PLASMA OXIDE-GROWTH ON SILICON AND TITANIUM DISILICIDE

The oxidation of silicon and TiSi2 in an r.f. oxygen plasma at floating potential in the 400-900-degrees-C temperature range has been investigated. Rutherford backscattering spectrometry and nuclear reaction analysis have been used to determine the kinetics of oxide growth and the elemental depth distribution. For oxides formed on both silicon and TiSi2 we have observed two different regimes in the growth, depending on the temperature. The transition temperature between these two regimes is about 600-degrees-C. In the case of TiSi2 plasma oxidation the nature of the oxide depends on temperature: almost pure SiO2 for the high temperature regime and a TiO2-SiO2 mixture for the low temperature regime. Thermodynamics and atomic transport have been resorted in order to explain such behaviour.