GLASS SUBSTRATE FOR MASK BLANKS

• Main Authors: TAKEUCHI MASAKI, YARITA NAOKI, HARADA HIROMI
• Format: Patent
• Language: English; Japanese
• Published: 23.12.2021
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; CINEMATOGRAPHY; ELECTROGRAPHY; GLASS; HOLOGRAPHY; JOINING GLASS TO GLASS OR OTHER MATERIALS; MATERIALS THEREFOR; METALLURGY; MINERAL OR SLAG WOOL; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

To provide a glass substrate for mask blanks that is highly flat, has low defects, has a surface with low roughness, has a sufficiently high reflectance of EUV light after film formation of a reflective film, and is suitable as a substrate for EUVL mask blanks for state-of-the-art applications.SOLUTION: Provided is a glass substrate for mask blanks that has the maximum value of a circular average power spectral density of spatial frequency 0.1 μm-1 or more and 20 μm-1 or less obtained by measuring the surface shape of a region of 10 μm×10 μm with an atomic force microscope is 1000 nm4 or less.SELECTED DRAWING: None 【課題】高平坦、低欠陥で、粗さが小さい表面を有し、反射膜成膜後のＥＵＶ光の反射率が十分に高く、最先端用途のＥＵＶＬマスクブランクス用基板として好適なマスクブランクス用ガラス基板を提供する。【解決手段】１０μｍ×１０μｍの領域の表面形状を原子間力顕微鏡で測定して得られる、空間周波数０．１μｍ-1以上２０μｍ-1以下の環状平均パワースペクトル密度の最大値が、１０００ｎｍ4以下であるマスクブランクス用ガラス基板。【選択図】なし