JP2008047251A - Inorganic resist pattern, method of forming inorganic resist pattern, optical master disk, method for manufacturing optical master disk, method for manufacturing optical disk pattern and method for manufacturing optical disk substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the formation of a crystalline boundary layer between an inorganic resist layer and an underlayer substrate thereof or an underlayer. <P>SOLUTION: The method comprises a step of forming the underlayer 2 on a substrate 1, a step of forming the inorganic resist layer 3 composed of a metal oxide on the underlayer 2, a step of forming a latent image 3a of a prescribed shape by irradiating the inorganic resist layer 3 with a laser beam 3b, and a step of forming rugged pattern of the inorganic resist layer 3 in which the portion formed with the latent image 3 is a recessed part on the substrate 1 by developing the inorganic resist layer 3. Prior to the step of forming the inorganic resist layer 3 on the substrate 1, there is provided a step of forming an intermediate layer 20 for suppressing the crystallization of the boundary of the inorganic resist layer on the underlayer 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inorganic resist pattern, an inorganic resist pattern forming method, an optical disc master, a method of manufacturing an optical disc master, a method of manufacturing an optical disc stamper, and an optical disc, which are suitable for manufacturing optical disc masters, optical disc stampers, and optical disc substrates. The present invention relates to a method for manufacturing a substrate.

  As a means for realizing a high resolution and high taper angle shape pattern, a method using an inorganic resist has been proposed. These use an electron beam or an ion beam as an active energy source for drawing a shape pattern (for example, refer to Patent Documents 1 and 2), use an extreme ultraviolet light (for example, refer to Patent Document 3), or use a laser beam (for example, Non-Patent Document 1) has been reported.

  Among those using laser light as drawing energy, a method using a metal oxide as an inorganic resist material has been proposed (see, for example, Patent Documents 4 and 5). Since this inorganic resist forms a latent image by a thermal reaction, exposure of a pattern smaller than the spot diameter is possible even by exposure with visible laser light of about 405 nm. For this reason, it has been attracting attention as a useful technique for Blu-ray Disc (trademark) or higher optical disc mastering technology corresponding to higher recording density.

  Hereinafter, an outline of conventional processes from the production of the optical disc master to the production of the optical disc substrate will be described with reference to FIG. First, as shown in FIG. 11A, a disk-shaped glass substrate (or silicon substrate) 101 is manufactured. Next, as shown in FIG. 11B, a resist 102 is applied on the glass substrate 101 while rotating the glass substrate 101.

  Next, as shown in FIG. 11C, the resist 102 applied on the glass substrate 101 is exposed to laser light 103 having a predetermined wavelength while rotating the glass substrate 101. As a result, a latent image pattern corresponding to the desired land and groove of the optical disk is formed on the glass substrate 101. Next, as shown in FIG. 11D, while the glass substrate 101 is rotated, the developing solution 104 is dropped on the glass substrate 101 to perform development processing. As a result, a concavo-convex pattern corresponding to the desired land and groove of the optical disk is formed on the glass substrate 101. Thus, the target optical disc master is obtained.

  Next, as shown in FIG. 11E, a plating layer 105 is formed by depositing a metal such as nickel on the optical disk master 111 by plating. Next, as shown in FIG. 11 (f), the plating layer 105 is peeled off from the optical disk master 111, and then trimmed to a predetermined size as shown in FIG. 106 is obtained. Then, as shown in FIG. 11 (h), the optical disc stamper 106 is mounted on a mold 107 of an injection molding apparatus, the mold 107 is closed to form a cavity, and the cavity is formed in a direction indicated by an arrow a. After injecting molten resin such as polycarbonate (PC), it is cured and the mold 107 is opened. Thereby, the optical disk substrate 108 to which the unevenness of the optical disk stamper 106 is transferred is obtained.

  By the way, when pattern formation is performed using an inorganic resist, the solubility in a developing solution is present between the inorganic resist layer and the base material that forms the layer, or a base layer that is formed for the purpose of adjusting the amount of heat storage. A layer different from the inorganic resist may be formed. This is particularly noticeable when the inorganic resist layer is a crystalline substance.

  As a countermeasure to suppress such a phenomenon, it is formed at the interface by combining a method of doping a substance having a different crystal structure into an inorganic material that easily causes crystallization and a method of cooling the temperature of the substrate to a very low temperature. An example in which the crystal is refined to less than 1 nm has been reported (see Non-Patent Document 2). In addition, a method of providing an organic layer on a substrate on which an inorganic resist is formed has been proposed (see, for example, Patent Document 6).

JP-A-6-132188 JP-A-8-69960 JP 2004-172272 A JP 2003-315988 A JP 2004-152465 A JP-A-8-15868 Japanese Journal of Applied Physics, 44, 3574-3577, 2005 Japanese Journal of Applied Physics, 32, 6218-6223, 1993

  When an amorphous inorganic resist layer is formed on a base material or a base layer formed on the base material, the layer that is often formed at the interface between the two and has a different solubility in the developer from the inorganic resist is large or small. In addition to having irregular irregularities, it sometimes grows to a protruding shape by heating. This interface layer is considered to be an inorganic resist crystal caused by the difference in interfacial tension or surface energy between the two materials.

  When the resist master is irradiated with an active energy ray and developed, surface irregularities of the undissolved interface layer appear under the inorganic resist dissolved by the development. In particular, when the inorganic resist is a heat-sensitive reaction type, unevenness may further grow at the laser heating portion on the interface layer and appear as a protrusion after development. Such a significant decrease in surface flatness causes a great deal of damage depending on the application of the transferred material when the transferred material is produced using this as a mold.

  On the other hand, if the taper angle of the pattern convex shape remaining after development can be controlled slowly or steeply, the application to which the inorganic resist can be applied is expanded accordingly. In particular, when the taper angle is made steep, the influence of “fogging” in microfabrication is reduced, so that higher density can be realized.

  The present invention has been made in view of the above-mentioned problems, and can suppress the formation of a crystalline interface layer between an inorganic resist layer and its base substrate or base layer, and can also adjust the taper angle of a convex pattern. An object of the present invention is to provide a pattern, an inorganic resist pattern formation method, an optical disc master, a method of manufacturing an optical disc master, a method of manufacturing an optical disc stamper, and a method of manufacturing an optical disc substrate.

  In solving the above problems, the present inventors have intensively studied, and as a result, an intermediate layer for suppressing crystallization at the interface of the inorganic resist layer made of an amorphous metal oxide between the base material and the inorganic resist layer. Thus, the formation of an inorganic resist layer and a crystalline interface layer on the base surface thereof is suppressed.

  That is, the inorganic resist pattern and the optical disc master of the present invention are an inorganic resist pattern and an optical disc master obtained by patterning an inorganic resist layer on a substrate, and the inorganic resist layer is made of an amorphous metal oxide. An intermediate layer for suppressing crystallization at the interface of the inorganic resist layer is provided between the substrate and the inorganic resist layer.

  The method for producing an inorganic resist pattern and an optical disc master according to the present invention includes a step of forming an inorganic resist layer made of a metal oxide on a substrate, and a latent image having a predetermined shape by irradiating the inorganic resist layer with laser light. Forming an inorganic resist layer on the substrate, and developing the inorganic resist layer to form a concavo-convex pattern of the inorganic resist layer in which the latent image forming portion is a recess. Before the step of forming, an intermediate layer for suppressing crystallization at the interface of the inorganic resist layer is formed on the substrate.

  Furthermore, the method for manufacturing an optical disc stamper according to the present invention includes a step of forming an inorganic resist layer made of a metal oxide on a substrate, and a step of forming a latent image of a predetermined shape by irradiating the inorganic resist layer with laser light. And developing the inorganic resist layer to produce an optical disc master having a concave / convex pattern of the inorganic resist layer in which the latent image forming portion is a concave portion on the substrate, and forming a metal plating layer on the optical disc master And a step of peeling the metal plating layer from the optical disc master, and before the step of forming the inorganic resist layer on the base material, for suppressing the crystallization of the interface of the inorganic resist layer on the base material. A step of forming an intermediate layer.

  The optical disk substrate manufacturing method of the present invention includes a step of forming an inorganic resist layer made of a metal oxide on a substrate, and a step of irradiating the inorganic resist layer with a laser beam to form a latent image of a predetermined shape. Developing an inorganic resist layer to produce an optical disc master having a concave-convex pattern of the inorganic resist layer in which a latent image forming portion becomes a concave portion on a base material; and an optical disc substrate using an optical disc master or a replica mold thereof And forming an intermediate layer for suppressing crystallization at the interface of the inorganic resist layer on the base material before the step of forming the inorganic resist layer on the base material.

  The crystalline interface layer formed at the interface of the inorganic resist layer has a difference in interfacial tension (or surface energy difference) between the inorganic resist layer and its base surface (base material or base layer formed on the base material). The place to rely on is great. Therefore, by inserting a material having an interfacial tension intermediate between these two interfacial tensions as an intermediate layer, the difference in interfacial tension between the inorganic resist layer and the underlying surface can be alleviated, and the generation of the crystalline interfacial layer is suppressed. be able to. As the intermediate layer, when a base layer is formed on a substrate, it is preferable to use an oxide of a material constituting the base layer.

  The underlayer is formed on the substrate as a heat storage layer, and can enhance the heat sensitivity of the exposed portion during laser exposure. Although the material which comprises a base layer is not specifically limited, The material excellent in flatness and the homogeneity of film quality is suitable, and an amorphous silicon is mentioned specifically ,. When amorphous silicon is used for the base layer, the intermediate layer can be made of silicon oxide.

  When the intermediate layer is made of an oxide, the convex taper angle of the resulting inorganic resist pattern can be made slow or steep by adjusting the oxygen content and film thickness of the intermediate layer. For example, when the taper angle is steep, the heat storage property of the underlying layer of the inorganic resist layer is increased by increasing the oxygen content of the intermediate layer. As a result, the temperature gradient between the surface and the bottom surface of the laser irradiation portion becomes gentle, so that the thermal reaction is made uniform and a resist pattern having a steep taper angle after development can be obtained.

  As described above, according to the present invention, an inorganic resist pattern and an optical disc excellent in surface flatness by suppressing the formation of a crystalline interface layer between the inorganic resist layer and the underlying base material or the underlying layer. Masters, optical disc stampers and optical disc substrates can be manufactured. Further, by adjusting the amount of oxygen and the film thickness contained in the intermediate layer, it becomes possible to adjust the taper angle of the convex shape of the resist pattern obtained after development.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram for explaining a manufacturing process of an optical disc master according to an embodiment of the present invention. FIG. 2 is a schematic diagram for explaining a manufacturing process of an optical disc stamper according to an embodiment of the present invention. FIG. 3 is a schematic diagram for explaining a manufacturing process of an optical disk substrate according to an embodiment of the present invention.

(Manufacturing process of optical disc master)
First, as shown to FIG. 1A, the smooth base material 1 which consists of a silicon substrate, a glass substrate, etc. is prepared or produced. Then, as shown in FIG. 1B, a base layer 2 for heat storage is formed on the substrate 1 by, for example, sputtering.

  As a material constituting the underlayer 2, for example, a mixture of zinc sulfide and silicon dioxide (ZnS-SiO2 mixture), tantalum pentoxide (Ta2O5), titanium (Ti), titanium oxide (TiO2), silicon (Si ), Silicon dioxide (SiO2), silicon nitride (SiN), germanium (Ge), germanium oxide (GeO2), and the like. In the present embodiment, the underlayer 2 is made of amorphous silicon excellent in high surface flatness and film thickness uniformity. The underlayer 2 can be omitted depending on the type of the substrate 1 or the like, and an inorganic resist layer 3 described later may be formed directly on the substrate 1.

  The underlayer 2 is appropriately provided as necessary to adjust the thermal sensitivity of the inorganic resist layer 3, and the film thickness can be arbitrarily determined according to the material composition and sensitivity of the inorganic resist layer. When the inorganic resist layer 3 is tungsten oxide and the substrate 1 is a silicon wafer, the thickness of the base layer 2 is preferably 15 nm or more and 100 nm or less. If it is less than 15 nm, sufficient exposure sensitivity cannot be obtained. On the other hand, if the thickness exceeds 100 nm, the sensitivity can be increased, but the reaction of the resist layer with respect to the laser power also becomes steep. Variations in the formed pattern are caused even by minute output fluctuations.

  Next, as shown in FIG. 1C, the intermediate layer 20 is formed on the base layer 2. The intermediate layer 20 is for reducing a difference in interfacial tension between the base layer 2 and the inorganic resist layer 3 as described later. The material constituting the intermediate layer 20 is not particularly limited as long as the material has an interfacial tension intermediate between the interfacial tension of the underlayer 2 and the inorganic resist layer 3, but the oxide of the material constituting the underlayer 2 is not limited. Is preferred. Therefore, in the present embodiment, since the base layer 2 is made of amorphous silicon, the intermediate layer 20 is made of silicon oxide (for example, SiO 2).

  Next, as shown in FIG. 1D, the inorganic resist layer 3 is formed on the intermediate layer 20. A metal oxide is used as a material constituting the inorganic resist layer 3.

  As the metal oxide used in the present invention, any material can be used depending on the process for producing the desired shape on the substrate 1. Specific examples include titanium monoxide (TiO), titanium dioxide (TiO2), barium titanate (BaTiO3), tungsten trioxide (WO3), tungsten dioxide (WO2), tungsten monoxide (WO), molybdenum dioxide (MoO2). ), Molybdenum trioxide (MoO3), molybdenum monoxide (MoO), vanadium pentoxide (V2O5), vanadium tetroxide (V2O4), vanadium trioxide (V2O3), bismuth oxide (Bi2O3), cerium oxide (CeO2), oxide Copper (CuO), niobium pentoxide (Nb2O5), stubium oxide (antimony oxide: Sb2O3), calcium fluoride (CaF2), magnesium fluoride (MgF2), silicon monoxide (SiO), gadolinium oxide (Gd2O3), tantalum oxide (Ta2O5), oxidized Thorium (Y2O3), nickel oxide (NiO), samarium oxide (Sm2O3), iron oxide (Fe2O3), tin oxide (SnO2), aluminum oxide (Al2O3), silicon dioxide (SiO2), chromium oxide (Cr2O3), zinc oxide ( ZnO), indium oxide (In2O3), zirconium oxide (ZrO2), magnesium oxide (MgO), barium sulfate (BaSO4), calcium sulfate (CaSO4), calcium carbonate (CaCO3), calcium silicate (CaSi2O5), magnesium carbonate (MgCO3) ), Lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), cobalt carbonate (CoCO3), strontium carbonate (SrCO3), nickel carbonate (Ni2CO3), bismuth carbonate ((BiO) 2CO3), phosphoric acid Luminium (AlPO4), barium hydrogen phosphate (BaHPO4), lithium phosphate (Li3PO4), zinc citrate (Zn3 (C6H5O7) 2), zinc borate (2ZnO.3B2O3), barium borate (BaB4O7), uranium oxide ( U3O8) can be cited as an example. These metal oxides can be used alone or in combination of two or more.

  Among these, as an inorganic resist that causes a difference in solubility (selection ratio) with respect to a developing solution by active energy rays such as laser, electron beam, ion beam, hydrogen plasma, ultraviolet ray, visible ray, and infrared ray, among metal oxides Tungsten, molybdenum, vanadium, tantalum, iron, nickel, copper, titanium, ruthenium, silver, zinc, aluminum, thallium, boron, germanium, niobium, silicon, uranium, tellurium, bismuth, cobalt, chromium, tin, zirconium Those containing manganese are known. Among these, tungsten, molybdenum, vanadium, tantalum, and iron can be used as the metal element. In particular, a metal oxide containing tungsten, molybdenum, and vanadium is preferably used as the inorganic resist layer 3. These metals can be used as a single oxide or as an oxide composed of two or more kinds of metals.

  As a method for forming the inorganic resist layer 3, as a dry method, a CVD method such as thermal CVD, plasma CVD, or photo-CVD (Chemical Vapor Deposition): depositing a thin film from a gas phase using a chemical reaction PVD methods (Physical Vapor Deposition) such as vacuum deposition, plasma-assisted deposition, sputtering, and ion plating: a material that is physically vaporized in a vacuum is agglomerated on a substrate to form a thin film Can be used. Moreover, as a wet method, in addition to coating methods such as bar coating, spin coating, and screen printing, LB (Langmuir Blodgett) method, chemical deposition method, anodic oxidation method, electrolytic deposition method, and the like can be used.

  Note that the composition ratio of oxygen to the metal element does not need to be stoichiometric, and can take any value within a range up to the maximum oxidation number that the metal element can take. For example, in the case of tungsten oxide, WOx can take an arbitrary value x of 0 <x ≦ 3.

  A method for adjusting the amount of oxygen constituting the metal oxide used as the inorganic resist can be appropriately selected according to each film forming method. For example, when film formation is performed by a sputtering method, a method of forming a metal target containing no oxygen by reactive sputtering of oxygen, or a method of forming a film of a target made of a metal oxide with a controlled oxygen content by sputtering Etc. can be adopted.

  Although the thickness of the inorganic resist layer 3 formed on the base material 1 can be set arbitrarily, it is necessary to set it so that a desired pit or groove depth can be obtained. For example, in the case of Blu-ray Disk (trademark), the thickness of the inorganic resist layer 3 is preferably in the range of 15 nm to 80 nm, and in the case of DVD-RW (Digital Versatile Disc-ReWritable), 20 nm to 90 nm. The following range is preferable.

  Next, as shown in FIG. 1E, while rotating the silicon substrate 1, the inorganic resist layer 3 is irradiated with an exposure beam (laser light) 3b to expose the entire surface of the inorganic resist layer 3. Thereby, a latent image 3a corresponding to the locus of the exposure beam 3b is formed over the entire surface of the inorganic resist layer 3.

  FIG. 4 is a schematic diagram showing a configuration example of the cutting apparatus 30 used for exposure of the inorganic resist layer 3. A blue semiconductor laser (BLD: Blue Laser Diode) 31 emits blue laser light having a wavelength of 405 nm. The laser light passes through the lens 32 and the lens 33, and then the laser optical axis is appropriately adjusted in the X and Y directions in the XY beam shifter 34. Next, after the polarization of the laser light is converted by the quarter-wave plate 35, the laser light is reflected by the mirror 36 and guided to the shutter 37, and the passage is controlled by the shutter 37.

  The laser light that has passed through the shutter 37 enters an acousto-optical deflector (AOD) 39 via a cylindrical mirror 38, and is optically deflected by the acousto-optic deflector 39. Next, the optically deflected laser light passes through the cylindrical mirror 40, is reflected by the mirror 41, and is guided to a polarization separation element (PBS) 42. Next, the laser light is reflected by the polarization separation element 42, the polarized light is converted by the quarter wavelength plate 43, and the beam diameter is converted by the beam expander 44. Thereafter, the laser light is reflected by the dichroic mirror 45 and condensed on the inorganic resist sample 61 by the objective lens 46. The inorganic resist sample 61 is placed on the turntable 47 and rotated by the spindle 48 at a predetermined speed. Further, the cutting device 30 includes a moving optical table 60, and the spot of the laser beam is moved in the radial direction of the inorganic resist sample 61 as the moving optical table 60 moves.

  The return light from the inorganic resist sample with respect to the irradiated laser light passes through the objective lens 46, is reflected by the dichroic mirror 45, and passes through the beam expander 44, the quarter wavelength plate 43 and the polarization separation element 42. . Thereafter, the return light is reflected by the mirror 49, passes through the lens 50, is attenuated by an ND (Neutral Density) filter 51, and is supplied to a charge coupled device (CCD) 52. Here, the charge coupled device 52 is arranged for the purpose of observing the spot shape, profile, etc. of the return light from the inorganic resist sample 61, and is used for confirming whether the exposure conditions are optimal.

  A focus LD (Laser Diode) 53 emits a focus laser beam having a wavelength of 633 nm. The light emitted from the focus LD 53 passes through a focus polarization splitter (PBS) 54, and the polarized light is converted by the quarter wavelength plate 55. Then, the laser light is reflected by the dichroic mirror 56, passes through the dichroic mirror 45, and is then focused on the inorganic resist sample 61 by the objective lens 46.

  Further, the return light from the inorganic resist sample 61 with respect to the focus laser beam is transmitted through the dichroic mirror 45, then reflected by the dichroic mirror 56, and its polarization is converted by the quarter wavelength plate 55. The return light is reflected by the focus polarization separation element 54 and supplied to a focus position detection element (F-PSD) 57. The focus position detection element 57 detects the position based on the supplied laser beam, and the objective lens 46 is controlled according to the detection result.

  Next, while rotating the substrate 1, a developer is dropped on the inorganic resist layer 3 to develop the inorganic resist layer 3 as shown in FIG. 1F. When the inorganic resist layer 3 is formed of a positive resist, the exposed portion exposed with the laser beam has a higher dissolution rate with respect to the developer than the non-exposed portion. Therefore, exposure with the laser beam (latent image 3a) A pattern corresponding to is formed on the inorganic resist layer 3. As described above, the optical disc master 10 in which the inorganic resist pattern is formed on the substrate 1 is produced.

  Any solution can be used as the developer as long as it dissolves the metal oxide thin film. As examples of acids, liquid acids such as hydrochloric acid, nitric acid, and acetic acid are appropriately diluted with water, and solid acids such as phosphoric acid, oxalic acid, citric acid, and tartaric acid are dissolved in water. Solutions can also be used. Examples of alkalis include tetramethylammonium hydroxide aqueous solution, ammonia aqueous solution, triethanolamine aqueous solution, diethanolamine aqueous solution, etc., as well as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, A solution in which a solid alkali such as disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, or potassium dihydrogen phosphate is dissolved in water can also be used.

  For the purpose of adjusting the development speed and efficiently removing development residues, the developer can be used by appropriately mixing an organic solvent with an aqueous solution or adding a penetrant or a surfactant. The temperature of the developer is not particularly limited, but a method such as adjusting the temperature appropriately may be employed to adjust the dissolution rate of the thin film.

(Optical disc stamper manufacturing process)
Next, as shown in FIG. 2A, a conductive film 4a such as a nickel film is formed on the concavo-convex pattern of the optical disk master 10 after development by, for example, an electroless plating method. Thereafter, the optical disc master 10 on which the conductive film 4a is formed is attached to an electroforming apparatus, and the conductive film 4a is plated to have a thickness of, for example, about 300 ± 5 μm by an electroplating method. As shown in FIG. 2, a plating layer 4 having a concavo-convex pattern is formed. In addition, as a material which comprises the plating layer 4, metals, such as nickel, can be used.

  Next, as shown in FIG. 2C, the plating layer 4 is peeled off from the optical disc master 10 with, for example, a cutter. Thereafter, the plated layer 4 is trimmed and processed to a predetermined size, and then the inorganic resist attached to the signal forming surface of the plated layer 4 is washed using, for example, acetone. Thus, the target optical disc stamper 11 can be obtained. The optical disc stamper 11 corresponds to a replica mold of the optical disc master 10.

(Manufacturing process of optical disk substrate)
Next, as shown in FIG. 3A, the concavo-convex pattern of the optical disc stamper 11 is transferred to a resin material such as polycarbonate (PC) by, for example, injection molding to produce the optical disc substrate 12. Specifically, for example, the optical disc stamper 11 is disposed in a molding die, the die is closed to form a cavity, a molten resin material such as polycarbonate is injected into the cavity, and the die is opened after curing. As a result, the optical disk substrate 12 to which desired pits and groove patterns are transferred is manufactured.

  Next, as shown in FIG. 3B, the information signal unit 5 is formed on the optical disk substrate 12. The information signal unit 5 is configured to be able to record and / or reproduce an information signal. The configuration depends on, for example, whether the desired optical disc is a reproduction-only type, a write-once type, or a rewritable type. It is selected appropriately.

  When the desired optical disk is a read-only type, the information signal unit 5 is made of, for example, a reflective film, and examples of the material of the reflective film include metal elements, metalloid elements, compounds or mixtures thereof. More specifically, for example, a simple substance such as Al, Ag, Au, Ni, Cr, Ti, Pd, Co, Si, Ta, W, Mo, Ge, or an alloy containing these simple substances as a main component is used. Can be mentioned. In consideration of practicality, it is preferable to use an Al-based material, an Ag-based material, an Au-based material, a Si-based material, or a Ge-based material among them. When the desired optical disk is a write-once type, the information signal unit 5 is a laminated film formed by sequentially laminating a reflective film and an organic dye film on the optical disk substrate 12, for example. When the desired optical disk is a rewritable type, the information signal unit 5 is formed by sequentially laminating a reflective film, a lower dielectric layer, a phase change recording layer, and an upper dielectric layer on the optical disk substrate 12, for example. It is a laminated film.

  Next, the information signal unit 5 on the optical disk substrate 12 is formed by a pressure-sensitive adhesive (PSA: Pressure Sensitive Adhesive) in which a planar annular light-transmitting sheet is uniformly applied to one main surface of the sheet in advance. Affix to the formed side. As a result, as shown in FIG. 3C, a light transmission layer 6 having, for example, 100 μm is formed on the information signal portion 5. The target optical disc 13 can be obtained by the above steps.

  In the above description, an example in which the optical disc substrate 12 and the optical disc 13 are manufactured using the optical disc stamper 11 has been described. However, the optical disc substrate 12 and the optical disc master 10 are used without using the optical disc stamper 11. It is also possible to manufacture the optical disc 13.

  As described above, the shape accuracy of the concavo-convex pattern formed on the surface of the optical disc substrate 12 depends on the shape accuracy of the concavo-convex pattern formed on the surface of the optical disc stamper 11. On the other hand, the shape accuracy of the concavo-convex pattern formed on the surface of the optical disc stamper 11 depends on the shape accuracy of the concavo-convex pattern formed on the surface of the optical disc master 10, that is, the inorganic resist pattern. Therefore, in order to form the optical disc substrate 12 with high accuracy, it is necessary to form the inorganic resist pattern of the optical disc master 10 with high accuracy.

(Formation of inorganic resist pattern)
Next, details of the method for forming an inorganic resist pattern in the present embodiment will be described. An inorganic resist using a metal oxide functions as a heat-sensitive inorganic resist. In particular, the inorganic resist layer 3 in the present embodiment is configured as a positive resist. As shown schematically in FIG. 5, the positive resist is generally formed by irradiating the inorganic resist layer 3 with laser light 3b to form a latent image 3a at the irradiated portion, and developing the latent image 3a. The formation part of the concavo-convex pattern forms a concave part.

  Hereinafter, the reaction mechanism presumed of the inorganic resist examined by the present inventors will be described.

  When a metal oxide is used as a heat-sensitive inorganic resist, it is due to local thermal expansion at the laser irradiation site of the resist film, oxygen redistribution (oxidation / reduction reaction) between the molecules constituting the resist, and decomposition of the metal oxide. It is thought that oxygen gas release occurs simultaneously. That is, due to the rapid increase in molecular vibration caused by local intense heat for a short time, instantaneous volume expansion and chemical reaction occur at the laser irradiation site, and at the same time, fine cracks are generated.

  Here, with reference to FIG. 6, some of the molecules ignited by laser irradiation release oxygen to form a reductant (for example, amorphous WO), and some receive the oxygen and oxidize. It becomes a body (for example, amorphous WO3, crystal WO3). Metal oxides such as tungsten oxide (WOx, 0 <x ≦ 3) and molybdenum oxide (MoO, 0 <x ≦ 3) used as an inorganic resist material in the present invention have high oxidation levels (x is large). Those having high alkali solubility and low oxidation level (small x) have low alkali solubility. Therefore, at the laser irradiation site, the oxidized portion has improved alkali solubility, and the reduced portion has reduced alkali solubility. In this way, if the oxidation product is subjected to alkali development in a state where the oxidation product and the reduction product are mixed, the oxidation product is dissolved, so that the reduction product dispersed therein is also detached together, and as a result. It is considered that the entire site where the oxidation / reduction reaction has occurred is developed to form a shape pattern.

In addition, during the oxidation / reduction reaction, the volume of the reductant decreases compared to the original molecule, and the volume of the oxidant increases. The specific gravity of the primary metal oxide used in the present invention, the crystal W3O (14.7g / cm ^3), amorphous WO1.5 (11g / cm ^3), crystal WO2 (10.8g / cm ^3), crystalline WO3 (7 0.2 g / cm ³ ), amorphous WO ³ (6.8 g / cm ³ ), crystalline MoO 2 (6.5 g / cm ³ ), crystalline MoO ³ (4.7 g / cm ³ ), and the specific gravity decreases as the oxidation proceeds. (Volume increases). Further, when the amorphous metal oxide layer formed is laser-heated, a large number of crystal particles are generated around the laser irradiation portion. Here, when comparing amorphous and crystal with respect to alkali solubility, if the compound has the same oxidation level, for example, WO3, the amorphous is shorter than the crystal with respect to the alkali because the lattice bond is not formed. Dissolve with. This property is used in pattern formation of a negative resist. It is considered that the increase and decrease in volume and the generation of crystal particles occur simultaneously in a short time, which is a cause of cracks.

  Furthermore, it is conceivable that oxygen released from the metal oxide by intense heat pushes cracks and creates voids between crystals. Here, a metal oxide such as tungsten oxide (WOx, 0 <x ≦ 3) or molybdenum oxide (MoOx, 0 <x ≦ 3), which has a relatively high oxidation level such as x of 2 or more, is heated by laser. It is considered that the rate of oxygen gas generation is also increased by this, and this is thought to expand the cracks or create voids between the crystals to greatly expand the volume (corresponding to the rise 3V in FIG. 6B). For this reason, the rising of the edge portion of the shape pattern obtained by development (corresponding to the rising 3W in FIG. 6C) also increases. On the contrary, if the oxidation level is relatively low, for example, x is less than 2, the amount of oxygen gas generated is considered to be small. For this reason, the volume expansion of the laser irradiation part is also reduced, and the rising 3W of the edge portion of the shape pattern obtained by development is reduced.

  In addition, it is thought that the generated crack and the space | gap between crystals contribute to improving the effect which penetrates a developing solution inside. For this reason, the higher the oxidation level, the higher the alkali solubility.

  By the way, when the inorganic resist layer 3 is formed on the base material 1 via the base layer 2 (directly on the base material 1 when the base layer 2 is omitted), as schematically shown in FIG. In addition, the interface layer 8 may appear between the base layer 2 and the inorganic resist 3. This is considered to be an inorganic resist crystal caused by the difference in interfacial tension (or difference in surface energy) between the two materials. This crystal grows further by heating. Accordingly, when the inorganic resist layer 3 is laser-heated, crystals existing in the heated portion grow greatly. As described above, when developing a laser-heated inorganic resist layer, the crystal generally takes longer to dissolve than amorphous because the lattice-like bond is not formed. For this reason, after the inorganic resist layer of the laser heating portion is dissolved, the crystal of the interface layer 8 may remain in a shape like the protrusion 8a.

  In the present embodiment, in order to suppress the generation of such an interface layer 8, an intermediate layer 20 is formed between the base layer 2 and the inorganic resist layer 3 as shown in FIG. 3 is reduced to suppress crystal generation at the interface with the inorganic resist layer 3. The intermediate layer 20 is a material having an intermediate surface tension between the metal oxide constituting the inorganic resist layer 3 and the material constituting the underlayer 2 (amorphous silicon in this embodiment) (in this embodiment, amorphous silicon oxide). ), The difference in interfacial tension between the underlayer 2 and the inorganic resist layer 3 can be reduced. The intermediate layer 20 may have a layer structure in which the interfacial tension is changed continuously or stepwise from the inorganic resist layer 3 to the base layer 2.

  When a material that easily generates fine crystals such as W / Mo / O = 32/8/60 (atomic ratio) is used as the inorganic resist layer 3, for example, a metal such as ZnS—SiO 2 is used as the underlayer 2. When a material containing an oxide is used, the interface layer 8 is hardly generated. However, when a material having an interfacial tension different from that of the inorganic resist layer 3 such as amorphous silicon capable of obtaining high surface flatness and film thickness uniformity is used as the underlayer 2, an intermediate for preventing crystallization at the interface of the inorganic resist layer 3 is used. It is necessary to provide the layer 20 between them.

  On the other hand, as an intermediate layer, for example, a method of using a film formed by mixing a small amount of a material different in crystallinity in the same material as the base layer or the inorganic resist layer can be considered. However, for example, when this method is used in the sputtering method, if the film is continuously formed in one sputtering chamber, the inorganic resist layer formed on the intermediate layer is contaminated with the above-mentioned material, and the characteristics change. There is a possibility. Therefore, in the present embodiment, as the intermediate layer 20, an oxide of the material used in the underlayer 2 is used, or a mixture of the material used in the underlayer 2 and the material used in the inorganic resist layer 3 is used. Yes.

  When the base layer 2 made of amorphous silicon is formed by sputtering, the film can be formed by using silicon as a sputtering target and argon as a sputtering gas. Subsequently to this, the intermediate layer 20 can be formed on the underlayer 2 by reactive sputtering in an oxidizing atmosphere using the silicon target as it is. In this case, the intermediate layer 20 made of silicon oxide is formed on the amorphous silicon layer by using a mixed gas of argon and oxygen as the sputtering gas.

  Similarly, after the base layer 2 made of amorphous silicon is formed, the intermediate layer 20 can be formed on the base layer 2 by co-sputtering a silicon target and an inorganic resist target. In this case, by using argon or a mixed gas of argon and oxygen as the sputtering gas, the intermediate layer 20 made of silicon and an inorganic resist or a mixture thereof is formed on the amorphous silicon layer.

  The mixing ratio and gas flow rate of the sputtering gas are not particularly limited, and can be appropriately adjusted according to the film forming speed, the flatness of the film, and the target degree of oxidation of the film. The same effect can be obtained by forming the intermediate layer 20 using a sputtering target of SiOx (0 <x ≦ 2). The film thickness of these intermediate layers 20 is not particularly limited, and can be appropriately adjusted according to the degree of suppression of the formation of the interface layer 8 and the heat storage amount of the base layer 2 and the intermediate layer 20 combined.

  When the inorganic resist layer 3 is formed on the obtained intermediate layer 20, the interface layer 8 is hardly generated between the inorganic resist layer 3 and the intermediate layer 20. When the interfacial tension difference between the inorganic resist layer 3 and the underlayer 2 is remarkably large, the intermediate layer 20 is formed while gradually increasing the oxygen concentration of the sputtering gas from a low concentration to a high concentration, or used in the underlayer 2 Crystals (interface layer 8) are further generated by a method of continuously changing the properties of the interface, such as film formation of the intermediate layer 20 while gradually increasing the concentration of the material used in the inorganic resist 3 relative to the material. Can be effectively prevented. Alternatively, a plurality of intermediate layers are laminated from the base layer 2 to the inorganic resist layer 3, and the oxygen content is gradually increased from the base layer 2 side toward the inorganic resist layer 3 side, or the material used in the inorganic resist layer 3 is included The same effect can be obtained by increasing the amount.

  Further, by adjusting the oxygen content and film thickness of the intermediate layer 20, the taper angle of the convex shape of the resulting inorganic resist pattern (angle θ between the pattern side wall and the bottom surface as shown in FIG. 1F) is slowed or Can be steep.

  That is, when the oxygen content of the intermediate layer 20 increases, the electrical conductivity decreases and the thermal conductivity also decreases. Therefore, the heat storage property of the intermediate layer 20 increases. Even if the thickness of the intermediate layer 20 is increased, the same effect can be obtained. When the inorganic resist layer 3 is formed on the intermediate layer 20 and a thermal reaction is caused by laser irradiation, the taper angle of the pattern shape becomes steep when the heat storage properties of the underlayer 2 and the intermediate layer 20 are high. This is because the temperature gradient from the front surface to the bottom surface is reduced in the laser irradiation portion of the inorganic resist layer 3 due to the heat stored in the underlayer 2, so that the thermal reaction is more likely to occur, and the taper angle after development. It is thought that it appears as steepness.

  Conversely, when the oxygen content of the intermediate layer 20 is reduced, the electrical conductivity is improved and the thermal conductivity is also increased. Therefore, the heat storage property of the intermediate layer 20 is reduced. Even if the thickness of the intermediate layer 20 is reduced, the same effect can be obtained. When the inorganic resist layer 3 is formed on the intermediate layer 20 and a thermal reaction is caused by laser irradiation, if the heat storage properties of the underlayer 2 and the intermediate layer 20 are low, the taper angle of the pattern shape becomes slow. This is because the temperature gradient from the front surface to the bottom surface becomes large in the laser irradiation portion of the inorganic resist layer 3 due to the release of heat from the underlayer 2, so that the heat reaction is likely to occur non-uniformly. This is probably because the taper angle appears sluggish.

  The intermediate layer 20 can also be used for the purpose of imparting heat storage properties, for example, when it is necessary to use a material with low heat storage properties as the underlying layer for reasons such as securing priority for surface flatness. . Since thermal conductivity is qualitatively proportional to electrical conductivity, measure the surface resistance when an underlayer, an intermediate layer, and an inorganic resist layer are formed on the base material, and measure the thermal conductivity. It can be.

  As described above, according to the present embodiment, since the intermediate layer 20 having an interfacial tension intermediate between these two interfacial tensions is formed between the base layer 2 and the inorganic resist layer 3, the inorganic resist The difference in interfacial tension between the layer 3 and the underlayer 2 can be relaxed, and the generation of the crystalline interface layer 8 can be suppressed. As a result, an inorganic resist pattern or an optical disc master 10 having excellent flatness at the bottom of the pattern recess can be obtained, and the optical disc stamper 11 and the optical disc substrate 12 as a transfer product can be formed with high accuracy.

  Moreover, according to this embodiment, the convex taper angle of the concavo-convex pattern can be arbitrarily adjusted by adjusting the amount of oxygen contained in the intermediate layer 20 or adjusting the film thickness of the intermediate layer 20. Thereby, for example, when the taper angle is steep, it is possible to further increase the density of the pattern. For example, when the taper angle is slow, the peelability of the optical disc stamper 11 and the optical disc substrate 12 can be improved when the optical disc master 10 is manufactured. Furthermore, since the pattern density can be easily changed only by adjusting the amount of oxygen or the film thickness contained in the intermediate layer 20, it can be easily applied to masters of other industrial products other than the manufacture of optical disc masters. It is.

  Examples of the present invention will be described below, but the present invention is of course not limited to these examples.

[Preparation conditions for resist master]
As the underlayer, a 100 nm underlayer made of amorphous silicon was provided on the substrate. The conditions for forming the underlayer are shown below.
Base material: 8 inch silicon wafer Target material: Silicon Film forming gas: Argon (Ar): 26 [sccm]
Deposition start gas pressure: 5.0 × 10 ⁻⁴ [Pa]
Deposition power: DC135 [W]

On this foundation layer, an intermediate layer was formed by the method shown in the following examples. Further thereon, an inorganic resist layer was formed by the following method to obtain a resist master (optical disc master). The film thickness of the inorganic resist layer was 27 nm.
Target material: Tungsten (W) / Molybdenum (Mo) / Oxygen (O)
= 32/8/60 (atomic ratio)
Deposition gas: Argon (Ar): 26 [sccm]
Deposition start gas pressure: 5.0 × 10 ⁻⁴ [Pa]
Deposition power: DC135 [W]

[Exposure and development conditions]
The optical disk master was subjected to laser irradiation and development under the following conditions to produce a DC groove pattern (pattern without wobble).
Light source: Semiconductor laser (wavelength 405 [nm])
Objective lens: numerical aperture NA = 0.9
Optical disc master feed rate: 0.32 [μm / revolution]
Spindle: CLV (Constant Linear Velocity) method: 4.9 [m / sec]
Developer: 2.38% tetramethylammonium aqueous solution

(Comparative Example 1)
Only the base layer and the inorganic resist layer were formed on the substrate. FIG. 8 shows the surface profile of the obtained master disc when laser irradiation and development are performed to produce a DC groove pattern as a cross-sectional profile of an AFM (atomic force microscope). The taper angle of the convex shape of the pattern was 36 °. Moreover, since the film thickness of an inorganic resist layer is 27 nm, it turns out that about 4 nm becomes an interface layer and is insoluble in a developing solution. And the protrusion of an interface layer has appeared in the bottom part of the groove | channel which forms a pattern recessed part (part shown with the circle of a broken line).

(Comparative Example 2)
Subsequent to the formation of the underlayer, an intermediate layer was formed by the following method. The film thickness after film formation was 5 nm.
Target material: Silicon Deposition gas: Argon (Ar): 25 [sccm]
Oxygen (O2): 1 [sccm]
Deposition start gas pressure: 5.0 × 10 ⁻⁴ [Pa]
Deposition power: 135 [W]

  FIG. 8 shows the surface profile of the obtained master disc when laser irradiation and development are performed to produce a DC groove pattern as a cross-sectional profile of an AFM (atomic force microscope). The level difference after development was 25 nm and the taper angle was 43 °. Since the film thickness of the inorganic resist layer is 27 nm, it can be seen that about 2 nm becomes an interface layer and is insoluble in the developer. A protrusion of the interface layer appears at the bottom of the groove (portion indicated by a broken-line circle). From this result, it can be seen that the film formation gas of Ar / O 2 = 25/1 does not oxidize silicon sufficiently to suppress the crystallization of the inorganic resist layer.

(Example 1)
Subsequent to the formation of the underlayer, an intermediate layer was formed by the following method. The film thickness after film formation was 5 nm.
Target material: Silicon Deposition gas: Argon (Ar): 24 [sccm]
Oxygen (O2): 2 [sccm]
Deposition start gas pressure: 5.0 × 10 ⁻⁴ [Pa]
Deposition power: 135 [W]

  FIG. 8 shows the surface profile of the obtained master disc when laser irradiation and development are performed to produce a DC groove pattern as a cross-sectional profile of an AFM (atomic force microscope). The level difference after development was 26 nm, and the taper angle was 46 °. Since the thickness of the inorganic resist layer is 27 nm, the thickness of the interface layer is 1 nm, and the generation of protrusions on the interface layer at the bottom of the groove is almost completely suppressed. From this result, it can be seen that the deposition gas of Ar / O 2 = 24/2 is effective in suppressing the crystallization of the inorganic resist layer.

(Example 2)
Subsequent to the formation of the underlayer, an intermediate layer was formed by the following method. The film thickness after film formation was 5 nm.
Target material: Silicon Deposition gas: Argon (Ar): 22 [sccm]
Oxygen (O2): 4 [sccm]
Deposition start gas pressure: 5.0 × 10 ⁻⁴ [Pa]
Deposition power: 135 [W]

  FIG. 8 shows the surface profile of the obtained master disc when laser irradiation and development are performed to produce a DC groove pattern as a cross-sectional profile of an AFM (atomic force microscope). The level difference after development was 27 nm and the taper angle was 49 °. The film thickness and level difference of the inorganic resist layer are almost the same, and the generation of the interface layer is almost completely suppressed. From this result, it can be seen that the deposition gas of Ar / O 2 = 22/4 is sufficient to suppress crystallization of the inorganic resist layer.

(Example 3)
Subsequent to the formation of the underlayer, an intermediate layer was formed by the following method. The film thickness after film formation was 10 nm.
Target 1 Material: Silicon Target 2 Material: Tungsten (W) / Molybdenum (Mo) / Oxygen (O)
= 32/8/60 (atomic ratio)
Deposition gas: Argon (Ar): 26 [sccm]
Deposition start gas pressure: 5.0 × 10 ⁻⁴ [Pa]
Deposition power of target 1: 135 [W]
Deposition power of target 2: 135 [W]

FIG. 8 shows the surface profile of the obtained master disc when laser irradiation and development are performed to produce a DC groove pattern as a cross-sectional profile of an AFM (atomic force microscope). The level difference after development was 26 nm and the taper angle was 31 °. Since the thickness of the inorganic resist layer is 27 nm, the thickness of the interface layer is 1 nm, and the generation of protrusions on the interface layer at the bottom of the groove is almost completely suppressed. From this result, the silicon target and the inorganic resist target (tungsten (W) / molybdenum (Mo) / oxygen (O) = 32/8/60 (atomic ratio)) were formed at the same deposition power for the same time, It can be seen that the intermediate layer formed by sputtering is effective in suppressing crystallization of the inorganic resist layer. The sputter rate of each target under the above conditions is
Target 1: 9.8 [sec / nm]
Target 2: 8.5 [sec / nm]
Therefore, the intermediate layer is a mixture of silicon and an inorganic resist in a ratio of approximately 1: 1.

  FIG. 9 is a list showing the relationship between the material composition of the intermediate layer and the resist pattern surface resistance, crystal layer thickness, and taper angle. FIG. 10 is a graph showing the relationship between the oxygen ratio of the film forming gas and the surface resistance of the resist pattern, the crystal layer thickness, and the taper angle when the constituent material of the intermediate layer is silicon oxide (SiOx). It is. As shown in FIG. 10, as the oxygen ratio of the deposition gas increases, the surface resistance and taper angle of the resist pattern formed on the intermediate layer increase while the crystal layer thickness at the interface decreases. I understand.

  As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to this, A various deformation | transformation is possible based on the technical idea of this invention.

  For example, the specific numerical values given in the above embodiments and examples are merely examples, and different numerical values may be used as necessary.

  In the above-described embodiment, the example in which the present invention is applied to the optical disk master and the manufacturing method thereof has been described. However, the present invention is not limited to this, and various devices having a fine uneven pattern, for example, light reflection prevention in solar cells. The present invention is also applicable to the structure, the fuel flow path in the fuel cell, and the manufacturing method thereof.

It is a cross-sectional schematic diagram for demonstrating the manufacturing method of the inorganic resist pattern and optical disc original disc by one Embodiment of this invention. It is a cross-sectional schematic diagram for demonstrating the manufacturing method of the optical disk stamper by one Embodiment of this invention. It is a cross-sectional schematic diagram for demonstrating the manufacturing method of the optical disk board | substrate by one Embodiment of this invention. It is a schematic block diagram of the cutting apparatus used for exposure of the inorganic resist layer. It is a schematic diagram explaining the formation method of the uneven | corrugated pattern of positive type inorganic resist. It is a schematic diagram for demonstrating the mode of the phase change of the metal oxide in the inorganic resist layer at the time of exposure. It is a schematic diagram for demonstrating the interface layer formed between an inorganic resist layer and a base layer, and its problem. It is a figure which compares and shows the result of the Example and comparative example of this invention. It is a figure which compares and shows the film-forming conditions of the intermediate | middle layer and the form of a resist pattern in the Example and comparative example of this invention. It is a figure which shows the relationship between the oxygen ratio of the film-forming gas of the intermediate | middle layer demonstrated in the Example of this invention, the surface resistance of a resist pattern, the crystal layer thickness of an interface, and the taper angle of a pattern convex part. It is a schematic diagram for demonstrating the outline of the conventional process from preparation of an optical disk original disk to preparation of an optical disk substrate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Base material, 2 ... Underlayer, 3 ... Inorganic resist layer, 8 ... Interface layer, 8a ... Surface unevenness (protrusion), 10 ... Optical disc master, 11 ... Optical disc stamper, 12 ... Optical disc substrate, 13 ... Optical disc, 20 ... Intermediate layer, 30 ... Cutting device

Claims (18)

An inorganic resist pattern formed by patterning an inorganic resist layer on a substrate,
The inorganic resist layer is made of an amorphous metal oxide,
An inorganic resist pattern, wherein an intermediate layer for suppressing crystallization at the interface of the inorganic resist layer is provided between the substrate and the inorganic resist layer. The inorganic resist pattern according to claim 1, wherein the intermediate layer is made of a material that relieves a difference in interfacial tension between the inorganic resist layer and a base surface thereof. A base layer as a heat storage layer is formed on the base material,
The inorganic resist pattern according to claim 1, wherein the intermediate layer is formed between the base layer and the inorganic resist layer. The inorganic resist pattern according to claim 3, wherein the intermediate layer is made of an oxide of a material constituting the base layer. The underlayer is made of amorphous silicon,
The inorganic resist pattern according to claim 4, wherein the intermediate layer is made of silicon oxide. The inorganic resist pattern according to claim 4, wherein the intermediate layer is formed so that an oxygen content increases from the base layer side toward the inorganic resist layer side. The inorganic resist pattern according to claim 4, wherein the intermediate layer is formed so that the content of the inorganic resist layer increases from the base layer side toward the inorganic resist layer side. . The inorganic resist pattern according to claim 3, wherein the intermediate layer is made of a mixture of a material constituting the underlayer and a material constituting the inorganic resist layer. The inorganic resist pattern according to claim 1, wherein the inorganic resist layer is made of an oxide of a transition metal. The inorganic resist pattern according to claim 9, wherein the transition metal is any one of tungsten, molybdenum, and vanadium. Forming an inorganic resist layer made of a metal oxide on a substrate;
Irradiating the inorganic resist layer with laser light to form a latent image of a predetermined shape;
Developing the inorganic resist layer to form a concave / convex pattern of the inorganic resist layer in which the latent image forming portion is a recess on the base material, and a method of forming an inorganic resist pattern,
Before the step of forming the inorganic resist layer on the substrate,
A method for forming an inorganic resist pattern, comprising: forming an intermediate layer for suppressing crystallization at an interface of the inorganic resist layer on the base material. Before the step of forming the intermediate layer on the substrate,
The method for forming an inorganic resist pattern according to claim 11, further comprising: forming a base layer as a heat storage layer on the base material. The method for forming an inorganic resist pattern according to claim 12, wherein an oxide of a material constituting the base layer is used as the intermediate layer. The inorganic resist pattern according to claim 13, wherein the intermediate layer is formed by reactive sputtering in an oxidizing atmosphere, and the intermediate layer is formed while gradually increasing the oxygen concentration. Forming method. An optical disc master formed by patterning an inorganic resist layer on a substrate,
The inorganic resist layer is made of an amorphous metal oxide,
An optical disc master, wherein an intermediate layer for suppressing crystallization at the interface of the inorganic resist layer is provided between the base material and the inorganic resist layer. Forming an inorganic resist layer made of a metal oxide on a substrate;
Irradiating the inorganic resist layer with laser light to form a latent image of a predetermined shape;
And developing the inorganic resist layer to form a concavo-convex pattern of the inorganic resist layer in which the latent image forming portion is a recess on the substrate,
Before the step of forming the inorganic resist layer on the substrate,
A method for producing an optical disc master, comprising: forming an intermediate layer on the substrate for suppressing crystallization of an interface of the inorganic resist layer. Forming an inorganic resist layer made of a metal oxide on a substrate;
Irradiating the inorganic resist layer with laser light to form a latent image of a predetermined shape;
Developing the inorganic resist layer to produce an optical disc master having a concave-convex pattern of the inorganic resist layer on which the latent image forming portion is a concave portion on the substrate;
Forming a metal plating layer on the optical disc master,
A method of manufacturing an optical disc stamper comprising a step of peeling the metal plating layer from the optical disc master,
Before the step of forming the inorganic resist layer on the substrate,
A method of manufacturing an optical disc stamper, comprising: forming an intermediate layer for suppressing crystallization at the interface of the inorganic resist layer on the substrate. Forming an inorganic resist layer made of a metal oxide on a substrate;
Irradiating the inorganic resist layer with laser light to form a latent image of a predetermined shape;
Developing the inorganic resist layer to produce an optical disc master having a concave-convex pattern of the inorganic resist layer on which the latent image forming portion is a concave portion on the substrate;
A method of manufacturing an optical disk substrate, comprising the step of forming an optical disk substrate using the optical disk master or a replica mold thereof,
Before the step of forming the inorganic resist layer on the substrate,
A method for producing an optical disk substrate, comprising: forming an intermediate layer for suppressing crystallization at an interface of the inorganic resist layer on the base material.

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