Differentiated liftoff process for ultra-shallow mask defined narrow trackwidth magnetic sensor

A method for manufacturing a magnetic read sensor, comprising:

• depositing a plurality of sensor layers;
• depositing a chemical mechanical polishing (CMP) stop layer over the plurality of sensor layers;
• forming a first mask structure directly onto the CMP stop layer, the first mask structure covering a field area removed from a sensor area and having an opening that extends over the sensor area and also over an area adjacent to the sensor area;
• depositing a hard mask layer over the CMP stop layer and over the first mask structure;
• forming a second mask structure, the second mask structure having a first portion that covers an area configured to define a sensor dimension and having a second portion that is formed over a portion of the first mask structure that is in the field area removed from the sensor area;
• transferring an image of the second mask structure onto the hard mask layer;
• and
• performing an ion milling.