| 摘要 |
In all fields of development and manufacture of microelectronic and optoelectronic components, there is an increasing requirement for high-resolution imaging systems which enable inspection, in the proximity of the process, of the submicrometer structures which are produced using modern lithography methods. Conventional scanning electron microscopes achieve a resolution of a few nanometers only when high acceleration voltages above approximately 20 kV are used, where resist structures and circuits are damaged and non-conductive or weakly conductive samples are charged. The low-voltage scanning electron microscope according to the invention (final electron energy EPE SIMILAR 0.2 to 5 keV) consists essentially of a field emission source (Q), a condensor lens (KL), a lens system (KO) having at least four 8-pole or 12-pole elements (KE1 to KE4) for the correction of spherical and chromatic distortion of the imaging lens system (OL), a two-stage deflection element (AE) which is arranged in the beam path immediately behind the corrector (KO), and an immersion lens (OL) having a centre electrode (KS1) as the objective lens. The detector (DT) for detecting the secondary electrons (SE) is arranged inside the immersion lens (OL), whose centre and sample-side electrodes (KS1 and KS2 respectively) are each constructed in the form of truncated cones (frustra). The electrode on the sample side of the immersion lens (OL) consists of an annular aperture (RB) in whose central hole a hollow cylinder (HZ) is arranged... Original abstract incomplete. <IMAGE>
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