Study of the stepwise oxidation and nitridation of Si(111): Electron stimulated desorption, Auger spectroscopy, and electron loss spectroscopy
Electron stimulated desorption, Auger line shape analysis, and electron loss spectroscopy measurements are reported for the electron activated stepwise oxidation and nitridation of the Si(111) surface. In ESD it is found that appreciable levels of surface hydrogen can be present which can lead to hydroxyl formation upon oxidation. The hydroxyl rich films are unstable in an electron beam, while surfaces oxidized with activated oxygen, where no OH is formed, are much more stable. The nitrided films are always stable in the electron beam even though there too hydrogen is always found. On the OH-free oxide, ESD shows two chemically distinct O species, one thought to be SiO/sub 2/ and the other adsorbed O/sub 2/ or a chemical intermediate. The Si(L/sub 23/VV) Auger spectra for both the oxide and nitride are treated by background subtraction, integration, deconvolution, and subtraction of the elemental part of the spectrum, as a function of reaction time over a well controlled series of reaction steps. The Auger spectra for both oxide and nitride films suggest that in the earliest stages of reaction, the reacted film is made up of low coordination intermediates which gradually evolve to the stoichiometric compound as the coordination increases. In loss spectroscopy, both the Si(L/sub 23/) core loss and the near elastic loss were measured. The L/sub 23/ core loss shows the same gradual evolution to the oxide seen in the Auger results, with an intermediate oxidation state dominating in the early stages of reaction. The near elastic loss spectra, by contrast, quickly saturate in the early stages of reaction to the final oxide spectrum which is characterized by features both of the full oxide and a suboxide. Similar results are found for the nitride.
- Research Organization:
- Sandia National Laboratories, Albuquerque, New Mexico 87185
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5656644
- Journal Information:
- J. Vac. Sci. Technol., B; (United States), Journal Name: J. Vac. Sci. Technol., B; (United States) Vol. 1:4; ISSN JVTBD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360603* -- Materials-- Properties
AUGER ELECTRON SPECTROSCOPY
CHALCOGENIDES
CHEMICAL REACTIONS
COLLISIONS
CONTAMINATION
DESORPTION
ELECTRON COLLISIONS
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY LOSSES
HYDROXYL RADICALS
LINE WIDTHS
LOSSES
MINERALS
NITRIDATION
NONMETALS
OXIDATION
OXIDE MINERALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
RADICALS
SEMIMETALS
SILICA
SILICON
SILICON COMPOUNDS
SILICON OXIDES
SPECTROSCOPY
SURFACE CONTAMINATION