Nt1310 Unit 9 Lab Report

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2.7.1 Measurements
XPS is used to measure:
1. Elemental composition of the surface (top 0 –10 nm usually)
2. Empirical formula of pure materials
3. Elements that contaminate a surface
4. Chemical or electronic state of each element in the surface
5. Uniformity of elemental composition across the top surface (or line profiling or mapping)
6. Uniformity of elemental composition as a function of ion beam etching (or depth profiling)

Because the energy of an X-ray with particularwavelength is known (for Al Kα X-rays, Ephoton =1486.7 eV), and because the emitted electrons'kinetic energies are measured, the electron binding energy of each of the emitted electrons can be determined by using an equation that is based on the work of Ernest Rutherford (1914): Ebinding=Ephoton-Ekinetic-ɸ (16)

where Ebinding is the binding energy (BE) of the electron, Ephoton is the energy of the X-ray photons being used, Ekinetic is the kinetic energy of the electron as measured by the instrument and ɸ is the work function dependent on both the spectrometer and the material. This equation is essentially a conservation of energy equation. The work function term is an adjustable instrumental correction factor that accounts for the few eV of kinetic energy given up by the
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Monochromatic aluminium K-alpha X-rays are normally produced by diffracting and focusing a beam of nonmonochromatic X-rays off of a thin disc of natural, crystalline quartz . The