within the discharge chamber []. Another alternative method to improve the ionisation efficiency is to employ a series of grids which serve to hinder the electrons from being attracted into the output ion beams []. Electromagnetically Steered Cathodic Arc Evaporation Cathodic arc evaporation (CAE) is a technique which creates a and low-voltage arc discharge over the surface of a conductive cathode (i.e. the target) in a vacuum environment. The cathode material is then evaporated as a fully ionised plasma and is in turn deposited onto the substrate [, ]. The main advantages of the CAE process are the capability of achieving a high degree of ionisation and high ion energies. The position where the arc discharge occurs at high current density is called the cathode spot [, ]. The performance of CAE can be improved by making use of a steering variable magnetic field, where an electromagnetic coil is applied to steer the arc spot motion. For this process, the manipulation procedure avoids overheating of the cathode spot, ensures uniform erosion and resuces the size/numberof metal droplets incorporated into vapour flux [, ]. These so-called are commonly found with a size range “macrodroplets” of 0.1-10 [, ]. If the emitted macrodroplets adhere to the growing film, μm it will lead to surface roughening, degradation of compositional uniformity and may consequently lead to exfoliation of the film []. Various measures have been developed to prevent the droplets from reaching the substrate. Generally, two main methods are available. The simpler one is to put a superconductor shield in front of the substrate which physically blocks the incident neutral macrodroplets. The
within the discharge chamber []. Another alternative method to improve the ionisation efficiency is to employ a series of grids which serve to hinder the electrons from being attracted into the output ion beams []. Electromagnetically Steered Cathodic Arc Evaporation Cathodic arc evaporation (CAE) is a technique which creates a and low-voltage arc discharge over the surface of a conductive cathode (i.e. the target) in a vacuum environment. The cathode material is then evaporated as a fully ionised plasma and is in turn deposited onto the substrate [, ]. The main advantages of the CAE process are the capability of achieving a high degree of ionisation and high ion energies. The position where the arc discharge occurs at high current density is called the cathode spot [, ]. The performance of CAE can be improved by making use of a steering variable magnetic field, where an electromagnetic coil is applied to steer the arc spot motion. For this process, the manipulation procedure avoids overheating of the cathode spot, ensures uniform erosion and resuces the size/numberof metal droplets incorporated into vapour flux [, ]. These so-called “macrodroplets” are commonly found with a size range of 0.1-10 μm [, ]. If the emitted macrodroplets adhere to the growing film, it will lead to surface roughening, degradation of compositional uniformity and may consequently lead to exfoliation of the film []. Various measures have been developed to prevent the droplets from reaching the substrate. Generally, two main methods are available. The simpler one is to put a superconductor shield in front of the substrate which physically blocks the incident neutral macrodroplets. The
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