Method for manufacturing a magnetic read sensor with narrow track width using amorphous carbon as a hard mask and localized CMP

A method for manufacturing a magnetic read sensor comprising:

• forming a magnetic shield;
• depositing a series of sensor layers over the magnetic shield;
• forming an amorphous carbon mask over the series of sensor layers, the amorphous carbon mask having first and second openings at first and second sides of a central trackwidth defining portion, the first and second openings and central trackwidth defining portion defining a sensor area;
• performing a first ion milling to remove portions of the series of sensor layers that are exposed through the openings in the amorphous carbon layer;
• depositing a non-magnetic, electrically insulating material followed by a magnetic material;
• forming a photoresist mask over the sensor area;
• performing a second ion milling to remove portions of the non-magnetic, electrically insulating material and the magnetic material that are not protected by the photoresist mask;
• removing the photoresist mask;
• performing a third ion milling to remove the non-magnetic, electrically insulating material and the magnetic material from side portions of the amorphous carbon layer;
• and
• performing a reactive ion etching to remove the remaining amorphous carbon layer.