JP4327706B2 - Optical information recording medium master manufacturing method, optical information recording medium stamper manufacturing method, optical information recording medium master, stamper, and optical information recording medium - Google Patents

Description

  The present invention relates to an optical information recording medium master manufacturing method, an optical information recording medium stamper manufacturing method, an optical information recording medium master, a stamper, and an optical information recording medium.

In general, an optical information recording medium such as an optical disk is manufactured using a disk substrate that is manufactured by injection molding or the like using a stamper having a predetermined uneven pattern.
Hereinafter, an example of a conventional method for manufacturing a stamper for an optical information recording medium will be described with reference to FIGS.

  In this conventional stamper manufacturing process, first, as shown in FIG. 5A, recording light 504 such as a laser beam or an electron beam is applied to a recording master 503 in which a resist 502 is formed in a thin film on a substrate 501. The desired pattern such as guide grooves and information pits is formed as a latent image 505 by the exposure according to the above.

  Subsequently, as shown in FIG. 5 (b), the exposed recording master 503 is subjected to a development process so that a desired pattern recorded as a latent image 505 has a concavo-convex pattern formed as a convex portion or a concave portion. A master 506 is produced. In addition, exposure with an ultraviolet laser or an electron beam and development with an alkaline solution are widely used for manufacturing a master disc of a DVD or its next generation optical information recording medium.

  Next, as shown in FIG. 5C, a conductive film 507 is formed on the master 506 by sputtering or electroless plating. Subsequently, as shown in FIG. 5D, a metal layer 508 is formed by plating using a conductive film 507. Thereafter, as shown in FIG. 5E, only the metal layer 508 or the metal layer 508 with the conductive film 507 is peeled from the master 506, and the metal layer 508 is subjected to shaping such as back surface polishing or punching. Apply. Thereby, the stamper 509a without the conductive film 507 or the stamper 509b with the conductive film 507 is completed. In some cases, a metal layer 508 peeled off from the master 506 may be subjected to plating, 2P method, or the like once or more to transfer the uneven pattern on the metal layer 508 as a stamper.

  A disc substrate of an optical information recording medium is manufactured by injection molding or the like using the stampers 509a and 509b manufactured as described above. Further, an optical information recording medium is manufactured using this disk substrate. Here, the case where a positive type photoresist is used is described. However, the case where a negative type photoresist is used also applies to the above description except that the unevenness on the master is reversed.

In the production of this conventional optical information recording medium stamper, a photoresist made of an organic material is generally used as the resist 502. However, when a photoresist made of an organic material is used as the resist 502, the amount of exposure continuously changes at the boundary between the exposed portion and the non-exposed portion. It is difficult to form sharply and is removed with a slight inclination. For this reason, there exists a problem that it is difficult to form a fine uneven | corrugated pattern. Therefore, the resist 502 is made of a heat-sensitive inorganic material such as a phase change material, and even when recording light having the same wavelength is used, the edge of the concavo-convex pattern portion is sharpened compared to the case where a photoresist made of an organic material is used. There has been proposed a stamper manufacturing method in which a fine concavo-convex pattern is formed (see, for example, Patent Document 1).
JP-A-10-97738

  By the way, a photoresist made of an organic material such as a novolak resin or PMMA, which has been widely used in the manufacture of a stamper of an optical information recording medium, is relatively stable when a metal layer that becomes a stamper material is formed by plating. Is expensive. However, when a resist made of an inorganic material such as a phase change material is used, it is possible to sharpen the edges of the concavo-convex pattern portion formed by development processing, but when forming a metal layer by plating There is a risk that the inorganic material will change state. Thus, when the state of the inorganic material changes, it becomes difficult to keep the shape of the concavo-convex pattern of the resist in a good state.

  The present invention has been made to solve the above-described conventional problems. Even when an inorganic material is used as a resist, the state change of the inorganic material is suppressed when a predetermined uneven pattern is transferred to the stamper side. An optical information recording medium master, a method for manufacturing an optical information recording medium stamper, an optical information recording medium master, a stamper, and an optical information recording medium are provided. This is a problem to be solved.

According to an aspect of the present invention, there is provided a method of manufacturing a master for an optical information recording medium, wherein a resist including an inorganic material that changes state by exposure processing is formed on a substrate, and the resist is subjected to exposure processing and development processing. By forming a concavo-convex pattern portion, and forming an isolation layer made of a second inorganic material containing fluoride on the concavo-convex pattern portion, a master disc of an optical information recording medium is manufactured. That is, in the stamper manufacturing method, an isolation layer is formed between the resist and the conductive film.
The isolation layer physically isolates the resist and the conductive film, thereby suppressing a chemical reaction between them.
Since the second inorganic material containing fluoride is used for the isolation layer, the peelability is improved and the residue of the inorganic isolation layer on the stamper can be suppressed.

An optical information recording medium master manufacturing method according to another aspect of the present invention is a master manufacturing method for transferring a predetermined concavo-convex pattern to a stamper of an optical information recording medium, wherein an exposure process is performed. A resist containing a first inorganic material whose state changes by the above process is formed on the substrate, and the concavo-convex pattern portion is formed by subjecting the resist to the exposure process and the development process, and a diamond-like pattern is formed on the concavo-convex pattern part. An isolation layer made of a second inorganic material containing carbon is formed.
Since the second inorganic material containing diamond-like carbon is used for the isolation layer, it is preferable to make a release product. Therefore, the residue of the inorganic isolation layer on the stamper can be suppressed.

An optical information recording medium master manufacturing method according to another aspect of the present invention is a master manufacturing method for transferring a predetermined concavo-convex pattern to a stamper of an optical information recording medium, wherein an exposure process is performed. Forming a resist including a first inorganic material that changes state on the substrate, subjecting the resist to the exposure process and the development process to form a concavo-convex pattern part, and forming an alkali on the concavo-convex pattern part An isolation layer made of a second inorganic material containing a soluble material is formed.
Since the second inorganic material containing an alkali-soluble material is used for the isolation layer, dissolution and removal are possible even when a residue of the isolation layer is generated on the stamper by being dissolved by the alkali.

An optical information recording medium master manufacturing method according to another aspect of the present invention is a method for transferring a predetermined concavo-convex pattern to a stamper of an optical information recording medium by performing an exposure process. A resist containing a first inorganic material that changes in state is formed on a substrate, and a concavo-convex pattern portion is formed by subjecting the resist to the exposure treatment and the development treatment. A tungsten oxide, niobium is formed on the concavo-convex pattern portion. An isolation layer made of a second inorganic material containing at least one of oxide, tin oxide, molybdenum oxide, and silicon is formed.
Since the isolation layer contains at least one of tungsten oxide, niobium oxide, tin oxide, molybdenum oxide, and silicon, it dissolves even if the isolation layer residue is generated on the stamper by melting with alkali. Removal is possible.

An optical information recording medium master manufacturing method according to another aspect of the present invention is a master manufacturing method for transferring a predetermined concavo-convex pattern to a stamper of an optical information recording medium, wherein an exposure process is performed. Forming a resist containing a first inorganic material that changes state on the substrate, subjecting the resist to the exposure process and the development process to form a concavo-convex pattern portion, and forming a water-soluble layer on the concavo-convex pattern portion. An isolation layer made of a second inorganic material containing the above material is formed.
Since the second inorganic material containing a water-soluble material is used for the isolation layer, even if a residue of the isolation layer is generated on the stamper, it can be dissolved and removed by using water.

An optical information recording medium master manufacturing method according to another aspect of the present invention is a master manufacturing method for transferring a predetermined concavo-convex pattern to a stamper of an optical information recording medium, wherein an exposure process is performed. Forming a resist containing a first inorganic material whose state changes by the above, and subjecting the resist to the exposure treatment and the development treatment to form a concavo-convex pattern portion. A separation layer made of a second inorganic material containing at least one of iron chloride, potassium iodide, and rubidium chloride is formed.
Since the second inorganic material containing at least one of sodium chloride, iron chloride, potassium iodide, and rubidium chloride is used for the isolation layer, water is also generated even if the isolation layer residue is generated on the stamper. It is possible to remove by dissolution.

An optical information recording medium master for transferring a predetermined concavo-convex pattern to a stamper of an optical information recording medium, comprising: a resist including a first inorganic material that changes state by being subjected to an exposure process; An isolation layer made of a second inorganic material, which is formed on a substrate, forms an uneven pattern portion by subjecting the resist to the exposure process and the development process, and includes an acid-soluble material on the uneven pattern portion. Form.
Since the second inorganic material containing an acid-soluble material is used for the isolation layer, even when a residue of the isolation layer is generated on the stamper, the removal can be performed by using water.

According to still another aspect of the present invention, a method for manufacturing a master of an optical information recording medium includes providing a release layer on an inorganic isolation layer in the master manufacturing method. By providing the release layer, even if a residue is generated on the stamper, it is easy to dissolve and remove the stamper, and the stamper can be manufactured satisfactorily. For the release layer, various inorganic and organic materials having high solubility in acids, alkalis, water, organic solvents, and the like can be used.
More preferably, the combined thickness of the isolation layer made of the inorganic material and the release layer made of the inorganic material is 150 nm or less, and the thickness of the isolation layer is 5 nm or more, or 15 nm or more.
  The thickness of the release layer made of an organic material is preferably 60 nm or less.

  According to the method for manufacturing a master of an optical information recording medium according to the present invention, even when an inorganic material is used as a resist, a concavo-convex pattern is suppressed by suppressing a change in state of the inorganic material when a predetermined concavo-convex pattern is transferred to the stamper Can be kept in a good state. Thereby, favorable plating can be performed, and it becomes possible to use as the resist an inorganic material in which a state change is caused by exposure, which has conventionally been difficult to plate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1. 1. First Embodiment (1) Overview of Manufacturing Method Hereinafter, an overview of a method for manufacturing a stamper for an optical information recording medium according to a first embodiment of the present invention will be described with reference to FIGS. .

  First, as shown in FIG. 1A, a recording light 104 such as a laser beam or an electron beam is applied to a recording master 103 in which a resist 102 made of an inorganic material that changes its state upon exposure is formed on a substrate 101. The desired pattern such as guide grooves and information pits is formed as the latent image 105 by the exposure by (exposure process).

Subsequently, as shown in FIG. 1B, the recording master 103 after exposure is subjected to a development process so that a desired pattern recorded as the latent image 105 is formed as a convex or concave portion on the recording master 103. A rough pattern portion is formed (development process).
Next, as shown in FIG. 1C, an inorganic isolation layer 107 is formed on the fine uneven pattern portion on the recording master 103, and the master 106 is manufactured (inorganic isolation layer forming step).

Subsequently, as shown in FIG. 1D, a conductive film 108 is formed on the inorganic isolation layer 107 by an electroless plating method (conductive film forming step). Note that the conductive film 108 may be formed by a sputtering method.
Then, as shown in FIG. 1E, a metal layer 109 is formed on the conductive film 108 by plating using the conductive film 108 (metal layer forming step).

  Thereafter, as shown in FIG. 1 (f), only the metal layer 109, or the metal layer 109 and the conductive film 108 are peeled off from the master 106, and the metal layer 109 is subjected to shaping such as back surface polishing or punching ( Peeling step). As a result, the stamper 110a without the conductive film 108 or the stamper 110b with the conductive film 108 to which the uneven pattern of the master 106 is transferred is completed. Furthermore, a substrate is manufactured by injection molding using the stamper, and an optical information recording medium is manufactured using the substrate.

If the method of the present invention is used, the production of a stamper having a higher recording density than that of the conventional method and the optical information can be obtained even with the recording light having the same wavelength as the conventional wavelength when the photoresist made of an organic material is exposed. A recording medium can be manufactured.
(2) Details of Manufacturing Method Hereinafter, the manufacturing method of the stamper of the optical information recording medium according to the first embodiment of the present invention will be described more specifically.

  As the substrate 101 of the recording master 103 exposed in the exposure step (see FIG. 1A), for example, a substrate made of various types of glass, silicon, resin, or the like is used. As a material of the resist 102 formed on the substrate 101, an inorganic material that changes its state by exposure, for example, germanium, tellurium, antimony, selenium, molybdenum, tungsten, titanium, or a compound such as an oxide thereof is a main component. Including materials are used. These inorganic materials contain noble metals such as gold, platinum group, silver and copper, or silicon dioxide, so that the remaining film ratio at the time of development can be improved and can be suitably used in the method of the present invention. it can. Here, the resist 102 made of an inorganic material that undergoes a phase change upon exposure is formed on the substrate 101 by, for example, a sputtering method, a vacuum evaporation method, a spin coating method, or the like. Therefore, it is possible to produce a resist 102 that can easily form a uniform good resist and can be suitably used in the method of the present invention. Note that the recording master 103 may include components other than those described above, for example, an interface layer and a reflective layer, as long as the above configuration is maintained.

  Next, an exposure method for the resist 102 of the recording master 103, that is, a pattern recording method on the recording master 103 will be described with reference to FIG. As shown in FIG. 2, the recording master 103 is placed on the turntable 201 and rotated together with the turntable 201. The recording light 104 emitted from the light source 202 is condensed on the surface of the recording master 103 by the lens 203. If necessary, the recording light 104 may be modulated and deflected in the light source 202. At the time of recording, the recording head 204 and the turntable 201 move relatively in parallel as indicated by an arrow A. Thereby, recording is performed in a spiral shape on the recording master 103, and a desired pattern is formed as the latent image 105 described above. As the recording light 104, a laser beam, an electron beam bundle, or the like can be used. In the recording master 103 in which a desired pattern is formed as the latent image 105, a state change such as a phase change due to exposure (hereinafter referred to as a “state change region”) and a state change are caused without being exposed. The etching rate is different from the non-region (hereinafter referred to as “state unchanged region”).

  Therefore, in the developing process (see FIG. 1B), the recording master 103 is developed by etching using this etching rate difference. Examples of etching include dry etching such as reactive ion etching, wet etching with acid or alkali, etc., but what if the etching rate is different between the state change region and the state unchanged region? Various methods may be used. By such development processing, a recording master 103 of an optical information recording medium having an uneven pattern portion is manufactured.

  In the inorganic isolation layer forming step (see FIG. 1C), for example, an inorganic material such as fluoride, oxide, nitride, diamond-like carbon (hereinafter referred to as DLC), for example, sputtering or vacuum deposition is used. A thin film is formed on the recording master 103 by a vacuum process such as a chemical vapor deposition method (hereinafter referred to as CVD). As a result, a master 106 in which an inorganic isolation layer 107 is added to the substrate 101 and the developed resist 102 (recording master 103) is manufactured. By this inorganic isolation layer 107, the resist 102 can be isolated from the conductive film 108 and the metal layer 109, and it is possible to prevent a reaction between them or a change in state of the resist 102. In addition, it is possible to make it difficult to produce a residue of the inorganic isolation layer 107 on the stamper 110.

In addition to the materials listed above, various materials can be used as the inorganic material, but materials satisfying the following requirements are inorganic materials that can be suitably used in the first embodiment of the present invention. .
(Requirement 1) Low electrical conductivity and difficult to be electrically decomposed.

(Requirement 2) Good peelability with respect to the conductive film 108.
(Requirement 3) It dissolves in a solvent that does not attack the surface of the conductive film 108.
Requirement 1 is essential for preventing the inorganic material from reacting or electrically decomposing with the conductive film 108 or the metal layer 109 formed by plating by application during plating. Fluorides, oxides, nitrides, and the like are very stable materials and can be suitably used in the method of the present invention.

Requirement 2 is effective in suppressing the generation of inorganic material residues on the stamper 110b when the stamper 110b with the conductive film 108 is manufactured.
Requirement 3 is that when manufacturing the stamper 110b with the conductive film 108, alkali, water, etc. (if the stamper 110b surface is a highly acid-resistant material such as gold or platinum group, an acid may be used). By using an inorganic material that is soluble in a solvent that does not attack the surface of the stamper 110b, when an inorganic material residue is generated on the stamper 110b, the residue can be removed without damaging the stamper 110b using alkali, water, acid, or the like. Effective to remove.

As described above, requirements 2 and 3 are requirements for suppressing or removing residues when manufacturing the stamper 110b with the conductive film 108, and the stamper 110a without the conductive film 108 is provided. This is not an essential requirement for manufacturing.
As specific materials satisfying these requirements, first, as satisfying requirement 1, fluorides such as magnesium fluoride and lanthanum fluoride, oxides such as silicon dioxide and molybdenum oxide, silicon nitride, aluminum nitride, etc. Nitrides, and mixtures thereof.

  Those satisfying Requirement 2 include fluorides such as magnesium fluoride, lanthanum fluoride, and calcium fluoride, DLC, and silicon dioxide (adhesive force to conductive film 108 and silicon dioxide such as gold, white metal, copper, and aluminum) Can be suitably used in the method of the present invention. When gold is used for the conductive film, titanium oxide, aluminum oxide, bismuth oxide, tin oxide, and the like have good peelability and can be used favorably in the method of the present invention. The inorganic material satisfying the requirement 2 can not only suppress the residue of the inorganic isolation layer 107 on the stamper 110b, but can also dissolve and remove the residue of the inorganic isolation layer 107 on the stamper 110b. .

  Examples of materials that satisfy requirement 3 include alkali-soluble materials such as tungsten oxide, niobium oxide, tin oxide, molybdenum oxide, and silicon, sodium chloride, iron chloride, potassium iodide, and rubidium chloride. A water-soluble material, or an acid-soluble material such as tin oxide or copper chloride (when the stamper surface is a highly acid-resistant material such as gold or platinum group) is preferably used in the method of the present invention. Can do. Of course, materials other than those exemplified here can be used in the method of the present invention as long as they satisfy the requirements.

In addition, what mixed the material quoted as the material which satisfy | fills the requirements 2 and 3 with the material quoted by the requirement 1 can also be used.
As a method for forming the inorganic isolation layer 107 made of the inorganic material described above, any method may be used as long as it can realize the thickness and uniformity described later. Note that a sputtering method is preferable as a method of forming the inorganic isolation layer 107 because it has high adhesion to the resist 102, hardly generates dust, and can easily form a stable film. However, it is difficult to use a sputtering method for DLC, and the inorganic isolation layer 107 can be suitably formed by using CVD.

  At this time, any sputtering method, CVD condition, etc. may be used. In addition, when a sputtering method is used to form the inorganic isolation layer 107, sputtering may be performed using an inert gas such as argon or xenon using a target having a desired composition such as silicon dioxide or silicon nitride in advance. Co-sputtering may be performed using a plurality of targets, or reactive sputtering may be performed using a target with insufficient composition such as fluorine, oxygen, or nitrogen (or a single target) with respect to a desired composition. Also good. For example, reactive sputtering may be performed by mixing fluorine, oxygen, or nitrogen with an inert gas such as argon or xenon. For example, in order to form the inorganic isolation layer 107 of silicon dioxide, using a silicon dioxide target, argon is introduced into a high vacuum to obtain a furnace pressure of 2 mTorr and an output of 400 W. RF sputtering may be performed. Of course, the scope of the present invention is not limited to the above-mentioned furnace pressure and output.

About the thickness of the inorganic isolation layer 107, it is necessary to satisfy the following two conditions.
(First condition)
When the metal layer 109 is plated, the resist layer 102 has a thickness that can suppress a single chemical reaction of the resist 102 or a chemical reaction between the resist 102 and the conductive film 108 or the metal layer 109.

(Second condition)
After the inorganic isolation layer 107 is formed, a desired height or shape uneven pattern can be formed on the surface of the inorganic isolation layer 107.

First, Example 1 performed regarding the first condition will be described.
Table 1 shows the results of manufacturing the stamper 110 and measuring the non-defective plating rate for four cases in which the type of the resist 102 and the type of the inorganic isolation layer 107 are different from each other. Here, as the resist 102, two types of resists 102 (resist A and resist B) made of Te oxide having low stability when the metal layer 109 is plated are used. As the material of the inorganic isolation layer 107, silicon dioxide and tungsten oxide are used. And the change of the plating tolerance of the resist 102 when the thickness of the inorganic isolation layer 107 was variously changed in the range of 0 to 15 nm was measured. The plating resistance is indicated by the number of times that good plating can be performed after plating 10 times for each case.

表１から明らかなとおり、無機隔離層１０７の厚さが５ｎｍ以上であれば、比較的メッキ耐性の高いレジストＢのメッキ耐性の向上効果が確実に生じ、１５ｎｍ以上であれば、いずれのレジストＡ、Ｂにおいても特に高いメッキ耐性の向上効果が生じている。なお、メッキ耐性の低い他のレジストを用いて無機隔離層１０７を検討した場合も、無機隔離層１０７の厚さ１５ｎｍ以上で特に高いメッキ耐性の向上効果が得られた。なお、第一の条件を満たすための無機隔離層１０７の厚さに上限は無いと考えられる。

As is apparent from Table 1, if the thickness of the inorganic isolation layer 107 is 5 nm or more, the effect of improving the plating resistance of the resist B having a relatively high plating resistance is surely produced, and if the thickness is 15 nm or more, any resist A , B also has a particularly high plating resistance improvement effect. When the inorganic isolation layer 107 was examined using another resist having low plating resistance, a particularly high plating resistance improvement effect was obtained when the inorganic isolation layer 107 had a thickness of 15 nm or more. Note that it is considered that there is no upper limit to the thickness of the inorganic isolation layer 107 for satisfying the first condition.

Next, Example 2 performed regarding the second condition will be described.
Table 2 shows the uneven pattern on the surface of the inorganic isolation layer 107 when the thickness of the inorganic isolation layer 107 is variously changed in the range of 15 to 240 nm for the two types of master 106 having an uneven pattern height of 35 nm or 90 nm. The result of having measured the height of is shown. The height of the concavo-convex pattern means the concavo-convex height h1 before the isolation layer formation shown in FIG. Further, the thickness of the inorganic isolation layer 107 refers to the thickness of the convex portion of the concave / convex pattern of the inorganic isolation layer 107. Here, the track pitch of the master 106 is 320 nm. Further, on the master 106, long and short pit rows having a shortest pit length of about 100 nm are formed as an uneven pattern. Silicon dioxide is used as the material of the inorganic isolation layer 107.

  In FIG. 3, the unevenness height h1 before forming the isolation layer indicates the height of the uneven pattern of the master 106 before forming the inorganic isolation layer, and the uneven height h2 after forming the isolation layer is the unevenness on the surface of the inorganic isolation layer 107. Indicates the height of the pattern.

表２から明らかなとおり、無機隔離層１０７の厚さが厚くなるにつれて、隔離層形成前凹凸高さｈ１と隔離層形成後凹凸高さｈ２との差が徐々に大きくなっていくが、高さの測定誤差が２〜３ｎｍ程度あることを考えると、無機隔離層１０７の厚さが１５０ｎｍ以下のときは、隔離層形成前凹凸高さｈ１と隔離層形成後凹凸高さｈ２とは実質的に同じであるといえる。この結果から、無機隔離層１０７の厚さが１５０ｎｍ以下のときに本発明の効果を特に高く得られることがわかる。ただし、無機隔離層１０７の厚さが１５０ｎｍを越える場合も、無機隔離層１０７の形成による凹凸形状の変化を許容できる用途においては、本発明の効果を得ることができる。また、隔離層形成後凹凸高さｈ２を制御するために、意図的に隔離層形成前凹凸高さｈ１と隔離層形成後凹凸高さｈ２とを変えたい場合は、１５０ｎｍ以上の無機隔離層１０７を用いてもよい。

As is clear from Table 2, as the thickness of the inorganic isolation layer 107 is increased, the difference between the uneven height h1 before formation of the isolation layer and the uneven height h2 after formation of the isolation layer is gradually increased. When the thickness of the inorganic isolation layer 107 is 150 nm or less, the unevenness height h1 before the formation of the isolation layer and the unevenness height h2 after the formation of the isolation layer are substantially equal to each other. The same can be said. From this result, it can be seen that the effect of the present invention can be obtained particularly high when the thickness of the inorganic isolation layer 107 is 150 nm or less. However, even when the thickness of the inorganic isolation layer 107 exceeds 150 nm, the effect of the present invention can be obtained in an application that can tolerate a change in the uneven shape due to the formation of the inorganic isolation layer 107. In addition, in order to control the unevenness height h2 before the formation of the isolation layer and the unevenness height h2 after the formation of the isolation layer in order to control the unevenness height h2 after the formation of the isolation layer, the inorganic isolation layer 107 having a thickness of 150 nm or more is desired. May be used.

According to the above measurement results, the thickness of the inorganic isolation layer 107 is preferably 5 nm or more and 150 nm or less, and more preferably 15 nm or more and 150 nm or less. The above is the description of the first and second embodiments.
In the conductive film forming step, a conductive film 108 made of a conductive material such as nickel or copper is formed on the inorganic isolation layer 107 of the master 106 by electroless plating. Note that the conductive film 108 made of a conductive material such as nickel, copper, or gold may be formed by a sputtering method, a vacuum evaporation method, or the like. The conductive film 108 is used as an electrode when the metal layer 109 is formed by plating in the metal layer forming step.

  In the metal layer forming step, for example, plating such as nickel electroforming is performed to form the metal layer 109 on the conductive film 108. Note that in the case where the electroless plating method is used to form the conductive film 108 in the conductive film formation step, the adhesion between the resist 102 and the conductive film 108 is lower than in the case where the sputtering method or the vacuum evaporation method is used. The residue of the inorganic isolation layer 107 can be suppressed from remaining on the stamper 110b.

  In the peeling step, only the metal layer 109 or a combination of the metal layer 109 and the conductive film 108 is peeled off from the master 106, and shaping processing such as polishing and punching of the back surface is performed. Thereby, the stampers 110a and 110b are completed. Note that in the case where only the metal layer 109 is peeled off from the master 106 in the peeling step, if the surface modification such as oxygen plasma treatment is performed on the conductive film 108 before entering the metal layer forming step, the peeling may occur. It becomes easy.

  By the way, when the metal layer 109 and the conductive film 108 are peeled from the master 106 as a unit, there is a possibility that a slight residue of the inorganic isolation layer 107 may remain on the conductive film 108 (on the stamper 110b). When such a residue becomes a problem, an inorganic material that satisfies (Requirement 2) or (Requirement 3) for the inorganic isolation layer material may be used as the inorganic isolation layer 107. If a material satisfying (Requirement 2) is used, there is a great effect in suppressing the residue, and even when a residue is generated, the residue can be easily peeled and removed using an adhesive sheet or the like. If a material satisfying (Requirement 3) is used, for example, an alkali isolation solution such as an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, tetramethylammonium hydroxide (TMAH), an acid such as water, hydrochloric acid, etc. The residue can be dissolved and removed using a solvent in which the material is soluble. However, when an acid is used for removing the residue, the surface of the stamper 110b may be affected. Therefore, it is preferable to make the conductive film 108 strong in acid resistance such as gold in advance. As a combination of (Requirement 2) and (Requirement 3), it is also possible to use silicon dioxide for the inorganic isolation layer 107 and acid-resistant noble metal such as gold or platinum group for the conductive film 108. Effective against residue. In that case, silicon dioxide and noble metal have a good releasability, so that not only has a great effect on suppressing residue, but also the surface of the stamper is covered with gold or the like having a strong resistance to acid. The residue can be removed by dissolving the silicon dioxide with an acid. In addition, about the density | concentration of hydrofluoric acid, it can use suitably other than the above.

  As described above, the inorganic material that undergoes a state change by exposure has been difficult to plate. However, according to the stamper manufacturing method of the optical information recording medium according to the first embodiment of the present invention, the plating is conventionally performed. It is possible to use an inorganic material that undergoes a state change due to difficult exposure as a resist. As a result, compared with a conventional stamper manufacturing method using a photoresist made of an organic material, even when a light source having a wavelength of the same degree is used, an inorganic pattern is transferred when a predetermined uneven pattern is transferred to the stamper 110 side. Since the shape of the concavo-convex pattern can be kept in a good state while suppressing a change in the state of the material, it is possible to manufacture a stamper with higher recording density and an optical information recording medium.

2. Second Embodiment Hereinafter, a second embodiment of the present invention will be described with reference to FIG. However, in the method for manufacturing the master of the optical information recording medium according to the second embodiment, the release layer 407b is newly formed on the inorganic isolation layer 407a, and the space between the inorganic isolation layer 407a and the conductive film 408 is formed in the stamper manufacturing method. The method is the same as the method for manufacturing the master disc of the optical information recording medium according to the first embodiment except that the release layer 407b is provided. Therefore, in the following, in order to avoid duplication of description, differences from the first embodiment will be mainly described with reference to FIGS.

In the stamper manufacturing method according to the second embodiment, the exposure step and the development step are the same as those in the first embodiment. In the inorganic isolation layer forming step, after forming the inorganic isolation layer 407a as in the first embodiment, the release layer 407b is formed. As a result, the master 406 is manufactured.
The step of forming the release layer 407b will be described in more detail. The release layer 407b is made of a material that is soluble in a solvent that does not damage the stamper 410, such as an alkali, an organic solvent, water, or an acid (when the stamper surface is a highly acid-resistant material such as gold or platinum group). When a stamper 410b with a conductive film 408 is produced, when a residue of an inorganic material is generated on the stamper 410b, the solvent is used to remove the residue without damaging the stamper 410b. effective. For the peeling layer 407b, inorganic materials such as tungsten oxide, niobium oxide, tin oxide, molybdenum oxide, and silicon that are soluble in alkali, sodium chloride, iron chloride, potassium iodide, rubidium chloride, and the like are used. Water-soluble substances such as tin oxide, those soluble in acids such as copper chloride, those soluble in organic solvents such as iron chloride and potassium iodide, etc. are preferably used in the method of the present invention. it can. As the organic material, a material soluble in an alkali, water, acid, or organic solvent such as a phenol resin or an acrylic resin can be suitably used in the method of the present invention. Of course, it is possible to use other solvents that do not damage the stamper, such as alkalis, organic solvents, water, and acids (when the stamper surface is a material with strong acid resistance such as gold or platinum group). Any soluble material can be used in the method of the present invention.

  When an inorganic material is used for the release layer 407b, the configuration is substantially the same as that described in the first embodiment. By separating the inorganic isolation layer 107 in the first embodiment into two functions of the inorganic isolation layer 407a and the release layer 407b in the second embodiment, the residue on the stamper 410b is high although the function as an isolation layer is high. Is used as the inorganic isolation layer 407a, or a material having a high solubility in alkali but a low function as the isolation layer can be used as the release layer. It is more effective than the method of one embodiment. About the formation method of the inorganic isolation layer 407a and the peeling layer 407b, it is the same as the formation method of the inorganic isolation layer 107 in 1st Embodiment, About the thickness of the inorganic isolation layer 407a and the peeling layer 407b, Example 1, 2 From the experimental results described in the above, it is preferable that the thickness of the inorganic isolation layer 407a is 5 nm or more, and the combined thickness of the inorganic isolation layer 407a and the release layer 407b is 150 nm or less. More preferably, the thickness is 15 nm or more, and the combined thickness of the inorganic isolation layer 407a and the release layer 407b is 150 nm or less.

  In the case of using an organic material for the release layer 407b, the formation method of the inorganic isolation layer 407a is the same as the formation method of the inorganic isolation layer 107 in the first embodiment, and the formation of the release layer 407b is performed by spin coating or vacuum deposition. Can be used. From the experimental results described in Examples 1 and 2, the thickness of the inorganic isolation layer 407a is preferably 5 nm to 150 nm, and more preferably 15 nm to 150 nm. When the release layer 407b made of an organic material is formed by a spin coating method or a vacuum deposition method, the uneven pattern of the inorganic isolation layer 407a reflecting the uneven pattern on the recording master 403 is a dimpled uneven pattern in the release layer 407b. Formed as. Here, in order to investigate the extent to which the uneven pattern is blunted, in the release layer 407b, the change in the surface unevenness height when the thickness was changed was examined. Table 3 shows the results when the release layer 407b is formed by a spin coating method, and Table 4 shows the results when it is formed by a vacuum evaporation method. The case where the unevenness of the surface of the inorganic separating layer at the time of measurement was 35 nm and 90 nm was used.

表３、表４より、剥離層４０７ｂの厚さの増大に応じて、剥離層４０７ｂの凹凸高さが小さくなる、すなわち凹凸パターンが鈍ることがわかる。また、剥離層４０７ｂの厚さが８０ｎｍ以上の場合、その厚さ自体の均一性に問題があった。このため、剥離層４０７ｂの厚さは、スピンコート法、真空蒸着法のいずれを用いた場合でも、６０ｎｍ以下が好ましい。しかし、以上のように剥離層４０７ｂの厚さが厚くなるほど、凹凸パターンを鈍らせる程度は大きくなることから、記録原盤４０３上の凹凸パターンをスタンパ４１０上により忠実に再現したい場合には、剥離層４０７ｂの厚さをできるだけ薄くするか、無機材料からなる剥離層４０７ｂを用いる方がより好ましい。

From Tables 3 and 4, it can be seen that the uneven height of the release layer 407b decreases, that is, the uneven pattern becomes dull as the thickness of the release layer 407b increases. Further, when the thickness of the release layer 407b is 80 nm or more, there is a problem in the uniformity of the thickness itself. Therefore, the thickness of the release layer 407b is preferably 60 nm or less regardless of whether the spin coating method or the vacuum deposition method is used. However, as the thickness of the release layer 407b increases as described above, the extent to which the uneven pattern is blunted increases. Therefore, when the uneven pattern on the recording master 403 is to be reproduced more faithfully on the stamper 410, the release layer It is more preferable to reduce the thickness of 407b as much as possible or to use a release layer 407b made of an inorganic material.

  In the stamper manufacturing method, the conductive film forming step, the metal layer forming step, and the peeling step are the same as in the first embodiment. Moreover, the removal of the residue on the stamper 410b is the same as that of the first embodiment except that the solvent used for the release layer 407b is used. When an organic material is used for the peeling layer 407b, removal by oxidation such as oxygen plasma treatment is effective as in the case of using DLC in the first embodiment.

The stampers 410a and 410b are completed through the above steps.
As described above, according to the method for manufacturing a stamper for an optical information recording medium according to the second embodiment of the present invention, it is possible to use, as a resist, an inorganic material that undergoes a change in state due to exposure, which has been difficult to perform with conventional plating. As a result, a stamper and even an optical information recording medium having a higher recording density can be manufactured even when a light source having the same wavelength is used as compared with a conventional stamper manufacturing method using a photoresist made of an organic material. It becomes possible to do.

  In addition, it is possible to manufacture a stamper that makes it easier to remove residues on the stamper than the stamper manufacturing method according to the first embodiment that does not use a release layer.

  The optical information recording medium master manufacturing method, the optical information recording medium stamper manufacturing method, the optical information recording medium stamper, and the optical information recording medium of the present invention are plated with a concavo-convex pattern manufactured using an inorganic material resist. In particular, it has an effect of enabling a plating process to be transferred in a favorable manner, and in particular, a nanometer-order microfabrication process having a process of transferring a pattern formed by photolithography by plating, for example, an optical information recording medium It is useful for manufacturing, micromachine manufacturing, and the like.

The figure which shows the pattern formation method in 1st Embodiment of this invention. The figure which shows the exposure method in the pattern formation in 1st Embodiment of this invention. The figure which shows the uneven | corrugated height of the pattern in the pattern formation in 1st Embodiment of this invention. The figure which shows the pattern formation method in 2nd Embodiment of this invention. The figure which shows the pattern formation method in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Substrate 102 Resist 103 Recording master 104 Recording light 105 Latent image 106 Master 107 Inorganic isolation layer 108 Conductive film 109 Metal layer 110a Stamper 110b Stamper 201 Turntable 202 Light source 203 Lens 204 Recording head 401 Substrate 402 Resist 403 Recording master 404 Recording light 405 Latent image 406 Master disk 407a Inorganic isolation layer 407b Release layer 408 Conductive film 409 Metal layer 410a Stamper 410b Stamper h1 Uneven height before formation of isolation layer h2 Unevenness height after formation of isolation layer

Claims (16)

A method of manufacturing a master of an optical information recording medium for transferring a predetermined uneven pattern to a stamper of the optical information recording medium,
Forming a resist including a first inorganic material that changes state by being subjected to an exposure process on the substrate;
Forming a concavo-convex pattern portion by subjecting the resist to the exposure process and the development process,
A method for producing a master disc for an optical information recording medium, comprising forming an isolation layer made of a second inorganic material containing fluoride on the concavo-convex pattern portion. A method of manufacturing a master of an optical information recording medium for transferring a predetermined uneven pattern to a stamper of the optical information recording medium,
  Forming a resist including a first inorganic material that changes state by being subjected to an exposure process on the substrate;
  Forming a concavo-convex pattern portion by subjecting the resist to the exposure process and the development process,
  A method for producing a master of an optical information recording medium, comprising forming an isolation layer made of a second inorganic material containing diamond-like carbon on the uneven pattern portion.   A method of manufacturing a master of an optical information recording medium for transferring a predetermined uneven pattern to a stamper of the optical information recording medium,
  Forming a resist including a first inorganic material that changes state by being subjected to an exposure process on the substrate;
  Forming a concavo-convex pattern portion by subjecting the resist to the exposure process and the development process,
  A method for producing a master for an optical information recording medium, comprising forming an isolation layer made of a second inorganic material containing an alkali-soluble material on the uneven pattern portion.   A method of manufacturing a master of an optical information recording medium for transferring a predetermined uneven pattern to a stamper of the optical information recording medium,
  Forming a resist including a first inorganic material that changes state by being subjected to an exposure process on the substrate;
  Forming a concavo-convex pattern portion by subjecting the resist to the exposure process and the development process,
  An isolation layer made of a second inorganic material containing at least one of tungsten oxide, niobium oxide, tin oxide, molybdenum oxide, or silicon is formed on the uneven pattern portion. A method for manufacturing a master of an optical information recording medium.   A method of manufacturing a master of an optical information recording medium for transferring a predetermined uneven pattern to a stamper of the optical information recording medium,
  Forming a resist including a first inorganic material that changes state by being subjected to an exposure process on the substrate;
  Forming a concavo-convex pattern portion by subjecting the resist to the exposure process and the development process,
  A method for producing a master of an optical information recording medium, comprising forming an isolation layer made of a second inorganic material containing a water-soluble material on the uneven pattern portion.   A method of manufacturing a master of an optical information recording medium for transferring a predetermined uneven pattern to a stamper of the optical information recording medium,
  Forming a resist including a first inorganic material that changes state by being subjected to an exposure process on the substrate;
  Forming a concavo-convex pattern portion by subjecting the resist to the exposure process and the development process,
  An optical information recording medium comprising an isolation layer made of a second inorganic material containing at least one of sodium chloride, iron chloride, potassium iodide, and rubidium chloride on the concavo-convex pattern portion. Manufacturing method of the master.   A method of manufacturing a master of an optical information recording medium for transferring a predetermined uneven pattern to a stamper of the optical information recording medium,
  Forming a resist including a first inorganic material that changes state by being subjected to an exposure process on the substrate;
  Forming a concavo-convex pattern portion by subjecting the resist to the exposure process and the development process,
  A method for producing a master of an optical information recording medium, comprising forming an isolation layer made of a second inorganic material containing an acid-soluble material on the concave / convex pattern portion. Method for manufacturing a master of an optical information recording medium according to any one of claims 1 to 7, characterized in that provision of the release layer on the isolation layer. 9. The method for producing a master disc for an optical information recording medium according to claim 8 , wherein the release layer contains an alkali-soluble material. The method for producing a master disc for an optical information recording medium according to claim 8 , wherein the release layer includes a water-soluble material. 9. The method for producing a master for an optical information recording medium according to claim 8 , wherein the release layer contains an acid-soluble material. 9. The method of manufacturing a master for an optical information recording medium according to claim 8 , wherein the release layer is made of an inorganic material. Both the isolation layer and the release layer are made of an inorganic material,
9. The method of manufacturing a master disc for an optical information recording medium according to claim 8 , wherein the total thickness of the isolation layer and the release layer is 150 nm or less, and the thickness of the isolation layer is 5 nm or more. 14. The method for manufacturing a master disc of an optical information recording medium according to claim 13 , wherein the thickness of the isolation layer is 15 nm or more. 9. The method for manufacturing a master disc for an optical information recording medium according to claim 8 , wherein the release layer is made of an organic material. 16. The method for producing a master for an optical information recording medium according to claim 15 , wherein the release layer has a thickness of 60 nm or less.

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