Nve Corporation

Nonvolatile Electronics, Incorporated

Honeywell G.m.b.h.

Seagate Technology Incorporated

Other

Arthur V Pohm

James M Daughton

Brenda Anne Everitt

Mark Christopher Tondra

Allan T Hurst, Jr

James C Fletcher

James G Deak

Dexin Wang

William J Debnam, Jr

Carl L Fales, Jr

Roger A Breckenridge

Brenda A Everitt

A ferromagnetic thin-film based digital memory having a plurality of bit structures interconnected with manipulation circuitry having a plurality of transistors so that each bit structure has transistors electrically coupled thereto that selectively substantially prevents current in at least one direction along a current path through that bit structure and permits selecting a direction of current flow through the bit structure if current is permitted to be established therein. A bit structure has a nonmagnetic intermediate layer with two major surfaces on opposite sides thereof and a memory film of an anisotropic ferromagnetic material on each of the intermediate layer major surfaces with an electrically insulative intermediate layer is provided on the memory film on which a magnetization reference layer is provided having a fixed magnetization direction.

Circuit selection of magnetic memory cells and related cell structures

A ferromagnetic thin-film based digital memory cell with a memory film of an anisotropic ferromagnetic material and with a source layer positioned on one side thereof so that a majority of conduction electrons passing therefrom have a selected spin orientation to be capable of reorienting the magnetization of the film. A disruption layer is positioned on the other side of the memory film so that conduction electrons spins passing therefrom are substantially random in orientation. The magnitude of currents needed to operate the cell can be reduced using coincident thermal pulses to raise the cell temperature.

Current switched magnetoresistive memory cell

A ferromagnetic thin-film based digital memory having bit structures therein with a magnetic material film in which a magnetic property thereof is maintained below a critical temperature above which such magnetic property is not maintained, and may also have a plurality of word line structures each with heating sections located across from the magnetic material film in a corresponding one of the bit structures. These bit structures are sufficiently thermally isolated to allow selected currents in the adjacent word lines or in the bit structure, or both, to selectively heat the bit structure to approach the critical temperature. Such bit structures may have three magnetic material layers each with its own critical temperature for maintaining versus not maintaining a magnetic property thereof.

Magnetic memory layers thermal pulse transitions

A ferromagnetic thin-film based digital memory having a bit structures therein a magnetic material film in which a magnetic property thereof is maintained below a critical temperature above which such magnetic property is not maintained, and may also have a plurality of word line structures each with heating sections located across from the magnetic material film in a corresponding one of the bit structures. These bit structures are sufficiently thermally isolated to allow selected currents in the adjacent word lines or in the bit structure, or both, to selectively heat the bit structure to approach the critical temperature. Such bit structures may have three magnetic material layers each with its own critical temperature for maintaining versus not maintaining a magnetic property thereof.

magnetic memory layers thermal pulse transitions

A ferromagnetic thin-film based digital memory having a substrate formed of a base supporting an electrically insulating material primary substrate layer in turn supporting a plurality of current control devices each having an interconnection arrangement with each of said plurality of current control devices being separated from one another by spacer material therebetween and being electrically interconnected with information storage and retrieval circuitry. A plurality of bit structures are each supported on and electrically connected to a said interconnection arrangement of a corresponding one of said plurality of current control devices and have magnetic material films in which a characteristic magnetic property is substantially maintained below an associated critical temperature above which such magnetic property is not maintained of which two are separated by at least one intermediate layer of a nonmagnetic material having two major surfaces on opposite sides thereof. A plurality of word line structures located across from a corresponding one of the bit structures on an opposite side of the intermediate layer of a corresponding one of said bit structures from its interconnection arrangement supporting that bit structure. Sufficient electrical current selectively drawn through each of these bit structures as interconnected can cause substantial heating of that bit structure to raise temperatures thereof to have at least one of the magnetic material films therein at least approach its corresponding associated critical temperature while being substantially above temperatures of at least an adjacent said bit structure because of sufficient thermal isolation.

Magnetoresistive memory SOI cell

A ferromagnetic thin-film based digital memory having a substrate supporting bit structures that are electrically interconnected with information storage and retrieval circuitry and having magnetic material films in which a characteristic magnetic property is substantially maintained below an associated critical temperature above which such magnetic property is not maintained separated by at least one layer of a nonmagnetic material with each bit structure having an interconnection structure providing electrical contact thereto at a contact surface thereof substantially parallel to the intermediate layer positioned between the first contact surface and the substrate. A plurality of word line structures located across from a corresponding one of the bit structures on an opposite side of the intermediate layer of a corresponding one of said bit structures from its interconnection structure provides electrical contact thereto. Sufficient electrical current selectively drawn through each of these bit structures and its interconnection structure can cause substantial heating of that bit structure to raise temperatures thereof to have at least one of the magnetic material films therein at least approach its corresponding associated critical temperature while being substantially above temperatures of at least an adjacent said bit structure because of sufficient thermal isolation.

Thermally operated switch control memory cell

A ferromagnetic thin-film based digital memory having a plurality of bit structures electrically interconnected with information storage and retrieval circuitry that avoids information loss in one bit structure because of operating the others through this circuitry. Each of these bit structures formed of a relative orientation maintenance intermediate layer having two major surfaces on opposite sides thereof with a pair of memory films of an anisotropic ferromagnetic material each on a corresponding one of said relative orientation maintenance intermediate layer major surfaces. The relative orientation maintenance intermediate layer is of a material and a selected thickness so as to maintain magnetizations of said memory films oriented in substantially opposite directions. Interconnection electrodes pairs are each in electrically conductive contact with a corresponding one of the bit structures on substantially opposite sides thereof near or at substantially opposite edges of the relative orientation maintenance intermediate layer major surface. A magnetization reference direction layer able to maintain relatively well its magnetization orientation can be provided across a nonmagnetic layer from one of the pair of memory films with the nonmagnetic layer being either electrically conductive or insulative.

Antiparallel magnetoresistive memory cells

A stabilized GMR device includes a GMR stack having a first and a second edge. Stabilization means are positioned adjacent to the first and the second edge of the GMR stack for stabilizing the GMR stack. The GMR stack includes a first layer of ferromagnetic material and a second layer of ferromagnetic material. A spacer layer is positioned between the first and the second ferromagnetic layers. A buffer layer is positioned adjacent to the first magnetic layer and a cap layer is positioned adjacent to the second ferromagnetic layer. The stabilization means include a first coupler layer positioned adjacent to the first edge of the GMR stack and a second coupler layer positioned adjacent to the second edge of the GMR stack. The stabilization means also include a first ferromagnetic layer positioned adjacent to the first coupler layer and a second ferromagnetic layer positioned adjacent to the second coupler layer.

Stabilization of GMR devices

A ferromagnetic thin-film based digital memory including a memory cell having a bit structure with a nonmagnetic intermediate layer having a memory film of an anisotropic ferromagnetic material on each of the opposite side major surfaces of an intermediate layer with there being a film thickness difference there of at least five percent, or a film effective anisotropy field difference because of different ferromagnetic materials used therefor, or both. An electrically insulative intermediate layer is provided on the memory film across from one intermediate layer major surface, this insulative intermediate layer having a major surface on a side opposite the memory film on which a magnetization reference layer is provided having a relatively fixed magnetization direction. Manipulation circuitry coupled to the bit structure selectively substantially prevents current in at least one direction along a current path through that bit structure, and permit selecting the occurrence of current flow through the bit structure if to be permitted at a selected time.

Circuit selected joint magnetoresistive junction tunneling-giant magnetoresistive effects memory cells

A ferromagnetic thin-film based digital memory (FIG. ) having in a bit structure ( ) a coupled moment material film ( ) in which magnetic moments of adjacent atoms, ions or molecules are coupled to one another to maintain some alignment thereof below a critical temperature above which such alignment is not maintained, and also having a plurality of word line structures ( ) each located across from the coupled moment material film ( ) in a corresponding one of the bit structures ( ). The bit structures ( ) are sufficiently thermally isolated to allow currents in the adjacent word lines ( ) and/or the bit structure ( ) to heat the bit structure ( ) to approach the critical temperature which may be supplied coincidently and then reduced to cool the bit structure ( ) while supplying a magnetic field during the cooling.

Growing community of inventors

Ames, IA, United States of America

Arthur V Pohm