Surface analysis of realistic semiconductor microstructures

The geometrical and insulating properties of regular arrays of oxide masked silicon trenches formed by reactive ion etching have been utilized to enable in situ x-ray photoelectron spectroscopy of specific parts of the trench structures. Different surface portions of the sample structure are differentiated by using (i) grazing incidence x-ray irradiation which results in shadowing of the trench bottoms and (ii) electrostatic charging of the insulating portions (e.g., the oxide mask) which shifts spectral features. We demonstrate the usefulness of this approach in analyzing the composition of the film passivating the silicon trench sidewall for a SF6/O2 trench etching process. © 1989, American Vacuum Society. All rights reserved.