Now our model can be used to analyze many spectra and obtain the film thickness vs. deposition time relation.

In the directory of example 3 of tutorial 1 you find 22 spectra named ag_1.std, ag_2.std, ... that contain the measured reflectance spectra after 1, 2 , 3, ... seconds of sputtering deposition. All files are in standard format. Try to load some of them and get the thickness from the automatic fit. Here are some values that I got:

 Deposition time        [s]                Thickness [nm]

 5                                6.3

 10                                13.0

 15                                20.0

 20                                26.6

I have processed all spectra completely automatic with the SCOUT batch control window and I get the following relation between film thickness and deposition time:

From the slope a sputtering rate of 1.3 nm/s is obtained.

Note that the thickness vs. time relation is not linear for small times (below 5 s). This is due to the fact that silver shows an inhomogeneous island growth in the beginning of the deposition. The model which assumes a homogeneous silver layer fails to reproduce the experimental spectra and the obtained thickness values are wrong. Here you need a suitable effective medium theory which will be the topic of another tutorial.