Surface Analysis (Allentown Lab)

Surface analysis provides comprehensive information about surface topography, texture, chemistry, and bonding to determine the surface properties of materials.

Surface analysis encompasses a wide range of techniques that individually examine specific properties of materials at the surface. These techniques work in conjunction to provide a clear picture of the material at the surface level to assist in research and development, failure analysis, troubleshooting, quality control, and contaminant identification.

Intertek Allentown scientists are experts across a wide breadth of materials and techniques. We work with our customers to understand and help define your surface related problem. We then recommend and execute the appropriate approach to solve the problem. Factors, such as depth, film thickness and lateral resolution needs, are critical in determining the correct analysis technique.

Surface analysis helps you understand how properties, including:

Adhesion (Roughness & Chemistry)
Visual Appearance
Chemical Reactivity
Photodegradation
Wetting
Reflectivity
Electrical and Ionic Transport

Intertek Allentown can help answer your surface questions, such as:

What does the surface look like?
Is surface texture impacting adhesion?
Are there defects on the surface of my material that are affecting surface properties?
Is there phase segregation?
What is the modulus/hardness of my film?
What is the roughness of my surface?
Why is my coating failing?
Is there variation in composition or texture of my treated material?
How thick and uniform is my coating?

The table below shows how various techniques can be used alone or in conjunction with each other to provide a comprehensive surface analysis package.

Technique	Depth	Resolution	Sensitivity	Information
AFM	2-3nm	5nm spatial, sub-nm vertical	0.05 nm vertical	Structural, Chemical, Mechanical
Optical Profiling	2-3nm	500 nm spatial, sub-nm vertical	~0.5 nm vertical	Structural
SEM & SEM/EDS	20nm SEM – 1,000 nm SEM/EDS	2nm spatial	1% for EDS	Structural, Elemental
Nanoindentation	Up to 1,000 nm	0.0002nm displacement resolution	-	Mechanical
XPS	3-5 nm, up to 1,000 nm with SDP	9 µm spatial	0.1 – 1%	Elemental, Chemical
TOF – SIMS	2-3 nm	1-3 monolayers depth, 400 nm spatial	Sub-monolayer	Elemental, Chemical
XRR	Min layer thickness of ~100 Å	~ 1% of thickness	-	Density, Thickness, Interfacial Roughness

Topography and surface texture, material structure

Atomic Force Microscopy (AFM) – A sharp tip (usually nm radius) is scanned across a material in a raster pattern to create a three-dimension map of surface heights and other material properties (such as stiffness, electrical). Measurement of surface heights allows for determination of surface roughness, identification of surface defects, and measurement of surface profiles. Surface imaging is to near atomic resolution, measuring atomic level forces at the sample surface.

Stylus Profilometry – A sharp probe tip is scanned across a material in a linear fashion to create a line profile of height vs distance. With this technique, we can obtain a general understanding of a material’s surface texture. Challenges do occur if the material is soft, or if higher spatial resolution is required.

Scanning White Light Interferometry – A broadband source illuminates a surface rather than a physical probe touching a surface as with stylus profilometry. With the technique, we can obtain three-dimensional maps of the surface structure. These maps help us to understand properties such as defects, dimension analysis, and roughness – properties that can be linked to material performance.

Scanning Electron Microscopy (SEM) – SEM services are used to study surfaces and particles, targeting failure analysis of components, visualization of texture and morphology, or contamination of materials or chemicals.

Surface chemistry and composition, material composition

X-ray Photoelectron Spectroscopy (XPS) – XPS analysis is used to study surface chemistry of thin films, residues, and surface defects to provide quantitative elemental composition information and the chemical states of components.

Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS) - A technique for molecular identification of materials based on their mass.

X-Ray Reflectance (XRR) – A technique where x-rays are reflected off a flat sample to generate an interference pattern from which layer thickness and density can be determined. This technique is dependent on knowing the composition of a thin film.