Magnetoresistance effect device

• US 20070070553A1
• Filed: 09/27/2006
• Published: 03/29/2007
• Est. Priority Date: 09/27/2005
• Status: Active Grant

• Current Assignee: Canon Anelva Corporation (Canon Inc.)
• Original Assignee: Canon Anelva Corporation (Canon Inc.)
• Inventors: Tsunekawa, Koji, Djayaprawira, David
• Granted Patent: US 7,813,088 B2
• Time in Patent Office: Days
• US Class Current: 360/313
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell

Abstract

A magnetoresistance effect device has a fixed ferromagnetism layer, a free ferromagnetism layer, and a barrier layer sandwiched by these ferromagnetic layers. It is constituted so that CoFeB whose amount of addition of boron B (b: atomic %) is 21%≦b≦23% may be used for the free ferromagnetism layer. In the magnetic resistance effect element, a magnetostrictive constant does not change steeply near the magnetostrictive constant zero. A MR ratio is maintained to be high.

Claims

1. A magnetoresistance effect device comprising a fixed ferromagnetism layer, a free ferromagnetism layer and a barrier layer sandwiched by said fixed ferromagnetism layer and said free ferromagnetism layer,

wherein CoFeB in which an amount (b:

atomic %) of addition of boron (B) satisfies a condition of 21%≦

b≦

23% is used for said free ferromagnetism layer.

2. The magnetoresistance effect device as set forth in claim 1, wherein said barrier layer contains an MgO layer.

3. The magnetoresistance effect device as set forth in claim 1, wherein said barrier layer contains only an MgO layer.

4. A magnetoresistance effect device comprising a fixed ferromagnetism layer, a free ferromagnetism layer and a barrier layer sandwiched by said fixed ferromagnetism layer and said free ferromagnetism layer,

wherein CoNiFeB in which an amount (a:

atomic %) of addition of nickel (Ni) satisfies a condition of 5%≦

b≦

17% is used for said free ferromagnetism layer.

5. The magnetoresistance effect device as set forth in claim 4, wherein said barrier layer contains an MgO layer.

6. The magnetoresistance effect device as set forth in claim 4, wherein said barrier layer contains only an MgO layer.