MRAM research or technical information

New SOT-MRAM device structure can be scaled up and is highly efficient

Researchers from Northwestern University, in collaboration with researchers from China, Italy and France, developed a new SOT-MRAM device structure that enables deterministic switching without any need for bias magnetic fields.

The new approach, unlike most earlier methods, can be scaled to large wafers with good uniformity, since it doesn't rely on having a structural asymmetry in the device. SOT-MRAM devices based on this structure could be faster and more energy-efficient than current designs.

Researchers suggest using stochastic MRAM elements to create highly efficient AI neural network devices

Researchers from Northwestern University developed a new method of building artificial neural networks using MRAM-based stochastic computing units. The researchers say that this design could enable AI devices that are highly energy efficient.

MTJ-based stochastic computing unit structure (Northwestern University)

Embedded MRAM technologies are being adopted at major foundries, which enable the use of these technologies for unconventional computing architectures that use the stochasticity of MRAM cells (rather than their nonvolatility), to perform energy-efficient computing operations. MRAM cells exhibit stochastic switching characteristics, which is a challenge for reliable memory devices. But for neural networks, this can be taken advantage of if the MTJs are appropriately designed.

Researchers developed a promising antiferromagnetic MRAM device structure

Researchers from Northwestern University and the University of Messina in Italy developed a new MRAM memory device composed of antiferromagnetic materials, which could be beneficial for use in AI systems and cryptocurrency mining.

Magnetic switching with antiferromagnet IrMn3 - device design

Antiferromagnetic materials (AFM), offer inherently faster dynamics than ferromagnetic materials (FM), have no macroscopic magnetic poles and can be scaled much better. AFM-based memory cannot be erased with external magnetic fields which could prove to be a major security advantage.

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.