Bilayer resist lift-off method and intermediate structure for forming a GMR sensor

A method for manufacturing a magnetic disk drive, the method comprising:

• providing a magnetic disk;
• movably disposing an actuator arm proximate the magnetic disk;
• forming a magnetoresistive head comprising a read sensor, wherein forming the read sensor comprises:
• forming a sensor layer;
• forming a release layer over the sensor layer;
• forming a resist layer over and adjacent to the release layer, the resist layer formed of an actinic radiation curable material;
• patterning the resist layer;
• plasma etching the release layer to remove at least a portion of the release layer that lies generally under the removed portion of the resist layer such that the release and resist layers form a bilayer mask;
• and
• removing a portion of the sensor layer that lies generally underneath the removed portions of the release and resist layers to define the read sensor;
• and
• attaching the magnetoresistive head to the actuator arm such that the read sensor is positioned to detect magnetically stored data on the magnetic disk.

A method for forming a lift-off mask, the method comprising:

• forming a release layer;
• forming a resist layer over the release layer;
• patterning the resist layer to form a patterned resist layer;
• anisotropically plasma etching away a first portion of the release layer;
• and
• isotropically etching away a second portion of the release layer to provide a patterned release layer disposed generally underneath the patterned resist layer.

A structure existing during formation of a read sensor of a magnetoresistive head, the structure comprising:

• a sensor layer;
• a patterned resist layer patterned to form a bridge over a portion of the sensor layer;
• and
• a patterned release layer disposed to support ends of the bridge of the patterned resist layer over the portion of the sensor layer, wherein at least a portion of the bridge is unsupported by the patterned release layer such that a gap exists between the bridge and the portion of the sensor layer.