Dominik Metzler, Robert L. Bruce, et al.
JVSTA
Paper
Grazing angle optical emission interferometry for end-point detection
Abstract
Light emitted from a plasma during reactive ion etching and reflected by the wafer surface at a grazing angle is utilized to determine the remaining film thickness with an accuracy of ±30 Å. This promises a more flexible etching approach, e.g., tailoring the final stage of etching to minimize lattice damage.