Characterization of Ultrathin Silicon-Oxynitride Films Using Grazing Incidence X-Ray
E Landree, Terrence J. Jach
This work describes the use of Grazing Incidence X-ray Photoemission Spectroscopy (GIXPS) to characterize the thickness of a silicon oxynitride ultrathin film. GIXPS utilizes the inherent optical and material properties of the film, along with the angle of the incident X-rays with respect to the sample surface to control the electric field penetration into the sample. By adjusting the angle of incident X-rays form zero to some value slightly greater than the angle for total X-ray external reflection, it is possible to nondestructively probe the nature of the film depth profile. The resulting angle dependent photoemission spectrum contains information that describes the physical properties of the sample, including density and thickness. Two different models for the oxynitride film profile were used as a starting point for a normalized least squares refinement comparing he measured angle dependent photoemission yield and the calculated photoemission yield. Both models produced potential solutions that were consistent with previous measurements of the total film thickness.