COMPARISON OF ELECTRON-CYCLOTRON-RESONANCE AND RADIOFREQUENCY INDUCTIVELY-COUPLED PLASMAS OF AR AND N-2 - NEUTRAL KINETIC ENERGIES AND SOURCE GAS CRACKING

Neutral mean kinetic energies and the amount of neutral source gas cra cking of particles emanating from an electron cyclotron resonance (ECR ) plasma source and a radio-frequency inductively coupled plasma (ICP) source are compared as a function of applied power by modulated beam time-of-flight analysis for Ar and N-2 gases. For both sources, the so urce chamber is maintained at 0.07 Pa by a constant flow of either Ar or N-2, while the applied power is varied from 50 to 250 W and from 50 to 550 W for the ECR and the ICP sources, respectively. For the Ar pl asmas, the neutral Ar mean kinetic energies are similar and range betw een 0.07 and 0.15 eV, with the ICP being somewhat higher. In the case of the N-2 plasmas, the ICP mean energies are also somewhat higher tha n those found for the ECR source. The mean energies range between 0.02 and 0.26 eV and 0.02 and 0.40 eV for the N-2 and N species, respectiv ely. The N:N-2 flux ratio for the ICP source increases to a plateau of approximately 0.021 +/- 0.002 after an applied power of 250 W is reac hed, while for the ECR plasmas, the N:N-2 flux ratio varies in a more complex fashion with a much higher value of 0.17 +/- 0.04. (C) 1998 Am erican Institute of Physics.