Chemistry: electrical and wave energy – Processes and products – Coating – forming or etching by sputtering
Patent
1997-05-23
1999-02-16
Beck, Shrive
Chemistry: electrical and wave energy
Processes and products
Coating, forming or etching by sputtering
2041922, 20419222, C23C 1446
Patent
active
058716220
ABSTRACT:
A process for making a spin valve magnetoresistive (SVMR) sensor includes forming a nickel-oxide (NiO) layer as the antiferromagnetic layer for pinning the magnetization of the pinned ferromagnetic layer in the SVMR sensor. The process includes forming the NiO layer directly on a substrate, which may be a wafer base having an alumina layer formed on it, by ion beam sputtering (IBS) a Ni target while simultaneously introducing oxygen into the IBS system. The high energy noble gas positive ions, which are typically Xe+ ions, eject the Ni atoms from the target with sufficient energy that they aid in the dissociation of the O.sub.2 at the substrate surface. The Xe+ beam is non-neutralized, thus simplifying the process for forming the subsequent layers of the SVMR sensor and increasing the throughput of the system. The alumina substrate can be formed on the wafer base prior to formation of the NiO layer by ion sputterring an Al target in the IBS system in the presence of the same oxygen atmosphere used for the subsequently deposited NiO layer. The SVMR sensor made according to the process has a ferromagnetic layer pinned by a substantially greater exchange field from the NiO layer and significantly improved magnetoresistance over SVMR sensors with NiO antiferromagnetic layers formed by prior art processes.
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Beck Shrive
International Business Machines - Corporation
Meeks Timothy
LandOfFree
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