Magnetic memory devices including oxide multiferroic material

摘要

A magnetic memory device is provided. The magnetic memory device includes a plurality of variable resistance devices connected to a word line, and a plurality of bit lines, each of which provides an electrical pathway between a corresponding one of the variable resistance devices and a read and write circuit. Each of the variable resistance devices includes a free layer and a pinned layer spaced apart from each other and having a tunnel barrier interposed therebetween, an assistant layer spaced apart from the tunnel barrier and having the free layer interposed therebetween, and an exchange coupling layer arranged between the free layer and the assistant layer. The exchange coupling layer has an electric polarization, which results from its ferroelectric property, and having a direction that can be changed by a voltage applied to the corresponding one of the bit lines.

主权项

1. A magnetic memory device, comprising:
a plurality of variable resistance devices connected to a word line; and a plurality of bit lines, each of which provides an electrical pathway between a corresponding one of the variable resistance devices and a read and write circuit, wherein each of the variable resistance devices comprises: a free layer and a pinned layer spaced apart from each other and having a tunnel barrier interposed therebetween; an assistant layer spaced apart from the tunnel barrier and having the free layer interposed therebetween; and an exchange coupling layer between the free layer and the assistant layer, wherein the exchange coupling layer has an electric polarization resulting from its ferroelectric property, wherein the electric polarization is fixed in a direction by applying a read voltage through a corresponding one of the bit lines, and is changed to have a second direction that is different from the first direction and is at an oblique angle with respect to a top surface of the free layer by applying a write voltage through a corresponding one of the bit lines, and wherein the write voltage is greater than the read voltage.