Energy Distribution Functions of Ions Impacted on a Negatively Biased Substrate in an Electron Cyclotron Resonance Microwave Plasma

Publisher Website
Google Scholar
Abstract
Impacted ion energy distribution functions (IIEDFs) in Ar electron cycltron resonance(ECR) microwave plasma have been measured on a substrate biased negatively using a conventional retarding grid analyzer. With an increasing ion-neutral elastic collision probability, the IIEDFs were found to spread toward the low-energy side, forming two peaks. At the high collision probability (> 80 %) realized at high biased-voltage and gas pressure, the lower-energy ions formed higher peaks than the higher-energy ones. This result was caused by the charge-exchange collision. The impacted ion temperature estimated from the semilog plot of the analyzer current-voltage characteristics was roughly constant (≃ 0.6 eV) for collision probability < 80%.