Comparison of the radio frequency hollow cathode to the microwave antenna discharge for plasma processing

Two nonconventional systems, the radio frequency hollow cathode discharge ( RHCD) and the microwave antenna discharge (MWAD), with almost identical geo metry of electrodes generating a nitrogen plasma at power level up to 60 W were compared. Both systems were used for deposition of nitride films at si milar experimental parameters. The Al-N films were deposited in the RHCD sy stem by reactive physical vapor deposition (PVD) using an Al radio frequenc y hollow cathode and the CNx films were deposited in the MWAD system by pla sma activated chemical vapor deposition (PACVD) from N-2+1% (alternatively 0.5% or 0.4%) C2H2 gas mixtures. The vibrational temperatures of nitrogen m olecules in both systems were compared as functions of experimental paramet ers and discussed with respect to the film growth rates in the particular s ystems. It was found that irrespective of frequency difference of two order s of magnitude the vibrational temperatures of nitrogen molecules were simi lar, between 3000 and 4600 K, in both systems at similar experimental condi tions. However, shapes of dependences of the vibrational temperature on par ticular parameters were different, due to different plasma generation princ iples. The nitride film growth rates were found to correlate to the vibrati onal temperatures of nitrogen molecules, but their dependences on experimen tal parameters were affected by specific features of the plasma generation in individual systems as well as by different mechanisms of the PVD and the PACVD of films. (C) 2001 American Institute of Physics.