A recent breakthrough in atomic-level analysis will help researchers in the development of advanced semiconductors and other nanometer-scale devices and materials. Scientists at FEI's nanotechnology center in Eindhoven, The Netherlands, broke the 1-Å image-resolution barrier using a 200-kV transmission electron microscope (see accompanying photos). This is the first time that images with <1 Å resolution can be directly viewed using commercially available technologies, according to the Hillsboro, OR–based metrology company.

The artifact-free imaging was accomplished with a Tecnai F20 ST TEM that was equipped with advanced electron optics capabilities
developed by FEI and its partner, Corrected Electron Optical Systems (CEOS) of Heidelberg, Germany. This enhanced analytical tool
enables novel, sub–angstrom-level resolution TEM techniques, including scanning probe applications, 3-D reconstruction with tomography, and in situ observations of specimen responses to stress, temperature, or chemical environment variations.

ATOMIC RESOLUTION: An enhanced TEM system can resolve subangstrom-level images, such as the silicon transistor gate interface shown here (inset). PHOTOS COURTESY OF FEI

"The successful use of an electron beam monochromator to improve the resolution of a spherical (Cs)-corrected electron microscope marks a major milestone in the field of electron microscopy," says Michael O'Keefe of the National Center of Electron Microscopy in Berkeley, CA, who characterized the breakthrough as an "outstanding achievement.... Theory has long predicted that a monochromator would be able to push the resolution of the super-twin lens beyond the 1.4-Å resolution demonstrated with spherical (Cs)-correction alone. However, the difficulties involved in implementation of a monochromator without compromising the imaging qualities of the electron beam are well known."

Also adding his congratulations was Hannes Lichte of the faculty of mathematics and natural sciences at the Institute of Structure Physics at Dresden University (Germany). "For the first time, the authors convincingly show that in a spherical (Cs)-corrected TEM by additional reduction of energy spread using a gun monochromator, they extend the total information limit to significantly better than 0.1 nm....They are not far off the theoretical limit of about 0.07 nm."