Lead overlay spin valve sensor with antiferromagnetic layers in passive regions for stabilizing a free layer

摘要

First and second hard bias layers abut first and second side surfaces of a spin valve sensor and first and second lead layers are connected to the sensor for conducting a sense current transversely therethrough. The spin valve sensor has a transverse length between the first and second side surfaces which is divided into a track width region between first and second passive regions wherein the track width region is defined by a space between the first and second lead layers. A free layer in the sensor has first and second passive portions in the first and second passive regions and the first and second passive portions have first and second surfaces respectively. First and second antiferromagnetic (AFM) layers are exchange coupled to the first and second surfaces of the free layer for longitudinally biasing the first and second passive portions of the free layer.