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US 12,402,537 B2Granted
Magnetoresistance effect element, magnetic memory, and film formation method for said magnetoresistance effect element
AssigneeTohoku University
InventorsKoichi Nishioka, Tetsuo Endoh, Shoji Ikeda, Hideo Sato, Hiroaki Honjo
Life of this patent
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Abstract
A magnetoresistance effect element includes a first reference layer, a first junction layer, a first divided recording layer, a second junction layer, a second divided recording layer, and a third junction layer. The first divided recording layer has a configuration having a high magnetoresistance ratio (MR ratio), and the second divided recording layer (3) has a configuration having a high effective magnetic anisotropy energy density (Kefft).
Claims8
A magnetoresistance effect element, comprising:
- a first reference layer (B1);
- a first junction layer (11) that is provided in direct contact to the first reference layer (B1);
- a first divided recording layer (2) that is provided in direct contact to an opposite side of the first junction layer (11) to the first reference layer (B1);
- a second junction layer (12) that is provided in direct contact to an opposite side of the first divided recording layer (2) to the first junction layer (11);
- a second divided recording layer (3) that is provided in direct contact to an opposite side of the second junction layer (12) to the first divided recording layer (2);
- and
- a third junction layer (13) that is provided in direct contact to an opposite side of the second divided recording layer (3) to the second junction layer (12), wherein
- the first junction layer (11), the second junction layer (12) and the third junction layer (13) contain oxygen (O) and Mg, and the first junction layer (11) is a tunnel barrier layer,
- the first divided recording layer (2), the second junction layer (12) and the second divided recording layer (3) constitute a first recording layer (A1),
- the first divided recording layer (2) contains at least Co and Fe, and has an interfacial magnetic anisotropy in a direction perpendicular to a film surface at an interface with the first junction layer (11) and at an interface with the second junction layer (12),
- a crystal structure at an interface with an entire first divided recording layer (2) or the first junction layer (11) is bcc,
- the second divided recording layer (3) contains at least Fe,
- a Co/Fe ratio of the entire first divided recording layer (2) is larger than a Co/Fe ratio of the entire second divided recording layer (3),
- a film thickness of the second junction layer (12) is 1.0 nm or less,
- the Co/Fe ratio of the first divided recording layer (2) is 0.18 or more and 3 or less, and
- a Boron (B) concentration of the entire first divided recording layer (2) is lower than a Boron (B) concentration of the entire second divided recording layer (3), and 20 at. % or more and 35 at. % or less.
13 more elements
A film formation method for a magnetoresistance effect element, the film formation method comprising:
- a step of depositing a first junction layer (11) on a deposited first reference layer (B1);
- a step of performing treatment of heating a film in which the deposited first junction layer (11) is an uppermost part;
- a step of performing treatment of cooling the film that has been applied the treatment of heating;
- a step of depositing a first divided recording layer (2) on the first junction layer (11) of the film that has been applied the treatment of cooling;
- a step of depositing a second junction layer (12) on the deposited first divided recording layer (2);
- a step of depositing a second divided recording layer (3) on the deposited second junction layer (12);
- a step of depositing a third junction layer (13) on the deposited second divided recording layer (3);
- and
- a step of depositing a second reference layer (B2) or an upper electrode (E2) on the deposited third junction layer (13), wherein
- the second junction layer (12) is not applied treatment of heating and cooling before the step of depositing the second divided recording layer (3);
- and
- the third junction layer (13) is not applied treatment of heating and cooling before the step of depositing the second reference layer (B2) or the upper electrode (E2).
9 more elements
Dependencies are inferred from the claim text.