Patent ID: 8564761
Filing Date: 2013-10-22
Classification: G01B,G03F

Abstract:
1. A surface shape measuring apparatus configured to measure a surface shape of a film formed on a substrate, the apparatus including: an illumination system arranged to split wide-band light from a light source into measurement light and reference light, the measurement light being illuminated to obliquely enter a surface on the substrate, the reference light being illuminated to obliquely enter a reference mirror; a light receiving system arranged to combine the measurement light reflected by the surface on the substrate and the reference light reflected by the reference mirror with each other and to introduce the combined light to a photoelectric conversion element; and a processing unit configured to calculate the surface shape of the film based on an interference signal detected by the photoelectric conversion element, wherein an incident angle of the measurement light upon the surface of the film and an incident angle of the reference light upon the reference mirror are each larger than the Brewster's angle, wherein the illumination system includes a first polarizer allowing passage of linearly polarized light in a predetermined direction, which is included in the wide-band light from the light source, wherein the light receiving system includes a second polarizer allowing passage of linearly polarized light in the predetermined direction, which is included in the measurement light reflected by the surface of the film and the reference light reflected by the reference mirror, wherein the linearly polarized light in the predetermined direction having passed the first polarizer enters the surface on the substrate as the measurement light and the reference mirror as the reference light, wherein the linearly polarized light in the predetermined direction having passed the first polarizer includes an s-polarized light component and a p-polarized light component in entering the surface on the substrate and in entering the reference mirror, wherein a polarization direction of linearly polarized light reflected by an interface between the film and the substrate is different from the predetermined direction, and wherein the linearly polarized light reflected by an interface between the film and the substrate is removed by the second polarizer.