EAG Application Solutions for Composition

Composition analysis studies the physical or chemical makeup of a material and the proportions of the various components present. Typically, this type of analysis looks for what is supposed to be in the material as well as the composition of what is actually present. Which technique you choose depends on three things:

1. What you know about the sample in advance
2. What you want to quantify (major elements, minor elements, chemical components, or molecular components)
3. Whether you want a layer, surface, or bulk analysis

Thin Layer Analysis

• Rutherford Backscattering Spectrometry (RBS) is the best technique to use when you have general knowledge of the elements beforehand and you want to quantify the major elements.
• Low Energy X-ray Emission Spectrometry (LEXES) is complementary to RBS, and has better sensitivity for light elements and 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 you do not know the major elements.
• Auger Electron Spectroscopy is a good option if the analysis area is restricted.
• Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy are well suited for obtaining chemical or molecular information. However, not all materials give good vibrational spectra. 

Surface Analysis

Elemental and chemical surface compositions are best done using techniques with near surface information depths, such as Auger for elemental composition and XPS for chemical state composition.

Bulk Analysis

Bulk analysis typically refers to non-surface compositions, such as the middle of a layer or below the surface, and does not provide depth information. In this instance, X-ray Fluorescence (XRF) provides quantification for major and minor elements.

Application Notes