Magnetoresistive spin-injection diode

摘要

A spin injected diode suitable for nonvolatile memory applications is made of a semiconducting channel capable of carrying current, a single ferromagnetic layer, and a barrier layer between the semiconducting channel and the ferromagnetic layer to protect the integrity of the semiconducting layer and to inhibit interdiffusion of the ferromagnetic material and the semiconductor. During diode readout the output modulation of the diode can be sensed either as the interface resistance between the semiconducting channel and the ferromagnetic layer, or as the output voltage between the semiconducting channel and the ferromagnetic layer when flowing current through the channel and not through the interface. Two of these spin injected diodes can be combined to form a spin injected field effect transistor. This transistor has a first ferromagnetic layer having a first coercivity and a second ferromagnetic layer having a second coercivity smaller than the first coercivity which are spaced apart. A gate is situated between the ferromagnetic layers and includes an insulating layer situated below the gate and between the two ferromagnetic layers. A semiconducting channel layer beneath the first and second ferromagnetic layers and beneath the gate forms a low impedance electrical path between the first and second ferromagnetic layers when a control signal is applied to the gate and a high impedance electrical path between these ferromagnetic layers at all other times. A key component is a barrier layer between the semiconducting channel and the two ferromagnetic layers which performs the same functions as in the diode.