Fabrication and characteristics of magnetic tunnel transistors using amorphous n-type Si films

Abstract

A magnetic tunnel transistor (MTT) device using an amorphous n-type Si semiconductor film for the base and collector consisting of [CoFe/NiFe] (free layer) and Si (top layer) multilayers is used to study the spin-dependent hot electron magnetocurrent (MC) and the tunneling magnetoresistance at room temperature. A large MC of more than 40.2% is observed at the emitter-base bias voltage V-BE of 0.62 V. The increasing emitter hot current and transfer ratio with the increase of the emitter-base voltage are due mainly to a rapid creation of a number of conduction-band states in the Si collector. However, above a V-BE of 0.62 V, a rapid decrease of the MC is observed in an amorphous Si-based MTT. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.