Analysis of chlorine-containing plasmas applied in III/V semiconductor processing

Capacitively coupled discharges of strongly reactive atmospheres containing mixtures of boron trichloride and chlorine are investigated with optical e mission spectroscopy and self-excited electron resonance spectroscopy. This analyzes the whole area spanned by these gases and their impact on importa nt plasma parameters like plasma density, electron temperature, and electro n collision rate with neutrals. Using these data, roughly calculated cross sections for these gases are obtained in the low-energy region. Molecular c hlorine ions, Cl-2(+), are evidently present to a preponderant amount as a main agent, which are accompanied by chlorine radicals, CI(I), in mixtures with chlorine. Absolutely no chlorine ions could be found in the plasma whi ch referred to the effective cooling of the Cl-containing species rather th an the nonexistence of these species. (C) 2000 American Vacuum Society.