https://www.spintec.fr/wp-content/uploads/2025/10/Plaquette_Spintec_2026.pdf
Context
Spintronic devices exploit the spin, as well as the charge, of electrons and could bring new capabilities to the microelectronics industry, that is facing major challenges related to the volatility of CMOS cache memory elements (usually SRAM and eDRAM) [1]. Magnetic random access memories (MRAM) devices are among the most credible non-volatile candidates that are low power and fast enough to compete with SRAM. Advanced MRAM devices are magnetic tunnel junctions (MTJ) that are operated by spin transfer torque (STT) effect. Spin-orbit torque (SOT) MRAM has emerged as a credible next-generation MRAM technology that allows for faster and more efficient magnetization writing [2]. In SOT-MRAM devices the ferromagnetic storage layer (FL) is in contact with a non-magnetic heavy metal (HM) channel such as Ta, W, or Pt [3]. When a current flows through the channel, a perpendicular spin current is generated and transferred to the magnetization of the FL via spin Hall effect (SHE)and Rashba- Edelstein effect (REE), inducing magnetization reversal. To enable SOT-MRAM as viable technology, several challenges need to be overcome. In terms of material innovation, improving the write efficiency (SOT material, interface) is key. Recently, the SHE and REE have been predicted to arise from more fundamental effects [4], namely Orbital Hall effect (OHE) and Orbital Rashba-Edelstein effect (OREE). These effects feature greater magnitudes and diffusion lengths compared to the spin counterpart and they are present in a much wider class of materials, including light metals with low resistivity. Hence, they offer the possibility to integrate more efficient, and more conductive material, possibly reducing the devices power consumption. We propose in this project to engineer and study materials combinations (thickness, compound), in order to improve SOT efficiency and address SOT-MRAM write challenges exploiting novel orbital effects.
[1] B. Dieny et al., “Opportunities and challenges for spintronics in the microelectronics industry”, Nat. Electron. 3, pp. 446-459 (2020)
[2] K. Garello et al.,”Manufacturable 300mm platform solution for Field-Free Switching SOT-MRAM”, IEEE Symp. VLSI Tech.,T194-T195 (2019)
[3] A. Manchon et. al, ““Current-induced spin-orbit torques in ferromagnetic and antiferromagnetic systems,” Rev. Mod. Phys., 035004, (2019)
[4] D. GO, et al., “Intrinsic Spin and Orbital Hall Effects from Orbital Texture”, Phys. Rev. Lett. 121, 086602 (2018)
Work program & Skills acquired during internship
The internship thesis will consist in:
i. Characterize magnetic properties (magnetization saturation, anisotropy) by the mean of VSM and MOKE.
ii. Fabrication of Hall bars via DUV lithography.
iii. Characterize spin torques amplitudes as a function of thicknesses and material compounds.
iv. Synthetize and report results.
- Requested background: Master 1 / Master 2
- Duration: 6 months
- Start period: From January 2026 to July 2026
- Possibility of PhD thesis: Yes