Realization of high tunability barium strontium titanate thin films by rf magnetron sputtering

Barium strontium titanate (BST) thin films with excellent dielectric properties are deposited by on-axis RF magnetron sputtering system. The effects of composition of the target and oxygen partial pressure on the microstructure of BST thin film have been investigated. The dielectric properties of the thin films are investigated. The results show that composition of BST thin film deposited with pure argon ambient by the target with 30atm% excess of Ba and Sr is stoichiometric. Perovskite phase can be observed in the thin film annealed in oxygen at 750 °C for 30 min. A metal-insulator-metal (MIM) capacitor is fabricated by microfabrication technique. The capacitance value at 2 GHz is 0.417 pF and 1.42 pF for 50 nm and 90 nm BST thin film respectively, and the leakage current density is 6×10-6 A/cm2 and 5.35×10-8 A/cm2 respectively.

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Stoichiometric Effects of Sputtered Barium Strontium Titanate Films

MRS Proceedings ◽

10.1557/proc-493-21 ◽

1997 ◽

Vol 493 ◽

Cited By ~ 4

Author(s):

B. A. Baumert ◽

T.-L. Tsai ◽

L.-H. Chang ◽

T. P. Remmel ◽

M. L. Kottke ◽

...

Keyword(s):

Dielectric Constant ◽

Magnetron Sputtering ◽

Strontium Titanate ◽

Barium Strontium Titanate ◽

Electrical Characterization ◽

Rf Magnetron Sputtering ◽

Sputtered Films ◽

Barium Strontium ◽

Powder Samples ◽

Increasing Temperature

ABSTRACTBarium Strontium Titanate films have been deposited by rf magnetron sputtering and have been studied with respect to Ba/Sr ratio. Physical and electrical characterization has been done as a function of temperature, thickness, and composition, and results show that dielectric constant increases with increasing temperature, thickness (up to ∼80 nm), and Ba/Sr ratio for the compositions studied. The lattice parameters for the sputtered films are larger than those expected for powder samples and also increase with increasing Ba/Sr ratio.

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Relation between Electro-Optic Effect and Dielectric Permittivity of Ba0.5Sr0.5TiO3 Thin Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.566.20 ◽

2013 ◽

Vol 566 ◽

pp. 20-24

Author(s):

Kotaro Takeda ◽

Takuya Hoshina ◽

Hiroaki Takeda ◽

Takaaki Tsurumi

Keyword(s):

Thin Film ◽

Thin Films ◽

Dielectric Permittivity ◽

Strontium Titanate ◽

Barium Strontium Titanate ◽

High Tunability ◽

Barium Strontium ◽

Electro Optic ◽

Ionic Mass ◽

Complex Admittance

The relation between the dielectric tunability and the electro-optic (EO) effect of barium strontium titanate (Ba0.5Sr0.5TiO3) thin film was discussed. The tunability of dielectric permittivity calculated from the complex admittance with planer electrodes reached to 53.1%, and the tunability of birefringence by EO effect was 0.6%. The birefringence change from EO effect was much lower than the tunability of dielectric permittivity. The materials with high tunability do not always exhibit high EO effect. This is concluded to arise due to the ionic mass in the EO materials.

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A post-growth processing methodology to achieve barium strontium titanate thin films with low dielectric loss and high tunability for reconfigurable tunable devices

Journal of Materials Science ◽

10.1007/s10853-009-3538-0 ◽

2009 ◽

Vol 44 (19) ◽

pp. 5332-5338 ◽

Cited By ~ 10

Author(s):

Melanie W. Cole ◽

Adrian Podpirka ◽

Shriram Ramanathan

Keyword(s):

Thin Films ◽

Dielectric Loss ◽

Strontium Titanate ◽

Barium Strontium Titanate ◽

Low Dielectric ◽

High Tunability ◽

Barium Strontium

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Effect of Annealing Temperature on the Microstructure of Barium Strontium Titanate Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.56 ◽

2008 ◽

Vol 368-372 ◽

pp. 56-58

Author(s):

Jia Xuan Liao ◽

En Qiu Li ◽

Zhong Tian ◽

Jiang Xu ◽

Hai Guang Yang

Keyword(s):

Magnetron Sputtering ◽

Strontium Titanate ◽

Barium Strontium Titanate ◽

Annealing Temperature ◽

Structural Characteristics ◽

Rf Magnetron Sputtering ◽

Surface And Interface ◽

Barium Strontium ◽

Bst Films

Barium strontium titanate (Ba1−xSrxTiO3, BST) films have been prepared on Pt/Ti/SiO2/Si by medium frequency (MF) magnetron sputtering, and subsequently in situ crystallized at 500-700°C. The microstructures of the MF-BST films are studied. BST films prepared by radio frequency (RF) magnetron sputtering and exhibited preferential (110) orientation, are compared. XRD shows that the MF-BST films exhibit preferential (111) orientation and better crystallization than the RF-BST films at the same annealing temperature. AFM displayed that the MF-BST films were smooth and compact. XPS analysis exhibited that the MF-BST films revealed better surface and interface structural characteristics. Their dielectric properties were also compared.

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