JPH0411932B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to the production of optical information recording medium substrates and optical information recording media that can optically record, reproduce, and erase information and that are read-only or rewritable. The present invention relates to a method, and in particular, to a method of manufacturing the substrate and the medium having information grooves for facilitating the tracking of light for recording, reproducing, or erasing information.

[Conventional technology]

2. Description of the Related Art In recent years, optical memory devices having optical information recording media (hereinafter referred to as "medium") have attracted attention as high-density, large-capacity memory devices. The reason why this medium has such high density and large capacity is that the pits, which are the unit of recording information, are determined by the wavelength of the light and the numerical aperture of the lens that focuses the light onto the recording layer, and the pits are made to have a size of about 1 μm. This is because it can be done. Note that reproduction is also performed by optically reading out the presence or absence of this pit. However, in order to accurately record and reproduce information, a precise mechanical mechanism with an electronic control system is required, which necessitates making the optical memory device larger. The structure shown is now adopted. That is, FIG. 9 shows a medium substrate 1 (hereinafter referred to as "substrate") made of glass and having a cylindrical through hole 1a in the center.This substrate 1 has a main surface 2 on which recording is provided. Etching,
For example, there are concentric guide grooves 3 (hereinafter referred to as "pregroups") that facilitate the tracking of light for recording and reproducing information, and small recesses 4 (hereinafter referred to as "pregroups") for indicating track numbers, sector numbers, etc. "Prepit"
That's what it means. )have. Note that the pregroove or prepit is hereinafter collectively referred to as an information groove.

Conventionally, the method for forming the information grooves 3 and 4 on the substrate 1 is to first apply a resist film to the main surface of a disc-shaped original plate made of glass, and then apply an Ar laser beam to the resist film. is irradiated through an objective lens to obtain a register pattern with the same width as the information groove. Next, the irradiated resist film is developed to form a resist pattern, and then, using the resist pattern as a mask, CF ₄
Sputtering is performed in an etching gas to etch the surface of the original plate that is not covered with the resist pattern, thereby forming information grooves 3 and 4. Next, the resist pattern was removed using a solvent such as acetone to create the substrate 1 provided with the information grooves 3 and 4. Then, a recording layer was coated on the information grooves 3 and 4 to create, for example, a sandwich-shaped medium.

[Problem that the invention seeks to solve]

However, the conventional technology has the following drawbacks.

When a resist film coated on a glass original plate is irradiated with a laser beam, the mode change of the laser beam causes fluctuations in the output of the laser beam, causing the area that should originally be irradiated to There was a drawback that a desired resist pattern could not be obtained without irradiation.

Even if the resist film is irradiated with laser light,
Because the surface reflectance of the resist film to the laser beam is low at a few percent, the laser beam cannot be tracked to the desired position on the resist film, and the laser beam is irradiated only where it is needed.As a result, the desired information cannot be displayed. There was a drawback that grooves could not be created.

Furthermore, in the conventional technology, the irradiation time to directly form the information grooves on the original plate requires at least several tens of minutes to an hour, depending on the size of the original plate. However, it had the disadvantage of poor productivity.

[Means for solving problems]

The present invention is a method for manufacturing a substrate and a medium that eliminates the above-mentioned drawbacks, and a first aspect of the invention is a method for manufacturing a substrate having an information groove, which includes a pattern for forming the information groove. , using a reference plate with a through hole in the center and an original plate for producing the substrate, which has a through hole in the center and whose main surface is coated with a photosensitive material, and the through holes in each of the reference plate and the original plate are used. Insert a jig to determine the position,
A method of manufacturing a substrate, comprising: determining the position of the center of each through hole of the reference plate and the original plate; transferring the pattern of the reference plate to the original plate; and forming the information groove. The second invention is
In a method for manufacturing an optical information recording medium in which a substrate is provided with an information groove, a reference plate having a pattern for forming the information groove and a through hole in the center; Using an original plate for forming the substrate whose surface is coated with a photosensitive material, a jig for determining the position is inserted into each of the through holes of the reference plate and the original plate, and each of the reference plate and the original plate is A method for manufacturing a medium, comprising: determining the position of the center of the through hole; transferring the pattern of the reference plate to the original plate; forming the information groove; and covering the information groove with a recording layer. It is.

As an aspect of the present invention, first, in the jig, the jig inserted into either the reference plate or the original plate has a convex cross section, and the jig inserted into the other has a concave cross section. and inserting the jig with a convex cross section into the recess to determine the positions of the centers of the respective through holes of the reference plate and the original plate, and in the jig, The jig inserted into the reference plate and the jig inserted into the original plate are integrated.

Example 1 This example will be explained in detail based on FIGS. 1 to 4. 1 and 2 are longitudinal sectional views, and the third
Figures a and 4a are plan views, and Figures 3b and 4b are front views.

First, precision polished, diameter 130 mm, thickness 2.3
Prepare a glass plate for the reference plate made of quartz glass with a through hole of 6 mm in diameter in the center.
A light-shielding Cr film (thickness: 1000 Å) is formed on one main surface (130 mm surface) by sputtering. Next, a positive electron beam resist (for example, PBS manufactured by Chitsuso Corporation) is applied onto the Cr film by spin coating, and the resist film (thickness:
1500 Å), then use an electron beam lithography system to form a concentric resist pattern with a width of 1 μm at 2 μm.
It was drawn to obtain an interval of m. Next, the resist film is developed with a developer prepared by adding water to a mixture of 5-methyl 2-hexanone and 2-pentanone to form a resist pattern. Next, using the resist pattern as a mask, the portions not covered with the resist film were etched using a mixed solution of ceric ammonium nitrate and perchloric acid, and the resist film was removed with sulfuric acid. A reference method is formed in which concave portions are provided with concentric chrome patterns for forming information grooves at intervals of 2 μm.

In addition, when creating a board with an information groove, the original board was precision-polished soda lime glass with an outer diameter of 130 mm, a thickness of 1.2 mm, and a through hole of 15 mm in diameter in the center.

Then, an information groove is formed on the main surface of the original plate on which the information groove is to be formed by electron beam evaporation.
coated with SiO ₂ film (thickness: 1000 Å), then this
_{Hexamethyldisilazane} (hereinafter referred to as
It's called "HMDS." ) was thinly coated to increase the adhesion between the resist film described later and the SiO ₂ film described above. Next, on the HMDS, for example, AZ-4007 photoresist manufactured by Hoechst (thickness:
1000 Å). Next, this original plate with a resist film was placed in a clean oven, and the resist film was prebaked at 90° C. for 30 minutes in a nitrogen atmosphere to prepare an original plate with a resist film.

Next, the reference plate 5 and the original plate 6 are placed in an exposure apparatus 7 as shown in FIG. The exposure device 7 includes a reference plate holder 10 fitted and fixed in a recess 9 formed in a left main body 8, a first vacuum chamber 11, and an exhaust pipe for evacuating the first vacuum chamber 11. 12 and the reference plate holder 10 is fitted and fixed in a recessed part 14 formed in the right side main body 13.
The original plate holder 15 moves leftward together with the right main body 13 so as to be close to or in contact with the original plate holder 15. Note that the first vacuum chamber 11 of the left main body 8 is
The bottom wall of the left main body 8 (not shown) forms a closed space. The exposure apparatus 7 also includes a second vacuum chamber 16 and an exhaust pipe 17 for evacuating the second vacuum chamber 16, and has a central portion of the bottom wall 18 of the second vacuum chamber 16. An original plate jig 19 for inserting and holding the original plate 6 and positioning it with respect to the reference plate 5 is fixed thereto. This original plate jig 19
As shown in FIG. 4, the cylindrical jig support part 1
91a and a disk-shaped portion 191b on which the original plate 7 is placed, a main portion 191 having a T-shaped cross section;
1 and a ring 193 provided on the upper surface 192 of the ring 1. In addition, the outer diameter of this ring 193 is
14.96mm, inner diameter is 12.02mm and ring thickness is
It is 1.47mm and the height is 1.1mm. Further, this upper surface 192 is provided with a ring-shaped groove 194 for inserting an O-ring. Furthermore, this exposure device 7 has an O-ring 20 implanted on the right side main body 13, and as shown in FIG. The left main body 8 is also provided with an exhaust pipe 22 for evacuating the third vacuum chamber 21.

Next, using this exposure device 7, the reference plate 5 is
A method of manufacturing a substrate having information grooves by transferring the pattern to the original plate 6 will be described below.

First, as shown in FIG. 1, the chrome pattern on the reference plate 5 is turned to the right, and the through hole 5
1, insert the reference plate jig 23 shown in FIG. 3, which holds the reference plate 5 and positions it with the original plate 6,
The reference plate 5 together with the reference plate jig 23 is vacuum-adsorbed onto the reference plate holder 10. Note that this reference plate jig 23 has a cylindrical portion 231 and a disk-shaped portion 232.
A cylindrical part 231 that has a convex cross section and is inserted into the through hole 51 of the reference plate 5 of this jig 23.
has a diameter of 5.96 mm and a height of 7 mm, and the disc-shaped portion 232, which is the portion inserted into the ring 193 of the original plate jig 19, has a diameter of 11.98 mm and a height of 1.0 mm.
mm. Further, a ring-shaped groove 234 for inserting an O-ring is provided on the reference plate side surface 233 of this disc-shaped portion 232. Therefore, the O-ring 24 provided on the reference plate holder 10,
Since the first vacuum chamber 11 is sealed by the O-ring 25 inserted into the ring-shaped groove 234 of the reference plate jig 23, the reference plate 5 and the reference plate jig 23 are sealed.
is sufficiently vacuum-adsorbed.

Next, the resist film is directed toward the reference plate 5 side, and the original plate 6
The ring 193 of the original plate jig 19 is inserted into the through hole 61 of
is inserted, and the original plate 6 is brought into contact with the upper surface 192 thereof, and the original plate 6 is also brought into contact with the original plate holder 15 and the original plate 6 is vacuum-adsorbed. At this time, as described above, the O-ring 26 of the original plate holder 15 and the original plate jig 1 are
O-ring 27 inserted into ring-shaped groove 194 of 9
As a result, the second vacuum chamber 16 is sealed, so that the original plate 6 is sufficiently vacuum-adsorbed.

Next, as shown in FIG. 2, the reference plate 5 and the original plate 6 are
(At this time, the disc-shaped part 232 of the reference plate jig 23 is inserted into the ring 193 of the original plate jig 19.
is inserted with a slight gap. ) A third vacuum chamber 21 is formed and evacuated through the exhaust pipe 22 to create a vacuum. Next, the first and second vacuum chambers 11, 16
Return to atmospheric pressure. Then, the reference plate 5 and the original plate 6 come into close contact with each other, and by irradiating the ultraviolet rays 28 in this state, the chrome pattern on the reference plate 5 is transferred to the original plate 6.
transferred to the resist film.

Next, by reversing the steps up to the exposure, the original plate 6
is removed from the exposure device 7, the original plate 6 is subjected to normal development, rinsing, and drying, and then post-baked in a clean oven at 110° C. for 30 minutes to produce a resist patterned original plate.

Next, the original plate with the resist pattern is placed in a capacitive dry etching device, and a CF ₄
Introducing gas and using the resist pattern as a mask, dry etching the SiO ₂ film coated on the main surface of the original plate to form concentric circles with a width of 1 μm and a depth of 800 Å.
Information grooves (corresponding to pregrooves in this example) were created at 2 μm intervals. At this time, the total pressure inside the apparatus was set to 0.1 Torr, the high frequency power density was set to 0.2 W/cm ² , and the flow rate of the CF ₄ gas was set to 50 standard cubic centimeters per minute (SCCM). Next, after this dry etching, O ₂ gas was introduced into the apparatus, and the resist pattern was removed by plasma ashes, thereby creating a substrate provided with information grooves. The conditions for this plasma ashing are that the total pressure is
0.5Torr, high frequency power density 0.3W/ ^cm2 and flow rate
It is 50SCCM.

Next, two substrates provided with the information grooves are prepared, a recording layer (thickness: 300 Å) made of Te is coated on each information groove, and the recording layers are placed facing each other, and the outer periphery of the substrate is A spacer was provided near the through hole, and a sandwich-like medium having a void inside was created.

As described above, the substrate provided with the information groove in this example is a substrate in which an original plate made of glass is coated with a SiO ₂ film, and the SiO ₂ film is etched to provide the information groove. Further, in this example, a method for forming a pregroove as an information groove has been described, but a prepit can also be formed in the same manner. In addition, in this example, the reference plate jig 23
Since it is removable, it is possible to select one suitable for the shape and size of the through hole 51 of the reference plate 5. Furthermore, the original plate jig 19 in this example is used as a reference plate jig, On the other hand, the reference plate jig 23 may be used as an original plate jig. Note that at this time, the shape of each jig is adapted to the size of each through hole in the reference plate and the original plate.

Example 2 This example will be explained based on FIGS. 5 and 6.
Note that a and b in these figures are a plan view and a front view, respectively, and _{FIG .}
FIG.

First, the difference from the first embodiment is the reference plate jig and the original plate jig. The reference plate jig 28 in this example has a cylindrical portion 28 as shown in FIG.
1, a disc-shaped portion 282, a truncated cone portion 283, and a ring-shaped groove 284 similar to that of the first embodiment, and has a convex cross section. On the other hand, the original plate jig 29 has a main part 291 having a T-shaped cross section and consisting of a cylindrical jig support part 291a and a disc-shaped part 291b that abuts the original plate 6.
and a ring 293 provided on the upper surface 292 of the ring 293. Furthermore, a recess 294 having the same shape as the truncated conical portion 283 is provided inside the ring 293, and an O-ring is provided as in the first embodiment. A ring-shaped groove 295 is provided for inserting.
The difference from the first embodiment is that the original plate is made of quartz glass, its main surface is directly coated with a photoresist film, and the information groove is directly provided on the original plate. The rest of the structure of the exposure device 7, the method of forming the information groove, etc. are the same as in the previous embodiment.

According to this example, the information groove can be formed directly on the original plate. In addition, the reference plate jig 28 of this example
Since the truncated cone portion 283 and the truncated cone-shaped recess 294 are provided in the reference plate jig 28 and the original plate jig 29, respectively, compared to the previous embodiment,
It can be easily fitted and the positioning accuracy can be improved. In this example, as in the first embodiment, the original plate jig may be used as a reference plate jig, and the reference plate jig may be used as an original plate jig.

Example 3 This example will be explained in detail based on FIGS. 7 and 8. In addition, FIG. 7 is a longitudinal cross-sectional view, and FIG.
is a plan view, and b is a front view.

As shown in FIG. 8, the positioning jig 30 used in this example is made by integrating the reference plate jig and the original plate jig of the first embodiment, and the reference plate jig and the original plate jig are integrated. It has the function of a tool. and,
This jig 30 includes a cylindrical jig support part 301,
The first disc-shaped portion 302 that contacts the original plate 6 and the original plate 6
It consists of a second disc-shaped part 303 that is inserted into the through-hole 61 of and abuts the reference plate 5, and a cylindrical part 304 that inserts the reference plate 5, and the jig support part 30.
1. A first disk-shaped portion 302, a second disk-shaped portion 303, and a columnar portion 304 are provided in sequence with the same center. Further, the upper surfaces 305 and 30 of the first disc-shaped portion 302 and the second disc-shaped portion 303 are
6 has a first ring-shaped groove 307 and a second ring-shaped groove 307 for inserting an O-ring, respectively, as in the first embodiment.
A ring-shaped groove 308 is provided. This jig 30 is also fixed to the bottom wall 18 of the second vacuum chamber 16 in the same way as the original plate jig in the first and second embodiments.

Next, a method of exposure using this jig will be described below.

Note that the reference plate 5 and the original plate 6 are the same as those in the first embodiment, and on the original plate 6 there are the same markings as in the first embodiment.
Covered with SiO ₂ film, HMDS and resist film.
Further, the other configurations of the exposure device 7 are also the same as in the first embodiment.

First, the original plate 6 is placed on the second disk-shaped portion 303 of the jig 30.
The second vacuum chamber 16 is evacuated and vacuum adsorption is performed. Next, the reference plate 5 is inserted into the cylindrical part 304 and the original plate 6 and the reference plate 5 are brought into contact with each other. Next, the original plate holder 15 is is moved so as to be in contact with the reference plate 5, and the first vacuum chamber 11 and the third vacuum chamber 21 are evacuated.
Thereafter, as in the first embodiment, the first and second vacuum chambers 11 and 16 are returned to atmospheric pressure, and the reference plate 5 and original plate 6 are brought into close contact with each other. Next, by irradiating ultraviolet light 28, the chrome pattern on the reference plate 5 is transferred to the resist film on the original plate 6. Next, the third vacuum chamber 21 is returned to atmospheric pressure, the second vacuum chamber 16 is evacuated, and the reference plate holder 10 is separated. At this time, the reference plate 5 is in close contact with the original plate 6, and the reference plate 5 and the original plate 6 are not separated. Next, the second vacuum chamber 16 is returned to atmospheric pressure, the reference plate 5 and the original plate 6 are taken out of the exposure apparatus 7, and the reference plate 5 and the original plate 6 are separated by hand. Thereafter, a substrate and a medium are produced in the same manner as in Example 1 above.

According to this example, the jig 30 has the functions of a reference plate jig and an original plate jig, and has a cylindrical part 304 into which the reference plate 5 is inserted and a second disc-shaped part into which the original plate 6 is inserted. 303 are manufactured with the same center, furthermore, the positioning of the original plate and the reference plate is perfect.

As mentioned above, in Examples 1 to 3, a disk-shaped reference plate was used as the reference plate, but the reference plate is not limited to this, and may be square-shaped. That is, any material having an area that allows the information groove to be transferred to a desired area may be used. Furthermore, the through-hole of the reference plate does not have to have a circular cross section.

Further, in Examples 1 and 3, the thin film for forming the information groove is a SiO ₂ film, but the invention is not limited to this, and silicon nitrides such as Si ₃ N ₄ , silicon oxides, oxides such as aluminum, etc. Thin film consisting of a single layer or multiple layers of etchingable materials such as oxides or nitrides consisting of elements of groups, groups, or groups of the periodic table, or chalcogen elements such as Se and Te, or compounds thereof. That's fine. Further, the thin film does not necessarily have to have a stoichiometric composition as long as it can form an information groove.

Also in the second embodiment, the glass on which the direct information grooves are provided may be any glass that can be dry etched or wet etched.

In addition, in Examples 1 and 3, HMDS was used to increase the adhesion between the resist film and the SiO ₂ film, but this is not limited to Cr film, Cr oxide film, or
A metal oxide film such as Al ₂ O ₃ may be used as a thin film of, for example, 20 Å to 200 Å.

Further, the arrangement of the reference plate and the original plate in Examples 1 to 3 was reversed, and the exposure light was changed to
The irradiation may be performed from the opposite side, or the reference plate holder 10 and the original plate holder 15 may be arranged one above the other. Further, the O-ring is not limited to a circular cross-section, but may be flat or rectangular. Further, in Examples 1 to 3, ultraviolet light was used for exposure, but other wavelengths may be used.

Further, in Examples 1 to 3, the original plate jigs 19, 29 and the jig 30 were fixed to the bottom wall 18 of the exposure apparatus 7, but for example, a rod-shaped convex portion was provided on the bottom wall 18. , while the jigs 19, 29 and 3
A recess may be provided in the axial direction of the jig support parts 191a, 291a, and 301 of No. 0, and the jig supports 191a, 291a, and 301 may be fitted into each other. In this way, an appropriate original plate jig can be selected according to the through hole 61 of the original plate 6.

Further, in Examples 1 to 3, the contact exposure method was described as the exposure method, but it is not necessary to bring anything into close contact, and any method may be used as long as the pattern of the reference plate is accurately transferred.

Furthermore, the recording layer to be coated is not limited to Te film, but also Se, GeTe, InTe, TeC, Te-O, Te
- Chalcogen elements such as Ge-O and Te-As-O, chalcogen compounds, elements of groups, groups, and groups of the periodic table and their compounds, and their oxides and nitrides,
Furthermore, it may be an organic material to which a light absorbing agent is added, or it may be a magneto-optical recording material such as GdFe, TbFe, GdTbFe, etc.

〔Effect of the invention〕

Since the present invention is a method as described above, it is possible to manufacture a substrate in which information grooves are accurately provided at desired positions, thereby making it possible to manufacture a good medium. Furthermore, since the present invention uses a positioning jig, it is possible to maintain good concentricity with the substrate during, for example, pre-grooving, and for example, the amount of eccentricity can be reduced to 100 μm or less.

Further, according to the present invention, the exposure time for forming the information groove is, for example, 10
It only takes about 20 minutes, which is 20 to 40 minutes shorter than the conventional method, and productivity has also improved.

[Brief explanation of drawings]

FIGS. 1 and 2 are longitudinal sectional views showing one embodiment of the present invention, and FIGS. 3 and 4 are diagrams showing a reference plate jig and an original plate jig of one embodiment, respectively. 3a and 4a are plan views, and FIGS. 3b and 4b are front views. 5 and 6 are views showing a reference plate jig and an original plate jig of other embodiments, respectively, and FIGS. 5a and 5b are a plan view and a front view, respectively. Figures a, b, and c are a plan view, a front view, and a sectional view taken along the line _X6 - _X6 of figure a, respectively. FIG. 7 and FIG. 8 are diagrams showing still other embodiments, with FIG. 7 being a longitudinal sectional view, and FIGS. 8 a and 8 b being a plan view and a front view of the jig, respectively. . FIG. 9 is a schematic perspective view of a substrate provided with an information groove. 3...Pregroove, 4...Prepit, 5...
...Reference plate, 6...Original plate, 7...Exposure device, 19,
29... jig for original plate, 23, 28... jig for reference plate, 30... jig having the functions of jig for reference plate and jig for original plate, 51... through hole in reference plate, 61... …
A through hole in the original plate.

Claims (1)

[Claims] 1. A method for manufacturing a substrate for an optical information recording medium having an information groove, comprising: a reference plate having a pattern for forming the information groove and having a through hole in the center; Using an original plate for producing the substrate, which has a through hole and whose main surface is coated with a photosensitive material, a jig for positioning is inserted into each through hole of the reference plate and the original plate, and the reference plate is coated with a photosensitive material on the main surface. determining the position of the center of each through hole of the plate and the original plate;
A method of manufacturing a substrate for an optical information recording medium, characterized in that the pattern of the reference plate is transferred to the original plate to form the information groove. 2. A jig inserted into either the reference plate or the original plate has a convex cross section, and a jig inserted into the other has a concave cross section, and the jig with the convex cross section is inserted into the concave portion. 2. The method of manufacturing a substrate for an optical information recording medium according to claim 1, further comprising inserting the reference plate and the original plate to determine the positions of centers of respective through holes of the reference plate and the original plate. 3. The method of manufacturing a substrate for an optical information recording medium according to claim 1, wherein the jig inserted into the reference plate and the jig inserted into the original plate are integrated. 4. A method for manufacturing an optical information recording medium in which a substrate is provided with an information groove, comprising: a reference plate having a pattern for forming the information groove and having a through hole in the center; A master plate for producing the substrate whose main surface is coated with a photosensitive material is used, and a jig for positioning is inserted into each through hole of the reference plate and the master plate, and a jig is inserted into the through hole of the reference plate and the master plate. Determine the center position of each through hole,
A method for manufacturing an optical information recording medium, comprising transferring the pattern of the reference plate to the original plate, forming the information groove, and coating the information groove with a recording layer. 5. A jig inserted into either the reference plate or the original plate has a convex cross section, and a jig inserted into the other has a concave cross section, and the jig with the convex cross section is inserted into the concave portion. 5. The method of manufacturing an optical information recording medium according to claim 4, further comprising inserting the reference plate and the original plate to determine the positions of centers of respective through holes of the reference plate and the original plate. 6. The method for manufacturing an optical information recording medium according to claim 4, wherein the jig inserted into the reference plate and the jig inserted into the original plate are integrated.