Influence of dcMS and HPPMS in a dcMS/HPPMS hybrid process on plasma and coating properties

Abstract

Within the physical vapor deposition (PVD) high power pulse magnetron sputtering (HPPMS) or high power impulse magnetron sputtering (HiPIMS) is a frequently studied technology in the last years. HPPMS offers the possibility to produce coatings with lower roughness, denser microstructure and better mechanical properties in comparison to direct current magnetron sputtering (dcMS). However, HPPMS is known to have much lower deposition rate due to the low duty cycle compared to dcMS. Therefore, from an economic point of view, dcMS is more effective compared to the HPPMS technology. An approach to overcome this issue is the dcMS/HPPMS hybrid technology, whereby dcMS and HPPMS cathodes are used simultaneously to combine the benefits of both technologies. In hybrid processes, the influence of dcMS and HPPMS on the plasma and coating properties is of crucial interest. Therefore, in the present work measurements on plasma properties as well as on coating properties using dcMS, dcMS/HPPMS hybrid and HPPMS (Cr,Al)N processes were carried out. The (Cr,Al)N coating system as well as the utilized steel substrates were chosen to address the application in plastics processing. In the first step of this work the plasmas of dcMS, dcMS/HPPMS hybrid and HPPMS processes were analyzed. Dependancies of the plasma properties on the type of the process as well as the pulse parameters such as the pulse length ton and the frequency f were investigated. The most significant influence was identified depending on the process type. In the second step (Cr,Al)N coatings were produced using the same process parameters. A similar behavior as with the plasma properties was observed for the coating properties. In the third step the measurements of the plasma and coating properties were correlated. It was proven that changes in the plasma and coating properties correlate significantly. Therefore, the coating development can be simplified through prediction of the coating properties with the more efficient plasma diagnostics.