MRAM research or technical information

IBM to reveal the world's first 14nm STT-MRAM node

IBM announced that during the 2020 IEEE International Electron Devices Meeting (IEDM 2020), that is now being held virtually, its researchers will reveal the first 14 nm node STT-MRAM. IBM says that efficient and high-performance STT-MRAM systems will help to address memory-compute bottlenecks in hybrid cloud systems.

IBM says that the 14 nm node embedded MRAM which will be revealed is the most advanced MRAM demonstrated to date. It features circuit design and process technology that could soon enable system designers to replace SRAM with twice the amount of MRAM in last-level CPU cache.

Researchers find that FGT is an excellent material for SOT-MRAM devices

Researchers from Seoul's National University and Pohang's University of Science and Technology (POSTECH) report that a 2D iron germanium telluride (Fe3GeTe2, or FGT) layer is an excellent candidate to be used as the basis SOT-MRAM material.

Fe3GeTe2-based SOT-MRAM device structure (POSTECH / SNU)

An SOT-MRAM based on FGT is highly energy-efficient, in fact the researchers say that the measured magnitude of SOT per applied current density is two orders of magnitude larger than the values reported previously for other candidate materials.

Researchers develop the world's smallest high-performance MTJ

Researchers from Tohoku University say they have developed the world's smallest (2.3 nm) high-performance magnetic tunnel junctions (MTJs).

Shape anisotropy MTJ scheme (Tohoku University)

The design is based on the Shape-anisotropy MTJ (developed by the same researchers in 2018) in which thermal stability is enhanced by making the ferromagnetic layer thick. In this new research, the scientists used a new structure that uses magnetostatically coupled multilayered ferromagnets - which enabled the scaling down to 2.3 nm diameters.

Superlattice and half-metallic magnets used to developed SS-MRAM, an ultra-high performance MRAM device

Researchers from the National Taiwan University developed an ultra-high performance MTJ, using a superlattice barrier and half-metallic magnets. The so-called superlattice-MTJ can be the basis of a new class of STT-MRAM (which the researcher call SS-MRAM) that achieves ultra-low power RA and write operations, high writing speed and unlimited endurance.

Geometric structure of a three-cell superlattice MTJ (National Taiwan University)

SS-MRAM adopts a superlattice barrier that replaces the MgO layer used in common STT-MRAM. The MgO layer is unstable and also suffers from a very large RA which results in high power consumption for writing operations. The superlattice has higher spin polarization than MgO and so the SS-MARM can provides not only ultra-high MR ratio but also ultra-low RA for high-speed and low power writing.

NTHU researchers discover that a thin film of platinum can enable faster and more efficient MRAM

A team of researchers from the National Tsing Hua University (NTHU) in Taiwan have discovered that by adding a layer of platinum only a few nanometers thick, one can switch the pinned magnetic moments at MRAM cells at will. This was never achieved before, and can lead to faster and more efficient MRAM devices.

The platinum layer is placed between the two layers of the MRAM device - the upper layer, a freely flipping magnet used for data computation and the bottom layer that consists of a fixed magnet, responsible for data storage. Due to spin-orbit interactions, the electric current drives the collective motion of electron spins first. The spin current then switches the pinned magnetic moment effectively and precisely.

New four-state MTJ architecture may lead to multi-level MRAM

An international team of researchers led by Israel's Bar Ilan University have developed a new type of MTJ that has four resistance states. The researchers also demonstrated how it is possible to switch between these four different states using spin currents.

The four-state design uses a structure that is in the form of two crossing ellipses instead of one of the standard magnetic layers of the MTJ. Such a design could be used to create multi-level MRAM which stores data more densely compared to current MRAM memories which only have two states in each MTJ.

Researchers add YSZ layers to MRAM devices to increase efficiency and speed

Researchers from the Korea Institute of Science and Technology (KIST) have managed to drastically incraese the speed of MRAM devices while reducing the power consumption by adding a layer of yttria-stabilized zirconia (YSZ) to MRAM devices.

KIST ultra-low power and high-speed MRAM prototype

The YSZ layer, which has high ion conductivity helps inject hydrogen ions into the MRAM cell. This resulted in an increase in the speed of the spin alignment direction changes 100-fold.

Successful MRAM Production Requires Good Magnetic Test Equipment

This is a sponsored post by Integral Solutions Int'l

MRAM is likely to be the most promising next-generation non-volatile memory technology today. Toggle MRAM and STT-MRAM are already entering the market, gaining market share in many applications. Next-generation MRAM technologies, such as SOT-MRAM could enable the replacement of even the fastest SRAM applications, with higher densities.

MRAM Manufacturing Process Flow (Coughlin)Source: Coughlin Associates, 2019

The MRAM production process has many stages, as device architecture is relatively complex, with a magnetic cell (frontplane) fabricated on top of a CMOS backplane. (use Figure 2 or Figure 3 from Coughlin). Measurement and characterization of devices are highly important, and the production of MRAM memories depend on measurement tools are are specialized for MRAM and STT-MRAM measurements.

New research may hold the key towards antiferromagnetic MRAM

Researchers from the University of Arizona discovered that in common Magnetic Tunnel Junctions (MTJ), there's a thin (2D) layer of Iron Oxide. This layer was found to act as a contaminant which lowers the performance achieved by MTJs, but it may also hold the key to use antiferromagnetism in MRAM devices.

Magnetic Tunnel Junction schematic (UArizona)

The researchers discovered that the layer behaves as a so-called antiferromagnet at extremely cold temperatures (below -245 degrees Celsius). Antiferromagnets are promising as these can be manipulated at Terahertz frequencies, about 1,000 times faster than existing, silicon-based technology. This is the first research that shows how Antiferromagnets can be controlled as part of MTJs and in the future may pave the way for its adoption in MRAM devices.

Researchers show how antiferromagnetic STT-MRAM technology can enable higher-density and lower energy memory

Researchers from Northwestern University suggest building STT-MRAM devices from antiferromagnetic materials - as opposed to the currently-used ferromagnetic ones. The researchers say that these materials will enable higher-density devices that feature high speed writing with low currents.

Antiferromagnetic materials are magnetically ordered at the microscopic scale, but not at the macroscopic scale. This means that there is no magnetic force between adjacent bits in MRAM cells built from these materials - which means you can pack them very close together.