Deposition rate

We determined the exact deposition rate with an atomic force microscope (AFM). Before the deposition experiments, we marked the exposed side of the glass samples with a red marker pen. As the marker ink is dissolved in IPA, we could perform a lift-off of ITO at those locations. We then measured the resulting step height between the ITO layer and the glass substrate. Dividing that value by the exact sputtering time yielded a precise value for the deposition rate.

Design of experiment

Assuming the responses of the experiment can be approximated well with a linear model, we opted for a fractional factorial design. For the first round of measurements, we chose to design the experiment such as to minimise the costs. As we have five factors, we used a 25-3 design (Table \ref{tab:experiment}) with the generator (1, 2, 3, 13, 23), yielding 8 measurement runs to perform. We added a null run in order to be able to test the lack-of-fit.
The system is of resolution III, meaning that the main effects are aliased with first order interactions (Table \ref{tab:aliasing}). The chuck temperature is the only factor not defining the plasma, we thus expect it to have little interaction with the other factors. In order to limit aliasing on the other factors, we chose the temperature to be factor 3. If required, after analysis of the first round of experiments it is possible to extend the experiment matrix with 8 additional runs and obtain a 25-1 fractional factorial design, allowing de-aliasing of the main effects and the first order interactions.