Rutherford backscattering spectrometry (RBS)

Technology Description:

Rutherford Backscattering Spectrometry (RBS) is an analytical technique based on the measuring of number and energy distribution of fast (1-3 MeV) light ions backscattered from the target. Conventional applications of this technique are the compositional thin film analysis and determination of impurity depth distributions (specifically for heavy elements in a light matrix). RBS in combination with channeling provides a possibility for analysis of structural quality of crystalline materials. The home-made RBS system at the Micro and Nanotechnology Laboratory at the University of Oslo (UiO MiNaLab) is based on 1 MeV NEC Tandem accelerator and H, Li, and He ions can be used as an analyzing beam.

Working Modes:

Random – this is the most common RBS mode used for the compositional analysis of the bulk and thin-film samples to depths up to ~1 mm.

Channeling – this mode can be used for crystalline materials when the analyzing beam is aligned with one of the main crystal orientations. This mode is typically used to analyze the crystalline quality of the materials or depth distribution of defects created by ion implantation.

Nuclear Reaction Resonance (NRA) – this mode can be used to enhance RBS sensitivity to light atoms, for example, using the ¹⁶O(a,a)¹⁶O resonance occurring at 3.045 MeV.

Technical Information:

Elements detected: B-U.

Detection limits: 0.001 – 10 at.% (depending on the combination of elements analyzed).

Depth of analysis: < 1 mm.

Depth resolution: 5 – 20 nm.

Non-destructive.

Quantitative without standards.

Samples: Vacuum compatible materials.

Sample sizes: 5 ×5 mm and 10 × 10 mm (standard).