Patent ID: 8197993

Claim:
A method of manufacturing a transfer mask with use of a mask blank in which a thin film for pattern formation and a chromium-based thin film are stacked on a transparent substrate in this order, the thin film for pattern formation being made of material containing silicon and a transition metal other than chromium, the chromium-based thin film being made of a material containing chromium, wherein: the transfer mask is adapted to an exposure light having a wavelength of 200 nm or less; and the transfer mask is produced by performing in the following order: a process of forming a resist film having a transfer pattern on the chromium-based thin film, a process of forming a transfer pattern in the chromium-based thin film with use of a mask of the resist film having the transfer pattern, a process of forming a transfer pattern in the thin film for pattern formation with use of a mask of the chromium-based thin film having the transfer pattern, and a process of removing the chromium-based thin film by etching; and a cleaning process of at least one of alkali solution cleaning, hot water cleaning, and ozone-containing water cleaning on the produced transfer mask until a width of a sidewall of the transfer pattern of the thin film for pattern formation is reduced by 4 nm or a space width of a sidewall of the thin film for pattern formation is increased by 4 nm.