Study on spatial resolution of three-dimensional analysis by full count TOF-RBS with beryllium nanoprobe

Three dimensional nanostructures fabricated by electron beam (EB) induced deposition were measured by time of flight (TOF) Rutherford backscattering spectrometry (RBS) for checking the spatial resolution of a three dimensional analysis. Pt peaks in TOF-RBS spectra for Pt stripes under a SiO2 layer on a Si substrate samples were slightly shifted to slower position with increasing the thicknesses of the SiO2 layer. The atomic thicknesses for SiO2 fabricated by EB induced deposition measured by TOF-RBS were approximately 25% of the physical thicknesses obtained by a scanning electron microscope. Because SiO2 fabricated by EB induced deposition was not a pure SiO2 layer. The depth resolution in the three dimensional analysis with the TOF-RBS was approximately 10 nm for SiO2 layer. Embedded Ga stripes under a SiO2 layer and Pt stripes on a Si substrate were observed by TOF-RBS. The in-plane resolution under the SiO2 layer was at least less than 70 nm in the three dimensional analysis with the TOF-RBS.