400 keV ion backscattering spectroscopy

The 400 keV ion accelerator in use at the Electrotechnical Laboratory has been expanded to set up a system comprising a beam collimation channel, a scattering chamber and a solid state detector for experimental work on ion backscattering spectroscopy in the middle energy region. Energy spectra of the backscattered particles from several samples are obtained using 400 keV H+ and He+ as incident primary ions From a spectrum of the sample of niobium film evaporated on a silicon crystalline substrate, the depth resolution of the system is estimated to be better than 20nm. Samples of W/GaAs structure prepared in several ways are comparatively examined. Distribution profiles of dysprosium atoms implanted into iron films are extracted from backscattering spectra. Some experimental results on the channeling effect are also shown. A primitive method to analyze a backscattering spectrum obtained in the middle energy region is explained, and some numerical tables of parameters used in the analysis are presented in the appendices. (author)