Search

Scanning soft x‐ray microtomography was used to obtain high‐resolution three‐dimensional images of a microfabricated test object. Using a special rotation stage mounted on the scanning transmission x‐ray microscope at the X1A beamline at the National Synchrotron Light Source, we recorded nine two‐dimensional projections of the 3D test object over an angular range of −50° to +55°. The x‐ray wavelength was 3.6 nm and the radiation dose to the object per projection was approximately 2×106 Gy. The object consisted of two gold patterns supported on transparent silicon nitride membranes, separated by 4.75 μm, with 100‐ to 300‐nm‐wide and 65‐nm‐thick features. We reconstructed a volumetric data set of the test object from the two‐dimensional projections using an algebraic reconstruction technique algorithm. Features of the test object were resolved to ∼100 nm in transverse and longitudinal extent with low artifact in three‐dimensional images rendered from the volumetric set.

Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by {approximately}5{mu}m. A series of nine 2-D images of the object were recorded at angles between {minus}50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of {approximately}1000 {Angstrom} was observed. Artifacts in the reconstruction limited the overall depth resolution to {approximately}6000 {Angstrom}, however some features were clearly reconstructed with a depth resolution of {approximately}1000 {Angstrom}. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to {approximately}1200 {Angstrom} overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range.

Ultra high resolution three dimensional images of a microscopic test object were made with soft x‐rays using a scanning transmission x‐ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows which were separated by ∼ 5μm. Depth resolution comparable to the transverse resolution was achieved by recording nine 2‐D images of the object at angles between −50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3‐D image using an algebraic reconstruction technique (ART) algorithm. We observed a transverse resolution of ∼1000 A. Artifacts in the reconstruction limited the overall depth resolution to ∼6000 A, however some features were clearly reconstructed with a depth resolution of ∼1000 A.

Ultrahigh-resolution three-dimensional images of a microscopic test object were made with soft x-rays collected with a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by approximately 5 micrometers. Depth resolution comparable to the transverse resolution was achieved by recording nine two-dimensional images of the object at angles between -50 and +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a three-dimensional image by means of an algorithm using an algebraic reconstruction technique. A transverse resolution of approximately 1000 angstroms was observed. Artifacts in the reconstruction limited the overall depth resolution to approximately 6000 angstroms; however, some features were clearly reconstructed with a depth resolution of approximately 1000 angstroms.