High tunability barium strontium titanate thin films for rf circuit applications

Journal Article · Mon Nov 08 04:00:00 EST 2004 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.1818724· OSTI ID:20634407

Pervez, N K; Hansen, P J; York, R A ^[1]

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1. Department of Electrical and Computer Engineering and Materials Department, University of California, Santa Barbara, California 93106 (United States)

Large variations in the permittivity of rf magnetron sputtered thin-film barium strontium titanate have been obtained through optimization of growth conditions for maximum dielectric strength and zero-field permittivity in a parallel-plate capacitor structure. Using nominal target compositions of Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3}, and Pt electrodes on c-plane sapphire substrates, adjustment of the O{sub 2} partial pressure during deposition was used to vary the excess Ti incorporation into the films, which influenced the low-field permittivity, loss tangent, and dielectric strength. By balancing the benefits of a high permittivity with dielectric strength and loss, we have produced films capable of sustaining short-duration fields greater than 4 MV/cm with over 13:1 (>90%) change in dielectric constant, and greater than 5:1 tunability in bias fields under 1 MV/cm.

• OSTI ID: 20634407
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 19 Vol. 85; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
CAPACITORS
DEPOSITION
ELECTRODES
FERROELECTRIC MATERIALS
MAGNETRONS
OPTIMIZATION
PARTIAL PRESSURE
PERMITTIVITY
PLATINUM
SAPPHIRE
STRONTIUM TITANATES
SUBSTRATES
THIN FILMS