, to stabilize said magnetoresistive sensor elements;depositing a uniform conductor thin film layer overlaying the entirety of said longitudinal bias thin film layer;conducting a photoresist process over said conductor thin film layer to develop a mask of said end regions and to expose a central region between said end regions;conducting a reactive-ion-etching process to completely etch said conductor thin film layer in said exposed central region to expose said longitudinal bias layer in said central region between said end regions;removing said photoresist mask; andconducting an ion milling process of at least said exposed longitudinal bias layer at said central region to a thickness thereof which is less than a null critical thickness, said null critical thickness comprising the thickness below which said longitudinal bias field is substantially zero, thereby forming a sensor region of said magnetoresistive sensor elements at said exposed longitudinal bias layer at said central region.