METHOD OF MANUFACTURING MASK BLANK AND METHOD OF MANUFACTURING TRANSFER MASK

摘要

Methods of manufacturing a mask blank and a transfer mask that reduce internal stress of a thin film. The methods include preparing a transparent substrate having a pair of opposing main surfaces and composed of a glass material having a hydrogen content of less than 7.4×1018 molecules/cm3, forming a thin film composed of a material containing silicon or metal on one of the main surfaces of the transparent substrate, and carrying out heating treatment or photo irradiation treatment on the transparent substrate with the thin film. The absolute value of a variation of flatness in a predetermined region, as calculated based on a difference in shape obtained from a shape of a main surface of the transparent substrate prior to forming the thin film and a shape of a main surface of the substrate exposed after removing the thin film, is not more than 100 nm.

主权项

1. A method of manufacturing a mask blank provided with a thin film on a transparent substrate, comprising:
a step of preparing a transparent substrate having a pair of opposing main surfaces that is composed of a glass material having a hydrogen content of less than 7.4×1018 molecules/cm3, a step of forming a thin film composed of a material containing at least one of silicon and metal on one of the main surfaces of the transparent substrate, and a step of carrying out heating treatment or photo irradiation treatment on the transparent substrate on which the thin film has been formed; wherein, the absolute value of a variation of flatness in a predetermined region, as calculated based on a difference in shape obtained from the shape of one of the main surfaces of the transparent substrate prior to forming the thin film and the shape of one of the main surfaces of the transparent substrate exposed after removing the thin film, is not more than 100 nm.