A layered thin film device, such as a MTJ (Magnetic Tunnel Junction) device can be customized in shape by sequentially forming its successive layers over a symmetrically curved electrode. By initially shaping the electrode to have a concave or convex surface, the sequentially formed layers conform to that shape and acquire it and are subject to stresses that cause various crystal defects to migrate away from the axis of symmetry, leaving the region immediately surrounding the axis of symmetry relatively defect free. The resulting stack can then be patterned to leave only the region that is relatively defect free.

A magnetic detection circuit for a magnetic random access memory (MRAM) is provided. The magnetic detection circuit includes a sensing array including a plurality of sensing cells and a controller. Each of the sensing cells includes a first magnetic tunnel junction (MTJ) device. The controller is configured to access the first MRAM cells to detect the external magnetic field strength of the MRAM. The controller determines whether to stop the write operation of a plurality of memory cells of the MRAM according to the external magnetic field strength of the MRAM, and each of the memory cells includes a second MTJ device. The first MTJ device is smaller than the second MTJ device.

A magnetic detection circuit for a magnetic random access memory (MRAM) is provided. The magnetic detection circuit includes a sensing array including a plurality of sensing cells and a controller. Each of the sensing cells includes a first magnetic tunnel junction (MTJ) device. The controller is configured to access the first MRAM cells to detect the external magnetic field strength of the MRAM. The controller determines whether to stop the write operation of a plurality of memory cells of the MRAM according to the external magnetic field strength of the MRAM, and each of the memory cells includes a second MTJ device. The first MTJ device is smaller than the second MTJ device.

A seed layer stack with a uniform top surface having a peak to peak roughness of 0.5 nm is formed by sputter depositing an amorphous layer on a smoothing layer such as Mg where the latter has a resputtering rate 2 to 30 that of the amorphous layer. The uppermost seed (template) layer is NiW, NiMo, or one or more of NiCr, NiFeCr, and Hf while the bottommost seed layer is one or more of Ta, TaN, Zr, ZrN, Nb, NbN, Mo, MoN, TiN, W, WN, and Ru. Accordingly, perpendicular magnetic anisotropy in an overlying magnetic layer is substantially maintained during high temperature processing up to 400 C. and is advantageous for magnetic tunnel junctions in embedded MRAMs, spintronic devices, or in read head sensors. The amorphous seed layer is SiN, TaN, or CoFeM where M is B or another element with a content that makes CoFeM amorphous as deposited.

A seed layer stack with a uniform top surface having a peak to peak roughness of 0.5 nm is formed by sputter depositing an amorphous layer on a smoothing layer such as Mg where the latter has a resputtering rate 2 to 30 that of the amorphous layer. The uppermost seed (template) layer is NiW, NiMo, or one or more of NiCr, NiFeCr, and Hf while the bottommost seed layer is one or more of Ta, TaN, Zr, ZrN, Nb, NbN, Mo, MoN, TiN, W, WN, and Ru. Accordingly, perpendicular magnetic anisotropy in an overlying magnetic layer is substantially maintained during high temperature processing up to 400 C. and is advantageous for magnetic tunnel junctions in embedded MRAMs, spintronic devices, or in read head sensors. The amorphous seed layer is SiN, TaN, or CoFeM where M is B or another element with a content that makes CoFeM amorphous as deposited.

Magnetic tunnel junction (MTJ) structures, spin transfer torque magnetic random access memory (STT MRAM) structures, and methods for fabricating integrated circuits including such structures are provided. In an embodiment, an MTJ structure includes a cobalt iron carbon (CoFeC) fixed reference layer. Further, the MTJ structure includes a cobalt iron carbon (CoFeC) free storage layer. Also, the MTJ structure includes a tunnel barrier layer between the fixed reference layer and the free storage layer.

Magnetic tunnel junction (MTJ) structures, spin transfer torque magnetic random access memory (STT MRAM) structures, and methods for fabricating integrated circuits including such structures are provided. In an embodiment, an MTJ structure includes a cobalt iron carbon (CoFeC) fixed reference layer. Further, the MTJ structure includes a cobalt iron carbon (CoFeC) free storage layer. Also, the MTJ structure includes a tunnel barrier layer between the fixed reference layer and the free storage layer.

Provided is a magnetoresistive element including: a storage layer of which a magnetization direction changes in accordance with information; a first magnetization fixed layer below the storage layer having a magnetization direction perpendicular to a film surface; a second magnetization fixed layer above the storage layer having a magnetization direction that is perpendicular to the film surface and that is opposite to the magnetization direction of the first magnetization fixed layer; a first intermediate layer between the first magnetization fixed layer and the storage layer; and a second intermediate layer between the second magnetization fixed layer and the storage layer. The storage layer includes a first magnetic material layer, a non-magnetic material layer, and a second magnetic material layer laminated in that order, and one of the first magnetic material layer and the second magnetic material layer has a magnetization direction parallel to the film surface.

A magnetoresistive element according to an embodiment includes: a first layer containing Al and at least one element of Ni or Co, the first layer having a CsCl structure; a first magnetic layer; a first nonmagnetic layer between the first layer and the first magnetic layer; and a second magnetic layer between the first layer and the first nonmagnetic layer, the second magnetic layer containing Mn and Ga.

A magnetoresistive element according to an embodiment includes: a first layer containing Al and at least one element of Ni or Co, the first layer having a CsCl structure; a first magnetic layer; a first nonmagnetic layer between the first layer and the first magnetic layer; and a second magnetic layer between the first layer and the first nonmagnetic layer, the second magnetic layer containing Mn and Ga.