Real time control of plasma etch utilizing multivariate statistical analysis

摘要

Hotelling's T.sup.2 statistical analysis and control is used to provide multivariate analysis of components of an RF spectra for real time, in-situ control of an ongoing semiconductor process. An algorithm calculates the T.sup.2 value which is then used to generate a feedback signal, if the T.sup.2 value is out of range, to indicate an out-of- tolerance condition.