Method for the rapid measurement of magnetoresistive read head dimensions

1. Field of the Invention An automated production process for the screening of the read-width (RW) and/or the stripe-height (SH) for every magnetoresistive (MR) read sensor element in a wafer substrate. The method of this invention uses the RW and/or SH values found with optical examination by electron microscopy of several of the MR sensor elements to estimate two substrate coefficients that relates the optical RW and SH measurements to heating-delta measurements, =(RH−RC)/RC, where RH is the sensor resistance when hot and RC is the sensor resistance when cold, both of which can be measured using automated equipment. These relationships are sufficiently similar among all MR sensor elements manufactured on a single wafer substrate during a single manufacturing procedure that, when the hot resistance RH is measured at a constant applied voltage, the heating-delta, may be used with a first substrate coefficient to estimate the read-width RW of each MR sensor element for quality-control purposes during manufacture. When the hot resistance RH is measured at a constant applied current, the heating-delta may be used with a second substrate coefficient to estimate the stripe-height SH of each MR sensor element for quality-control purposes during manufacture.