Patent ID: 7177178

Claim:
A ferromagnetic thin-film material based digital memory, said memory comprising: a plurality of bit structures, each supported on a substrate and separated from one another by spacer material therebetween, and that are electrically interconnected with information retrieval circuitry, said bit structures each comprising a first magnetic material film in which a characteristic magnetic property is substantially maintained below a first critical temperature above which such magnetic property is not maintained, and further comprising a second magnetic material film such that said second magnetic material film is separated from said first magnetic material film by at least a layer of nonmagnetic material, said bit structures each having a first interconnection structure providing electrical contact thereto positioned against at least one side thereof; and a plurality of word line structures each having a pair of word line end terminal regions adapted to conduct electrical current in at least one direction therethrough, each of said pairs of word line end terminal regions having an electrical conductor electrically connected therebetween which is located across said spacer material from said first and second magnetic material films in a corresponding one of said bit structures and exhibiting sufficient electrical resistance there for a sufficient electrical current therethrough to cause substantial heating of a selected said corresponding bit structure, a pair of said word line structures each having said electrical conductor thereof positioned on opposite sides of a said bit structure corresponding thereto so as to have said bit structure common to each and with these said electrical conductors extending in different directions so that a sufficient electrical current through each causes substantial heating of said common corresponding bit structure to raise temperatures thereof to have said first magnetic material film therein at least approach said first temperature while being substantially above temperatures of at least an adjacent said bit structure because of sufficient extents of, and smallness of thermal conductivities of, said first interconnection structure positioned against said selected bit structure and of those portions of said substrate and said spacer material positioned thereabout.