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Growing Film (growing + film)
Selected AbstractsIonized physical vapor deposited Al2O3 films: Does subplantation favor formation of ,-Al2O3?PHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 7 2010K. Sarakinos Abstract The broad energy distributions of the condensing particles typically encountered in ion assisted vapor deposition techniques are often a drawback when attempting to understand the effect of the energetic bombardment on the film properties. In the current study, a monoenergetic Al+ beam generated by a filtered cathodic arc discharge is employed for the deposition of alumina (Al2O3) films at well defined Al+ ion energies between 4 eV and 200 eV at a substrate temperature of 720 °C. Structural analysis shows that Al+ energies of 40 eV or larger favor the formation of the thermodynamically stable ,-Al2O3 phase at the expense of other metastable Al2O3 polymorphs. The well defined ion energies are used as input for Monte-Carlo based simulations of the ion,surface interactions. The results of these simulations reveal that the increase of the Al+ ion energy leads to an increase in the fraction of ions subplanted into the growing film. These findings underline the previously not considered role of subsurface processes on the phase formation of ionized physical vapor deposited Al2O3 films. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Reactive magnetron sputtering of highly (001)-textured WS2,x films: Influence of Ne+, Ar+ and Xe+ ion bombardment on the film growthPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2006K. Ellmer Abstract Layer-type van der Waals semiconductor WS2,x films were grown by radio frequency reactive magnetron sputtering from a metallic tungsten target onto oxidized silicon substrates. The sputtering atmosphere consisted of 75% hydrogen sulfide and 25% neon, argon or xenon. The substrate voltage and hence the energy of the ions bombarding the growing film, was varied from about 20 V (floating potential) to ,80 V. By in situ energy-dispersive X-ray diffraction the growth of the films was monitored and by elastic recoil detection analysis the film composition was measured. It was found that with xenon in the sputtering atmosphere a substrate voltage of ,20 V is sufficient to suppress the crystalline film growth, while for argon as the sputtering rare gas this occurs only at ,80 V. The disturbed film growth is accompanied by a sulfur loss of the growing WS2,x films down to x = 1.1 for sputtering in Ar + H2S at a substrate potential of ,60 V. The results are tentatively explained by the different momentum transfers to sulfur atoms, which is highest for argon ions. It has also to be taken into account that the low-energy xenon bombardment is a many-body cascade process with a much higher local energy density compared to argon and neon bombardment and leading to a higher defect density and a supression of the crystalline growth. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Highly (001)-textured WS2,x films prepared by reactive radio frequency magnetron sputteringPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 14 2004K. Ellmer Abstract Highly (001)-oriented WS2,x films were grown onto oxidized silicon substrates by reactive magnetron sputtering from a metallic tungsten target in argon-hydrogen sulfide mixtures. The best films with respect to the van-der-Waals orientation, i.e. with the (001) planes parallel to the substrate surface, were grown by excitation of the plasma with radio frequency of 27.12 MHz. These films exhibit the largest grains and the lowest film strain. It is shown that this effect is not due to the lower deposition rate at this high excitation frequency. Instead it was found that the lower DC voltage at the sputtering target is advantageous for the film growth since the bombardment of the growing film by highly energetic particles is avoided by this type of plasma excitation. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Deposition of Cubic Boron Nitride in a Supersonic Plasma Jet Reactor with Secondary DischargePLASMA PROCESSES AND POLYMERS, Issue S1 2007Jami McLaren Abstract We have deposited cubic boron nitride thin films with a supersonic plasma jet chemical vapor deposition system with bipolar pulsed substrate bias. Deposited films were characterized by Fourier transform infrared spectroscopy, micro-X-ray diffraction, and scanning electron microscopy. The cubic boron nitride content is observed to scale well with the degree of ion bombardment of the substrate and growing film, which is affected most drastically by the substrate bias pulse frequency, and positive and negative duty cycle. The magnitude of the negative substrate bias was also critical in depositing cubic boron nitride, with a threshold voltage of approximately 90 V necessary for cubic boron nitride deposition. [source] Cu(In,Ga)Se2 thin films grown with a Cu-poor/rich/poor sequence: growth model and structural considerationsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 5 2003J. Kessler Thin films of Cu(In,Ga)Se2 are grown by a co-evaporation process in which the In, Ga, and Se fluxes, as well as the substrate temperature, are constant and the only variable is the Cu flux. This Cu flux varies in three steps in such a way that the growing film evolves from Cu-poor to Cu-rich and then back to Cu-poor. The film growth is monitored by the ,end point detection' method, and film thicknesses of the order of 2,,m are deposited in less than 20,min. Quality devices (efficiencies above 15%) are produced in our baseline processes for all of the other synthesis steps. The Cu(In,Ga)Se2 layers are studied from a (112) versus (220) (204) orientation and recrystallization point of view. Including the results from a previous study on the influence of the substrate temperature to the present X-ray diffraction and scanning as well as tunneling electron microscopy data, a five-stage growth model for the films is described. The specific features of these films are that they are weakly (220) (204) oriented and exhibit crevices in their top fractions. The growth model hypothesizes about the origins of these crevices and on how to avoid them. Copyright © 2003 John Wiley & Sons, Ltd. [source] A Simple Index to Restrain Abnormal Protrusions in Films Fabricated Using CVD under Diffusion-Limited Conditions,CHEMICAL VAPOR DEPOSITION, Issue 4 2004Y. Kajikawa Abstract Cauliflower-like protrusions formed in CVD processes under diffusion-limited conditions have been studied both experimentally and theoretically. Both approaches indicate that the difference in diffusion fluxes to the film and to the protrusions controls the growth of such protrusions. However, direct comparisons of these two approaches have never been done, probably due to the complexity of the theoretical models. To simplify model protrusion growth, we developed a one-dimensional (1D) analytical model by hypothesizing the diffusion of growth species in the boundary layer above a growing film. Based on this model, we propose a non-dimensional quantity, ksf/D, as an index of protrusion growth (D is the diffusion coefficient of the growth species, ks is the surface reaction-rate coefficient, and f is film thickness). This index represents more directly the protrusion growth than does the previously proposed index, the Damköhler number, Da,=,ks,/D, where , is boundary layer thickness. To obtain smooth, protrusion-free films, D/ks should be kept larger than the desired film thickness. By controlling the process conditions to satisfy this index, we successfully fabricated protrusion-free films with SiC deposition from dichlorodimethylsilane (DDS). [source] | |||||||||||||