Chemical Vapor Deposition

Cover image for Chemical Vapor Deposition

March, 2005

Volume 11, Issue 3

Pages 123–176

    1. Very High Yield Growth of Vertically Aligned Single-Walled Carbon Nanotubes by Point-Arc Microwave Plasma CVD (pages 127–130)

      G. F. Zhong, T. Iwasaki, K. Honda, Y. Furukawa, I. Ohdomari and H. Kawarada

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200404197

      A very high yield, selective growth of dense, vertically aligned single-walled carbon nanotubes (SWNTs) has been demonstrated for the first time on Si substrates with a sandwich-like coating structure of Al2O3/Fe/Al2O3 at a low (600 °C) temperature by point-arc microwave plasma CVD. The SWNT film thickness increases continuously with the growth time, suggesting an almost unlimited life time for the catalyst. A film thickness of 420 μm, and production yield of SWNTs to catalyst of about 770 000 % can be achieved within 2 h.

    2. A Novel Study of the Growth and Resistivity of Nanocrystalline Pt Films Obtained from Pt(acac)2 in the Presence of Oxygen or Water Vapor (pages 130–135)

      G. A. Battiston, R. Gerbasi and A. Rodriguez

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200404201

      Reaction mechanisms between platinum acetylacetonate Pt(acac)2 and O2 or water vapor to deposit nanostructured, conductive platinum thin films at 240–300 or 280–440 °C respectively, are studied to elucidate the effects of experimental parameters on the film microstructure and resistivity. The use of water vapor during the decomposition process of Pt(acac)2 permits slower, homogeneous film growth along the reactor. Although decomposition of Pt(acac)2 assumes different characteristics in the presence of O2 and H2O, a universal trend crystallite size–resistivity was found for almost all obtained films, representing a starting point for correlation of experimental conditions with applicative performances.

    3. Characterization of a TiO2 Photocatalyst Film Deposited by CVD and Its Photocatalytic Activity (pages 137–141)

      S.-C. Jung, B.-H. Kim, S.-J. Kim, N. Imaishi and Y.-I. Cho

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200406321

      TiO2 photocatalyst films were prepared by low-pressure (LP)MOCVD using TTIP. The structure of the film was found to be strongly dependent on the reaction temperature and deposition time. The photocatalytic activity strongly depends on the film thickness, although the relationship is nonlinear. The optimum thickness of the TiO2 catalyst film grown by LPMOCVD is shown to be between 3 and 5 μm (Figure).

    4. Preparation and Properties of SrTiO3 Thin Films Produced by Mist Plasma Evaporation Using a Metal Nitrate Aqueous Precursor (pages 142–146)

      H. Huang, X. Yao and O. K. Tan

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200406329

      A mist plasma evaporation technique has been developed to deposit SrTiO3 thin films under atmospheric pressure using an aqueous solution of strontium nitrate and titanium nitrate as precursors. The technique is characterized by the injection of liquid reactants into thermal plasma where droplets of the precursor solution are partially or totally evaporated, decomposed, and ionized to their elements. The films deposited by mist plasma evaporation were cubic perovskite SrTiO3, and showed paraelectric properties at room temperature.

    5. High-Temperature Growth of Silica Sheathed Bi2S3 Semiconductor Nanowires (pages 147–152)

      H.-X. Zhang, J.-P. Ge and Y.-D. Li

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200406334

      Silica sheathed Bi2S3 nanowires (preferential growth along the c-axis) and monoliform nanowires (Figure) have been grown on Si(001) substrates through one step atmospheric pressure (AP) CVD with BiCl3 and sulfur precursors. The mechanism of formation is presented.

    6. Kinetic Analysis of the Processing of Porous Biomorphic Titanium Carbide Ceramics by Chemical Vapor Infiltration (pages 153–158)

      N. Popovska, D. Almeida-Streitwieser, C. Xu, H. Gerhard and H. Sieber

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200306319

      Porous biomorphic TiC ceramics, derived from carbon biotemplates of three different wood types, were produced by chemical vapor infiltration (CVI) with TiCl4/H2. The infiltration depth in the pores, expressed as the infiltration factor, was estimated using a model, considering the rate of the chemical reaction, the effective diffusion coefficient, and the geometry of the pores. The calculated infiltration depths are verified by SEM.

    7. Deposition of HfO2, Gd2O3 and PrOx by Liquid Injection ALD Techniques (pages 159–169)

      R. J. Potter, P. R. Chalker, T. D. Manning, H. C. Aspinall, Y. F. Loo, A. C. Jones, L. M. Smith, G. W. Critchlow and M. Schumacher

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200406348

      Thin films of HfO2, (Figure) Gd2O3, and PrOx have been deposited by liquid injection ALD. XRD analysis shows that as-grown films of HfO2 are amorphous, but crystallize into the monoclinic phase after annealing in air; as-grown Gd2O3 and PrOx films have some degree of crystallinity. In each case, ALD growth was not fully self-limiting; this is attributed to the β-hydride elimination of the mmp (OCMe2CH2OMe) group of the precursors, liberating alkene and generating reactive [M-OH] surface sites during each ALD cycle.

    8. Composite Platinum/Silicon Dioxide Films Deposited using CVD (pages 170–174)

      T. P. Martin, C. P. Tripp and W. J. DeSisto

      Version of Record online: 24 MAR 2005 | DOI: 10.1002/cvde.200406344

      Low-temperature deposition of Pt/SiO2 composite films from tetraethylorthosilicate (TEOS) and platinum acetylacetonate (Pt(acac)2) is demonstrated. Films were grown at temperatures of 300–440 °C, using a 5:1 flow rate of TEOS to Pt(acac)2 and in 0–70% oxygen atmosphere. The overall growth rate was maximized at 400 °C and the overall activation energy of the thin film formation was ∼80 kJ mol–1. The SiO2 phase was amorphous and the platinum phase crystalline Despite the high Si/Pt ratio in the feed, the maximum observed Si/Pt ratio in the film was 1:1, suggesting a cooperative TEOS/Pt(acac)2 decomposition mechanism.