Two separate modeling approaches are shown to be able to estimate the spatially local end point time distribution of a plasma etch, from nonochromatic emission data, before the etch is complete. The distribution can be used to determine optimum stop-etch time.
R. Russell Rhinehart,
"On-line optimization of stop-etch time", Proc. SPIE 2091, Microelectronic Processes, Sensors, and Controls, (15 February 1994); doi: 10.1117/12.167361; https://doi.org/10.1117/12.167361