Paper TF2-TuA8
Molecular Layer Deposition of Alucones and Zincones Using Hydroquinone

Tuesday, October 30, 2012, 4:20 pm, Room 11

Alucones and zincones are metal alkoxide polymer films that can be grown using molecular layer deposition (MLD) techniques. In this study, alucones and zincones were grown using trimethlyaluminum (TMA) and diethylzinc (DEZ) as the metal precursors and hydroquinone (HQ) as the organic reactant. HQ is an aromatic diol that has a rigid structure with a central benzene ring. The benzene ring may lead to interesting electrical conductivity and the rigid structure may help to avoid “double reactions”. Quartz crystal microbalance measurements and X-ray reflectivity (XRR) studies were employed to examine film growth. Individual mass gains after the TMA and HQ exposures were consistent with a TMA:HQ stoichiometry of 4:3 in the MLD film. This TMA:HQ stoichiometry suggests the presence of Al₂O₂ dimeric core species. In comparison, individual mass gains after the DEZ and HQ exposures were consistent with a DEZ:HQ stoichiometry of 1:1 in the MLD film. XRR studies measured growth rates at 150°C of 2.6 Å/cycle for TMA/HQ and 2.7 Å/cycle for DEZ/HQ. The alucone and zincone MLD films were also annealed in air at temperatures up to 350^oC. There is evidence that the benzene rings polymerize after heating to 200°C. The films turn brown and a strong absorbance observed at ~320 nm is consistent with an expanded π-conjugated system. The polymerization of the benzene rings should change the mechanical properties of these annealed MLD films. Alucone and zincone films were also grown using tetrafluorohydroquinone to observe the effect of fluorination of the benzene ring.