Effect of incorporated nitrogen on the kinetics of thin rapid thermal N₂O oxides

We have grown ∼10 nm O₂ and N₂O-oxides on Si(100) by RTO (rapid thermal oxidation) over the temperature range 800-1200°C. Although the growth rates of both oxides exhibit Arrhenius behavior over the entire temperature range, the N₂O-oxides exhibit a large change in the Arrhenius preexponential factor for oxidation temperatures greater than 1000°C. Above this temperature, N₂O-oxides grow a factor of 5 slower than O₂ oxides. Below this temperature, N₂O-oxide growth rates approach those of O₂-oxides. This growth rate inflection can be explained in terms of N incorporation, which increases with increasing oxidation temperature. The equivalent of one monolayer of N coverage is achieved at about 1000°C, coincident with the inflection. The incorporated N retards the linear growth of the thin N₂O-oxides either by occupying oxidation reaction sites or inhibiting transport of oxidant species to the vicinity of the interface.