Spin valve transistor using a magnetic tunnel junction

摘要

A spin valve transistor sensor is provided having a emitter element, a collector element and a common base element. The negatively biased emitter element injects a spin polarized hot electron current into the base element by tunneling from a ferromagnetic pinned layer to a ferromagnetic free layer through a first tunnel barrier layer. The positively biased collector element, comprising a second tunnel barrier layer and a nonmagnetic metal layer, collects the fraction of the hot electron current that passes through the base element and over the barrier height of the second tunnel barrier layer. The hot electron current is strongly spin polarized and due to the GMR effect in the magnetic tunnel junction element, the magnitude of the base-collector current is strongly dependent on external magnetic (signal) fields. A process is provided for fabrication of a spin valve transistor sensor suitable for high density magnetic recording applications.