High density optical recording medium having multiple recording layers

An optical recording medium, comprising:

• two or more recording layers;
• and
• a light irradiation surface that is irradiated with light for recording an information signal on the two or more recording layers,
• wherein among the two or more recording layers, at least one layer other than a layer located on a deepest side from the light irradiation surface includes an oxide of a metal A, an oxide of a metal B, an oxide of a metal C, and an oxide of a metal D,
• the metal A is at least one kind among W, Mo, and Zr, the metal B is Mn, the metal C is at least one kind among Cu, Ag, and Ni, and the metal D is at least one kind of Zn and Mg, and
• ratios of the metal A, the metal B, the metal C, and the metal D satisfy a relationship of 0.46≤x2 (provided that, x2=(0.1d+a)/(b+0.8c), a representing an atomic ratio [atom %] of the metal A with respect to a sum of the metal A, the metal B, the metal C, and the metal D, b representing an atomic ratio [atom %] of the metal B with respect to the sum of the metal A, the metal B, the metal C, and the metal D, c representing an atomic ratio [atom %] of the metal C with respect to the sum of the metal A, the metal B, the metal C, and the metal D, and d representing an atomic ratio [atom %] of the metal D with respect to the sum of the metal A, the metal B, the metal C, and the metal D),
• wherein among the two or more recording layers, all of the recording layers other than the layer located on the deepest side from the light irradiation surface include the oxide of the metal A, the oxide of the metal B, the oxide of the metal C, and the oxide of the metal D, and the relationship of 0.46≤x2 is satisfied, and
• wherein a value of x2 becomes larger in a recording layer that is closer to the light irradiation surface.

An optical recording medium, comprising:

• two or more recording layers;
• and
• a light irradiation surface that is irradiated with light for recording an information signal on the two or more recording layers,
• wherein among the two or more recording layers, at least one layer other than a layer located on a deepest side from the light irradiation surface includes an oxide of a metal A, an oxide of a metal B, and an oxide of a metal C,
• the metal A is at least one kind among W, Mo, and Zr, the metal B is Mn, and the metal C is at least one kind among Cu, Ag, and Ni, and
• ratios of the metal A, the metal B, and the metal C satisfy a relationship of 0.46≤x1 (provided that, x1=a/(b+0.8c), a representing an atomic ratio [atom %] of the metal A with respect to a sum of the metal A, the metal B, and the metal C, b representing an atomic ratio [atom %] of the metal B with respect to the sum of the metal A, the metal B, and the metal C, and c representing an atomic ratio [atom %] of the metal C with respect to the sum of the metal A, the metal B, and the metal C),
• wherein at least two layers among the two or more recording layers include the oxide of the metal A, the oxide of the metal B, and the oxide of the metal C, and the relationship of 0.46≤x1 is satisfied, and
• wherein a relationship in which a value of x1 is greater in a recording layer that is closer to the light irradiation surface is satisfied.

An optical recording medium, comprising:

• two or more recording layers;
• and
• a light irradiation surface that is irradiated with light for recording an information signal on the two or more recording layers,
• wherein among the two or more recording layers, at least one layer other than a layer located on a deepest side from the light irradiation surface includes an oxide of a metal A, an oxide of a metal B, an oxide of a metal C, and an oxide of a metal D,
• the metal A is at least one kind among W, Mo, and Zr, the metal B is Mn, the metal C is at least one kind among Cu, Ag, and Ni, and the metal D is at least one kind of Zn and Mg, and
• ratios of the metal A, the metal B, the metal C, and the metal D satisfy a relationship of 0.46≤x2 (provided that, x2=(0.1d+a)/(b+0.8c), a representing an atomic ratio [atom %] of the metal A with respect to a sum of the metal A, the metal B, the metal C, and the metal D, b representing an atomic ratio [atom %] of the metal B with respect to the sum of the metal A, the metal B, the metal C, and the metal D, c representing an atomic ratio [atom %] of the metal C with respect to the sum of the metal A, the metal B, the metal C, and the metal D, and d representing an atomic ratio [atom %] of the metal D with respect to the sum of the metal A, the metal B, the metal C, and the metal D),
• wherein at least two layers among the two or more recording layers include the oxide of the metal A, the oxide of the metal B, the oxide of the metal C, and the oxide of the metal D, and the relationship of 0.46≤x2 is satisfied, and
• wherein a relationship in which a value of x2 is greater in a recording layer that is closer to the light irradiation surface is satisfied.

A method of manufacturing an optical recording medium, comprising:

• a process of forming two or more recording layers by reactive sputtering with at least oxygen,
• wherein among the two or more recording layers, at least one layer other than a layer located on a deepest side from the light irradiation surface irradiated with light for recording an information signal on the two or more recording layers includes an oxide of a metal A, an oxide of a metal B, and an oxide of a metal C,
• the metal A is at least one kind among W, Mo, and Zr, the metal B is Mn, and the metal C is at least one kind among Cu, Ag, and Ni, and
• ratios of the metal A, the metal B, and the metal C satisfy a relationship of 0.46≤x1 (provided that, x1=a/(b+0.8c), a representing an atomic ratio [atom %] of the metal A with respect to a sum of the metal A, the metal B, and the metal C, b representing an atomic ratio [atom %] of the metal B with respect to the sum of the metal A, the metal B, and the metal C, and c representing an atomic ratio [atom %] of the metal C with respect to the sum of the metal A, the metal B, and the metal C),
• wherein among the two or more recording layers, all of the recording layers other than the layer located on the deepest side from the light irradiation surface include the oxide of the metal A, the oxide of the metal B, and the oxide of the metal C, and the relationship of 0.46≤x1 is satisfied, and
• wherein a value of x1 becomes larger in a recording layer that is closer to the light irradiation surface.

A method of manufacturing an optical recording medium, comprising:

• a process of forming two or more recording layers by reactive sputtering with at least oxygen,
• wherein among the two or more recording layers, at least one layer other than a layer located on a deepest side from the light irradiation surface irradiated with light for recording an information signal on the two or more recording layers includes an oxide of a metal A, an oxide of a metal B, an oxide of a metal C, and an oxide of a metal D,
• the metal A is at least one kind among W, Mo, and Zr, the metal B is Mn, the metal C is at least one kind among Cu, Ag, and Ni, and the metal D is at least one kind of Zn and Mg, and
• ratios of the metal A, the metal B, the metal C, and the metal D satisfy a relationship of 0.46≤x2 (provided that, x2=(0.1d+a)/(b+0.8c), a representing an atomic ratio [atom %] of the metal A with respect to a sum of the metal A, the metal B, the metal C, and the metal D, b representing an atomic ratio [atom %] of the metal B with respect to the sum of the metal A, the metal B, the metal C, and the metal D, c representing an atomic ratio [atom %] of the metal C with respect to the sum of the metal A, the metal B, the metal C, and the metal D, and d representing an atomic ratio [atom %] of the metal D with respect to the sum of the metal A, the metal B, the metal C, and the metal D),
• wherein among the two or more recording layers, all of the recording layers other than the layer located on the deepest side from the light irradiation surface include the oxide of the metal A, the oxide of the metal B, the oxide of the metal C, and the oxide of the metal D, and the relationship of 0.46≤x2 is satisfied, and
• wherein a value of x2 becomes larger in a recording layer that is closer to the light irradiation surface.

A method of manufacturing an optical recording medium, comprising:

• a process of forming two or more recording layers by reactive sputtering with at least oxygen,
• wherein among the two or more recording layers, at least one layer other than a layer located on a deepest side from the light irradiation surface irradiated with light for recording an information signal on the two or more recording layers includes an oxide of a metal A, an oxide of a metal B, and an oxide of a metal C,
• the metal A is at least one kind among W, Mo, and Zr, the metal B is Mn, and the metal C is at least one kind among Cu, Ag, and Ni, and
• ratios of the metal A, the metal B, and the metal C satisfy a relationship of 0.46≤x1 (provided that, x1=a/(b+0.8c), a representing an atomic ratio [atom %] of the metal A with respect to a sum of the metal A, the metal B, and the metal C, b representing an atomic ratio [atom %] of the metal B with respect to the sum of the metal A, the metal B, and the metal C, and c representing an atomic ratio [atom %] of the metal C with respect to the sum of the metal A, the metal B, and the metal C),
• wherein at least two layers among the two or more recording layers include the oxide of the metal A, the oxide of the metal B, and the oxide of the metal C, and the relationship of 0.46≤x1 is satisfied, and
• wherein a relationship in which a value of x1 is greater in a recording layer that is closer to the light irradiation surface is satisfied.

A method of manufacturing an optical recording medium, comprising:

• a process of forming two or more recording layers by reactive sputtering with at least oxygen,
• wherein among the two or more recording layers, at least one layer other than a layer located on a deepest side from the light irradiation surface irradiated with light for recording an information signal on the two or more recording layers includes an oxide of a metal A, an oxide of a metal B, an oxide of a metal C, and an oxide of a metal D,
• the metal A is at least one kind among W, Mo, and Zr, the metal B is Mn, the metal C is at least one kind among Cu, Ag, and Ni, and the metal D is at least one kind of Zn and Mg, and
• ratios of the metal A, the metal B, the metal C, and the metal D satisfy a relationship of 0.46≤x2 (provided that, x2=(0.1d+a)/(b+0.8c), a representing an atomic ratio [atom %] of the metal A with respect to a sum of the metal A, the metal B, the metal C, and the metal D, b representing an atomic ratio [atom %] of the metal B with respect to the sum of the metal A, the metal B, the metal C, and the metal D, c representing an atomic ratio [atom %] of the metal C with respect to the sum of the metal A, the metal B, the metal C, and the metal D, and d representing an atomic ratio [atom %] of the metal D with respect to the sum of the metal A, the metal B, the metal C, and the metal D),
• wherein at least two layers among the two or more recording layers include the oxide of the metal A, the oxide of the metal B, the oxide of the metal C, and the oxide of the metal D, and the relationship of 0.46≤x2 is satisfied, and
• wherein a relationship in which a value of x2 is greater in a recording layer that is closer to the light irradiation surface is satisfied.