Composition analysis is generally the confirmation of the identity and amounts of the major components present in a material or film.
The technique of choice for the analysis depends on several factors:
- What is known about the sample already?
- What needs to be quantified (major elements, minor elements, chemical components, or molecular components)?
- Whether this is a surface, bulk or layer analysis?
Elemental and chemical surface compositions are best measured using quantitative techniques with shallow information depths (<100Å), such as Auger Electron Spectroscopy or X-Ray Photoelectron Spectroscopy.
Bulk composition is best determined with techniques that have large/deep information depths that ignore compostional variations at surfaces. Depth-specific information is typically not available with these methods. X-ray Fluorescence (XRF) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) are the most relevant techniques that can quantify both major and minor elemental components.
Thin Layer Analysis
- Rutherford Backscattering Spectrometry (RBS) is the technique of choice for the quantitation of known major elements in a thin film.
- Low Energy X-ray Emission Spectrometry (LEXES) is complementary to RBS, and has good sensitivity for light elements and lower level impurities. It can also be used to map film composition and thickness over entire wafers.
- X-ray Photoelectron Spectroscopy (XPS) is a good choice, if the major components of the film of interest are not known.
- Auger Electron Spectroscopy (AES) is a good option if the analysis area is restricted in size.
- Secondary Ion Mass Spectrometry (SIMS) has a range of applications for high precision compositional measurement of compound semiconductor thin films.
- Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy are well suited for obtaining chemical or molecular information from organic films.