A study of plasma parameters in a BAI 730 M triode ion plating system by means of a Langmuir probe and plasma mass and energy spectroscopy

The plasma in a physical vapor deposition (PVD) system used for the deposit ion of hard coatings (TiN, CrN) was studied by means of a Langmuir probe an d energy resolved spectroscopy (Balzers plasma process monitor PPM 421). I- V measurements gave the plasma (U-pl) and floating (U-fl) potentials, as we ll as the electron temperature T-e and plasma density n(i). U-pl deduced fr om I-V measurements agreed well with the peak of the positive ion energy di stribution, as well as with the highest positive potential for the given op erational mode. Energy spectra measured in deposition of TiN show a high de gree of ionization of Ti, with Ti2+ as the prevalent ion. T-e calculated fr om the Maxwellian distribution for the standard deposition of TiN is rather high (T-e = 6-8 eV). We believe that the oscillations of the plasma potent ial with the measured amplitude up to 15 V are most probably the reason. Th e electron energy distribution F(E) is better described by the Druyvesteyn distribution one than by a Maxwellian one. (C) 2001 Elsevier Science B.V. A ll rights reserved.