JPH11134725A - Apparatus for production of casting mold for resin plate production and production of casting mold for resin plate production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to suppress etching of a mask material and to efficiently remove the natural oxidized film of a master disk surface by supplying gas exerting a physical effect only for the specified time from the start of etching and continuing the etching by gas exerting a chemical effect after the lapse of the specified time. SOLUTION: The surface of the silicon master disk 100 is etched down to a specified depth by supplying the gas having the high physical effect in an initial period of etching, by which the natural oxidized film 103 is removed. The gas having the high physical effect is then switched to the gas having the high chemical effect relating supplied etching gas and while the etching of resist patterns 102 is suppressed, the silicon master disk 100 is etched down to the required depth. As a result, the uniform and efficient etching of even the silicon master disk 100 generated with the natural oxidized film is made possible and the need for forming the resist patterns 102 excessively thick is eliminated. The accuracy at the time of exposure is thus enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for manufacturing a resin plate having an uneven surface on its surface, such as an optical recording medium, and more particularly to a mold on which a hard oxide film such as silicon is formed. The present invention relates to improvement of an etching technique which is effective when a material which is easy to use is used for a master.

[0002]

2. Description of the Related Art A technique using silicon or quartz as a mold, for example, as a stamper for an optical recording medium is disclosed in Japanese Patent Laid-Open No. 5-220.
No. 751. If silicon or the like is used as the material of the mold, processing can be performed with high accuracy. Therefore, this technique is preferable for manufacturing a stamper for high-density recording.

In the manufacture of a stamper, a technique for etching a silicon master with high precision is required. As a typical method for etching silicon, there are methods called wet etching and dry etching. In wet etching, the silicon surface is etched by a chemical reaction using an etchant such as hydrofluoric acid. Dry etching is a method in which an etching gas is introduced into a evacuated container, gas plasma (ions or neutral radicals) generated by high frequency or the like is accelerated by an electric field, and the gas plasma is applied to a material to be etched to perform etching.

[0004] Among these, dry etching can perform highly anisotropic etching with little so-called side etching, which is caused by erosion of the side wall.
It is suitable for an etching method for manufacturing a stamper for high-density recording. In dry etching, the physical action and the chemical action exerted on the material to be etched differ depending on the etching gas and etching conditions used, and both are used depending on the purpose.

However, the surface of the silicon master is shown in FIG.
As shown in (a), a natural oxide film easily grows and has a non-uniform thickness.

When etching with a strong chemical action is performed, the surface on which such a natural oxide film has grown cannot be etched uniformly, as shown in FIG. Then, the remaining natural oxide film functions as a fine mask for the silicon master, which causes an increase in the roughness of the etched surface as shown in FIG. An optical recording medium manufactured from a stamper having a large surface roughness has an unstable recording / reproducing signal and is not suitable for high-density recording.

On the other hand, when etching having a strong physical action is performed, as shown in FIG. 5B, a natural oxide film grown on a silicon master can be effectively removed. As a result, The etched surface can be made smooth. However, in etching with strong physical action,
The etching of the mask material progresses rapidly with the silicon master. It is considered that the mask material, that is, the photoresist layer may be formed thick from the beginning in order to prevent the mask material from being removed by the etching. However, in order to expose a photoresist layer to form a fine resist pattern, an objective lens having a large numerical aperture (NA) is required. When the NA of the objective lens becomes large, the depth of focus becomes shallow, and when the photoresist layer is thick, there is a problem that the entire layer cannot be sufficiently exposed.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an etching method suitable for forming a stamper capable of high-density recording in silicon on which a natural oxide film tends to grow. And

That is, a first object of the present invention is to provide an etching gas having a strong physical action at an initial stage to efficiently remove a natural oxide film grown on the surface of a master, thereby obtaining a rough surface of an etching surface. An object of the present invention is to provide a manufacturing technique of a resin plate manufacturing mold capable of preventing an increase in the thickness and smoothing the surface of the etched surface, thereby enabling high density recording of the resin plate manufacturing mold.

[0010] A second object of the present invention is to enable an effective etching of a master by allowing an etching gas having a strong chemical action to act mainly after applying an etching gas having a strong physical action, and An object of the present invention is to provide a technique for manufacturing a mold for manufacturing a resin plate, which can prevent the pattern from being excessively etched and can thereby reduce the thickness of the mask material.

A third object of the present invention is to control the applied electric field so that the physical action of the etching gas acts more at the initial stage and the chemical action acts more at the later stage.
By effectively removing the native oxide film that has grown on the master surface, it is possible to prevent an increase in etching surface roughness,
Further, it is an object of the present invention to provide a technique for manufacturing a resin plate manufacturing mold that enables high-density recording of a resin plate manufacturing mold by preventing excessive etching of a mask material.

[0012]

According to the first aspect of the present invention, an etching gas is supplied to a reaction vessel containing a master, and a high-frequency voltage is applied to the etching gas in the reaction vessel. The present invention also relates to a manufacturing apparatus and a manufacturing method of a mold for manufacturing a resin plate for dry-etching the master along a predetermined pattern.

In the present invention, a gas having a chemical action on the master and a gas having a physical action on the master are used together. Then, the flow rate of the gas exerting the physical action is changed in a time series.

The gas that exerts a physical effect has a small difference in the etching rate between the master such as silicon and the natural oxide film grown on the surface thereof. Therefore, the natural oxide film is efficiently etched by this gas. The etching of the mask material such as the pattern progresses rapidly. On the other hand, the gas that exerts a chemical action has a large difference in the etching rate between the master such as silicon and the natural oxide film grown on its surface.
If the natural oxide film exists unevenly, it acts as a mask, and the surface of the master cannot be etched smoothly. According to the present invention, since the flow rate of the gas exerting the physical action is changed in time series, the etching of the mask material can be suppressed, and the natural oxide film on the surface of the master can be efficiently removed.

Therefore, according to the present invention, a gas which exerts a physical action for a certain period of time from the start of etching is supplied, and subsequent supply is prohibited.

According to the present invention, after the supply of the gas is prohibited, the etching by the gas exerting the chemical action continues, and the master is etched with high selectivity to the mask material. Excessive etching is prevented.

In this specification, the term "gas exerting a physical action" refers to a gas exerting a relatively strong physical action as compared to a chemical action, and "a gas exerting a chemical action". The term "gas" refers to a gas to which a chemical action is exerted relatively stronger than a physical action. The etching gas has a dual nature in that the constituent molecules have a chemical action, have a constant mass, and can also exert a physical action, since they can exert both a chemical action and a physical action. For this reason, when comparing both functions, it is necessary to properly use an etching gas from the viewpoint of which function is more strongly exerted.

The certain time refers to a time sufficient for removing the native oxide film of the master.

Further, according to the present invention, the flow rate of a gas exerting a physical action is gradually reduced from the start of etching. According to the present invention, as the natural oxide film is removed, the flow rate of the gas exerting a physical effect is reduced, so that excessive etching of the mask material is prevented.

Further, according to the present invention, the flow rate of a gas exerting a physical action is gradually reduced from the start of etching.
According to the present invention, since the flow rate is changed stepwise, the gas flow rate control is easy.

According to the invention for solving the second problem of the present invention, the flow rate of gas exerting a chemical action is changed in a time series.

According to the present invention, since the flow rate of the gas exerting the chemical action is relatively changed as compared with the flow rate of the gas exerting the physical action, the master is efficiently removed after the natural oxide film is removed. And etching of the mask material can be suppressed.

That is, according to the present invention, the supply of the gas exerting the chemical action is started after a lapse of a predetermined time from the start of the etching. According to the present invention, after the natural oxide film is removed by the gas exerting the physical action, the gas exerting the chemical action is supplied, so that the master from which the natural oxide film has been removed has a high selection with respect to the mask material. Etching is possible
On the other hand, etching of the mask material is prevented. The certain time refers to a time that is sufficient to remove the natural oxide film.

In the present invention, the flow rate of the gas exerting a chemical action is gradually increased from the start of etching.

Further, according to the present invention, the flow rate of a gas exerting a chemical action is increased stepwise from the start of etching.
According to the present invention, since the flow rate is changed stepwise, the gas flow rate control is easy.

According to the invention for solving the third problem of the present invention, an etching gas is supplied to a reaction vessel in which a master is accommodated, and a high frequency voltage is applied to the etching gas in the reaction vessel so that the master is fixed to a predetermined state. The present invention relates to a manufacturing apparatus and a manufacturing method of a mold for manufacturing a resin plate for performing dry etching along a pattern.

The present invention uses both a gas that chemically acts on the master and a gas that physically acts on the master. The present invention is characterized in that the high-frequency voltage applied to the etching gas in the reaction vessel is changed in time series.

By changing the high frequency voltage, the physical action of the gas plasma applied to the master can be controlled, so that the etching of the mask material is suppressed and the natural oxide film on the surface of the master is efficiently removed. Can be.

That is, in the present invention, the high frequency voltage is gradually reduced from the start of etching. According to the present invention,
Since the physical action of the etching gas decreases as the natural oxide film is removed, excessive etching of the mask material is prevented.

In the present invention, the high-frequency voltage is reduced stepwise from the start of etching. According to the present invention, since the high-frequency voltage is changed stepwise, control of the high-frequency voltage is easy.

The gas exerting a physical effect in the present invention is an inert gas such as Ar, He, Ne, Kr or Xe, or a halogen-based gas containing at least one element of Cl, Br or I. One of the gases. According to such an inert gas or a gas containing a halogen element having a large mass, a natural oxide film can be efficiently etched by acceleration by an electric field.

The gas exerting a chemical action in the present invention is a fluorine-based gas such as SF ₆ , CF ₄ and CHF ₃ .
According to these molecules, fluorine radicals having high reactivity with silicon are easily generated, and silicon can be efficiently etched.

[0033]

Next, a preferred embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1) Embodiment 1 provides an example of the manufacturing apparatus of the present invention and a method for controlling an etching gas.

FIG. 1 shows a block diagram of the manufacturing apparatus of the first embodiment. As shown in the figure, a stamper manufacturing apparatus, which is a mold for manufacturing a resin plate, includes a reaction vessel 10, a high-frequency electrode 11, an oscillator 12, a vacuum pump 13, an electromagnetic valve 14,
Ground electrode 15, electromagnetic valves 16, 17, tanks 18,
9 and a sequencer 20.

This manufacturing apparatus is an apparatus for processing an etching step (FIG. 3E) in a stamper manufacturing step described later with reference to FIG. The silicon master 100 stored in the reaction container 10 corresponds to the master after the development process (FIG. 2D).

The reaction container 10 accommodates the silicon master 100 in a replaceable manner, and can be controlled to a constant pressure by evacuating the vacuum by the vacuum pump 13 and to the tanks 18 and 1.
9 is configured to be able to flow and exhaust the etching gas.

The high-frequency electrode 11 and the ground electrode 15 are arranged above and below the reaction vessel 10 with the silicon master 100 interposed therebetween, and are configured to ionize the etching gas inside the reaction vessel.

The oscillator 12 is configured to generate a high-frequency (RF) voltage, shape the waveform, and apply this to the high-frequency electrode 11.

The vacuum pump 13 is configured to evacuate the air inside the reaction vessel 10 and maintain it at a constant pressure. The electromagnetic valve 14 controls the vacuum pump 1 under the control of the sequencer 20.
3 and the reaction vessel 10 can be opened and closed.

The tank 18 is a container for filling a gas which exerts a strong chemical action on the master. The electromagnetic valve 16 controls the reaction vessel 1 from the tank 18 under the control of the sequencer 20.
The flow rate of the gas supplied to 0 is configured to be controllable.

The tank 19 is a container for filling a gas that strongly exerts a physical action on the master. The electromagnetic valve 17 controls the reaction vessel 1 from the tank 19 under the control of the sequencer 20.
The flow rate of the gas supplied to 0 is configured to be controllable.

The sequencer 20 is a computer device and includes a CPU, a memory, an interface circuit and the like (not shown). A general-purpose personal computer may be applied as the sequencer 20.
However, the sequencer 20 is configured to be able to execute a program for controlling the gas flow rate as shown in FIGS. The sequencer 20 can open and close the electromagnetic valves 14, 16 and 17 and change the degree of throttle according to the program. In addition, the oscillator 12 can generate a high-frequency voltage having an arbitrary frequency and amplitude at an arbitrary timing.

Examples of the gas having a strong physical effect include an inert gas such as Ar, He, Ne, Kr, and Xe, or a halogen-based gas containing at least one element of Cl, Br or I. Use one of these gases. It is a gas containing elements with relatively low chemical action and relatively large mass. This gas enables the natural oxide film and the master to be etched at substantially the same etching rate by the physical effect of collision of molecules having a relatively large mass.

As a gas which exerts a strong chemical action, a fluorine-based gas such as SF ₆ , CF ₄ or CHF ₃ is used. When a high-frequency voltage is applied to these gases, ions and fluorine radicals are generated by ionization. Fluorine radicals react strongly with silicon to form SiF ₄ , so that etching of silicon proceeds selectively. On the other hand, these gases have no significant effect on the resist material.

FIG. 2 is a perspective view of a stamper manufactured by the manufacturing apparatus and the manufacturing method of the present invention. As shown in the figure, the stamper 1 manufactured in the present embodiment is obtained by grinding single-crystal or non-crystalline silicon into a disk shape and precisely polishing the information recording surface to a certain surface roughness or less. According to the manufacturing method of the present invention, the semiconductor device is manufactured by forming an uneven shape corresponding to predetermined information. In manufacturing an optical recording medium as a product, that is, an optical disk, a substrate obtained by transferring the unevenness formed on the information recording surface of the stamper 1 to a resin is used as a substrate.

The material of the stamper is preferably silicon that can be precision-processed in order to manufacture an optical recording medium for high-density recording. However, if precision processing is possible, another material may be used. Even if there is, the present invention is applicable.

(Method of Manufacturing Stamper) Next, a method of manufacturing a stamper will be described with reference to FIG. This figure is shown in FIG.
FIG. 4 is a cross-sectional view of a manufacturing process in which a layer structure of each manufacturing process is viewed from an aa cut surface in FIG.

Grinding Step (FIG. 3A): First, high-purity silicon is ground into a disc shape, and its information recording surface is precisely polished to a certain surface roughness or less, thereby producing a silicon master 100. The upper surface of the figure is a recording surface that has been precisely polished.
For example, a silicon wafer having a diameter of 8 inches is used as the master.

Step of forming resist layer (FIG. 2B): A photoresist 101 is applied to the recording surface of the silicon master 100. Photoresist is a material that changes into a substance that is insoluble in a developer when irradiated with light of a certain intensity or more when it is called a negative type, and is developed when irradiated with light with a certain intensity or more when it is called a positive type. It is a material that changes to a substance that is easily soluble in liquid. Therefore, it is possible to form a pattern by thinning the photoresist, exposing it to a pattern, and then treating it with a developing solution. The photoresist may be positive or negative. The photoresist is applied on the silicon master 100, for example, by a spin coating method to a thickness of about 100 nm, and is fixed by heat treatment.

Exposure Step (FIG. 10C): In the exposure step, exposure is performed by laser light or the like in accordance with a predetermined pattern. For example, a laser beam having a wavelength of 351 nm is squeezed with an objective lens having a numerical aperture of 0.9 on a silicon master on which a resist layer has been formed, and is condensed on the resist layer. Expose. The pattern to be exposed is obtained by modulating information to be recorded on an optical recording medium according to a signal format of the optical recording medium. When a negative photoresist is used, the resist in the region irradiated with the light is cured to form a resist pattern 102.

Developing Step (FIG. 2D): In the developing step, the photoresist 10 other than the resist pattern 102 is removed.
1 is dissolved in a developing solution and removed.
Only leave. Examples of the developing solution include sodium hydroxide, potassium hydroxide, calcium hydroxide, a mixed solution of sodium phosphate and sodium silicate, an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH), or an organic solvent such as xylene and butyl acetate. And the like.

Etching step (FIG. 7E): This etching step is a feature of the present invention. In order to process the etching process, the silicon master 100 is housed in the manufacturing apparatus of the present embodiment. The detailed description of the etching step will be described later. After etching, silicon master 1
At 00, an uneven shape corresponding to the information is formed.

Resist removing step (FIG. 9F): In the resist removing step, the resist pattern 1 after etching is removed.
02 is removed by dissolving in a solvent or ashing (ashing). Next, when the master is washed and dried, the stamper 1 is completed.

(Resin Plate Manufacturing Step) After the stamper 1 is formed, the resin plate, that is, the optical recording medium, is manufactured by transferring the concave and convex shape of the silicon master to the resin. FIG.
Fig. 2 shows a manufacturing process diagram of the resin plate.

Forming resin layer forming step (FIG. 4B): A forming resin is applied to the recording surface of the stamper 1 (FIG. 4A) manufactured as described above to form a curable resin layer 104. I do. As the molding resin, various resins such as a thermoplastic resin such as a polycarbonate resin, an amorphous polyolefin resin, and an acrylic resin, and an ultraviolet curable resin can be used. For example, the molding resin layer 104 is formed by injection molding of a thermoplastic resin or the like, or by pressure molding of an ultraviolet curable resin or the like. When using a thermoplastic resin, after molding, the resin is cooled to cure the resin.
When using an ultraviolet curable resin, the material is cured by irradiating ultraviolet rays. The molding resin layer 104 is molded into the outer shape of the optical recording medium. On the surface of the molding resin layer 104,
The concavo-convex shape provided on the recording surface of the stamper 1 is transferred.

Bonding step (FIG. 10C): After the molding resin layer 104 is formed, the flat substrate 105 is bonded to the back surface (the upper surface in the same figure) of the curable resin layer 104. The flat substrate 105 serves as an auxiliary material for improving the reliability such as the mechanical strength of the resin layer 104 or as an auxiliary material for improving the productivity of the substrate, and is used as a substrate of an optical recording medium to be manufactured. It is not always necessary if the required reliability and productivity can be secured. As the material of the flat substrate, for example, resins such as polycarbonate, amorphous polyolefin, and polymethyl methacrylate, glass, metal, and ceramic can be used. Then, when the molded resin layer 104 is cured after the flat substrate 105 is bonded, the flat substrate 105 and the molded resin layer 104 are brought into close contact with each other.

Peeling Step (FIG. 5D): The molded resin layer 104 to which the flat substrate 105 is attached is peeled from the stamper 1. The peeled molded resin layer 104 is the substrate of the optical recording medium.

(Detailed Description of Etching Step) The surface of the silicon master 100 is immediately oxidized when exposed to air, and a natural oxide film (SiO ₂ ) grows. For example, as shown in FIG. 4A, the native oxide film 103 is
Non-uniform thickness (e.g., 10 mm to
(Thickness of about 50 °). After some growth,
The growth of the native oxide film stops. FIG. 6 (same for FIGS. 7 to 18) shows this native oxide film growth region.

When an etching gas that exerts a chemical action is supplied to the surface of the silicon master 100 on which the natural oxide film 103 has grown with an uneven thickness, the natural oxide film 103 is gradually etched. If the thickness of the natural oxide film is not uniform, a portion where the natural oxide film is removed and the silicon is exposed is also unevenly generated (FIG. 4B). In dry etching by a chemical action, generally, the etching rate for silicon is high, but the etching rate for a natural oxide film is low. Since the chemical action is exerted on the portion where the silicon is exposed, the silicon is etched at a high etching rate. On the other hand, in the portion where the silicon oxide is not exposed and the natural oxide film remains, the etching rate is low and the etching progresses slowly. Therefore, as the etching time elapses, a large difference occurs in the depth of the silicon to be etched (FIG. 4C). For example, a surface roughness of about 10 to 20 ° in center line average roughness occurs. I will. This cannot be used as a stamper for high-density recording.

Therefore, in this embodiment, as shown in FIG. 5, at the beginning of the etching, a gas having a strong physical effect is supplied to etch the surface of the silicon master 100 to a certain depth to remove the natural oxide film. (FIG. 5B). Then, the supplied etching gas is switched from a gas having a strong physical action to a gas having a strong chemical action, so that the silicon is etched to a required depth while suppressing the etching of the resist pattern 102 (FIG. 5).
(C)).

Therefore, in the first embodiment, the sequencer 2
0 performs the etching control as shown in FIG. First,
The sequencer 20 adjusts the etching conditions. The vacuum pump 13 is driven, the electromagnetic valve 14 is opened, and a vacuum is drawn. The temperature of the silicon master 100 is maintained at about 20 ° C.

Next, an etching gas is circulated and the pressure is maintained at about 10 Pa. Initially, the electromagnetic valve 16 is closed and the electromagnetic valve 17 is opened to allow the etching gas exerting a physical action to flow through the reaction vessel 10. The gas flow rate is about 50 SCCM. Then, the oscillator 12
Oscillation is performed at an output of about 300 W using a high frequency voltage source having a frequency of about 13.56 MHz. The supply time of the gas having a strong physical action is a time that the natural oxide film 103 is sufficiently removed by the gas that exerts a physical action, and is a time that the resist pattern 102 is not excessively etched, for example, a natural time. Oxide film etching rate is 500Å
/ Min gas, the etching time is 1
Set to about 0 seconds.

After the supply of the gas having a strong physical action, the sequencer 20 closes the electromagnetic valve 17 and opens the electromagnetic valve 16 to allow the gas having a strong chemical action to flow through the reaction vessel 10. The gas flow rate is about 70 SCCM. The etching time by the gas having a strong chemical action is a time during which the silicon master can be etched to a desired depth, for example, about 800 ° which is the same depth as the pit, and is determined by the relationship with the etching rate. For example, if the etching rate is 200
When a gas of 0 ° / min is used and the etching is performed at about 80 ° by a gas having a strong physical action, the etching time is set to about 20 seconds.

According to the first embodiment, first, a gas having a strong physical action is allowed to flow for a certain period of time, and after the natural oxide film is removed, etching is switched to etching using a gas having a chemical action. Even on a master where a film is generated, uniform and efficient etching is possible. Also,
Since the etching by the gas having a strong physical action is stopped while the resist pattern has a sufficient thickness, the resist pattern does not need to be excessively thick, and the accuracy at the time of exposure can be improved. Therefore, the stamper manufactured according to the present embodiment is suitable as a mold for high-density recording.

In particular, in this embodiment, since the adjustment is made only by opening and closing each gas, the control is simple. In addition, since gases having different functions are allowed to act in a time-separated manner, the surface roughness can be efficiently reduced.

(Embodiment 2) In Embodiment 2 of the present invention, similarly to Embodiment 1, in addition to initially supplying a gas having a strong physical action, a gas having a strong chemical action is continuously changed. is there.

The manufacturing apparatus used in the second embodiment is the same as that used in the first embodiment. However, sequencer 2
A value of 0 controls the etching at the timing shown in FIG.

Now, in the above configuration, the sequencer 20
Prepares the etching conditions for this embodiment. The vacuum pump 13 is driven, the electromagnetic valve 14 is opened, and a vacuum is drawn. The temperature of the silicon master 100 is maintained at about 20 ° C.

Next, an etching gas is circulated. By opening the electromagnetic valve 17, an etching gas having a strong physical action is circulated in the reaction vessel 10. Gas flow rate is 5
Approximately 0 SCCM. Then, the frequency 1 is supplied to the oscillator 12.
Using a high frequency voltage source of about 3.56 MHz, output 300
Oscillate at about W to generate plasma. The supply time of the gas having a strong physical action is such a time that the natural oxide film 103 is sufficiently removed by the gas having a strong physical action, and is a time that the resist pattern 102 is not excessively etched, for example, etching. Rate is $ 500 /
When a gas of about min is used, the etching time is 10
About a second.

In parallel with the supply of a gas having a strong physical action,
The sequencer 20 gradually opens the electromagnetic valve 16 to increase the flow rate of the gas having a strong chemical action. The rate at which the flow rate is increased is about 5 SCCM / sec. The supply time of the gas having a strong chemical action is a time during which the silicon master can be etched to a desired depth, for example, about 800 ° which is the same depth as the pit, and is determined by the relationship with the etching rate.

According to the second embodiment, first, a gas having a strong physical effect is circulated to remove the natural oxide film, and the circulation is stopped while the resist pattern has a sufficient thickness. . On the other hand, since the flow rate of the gas having a strong chemical action is gradually increased, uniform and efficient etching can be performed even on a master where a natural oxide film is generated. Also,
Since etching with a gas having a strong physical action is limited to a certain time, the resist pattern does not need to be excessively thick, and the accuracy at the time of exposure can be improved. Therefore,
The stamper manufactured according to the present embodiment is suitable as a mold for high-density recording.

The gas having a strong chemical action may be increased linearly, may be increased in a curved line, or may be supplied intermittently to increase the flow rate.

As shown in FIG. 8, a gas having a strong chemical action may be gradually increased. If the amount is increased stepwise, the flow rate adjustment of the electromagnetic valve 16 becomes easier, which is preferable for simplifying the control.

Further, as shown in FIG. 9, a gas having a strong chemical action may be flowed at a constant flow rate first, and then the flow rate may be further gradually increased. If the flow rate is too low, it is difficult to control the flow rate, and the effect may be too small.

(Embodiment 3) Embodiment 3 of the present invention is different from Embodiment 1 in that the flow rate of a gas having a strong physical action is gradually reduced.

The manufacturing apparatus used in the third embodiment is the same as that used in the first embodiment. However, sequencer 2
A value of 0 controls the etching at the timing shown in FIG.

Now, in the above configuration, the sequencer 20
Prepares the etching conditions for this embodiment. The vacuum pump 13 is driven, the electromagnetic valve 14 is opened, and a vacuum is drawn. The temperature of the silicon master 100 is maintained at about 20 ° C.

Next, an etching gas is circulated. By opening the electromagnetic valve 17, an etching gas having a strong physical action is allowed to flow through the reaction vessel 10, and the pressure is maintained at about 10 Pa. Then, the frequency 13.56 is supplied to the oscillator 12.
Oscillation is performed at an output of about 300 W using a high-frequency voltage source of about MHz. The gas flow rate is initially about 80 SCCM, but the gas flow rate is reduced over time. The rate of decreasing the flow rate is about 5 SCCM / sec. The supply time of the gas having a strong physical action is such that the natural oxide film 103 is sufficiently removed by the gas having a strong physical action and is such a time that the resist pattern 102 is not excessively etched.

After a certain time has passed since the supply of the gas having a strong physical action, the electromagnetic valve 16 is opened to allow the gas having a strong chemical action to flow through the reaction vessel 10. The gas flow rate is 7
Approximately 0 SCCM. The timing of supplying the gas having a strong chemical action is after a lapse of time to the extent that the natural oxide film is sufficiently removed from the gas having a strong physical action. The supply time of the gas having a strong chemical action is a time during which the silicon master can be etched to a desired depth, for example, about 800 ° which is the same depth as the pit, and is determined by the relationship with the etching rate.

According to the third embodiment, the natural oxide film is removed by flowing a gas having a strong physical effect while gradually reducing the natural oxide film so that the resist pattern can maintain a sufficient thickness. Supply a highly chemically acting gas. Therefore, uniform and efficient etching can be performed even on a master where a natural oxide film is generated. Further, since the flow rate of the gas having a strong physical action is reduced, the resist pattern does not need to be excessively thick, and the accuracy at the time of exposure can be improved. Therefore,
The stamper manufactured according to the present embodiment is suitable as a mold for high-density recording.

The gas having a strong physical action may be reduced linearly, may be reduced in a curved line, or may be supplied intermittently to reduce its flow rate.

Further, as shown in FIG. 11, a gas having a strong physical action may be gradually reduced. Decreasing the pressure stepwise makes it easier to adjust the flow rate of the electromagnetic valve 17, and is therefore preferable for simplifying the control.

Further, as shown in FIG. 12, a gas having a strong physical effect may be flowed for a certain amount for a certain period, and then the flow may be gradually reduced.

(Embodiment 4) Embodiment 4 of the present invention is a combination of the method for supplying gas having strong chemical action in Embodiment 2 and the method for supplying gas having strong physical action in Embodiment 3.

The same manufacturing apparatus as that used in the first embodiment is used as the manufacturing apparatus used in the fourth embodiment. However, sequencer 2
In the case of 0, the etching control is performed at the timing shown in FIG.

In the above configuration, first, the sequencer 20 adjusts the etching conditions for the present embodiment. The vacuum pump 13 is driven, the electromagnetic valve 14 is opened, and a vacuum is drawn. The temperature of the silicon master 100 is 20
Maintain at about ° C.

Next, an etching gas is circulated. By opening the electromagnetic valve 17, an etching gas having a strong physical action is allowed to flow through the reaction vessel 10, and the pressure is maintained at about 10 Pa. Then, the frequency 13.56 is supplied to the oscillator 12.
Oscillation is performed at an output of about 300 W using a high-frequency voltage source of about MHz to generate plasma. The gas flow rate is initially about 80 SCCM, but the gas flow rate is reduced over time. The rate of decreasing the flow rate is about 5 SCCM / sec. The supply time of the gas having a strong physical action is such that the natural oxide film 103 is sufficiently removed by the gas having a strong physical action and is such a time that the resist pattern 102 is not excessively etched.

In parallel with the supply of a gas having a strong physical action,
The sequencer 20 gradually opens the electromagnetic valve 16 to increase the flow rate of the gas having a strong chemical action. The rate of increasing the flow rate is about 5 SCCM / sec. The supply time of the gas having a strong chemical action is a time during which the silicon master can be etched to a desired depth, for example, about 800 ° which is the same depth as the pit, and is determined by the relationship with the etching rate.

According to the fourth embodiment, the natural oxide film is removed by flowing a gas having a strong physical effect while gradually decreasing the gas so that the resist pattern can maintain a sufficient thickness. On the other hand, as the natural oxide film is removed by the gas having a strong physical action, the flow rate of the gas having a strong chemical action increases. Therefore, uniform and efficient etching can be performed even on a master where a natural oxide film is generated. Further, since the flow rate of the gas having a strong physical action is reduced, the resist pattern does not need to be excessively thick, and the accuracy at the time of exposure can be improved. Therefore, the stamper manufactured according to the present embodiment is suitable as a mold for high-density recording.

The flow rates of the gas having a strong chemical action and the gas having a strong physical action are not only increased and decreased linearly, but also increased or decreased in a curved manner while intermittently supplying them. It may be something.

Further, as shown in FIG. 8, even if a gas having a strong chemical action is supplied in a stepwise manner, as shown in FIG. 11, a gas having a strong physical action is gradually reduced. It may be supplied after being supplied. If it is increased or decreased stepwise, the flow rate adjustment of the electromagnetic valves 16 and 17 becomes easier, which is preferable for simplifying the control.

Further, as shown in FIG. 9, even if a gas having a strong chemical action is supplied for a certain amount of time and then gradually supplied, as shown in FIG. The gas may be supplied at a constant rate for a fixed period and then gradually reduced.

(Fifth Embodiment) A fifth embodiment of the present invention is different from the above embodiments in that the flow rate of only a gas having a strong physical action is controlled.

The same manufacturing apparatus as that used in the first embodiment is used as the manufacturing apparatus used in the fourth embodiment. However, sequencer 2
0 indicates that the etching control is performed at the timing shown in FIG. Since it is not necessary to control the flow rate of the gas having a strong chemical action, the electromagnetic valve 16 does not need to be configured to be controllable by the sequencer 20.

Now, in the above configuration, the sequencer 20
Prepares the etching conditions for this embodiment. The vacuum pump 13 is driven, the electromagnetic valve 14 is opened, and a vacuum is drawn. The temperature of the silicon master 100 is maintained at about 20 ° C.

Next, an etching gas is circulated. First, the electromagnetic valve 16 is opened to allow a gas having a strong chemical action to flow through the reaction vessel 10. Gas flow rate is 50 SCCM
Degree. The supply time of the gas having a strong chemical action is a time during which the silicon master can be etched to a desired depth, for example, about 800 ° which is the same depth as the pit, and is determined by the relationship with the etching rate.

In parallel with the supply of a gas having a strong chemical action,
By opening the electromagnetic valve 17, an etching gas having a strong physical action is allowed to flow through the reaction vessel 10, and the pressure is maintained at about 10 Pa. The gas flow rate is about 20 SCCM. Then, a high-frequency voltage source having a frequency of about 13.56 MHz is used as the oscillator 12 and oscillated at an output of about 300 W to generate plasma. The supply time of the gas having a strong physical action is such that the natural oxide film 103 is sufficiently removed by the gas having a strong physical action and is such a time that the resist pattern 102 is not excessively etched.

According to the fifth embodiment, a gas having a strong physical action is initially circulated in a container through which a gas having a strong chemical action flows, so that the resist pattern has a sufficient thickness. Then, the distribution is stopped. As the natural oxide film is removed, a gas having a strong chemical action acts on the silicon, so that uniform and efficient etching can be performed even on a master where a natural oxide film is generated. Also, since etching with a gas having a strong physical action is limited to a certain time,
The resist pattern does not need to be excessively thick, and the accuracy at the time of exposure can be improved. Therefore, the stamper manufactured according to the present embodiment is suitable as a mold for high-density recording.

In particular, since it is not necessary to control the flow rate of the gas having a strong chemical action, the adjustment of the manufacturing conditions is further simplified.

The gas having a strong physical action may be supplied linearly for a certain period of time, or may be decreased linearly as shown in FIG. Further, the flow rate may be reduced in a curved manner, or the flow rate may be reduced while supplying intermittently.

Further, as shown in FIG. 11, the flow rate of a gas having a strong physical action may be gradually reduced. If the value is decreased stepwise, the flow rate of the electromagnetic valve 17 can be more easily adjusted, which is more preferable for simplifying the control.

Further, as shown in FIG. 12, a gas having a strong physical action may be flowed for a certain period of time and then gradually decreased.

(Embodiment 6) Unlike Embodiment 6, Embodiment 6 of the present invention is to control the applied high frequency voltage instead of setting the gas flow rate to be constant.

The manufacturing apparatus used in the sixth embodiment is the same as that used in the first embodiment. However, the reaction vessel 10
One type of gas is used without using a plurality of types of gas to be circulated. For example, a fluorine gas such as SF _6, CF ₄ , or CHF ₃ or a gas such as Cl ₂ , SiCl ₄ , HBr, or HI is used. This gas exerts both a chemical action and a physical action on the silicon master. That is, the intensity of the electric field applied to the ionized ions varies depending on the amplitude of the applied high-frequency voltage. The strength of this electric field is proportional to the energy applied to the ions. Thus, the high frequency voltage is proportional to the energy in the physical action of the ions.

The gas flow rate is fixed at a constant flow rate. Since there is only one kind of gas, only one of the tanks 18 or 19 is required, and the control of the electromagnetic valve 16 or 17 by the sequencer 20 is not required. Here, for convenience,
The etching gas is stored in the tank 18 and the electromagnetic valve 1
It is assumed that the gas is circulated through only 6.

The sequencer 20 is configured so that the amplitude value of the high frequency voltage of the oscillator 12 can be adjusted in time series.
The control characteristics are performed according to the characteristics as shown in FIG.

Now, in the above configuration, the sequencer 20
Prepares the etching conditions for this embodiment. The vacuum pump 13 is driven, the electromagnetic valve 14 is opened, and a vacuum is drawn. The temperature of the silicon master 100 is maintained at about 20 ° C. Further, the electromagnetic valve 16 is opened to allow the etching gas to flow through the reaction vessel 10. The gas flow rate is
Approximately 80 SCCM.

Next, the sequencer 20 supplies the oscillator 12 with
Using a high frequency voltage source having a frequency of about 13.56 MHz, first oscillate with an output of about 500 W, and then oscillate the amplitude,
It is reduced according to the characteristics of FIG. The speed at which the voltage is reduced is about 5 W / sec. The initial voltage value and the falling speed are such that the natural oxide film 103 is sufficiently removed by the physical action of the gas and that the resist pattern 102 is not excessively etched.

According to the sixth embodiment, since a high high-frequency voltage is applied first, the energy given to the etching gas is high and the speed is high. For this reason, the physical effect of the etching gas is large, and the natural oxide film is efficiently etched. However, since the amplitude of the high-frequency voltage is reduced while the resist pattern has a sufficient thickness, the resist pattern does not need to be excessively thick, and the accuracy at the time of exposure can be improved. Therefore, the stamper manufactured according to the present embodiment is suitable as a mold for high-density recording.

Since the physical action of the etching gas is relatively small and the chemical action is relatively large, uniform and efficient etching is possible even on a master where a natural oxide film is generated. .

The output of the high-frequency voltage may be reduced linearly, may be reduced in a curved line, or may be reduced intermittently while being supplied intermittently. Also,
As shown in FIG. 17, the output may be gradually reduced.

Further, as shown in FIG. 18, the high frequency voltage may be gradually reduced after being applied with a constant output for a fixed period.

(Other Modifications) The present invention can be applied in various modifications regardless of the above embodiment.

The manufacturing apparatus may have a different configuration irrespective of the above embodiment as long as it has a configuration capable of performing dry etching. For example, in addition to the parallel plate type etching apparatus as described above,
For example, an apparatus having a plasma generation mechanism such as an inductive coupling type (ICP) type, an electron cyclotron resonance (ECR), or a helicon wave excitation type may be used.

The material of the ground electrode may be Teflon, carbon, or the like. When Teflon or carbon is used, fluorine radicals are removed, and the selectivity with silicon is improved.

Further, as the etching gas, a gas having another composition can be applied as long as the gas has a strong physical reaction and a chemical reaction irrespective of the above composition. For example, C ₂ H ₄ to CF ₄ or H ₂
May be mixed to improve the selectivity. The etching rate may be increased by doping phosphorus (P) or boron (B).

In the above embodiment, the irregularities formed on the master are based on the recorded information. However, the irregularities for decorative or other purposes not for recording information are used. It may be. Further, in the above-described embodiment, the master has a disk shape, but may have other shapes such as a square.

[0119]

According to the present invention, an excessive etching gas having a strong physical action is made to act at the beginning, and the degree of exerting the physical action is suppressed, thereby preventing the resist pattern from being excessively etched. Therefore, high-density recording of the mold for manufacturing a resin plate can be made possible by forming a thin pattern.

According to the present invention, an etching gas having a strong chemical action is supplied after an etching gas having a strong physical action is exerted. Therefore, the natural oxide film can be effectively etched, and the increase in the surface roughness of the etched surface due to the remaining natural oxide film can be suppressed.

According to the present invention, by controlling the applied electric field, the physical action of the etching gas is increased at the initial stage, and the chemical action is increased at the latter stage. Therefore, it is possible to prevent the resist pattern from being excessively etched and to form a thin resist pattern, thereby enabling high-density recording of a mold for manufacturing a resin plate.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a stamper manufacturing apparatus according to an embodiment.

FIG. 2 is a perspective view of a stamper according to the embodiment.

FIG. 3 is a cross-sectional view illustrating a manufacturing process of a silicon stamper.
(A) is an original silicon master, (b) is a resist layer forming step, (c) is an exposing step, (d) is a removing step, (e) is an etching step, and F is a resist removing step.

FIG. 4 is a cross-sectional view of a manufacturing process of a silicon master for explaining a problem of etching in the related art. (a) is a cross-sectional view before etching, (b) is a cross-sectional view in an etched state, and (c) is a cross-sectional view in a state where etching is further advanced.

FIG. 5 is a cross-sectional view of the manufacturing process of the silicon master. (a) is a cross-sectional view before etching, (b) is a cross-sectional view in an etching state illustrating the etching in the present embodiment, (c)
FIG. 4 is a cross-sectional view in an etching state where etching has further progressed.

FIG. 6 is an etching characteristic diagram according to the first embodiment.

FIG. 7 is an etching characteristic diagram in the second embodiment.

FIG. 8 is a modification of the etching characteristic diagram in the second embodiment.

FIG. 9 is another modification of the etching characteristic diagram in the second embodiment.

FIG. 10 is an etching characteristic diagram in the third embodiment.

FIG. 11 is a modification of the etching characteristic diagram in the third embodiment.

FIG. 12 is another modification of the etching characteristic diagram in the third embodiment.

FIG. 13 is an etching characteristic diagram in the fourth embodiment.

FIG. 14 is an etching characteristic diagram in the fifth embodiment.

FIG. 15 is a modification of the etching characteristic diagram in the fifth embodiment.

FIG. 16 is an etching characteristic diagram in the sixth embodiment.

FIG. 17 is a modification of the etching characteristic diagram in the sixth embodiment.

FIG. 18 is another modification of the etching characteristic diagram in the sixth embodiment.

FIG. 19 is a sectional view of a manufacturing process for manufacturing a resin plate from a stamper, (a) is a stamper prototype, (b) is a curable resin application process, (c) is a flat substrate bonding process,
(D) is a cross-sectional view of the peeling step and (e) is a completed optical recording medium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stamper 10 ... Reaction vessel 11 ... High frequency electrode 12 ... Oscillator 13 ... Vacuum pump 14, 16, 17 ... Electromagnetic valve 15 ... Grounding electrode 18, 19 ... Tank 20 ... Sequencer (control device) 100 ... Silicon master disk 101 ... Resist layer 102: resist pattern 103: natural oxide film

Claims (26)

[Claims] A resin plate for supplying an etching gas to a reaction vessel containing a master and applying a high-frequency voltage to the etching gas in the reaction vessel to dry-etch the master along a predetermined pattern. In the apparatus for manufacturing a mold for production, a first tank filled with a gas having a chemical effect on the master so as to be supplied to the reaction vessel, and a gas having a physical action on the master is supplied to the reaction vessel. A second tank filled as much as possible, and a control device for controlling a flow rate of a gas that exerts a physical action to be supplied from at least the second tank to the reaction vessel, wherein the control apparatus is configured to perform the physical action By changing the flow rate of the gas that exerts the influence in time series, it is possible to suppress the etching of the mask material for forming the pattern and to remove the natural oxide film on the surface of the master. Resin plate for producing a mold of the manufacturing apparatus according to claim. 2. The apparatus according to claim 1, wherein the controller supplies a gas that exerts the physical action for a certain period of time from the start of etching, and prohibits subsequent supply. 3. The apparatus according to claim 1, wherein the control device gradually reduces the flow rate of the gas exerting the physical action from the start of the etching. 4. The apparatus according to claim 1, wherein the controller reduces the flow rate of the gas exerting the physical action stepwise from the start of etching. 5. The apparatus according to claim 1, wherein the controller further changes the flow rate of the gas exerting the chemical action in a time-series manner. 6. The apparatus for manufacturing a mold for manufacturing a resin plate according to claim 5, wherein the control device starts supplying the gas exerting the chemical action after a lapse of a predetermined time from the start of etching. 7. The apparatus according to claim 5, wherein the controller gradually increases the flow rate of the gas exerting the chemical action from the start of etching. 8. The apparatus according to claim 5, wherein the control device increases the flow rate of the gas exerting the chemical action stepwise from the start of etching. 9. A resin plate for supplying an etching gas to a reaction vessel containing a master and applying a high-frequency voltage to the etching gas in the reaction vessel to dry-etch the master along a predetermined pattern. In the apparatus for manufacturing a mold for production, a first tank filled with a gas having a chemical effect on the master so as to be supplied to the reaction container, and a gas having a physical effect on the master is supplied to the reaction container. A second tank filled as much as possible, and a control device for controlling a high-frequency voltage applied to the etching gas in the reaction vessel, wherein the control device changes the high-frequency voltage in time series, An apparatus for manufacturing a mold for manufacturing a resin plate, wherein etching of a mask material for forming the pattern is suppressed, and a natural oxide film on the surface of the master is removed. 10. The apparatus according to claim 9, wherein the control device gradually reduces the high-frequency voltage from the start of etching. 11. The apparatus according to claim 9, wherein the control device gradually reduces the high-frequency voltage from the start of etching. 12. The gas having a physical effect is A
an inert gas such as r, He, Ne, Kr, or Xe;
The apparatus for manufacturing a mold for manufacturing a resin plate according to any one of claims 1 to 11, wherein the apparatus is any one of a halogen-based gas containing one or more elements of Cl, Br, and I. 13. The gas having a chemical effect is SF.
_6, CF _4, or a resin plate for producing a mold of the manufacturing apparatus according to any one of claims 1 to 12 is a fluorine-based gas CHF ₃ or the like. 14. A method of manufacturing a mold for manufacturing a resin plate for transferring a concave-convex shape formed on a recording surface to a resin plate, comprising: a resist pattern forming step of forming a resist pattern on a master; An etching step of dry-etching the formed master, wherein in the etching step, both a gas having a chemical action on the master and a gas having a physical action on the master are supplied, and at least the physical Manufacturing method of a resin plate manufacturing mold, characterized in that etching of the resist pattern is suppressed and a natural oxide film on the surface of the master is removed by changing a flow rate of a gas exerting an action in a time-series manner. . 15. The method according to claim 14, wherein in the etching step, a gas that exerts the physical action is supplied for a certain period of time from the start of etching, and the supply after that is prohibited. 16. The method according to claim 14, wherein in the etching step, the flow rate of the gas exerting the physical action is gradually reduced from the start of the etching. 17. The method according to claim 14, wherein in the etching step, the flow rate of the gas exerting the physical action is reduced stepwise from the start of the etching. 18. The method according to claim 14, wherein, in the etching step, a flow rate of the gas exerting the chemical action is changed in a time series. 19. The method according to claim 18, wherein in the etching step, supply of the gas exerting the chemical action is started after a lapse of a predetermined time from the start of the etching. 20. The method according to claim 18, wherein in the etching step, the flow rate of the gas exerting the chemical action is gradually increased from the start of the etching. 21. The method according to claim 18, wherein in the etching step, the flow rate of the gas exerting the chemical action is increased stepwise from the start of etching. 22. A method of manufacturing a mold for manufacturing a resin plate for transferring a concavo-convex shape formed on a recording surface to a resin plate, comprising: a resist pattern forming step of forming a resist pattern on a master; An etching step of dry-etching the formed master, wherein in the etching step, both a gas having a chemical action on the master and a gas having a physical action on the master are supplied, and A method for producing a mold for producing a resin plate, wherein a high-frequency voltage applied to an etching gas in a reaction vessel is changed in a time series. 23. The method according to claim 22, wherein in the etching step, the high-frequency voltage is gradually reduced from the start of etching. 24. The method according to claim 22, wherein in the etching step, the high-frequency voltage is reduced stepwise from the start of etching. 25. The gas having a physical effect is A
an inert gas such as r, He, Ne, Kr, or Xe;
25. The method for producing a mold for producing a resin plate according to any one of claims 14 to 24, wherein the method is any one of a halogen-based gas containing one or more elements of Cl, Br or I. 26. The gas having a chemical effect is SF.
_6, CF ₄ or CHF ₃ or the like method for producing a resin plate for producing a mold according to any one of claims 14 to 25 which is a fluorine-based gas.