Patterned MR Device with Controlled Shape Anisotropy

A magnetic sensor, comprising:

• a magnetoresistive (MR) device comprising a plurality of layers and patterned in the form of a MR stripe having a first bottom surface, a top layer that is a magnetically free layer having a first top surface, a first thickness, an aspect ratio of at least 5, and a pair of opposing first edges that are equidistant from a center plane that bisects the MR stripe in a lengthwise direction that is perpendicular to a width of the free layer along a second direction, each of the opposing first edges is formed along a side of each of the plurality of layers including the free layer;
• and
• a pair of flux absorbing stripes each with a second bottom surface formed at or above a first plane that includes the first top surface or each with a second top surface formed at or below a second plane that includes the first bottom surface, and having a second edge facing the center plane, and a second thickness between the second top surface and the second bottom surface, a product of flux absorbing stripe magnetization times the second thickness is greater than a product of free layer magnetization times the first thickness, and wherein the second edge of a first flux absorbing stripe is offset from one of the opposing first edges of the free layer and MR sensor along the second direction, and the second edge of a second flux absorbing stripe is offset from another of the opposing first edges of the free layer and MR sensor along the second direction, and wherein adjacent pairs of opposing first edges and second edges are aligned parallel to each other such that the flux absorbing layers are not aligned above or below any portion of the free layer.

A magnetic sensor, comprising:

• a magnetoresistive (MR) device comprising a plurality of layers and patterned in the form of a MR stripe having a first bottom surface, a top layer that is a magnetically free layer having a first top surface, a first thickness, an aspect ratio of at least 5, and a pair of opposing first edges that are equidistant from a center plane that bisects the MR stripe in a lengthwise direction that is perpendicular to a width of the free layer along a second direction, each of the opposing first edges is formed along a side of each of the plurality of layers including the free layer;
• and
• a pair of flux absorbing stripes each with a second bottom surface formed at or above a first plane that includes the first top surface, and having a second edge facing the center plane, and a second thickness between the second top surface and the second bottom surface, and wherein the second edge of a first flux absorbing stripe is offset from one of the opposing first edges of the free layer and MR sensor along the second direction, and the second edge of a second flux absorbing stripe is offset from another of the opposing first edges of the free layer and MR sensor along the second direction, and wherein adjacent pairs of opposing first edges and second edges are aligned parallel to each other, each flux absorbing stripe is further comprised of a tapered third edge that extends from the second edge to the second top surface such that each flux absorbing stripe is thinnest at the second edge and becomes thicker with increasing distance from the second edge until reaching the second thickness.

A magnetic sensor, comprising:

• a magnetoresistive (MR) device comprising a plurality of layers and patterned in the form of a MR stripe having a first bottom surface, a top layer that is a magnetically free layer having a first top surface, a first thickness, an aspect ratio of at least 5, and a pair of opposing first edges that are equidistant from a center plane that bisects the MR stripe in a lengthwise direction that is perpendicular to a width of the free layer along a second direction, each of the opposing first edges is formed along a side of each of the plurality of layers including the free layer;
• and
• a pair of flux absorbing stripes each with a second top surface formed at or below a second plane that includes the first bottom surface, and having a second edge facing the center plane, and a second thickness between the second top surface and the second bottom surface, and wherein the second edge of a first flux absorbing stripe is offset from one of the opposing first edges of the free layer and MR sensor along the second direction, and the second edge of a second flux absorbing stripe is offset from another of the opposing first edges of the free layer and MR sensor along the second direction, and wherein adjacent pairs of opposing first edges and second edges are aligned parallel to each other, each flux absorbing stripe is further comprised of a tapered third edge that extends from the second edge to the second bottom surface such that each flux absorbing stripe is thinnest at the second edge and becomes thicker with increasing distance from the second edge until reaching the second thickness.