MANUFACTURING METHOD OF PHOTOMASK

SOLUTION: To provide a method of manufacturing a photomask, which is characterized in that from a photomask blank that has a first inorganic film that contains silicon and does not contain chromium, and a second inorganic film that contains chromium and does not contain silicon, and the first inorganic film and the second inorganic film are formed in contact, a resist film is formed in contact with the second inorganic film and the second inorganic film and the first inorganic film are together fluorine-based-dry-etched to form a pattern to form a photomask.EFFECT: According to the present invention, the adhesion of a resist film is ensured regardless of a film quality of a silicon-containing film, and the problem of resist residue, which is a problem in a silylation treatment of silicon-containing film is avoided and without adding a new process, photomasks free from defects can be manufactured.SELECTED DRAWING: Figure 1 【解決手段】透明基板と、ケイ素を含有し、クロムを含有しない第１の無機膜と、クロムを含有し、ケイ素を含有しない第２の無機膜とを有し、第１の無機膜と第２の無機膜とが接して形成されているフォトマスクブランクから、第２の無機膜に接してレジスト膜を形成し、第２の無機膜及び第１の無機膜を、共にフッ素系ドライエッチングによりパターンを形成することによりフォトマスクを製造する。【効果】本発明によれば、ケイ素含む膜の膜質によらず、レジスト膜の密着性が確保され、ケイ素を含む膜に対するシリル化処理において問題となる、レジスト残渣の問題を回避して、新たな工程を追加することなく、欠陥が少ないフォトマスクを製造することができる。【選択図】図１