The energetics of the atomic process of Si-oxide growth on Si(100) surfaces and at ${\mathrm{SiO}}_2$/Si(100) interfaces are theoretically studied by first-principles calculation. It is found that the stress induced during the growth plays a crucial role in the growth procedure itself. The preferential growth direction of the oxide nucleus on the surfaces is vertical to the substrate, whereas that at the interfaces is lateral. Moreover, Si atoms are inevitably emitted from the interface to release the stress induced during Si oxide growth.

• Received 8 July 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.5936