Tunnel magnetoresistance read head with narrow shield-to-shield spacing
View Patent ↗A tunnel magnetoresistance (TMR) read sensor having a tabbed AFM layer and an extended pinned layer and methods for making the same are provided. The TMR read sensor has an AFM layer recessed from the air bearing surface, providing a reduced shield-to-shield distance.
1. A method, comprising:
obtaining a substrate comprising a shield layer;
depositing a read sensor seed layer on the substrate over the shield layer;
forming a photoresist pattern on the read sensor seed layer;
etching the read sensor seed layer and shield layer to form a region for antiferromagnetic layer and antiferromagnet exchange biased pinned layer deposition, the region being recessed from an air bearing surface plane;
depositing the antiferromagnetic layer in the region; and
depositing the antiferromagnet exchange biased pinned layer in the region over the antiferromagnetic layer.
2. The method of claim 1 , further comprising:
etching the substrate for surface planarization after depositing the antiferromagnet exchange biased pinned layer in the region;
depositing a second pinned layer over the antiferromagnet exchange biased pinned layer and the remaining read sensor seed layer intersecting the air bearing surface plane;
depositing a barrier layer over the second pinned layer and intersecting the air bearing surface plane;
depositing a free layer over the barrier layer and intersecting the air bearing surface plane; and
depositing a capping layer over the free layer and intersecting the air bearing surface plane.
3. The method of claim 2 , further comprising magnetically annealing an assembly formed after the step of depositing the capping layer.
4. The method of claim 1 , wherein the steps of etching the read sensor seed layer and shield layer to form a region for the antiferromagnet exchange biased pinned layer deposition and depositing the antiferromagnet exchange biased pinned layer are performed in situ.
5. The method of claim 1 , wherein the steps of etching the read sensor seed layer and shield layer to form a region for the antiferromagnet exchange biased pinned layer deposition and depositing the antiferromagnet biased pinned layer are performed ex situ.
6. The method of claim 1 , wherein the step of depositing the antiferromagnet exchange biased pinned layer comprises:
depositing a first soft ferromagnetic layer over the antiferromagnetic layer;
depositing a non-magnetic layer over the first soft ferromagnetic layer; and
depositing a second soft ferromagnetic layer over the non-magnetic layer; and
the non-magnetic layer having a thickness approximately equal to a first or a second oscillatory peak of the exchange coupling between the first soft ferromagnetic layer and the second soft ferromagnetic layer; and
the non-magnetic layer comprising Ru, Cr, Ag, or Au.