Abstract

Surface analysis is the study of the atoms at surfaces and their connectivity, including their relative depth distribution, concentration, chemical state, and crystallinity. These characteristics govern many important material properties. X-ray photoelectron spectroscopy (XPS) is one of the most widely used surface analysis techniques. Proper interpretation of XPS spectra including the appropriate use of backgrounds, peak shapes, peak positions, and charge compensation, with appropriate constraints on fitting parameters provide valuable information about elemental composition, concentration, depth distribution, and chemical speciation of surface atoms. However, despite widespread use, much of the XPS literature contains poor interpretations and irreproducible results which undermine the potential of XPS. Herein, I introduce XPS, highlight common errors in analysis, clarify terminology, analyze the reporting practices of the Near Ambient Pressure-XPS (or NAP-XPS) community, and discuss background features. In addition, pioneers in the field who were interviewed provide historical perspective and insights into best practices moving forward. Low Energy Ion Scattering (LEIS) is a complementary surface analysis technique that provides information about the outermost atomic layer of a material. Although relatively new, LEIS is experiencing rapid growth. To aid new users in spectral interpretation, we present a practical guide to interpreting LEIS spectra, providing ample spectra of various samples, and walk through important features and phenomenon. The interpretation of XPS and LEIS spectra remains a challenge for many researchers. We also explore the cause of various background phenomena in both techniques. These include abnormalities in spectra that are not accompanied by zero-loss photoemission or surface peaks. These are the result of buried atoms just below the sampling depth of each respective technique. Data smoothing reduces noise while preserving key features. Savitzky-Golay smoothing, a widely used method, fits a polynomial to a moving window using a pre-defined convolution matrix, effectively performing a least-squares fit. This approach minimizes distortion of peaks and critical features and will be explored in detail in subsequent chapters. Finally, I include several publications showcasing the diverse applications of spectroscopic ellipsometry, with applications for porous and ALD films.

Degree

PhD

College and Department

Chemistry and Biochemistry; Computational, Mathematical, and Physical Sciences

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2026-01-21

Document Type

Dissertation

Keywords

X-ray photoelectron spectroscopy, Low energy ion scattering, spectroscopic ellipsometry, atomic layer deposition, common errors.

Language

english

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