[11a-E208-1~11] 10.3 Spin devices, magnetic memories and storages

11:15 AM - 11:30 AM JST(2:15 AM - 2:30 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[11a-E208-9] High Tunneling Magnetoresistance Ratio in Magnetic Tunnel Junctions with Metastable Zinc-Blende GaN Tunnel Barriers

〇(D)Hyeokjin Kwon^1,2, Kumar Deepak², Kenya Suzuki^1,2, Soma Miki², Tomohiro Ichinose², Shigemi Mizukami^2,3 (1.Dept. Appl. Phys., Tohoku Univ., 2.WPI-AIMR, Tohoku Univ., 3.CSIS, Tohoku Univ.)

Keywords:

MRAM,TMR,MTJ

Magnetoresistive random access memory (MRAM) requires low tunnel barrier resistance to prevent high-speed dielectric breakdown, which severely limits ultra-thin MgO barriers. To balance speed and reliability, we investigate metastable cubic GaN(001) with a small bandgap (~3 eV). Multilayers with a Cr(40)/CoMnFe(10)/Mg(0.5)/MgO(0.6)/GaN(0.9)/Mg(0.5)/MgO(0.6)/CoMnFe(8)/IrMn(10)/Ru(10) (nm) structure were deposited on MgO(001) via UHV magnetron sputtering, with MgO seed and Mg buffer layers to promote the cubic phase and suppress interdiffusion. Properties were evaluated via CIPT, DC four-probe, and PPMS. The Mg insertions effectively suppressed interdiffusion and oxidation. A distinct room-temperature TMR effect reached 134%, proving robust coherent tunneling. Bias dependence revealed exceptionally high V_half, demonstrating suppressed inelastic spin-flip scattering and highlighting GaN barriers' potential for high-performance STT-MRAM.