Photoresist for optical disc and method of preparing optical disc utilizing photoresist

A method of preparing an optical disc comprising the steps of:

• preparing a positive-type photoresist consisting essentially of a base resin and a photosensitive material and also preparing a glass substrate;
• coating the photoresist on the glass substrate to form a resist film;
• forming a pit pattern through a light exposure at a wavelength of 351 nm to the resist film;
• developing the resist film after the light exposure to form a resist original;
• effecting a plating treatment to the resist original to form a stamper;
• forming a replica disc through an injection molding process by utilizing the stamper;
• forming a reflection film on the replica disc;
• and
• forming an overcoat layer on the reflection film,
• wherein the positive-type photoresist satisfies a condition that a value of A in a formula A=(a1−a3)m10, wherein a1 represents a molar absorption coefficient of the photosensitive material with respect to a light utilized for an actual recording, a3 represents a molar absorption coefficient of a decomposed product derived from the photosensitive material with respect to light utilized for actual recording and m10 represents an original density of the photosensitive material, is in a range of 1.2≦A value ≦2.0, and that a value of B in a formula B=(a2m20+a3m10), wherein a2 represents a molar absorption coefficient of the base resin with respect to light utilized for actual recording, a3 represents a molar absorption coefficient of a decomposed product derived from the photosensitive material with respect to a light utilized for actual recording, m10 represents an original density of the photosensitive material and m20 represents a density of the base resin, being constant, is in a range of B value ≦0.3.