Co-Authors:
Avni, R., Nuclear Research Cent-Negev, Beer Sheva, Isr, Nuclear Research Cent-Negev, Beer Sheva, Isr
Carmi, U., Nuclear Research Cent-Negev, Beer Sheva, Isr, Nuclear Research Cent-Negev, Beer Sheva, Isr
Rosenthal, I., Nuclear Research Cent-Negev, Beer Sheva, Isr, Nuclear Research Cent-Negev, Beer Sheva, Isr
Inspektor, A., Nuclear Research Cent-Negev, Beer Sheva, Isr, Nuclear Research Cent-Negev, Beer Sheva, Isr
Abstract:
Hydrocarbons such as CH//4 or C//3H//6, and chlorosilanes such as SiCl//4 or SiHCl//3 in concentrations of 3-10 v/o introduced into a microwave (2. 45 GHz) plasma of Ar or mixtures of Ar plus H//2, at low pressures (1-10 Torr) results with the formation of solid carbon (pyro-carbon) or silicon, respectively. In the plasma state, both hydrocarbons and chlorosilanes, polymerize to CxHy and Si//xHy forms with x greater than 1 and x greater than y. It was found that the polymerization process, in the Ar (without H//2) microwave plasma was mainly propagated by an ion-molecule mechanism, while additions of H//2 (6-20 v/o) to the Ar plasma propagates the polymerization mainly by a radical mechanism. The two mechanisms were determined by sampling the microwave plasmas with a quadrupole mass spectrometer (QMS), by indirect measurement of the plasmas free radicals concentration by an electron paramagnetic resonance (EPR) spectrometer and by measuring the deposition rate of pyrocarbon and silicon substrates floated, grounded or biased to minus 100 volts.