Low temperature wafer bonding of a low-k dielectric film of carbon-doped oxide (CDO) is studied. Direct bonding of wafers coated with CDO film is successfully accomplished after careful surface preparations including polishing, oxygen plasma activation, and deionized water rinse. O-2 plasma activation is highly effective in modifying the CDO surface for hydrophilic wafer bonding with a significant improvement in the bond strength. CDO wafer bonding also outperforms the control wafers with plasma-enhanced tetraethyl orthosilicate oxide by 46.2% in terms of bond strength after a 3 h annealing at 300 degrees C in N-2 ambient. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3266904] All rights reserved.