Graphene magnetic tunnel junction spin filters and methods of making
AssigneeUniversity of North Texsas
InventorsJeffry Kelber, Mi Zhou
Life of this patent
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Abstract
A Tunnel Magnetic Junction of high magnetoresistance is prepared at temperatures and pressure consistent with Si CMOS fabrication and operation. A first metal layer of cobalt or nickel is grown on an interconnect or conductive array line of e.g., copper. The metal layer is formed by electron beam irradiation. Annealing at UHV at temperatures below 700K yields a carbon segregation that forms a few layer thick (average density 3.5 ML) graphene film on the metal layer. Formation of a second layer of metal on top of the graphene barrier layer yields a high performance MTJ.
Claims17
A method for forming a few molecular layer thick film of graphene on a metal layer, comprising depositing said metal layer on a substrate by electron beam deposition, and annealing the metal layer so deposited at temperatures below 700 K for a period of time sufficient to induce segregation of carbon in said metal layer to a surface of that metal layer, whereby a few molecule layer thick film of graphene is formed on said metal layer.
A magnetic tunnel junction (MTJ) of high tunneling magnetoresistance (TMR) in excess of 250%, comprising a first metal layer, a few molecule layer film of graphene on said first metal layer, and a second metal layer on said graphene film.
A magnetoresistive random access memory (MRAM) comprising a first array of parallel conductive lines disposed on a substrate and a second array of parallel conductive lines over said first array, wherein said first and second array are perpendicular with respect to each other, and at least one crossing point there between, wherein said crossing point comprises an MTJ of a first layer of metal in electrical contact with at least one line of said first array, a few molecule thick layer of graphene on said first layer of metal, and a second layer of metal on said thin film of graphene, wherein said second metal layer is in electrical contact with at least one line of said second array.
Dependencies are inferred from the claim text.