Development of magnetic tunnel junction for toggle-MRAM

Author

Kim, H.-J. ; Ha, Y.K. ; Oh, S.C. ; Bae, J.S. ; Nam, K.T. ; Lee, J.E. ; Park, S.O. ; Kim, H.S. ; Lee, N.L. ; Chung, U-in ; Moon, J.T. ; Kang, H.K.

Author_Institution

Samsung Electron. Co., Ltd., Yongin, South Korea

fYear

2005

fDate

4-8 April 2005

Firstpage

837

Lastpage

838

Abstract

MRAM using ´toggle´ switching mode is tested and characterized with respect to the free layer material and thickness combinations of SAF (synthetic antiferromagnet) structure. The tested MTJ cell size is 0.4 × 0.8 μm² with elliptical shape. The switching characteristics of toggle-MRAM depend strongly on Hk (crystal anisotropy field) and Hex (exchange coupling field). To get small switching field, the main effort should be focused on reducing Hk, since Hk mainly affects the spin-flop field (Hsf) while Hex mainly affects the saturation field (Hsat). Comparing several materials as free layer, it is found that Hk of NiFe is smaller than that of CoFeB. A smaller switching field in MTJ stacks can be obtained with NiFe SAF free layer.

Keywords

antiferromagnetic materials; boron alloys; cobalt alloys; crystal field interactions; exchange interactions (electron); iron alloys; magnetic storage; magnetic switching; magnetic tunnelling; nickel alloys; random-access storage; CoFeB; MTJ cell size; NiFe; crystal anisotropy field; exchange coupling field; free layer material; magnetic tunnel junction; saturation field; spin-flop field; switching field; synthetic antiferromagnet; toggle-MRAM; Anisotropic magnetoresistance; Antiferromagnetic materials; Crystalline materials; Magnetic anisotropy; Magnetic tunneling; Magnetization; Materials testing; Moon; Shape; Writing;

fLanguage

English

Publisher

ieee

Conference_Titel

Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International

Print_ISBN

0-7803-9009-1

Type

conf

DOI

10.1109/INTMAG.2005.1463847

Filename

1463847