In-Situ Detection Method of Abnormal Plasma Discharge in Plasma-Assisted Deposition Processes

Arc is an abnormal discharge in a plasma-processing chamber that results in high current discharge marks and particles on wafers. However, it is difficult to identify or observe it during an ongoing process. In this study, we report on the observations of plasma arcs during various plasma processes through a non-invasive optical plasma monitoring system devised for the in situ detection of abnormal discharge. The employed optical monitoring based arc detection system provides valuable indications of particle generation resulting from a charge imbalance in the chamber. The devised non-invasive and real-time method can detect such disturbances down to the order of tens of microseconds. Successful monitoring of arcs that appear in various types of plasma-assisted deposition processes are presented in this paper. We also present examples of detected arcs in various plasma processes, such as plasma-enhanced chemical vapor deposition, high density plasma-chemical vapor deposition, amorphous carbon layer deposition, and plasma-enhanced atomic layer deposition. The suggested method plays an important role for the next level of arc-detection research and plasma diagnostics applications. © 2018, The Korean Institute of Electrical and Electronic Material Engineers.