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US 12,727,389 B2Granted
Methods of manufacturing a magnetic field sensor
AssigneeEverspin Technologies, Inc.
InventorsRenu Whig, Phillip Mather, Kenneth Smith, Sanjeev Aggarwal, Jon Slaughter, Nicholas Rizzo
Life of this patent
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Abstract
A semiconductor process integrates three bridge circuits, each include magnetoresistive sensors coupled as a Wheatstone bridge on a single chip to sense a magnetic field in three orthogonal directions. The process includes various deposition and etch steps forming the magnetoresistive sensors and a plurality of flux guides on one of the three bridge circuits for transferring a “Z” axis magnetic field onto sensors orientated in the XY plane.
Claims22
A method of manufacturing an integrated magneto-resistive sensor, the method comprising:
- forming a plurality of magneto-resistive sensor elements on or over a substrate, wherein each magneto-resistive sensor element comprises a reference layer and a sensing layer,
- forming conductors to electrically connect the plurality of magneto-resistive sensor elements into a single circuit;
- depositing a first insulating material over each of the plurality of magneto-resistive sensor elements;
- and
- forming one or more flux guides directly on or in the first insulating material or directly on or in the substrate, wherein (i) the one or more flux guides comprise a magnetic material;
- and (ii) wherein an entirety of each flux guide of the one or more flux guides is adjacent to and laterally offset from at least one magneto-resistive sensor element of the plurality of magneto-resistive sensor elements,
- wherein forming one or more flux guides directly on or in the first insulating material or directly on or in the substrate includes:
- forming at least one flux guide below, adjacent to, and laterally offset from each magneto-resistive sensor element, or
- forming at least one flux guide above, adjacent to, and laterally offset from each magneto-resistive sensor element.
6 more elements
A method of manufacturing an integrated magneto-resistive sensor, the method comprising:
- forming one or more flux guides, wherein forming the one or more flux guides includes:
- depositing an etch stop layer over a substrate,
- depositing a first dielectric layer over the etch stop layer,
- etching a plurality of trenches through the first dielectric layer to the etch stop layer,
- depositing magnetic permeable material in the plurality of trenches and on the first dielectric layer,
- back sputtering away the magnetic permeable material from a bottom of the first plurality of trenches and from a top of the first dielectric layer, and
- depositing a second dielectric layer on the etch stop layer in the first plurality of trenches and on the dielectric layer;
- and
- forming a plurality of magneto-resistive sensor elements, wherein forming the first plurality of magneto-resistive sensor elements includes:
- forming a first reference layer,
- forming a first intermediate layer on the first reference layer, and
- forming a first sensing layer on the first intermediate layer;
- forming one or more conductors to electrically interconnect the magneto-resistive sensor elements of the plurality of magneto-resistive sensors elements to form a bridge circuit, wherein forming the one or more conductors includes etching a plurality of vias and depositing a conductive material within the plurality of vias;
- and
- depositing an insulating material over the first plurality of magneto-resistive sensor elements,
- wherein each of the one or more flux guides include a magnetic permeable material and is juxtaposed to and laterally offset from an associated magneto-resistive sensor element of the first plurality of magneto-resistive sensor elements, wherein the magnetic material of the one or more flux guides comprises one or more of nickel, iron, cobalt, and/or an alloy including one or more of nickel, iron, and cobalt.
13 more elements
A method of manufacturing an integrated magneto-resistive sensor, the method comprising:
- forming one or more flux guides, wherein forming the one or more flux guides includes:
- depositing an etch stop layer over a substrate,
- depositing a first dielectric layer over the etch stop layer,
- etching a plurality of trenches through the first dielectric layer to the etch stop layer,
- depositing magnetic permeable material in the plurality of trenches and on the first dielectric layer,
- removing the magnetic permeable material from a bottom of the first plurality of trenches and from a top of the first dielectric layer, and
- depositing a second dielectric layer on the etch stop layer in the first plurality of trenches and on the dielectric layer;
- and
- forming a plurality of magneto-resistive sensor elements, wherein forming the first plurality of magneto-resistive sensor elements includes:
- forming a first reference layer,
- forming a first intermediate layer on the first reference layer, and
- forming a first sensing layer on the first intermediate layer;
- forming one or more conductors to electrically interconnect the magneto-resistive sensor elements of the plurality of magneto-resistive sensors elements to form a bridge circuit, wherein forming the one or more conductors includes etching a plurality of vias and depositing a conductive material within the plurality of vias;
- depositing an insulating material over the first plurality of magneto-resistive sensor elements,
- wherein each of the one or more flux guides include a magnetic permeable material and is juxtaposed to and laterally offset from an associated magneto-resistive sensor element of the first plurality of magneto-resistive sensor elements, wherein the magnetic material of the one or more flux guides comprises one or more of nickel, iron, cobalt, and/or an alloy including one or more of nickel, iron, and cobalt.
12 more elements
Dependencies are inferred from the claim text.