PELLICLE INSPECTION APPARATUS

摘要

Provided with a pellicle inspection apparatus that inspects a pellicle film of a mask provided with a pellicle and used in EUV lithography. The pellicle inspection apparatus includes: an illumination optical system that projects a converging illuminating beam toward the pellicle film;;a light collection optical system including an object lens having an optical axis substantially orthogonal to the pellicle film and that collects scattering light outgoing from a foreign substance present on the pellicle film; and a detection system that detects the scattering light collected by the light collection optical system, wherein an incident angle θ2 of the illuminating beam with respect to the pellicle film satisfies Expression θ2−θ0>θ1+23°, where θ0 is a collecting angle (half angle) of the illuminating beam, and θ1 is a maximum light-receiving angle (half angle) of the object lens.

主权项

1. A pellicle inspection apparatus that inspects a pellicle film of a mask provided with a pellicle and used in EUV lithography, the pellicle inspection apparatus comprising:
an illumination optical system that projects a converging illuminating beam toward the pellicle film; a light collection optical system including an object lens having an optical axis substantially orthogonal to the pellicle film and that collects scattering light outgoing from a foreign substance present on the pellicle film; and a detection system that detects the scattering light collected by the light collection optical system, wherein an incident angle θ2 of the illuminating beam with respect to the pellicle film satisfies Expression (1)
θ2−θ0>θ1+23°  (1)where θ0 is a collecting angle (half angle) of the illuminating beam, and θ1 is a maximum light-receiving angle (half angle) of the object lens.