DEPTH-PROFILING OF HYDROGEN AND HELIUM-ISOTOPES BY MEANS OF THE ERD EXB TECHNIQUE

The ion beam analysis technique of elastic recoil detection, with an E x B filter, has been upgraded to depth profile all isotopes of hydrogen and helium in light materials (Z < 25). The adjustment of the E x B filter as well as a discussion of the depth-resolution and the sensitivity are presented for every isotope detected. Typically, when a 350 keV He beam is used, the depth resolution (which depends significantly on the material) is almost-equal-to 4 nm at the surface decreasing to 15 nm at a depth of 100 nm, while the depth probed is almost-equal-to 100 nm and the sensitivity is almost-equal-to 1 at%. The possibility of using a 1 MeV He beam is also discussed. Examples of measured isotope profiles are presented.