Patent ID: 8208230

Claim:
A method to form a two state magneto-resistive (MR) device, comprising: providing a bottom shield, having a lower surface that is on a substrate, and depositing in succession, on said bottom shield, a seed layer, a pinning layer, a pinned layer, a spacer layer, a free layer, and a capping layer, thereby forming a MR complex; patterning said MR complex to form a MR device stack having a front edge that is normal to said bottom shield and a back edge comprising an upper part that is normal to said bottom shield and a lower part that slopes away from said front edge at an angle; said upper part comprising said capping layer and said lower part comprising said seed layer, said pinned and pinning layers, said spacer layer and said free layer; then lapping said front edge to form an air bearing surface (ABS) whose width defines a track width (TW), and whose distance from said back edge defines a stripe height (SH); said SH value ranging from 0.9 to 2 times said TW value; forming a back end of said MR complex that extends away from said back edge over said bottom shield; and ensuring that said free layer has zero magnetization in a direction parallel to said ABS, whereby, in the presence of an external magnetic field, said MR device has one of only two possible resistance values, giving it a utilization rate of at least 80% and an output signal of at least 56 mV at a full dR/R of about 50% and an applied voltage of about 140 mV.