Tomographic reconstruction of an integrated circuit interconnect

An Al-W-silica integrated circuit interconnect sample was thinned to several mu m and scanned across a 200 nm focal spot of a Fresnel zone plate operating at photon energy of 1573 eV. The experiment was performed on beamline 2-ID-B of the Advanced Photon Source, a third-generation synchrotron facility. Thirteen scanned projections of the sample were acquired over the angular range +/-69.2 degrees. At least 301 X 301 pixels were acquired at each angle with a step size of 77 X 57 nm. A three-dimensional image with an approximate uncertainty of 400 nm was reconstructed from projection data using a standard algorithm. The two layers of the integrated circuit and the presence of the focused ion beam markers on the surface of the sample are clearly shown in the reconstruction. (C) 1999 American Institute of Physics. [S0003-6951(99)03701-8].