CPC G01N 23/20008 (2013.01) [H01F 7/0273 (2013.01); H05K 9/0075 (2013.01); G01N 2223/052 (2013.01); G01N 2223/20 (2013.01); G01N 2223/30 (2013.01)] | 20 Claims |
1. An inspection system comprising:
an array of electron beam columns, each comprising an electron source configured to emit electrons toward a stage;
a first permanent magnet array configured to condense the electrons from each electron source into an array of electron beams, wherein the first permanent magnet array is arranged at a first end of the array of electron beam columns; and
a plurality of shielding plates extending across the array of electron beam columns downstream of the first permanent magnet array in a direction of electron emission;
wherein the plurality of shielding plates each comprise a plurality of apertures and have a thickness between 1 μm and 1 mm, and the array of electron beams pass through the plurality of apertures; and
whereby the plurality of shielding plates reduce stray magnetic field in a radial direction of the array of electron beams.
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