AVS 58th Annual International Symposium and Exhibition
    Thin Film Division Wednesday Sessions
       Session TF1+EM-WeM

Paper TF1+EM-WeM3
Metalcone and Metalcone/Metal Oxide Alloys Grown Using Atomic & Molecular Layer Deposition Techniques

Wednesday, November 2, 2011, 8:40 am, Room 110

Session: ALD/MLD: Hybrid Organic Films
Presenter: Byoung H. Lee, University of Colorado, Boulder
Authors: B.H. Lee, University of Colorado, Boulder
V.R. Anderson, University of Colorado, Boulder
S.M. George, University of Colorado, Boulder
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A new class of films known as the “metalcones” can be grown using atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques. Metalcones are hybrid organic-inorganic materials derived from the sequential, self-limiting reactions of metal and organic alcohol precursors. The first metalcones were the “alucones” based on trimethylaluminum and ethylene glycol (EG) and the “zincones” based on diethylzinc and EG. Other metalcones can be fabricated with various properties using different metal precursors together with organic alcohols. This talk reports new metalcones known as the “zircones” using zirconium tert-butoxide (ZTB) and EG. In addition, this talk will discuss two new tunable ALD:MLD films based on alloys of alucone MLD/Al2O3 ALD and zircone MLD/ZrO2 ALD. Zircone MLD films were grown by using zirconium tert-butoxide (ZTB) and EG. MLD growth was observed at temperatures ranging from 105 to 195°C. In situ quartz crystal microbalance and ex situ X-ray reflectivity (XRR) experiments confirmed linear growth of zircone MLD versus number of ZTB/EG reaction cycles. Zircone MLD growth rates decreased versus temperature and varied from 1.6 Å per cycle at 105°C to 0.3 Å per cycle at 195°C. A constant density of ~2.3 g/cm3 was measured for all growth temperatures. XRR measurement also showed that zircone MLD films were very stable under ambient conditions. The metalcones will have useful mechanical, optical and electrical properties that can be tuned by growing alloys of the metalcones and their parent metal oxides. For example, this tuning allows the density of alucone MLD/Al2O3 ALD alloys to be varied from 1.6 g/cm3 to 3.0 g/cm3. The density of zircone MLD/ZrO2 ALD alloys could also be varied from 2.3 g/cm3 to 4.0 g/cm3. The reflective index of zircone MLD/ZrO2 MLD alloys was also tuned continuously between 1.63 and 1.86. These new metalcone materials provide a tool set for engineering the functional properties of thin films. These materials can be grown with atomic control of thickness and excellent conformality. The metalcones and metalcone alloys can also be thermally annealed to remove the organic constituent and create porous metal oxide films.