Spectroscopic ellipsometry of oxides and interfaces thermally formed on (100)Si and (111)Si

Thin oxides and their interface, formed by dry oxidation of hydrogen-enriched (100)Si and (111)Si substrates via r.f. hydrogen plasma exposure at 850°C, are studied by multiple-angle spectroscopic ellipsometry in the range 280–632.8 nm. Comparison with the standard oxidation of RCA cleaned Si shows that on plasma treated Si the initial oxide growth rate is higher and a thicker interface is formed with a different composition. Various processes involving hydrogen are suggested to be responsible for changes in interface properties.