[NanoIC topic] Investigation of magnetic material properties for enhanced SOT-MRAM performance

/ [NanoIC topic] Investigation of magnetic material properties for enhanced SOT-MRAM performance

[NanoIC topic] Investigation of magnetic material properties for enhanced SOT-MRAM performance

Unlocking the full potential of field-free SOT-MRAM by engineering and understanding the magnetic behavior of in-plane ferromagnets.

With the increasing demand fordata storage, the present charge-based memory technologies are reaching theirfundamental limits due to their poor reliability and volatile nature.Spintronic devices, leveraging spin's degree of freedom, offers a promisingsolution thanks to their non-volatility, fast processing, and higherintegration capabilities.

Spintronics has already beeninstrumental in various storage technologies, from hard disk drive read headsto Magnetic Random-Access Memory (MRAM). The heart of MRAM technology lies inthe Magnetic Tunnel Junction (MTJ), comprising an oxide tunnel barrier betweentwo ferromagnetic layers.

While Spin-Transfer Torque(STT)-MRAM has matured, its write operation by injecting current through thejunction to switch the free-layer magnetization, faces intrinsic trade-offsbetween switching speed and endurance due to shared read/write current paths.

To overcome these limitations,Spin-Orbit Torque (SOT)-MRAM employs separated write and read paths, enablingfaster operation and improved endurance, making it a promising next-generationmemory technology. SOT-MRAM operates by converting charge current into spincurrent in a heavy metal layer adjacent to the MTJ, allowing efficientswitching of the storage magnetic layer.

SOT-MRAM devices withperpendicular magnetic anisotropy, crucial for scalability potential, requirean external in-plane magnetic field for deterministic switching, limitingpractical applications. Although field-free approaches using stray fields orstructural symmetry breaking have been explored, achieving reliable and robustfield-free switching remains a key challenge for SOT-MRAM technology.

Recently, field-free SOTswitching has been demonstrated by adding an extra spin source by placing anin-plane magnetic layer beneath a non-magnetic metal. These bi-layersmaterialsgenerate an unconventional spin current to enable the switchingwithout an external magnetic field. In this concept, the in-plane magnet iscritical for field-free switching of the MTJ. However, recent results from imecshowed that weak magnetization can destabilize the in-plane magnet, therebylimiting the reliability of field-free switching. Therefore, improving magneticproperties of in-plane magnetic plays an important role in advancing thisdevice concept.

The internship project aims tosystematically investigate the magnetic properties of the in-plane ferromagnet,like saturation magnetization and canting by varying the material and substrate.The study will leverage advanced magnetic characterization techniques,including vibrating-sample magnetometry (VSM) and ferromagnetic resonance (FMR)technique to correlate processing conditions with magnetic performance.

Additionally, microscalehallbar structures can be fabricated in imec cleanroom for preliminaryunderstanding of patterning effect, i.e. shape anisotropy, offering guidancefor nanoscale structures.Furthermore, structural analysis like TEM andEDS can be applied to understand the interdiffusion of the in-plane magnet andthe adjacent layers. The outcomes of this research will provide practicalguidelines for materials engineering, paving the way for improved reliabilityand performance of next-generation SOT-MRAM technology.

Type of internship: Master internship, PhD internship

Duration: 6 - 12 months

Required educational background: Physics, Nanoscience & Nanotechnology, Materials Engineering, Other, Electrotechnics/Electrical Engineering

Supervising scientist(s): For further information or for application, please contact Birte Coester ( Birte.Coester@imec.be )

The reference code for this position is 2026-INT-348. Mention this reference code in your application.

Only for self-supporting students.