Influences of Gap Distance on Plasma Characteristics in Narrow Gap Capacitively Coupled Radio-Frequency Discharge

The narrow gap distance of a parallel plate was studied experimentally to investigate plasma characteristics in a capacitively coupled radio-frequency (RF) discharge. It was revealed that by increasing the gap distance from 1 cm to 4 cm, temperature and density of electrons markedly decreases and increases, respectively. It was also found that RF sheath electric field penetration into the bulk plasma increases with decreasing gap distance so as to sustain the discharge, resulting in an increase in the high-energy component of electron energy distribution.