A SIMPLE ION FLUX ESTIMATION IN A LOW-PRESSURE RF PLASMA (13.56 MHZ)

A new application of the sputtering rate measurement is given in this paper. In fact, by measuring the sputtering rate of different material s fixed on the radio frequency (r.f.) biased electrode, it is possible to determine easily ion flux that falls onto this biased electrode. T his study is realized in a low pressure (0.4 Pa) argon planar r.f. dis charge system (13.56 MHz). This sputtering method is interesting to ha ve informations about the deposition process in physical vapour deposi tion. In order to demonstrate the validity of this method, experiments have been carried out in two reactors, each one with different geomet rical parameters and the results obtained have been compared and confi rmed using the Child-Langmuir law. The ion flux increases as a functio n of the incident r.f. power (0-300 W). The values obtained range from 10(18) to 10(19) ions m(-2) s(-1). These results in an argon plasma a re applied to estimate incident ion flux in a nitrogen atmosphere. Fin ally, we show that it is possible to evaluate the incident ion flux by measuring the sputtering rate when the plasma is densified using eith er an auxiliary hot cathode discharge or an additional magnetic field. These experimental cases correspond respectively to r.f. triode ion p lating or r.f. magnetron sputtering.