ELECTRON BEAM FOCUSING APPARATUS WHICH FORMS UNIFORM ELECTROMAGNETIC FIELD BETWEEN WAFER AND ELECTRON BEAM EMITTER AND ELECTRON BEAM PROJECTION LITHOGRAPHY SYSTEM EMPLOYING THE APPARATUS

摘要

PURPOSE: An electron beam focusing apparatus and an electron beam projection lithography system employing the apparatus are provided, to allow a uniform electromagnetic field to be formed between a wafer and an electron beam emitter and to minimize the bending of an electron beam path due to the vibration of a vacuum chamber. CONSTITUTION: The electron beam focusing apparatus comprises upper and lower magnets(161, 162) which are arranged in the upper and lower exterior parts of a vacuum chamber(110) surrounding the space where a wafer(130) is mounted, respectively, and form a magnetic field inside the vacuum chamber; upper and lower pole pieces(171, 172) which penetrate the ceiling wall and bottom wall of the vacuum chamber, respectively and are magnetically contact with the upper and lower magnets, respectively; and upper and lower projection parts(191, 192) which are projected in a ring-shape in the mutual corresponding faces of the upper and lower pole pieces. Preferably rubber plates(181, 182) containing a ferromagnetic material are inserted between the upper and lower magnets and the upper and lower pole pieces, respectively.