Magnetic ram and method of writing and reading data using the magnetic ram

Abstract

A magnetic RAM (MRAM) using a thermo-magnetic spontaneous Hall effect includes a MOS transistor formed on a substrate; a heating means formed above the MOS transistor and connected to a source region of the MOS transistor; a memory layer having a data write area to which data is written, the data write area being formed on the heating means; a bit line formed on the data write area; an upper insulating film formed on the bit line and the memory layer; and a write line formed on the upper insulating film so that a magnetic field necessary for writing data is generated in at least the data write area of the memory layer. The MRAM writes or reads data using the fact that a spontaneous Hall voltage greatly differs according to the magnetization state of a memory layer, thereby providing the device a high data sensing margin.

Description

technical field [0001] The present invention relates to the field of magnetic RAM (random access memory) (MRAM) and the method for reading and writing data thereof, more specifically, relate to a kind of MRAM and its read The method for writing data. Background technique [0002] Giant magnetoresistance (GMR) results from the change in sheet resistance when electrons pass through two adjacent magnetic layers, depending on whether the two adjacent magnetic layers are magnetized parallel or antiparallel. GMR can be described with reference to spin-dependent scattering. [0003] Even if an aluminum oxide film (Al 2 o 3 ) for insulating films, but not for metallic films, spin-dependent scattering also occurs. This spin-dependent scattering is known as tunneling magnetoresistance (TMR). [0004] Conventional MRAM is a non-volatile memory that utilizes this GMR or TMR. Therefore, compared to DRAM or SRAM, the information recorded in MRAM is not lost even if the power is cut ...

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Problems solved by technology

However, when the size of the TMR memory is reduced, its operating time is extended and the noise increases because the TMR memory has a large resistance, for example, about 106 Ωμm 2

[0007] In such conventional MRAM, when the cell size is reduced to sub-micron or smaller, the coercive force increases and the thermal stability of the cell decreases

This greatly hinders the integration of

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