Thin seeded Co/Ni multilayer film with perpendicular anisotropy for spintronic device applications

US8064244B2 · kind B2 · utility

Assignees

• TDK CORPORATION · JP
• Kabushiki Kaisha Toshiba · JP

Inventors

• Kunliang Zhang · Fremont, US
• Min Li · Dublin, US
• Yuchen Zhou · San Jose, US
• Soichi Oikawa · Hachioji, JP
• Kenichiro Yamada · Tokyo, JP
• Katsuhiko Koui · Yokohama, JP

Key dates

• Filing date: Jun 19, 2009
• Grant date: Nov 22, 2011
• Expiry date: Jun 4, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/1143
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A spin valve structure for a spintronic device is disclosed and includes a composite seed layer made of at least Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (Co/Ni)x multilayer. The (Co/Ni)x multilayer is deposited by a low power and high Ar pressure process to avoid damaging Co/Ni interfaces and thereby preserving PMA. As a result, only a thin seed layer is required. PMA is maintained even after annealing at 220° C. for 10 hours. Examples of GMR and TMR spin valves are described and may be incorporated in spin transfer oscillators and spin transfer MRAMs. The free layer is preferably made of a FeCo alloy including at least one of Al, Ge, Si, Ga, B, C, Se, Sn, or a Heusler alloy, or a half Heusler alloy to provide high spin polarization and a low magnetic damping coefficient.