Heat flux into the substrate and electric power measurement in radio frequency discharge plasma

Abstract

SUMMARYWe performed measurements of the radio frequency power and temperature of electrodes and plasma parameters of rf discharge. The purpose of this research is to check the accuracy of the measurement of energy consumed in plasmas. The heat energy in plasma was obtained by heat flux that was calculated from substrate temperature. The temperature was measured by a laser interferometer using LiNbO 3 crystals. In the case of electrode spacings of 2, 3, and 4 cm, the heat energy toward electrodes was 7.7, 5.4, and 4.0 W, respectively. The current and voltage measurement was made at the driven electrode. The input power was 8.2, 5.1, and 7.7 W for electrode spacings of 2, 3, and 4 cm, respectively. The heat energy calculation based on the electron density distribution measured was conducted by estimating the Bohm flux and ambipolar diffusion flux. It was found that the heat energy toward electrodes was 1.4, 1.8, and 1.5 W for electrode spacings of 2, 3, and 4 cm, respectively, and the heat toward the wall was negligible.

Measurement of Heat Flux Applied from Atmospheric Pressure Plasma Jets to Substrate Using a LiNbO₃ Laser Interferometer

“…However, it is difficult to directly obtain the energy input from an ARRJ to a substrate. To obtain the energy input directly, one can use a laser interferometer using birefringence of Litiumniobate (LiNbO 3 ), which is a temperature measurement method for obtaining the heat flux from the APPJ to the substrate [1,2].…”