Magnetic films for GHz applications (abstract)
- Bell Labs, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States)
Tremendous growth of the communications industry and the increasingly high demand for low-cost light-weight/small-size products drive technology to designs with a high degree of integration. In particular, planar inductors used in integrated circuits with significantly improved inductance per unit area characteristics are needed for further miniaturization of cellular phones operating at 0.95 and 1.9 GHz. Little has been done, however, to use magnetic films to improve the performance and/or reduce size of planar magnetic flux devices. The successful thin-film material would have a high ferromagnetic resonance (FMR) frequency (well above the operating frequency of the device), large permaeability, and low magnetic loss, and very importantly be technologically attractive, i.e., be process compatible with IC technology and have as few preparation steps as possible. Here, we report on fabrication of metallic ferromagnetic films of CoNbZr, CoNbZr/AlN mulitilayered laminates, and exchange-biased structures suitable for GHz applications. Lamination of CoNbZr with thin insulating layers of AlN is shown to significantly improve the microstructure and dc magnetic properties of the films having thicknesses {gt}0.2 {mu}m, as well as to be effective in suppressing eddy current losses at frequencies up to 1{endash}2 GHz. We use exchange biasing to increase the FMR frequency of soft CoNbZr. In-plane unidirectional anisotropy fields of {approximately}50 Oe are achieved, which result in FMR frequencies {gt}2 GHz. Permeability values of {approximately}200 with quality factors of {approximately}10 at 1 GHz are demonstrated. The films are deposited at room temperature and require no postdeposition processing. Application of these films in planar inductors is discussed.{copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 496526
- Report Number(s):
- CONF-961141--
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Application of sub-micrometer patterned permalloy thin film in tunable radio frequency inductors
Soft magnetism, magnetostriction, and microwave properties of FeGaB thin films