Benchmark for Surface Imaging in the Subnanometer Set by Zeiss
Carl Zeiss announced it has set a new world record resolution benchmark for scanning electron and ion microscopy, pushing scanning beam technologies beyond current limits. Using its Orion helium-ion microscope, a surface resolution of 0.24 nm was repeatedly achieved (25-75 percent edge-rise criterion) on various samples. This resolution, which is close to the diameter of a single atom, is three times better than even the most sophisticated scanning electron microscopes can achieve today with the same surface sensitivity, the company said. The secret behind its extreme high resolution lies in the proprietary source technology and in the interaction between the scanning ion beam and the surface of the specimen, according to the company. The source of the microscope is very small and the helium ions emanate from a region as small as a single atom. Unlike electrons, the helium ions have a very small wavelength and do not suffer appreciably from adverse diffraction effects –- a law of physics which fundamentally limits the imaging resolution of electrons. Also, the helium-ion beam triggers signals directly from the surface of the sample and stays very collimated upon entering the sample, resulting in very sharp and surface sensitive images that can be easily interpreted. For a typical scanning electron microscope, the majority of the secondary electrons used for imaging come from deeper and much less confined regions within the sample, creating blurrier images with less resolution, Zeiss said.