FIELD-EFFECT TRANSISTOR WITH SPIN-DEPENDENT TRANSMISSION CHARACTERISTIC AND NONVOLATILE MEMORY USING SAME

摘要

When a gate voltage VGS is applied, the Schottky barrier width due to the metallic spin band in the ferromagnetic source is decreased, and up-spin electrons from the metallic spin band are tunnel-injected into the channel region. However, down-spin electrons from the nonmagnetic contact (3b) are not injected because of the energy barrier due to semiconductive spin band of the ferromagnetic source (3a). That is, only up-spin electrons are injected into the channel layer from the ferromagnetic source (3a). If the ferromagnetic source (3a) and the ferromagnetic drain (5a) are parallel magnetized, up-spin electrons are conducted through the metallic spin band of the ferromagnetic drain to become the drain current. Contrarily, if the ferromagnetic source (3a) and the ferromagnetic drain (5a) are antiparallel magnetized, up-spin electrons cannot be conducted through the ferromagnetic drain (5a) because of the energy barrier Ec due to the semiconductive spin band in the ferromagnetic drain (5a). Thus, a high-performance high-degree of integration non-volatile memory composed of MISFETs operating on the above operating principle can be fabricated. IMAGE IMAGE