Measure the very top surface chemistry (1-12 nm) of any material
X-ray photoelectron spectroscopy (XPS) is a quantitative spectroscopic technique that measures elemental composition, empirical formula, chemical state and electronic state of the elements that exist within a material. XPS spectra are obtained by irradiating a material with a beam of X-rays while simultaneously measuring the kinetic energy and number of electrons that escape from the top 1 to 12 nm of the material being analyzed. XPS requires ultra-high vacuum (UHV) conditions.
XPS is a surface chemical analysis technique that can be used to analyze the surface chemistry of a material in its’ “as received” state, or after some treatment, for example: fracturing, cutting or scraping in air or UHV to expose the bulk chemistry, ion beam etching to clean off some of the surface contamination, exposure to heat to study the changes due to heating, exposure to reactive gases or solutions, exposure to ion beam implant, exposure to ultraviolet light.
- XPS is also known as ESCA, an abbreviation for “electron spectroscopy for chemical analysis” introduced by Kai Siegbahn and his research group.
- Detection limits for most of the elements are in the parts per thousand range (1,000 PPM). Detection limits of parts per million (ppm) are possible, but require special conditions: concentration at top surface or very long collection time (5 hr).
- XPS is routinely used to analyze inorganic compounds, metal alloys, semiconductors, polymers, elements, catalysts, glasses, ceramics,
paints, papers, inks, woods, plant parts, make-up, teeth, bones, medical implants, bio-materials, viscous oils, glues, ion modified materials and many others.
XPS is used to measure:
- elemental composition of the surface (top 1–10 nm usually)
- empirical formula of pure materials
- elements that contaminate a surface
- chemical or electronic state of each element in the surface
- uniformity of elemental composition across the top surface (or line profiling
- uniformity of elemental composition as a function of ion beam etching (or
Wide-scan survey spectrum for all elements.
High-energy resolution spectrum for Si(2p) signal.
Rough schematic of XPS physics – “Photoelectric Effect“
60×60 mm Sample Mount with Samples