Patent ID: 7266013
Filing Date: 2007-09-04
Classification: G11C,H01L

Abstract:
1. 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 in which a characteristic magnetic property is substantially maintained below a second critical temperature above which such magnetic property is not maintained, and yet further comprising a third magnetic material film in which a characteristic magnetic property is substantially maintained below a third critical temperature above which such magnetic property is not maintained, such that said third magnetic material film is separated from said first and second magnetic material films by at least one layer of a 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, second and third 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 to raise temperatures thereof to have said first, second and third magnetic material films therein at least approach that one of said first, second and third critical temperatures of greatest value while being substantially above temperatures of at least an adjacent said bit structure because of sufficient extent 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.