摘要 |
A method for forming metrology structures on a wafer on which magnetic transducers are being fabricated is disclosed. The metrology structures have a measurable electrical resistance which is an accurate surrogate for a physical dimension of a structure of the magnetic transducer, such as a pole piece tip. The metrology structure is preferably a resistor with pads usable with a four point probe. The resistor is preferably formed by creating a sacrificial pole piece structure over a pad of resistive material. The narrow dimension of the pole tip is then used as a mask to replicate the width of the pole tip in the resistive material through a milling process which removes resistive material outside of the masked area of the resistor pad. Control structures with unmilled pads of resistive material are formed along with the metrology structures to provide the sheet resistance of the pads prior to milling. Knowledge of the sheet resistance allows the resistance of the milled structure to be converted into an accurate measure of the physical dimension of the pole piece tip.
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