Patent ID: 8296930

Claim:
A method for manufacturing a magnetoresistive sensor, comprising: providing a substrate; depositing a plurality of sensor layers over the substrate; depositing a first thin high density carbon CMP stop layer over the plurality of sensor layers; forming a mask structure over the thin high density carbon CMP stop layer; transferring an image of the mask structure onto the thin high density carbon CMP stop layer; performing an ion milling to remove a portion of the plurality of sensor layers that are not protected by the mask and the thin high density carbon CMP stop layer; depositing a layer of hard magnetic bias material; depositing a capping layer over the hard bias material, the capping layer comprising a layer of Ta and at least one layer of Cr or Rh; depositing second high density carbon CMP stop layer; performing a chemical mechanical polishing to remove the mask structure, the chemical mechanical polishing including a first CMP step followed by a second CMP step, the first CMP step being more aggressive than the second CMP step; and performing a reactive ion etching to remove the first and second thin high density carbon CMP stop layer.