Magnetoresistive effect element and magnetic memory

Abstract

It is made possible to provide a highly reliable magnetoresistive effect element and a magnetic memory that operate with low power consumption and current writing and without element destruction. The magnetoresistive effect element includes a first magnetization pinned layer comprising at least one magnetic layer and in which a magnetization direction is pinned, a magnetization free layer in which a magnetization direction is changeable, a tunnel barrier layer provided between the first magnetization pinned layer and the magnetization free layer, a non-magnetic metal layer provided on a first region in an opposite surface of the magnetization free layer from the tunnel barrier layer, a dielectric layer provided on a second region other than the first region in the opposite surface of the magnetization free layer from the tunnel barrier layer; and a second magnetization pinned layer provided to cover opposite surfaces of the non-magnetic metal layer and the dielectric layer from the magnetization free layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-197877 filed on Jul. 6, 2005 in Japan, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a magnetoresistive effect element and a magnetic memory. [0004] 2. Related Art [0005] Magnetoresistive effect elements using magnetic material films are used in, for example, magnetic heads and magnetic sensors. In addition, it is proposed to use the magnetoresistive effect elements in solid state MRAMs (Magnetic Random Access Memories). [0006] As a magnetoresistive effect transistor element which has a sandwich structure film formed by inserting a single layer of a dielectric between two ferromagnetic layers, which lets a current flow perpendicularly to the film surface, and utilizes a tunnel current, the so-called “ferro...

AI Technical Summary

Benefits of technology

[0019] The present invention has been achieved on the basis of recognition of such problems. An object of the present invention is to provide a highly reliable magnetoresistive effect element that operates with low power consumption and low current writing, and a magnetic memory using such a magnetoresistive effect element.

Problems solved by technology

As regards the cell size of the memory, there is a problem that the size cannot be made smaller than a semiconductor DRAM (Dynamic Random Access Memory) or less in the case where an architecture in which a memory cell is formed of one transistor and one TMR element.

In either case, inversion is conducted using a current magnetic field based on a current pulse when writing to the magnetic recording layer is executed, resulting in high power consumption.

When the capacity is increased, there is a limit in allowable current density for wiring and consequently a large capacity cannot be obtained.

As compared with other non-volatile solid-state memories, such as ferroelectric random access memories using ferroelectric capacitors or flash memories, there is a problem that the chip becomes large and competitive power is lost.

Even if they are used, however, it is very difficult to cause the write current value to become 1 mA or less.

In the case where the spin injection method is applied to the TMR element, there is a problem of element destruction such as breakdown of a tunnel insulation film and there is a problem in element reliability.

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