Real-Time Plasma Uniformity Measurement Technique Using Optical Emission Spectroscopy With Revolving Module

A measurement technique for analyzing real-time plasma abnormality using optical emission spectroscopy (OES) is proposed to detect process uniformity during semiconductor processing. Among many measurement techniques, OES is a non-contact plasma measurement system for detecting process end points and plasma abnormality without influencing the process. Thus, this system can be widely used and utilized essentially in almost all tools for plasma processing. Despite easy installation and high utilization in plasma manufacturing tools, most OES systems are not able to detect real-time plasma uniformity. Therefore, the improved OES systems are required to overcome the limitations. In this paper, the measurement technique of the plasma light intensity in the left and right sides of a process chamber by a revolving module adapted to conventional OES in real time is investigated. This technique can be used to measure the plasma light in specific regions in the process chamber and detect real-time plasma process abnormalities by comparing light intensities from different regions.