Real-time observation of the dry oxidation of the Si(100) surface with ambient pressure x-ray photoelectron spectroscopy

We have applied ambient-pressure x-ray photoelectron spectroscopy with Si 2p chemical shifts to study the real-time dry oxidation of Si(100), using pressures in the range of 0.01-1 Torr and temperatures of 300-530 degrees C, and examining the oxide thickness range from 0 to similar to 25 angstrom. The oxidation rate is initially very high (with rates of up to similar to 225 angstrom/h) and then, after a certain initial thickness of the oxide in the range of 6-22 angstrom is formed, decreases to a slow state (with rates of similar to 1.5-4.0 angstrom/h). Neither the rapid nor the slow regime is explained by the standard Deal-Grove model for Si oxidation. (C) 2008 American Institute of Physics.