JP2000231007A - Formation of array pattern with fine recesses and planar lens array, liquid crystal display device and planar oil trap produced by the forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming an array pattern with fine recesses to be used for the production of a microlens array or the like. SOLUTION: In this method, an array pattern having plural fine recesses each in an almost spherical or polygonal shape is one-dimensionally or two- dimensionally arranged on the substrate face of a planar substrate 11. This method includes a process to form an etching-resistant protective layer 12A on the surface of the planar substrate 11, a process to form a desired pattern in the protective layer on the surface of the substrate 11, a first dry etching process to isotropically or anisotropically etch the substrate face of the planar substrate 11 with the protective layer by a dry etching method to form recesses 14A each having the cross section of an almost hemisphere or V-shaped groove on the surface of the planar substrate 11, a process to remove the protective layer 12A on the surface of the planar substrate 11 after the first dry etching process, and a second etching process to etch the whole substrate face of the planar substrate 11 after the protective layer 12A is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to the production of a microlens array for a liquid crystal display element, a liquid crystal display element using the microlens array, or an oil trap used as a mechanical component to improve lubrication performance. A method of forming an array pattern of a plurality of concave microscopic shapes having a substantially spherical or polygonal shape arranged one-dimensionally or two-dimensionally on a substrate surface of a flat substrate, and a method of forming the same The present invention relates to a flat lens array, a liquid crystal display element, and a flat oil trap manufactured by using the method described above.

[0002]

2. Description of the Related Art In a conventional liquid crystal projector, a TFT (TFT) having excellent display quality such as a contrast ratio and a response speed is used.
hin Film Transistor)-LCD (Liquid Crystal Debyc)
e) is adopted. However, in a liquid crystal display element composed of a TFT-LCD, a bus line (space for circuit wiring) must be formed for the TFT-LCD wiring. Therefore, as the definition becomes higher, the aperture ratio (the pixel opening relative to the display area) increases. Area ratio), and the display screen becomes darker. For this reason, there is an inconvenience that the room must be darkened in order to appreciate a large-screen image.

As a method for solving this problem, proposals have been made to increase the brightness of the light source and to use a reflective liquid crystal display panel having a high aperture ratio, but they have not been put to practical use. The only method that has been put into practical use is to arrange a fine lens (microlens) corresponding to each pixel of a TFT-LCD panel to increase the light use efficiency of the light source, and to irradiate the light to the bus line. This is a method in which light is condensed on an opening (pixel) region to effectively improve the aperture ratio and brighten a display pixel. When a microlens array is not used, most of the light incident on the liquid crystal panel is blocked by the black matrix. If a microlens array is introduced on the light incident surface side, light incident on the liquid crystal panel can be collected in the pixel portion, and the amount of light transmitted through the liquid crystal panel can be increased. .

Incidentally, as a method of manufacturing the above-described microlens array for a liquid crystal panel, there are a method of manufacturing a refractive index distribution type lens by an ion exchange method (JP-A-57-53702), a concave lens by a chemical etching method using a solution. There are a manufacturing method (JP-A-5-45624), a convex lens manufacturing method by a dry etching method (see JP-A-1-219702), and the like.

On the other hand, as a method of forming a concave fine shape, in a semiconductor process, a process of manufacturing a groove structure in a thin film deposited on a substrate by using a dry etching method is performed. The purpose of this is to make an electrical wiring circuit pattern by digging vertically. Therefore, the microstructure is not manufactured by etching the substrate itself, nor is the cross-sectional shape after the etching made into a substantially spherical shape or a substantially polygonal shape.

[0006]

Among the above-described microlens manufacturing methods, when a refractive index distribution type lens is manufactured by an ion exchange method, diffusion of ions proceeds during use, resulting in poor environmental resistance. However, there are problems such as deterioration of optical performance, large variation in the substrate, and lack of design freedom such as focal length. In the method of manufacturing a concave lens by chemical etching using a solution, defects occur during chemical etching (the cross-sectional shape becomes elliptical, the mask peels off from the glass substrate during the etching), and the etching becomes non-uniform There is a problem that mirror etching cannot be performed and the glass composition is limited. The method of manufacturing a convex lens by dry etching has a problem that the focal length cannot be shortened when the difference in refractive index between a glass material and a material (such as an adhesive) that is combined with the glass material is small.

The present invention has been made in view of the above circumstances, and aims to solve the above-mentioned drawbacks in the prior art. That is, an object of the present invention is to provide a novel method of forming an array pattern of a concave fine shape applied to the production of a microlens array or the like. In addition, the present invention provides an array-shaped pattern having a concave fine shape that is excellent in environmental resistance, has no variation in a substrate, has a large degree of design freedom such as a focal length, has few defects, and can manufacture a substrate for a microlens array. It is intended to provide a way. Further, the present invention provides a method for forming an array pattern of a concave fine shape having good adhesion between a mask and a glass substrate, a uniform cross-sectional shape, and excellent shape controllability and reproducibility, without any limitation on the glass composition. It is intended to provide. Further, the present invention realizes the production of a high NA double-sided lens by producing a lens substrate by using the above-described method of forming an array of concave fine shapes,
It is an object of the present invention to provide a flat lens array capable of further improving light use efficiency as compared with a conventional lens configuration. In addition, the present invention has a high degree of design freedom by changing the lens shape and depth by manufacturing a lens substrate by using the above-mentioned concave fine shape array pattern forming method because of excellent shape controllability and reproducibility. Accordingly, it is an object of the present invention to provide a flat lens array in which the focal length can be controlled, a spherical surface or an aspherical surface can be arbitrarily manufactured, a mirror surface can be obtained, and the focal length can be shortened. An object of the present invention is to provide a liquid crystal display device having improved light use efficiency by using the flat lens array. Furthermore, in the present invention, a concave shape is produced in a controlled arrangement and structure on the surface of a metal material or a ceramic material by using the above-described method for forming an array pattern of a concave fine shape, thereby forming a structural material for a mechanical component. An object of the present invention is to provide a flat-plate oil trap having an oil trap structure for improving required abrasion resistance on a substrate surface and having improved lubricant holding power.

[0008]

According to the present invention, there is provided a method for forming a plurality of substantially spherical or substantially polygonal concave micropatterned array patterns arranged one-dimensionally or two-dimensionally on a substrate surface of a flat substrate. It is about. Here, the “substantially spherical shape” of the concave fine shape means a shape obtained by cutting a spherical surface having a spherical cross-sectional shape, an elliptical shape, an aspherical shape, a cylinder shape, a toroidal shape, and the like. However, these shapes differ depending on the pattern shape formed on the substrate surface. Further, the “substantially polygonal shape” is a completed shape when the pattern shape formed on the substrate surface is a polygonal shape and is processed into a pyramid shape.

In order to solve the above-mentioned problems, in the present invention, a concave array pattern is formed on the surface of a flat substrate. The material of the flat substrate may be glass, quartz, metal, ceramics, crystalline material, or the like. As a matter of course, a material obtained by bonding glass, quartz, a crystalline material, and a plastic material having different refractive indexes can be used. The steps of forming the concave shape on the surface of the flat substrate material include: (1) forming an etching-resistant protective layer on the surface of the flat substrate;
(2) a step of forming a desired pattern on the protective layer on the substrate surface; and (3) isotropically and / or anisotropically etching the substrate surface of the planar substrate with the protective layer by a dry etching method. A first dry etching step of forming a recess having a substantially semicircular or substantially V-shaped cross section on the substrate surface of the flat substrate; and (4) removing the protective layer on the flat substrate surface after the first dry etching step. Process and (5)
A second etching step of etching the entire surface of the planar substrate after removing the protective layer (claim 1). However, when the target shape can be manufactured in the steps (1) to (3), it goes without saying that the steps (4) and (5) can be omitted.

Here, in the (1) step of forming an etching-resistant protective layer on the surface of a flat substrate, (a) Cr, W, W-Si, W-Ti, Si, Ti
-Si, Ti, Mo, Cu, Fe, Al, Ni, Sn,
Metals such as Pb, or SiO ₂ , TiO, Al ₂ O ₃ ,
Forming a thin film by a dry process such as a sputtering method, a vacuum evaporation method, a CVD method, an ECR film forming method, or a plating method using a ceramic such as ITO as a thin film material, and / or (b) photosensitivity A thin film is formed from an organic substance such as a polymer material (claim 2).

In the above step (1), after forming an etching-resistant protective layer of a metal or ceramic material on the surface of the planar substrate material, (2) forming a desired pattern on the protective layer on the substrate surface (A) After applying and patterning a photosensitive polymer material on the metal or ceramic material protective layer, wet etching or dry etching of the protective layer is performed using the pattern of the photosensitive polymer material as a mask. A pattern forming method of patterning by etching (claim 3), or (b) forming a photosensitive polymer material as the protective layer, patterning the photosensitive polymer material, and using this pattern as it is. A desired fine pattern can be formed by using the following pattern forming method (Claim 4). As another pattern formation method, (c) a step of forming an etching-resistant protective layer on the surface of a planar substrate material and a step of forming a desired pattern on the protective layer on the substrate surface are simultaneously performed,
A mask having a desired pattern was placed on a flat substrate on which a pattern was to be formed via a spacer, and a material constituting the pattern was deposited from above the mask through an opening hole on the surface of the substrate by a vacuum film forming method. Thereafter, the spacer and the mask are removed to form a thin film pattern having a film thickness distribution larger than the inner diameter of the opening hole, and (d) etching resistance is applied to the surface of the planar substrate material. The step of forming a protective layer having a conductive property and the step of forming a desired pattern on the protective layer on the surface of the substrate at the same time to form a photosensitive polymer material or an organic / inorganic material on a flat substrate on which a pattern is to be formed. Paint or the like directly on a flat substrate or through a mask according to a pre-programmed signal using the ink jet method or the like. Pattern in a portion where the protective film by applying a drop by drop is not coated with the coating portions - pattern forming method (claim 6) training, it is possible to form a desired fine pattern using.

(3) In the first dry etching step of forming a recess having a substantially semicircular or V-groove cross section on the flat substrate surface by dry etching such as reactive ion etching on the substrate with a protective layer, This is a step of etching isotropically and / or anisotropically. (A) By changing the etching conditions continuously and / or stepwise with time according to the etching time, By changing the mixing ratio of ions, radicals, and neutral particles, the ratio of the isotropic etching component to the anisotropic etching component, that is, the ratio of the etching rates of both components, is continuously and / or discontinuously changed. (B) etching isotropically and / or anisotropically by changing over time, and (b) etching conditions to change are Continuous and / or discontinuous over time by controlling the type, mixing ratio, partial pressure, introduction amount, reaction chamber pressure, plasma density, substrate bias power, substrate temperature, etc. of the reactive gas for etching the layer (C) that the concave portion having a substantially semicircular cross section formed on the plane substrate surface is controlled to have a controlled spherical or aspherical shape; and (d) formed on the plane substrate surface. The shape of the present invention can be formed by controlling the shape of a concave portion having a substantially semicircular or V-shaped cross section so that the ridge line is formed of a straight line or a curved surface (claim 7).

(4) The step of removing the protective layer on the surface of the flat substrate after the first dry etching step is a step of removing the protective layer by isotropically and / or anisotropically etching, and is a wet etching method. May be removed by dry etching, or may be removed by wet etching.When removing by wet etching, immersion in a solution that dissolves each protective film, and when removing by dry etching, ,
The removal of the protective film can be controlled by controlling the type, mixing ratio, partial pressure, introduction amount, reaction chamber pressure, plasma density, substrate bias power, substrate temperature, etc. of the reactive gas for etching the protective film ( Claim 8).

(5) The second etching step of etching the entire substrate surface of the flat substrate after removing the protective layer is a step of etching the substrate isotropically and / or anisotropically. The condition is changed isotropically and / or anisotropically by changing the condition continuously and / or stepwise with time according to the etching time. Type of reactive gas, mixing ratio, partial pressure,
By controlling the amount of introduction, pressure in the reaction chamber, plasma density, substrate bias power, substrate temperature, etc., continuously and / or
Alternatively, it is possible to create the final shape of the present invention by changing it with time discontinuously (claim 9).

The recesses having a substantially semicircular or V-groove cross section manufactured through the above steps (1) to (5) control the gap between adjacent patterns. )
Controlling the arrangement to the same size as the gap when the desired pattern is formed; or (b) controlling the arrangement to be wider than the gap when the desired pattern is formed; or (c).
Adjacent arrangement control can be achieved without any gap (claim 10).

Further, by forming concave and fine array-shaped patterns manufactured through the above-described steps (1) to (5) on both surfaces of a flat substrate, a light refracting surface having an optical function can be formed on both surfaces. Excellent optical performance (high NA)
(Improvement of lens performance) A lens can be obtained, and a portion formed in a concave conical shape or a concave polygonal pyramid shape is filled with a transparent substance having a refractive index larger than the refractive index of the substrate material. The light incident on the surface of is collected at the vertex of each concave pyramid while being totally reflected at the interface,
Each vertex becomes like a point light source, and the light emitted from the microlens becomes parallel light by the combination of the microlenses, so that the viewing angle characteristics in the reflective optical element are improved,
An optical element capable of improving light use efficiency can be obtained (claim 11).

As described above, the constituent material of the flat substrate is glass, quartz, metal, ceramics, a crystalline material, or a material obtained by bonding a plurality of glasses, quartz, crystalline materials, and plastic materials having different refractive indices. Can be used (claim 12). In addition, when a material in which a plurality of glasses having different refractive indexes, quartz, a crystalline material, and a plastic material are joined as a constituent material of the flat substrate,
The bonding of the plurality of substrate materials includes bonding using an adhesive,
It can be joined or welded by electrochemical joining (claim 13).

By manufacturing a lens substrate using a transparent flat substrate such as a glass substrate by the method for forming an array pattern having a concave fine shape described above, a transparent flat substrate having an array pattern having a concave fine shape is formed. And a lens array formed as a convex or lenticular lens by filling a concave portion of the array pattern of the planar substrate with a transparent resin having a higher refractive index than the substrate, wherein the lens array has a concave portion filled with resin. A resin layer continuous with the portion, the surface of the resin layer facing the lens surface is flat, and the resin layer has a thickness such that parallel light rays incident from the glass substrate converge near the resin layer surface. Can be manufactured (claim 14).

In the above-mentioned flat lens array,
Placing a film sheet with a smooth surface on the resin layer,
Alternatively, a thin glass plate provided with an inorganic layer and / or an organic layer made of an adhesive or adhesion reinforcing material, which is heated and cured after applying an inorganic material containing a glass component or the like on the surface in advance, and further disposed on a flat substrate Manufactures a flat lens array with a thickness-adjusting spacer arranged so that the resin layer has a thickness so that the parallel rays incident from the substrate on the unetched portion from the substrate are focused near the resin layer surface. (Claim 15). In this case, as a smooth film sheet or a thin glass plate on the resin layer,
A thin film sheet or a smooth film sheet whose thickness is adjusted so that the light is condensed in the vicinity of the surface of the glass sheet or the glass plate can be used.

Further, according to the present invention, there is provided a flat film sheet or a thin glass plate surface having the above-mentioned flat lens array, the thickness of which is adjusted so that light of the flat lens array is focused. Has a second substrate on which a black matrix and / or a transparent electrode is formed and on which a pixel electrode of p-Si, TFT type is formed.
A liquid crystal display device having a structure in which a liquid crystal is sandwiched between a substrate and a transparent electrode can be manufactured.

In the flat lens array and the liquid crystal display element according to the present invention, the optical path length and the focal length are adjusted by disposing a resin layer, a film sheet, a thin glass plate and the like on the substrate surface of the lens substrate.

Further, in the present invention, by applying the above-described method of forming an array pattern of concave fine shapes, an array of regularly controlled concave fine shapes manufactured on a metal or ceramic substrate by the above-described forming method is applied. It is composed of a member having a pattern, and by filling the concave portion of the array-shaped pattern of the member with a lubricant, the supply and holding of the lubricant to a mechanical sliding portion between the member and a mating member forming a pair can be performed. A flat type oil trap characterized in that the friction force is reduced can be manufactured (claim 18).

As described above, the substrate manufactured by the method of forming an array pattern of concave fine shapes according to the present invention has a concave fine shape that is regularly controlled, and thus has excellent environmental resistance. Low in-substrate variation, large design freedom, few defects, controllable shape such as spherical / aspherical surface, uniform cross-sectional shape, unlimited glass composition, high-NA double-sided lens performance In addition, it is possible to supply a device substrate with a microlens having excellent shape controllability and reproducibility.

As described above, the "flat lens array" of the present invention is an optical element designed in accordance with the configuration of the liquid crystal display element, and has a high degree of freedom in selecting the constituent material of the microlens. Further, the optical performance of the lens is simulated by the configuration of the liquid crystal display element, a lens having a dense structure conforming to the simulation is manufactured, and a micro optical element for condensing light on each device pixel can be provided. Also, by using the flat lens array of the present invention for a liquid crystal display device, a liquid crystal display device with improved light use efficiency can be manufactured.

Further, since the substrate manufactured by the method of forming an array pattern of concave fine shapes according to the present invention has a large number of fine concave portions arranged in an array, lubricant is applied to the concave portions of the substrate. By filling, the lubricant is supplied and held to the mechanically sliding part with the mating part forming a pair, and the frictional force can be reduced, so that a flat oil trap is manufactured. Can be.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a view showing an embodiment of the present invention, in which a manufacturing process for manufacturing a flat lens array using the method for forming an array pattern having a concave fine shape according to the present invention. FIG. 2 and 3 correspond to FIG.
FIG. 4 is an enlarged view showing a main part of the substrate during a manufacturing process of FIG. First, a quartz substrate 11 is used as a planar substrate.
A Cr film was formed as a plasma etching resistant protective film 12A on the surface of the substrate by sputtering. Of course, the effect is the same with an Al film. Next, the positive photosensitive polymer material 12B is coated, exposed, developed, and rinsed to form an array pattern with small openings. At this time, it is desirable that the pattern of the mask or reticle to be exposed has a pitch of the target lens array, and the opening diameter is sufficiently smaller than the diameter of the lens to be finally obtained. In this embodiment, the pitch of the target array is 100 μm, the formed small opening array is a lattice-like array, and the opening diameter is 60 μm.
m. As a result, an array pattern of grid-like small openings made of the photosensitive polymer material 12B is obtained (FIG. 1).
(A)). Next, the substrate 11 with the Cr protective film having the small opening array pattern is immersed in a commercially available Cr wet etchant, and the portion of the Cr protective film not covered with the photosensitive polymer material 12B is dissolved by etching. A small opening 13 reaching the substrate surface is formed (FIG. 1B, FIG. 2).
(A)). After etching, the photosensitive polymer material 12B
May or may not be stripped (has no substantial effect on subsequent processes). If not peeled, use Cr
The film 12A and the photosensitive polymer material 12B form a pattern of the protective film 12 (FIG. 1 shows an example of peeling, and FIG. 2 shows an example of no peeling).

Next, the substrate 11 was set in a reactive ion etching apparatus, and dry etching was performed.
As the etching method, there are (a) isotropic etching and (b) anisotropic etching having etching characteristics as shown in FIG. 4, and in the present invention, both are appropriately selected and performed. In this embodiment, an RIE etching apparatus is used, and CF ₄ , C ₄
A mixed gas of F ₈ , Ar and SF ₆ was used. The pressure of the etching apparatus is 5 to 50 mTorr, and the RF power is 50 watts.
Performed at １1 Kw. The etching conditions are as follows: (1) Initial: 5 mToor, Ar: SF ₆ = 1: 10 mixed gas, RF power-500 w, end: 20 mToor, Ar: SF ₆ = 1: 20 mixed gas, RF power-1 Kw, 5 minutes. (2) Initial: 20 mToor, mixed gas of Ar: CF ₄ : SF ₆ = 1: 5: 5, RF power-1 Kw End: 50 mToor, mixed gas of Ar: CF ₄ : SF ₆ = 1: 10: 5, RF Power-500w for 10 minutes. (3) From beginning to end: 50 mTool, Ar: CF ₄ : C ₄ F ₈ : SF ₆ = 1: 5: 5: 5 mixed gas, RF power-500 w, 20 minutes.

When etching is performed under the above conditions, (1)
In (2), side etching is performed in the horizontal direction parallel to the substrate surface (under these conditions, the pressure is high, and the CF ₄ gas is introduced. Also, the etching rate in the horizontal direction is large, and the bottom surface has a larger opening diameter than the pattern formed relatively flat.) In (3), isotropic etching is performed on the substrate surface (under these conditions). In this case, since the pressure is higher, the etching rates in the vertical and horizontal directions are almost equal, and the bottom surface is etched relatively concentrically.)
FIG. 5 shows an example of the general relationship between the cross-sectional shape of dry etching and pressure. Further, when the etching conditions are controlled, the cross-sectional shape differs. In the present invention, the shape is controlled by the gas type, pressure, introduced power condition, partial pressure, process, and the like. (1) to (3) steps can creating a spherical concave 14A radius of curvature r having a large opening diameter D ₁ than the small opening diameter d Through the (FIG. 1 (c), the
(D), FIG. 2 (b)).

Under the above conditions, an array pattern of a concave fine shape having a diameter of 80 μm is formed, and each concave portion can be a concave microlens. However, under the above conditions, a gap of 20 μm (space) was formed between the recesses on the substrate surface 11A.
Su) remains. A space may remain in a microlens array used in the optical communication field or the like, but in a liquid crystal field, it is better not to leave the space because light utilization efficiency is reduced. Therefore, the Cr remaining on the substrate surface 11A
In order to remove the mask pattern by the protective film 12A, R
Cl ₂ gas was introduced into the IE apparatus to perform selective etching. By this operation, the Cr film on the substrate can be removed without opening the apparatus (FIGS. 2C and 3A). Then, under the condition (3), isotropic etching is performed for 2 hours.
When the process was performed for 0 minutes, a substantially spherical concave microlens 14 having an opening diameter D ₂ and a curvature radius R could be formed, and a concave microlens array could be obtained (FIGS. 1E and 2D).
In this example, a flat lens array having a concave microlens array having a diameter of 100 μm and a depth of 20 μm was manufactured. Further, by filling a concave portion formed in the substrate 11 with a transparent resin 16 having a higher refractive index than that of the substrate material, a flat lens array having a convex or lenticular lens in the lens portion is manufactured (FIG. 1F). , FIG. 2
(E))

Further, by further etching the substrate surface side 15, the space between the lenses 18 can be completely eliminated as shown in FIG. 3B. Further, the radius of curvature R of the concave microlens can be increased by this etching. Of course, it is needless to say that the opening ratio of the conductance valve is controlled in order to control the desired shape, and the RF power is controlled with time in order to control the plasma density. These control methods can be theoretically determined to some extent, but ultimately determine the conditions by experiment. Specifically, the above (1) to
Under the condition (3), a program for reducing the substrate bias every 10 seconds and increasing the pressure every 10 seconds is manufactured and controlled. The above conditions enable the creation of a concave shape with a curvature R. Further, it is needless to say that an aspherical shape can be created at the time of etching under the condition (3) by controlling the wound shape under the conditions (1) and (2).

(Embodiment 2) FIG. 6 is a view showing another embodiment of the present invention. FIG. 6 is a view showing a process of manufacturing a flat lens array using the method of forming an array pattern of a concave fine shape according to the present invention. It is a figure showing a process. The form of the concave fine shape at the time of etching is the same as that of FIG. First, a quartz substrate 21 was used as a planar substrate, and a W-Ti film was formed on the surface of the quartz substrate as a plasma etching-resistant protective film 22A by sputtering at a thickness of 3000 Å by sputtering. Next, a positive photosensitive polymer material 22B is applied, exposed, developed, and rinsed to form an array pattern with small openings (FIG. 6A).
At this time, the pattern of the mask or reticle to be exposed is
It is desirable to have the pitch of the target lens array arrangement and the aperture diameter is sufficiently smaller than the diameter of the lens finally obtained. In this embodiment, the pitch of the target array is 26 μm, and the formed small aperture array is a grid-like array with an aperture diameter of 16 μm. Thus, an array pattern of small openings made of the photosensitive polymer material 22B for forming a grid-like microlens array for a 1.3 ″ XGA liquid crystal projector can be obtained.

As shown in FIG. 6A, a convex microlens array 25 manufactured at the same pitch in advance is formed on the opposite surface of the substrate 21. Registration marks (not shown) for front / back alignment are manufactured on the microlens array surface formed first. The array pattern made of the photosensitive polymer material 22B is positioned so as to be aligned with the registration marks on the front and back.

Substrate 21 with W-Ti film having small aperture array pattern made of photosensitive polymer material 22B
Is dry-etched by using a pattern of the photosensitive polymer material 22B as a mask and using a mixed gas of Ar and SF _{6 in} an ECR apparatus using a pattern not covered with the photosensitive polymer material. Then, the portion of the W-Ti protective film 22A which is not covered with the mask of the photosensitive polymer material 22B is selectively etched to eliminate the thin film, and an array pattern of the small openings 23 reaching the substrate surface 21A is obtained. Note that the remaining photosensitive polymer material may or may not be peeled off (there is no substantial effect on subsequent processes).

Next, the substrate 21 was set in a plasma etching apparatus, and dry etching was performed. As the etching method, isotropic etching and anisotropic etching are appropriately selected and performed as in the first embodiment. In this embodiment, an ECR etching apparatus was used, and a mixed gas of CF ₄ , C ₄ F ₈ , and Ar was used as a reactive etching gas in this apparatus. The pressure of the etching apparatus is 0.1-30.
The measurement was performed with mToor at a substrate bias of 50 w to 1 Kw, a microwave power of w, and a coil current of A. The etching conditions are as follows: (1) Initial: 0.5 mTorr, Ar: CF ₄ : C ₄ F ₈ = 1: 5: 5 mixed gas, substrate bias 1 Kw, end: 5 mTorr, Ar: CF ₄ : C ₄ F ₈ = 1: 5: 5 mixed gas, substrate bias 500w, 5 minutes. (2) _{First: 5mToor, Ar: CF 4:} C 4 F 8 = 1: 5: mixed gas of 5, substrate bias 500 w, _{End: 50mToor, Ar: CF 4:} C 4 F 8 = 1: 5: 10 of 10 minutes with mixed gas, substrate bias 500w. (3) Beginning to end: 50 mTorr, Ar: CF ₄ : C ₄ F ₈ = 1: 5: 10 mixed gas, substrate bias 500 w, 20 minutes.

When etching is performed under the above conditions, (1)
In (2), side etching is performed in the horizontal direction parallel to the substrate surface (under this condition, the pressure is high, so that the vertical direction is faster than the horizontal etching rate because of the higher pressure. And the bottom surface has a larger opening diameter than the pattern formed relatively flat), (3)
In this case, isotropic etching is performed on the substrate surface (under this condition, since the pressure is very high, the etching rates in the vertical and horizontal directions are almost equal, and the bottom surface is etched concentrically. And the etching rate is relatively slow). By controlling the etching conditions, the cross-sectional shape changes. In the present invention, the shape is controlled by the gas type, pressure, introduced power condition, partial pressure, process, and the like. Through the steps (1) to (3), a spherical concave shape 24A having an opening diameter larger than the small opening diameter of the array pattern formed by the protective film 22A can be created (FIG. 6).
(C), (d)).

Under the above conditions, a spherical concave shape 24A having a diameter of 20 μm is formed, and a concave microlens array is obtained. However, under the above conditions, a space of 6 μm was set between the lenses.
Are left. In the liquid crystal field, it is better not to leave the space because the light use efficiency is reduced. Therefore, mask pattern by W-Ti protective film that remained on the substrate surface 21A - to remove emissions were selectively etched by introducing a Cl ₂ gas into the ECR apparatus. By this operation, the W-Ti film 22A on the substrate 21 can be removed without opening the device. Next, when isotropic etching was performed for 20 minutes under the condition (3), a substantially spherical concave portion 24 having an increased radius of curvature was formed, and a concave microlens array could be obtained (FIG. 7). 6 (e)). In this embodiment, a concave microlens array having a diameter of the opening of 26 μm and a depth of 7 μm was manufactured. In this embodiment, since the convex microlenses 25 are formed on one side of the substrate 21 in advance, a flat lens array having microlens arrays on both sides can be manufactured. Also, by filling the concave portion 24 formed in the substrate 21 with a transparent resin 26 having a higher refractive index than the material of the substrate, a flat lens array in which the micro lens arrays on both surfaces are convex or lenticular lenses can be manufactured (FIG. 6). (F))

As is well known, the opening rate of the conductance valve is controlled in order to control the desired shape, and the microwave, coil current, and RF power are controlled over time to control the plasma density. Needless to control. These control methods can be theoretically determined to some extent, but ultimately determine the conditions by experiment. Specifically, under the conditions (1) to (3), a program for reducing the substrate bias every 10 seconds and increasing the pressure every 10 seconds is manufactured and controlled. According to the above conditions,
It is possible to create a concave shape with a curvature R. Also, (1),
By controlling the shape of the wound under the condition (2),
At the time of etching under the condition (3), it goes without saying that an aspherical shape can be created.

(Embodiment 3) FIG. 7 is a view showing another embodiment of the present invention. FIG. 7 shows a method of manufacturing a flat lens array by using the method of forming an array of concave fine shapes according to the present invention. It is a figure showing a process. The form of the concave fine shape at the time of etching is the same as that of FIG. First, after a positive photosensitive polymer material is applied as a protective layer 32 to a quartz substrate 31 which is a flat substrate, a mask (or reticle) 37 is used.
Is exposed to the photosensitive polymer material 32 (FIG. 7).
(A)), the mask 37 is removed, and development and rinsing are performed. At this time, the pattern of the mask (or reticle) 37 to be exposed has the pitch of the target lens array, and the opening diameter is sufficiently smaller than the diameter of the lens finally obtained. desirable. In this embodiment, the pitch of the target array is 26 μm, and the formed small aperture array is a grid-like array with an aperture diameter of 16 μm. As a result, an array pattern of minute openings made of the photosensitive polymer material 32 for forming a grid-like microlens array for a 1.3 ″ XGA liquid crystal projector is obtained (FIG. 7).
(B)).

A convex microlens array 35 manufactured at the same pitch is formed on the opposite surface of the substrate 31 in advance. Registration marks (not shown) for front / back alignment are manufactured on the microlens array surface formed first. The array pattern of the minute openings is positioned so as to be aligned with the registration marks on the front and back.

The substrate 31 with the photosensitive polymer material having the array pattern of the small openings is replaced with the photosensitive polymer material 32.
Is used as a mask for dry etching. That is, the substrate 31 was set in a plasma etching apparatus and dry etching was performed. As the etching method, isotropic etching and anisotropic etching are appropriately selected and performed as in the first embodiment. In this embodiment, an ECR etching apparatus is used, and C is used as a reactive etching gas.
A mixed gas of F ₄ , CHF ₃ , O ₂ , and Ar was used. The pressure of the etching apparatus was 0.1 to 30 mTorr, the substrate bias was 50 w to 1 Kw, the microwave power was w, and the coil current was A. The etching conditions are as follows: (1) Initial: 0.5 mTool, mixed gas of Ar: CF ₄ : CHF ₃ = 1: 5: 5, substrate bias 1 Kw, end: 3 mTool, Ar: CF ₄ : CHF ₃ = 1: 5 : 5 minutes with a mixed gas of 5 and a substrate bias of 500 w. (2) _{First: 3mToor, Ar: CF 4:} CHF 3 = 1: 5: mixed gas of 5, substrate bias 500 w, _{End: 10mToor, Ar: CF 4:} CHF 3 = 1: 10: mixed gas of 5, substrate 10 minutes at a bias of 500 w. (3) Initial: 10 mToor, Ar: CF ₄ : CHF ₃ : O ₂ = 1: 10: 5: 0 mixed gas, substrate bias 300 w, end: 10 mToor, Ar: CF ₄ : CHF ₃ : O ₂ = 1: 20 minutes with a mixed gas of 10: 5: 0.5 and a substrate bias of 300 w.

When etching is performed under the above conditions, (1)
In (2), side etching is performed in the lateral direction parallel to the substrate surface (under this condition, the pressure is relatively high, so the vertical etching is more in the vertical direction). Larger than the speed, and the bottom has a larger opening diameter than the pattern formed relatively flat),
In (3), isotropic etching is performed on the substrate surface (under this condition, since the pressure is high, the etching rates in the vertical and horizontal directions are substantially equal, and the bottom surface is etched concentrically. However, the etching rate is relatively slow). By controlling the etching conditions, the cross-sectional shape changes. In the present invention, the shape is controlled by the gas type, pressure, introduced power condition, partial pressure, process, and the like. Through the steps (1) to (3), a spherical concave shape 34A having an opening diameter larger than the small opening diameter of the mask of the photosensitive polymer material 32 can be created (FIG. 7).
(C), (d)). At this time, the photosensitive polymer material 32 gradually disappears due to the gradual introduction of O _{2 in} (3). When the isotropic etching is performed for 10 minutes under the condition (3) after the process (3), a substantially spherical concave portion 34 having an increased radius of curvature is formed, and the concave microlens array is formed. Was obtained (FIG. 7 (e)). In this embodiment, the diameter of the opening is 26 μm and the depth is 10.5.
A μm concave microlens array was produced. In this embodiment, since the convex microlenses 35 are formed on one side of the substrate 31 in advance, a flat lens array having microlens arrays on both sides can be manufactured. Further, by filling a concave portion 34 formed in the substrate 31 with a transparent resin 36 having a higher refractive index than that of the substrate material, a flat lens array in which the micro lens arrays on both sides are convex or lenticular lenses can be manufactured (FIG. 7). (F))

As is well known, to control the target shape, the opening rate of the conductance valve is controlled, and to control the plasma density, the microwave, coil current, and RF power are changed over time. Needless to control. These control methods can be theoretically determined to some extent, but ultimately determine the conditions by experiment. Specifically, under the conditions (1) to (3), a program for reducing the substrate bias every 10 seconds and increasing the pressure every 10 seconds is manufactured and controlled. According to the above conditions,
It is possible to create a concave shape with a curvature R. Also, (1),
By controlling the shape of the wound under the condition (2),
At the time of etching under the condition (3), it goes without saying that an aspherical shape can be created.

(Embodiment 4) Next, still another embodiment of the manufacturing process of the flat lens array according to the present invention will be described. In the present embodiment, an example in which the formation of a protective film and the formation of a pattern on a flat substrate are performed at the same time is shown. The etching process after the formation of an array pattern with small openings is substantially the same as that in the first embodiment. FIG. 8 is an explanatory view of a spacer and a mask used for pattern formation, and FIG. 9 is an explanatory view of a step of simultaneously forming a protective film and forming a pattern. As shown in FIG.
A 15 μm spacer 52 is arranged on a peripheral portion of a low expansion glass (Neoceram, N-0) substrate 51 which is a flat substrate, and a desired cylinder-shaped opening 54 is formed on the spacer 52 in a one-dimensional arrangement in a cylinder arrangement pitch: A mask 53 of 250 μm, opening diameter: 50 μm, made of a microhoming-processed Ni or SUS plate and having a thickness of 30 μm was arranged. At this time, a gap 55 corresponding to the thickness of the spacer 52 is formed between the mask 53 and the substrate surface. In order to perform more accurate patterning, as shown in FIG.
The spacer 57 may be arranged so as to surround the opening 54 of the mask 53.

In this embodiment, the one set as shown in FIG. 8A was set as one component in a vacuum deposition machine (FIG. 9A). After that, vacuuming was performed by a normal predetermined operation, and an Al—Si—Cu film was formed by a sputtering method (FIG. 9B). After the film formation, the mask 53
By removing the spacer 52 and the one-dimensional array, the arrangement pitch: 250 μm, the Al—Si—Cu film width: 50 μm
A small opening pattern having a cylinder structure of m can be manufactured (FIG. 9C). At this time, it is desirable that the vapor deposition pattern to be formed has a pitch of the target arrangement of the lens array, and the opening diameter is sufficiently smaller than the diameter of the lens finally obtained. In this embodiment, the pitch of the target array is
The small aperture array formed was a grid-like array and the aperture diameter was 50 μm. As a result, a cylindrical small opening pattern is obtained. After the formation of the small opening pattern, an etching step similar to the steps of FIGS. 1C to 1E is performed.

The substrate 41 having the Al-Si-Cu film having the small opening is dry-etched using the Al-Si-Cu film as a mask. That is, the substrate was set in a plasma etching apparatus and dry etching was performed.
In this embodiment, an ECR etching apparatus is used, and CF ₄ , CHF ₃ , and SF are used as reactive etching gases in this apparatus.
A mixed gas of ₆ and Ar was used. The pressure of the etching apparatus is 0.1 to 30 mTorr and the substrate bias is 50 w
The test was performed at 1 Kw, microwave power: w, and coil current: A. The etching conditions are as follows: (1) Initial: 0.5 mTool, mixed gas of Ar: CF ₄ : CHF ₃ = 1: 5: 5, substrate bias 1 Kw, end: 3 mTool, Ar: CF ₄ : CHF ₃ = 1: 5 : 5 minutes with a mixed gas of 5 and a substrate bias of 500 w. (2) _{First: 3mToor, Ar: CF 4:} CHF 3 = 1: 5: mixed gas of 5, substrate bias 500 w, _{End: 10mToor, Ar: CF 4:} CHF 3 = 1: 10: mixed gas of 5, substrate 10 minutes at a bias of 500 w. (3) Initial: 10 mTool, Ar: CF ₄ : CHF ₃ : SF ₆ = 1: 10: 5: 1 mixed gas, substrate bias 300 w, end: 10 mTool, Ar: CF ₄ : CHF ₃ : SF ₆ = 1: 20 minutes with 10: 5: 5 mixed gas, substrate bias 300w.

When etching is performed under the above conditions, (1)
In (2), side etching is performed in the lateral direction parallel to the substrate surface (under this condition, the pressure is relatively high, so the vertical etching is more in the vertical direction). The opening diameter is larger than the speed, and the opening diameter is larger than the pattern formed with a relatively flat bottom.)
In (3), isotropic etching is performed on the substrate surface (under this condition, since the pressure is high, the etching rates in the vertical and horizontal directions are substantially equal, and the bottom surface is etched concentrically. However, the etching rate is relatively slow). By controlling the etching conditions, the cross-sectional shape changes. In the present invention, the shape is controlled by the gas type, pressure, introduced power condition, partial pressure, process, and the like. By performing the above steps (1) to (3), FIG.
An aspherical concave shape having an opening diameter larger than the small opening diameter similar to (d) could be created.

Under the above conditions, a concave microlens having a diameter of 220 μm is formed. However, under the above conditions, a gap (space) of 30 μm remains between the concave portions. A space may remain in a microlens array in the optical communication field or the like. However, the Al-Si-C remaining on the substrate surface
In order to remove the u mask pattern, Cl
_Two gases were introduced to perform selective etching. By this operation, the Al-Si-Cu film on the substrate can be removed without opening the apparatus. However, in this embodiment, a sufficient optical coupling efficiency cannot be obtained with a spherical structure because of a single-sided microlens. Therefore, in the present embodiment, an object is to obtain an aspherical shape by finely controlling the etching condition (3) in the final stage. (4) Initial: 10 mTool, Ar: CF ₄ : CHF ₃ : SF ₆ : O ₂ = 1: 10: 5: 1: 0 mixed gas, substrate bias 300 w, end: 10 mTool, Ar: CF ₄ : CHF ₃ : SF ₆ : O ₂ = 1: 10: 5: 5: 2 mixed gas, substrate bias 500w, 20 minutes. That is, when selective and controlled etching was performed for 20 minutes under the condition (4), a non-spherical concave microlens array almost as designed was obtained. In the present example, a concave aspherical microlens array having a concave shape with a diameter of the opening: 250 μm and a depth: 10 μm could be manufactured.

It is needless to say that the opening ratio of the conductance valve is controlled in order to control the desired shape, and the RF power is controlled with time in order to control the plasma density. . These control methods can be theoretically determined to some extent, but ultimately determine the conditions by experiment. Specifically, the above (1) to
Under the condition (4), a program for reducing the substrate bias every 30 seconds and increasing the pressure every 30 seconds is manufactured and controlled.

(Embodiment 5) Next, still another embodiment of the manufacturing process of the flat lens array according to the present invention will be described. In the present embodiment, an example in which the formation of a protective film and the formation of a pattern on a flat substrate are performed at the same time is shown. The etching process after the formation of an array pattern with small openings is substantially the same as that in the first embodiment. First, a positive photosensitive polymer material is charged into a coating machine with an ink jet nozzle which has been programmed in advance,
It is applied on a low expansion glass (Neoceram N-0) substrate which is a flat substrate. In this case, it is desirable that the application pattern has a pitch of the target lens array, and the opening diameter is sufficiently smaller than the diameter of the lens finally obtained. In this embodiment, the pitch of the target array is 25
0 μm, and the formed small opening arrangement is a lattice-like arrangement and the opening diameter is 200 μm. As a result, a small aperture pattern for forming a grid-like communication microlens array is obtained. Immediately after the photosensitive polymer material is applied, post-baking is performed. Then, an etching step similar to the steps of FIGS. 1C to 1E is performed.

Using the substrate having a photosensitive polymer material film having the small opening, dry etching is performed using the photosensitive polymer material as a mask. That is, the substrate was set in a plasma etching apparatus and dry etching was performed. In this embodiment, an ECR etching apparatus is used, and CF ₄ , CHF ₃ , O ₂ ,
A mixed gas of Ar was used. The pressure of the etching equipment is
Substrate bias: 0.1 to 30mToor: 50w to 1K
w, microwave power: w, coil current: A. The etching conditions are as follows: (1) Initially: 1 mToor, mixed gas of Ar: CF ₄ : CHF ₃ = 1: 5: 5, substrate bias 1 Kw, end: 5 mToor, Ar: CF ₄ : CHF ₃ = 1: 5: 5 5 minutes with a mixed gas of 500 w at a substrate bias of (2) First: 5mToor, Ar: CF4: CHF 3 = 1: 5: mixed gas of 5, substrate bias 500 w, _{End: 30mToor, Ar: CF 4:} CHF 3 = 1: 10: mixed gas of 5, substrate bias 10 minutes at 500w. (3) First: 30 mToor, Ar: CF ₄ : CHF ₃ : O ₂ = 1: 10: 5: 0, mixed gas, substrate bias 500 w, end: 50 mTool, Ar: CF ₄ : CHF ₃ : O ₂ = 1: 20 minutes with a mixed gas of 10: 5: 0.5 and a substrate bias of 500 w.

When etching is performed under the above conditions, (1)
In (2), side etching is performed in the lateral direction parallel to the substrate surface (under this condition, the pressure is relatively high, so the vertical etching is more in the vertical direction). The opening diameter is larger than the speed, and the opening diameter is larger than the pattern formed with a relatively flat bottom.)
In (3), isotropic etching is performed on the substrate surface (under this condition, since the pressure is high, the etching rates in the vertical and horizontal directions are substantially equal, and the bottom surface is etched concentrically. However, the etching rate is relatively slow). By controlling the etching conditions, the cross-sectional shape changes. In the present invention, the shape is controlled by the gas type, pressure, introduced power condition, partial pressure, process, and the like. By performing the above steps (1) to (3), FIG.
An aspherical concave shape having an opening diameter larger than the small opening diameter similar to (d) could be created.

Under the above conditions, a concave microlens having a diameter of 220 μm is formed. However, under the above conditions, a gap (space) of 30 μm remains between the concave portions. However, a space may remain in a microlens array in an optical communication field or the like. However, in this embodiment, a sufficient optical coupling efficiency cannot be obtained with a spherical structure because of a single-sided microlens.
Therefore, in the present embodiment, an object is to obtain an aspherical shape by finely controlling the etching condition (3) in the final stage. (4) Initial: 50 mTorr, Ar: CF ₄ : CHF ₃ : SF ₆ : O ₂ = 1: 10: 5: 1: 0, mixed gas, substrate bias 500 w, end: 60 mTool, Ar: CF ₄ : CHF ₃ : SF ₆ : O ₂ = 1: 10: 5: 5: 2 mixed gas, substrate bias 600w, 20 minutes. That is, when the selective and controlled etching was performed for 20 minutes under the condition (4), a concave microlens array having an aspherical shape substantially as designed was obtained. In this example, a flat lens array having a concave aspherical microlens array having a diameter of 250 μm and a depth of 8 μm was manufactured.

It is needless to say that the opening ratio of the conductance valve is controlled in order to control the desired shape, and the RF power is controlled with time in order to control the plasma density. . These control methods can be theoretically determined to some extent, but ultimately determine the conditions by experiment. Specifically, the above (1) to
Under the condition (4), a program for reducing the substrate bias every 30 seconds and increasing the pressure every 30 seconds is manufactured and controlled.

(Embodiment 6) FIG. 10 is a view showing still another embodiment of the present invention, in which a flat type oil trap is manufactured by using the method of forming an array of concave fine shapes according to the present invention. It is a figure which shows a preparation process. First, a cemented carbide substrate 61, which is a flat substrate and has no ultrafine particle dies, is used.
After applying a positive photosensitive polymer material 62 to the surface of
After exposing the pattern of the mask (or reticle) 67 to the photosensitive polymer material 62 (FIG. 10A), the mask 67
Remove and develop and rinse. At this time, the pattern of the mask (or reticle) 67 to be exposed has a pitch of an array of the target concave fine shape array, and the opening diameter is sufficiently larger than the diameter of the concave portion to be finally obtained. Desirably small. In this embodiment, the pitch of the target array is a pitch of 5 μm, and the formed small aperture array is a lattice-like array having an aperture diameter of 3 μm. As a result, a small opening pattern for forming a desired friction coefficient reduction oil trap is obtained (FIG. 10B). The substrate is polished on both sides in advance, and is manufactured with a parallelism of 2.5 μm / 4 inch or less.

The hard metal substrate 61 with the photosensitive polymer material film having the small opening is dry-etched using the photosensitive polymer material 62 as a mask. That is, the substrate 61 was set in a plasma etching apparatus, and dry etching was performed. In the present embodiment, an ECR etching apparatus is used, and CF ₄ ,
A mixed gas of CHF ₃ , O ₂ , and Ar was used. The pressure of the etching apparatus is 0.1 to 30 mTorr and the substrate bias is:
50 w to 1 Kw, microwave power: w, coil current: A
I went in. The etching conditions are the same as in the third embodiment.

Through the above steps, a spherical concave shape having an opening diameter larger than the small opening diameter of the mask could be created (FIGS. 10C and 10D). At that time, when etching is performed under the same etching conditions as in (3) of the third embodiment, the photosensitive polymer material 62 gradually disappears due to the gradual introduction of O ₂ . Thus, an array pattern of the substantially spherical concave portions 64 could be obtained (FIG. 10E). In the present embodiment, the diameter of the opening: 3.5 μm
A flat oil trap having an array pattern of concave portions 64 having a depth of 0.9 μm was obtained.

As is well known, the opening rate of the conductance valve is controlled in order to control the desired shape, and the microwave, coil current, and RF power are controlled over time to control the plasma density. Needless to control. These control methods can be theoretically determined to some extent, but ultimately determine the conditions by experiment. Specifically, etching conditions (1) to (4) similar to those in Example 3 were used.
Under the condition (3), a program for reducing the substrate bias every 10 seconds and increasing the pressure every 10 seconds is manufactured and controlled.

The surface of the substrate 61A on the concave array side of the flat type oil trap manufactured in this example was subjected to a surface treatment of an organic film, and a friction test was performed after applying an F-based lubricant. This was reduced to 1/3 compared to the case where the concave array was not manufactured. Also, the life of the cemented carbide was increased about 10 times.

(Embodiment 7) Next, an embodiment of a flat lens array will be described. FIG. 11 is a sectional view of a main part showing an embodiment of a flat lens array. In this example, a lens portion is formed by filling the concave portion of the quartz substrate 11 of the flat lens array manufactured in Example 1 with an epoxy resin material 16 having a higher refractive index than the quartz substrate. Next, a quartz cover glass substrate 71 different from the substrate 11 on which the lens array is manufactured is prepared, and a low-viscosity epoxy material 72 for adjusting the refractive index and enhancing the adhesion is applied on the substrate 71 by a spinner. This is cured by a predetermined curing method (a UV method or a thermosetting method may be used). Next, an adhesive 73 made of an epoxy resin material having a higher refractive index than that of the quartz substrate is applied to the surface of the lens array substrate 11, and is bonded to the cover glass substrate 71 on which the low viscosity epoxy material 72 is applied by a spinner. Insert the agent so that air does not enter. Air and an adhesive are extruded by applying pressure from above to a mirror-polished glass plate to control the thickness to a predetermined thickness. In addition, a spacer may be provided in advance in a gap between lens parts for thickness control. Thereafter, the epoxy adhesive is cured by heating. Next, in order to adjust the optical path length and the focal length, the quartz cover glass substrate 71 is polished on one side to finish it to a predetermined thickness. Thereby, a flat lens array having desired optical characteristics can be obtained.

(Embodiment 8) Next, FIG. 12 is a sectional view of a principal part showing another embodiment of the flat lens array. In this example, the 1.3 ″ X manufactured in Example 2 (or Example 3) is used.
The concave portion of the quartz substrate 21 on the concave microlens array side for the GA liquid crystal projector is filled with an epoxy resin material 16 having a higher refractive index than the quartz substrate to form a lens portion. Next, a quartz cover different from the substrate 21 on which the lens array was manufactured.
A glass substrate 74 is prepared, and a low-viscosity epoxy material 75 for adjusting the refractive index and increasing the adhesion is applied on the substrate 74 by a spinner. This is cured by a predetermined curing method (a UV method or a thermosetting method may be used). Next, an epoxy resin material 76 having a refractive index higher than that of the quartz substrate is applied as an adhesive to the surface of the microlens array substrate 21, and a cover glass substrate 74 on which the low-viscosity epoxy material 75 is applied by a spinner. Hold the adhesive so that air does not enter. Air and an adhesive are extruded by applying pressure from above to a mirror-polished glass plate to control the thickness to a predetermined thickness. In addition, a spacer may be provided in advance in a gap between lens parts for thickness control. Thereafter, the epoxy adhesive is cured by heating. Next, the cover glass substrate 74 is polished on one side to obtain a desired microlens array element for a liquid crystal projector to a predetermined thickness (for example, 121 μm). Quartz glass has a refractive index of 1.45 and high refractive index epoxy-based adhesive has a refractive index of 1.63. Since the lens radius of the flat lens array manufactured this time was 30 μm, the focal length f in the resin was given by f = (− r) * (n ′) / (n′−n), where r = 0. 015 mm, n '= 1.63, n
Since f = 1.45, f = 0.136 mm.

(Embodiment 9) As still another embodiment of the flat lens array, in place of the quartz substrate of the concave microlens array for the 1.3 ″ XGA liquid crystal projector manufactured in the embodiment 2 or 3, A flat lens array having the same structure as that shown in Fig. 12 was manufactured by using a quartz substrate and a substrate obtained by anodically bonding a BK-7 material, and the lens array substrate was composed of a quartz substrate having a lower refractive index closer to the cover glass. BK-7 was used on the side that focuses light, and the thickness of the quartz material was 9 μm.The processing conditions were the same as those in Examples 2 and 3, but the processing conditions were the same. A shape was obtained.
The concave portion of the substrate was filled with an epoxy resin material having a higher refractive index than the quartz substrate to form a lens portion. And Example 8
A cover glass substrate coated with a low-viscosity epoxy material by a spinner in the same manner as described above was bonded to a lens array substrate with an adhesive made of an epoxy resin material. In the case of the present embodiment, since the light incident on the central part of the microlens does not receive much lens effect, the focal length is slightly longer than that of the eighth embodiment, but almost the same performance is obtained. . In particular,
The light condensing state at the focal position slightly varied, and the focal distance f was f = 0.129 mm. The performance when actually incorporated in a liquid crystal display element was almost the same.

(Embodiment 10) Next, an embodiment of a liquid crystal display device will be described. FIG. 13 is a cross-sectional view of a main part showing one embodiment of a liquid crystal display element. In this example, a flat lens array 77 manufactured in the same manner as in the first embodiment is used, and an epoxy resin material 77B having a higher refractive index than the quartz substrate 77B is formed in the concave portion of the quartz substrate 77A.
To form a lens portion. Further, the lens portion has a continuous resin layer, and the surface of the resin layer facing the lens surface is formed flat, and a film sheet 77C having a smooth surface (or a low viscosity film similar to FIG. 11) is formed thereon. A cover glass substrate coated with an epoxy material by a spinner is adhered, and on the surface thereof, a transparent electrode 78A made of ITO or the like constituting the liquid crystal element portion 78 and a black matrix 78B are formed. The liquid crystal layer 78C
A second substrate 78F on which a p-Si, TFT type pixel electrode 78D and a thin film transistor (TFT) 78E are formed is provided on the side opposite to the other. In the liquid crystal display device having the above-described configuration, light can be focused on the pixel portion of the liquid crystal device by the microlens array.
The light use efficiency can be improved and the amount of transmitted light can be increased.

The flat lens array used in the liquid crystal display device having such a structure is described in Examples 2 and 3.
A flat lens array having a microlens array on both sides of a substrate, such as the one manufactured by the above, is also suitable. For example, a transparent electrode and a black matrix are formed on a cover glass of a flat lens array having a structure shown in FIG. And a second substrate on which a p-Si, TFT type pixel electrode and a TFT are formed is provided on the opposite side with the liquid crystal layer interposed therebetween, whereby a liquid crystal display element can be manufactured.

(Embodiment 11) FIG. 14 is a view showing still another embodiment of the present invention, and is an explanatory view of a configuration of a flat lens array having microlens arrays on both sides. FIG.
FIG. 4A shows an example in which concave microlens arrays 82 and 83 are formed on both sides of a transparent flat substrate 81 and connected to a liquid crystal panel 84.
Can be created by performing on both sides. In the case where a double-sided concave lens is used, the light use efficiency can be improved. Note that a structure in which one or both of the concave portions formed in the planar substrate are filled with a resin material having a higher refractive index than the substrate material may be employed.

FIG. 14B shows an example in which a convex lens is provided on one surface of a transparent flat substrate 85 and a concave lens is provided on the other surface. Can be created. In the configuration shown in the figure, a thin cover glass 89 or a film sheet having a smooth surface is provided on the surface on the convex lens side via a resin layer 88, and when used for a liquid crystal display element, a black matrix is provided on the surface. 90, a transparent electrode, and the like.
With the flat lens array having such a configuration, the light use efficiency can be improved and a high NA lens can be manufactured. Note that a structure in which a resin material having a higher refractive index than the substrate material is filled in the concave portion formed in the flat substrate 85 may be employed.

FIG. 14C shows a convex flat lens 94 on one surface of a transparent flat substrate 92 and a concave pyramid lens 9 on the other surface.
3 is provided, and can be formed by controlling the etching conditions by applying the forming process described in the second or third embodiment. In the illustrated configuration, a film sheet 96 having a smooth surface is provided on the surface on the convex lens side via a resin layer 95.
And a thin cover glass. In the flat lens array having such a configuration, the tip of the concave pyramid lens unit 93 functions as a point light source, and the light emitted from the convex lens 94 can be converted into parallel light.

[0068]

As described above, according to the method of forming an array pattern having a concave fine shape according to the present invention, the manufactured substrate has a concave fine shape that is regularly controlled, so that it has a high resistance. Excellent environmental characteristics, small variation in the substrate, large design flexibility, few defects, controllable shape such as spherical / aspherical surface, uniform cross-sectional shape,
It is possible to supply a device substrate with a microlens having the performance of a double-sided lens with a high NA, which is not limited by the glass composition, and excellent in shape controllability and reproducibility. Further, according to the present invention, the flat lens array can be designed according to the configuration of the liquid crystal display element and the like, and further, the degree of freedom in selecting the constituent materials of the microlenses is large, so that the light use efficiency is improved. be able to. Further, since the degree of freedom in design is high, the present invention can be applied to various optical devices, not limited to liquid crystal display elements. Also, by using this flat lens array, the optical performance of the lens can be simulated.
Then, a lens having a dense structure conforming to this can be manufactured, and a micro-optical element that condenses light on individual device pixels can be provided. Therefore, the amount of light transmitted through the pixel can be increased, and a bright liquid crystal display device can be realized.

Since the substrate manufactured by the method of forming an array pattern of concave fine shapes according to the present invention has a large number of fine concave portions arranged in an array, it is necessary to fill the concave portions of the substrate with a lubricant. Thus, the lubricant is supplied to and held in the mechanically sliding portion with the mating component that forms a pair with this, and the frictional force can be reduced, so that a flat oil trap can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a step of producing a flat lens array according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing a main part of the substrate during a forming process of FIG. 1;

FIG. 3 is an enlarged view showing a main part of the substrate during the production process of FIG. 1;

FIG. 4 is an explanatory view of dry etching, showing a cross-sectional shape of the substrate when isotropic etching and anisotropic etching are performed.

FIG. 5 is a diagram showing an example of a relationship between a cross-sectional shape and a pressure after dry etching.

FIG. 6 is an explanatory view of a step of forming a flat lens array according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram of a step of producing a flat lens array according to still another embodiment of the present invention.

FIG. 8 is a view showing still another embodiment of the present invention,
FIG. 4 is a diagram illustrating an example of a mask and a spacer when a protective film is simultaneously formed and a pattern is formed.

FIG. 9 is a view showing still another embodiment of the present invention,
FIG. 4 is an explanatory diagram of a pattern forming step when forming a protective film and forming a pattern at the same time.

FIG. 10 is an explanatory view of a step of producing a flat-plate type oil trap showing still another embodiment of the present invention.

FIG. 11 is a cross-sectional view of a main part of a flat lens array showing still another embodiment of the present invention.

FIG. 12 is a sectional view of a main part of a flat lens array showing still another embodiment of the present invention.

FIG. 13 is a cross-sectional view of a main part of a liquid crystal display device showing still another embodiment of the present invention.

FIG. 14 is a view showing still another embodiment of the present invention;
FIG. 2 is a configuration explanatory view of a flat lens array provided with microlens arrays on both sides.

[Explanation of symbols]

11, 21, 31, 51, 61, 81, 85, 92: planar substrate 12A, 22A, 32, 56, 62: protective layer 14, 24, 34, 64: concave portion 71, 74, 89: cover glass substrate 77: Flat lens array 77A: quartz substrate (flat substrate) 77C, 96: film sheet 78: liquid crystal element part 78A: transparent electrode 78B, 90: black matrix 78C, 91: liquid crystal layer 78D: pixel electrode 78E: TFT (thin film transistor) 78F : Second substrate

Claims (18)

[Claims] 1. A method for forming an array pattern of a plurality of concave fine shapes having a substantially spherical shape or a substantially polygonal shape arranged one-dimensionally or two-dimensionally on a substrate surface of a flat substrate.
(1) a step of forming an etching-resistant protective layer on the surface of the planar substrate; (2) a step of forming a desired pattern on the protective layer on the substrate surface; and (3) a substrate of the planar substrate with the protective layer. The surface is isotropically and / or anisotropically etched by a dry etching method.
A first dry etching step of forming a recess having a substantially semicircular or substantially V-shaped cross section; (4) a step of removing the protective layer on the surface of the flat substrate after the first dry etching step; A second etching step of etching the entire surface of the planar substrate after removing the protective layer, and a method of forming an array of concave fine shapes, the method comprising: 2. The method according to claim 1, wherein in the step of (1) forming an etching-resistant protective layer on the surface of the planar substrate, (a) Cr, W, W-Si, W-Ti, Si, Ti
-Si, Ti, Mo, Cu, Fe, Al, Ni, Sn,
Metals such as Pb, or SiO ₂ , TiO, Al ₂ O ₃ ,
Forming a thin film by a dry process such as a sputtering method, a vacuum evaporation method, a CVD method, an ECR film forming method, or a plating method using a ceramic such as ITO as a thin film material, and / or (b) photosensitivity A method of forming an array pattern having a concave fine shape, comprising forming a thin film using an organic substance such as a polymer material. 3. The method according to claim 1, wherein an etching-resistant protective layer made of a metal or ceramic material is formed on the surface of the planar substrate material in the step (1). Then, (2) in the step of forming a desired pattern on the protective layer on the substrate surface, a photosensitive polymer material is applied on the protective layer of the metal or ceramic material and patterned, and then the photosensitive layer is formed. A method of forming an array of concave fine patterns, characterized by using a pattern forming method in which the protective layer is patterned by wet etching or dry etching using a pattern of a molecular material as a mask. 4. The method according to claim 1, wherein in the step (1), an etching-resistant protective layer made of a photosensitive polymer material is provided on the surface of the planar substrate material. After forming
(2) In the step of forming a desired pattern on the protective layer on the surface of the substrate, the photosensitive polymer material is patterned, and a pattern forming method using the pattern as it is is used. Array pattern forming method. 5. The method of forming an array of concave fine patterns according to claim 1 or 2, wherein: (1) a step of forming an etching-resistant protective layer on the surface of a planar substrate material; and (2) a surface of the substrate. And a step of forming a desired pattern on the protective layer at the same time, a mask having a desired pattern is placed via a spacer on a flat substrate on which a pattern is to be formed, and a material constituting the pattern is formed from above the mask. A method for forming an array of concave fine patterns, wherein a pattern is formed by depositing through a hole on a surface of a substrate by a vacuum film forming method and generating a pattern of a protective film. 6. The method of forming an array of concave fine patterns according to claim 1 or 2, wherein (1) a step of forming an etching-resistant protective layer on the surface of a planar substrate material; and (2) a surface of the substrate. The step of forming a desired pattern on the protective layer is performed at the same time, and a photosensitive polymer material or a paint containing an organic / inorganic material is applied on a flat substrate on which a pattern is to be formed, in accordance with a pre-programmed signal. A concave fine pattern-shaped array pattern characterized by using a pattern forming method in which a protective film is applied on a flat substrate and a protective film is applied by dropping one by one through a mask, thereby patterning a portion where a protective film is not applied. Forming method. 7. The method for forming an array pattern having a concave fine shape according to any one of claims 1 to 6, wherein (3) the substrate surface of the flat substrate with a protective layer is isotropically and / or dry-etched. Or anisotropically etched,
The cross section is substantially semicircular or substantially V
In the first dry etching step for forming a groove-shaped concave portion, (a) isotropic and / or anisotropic by changing the etching conditions continuously and / or stepwise with time according to the etching time; (B) The etching conditions to be changed include the type of reactive gas for etching the planar substrate layer, the mixing ratio, the partial pressure, the introduced amount, the reaction chamber pressure, the plasma density, the substrate bias power,
Changing the substrate temperature, etc. continuously and / or discontinuously over time by controlling the temperature, etc .; (c) the concave portion having a substantially semicircular cross section formed on the plane substrate surface has a controlled spherical shape Or (d) a concave portion having a substantially semicircular or V-groove-shaped cross section formed on the plane substrate surface is controlled to a shape in which a ridge line is formed of a straight line or a curved surface. A method of forming an array pattern having a concave fine shape. 8. The method according to claim 1, wherein the step of removing the protective layer on the surface of the planar substrate after the first dry etching step comprises: This is a step of removing the protective layer by isotropically and / or anisotropically etching, and may be removed by a wet etching method, may be removed by a dry etching method, or may be removed by a wet etching method. If so, immerse in a solution that dissolves each protective film,
In the case of removing by a dry etching method, depending on the type of reactive gas for etching the protective layer, the mixing ratio, the partial pressure, the introduced amount, the reaction chamber pressure, the plasma density, the substrate bias power, the substrate temperature, etc. A method for forming an array pattern having a concave fine shape, characterized by controlling removal. 9. The method according to claim 1, wherein (5) second etching is performed on the entire surface of the flat substrate after removing the protective layer. The step is a step of isotropically and / or anisotropically etching the substrate. (A) By changing the etching conditions continuously and / or stepwise with time according to the etching time, Etching isotropically and / or anisotropically. (B) The etching conditions to be changed include the type of reactive gas for etching the planar substrate layer, the mixing ratio, the partial pressure, the introduced amount, the pressure in the reaction chamber, and the plasma. Density, substrate bias power,
A method for forming an array pattern having a concave fine shape, wherein the temperature is changed continuously and / or discontinuously by controlling a substrate temperature or the like. 10. The method for forming an array pattern having a concave fine shape according to claim 1, wherein a cross section manufactured by performing the steps (1) to (5) has a substantially semicircular shape. The concave portion having the shape or the V-groove shape controls the gap between the adjacent patterns, and (a) controls the arrangement to have the same size as the gap when the desired pattern is formed; or
(B) a method of forming an array pattern having a concave fine shape, wherein the arrangement is controlled to be wider than a gap at the time of forming a desired pattern, or (c) the arrangement is controlled to be adjacent without any gap. . 11. The method of forming an array of concave fine patterns according to any one of claims 1 to 10, wherein the steps (1) to (5) are performed on both surfaces of the flat substrate,
By fabricating a desired concave micro-shaped array pattern on both sides of the flat substrate, a lens having excellent optical performance (high N
A) The method of forming an array pattern having a fine concave shape, wherein an optical element capable of improving light use efficiency is obtained. 12. The method for forming an array pattern having a concave fine shape according to any one of claims 1 to 11, wherein the planar substrate is made of glass, quartz, metal, ceramics, crystalline material, or A method for forming an array pattern having a concave fine shape, characterized by using a material obtained by bonding a plurality of glasses, quartz, crystalline materials, and plastic materials having different refractive indexes. 13. A method according to claim 12, wherein a material formed by bonding a plurality of glasses, quartz, crystalline materials, and plastic materials having different refractive indexes is used as a constituent material of the planar substrate. Is a method of forming an array of concave fine shapes, wherein the plurality of materials are joined or welded by using an adhesive or by electrochemical joining. 14. A transparent flat substrate having an array pattern of a concave fine shape manufactured by the method according to claim 1, and a concave portion of the array pattern of the flat substrate. A lens array formed by filling a transparent resin having a higher refractive index than the substrate with a convex or lenticular lens, wherein the lens array has a resin layer continuous with a resin portion filled with resin in a concave portion; A flat lens array, wherein the surface of the layer facing the lens surface is flat, and the resin layer has a thickness such that parallel rays of light incident from the glass substrate converge near the resin layer surface. 15. The flat lens array according to claim 14, wherein a film sheet having a smooth surface is disposed on the resin layer, or an inorganic material containing a glass component or the like is applied on the surface in advance. A thin glass plate provided with an inorganic layer and / or an organic layer made of an adhesive or an adhesion reinforcing material, which is subsequently heated and cured, is arranged, and further, a resin layer is incident on the non-etched portion of the flat substrate from the substrate. A flat lens array, wherein a spacer for adjusting the thickness is arranged so as to have a thickness such that light rays are condensed near the surface of the resin layer. 16. A flat lens array according to claim 15, wherein said light is collected near the surface of said film sheet or thin glass plate as a smooth film sheet or thin glass plate on said resin layer. A flat lens array having a smooth film sheet or a thin glass plate whose thickness is adjusted to emit light. 17. A surface of a flat film sheet or a thin glass plate having the flat lens array according to claim 15 or 16 and having a thickness adjusted so that light from the flat lens array is condensed. Has a black matrix and / or
Alternatively, it has a second substrate on which a transparent electrode is formed and a p-Si, TFT type pixel electrode is formed, and has a structure in which a liquid crystal is sandwiched between the second substrate and the transparent electrode. A liquid crystal display device characterized by the above-mentioned. 18. The method according to claim 1, wherein the metal or ceramic substrate is provided.
11. A member having an array pattern of regularly controlled concave and fine shapes manufactured by the forming method according to any one of items 10 to 10, and a lubricant is filled in the concave portion of the array pattern of the member. Thus, a flat type oil trap is provided in which lubricant is supplied and held to a mechanically slidable portion between the member and a mating member forming a pair, thereby reducing frictional force.