Detection of monolayer quantities of oxygen on silicon using energy-dispersive x-ray spectrometry

Abstract
The sensitivity of energy‐dispersive x‐ray spectrometry (EDXS) has been determined for the detection of oxygen in thin oxides on silicon. A detection limit of about one monolayer by EDXS was within a factor of 10 of that detected by Auger electron spectroscopy under the analysis conditions employed (i.e., 150 nA of 5‐keV electrons for 60 s). Measurements, including in situ sputter‐thinning of an oxide of known thickness, were performed in a standard Auger system with an ultrathin‐windowed Si(Li) x‐ray detector attached. A linear relationship between the oxide thickness and the O(K) x ray intensity was found for thicknesses up to 200 Å. Optimization of the EDXS arrangement by improving the solid angle for x‐ray detection and the x‐ray takeoff angle should improve the sensitivity for oxygen and other elements with atomic number Z⩾6.

This publication has 3 references indexed in Scilit: