Pole track width

Deposition and patterning of the bottom magnetic pole follow. The pole is usually electroplated with a through-photoresist window frame mask to a thickness level of 2 to 4 fim. Note that whereas the magnetic pole is made into a pancake shape to increase the head efficiency, it is the narrow p>ole tip s dimension that determines the narrow track width. As stated, the widely used Co-based alloy magnetic poles are elec-trodeposited (wet process). Nanocrystalline FeN-based alloys are sputter-deposited in a vacuum chamber (dry process). 

As the head track width decreases, remanent magnetization of the main pole tip is likely to occur because of stress-induced anisotropy and increased shape anisotropy in the normal direction to the ABS. The field from this remanent magnetization can... 

The increase in the peak width as well as the amplitude and slope of the skew term over time is a natural consequence of detector aging, and can be tracked by the periodic calibration of these parameters. The appearance of a long left skew and a signiftcant, irremovable right skew can be signs of the damage to the semiconductor crystal, which can temporarily be fixed by adjusting the pole/zero in the RC-feedback preamplifier. 

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