Surface roughness, waviness, and shape induced effects in angle‐resolved XPS

Abstract

The experimentally determined topographies of engineering surfaces are decomposed using multiresolution analysis to better understand the impact of surface roughness on angle-resolved XPS. Multiresolution analysis is a powerful mathematical tool based on wavelets, which allows one to unambiguously distinguish between the roughness, waviness, and shape of any engineering surface. Exploiting exactly these features, here the separate effects of roughness, waviness, and shape on angleresolved XPS are computationally investigated in the case of some engineering surfaces by locally (almost pointwise) applying the Beer-Lambert law at various levels of resolution.

Numerical approximation of AR-XPS spectra for rough surfaces considering the effect of electron shadowing

“…As a continuation of the work published by Katona et al . and Bianchi et al ., where BLL was combined with a nonuniform rational B‐spline (NURBS) description of a given topography and thus for the spatially resolved surface normals, here, the numerical scheme for the shadowing of the electrons is explicitly described in analogy with Bianchi et al . In contrast with Katona et al .…”

“…In contrast with Katona et al . and Bianchi et al ., in this work, a first‐order NURBS surface is considered that corresponds to a facet approximation to the rough surface. In addition, BLL is further extended.…”

Through‐layer XPS investigations of the Si3N4/AlGaN interface

“…Hence, a cleavage of bonds and intermixing of atoms in this thickness prohibits accurate analysis after sputtering. In addition, the surface roughness increases, which causes additional accuracy problems during measurement . Additional AES analysis (not shown) demonstrates that already 3 at.% Ar appear in the spectrum after only 0.25 min of sputtering.…”