Low-energy ion scattering and Rutherford backscattering
There are two distinct parameter regimes for ion scattering analysis of surfaces and new-surface layers, and accordingly two different techniques. In low-energy ion scattering or ion scattering spectroscopy (ISS), primary ion energies of between 0.5 keV and 5 keV are used with noble gas ions (He(+), Ne(+), Ar(+)) and also alkali ions (Li(+), Na(+), K(+)). With this method, information is obtained from the topmost atomic layer, under certain circumstances also from the second of third layer. In Rutherford backscattering (RBS) the primary ion energy ranges from about 100 keV (for H(+)) to several MeV (for He(+) and heavier ions). The ion-target atom interaction can be described using the Coulomb potential from which the Rutherford scattering cross-section is derived, which allows absolute quantification of the results. Information in principle arises from a thickness of the order of 100 nm, but surface analysis is also possible by using channelling/blocking techniques. In this article the physical basis of ion scattering is explained in detail, for low and high energy techniques together. In the subsequent sections, experimental instrumentation, physical characteristics and typical results are described for RBS and ISS individually. The descriptions and the examples are selected with the intention to demonstrate and explain the potential and typical achievements of the methods.
Bibliographic Reference: Article: Surface Analysis - The Principal Techniques (1997) pp. 215-266
Record Number: 199711270 / Last updated on: 1997-10-10
Original language: en
Available languages: en