In situ reaction mechanism studies of plasma-assisted atomic layer deposition of Al2O3

Reaction mechanisms during plasma-assisted atomic layer deposition (ALD) of Al2O3 from Al(CH3)(3) and O-2 plasma were studied by time-resolved quartz crystal microbalance measurements, mass spectrometry, and optical emission spectroscopy. Al(CH3)(3) chemisorption on the oxide surface after the plasma pulse releases CH4 products while from the detection of CO, CO2, and H2O in the O-2 plasma it is established that surface -CH3 groups are predominantly removed by O radical-driven combustionlike reactions. Also a second pathway exists for -CH3 removal driven by H2O generated in this plasma step. These reaction pathways are expected to be generic for plasma-assisted ALD of oxides from metal organic precursors. (c) 2006 American Institute of Physics.