An internal reflection infrared cell has been employed to study aqueous hydrofluoric acid (HF) and ultraviolet (UV)/ozone processing of Si(100) surfaces in situ. The useful range of the infrared experiment was extended below 1500 cm-1 to examine the Si—O--Si asymmetric stretching region by using a thin (75 /im) silicon single crystal in optical contact with a germanium internal reflection element. UV/ozone cleaning produces hydrophilic surfaces by oxidative removal of adventitious hydrocarbon on SiO2 or by oxidation of hydrogen terminated silicon to SiO2. Hydrophobic Si—H terminated surfaces are produced using dilute aqueous HF and are characterized by an increase in the intensity of the Si—H stretching mode and a concomitant decrease in the intensity of the Si---O—Si mode. UV/ozone oxidation of the HF treated surface produces oxidized silicon hydrides while removing Si—H and growing SiO2. Where appropriate, comparisons will be made between the corresponding XPS and infrared spectra to demonstrate the complementary information provided by these spectroscopies.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films|
|State||Published - Jul 1993|
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