TWI243372B - Method of manufacturing original disk for optical disks, and method of manufacturing optical disk - Google Patents

Abstract

The present invention provides a method of producing an optical disk-use original and a method of producing an optical disk, capable of realizing the higher storage capacity of an optical disk by using an existing exposure system. The present invention is characterized in using an original formed with a specified uneven pattern that is formed by forming on a substrate a resist layer consisting of a resist material containing the imperfect oxide of a transition metal such as W and Mo, the imperfect oxide having an oxygen content smaller than that of a stoichiometric composition according to a valency capable of being possessed by the transition metal, and then by selectively exposing and developing the resist layer by a laser beam in conformity with a recording signal pattern, the uneven pattern then being transferred onto the optical disk.

Description

1243372 Description of the invention: [Technical field to which the invention belongs] 1. The present invention relates to a method for manufacturing a high-precision optical disc master and a method for manufacturing the optical disc using the original disc. [Prior art] previously, the recording medium stores various log information of the very significant development, particularly with respect to the small recording medium, the recording mode by the optical recording medium toward the magnetic recording medium while transferring the 'recording capacity is increased by the mb one thousand dead bit) level progress: ~ Byte: (GigaByte terabytes) level towards GB. In recent years, 'optical recording media, progress also by a small disc (CD) (registered trademark) Syria transferred toward the light, i 2em diameter of the CD-ROM appears (DVD_R〇Mk single person has 4.7GB capacity. In this way, can ⑽ be knocking color standard way of recording two hours of video. ... ,, and, along with the rapid development of information and communication and image processing technologies in recent years, the 'recording capacity will reach up to now it has become a multiple of the disc to the Question: For example, the next-generation optical disc on the extension line of digital audio-visual discs is required to make the information capacity of gb on one side of a disc with a diameter of 12 cm. This is a digital high-quality image that can record about 2 hours. the level above the transparent disc based on one main surface of the optical polycarbonate substrate, a pit represents a concave-convex pattern (Plt) of information signals or grooves (Gr〇〇ve) or the like of the fine 'in A reflective film composed of a metal thin film such as Shao is formed thereon, and a protective film structure is further formed on the reflective film. In such a structure of the recording medium, the above-mentioned uneven pattern can be made finer.

0 \ 87 \ 87377.DOC -6- 1243372 to increase the recording density and thus increase the recording capacity. Here, with reference to FIG 1〇 be described about the light fine concave-convex pattern of the DVD disc of this process. First, a photoresist layer 91 is uniformly formed on the substrate 90 (FIG. 10 (a)). Next, a selective exposure corresponding to the signal pattern is applied to the photoresist layer 91 to make it photosensitive (FIG. 10 (b)). By developing the photoresist layer 91, an original disc 92 (FIG. 10 (c )). On the production of this original disk, the following example of a method based representation of the PRC since previously. A glass substrate with a sufficiently smooth surface is used as a substrate, and the substrate is placed on a rotating base, so that the glass substrate is rotated at a specific rotation number, and a photosensitive photoresist (organic photoresist) is supplied onto the glass substrate. Coated. Second, rotating the glass substrate extends photoresist spin coating to form a round light-blocking layer. Next, recording by laser beam exposure of the photoresist to a particular pattern formed latent image corresponding information signals. Secondly, this developing solution developed remove exposed portions or unexposed portions. Accordingly, to obtain a resist forming a photoresist master of the particular configuration of the concavo-convex pattern on the glass substrate. Next, a metal nickel film is deposited on the concave-convex pattern surface of the photoresist master disk 92 by the electroforming method (FIG. 10 (d)), and after the photoresist master disk 92 is peeled off, a specific process is applied to obtain the photoresist master disk 92. The stamping die 93 for molding to which the uneven pattern is transferred (FIG. 10 (e)). Using this molding die 93, a resin-made disc substrate 94 made of polycarbonate made of thermoplastic resin is molded by injection molding (Fig. 10 (f)). Next, the “peeling die (FIG. 10 (g))” was obtained by forming a reflective film 95 (FIG. 10 (h)) and a protective film 96 of an A1 alloy film on the uneven surface of the resin-made disc substrate 94.

O: \ 87 \ 87377 DOC 1243372 disc (Figure 10 (i)). = This, the fine concave-convex pattern of the DVD system by using a high precision formed through h :: pattern of the convex press die, and immediately on the substrate faithfully replicate the pattern of: Cheng produced Si 'into - further traced if' lines which follow by laser light to the photoresist layer is exposed to form a latent image, i.e., by how the cut-shaped fine uneven pattern is determined. ^ For example: the 4.7GB read-only DVD (DVD-ROM) with the information capacity previously described 'make the shortest pits with a length of 0.4 ceramics and a track interval of 0.74 μχη on the stamping die and spiral applying cutting. In this cutting, a laser with a wavelength of 413 nm and a numerical aperture around NAg 0.90 (for example, ·····%) are used. And, if the wavelength of the light source is set to λ (μηι), the numerical aperture of the set να, were exposed length of the shortest pit ρ (μιη) lines represented by the following formula (1). Furthermore, κ is a proportionality constant. p = κ · λ / NA… (1) Here, the wavelength A of the light source and the numerical aperture NA of the objective lens are determined according to the type of laser device that becomes the light source, and the proportionality constant κ is based on the laser device and light An item determined by the combination of the original discs. In the case of making the above-mentioned optical disc with a capacity of 4.7 GB, since the wavelength is 0.413 μm, the numerical aperture NA is 0.90, and the shortest pit length is 0.40 μm, the proportionality constant K = 0.87 according to the above formula (1). On the other hand, in order to respond to the requirements of the above-mentioned 25 GB optical disc, the shortest pit length must be miniaturized to 0.17 μιη, and the track interval must be miniaturized to 0.32 μιη degree 0

O: \ 87 \ 87377.DOC 1243372 In general, the miniaturization of the uneven pattern (formation of extremely fine pits) described earlier is achieved by shortening the wavelength of the laser light. That is, in order to obtain the shortest pit length of 0.17 μηι required for a single-sided 25 GB high-density optical disc, in the case of a proportional constant κ = 0.87 and a numerical aperture να = = 0.95, there must be a laser wavelength and = 〇 · i 8 μηΐ2 light source. The required wavelength of 0.18 μm is shorter than the wavelength of ArF laser with a wavelength of 193 nm developed as a light source for next-generation semiconductor lithography. Realizing such a short-wavelength exposure device is not only a laser for a light source, but also optical components such as lenses require special ones, which are very expensive. That is, #from the short wavelength of the exposure wavelength and the large aperture of the numerical aperture of the objective lens to 1 ^ 8, to improve the optical resolution to correspond to the extremely fine processing. With the progress of miniaturization, it is not possible to use the existing exposure device. & It is necessary to introduce an expensive exposure device, so it is extremely unsuitable for the purpose of providing components at a low price. Therefore, there is a limit to increasing the memory capacity of the disc by the functionalization of the field irradiator in the exposure device. See, for example, 7-phenol-based resist composition, chemically amplified resist and other organic photoresist, & as a UV exposure method of exposing the source of generally widely utilized. The organic photoresist is universal and widely used in the field of lithography. However, the pattern of the boundary between the exposed portion and the unexposed portion is formed by the formula ^ 子 · 吾 'o * TT- > 4.1. not the corresponding bit micro-machining system 25 GB high-capacity DVD has a problem of accuracy of registration surface.

In contrast, the benefits of UU…, machine-first resistance, especially amorphous silicon inorganic photoresist, because the smallest structural unit is the size of the wide + mass level, so you can get the bright and dark mouth of the boundary between the exposed part and the unexposed part. Compared to organic photoresistors, the pattern can achieve high precision

O: \ 87 \ 87377 D0C 1243372's microfabrication ’is hoped to be suitable for high-capacity discs. This series includes microfabrication examples using M03 or W3 as photoresist materials and ion beams as exposure sources (for example: NobuyosM KosMda, Kazuy〇sM Yoshida, Shinichi Watanuki, Masanori Komuro and Nobufumi Atoda · 50 -nm Metal Line Fabrication by Focused

Ion Beam and Oxide Resists (50-nm metal wires made with focused ion beam and oxidized photoresist) ", jpn · J. Αρρ1 · Phys ν〇1 · 30 (1991) ρρ3246.) Also, Si〇2 is used. As a photoresist material, a processing example using an electron beam as an exposure source (for example: Sucheta M · Gorwadkar, Toshimi Wada? Satoshi Hiraichi, Hiroshi Hiroshima, Kenichi Ishii and Masanori Komuro: f, Si02 / c-Si Bilayer

Electron-Beam Resist Process f〇r Nano-Fabrication, jpn · j · Αρρΐ · phys · ν〇1 · 35 (1996) pp6673) . In addition, the method of using selenium-selenium-tellurium glass as a photoresist 'using lasers with a wavelength of 476 nm and a wavelength of 532 nm and ultraviolet light from a mercury gas lamp as an exposure source is also reviewed (for example: s. A. K〇styukevycll: Investigations and modelling of physical processes in inorganic resists for the use in UV and laser lithography., SPIE Vol. 3424 (1998) pp20. ). However, 'the use of an ion beam or an electron beam as the exposure light source, the photoresist material may be a combination of inorganic species of as much as described above, were thin congregation by electron beam or ion beam' of the fine asperity pattern can be, however, mounted electronic The structure of the beam and ion beam irradiation source is complicated and extremely expensive, so it is not suitable

O: \ 87 \ 87377 DOC -10- 1243372 Supply of cheap discs. About this point, as to be mounted on a use, to find the particular deposit device laser light exposure apparatus' i.e. ultraviolet or visible, preferably nine ^ regulation, however, the inorganic resist material in this winter, outside or visible Light-cutting is made of shiinaishixi ...; the material of L is limited, so far in the report only ^ ° This is because ultraviolet or visible light passes through the sulfur photoresist material of inorganic photoresist material, light energy κ…. (Iv) "to absorb significantly less in 'non-existing APPLICABILITY The exposure apparatus in combination with sulfur, selenium tellurium materials in ,, sacrifice: for, on the back of a combination of practical, however, contain a material having iv Ag2S3, Ag_As2S3, M2se-Gese # The problem of materials harmful to the human body is difficult to use from an industrial point of view. ", 釺 = As mentioned above, the manufacture of optical discs with high record valleys of existing exposure devices has not yet been realized. The present invention has been proposed by the present invention in order to solve such a conventional problem, and it is to provide a photoresist M 4 ′ which is safe and does not use expensive electron beams or ion beams, and achieves high-precision microfabrication. It can realize the manufacturing method of the original disk and the manufacturing method of the optical disk by using the existing discontinuity and further reducing the memory capacity of the original disk. SUMMARY OF THE INVENTION disks were described above, since the previous use of the green-based materials and the like M0〇4W〇3 full transition metal oxide as electron beam or ion beam used, the other of% Λ ', outside or visible light transparent, absorbent significantly small, it is difficult for an outside or visible light r in the fine processing as the source of exposure. Ding Μ purple contrast, the review results of the present inventors have found that as long as the oxygen containing denier

O: \ 87 \ 87377.DOC -11-1243372 Slightly deviates from the stoichiometric composition of the transition metal oxide. This oxide suddenly absorbs ultraviolet or visible light. At the same time, by absorbing ultraviolet or visible light, its chemical Its properties are ㈣, and it can be applied to the manufacturing methods of photoresist materials and original discs for optical discs. That 'whereby the proportionality constant κ improvement of the above-described formula ⑴' can be achieved to reduce the shortest pit length Ρ. The method for manufacturing an original disc for an optical disc according to the present invention is designed based on the above considerations, and is characterized in that a film containing an incomplete oxide of a transition metal is formed on a substrate, and the oxygen content ratio of the incomplete oxide is in accordance with the foregoing. After the photoresist layer composed of a photoresist material with a stoichiometric composition of transition metal with a small amount of oxygen content, the photoresist layer is selectively exposed and developed corresponding to the signal pattern for recording to form a specific uneven pattern. In addition, the manufacturer S of the optical disc of the present invention is characterized in that a film containing an incomplete oxide of a transition metal is formed on a substrate, and the oxygen content ratio of the incomplete oxide is in accordance with the chemistry of the transition metal valence. After measuring a photoresist layer composed of a photoresist material with a small oxygen content, a master disc that selectively exposes and develops the photoresist layer corresponding to the signal pattern for recording to form a specific uneven pattern is used to make the uneven pattern. Printed disc. In the definition of the incomplete oxide of transition metals is called here: toward oxygen content ratio in accordance with the amount of the number of chemically made ten mining price may be composed of a transition metal compound of less and departing directions, i.e., incomplete oxide of transition metals of A compound having a lower oxygen content than an oxygen-containing substance having a stoichiometric composition based on the valence of the transition metal. Moreover, the complex containing the transition metal species, the part of the transition metal atoms of the i-crystal structure may be replaced with other transition metal atom,

O: \ 87 \ 87377.DOC -12- 1243372 2 And whether the oxygen content is sufficient for the recoverable chemical metrological composition of these plural kinds of transition metals to determine whether it is an incomplete oxide. _ The incomplete oxide of the transition metal used in the photoresist material of the present invention shows absorption of ultraviolet or visible light, so exposure can be performed without using a special exposure source such as an electron beam or an ion beam. x, incomplete oxide of the transition metal of a low molecular weight "it is compared with the organic photoresist consisting of a polymer, and the Realm portion (iv) exposure of the unexposed portion, so that by using this photoresist as: can be high after Precision photoresist pattern. [Embodiment Hereinafter, I test described in detail one of the drawings of the optical disc manufacturing method of the present invention patterns. The method of manufacturing a CD or less, the summary of FIG. 1 explained suitable process according to the present invention. Next, using an exposure device provided with an existing laser device, a selective exposure corresponding to a signal pattern is applied to the photoresist layer 102 to make it photosensitive (photoresist sacrifice process SI 1 (b)). Furthermore, the original disc with the uneven pattern determined by the development of the photoresist layer 102 is called the photoresist layer development process, and the figure is followed by the method of electric prayer, which is deposited on the surface of the uneven pattern of the g handle_1Λ and the original 103 after the first metal, on the substrate 100, a photoresist layer by a sputtering method, consisting of a uniform deposition of the inorganic particular material 102 resist (resist layer forming step, FIG materials suitable for consumption in detail to be described later of the photoresist layer ⑻ . Also, in order to improve the exposure sensitivity of the photoresist layer 102, a specific intermediate layer 101 can also be formed between the substrate ⑽ and the photoresist layer 1G2. Fig. 1 shows the state. Furthermore, the film thickness of the photoresist layer 102 may be arbitrarily set, however, preferably in the range of 1G~80 coffee.

O: \ 87 \ 87377.DOC • 13- 1243372 Nickel film (Fig. 1 (d)) 'After peeling this from the original plate 103, apply specific processing' To obtain the stamping die for molding transferred from the uneven pattern of the original plate 103 (Figure 1 (e)). , ° using the stamping die 1〇4 molding, injection molding process by molding the resin disc substrate composed of a polycarbonate 1〇5 thermoplastic resin (FIG. 1. Next, release the punching die (FIG. 1 (g) ), with the concave surface of the disc substrate 2 of the resin forming the A1 alloy reflection film 106 (FIG. 1 (H)) and the degree of the thickness of the protective film 107 is obtained 〇i CD (FIG. 1 (a)) Furthermore, by the above step until the photoresist to obtain the original CD = previous to the conventional manufacturing techniques can photoresist material suitable for the material of the photoresist of photoresist layer 102 is an incomplete oxide of a transition metal. in this' An incomplete oxide of a transition metal is defined as a compound whose oxygen content deviates in a direction smaller than the stoichiometric composition according to the recoverable valence of the transition metal, that is, the oxygen content ratio of the incomplete oxide of the transition metal According to the valence of the transition metal, the compound with low oxygen content can be used. For example, the chemical formula Mo03 will be described as an oxide of the transition metal. If the chemical formula Moo; the oxidation state is converted into the composition ratio , Relative to χ = 〇 · 7 5 where the fully monoxide, square < χ < square · 75 ^ represents the case may be, said oxygen content is less than the stoichiometric composition of the incomplete oxide and transition metal, an element may also be formed. Those with different valences, however, in this case, the scope of the present invention means that the actual oxygen content ratio is less than the stoichiometric composition of the transition metal's recoverable valence = O: \ 87 \ 87377 .DOC -14-1243372. For example: Mo is the most stable trivalent oxide (m003) described previously. However, there are other i-valent oxides (M00). Here In this case, if it is converted into a composition ratio ΜΟχχχ, Nichiji in the range of 〈χ〉 can be said to be an incomplete oxide whose oxygen content is less than the stoichiometric composition. Furthermore, transition metal oxidation The value of the substance can be analyzed by a commercially available analysis device. The incomplete oxide of this transition metal shows absorption of ultraviolet or visible light, and its chemical properties change due to being irradiated by ultraviolet or visible light. The details will be described later, but its As a result, although it is an inorganic photoresist, In the process, the difference between the # engraving speed of the exposed portion and the unexposed portion results in the so-called selection ratio. In addition, the photoresist composed of incomplete oxide of the transition metal is due to the small particle size of the film material. portion of the boundary pattern portion of the apparent exposure, the resolution can be improved brother, however, an incomplete oxide of a transition metal oxide because of the extent, which also vary as the characteristics of the photoresist material, for example, it should be suitably selected optimum: oxygen content significantly exact stoichiometric composition of the oxide of a transition metal of less imperfect oxide, which process requires the exposure system along with a large irradiation power, or developing inconvenience such treatment requires a long time. Thus, there are S = oxygen a little more than a transition metal A complete oxide having a small stoichiometric composition is preferred. Specific transition metals called photoresistive materials can be exemplified. Β Μη, Fe, Nb, Cu, Ni, Co, Mo, Ta, W, 7 "η

Zr, Ru, Ag, etc. Among them, Mo, W, Cr, Fe, Nb is preferred, and Shixinju is considered from the viewpoint of using UV or visible light to obtain large chemical changes. _ Qiaoli, especially for use Μ square, is preferred.

O: \ 87 \ 87377 DOC -15-1243372 Furthermore, as a transition metal, & ^ Where king lice compounds, in addition to an incomplete oxide of a transition metal, add goods Those with transition metals, even those with multiple types of transition metals, i ^ ^ + ', those with metals other than transition metals, are included in the scope of the present invention, and those with multiple metal elements Better. In addition, in addition to the eight metals of one transition metal + 70 total lice compounds, those who add a second transition metal, or even three kinds of transition metals that are μ μ, wind, or more than A + may have one transition metal atoms in the crystal structure of a ^ b mound blade may be replaced with other month transition metal atom, however, the oxygen containing recoverable metal oxides the stoichiometric composition. Whether the amount is sufficient for these plural types of transitions to determine whether they are incomplete. At least one of A, C, B, Si, and Ge may be used for elements other than transition metals. By a combination of two or more of the transition metal to be used, or add other elements other than the transition metal, since the crystallinity of the incomplete oxide of the transition metal particles becomes small, so that the non-exposed portion and the exposed portion of the boundary portion better understood reach The purpose of greatly improving the resolution can also improve the exposure sensitivity. Further, in the above-described photoresist material by containing a specific target of the transition metal in the atmosphere of Ar + sputtering 〇2 can be produced. For example, 相对 2 is 5 to 20% with respect to the full flow rate of the gas introduced into the reaction chamber, and the gas pressure is the gas pressure of the usual sputtering method (1 to 10 Pa). Manufacturing method of optical disc master Next, a detailed description will be given of a manufacturing method of the optical disc master which constitutes the fundamental method of manufacturing the optical disc. As one embodiment of the manufacturing method of the original disc for optical discs of the present invention, the

O: \ 87 \ 87377.DOC -16- 1243372 is a photoresist material composed of, for example, p # < on the substrate, "incomplete oxide of transition metal", Process, the process of selective exposure and photosensitivity in the photoresist layer, and measures to form the bump pattern formed by displaying the photoresist layer of the shirt. The following describes the fine photoresist layer forming process f of each step. A photoresist layer composed of an incomplete emulsion of a transition metal is formed on a substrate with a sufficiently smooth surface. Specific film-forming methods can be exemplified by a method of using a dry material composed of a transition metal monomer to make money in an ammonia or oxygen atmosphere by means of an extinguishing method. In this case, by changing the oxygen gas concentration in the vacuum gas flood, the degree of oxidation of incomplete oxides of the transition metal can be controlled. Case where incomplete oxides of transition metals containing two or more types of transition metals are formed by the method ′ Plural types of transition metals are mixed by frequently rotating the substrate by spraying dry materials of different types on the dry material. The mixing ratio of a sputtering system by changing the input power are controlled. Furthermore, in addition to the previously described method of firing metal dry materials in an oxygen atmosphere, 'dry materials composed of incomplete oxides of transition metals containing a desired amount of oxygen in advance are used in a normal argon atmosphere. A photoresist layer composed of an incomplete oxide of a transition metal can also be formed by the coinjection method. In addition to the 1 shot method, a photoresist layer composed of incomplete oxide of a transition metal can be easily formed by a vapor deposition method. The substrate may be glass, plastic, etc. (iv) polycarbonate, stone Xi, Shao oxidation of carboniferous Chin, nickel and the like. May be set at a film thickness of 10~8〇 nm photoresist layers can be arbitrarily set, e.g.

O: \ 87 \ 87377.DOC -17- 1243372. Photoresist layer exposure process ~ Secondly, the substrate on which the film formation of the photoresist layer is completed (hereinafter referred to as the photoresist substrate) is arranged on the upper side with the photoresist film-forming surface and is mounted on the rotating stage of the exposure device shown in FIG. 2 1 1 This exposure system is provided with, for example, an exposure photoresist layer, such as a beam generating source 12 ′ that generates laser light and has the laser light generated thereby focused by a collimating lens 13, a beam splitting of 14, and an objective lens 15. The photoresist layer is irradiated with a photoresist layer. In addition, the exposure device has the reflected light from the photoresist substrate 1 connected to a split light sensor 17 via a beam splitter 14 and a condenser objective lens 16. constitutes segmentation reflected light detecting optical sensor 17 'of the substrate 1 is formed from a photoresist whereby the detection result of the focus error signal obtained Shu 8, and transmitted to the focus actuator 19. the focus actuator 19 based The position controller for the height direction of the objective lens 15. A transfer mechanism (omitted) is provided on the rotary table U, which can change the exposure position of the photoresistive substrate 1 with good accuracy. Also, in this exposure device, the laser drive circuit 23 is 20 The amount of reflected light information signal Signal 21 and non-compliance error signal 22, while controlling the beam generating source 12, perform exposure or focusing. Furthermore, a spindle motor control system 24 is set on the central axis of the rotary table, according to the radial position of the optical system and the desired line Speed, set the optimal spindle rotation number, and control the spindle motor. In the previous exposure process for the photoresist layer composed of organic photoresist, the light source itself for exposure was not used to focus on the photoresist layer. This exposing the photoresist was due to the change in the organic chemical nature of the continuity, it is necessary extent even in a focus of a feeble light, which is irradiated by the light, the organic material

OA87 \ 87377.DOC -18 * 1243372 will make unnecessary exposure. Therefore, prepare another organic light source that does not have a wavelength of sensitivity, for example, a red light source with a wavelength of 633 planes, and use this light to enter the pole to flatten the light source. In this way, the conventional exposure device for organic photoresist used two light sources with different wavelengths. Therefore, it was necessary to set an optical system with separable wavelengths. Therefore, the optical system became very complicated, or its cost increased. Even 'antecedent organic photoresist with an exposure apparatus, since a focus error signal based resolution for the control of the height position of the objective and by: bismuth of the light source (eg: 633 proportional to the wavelength of the wavelength, it can not & Aberdeen to the resolution of the obtained light source for exposure, the problem of not having a stable and high accuracy of focus. in contrast, the resist material of the present invention of FIG inorganic materials based power source for irradiating the exposure of The relationship between the difference in the engraving speed of the exposed and unexposed parts (contrast) shows that 'exposure is extremely steep in the change in chemical properties I, that is, the exposure to the threshold power p0 of the exposure at the beginning of the under exposure. Power 'does not make unnecessary exposure even for repeated irradiation, ㈣ can be used to expose the light source from the less than full irradiation power' 9 The method for manufacturing the original disc for optical discs of the present invention does not require wavelength division: Guangguang reached an exposure device the cost reduction while achieving high-precision phase :: * the focus of the first wavelength, the fine processing can be achieved correctly. again under weak light irradiation threshold power P0, the inorganic Barrier material will not be exposed, hence it is usually not necessary to use an organic: f King barrier means are necessary for blocking of the interior lighting of the ultraviolet light as described above, for producing short-tailed make full use of the light irradiation threshold power P0 of. Turntable _ move to the desired radius position. Here, solid

O: \ 87 \ 87377.DOC -19- 1243372 The position of the optical system in the direction of the surface 'changes the exposure position of the photoresistive substrate 1 by moving the turntable " The rotation stage of the resistive substrate 1 changes the position of the optical system. Light beam generating source 12 and irradiating the laser beam, while rotating the rotary table u, for the photoresist layer is exposed. This exposure system by - surface of the rotary table ⑽ turn, - the rotation surface ⑼ resist the radial direction of the continuous movement of the substrate i slight distance, to form a latent image of tiny irregularities' i.e. the coil is formed by a recording system of the disc case Like the guide groove. Also, the case of disc-based data form information uneven pit and hunting guide ditch as a latent image of a fine uneven. Yet, such as the use Drive system for a magnetic disc of the executors of concentric occasion, can not by continuity, but gradually transferred to the turntable 11 or a corresponding optical system. With the above-described 1, according to information resources g, corresponding to a desired irradiation of the pulse P0 above the pits or guide grooves of the irradiation threshold power or the power of the continuous light are sequentially irradiated by the desired position on the substrate of a photoresist photoresist layer is exposed. An example of the irradiation pulse is shown in Fig. 4B, and continuous light is shown in Fig. 4C. The photoresist material composed of the incomplete oxide of the transition metal of the present invention is irradiated with ultraviolet or visible light with a threshold power P0 or higher: the change of the chemical properties is as follows: In this case, the selection ratio can also be obtained. At this time, the lower the irradiation power, the shorter and narrower pits can be formed. However, if the irradiation power is extremely extreme, the team's W An'an shooting threshold power, it is difficult to ^ the pattern piece goods must therefore be adapted% were reported ΤΞ7, Fen qe shoulder irradiation field 5 takes power and Cloth Sik

exposure. W

\ S7 \ 87377.DOC -20-1243372 Furthermore, the present inventors have actually confirmed that by combining the photoresist material of the present invention, the red semiconductor laser with a wavelength of _ legs, and the light from the wavelength plane, ..., and 405 !! „1 degree of exposure to mercury lamps with peaks can obtain a selection ratio to form a fine pit pattern. The photoresist layer development process is followed by developing a photoresist substrate exposed to this pattern and developing it to obtain an optical disc. A photoresist master is formed by forming pits or fine irregularities of a guide groove according to a specific exposure pattern. The development process can obtain a selection ratio by a wet process of a liquid such as acid or alkali, and can be selected according to the purpose of use, Uses, equipment, etc. are appropriately differentiated. The alkali developing solution used in the dry process can be an inorganic alkali aqueous solution such as tetramethylammonium hydroxide solution, KOH, NaOH, Na2C03, and the acid developing solution can be hydrochloric acid or nitric acid. , Sulfuric acid, phosphoric acid, etc. In addition, the present inventors confirmed that, in addition to the wet process, even if a dry process called plasma or reactive ion etching (Reactive Ion Etching: RIE) is used, it is possible to use The development of the entire gas type and the mixing ratio of multiple gases is performed. Here, the method of adjusting the exposure sensitivity will be described. For example, when the oxide of the transition metal expressed by the chemical formula wo; is converted to the composition ratio wlx〇x, the X In the range larger than 0 · 1 and less than 0 · 7 5, a good exposure sensitivity can be obtained. At this time, X = 0 · 1 because the exposure process requires a large irradiation power, or the development process requires a long time and other inconveniences. The critical value. In addition, X is in the range of 0.4 to 0.7, and the highest exposure sensitivity can be obtained. In addition, the transition metal oxide represented by the chemical formula Mo03 is converted into a composition ratio, and X is larger than 〇 · 1. In the range of less than 0.75, a good exposure sensitivity of O: \ 87 \ 87377 DOC -21-1243372 can be obtained. At this time, a large irradiation power is required for the χ20. 丨 series exposure process, or a long development process is required. time inconvenience threshold: and, x is the degree of 0.4~0.7, the highest exposure sensitivity can be obtained in turn, will be represented by the chemical formula Fo square in terms of a transition metal oxide composition of Example Μ〇1.χ〇χ dagger% 'In Wubi 〇1 is bigger and less than ο' Inner circle, accessible, good sense of the degree of exposure. In this case, χ = 〇1 phylogenetic requires a large exposure step, ¾ transmit power, or a developing process requires a long time and the like inconvenience threshold. The higher the exposure sensitivity of the photoresist material, in addition to reducing the exposure power at the time of exposure, it also has the ability to shorten the exposure time corresponding to the pulse width or line speed. However, on the contrary, the right sensitivity is too high, which causes unnecessary focus settings. Exposure 'or the inconvenience caused by the lighting environment of the process room, etc., so the optimum exposure sensitivity is appropriately selected according to the application. In addition to adjusting the exposure sensitivity of the photoresist material of the present invention, in addition to increasing or decreasing the oxygen content, adding a second transition metal to an incomplete oxide of the transition metal is also effective. For example: Add M by I.χ0χ. , Can improve the exposure sensitivity. ^ In addition to the adjustment of the photoresist, the composition of the photoresist material can be changed by selecting the substrate material or applying pre-exposure treatment to the substrate. In the past, the use of quartz, stone, glass, and plastic (polycarbonate) as the substrate 'Investigate the sensitivity of the exposure caused by the type of substrate: different, confirm that the exposure sensitivity is different due to the type of substrate, Specifically, the order of sensitivity is Shi Xi, quartz, glass, and plastic wins. This sequence ... The order of the conductivity corresponds to the result. As a result, the smaller the thermal conductivity of the substrate, the better the sensitivity. This is because the thermal conductivity of the substrate smaller, and increased exposure of the more obvious the 'accompanying the temperature rise and therefore, the chemical nature of the photoresist material

O: \ 87 \ 87377.DOC -22- 1243372 , Heat treatment, ultraviolet irradiation treatment or the like - with a processing process before the exposure of an intermediate layer formed between the substrate and the photoresist material. In particular, when using a substrate with a large thermal conductivity, such as a stone crystal wafer composed of% monocrystalline stone, the exposure sensitivity can be improved by using a layer with a low thermal conductivity layer on the substrate as an intermediate because the intermediate layer The accumulation of heat toward the photoresist material during exposure is improved. Further, amorphous silicon, silicon dioxide (Si〇2), Xi nitride (SiN), alumina (Shu 2〇3 eight) or the like based material suitable as a low thermal conductivity of the intermediate layer. Further, if the intermediate layer by sputtering or other vapor plating method may be formed. —After 5 μm UV-curing resin was spin-coated on the quartz substrate, the substrate with liquid resin hardened by…, external lines, and its exposure sensitivity was confirmed. It was improved on the untreated quartz substrate. Also goes by the ultraviolet curing resin whose thermal conductivity is low and the degree of plastic described. In addition, the straw is pre-exposed by heat treatment, ultraviolet irradiation, etc., and it can also be modified + light sensitivity. Because by applying such pre-exposure treatments, although not completely, the chemical properties of the photoresist material of the present invention have changed to some extent. As mentioned above, through the material composition, development conditions, choice of substrates, etc., the photoresistance function composed of incomplete oxides of various transition metals can be further expanded by expanding the application range of photoresist materials. Point of view The 2-layer photoresist method is extremely effective. Hereinafter, the outline of the two-layer photoresist method will be described with reference to FIGS. 5A to 5D. First, before the first photoresist layer 30 composed of the incomplete oxide of the transition metal of the present invention is deposited, as shown in FIG. 5A, the first photoresist layer 30 is formed on the substrate 31.

O: \ 87 \ 87377 DOC -23-1243372 Among the incomplete oxides of the transition metal of the photoresist layer 30, a material with a very high selectivity can be stacked as the second photoresist layer 32. -Next, as shown in FIG. 5B, 'the first photoresist layer 30 is exposed and developed' and the first photoresist layer 30 is patterned. Next, a pattern 30 consisting of the first photoresist layer as a mask, 32, a high selection ratio of the condition (iv) (iv) performed in the second photoresist layer. Accordingly, as shown in FIG. 5C, the transfer of - 30 of the patterned photoresist layer 32 on the second photoresist layer. Finally, by removing the first photoresist layer 3〇, the end pattern of the second resist layer 32. As shown in the FIG. 5〇. - Moreover, the photoresist layer 2 on the application of the method of the present invention, by, for example: quartz as the substrate, use of transition metals such as Cr second photoresist layer, using a gas of a fluorine-based gas for RIEL engravings, available at configuration - of an incomplete oxide of a transition metal of the photoresist layer between the second optical ..., to obtain a large: the infinite selectivity. As described above, in the method for manufacturing an original disc for an optical disc of the present invention, since a photoresist material composed of an incomplete oxide of a transition metal as described above is used, an inorganic photoresist can be used, and at the same time, ultraviolet rays can be used in combination. The advantages of custom exposure. This system is completely different from inorganic photoresist because it is optically transparent to ultraviolet or visible light, so it cannot be used as an exposure source, and expensive exposure devices such as electron beams or ion beams become. + The missing rule / 丨 My visible light, so compared to the original disc using inorganic photoresistor, the original disc manufacturing; $ method, can greatly reduce the time required for exposure. O: \ 87 \ 87377.DOC -24- 1243372 inorganic photoresist material, to achieve high-precision focusing, therefore, the use of "metal incomplete oxide materials, so the exposed and unexposed parts of the Fine processing of pattern brightness in the realm. And 'resolution can be obtained with an exposure source itself Bureau exposure. System: Two: When forming a fine pattern 'of the original disc for the optical disc of the present invention; in the relationship represented by second-hand ΓP = Κ.λ_, the method of reducing the proportionality constant K: is different from shortening the exposure wavelength λ, The previous method of realizing microfabrication with a large aperture NA and large diameter can benefit: Existing exposure devices have progressed further-further miniaturization. Specifically, according to the present invention, the proportionality constant? Can be less than 0.8, and the work period f of the workpiece can be made as small as shown below. # f < 0.8 λ / ΝΑ According to the present invention, by using the existing exposure device as it is, the original disc for optical discs, which is cheaper and more finely processed than in the past, is realized. 〃 Example 1 The following examples will be described based on experimental results regarding specific examples to which the present invention is applicable. Example 1 Example 1 uses a trivalent incomplete oxide of w (yan) as a photoresist material 'to make a photoresist master for optical discs. " A photoresist layer composed of an incomplete oxide of W was uniformly formed by sputtering on a glass substrate smoothed with a knife. At this time, a dry material made of a monomer made of w is used to shoot in a mixed atmosphere of argon and oxygen to change the oxygen gas concentration to control the degree of oxidation of the incomplete oxide. (B) knife X-ray spectrometer (Energy Dispersive x_ray

O: \ 87 \ 87377 DOC -25-1243372 spectrometer. EDX) When the stacked photoresist layer is analyzed and expressed in terms of composition ratio, X == 〇 · 63. Further, the film thickness of the photoresist layer was 40 nm. The wavelength dependence of the refractive X factor was measured by a spectroscopic ellipsometry method. The finished photoresist layer is placed on the turntable of the exposure apparatus shown in FIG. 2. And, on one side of the turntable at a desired rotation number of the rotation, -: irradiating laser irradiation under the threshold power, to activate the setting height position of the objective lens, to focus on the photoresist layer. Its "person" is in a state of fixed optical system, and the rotating table is moved to a desired radius position by a transfer mechanism provided on the rotating table. According to the information of the information, the photoresist layer is irradiated with the corresponding pulse of the pit and exposed Photoresist layer. This time 'in the state that the rotation of the turntable, the turntable side of the radial direction of the resist substrate is continuously moved slightly from side exposure. Furthermore, exposure 4〇5nm wavelength, the numerical aperture of the exposure optical systems of financial iv. The linear velocity during exposure was 2.5 m / s, and the irradiation power was 60 °. Then, using an alkali developing solution by the wet process, developing the photoresist exposed end of the substrate. This development process is to immerse the photoresist substrate in a developing solution. In order to improve the homogeneity of the narration, the development is performed under the state of applying ultrasound. After the development is completed, it is washed thoroughly with pure water and isopropyl alcohol. Clean and dry with 'blow mow)' to end the process. Test developer using an aqueous solution of tetramethyl ammonium hydroxide, the development time was 3 minutes square. Figure 6 is a scanning electron microscope and a scanning electron microscope.

MlCrOSCoPe: SEM) to observe the photoresist pattern after development. In FIG. 6, the pit / knife corresponds to the exposed portion, and the photoresist layer of the unexposed portion becomes a recessed portion. In this way, a photoresist material composed of an incomplete oxide of w becomes a so-called positive photoresist.

〇: \ 87 \ 87377 DOC -26 · 1243372 f is a photoresist layer composed of incomplete oxide in W. The 2 speed of the unexposed part is slower than that of the exposed part, so the photoresist layer of the unexposed part. After "" ", the film thickness after film formation is also maintained approximately. In contrast, the photoresist layer in the exposure section is removed by money engraving, and the surface of the glass substrate is exposed in the exposure section. Furthermore, Fig. 6 4 shows the pit, the pit is the minimum width 〇15 array, the array length of 0.16. thus, it is found by using the photoresist material of the disc of the present invention is a method of manufacturing a master disk, as compared to the previous organic photoresist expected pit width of 0.39 μιη, resolution can be improved significantly. In addition, also known from Figure 6, the edge of the pit is very clear. and 'found after the pit width and the length of the developing line by the irradiation of the exposure light source and power The pulse width varies. Comparative Example 1 Comparative Example 1 uses W's complete oxide w03 as a photoresist material, and attempts to make a photoresist master for optical discs. First, a complete oxidation of w is deposited on a glass substrate by a sputtering method. Photoresist layer composed of objects. Analysis of stacked photoresist by EDX When expressed by the composition ratio WuxOx, χ = 0.75β, and from the analysis results of electron beam diffraction using a transmission electron beam microscope, it is confirmed that the crystalline state of the exposure of wo incomplete oxide is amorphous. in Example 1, the same intensity or radiation power sufficient exposure this photoresist layer can not be obtained selectivity of greater than 1, of a desired dimple pattern can not be formed. in summary, for full exposure of the W oxide source on the optical transparent, so the absorption is small, does not cause chemical changes photoresist. Example 2

O: \ 87 \ 87377.DOC -27- 1243372 In Example 2, the incomplete oxide of trivalent W and trivalent Mo were used as the photoresist material, and the photoresist for optical discs was actually made according to the process shown in Figure 1. the original disk 'and eventually create a disc. Hereinafter, implementation contents will be described with reference to FIG. 1. First, a Shixi wafer was used as a substrate 100, and an intermediate layer composed of amorphous silicon with a film thickness of 80 nm was uniformly formed on the substrate by a low-frequency method. Secondly, by a sputtering method, a uniform deposition thereon w & M〇 incomplete oxide of the group into the photoresist layer 1〇2 (FIG. L (a)). At this time, w & a sputtering target composed of the incomplete oxide M〇, sputtering in an argon atmosphere. At this time, the stacked photoresist layer is analyzed by EDx, and the film is formed of incomplete oxide of w & M0 ...

The ratio of Mo is st 2 0, and the content of oxygen is 60%. Further, the film thickness of the photoresist layer was 55 nm. Furthermore, through the use of the analysis result by the electron beam type electron beam diffraction of a microscope, it was confirmed WM〇〇 imperfect oxide crystalline state before exposure of the amorphous pieces. Exposing the photoresist layer sequence money, in addition to the exposure condition, the rest are the same as in Example 1 into Ding processing conditions to produce a resist master disc ⑻ (FIG. 1 (b), (c)). The exposure conditions of Example 2 are shown below. • exposure wavelength: 405 nm

• Numerical aperture NA of the exposure optical system: 0.95 • Modulation: 17PP • Pit length: 112 nm • Track interval: 320 nm • Linear speed during exposure: 4.92 m / s • Exposure irradiation power: 6.0 mW • Write Loading method: the same simple writing method as the phase change disc

O: \ 87 \ 87377.DOC -28- 1243372 Fig. 7 shows an example of the photoresist pattern of the photoresist original plate for m-anchor plate after SEM observation and development. W and Mo's incomplete child servants-, the photoresist material composed of χ 王 王 lice compounds == ΓΓ. In FIG. 7, the pit portion corresponds to the exposed portion, and the light of the unexposed portion ΒΠ 'pit' and 'M' has a pit length (diameter) of 130 mm. It is confirmed that the shortest pit length required for the high-density optical disc of early W is reached. —O P㈣ or less. Even, the photoresist pattern was observed in a pit row with intervals 3〇〇 direction, a direction 320 executors of some spacing intervals of the pits of the same shape as a state of 'confirm the formation of pits can be stable. Secondly, a metal recording film is deposited on the concave-convex pattern surface of the photoresist original disk by the electroforming method (Fig. 1 (d)). After peeling from the photoresist original disk, a specific process is applied to obtain a concave-convex pattern of the photoresist original disk The transferred stamping die 104 (Fig. 1 (e)). The press molding using the die 'was formed by injection molding a disc substrate made of a resin 1〇5 (FIG. 1 (f)) composed of a thermoplastic polycarbonate resin. Secondly, peeling stamping die (FIG. 1 (G)), by the reflective film 1〇6 irregularities of the resin disc substrate deposition surface alloy A1 (FIG. 1 (H)) and the protective film having a thickness of 1 oj mm 〇7 of 12 cm diameter to obtain a disc (FIG. 1 (i)). Further, the above step is eligible for a resist master disc to get the system up to the previous conventional art of manufacturing. FIG 8 is represented by an SEM observation of one embodiment of the dimple pattern of the surface of the disc. Here, pits having a length of 150 nm, linear pits having a width of 130 nm, and the like are formed in a state corresponding to the pattern of the ## pattern, and it has been confirmed that the recording disc has a recording capacity of 25 GB. Next, the following conditions read above the disc, an RF signal which is obtained as an eye pattern, and signal evaluation. The results are shown in Figs. 9A to 9C. O: \ 87 \ 87377 DOC -29- 1243372 Obedient servo · Push-pull calculation positioning method

5 cycles: 1 7 P P pit length · 1 1 2 nm Gap interval · 320 nm Read linear speed: 4.92 m / s

Mastering irradiation power: 0.4 mW About the eye diagram (Figure 9A), the eye diagram (Figure 9B) with the basic equalization process has a jitter value of 8.0%, and the eye diagram with the limited equalization process (Figure 9c) ): The value is 4.6%, which is an extremely low value. As a ROM disc with a recording capacity of 25 GB, good results are obtained without practical problems. Furthermore, the photolithography technology from the formation of the photoresist layer to the development of the present invention: can also be applied to DRAM (Dynamic — heart ⑽ —: random access memory), flash memory, cpu (cen㈣Μ⑽⑽ central Processing unit), ASlC (Application Specific ic) and other semiconductor components; magnetic components such as magnetic heads; liquid crystal, EL (EleCtro Luminescence: electroluminescence), clear coffee & this coffee, 1: Production of display elements such as electro-polymer display panels); optical recording media, light modulation elements, and other optical elements. As mentioned above, in the manufacturing method of the original disc for optical discs of the present invention, since the photoresist layer is composed of an inferior oxide of a transition metal that absorbs ultraviolet or visible light, it can be used in the existing ultraviolet or visible light. The light is exposed by an exposure device of an exposure source. [chi], an incomplete oxide of a transition metal according to the present invention, the use of smaller size molecules as a photoresist material, it is white light-blocking layers in u I obtained a good edge pattern of Aberdeen, can be achieved with high accuracy of FIG.

O: \ 87 \ 87377.DOC -30-1243372. Therefore, the manufacturing method of an optical disc using such an original disc for an optical disc can be a high-capacity optical disc with a memory capacity of 2 times by a method using an existing exposure device. [Brief description of the drawings] Figs. 1 (a) to 1 (i) are process drawings showing an optical disc to which the manufacturing method of the optical disc of the present invention is applied. Fig. 2 is a schematic view showing an exposure apparatus used in a method for manufacturing a master disc for an optical disc according to the present invention. 3 are diagrams of the case where a photoresist layer consisting of a photoresist for exposure of the present invention showing the relationship of the difference between the name of the exposure irradiation light source of power and the exposure unit and the exposure unit of the speed is not engraved. 4A to 4C are characteristic diagrams showing examples of irradiation patterns in the exposure process. 4A and 4B are diagrams embodiment irradiation pulses, FIG. 4c are diagrams of the continuous light embodiment. FIG. \ A to 5D are diagrams important schematic sectional view of the portion of photoresist layer 2. FIG. 5A is the first photoresist layer and the second photoresist layer film forming process, FIG. A is the first photoresist layer patterning process, FIG. 5C is the second photoresist layer pattern, and FIG. 5D is the first photoresist layer removal Procedure. FIG 6 is a photograph of a photoresist layer to w (crane) after the development of SEM observation of incomplete oxidation. Fig. 7 is a photo of a photoresist layer made of incomplete oxides of W and Mo based on SE Μ 窣 窣 会 χ / &a; τ gauge ", ^ Fig. 8 is based on SEM observation of the recording capacity produced in Example 2 is

0 \ 87 \ 87377.DOC -31-1243372 Photo of the pit pattern on the surface of the disc. 9A to 9C are diagrams showing signal evaluation results of an optical disc with a recording capacity of 25 manufactured in Example 2. FIG. FIG. 10 (a) to FIG. 10 (1) are process diagrams showing a conventional optical disc. [Illustration of representative symbols of the drawings] 1 Photoresistive substrate 11 Rotary table 12 Beam generation source 13 Collimator lens 14 Beam splitter 15 Objective lens 16 Condensing objective lens 17 Split light sensor 18 Focus error signal 19 Focus actuator 20 Information Signal 21 Reflected light quantity signal 22 Tracking error signal 23 Laser drive circuit 24 Spindle motor control system 30 First photoresistive layer 31, 90, 100 Substrate 32 Second photoresistive layer 91, 102 Photoresistive layer O: \ 87 \ 87377 .DOC -32-1243372 92, 103 original disc 93, 104 stamping dies 94, 105 resin disc substrate 95, 106 reflective film 96, 107 protective film 101 intermediate layer f minimum micromachining cycle K proportionality constant NA numerical aperture P Shortest pit length P0 Radiation threshold power λ (of the light source) Wavelength, exposure wavelength O: \ 87 \ 87377.DOC-33-

Claims (1)

1243372 Scope of application and patent application ... 1 · An original disc used for optical discs contains transitions that belong to the no :: method, which is characterized in that it is ... on the substrate ... oxygen of δ has in the through milk § metering group billion a chemically number of recoverable t eight and metals price ratio in response to a rear classification photoresist layer is formed smaller the amount of green (iv) the structure, so that " the first resist layer corresponding to the recording signal pattern selectively exposing and developing a particular form of the concave-convex pattern. 2. The manufacturing method of the original disc for optical discs according to item 丨 of the patent application, wherein the aforementioned photoresist material is an amorphous inorganic material containing an oxide. 3. For example, the manufacturing method of the original disc for optical discs in the scope of application for patent i, wherein the transition metals are Ti, v, Cr, Mn, Fe, Nb, Cu, Qin, co, Mo, Ta, W, Zr, RU And at least i of Ag. 4. The patentable scope of application # 1, Paragraph disc manufacturing method of the master disc, wherein the said transition metal is Mo, W is any one or both. 5. The term of the patent scope of the DVD 1 by the method of manufacturing a master disk, wherein is further added additional elements other than the transition metal in the incomplete oxide of the transition metal. 6. The patent application range DVD, Paragraph 5 of the method for manufacturing a master disk, wherein said additional elements other than the transition metal A; l, C, B, Si, Ge least one kind of matter. 7. The scope of the patent DVD, Paragraph 1 of the method for manufacturing a master disk, wherein the system by an ultraviolet or visible light exposure. 8. The manufacturing method of the original disc for optical discs according to item 1 of the scope of patent application, in which the above-mentioned ultraviolet or visible light has a wavelength of 150 nm to 410 nm ° O: \ 87 \ 87377.DOC 1243372 9 · If the patent application range is 笫 1 jg $ & μ m The manufacturing method of the original disc for the first disc, which is formed on a substrate composed of at least one of glass, plastic, silicon, oxide button, aluminum oxide, titanium nitride, and nickel. Photoresist layer. ίο. 2 The method of manufacturing a master disc for an optical disc according to item 9 of the scope of patent application, which makes the «substrate and the aforementioned photoresist layer H become an intermediate layer with a small heat transfer rate ^ substrate. Paragraph Π · CD as patent application first range Π) 'wherein at least the intermediate layer based film composed of the amorphous silicon, silicon dioxide, silicon nitride, aluminum oxide of one kind of method for manufacturing a master. m patent application scope! Paragraph disc, wherein the system by sputtering or vapor deposition method for forming the above-described method for manufacturing a photoresist layer of the master. -A method for manufacturing an optical disc, characterized in that an incomplete oxide of a transition metal is contained on a substrate, and the oxygen content of the incomplete oxide is in a ratio based on the stoichiometric composition of the recoverable valence of the foregoing transition metal. After forming a photoresist layer composed of a small photoresist material with oxygen, the photoresist layer is selectively exposed and developed corresponding to the signal pattern for recording to develop a master disc with a specific concave-convex pattern. The master disc is used to make a transfer Bump pattern sheet. / Clam O: \ 87 \ 87377.DOC