Comments on the Langmuir probe measurements of radio-frequency capacitive argon-hydrogen mixture discharge at low pressure

Abstract

In this paper, the current-voltage graphs of discharge in the chamber of capacitive coupled radio frequency (CCRF) at low pressure were presented for Langmuir probe. The Langmuir probe measurements for estimating the electron density and temperature in capacitive coupled discharges at low pressures were presented and the electron temperatures of the Ar-H-2 mixture discharge generated at different conditions were reported using the Langmuir probe. The focus of this study is that the CCRF discharge can be determined and explained using the characteristics of plasma by means of Langmuir probe measurements for the different hydrogen rates in Ar-H-2 mixture discharge. The measurement results of Langmuir probe gave values around 10(15) m(-3) for the electron density. The floating potential depended on the electronegative gas amount. It was found that the increase of hydrogen gas amount in the mixture discharge caused the decrease of the floating potential. Also, a decrease in the argon (Ar) metastable with the increase in hydrogen (H-2) content was obtained. When the applied radio frequency (RF) power was increased, the thickness and collisionless sheath occurring at lower RF power could transform to thin sheath.