Stage devices including linear motors that produce reduced beam-perturbing stray magnetic fields, and charged-particle-beam microlithography systems comprising same

Abstract

Stage devices are disclosed that achieve high positioning and movement accuracy while producing substantially reduced outwardly extending stray magnetic fields. The stage devices are especially suitable for use in a charged-particle-beam (CPB) microlithography system because they cause substantially reduced beam perturbations. A stage device comprises multiple linear motors and a slider arranged relative to each other such that the intersection point of drive forces applied by the linear motors to move the slider coincides with the center of gravity of the slider. Each linear motor includes a respective yoke in which permanent magnets are disposed such that pairs of opposing magnets face one another across a gap, each pair of opposing magnets has similarly oriented respective poles, and the orientation is alternatingly reversed in each subsequent pair of opposing magnets in the yoke. Also, the poles of respective opposing pairs of magnets in adjacent yokes are similarly oriented, with the orientation being alternatingly reversed in each subsequent pair in the yokes. Consequently, circuits of magnetic flux are kept tightly confined to the yokes, which substantially reduces interaction of the magnetic flux with the charged particle beam.

Dependencies are inferred from the claim text.