Stamper for producing optical recording medium, optical recording medium, and methods of producing the same

A method for producing a stamper for producing an optical recording medium by transferring relief shapes to a surface of a medium substrate of the optical recording medium, said method including steps of:

• mirror polishing one main surface of a base member;
• forming a resist film on the mirror polished main surface of the base member;
• processing the resist film in a pattern corresponding to the relief shapes;
• processing the mirror polished main surface of the base member to the relief shapes by using the resist film as a mask;
• grinding an inner circumference and an outer circumference of the base member using a grinding wheel rotating at a speed of at least 10,000;
• and
• grinding the circumferences using a plastic grinding wheel or a vitrified grinding wheel mixed with diamond powder in at least a finishing process of the step of grinding the inner circumference and outer circumference of the base member.

A method for producing a stamper for producing an optical recording medium by transferring relief shapes to a surface of a medium substrate of the optical recording medium, said including steps of:

• mirror polishing one main surface of a base member;
• forming a resist film on the minor polished main surface of the base member;
• processing the resist film in a pattern corresponding to the relief shapes;
• processing the mirror polished main surface of the base member to the relief shapes by using the resist film as a mask;
• grinding an inner circumference and an outer circumference of the base member using a grinding wheel rotating at a speed of at least 10,000 rpm;
• and
• placing a dummy plate made by the same material as the base member or a material having an equivalent hardness against at least on the minor polished main surface and co-grinding the base member and the dummy plate in the step of grinding the inner circumference and outer circumference of the base member.