Recent developments in plasma assisted physical vapour deposition

Recent developments in plasma assisted physical vapour deposition (PAPVD) p rocesses an reviewed. A short section on milestones in advances in PAPVD co vering the time period from 1938 when the first PAPVD system was patented t o the end of the 1980s is followed by a more detailed discussion of some mo re recent advances, most of which have been related to increases in plasma density. It has been demonstrated that the state of the art PAPVD processes operate in a plasma density range of 10(11) to 10(13) cm(-3). In this rang e a substantial fraction of the plasma consists of ionized film forming spe cies. Hence, the energy of the condensing film forming species can be direc tly controlled, as opposed to utilizing indirect energy control with, for e xample, ionized inert gas bombardment. For a large variety of applications ranging from ceramic film synthesis at conditions far from thermodynamic eq uilibrium to state of the art metallization technology, such direct energy control of the condensing film forming species is of critical importance, a nd offers the possibility to engineer the coating microstructure and hence the coating properties.