JPH0251434A - Mold for press-molding glass - Google Patents

Abstract

PURPOSE:To prevent the melt sticking of glass to be molded to the molding surface of a mold for molding by forming a carbon film on a glass substrate having a prescribed fine pattern. CONSTITUTION:A thin film of a metal such as Cr, Mo, Ta, W, Zn or Ti or a metalloid such as Si having 300-1,500Angstrom thickness is formed on an SiO2-based glass substrate 5a by sputtering, CVD or other method and a resist film is formed on the thin film and patterned by lithography. The thin film is etched with the resulting fine resist pattern as a mask and the resist pattern is removed to obtain a fine pattern 6. Carbon films 8a, 8b having <=1mum thickness are formed on the substrate 5a and a glass substrate 5b.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mold for glass press molding, and more specifically to a mold for producing a thin glass molded body having a fine pattern such as grooves and holes on the surface. Regarding a mold for glass press molding. Although the glass press molding mold of the present invention is not limited thereto, it is particularly preferably used for manufacturing substrates for information recording media such as optical disk substrates.

[Prior art and its problems] In order to obtain an optical disc that can store records for a long time, it is necessary to use a disc substrate that does not deform over time, and for this purpose, a glass substrate is used rather than a plastic substrate. It is desired to do so.

Conventionally, when using a glass substrate as a substrate, guide grooves for tracking laser light during information recording and reproduction are formed after a resist pattern is obtained on the substrate using photolithography or electron beam lithography.
The substrate is etched using this resist pattern as a mask, and then the resist pattern is peeled off. However, this method H requires high viscosity in the resist pattern forming process, substrate etching process, etc., and has the disadvantage that it requires a large number of steps to form the guide grooves.

Therefore, in order to eliminate the drawbacks of the above-mentioned method, a method of manufacturing a glass disk substrate with guide grooves by a press molding method using a mold has been attempted (Japanese Patent Laid-Open No. 62-10
(See Publication No. 0429). This method involves providing a coating film of a platinum-based noble metal alloy on a ceramic substrate such as tungsten carbide or titanium carbide sintered body, and then micromachining the surface of the coating film into a shape that corresponds to the guide groove of the optical disc. Although it is used as a mold, it is extremely difficult to micro-process the platinum-based coating film during the manufacturing of the mold, making it difficult to obtain the desired fine pattern. In negative manufacturing of disk substrates, the glass to be formed tends to be fused to the mold, resulting in a disadvantage that the quality of the resulting optical disk substrate is poor.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide a molded glass that has a predetermined fine pattern corresponding to the shape of a glass molded body to be manufactured. An object of the present invention is to provide a glass press molding mold which can obtain a glass molded article with excellent precision without being fused to the molding surface of the molding mold.

[Means for Solving the Problems] The glass press molding mold of the present invention comprises a glass substrate provided with a predetermined fine pattern corresponding to the shape of the glass molded body to be manufactured, and this patterned glass substrate. A top layer made of a carbon film formed to cover the mold, and a glass press molding mold having such a structure has the disadvantages of the above-mentioned conventional glass press molding molds. , it is possible to solve problems such as difficulty in microfabrication during manufacturing of molds and deterioration in quality of glass molded bodies due to fusion of glass to be molded.

Further, according to a preferred embodiment of the present invention, an intermediate layer made of silicon carbide and/or silicon nitride film may be provided between the finely patterned glass substrate and the uppermost layer made of carbon film, and this intermediate layer is provided. This prevents the top layer from peeling off even if the glass press mold is used repeatedly over a long period of time, thereby extending the life of the mold.

The present invention will be explained in detail below.

The glass press molding mold of the present invention uses a glass base as a base, and the glass base has silicon dioxide as a main component.

Examples of such glasses include quartz glass or 47-
68% by weight of silicon dioxide as the first component, and 6-2% by weight of silicon dioxide as the first component.
Mention may be made of glasses containing 3% aluminum oxide as a second component. The latter glass containing silicon dioxide and aluminum oxide as essential components may be made of 19
It may contain at least one of the following: zinc oxide in an amount of up to 18% by weight, magnesium oxide in an amount of up to 133% by weight, and further calcium oxide,
It may contain small amounts of components such as strontium oxide, barium oxide, lead oxide, alkali metal oxides, and fluorine.

The above-mentioned quartz glass has a glass transition temperature of about 1200°C and a thermal expansion coefficient of 5X10-7/''C, while the above-mentioned glass containing silicon dioxide and aluminum oxide as essential components has a glass transition temperature of 600 to 800°C. ℃, the thermal expansion coefficient is 30 x 10.' to 60 x 10-7/''C,
Both glasses have high glass transition temperatures and low coefficients of thermal expansion, so they are suitable as base materials for glass press molding molds.

In the glass press molding mold of the present invention, a predetermined fine pattern corresponding to the shape of the glass molded body to be manufactured is provided on the glass substrate.

To form this fine pattern on a glass substrate, first, a thin film is formed on the glass substrate by a vacuum evaporation method, a sputtering method, a plasma CVD method, a CVD method, an ion blasting method, an immersion method, a spin code method, etc. .

Here, the thin film materials include Or, Mo, Ta, W, and Z.
Examples include metals such as n, Ti, semimetals such as 3i, and alloys or compounds containing at least one of these metals and semimetals (for example, carbides, nitrides, oxides, etc.). A solution containing a metal alkoxide and/or a silicon alkoxide is applied onto a substrate by, for example, a dipping method or a spin-coating method, and then heated to convert the metal alkoxide and/or silicon alkoxide into a metal oxide and/or a silicon oxide. A thin film may be formed by a so-called sol-gel method. The thickness of the thin film is determined by the desired height of the fine pattern, but is usually 300~
'There are 1,500 people.

Next, a resist film is formed on the thin film thus obtained, and then a fine resist pattern is formed on the thin film using ordinary photolithography or electron beam lithography.

Next, using this resist pattern as a mask, the thin film is etched by a normal dry or wet etching method, and then the resist pattern is peeled off to form a fine pattern of the thin film on the glass substrate. The shape of this fine pattern is selected as appropriate depending on the shape of the glass molded body to be produced. For example, when the glass molded body to be manufactured is a substrate for an information recording medium such as an optical disk, the fine pattern is formed into a spiral convex shape in order to provide a spiral guide groove to the information recording medium substrate. It must consist of a pattern. Furthermore, when producing a diffraction grating or the like using the glass press-molding mold of the present invention, the shape of the fine pattern is determined in accordance with the shape of these glass molded bodies.

In the glass press molding mold of the present invention, a top layer made of a carbon film is provided on the above-mentioned finely patterned glass substrate as a fusion prevention layer for the glass to be formed. Preferably, this top layer has a thickness of 1 μm or less.

The carbon film constituting the uppermost layer is formed by a sputtering method, a plasma CVD method, a CVD method, a vacuum evaporation method, an ion blating method, or the like.

When forming a carbon film by sputtering, the substrate temperature is 250 to 600°C, and the Rf power density is 5 to 15 W/
i, Vacuum degree during sputtering 5 x 10-4 ~ 5 x 1
It is preferable to perform sputtering using an inert gas such as Ar as a sputtering gas and graphite as a sputtering target in the range of 0'' Torr.

When forming a carbon film by the microwave plasma CVD method, the substrate temperature is 650 to 1000°C, the microwave power is 200 W to IKW, and the gas pressure is 10-2 to 5 Q.
It is preferable to form a film under Torr conditions using methane gas and hydrogen gas as source gases.

When forming a carbon film by a vacuum evaporation method, it is preferable to evaporate the carbon rod by arc discharge in a vacuum.

When forming a carbon film by an ion blating method, it is preferable to ionize benzene gas.

The glass press molding mold of the present invention, which has a finely patterned glass base and an uppermost layer provided thereon, produced in this manner has the following technical advantages.

(2) Thin film patterns on glass substrates can be formed using a pattern forming technique that combines, for example, lithography and etching, making it easier to form thin film patterns compared to microfabrication of platinum-based coating films in the conventional technology described above. Moreover, the formed thin film pattern has excellent dimensions and shape viscosity. In addition, since the top layer on the @ film patterned substrate can be formed by a film forming method with excellent film thickness controllability, such as sputtering or plasma CVD, the pattern formed by the top layer also has dimensional and shape accuracy. It faithfully corresponds to the excellent thin film pattern. Therefore, when a mold having such a fine pattern is used, a glass molded article with excellent dimensional and shape accuracy can be obtained.

The uppermost layer made of a ring carbon film prevents the glass to be formed from being fused to the forming surface of the mold during glass press molding, so that the dimensions, shape, etc. of the resulting glass molded body are not impaired.

The glass press molding mold of the present invention having the above-mentioned technical advantages is applicable to thin glass molded bodies forming fine patterns such as grooves and holes, especially substrates for information recording media such as optical disk substrates, etc.
It is preferably used for $I construction of diffraction gratings, etc.

In the glass press mold of the present invention, an intermediate layer made of silicon carbide and/or silicon nitride film can be provided between the finely patterned glass substrate and the uppermost layer, if necessary. According to studies by the present inventors, this intermediate layer improves the adhesion between the finely patterned glass II and the top layer to prevent peeling of the top layer, and as a result, the top layer is fused. It can function as a prevention layer for a long period of time, prolonging the life of the mold, and is a one-time solution.
It has become clear that technical effects such as the ability to obtain a desired glass molded body without defects can be obtained.

Preferably, this intermediate layer typically has a thickness of less than 1 μI.

This intermediate layer consisting of a silicon carbide and/or silicon nitride film is formed by a method such as a sputtering method, an ion blasting method, a plasma CVD method, a vacuum lid method, or the like.

When forming an intermediate layer made of a silicon carbide film by a sputtering method, the substrate temperature is 250 to 600°C, the Rf power density is 3 to 15 W/cm, and the degree of vacuum during sputtering is 5X.
It is preferable to perform sputtering using the following combination of sputter target and sputter gas in the range of 10' to 5×10 −1 Torr.

Target gas combination■ SiCARr or (Ar+H2)■(S i
c+c> A r or (Ar+H2) ■ S i
(CH4+Ar) Also, in order to form an intermediate layer consisting of a silicon nitride film by sputtering, the substrate temperature must be 25
0 to 600°C, Rf power density 3 to 15 W/cn, degree of vacuum during sputtering 5 x 10' to 5 x 10-1
It is preferable to perform sputtering using the following combination of sputter targets and sputter gases within the range of Torr.

Target gas combination■ Si3N4 Ar or (Ar+N2)■
When forming an intermediate layer consisting of a SiN2 or (Ar+N2) silicon carbide film by the ion blasting method, the 3i ingot is melted and evaporated with an electron beam or the like, and then a hydrocarbon gas such as CHa gas or the hydrocarbon gas is and Ar gas, and the degree of vacuum is 10'T.
Preferably, the silicon carbide film is deposited on a substrate heated to 250 to 600° C. by activation through a glow discharge atmosphere of about 200° C. or more. Note that instead of the glow discharge, the gas and the evaporated metal may be ionized by high frequency or the like.

To form an intermediate layer made of a silicon nitride film by the ion-blating method, a Si ingot is melted and evaporated with an electron beam or the like, then N2 gas or a mixed gas of N2 gas and Ar gas is used to form the intermediate layer, and the degree of vacuum is reduced. Activated through a glow discharge atmosphere of about 10-2 Torr,
Preferably, the silicon nitride film is deposited on a substrate heated to ~600<0>C. Note that instead of the glow discharge, the gas and the evaporated metal may be ionized by high frequency or the like.

When forming the intermediate layer made of silicon III carbide by plasma CVD, DC plasma CVO is used.

Methods such as Rf plasma CVO and microwave plasma CVD are effective. Using silicon tetrachloride, propane, and hydrogen as raw material gases, the base temperature is 700 to 900°C and the pressure is 0.
．． Preferably, the silicon carbide film is deposited on the substrate in the range of 1 to 300 Torr(7).

Similarly, DC plasma CVD is used to form an intermediate layer made of a silicon nitride film using plasma CVD.

Methods such as Rf plasma CVD and microwave plasma CVD are effective, and silicon tetrachloride, ammonia, and hydrogen are used as raw material gases to coat the substrate at a substrate temperature of 700 to 900°C and a pressure of 0.1 to 10 Torr. Preferably, a silicon nitride film is deposited.

When forming an intermediate layer consisting of a silicon carbide film by a vacuum evaporation method, a CO2 laser is applied tangentially to the outer peripheral surface of a silicon carbide sintered body rotating in a chamber evacuated to about 10' Torr. Preferably, the beam is applied at a power density of about 10'W/cj to vaporize the silicon carbide and deposit it on the opposing substrate. In addition, the base temperature is 2
The temperature is 50-600°C. Alternatively, a tablet of silicon carbide sintered body may be placed in a crucible, evaporated by an electron beam, and attached to a substrate heated to 250 to 600°C.

When forming an intermediate layer made of a silicon nitride film by a vacuum evaporation method, a CO2 laser beam is tangentially applied to the outer circumferential surface of a silicon nitride sintered body rotating in a chamber with a vacuum pressure of about 10-4 Torr. It is preferable to irradiate the silicon nitride with a power density of about 10' W/d to vaporize the silicon nitride and deposit it on the opposing substrate. The base temperature is 25
The temperature is 0 to 600°C. In addition, a tablet of silicon nitride sintered body was placed in a crucible and evaporated with an electron beam.
It can also be applied to a substrate heated to 50-600°C.

Note that the intermediate layer may be formed of a mixture of silicon carbide and silicon nitride. Further, part of the intermediate layer can be made of a silicon carbide film, and the rest can be made of a silicon nitride film.

[Example] The present invention will be explained in detail below.

Example 1 An example of a glass press molding apparatus including a mold of the present invention is shown in FIG. In Figure 2, the molds are upper mold 1 and lower mold 2.
and a guide mold 3, and the upper mold 1 and the lower mold 2 are composed of the guide mold 3.
A flat glass gob 4 to be molded is set between the upper mold 1 and the lower mold 2.

As shown in FIG. 1, the upper mold 1 is placed on a glass substrate 5a.
A spiral convex fine pattern 6 is provided, and an uppermost layer 8a is further provided on this fine pattern 6. On the other hand, in the lower mold 2, an uppermost layer 8b is provided on a glass substrate 5b.

The method for manufacturing these upper and lower molds is as follows.

e) Method for manufacturing the upper mold 1 First, as the glass substrate 5a, the raw material composition is 5i02 in rough percentage.
57. O, A120316. O, ZnO6,0, MQO
9.0, B2037.01Na20 1.0. CaO1
,0, BaO1,0, PbO1,0, K2O1,0, glass with a diameter of 89m+ and a height of 2.3#l+ (transition temperature 690℃, coefficient of thermal expansion 38x10'/'C) is precisely processed into an optical A glass substrate 5a with a mirror finish is used, and a thickness of 7.
00 people formed a molybdenum silicide film.

Sputtering conditions Base temperature 200℃ Rf power density 2.5W/cj Vacuum degree (Ar pressure) 10-2Torr target
MOSi2 Next, 3 photoresists (Hoechst Co., Ltd. 11jAZ1350) were applied on this molybdenum silicide film by a spin code method.
After coating the photoresist to a thickness of 0.000 mm and heat-treating it at 90°C for 30 minutes, a latent image is formed on the photoresist by an ultraviolet exposure method using a photomask having a predetermined fine pattern. Special developer (AZ
A resist pattern was formed by developing the film using a developer.

Next, using this resist pattern as a mask, the molybdenum silicide film was dry etched under the following etching conditions.

Etching condition temperature V temperature reaction gas flow fit CF 4 40 secm02
10SCCI11 Reaction gas pressure 0.1 Torr Rf power density 0.5 W/cj Next, the resist pattern is peeled off using sulfuric acid heated to 90°C, and a spiral convex fine structure made of molybdenum silicide film is formed on the glass substrate 5a. Pattern 6 (pitch 1.
A full width of 0.5 μm between 6μ11 patterns and a groove depth of 600 mm) was formed. The obtained fine convex pattern 6 faithfully reproduced the pattern of the photomask used during ultraviolet exposure and had excellent dimensional and shape accuracy.

Next, on the glass substrate 5a with the fine pattern 6, an uppermost layer 8a consisting of a carbon film having a thickness of 500 mm was formed under the following sputtering conditions to complete the production of the upper mold 1.

Sputtering conditions Base temperature: 300°C Rf power density: 9 W/m Vacuum level: 5 x 10-3 Torr Target C The formed top layer 8a has a uniform thickness, and the fine pattern formed by this top layer 8a also has dimensional and shape accuracy. It was excellent.

(f) Method for manufacturing the lower mold 2 The same glass substrate 5a as the glass substrate 5a is used as the glass substrate 5b, and this glass substrate! On top of 85b, a top layer 8 consisting of a carbon film with a thickness of 500 mm is formed under the following sputtering conditions.
b was formed to complete the production of the lower mold 2.

Sputtering conditions Base part 1 300°C Rf power density 9 W / ci Vacuum degree 5
A mold was constructed using a guide mold 3 made of a silicon carbide sintered body, and press molding of glass was performed using the mold as follows. That is, a flat glass lump 4 of alkali-containing aluminosilicate glass (transition temperature 500° C., yield point 562° C., thermal expansion coefficient 91×10′/”C) is placed in the mold as the glass to be formed, and supported. Placed on a rod 9 via a support stand 10, in an N2 atmosphere, the glass gob 4 together with the mold is heated with a heater 12 wound around the outer periphery of a quartz tube 11, and the push rod 13 is lowered to 600°C. Pressing was carried out for 30 seconds at a pressure of 50 Kfl/cm.Then, the pressure was released, and the obtained glass press molded product was slowly cooled to the above transition temperature while in contact with the upper mold 1 and the lower mold 2. The glass press-molded product was then rapidly cooled to around room temperature and taken out from the mold.

In this glass press molded product, the surface shapes of the upper and lower molds are transferred extremely faithfully, and the surface in contact with the upper mold has a spiral 1! Since fine vortices are formed, it is preferably used as an optical disk substrate with guide grooves. Further, this glass press-molded product had no adhesion to the mold, and no defects were observed.

Example 2 As shown in FIG. 3, glass M plates 5a and 5b and the top layer 8
An upper mold 1 and a lower mold 2 in which intermediate layers 7a and 7b were provided between the molds a and 8b were produced as follows.

That is, in producing the upper mold 1, a spiral convex fine pattern 6 with excellent dimensional and shape accuracy was formed on the glass substrate 5a by the same method as in Example 1. Next is a glass base with a spiral convex fine pattern 6! An intermediate layer 7a made of a silicon carbide film having a thickness of 300 mm was formed on 15a under the following sputtering conditions.

Sputtering conditions Base temperature: 300° C. Rf power density: 5 W/d Degree of vacuum: 5 x 10' Torr Target Sac Thereafter, the top layer 8a was formed on the intermediate layer 7a under the same sputtering conditions as in Example 1, and the glass substrate 5a was formed. above,
An upper mold 1 was obtained in which a fine pattern 6, an intermediate layer 7a, and an uppermost layer 1i18a were sequentially provided. This upper mold 1 consists of a fine pattern 6 having excellent dimensions, shape, and viscosity, an intermediate layer 7a, and a top layer 8a.
Since it was formed by a film forming method with excellent film thickness controllability, the pattern formed by the uppermost layer 8a also had excellent dimensional and shape accuracy.

Further, in the production of the lower mold 2, an intermediate layer 7b made of a silicon carbide film having a thickness of 300 mm was formed on the glass substrate 115b under the same sputtering conditions as when the intermediate layer 7a was formed.

Next, the intermediate layer 7b was formed under the same sputtering conditions as in Example 1.
A lower mold 2 was obtained in which the uppermost layer 8b was formed on the glass substrate 5b and the intermediate layer 7b and the uppermost layer 8b were sequentially provided on the glass substrate 5b.

Using the obtained upper mold 1 and lower mold 2, glass was press-molded in the same manner as in Example 1 to obtain a glass press-molded product.

The obtained glass press-molded product has the surface shapes of the upper and lower molds extremely faithfully transferred, and a fine spiral groove is formed on the contact surface with the upper mold, so it can be used as an optical disk substrate with guide grooves. Preferably used.

In addition, this glass press-molded product had no defects and no defects were observed.

When the above-mentioned molding operation was repeated, after about 500 times, the top layer started to show slight roughness.
It has been found that it can be used up to 1000 times. 10
After 00 molding operations, the uppermost carbon film was removed by oxygen plasma ashing, and the intermediate layer was resurfaced by reverse sputtering, and then the uppermost layer was formed again and used for subsequent press molding.

Example 3 A pattern made of Cr1Q was formed as the convex fine pattern 6, an ion blating method was used to form the intermediate layers 7a and 7b, and the uppermost layers 8a and 8
An upper mold 1 and a lower mold 2 having the configuration shown in FIG. 3 were obtained in the same manner as in Example 2 except that the microwave plasma CVD method was used to form b. These manufacturing methods are shown in more detail as follows. That is, upper mold 1 was produced as follows. As a glass material, the raw material composition is S i 0257, 01AI203 in weight%
12.0, ZnO10.0, MQO6.0, CaO10
,0,PbO3,O (transition temperature 730℃
, a coefficient of thermal expansion of 43X10-7/'C), and this glass was heated directly to 1!150 am+.

A Cr film with a thickness of 700 mm was formed on the substrate 5a which had been externally processed to have a thickness of 2.3 mm under the following sputtering conditions.

Sputtering Bonding substrate temperature 200℃ Rf power density 1W/clJ Vacuum degree (Ar pressure) 10'Torr target
Cr Next, after forming a photoresist pattern in the same manner as in Example 1, using this photoresist pattern as a mask,
The r film was wet-etched using a mixed aqueous solution of ceric ammonium nitrate and perchloric acid, and then the photoresist pattern was removed using an organic solvent (methyl cellosolve acetate) to form a Cr film that corresponded to the shape of the glass press-molded product.
A convex fine pattern 6 made of a film was formed.

Next, the glass substrate 5a with the fine pattern 6 obtained above is
An intermediate layer 7a consisting of a 500-layer silicon carbide film was formed thereon by an ion blasting method under the following conditions.

Ion blating conditions Base temperature: 500°C Evaporated gold aS Vacuum degree: 5 x 10-2 Torr Reaction gas: C
Ha+Ar electron beam 10KV, 400-450mA Furthermore, on this intermediate layer 7a, the uppermost N8 consisting of a carbon film of 700
a by a microwave plasma CVD method under the following conditions to form a fine pattern 6 and an intermediate layer 7 on a glass substrate 5a.
A, jl An upper mold 1 having an upper layer 8a was obtained.

Microwave plasma CVD conditions M plate temperature 700°C Raw material gas methane + hydrogen 100 CC/1n methane flux (CHa /CH4+H2) 8101% Microwave power 500W Reaction time 60 minutes Also, the lower mold 2 was prepared using a fine pattern made of 1llll of Cr. A lower mold 2 having an intermediate layer 7b and an uppermost layer 8b on a base plate 5b was obtained by manufacturing the upper mold 1 in the same manner as the upper mold 1 except that the mold 6 was not formed.

Assemble a mold using the obtained upper mold 1 and lower mold 2,
As a result of press-molding glass, a thin glass molded body having a spiral-shaped fine filling was able to be obtained. Further, even after press molding was repeated 1000 times, no change was observed in the mold, and a highly accurate glass molded product could still be obtained.

Example 4 As the material of the base 5a, quartz glass (transition temperature: 120
0° C.), and a molybdenum silicide pattern 6 was formed on this substrate 5a in the same manner as in Example 1.

Next, on this patterned base 115a, an intermediate layer 7a consisting of a silicon nitride film of 800 layers was formed by plasma CVD under the following conditions.

Plasma CVD conditions Raw material gas: silicon tetrachloride, nitrogen, hydrogen Reaction temperature: 800° C. Reaction time: 5 minutes Further, on this intermediate layer 17a, a top layer 8a consisting of an 800-layer carbon film was formed by microwave plasma CVD method under the following conditions. Thus, upper mold 1 was obtained.

Microwave plasma CvD strip base temperature 900℃ Raw material gas methane + hydrogen 150cc/min methane m
Temperature (CHa /CH4+H2) 151101% Microwave power 550 W Reaction time 10 minutes Lower mold 2 was manufactured in the same manner as upper mold 1 except that fine pattern 6 was not formed.

Assemble a mold using the obtained upper mold 1 and lower mold 2,
As a result of press molding the glass, the same results as in Example 3 were obtained.

Example 5! ! As the material of 115a, quartz glass (transition temperature 1
200° C.), and a silicon oxide pattern 6 was formed on this base 15a by the following method.

That is, first, a silicon oxide film with a thickness of 700 mm was formed on the glass substrate 5a under the following sputtering conditions.

Sputtering condition base 24 200'C Rf par'7-'m degree 1.0W/cj Vacuum degree (Ar
pressure) 10-2Torr target 5i
Q2 Next, a photoresist (Hoechst Co., Ltd. 11AZ1350) was coated on this silicon oxide film to a thickness of 3000 mm using a spin coating method, and after heat treatment at 90'C for 30 minutes, a photomask having a predetermined fine pattern was formed. A latent image was formed on the photoresist using an ultraviolet exposure method, and then development was performed using the photoresist exclusive developer (AZ Developed Tuber) to form a resist pattern.

Next, using this resist pattern as a mask, the silicon oxide film was dry etched under the following etching conditions.

Etching conditions Temperature room temperature Reaction gas flow rate CF a 40 sec Reaction gas pressure Q, 1 Torr Rf power density 0.5 W/d Next, the resist pattern is removed using sulfuric acid heated to 90°C, and a silicon oxide film is formed on the glass substrate 5a. A spiral convex fine pattern 6 (pitch 1.6 μm)
, groove width between patterns 0.5μtg, 54 depth 600 people)
was formed. The obtained fine convex pattern 6 faithfully reproduced the pattern of the photomask used during ultraviolet exposure and had excellent dimensional and shape accuracy.

Next, on this WNSa with pattern 6, an intermediate layer 7a made of 800 silicon carbide films was formed by sputtering in the same manner as in Example 2.

Further, on this intermediate layer 7a, a top layer 8a consisting of an 800-layer carbon film was formed in the same manner as in Example 4 by microwave plasma C.
The upper mold 1 was obtained by forming by the VD method.

Further, the lower mold 2 was manufactured in the same manner as the upper mold 1 except that the fine pattern 6 was not formed.

Assemble a mold using the curved upper mold 1 and lower mold 2,
As a result of glass press molding, a highly accurate glass molded body could be obtained.

In Examples 1 to 5, the fine pattern to be transferred was formed on the upper mold, but similar results were obtained even if it was formed on the lower mold.

[Effects of the Invention] As described above, the glass press molding mold of the present invention has the following effects:
It has the following technical effects.

B) Since the molding surface of the mold has a fine pattern with excellent dimensional and shape accuracy, a glass molded article with excellent dimensional and shape accuracy can be obtained.

(b) Since the uppermost layer of the mold is made of a carbon film, the glass to be molded is prevented from being fused to the molding surface, and the quality of the resulting glass molded body is improved.

Further, by providing an intermediate layer between the finely patterned substrate and the uppermost layer as necessary, the problem of the uppermost layer peeling off over time can be solved.

The glass press molding mold of the present invention is particularly preferably used for producing thin glass molded bodies having fine patterns such as grooves and holes, particularly for producing substrates for information recording media such as optical disk substrates.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an upper mold and a lower mold constituting the glass press molding mold of the present invention, FIG. 2 is a diagram showing a glass press molding apparatus including the glass press molding mold of the present invention, and FIG. The figure is a diagram showing another upper mold and a lower mold constituting the glass press molding mold of the present invention. 1... Upper mold, 2... Lower mold, 3... Guide mold, 4...
・Glass lump, 5a, 5b...Glass 1511.6...
- Fine pattern, 7a, 7b...intermediate layer, 8a, 8b
...Top layer, 9...Support rod, 1°...Support stand, 1
1...quartz tube, 12...heater, 13...push rod, 14...thermal lightning pair.

Claims (3)

[Claims] (1) It has a glass substrate provided with a predetermined fine pattern corresponding to the shape of the glass molded body to be manufactured, and a top layer made of a carbon film formed to cover the glass substrate with the fine pattern. A mold for glass press molding characterized by: (2) Glass press molding according to claim (1), wherein an intermediate layer made of silicon carbide and/or silicon nitride film is provided between the finely patterned glass substrate and the uppermost layer made of carbon film. Type. (3) The glass press molding mold according to claim (1) or (2), which is used for producing a thin glass molded body having a fine pattern such as a groove or a hole.