X-ray Photoelectron Spectroscopy/Electron Spectroscopy for Chemical Analysis (XPS/ESCA)

X-ray Photoelectron Spectroscopy (XPS), also known as Electron Spectroscopy for Chemical Analysis (ESCA), is used to determine quantitative atomic composition and chemistry. It is a surface analysis technique with a sampling volume that extends from the surface to a depth of approximately 50-70 Angstroms. Alternatively, XPS can be utilized for sputter depth profiling to characterize thin films by quantifying matrix-level elements as a function of depth. XPS is an elemental analysis technique that is unique in providing chemical state information of the detected elements, such as distinguishing between sulfate and sulfide forms of the element sulfur. The process works by irradiating a sample with monochromatic x-rays, resulting in the emission of photoelectrons whose energies are characteristic of the elements within the sampling volume.

Evans Analytical Group® (EAG) uses this technique in a variety of applications to help customers, across a range of industries, with R&D, as well as process development/improvement. Examples include:

• Identifying stains and discolorations
• Characterizing cleaning processes
• Analyzing the composition of powders and debris
• Determining contaminant sources
• Examining polymer functionality before and after processing to identify and quantify surface changes
• Measuring lube thickness on hard disks
• Obtaining depth profiles of thin film stacks (both conducting and non-conducting) for matrix level constituents
• Assessing the differences in oxide thickness between samples

These insights into a product’s chemical makeup allow you to make product and process improvements more quickly, enabling you to reduce cycle time and save money.

With EAG, you also have access to the best facilities, instruments, and scientists available for performing an XPS analysis. We handle many different materials from multiple industries, giving us a wide variety of experience. Plus, our person-to-person service ensures that you will receive answers to all of your questions.

View Application Notes

Ideal Uses for XPS Analysis		Relevant Industries for XPS Analysis
Surface analysis of organic and inorganic materials, stains, or residues Determining composition and chemical state information from surfaces Depth profiling for thin film composition Silicon oxynitride thickness and dose measurements Thin film oxide thickness measurements (SiO2, Al2O3 etc.)		Aerospace Automotive Biomedical/biotechnology Compound Semiconductor Data Storage Defense Displays Electronics Industrial Products Lighting Pharmaceutical Photonics Polymer Semiconductor Solar Photovoltaics Telecommunications
Strengths of XPS Analysis		Limitations of XPS Analysis
Chemical state identification on surfaces Identification of all elements except for H and He Quantitative analysis, including chemical state differences between samples Applicable for a wide variety of materials, including insulating samples (paper, plastics, and glass) Depth profiling with matrix-level concentrations  Oxide thickness measurements		Detection limits typically ~ 0.1 at% Smallest analytical area ~10 µm Limited specific organic information Sample compatibility with UHV environment

Application Notes