Answers are grounded in this paper and cite their sources.
A principal component analysis (PCA) of plasma-generated harmonics monitored using a non-invasive ex-situ probe is reported. PCA trends due to gas pressure and RF power were demonstrated. Changes in harmonic levels during photoresist stripping have also been detected and were analysed with PCA to provide process end-point detection.
No takes yet. Share an insight, caveat, or question.
Koh et al. (1999) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: