Amorphous Sol-Gel Insulating Films

1992 ◽  
Vol 284 ◽  
Author(s):  
C. Jeffrey Brinker ◽  
William L. Warren ◽  
Monica N. Logan ◽  
Carol S. Ashley
Keyword(s):  
Capillary Pressure ◽  
Film Formation ◽  
Sol Gel ◽  
Silicon Substrates ◽  
Inorganic Polymers ◽  
Silica Films ◽  
Insulating Films ◽  
Polymer Reaction ◽  
Passivation Layers ◽  
Relationship Of

ABSTRACTThe porosity of sol-gel thin films may be tailored for specific applications through control of the size and structure of inorganic polymers within the coating sol, the extent of polymer reaction and interpenetration during film formation, and the magnitude of the capillary pressure exerted during the final stage of drying. By maximizing the capillary pressure and avoiding excessive condensation, dense insulating films may be prepared as passivation layers on silicon substrates. Such films can exhibit excellent dielectric integrity, viz., low interface trap densities and insulating properties approaching those of thermally grown SiO2. Alternatively, through exploitation of the scaling relationship of mass and density of fractal objects, silica films can be prepared that show a variation in porosity (7–29 %) and refractive index (1.42 ndash;1.31) desired for applications in sensors, membranes, and photonics.

Electrical Properties of Metal-Oxide-Silicon Structures Wrm Sol-Gel Oxides

1988 ◽  
Vol 121 ◽  
Author(s):  
W. L. Warren ◽  
P. M. Lenahan ◽  
C. J. Brinker
Keyword(s):  
Sol Gel ◽  
Interface Trap ◽  
Silicon Substrates ◽  
Insulating Films ◽  
Device Applications ◽  
Silicon Structures ◽  
Radiation Induced ◽  
Sol Gel Films ◽  
Radiation Hard ◽  
Silicon Interface

ABSTRACTWe have investigated the electronic properties of sol-gel derived films on silicon substrates. Our investigation involves SiO2, aluminosilicate and borosili cate oxides on silicon. Seme sol-gel oxides are excellait insulators; seme sol-gel films on silicon also exhibit quite low oxide/silicon interface trap densities. We have also subjected sol-gel films on silicon to 4 Mrad(SiO2) of radiation and have found that these structures appear to be radiation hard (very little radiation induced oxide space charge or interface trap generation). Our results strongly suggest that sol-gel processing could provide insulating films for a variety of microelectronic device applications.

Influence of the wettability of silicon substrates on the thickness of sol-gel silica films

1995 ◽  
Vol 30 (15) ◽  
pp. 3893-3896 ◽  
Author(s):  
M. C. Gomes ◽  
A. C. Fernandes ◽  
B. S. Almeida ◽  
R. M. Almeida
Keyword(s):  
Sol Gel ◽  
Silicon Substrates ◽  
Silica Films

Nanostructured Doped Silica Films Application as Sensitive Layers for Chemical Sensors

2013 ◽  
Vol 684 ◽  
pp. 7-11
Author(s):  
Sergey Krutovertsev ◽  
Alla Tarasova ◽  
Olga Ivanova ◽  
Larisa Krutovertseva
Keyword(s):  
Initial Conditions ◽  
Sol Gel ◽  
Silica Films ◽  
Adsorption Activity ◽  
Developed Surface ◽  
Sol Gel Process ◽  
Sensitive Characteristics ◽  
The Right ◽  
Kinetics Of ◽  
Matrix Factors

The sensor behavior of nanostructured doped silica films produced by sol-gel way were examined. Hygroscopic substances and polyoxometalates were used as additives to make more significant sensitive characteristics of initial matrix. Factors that have effect on sol preparation and films forming were investigated. Adsorption activity of the sensitive films was studied and it was shown that the films had a highly developed surface with nano-size pores. Change of initial conditions of sol-gel process gives opportunity to influence on kinetics of gel formation and consequently, on structure and properties of final materials. The study showed that the conditions of the environment affected the sensors characteristics markedly, which can be improved by choosing of the right procedure of forming and treatment. Influence of type and additive substances quantity into doped films was discussed in the paper

Microwave Absorbing Ferrite Thin Films for Microwave Heating of Microstructured Reactors

2009 ◽  
Vol 1222 ◽  
Author(s):  
Pengzhao Gao ◽  
Evgeny V. Rebrov ◽  
Jaap C. Schouten ◽  
Richard Kleismit ◽  
John Cetnar ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Microwave Heating ◽  
Near Field ◽  
Coplanar Waveguide ◽  
Sol Gel ◽  
Microwave Cavity ◽  
Silicon Substrates ◽  
Microwave Microscopy ◽  
Zn Ferrite

AbstractNanocrystalline Ni0.5Zn0.5Fe2O4 thin films have been synthesized with various grain sizes by sol–gel method on polycrystalline silicon substrates. The morphology and microwave absorption properties of the films calcined in the 673–1073 K range were studied by using XRD, AFM, near–field evanescent microwave microscopy, coplanar waveguide and direct microwave heating measurements. All films were uniform without microcracks. The increase of the calcination temperature from 873 to 1073 K and time from 1 to 3h resulted in an increase of the grain size from 12 to 27 nm. The complex permittivity of the Ni-Zn ferrite films was measured in the frequency range of 2–15 GHz. The heating behavior was studied in a multimode microwave cavity at 2.4 GHz. The highest microwave heating rate in the temperature range of 315–355 K was observed in the film close to the critical grain size of 21 nm in diameter marked by the transition from single– to multi–domain structure of nanocrystals in Ni0.5Zn0.5Fe2O4 film and by a maximum in its coercivity.

Sol-gel process of non-linear optical silica films with organic chromophore as side chain

1996 ◽  
Vol 31 (9) ◽  
pp. 2443-2446 ◽  
Author(s):  
Po-Hou Sung ◽  
Shao-Ling Wu ◽  
Chien-Yang Lin
Keyword(s):  
Sol Gel ◽  
Side Chain ◽  
Silica Films ◽  
Sol Gel Process ◽  
Non Linear ◽  
Linear Optical ◽  
Organic Chromophore

Sol–gel derived mesoporous silica films using amphiphilic triblock copolymers

2003 ◽  
Vol 332 (1-3) ◽  
pp. 199-206 ◽  
Author(s):  
Nobuaki Kitazawa ◽  
Hideyoshi Namba ◽  
Masami Aono ◽  
Yoshihisa Watanabe
Keyword(s):  
Mesoporous Silica ◽  
Triblock Copolymers ◽  
Sol Gel ◽  
Silica Films

Effect of Precursor Sol Ageing on Sol-Gel Derived Ruthenium Oxide Thin Films

1999 ◽  
Vol 606 ◽  
Author(s):  
S. Bhaskar ◽  
S. B. Majumder ◽  
P. S. Dobal ◽  
R. S. Katiyar ◽  
A. L. M. Cruz ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Ruthenium Oxide ◽  
Precursor Solution ◽  
Silicon Substrates ◽  
Solution Deposition ◽  
Precursor Material ◽  
Afm Analysis

AbstractIn the present work we have optimized the process parameters to yield homogeneous, smooth ruthenium oxide (RuO2) thin films on silicon substrates by a solution deposition technique using RuCl3.×.H2O as the precursor material. Films were annealed in a temperature range of 300°C to 700°C, and it was found that RuO2 crystallizes at a temperature as low as 400°C. The crystallinity of the films improves with increased annealing temperature and the resistivity decreases from 4.86µΩ-m (films annealed at 400°C) to 2.94pµΩ (films annealed at 700°C). Ageing of the precursor solution has a pronounced effect on the measured resistivities of RuO2 thin films. It was found that the measured room temperature resistivities increases from 2.94µΩ-m to 45.7µΩ-m when the precursor sol is aged for aged 60 days. AFM analysis on the aged films shows that the grain size and the surface roughness of the annealed films increase with the ageing of the precursor solution. From XPS analysis we have detected the presence of non-transformed RuCl3 in case of films prepared from aged solution. We propose, that solution ageing inhibits the transformation of RuCl3 to RuO2 during the annealing of the films. The deterioration of the conductivity with solution ageing is thought to be related with the chloride contamination in the annealed films.

scholarly journals Synthesis and Characterization of TiO2/SiO2 Monoliths as Photocatalysts on Methanol Oxidation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Rigoberto Regalado-Raya ◽  
Rubí Romero-Romero ◽  
Osmín Avilés-García ◽  
Jaime Espino-Valencia
Keyword(s):  
Thin Film ◽  
Methanol Oxidation ◽  
Immersion Time ◽  
Film Formation ◽  
Anatase Phase ◽  
Sol Gel ◽  
Packed Bed ◽  
Dip Coating ◽  
Packed Bed Reactor ◽  
Titanium Butoxide

Photocatalytic materials based on silica-titania (SiO2-TiO2) were synthesized by sol-gel and dip-coating method. TEOS and titanium butoxide were used as precursors of the silica-titania, respectively. A thin film with anatase phase was obtained on the surface of the support. The effect of variables as dispersion mechanism, immersion time, and number of treatment cycles were studied. The materials were characterized using X-ray diffraction, scanning electron microscopy, energy dispersion scanning, and N2 adsorption-desorption. The highest crystallinity of TiO2 on silica, high specific surface area in TiO2-SiO2 materials, and thin film formation were obtained by using a stirring plate and minimum immersion time. The so synthesized catalyst allowed the production of formaldehyde from the photocatalyzed methanol oxidation in a packed-bed reactor.

Chemical Analyses of Sol/Gel Surfaces and Thin Films

1984 ◽  
Vol 32 ◽  
Author(s):  
Carlo G. Pantano ◽  
C. A. Houser ◽  
R. K. Brow
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Silica Films ◽  
Alumina Films ◽  
Surface Analysis Techniques ◽  
Relative Water ◽  
Temperature Programmed

ABSTRACTThe application of surface analysis techniques to the characterization of sol/gel surfaces and thin films is described. Secondary-ion mass spectroscopy (SIMS), x-ray photoelectron spectroscopy (XPS) and sputter-induced photon spectroscopy (SIPS) are used to measure the composition of multicomponent silicate films, the relative water content of alumina films, the nitrogen content of ammonia treated silica films, and the depth profiles for films on black chrome. The determination of chemical structure using XPS and SIMS is also discussed. Finally, a brief introduction to temperature-programmed desorption (TPD) and its potential for studying surface chemical reactions, in situ, is presented.

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