US 5,479,308 A · Magnetoresistive transducer including interdiffusion layer

Abstract

A magnetoresistive transducer has a sensor which includes a magnetic layer and an interdiffusion layer. An active central region of the sensor extends between two passive end regions which are used to magnetically bias the active central region longitudinally. The biasing function is attained by fabricating the transducer on a wafer in an H-configuration, with the crossbar of the H as the active central region and a portion of the side legs as the passive end regions. When short current pulses are passed through the side legs of the H, the associated heating of the side legs (but not the crossbar of the H) causes interdiffusion between the interdiffusion layer and the magnetic layer and transforms the magnetic layer from soft magnetism to hard magnetism as required for the biasing function. The wafer is diced near the crossbar of the H and then processed further to form the finished transducer.

Claims12

Dependent claims

A magnetoresistive read transducer comprising:

a sensor configuration having passive end regions separated by an active central region;
a first layer of a magnetoresistive conductive material, said magnetoresistive conductive material containing a nickel-iron alloy;
a second layer of nonmagnetic material in contact with said first layer and extending over said active central region and said passive end regions, said nonmagnetic material containing a member of the group consisting of titanium, tantalum, chromium, and the refractory and transition metals, wherein the passive end regions have been heated above an activation temperature, thereby causing an interdiffusion between the materials of the first and second layers, and wherein said interdiffusion has transformed the magnetic characteristics of the first layer from soft-magnetic to hard-magnetic such that said passive end regions provide longitudinal magnetic biasing of said active central region.

Dependencies are inferred from the claim text.

Magnetoresistive transducer including interdiffusion layer

Life of this patent

Magnetoresistive transducer including interdiffusion layer

Life of this patent

Abstract

Claims12