Allegro Microsystems, LLC

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Paolo Campiglio

Maxim Klebanov

Yen Ting Liu

Sundar Chetlur

Rémy Lassalle-Balier

Bryan Cadugan

Claude Fermon

Noémie Belin

Samridh Jaiswal

Amal Hamdache

Jeffrey Eagen

Alexander Latham

Harianto Wong

Myriam Pannetier-Lecoeur

Marie-Claire Cyrille

Cyril Dressler

Julien Voillot

Damien Dehu

Ronald Lehndorff

Yu-Ming Wang

Pierrick Charlier

Florian Pallier

In one aspect, a method includes depositing magnetoresistance (MR) layers of a MR element on a semiconductor structure; depositing a first hard mask on the MR layers; depositing and patterning a first photoresist on the first hard mask using photolithography to expose portions of the first hard mask; etching the exposed portions of the first hard mask; etching a portion of the MR layers using the first hard mask; depositing a second hard mask on a first capping layer; depositing and patterning a second photoresist on the second hard mask using photolithography to expose portions of the second hard mask; etching the exposed portions of the second hard mask; etching the MR element using the second hard mask; etching portions of the first hard mask down to a top MR layer of the MR element; and depositing a conducting material on the top MR layer to form an electroconductive contact.

Fabricating an electroconductive contact on a top layer of a tunneling magnetoresistance element using two hard masks

In one aspect, a method includes manufacturing a magnetic-field angle sensor on a wafer. The manufacturing includes forming a cosine bridge that includes forming a first magnetoresistance (MR) element. The manufacturing also includes forming a sine bridge that includes forming a second MR element. Forming the first MR element includes using a process to reduce orthogonality errors between the sine bridge and the cosine bridge caused by anisotropy present in magnetic material in the first MR element.

Reducing angle error in angle sensor due to orthogonality drift over magnetic-field

Methods and apparatus for a magnetoresistive (MR) sensor a free layer with a thickness of the CoFeB material to produce out-of-plane sensing for the sensor and a reference layer magnetically coupled to the free layer. A dusting layer of an oxide material is disposed on the free layer to achieve perpendicular magnetic anisotropy for an interface of the oxide layer and the free layer for a desired sensitivity for the sensor.

Controlling out-of-plane anisotropy in an MR sensor with free layer dusting

In one aspect, a method includes depositing a capping layer on a semiconductor device structure. The semiconductor device includes a plurality of tunneling magnetoresistance (TMR) elements, a corresponding one hard mask on each TMR element, a metal layer, and a plurality of electroconductive vias directly connecting the TMR elements to the metal layer. The method further includes depositing an insulator on the capping layer, depositing a first photoresist on the insulator, patterning the first photoresist using photolithography to expose portions of the insulator, etching the exposed portions of the insulator and the hard masks to expose top surfaces of the TMR elements, stripping the first photoresist, and depositing a conducting material on the top surfaces of the TMR elements to form an electroconductive contact.

Fabricating an electroconductive contact on a top surface of a tunneling magnetoresistance element

In one aspect, a bridge includes at least eight sets of sub-arrays. Each one of the at least eight sets of sub-arrays forms a corresponding one magnetoresistance element. Each one of the at least eight sets of sub-arrays has a reference direction. The at least eight sets of sub-arrays are arranged in a matrix on a die. A reference direction of each one of the at least eight sets of sub-arrays is different from a reference direction of at least one other of the at least eight sets of sub-arrays.

Interleaving sub-arrays of magnetoresistance elements based on reference directions to compensate for bridge offset

In one aspect, a sensor includes a first metal layer portion and a second metal layer portion separated by an insulator material; a conductive material layer in electrical contact with the first metal layer portion and the second metal layer portion; and a tunnel magnetoresistance (TMR) element positioned on and in electrical contact with the conductive material layer. A first current is configured to flow from the first metal layer portion, through the conductive material layer, to the second metal layer portion, and a second current is configured to flow from the first metal layer portion, through the conductive material layer, through the TMR element, and exiting through a top of the TMR element.

Multi-terminal devices using magnetoresistance elements

In one aspect, a dual double-pinned spin valve element includes a first spin valve that includes a first pinned layer and a second pinned layer and a second spin valve disposed on the first spin valve and comprising a third pinned layer and a fourth pinned layer. The first, second, third and fourth pinned layers each have a magnetization in a first direction.

Dual double-pinned spin valve element having magnet bias with increased linear range

In one aspect, a method includes forming a coil in a coil layer, performing planarization on the coil layer, and depositing a magnetoresistance (MR) element on the planarized coil layer. No dielectric material is between the planarized coil layer and the MR element. In another aspect, a magnetic field sensor includes a substrate, a planarized coil layer comprising a coil on the substrate, a magnetoresistance (MR) element in contact with the planarized coil layer, and a capping layer deposited over the MR element and the planarized coil layer. No dielectric material is between the planarized coil layer and the MR element.

Fabricating planarized coil layer in contact with magnetoresistance element

Methods and apparatus for a magnetoresistive (MR) sensor including a seed layer having a CoFe layer for canceling hysteresis in the MR sensor. The MR stackup can include a free layer and a reference layer. The seed layer having CoFe provides a desired texturing of the stackup to cancel hysteresis effects.

Magnetoresistive sensor having seed layer hysteresis suppression

In one aspect, a method includes forming a metal layer on a substrate, wherein the metal layer comprises a first coil, forming a planarized insulator layer on the metal layer, forming at least one via in the planarized insulator layer, depositing a magnetoresistance (MR) element on the planarized insulator layer, and forming a second coil extending above the MR element. The at least one via electrically connects to the metal layer on one end and to MR element on the other end.

Fabricating a coil above and below a magnetoresistance element

Methods and apparatus for a sensor including a series of tunneling magnetoresistance (TMR) pillars and a heatsink adjacent to at least one of the TMR pillars, where the heatsink comprises Titanium Nitride (TiN).

TMR assembly having a heat sink

In one aspect, an integrated circuit includes a first conductive layer and a magnetoresistance element (MRE) disposed over and coupled to the first layer through first vias. The MRE is magnetized to produce a first magnetic orientation. The first layer is disposed over and coupled to a second conductive layer in the circuit through second vias. The circuit also includes a metal filler disposed proximate to the MRE. The metal filler is positioned over and coupled to the second layer through third vias. The circuit also includes a thermal dissipation path resulting from a physical input applied to the first MRE. The thermal dissipation path extends through the first through third vias, the first and second layers, an integrated circuit interconnection, and the metal filler.

Multi-layer integrated circuit with enhanced thermal dissipation using back-end metal layers

In one aspect, a dual tunnel magnetoresistance (TMR) element structure includes a first TMR element and a second TMR element. The TMR element structure also includes a conducting layer that is disposed between the first TMR element and the second TMR element and is in direct contact with the first TMR element and the second TMR element.

Dual tunnel magnetoresistance (TMR) element structure

A magnetoresistance assembly can include a substrate and a first GMR element disposed over the substrate, the first GMR element having a bottom surface and top surface. The magnetoresistance assembly can further include a first TMR element disposed over the substrate, the first TMR element having a top surface and a bottom surface, wherein a line perpendicular to and intersecting the top or bottom surface of the first TMR element intersects the first GMR element. The first GMR element and the first TMR element are in electrical communication.

Magnetoresistance assembly having a TMR element disposed over or under a GMR element

In one aspect, a bridge includes a first magnetoresistance element that includes a first set of pillars, a second magnetoresistance element that includes a second set of pillars, a third magnetoresistance element that includes a third set of pillars and a fourth magnetoresistance element that includes a fourth set of pillars. The first set of pillars and the fourth set of pillars are disposed in a first matrix and the second set of pillars and the third set of pillars are disposed in a second matrix. The second magnetoresistance element is in series with the first magnetoresistance element, the third magnetoresistance element is in parallel with the first magnetoresistance element and the fourth magnetoresistance element is in series with the third magnetoresistance element.

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Arcueil, France

Paolo Campiglio