SPIN TRANSISTOR

PROBLEM TO BE SOLVED: To provide a spin transistor which can efficiently take out a spin-polarized carrier from a drain. SOLUTION: In a spin transistor 1 which is provided with a source 20 which is made of a ferromagnetic material; a drain 30 which is made of a ferromagnetic material; a first conductivity-type semiconductor layer 10, which has a contact surface which makes Schottky contact with the source 20 and the drain 30; and a gate electrode 40, which is provided directly or via an insulator layer 12 on the surface of the semiconductor layer 10 located opposite to the contact surface; when the height of a Schottky barrier in an interface of the source 20 and the semiconductor layer 10 is ΦB, at least the impurity doping concentration of the semiconductor layer 10 close to a source 20 is (20×ΦB-1)×1018cm-3or higher and 2×1019cm-3or lower. COPYRIGHT: (C)2009,JPO&INPIT