SOT-MRAM

Researchers from the Institute of Science Tokyo (formerly Tokyo Tech), in collaboration with Western Digital, has developed a new high-performance material suitable for low-power SOT-MRAM.

The researchers are using BiSb material under the CoFeB/MgO, with perpendicular magnetic anisotropy. By optimizing the interfacial layer thickness as well as deposition condition of BiSb, the researchers managed to achieve a large effective spin Hall angle and relatively high electrical conductivity. The researchers continued to demonstrate spin–orbit torque-induced magnetization switching driven by a small threshold current density.

Everspin Technologies is at the forefront of the MRAM industry, with a product range that spans Toggle MRAM and STT-MRAM, embedded MRAM IP, more. The company's president and CEO, Sanjeev Aggarwal, was kind enough to answer a few questions we had about the company, it's recent announcements and its future roadmap.

Thank you for your time Sanjeev, we appreciate it. A few days ago, Everspin announced it had received a strategic $14.55 million 2.5-year DoD project to provide continued and stable manufacturing services. Can you share more info? How will that money be allocated, and how will you ensure stable support?

Everspin has partnered with the DoD on various projects to deploy our MRAM technology and fab MRAM products for Defense Industrial Base customers in Chandler, Arizona. The award money will be used to strength the US MRAM manufacturing supply chain.  Everspin will look at its supply chain and mitigate any risks identified. This can include second-sourcing gases and chemicals as well as upgrading processes.  

The New York Center for Research, Economic Advancement, Technology, Engineering, and Science (NY CREATES) and CEA-Leti announced a two-year strategic R&D partnership, that will initially focus on the research and co-development of MRAM devices.

NY CREATES and CEA-Leti will develop and produce both STT-MRAM and SOT-MRAM devices on 300 mm substrates. CEA-Leti will contribute its expertise in magnetics, spintronics, and the testing of related devices, and NY CREATES will provide the facilities, process integration expertise, and materials process development to run the 300mm silicon hardware.

In 2022, Taiwan's Industrial Technology Research Institute (ITRI) announced an agreement with Taiwan Semiconductor Manufacturing Company (TSMC) to collaborate on SOT-MRAM R&D. ITRI and TSMC now announced that they have developed SOT-MRAM array chips that boasts a power consumption of merely one percent of a comparable STT-MRAM device. 

ITRI and TSMC published a new research paper that was presented at the 2023 IEE International Electron Devices Meeting (IEDM 2023). ITRI explains that the new unit cell achieves simultaneous low power consumption and high-speed operation, reaching speeds as rapid as 10 nanoseconds. And its overall computing performance can be further enhanced when integrated with computing in memory circuit design. 

Researchers from the Tokyo Institute of Technology have successfully demonstrated fast p-MTJ switching (1 ns, compared to current switching that is >10 ns). "The researchers achieved this using the topological insulator BiSb as the SOT layer, and say the device offers a current density about 20 times smaller than typical.

The researchers say that this technology can be applied to develop p-MTJs for SOT-MRAM that will offer ultrafast operations and ultra low power consumption, while also offering higher reliability. This follows earlier work by the same group on BiSb p-MTJs.

Researchers from the School of Engineering at Stanford University discovered that a metallic compound called manganese palladium three MnPd3 is a promising material to build SOT-MRAM memory devices. 

The researchers say that the new material enables a breakthrough in SOT-MRAM device performance, as it is the first material that generates spin in the z-direction, rather than the y-direction as in most materials, which is a property needed in high-performance SOT-MRAM. In fact MnPd3 is able to generate spins in any orientation because its internal structure lacks the kind of crystal symmetry that would force all of the electrons into a particular orientation.

Hprobe, a developer of testing equipment for magnetic devices, announced a new addition to its product line, the RF Pulse Module. The company says that this is the commercially available testing system to both collect statistics of error rate of the memory unit cell and take a deep look into switching dynamics of resistive memories.

Hprobe's IBEX system

Hprobe says that the RF Pulse Module is two orders of magnitude faster than existing devices and can help increase manufacturing yields. Hprobe has already begun shipping to tier-1 companies and major research institutes around the world.

Taiwan's Industrial Technology Research Institute (ITRI) announced two new MRAM collaborations. The first one is with Taiwan's TSMC, for the development of SOT-MRAM array chips. The second collaboration is with National Yang Ming Chiao Tung University (NYCU) to develop magnetic memory technology that can perform across a wide operating temperature range of nearly 400 degrees Celsius.

Together with TSMC, ITRI is developing low-voltage and current SOT-MRAM, that features high write efficiecny and low write voltage. ITRI says that its SOT-MRAM achieves a writing speed of 0.4 nanoseconds and a high endurance of 7 trillion reads and writes. The memory also offers a data storage lifespan of over 10 years.

Integral Solutions International (ISI) announced a new 3-Axis Magnet Option for wafer-level testing. Combined with ISI's WLA5000 Tester, the 3D magnetic fields produced by this system can be used for characterization of MRAM devices in addition to 2D/3D Magnetic Sensors.

ISI says that for MRAM applications, the 3D Magnetic fields produced by ISI’s 3-Axis Magnet Option delivers solutions for both STT-MRAM and SOT-MRAM applications.

Taiwan-based Industrial Technology Research Institute (ITRI) announced an agreement with the University of California, Los Angeles (UCLA) to co-develop Voltage-Control MRAM (VC-MRAM) technologies.

ITRI says that VC-MRAM is a type of SOT-MRAM that offers improved performance - 50% higher writing speed and 75% less energy consumption. VC-MRAM is said to be ideal for AIoT and automotive industry applications. The partnership is expected to strengthen the link between both parties and accelerate the R&D and industrialization of new memory technologies.