MASK BLANK, TRANSFER MASK AND MANUFACTURING METHOD FOR MASK BLANK AND TRANSFER MASK

摘要

PROBLEM TO BE SOLVED: To provide a mask blank for manufacturing a long-life transfer mask that can suppress occurence of a problem accompanied by a repeated cleaning.SOLUTION: The mask blank includes a thin film for formation of a transfer pattern on a principal surface of a translucent substrate, and the principal surface on a thin film-formed side of the translucent substrate has a dent defective part. The thin film is composed of a material containing transition metal and silicon, and an oxide layer is formed on a surface layer of the thin film. An internal area at a part of the thin film formed on the dent defective part has a low density area and density in the low density area is relatively lower than density in an internal area at a part of the thin film formed on a principal surface where the dent defective part is not present. Oxygen concentration in the low density area is relatively higher than oxygen concentration in an internal area excluding the surface layer at the part of the thin film formed on the principal surface where the dent defective part is not present.