On the dynamics of unipolar and bipolar pulsed d.c. discharges used for plasma CVD

摘要: Abstract Investigations of the development discharges relevant for production titanium nitride (TiN) coatings using tetrachloride (TiCl 4 ) as a feedstock gas have shown that under certain loading conditions spreading discharge during pulse is too slow. Recently, we demonstrated ignition and behaviour can be very much improved by superposition short high voltage pulses at beginning each conventional pulse. However, an extra power supply needed. In present work investigate another possibility to get better performance discharge, bipolar operation supply. Discharge current measurements video observations reveal this mode negative durations positive least 50 μs. The reason might end pulse-off time which follows after more powerful charge carriers remain hence, density should enough allow