Scaling properties of perpendicular MTJ with dual-CoFeB/MgO interfaces and step-etch structure

Author

Cheng-Wei Chien ; Ding-Yeong Wang ; Sheng-Huang Huang ; Kuei-Hung Shen ; Shan-Yi Yang ; Jia-Hong Shyu ; Keng-Ming Kuo ; Young-Shying Chen ; Yung-Hung Wang ; Tzu-Kun Ku ; Deng, Dennis

Author_Institution

Ind. Technol. Res. Inst., Hsinchu, Taiwan

fYear

2014

fDate

28-30 April 2014

Firstpage

1

Lastpage

2

Abstract

We had built and studied the size scaling effect of perpendicular magnetic tunnel junctions (p-MTJs) with dual MgO/CoFeB interface and step-etch structure. Although the spin-torque-transfer (STT) switching current reduces with MTJ area, the current density increases. Our micromagnetic simulations verify that this is an intrinsic property of STT switching. The switching mode shifts gradually from coherent switching in small junctions to incoherent in large junctions. The energy density of coherent switching is higher and demands higher spin current density. At same current density, smaller size takes longer time to switch. Fortunately, the write efficiency (Δ/Isw) is higher for smaller MTJ.

Keywords

cobalt compounds; current density; etching; iron compounds; magnesium compounds; magnetic tunnelling; magnetoelectronics; micromagnetics; perpendicular magnetic anisotropy; CoFeB-MgO; STT switching intrinsic property; coherent switching; micromagnetic simulations; perpendicular MTJ; perpendicular magnetic tunnel junctions; scaling property; size scaling effect; spin current density; spin-torque-transfer switching current; step-etch structure; switching mode shifts; write efficiency; Current density; Junctions; Magnetic tunneling; Stability analysis; Switches; Thermal factors; Thermal stability;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology, Systems and Application (VLSI-TSA), Proceedings of Technical Program - 2014 International Symposium on

Conference_Location

Hsinchu

Type

conf

DOI

10.1109/VLSI-TSA.2014.6839662

Filename

6839662