Optical recording medium and its manufacturing method

A method of manufacturing an optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising the steps of:

• manufacturing a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• forming a film formation layer having at least a recording layer;
• forming a light transmission flattening film having a transmittance to the irradiated light and filling in a concave-convex surface generated on a surface of the film formation layer to flatten the surface;
• and
• forming a hydrophilic material film on a surface where the light transmission flattening film is to be formed before the step of forming a light transmission flattening film and
• the substrate has a central hole,
• a non-film formation region for the film formation layer across a predetermined width around the central hole over the substrate at the step of forming a film formation layer having a recording layer;
• and
• forming the hydrophilic material film across the film formation layer and the substrate of the non-formation region in the central part region of the film formation layer.

An optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising:

• a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• a film formation layer provided with a concave-convex surface corresponding to the concave-convex portion which includes at least a recording layer over the main surface of the substrate;
• and
• a light transmission flattening film having a transmittance to the irradiated light which is formed on the film formation layer through a hydrophilic material film;
• wherein,
• the concave-convex surface on a surface of the film formation layer is filled with the light transmission flattening film and is thus flattened,
• the light transmission flattening film is formed of a spin on glass,
• the spin on glass is formed of an inorganic material containing SiO2 as a principal component and having a firing temperature of 150° C. or less, and the substrate is formed of polyethersulfone.

An optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising:

• a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• a film formation layer provided with a concave-convex surface corresponding to the concave-convex portion which includes at least a recording layer over the main surface of the substrate;
• and
• a light transmission flattening film having a transmittance to the irradiated light which is formed on the film formation layer through a hydrophilic material film;
• wherein,
• the concave-convex surface on a surface of the film formation layer is filled with the light transmission flattening film and is thus flattened
• the light transmission flattening film is formed of a spin on glass
• the spin on glass is formed of an inorganic material containing SiO2 as a principal component and having a firing temperature of 150° C. or less, and
• the substrate is formed of poletherimide.

A method of manufacturing an optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising the steps of:

• manufacturing a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• forming a film formation layer having at least a recording layer;
• forming a light transmission flattening film having a transmittance to the irradiated light and filling in a concave-convex surface generated on a surface of the film formation layer to flatten the surface;
• and
• forming a hydrophilic material film on a surface where the light transmission flattening film is to be formed before the step of forming a light transmission flattening film;
• wherein,
• the substrate has a central hole,
• a non-film formation region for the film formation layer across a predetermined width around the central hole over the substrate at the step of forming a film formation layer having a recording layer,
• forming the hydrophilic material film across the film formation layer and the substrate of the non-formation region in the central part region of the film formation layer, and the light transmission flattening film is formed by spin coating.

A method of manufacturing an optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising the steps of:

• manufacturing a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• forming a film formation layer having at least a recording layer;
• forming a light transmission flattening film having a transmittance to the irradiated light and filling in a concave-convex surface generated on a surface of the film formation layer to flatten the surface;
• forming a hydrophilic material film on a surface where the light transmission flattening film is to be formed before the step of forming a light transmission flattening film;
• wherein,
• the substrate has a central hole,
• a non-film formation region for the film formation layer across a predetermined width around the central hole over the substrate at the step of forming a film formation layer having a recording layer,
• forming the hydrophilic material film across the film formation layer and the substrate of the non-formation region in the central part region of the film formation layer,
• the light transmission flattening film is formed by spin coating, and
• the light transmission flattening film is formed of a spin on glass material containing SiO2 as a principal component and having a firing temperature of 150° C. or less.

A method of manufacturing an optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising the steps of:

• manufacturing a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• forming a film formation layer having at least a recording layer;
• forming a light transmission flattening film having a transmittance to the irradiated light and filling in a concave-convex surface generated on a surface of the film formation layer to flatten the surface;
• and
• forming a hydrophilic material film on a surface where the light transmission flattening film is to be formed before the step of forming a light transmission flattening film;
• wherein,
• the substrate has a central hole,
• a non-film formation region for the film formation layer across a predetermined width around the central hole over the substrate at the step of forming a film formation layer having a recording layer,
• forming the hydrophilic material film across the film formation layer and the substrate of the non-formation region in the central part region of the film formation layer,
• the light transmission flattening film is formed by spin coating,
• the light transmission flattening film is formed of a spin on glass material containing SiO2 as a principal component and having a firing temperature of 150° or less, and
• the substrate is constituted by an organic material, and the light transmission flattening film is formed by firing at 150 C or less.

A method of manufacturing an optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising the steps of:

• manufacturing a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• forming a film formation layer having at least a recording layer;
• forming a light transmission flattening film having a transmittance to the irradiated light and filling in a concave-convex surface generated on a surface of the film formation layer to flatten the surface;
• and
• forming a hydrophilic material film on a surface where the light transmission flattening film is to be formed before the step of forming a light transmission flattening film;
• wherein,
• the substrate has a central hole,
• a non-film formation region for the film formation layer across a predetermined width around the central hole over the substrate at the step of forming a film formation layer having a recording layer,
• forming the hydrophilic material film across the film formation layer and the substrate of the non-formation region in the central part region of the film formation layer,
• the light transmission flattening film is formed by spin coating, the light transmission flattening film is formed of a spin on glass material containing SiO2 as a principal component and having a firing temperature of 150° C. or less,
• the substrate is constituted by an organic material, and the light transmission flattening film is formed by firing at 150° C. or less, and
• the substrate is formed of polyethersulfone.

A method of manufacturing an optical recording medium for carrying out at least one of record and reproduction of information by light irradiation, comprising the steps of:

• manufacturing a substrate having a concave-convex portion formed on a main surface on a side where the light irradiation is to be carried out;
• forming a film formation layer having at least a recording layer;
• forming a light transmission flattening film having a transmittance to the irradiated light and filling in a concave-convex surface generated on a surface of the film formation layer to flatten the surface;
• forming a hydrophilic material film on a surface where the light transmission flattening film is to be formed before the step of forming a light transmission flattening film;
• wherein,
• the substrate has a central hole,
• a non-film formation region for the film formation layer across a predetermined width around the central hole over the substrate at the step of forming a film formation layer having a recording layer,
• forming the hydrophilic material film across the film formation layer and the substrate of the non-formation region in the central part region of the film formation layer,
• the light transmission flattening film is formed by spin coating,
• the light transmission flattening film is formed of a spin on glass material containing SiO2 as a principal component and having a firing temperature of 150° C. or less,
• the substrate is constituted by an organic material, and the light transmission flattening film is formed by firing at 150° C. or less, and the substrate is formed of poletherimide.