Detection of interfaces with atomic resolution during material processing by optical second harmonic generation

摘要

A technique for observing optical second harmonic generation effect at a surface of a material during processing thereof, particularly in the presence of a plasma, for controlling the processing of the material. A preferred form of the apparatus and method includes a combination of spectral, spatial, polarization and temporal filtering to allow observation of optical second harmonic generation and control of processing of the material with processes such as reactive ion etching to a high degree of resolution.