Hot Filament technology has been used for ionisation enhancement of different PVD technologies like Electron Beam Evaporation (eBE) and Magnetron Sputtering (MS). These applications form part of standard industrial production processes in coatings like eBE TiN and MS DLC.
Regarding large area scalability MS is an attractive PVD technology. However, basic MS processes lack the ionisation required for hard coatings. Therefore, additional technology needs to be utilised to increase MS ionisation. Inductively coupled RF or HIPIMS offer higher plasma densities. Both methods however present challenges when it comes to large area coatings. RF discharges become difficult to control over large areas. Likewise, HIPIMS discharges on large area cathodes present challenges, like peak power delivery ability, arcing control and cabling.
An alternative method for large area systems would be to add hot filament based technology for enhanced ionisation. Although this method could offer a more economic route to large area industrialisation, further control of ionisation enhancement is needed. To achieve reliable results for industrial production, careful design of the deposition system, with integration and control of ionisation enhancement, is required.
The paper presents results on development of a hot filament assisted process that is able to achieve dense, hard coating structures.