Method for manufacturing master mold for imprinting

A method for manufacturing a master mold for imprinting, the master mold having structures formed in a bump pattern, the method for manufacturing a master mold for imprinting characterized by comprising a mask formation step in which a mask is formed on a front surface of a light-transmitting base material, a coating step in which a negative resist having a predetermined film thickness is coated on the mask, an exposure step in which light is directed from the back-surface side of the base material and the resist coated on the mask via the mask is exposed, and a development step in which the exposed resist is developed, the mask formation step being a step involving forming a light-shielding-part film and a grayscale-part film on the front surface of the base material and forming, on the front surface of the base material, a grayscale mask that is constituted of light-transmitting parts, light-shielding parts, and grayscale parts provided to boundaries between said light-transmitting parts and said light-shielding parts, these grayscale parts are being provided along the entire periphery of peripheral edges of said the light-transmitting parts so as to surround the light-transmitting parts, and the exposure step being a step in which predetermined portions of the resist are exposed through the grayscale mask at an exposure amount equal to or less than Df (described below) so that the side surface shape of the structures constituted of the resist formed by development in the development step is forward taper, the exposure amount being determined on the basis of the relationship between the exposure amount for a predetermined thickness of the resist ascertained in advance and the taper angle of the forward taper;

• wherein Df is the minimum exposure amount at which the resist coated on the base material undergoes solarization across the entire thickness of the resist.

A method for manufacturing a master mold for imprinting, the master mold having structures formed in a bump pattern, the method for manufacturing a master mold for imprinting characterized by comprising a coating step in which a positive resist having a predetermined film thickness is coated on a base material, an exposure step in which light is directed from the front-surface side of the base material and the resist coated on the base material is exposed through a photomask, and a development step in which the exposed resist is developed, the photomask being a grayscale mask that is constituted of light-transmitting parts, light-shielding parts, and grayscale parts provided at boundaries between the light-transmitting parts and the light-shielding parts and is constituted such that these grayscale parts are provided along the entire periphery of peripheral edges of the light-shielding parts so as to surround the light-shielding parts, and the exposure step being a step in which predetermined portions of the resist are exposed through the grayscale mask at an exposure amount equal to or less than Df (described below) so that the side surface shape of the structures constituted of the resist formed by development in the development step is forward taper, the exposure amount being determined on the basis of the relationship between the exposure amount for a predetermined thickness of the resist ascertained in advance and the taper angle of the forward taper, wherein Df is the minimum exposure amount at which the resist coated on the base material undergoes solarization across the entire thickness of the resist.