Parallel charged particle beam exposure system

Abstract

A parallel exposure electron beam lithography system for directly writing an integrated circuit pattern simultaneously at a plurality of locations on the surface of a resist-coated semiconductor wafer is disclosed. An electron source produces an electron beam which is used to illuminate an object aperture. A screen lens consisting of a multiplicity of holes breaks up the flood electron beam emanating from the object aperture into a multiplicity of beams in parallel and focuses them on a resist-coated substrate. Each hole in the screen lens acts like a small aperture lens when a positive potential is applied to the wafer with respect to the screen lens. A pair of octupole deflectors electronically control the angle with which the electron beam strikes the screen lens. This controls the deflection of the images beneath each of the screen lenses. An interferometer-controlled stage moves in a direction orthogonal to the direction of beam deflection and, in conjunction with the synchronous blanking of the flood electron beam, effectively scans out a predetermined integrated circuit pattern under each lens. Alternatively, an ion source may be used with an ion-sensitive resist coated substrate or ions may be implanted directly into a substrate.