Patent ID: 8785878

Claim:
An apparatus which performs drawing on a substrate with a charged particle beam, the apparatus comprising: an irradiation device configured to emit the charged particle beam to irradiate the substrate with the charged particle beam; a measurement device configured to measure an irradiation position of the charged particle beam emitted by the irradiation device; and a controller configured to correct a measurement result obtained by the measurement device, based on correction information, and control the irradiation position of the charged particle beam on the substrate based on the corrected measurement result, wherein the measurement device includes: a plate including first and second knife edges, wherein at least a part of the charged particle beam incident on the measurement device is blocked by the plate, thereby the plate is deformed; and a sensor configured to detect another part of the charged particle beam incident on the measurement device, while the charged particle beam is scanned relative to the plate so that the charged particle beam traverses the first and second knife edges, and wherein the controller is configured to determine an interval between the first and second knife edges of the plate which has been deformed, based on a result detected by the sensor, and generate the correction information based on the determined interval.