Patent ID: 7147747
Filing Date: 2006-12-12
Classification: G01N,H01J,H01L,H05H

Abstract:
1. A plasma processing apparatus having a process chamber in which substrates are subjected to plasma processing in lots comprising; a light-receiving part for monitoring a plasma emission in said process chamber; a spectrometer unit for performing a spectrometry on said plasma emission and to convert the same into a multi-channel signal; an arithmetic unit for performing principal component analysis on the multi-channel signal for each substrate to obtain an average of principal component scores (P a database for storing a filter vector for obtaining the principal component scores; first means to determine a difference (D second means to determine an average, a difference of minimum and maximum, and a standard deviation of (D third means to compare the average, the difference of minimum and maximum, and the standard deviation, as determined, with preset thresholds to determine an end point of seasoning; and a controller for controlling an operation of said plasma processing apparatus.