Advancing XPS Depth Profiling with the Hypulse Surface Analysis System

Expanding the capabilities of XPS surface analysis

As materials become more complex and functionally engineered, accurate surface and interface characterization has become essential to modern materials research. X-ray photoelectron spectroscopy (XPS) provides detailed information about elemental composition, chemical state, and electronic structure at material surfaces. However, many applications, such as thin films, advanced coatings, and hybrid materials, require compositional information beyond the first few nanometers of depth.

The Thermo Scientific Hypulse Surface Analysis System expands the reach of XPS analysis by integrating multiple depth profiling technologies within one instrument. This combination helps researchers analyze a broader range of materials while preserving chemical accuracy and minimizing sample damage.

Illustration of the depths that can be accessed with XPS depth profiling, including surface = 1 nm, ultra-thin film = 1 to 10 nm, thin film = 10 nm to 2 micrometer, and the bulk. — The different depths that often hold critical information for advanced materials analysis. XPS depth profiling is capable of accessing all of these through the use of multiple sputtering and ablation technologies.

The evolution of XPS depth profiling

Over time, XPS depth profiling has expanded from single-mode ion sources to more advanced hybrid approaches. The Hypulse System reflects this evolution and addresses the limitations of traditional sputtering techniques by combining three complementary methods: monatomic and gas-cluster ion-beam sputtering along with femtosecond laser ablation.

Monatomic ion beams: precise characterization of metallic and inorganic layers

Monatomic ion beams have long been the foundation of XPS depth profiling. Operating at energies between 100 eV and 5 keV, they offer controlled sputtering of metals, oxides, and thin films. These beams create flat, well-defined craters that are suited for high-resolution compositional analysis. While reliable for most inorganic materials, this technique can alter polymeric or soft surfaces, limiting its use for certain sample types.

Gas cluster ion beams: gentle sputtering for sensitive materials

Sputtering with gas-cluster ion beams was developed as an alternate method of material ablation that minimizes chemical alteration during profiling. The Thermo Scientific MAGCIS Dual-Mode Ion Source is incorporated in the Hypulse System and generates clusters of loosely bound argon atoms. When these clusters impact a sample surface, they remove material through collective energy transfer, significantly reducing atomic-scale damage.

This approach is particularly effective for polymers and hybrid materials. For example, in the analysis of lithium phosphorus oxynitride (LiPON) films, gas-cluster ion profiling maintained stoichiometric accuracy, while traditional monatomic sputtering introduced lithium enrichment artifacts. This illustrates how cluster beams deliver reliable depth profiles, even in chemically sensitive systems. Read more (PDF) >

Femtosecond laser ablation: extending depth and material compatibility

The Hypulse System further advances XPS profiling through femtosecond (fs) laser ablation. This method uses ultra-short laser pulses to precisely remove material without introducing thermal or chemical damage. The short pulse duration minimizes heat diffusion, preserving the true composition of underlying layers.

Femtosecond laser ablation is especially valuable for oxides such as titanium dioxide (TiO₂), which are prone to reduction during ion beam analysis. As we have previously demonstrated, fs-laser ablation is able to accurately restore the Ti⁴⁺ oxidation state, confirming that this technique can remove surface material while maintaining chemical integrity. Read more (PDF) >

Analytical technologies integrated in the Hypulse Surface Analysis System including MAGCIS, fs laser, X-ray, UV, enabled by a TTL camera, HS camera, and flood source. — Illustration highlighting the wide range of technologies integrated in the Hypulse Surface Analysis System.

Comprehensive XPS depth profiling in one instrument

The Hypulse System enables comprehensive analysis across diverse materials by combining three complementary sputtering and ablation technologies.

Technique	Suitable applications	Key advantages
Monatomic ion beam	Metals, oxides, thin films	High-precision, established methodology
Gas cluster ion beam	Polymers, organics, hybrid materials	Gentle sputtering with minimal chemical modification
Femtosecond laser ablation	Metals, oxides, polymers, composite systems	Rapid, damage-free ablation for deeper profiling

This integrated approach allows researchers to match the material removal method to each specific sample, helping to improve data accuracy, throughput, and reproducibility.

Supporting the future of materials characterization

The Hypulse Surface Analysis System provides a flexible platform for XPS-based surface and depth analysis across semiconductor research, energy storage, coating development, corrosion science, and more. By integrating ion beam and laser ablation technologies, the Hypulse System facilitates accurate, high-resolution depth profiles with minimized surface alteration. This combination of analytical versatility and precision supports the continued advancement of materials science and engineering.

Explore complementary solutions for XPS, AES, and SIMS on our XPS Surface Analysis page >

Learn more about XPS depth profiling >