2 Magnetron Sputter Ion Plating
(MSIP)
Since the first development of an apparatus for sputtering solids by bombarding particles in a vacuum by Penning in 1936, numerous technological developments and research efforts have driven magnetron sputtering as a coating technology. Approximately 50 years ago, the development of sputtering technology progressed greatly and was characterized by successes in improving deposition rates, process stability, and cost efficiency in the following years. At present, magnetron sputtering is widely known as a reliable and cost-effective coating process that has already become established in numerous industries [8]. The MSIP-PVD process is also known as cathode sputtering and can be used for the deposition of metallic coatings (e.g., Ti, Al, Cr), nitride coatings (e.g., CrAlN, TiAlN, TiN, CrN), or oxide ceramic coatings (e.g., Al2O3, Cr2O3). The coating can also be produced in several layers, in so-called multilayer coatings. The base material for the deposition of a coating is called the target and is fixed onto a target carrier in the deposition source, the magnetron. Here, the target can be a pure solid material or it can be bonded to a copper backing plate. Bonded targets are often preferred when the target material is expensive and, depending on the target material, it can be necessary to use a backing plate, for instance, if the material is brittle. In the magnetron, magnets, cooling, and a current feed-through to the target are present behind the target. The target is also called the cathode because it is connected to the negative pole of the power supply, whereby it is electrically isolated from the rest of the magnetron. The anode of the magnetron is frequently connected to the coating chamber as a reference potential and the combination of a magnetron source with a power supply defines the particular sputtering process. The selection of different power sources for cathode sputtering allows for a large number of different process variations. Proven processes in practice are direct current magnetron sputtering (DCMS), pulsed magnetron sputtering (PMS), and pulsed high current magnetron sputtering (HIPIMS). The DCMS process is well-suited for sputtering metallic target materials. However, by choosing the PMS method with a power source that can be operated with a pulse mode in the range of medium frequencies (e.g., 100 kHz to 350 kHz), even nonconductive target materials (e.g., Al2O3 or SiO2) can be sputtered [9]. The unipolar or bipolar pulsed operation of magnetron sputtering power supplies offers a wide range of variations in parameters by changing the pulse frequency and pulse duty cycle. With regard to the development of new coating processes or the optimization of existing coating systems, this results in a wide range of potential.