In Situ Quartz Crystal Microbalance and Quadrupole Mass Spectrometry Studies of Atomic Layer Deposition of Aluminum Oxide from Trimethylaluminum and Water

Reaction mechanisms in the atomic layer deposition of Al 2 O 3 from Al(CH 3 ) 3 and water were studied with a quartz crystal microbalance at 150−350 °C and with a quadrupole mass spectrometer at 150−400 °C. The growth rate was the highest at 250 °C. At lower temperatures the growth was limited due to kinetic reasons and at higher temperatures due to lower amount of surface −OH groups. About half of the ligands were released during the Al(CH 3 ) 3 pulse and the other half during the water pulse. The reaction temperature had no marked effect on the growth mechanisms, in the temperature range studied.