Erratum: "Explicit pure-state density operator structure for quantum tomography" [As part of an effort to develop high resolution microtomography for engineered structures, a two-level copper integrated circuit interconnect was imaged using 1.83 keV x rays at 14 angles employing a full-field Fresnel zone plate microscope. A major requirement for high resolution microtomography is the accurate registration of the reference axes in each of the many views needed for a reconstruction. A reconstruction with 100 nm resolution would require registration accuracy of 30 nm or better. This work demonstrates that even images that have strong interference fringes can be used to obtain accurate fiducials through the use of Radon transforms. We show that we are able to locate the coordinates of the rectilinear circuit patterns to 28 nm. The procedure is validated by agreement between an x-ray parallax measurement of 1.41Ϯ0.17 m and a measurement of 1.58 Ϯ0.08 m from a scanning electron microscope image of a cross section.
Articles you may be interested inTwo-dimensional dopant concentration profiles from ultrashallow junction metal-oxide-semiconductor field-effect transistors using the etch/transmission electron microscopy method Transmission electron microscopy ͑TEM͒ image contrast was used to characterize doping-dependent etching of n ϩ /p junctions in silicon. The local variations in crystal thickness give rise to the appearance of thickness fringes which may be interpreted as two-dimensional iso-concentration contours that map the dopant distribution. The etchant solution used for selective chemical etching of TEM samples prepared using wedge technique was modified to reduce the etch rate and maintain high selectivity to the n ϩ doped region. The two-dimensional dopant profiles were quantified by calibrating against one-dimensional secondary ion mass spectroscopy data and also compared with one-dimensional spreading resistance analysis data.
Xradia has developed a laboratory table-top transmission x-ray microscope, TXM 54-80, that uses 5.4 keV x-ray radiation to nondestructively image buried submicron structures in integrated circuits with at better than 80 nm 2D resolution. With an integrated tomographic imaging system, a series of x-ray projections through a full IC stack, which may include tens of micrometers of silicon substrate and several layers of Cu interconnects, can be collected and reconstructed to produce a 3D image of the IC structure at 100 nm resolution, thereby allowing the user to detect, localize, and characterize buried defects without having to conduct layer by layer deprocessing and inspection that are typical of conventional destructive failure analysis. In addition to being a powerful tool for both failure analysis and IC process development, the TXM may also facilitate or supplant investigations using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and focused ion beam (FIB) tools, which generally require destructive sample preparation and a vacuum environment.
A 300 keV scanning transmission electron microscope was used to obtain tilt-series images of two two-level copper integrated circuit samples. The center-to-center layer spacing obtained from the tilt series showed internal consistency at the level of 15%, and external validity at the level of 20%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.