PATTERN INSPECTION APPARATUS AND PATTERN INSPECTION METHOD

摘要

A pattern inspection apparatus includes a transmitted illumination optical system to illuminate change the shape of a first inspection light, a reflected illumination optical system to illuminate a mask substrate with a second inspection light by using an objective lens and a polarizing element, and let a reflected light from the mask substrate pass therethrough, a drive mechanism to enable the polarizing element to be moved from/to outside/inside an optical path, a sensor to receive a transmitted light from the mask substrate illuminated with the first inspection light during stage moving, and an aperture stop, between the mask substrate and the sensor, to adjust a light flux diameter of the transmitted light so that the transmitted light reaching the sensor can be switched between high and low numerical aperture (NA) states with which the transmitted light from the mask substrate can enter the objective lens.

主权项

1. A pattern inspection apparatus comprising:
a stage configured to mount a mask substrate with a pattern formed thereon and to be movable; a transmitted illumination optical system configured to illuminate the mask substrate with a first inspection light, and to be able to change an illumination shape of the first inspection light; a reflected illumination optical system configured to include an objective lens and a polarizing element, illuminate the mask substrate with a second inspection light by using the objective lens and the polarizing element, and let a reflected light from the mask substrate pass through the reflected illumination optical system; a drive mechanism configured to enable the polarizing element to be moved from outside to inside an optical path, and from the inside to the outside the optical path; a sensor configured to receive a transmitted light from the mask substrate illuminated with the first inspection light while the stage is moving; an image forming optical system configured to receive the transmitted light through the objective lens, and focus a received transmitted light to form an image on the sensor; and an aperture stop placed between the mask substrate and the sensor, and configured to adjust a light flux diameter of the transmitted light so that the transmitted light reaching the sensor can be switched between a transmitted light corresponding to a state of high numerical aperture (NA) with which the transmitted light from the mask substrate can enter the objective lens and a transmitted light corresponding to a state of low numerical aperture with which the transmitted light from the mask substrate can enter the objective lens.