Magnetic field sensor

A method of fabricating a spin valve giant magnetoresistive sensor in a Wheatstone bridge configuration, comprising in combination:

• depositing at least one metal layer;
• depositing spin valve element layers to form spin valve elements;
• depositing dielectric layers substantially between the at least one metal layer and the spin valve elements;
• and
• applying a current pulse to the at least one metal layer.

A method of fabricating a spin valve GMR sensor in a bridge configuration, comprising in combination:

• forming a first spin valve element pair in which each spin valve element contains at least a free layer, a space layer, a pinning layer and a bias layer, wherein the bias layer includes a first bias layer and a second bias layer, wherein the first bias layer is located substantially between the pinning layer and the second bias layer, and wherein the pinning layer is substantially thicker than the second bias layer;
• forming a second spin valve element pair in which each spin valve element contains at least a free layer, a space layer, a pinning layer and a bias layer, wherein the bias layer includes a first bias layer and a second bias layer, wherein the first bias layer is located substantially between the pinning layer and the second bias layer, and wherein the pinning layer is substantially thinner than the second bias layer;
• and
• applying a magnetic field to the first spin valve element pair and the second spin valve element pair, thereby setting a direction of magnetization in the pinning layer of the first pair of spin valve elements that is substantially antiparallel to a direction of magnetization in the pinning layer of the second pair of spin valve elements.