From cathode to substrate: Plasma diagnostics on high power pulsed magnetron sputtering deposition of titanium nitride

Abstract

The present study focuses on an approach to measure the plasma properties from cathode to substrate parallel at three different positions in the coating chamber with activated substrate bias. High power pulsed magnetron sputtering is a powerful tool for the application in various coating systems with advantageous properties. For this reason it was investigated by countless studies during the last years. Several of these studies focusing on investigating the coating and plasma properties. Moreover, they investigated the plasma properties either at a high distance from the target or at different points in time at different chamber positions. The investigated positions were in front of the substrate, in front of the target and between both of them. After the plasma diagnostic measurements by optical emission spectroscopy, titanium nitride coatings were deposited. The coating thickness and deposition rate were investigated by scanning electron microscope. The indentation modulus EIT, the indentation hardness HIT as well as the plastic Wpl and elastic work Wel were investigated by nanoindentation. The chemical composition of the coatings was investigated by glow discharge optical emission spectroscopy (GDOES). For a pulse-on time ton variation of the cathode pulse, the relative deviation between the optical emission spectroscopy and GDOES results was determined for the different chamber positions. The best fit between the optical emission spectroscopy and GDOES results were found for the optical emission spectroscopy measurements conducted closest to the substrate. The present study shows that optical emission spectroscopy measurements close to the substrate are more suitable for the prediction of coating properties than optical emission spectroscopy measurements in front of the cathode.