AVS 61st International Symposium & Exhibition
    Thin Film Wednesday Sessions
       Session TF+MS+PS-WeM

Paper TF+MS+PS-WeM12
Pyrolysis of Alucone MLD Films to Form Electrically Conducting and Nanodomained Al2O3/C Composite Films

Wednesday, November 12, 2014, 11:40 am, Room 307

Session: Applied ALD: Nanoelectronics and Emerging Applications
Presenter: Steven George, University of Colorado, Boulder
Authors: J.J. Travis, University of Colorado, Boulder
J.W. DuMont, University of Colorado, Boulder
S.M. George, University of Colorado, Boulder
Correspondent: Click to Email
Alucone is an aluminum alkoxide polymer grown using molecular layer deposition (MLD) techniques with trimethylaluminum and organic diols or triols as the reactants. Alucone films can be pyrolyzed under inert atmosphere or vacuum to yield electrically conductive Al2O3/C composite films. This pyrolysis provides a pathway to deposit ultrathin, conformal and conducting Al2O3/C films on high surface area substrates. Our recent results have shown that the electrical conductance of the Al2O3/C films is dependent upon the amount of carbon in the film. The initial alucone films are non-conducting. After pyrolysis to 850°C, alucone films grown using glycerol, with three carbons, or hydroquinone, with six carbons, display high electrical conductivity of ~1-3 S/cm. In contrast, pyrolyzed alucone films grown using ethylene glycol, with only two carbons, remain non-conducting. In situ transmission Fourier transform infrared (FTIR) spectroscopy was used to monitor the pyrolysis of the alucone films. The C-H, C-O and C-C vibrational features were lost from the alucone films between 300-450°C. The vibrational spectra also showed prominent carboxylate features at 400-450°C. Carboxylate features are consistent with COO- – Al3+ complexes at the interfaces between the Al2O3 and carbon regions of the composite. High resolution transmission electron microscopy (HRTEM) images are consistent with a highly interfacial nanodomained Al2O3/C composite. These Al2O3/C composite films may provide electrical conductivity and oxidation resistance during electrochemical processes on metal and carbon electrodes.