DOUBLE SYMMETRIC MAGNETIC LENSES AND TWO STEP MAGNETIC LENS SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide double symmetric magnetic lenses which improve a non- focused image caused by an aberration of an optical system. ;SOLUTION: A double symmetric magnetic lenses for a charged corpuscular ray aligner is provided to apply a corpuscular ray passing through a pattern of a reticule 1 to a wafer 2, in order to form a pattern image on the wafer 2. In this aligner, the length of lens S is specified to satisfy a relation of L[1-{1/(m-0.5)}≤S≤L[1-{1/(m+1)}], where a lens-barrel length of the double symmetric magnetic lens is L, and a rate of reduction is 1/m, and a lens length of the reticule side lens 3 arranged to the reticule side to construct the double symmetric magnetic lenses is S, and accordingly an image being not focused can be improved as mush as possible.;COPYRIGHT: (C)1998,JPO