Ultra thin seed layer for CPP or TMR structure

US7646568B2 · kind B2 · utility

Assignee

• Headway Technologies, Inc. · US

Inventors

• Kunliang Zhang · Fremont, US
• Hui-Chuan Wang · Pleasanton, US
• Tong Zhao · Eden Prairie, US
• Yu-Hsia Chen · Mountain View, US
• Min Li · Dublin, US
• Cherng-Chyi Han · San Jose, US

Key dates

• Filing date: Dec 23, 2005
• Grant date: Jan 12, 2010
• Expiry date: Oct 23, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49021
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Improved magnetic devices have been fabricated by replacing the conventional seed layer (typically Ta) with a bilayer of Ru on Ta. Although both Ru and Ta layers are ultra thin (between 5 and 20 Angstroms), good exchange bias between the seed and the AFM layer (IrMn about 70 Angstroms thick) is retained. This arrangement facilitates minimum shield-to-shield spacing and gives excellent performance in CPP, CCP-CPP, or TMR configurations.