Patent ID: 7341644
Filing Date: 2008-03-11
Classification: H01J,H01L

Abstract:
1. A method for predicting the consumed degree of a consumable supply for use in a processing system for carrying out a predetermined processing for a processing object with plasma which is produced from a process gas by applying a high-frequency power, said method comprising the steps of: measuring a plurality of electric data, which vary in accordance with the consumed degree of a consumable supply, with elapsed time; and using the measured electric data to carry out a multivariate analysis to predict said consumed degree; wherein said consumable supply is a focus ring, and said consumed degree is based on the thickness of said consumable supply, and said step of carrying out the multivariate analysis to predict the consumed degree comprises carrying out a multiple regression analysis to predict the consumed degree; wherein the voltages and currents of a fundamental wave and waves having frequencies integer times as many as that of the fundamental wave between a matching circuit in a high-frequency power supply line and a processing chamber are used as said electric data; wherein the said fundamental and waves having frequencies integer times as many as that of the fundamental wave are of four kinds of high-frequency waves including said fundamental wave and its double, triple and quadruple waves.