Magnetoresistive transducer including interdiffusion layer

摘要

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.