SPECTROSCOPIC STUDIES OF A MAGNETRON SPUTTERING DISCHARGE FOR BORON-NITRIDE DEPOSITION

Magnetron sputtering discharges for the deposition of cubic boron nitr ide have been investigated using optical emission spectroscopy and Lan gmuir double probes. Spatially resolved measurements revealed the inho mogeneous discharge structure with respect to the distribution of exci ted species, electron density and electron temperature. The optical em ission spectra were analysed by means of the corona model. The vibrati onal excitation of the nitrogen molecule was examined. The ratio of se lected Ar and N-2 emission intensities provided a qualitative measure of the electron temperature, which was determined by probe measurement s. However. the intensity ratios of Ar and Ar+ lines did not correspon d to changes in electron temperature. Varying the electron density in a wide range, it could be demonstrated that the excitation mechanisms do not remain constant, mainly due to multistep excitation. The vibrat ional temperature of N-2 (C-3 Pi(u)) has been found to be much higher in the case of r.f. sputtering than in the d.c. mode. (C) 1998 Elsevie r Science S.A.