Patent ID: 6555818
Filing Date: 2003-04-29
Classification: H01J

Abstract:
A transmission electron microscope comprising:an illumination system for illuminating a specimen position with an electron beam, said illumination system having two illumination lenses that are interlocked to form an image of a source at a first crossover point at a first position in the immediate vicinity of said specimen position and upstream thereof; an objective lens for focusing an image of said specimen at a point at infinity, said objective lens forming an image of said first crossover point at a second crossover point at a second position in the vicinity of said objective lens and downstream thereof; a first multipole element for producing a magnetic field with three-fold symmetry, said first multipole element being located at said second position; a second multipole element for producing a magnetic field with three-fold symmetry, said second multipole element being located downstream of said first multipole element; and a doublet lens located between said first and second multipole elements to project said second crossover point onto the position of said second multipole element as a third crossover point.