AVS 59th Annual International Symposium and Exhibition
    Thin Film Monday Sessions
       Session TF-MoM

Paper TF-MoM10
Alloy Films Grown Using Al2O3 ALD and Alucone MLD: Critical Tensile Strains, Water Vapor Transmission Rates and Compliant Interlayers

Monday, October 29, 2012, 11:20 am, Room 11

Session: ALD Enabled Applications
Presenter: S.M. George, University of Colorado, Boulder
Authors: S.H. Jen, University of Colorado, Boulder
B.H. Lee, University of Colorado, Boulder
S.M. George, University of Colorado, Boulder
P.F. Carcia, DuPont Central Research and Development
R.S. McLean, DuPont Central Research and Development
Correspondent: Click to Email
Hybrid organic-inorganic alloy films can be grown using Al2O3 ALD and alucone MLD. These alloy films may display the excellent gas diffusion barriers properties of Al2O3 ALD films and also may be more flexible than Al2O3 ALD films. Critical tensile strains (CTSs) and water vapor transmission rates (WVTRs) were measured for the ALD:MLD alloy films using trimethylaluminum, ethylene glycol and H2O as the reactants. The alloy composition was controlled by varying the ratio of ALD: MLD cycles during film growth. The CTS reached its highest values of ~1.0 % for the 3:1 alloy. The WVTR decreased 4 orders of magnitude versus alloy composition. The 7:2, 5:1 and 6:1 alloys had the lowest WVTRs of ~1×10-4 g/m2/day at the sensitivity limit. These alloys are more flexible than Al2O3 ALD and may serve as gas diffusion barriers for flexible thin film devices. The alucone MLD film was also used as a compliant interlayer to minimize stress caused by thermal expansion mismatch between Al2O3 ALD films and Teflon FEP substrates. Without the alucone MLD interlayer, the Al2O3 ALD films are susceptible to cracking resulting from the high coefficient of thermal expansion mismatch between Al2O3 ALD and Teflon FEP. With an alucone compliant interlayer, the Al2O3 ALD film has a crack density that is reduced progressively versus alucone interlayer thickness.