Magneto-resistive element having a ferromagnetic layer containing boron

• US 9,209,386 B2
• Filed: 01/16/2014
• Issued: 12/08/2015
• Est. Priority Date: 09/06/2013
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Young-Min Eeh
• Inventors: Nagamine, Makoto, Eeh, Youngmin, Ueda, Koji, Watanabe, Daisuke, Sawada, Kazuya, Nagase, Toshihiko
• Primary Examiner(s): EVANS, JEFFERSON A
• Application Number:
  US14/157,356
• Publication Number:
  US 20150069542A1
• Time in Patent Office: 691 Days
• Field of Search: 360/324.1, 360/324.11, 360/324.12, 360/324.2
• US Class Current: 1/1
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

According to one embodiment, a magneto-resistive element includes a first ferromagnetic layer formed on a substrate, a tunnel barrier layer formed on the first ferromagnetic layer, and a second ferromagnetic layer containing B formed on the tunnel barrier layer, the second magnetic layer containing therein any of He, Ne, Ar, Kr, Xe and N₂.

Claims

1. A magneto-resistive element comprising:

a first ferromagnetic layer formed on a substrate;

a tunnel barrier layer formed on the first ferromagnetic layer; and

a second ferromagnetic layer containing B formed on the tunnel barrier layer, the second magnetic layer containing therein any of He, Ne, Ar, Kr, Xe and N₂,

wherein a concentration of any of He, Ne, Ar, Kr, Xe and N₂ contained in the second ferromagnetic layer is higher in a central portion in a depth direction of the second ferromagnetic layer than the concentration in an upper portion of the second ferromagnetic layer.

2. The magneto-resistive element of claim 1, wherein the concentration of any of He, Ne, Ar Kr, Xe and N₂ contained in the second magnetic layer is 1% or higher in the central portion of the second magnetic layer in a depth direction thereof, and the concentration in an upper surface of the second magnetic layer is less than 1%.

3. The element of claim 1, wherein one of the first and second ferromagnetic layers is a magnetization fixed layer in which a direction of magnetization is fixed to be unchanged, the other of the first and second ferromagnetic layers is a magnetization free layer in which the direction of magnetization is easily reversible, and the magneto-resistive element is used as a memory cell of a magnetic random access memory.

4. The element of claim 1, wherein the second ferromagnetic layer contains Co, Fe and B.