The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 08, 1992
Filed:
Apr. 25, 1991
Erich Plies, Munich, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
Particle beam apparatus for improving the spatial resolution of a conventional scanning electron microscope given low electron energies and adequately great working distances, an electrostatic immersion lens is arranged in the region of an intermediate image generated by a condenser unit. The immersion lens is composed of a beam-guiding tube that is at an anode potential and of a further tube electrode that is arranged and insulated in the column of the scanning electron microscope and is charged with a high positive potential. Since the tube electrode extends into the region of the pole piece gap of the objective lens, an electrical field that decelerates the electrons to the desired ultimate energy is built up at this location. Due to the retarding field overlaid on the focusing magnetic field of the objective lens, the lens has extremely low chromatic aberration and spherical aberration constants. Moreover, the influence of the Boersch effect is considerably diminished as a consequence of the high average kinetic energy of the primary electrons in the column.