Charged-particle-beam microlithography apparatus and methods for preventing coulomb effects using the hollow-beam technique

摘要

Apparatus and methods are disclosed for charged-particle-beam (CPB) microlithography using a hollow beam. The hollow beam is produced by passing the charged particle beam through a scattering aperture. However, passage of the beam is performed in a manner by which the scattering aperture is prevented from overheating. Also, the scattering aperture can be made from a material that is micro-machined easily. The scattering aperture can be configured as a beam-scattering aperture plate defining voids that collectively define an annular aperture. The scattering aperture is situated at a beam-crossover plane. As the charged particle beam strikes the scattering aperture, particles pass readily through the voids as a “transmitted beam.” Particles incident on the scattering aperture plate are scattered and become a “scattered beam.” The transmitted beam passes readily through a downstream blocking aperture, whereas most particles of the scattered beam are absorbed by the blocking aperture.