Magnetic tunnel transistor with a silicon hot-electron emitter

We report on a modified magnetic tunnel transistor having a silicon tunnel emitter. The device has the structure Si/Al2O3 /base/Si with a spin-valve metal base, a Schottky barrier collector, but a silicon emitter separated from the base by a thin tunnel oxide. The energy of the hot electrons injected from the Si emitter into the base can be tuned by the emitter bias, which drops partly over the Si depletion region. Compared to a magnetic tunnel transistor with a metal emitter, the voltage drop over the thin tunnel oxide is reduced, enabling stable device operation at higher biasing conditions. We fabricated devices with a magnetocurrent up to 166% and a steeply enhanced transfer ratio reaching 6 10-4 at an emitter current of 200 mA.