Growth and Characterization of Ba0.5Sr0.5TiO3 Thin Films on Si (100) By 90° Off-Axis Sputtering

ABSTRACTWe have studied BaxSr1-xTiO3 (BST) thin films (x=0.5) grown on Si (100) with and without a Pt/Ta barrier layer using 90° off-axis RF sputtering. The growth conditions were optimized according to film crystallinity, stoichiometry, and dielectric properties. Polycrystalline BST films with strong (100) texture were obtained via growth on Si (100). The measured dielectric constant from these films was low, presumably because of the parasitic effect of native oxide at BST/Si interface as revealed by TEM. On the other hand, BST films grown on Si with Pt/Ta barrier layers have crystallinity inferior to that on bare Si as determined by X-ray diffraction. Nevertheless, the best BST films on Pt/Ta layers still have good dielectric properties with dielectric constant exceeding 330, leakage current density < 1×10−6 A/cm2 (±1 V), and loss tangent 0.05 at 1 MHz.

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Three-Step Deposition Method for Improvement of the Dielectric Properties of BST Thin Films

MRS Proceedings ◽

10.1557/opl.2012.451 ◽

2012 ◽

Vol 1397 ◽

Cited By ~ 1

Author(s):

H. Liu ◽

V. Avrutin ◽

C. Zhu ◽

J.H. Leach ◽

E. Rowe ◽

...

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Dielectric Properties ◽

Diffraction Measurement ◽

X Ray Diffraction ◽

Step Method ◽

Bst Thin Films ◽

Different Temperatures ◽

Different Strains ◽

High Dielectric

ABSTRACTEpitaixal Ba0.5Sr0.5TiO3 (BST) thin films were grown on SrTiO3 (STO) and DyScO3 substrates by radio-frequency magnetron sputtering system using three-step method which involves a relatively low-temperature (573-773 K) growth of a BST interlayer sandwiched between two BST layers deposited at a high substrate temperature of 1068 K. X-ray diffraction measurement showed different strains on the films with interlayers grown at different temperatures. Post-growth thermal treatment reduced film strain to a great extent (the film strain of a tri-layer film with a 773 K grown interlayer is only -0.001). Comparing with the control films grown at high temperature, three-step technique improved the dielectric properties, especially increased dielectric constant by 60% for BST/STO and 31% for BST/DyScO3, respectively. High dielectric constant of 1631.4 and its tuning of 36.7% were achieved on the BST/STO with an interlayer grown on 773 K.

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Physical Characterization of Thin Films of Lithium Niobate Deposited on Silicon Substrates

MRS Proceedings ◽

10.1557/proc-200-25 ◽

1990 ◽

Vol 200 ◽

Cited By ~ 5

Author(s):

Robert C. Baumann ◽

Timothy A. Rost ◽

Thomas A. Rabson

Keyword(s):

Thin Films ◽

Rf Sputtering ◽

Depth Profiling ◽

Silicon Substrates ◽

X Ray Diffraction ◽

X Ray ◽

Surface Optical ◽

Auger Electron Spectroscopy Depth ◽

Deposition Conditions

ABSTRACTThin films (.1-.6 μm) of LiNbO3 have been deposited on silicon substrates by reactive rf sputtering. Under optimized deposition conditions the resulting thin films of LiNbO3 were optically transparent, adhered well to the silicon substrates, and were found to be polycrystalline and uniaxial with the c axis oriented normal to the silicon surface. Optical microscopy and scanning electron microscopy were used to examine film morphology. Both methods indicated that the films were smooth and contained no gross irregularities. The ratio of oxygen to niobium in these films was measured by Rutherford backscattering to be approximately 3 to 1. Auger electron spectroscopy depth profiling revealed that the films had the expected ratio of Li, Nb, and O. This information, together with Bragg x-ray diffraction data, indicates that the thin films deposited on silicon were stoichiometric, crystalline LiNbO3.

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Effects of LSCO Buffer Layer on the Microstructure and Dielectric Properties of Ba0.6Sr0.4TiO3 Films Prepared by Sol-gel Methods

MRS Proceedings ◽

10.1557/proc-1199-f03-23 ◽

2009 ◽

Vol 1199 ◽

Author(s):

Songwei Han ◽

Shengwen Yu ◽

Jinrong Cheng

Keyword(s):

Thin Films ◽

Dielectric Properties ◽

Sol Gel ◽

Buffer Layers ◽

X Ray Diffraction ◽

Random Orientation ◽

X Ray ◽

Bst Thin Films ◽

Structure And Morphology ◽

Bst Films

AbstractIn this work, Ba0.6Sr0.4TiO3(BST) thin films were deposited on Ti substrates using conductive La0.5Sr0.5CoO3 (LCSO) as buffer layers. Both BST and LSCO films were prepared by sol-gel methods. The structure and morphology of BST and LSCO films were analyzed by X-ray diffraction (XRD). XRD results show that both BST and LSCO films have perovskite structure with random orientation. The dielectric properties of BST films were dependent on the thickness of LSCO buffer layers. Upon using LSCO buffer layers, the dielectric properties of BST films were significantly improved. The dielectric constant, tunability, and dielectric loss of BST thin films for LSCO of 150 nm achieved about 453, 0.032 and 31.26% respectively.

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Role of stress on the phase control and dielectric properties of (1-x) BiFeO3 - xBa0.5Sr0.5TiO3 solid solution thin films

MRS Proceedings ◽

10.1557/proc-875-o12.10 ◽

2005 ◽

Vol 875 ◽

Author(s):

Chin Moo Cho ◽

Hee Bum Hong ◽

Kug Sun Hong

Keyword(s):

Thin Films ◽

Solid Solution ◽

Dielectric Properties ◽

Loss Tangent ◽

Lattice Parameter ◽

X Ray Diffraction ◽

Parameter Mismatch ◽

Si Substrates ◽

Bst Films

AbstractDielectric properties and structure of (1-x) BiFeO3 (BFO) - x Ba0.5Sr0.5TiO3 (BST) (x = 0 ∼1) solid solution thin films were investigated. All films were prepared at 600 oC on (111) oriented Pt / TiO2 / SiO2 / Si substrates by pulsed laser deposition (PLD) technique. Solid solution could be achieved in all composition ranges, evidenced by X-ray diffraction (XRD) and field emission scanning electric microscope (FE-SEM). The intermediate compositions (0.4 = x = 0.8) exhibited a distinct (111) oriented cubic perovskite structure, while rhombohedra symmetry was found in the x < 0.4 range. Dielectric constant and tunability of the (1-x) BFO – x BST films within this composition region (0.4 = x = 0.8) decreased from 1110 to 920 at 1 MHz, and increased from 28.34 % to 32.42 % at 200 kV/cm, respectively, while loss tangent remains constant. A systematic decrease in lattice parameter with BST addition reduced stress due to reduction of lattice parameter mismatch between film and the substrate. In that range, the improvement of the dielectric properties without a degradation of loss tangent is attributed to the presence of the stress relaxation, which was quantitatively confirmed by a surface profiler based on Stoney's equation.

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Thickness Dependence of Induced Ferroelectricity in Epitaxially Grown Ba0.44Sr0.56TiO3 Thin Films

MRS Proceedings ◽

10.1557/proc-361-465 ◽

1994 ◽

Vol 361 ◽

Cited By ~ 4

Author(s):

Kazuhide Abe ◽

Shuichi Komatsu

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Dielectric Properties ◽

Magnetron Sputtering ◽

Lattice Constant ◽

Rf Magnetron Sputtering ◽

Thickness Dependence ◽

Thickness Direction ◽

Deposition Technique ◽

Bst Films

ABSTRACTBa0.44Sr0.56TiO3 (BST) thin films with various thicknesses were epitaxially grown on Pt/MgO(100) substrates with rf magnetron sputtering. The thickness dependence of lattice constant, D-E hysteresis and dielectric constant were evaluated for the BST films. The lattice constant in the thickness direction is elongated through the thickness range (33 to 221 nm), whereas the ferroelectric and the dielectric properties had strong thickness dependencies. The mechanism of the induced ferroelectricity is discussed in terms of the thickness dependence and deposition technique.

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Dielectric Properties of Bi2Ti2O7 Thin Films With (111) Orientation

MRS Proceedings ◽

10.1557/proc-592-135 ◽

1999 ◽

Vol 592 ◽

Cited By ~ 1

Author(s):

Zhuo Wang ◽

J. Huang ◽

S.W. Wang ◽

X.X. Hong ◽

Y. Hou ◽

...

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Dielectric Properties ◽

Bismuth Titanate ◽

X Ray Diffraction ◽

Titanium Butoxide ◽

X Ray ◽

Ceramic Films ◽

Current Voltage ◽

Source Materials

ABSTRACTBismuth titanate thin films have been prepared on silicon by metalorganic decompositionMOD) technique with bismuth nitrate and titanium butoxide as source materials. The growth procedure of the Bi2Ti2O7 thin films is discussed in this paper. The surface morphology of the Bi2Ti2O7 film was investigated by using Electric Force Microscope (EFM), and the crystallization of the films was studied by x-ray diffraction (XRD). Bismuth titanate thin film prepared on (100) silicon substrate showed strong (111) orientation. Its dielectric properties and the current-voltage (I-V) characteristics were measured. The dielectric constant of the Bi2Ti2O7 thin films vs. frequency, in the temperature range of 100-800 °C, were studied. The dielectric constant and the dielectric loss for Bi2Ti2O7 are 118 and 0.07 respectively at 100KHz. For the Bi2Ti2O7 films with 0.4µm in thickness annealed at 580 °C for 40 minutes, their leakage current density is 4.06×10−7 A/cm2 at an applied voltage of 15V.The ferroelectric phase transition has been observed distinctly and the Curie temperature was determined for the Bi2Ti2O7 ceramic films. Capacitance vs. temperature was measured from 27-800 at 1KHz, 100KHz, 100KHz and 1MHz.

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Dielectric Properties of Pb0.97La0.02Zr0.95Ti0.05O3 Antiferroelectric Thin Films Prepared at Different Annealing Temperatures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.2460 ◽

2011 ◽

Vol 287-290 ◽

pp. 2460-2463

Author(s):

Wen Ping Geng ◽

Xiu Jian Chou ◽

Ya Ting Zhang ◽

Mao Xiang Guo ◽

Jun Liu

Keyword(s):

Thin Films ◽

Dielectric Properties ◽

Electric Field ◽

Sol Gel ◽

X Ray Diffraction ◽

Temperature Dependent ◽

Dielectric Constant And Loss ◽

Sol Gel Process ◽

Plzt Thin Films

Pb0.97La0.02Zr0.95Ti0.05O3(PLZT) antiferroelectric thin films were prepared on Pt (111)/ Ti/SiO2/Si (100) substrates by a sol-gel process. The influences of annealing temperature on the structures and dielectric properties of the PLZT antiferroelectric thin films were investigated. And the phase structure and crystal orientation were studied by X-ray diffraction analyses (XRD). The antiferroelectric characterization of the PLZT thin films annealed at different temperature was demonstrated by P(polarization)-E(electric field) and C(capactitance)-E(electric field) curves. The maximum polarizations for the films annealed at 650°C, 700°C and 750°C were 35μC/cm2, 42μC/cm2and 47μC/cm2, respectively. The temperature dependent of the dielectric constant and loss was measured under the frequency 1, 10, 100 and 1000 kHz. The films annealed at 700°C have high (100)-preferred orientation and excellent dielectric properties.

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Microstructural and Electrical Characterization of Barium Strontium Titanatebased Solid Solution Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition

MRS Proceedings ◽

10.1557/proc-720-h2.4 ◽

2002 ◽

Vol 720 ◽

Author(s):

Costas G. Fountzoulas ◽

Daniel M. Potrepka ◽

Steven C. Tidrow

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Pulsed Laser Deposition ◽

Pulsed Laser ◽

Electrical Characterization ◽

Field Variable ◽

Laser Deposition ◽

X Ray Diffraction ◽

Ceramic Substrates ◽

Nominal Thickness

AbstractFerroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0.6Sr0.4Ti1-y(A 3+, B5+)yO3 thin films, of nominal thickness of 0.65 μm, were synthesized initially at substrate temperatures of 400°C, and subsequently annealed to 750°C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.

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