Issues in magnetron sputtering of hard coatings

Magnetron sputtering has been used for the deposition of hard coatings for some years, and the technology can produce a wide range of excellent hard materials. However, the machines available do not seem to provide as high a quality coating as the low voltage electron beam chambers. The limits to the performance of the coatings are set not by poor coating properties, but by the lack of control of other aspects of the coating technology. Areas which should be explored are the cleaning of the substrates and adhesion, the role of support layers, the control of temperature, and reducing the number of particulates. One way to improve the quality would be to use smaller chambers, with equal or similarly sired tools located in equivalent positions, but this may push up costs.