Tunnel magnetoresistance element to detect out-of-plane changes in a magnetic field intensity of a magnetic field

A tunnel magnetoresistance (TMR) element comprising:

• antiferromagnetic material comprising a plurality of antiferromagnetic layers having magnetization directions alternating by layer between a first direction and a second direction opposite the first direction, a top layer of the plurality of antiferromagnetic layers having a magnetization direction in the first direction;
• a ferromagnetic layer in direct contact with the top layer of the plurality of antiferromagnetic layers;
• a first multilayer structure in direct contact with the ferromagnetic layer;
• a metal layer in direct contact with the first multilayer structure;
• and
• a second multilayer structure in direct contact with the metal layer, wherein the second multilayer structure is part of a reference layer,
• wherein the ferromagnetic layer, the first multilayer structure and the second multilayer structure are each parallel to an x-y plane,
• wherein the first direction is either in a z-direction or in a −z direction,
• wherein a magnetization direction of the second multilayer structure is in the second direction and is determined by and is opposite of the magnetization direction of the top layer of the plurality of antiferromagnetic layer, and
• wherein the magnetization direction of the second multilayer structure is a reference direction of the TMR element.

A magnetic field sensor comprising:

• a bridge comprising:
• a source;
• a first leg comprising:
• a first tunnel magnetoresistance (TMR) element;
• and
• a second TMR element electrically in series with the first TMR element and electrically closer to the source than the first TMR element;
• and
• a second leg comprising:
• a third TMR element;
• and
• a fourth TMR element electrically in series with the third TMR element and electrically closer to the source than the third TMR element,
• wherein the first TMR element, the second TMR element, the third TMR element and the fourth TMR elements each comprises:
• antiferromagnetic material comprising a plurality of antiferromagnetic layers having magnetization directions alternating by layer between a first direction and a second direction opposite the first direction, a top layer of the plurality of antiferromagnetic layers having a magnetization direction in the first direction;
• a ferromagnetic layer in direct contact with the top layer of the plurality of antiferromagnetic layers;
• a first multilayer structure in direct contact with the ferromagnetic layer;
• a metal layer in direct contact with the first multilayer structure;
• and
• a second multilayer structure in direct contact with the metal layer, wherein the second multilayer structure is part of a reference layer,
• wherein the ferromagnetic layer, the first multilayer structure and the second multilayer structure are each parallel to an x-y plane,
• wherein the first direction is either in a z-direction or in a −z direction,
• wherein a magnetization direction of the second multilayer structure is in the second direction and is determined by and is opposite of the magnetization direction of the top layer of the plurality of antiferromagnetic layer,
• wherein the magnetization direction of the second multilayer structure is a reference direction of the TMR element, and
• wherein the first TMR element and the fourth TMR element each have a reference direction in the z-direction, and
• wherein the second TMR element and the third TMR element each have a reference direction in the −z-direction.