DUAL GMR WITH LEAD OVERLAY STRUCTURE
Original Publication Date: 2002-May-11
Included in the Prior Art Database: 2003-Jun-21
We disclose a design where the Free layer is sandwiched between two pinned layers. The bottom Pinned layer can be either self-pinned (i.e. no antiferromagnet used for pinning) or pinned with an antiferromagnet. The top Pinned layer is self-pinned. The hard bias layer stabilizes the Free layer. The current carrying leads overlap the hard bias layers and extend over the sensor stack and define the actual read sensor width. Before disposition of the leads, the top surface of the top pinned layer is ion etch cleaned. In this design, the Free layer is protected from the ion etch cleaning process which is known to cause damage to the Free layer through changes in film composition. The layers in this structure are: Al2O3/NiFeCr/NiFe/PtMn/CoFe/Ru/CoFe/Cu/CoFe/NiFe/CoFe/Cu/CoFe/Ru/CoFe/Ta/ The layers between the two "Cu" layers form the Free layer. Layers above the top "Cu" layer form the top Pinned layer.