Easy-to-use detection method for micro-arc discharge in plasma etching equipment by measuring current flowing to ground

A simple monitoring method for micro-arc discharge in plasma etching process has been developed. This method employs a current transformer, a Rogowski coil, which is externally attached to encircle a ground lead of a process chamber in plasma etching equipment without touching the lead. The results in this study demonstrate that this method can monitor the current flowing to ground, which reflects load current, and can detect microarc discharge occurring in plasma etching process. This easy-to-use, noncontact, and inexpensive method can contribute to improving the overall equipment effectiveness and the production yield in the wafer process in the mass production of LSI. (C) 2018 The Japan Society of Applied Physics