X射线光电子能谱（XPS光谱）

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

Technical Definition:
XPS is a surface-sensitive analytical technique (sampling depth: 50-100 Å) that determines:

• Quantitative atomic composition (detection limit: 0.1-1 at%)

• Chemical state information (e.g., sulfate vs. sulfide)

• Depth profiles via Ar⁺ sputtering

Working Principle:

• Monochromatic X-rays (typically Al Kα at 1486.6 eV) eject photoelectrons

• Kinetic energy analysis identifies elements (Li-U) and bonding states

• Escape depth limitation: Only electrons from top 100 Å reach detector

EAG Laboratory Capabilities:
✓ Full-spectrum survey scans (element identification)
✓ High-resolution narrow scans (chemical bonding analysis)
✓ Depth profiling for thin-film characterization
✓ Oxide thickness measurements (SiO₂, Al₂O₃)

Typical Applications:
• Stain/discoloration analysis
• Cleaning process validation
• Powder/particulate composition
• Contamination source identification
• Polymer surface modification studies
• Hard disk lubricant thickness measurement

Technical Specifications

Strengths
✔ Chemical state differentiation (e.g., oxidation states)
✔ Universal detection (all elements except H/He)
✔ Quantitative comparison of chemical states
✔ Insulator-compatible (polymers, glasses)
✔ Depth-resolved composition analysis

Limitations
▲ ~0.1 at% detection limit
▲ Minimum analysis area: ~10 µm
▲ Limited organic specificity
▲ Requires UHV compatibility

Value Proposition:
XPS provides critical chemical insights accelerating product/process improvements, while EAG's expertise ensures:

• Industry-leading instrumentation (including small-spot XPS)

• Cross-material experience (semiconductors to biomaterials)

• Scientist-to-client data interpretation