Film thickness measuring device and film thickness measuring method

Abstract

A film thickness measuring apparatus measures a film thickness of a sample during a manufacturing step. The film thickness measuring apparatus includes a lens focusing light (plasma light) generated in the manufacturing step and reflected by one surface of the sample, an inclined dichroic mirror having a transmissivity and a reflectivity changing in accordance with a wavelength in a predetermined wavelength region and separating light focused by the lens through transmission and reflection, an area sensor capturing an image of light separated by the inclined dichroic mirror, and a control apparatus estimating the film thickness of the sample on the basis of a signal from the area sensor capturing an image of light and obtaining a film thickness distribution on the one surface of the sample. Light reflected by the sample includes light having a wavelength included in the predetermined wavelength region of the inclined dichroic mirror.

Dependencies are inferred from the claim text.