# Activation energy of SiO2

1. Jul 21, 2011

### mama79

Hi..
How to calculate the activation energy of oxidation of Si. For example, from the Arrhenius plot (parabolic constant versus 1000/T (K-1)).

2. Jul 22, 2011

### JaWiB

If you have an Arrhenius plot of the rate constant, it's pretty simple. You have
$k = A e^{-E_a/kT}$
Take the logarithm, which is what you plot:
$ln(k) = ln(A) -E_a/kT$
So the activation energy is proportional to the slope of the plot, which means you just do a linear fit and multiply the slope by a constant. Note that sometimes people plot log10(k) instead of the natural logarithm, but you can deal with that by applying the change of base formula.

3. Jul 27, 2011

### mama79

Thank you very much..
So far, I have difficulties to extract the parabolic constant and intercept of the graph (t/xo+t1) vs xo), where t is oxidation time, xo is thickness and t1 is the time value after extrapolating the curve of oxidation time vs thickness (refer to deal and grove) model. This equation is for the dry oxygen case.