THE PLASMA MONITORING METHOD AND THE PLASMA MONITORING APPARATUS

摘要

PURPOSE: A plasma monitoring method and an apparatus thereof are provided to monitor chamber wall state and plasma, by measuring spectrum emitted from plasma through the window of the chamber confining the plasma. CONSTITUTION: A chamber including a window and confining plasma is prepared(S100). An optical signal is generated by measuring spectrum emitted from the plasma through the window of the chamber(S200). A reference signal is extracted from the optical signal by considering transmission reduction of the window(S300). Signal variation is extracted using the reference signal and the optical signal(S400). The chamber is controlled by using the signal variation(S500). Reduction rate is calculated by using the temporal variation of the optical signal.