A method and structure for a spin valve transistor (SVT) comprises a magnetic
field
sensor, an insulating layer adjacent the magnetic field sensor, a bias layer adjacent
the insulating layer, a non-magnetic layer adjacent the bias layer, and a ferromagnetic
layer over the non-magnetic layer, wherein the insulating layer and the non-magnetic
layer comprise antiferromagnetic materials. The magnetic field sensor comprises
a base region, a collector region adjacent the base region, an emitter region adjacent
the base region, and a barrier region located between the base region and the emitter
region. The bias layer is between the insulating layer and the non-magnetic layer.
The bias layer is magnetic and is at least three times the thickness of the magnetic
materials in the base region.