Patent ID: 8618515

Claim:
A lithography apparatus including a stage which includes a reference mark and configured to hold a substrate, a projection system configured to project a plurality of charged-particle beams onto the substrate, a first measurement device configured to irradiate a mark on the substrate with a light and to detect a light reflected by the mark to measure a position of the mark, a second measurement device configured to irradiate the reference mark with a charged-particle beam via the projection system and to detect a charged-particle beam that reaches the second measurement device from the reference mark to measure a position of the reference mark, and a detector configured to detect a position of the stage in a first direction parallel to an axis of the projection system and a second direction perpendicular to the axis, the apparatus drawing a pattern on the substrate with the plurality of charged-particle beams, the apparatus comprising: a controller configured to determine, among the plurality of charged-particle beams, a charged-particle beam of which an incident angle, relative to the first direction, on the reference mark falls within a tolerance, and to obtain a baseline of the first measurement device based on a position of the reference mark measured by the second measurement device using the determined charged-particle beam and a position of the reference mark measured by the first measurement device.