JPS6314066B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] This invention relates to a disk substrate made of an acrylic base material or a glass base material used for optical disk memory, with a width of 0.2 to 1.5 μm, a depth of 0.03 to 0.2 μm, and a spacing of 1.2 to 3 μm.
The present invention relates to a method for manufacturing a stamper that makes it possible to form a fine pattern on the order of m. [Technical background of the invention and its problems] As a conventional method for manufacturing a stamper, there is an example in which the Ni electrodeposition method for record masters is applied. FIGS. 1A to 1D show cross-sectional views of semifinished stampers according to this method in the order of steps. First, in the first step, a liquid positive type photoresist is applied with a spinner to a glass plate 1 on which a Cr thin film 2 has been vapor-deposited, and then baked. The glass plate is rotated and the laser beam is moved while irradiating the glass plate for exposure. Next, when development and etching are carried out, a master disk having a fine pattern 3 consisting of spiral concave portions is produced as shown in FIG. Next, in a second step, a silver coating 4 having a thickness of 0.05 to 0.5 μm is adhered to the master surface by silver mirror reaction, serving both as conductivity necessary for Ni electrodeposition and as a transfer of a fine pattern. At this time, the silver coating 4' also adheres to part of the side and back surfaces of the master. Since Ni electrodeposition is not carried out at a high current density on this thin silver film, the cathode dropper method using the silver film as a negative electrode
2-5μ thick at a current density of 1-3A/ ^dm2 in a bathtub
A base Ni layer 5 of m is formed and taken out. Figure B shows this state. A Ni layer is also distributed on the surface as 5'. In the third step, the master disk is attached with synthetic resin screws 7 by mechanically contacting the silver coating 4' and base Ni layer 5' attached to the back surface of the master disk with the table surface 6' of the rotating cathode 6. After covering with the current concentration prevention cover 8, 2 to 4 A/dm ² in a high-speed Ni electrodeposition bath.
A preliminary Ni layer 9 with a thickness of 5 to 20 .mu.m is formed at a current density of ² to 20 A/dm2, and a main Ni layer 10 of 180 to 350 .mu.m in thickness is further formed at a high current density of 8 to 20 A/dm.sup.2. This state is shown in C. Next, the silver coating 4 and Ni layers 5, 9, and 10 formed in the fourth step are separated from the glass plate.
At this time, some or all of the photoresist on which the fine pattern was formed remains on the silver film, so the resist is etched with a resist stripping solution to form the Ag film 4 with the surface to which the fine pattern has been transferred.
and Ni layers 5, 9, and 10. This state is shown in d. Either surface oxidize the Ag coating of this stamper or
Alternatively, after etching the Ag film, Cr plating is applied to the Ni surface, and a master disk is obtained by electrodepositing Ni on the surface and separating, to obtain a mother disk, and a stamper can be manufactured from the mother disk in the same way.
The mother board can also be used as a mother stamper. Disadvantages of this manufacturing method include (1) The adhesion of the photoresist is poor even on a glass plate on which the Cr thin film 2 is vapor-deposited. Furthermore, the adhesion is extremely poor at the photoresist areas that extend around the side and back surfaces of the substrate. (2) The biggest drawback of photoresists is that they tend to attract dust and are difficult to remove.
In addition, the master disc has many defects such as uneven coating that changes the depth of the recesses and uneven development that causes the recesses to disappear. (3) It is difficult to control the reaction rate of the Ag film produced by the silver mirror reaction, and the film thickness tends to be uneven.
becomes crushed crystals and deteriorates the transferability of fine patterns. Furthermore, the surface of Ag is susceptible to silver chloride and silver sulfide, which also deteriorates transferability. (4) The Ag film 4' and base Ni layer 5' that have wrapped around the back surface have weak adhesion to the glass plate 1, and if mechanically and electrically contacted, they will cause poor conduction or peeling. (5) In order to suddenly change the current density when taking out the Ni bath after forming the base Ni layer 4 or when forming the main Ni layer 10 from the preliminary Ni layer 9,
The crystal consistency of Ni is poor, causing peeling between Ni layers or warping due to electrodeposition stress. etc. can be counted. [Object of the invention] This invention does not use such a conventional master disc,
We create a master disc with an excellent fine pattern, form a conductive thin film on the master disc that transfers this fine pattern without damaging it, and ensure reliable conduction with the negative electrode.
The present invention provides a stamper manufacturing method for forming a Ni electrodeposition stamper. [Summary of the Invention] That is, the present invention consists of (1) forming a low melting point metal reaction film having both energy absorbing and gas releasing properties on a circular glass substrate with a hole in the center, and irradiating the film surface with an energy beam; A master disc is created by irradiating it to form a fine pattern consisting of spiral or concentric irregularities, and after forming a thin metal film on the master disc without damaging the fine pattern, the master disc is placed on the end face of a rotating cathode. It is held removably through a flanged cylindrical fitting by bolts screwed through the master hole, and this metal thin film is used as a cathode.
When laminating the Ni electrodeposition layer, by interposing a metal donut plate between the metal thin film and the flange of the metal fitting, the metal thin film, metal donut plate, and Ni electrodeposition layer are integrated, and the adhesion, transferability, A method for manufacturing a stamper to obtain a stamper with good durability;
or (2) Au, Cr, where the metal thin film is 0.03 to 0.2 μm thick,
The method for producing a stamper according to item 1 above, which is made of at least one of Ir, Pd, Pt, Rh, Ru, Ti, Zr, and Ta, or (3) the metal donut plate has a thickness of
0.02~0.2mm Ni, Fe, Co, phosphor bronze, brass, stainless steel plate with a thickness of 5μm or less, Ag,
The method for manufacturing a stamper according to item 1 above, wherein the stamper is coated with a plating layer or a vapor deposited layer of Au, Pd, Pt, or Rh (4) The metal donut plate is made of Ag,
The method for producing a stamper according to item 1 above, in which Au, Pd, Pt, Rh, Ni, stainless steel, or (5) Ni
In the method for producing a stamper according to item 1, the electrodeposited layer is formed by sequentially or stepwise increasing current in the same bath. In the stamper manufacturing method of the present invention, a target of a low melting point metal such as Te, Bi, Zn, or Sb is first reacted with a gas plasma containing components such as C, H, N, and O on a glass substrate in a vacuum. By sputtering, a low melting point metal reaction film with excellent adhesion, uniform thickness, energy absorption and gas release properties is formed. By rotating the glass substrate on which this low-melting point metal reaction film is formed and irradiating the laser beam with a constant power so as to form spiral convex parts without forming holes, a fine pattern can be formed. A master disc with no defects can be obtained. A thin metal film that imparts conductivity without deteriorating transferability and has good adhesion to the master disc is formed on the surface of the master disc thus formed by vacuum deposition, and Ni electrodeposition is performed directly on the metal thin film. A metal donut plate is placed in contact with the edge of the opening at the center of the master disk, and a flanged cylindrical metal fitting is screwed onto the end face of the rotating cathode with bolts, and a Ni layer is continuously electrodeposited from the base in the same Ni bath. Ni is also electrodeposited on the intervening metal plate,
A Ni layer integrated with the metal thin film is formed,
This allows you to obtain a stamper with no defects. [Embodiments of the Invention] Examples of the present invention will be described below with reference to the drawings. FIGS. 2A to 2D are cross-sectional views showing semifinished products according to each example of the stamper manufacturing method in the order of steps. (1) The description here is made in general terms. First, as a first step, a glass substrate 11 with a hole in the center is made of, for example, Te as a target in a vacuum.
Perform reactive sputtering with CH ₄ gas plasma. As a result, the low melting point metal reaction film of Te ₆₀ C ₂₀ H ₂₀ , which has excellent adhesion, no uneven film thickness, and has both energy absorption and gas release properties, has a thickness of 0.15.
~0.4 μm is formed. When this glass substrate coated with a low melting point metal reaction film is rotated and a continuous beam of He-Ne or Ar gas laser or GaAlAs semiconductor laser is continuously moved in the radial direction,
Convex portions having the same shape are formed in a spiral shape, thereby forming a master disk having a fine pattern 12.
This state is shown in A. Next, as a second step, the surface of the master disk with this fine pattern is given the conductivity necessary for Ni electrodeposition, and a metal such as Au, Pd, Rh, or Pt, which has good adhesion without deteriorating transferability, is applied. is vacuum-deposited to a thickness of 0.03 to 0.2 μm to form a metal thin film 13 as shown in FIG. The third step is to electrically contact and attach the master disk with the metal thin film 13 on its surface to the rotating cathode 14, which is formed in advance into a donut shape with a thickness of 0.02 mm.
~0.2mm Ni, Fe, Cu, Co, phosphor bronze, brass,
Ag with a thickness of 5 μm or less on a piece of stainless steel, etc.
A metal donut plate 15 plated with a noble metal such as Au or Pt having low contact resistance is manufactured. This metal donut plate 15 is arranged so that its center is aligned with the master, and the flanged cylindrical metal fitting 16 and the washer 1 are placed.
The master disk and the rotating cathode 14 are connected by bolts 18 through 7.
Tighten. Further, an insulating cap 19 is placed over unnecessary parts such as bolt heads to prevent electrodeposition. Furthermore, after covering the master with a current concentration prevention cover 20, a base Ni layer 21 with a thickness of 2 to 5 μm is formed at a current density of 1 to 3 A/dm ² using depolyzed nickel as an anode in a Ni electrodeposition bath. death,
Increase the current continuously or in steps, from 8 to
After reaching a high current density of 15A/ ^dm2 ,
A real Ni layer 22 with a thickness of 180 to 350 μm is formed. This state is shown in c. Continuous Ni
When electrodeposition is performed, the base Ni layer, the Ni layer during current increase,
The more unclear the interlayers of the present Ni layer are, the better the crystal consistency of the Ni electrodeposited layer is formed. On the other hand, since the interposed metal donut plate 15 is also electrodeposited from the base Ni layer to integrate the Ni electrodeposition layer, the electrical contact is significantly improved. Also, metal thin film 1
Au, Pd, Rh, or Pt, etc. in 3. interdiffuse between the interfaces of the base Ni layer due to heat generated during electrodeposition.
It won't peel off because of this. The fourth process includes the glass substrate, metal thin film, and metal donut plate.
The Ni layer is separated and the remaining low melting point metal reaction film adhering to the metal thin film surface is removed by electrolytic cleaning to obtain a stamper with a fine pattern transferred thereon. Show this stamper on d. In order to eliminate various problems caused by the conventional photoresist master method, the stamper manufacturing method that involves these steps uses a low-melting point metal reaction film instead of a photoresist that forms a fine pattern, and improves transferability. We are trying to obtain a stamper with many excellent characteristics such as adhesion and crystal bonding properties. The following examples are specific. (2) First, the thickness is 12mm, the outer diameter is 350mmφ, and the center inner diameter is 20mm.
Reactive sputtering is performed on the surface of a glass substrate 11 made of φ with a hole in the center using CH ₄ gas plasma with Te as a target in a vacuum.
A low melting point metal reaction film of Te ₆₀ C ₂₀ H ₂₀ is formed to a thickness of 0.3 μm. This glass substrate coated with a low-melting point metal reaction film is rotated and irradiated with a continuously moving continuous beam of He-Ne gas laser. The rotational speed during irradiation is controlled so that the linear speed is 4 m/sec, and the beam is moved at regular intervals in the radial direction. In addition, the power of the He-Ne gas laser is 7 mW. The low melting point metal reaction film irradiated with the laser beam in this way has a spacing of 2 μm, a width of 0.7 μm, and a height of
A master disk having a fine pattern 12 is obtained by forming convex portions of the same shape in a spiral shape of 0.1 μm.
This situation is as shown in A. Next, on the master disk with this fine pattern, Au was targeted in vacuum and Ar gas plasma was applied at a deposition rate of 3 Å/3.
sec sputtering to deposit a thickness of 100 Å, then reduce the deposition rate to 10 Å/sec to a total thickness of 100 Å.
A metal thin film 13 of 0.1 μm is formed. B indicates this state. Next, a doughnut-shaped metal plate 15 must be prepared in advance to ensure electrical contact and attachment between the master disk having the metal thin film 13 on its surface and the rotating cathode 14. In this example, a Ni plate with a thickness of 50 μm is used with an outer diameter of 36 mmφ and an inner diameter of
Form into a donut shape of 20.1mmφ. This molding uses an etching process that does not generate burrs or warpage. Further, the entire surface of the donut-shaped Ni plate is plated with Au to a thickness of 2 μm to form a metal donut plate 15. The metal donut plate 15 produced in this way is placed centered on the periphery of the hole in the master disk whose surface is the metal thin film 13, and the master disk and the rotating cathode 14 are integrally connected with bolts 18 via flanged cylindrical fittings 16 and washers 17. Tighten. Further, after covering the master disc with an insulating cap 19 and a current concentration prevention cover 20 to prevent electrodeposition on parts such as bolt heads that are higher than the metal plate, electrodeposition is carried out in the following nickel sulfamic acid bath.

〔Effect of the invention〕

According to the manufacturing method of the present invention, a Ni layer is integrated from a metal thin film using a defect-free master disk that has good adhesion to a glass substrate and has uniform convex portions, with good transferability and with a metal donut plate interposed. Since the stamper is formed using a photoresist, it is possible to obtain a stamper free of various drawbacks.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a semi-finished product shown in order of steps to explain a conventional stamper manufacturing method, and Fig. 2 is a cross-sectional view of a semi-finished product shown in order of steps to explain the stamper manufacturing method of the present invention. The right side has been omitted. In both figures, 1...Glass substrate, 2...Cr thin film,
3... Fine pattern, 4... Ag coating, 5... Base Ni layer, 6... Rotating cathode, 7... Synthetic resin screw, 8... Current concentration prevention cover, 9... Spare
Ni layer, 10... real Ni layer, 11... glass substrate,
12... Fine pattern, 13... Metal thin film, 14
... Rotating cathode, 15 ... Metal donut plate, 16
... Cylindrical metal fitting with flange, 17 ... Washer, 18 ... Bolt, 19 ... Insulation cap, 2
0...Current concentration prevention cover, 21...Ni base layer,
22... Actual Ni layer.

Claims (1)

[Claims] 1. A low melting point metal reaction film having both energy absorbing and gas releasing properties is formed on a circular glass substrate with a hole in the center, and the film surface is irradiated with an energy beam to form a spiral shape. Alternatively, a master disk is created by forming a fine pattern consisting of concentric irregularities, a thin metal film is formed on the master disk without damaging the fine pattern, and then the master disk is screwed through the hole in the master disk onto the end surface of the rotating cathode. By holding the metal donut plate between the metal thin film and the flange of the metal fitting when laminating the Ni electrodeposition layer using this metal thin film as a cathode, By integrating metal thin film, metal donut plate, and Ni electrodeposition layer,
A method for producing a stamper, characterized by obtaining a stamper with good adhesion, transferability, and durability. 2 Au, Cr, Ir, 0.03 to 0.2 μm thick metal thin film,
The method for manufacturing a stamper according to claim 1, characterized in that the stamper is made of at least one of Pd, Pt, Rh, Ru, Ti, Zr, and Ta. 3 The metal donut plate is made of Ni, Fe, with a thickness of 0.02 to 0.2 mm,
It is characterized by having a plating layer or a vapor deposited layer of Ag, Au, Pd, Pt, or Rh with a thickness of 5 μm or less applied to a plate made of Co, phosphor bronze, brass, or stainless steel. A method for manufacturing a stamper according to claim 1. 4 Metal donut plate is Ag, Au, Pd, Pt, Rh,
The method for manufacturing a stamper according to claim 1, characterized in that the stamper is made of either Ni or stainless steel. 5. The method for manufacturing a stamper according to claim 1, wherein the Ni electrodeposited layer is formed by sequentially or stepwise increasing current in the same bath.