Pressure and helium mixing effects on plasma parameters in temperature control using a grid system

Pressure and He mixing effects on plasma parameters in electron temperature control using a grid system are investigated. Electron temperature is high er in lower pressure, when the electron temperature is high and not control led. Electron density can be increased by about three times by decreasing t he source gas pressure from 20 to 1 mTorr, and by about two times by He mix ing in the temperature controlled region (diffusion region), while the elec tron density is decreased in the source region. This electron density incre ase is mainly due to the increase of the high energy electron population, a nd the measured electron energy distribution functions clearly show this. ( C) 2001 American Institute of Physics.