Analysis of the Characteristics of Radio Frequency Power Transmission Lines Using a Voltage Current Probe in Low-Pressure Discharge

Abstract

As a radio frequency (RF) power and plasma process monitoring sensor, a voltage current (VI) probe has been utilized and developed to monitor and optimize plasma processes in semiconductor fabrication. However, many components are needed to deliver the RF power from the power supply to the plasma electrodes such as an RF connector and RF cable which affect the RF power transmission efficiency. Therefore, it is necessary to analyze the characteristics of RF power transmission lines with respect to the external parameter configuration using a VI probe. In this study, we investigated the characteristics of RF signals using a VI probe for various RF power transmission lines, including the VI probe installation position, RF connector type, and RF cable length. The RF signals were measured as a function of the input power in a lowpressure argon discharge. Consequently, the RF power loss was significant when long RF cables were used for the transmission line. Analyzing the characteristics of RF transmission lines using a VI probe can improve the reliability of RF measurement properties for plasma processing applications.