| 摘要 |
PURPOSE:To measure a displacement in a deflection accuracy between a positioning deflection system and a scanning deflection system by a method wherein a vernier pattern in which an original point of each exposure section is determined by a positioning deflection system is lithographed from the original point determined by the positioning deflection system along a main scale pattern lithographed as a whole by the scanning deflection system. CONSTITUTION:In an instrument having a positioning deflection system and a scanning deflection system, an original point P is set in a lithographic field by the positioning deflection system, and a main scale pattern in which exposure sections 10 and non- exposure sections 12 are arranged alternately is lithographed. Along the main scale a, a vernier pattern in which exposure sections 16 and non-exposure sections 18 are alternately arranged is set by the positioning deflection system in terms of original points P1, P2... of exposure sections, and they are in turn lithographed by the scanning deflection system. When the accuracy of both systems is the same, the instrument is constructed so that the main scale a corresponds completely with the vernier b. With this construction, when a relative accuracy error exists between both deflection system, it can be easily read out optically as a pitch difference between both patterns. |
