Temperature dependence of magnetocurrent in a magnetic tunnel transistor

Abstract

The temperature dependence of magnetocurrent (MC) and transfer ratio has been investigated in a magnetic tunnel transistor (MTT) with a ferromagnetic (FM) emitter of Co or Ni80Fe20. MTT devices of sizes ranging from 10 to 100 mu m in diameter were fabricated using a standard photolithography process and predefined Si substrates. This reduces the edge leakage current across the collector Schottky diode and enables room-temperature operation. For the MTT with both Co and Ni80Fe20 emitter, we obtain a MC of about 80% at room temperature. This corresponds to a tunnel spin polarization of the FM emitter/Al2O3 interface of 29% at 1 V, demonstrating that the tunnel current is still spin-polarized at a high bias voltage. (c) 2005 American Institute of Physics.