Magnetic head, disk drive with the same and method of manufacturing magnetic head

A disk drive comprising:

• a disk-shaped recording medium comprising a magnetic recording layer;
• and
• a magnetic head assembly configured to record data on the recording medium, the magnetic head assembly comprising:
• a slider comprising an air bearing surface, a first surface crossing the air bearing surface, and a second surface crossing the air bearing surface;
• a main pole in the slider, configured to produce a magnetic field for recording and comprising a distal end portion extending to the air bearing surface;
• a write shield in the slider, opposing the distal end portion of the main pole with a write gap therebetween;
• a high-frequency oscillator provided between the main pole and the write shield within the write gap and electrically connected to the main pole and the write shield, the high-frequency oscillator comprising a spin injection layer and an oscillation layer stacked one on another, and at least the oscillation layer being recessed in a direction away from the air bearing surface with respect to the main pole and the write shield;
• a contact pad provided on the first surface and electrically connected to the high-frequency oscillator;
• and
• a connection terminal provided on the second surface and electrically connected to the high-frequency oscillator to supply electricity to the high-frequency oscillator;
• wherein the write gap is formed to be 30 nm or less, and the oscillation layer is recessed by 1 nm or more;
• and
• wherein a length of the write gap is represented by Lwg (nm) and a depth of recess of the oscillation layer from the air bearing surface is represented by rh (nm), the depth rh satisfies a relationship:
• (−0.00407×Lwg2+0.0934×Lwg+1.1)<rh<9.