1. Ferromagnetic Coupling Field Reduction in CoFeB Tunnel Junctions Deposited by Ion Beam.
- Author
-
Cardoso, Susana, Ferreira, Ricardo, Freitas, Paulo P., MacKenzie, Maureen, Chapman, John, Ventura, João O., Sousa, Joao B., and Kreissig, Ulrich
- Subjects
FERROMAGNETIC materials ,FERROMAGNETISM ,MAGNETIC materials ,ELECTRODES ,ELECTRIC resistors ,ION bombardment - Abstract
In this paper, junctions with reduced H
f coupling were fabricated by ion beam deposition and oxidation, using CoFeB electrodes. The CoFeB layer has a strong (111) texture that can be the origin of lower Hf and coercivity when compared, with CoFe. Junctions processed down to 2 × 4 μm² with 40-Å-thick CoFeB bottom electrodes have 42% of tunneling magnetoresistance (TMR), (R × A ∼ 400 Ω·μm²), Hc of ∼10 Oe and Hf of ∼2 Oe. CoFe-based junctions (R × A ∼ 500 Ω·μm²) have lower TMR (∼35%) and larger Hf (∼5-6 Oe) and Hc (∼12-14 Oe). Local chemical. composition analysis of the cross section indicated Fe-O segregation with very little Co grown on top of the barrier for CoFe-based junctions and not for CoFeB ones. [ABSTRACT FROM AUTHOR]- Published
- 2004
- Full Text
- View/download PDF