HIGH DEPTH RESOLUTION RUTHERFORD BACKSCATTERING METHOD FOR ASSESSING HIGH-T(C) STRUCTURES

We consider how to improve the depth resolution of Rutherford backscat tering of ions as applied to the composition analysis of thin high-T(c ) films and structures by optimizing the ion spectrometer. It is shown that the energy resolution can be brought close to the theoretical li mit for He-4+ energies under 2 MeV, the range commonly used by the met hod when using Si-detectors of alpha-particles with energies of congru ent-to 5 MeV. A depth resolution of congruent-to 100 angstrom was obta ined in studies of Yba2cu3o7-delta and Y2BaCuO5 thin films (congruent- to 10(3) angstrom) on MgO substrates. With a tilted ion beam, the reso lution is congruent-to 40 angstrom. Ions with energies up to 8 MeV wer e used for films under 10(4) angstrom thick, which resulted in a resol ution of 3% of the film depth.