| 摘要 |
Methods are disclosed for performing reticle-substrate alignments in the context of charged-particle-beam (CPB) microlithography. More specifically, the subject methods pertain to detecting an amount of relative rotation between the "transfer-receiving" (e.g., substrate) side and the "transfer-originating" (e.g., reticle) side in one operation simply by detecting marks that are disposed near an axis of the CPB-optical system. A charged particle beam is passed through an alignment mark(s) situated relative to an alignment axis of the reticle and thus indicates reticle orientation. One or more respective index marks are defined on the substrate relative to an alignment axis of the substrate, thereby indicating substrate orientation. E.g., two index marks can be provided on the substrate, one convex and the other concave, but otherwise similarly shaped. The index marks can be situated linearly aligned with each other or at an angle to each other. Production of backscattered charged particles from the index marks is mutually canceling whenever the reticle is oriented exactly with the substrate, but not whenever the reticle and substrate are misoriented. The angle of misalignment can be calculated by analyzing the output pattern of an electrical signal corresponding to detected backscattered charged particles.
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