US 9,865,804 B2Granted

Magnetoresistive device and method of manufacturing same

AssigneeEverspin Technologies, Inc.

InventorsSarin A. Deshpande, Sanjeev Aggarwal, Kerry Joseph Nagel

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Abstract

A magnetoresistive-based device and method of manufacturing a magnetoresistive-based device using one or more hard masks. The process of manufacture, in one embodiment, includes patterning a mask over a selected portion of the third layer of ferromagnetic material, wherein the mask is a metal hard mask. Thereafter, etching through the third layer of ferromagnetic material to provide sidewalls of the second synthetic antiferromagnetic structure, through the second tunnel barrier layer to form a second tunnel barrier and provide sidewalls thereof and the second layer of ferromagnetic material to provide sidewalls thereof. Thereafter, etching, through the first tunnel barrier layer to form a first tunnel barrier to provide sidewalls thereof and etching the first layer of ferromagnetic material to provide sidewalls thereof. The process may then include oxidizing the sidewalls of (i) the first tunnel barrier and (ii) the first layer of ferromagnetic material. Thereafter, the metal hard mask may be connected to an electrical conductor.

Claims21

Dependent claims

A method of manufacturing a magnetoresistive device from:

(i) a first layer of ferromagnetic material disposed over a first electrically conductive material, wherein the first layer of ferromagnetic material includes a first synthetic antiferromagnetic structure, (ii) a first tunnel barrier layer disposed over the first layer of ferromagnetic material, (iii) a second layer of ferromagnetic material disposed over the first tunnel barrier layer, (iv) a second tunnel barrier layer disposed over the second layer of ferromagnetic material, (v) a third layer of ferromagnetic material disposed over the second tunnel barrier layer, wherein the third layer of ferromagnetic material includes a second synthetic antiferromagnetic structure, and (vi) a first layer of electrically conductive material disposed over the third layer of ferromagnetic material, method comprising:
patterning a mask over a selected portion of the first layer of electrically conductive material;
after patterning the mask, etching (a) through the first layer of electrically conductive material to form an electrically conductive electrode, and (b) through the third layer of ferromagnetic material to provide sidewalls of the second synthetic antiferromagnetic structure;
providing a first insulating material on the sidewalls of the third layer of ferromagnetic material;
etching (a) through the second tunnel barrier layer to form a second tunnel barrier and provide sidewalls thereof and (b) the second layer of ferromagnetic material to provide sidewalls thereof;
after etching through the second tunnel barrier and etching the second layer of ferromagnetic material, etching (a) through the first tunnel barrier layer to form a first tunnel barrier to provide sidewalls thereof and (b) the first layer of ferromagnetic material to provide sidewalls thereof;
providing a second insulating material on the sidewalls of (i) the first tunnel barrier and (ii) the first layer of ferromagnetic material;
and
after providing the second insulating material, etching the first electrically conductive material to form a bottom electrode.

6 more elements

A method of manufacturing a magnetoresistive device from:

(i) a first layer of ferromagnetic material disposed over a first electrically conductive material, wherein the first layer of ferromagnetic material includes a first synthetic antiferromagnetic structure, (ii) a first tunnel barrier layer disposed over the first layer of ferromagnetic material, (iii) a second layer of ferromagnetic material disposed over the first tunnel barrier layer, (iv) a second tunnel barrier layer disposed over the second layer of ferromagnetic material, and (v) a third layer of ferromagnetic material disposed over the second tunnel barrier layer, wherein the third layer of ferromagnetic material includes a second synthetic antiferromagnetic structure, method comprising:
patterning a metal hard mask from a metal layer disposed over a selected portion of the third layer of ferromagnetic material;
after patterning the metal hard mask, etching through the third layer of ferromagnetic material to provide sidewalls of the second synthetic antiferromagnetic structure;
etching (a) through the second tunnel barrier layer to form a second tunnel barrier and provide sidewalls thereof and (b) the second layer of ferromagnetic material to provide sidewalls thereof;
after etching through the second tunnel barrier and etching the second layer of ferromagnetic material, etching (a) through the first tunnel barrier layer to form a first tunnel barrier to provide sidewalls thereof and (b) the first layer of ferromagnetic material to provide sidewalls thereof;
and
providing a first insulating material on the sidewalls of (i) the first tunnel barrier and (ii) the first layer of ferromagnetic material;
and
connecting the metal hard mask to an electrical conductor.

6 more elements

A method of manufacturing a magnetoresistive device from:

(i) a first layer of ferromagnetic material disposed over a first electrically conductive material, wherein the first layer of ferromagnetic material includes a first synthetic antiferromagnetic structure, (ii) a first tunnel barrier layer disposed over the first layer of ferromagnetic material, (iii) a second layer of ferromagnetic material disposed over the first tunnel barrier layer, (iv) a second tunnel barrier layer disposed over the second layer of ferromagnetic material, and (v) a third layer of ferromagnetic material disposed over the second tunnel barrier layer, wherein the third layer of ferromagnetic material includes a second synthetic antiferromagnetic structure, method comprising:
patterning a mask over a selected portion of the third layer of ferromagnetic material, wherein the mask is a metal hard mask;
after patterning the mask, etching (a) through the third layer of ferromagnetic material to provide sidewalls of the second synthetic antiferromagnetic structure, (b) through the second tunnel barrier layer to form a second tunnel barrier and provide sidewalls thereof and (c) the second layer of ferromagnetic material to provide sidewalls thereof;
after etching through the third layer of ferromagnetic material, etching through the second tunnel barrier, and etching the second layer of ferromagnetic material, etching, (a) through the first tunnel barrier layer to form a first tunnel barrier to provide sidewalls thereof and (b) the first layer of ferromagnetic material to provide sidewalls thereof;
oxidizing the sidewalls of (i) the first tunnel barrier and (ii) the first layer of ferromagnetic material;
and
connecting the metal hard mask to an electrical conductor.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/630,377Filed 22 Jun 2017 · division
Priority: 14 Aug 2012
Published: US 2017/0288136 A15 Oct 2017
Granted: 9 Jan 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

H10N 50/01
Galvanomagnetic devices: manufacture or treatment
G11B 5/84
Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor: processes or apparatus…
G11C 11/161
Using elements in which the storage effect is based on magnetic spin effect: details concerning the memory cell structure, e.g. the layers of the…
H10B 61/00
Magnetic memory devices

Family

Application61/682,860Us provisional application · filed 14 Aug 2012
Application13/830,082Parent of this division · filed 14 Mar 2013
Application14/264,520Parent of this division · filed 29 Apr 2014
US 8,747,680 B1Parent of this division · filed 10 Jun 2014
Application14/845,697Parent of this division · filed 4 Sep 2015
US 9,166,155 B2Parent of this division · filed 20 Oct 2015
Application15/081,397Parent of this division · filed 25 Mar 2016
US 9,306,157 B2Parent of this division · filed 5 Apr 2016
US 2017/0288136 A1Pre-grant publication · published 5 Oct 2017
US 9,698,341 B2Parent of this division
US 2014/0315329 A1Published application
US 2015/0380640 A1Published application
US 2016/0211441 A1Published application
US 9,865,804 B2This patent

From the US filing history. Foreign family members aren’t listed.