IP Library Granted Patent US 11,127,518
Granted Patent B2
US 11,127,518 · App. 16/574,419 · Granted Sep 21, 2021

Tunnel magnetoresistance (TMR) element having cobalt iron and tantalum layers

Inventors: Paolo Campiglio (Arcueil, FR); Amal Hamdache (Limours, FR); Julien Voillot (Chilly Mazarin, FR)
Assignee: ALLEGRO MICROSYSTEMS, LLC
H01F10/3254
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Quick Facts
Patent No.
US 11,127,518
App. No.
16/574,419
Granted
Sep 21, 2021
Kind
B2
Abstract

In one aspect, a tunnel magnetoresistance (TMR) element includes a magnesium oxide (MgO) layer, a cobalt iron boron (CoFeB) layer in direct contact with the MgO layer and a cobalt iron (CoFe) layer. The TMR element also includes a tantalum layer in direct contact with the CoFeB layer and the CoFe layer.

Claims (26)

1. A tunnel magnetoresistance (TMR) element, comprising:

a cap layer;

a bias layer in direct contact with the cap layer, the bias layer comprises:

a first platinum manganese layer in direct with the cap layer;

a first cobalt iron layer in direct contact with the first PtMn layer; and

a first ruthenium layer in direct contact with the first CoFe layer;

a free layer in direct contact with the bias layer, the free layer comprising:

a nickel iron layer in direct contact with the first Ru layer;

a second CoFe layer in direct contact with the NiFe layer;

a first tantalum layer in direct contact with the second CoFe layer; and

a first cobalt iron boron in direct contact with the first Ta layer;

a magnesium oxide MgO layer in direct contact with the first CoFeB layer;

a reference layer in direct contact with the MgO layer, the reference comprising:

second CoFeB layer in direct contact with the MgO layer;

a third CoFe layer in direct contact with a second Ta layer;

the second Ta layer in direct contact with the second CoFeB layer and the third CoFe layer;

a second Ru layer in direct contact with the third CoFe layer;

a fourth CoFe layer in direct contact with the second Ru layer; and

a second PtMn layer in direct contact with the fourth CoFe layer; and

a seed layer in direct contact with the second PtMn layer,

wherein the first PtMn layer pins the bias layer, and

wherein the second PtMn layer pins the fourth CoFe layer.

2. The TMR of claim 1 , wherein the first and second CoFeB layers are each 0.9 nanometers thick.

3. The TMR of claim 1 , wherein the first, second, third and fourth CoFe layers are each 0.9 nanometers thick.

4. The TMR of claim 1 , wherein the first and second tantalum layers are each 0.1 nanometers thick.

5. The TMR of claim 1 , wherein a thickness of the first and second tantalum layers are each between 0.05 nanometers and 0.3 nanometers.

Assignments (6)
RELEASE OF SECURITY INTEREST IN PATENTS AT REEL 053957/FRAME 0874 Recorded Nov 1, 2023
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH, AS COLLATERAL AGENT
To: ALLEGRO MICROSYSTEMS, LLC
Reel/Frame 065420/0572 →
RELEASE OF SECURITY INTEREST IN PATENTS (R/F 053957/0620) Recorded Jun 22, 2023
From: MIZUHO BANK, LTD., AS COLLATERAL AGENT
To: ALLEGRO MICROSYSTEMS, LLC
Reel/Frame 064068/0360 →
PATENT SECURITY AGREEMENT Recorded Jun 22, 2023
From: ALLEGRO MICROSYSTEMS, LLC
To: MORGAN STANLEY SENIOR FUNDING, INC., AS THE COLLATERAL AGENT
Reel/Frame 064068/0459 →
PATENT SECURITY AGREEMENT Recorded Oct 1, 2020
From: ALLEGRO MICROSYSTEMS, LLC
To: MIZUHO BANK LTD., AS COLLATERAL AGENT
Reel/Frame 053957/0620 →
PATENT SECURITY AGREEMENT Recorded Oct 1, 2020
From: ALLEGRO MICROSYSTEMS, LLC
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH, AS COLLATERAL AGENT
Reel/Frame 053957/0874 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 7, 2019
From: CAMPIGLIO, PAOLO; HAMDACHE, AMAL; VOILLOT, JULIEN; ALLEGRO MICROSYSTEMS FRANCE SAS; ALLEGRO MICROSYSTEMS EUROPE LIMITED; CRIVASENSE TECHNOLOGIES SAS
To: ALLEGRO MICROSYSTEMS, LLC
Reel/Frame 050636/0556 →
Continuity (2)
Provisional Application 62894114 · Aug 30, 2019
Related Publication 20210065949A1 · Mar 4, 2021
Cited By (2)
US 12,320,870 US 12,510,609