OPTICAL STORAGE MEDIUM, AND METHOD AND SYSTEM FOR MANUFACTURING OPTICAL STORAGE MEDIUM - Patent application

Abstract

An optical storage medium, a method for manufacturing an optical storage medium, and a system for manufacturing the optical storage medium are provided. In this application, the optical storage medium includes a substrate and at least one data layer, the data layer including a recording layer and a spacer layer, the recording layer being located on the spacer layer, and the data layer being located on the substrate. The recording layer can store data, and the recording layer includes an area where a phase-change material is distributed and an area where the phase-change material is not distributed, and the two different areas can represent different data. In the optical storage medium, there is a clear difference between the area where the phase-change material is distributed and the area where the phase-change material is not distributed. Therefore, even if the number of recording layers of the optical storage medium is increased to store more data, the area where the phase-change material is distributed and the area where the phase-change material is not distributed can be differentiated. As long as the accuracy of reading and writing data is ensured, the capacity of the optical storage medium can be increased by increasing the number of recording layers of the optical storage medium.

Description

[Technical field]

[0001] The present application relates to the field of communication technologies, in particular to optical storage media, methods and systems for manufacturing optical storage media. [Background technology]

[0002] With the advent of the communication era, the amount of data has increased explosively, and the demand for data storage has become higher. At present, the main storage technologies used are optical storage, magnetic storage, and semiconductor storage. Optical storage media have the advantages of long storage life, low maintenance cost, energy saving, environmental protection, etc., and Blu-ray disc is one of the representative optical storage media.

[0003] By writing data to the recording layer of a Blu-ray disc via a laser, the state of the phase change material in the recording layer changes; for example, the area where the state changes represents the data "1," and the area where the state does not change represents the data "0." With Blu-ray discs, the more recording layers there are, the larger the capacity they can accommodate. Assuming that the transmittance of the recording layer is ensured, the more recording layers there are, and the more areas in the recording layer where the state changes and the areas where the state does not change, the more data there is. do not The discrimination between the areas is reduced, i.e., the signal contrast is reduced. Therefore, the data cannot be read correctly from the Blu-ray disc after that. Controlling the amount of the recording layer within a narrow range limits the capacity of the Blu-ray disc. Summary of the Invention

[0004] The present application provides an optical storage medium, a method for manufacturing an optical storage medium, and a system for increasing the capacity of optical storage media.

[0005] According to a first aspect, an embodiment of the present application provides an optical storage medium. The optical storage medium includes a substrate and at least one data layer, the data layer includes a recording layer and a spacer layer, the recording layer is located on the spacer layer, and the data layer is located on the substrate. That is, the spacer layer and the recording layer are sequentially located on the substrate. The recording layer can store data, the recording layer includes an area where a phase change material is distributed and an area where the phase change material is not distributed, and the two different areas can represent different data. For example, the area where the phase change material is distributed can represent data "1", and the area where the phase change material is not distributed can represent data "0". Alternatively, the area where the phase change material is distributed can represent data "0", and the area where the phase change material is not distributed can represent data "1". The spacer layer can separate the recording layer from other layers (such as the substrate and other recording layers) in the optical storage medium to avoid contact between the recording layer and other layers.

[0006] In an optical storage medium, data can be stored in a recording layer since different data can be displayed in an area where a phase change material is distributed and an area where a phase change material is not distributed. In the optical storage medium provided in this embodiment of the present invention, since there is a clear difference between an area where a phase change material is distributed and an area where a phase change material is not distributed, even if the number of recording layers of the optical storage medium is increased to store more data, the area where a phase change material is distributed and the area where a phase change material is not distributed can be differentiated. This allows data to be read and written correctly. Therefore, the optical storage medium provided in the embodiment of the present invention can provide more recording layers, thereby increasing the capacity of the optical storage medium.

[0007] In a possible implementation, the optical storage medium may include multiple data layers stacked on a substrate.

[0008] In optical storage media, the optical storage medium can contain multiple data layers stacked on top of each other, so that the optical storage medium can have more recording layers on which data can be stored, thus increasing the capacity of the optical storage medium.

[0009] In a possible implementation, the components of the phase change material include antimony (Sb) and tellurium (Te).

[0010] In optical storage media, the phase change material containing antimony (Sb) and tellurium (Te) is an inorganic phase change material. After the phase change occurs in the inorganic phase change material, the state of the material is stable, so the phase change material can display data well.

[0011] In a possible implementation, the thickness range of the recording layer may be {10 nm, 50 nm}, i.e. the thickness of the recording layer may be between 10 nm and 50 nm or may be equal to 10 nm or 50 nm.

[0012] Since the thickness of the recording layer of an optical storage medium is thin, if the thickness of the optical storage medium is kept constant, the number of recording layers of the optical storage medium can be increased, and the capacity of the optical storage medium can be increased.

[0013] In a possible implementation, the thickness range of the spacer layer is {10 micrometers, 30 micrometers}, i.e., the thickness of the spacer layer is between 10 micrometers and 30 micrometers, or 10 It may be equal to 30 micrometers or 1 / 2 micrometer.

[0014] In optical storage media, because the thickness of the spacer layer is small, the ratio of the spacer layer to the entire optical storage medium can be reduced, and the ratio of the recording layer can be increased. By increasing the amount of the recording layer, the capacity of the optical storage medium can be further increased.

[0015] In a possible implementation, the amount of data layers is in the range {30,100}, i.e. the amount of data layers may be equal to 30, may be 100, or may be between 30 and 100.

[0016] In optical storage media, the amount of data layers can reach a large range, ensuring that the optical storage media can store a large amount of data.

[0017] In a possible implementation, the optical storage medium further comprises a reflective layer. The reflective layer is located between the data layer and the substrate. In the case of multiple data layers, the reflective layer is located between the substrate and the data layer closest to the substrate. The reflective layer is capable of reflecting light projected onto the optical storage medium back to the data layer.

[0018] In optical storage media, a reflective layer is configured to reflect servo light projected onto the optical storage media to aid in writing and reading of data.

[0019] In a possible implementation, the optical storage medium further comprises a protective layer, the protective layer being located on the recording layer furthest from the substrate, the protective layer being configured to prevent the recording layer from contacting the outside.

[0020] In optical storage media, the protective layer can isolate the recording layer from the outside and prevent the recording layer from being damaged.

[0021] According to a second aspect, the embodiment of the present application provides a method for manufacturing an optical storage medium. For advantageous effects, please refer to the description of the first aspect. Details will not be described again here. In this method, first, a first spacer layer is prepared on a substrate. Then, a layer of a phase change material is grown on the first spacer layer as a first phase change layer. Then, after the layer of the phase change material is grown, data can be written in the phase change material. For example, the first data to be stored can be written in the phase change material of the first phase change layer via a laser, and the laser can be projected onto the phase change material. A phase change occurs in the phase change material at the projected point, and no phase change occurs in the place where the laser is not projected. After the writing is performed, a part of the phase change material of the first phase change layer where data is not written may be removed. Specifically, a part of the phase change material where the laser is not projected may be removed.

[0022] In possible implementations, there are many ways to remove the phase change material from the first phase change layer where the first data is not written. For example, a wet etching method can be used to remove the phase change material with a developer to dissolve the parts of the phase change material where the data is not written. Of course, a dry etching method can also be used. Any method of removing the phase change material from the first phase change layer where the first data is not written is applicable to this embodiment of the present application.

[0023] In a possible implementation, the phase change material of the first phase change layer where the first data is not written is removed, and then the recording layer is formed. Then, multiple recording layers can be manufactured on the recording layer by similar operations, i.e., preparing a second spacer layer containing a phase change material and a second phase change layer, then writing the second data to be stored on the phase change material of the second phase change layer by a laser, and then removing the part of the second phase change layer where the data is not written. The above operations can be repeated to form a structure in which the second spacer layer and the recording layer are stacked.

[0024] In possible implementations, there are many ways to prepare the first spacer layer. For example, the first spacer layer can be prepared on the substrate via spin coating.

[0025] In a possible implementation, a reflective layer may be first provided on the substrate to reflect the light projected onto the optical storage medium, and then a first spacer layer may be provided on the reflective layer.

[0026] In a possible implementation, after the phase change material of the last phase change layer on which no data has been written is removed, a protective layer may be provided on the phase change layer, which may be configured to prevent the phase change material from coming into contact with the outside.

[0027] In a possible implementation, the components of the phase change material include at least antimony (Sb) and tellurium (Te).

[0028] In a possible implementation, the thickness of the phase change material may be in the range of {10 nanometers, 50 nanometers}, i.e., the thickness of the phase change material may be between 10 nanometers and 50 nanometers, or may be equal to 10 nanometers or 50 nanometers.

[0029] In a possible implementation, the thickness range of the first spacer layer or the second spacer layer is {10 micrometers, 30 micrometers}, that is, the thickness of the first spacer layer and the second spacer layer is greater than or equal to 10 micrometers and less than or equal to 30 micrometers.

[0030] According to a third aspect, an embodiment of the present application further provides a storage system, comprising an optical storage medium as provided in any of the above aspects and a data reading device, the data reading device being capable of reading data from the optical storage medium. [Brief description of the drawings]

[0031] [Figure 1] 3 is a flow chart of a method for manufacturing an optical storage medium according to the present application.

[0032] [Diagram 2] 1 is a schematic diagram of a method for manufacturing an optical storage medium according to an embodiment of the present application.

[0033] [Diagram 3] 1 is a schematic diagram of a structure of an optical storage medium according to an embodiment of the present application;

[0034] [Figure 4] 1 is a schematic diagram of a structure of a storage system according to an embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Before describing the optical storage medium, the method for manufacturing the optical storage medium, and the system provided in the embodiments of the present application, some basic concepts regarding optical disks will first be explained.

[0036] 1. Optical disc data recording method

[0037] Optical discs realize data writing (also called data recording) via a laser. When a laser is projected onto the recording layer of an optical disc, the material forming the recording layer undergoes physical or chemical changes, changing the state of the material forming the recording layer. The data to be recorded is characterized by the state of the material.

[0038] In the embodiment of the present application, the material forming the recording layer is a phase change material. When a laser is projected onto the recording layer, the state of some of the materials in the phase change material is converted from an amorphous state to a crystalline state. The phase change material in the crystalline state can represent and record a certain type of data, for example, data "1". The area in the recording layer where the phase change material is not distributed can represent another type of data, for example, data "0". Of course, the phase change material in the crystalline state can represent data "0", and the area in the recording layer where the phase change material is not distributed can represent data "1".

[0039] For example, to write data to an optical disk, two beams of light (which may be lasers) are required: to make it easier to distinguish, one beam is the write beam, used to write the data, and the other beam is the servo beam, used to point the track of data while writing the data.

[0040] The servo write is projected onto a reflective layer on the substrate of the optical disc. Whether the servo write is projected onto a groove on the substrate is determined based on the intensity of the reflected light of the servo write (when the intensity of the reflected light of the servo light projected onto the groove reaches a set value, or when the intensity of the reflected light of the servo light not projected onto the groove does not reach a set value, e.g., is close to 0). When the servo light is projected onto the position of the groove on the substrate, the position of the groove becomes the track of the data recorded on the optical disc. The write beam is projected onto the recording layer, and the data is written onto the track of the recording layer along the track indicated by the servo light. As a result, the data recorded onto the recording layer is recorded along the track indicated by the groove.

[0041] 2. Optical disc data reading method

[0042] After data is written to the optical disc, the areas representing different data in the recording layer have different reflectivities. After the light beam reaches the recording layer, the data is read out from the optical disc through signals formed by the reflectivity change format of "1" and "0".

[0043] For example, to read data from an optical disk, two beams of light (sometimes called lasers) are needed: to make it easier to distinguish, one beam is the read beam, used to read the data, and the other beam is the servo light, used to point to the data track while reading the data.

[0044] The servo light is projected onto a reflective layer on the substrate of the optical disc, and whether the servo light is projected onto a groove on the substrate is determined based on the intensity of the reflected light of the servo light. When the servo light is projected onto the groove on the substrate, the position of the groove becomes a track of data recorded on the optical disc. A data reading device projects a reading light onto the recording layer, and can read the data recorded by the recording layer along the track indicated by the servo light. In other words, the data reading device can determine the data recorded by the recording layer along the track based on the change in reflectance of the reflected light projected by the reading light onto the recording layer.

[0045] Hereinafter, the manufacturing method of an optical storage medium provided in each embodiment of the present application will be described with reference to the accompanying drawings, taking an example in which the optical storage medium is an optical disc. Figure 1 shows a manufacturing method of an optical disc according to an embodiment of the present application. The method includes the following steps:

[0046] Step 101: Prepare a substrate.

[0047] In this embodiment of the present application, the method of preparing the optical disk substrate is not limited. In this embodiment of the present application, an optical disk master with a groove is selected, and a child disk of the optical disk master is used as a template, and polycarbonate (PC) is injected into the child disk using an injection molding machine to form a substrate with a groove. The optical disk master is a mold for preparing a child disk, and the master and the child disk are identical. That is, the protrusions of the master correspond to the recesses of the child disk. In the embodiment of the present application, the material of the child disk is not limited. For example, an electroformed nickel child disk with high stability and strength can be selected as the material.

[0048] An optical disc has a groove on its substrate that is arranged to provide a track for the data recorded on the optical disc, i.e., all data recorded on the recording layer is recorded along the track.

[0049] Step 102: Providing a reflective layer on a substrate.

[0050] After preparing the substrate, a reflective layer can be prepared on the substrate. The reflective layer is configured to reflect light projected onto the optical disc, and can reflect the light to a recording layer in the optical disc. Therefore, the reflective layer needs to have a strong reflecting ability, and a material with good reflecting performance can be used for the reflective layer. In the embodiment of the present application, the material of the reflective layer is not limited. For example, a metal material such as silver or aluminum may be used, a metal compound material such as zinc dioxide or titanium dioxide, or some alloy material may be used.

[0051] In this embodiment of the present application, a reflective layer provided on the substrate is configured to reflect the servo light projected onto the reflective layer during data writing and data reading, and to determine whether to project the servo light onto the groove position on the substrate based on the intensity of the servo light, thereby finding the track required for data writing and the track of data during data reading.

[0052] There are several methods for preparing the reflective layer, such as plasma enhanced chemical vapor deposition (PECVD) (this method can be used to prepare metal compound materials), magnetron sputtering (this method can be used to prepare metal and alloy materials), and pulsed laser deposition (PLD) can be used.

[0053] Step 103: Providing a spacer layer on the reflective layer.

[0054] The spacer layer is configured to separate the subsequently prepared recording layers, so that the recording layers do not contact with another layer. Before each recording layer is prepared, one spacer layer is prepared first, so that any two recording layers do not contact each other. Then, when data needs to be read from the optical disc, no crosstalk occurs between the data read from different recording layers via light.

[0055] In the embodiment of the present application, the material and manufacturing method of the spacer layer are not limited. PC may be used, or organic materials such as polymethyl methacrylate (PMMA), polystyrene (PS), polyethylene terephthalate (PET), polyamide (PA), polyvinyl chloride (PVC), etc. may be used. The spacer layer may be prepared by convenient and low-cost spin coating, or a high-density spacer layer may be prepared by chemical vapor deposition or magnetron sputtering.

[0056] Step 104: Providing a phase change layer on the spacer layer, where the phase change layer includes a phase change material.

[0057] A phase change layer may be provided on the spacer layer, and the material of the phase change layer may be a phase change material. A phase change material (PCM) is a material that can change its physical state within a certain temperature range. Phase change materials include inorganic phase change materials such as antimony Sb or tellurium Te-based phase change materials and phase change materials such as GeSbTe and AgInSbTe. The physical state of the phase change material containing antimony Sb or tellurium Te becomes crystalline at high temperatures, and the physical state of the phase change material containing antimony Sb or tellurium Te remains amorphous at low temperatures.

[0058] There are several ways to prepare the phase change material layer, for example it can be done by PECVD or by magnetron sputtering.

[0059] Step 105: Writing data to the phase-change material in the phase-change layer.

[0060] After preparing the phase change layer, data can be written into the phase change layer. In the embodiment of the present application, the phase change material of the phase change layer is heated via a laser by laser writing, the temperature of the heated portion of the phase change material increases, and the physical state can change from an amorphous state to a crystalline state. The phase change material in the crystalline state can represent data "1". The temperature of the unheated portion of the phase change material does not change, the physical state remains amorphous, and the phase change material in the amorphous state can represent data "0". The phase change material in the crystalline state and the phase change material in the amorphous state are formed by laser writing. The phase change material in the crystalline state and the phase change material in the amorphous state can be distributed to represent the data recorded in the recording layer.

[0061] Step 106: Remove the phase-change material that is not written with data from the phase-change layer, i.e., remove the amorphous phase-change material to form a recording layer. The recording layer is configured to record data and is one of the core layers of the optical disc.

[0062] After writing data to the phase change material in the phase change layer, the phase change material in the amorphous state may be removed with a developer. In an embodiment of this application, after writing data, the phase change material in the phase change layer may be immersed in a developer. The developer may react with a portion of the phase change material in an unstable state (i.e., a non-crystalline state) to dissolve a portion of the phase change material in the amorphous state and retain a portion of the phase change material in a crystalline state.

[0063] After a portion of the amorphous phase-change material is removed with a developer, the developer remaining on the recording layer can be removed by washing, drying, or the like.

[0064] After performing step 106, a recording layer is formed on the spacer layer, and only the phase change material in the crystalline state is distributed in the recording layer. In order to remove the amorphous portion, the spacer layer under the recording layer is exposed at that portion. In the recording layer thus finally formed, the phase change material in the crystalline state can represent data "1", and the area where the phase change material does not exist can represent data "0". Since there is a clear difference between the area where the phase change material exists and the area where the phase change material does not exist in the recording layer, even if the amount of the recording layer of the optical disc is increased, the part where the phase change material exists in the recording layer can be better distinguished. That is, even if the amount of the recording layer is increased, the data can be accurately read from the recording layer. In addition, since there is a portion where the phase change material is not distributed in the recording layer, the light transmittance of the optical disc can also be improved. In addition, it is also possible to increase the amount of the recording layer of the optical disc to increase the capacity of the optical disc.

[0065] Repeat steps 103 to 106. Specifically, continue to create a spacer layer on the recording layer, and after the spacer layer is prepared, continue to create a phase change layer on the spacer layer, write data to the phase change material in the phase change layer (corresponding data is written in each phase change layer, and the data written in different phase change layers can be the same or different), and remove the part where data is not written (i.e., the phase change material in the amorphous state). Continue to create a spacer layer on the recording layer, continue to create a phase change material layer on the spacer layer, write data on the phase change material, and remove the part where data is not written. The steps can be performed periodically N times. That is, N spacer layers and N recording layers are prepared.

[0066] In the embodiment of the present application, one recording layer and one spacer layer can be used as the data layer. The optical disc can include multiple data layers, and the multiple data layers are sequentially stacked on the substrate. That is, multiple data layers can be formed by creating a reflective layer on the substrate, creating a first data layer, and then creating a second data layer on the first data layer. The amount of data layers is not limited in this embodiment of the present application. Compared with the optical disc with a limited amount of layers, the optical disc of the embodiment of the present application has 30 to 100 data layers, on the premise of ensuring the light transmittance.

[0067] Step 107: Prepare a protective layer on the last recording layer. The protective layer is configured to protect the recording layer and isolate the recording layer from the outside. In the embodiment of the present application, the material of the protective layer can be, for example, a shadowless adhesive (UV adhesive).

[0068] For the manufacturing method of the optical disc provided in the embodiment of the present application, please refer to FIG. 2. FIG. 2 is a schematic diagram of the manufacturing method of the optical disc according to the embodiment of the present application. In FIG. 2, (1) prepare a substrate with a groove; (2) prepare a reflective layer on the substrate; (3) prepare a spacer layer on the reflective layer by spin coating; (4) prepare a layer of phase-change material on the spacer layer by magnetron sputtering; (5) write data on the phase-change material layer by laser writing on the phase-change material to form a crystalline phase-change material and an amorphous phase-change material; (6) then remove the amorphous phase-change material in the phase-change material layer by developer, remove the residual developer and dry to form a recording layer; (7) then continue to prepare a spacer layer on the recording layer, and form a recording layer on the spacer layer in the above manner, repeatedly preparing N layers; (8) then prepare a protective layer on the last recording layer.

[0069] 3 is a schematic diagram of the structure of an optical disc according to an embodiment of the present application. The optical disc includes a substrate and at least one data layer located on the substrate. Each data layer includes a spacer layer and a recording layer.

[0070] The spacer layer is configured to separate the recording layer from other components in the optical disk. The recording layer is configured to record data, and the recording layer includes two distinct regions: a region in which the phase change material is distributed, and the phase change material in the region may be in a crystalline state, and a region in which the phase change material is not distributed, and the spacer layer below the recording layer may be exposed in the region in which the phase change material is not present. The regions in the recording layer in which the phase change material is distributed and the regions in which the phase change material is not distributed can show different data.

[0071] For example, in the recording layer, the area where the phase-change material is distributed represents data "1", and the area where the phase-change material is not distributed represents data "0". Alternatively, the area where the phase-change material is distributed represents data "0", and the area where the phase-change material is not distributed represents data "1". Please refer to the above for the explanation of the phase-change material. Details will not be described again here.

[0072] A reflective layer is further included between the substrate and the first data layer, the reflective layer being configured to reflect light projected onto the optical disc and to reflect the light onto each of the recording layers, whereby data can then be read from the optical disc.

[0073] The amount of data layers is not limited in this embodiment of the present application. There may be one or more data layers. When there are multiple data layers, the data layers are stacked on the substrate.

[0074] A protective layer may be disposed on the recording layer of the last data layer, the protective layer being configured to protect the recording layer and prevent the recording layer from contacting the outside.

[0075] In an optical disc, the data layer is the main core part of the optical disc. The more data layers there are, the larger the capacity of the optical disc, which indicates that more data can be recorded on the optical disc. The amount of data layers can be distributed in the interval of {30,100}. That is, the amount of data layers is less than 100 and more than 30. The thickness of the recording layer and the spacer layer is not limited in this embodiment of the present application. The thickness of the recording layer and the thickness of the spacer layer are related to the thickness that the optical disc needs to reach and the amount of data layers in the optical disc. Assuming that the thickness that the optical disc needs to reach is fixed, for example, when the thickness of the optical disc is 1.2 millimeters, the more data layers there are, the thinner the thickness of the recording layer and the thinner the thickness of the spacer layer. When the thickness of the optical disc is 1.2 millimeters, the range of the thickness of the recording layer is {10 nanometers, 50 nanometers}, that is, the thickness of the recording layer is less than 50 nanometers and more than 10 nanometers. And the range of the thickness of the spacer layer is {10 micrometers, 30 micrometers}, that is, the thickness of the spacer layer is less than 30 microns and more than 10 microns.

[0076] 4 shows a storage system according to an embodiment of the present application. The system 10 includes the optical disc 100 provided in the previous embodiment, and may further include a data reading device 200.

[0077] The data reading device 200 is capable of reading data from an optical disc by projecting a light beam onto the optical disc.

[0078] If necessary, the storage system may further include a decryption device 300. The decryption device 300 may decrypt the data read by the data reading device to generate data that can be identified by a user.

[0079] Please note that the optical disc is used only as an example, other types of optical storage media that can be manufactured using the methods provided in the embodiments of the present application or have the structures of the optical storage media provided in the embodiments of the present application are also applicable to the embodiments of the present application.

[0080] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the scope of the embodiments of the present application. The present application intends to cover these modifications and variations of the embodiments of the present application if they fall within the scope of the claims of the present application and their equivalent techniques.

Claims

1. 1. An optical storage medium comprising a substrate and a number of data layers stacked on the substrate; the data layer includes a recording layer and a spacer layer, the recording layer being located on the spacer layer; 1. An optical storage medium, comprising: a recording layer configured to store data, the recording layer including an area in which a phase-change material is distributed and an area in which the phase-change material is not distributed, the area in which the phase-change material is distributed and the area in which the phase-change material is not distributed representing different data, and the area in which the phase-change material is not distributed exposing the underlying spacer layer.

2. 2. The optical storage medium of claim 1, wherein the phase change material components include antimony (Sb) and tellurium (Te).

3. 3. The optical storage medium according to claim 1, wherein the thickness of the recording layer is between 10 nanometers and 50 nanometers.

4. 4. The optical storage medium of claim 1, wherein the spacer layer has a thickness of at least 10 micrometers and at most 30 micrometers.

5. 4. The optical storage medium according to claim 1, wherein the number of data layers is ≥ 30 and ≤ 100.

6. 5. The optical storage medium of claim 1 , further comprising a reflective layer, the reflective layer being located between the data layer and the substrate, the reflective layer being configured to reflect light projected onto the optical storage medium.

7. 7. The optical storage medium of claim 1, further comprising a protective layer located on the recording layer furthest from the substrate, the protective layer being configured to prevent the recording layer from contacting the outside.

8. 1. A method for manufacturing an optical storage medium, comprising the steps of: Providing a first spacer layer over a substrate; growing a first phase change layer on the first spacer layer, the first phase change layer comprising a phase change material; writing first data to be stored on the phase change material of the first phase change layer with a laser; removing phase change material from the first phase change layer where the first data is not written, exposing the underlying first spacer layer in areas where the phase change material is removed; providing a second spacer layer on the first phase change layer; growing a second phase change layer on the second spacer layer, the second phase change layer comprising a phase change material; writing second data to be stored on the phase change material of the second phase change layer via a laser; removing the phase change material from the second phase change layer that does not contain the second data; The method includes:

9. The step of removing the phase change material not having the first data written thereto from the first phase change layer includes:

9. The method of claim 8, further comprising washing the first phase change layer with a developer to dissolve phase change material in the first phase change layer that is not written with the first data.

10. Providing a first spacer layer over the substrate includes: providing a reflective layer on the substrate, the reflective layer configured to reflect light projected onto the optical storage medium; spin coating the first spacer layer on the reflective layer; The method of claim 8 or 9, comprising:

11. A plurality of second spacer layers and a plurality of second phase change layers are sequentially provided on the first phase change layer, the method comprising:

9. The method of claim 8, further comprising the step of preparing a protective layer on the last second phase change layer after the second data is not written and the phase change material in the last second phase change layer is removed, the protective layer being used to prevent the last second phase change layer from contacting the outside.

12. 12. The method according to claim 8, wherein the phase change material components include at least antimony (Sb) and tellurium (Te).

13. 13. The method according to claim 8, wherein the thickness of the phase change material is greater than or equal to 10 nanometers and less than or equal to 50 nanometers.

14. 14. The method of claim 8, wherein the first spacer layer has a thickness in the range of 10 micrometers to 30 micrometers.

15. 1. A storage system comprising:

8. An optical storage medium according to any one of claims 1 to 7, and a data reading device, The data reading device is configured to read data from the optical storage medium.

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