Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Masayuki Sagoi

Kentaro Nakajima

Yoshiaki Saito

Tatsuya Kishi

Koichiro Inomata

Minoru Amano

Shigeki Takahashi

Yoichiro Tanaka

Reiji Nishikawa

Yoshihisa Iwata

Osamu Watanabe

Masayuki Itoh

Akio Hori

Hiroki Nakamura

Yuui Shimizu

Yoshiaki Terashima

Tadao Miura

Masami Miyauchi

Kunio Sekine

Noritsugu Kawashima

A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni&#x2014;Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.

Magnetoresistive element and magnetic memory device

A method of manufacturing a magnetoresistance effect device, including: forming a first ferromagnetic body, a nonmagnetic dielectric layer on the first ferromagnetic body, and a second ferromagnetic body on the nonmagnetic dielectric layer; etching part of an external region of a predetermined ferromagnetic tunnel junction region using a first linear mask pattern which is traversing the predetermined ferromagnetic tunnel junction region; and etching another part of the external region of the predetermined ferromagnetic tunnel junction region using a second linear mask pattern which is traversing the predetermined ferromagnetic tunnel junction region and intersecting with the first linear mask pattern.

Method of manufacturing a magnetoresistance effect device

A semiconductor memory device comprises word lines, bit lines, memory cells, a row decoder, a column decoder, and a write circuit. The word lines are formed along a first direction. The bit lines are formed along a second direction. Memory cells include magneto-resistive elements and are arranged at intersections of the word lines and the bit lines. The row decoder selects at least one of the word lines. The column decoder selects at least one of the bit lines. The write circuit supplies first and second write currents to a selected word line and selected bit line respectively and writes data into a selected memory cell arranged at the intersection of the selected word line and the selected bit line. The write circuit changes the current values of the first and second write currents according to a temperature change.

Semiconductor memory device having memory cells including ferromagnetic films and control method thereof

There is provided a magnetoresistance effect element including a first pinned ferromagnetic layer, a second pinned ferromagnetic layer facing the first pinned ferromagnetic layer, surface regions of the first and second pinned ferromagnetic layer facing each other being different from each other in composition, a free ferromagnetic layer intervening between the first and second pinned ferromagnetic layers, a first tunnel barrier layer intervening between the first pinned ferromagnetic layer and the free ferromagnetic layer, and a second tunnel barrier layer intervening between the second pinned ferromagnetic layer and the free ferromagnetic layer.

Ferromagnetic double tunnel junction element with asymmetric energy band

There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.

Magnetic memory with reduced write current

A magnetoresistive element has a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second dielectric layer/a third ferromagnetic layer/a second antiferromagnetic layer. The second ferromagnetic layer that is a free layer consists of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni&mdash;Fe alloy/a Co-based alloy. A tunnel current is flowed between the first ferromagnetic layer and the third ferromagnetic layer.

Magnetic memory having antiferromagnetically coupled recording layer

A magnetoresistance effect devices having a magnetization free layer free to rotate in an applied magnetic field. The magnetization free layer may include first and second ferromagnetic material layers with a nonmagnetic material layer disposed between the two ferromagnetic material layers. Those ferromagnetic materials are antiferromagnetically coupled with each other at a magnetic coupling field J (&minus;3 &lsqb;kOe&rsqb;&lE;J<0 &lsqb;kOe&rsqb;) or ferromagnetically coupled with each other. Alternatively, the magnetization free film includes a first ferromagnetic material layer including a center region having a first magnetization and edge regions having a second magnetization different from the first magnetization and a second ferromagnetic material layer including a center region having a third magnetization parallel to the first magnetization and edge regions having a fourth magnetization different from the third magnetization. In another embodiment, a roughness at an interface between the first ferromagnetic material layer and the first nonmagnetic material coupling layer or an interface between the first second ferromagnetic material layer and the first nonmagnetic material coupling layer is more than 2 angstroms. Also, the magnetization free layer may be formed of ferromagnetic material portions ferromagnetically coupled to each other, or of a nonmagnetic material layer and a first ferromagnetic material layer having a non-uniform film thickness.

Magnetoresistance effect device

Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The magnetoresistance effect devices may be used in a magnetic memory apparatus, such as a random access memory, a personal digital assistance, a magnetic reproducing head, and a magnetic information reproducing apparatus.

Magnetoresistance effect device, magnetic memory apparatus, personal digital assistance, and magnetic reproducing head, and magnetic information

A magnetic memory device includes a plurality of magnetoresistive elements arranged on a first plane in a matrix form, a plurality of first writing lines which are arranged on a second plane different from the first plane adjacent to the magnetoresistive elements, a first address decoder which selects a desired one from the plurality of first writing lines, a plurality of second writing lines crossing the plurality of first writing lines on a third plane different from the second plane and having parts adjacent to the plurality of magnetoresistive elements on the second plane and parallel to the plurality of first writing lines, and a second address decoder which selects a desired one from the plurality of second writing lines.

Growing community of inventors

Yokohama, Japan

Masayuki Sagoi