Method and system for removing an antiferromagnetic seed structure

A method for fabricating a transducer on a substrate having a device region and a field region, the device region and the field region each including an antiferromagnetic seed structure and magnetic materials residing on the antiferromagnetic seed structure, the antiferromagnetic seed structure including a first NiFe layer, a first multilayer, a second NiFe layer, and a second multilayer, the first multilayer including a first CoFe layer, a second CoFe layer and a first Ru layer between the first CoFe layer and the second CoFe layer, the first multilayer residing between the first NiFe layer and the second NiFe layer, the second multilayer including an IrMn layer, a third NiFe layer, and a second Ru layer between the third NiFe layer and the IrMn layer, the second multilayer residing on the second NiFe layer, the method comprising:

• removing at least the second multilayer, the second NiFe layer and at least a portion of the first Ru layer using a first wet etch process, the first wet etch process using a first etchant combination including a first etch bath, a second etch bath, and at least one lift-off mechanism coupled with at least one of the first etch bath and the second etch bath, Ru being insoluble in the first etchant combination, IrMn being partially soluble in the first etchant combination, the first etchant combination being configured to remove NiFe, CoFe, and CoNiFe, the first etch bath including at least nine and not more than eleven volume percent hydrochloric acid, the second etch bath including at least five and not more than seven volume percent hydrochloric acid, at least ten and not more than twelve volume percent sulfuric acid, and at least nine and not more than eleven volume percent hydrogen peroxide, the at least one lift-off mechanism including at least one of an etch time in the second etch bath of at least three minutes, agitating at least the second etch bath at an agitation speed of at least 50 mm/s, applying ultrasound to at least the second etch bath and applying at least one high pressure spray, at least the second Ru layer and at least a portion of the IrMn layer being removed through lift-off due to etching of the second NiFe layer;
• removing a remaining portion of the first Ru layer using a second wet etch process, the second wet etch process configured to remove Ru and including nitric acid and ceric ammonium nitrate;
• removing a remaining portion of the first multilayer and the first NiFe layer using a third etch process, the third etch process configured to remove the NiFe and the CoFe and including sulfuric acid, hydrochloric acid, and hydrogen peroxide.