Fabrication and Characterization of Spin-On Silica Xerogel Films

1998 ◽  
Vol 511 ◽  
Author(s):  
S. Nitta ◽  
A. Jain ◽  
V. Pisupatti ◽  
W. N. Gill ◽  
P. C. Wayner ◽  
...  
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Convective Diffusion ◽  
Ambient Pressure ◽  
Silica Xerogel ◽  
High Porosity ◽  
Thermal Oxide ◽  
Fabrication And Characterization ◽  
Xerogel Films

ABSTRACTXerogel films of high porosity were fabricated using an ambient pressure technique. The same porosity can be obtained with different microstructures by varying the aging time of the films. The dielectric constant of these films as a function of porosity at 1 MHz follows correlations originally developed for bulk aerogels. Diffusion of copper is orders of magnitude faster in these xerogels than in the corresponding thermal oxide. An activation energy of 0.9 eV was estimated based on a convective diffusion model.

Processing and Characterization of Silica Xerogel Films for Low-K Dielectric Applications

1999 ◽  
Vol 565 ◽  
Author(s):  
Anurag Jain ◽  
Svetlana Rogojevic ◽  
Satya V. Nitta ◽  
Venumadhav Pisupatti ◽  
William N. Gill ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Concrete Surface ◽  
Dielectric Constants ◽  
Silica Xerogel ◽  
High Porosity ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Lift Off ◽  
Surface Modified ◽  
Xerogel Films

AbstractSurface modified silica xerogel films of high porosity (60 - 90 %) and uniform thickness (0.4–2 μm) were fabricated at ambient pressure on silicon and silicon dioxide. The rheological properties that govern film uniformity were determined. A relation between the final dried film thickness and spin speed was developed. The porosity and thickness of the films could be controlled independently. The same porosity could be obtained over a wide range of aging time and temperature combinations. Fracture toughness was measured using the edge-lift-off technique. The best values were comparable to concrete. Surface modification was affected by treating the film with trimethylcholorosilane (TMCS) and other modifiers. Moisture adsorption was studied at 100% RH using a quartz crystal microbalance technique. Depending upon the degree and kind of surface treatment, films absorbed as much as 32% or as little as 2% of their weight in water. Dielectric constants (K), losses and breakdown strengths were comparable to values for calcined, bulk aerogels. Thin (≤ 500 Å) films of Copper (Cu) and Tantalum (Ta) were deposited on xerogel films and subjected to thermal annealing. No diffusion was observed within the limits of RBS. High-density plasma etching showed that the films etch an order of magnitude faster than conventional SiO2 films.

Processing, Characterization and Reliability of Silica Xerogel Films for Interlayer Dielectric Applications

2000 ◽  
Vol 612 ◽  
Author(s):  
Anurag Jain ◽  
Svetlana Rogojevic ◽  
Feng Wang ◽  
William N. Gill ◽  
Peter C. Wayner ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Aging Time ◽  
Ion Beam ◽  
Ambient Pressure ◽  
Silica Xerogel ◽  
High Porosity ◽  
Interlayer Dielectric ◽  
Lift Off ◽  
Surface Modified ◽  
Xerogel Films

AbstractSurface modified silica xerogel films of high porosity (25-90 %) and uniform thickness (0.4-2 µm) were fabricated at ambient pressure on silicon and other substrates. Mechanical reliability of the films was determined by measuring fracture toughness (adhesive) as a function of aging time and temperature using the modified edge-lift-off technique. There is an optimum aging time at 60 °C aging to obtain maximum fracture toughness for the procedure used here.Cu/xerogel/Si and Ta/xerogel/Si structures were annealed at different temperatures and in different ambient environments were analyzed using RBS and optical microscopy to assess the extent of interaction with the xerogel film. When annealed in N2 with trace amounts of O2 (equivalent to 10-7-10-6 Torr vacuum), RBS analysis does not show diffusion of Cu or Ta through the xerogel up to 450 °C. At higher temperatures, or in the presence of larger concentrations of O2, Cu and Ta oxidize. Cu oxidation leads to significant diffusion through the xerogel. Ta oxidation also results in diffusion-like RBS spectra. Using the micron-size ion beam to probe the Ta surface, this was found to be solely due to buckling of Ta films on xerogel. A thin SiNx layer on top of Cu and Ta prevents metal oxidation up to 640 °C, Cu diffusion, and Ta buckling.

scholarly journals Synthesis and electrical characterization of Ca2Nd4Ti6O20 ceramics

2016 ◽  
Vol 34 (1) ◽  
pp. 164-168
Author(s):  
Raz Muhammad ◽  
Muhammad Uzair ◽  
M. Javid Iqbal ◽  
M. Jawad Khan ◽  
Yaseen Iqbal ◽  
...  
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Room Temperature ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Sintered Sample ◽  
First Time ◽  
Alkoxide Precursors ◽  
Room Temperature Dielectric Constant

AbstractCa2Nd4Ti6O20, a layered perov skite structured material was synthesized via a chemical (citrate sol-gel) route for the first time using nitrates and alkoxide precursors. Phase analysis of a sample sintered at 1625 °C revealed the formation of an orthorhombic (Pbn21) symmetry. The microstructure of the sample after sintering comprised rod-shaped grains of a size of 1.5 to 6.5µm. The room temperature dielectric constant of the sintered sample was 38 at 100 kHz. The remnant polarization (Pr) and the coercive field (Ec) were about 400 μC/cm2 and 8.4 kV/cm, respectively. Impedance spectroscopy revealed that the capacitance (13.7 pF) and activation energy (1.39 eV) of the grain boundary was greater than the capacitance (5.7 pF) and activation energy (1.13 eV) of the grain.

scholarly journals CISSY: A station for preparation and surface/interface analysis of thin film materials and devices

2016 ◽  
Vol 2 ◽  
Author(s):  
Iver Lauermann ◽  
Alexander Steigert
Keyword(s):  
Thin Film ◽  
Molecular Beam ◽  
Ambient Pressure ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
X Ray ◽  
Fabrication And Characterization ◽  
X Ray Absorption ◽  
Thin Film Devices

The CISSY end station combines thin film deposition (sputtering, molecular beam epitaxy ambient-pressure methods) with surface and bulk-sensitive analysis (photo emission, x-ray emission, x-ray absorption) in the same UHV system, allowing fast and contamination–free transfer between deposition and analysis. It is mainly used for the fabrication and characterization of thin film devices and their components like thin film photovoltaic cells, water-splitting devices and other functional thin film materials.

Porous silica xerogel films as antireflective coatings – Fabrication and characterization

2011 ◽  
Vol 33 (12) ◽  
pp. 1989-1994 ◽  
Author(s):  
Paweł Karasiński ◽  
Janusz Jaglarz ◽  
Manuela Reben ◽  
Edyta Skoczek ◽  
Jacek Mazur
Keyword(s):  
Porous Silica ◽  
Silica Xerogel ◽  
Antireflective Coatings ◽  
Fabrication And Characterization ◽  
Xerogel Films

scholarly journals Processing and Characterization of High Porosity Aerogel Films

1994 ◽  
Vol 371 ◽  
Author(s):  
Lawrence W. Hrubesh ◽  
John F. Poco
Keyword(s):  
Dielectric Constant ◽  
Molecular Transport ◽  
Solid Material ◽  
Porous Solids ◽  
High Porosity ◽  
Transport Mechanisms ◽  
Mechanical And Electrical Properties ◽  
Highly Porous ◽  
Aerogel Films

AbstractAerogels are highly porous solids having unique morphology among materials because both the pores and particles making up the material have sizes less than wavelengths of visible light. Such a unique morphology modifies the normal molecular transport mechanisms within the material, resulting in exceptional thermal, acoustical, mechanical, and electrical properties. For example, aerogels have the lowest measured thermal conductivity and dielectric constant for any solid material. Special methods are required to make aerogel films with high porosity. In this paper, we discuss the special conditions needed to fabricate aerogel films having porosities greater than 75% and we describe methods of processing inorganic aerogel films having controllable thicknesses in the range 0.5 to 200 micrometers. We report methods and results of characterizing the films including thickness, refractive index, density (porosity), and dielectric constant. We also discuss results of metallization and patterning on the aerogel films for applications involving microminiature electronics and thermal detectors.

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