Low resistance magnetic tunnel junctions and their interface structures

Journal Article · Fri Jun 01 04:00:00 EDT 2001 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1361054· OSTI ID:40204119

Fujikata, J; Ishi, T; Mori, S; Matsuda, K; Mori, K; Yokota, H; Hayashi, K; Nakada, M; Kamijo, A; Ohashi, K

Effects of interface structure and oxidation state were studied in stacked magnetic tunnel junction (MTJ) structures with top and bottom antiferromagnetic layers to obtain optimum resistance and high tunneling magnetoresistance (TMR) ratios for read heads. The roughness of the NiFe surface and the Al coverage were significantly improved by introduction of O{sub 2} surfactant gas on the Ta-seed-layer surface, which increased TMR ratios of the MTJ with low resistance area (RA) products of less than 10 {Omega}{mu}m2. Furthermore, it was found that avoidance of Ni oxidation and Co oxidation at the tunnel barrier interface is essential to obtaining high TMR ratios, and that a good Al coverage and Fe{endash}oxide formation may enhance TMR ratios when Fe-rich magnetic materials are used. For the top-type and bottom-type structures, a TMR ratio of 12%{endash}17% with RA products of 6{endash}7 {Omega}{mu}m2 was obtained, which provides sufficient performance for read heads. {copyright} 2001 American Institute of Physics.

• Sponsoring Organization: (US)
• OSTI ID: 40204119
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 89; ISSN 0021-8979
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AVOIDANCE
MAGNETIC MATERIALS
MAGNETORESISTANCE
OXIDATION
PERFORMANCE
PHYSICS
ROUGHNESS
SURFACTANTS
TUNNELING
VALENCE