Direct observation of synchrotron-radiation-stimulated desorption of thin SiO2 films on Si(111) by scanning tunneling microscopy

Abstract This is the first report of the use of scanning tunneling microscopy (STM) to study changes in the surface morphology during synchrotron-radiation (SR) stimulated desorption of SiO 2 films on Si(111). An atomically flat surface was obtained after SR irradiation for 2 h at a surface temperature of 700°C. The STM topograph indicates that the SR desorption mechanism is quite different from the thermal desorption of SiO 2 . The lack of formation of multi-step holes on the exposed silicon surface indicates that the desorption of oxygen atoms and molecules by SR excitation leaving volatile SiO is an important mechanism.

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