Chemical Vapor Deposition

Cover image for Chemical Vapor Deposition

January, 2003

Volume 9, Issue 1

Pages 3–50

    1. Growth of Lanthanum Silicate Thin Films by Liquid Injection MOCVD Using Tris[bis(trimethylsilyl)amido]lanthanum (pages 7–10)

      H.C. Aspinall, P.A. Williams, J. Gaskell, A.C. Jones, J.L. Roberts, L.M. Smith, P.R. Chalker and G.W. Critchlow

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290009

      Lanthanum silicate is deposited from a single-source precursor by injection MOCVD using La[N(SiMe3)2]3 as precursor. The depositions are carried out over 350–600 °C without an additional silicon source. SEM analysis (Figure) shows that deposited films are smooth and featureless. AES analysis indicates that all the films are lanthanum silicate with silicon concentration ranging from 8.5 to 15.2 at.-%.

    2. Dual-Source Atmospheric Pressure CVD of Amorphous Molybdenum Phosphide Films on Glass Using Molybdenum(V) Chloride and Cyclohexylphosphine (pages 10–13)

      C.S. Blackman, C.J. Carmalt, T.D. Manning, S.A. O’Neill, I.P. Parkin, L. Apostolico and K.C. Molloy

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290000

      Molybdenum phosphide films are deposited on glass from MoCl5 and 2P(C6H11)H2. The atmospheric pressure depositions are carried out at 550 and 600 °C producing silver brown shiny films. The composition of the film is shown to be MoP1.8 with a resistivity value of ca. 3800 μΩ cm. X-ray analysis of the deposited films indicates that they are amorphous. XPS analysis revealed binding energy shifts of 228.4 eV for Mo 3d5/2 and 128.8 eV for P 2p. The deposits passed the scotch test and could not be scratched with steel or brass scalpels. They are also resistant to common solvents but dissolve in concentrated acids.

    3. Atomic Layer Deposition of CuxS for Solar Energy Conversion (pages 15–20)

      L. Reijnen, B. Meester, A. Goossens and J. Schoonman

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290001

      Atomic layer deposition (ALD) of photoactive Cu1.8S films is achieved from Cu(thd)2 and H2S precursors at 200 °C (Figure) as a first step in the construction of nanoporous heterojunctions of TiO2/Cu1.8S. The ALD process has two temperature regimes. Below 175 °C, adsorption of the whole Cu(thd)2 molecule occurs followed by an exchange reaction with H2S yielding CuS, while above 175 °C, Cu(thd)2 reduces upon adsorption and slowly decomposes yielding Cu1.8S.

    4. Atomic Layer Deposition of Epitaxial and Polycrystalline SnO2 Films from the SnI4/O2 Precursor Combination (pages 21–25)

      J. Sundqvist, A. Tarre, A. Rosental and A. Hårsta

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290002

      Thin SnO2 films are successfully deposited by ALD using a SnI4–O2 precursor combination on SiO2/Si(100) and single crystalline α-Al2O3(012) in the temperature range 400–750 °C. The films are found to grow as a tetragonal SnO2 phase (cassiterite). The film is polycrystalline on SiO2/Si(100) and epitaxial on α-Al2O3(012) with an in-plane orientation relationship [010]math image ∥ [100]math image. In general the growth rate is high and ranges from 0.1 nm cycle–1 at 500 °C to 0.12 nm cycle–1 at 750 °C for α-Al2O3(012) and from 0.04 nm cycle–1 at 400 °C to 0.24 nm cycle–1 at 750 °C for SiO2/Si(100).

    5. Template-Directed CVD of Dielectric Nanotubes (pages 26–33)

      L. Zambov, A. Zambova, M. Cabassi and T.S. Mayer

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290003

      Dielectric nanotubes are fabricated from a binary source reagent (SiH4-O2 (Figure) and SiH4-N2) using template-based electron cyclotron resonance (ECR) plasma-assisted CVD. The nanotubes are smooth, transparent and at least 10 μm long. A mathematical description of the template-directed CVD is developed to elucidate the process parameters that enable the growth of nanocylinders with high aspect ratio and uniform wall thickness.

    6. In-Situ Optical Pyrometry in the CVD of Metallic Thin Films for Real Time Control of the Growth (pages 34–39)

      C. Gasqueres, F. Maury and F. Ossola

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290004

      In-situ IR pyrometry is used for real-time monitoring of metallic-type thin films at early stages of growth. Significant variations of the pyrometric signal are observed during the MOCVD of Cr-based thin films due to changes of emissivity of the film/substrate system. The pyrometric signal is predominantly dependent on the nature, the thickness and the surface roughness of the growing film. As a result, fruitful information on the formation of an interphase or the existence of an induction period can be obtained in real time by the detection technique. The paper concludes that radiation pyrometry is a sensitive low-cost diagnostic tool.

    7. In-Situ Preparation of Polymer-Coated Alumina Nanopowders by Chemical Vapor Synthesis (pages 40–44)

      M. Schallehn, M. Winterer, T.E. Weirich, U. Keiderling and H. Hahn

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290006

      Nanocrystalline alumina particles coated with polyethylene are prepared by a two-step chemical vapor synthesis (CVS) process using a hot-wall reactor to synthesize a nanocrystalline alumina core, followed by polymer coating in an RF plasma reactor. The particle radius is 4 nm with a ceramic core radius of 2.5 nm and a coating thickness of 1.5 nm. The success of the preparation is shown by the combined characterization results of FTIR, XRD, BET, SANS, and HRTEM (Figure).

    8. Ruthenium Thin Films Grown by Atomic Layer Deposition (pages 45–49)

      T. Aaltonen, P. Alén, M. Ritala and M. Leskelä

      Version of Record online: 13 JAN 2003 | DOI: 10.1002/cvde.200290007

      Thin films of metallic ruthenium are grown by ALD in the temperature range 275–400 °C using bis(cyclopentadienyl)ruthenium and oxygen as precursors. The films are grown on thin Al2O3 and TiO2 films on glass. XRD analysis indicates that the films are polycrystalline metallic ruthenium and SEM studies shows that the films have excellent conformality. The impurity contents are very low as measured by time-of-flight elastic recoil detection analysis. All deposited films show resistivity below 20 μΩ cm, higher than the resistivity of the bulk metal. The resistivity of the films decreases as the deposition temperature is increased.