Multilayer film forming apparatus and film forming method

Abstract

A multilayer film forming apparatus including a film forming chamber, a substrate on which a multilayer film is formed, an optical thickness monitoring substrate which controls an optical thickness of each layer of a multilayer film, a monitor exchange system which exchanges the optical thickness monitoring substrate for each layer and a multilayer film monitoring substrate which is disposed under the optical thickness monitoring substrate to observe spectral characteristics of the multilayer film. The invention also includes a light source which irradiates light to the optical thickness monitoring substrate and to the multilayer film monitoring substrate, an optical lens which reshapes the light radiated from the light source, an optical window which lets the light into and out of the film forming chamber, a detector which detects the light quantity reflected from the optical thickness monitoring substrate and a spectral characteristics evaluation device which measures spectral characteristics of the light reflected from the multilayer film monitoring substrate. The multilayer film monitoring substrate is fixed to a holding jig to prevent itself from inclining more than ten minutes against the disposed state.