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As-deposited Films (as-deposited + film)

Distribution by Scientific Domains
Polymers and Materials Science57%
Physics and Astronomy42%

Selected Abstracts

Ultralow Dielectric Constant Tetravinyltetramethylcyclotetrasiloxane Films Deposited by Initiated Chemical Vapor Deposition (iCVD)

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
Nathan J. Trujillo
Abstract Simultaneous improvement of mechanical properties and lowering of the dielectric constant occur when films grown from the cyclic monomer tetravinyltetramethylcyclotetrasiloxane (V4D4) via initiated chemical vapor deposition (iCVD) are thermally cured in air. Clear signatures from silsesquioxane cage structures in the annealed films appear in the Fourier transform IR (1140,cm,1) and Raman (1117,cm,1) spectra. The iCVD method consumes an order of magnitude lower power density than the traditional plasma-enhanced CVD, thus preserving the precursor's delicate ring structure and organic substituents in the as-deposited films. The high degree of structural retention in the as-deposited film allows for the beneficial formation of intrinsically porous silsesquioxane cages upon annealing in air. Complete oxidation of the silicon creates ,Q' groups, which impart greater hardness and modulus to the films by increasing the average connectivity number of the film matrix beyond the percolation of rigidity. The removal of labile hydrocarbon moieties allows for the oxidation of the as-deposited film while simultaneously inducing porosity. This combination of events avoids the typical trade-off between improved mechanical properties and higher dielectric constants. Films annealed at 410,°C have a dielectric constant of 2.15, and a hardness and modulus of 0.78 and 5.4,GPa, respectively. The solvent-less and low-energy nature of iCVD make it attractive from an environmental safety and health perspective. [source]

Nitridation and reoxidation of high- k metal oxide thin films using argon excimer sources

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2006
J. J. Yu
Abstract We report for the first time the nitridation and reoxidation of metal oxide films with the active nitrogen and oxygen species produced by argon excimer sources. Preliminary results on 9 nm Ta2O5 films using this method exhibited excellent electrical properties with the leakage current density being up to 3 orders of magnitude lower than the as-deposited films. Breakdown fields were found to be greater than 13 MV/cm. Accumulation capacitance with the nitrided film increased by 25% compared with the as-deposited film. Optical transmittance was as high as 99% in the visible region and more than 74% in the UV region. The refractive index at 632.8 nm was high up to 2.2. The Ar excimer source emitted energetic VUV photons which could break nitrogen triple bonds to produce active nitrogen species and photodissociate O2 to form strong oxidant O3 and highly reactive O (1S) atoms, leading to the nitridation and reoxidation of Ta2O5 without the need for the use of H2O, NH3 and high temperature substrate heating. The nitridation process for a specific film thickness can be optimised by adjusting the VUV irradiation time to achieve increased accumulation capacitance and improved leakage property simultaneously. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Effect of annealing on the structural, electrical and optical properties of nanostructured TiO2 thin films

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2009
S. Sankar
Abstract Nanostructured titanium dioxide thin films were prepared using reactive pulsed laser ablation technique. Effects of annealing on the structural, morphological, electrical and optical properties are discussed. The structural, electrical and optical properties of TiO2 films are found to be sensitive to annealing temperature and are described with GIXRD, SEM, AFM, UV-Visible spectroscopy and electrical studies. X-ray diffraction studies showed that the as-deposited films were amorphous and at first changed to anatase and then to rutile phase with increase of annealing temperature. Optical constants of these films were derived from the transmission spectra and the refractive index dispersion of the films, subjected to annealing at different temperatures, is discussed in terms of the single oscillator-Wemple and Didomenico model. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Ultralow Dielectric Constant Tetravinyltetramethylcyclotetrasiloxane Films Deposited by Initiated Chemical Vapor Deposition (iCVD)

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
Nathan J. Trujillo
Abstract Simultaneous improvement of mechanical properties and lowering of the dielectric constant occur when films grown from the cyclic monomer tetravinyltetramethylcyclotetrasiloxane (V4D4) via initiated chemical vapor deposition (iCVD) are thermally cured in air. Clear signatures from silsesquioxane cage structures in the annealed films appear in the Fourier transform IR (1140,cm,1) and Raman (1117,cm,1) spectra. The iCVD method consumes an order of magnitude lower power density than the traditional plasma-enhanced CVD, thus preserving the precursor's delicate ring structure and organic substituents in the as-deposited films. The high degree of structural retention in the as-deposited film allows for the beneficial formation of intrinsically porous silsesquioxane cages upon annealing in air. Complete oxidation of the silicon creates ,Q' groups, which impart greater hardness and modulus to the films by increasing the average connectivity number of the film matrix beyond the percolation of rigidity. The removal of labile hydrocarbon moieties allows for the oxidation of the as-deposited film while simultaneously inducing porosity. This combination of events avoids the typical trade-off between improved mechanical properties and higher dielectric constants. Films annealed at 410,°C have a dielectric constant of 2.15, and a hardness and modulus of 0.78 and 5.4,GPa, respectively. The solvent-less and low-energy nature of iCVD make it attractive from an environmental safety and health perspective. [source]

Silicon Carbide Films by Laser Pyrolysis of Polycarbosilane

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2001
Paolo Colombo
Thin films of polycarbosilane were deposited on Si and SiO2 substrates. Instead of conventional oven annealing (high temperatures, inert atmosphere), laser pyrolysis was used to achieve the polymer-to-ceramic conversion. In some conditions, especially when laser radiation absorption was enhanced by depositing a carbon layer on the surface of as-deposited films or by embedding graphite particles, this processing method yielded SiC ceramic coatings, without damaging the substrate. Processing in air or low vacuum did not result in oxidized coatings, contrary to what happens for oven pyrolysis. Laser-converted films were similar to oven-heated films processed at 1000° to 1200°C. [source]

Nitridation and reoxidation of high- k metal oxide thin films using argon excimer sources

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2006
J. J. Yu
Abstract We report for the first time the nitridation and reoxidation of metal oxide films with the active nitrogen and oxygen species produced by argon excimer sources. Preliminary results on 9 nm Ta2O5 films using this method exhibited excellent electrical properties with the leakage current density being up to 3 orders of magnitude lower than the as-deposited films. Breakdown fields were found to be greater than 13 MV/cm. Accumulation capacitance with the nitrided film increased by 25% compared with the as-deposited film. Optical transmittance was as high as 99% in the visible region and more than 74% in the UV region. The refractive index at 632.8 nm was high up to 2.2. The Ar excimer source emitted energetic VUV photons which could break nitrogen triple bonds to produce active nitrogen species and photodissociate O2 to form strong oxidant O3 and highly reactive O (1S) atoms, leading to the nitridation and reoxidation of Ta2O5 without the need for the use of H2O, NH3 and high temperature substrate heating. The nitridation process for a specific film thickness can be optimised by adjusting the VUV irradiation time to achieve increased accumulation capacitance and improved leakage property simultaneously. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Deposition of Niobium Nitride Thin Films from Tert -Butylamido- Tris -(Diethylamido)-Niobium by a Modified Industrial MOCVD Reactor

CHEMICAL VAPOR DEPOSITION, Issue 10-12 2009
Tobias B. Thiede
Abstract Niobium nitride thin films are deposited on 2, silicon (100) wafers using a modified industrial metal-organic (MO) CVD reactor of the type AIX-200RF, starting from tert -butylamido- tris -(diethylamido)-niobium (TBTDEN) and ammonia. Films of thicknesses 50-200,nm are deposited at temperatures ranging from 400,°C to 800,°C under reactor pressures of 1 and 5 mbar using various ammonia flow rates, and are characterized by the use of complementary techniques, namely X-ray diffraction (XRD), scanning electron microscopy (SEM), secondary neutral mass spectrometry (SNMS), Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), and electrical measurements. Films deposited above 450,°C consist of the cubic , -NbN phase, apart from the presence of Nb-O and Nb-O-N species predominantly in the outermost film regions. The lowest specific resistivities, determined by four point probe measurements, are in the range 500,600,µ, cm. A NbN/SiO2/p-Si gate stack is fabricated using the grown niobium nitride films. From the capacitance-voltage (C - V)-curves, flat-band voltages are extracted which, when plotted against SiO2 -insulator thickness, yield a work function of 4.72,eV for as-deposited films. [source]