Methods for fabricating a magnetic sensor head using a cmp defined hard bias and a totally flat reader gap

A method for fabricating magnetic sensor heads with flat reader gaps, the method comprising:

• defining a track width of a read sensor of a magnetic sensor head;
• depositing an insulator layer on the read sensor;
• depositing a hard bias layer on the insulator layer;
• performing a lift-off process to remove a mask structure deposited while defining the read sensor, wherein the mask structure is removed on side regions of the read sensor;
• and
• performing a chemical mechanical polishing (CMP) process down to a protective layer on the read sensor deposited while defining the read sensor to remove an overfill portion of the hard bias layer above the protective layer and to remove the mask structure above the protective layer.

A method for fabricating magnetic sensor heads with flat reader gaps, the method comprising:

• depositing sensor layers;
• depositing a protective layer on the sensor layers;
• depositing a masking layer on the protective layer, wherein the masking layer is etchable for definition of a mask structure;
• etching the protective layer around the mask structure to remove a portion of the protective layer;
• etching the sensor layers to define a read sensor;
• depositing an insulator layer on the read sensor;
• depositing a hard bias layer on the insulator layer;
• and
• performing a chemical mechanical polishing (CMP) process down to the protective layer to remove an overfill portion of the hard bias layer above the protective layer and to remove the mask structure above the protective layer.