Chemical Vapor Deposition

Cover image for Chemical Vapor Deposition

May, 2006

Volume 12, Issue 5

Pages 251–301

    1. Synthesis of Al2O3–SiO2 Films by Ar/O2 Plasma-Enhanced CVD from Alkoxide Precursors (pages 255–258)

      Y. Li, S. Shimada and A. Hirose

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200504223

      Amorphous Al2O3, SiO2, and Al2O3–SiO2 composite films have been produced at 800 °C from alkoxide solution precursors by liquid-injection oxygen plasma enhanced CVD. The films' structures and morphologies are affected by the feed rate of the liquid precursor and their compositions can be controlled by adjusting the Si/Al ratios in the starting source. Steel substrates coated with the above films gained excellent protection when they were exposed to high temperature atmosphere containing KCl vapor.

    2. Positive- and Negative-Tone CVD Polyacrylic Electron-Beam Resists Developable by Supercritical CO2 (pages 259–262)

      Y. Mao, N. M. Felix, P. T. Nguyen, C. K. Ober and K. K. Gleason

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200506416

      Resists sensitive to electron-beam exposure and developable in supercritical CO2 were synthesized by initiated CVD (iCVD), resulting in an all-dry lithographic process. The low energy of the iCVD method permits the retention of the irradiation-sensitive functional groups and the incorporation of the fluorinated acrylates needed for increased solubility in supercritical CO2. Both positive- and negative-tone images with 300 nm feature size were achieved.

    3. The Growth of Thermochromic VO2 Films on Glass by Atmospheric-Pressure CVD: A Comparative Study of Precursors, CVD Methodology, and Substrates (pages 263–274)

      D. Vernardou, M. E. Pemble and D. W. Sheel

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200506419

      VO2 is a thermochromic material, in that it undergoes a thermally induced semiconducting-to-metallic phase transition resulting in a dramatic change in optical transmittance and reflectivity in regions of the spectrum that are major contributors to solar heating. This paper presents data that, for the first time, clearly identifies the useful CVD parameter space windows where VO2 films possessing desired qualities can be deposited using atmospheric pressure CVD. The critical importance of using the optimum CVD growth parameters in terms of controlling film morphology and determining the oxidation state of the vanadium oxide is highlighted.

    4. In Situ Reflective High-Energy Electron Diffraction Analysis During the Initial Stage of a Trimethylaluminum/Water ALD Process (pages 275–279)

      R. Bankras, J. Holleman, J. Schmitz, M. Sturm, A. Zinine, H. Wormeester and B. Poelsema

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200506433

      First results of in situ reflective high-energy electron diffraction (RHEED) measurements during atomic layer deposition of Al2O3 on Si(001) are presented, using Al(CH3)3 and H2O as precursors. The results show growth initiation by TMA, growth inhibition for over 10 cycles, and sensitivity to the chemisorption of TMA and H2O. A simple model of ALD and RHEED is used to describe and analyze the measured decay in reflected intensity.

    5. New Precursors for the CVD of Zirconium and Hafnium Oxide Films (pages 280–284)

      J.-S. M. Lehn, S. Javed and D. M. Hoffman

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200506434

      Tetrakis(trimethylhydrazido)zirconium and hafnium, Zr-(NMeNMe2)4 and Hf(NMeNMe2)4, and Hf[tBuNCH2CH2N-tBu]2 have been used with oxygen as precursors to zirconium and hafnium oxide films in a low-pressure CVD process at substrate temperatures < 400 °C. The as-deposited films are amorphous, featureless, and transparent. The X-ray crystal structure of Hf[tBuNCH2CH2N-tBu]2 revealed that it has an elongated tetrahedral geometry in the solid state.

    6. Amorphous Highly Conjugated Chemical-Vapor-Deposited Polymer Thin Films (pages 285–289)

      J. J. Senkevich, B. W. Woods, B. P. Carrow, R. D. Geil and B. R. Rogers

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200506454

      2-trifluoroacetyl-α,α,α′tribromo-p-xylene was synthesized as a chemical-vapor-depositable precursor to yield an amorphous α-brominated poly(trifluoroacetyl-p-xylylene) polymer. With post-deposition anneals at 200 and 300 °C the polymer undergoes multiple dehydrohalogenations of HBr to yield a highly conjugated polymer with vinyl and ethynyl moieties that remain amorphous. Such a methodology, namely placing a bulky group on the phenyl group of the polymer, allows these CVD polymers to be applied to optical applications where the polymer must remain amorphous after subsequent thermal processing.

    7. Atomic Layer Deposition of Pd on an Oxidized Metal Substrate (pages 290–294)

      G. A. Ten Eyck, S. Pimanpang, H. Bakhru, T.-M. Lu and G.-C. Wang

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200506456

      Palladium thin films have been successfully grown using atomic layer deposition with palladium(II) hexafluoroacetylacetonate as the solid source precursor on oxidized metal substrates without the use of a plasma. XPS and RBS have been used to analyze the film growth rate and chemical characteristics. The data presented demonstrates that high-quality film growth can be achieved without the use of a plasma, even on air-exposed metal surfaces.

    8. Liquid-Injection MOCVD of ZrO2 Thin Films using Zirconium Bis(diethlyamido)-bis(di-tert-butylmalonato) as a Novel Precursor (pages 295–300)

      R. Thomas, A. Milanov, R. Bhakta, U. Patil, M. Winter, P. Ehrhart, R. Waser and A. Devi

      Version of Record online: 19 MAY 2006 | DOI: 10.1002/cvde.200506481

      Tuning Zr alkylamide with malonates as chelating ligands resulted in a stable mononuclear complex [Zr(NEt2)2-(dbml)2] (see Figure) which could find application as a CVD precursor for Zr-based oxide thin films. The application of this new class of precursor for ZrO2 thin-film deposition using liquid-injection MOCVD iis demonstrated. The new precursor is reliable and reproducible for low- (∼ 400 °C) and high-temperature (> 500 °C) depositions of amorphous or crystalline films, respectively.