CHEMICAL NANOFABRICATION & CHARACTERIZATION EQUIPMENT
KRATOS ANALYTICAL AXIS ULTRA X-RAY PHOTOELECTRON SPECTROSCOPY
Equipment Configuration
15 ?m spatial resolution monochromatic Al k? x-ray source autostage, autovalving sample rotation stage (for enhanced depth resolution during profiling) UHV in situ sample preparation chamber
Specifications
- Elements detected: Li-U
- Sensitivity: 0.01-0.5% (atomic)
- Sampling depth: 0-10 nm
- Lateral resolution: 15 ?m
- Quantitative: Yes, without standards
Description
Soft x-rays (<1.5 keV) ionize atoms in a solid producing photoelectrons from core shells (the photoelectric effect). The kinetic energy of the emitted electron is equal to the x-ray energy less the energy that the electron is bound to the atom (K.E. = h? - B.E.). The low kinetic energy (by definition < 1.5 keV) makes the technique inherently surface sensitive with the majority of the photoelectrons in a given sample originating from the outer 5 nm. The number of electrons detected is proportional to the concentration in the sample. Perhaps most importantly, the exact binding energy is a function of the local environment of the atom yielding a chemical (or oxidation) state sensitive tool.
Technique Advantages
- Surface sensitive (top 1-10 nm)
- Quantitative without standards
- Chemical state information available for many elements
- In-depth information available by changing sampling geometry or ion beam depth profiling
Typical Applications
Organic Coatings and Films
- Surface functionality
- Surface modification
- Molecular orientation
- Adhesion studies
- Surface segregation
- Failure analysis
- Metallized layers
Ceramics, Glasses & Minerals
- Composition and thickness of optical coatings
- Fiberglass coatings
- Powder surface chemistry
- Mineral weathering
- Layer thickness and composition
- Organic coatings
- Impurity determination
- Bridging vs. non-bridging oxygen
Semiconductors
- Film stoichiometry
- Layer thickness
- Etch residues
- Low energy ion implant characterization
- Surface contaminants
- Reverse engineering
- Gate dielectrics
Metallurgy
- Diffusion studies
- Surface segregation
- Interface formation
- Corrosion and oxidation studies
- Surface contaminants
Catalysts
- Zeolite composition
- Catalyst poisoning
- Oxidation state determination
Sample Requirements
- Any vacuum compatible solid (thin films, powders, fibers, bulk materials)
- Size (< 50 mm X 50 mm X 25 mm)
