Magnetic etch-stop layer for magnetoresistive read heads
View Patent ↗A tunneling magnetoresistive read head produced thereby are disclosed. A shield layer is provided. A magnetic etch-stop layer is formed over the shield layer, where the magnetic etch-stop layer comprises a nonmagnetic metal and a soft magnetic material with overall property still being magnetically soft. A sensor stack is formed over the magnetic etch-stop layer. A patterned mask layer is formed over the sensor stack. Material from a portion of the sensor stack not covered by the patterned mask is removed.
1. A tunneling magnetoresistive read head comprising:
a shield layer;
a magnetic etch-stop layer disposed over the shield layer, the magnetic etch-stop layer comprising a nonmagnetic metal and a soft magnetic material, wherein the magnetic etch-stop layer comprises an alloy of the nonmagnetic metal and the soft magnetic material; and
a patterned sensor stack disposed over the magnetic etch-stop layer.
2. The tunneling magnetoresistive read head of claim 1 , wherein the patterned sensor stack comprises a plurality of magnetic layers.
3. The tunneling magnetoresistive read head of claim 2 , wherein the plurality of magnetic layers comprise a first magnetic layer comprising an antiferromagnetic material.
4. The tunneling magnetoresistive read head of claim 3 , further comprising a patterned magnetic seed layer disposed between the magnetic etch-stop layer and the first magnetic layer.
5. The tunneling magnetoresistive read head of claim 4 , further comprising an isolation layer comprising a nonmagnetic metal, the isolation layer disposed between the patterned magnetic seed layer and the first magnetic layer, the isolation layer configured to provide a magnetic isolation between the magnetic etch-stop layer and the first magnetic layer.
6. The tunneling magnetoresistive read head of claim 4 , wherein the magnetic seed layer comprises an alloy of iridium and manganese (IrMn), an alloy of cobalt, iron, and boron (CoFeB), or an alloy of nickel and iron (NiFe).
7. The tunneling magnetoresistive read head of claim 4 , wherein a composition of the nonmagnetic metal and the soft magnetic material provides the magnetic etch-stop layer an etching selectivity of at least 1.5 with respect to a material comprising the magnetic seed layer.
8. The tunneling magnetoresistive read head of claim 4 , wherein a composition of the nonmagnetic metal and the soft magnetic material provides the magnetic etch-stop layer an etching selectivity of at least 5 with respect to a material comprising the magnetic seed layer.
9. The tunneling magnetoresistive read head of claim 1 , wherein the nonmagnetic metal comprises Ta, Cr, or Zr.
10. The tunneling magnetoresistive read head of claim 1 , wherein the soft magnetic material comprises one or more of cobalt (Co), nickel (Ni), and iron (Fe).
11. The tunneling magnetoresistive read head of claim 1 , wherein the alloy is CoFeTa, NiFeTa, CoFeCr, NiFeCr, CoFeZr, or NiFeZr.
12. The tunneling magnetoresistive read head of claim 1 , wherein the magnetic etch-stop layer comprises a set of alternating layers of the nonmagnetic metal and the soft magnetic material.