Spin valve sensor with encapsulated keeper layer and method of making

摘要

A spin valve sensor is provided with a keeper layer which forms a partial flux-closure with a reference layer so as to minimize sensitivity of readback signal asymmetry to the sensor stripe height while maintaining a high readback signal. The keeper layer is encapsulated with top and bottom oxide layers, as well as first and second side oxide layers which form contiguous junctions with first and second side edges of the keeper layer. The top oxide layer may be a seed layer for the spin valve sensor for improving its giant magnetoresistance properties. The bottom oxide layer may be an antiferromagnetic film for pinning the magnetic moment of the keeper layer. The first and second side oxide layers function as refill first gap layers for minimizing the risk of electrical shorts between the bottom shield layer and the first and second hard bias and lead layers of the read head.