Relationships between cluster secondary ion mass intensities generated by different cluster primary ions

Area of Science:

• Materials Science
• Surface Science
• Analytical Chemistry

Background:

• Secondary Ion Mass Spectrometry (SIMS) is a powerful surface analysis technique.
• Previous models described SIMS spectra for organic materials using component spectra and powers.
• Extending this model to inorganic materials and cluster ions is crucial for broader applicability.

Purpose of the Study:

• To evaluate the constitution of SIMS spectra for silicon oxide and silicon using cluster primary ions.
• To test and confirm a generalized model for SIMS spectral analysis.
• To correlate spectral intensity with primary ion deposited energy.

Main Methods:

• Secondary ion mass spectrometry (SIMS) measurements were performed on silicon oxide and silicon.
• Primary ions included Bi(n)+, Au(-), Au(3)-, Al(-), and Al(2)- with varying energies.
• Spectra were analyzed using a model involving material-dependent component spectra and power laws.

Main Results:

• SIMS spectra of (SiO(2))(t)OH(-) from silicon oxide were accurately described (2.4% std dev) by a constant, a spectrum H(SiOH)*, and a power law in t.
• Published data for Si(t)(+) from silicon confirmed a similar model with H(Si)* and an exponential dependence on t.
• Spectral intensity was strongly correlated with the deposited energy of the primary ion at the surface.

Conclusions:

• The generalized model accurately describes SIMS spectra for both organic and inorganic materials, using monatomic and cluster primary ions.
• The model's consistency across different materials and ion types highlights its robustness.
• Deposited energy of the primary ion is the dominant factor influencing SIMS spectral intensity.