# Deposition of 3 YSZ-TiC PVD Coatings with High-Power Impulse Magnetron Sputtering (HiPTMS)
## 3 Results
### Results of the Parameter Study  
In the preliminary experiments with the 3 YSZ-TiC target, the measured maximum table current varied between 19 and 49 A. An increasing working gas flow led to a decreasing table current. Krypton had a bigger impact on the current than argon. With a very low working gas flow (argon 0/50/100 sccm, krypton 0 sccm and argon 0 sccm, krypton 50 sccm) the process broke down. Four currents with the respective working gas compositions were chosen for the main experiments, as shown in Table 3.  
Firstly, we chose the maximum table current of 49 A (argon 150 sccm, krypton 0 sccm) for the main experiments. Secondly, we selected a very low table current of 20 A (argon 0 sccm, krypton 550 sccm). Finally, we picked two currents in the lower and higher mid-table at 30 and 40 A (argon 100 sccm, krypton 50 sccm and argon 50 sccm, krypton 200 sccm).  
We could not observe a stable plasma at 400 Hz with any mix of pulse parameters. In general, we could observe decreasing maximum table currents with increasing gas loads. With an increasing frequency, we could observe decreasing values of the maximum table currents, with 500 Hz showing the highest maximum table currents. The highest value measured was 152 A at 150 Ar0 Kr, 500 Hz, a 20 \(\upmu\)s on-time cathode, a 50 \(\upmu\)s on-time bias and a bias offset of 20 \(\upmu\)s. The minimum measured was 3 A at 0 Ar550 Kr, 2000 Hz, an on-time cathode of 60 \(\upmu\)s, an on-time bias of 30 \(\upmu\)s and a 0 \(\upmu\)s offset.  
Figure 2 shows all results of the 500 Hz measurements with different on-time cathodes at 150 Ar0 Kr. One can see that the maximum table currents increased with the decreasing on-time values of the cathode.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Gas Mix** & **Max. Table Current [A]** \\ \hline
150 Ar0 Kr & 49.1 \\
100 Ar50 Kr & 40.1 \\
50 Ar200 Kr & 30.1 \\
0 Ar550 Kr & 20.2 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Working gas compositions chosen for the main experiments.  
Figure 1: Results of the gas flow experiments with yttria-stabilized zirconia (3 YSZ)-TiC.  
An increasing on-time of the cathode with other parameters kept constant led to a decrease of the table current. The maximum table current for the 20 \(\upmu\)s cathode on-time was approximately twice the maximum table current for the 60 \(\upmu\)s on-time. The on-time of the bias had no measurable impact on the maximum current at the substrate table. For measurements of the bias offset, the results did not show linear behavior. Figure 3 shows the results of the bias offset with 150 Ar0 Kr at 500 Hz, a cathode on-time of 20 \(\upmu\)s and a bias on-time of 50 \(\upmu\)s.  
Figure 3: Results of bias offset at 150 Ar0 Kr, 500 Hz, a cathode on-time of 20 \(\upmu\)s and a bias on-time of 50 \(\upmu\)s.  
Figure 2: Results of all 500 Hz measurements with different pulse on-time values of the cathode with a 150 Ar0 Kr gas mix. The red highlighted measurements are the results of the bias offset range 0–80 \(\upmu\)s with 150 Ar0 Kr at 500 Hz, a 20 \(\upmu\)s cathode on-time and a bias on-time of 50 \(\upmu\)s, which is also shown in Figure 3.  
One can observe an increase of the maximum table current from 130 A to 152 A with an increase in the bias offset. With a further increase of the bias offset beyond 20 \(\upmu\)s, the maximum table current decreased rapidly.  
The offset had a bigger impact on the maximum table current for the lower bias on-times than for the higher ones. Moreover, the bias on-time had an influence on the ideal offset, meaning the offset with the highest maximum table current. The ideal offset varied between 30 and 60 \(\upmu\)s, with 30 \(\upmu\)s being mostly for a low bias on-time and 60 \(\upmu\)s for a high bias on-time. A low on-time of the bias caused more arcs and less process stability. In addition, at low offsets between 0 and 30 \(\upmu\)s, as well as high offsets between 60 and 80 \(\upmu\)s, most arcs were detected.  
The highest maximum table currents are shown in Table 4.