Fabrication technology for miniaturization of the spin-valve transistor

A new fabrication technology that allows miniaturization of the spin-valve transistor is presented. The spin-valve transistor consists of a spin-valve base (Pt 2 nm/NiFe 3 nm/Au 3.5 nm/Co 3 nm/Au 4 nm) sandwiched between a Si emitter and collector. With the use of a silicon-on-insulator wafer and vacuum metal bonding, spin-valve transistors down to a few tens of micron size are realized through conventional photolithography and etching processes. These spin-valve transistors show 275% magnetocurrent at 87 K and 170% at room temperature in small magnetic fields.