Real-time detection of chamber condition by observing the plasma spectrum intensity

Chamber leakage, transfer shift and particle on lower electrode are the major causes of yield loss during plasma etch process. However, there is still no effective tool for real-time detecting these abnormal chamber conditions. The experiment result demonstrate that the plasma spectrum intensities are strongly correlated to the chamber conditions. One can real-time monitor the chamber conditions by comparing the plasma spectrum intensity with specific control rules. This paper provides an effective method to detect the chamber condition by observing the plasma spectrum intensity.