Method and system for defining a read sensor using an ion mill planarization

A method for fabricating a magnetic transducer having a magnetoresistive stack, the method comprising:

• providing a mask on the magnetoresistive stack corresponding to a magnetic junction;
• performing at least one of an ion milling and a reactive ion etch on an exposed portion of the magnetoresistive stack to define the magnetic junction, the magnetic junction having a top and a plurality of sides, the step of ion milling the magnetic junction redepositing a portion of the magnetoresistive stack and forming fencing adjacent to the top of the magnetic junction;
• providing at least one hard bias structure after the magnetoresistive structure is defined, a first portion of the at least one hard bias structure being substantially adjacent to the magnetoresistive junction in a track-width direction, the at least one hard bias structure including at least one seed layer, at least one hard bias material on the at least one seed layer, and a capping layer on the at least one hard bias material, the capping layer having a thickness of not more than twenty nanometers;
• removing a remaining portion of the mask after the at least one hard bias structure is provided;
• depositing a sacrificial layer covering the magnetic junction, the fencing, and the at least one hard bias structure, the sacrificial layer having an ion milling removal rate depending on a milling angle, the sacrificial layer being solid and having a thickness of at least twenty Angstroms and not more than sixty Angstroms;
• ion milling the transducer at an angle of at least seventy degrees from a normal to a surface of the magnetic transducer;
• and
• optionally repeating the steps of depositing the sacrificial layer and ion milling until the fencing is removed without chemically mechanically planarizing the magnetic transducer.