Is there a way to improve the uniformity of TiN deposition conditions in large pulsed d. c. plasma CVD reactors?

摘要

Recent investigations of the dynamics of pulsed direct-current discharges relevant for the production of titanium nitride coatings by plasma-assisted chemical vapor deposition in large reactors have shown that,when titanium tetrachloride is used as a feed stock gas, the spreading of the discharge is slow, reaching some parts of the reactor with substantial delay. The result is a non-uniform plasma power density in front of the substrates as well as a spatially varying exposure time of the surface to the plasma. These problems can be solved by measures, which increase the conductivity of the plasma at the beginning of the pulses. One way to achieve this goal is the use of synchronized additional short high-voltage pulses. The present study investigates the dependence of the evolution of the discharge on parameters of the additional short high-voltage pulses.