METHOD OF MANUFACTURING OPTICAL FILTER

摘要

Provided is a method of manufacturing an optical filter having excellent film quality in which extraneous matters adhered to the surface of a substrate are removed by cleaning before formation of a thin film. It is possible to effectively remove extraneous matters adhered to the surface of a substrate (S) by executing a cleaning process (P1) in which the substrate (S) is cleaned by using a solution containing water, a pretreatment process (P3) in which a plasma treatment using plasma of oxygen gas is performed on the surface of the substrate (S) cleaned in the cleaning process (P1), and a thin film formation process (P4, P5) in which a thin film is formed on the surface of the substrate (S) having been subjected to the plasma treatment in the pretreatment process (P3).  In the pretreatment process (P3), by introducing only the oxygen gas in an area wherein the plasma is generated and setting the flow rate of introduced oxygen gas larger than the flow rate of oxygen gas to be introduced in the thin film formation process, the extraneous matters adhered to the surface of the substrate (S) through OH group bond in the cleaning process can be effectively removed before the thin film formation process (P4, P5) and the occurrence of a portion without any film can be prevented.