Etching of the Si(001) Surface with Molecular Oxygen

We have used low-energy electron microscopy to study the etching of large terraces on Si(001) with molecular oxygen. By imaging the etching process in situ, and comparing the results to detailed kinetic models, we determine and quantify the dominant mechanisms by which oxygen attacks the surface. We find that the etch rate follows an Arrhenius form with an activation energy of 2.0±0.4eV, significantly lower than estimates reported in modulated beam investigations.