Effect of crystallinity on the dielectric loss of sputter-deposited (Ba,Sr)TiO3 thin films in the microwave range

2003 ◽  
Vol 18 (3) ◽  
pp. 682-686 ◽  
Author(s):  
Tae-Gon Kim ◽  
Jeongmin Oh ◽  
Taeho Moon ◽  
Yongjo Kim ◽  
Byungwoo Park ◽  
...  
Keyword(s):  
Thin Films ◽  
Equivalent Circuit Model ◽  
Sputter Deposition ◽  
Dielectric Losses ◽  
Polar Regions ◽  
Microwave Range ◽  
Si Substrate ◽  
Microwave Dielectric ◽  
Sputter Deposited ◽  
Tan Δ

The crystallinity dependence of the microwave dielectric losses in (Ba,Sr)TiO3 thin films was investigated. The sputter-deposition temperatures were altered to vary the level of thin-film crystallinity on a Pt/Si substrate. The dielectric losses (tan δ) were measured up to 6 GHz without parasitic (stray) effects by using a circular-patch capacitor geometry and an equivalent-circuit model. The microwave dielectric losses increased from 0.0024 ± 0.0018 to 0.0102 ± 0.0017 with increasing crystallinity. These deteriorated dielectric losses showed a good correlation with the symmetry-breaking defects, as confirmed by Raman spectra at approximately 760 cm−1, inducing microscopic polar regions above the Curie temperature of the bulk (Ba0.43Sr0.57)TiO3.

scholarly journals Sputter Deposited Metal Layers Embedded in Composites—From Fundamentals to Applications

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 190
Author(s):  
Florian Cougnon ◽  
Mathias Kersemans ◽  
Wim Van Paepegem ◽  
Diederik Depla
Keyword(s):  
Thin Films ◽  
Heat Flux ◽  
Sputter Deposition ◽  
Image Correlation ◽  
Fiber Reinforced Polymers ◽  
Thermal Probe ◽  
Reinforced Polymers ◽  
Magnetron Sputter Deposition ◽  
Sputter Deposited ◽  
Metal Layers

Due to the low heat flux towards the substrate, magnetron sputter deposition offers the possibility to deposit thin films on heat sensitive materials such as fiber-reinforced polymers, also known as composite materials. Passive thermal probe measurements during the sputter deposition of metal layers show indeed that the temperature increase remains well below 25 °C for film thicknesses up to 600 nm. The latter thickness threshold is based on the influence of embedded metal films on the adhesion of the composite plies. Films thicker than this threshold deteriorate the mechanical integrity of the composite. The introduction of the uncured composite in the vacuum chamber strongly affects the base pressure by outgassing of impurities from the composite. The impurities affect the film properties as illustrated by their impact on the Seebeck coefficient of sputter deposited thermocouples. The restrictions to embed thin films in composites, as illustrated by both the heat flux measurements, and the study on the influence of impurities, are however not insurmountable. The possibility to use embedded thin films will be briefly demonstrated in different applications such as digital volume image correlation, thermocouples, and de-icing.

Preparation and Influencing Factors of Molybdenum Targets and Magnetron-Sputter-Deposited Molybdenum Thin Films

2018 ◽  
Vol 913 ◽  
pp. 853-861 ◽  
Author(s):  
Geng An ◽  
Jun Sun ◽  
Yuan Jun Sun ◽  
Wei Cheng Cao
Keyword(s):  
Thin Films ◽  
Grain Orientation ◽  
Sputter Deposition ◽  
Powder Metallurgy Method ◽  
Total Deformation ◽  
Electrical Conductivities ◽  
Diffraction Peaks ◽  
Magnetron Sputter ◽  
Sputter Deposited ◽  
Surface Morphologies

Aiming to produce qualified molybdenum (Mo) target for sputter deposition, Mo targets were prepared by utilizing powder metallurgy method in this research. The influences of sintering modes, press working modes and total deformation on microstructure and properties of Mo target were studied. Furthermore, magnetron sputtering test was conducted in vacuum environment by using the prepared Mo targets to deposit Mo thin films of which the surface morphologies, electrical conductivities, and crystalline properties were analyzed. The results show that vacuum presintering followed by hydrogen sintering mode can greatly decrease the impurity contents of Mo slabs. It is favorable to obtain the Mo target with fine and uniform grains on size and distribution by using forging mode or forging cogging mode and more than 70% total deformation. With the increase of sputtering currents of Mo target, the grain size and the thickness of the Mo thin films significantly rise, while FWHM of diffraction peaks of grain orientation (110), surface roughness and electrical resistivity of thin films decrease accordingly.

Reduction of microwave dielectric losses in KTa1−xNbxO3 thin films by MgO-doping

2009 ◽  
Vol 517 (20) ◽  
pp. 5940-5942 ◽  
Author(s):  
Q. Simon ◽  
V. Bouquet ◽  
W. Peng ◽  
J.-M. Le Floch ◽  
F. Houdonougbo ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Losses ◽  
Microwave Dielectric

ELECTRODE MATERIAL EFFECT ON CAPACITANCE AND LOSS TANGENT OF THE ORGANIC ZnPc SEMICONDUCTING THIN FILMS

2007 ◽  
Vol 21 (01) ◽  
pp. 55-67 ◽  
Author(s):  
A. O. ABU-HILAL ◽  
R. D. GOULD ◽  
M. I. ABU-TAHA ◽  
A. M. SALEH
Keyword(s):  
Thin Films ◽  
Loss Tangent ◽  
Strong Dependence ◽  
Electrical Contact ◽  
Equivalent Circuit Model ◽  
Zinc Phthalocyanine ◽  
Strong Temperature Dependence ◽  
Low Frequencies ◽  
Tan Δ ◽  
Semiconducting Thin Films

The capacitance and loss tangent of thermally evaporated zinc phthalocyanine, ZnPc , semiconducting thin films were measured in the temperature range of 180–430 K and frequency between 0.1 and 20 kHz. Aluminum and gold electrical contact electrodes were employed to sandwich ZnPc films. For both electrode types, the capacitance and loss tangent showed strong dependence on both temperature and frequency. Such dependence is related to the relevant temperature and frequency range under consideration. The capacitance has strong temperature dependence for T>240 K and frequency below 3 kHz, while it becomes a constant at higher frequencies and all temperatures. The loss tangent dependence on temperature is more evident at low frequencies and a minimum or an indication of a minimum was observed in tan δ versus f curves. Loss tangent variation with temperature was not monotonic for all frequencies. An anomaly (maximum) in tan δ was observed approximately between 300 and 360 K. This maximum was attributed to the presence of oxygen molecules in the sample and their subsequent exhaustion as the temperature is increased. The behavior of capacitance and loss tangent (for both Al and Au -electrodes) may be explained qualitatively and successfully in terms of an equivalent circuit model.

Structural characterization of sputter-deposited LaNiO3 thin films on Si substrate by x-ray reflectivity and diffraction

1997 ◽  
Vol 12 (11) ◽  
pp. 3165-3173 ◽  
Author(s):  
Hsin-Yi Lee ◽  
Tai-Bor Wu
Keyword(s):  
Thin Films ◽  
Transition Layer ◽  
Mass Density ◽  
Composition Analysis ◽  
X Ray Diffraction ◽  
Diffraction Intensity ◽  
Si Substrate ◽  
X Ray ◽  
Sputter Deposited ◽  
Reflectivity Data

X-ray reflectivity and diffraction were applied to characterize the highly (100)-textured thin films of LaNiO3, which were deposited on Si substrate via radio frequency magnetron sputtering at temperatures ranging from 250 to 450 °C. Two interference fringes of different period were observed from the reflectivity curves, and the fitting result indicates that in addition to the normal lanthanum-nickel oxide layer, a transition layer, which has a larger mass density than the previous one, exists in the sputter-deposited films. A comparison of the measured x-ray diffraction intensity with that calculated from layer thickness and mass density obtained from reflectivity data indicates that the transition layer is noncrystalline. The x-ray diffraction result also shows that there is a significant decrease of (100) diffraction intensity relative to that of (200) as increasing the deposition temperature. Using the reflectivity and diffraction data along with results of electron diffraction and film composition analysis from our other studies, such a change of relative intensity between the two diffraction peaks is attributed to the increasing content of two also highly textured La-rich phases, i.e., (110)-textured La4Ni3O10 and (100)-textured La2NiO4, in addition to the LaNiO3.

scholarly journals Dielectric Properties and Impedance Spectroscopy of RF Sputtered Nanocrystalline (Mg0.95Zn0.05)TiO3 Films for Electronic Applications

2021 ◽  
Author(s):  
Pallabi Gogoi ◽  
Pramila Rani PNVVL ◽  
K A Emmanuel ◽  
L Robindro Singh ◽  
Pamu D
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Broad Band ◽  
Equivalent Circuit Model ◽  
Pure Oxygen ◽  
Oxygen Environment ◽  
Microwave Dielectric ◽  
Wide Range

Abstract Oxide thin films attracted significant attention because of their favorable responses, especially dielectric and stable electrical properties. In this study, nanocrystalline (Mg0.95Zn0.05)TiO3 (MZT) films are deposited on Pt/TiO2/SiO2/Si and quartz substrates by radio-frequency (RF) reactive magnetron sputtering. The effect of deposition gas ratio, i.e., the proportion of oxygen and argon (O2/Ar) on broad band and microwave dielectric properties and impedance spectroscopy of MZT films are investigated. The dielectric properties showed a wide range of variation with the different O2/Ar ratios. The MZT film deposited in a pure oxygen environment showed the best dielectric properties, and the plasma survived which shows that the target is not fully oxidized. The impedance spectroscopy of the film deposited under a pure oxygen environment exhibited the single semi-circular arc. The Ag/ MZT/Pt thin films capacitors exhibited the best dielectric constant with low loss tangent. The microwave dielectric constant measured at different spot frequencies in the GHz range displayed inferior dielectric response as compared to their bulk counterparts. An equivalent circuit model to explain the Nyquist plots of MZT films are worked out. The observed electrical and dielectric characteristics of the thin films suggest interesting applications in dielectric mirror and integrated circuits.

Local Optical Probes of Microwave Dielectric Dispersion in Ferroelectric Thin Films

1999 ◽  
Vol 603 ◽  
Author(s):  
Charles Hubert ◽  
Jeremy Levy ◽  
E. J. Cukauskas ◽  
Steven W. Kirchoefer ◽  
Jeffrey M. Pond ◽  
...  
Keyword(s):  
Thin Films ◽  
Soft Mode ◽  
Dielectric Dispersion ◽  
Ferroelectric Thin Films ◽  
Optical Measurements ◽  
Polar Regions ◽  
Time Resolved ◽  
Microwave Dielectric ◽  
Confocal Scanning ◽  
Scanning Optical Microscopy

AbstractThe soft-mode contribution to the dielectric response of Ba0.5Sr0.5TiO3 ferroelectric thin films is measured locally at microwave frequencies using time-resolved confocal scanning optical microscopy. Optical measurements performed on an ensemble of nanometer-scale regions show a well-defined phase shift between the paraelectric and ferroelectric response at 2-4 GHz. Application of a static electric field produces large local variations in the phase of the ferroelectric response. These variations are attributed to the growth of a-axis ferroelectric nanodomains whose size-dependent relaxation frequencies lead to strong dielectric dispersion at mesoscopic scales. The in-plane paraelectric response is believed to arise from the surrounding c-axis matrix and non-polar regions, and shows negligible dispersion. These results provide a direct view of the soft-mode mechanisms of microwave dielectric loss in ferroelectric thin films.

Effect of Thermal Treatment on the Hardness and Fracture Toughness of Sputter Deposited Bi-Layered Thin Films on Silicon

1998 ◽  
Vol 516 ◽  
Author(s):  
M. Manoharan ◽  
B. Narayanan ◽  
G. Muralidharan
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Intermediate Phase ◽  
Si Substrate ◽  
Microhardness Testing ◽  
Sputter Deposited ◽  
Cu Thin Film ◽  
Composite Hardness ◽  
Radial Cracks

AbstractMicrohardness testing is widely used for characterizing the mechanical properties of both bulk materials and thin films. Although this technique is usually associated with hardness measurements, fracture properties of brittle materials can also be studied with cracking associated with microhardness indentations. It is well known that the length of radial cracks emanating from the comers of indents made with Vickers and Berkovich indenters is related to the fracture toughness of the material. In the present study, microhardness testing has been used to follow the evolution of the mechanical properties of a 10 nm.Cu/200 nm. Ni(V)/300 nm. Al(Cu) thin film deposited on a Si substrate. Composite hardness and fracture toughness have been followed as a function of heat treatment temperatures and times and were found to be dependent on both variables. The roles of residual stresses, interdiffusion, and intermediate phase formation in the observed variation in hardness and fracture toughness are discussed.

Dielectric Properties Analysis in Paraelectric ZrTiO4 Thin Films

2001 ◽  
Vol 666 ◽  
Author(s):  
Kyunghae Kim ◽  
Jinhee Heo ◽  
Taeseok Kim ◽  
Byungwoo Park ◽  
Junsin Yi
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Equivalent Circuit ◽  
Deposition Temperature ◽  
Equivalent Circuit Model ◽  
Reactive Sputtering ◽  
Dielectric Constants ◽  
Dielectric Losses ◽  
Post Annealing ◽  
Dc Magnetron Reactive Sputtering

ABSTRACTThe dielectric constants and dielectric losses of ZrTiO4 thin films deposited by DC magnetron reactive sputtering were investigated. The paraelectric properties were measured in the 100kHz range and compared with an equivalent circuit model. As the deposition temperature increased (up to 600°C), the dielectric losses (tanσ) decreased (down to 0.017±0.007), while the dielectric constants (ε) were in the range of 35±7. Post annealing at 800°C in oxygen for 2h reduced tanσ down to 0.005±0.001, higher than those of well-sintered bulk ZrTiO4.

Sputter-Deposited Shape-Memory Alloy Thin Films: Properties and Applications

MRS Bulletin ◽  
2002 ◽  
Vol 27 (2) ◽  
pp. 111-114 ◽  
Author(s):  
Akira Ishida ◽  
Valery Martynov
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Microelectromechanical Systems ◽  
Sputter Deposition ◽  
Bulk Materials ◽  
Shape Memory Actuators ◽  
Sputter Deposited ◽  
Memory Characteristics

AbstractShape-memory alloy (SMA) thin films formed by sputter deposition have attracted considerable attention in the last decade. Current intensive research demonstrates that unique fine microstructures are responsible for the superior shape-memory characteristics observed in thin films as compared with bulk materials. Simultaneously, much effort has been undertaken to develop and fabricate micro devices actuated by SMA thin films. This article reviews the research to date on shape-memory behavior and the mechanical properties of SMA thin films in connection with their peculiar microstructures. Promising applications such as microvalves are demonstrated, along with a focused discussion on process-related problems. All of the results indicate that thin-film shape-memory actuators are ready to contribute to the development of microelectromechanical systems.

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