Void formation on ultrathin thermal silicon oxide films on the Si(100) surface

The formation of voids on the thermally grown (650 degrees C) ultrathin (similar to 1 nm) silicon oxide films on the Si(100) surface was investigated by using ultrahigh vacuum scanning tunneling microscopy. Voids form randomly on the ultrathin oxide film upon thermal annealing at 750 degrees C. In contrast to void formation observed on thicker (>5 nm) thermal silicon oxide films and that observed on ultrathin (similar to 1 nm) oxide films formed by room temperature O-2 adsorption, the number of voids increases during annealing. We find that Si monomer creation and SiO production compete kinetically in the void formation process. (C) 1996 American Institute of Physics.