Surface Analysis

Survey Spectra

• Acquire wide scan (0-1200 eV) for elemental identification
• Identify all elements present above detection limit (~0.1 at%)
• Note adventitious carbon for charge referencing

Atomic Force Microscopy (AFM)

1. Imaging Mode Selection

   • Contact mode: Hard surfaces, atomic resolution
   • Tapping mode: Soft samples, reduced tip wear
   • Non-contact: Minimal surface interaction

2. Image Analysis

   • Calculate roughness parameters (Ra, RMS, Rmax)
   • Identify surface features and defects
   • Measure step heights and feature dimensions

3. Force Spectroscopy

   • Acquire force-distance curves
   • Extract adhesion forces
   • Map mechanical properties (modulus, stiffness)

Contact Angle Analysis

1. Measurement Methods

   • Sessile drop for static contact angle
   • Advancing/receding for dynamic behavior
   • Wilhelmy plate for surface tension

2. Surface Energy Calculation

   • Owens-Wendt method (dispersive + polar)
   • Van Oss-Chaudhury-Good (acid-base)
   • Use multiple probe liquids (water, diiodomethane, formamide)

3. Interpretation

   • Hydrophilic: Contact angle < 90 degrees
   • Hydrophobic: Contact angle > 90 degrees
   • Superhydrophobic: Contact angle > 150 degrees

Process Integration

• MS-003: Spectroscopic Analysis Suite
• MS-015: Thin Film Deposition Protocol

Input Schema

{
  "sample_id": "string",
  "technique": "XPS|AFM|contact_angle|profilometry",
  "analysis_type": "survey|depth_profile|imaging|force_spectroscopy|wettability",
  "parameters": {
    "scan_area": "number (um x um for AFM)",
    "sputter_depth": "number (nm for XPS)",
    "probe_liquids": ["string (for contact angle)"]
  }
}

Output Schema

{
  "sample_id": "string",
  "xps_results": {
    "elemental_composition": [
      {
        "element": "string",
        "concentration": "number (at%)",
        "chemical_states": [
          {
            "state": "string",
            "binding_energy": "number (eV)",
            "fraction": "number (percent)"
          }
        ]
      }
    ],
    "depth_profile": {
      "depth": ["number (nm)"],
      "composition": {}
    }
  },
  "afm_results": {
    "roughness": {
      "Ra": "number (nm)",
      "RMS": "number (nm)",
      "Rmax": "number (nm)"
    },
    "features": ["string"]
  },
  "surface_energy": {
    "total": "number (mJ/m2)",
    "dispersive": "number (mJ/m2)",
    "polar": "number (mJ/m2)"
  }
}

Best Practices

1. Clean samples appropriately before analysis (solvent, plasma)
2. Use charge neutralization for insulating samples in XPS
3. Reference XPS binding energies to C 1s at 284.8 eV
4. Calibrate AFM z-scale with step height standards
5. Use fresh probe liquids for contact angle measurements
6. Report measurement conditions and uncertainties

Integration Points

• Connects with Spectroscopy Analysis for complementary chemical information
• Feeds into Thin Film Deposition for process monitoring
• Supports Failure Analysis for surface contamination identification
• Integrates with Corrosion Assessment for passive layer analysis