Giant tunnel magnetoresistance and high annealing stability in CoFeB/MgO/CoFeB magnetic tunnel junctions with synthetic pinned layer

被引：167

作者：

Lee, Y. M.

Hayakawa, J.

Ikeda, S.

Matsukura, F.

Ohno, H.

机构：

[1] Tohoku Univ, Res Inst Elect Commun, Lab Nanoelect & Spintron, Aoba Ku, Sendai, Miyagi 9808577, Japan

[2] Hitachi Ltd, Adv Res Lab, Kokubunji, Tokyo 1858601, Japan

来源：

APPLIED PHYSICS LETTERS | 2006年 / 89卷 / 04期

关键词：

D O I：

10.1063/1.2234720

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We investigated the relationship between tunnel magnetoresistance (TMR) ratio and the crystallization of CoFeB layers through annealing in magnetic tunnel junctions (MTJs) with MgO barriers that had CoFe/Ru/CoFeB synthetic ferrimagnet pinned layers with varying Ru spacer thickness (t(Ru)). The TMR ratio increased with increasing annealing temperature (T-a) and t(Ru), reaching 361% at T-a=425 degrees C, whereas the TMR ratio of the MTJs with pinned layers without Ru spacers decreased at T-a over 325 degrees C. Ruthenium spacers play an important role in forming a (001)-oriented bcc CoFeB pinned layer, resulting in a high TMR ratio through annealing at high temperatures.

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页数：3

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