Synthesis and Oxidation Kinetics of Sol-Gel and Sputtered Tantalum Nitride Thin Films

1995 ◽  
Vol 410 ◽  
Author(s):  
Gerald T. Kraus ◽  
Cory S. Oldweiler ◽  
Emmanuel P. Giannelis

ABSTRACTTantalum nitride thin films were produced by nitridation of sol-gel tantala thin films. The oxidation kinetics and the activation energy for oxidation were investigated and compared to those of sputtered tantalum nitride thin films. Data was gathered from in situ sheet resistance measurements taken between 550 and 720 K. Sol-gel films exhibited parabolic oxidation kinetics and had an activation energy of 1.9 eV. Sputtered films displayed quartic oxidation kinetics at lower temperatures tending toward cubic kinetics at higher temperatures and had an activation energy of 1.6 eV.

2002 ◽  
Vol 17 (6) ◽  
pp. 1463-1468 ◽  
Author(s):  
Woo-Chul Kwak ◽  
Yun-Mo Sung

The crystallization kinetics of Sr0.7Bi2.3Ta2O9 (SBT) and 0.7SrBi2Ta2O9–0.3Bi3TiTaO9 (SBT-BTT) thin films formed by the sol-gel and spin coating techniques were studied. Phase formation and crystal growth are greatly affected by the film composition and crystallization temperature. Isothermal kinetic analysis was performed on the x-ray diffraction results of the thin films heated in the range of 730 to 760 °C at 10 °C intervals. Activation energy and Avrami exponent values were determined for the fluorite-to-Aurivillus phase transformation. A reduction of approximately 51 kJ/mol in activation energy was observed for the SBT-BTT thin films, and an Avrami exponent value of approximately 1.0 was obtained for both the SBT and SBT-BTT. A comparison is made, and the possible crystallization mechanism is discussed.


1996 ◽  
Vol 11 (2) ◽  
pp. 353-357 ◽  
Author(s):  
Xin Min Du ◽  
Rui M. Almeida

The sintering behavior of 80SiO2–20TiO2 sol-gel thin films on Si wafers, prepared by spin coating, was studied by the calculation of density as a function of temperature, from refractive index measurements and the Lorenz–Lorentz relationship. The sintering kinetics of the films were fit to the Mackenzie and Shuttleworth model, over the temperature range of 700 °C–850 °C. Using this model, the viscosity was determined as a function of temperature. These gel films sintered to full density at 850 °C.


2011 ◽  
Vol 1352 ◽  
Author(s):  
Radomír Kužel ◽  
Lea Nichtová ◽  
Zdeněk Matěj ◽  
Zdeněk Hubička ◽  
Josef Buršík

ABSTRACTIn-situ laboratory measurements in X-ray diffraction (XRD) high-temperature chamber and detailed XRD measurements at room temperature were used for the study of the thickness, temperature and time dependences of crystallization of amorphous TiO2 thin films. The films deposited by magnetron sputtering, plasma jet sputtering and sol-gel method were analyzed. Tensile stresses were detected in the first two cases. They are generated during the crystallization and inhibit further crystallization that also depends on the film thickness. XRD indicated quite rapid growth of larger crystallites unlike the sol-gel films when the crystallites grow mainly by increasing of annealing temperature.


2019 ◽  
Vol 66 (5) ◽  
pp. 638-643
Author(s):  
Jinsong Luo ◽  
Ligong Zhang ◽  
Haigui Yang ◽  
Nan Zhang ◽  
Yongfu Zhu ◽  
...  

Purpose This paper aims to study the oxidation kinetics of the nanocrystalline Al ultrathin films. The influence of structure and composition evolution during thermal oxidation will be observed. The reason for the change in the oxidation activation energy on increasing the oxidation temperature will be discussed. Design/methodology/approach Al thin films are deposited on the silicon wafers as substrates by vacuumed thermal evaporation under the base pressure of 2 × 10−4 Pa, where the substrates are not heated. A crystalline quartz sensor is used to monitor the film thickness. The film thickness varies in the range from 30 to 100 nm. To keep the silicon substrate from oxidation during thermal oxidation of the Al film, a 50-nm gold film was deposited on the back side of silicon substrate. Isothermal oxidation studies of the Al film were carried out in air to assess the oxidation kinetics at 400-600°C. Findings The activation energy is positive and low for the low temperature oxidation, but it becomes apparently negative at higher temperatures. The oxide grains are nano-sized, and γ-Al2O3 crystals are formed at above 500°C. In light of the model by Davies, the grain boundary diffusion is believed to be the reason for the logarithmic oxidation rate rule. The negative activation energy at higher temperatures is apparent, which comes from the decline of diffusion paths due to the formation of the γ-Al2O3 crystals. Originality/value It is found that the oxidation kinetics of nanocrystalline Al thin films in air at 400-600°C follows the logarithmic law, and this logarithmic oxidation rate law is related to the grain boundary diffusion. The negative activation energies in the higher temperature range can be attributed to the formation of γ-Al2O3 crystal.


2002 ◽  
Vol 17 (3) ◽  
pp. 550-555 ◽  
Author(s):  
Kyle Hukari ◽  
Rand Dannenberg ◽  
E. A. Stach

The crystallization behavior of amorphous TiOxNy (x ≫ y) thin films was investigated by in situ transmission electron microscopy. The Johnson–Mehl–Avrami–Kozolog (JMAK) theory was used to determine the Avrami exponent, activation energy, and the phase velocity pre-exponent. Addition of nitrogen inhibited diffusion, increasing the nucleation temperature, while decreasing the growth activation energy. Kinetic variables extracted from individual crystallites were compared to JMAK analysis of the fraction transformed, and a change of 6% in the activation energy led to agreement between the methods. From diffraction patterns and index of refraction the crystallized phase was found to be predominantly anatase.


1996 ◽  
Vol 431 ◽  
Author(s):  
J. Samuel ◽  
A. J. Hurd ◽  
F. van Swol ◽  
L. J. Douglas Frink ◽  
C. J. Brinker ◽  
...  

AbstractWe have used a novel technique, measurement of stress isotherms in microporous thin films, as a means of characterizing porosity. The stress measurement was carried out by applying sol-gel thin films on a thin silicon substrate and monitoring the curvature of the substrate under a controlled atmosphere of various vapors. The magnitude of macroscopic bending stress developed in microporous films depends on the relative pressure and molar volume of the adsorbate and reaches a value of 180 MPa for a relative vapor pressure, P/Po = 0.001, of methanol. By using a series of molecules, and observing both the magnitude and the kinetics of stress development while changing the relative pressure, we have determined the pore size of microporous thin films. FTIR measurements were used to acquire adsorption isotherms and to compare pore emptying to stress development, about 80% of the change in stress takes place with no measurable change in the amount adsorbed. We show that for sol-gel films, pore diameters can be controlled in the range of 5 – 8 Å by “solvent templating”.


1990 ◽  
Vol 187 ◽  
Author(s):  
Ann C. Herrmann ◽  
D William E. Brower ◽  
Shashi Lalvani

AbstractThe effetzct of the amorphous state and the disordered sputtered state on the oxidation kinetics of nickel films was investigated by a comparison with annealed films and with pure nickel foil and powder. Specimens were exposed to oxygen in a thermogravimetric analyzer (TGA) in the temperature scan mode. An electrodeposited amorphous Ni-P alloy and sputtered pure nickel films were annealed in situ in argon and then oxidized in the same manner as the as deposited films. The as sputtered films oxidized faster at 500%C than pieces of the same film first annealed in argon. Conversely, the as deposited Ni-P film was more oxidation resistant below its crystallization temperature than the annealed Ni-P films.


2003 ◽  
Vol 18 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Mary M. Sandstrom ◽  
Paul Fuierer

Control over crystallographic orientation in thin films is important, particularly with highly anisotropic structures. Because of its ferroelectric nature, the layered perovskite La2Ti2O7 has interesting piezoelectric and electrooptic properties that may be exploited when films are highly textured. Sol-gel films with an orientation factor of greater than 95% were fabricated without relying on epitaxial (lattice-matching) growth from the substrate. Film orientation and crystallization were confirmed by x-ray diffraction, scanning electron microscopy, atomic force microscopy, and optical measurements. The particle sizes in all precursor solutions were measured by dynamic light scattering experiments. Experimental results indicate that film orientation is a function of precursor solution concentration, size of the molecular clusters in the solution, and film thickness.


2002 ◽  
Vol 16 (17n18) ◽  
pp. 2454-2460 ◽  
Author(s):  
X. P. ZHAO ◽  
X. DUAN

In-situ sol-gel method to prepare colloidal hybrids of surfactant modified polysucchride and titanium oxide has been presented, and experiments indicated these highly ER active particles exhibited a remarkable ER effect. The static shear stress can be up to 37 k Pa (shear rate 5 S -1) under DC field of 4 kV/mm at root temperature, well above that of simple blends of starch and TiO 2. In the meanwhile, temperature dependence and sedimentation stability were also greatly improved. Based on recent experimental facts, we find that dielectric properties and surface (interface) activity are two necessary conditions fulfilling the requirement of high ER activity. Adequate grinding of particles with oil can effectively enhance the shear stress, which may be owed to the decline of the activation energy needed for restructuring. It has provided us a new horizon for preparation of excellent ER materials and further studies should be continued to make.


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