Patent ID: 7097777

Claim:
A method of patterning metal stack layers of a magnetic switching device, the method comprising: providing a substrate having a first conductive line and a second conductive line formed therein and having a first dielectric layer formed over the substrate, the first dielectric layer having a via formed therethrough, the via being in electrical contact with the first conductive line, a magnetic tunnel junction stack being formed over the first dielectric layer; forming a first hardmask layer over the magnetic tunnel junction stack; forming a second hardmask layer over the first hardmask layer; patterning the second hardmask layer such that a first portion of the second hardmask layer over the first conductive line is removed and a second portion of the second hardmask layer over the second conductive line remains; patterning the first hardmask layer such that a portion of the first hardmask layer overlying the first conductive line and the second conductive line remains; patterning the magnetic tunnel junction stack in accordance with remaining portions of the first hardmask layer; and patterning the first hardmask layer in accordance with remaining portions of the second hardmask layer.