Tunnel Valve Flux Guide With Active Region AP Free Layer Structure and a Single Magnetic Layer Flux Guiding Element
Original Publication Date: 2003-Feb-02
Included in the Prior Art Database: 2003-Jun-21
Disclosed is a tunnel-valve flux guide structure that has an anti-parallel (AP) free layer structure. During the fabrication process, one layer of the AP free layer structure is selectively oxidized to form the magnetic conducting flux guide which propagates flux from the air bearing surface to the sensing region. The fabrication sequence uses an insitu deposition of all the tunnel valve layers (pinned layer on the top structure), local ion milling to remove all layers of the tunnel valve down to the top layer of the ap free layer, and selective oxidation of the top layer of the ap free layer. The advantage of this design is two fold: 1) only the bottom free layer and the ap spacer layer and the bottom lead material are exposed at the abs or more specifically no gap barrier material is exposed at the abs 2) the net moment of the resulting flux guide layer is greater than the net moment of the ap layer free layer. These two points provide a more corrosion resistant sensor at the air-bearing surface (ABS) and a more efficient tunnel valve structure.