Method for making a tunneling magnetoresistive (TMR) sensor

A tunneling magnetoresistive sensor has an extended pinned layer wherein both the MgO spacer layer and the underlying ferromagnetic pinned layer extend beyond the back edge of the ferromagnetic free layer in the stripe height direction and optionally also beyond the side edges of the free layer in the trackwidth direction. A patterned photoresist layer with a back edge is formed on the sensor stack and a methanol (CH3OH)-based reactive ion etching (RIE) removes the unprotected free layer, defining the free layer back edge. The methanol-based RIE terminates at the MgO spacer layer without damaging the underlying reference layer. A second patterned photoresist layer may be deposited and a second methanol-based RIE may be performed if it is desired to have the reference layer also extend beyond the side edges of the free layer in the trackwidth direction.