REANTIREFLECTION PLATE AND CHARGED-PARTICLE BEAM ALIGNER HAVING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a reantireflection plate which does not cause an aberration even in the case where the reantireflection plate is used jointly with a secondary electron detector and can lessen the amount of reflected electrons. SOLUTION: A reantireflection plate 31 is arranged in opposition to the surface 15a to be exposed of a wafer 15. A plurality of axisymmetric wedge type recessed parts 33 being opened toward the direction under the lower surface of the plate 31 are formed all over the lower surface of the plate 31. The centerlines of the wedge type recessed parts 33 are located on a conical surface formed with the intersecting point 15b of the optical axis with an exposure optical as its apex surface 15a.