RESOLUTION CAPABILITIES OF CHROMATIC SENSING IN THE MONITORING OF SEMICONDUCTOR PLASMA PROCESSING SYSTEMS

An on-line monitoring system for semiconductor plasma processing systems, based on the chromatic monitoring of the emission spectra of a plasma has been developed. The system offers low cost operation, lack of interference with the processing plasma and a fast response. Previous work has shown that the chromatic signature is a good indicator of the quality of the final product. In this contribution an analysis of the signal-to-noise performance of the chromatic system is presented. It is shown that chromatic systems, because of their integrative nature, offer a higher signal-to-noise ratio than comparable optical systems. These results provide further evidence that the chromatic monitoring is suitable for on-line control of plasma processing systems.