Study of an argon magnetron discharge used for molybdenum sputtering. I: collisional radiative model

A collisional radiative model for the buffer gas in a DC magnetron discharge has been developed. The model was constructed for argon and was made self-consistent with the electron energy distribution function (EEOF) by solving the time-dependent Boltzmann equation. The evaluation of the importance of stepwise excitation and the role of 4s states as intermediate levels has been studied, as well as the role of radiative cascades from high lying excited states. The influence of the sputtered material on the EEDF and on electron collision rates has been included in the model. Molybdenum was chosen as a representative example of sputtered material. In the second pari of this double paper we use the results of this model calculation to analyse experimental spectroscopic data obtained from DC magnetron sputtering of molybdenum in argon.