Patent ID: 7257457
Filing Date: 2007-08-14
Classification: G05B,H01J,H01L

Abstract:
1. A monitoring method comprising the steps of: (a) acquiring from a plasma etching apparatus a plurality of pieces of process data including values of a plurality of process parameters which are obtained while the plasma etching apparatus is in operation; (b) after the step (a), dividing the plurality of pieces of process data for the respective process parameters and for respective steps of a process recipe for operating the plasma etching apparatus; (c) after the step (b), creating a multivariate analysis model using data obtained by dividing the plurality of pieces of process data; (d) after the step (c), obtaining a principal component value from the plurality of pieces of process data which are newly acquired, by using the multivariate analysis model; and (e) after the step (d), determining whether the plasma etching apparatus is in normal operation or abnormal operation using the principal component value, wherein the plurality of pieces of process data includes: a gas pressure and plasma emission voltage in a reaction chamber, a flow rate of helium gas flowing between a lower electrode and a wafer; and powers of a progressive wave and a reflected wave of a high frequency power supplied from a high frequency power supply to the lower electrode.