Void growth during thermal decomposition of silicon oxide layers studied by low-energy electron microscopy

Low-energy electron microscopy (LEEM) has been used to investigate void growth during thermal decomposition of 1-2-nm-thick silicon oxide on Si substrates. Real-time LEEM observations clarify that the void size (square root of the void area) grows linearly with time. The temperature dependence of the growth rate reveals that the activation energy of the void growth is about 4.0 eV. We also find that the void density increases at faster rates in later stages of the oxide decomposition. This suggests that the nucleation is not initiated by a random single event. Additionally, we demonstrate that the voids become shallower because the void shape changes during the growth. (c) 2006 American Institute of Physics.