Patent ID: 8921807
Filing Date: 2014-12-30
Classification: B08B,B82Y,G03F,H01J

Abstract:
1. A lithographic apparatus which performs drawing a pattern on a substrate with a plurality of charged-particle beams, the apparatus comprising: an optical system including, at an end of the optical system, which faces the substrate, an aperture plate having a plurality of apertures to pass the plurality of charged-particle beams; and a cleaning unit, comprising a case including an emitting hole plate having a plurality of emitting holes, an active species source configured to generate active species in the case, and a driving mechanism configured to move the case relative to the optical system in a state that the emitting hole plate faces the aperture plate, configured to remove contaminants deposited on the plurality of apertures, using the active species emitted from the plurality of emitting holes wherein the plurality of apertures includes a first aperture, a second aperture and a third aperture, wherein the plurality of emitting holes includes a first emitting hole and a second emitting hole, wherein an interval between the first aperture and the second aperture matches an interval between the first emitting hole and the second emitting hole, and wherein the driving mechanism is configured to move the case to a position, where the cleaning unit is capable of removing contaminants deposited on the first aperture using active species emitted from the first emitting hole, and the cleaning unit is capable of removing contaminants deposited on the second aperture using active species emitted from the second emitting hole, and then to a position where the cleaning unit is capable of removing contaminants deposited on the third aperture using active species emitted from the first emitting hole.