JP3381945B2 - Method of forming fine uneven pattern on substrate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a concavo-convex pattern, and more particularly to a substrate for an optical disk, a glass substrate for a liquid crystal display cell provided with projections for controlling a cell gap, and diffraction. The present invention relates to a method for forming a fine concavo-convex pattern required for a grating, an imaging element, an optical component, and the like. 2. Description of the Related Art Conventionally, as a method of forming a fine uneven pattern on a substrate, for example, an ortho-organic compound in which a functional group having the same number of valences as a metal organic compound is directly bonded to the metal is used. A solution containing polyethylene glycol as a thickener containing silicate is applied on a glass substrate to form a plastic coating film, and a mold having a fine uneven pattern is pressed on the coating film to correspond to the peak shape of the mold. Japanese Patent Application Laid-Open No. Sho 62-10244 discloses a method in which a groove shape is transferred, and thereafter, a coating film on which a concavo-convex pattern is transferred is heated and baked to be solidified.
No. 5, JP-A-62-225273, and JP-A-6-225273.
It is disclosed in JP-A-3-158168. [0003] However, in the above-mentioned prior art method, since a metal organic compound in which functional groups are directly bonded to all metal bonds is used, the temperature of about 300 ° C. By heating and baking, although there is an advantage that the film body having the uneven pattern becomes inorganic amorphous,
Because the solution contains a thickener, the film shrinks due to the heating and baking of the coating film, and the shape of the formed concavo-convex pattern has a smaller concavo-convex depth than that of the mold, and it is difficult to obtain a concavo-convex pattern of a predetermined size. There was a problem. In addition, since the thickener is used, the resulting film is porous, and therefore, has a problem that moisture is easily adsorbed, the refractive index of the film body having irregularities changes, and the film thickness changes. Was. Further, in the method of the prior art described above, the thickness of the film having irregularities is set to 0.
When the thickness is 5 μm or more, cracks occur in the film body, and there is a problem that the film is separated from the substrate, and it is difficult to form an uneven pattern having a depth exceeding 0.5 μm on the substrate. The present invention has been made in order to solve the above problems, and provides a method for forming a concavo-convex pattern with high dimensional accuracy, particularly for forming a fine concavo-convex pattern in which a distance between a convex vertex and a concave bottom is large. The purpose is. [0004] The present invention, on the mold with a substrate and / or fine concavo-solution to form a coating film with a containing a metal organic compound of the following Formula 1 that can hydrolyze, polycondensation, the substrate and a membrane having the form of a concavo-convex pattern the coating film by joining pressing the mold, by thereafter the <br/> type was released from the membrane body, heating the film body on the substrate a polycondensate of the organometallic compound, a method for forming a fine concave-convex pattern on the substrate. Chemical formula 1: X _k M _A R _m M _A : Metal having a valence of 4 X: Polymerizable functional group R: Alkyl or aryl group (k is a natural number, m is an integer of 1 or 2, and k + m = 4) Examples of the metal organic compound include (CH ₃ O) ₃ S
iCH ₃ , (C ₂ H ₅ O) ₃ SiCH ₃ , (CH ₃ O) ₃ Si
_{C 2 H 5, (C 2} H 5 O) 3 SiC 2 H 5, (CH 3 O) 3 Si
C ₆ H ₅ , (C ₂ H ₅ O) ₃ SiC ₆ H ₅ , Cl ₃ SiCH ₃ ,
Cl ₃ SiC ₂ H ₅ , Cl ₃ SiC ₆ H ₅ , (CH ₃ O) ₂ Si
(CH ₃ ) ₂ , Cl ₂ Si (CH ₃ ) ₂ , (CH ₃ O) ₂ Si
(CH ₂ CF ₃ ) ₂ , Cl ₂ Si (CH ₂ CF ₃ ) ₂ , (CH ₃
O) Si (CH ₃ ) ₃ , ClSi (CH ₃ ) ₃ , (CH
₃ O) Si (CH ₂ CF ₃ ) ₃ , ClSi (CH ₂ C
F ₃ ) ₃ , (CH ₃ O) ₂ Si (CH ₂ CF ₃ ) ₂ , Cl ₂ Si
(CH ₂ CF ₃ ) ₂ , (CH ₃ O) ₃ Si (CH ₂ CF ₃ ),
Cl ₃ Si (CH ₂ CF ₃ ), (CH ₃ O) ₃ TiCH ₃ ,
(C ₂ H ₅ O) ₃ TiCH ₃ , (CH ₃ O) ₂ Ti (C
_{H 3) 2, (C 2} H 5 O) 2 Ti (CH 3) 2, Cl 3 TiCH
₃ , Cl ₂ Ti (CH ₃ ) ₂ , (CH ₃ O) ₃ Ti (CH ₂ C
F ₃ ) and Cl ₃ Ti (CH ₂ CF ₃ ). Among them, (CH ₃ O) ₃ SiCH ₃ , (C ₂ H ₅ O) ₃ SiC
_{H 3, (CH 3 O)} 3 SiC 2 H 5, (C 2 H 5 O) 3 SiC 2
_{H 5, (CH 3 O)} 3 SiC 6 H 5, (C 2 H 5 O) 3 SiC 6
_{H 5, Cl 3 SiCH 3,} Cl 3 SiC 2 H 5, Cl 3 SiC 6
Such as H _5, because it is easy organosilicon compound to form a homogeneous film structure represented by the general formula RSiX ₃ preferred. In the solution used in the present invention, in addition to the metal organic compound represented by the above-mentioned chemical formula 1, in order to adjust the optical properties such as the refractive index and the mechanical properties such as the hardness of the film having a concavo-convex pattern. As the second organometallic compound, a metal alcoholate represented by the following chemical formula 2 can be included. [0007] Chemical Formula _{2: M B (OR) n} M B: metal having a valence of n (n is an integer of 1 to 4), OR: alkoxy group, (R is an alkyl group having 1 to 3 carbon atoms) wherein in, the metal _{M B, Si, Ti, Zr} , Ca, A
Metals such as 1, Na, Pb, B, Sn, and Ge can be used, and R of the alkoxyl group can be an alkyl group such as methyl, ethyl, and propyl. Further, a metal chelate complex and —Cl, —COOH, —COOR, —NH ₂ , Such a compound having a functional group may be included as the second metal organic compound. Among them, metal alcoholates of the above formula 2 are preferable, and among them, Si (OCH ₃ ) ₄ , S
i (OC ₂ H ₅ ) ₄ , Ti (OC ₃ H ₇ ) ₄ , Ti (OC
_{4 H 9) 4, Zr (} OC 3 H 7) 4, Zr (OC 4 H 9) 4, A
1 (OC ₃ H ₇ ) ₃ and Al (OC ₄ H ₉ ) ₃ are preferred from the viewpoint of controlling the optical properties such as the refractive index of the obtained film and improving the weather resistance. Further, the ratio of the metal organic compound of Chemical Formula 1 to the total metal organic compound in the solution was 60 mol%.
By setting the content to be less than 100 mol%, a fine uneven pattern having a large distance between the convex top and the concave bottom can be formed by heating to reduce the contraction rate of the film body without greatly reducing the hardness of the obtained film. Can be advanced. Also,
The hardness of the obtained film body can be increased. In particular, in order to form a film having an unevenness of 0.5 μm or more, the metal organic compound represented by the chemical formula 1 and the second metal organic compound are contained in the above solution, and the ratio of the compound represented by the chemical formula 1 is determined by the total metal organic compound. 60 to 80 mol%, more preferably 70 to 80 mol%. The metal organic compound used in the present invention is a solution mixed with an organic solvent such as water and alcohol, and, if necessary, an acid or alkali hydrolysis catalyst. The proportion of the metal organic compound in the entire solution is determined by the viscosity of the solution, the thickness of the film to be formed, and the like.
The content is preferably 20 to 70 mol%. As the substrate that can be used in the present invention, any substrate such as glass, ceramics, metal, plastic, etc. can be used. [0010] The mold used in the present invention is not particularly limited as long as it has resistance to the solvent of the coating solution. Materials such as glass, ceramics, metal, and plastic can be used. In order to improve the releasability between the film body and the mold, a release layer may be provided on the surface of the mold. It is preferable to select a mold material having a coefficient of thermal expansion close to that of a substrate on which a fine uneven pattern is formed on the surface, in order to prevent deterioration in dimensional accuracy of the uneven pattern due to thermal expansion when heating the applied film. The shape of the fine concavo-convex pattern of the mold used in the present invention is, for example, a read-only optical disk (C
0.7 usable as a pit pattern of D-ROM)
An uneven pattern having a width of about μm and a height of about 150 nm, a fine uneven pattern having a width of about 1 μm usable as a guide groove for an optical disk and a depth of 50 to 200 nm, a diffraction grating, and a grating lens Examples thereof include a rectangular or saw-tooth pattern having a depth of several 100 nm to several μm that can be used as a substrate, and a depth of about 10 μm that can be used as a spacer for a liquid crystal display element substrate. The metal organic compound contained in the solution used in the present invention has hydrolytic polycondensation, so that the solution can be applied thickly on the substrate. Further, the alkyl group and the aryl group directly bonded to the metal of the organometallic compound used in the present invention make the coating film flexible and enable the formation of a film having a concavo-convex pattern by molding and screen printing, and the coating. Upon subsequent heating, the film body does not shrink. Therefore, it is not necessary to include a viscosity modifier such as polyethylene glycol in the coating solution, and the dimensional accuracy of the shape of the film having irregularities formed on the substrate can be improved. By the action of imparting flexibility and reducing the amount of shrinkage of this organometallic compound,
A fine concavo-convex pattern having a large distance between the convex top and the concave bottom can be formed on the substrate with high dimensional accuracy. Embodiments of the present invention will be described below with reference to embodiments.
Figure 1 is a partial sectional view of a substrate having a fine concavo-convex pattern obtained by the present invention is formed on the surface, respectively Figure 1 embodiment
FIG. 2 is a partial cross-sectional view of the substrate with a fine concavo-convex pattern obtained in 1 . Example 1 Methyltriethoxysilane (CH ₃ Si (OC ₂ H ₅ ) ₃ )
After weighing 0.05 mol, 0.05 mol of ethanol and 0.2 mol of water (including 0.1 wt% hydrochloric acid (HCl)) were added thereto, and the mixture was stirred at room temperature for 30 minutes to obtain a coating solution 1. And Here, the molar ratio of HCl to methyltriethoxysilane is 0.002. Coating solution 1
Soda-lime glass substrate (100mm x 100mm x 2m
m) was dropped onto the glass substrate, and the coating was formed on the glass substrate by rotating the glass substrate at 1000 rpm.
Next, a resin mold (100 mm × 100 mm × 1 m) having a large number of hemispherical convex patterns having a diameter of 10 μm and a height of 5 μm.
m) and this glass substrate were pressed together in the air to prevent air from entering. Thereafter, heating is performed at 120 ° C. for 10 minutes in this state, and then, the mold and the glass substrate are separated from each other.
For 15 minutes. By this heating and baking operation, the coating film became a methyl group-containing SiO ₂ glass-like film having a film thickness of about 10 μm due to scattering of ethanol, moisture, and the like. A glass substrate having a lens function and having a large number of hemispherical concave patterns formed on the surface is prepared by using S
When observed by EM (scanning electron microscope), the diameter was 10
Many concave patterns having a depth of about 4.5 μm were formed. Similar results were obtained when non-alkali glass and quartz glass were used instead of the soda-lime glass substrate. Example 2 Methyltriethoxysilane (CH ₃ Si (OC ₂ H ₅ ) ₃ )
0.05 mol was weighed, and 0.2 mol of ethanol and 0.2 mol of water (containing 0.1 wt% HCl) were added thereto, and the mixture was stirred at room temperature for 30 minutes. What was added and stirred for 5 minutes was designated as coating solution 2. The molar ratio of HCl to methyltriethoxysilane is 0.002. 4 ml of the coating solution 2 was dropped on a chemically strengthened glass disk substrate (130 mm in outer diameter, 15 mm in inner diameter, 1.2 mm in thickness), and rotated at 800 rpm for 25 seconds in an ethanol atmosphere bath to form a coating film on the substrate. . Next, a pitch of 1.6 μm and a depth of 100 n
m, an optical disk groove pattern having a groove width of 0.5 μm having a radius of 2
A polycarbonate mold having an outer diameter of 130 mm and a thickness of 1.2 mm having a range of 5 mm to 60 mm, and this glass substrate were subjected to 50 kgf / c under reduced pressure of 5 × 10 ⁻⁶ Torr.
Pressing was performed with a pressure of m ² . Thereafter, the glass disk substrate was taken out under atmospheric pressure while being pressed, and heated at 120 ° C. for 10 minutes in a clean oven. Thereafter, the mold and the glass disk substrate were released, and a film body having irregularities was formed. The glass disk substrate was heated at 350 ° C. for 15 minutes. By this heating operation, ethanol and moisture etc. are scattered in the coating film, and a methyl group-containing S
It was an iO ₂ glass-like film. Observation of the glass disk substrate for an optical disk produced by the above operation by STM revealed that a uniform fine groove pattern having a pitch of 1.6 μm, a depth of 90 nm and a peak width of 0.5 μm was formed on the substrate. The obtained substrate sufficiently satisfies the specifications as an optical disk substrate in all of the groove shape uniformity, physical characteristics, mechanical characteristics, and signal characteristics. Instead of using a polycarbonate mold, a fine concave / convex pattern is transferred by using a 2P / epoxy mold prepared by a 2P manufacturing method in which a photoreactive curable resin is developed and exposed between an epoxy substrate and a nickel stamper. Even when the injection-molded polyolefin mold was used, a substrate having good characteristics as an optical disk substrate similar to the above was obtained. Instead of the groove pattern for the optical disk, the pitch is 1.6 μm, the height is 110 nm, and the width is 0.7 μm.
Many fine pit patterns with a radius of 25 mm to 60
outer diameter 130 mm, thickness 1.2 on the surface in the range of mm
A film having irregularities was formed on a glass substrate by using a polycarbonate mold having a thickness of 2 mm. The read-only optical disk using the substrate manufactured by the above operation has a pitch of 1.
A uniform fine pit pattern having a thickness of 6 μm, a depth of 100 nm, and a pit width of 0.7 μm is formed on the substrate, exhibits a low error rate, and has a uniform groove shape, physical characteristics, mechanical characteristics, and signal characteristics. Was sufficiently satisfied. Example 3 Methyltriethoxysilane (CH ₃ Si (OC ₂ H ₅ ) ₃ )
0.04 mol and tetraethoxysilane (Si (OC
₂ H ₅ ) ₄ ) Weigh 0.01 mol of this into 0.05 mol of ethanol and 0.2 mol of water (0.1 wt% HCl).
) And stirred at room temperature for 30 minutes to obtain a coating solution 3. Here, the molar ratio of HCl to the sum of methyltriethoxysilane and tetraethoxysilane is
0.002. Using the coating solution 3, a fine concavo-convex pattern similar to that of Example 1 was formed on the substrate. When a resin mold having a large number of hemispherical convex patterns having a diameter of 10 μm and a height of 5 μm is used, a diameter of 10 μm is used.
m, a concave pattern having a depth of about 4.5 μm was formed on the glass substrate. Example 4 Methyltriethoxysilane (CH ₃ Si (OC ₂ H ₅ ) ₃ )
0.04 mol and tetraethoxysilane (Si (OC
₂ H ₅ ) ₄ ) Weigh 0.01 mol, add 0.2 mol of ethanol and 0.2 mol of water (containing 0.1 wt% HCl), stir at room temperature for 30 minutes, and then What further added 0.2 mol of ethanol and stirred for 5 minutes was set as coating solution 4. Here, the molar ratio of HCl to the sum of methyltriethoxysilane and tetraethoxysilane is
0.002. Using the coating solution 4, the same fine concavo-convex pattern as in Example 2 was formed on the substrate. Pitch 1.6
When a polycarbonate mold having an outer diameter of 130 mm and a thickness of 1.2 mm having a groove pattern for an optical disk having a diameter of 100 μm, a depth of 100 nm, and a groove width of 0.5 μm in a radius of 25 mm to 60 mm is used, the pitch is 1.6 μm and the depth is A uniform fine groove pattern having a thickness of 90 nm and a peak width of 0.5 μm was formed on the glass disk substrate. An outer diameter of 130 mm and a thickness of 1.2 having a number of fine pit patterns having a pitch of 1.6 μm, a height of 110 nm and a width of 0.7 μm in a range of a radius of 25 mm to 60 mm.
When molding was performed using a polycarbonate mold having a pitch of 1.6 μm, a depth of 100 nm, and a pit width of 0.1 mm.
A uniform fine pit pattern of 7 μm was formed on the substrate. By adding tetraethoxysilane to methyltriethoxysilane, the refractive index of the finally obtained film having a concavo-convex pattern was improved. In the above conditions for preparing the coating solution, when 0.01 mol of titanium tetraethoxide or 0.01 mol of zirconium tetraethoxide is added instead of tetraethoxysilane, a substrate having a good fine uneven pattern can be obtained. Was. In both cases where titanium tetraethoxide was added and where zirconium tetraethoxide was added, the refractive index of the film having a concavo-convex pattern finally obtained increased, but the amount of shrinkage before and after heating was small. In Examples 3 and 4 , the metal-organic compound represented by Chemical Formula 2 of tetraethoxysilane, titanium tetramethoxide, zirconium tetramethoxide, titanium tetraethoxide, and zirconium tetraethoxide was replaced by the organic metal compound represented by Chemical Formula 1. When the molar ratio with respect to a certain methyltriethoxysilane is more than 1, it is difficult to make the thickness of the film body having irregularities 10 μm or more. Comparative Example 1 Tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ) 0.05
A mole was weighed, and 0.05 mole of ethanol and 0.1 mole were added thereto.
2 mol of water (containing 0.1 wt% HCl) was added, and the mixture was stirred at room temperature for 30 minutes to obtain a coating solution 5. Here, the molar ratio of HCl to tetraethoxysilane is
0.002. 4 ml of the coating solution 5 was dropped on a soda-lime glass substrate (100 mm × 100 mm × 2 mm), and the substrate was rotated at 1000 rpm to form a coating film on the glass substrate. Next, when the resin mold was pressed against the coating film, cracks occurred in the coating film, and good pattern molding could not be performed. Comparative Example 2 Tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ) 0.05
Weigh 0.2 mol of ethanol and 0.2 mol of
Molar water (containing 0.1 wt% HCl) was added, and the mixture was stirred at room temperature for 30 minutes. Thereafter, 0.2 mol of ethanol was further added, and the mixture was stirred for 5 minutes to obtain a coating solution 6. HC
The molar ratio of 1 to tetraethoxysilane is 0.00
2. 4 ml of the coating solution 6 was dropped on a chemically strengthened glass disk substrate (outer diameter 130 mm, inner diameter 15 mm, thickness 1.2 mm), and 800 rpm in a tank in an ethanol atmosphere.
m for 25 seconds to form a coating film on the substrate. Next, the pitch is 1.6 μm, the depth is 100 nm, and the groove width is 0.5.
μm groove pattern for optical discs with a radius of 25 mm to 60 mm
A mold made of polycarbonate having an outer diameter of 130 mm and a thickness of 1.2 mm in a range of 0.1 mm and a glass substrate having the above-mentioned coating film formed on the surface thereof are reduced to 50 kgf under reduced pressure of 5 × 10 ⁻⁶ Torr.
/ Cm ² . Thereafter, the pressed body was taken out under atmospheric pressure and observed. When the coating film was hard, the pressing between the mold and the coating film was not sufficiently performed, and a film body having a fine uneven pattern could not be formed. Pressing pressure between the mold and the coating film is 50kgf / cm ² to 200kgf / cm
^{Even when the number} was increased to ² , the pressing of the mold and the coating film was not sufficient, and the concavo-convex pattern could not be transferred to the coating film. Comparative Example 3 A coating solution 7 was prepared by adding 3 g of polyethylene glycol to the coating solution 6. Comparative Example 2 Using Coating Solution 7
The same concavo-convex pattern as described above was formed on a glass substrate. When the glass disk substrate for an optical disk manufactured by the above operation was observed with an STM (scanning transmission electron microscope),
A uniform groove pattern having a pitch of 1.6 μm, a depth of 50 nm, and a peak width of 0.5 μm was formed on the substrate. The glass substrate for an optical disc described above satisfies the specifications as a substrate for an optical disc in all of the groove shape uniformity, physical characteristics, mechanical characteristics, and signal characteristics, but the groove depth is about 50 times that of the mold. %
And the shape of the groove was also dull.
Further, the porosity of the film was high, and the amount of adsorbed water was large. According to the present invention, a film having a fine shape and a large surface unevenness can be formed on a substrate. This makes it possible to manufacture an optical disk substrate having a fine concavo-convex pattern on its surface, a substrate with spacers for a liquid crystal display cell, and optical components such as a diffraction grating and an imaging element without forming grooves on the substrate itself.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional view of the substrate obtained in real Example 1. [Description of Signs] 1 ... Film body having fine concavo-convex pattern, 2 ... Glass substrate, 3 ... Substrate with fine concavo-convex pattern

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiki Mitsuhashi 3-5-11 Doshomachi, Chuo-ku, Osaka-shi, Osaka Inside Nippon Sheet Glass Co., Ltd. (56) References JP-A-62-102445 (JP, A) JP-A-63-143978 (JP, A) JP-A-1-194980 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05D 5/06 104 B05D 3/02 B05D 7/24 302 B29C 59/02 G02F 1/1333 500

Claims (1)

(57) [Claim 1] A coating film formed on a substrate and / or a mold having a fine concavo-convex pattern by using a solution containing a metal organic compound of the formula 1 capable of hydrolysis and condensation polymerization. forming a, the coating film by joining pressing the group <br/> plate and the mold and film body having the form of the uneven pattern, and then releasing the mold from the membrane body, on the substrate a polycondensate of the <br/> organometallic compound by heating the film body, a method for forming a fine concave-convex pattern on a substrate, the chemical formula _{1: X k M a R m} M a: atoms metal X of valence of 4: polymerizable functional group R: alkyl group or an aryl group (k is a natural number, m is 1 or 2 as an integer, satisfying a k + m = 4) to the solution, the metal organic compound of formula 2 Further included
Of all metal organic compounds that can be represented by Chemical Formula 1
The case of 60 mol% or more, the chemical formula _{2: M B (OR) n} M B: valency n of the metal (n is an integer of 1 to 4), OR: alkoxy group, (R is a carbon number 1 to 3 Archi
Le group) wherein said chemical formula 2 of the metal M _B forms a fine concavo-convex pattern <br/> substrate, characterized in that is Si.