JP2005215624A - Method for manufacturing microlens, microlens, electrooptical device equipped with same, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To design the lens curved surfaces of microlenses with a larger degree of freedom. <P>SOLUTION: A method for manufacturing microlenses includes the processes of: forming a 1st film including a part where the etching rate for a specified kind of etchant varies in a contour shape in a plane along one surface of a substrate in individual lens formation regions on the one surface; forming on the 1st film a mask having holes opened at positions corresponding to the vicinity of the centers of the microlenses to be formed in the lens formation areas; and performing wet etching through the mask to dig aspherical concave parts prescribing the curved surfaces of the microlenses. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a microlens that constitutes a microlens array plate used in an electrooptical device such as a liquid crystal device, a microlens manufactured by the manufacturing method, an electrooptical device including the microlens, and the The present invention relates to a technical field of electronic equipment including an electro-optical device.

  As disclosed in Patent Document 1 or Patent Document 2, in an electro-optical device such as a liquid crystal device, for example, a microlens corresponding to each pixel is formed on a counter substrate, or a plurality of such microlenses are formed. A microlens array plate with a built-in is attached. By using such a microlens array, bright display is realized in the electro-optical device.

  Here, the microlens is manufactured as follows. That is, first, on a transparent substrate, for example, a mask having a hole at a position corresponding to the center of the microlens to be formed is formed. Next, the transparent substrate is wet-etched through this mask to dig a spherical recess that defines the curved surface of the microlens. Then, after removing the mask, the concave portion is filled with a transparent medium having a high refractive index. Thereby, a microlens having a hemispherical lens curved surface is formed in the recess.

  However, the lens curved surface of the microlens is not necessarily an optically ideal shape as a hemispherical surface. Patent Document 1 or 2 discloses a microlens having an aspheric lens curved surface. According to such a microlens, for example, spherical aberration is reduced, so that the depth of focus can be increased and the light transmittance in each pixel can be improved.

JP-A-8-304811 Japanese Patent Laid-Open No. 7-244278

  However, when the depth of focus of the microlens is increased, light is concentrated and irradiated at each point in each pixel, so that components arranged at the one point may deteriorate and the life of the electro-optical device may be shortened. Alternatively, for example, when an electro-optical device is used as a light valve of a liquid crystal projector, matching with an optical system for making light incident on the light valve from a light source or projecting display light from the light valve onto a screen Need to do. Therefore, it is desired to design the microlens with a greater degree of freedom.

  The present invention has been made in view of the above-described problems, and a microlens manufacturing method capable of designing a lens curved surface of a microlens with a higher degree of freedom, a microlens manufactured by the manufacturing method, It is an object of the present invention to provide an electro-optical device including a microlens and an electronic apparatus including the electro-optical device.

  In order to solve the above-described problem, the first microlens manufacturing method of the present invention provides an etching rate for a predetermined type of etchant on one surface of a substrate in each lens forming region on the one surface within a plane along the one surface. Forming a first film including a portion that changes to a contour line, and forming a mask having a hole in a position corresponding to the approximate center of the microlens to be formed in the lens formation region on the first film. And a step of digging an aspherical recess defining the curved surface of the microlens in the substrate by wet etching through the mask.

  According to the first microlens manufacturing method of the present invention, first, a first film is formed on one surface of a substrate such as a quartz substrate or a glass substrate. In each lens formation region, the etching rate for a predetermined type of etchant such as hydrofluoric acid in the first film changes in a contour line within a plane along the one surface. Here, the “contour line shape” is a word indicating any shape such as a concentric circular shape, an eccentric circular shape, or a concentric rectangular shape regardless of the circular shape. More specifically, in each lens formation region, the etching rate in a portion along the one surface of the first film made of a single layer film or a multilayer film is contoured in a plane along the one surface. It changes so as to become smaller or larger from the center of the formation region toward the outside. That is, in this case, in each lens formation region, a plurality of regions are arranged in a contour line corresponding to each value of the etching rate.

  Subsequently, a mask having a hole formed at a location corresponding to the approximate center of the microlens to be formed is formed on the first film. Such a mask is formed, for example, by patterning a second film on one surface of the first film by CVD (Chemical Vapor Deposition), sputtering, etc., and then forming a hole by photolithography and etching. May be. Alternatively, the mask may be directly formed in a region excluding the hole on the first film.

  Thereafter, the first film and the substrate are wet-etched through such a mask. In each lens formation region, a plurality of regions are defined as described above based on the value of the etching rate for the etchant used in the wet etching in the first film. In each of the plurality of regions, when a hole penetrating the first film is opened by wet etching, the degree of etching of the first film and the degree of etching of the substrate are different from each other. In any of the plurality of regions, the degree to which the first film is etched by wet etching may be equal to the degree to which the substrate is etched.

  Here, when the value of the etching rate in each of the plurality of regions is larger than that of the substrate, the hole in the first film becomes larger with respect to the substrate, and the etching of the substrate accelerates in the in-plane direction than in the vertical direction. Is done. As a result, the concave portion formed in the substrate has a conical shape, and the angle of the cross-sectional portion with respect to the substrate decreases as the etching rate of the corresponding first film region increases, and the etching rate of the corresponding region of the first film decreases. In some cases, the angle of the cross section with respect to the substrate increases.

  Therefore, by changing the etching rate of the first film in each lens forming region as described above, the shape of the curved surface of the concave portion can be controlled. As a result, an aspherical concave portion can be dug in each lens forming region. Accordingly, the curved surface of the microlens can be designed with a high degree of freedom, and an optically optimal shape can be obtained.

  In one aspect of the first microlens manufacturing method of the present invention, the first film includes a portion where the etching rate changes concentrically in a plane along the one surface in each lens formation region. Form.

  According to this aspect, in each lens formation region, the etching rate in a portion along the one surface of the first film is concentrically within a plane along the one surface and is directed outward from the center of the lens formation region. It is possible to change so as to become smaller or larger.

  In another aspect of the manufacturing method of the first microlens of the present invention, the first film includes a portion where the film thickness changes in a contour line in a plane along the one surface in each lens forming region. Form.

  According to this aspect, in each lens forming region, the film thickness in the portion along the one surface of the first film decreases in a contour line from the center to the outside when the hole of the mask is viewed in plan. Or change to be larger. As a result, the degree of etching of the first film and the degree of etching of the substrate are equal or different from each other depending on the change in film thickness in addition to the above-described change in etching rate in the first film. be able to. As a result, the shape of the curved surface of the recess can be controlled.

  In this aspect in which the first film is formed so that the film thickness changes, the first film includes a portion where the film thickness changes concentrically in a plane along the one surface in each lens formation region. You may manufacture so that it may form.

  If manufactured in this way, in each lens formation region, the film thickness in the portion along the one surface of the first film is reduced concentrically from the center to the outside as seen in a plan view of the hole of the mask. It becomes possible to change so that it may become.

  In another aspect of the first microlens manufacturing method of the present invention, in the step of forming the first film, in each lens formation region, a plurality of films each having a different etching rate are contoured on the one surface. Including a step of arranging and forming in a shape.

  According to this aspect, in each lens forming region, a plurality of films each having a different etching rate are formed on the one surface by using a film forming method such as a CVD (Chemical Vapor Deposition) method or a sputtering method. And it arranges and forms in the shape of a contour line.

  For example, each of the plurality of films is patterned with a shape or size corresponding to the etching rate. More specifically, for example, the films having a higher etching rate are patterned so as to have a smaller size, and are stacked in order from the larger etching rate to the smaller etching rate. As a result, as the film laminated on the upper layer, the etching rate decreases and the size of the film increases. In the lens forming region, the etching rate and film thickness are within the plane along the one surface. Thus, it can be formed in a contour line so as to become smaller from the center of the lens formation region toward the outside.

  That is, according to this aspect, in each lens formation region, the first film whose etching rate or film thickness changes in a contour line within a plane along the one surface can be formed as, for example, a multilayer film. For example, as described above, the multilayer film is formed such that the closer to the center in the lens formation region, the larger the number of laminated films.

  In this aspect in which a plurality of films having different etching rates are formed, the plurality of films may be manufactured so as to be formed in a disk shape.

  If manufactured in this way, in each lens forming region, the first film whose etching rate and film thickness change concentrically or eccentrically in a plane along the one surface can be formed as a multilayer film. it can. In addition, the patterning of each film can be performed relatively easily, and at this time, the situation where the shape of the film already formed is damaged by the over-etching in the patterning of the film formed after the film is prevented. It becomes possible to do.

  Alternatively, in the aspect in which the plurality of films having different etching rates are formed, the plurality of films may be manufactured so as to be formed in a substantially square shape.

  If manufactured in this way, in each lens formation region, the first film whose etching rate and film thickness change concentrically or eccentrically in a substantially rectangular shape within a plane along the one surface can be formed as a multilayer film. .

  Alternatively, in the aspect in which the plurality of films having different etching rates are formed, the step of forming the first film includes a step of stacking the plurality of films on the one surface in the ascending order or the decreasing order. May be manufactured.

  If manufactured in this way, the etching rate and the film thickness of the first film in the lens forming region become smaller from the center of the lens forming region to the outside in a contour line in a plane along the one surface. Alternatively, it can be formed to be large. However, the stacking order is not limited to this, and various curved lens surfaces can be formed by changing the stacking order.

  Alternatively, in the aspect in which a plurality of films having different etching rates are formed, the etching rate of each film may be manufactured to be controlled by a film forming temperature, a film forming speed, or a film forming pressure.

  If manufactured in this way, the etching rate of each film can be set to different values. For example, when the deposition temperature is increased, a denser film is formed, and the etching rate in the film is decreased. Conversely, when the deposition temperature is decreased, the etching rate is increased. Alternatively, when the deposition rate is increased, the etching rate of the deposited film is increased, and conversely, when the deposition rate is decreased, a denser film is formed and the etching rate is decreased. Furthermore, the etching rate of each film can be controlled by changing the film formation pressure by controlling the gas flow rate.

  Alternatively, in the aspect in which the plurality of films having different etching rates are formed, the films are formed by the CVD method, and the etching rate of each film is controlled by the composition ratio of the source gas. May be.

  If manufactured in this way, the etching rates of the formed films can be made different from each other by controlling the density of each film by the composition ratio of the source gas.

  In another aspect of the manufacturing method of the first microlens of the present invention, the step of forming the first film includes at least a plurality of films having different etching rates on the one surface in each lens forming region. The second and subsequent films from the center include a step of forming them in a ring shape and coaxially with each other.

  According to this aspect, in each lens formation region, the plurality of films having different etching rates are patterned after film formation using a film formation method such as a CVD (Chemical Vapor Deposition) method or sputtering, and at least the center is formed. The second and subsequent films are formed in a ring shape and coaxially with each other. That is, in this aspect, the first film is composed of a single layer film arranged side by side in a ring shape so that a plurality of films do not overlap each other in the lens forming region. Or you may form a 1st film | membrane as a multilayer film with many films | membranes laminated | stacked so that it is far from the center in a lens formation area.

  Here, in each lens formation region, the etching rate in the first film is reduced in a contour line within the plane along the one surface, and decreases from the center of the lens formation region to the outside. Form as follows. A plurality of films are formed side by side from the inner side to the outer side of the lens formation region in the descending order of the etching rate, or are laminated from the outer side to the inner side of the lens forming region in the order of decreasing etching rate. Form. When formed in such a manner, the first film can be formed so that the thickness of the first film increases from the center of the lens formation region to the outside.

  On the other hand, in each lens formation region, the etching rate in the first film is increased in a contour line in the plane along the one surface, and increases from the center of the lens formation region to the outside. Similarly to the case where the etching rate decreases from the center of the lens formation region to the outside, the plurality of films are formed side by side or stacked in order according to the etching rate of each of the plurality of films.

  Therefore, according to this aspect, it is possible to form the first film in which the etching rate or the film thickness changes in a contour line in a plane along the one surface.

  In the aspect in which the step of forming the first film includes a step of forming a plurality of films in a ring shape and coaxially with each other, the step of forming the first film includes the step of forming the plurality of films. You may manufacture so that the process of forming in a line in the said plane may be included.

  If manufactured in this way, the first film having a flat surface can be formed.

  In the aspect in which the step of forming the first film includes a step of forming a plurality of films in a ring shape and coaxially with each other, the step of forming the first film includes the step of forming the first film on the one surface. After forming the precursor film of the first film, in the lens forming region, the precursor film is divided into a plurality of processing regions in the ring shape or substantially disk shape, and a plurality of types of ions are applied to the plurality of processing regions. You may manufacture so that the process of performing injection | pouring may be included.

  If manufactured in this way, a plurality of types of ion implantation into a plurality of processing regions are performed by changing the amount of ion implantation for each type, for example, thereby forming a plurality of films having different etching rates on the one surface. At least the second and subsequent films from the center can be formed in a ring shape and coaxially with each other.

  In an aspect in which the step of forming the first film includes the step of forming a precursor film of the first film, the precursor film is manufactured so that the etching rate is different from that of the substrate. May be.

  If manufactured in this way, the type of ion implantation performed on the precursor film as described above can be reduced, and the first film can be formed more easily.

  In order to solve the above-described problem, the second microlens manufacturing method of the present invention changes the film thickness to a contour line on one surface of the substrate, in each lens forming region on the one surface, in a plane along the one surface. Forming a first film including a portion to be formed, forming a mask having a hole in a portion corresponding to a substantially center of a microlens to be formed in the lens formation region on the first film, And a step of digging an aspherical recess defining the curved surface of the microlens into the substrate by wet etching through a mask.

  According to the second microlens manufacturing method of the present invention, in each lens forming region, the film thickness in the portion along the one surface of the first film is outside from the center when the hole of the mask is viewed in plan. Toward, it changes so as to become smaller or larger in a contour line shape. As a result, in the wet etching of the substrate and the first film, the degree of etching of the first film and the degree of etching of the substrate may be equal to or different from each other due to a change in the film thickness of the first film. it can. Accordingly, since the shape of the curved surface of the concave portion can be controlled, an aspheric concave portion can be dug in each lens forming region. Accordingly, the curved surface of the microlens can be designed with a high degree of freedom, and an optically optimal shape can be obtained.

  In another aspect of the first or second method for producing a microlens of the present invention, an antireflection film is formed so as to cover the surface of the recess using at least one transparent member in at least the recess of the substrate. The method further includes a forming step.

  According to this aspect, it is possible to improve the light use efficiency in each microlens. Here, the antireflection film is configured using one type of transparent member having a refractive index between the substrate and the microlens. Alternatively, the antireflection film may be formed by stacking a plurality of transparent members using a plurality of transparent members having a refractive index between the substrate and the microlens. Furthermore, in addition to the transparent member having a refractive index between the substrate and the microlens, a transparent member having a higher refractive index than the substrate and the microlens is used to form the antireflection film by laminating the plurality of transparent members. Also good. The antireflection film is formed to a thickness that does not fill the concave portion with the antireflection film, and to a thickness that does not affect the refractive action of the microlens.

  In another aspect of the manufacturing method of the first or second microlens of the present invention, the substrate is made of a transparent substrate, and further includes a step of placing a transparent medium having a refractive index larger than that of the transparent substrate in the recess. .

  According to this aspect, since the transparent medium having a higher refractive index is placed in the recess formed in the substrate made of the transparent substrate, a microlens having a lens curved surface having an optically optimal shape is manufactured on the transparent substrate. It becomes possible. At this time, the transparent medium is made of a transparent resin or the like and may also serve as an adhesive. For example, you may serve as the adhesive agent at the time of bonding a cover glass to a transparent substrate.

  In order to solve the above-described problems, the microlens of the present invention is manufactured by the above-described method for manufacturing the first or second microlens of the present invention (including various aspects thereof).

  In the microlens of the present invention, a microlens having a lens curved surface having an optically optimal shape can be realized.

  In order to solve the above-described problems, an electro-optical device of the present invention includes at least one of the above-described microlens of the present invention, a display electrode facing the microlens, a wiring connected to the display electrode, and an electronic element. With.

  The electro-optical device of the present invention includes, for example, an island-shaped pixel electrode arranged as a “display electrode” for each pixel, a wiring such as a scanning line and a data line, and a thin film transistor (Thin Film Transistor; And an electronic device such as an active matrix driving type liquid crystal device in which electronic elements of a thin film diode (hereinafter referred to as “TFD”) are connected.

  Since the electro-optical device of the present invention includes the above-described microlens of the present invention, when used as a light valve of a liquid crystal projector, matching with an optical system can be performed relatively easily. Alternatively, it is possible to disperse light incident from the outside to each pixel, and it is possible to prevent a situation where light is concentrated and irradiated at one point in each pixel. As a result, the life of the electro-optical device can be extended.

  In order to solve the above problems, an electronic apparatus according to the present invention includes the above-described electro-optical device according to the present invention (including various aspects thereof).

  Since the electronic apparatus of the present invention includes the above-described electro-optical device of the present invention, for example, a projection display device, a television, a mobile phone, an electronic notebook, a word processor, and a viewfinder type that can extend the life. Alternatively, various electronic devices such as a monitor direct-view video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. In addition, as an electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper, an electron emission device (Field Emission Display and a Conduction Electron-Emitter Display), an electrophoretic device, and an apparatus using the electron emission device, DLP (Degital Light Processing) and the like can also be realized.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1: First Embodiment>
A first embodiment according to a method of manufacturing a microlens of the present invention will be described with reference to FIGS.

<1-1: Microlens array plate>
First, a microlens array plate that can be manufactured by the microlens manufacturing method of the present invention will be described with reference to FIGS. Here, FIG. 1 is a schematic perspective view of the microlens array plate, FIG. 2A is a partial enlarged cross-sectional view of the microlens array plate of the present embodiment, and FIG. 2B is the present embodiment. It is the elements on larger scale which expand and show the part which concerns on four microlenses among the microlens array plates of a form, FIG.3 (a) and FIG.3 (b) expand further the part concerning one microlens. It is a partial expanded sectional view shown. FIG. 4 is a partially enlarged cross-sectional view of the microlens array plate in the modified embodiment.

  As shown in FIG. 1, the microlens array plate 20 of this embodiment includes a transparent plate member 210 made of, for example, a quartz plate and covered with a cover glass 200. In the transparent plate member 210, a large number of concave depressions, that is, depressions are formed in a matrix. And, in this concave recess, the cover glass 200 and the transparent plate member 210 are bonded to each other, for example, an adhesive made of a photosensitive resin material is cured, and has a higher refractive index than the transparent plate member 210. A transparent adhesive layer 230 is filled. As a result, a large number of microlenses 500 arranged in a matrix on a plane are constructed.

  Thus, in the present embodiment, an example of the “substrate” according to the present invention is configured from the transparent plate member 210, and an example of the “transparent medium” according to the present invention is configured from the adhesive layer 230.

  In the present embodiment, as shown in FIG. 2A, an antireflection film 240 that covers the surface of the recess is continuously formed in the recess from the inside of the recess to the outside of the recess. Is in close contact with the cover glass 200. The microlens 500 is formed by the adhesive layer 230 filled in the concave portion covered with the antireflection film 240. That is, the microlens 500 is constructed as a plano-convex lens having a lens curved surface defined by the recess.

  Here, the antireflection film 240 is configured using one type of transparent member having a refractive index between the transparent plate member 210 and the microlens 500. Alternatively, the antireflection film 240 may be formed by using a plurality of types of transparent members having a refractive index between the transparent plate member 210 and the microlens 500 and laminating the plurality of transparent members. Furthermore, in addition to the transparent member having a refractive index between the transparent plate member 210 and the microlens 500, the transparent member having a higher refractive index than the transparent plate member 210 and the microlens 500 is used to laminate the plurality of transparent members. Thus, the antireflection film 240 may be formed. The antireflection film 240 is formed to a thickness that does not fill the recesses with the antireflection film 240 and to a thickness that does not affect the refractive action of the microlens 500.

  In the present embodiment, the first film 220 is left in the vicinity of the edge of each microlens 500 because it is manufactured by a manufacturing method unique to the present invention as will be described later. FIG. 2B shows the positional relationship, particularly focusing on the first film 220 and the microlens 500. The first film 220 is made of, for example, a transparent silicon oxide film. As shown in FIG. 2A, the antireflection film 240 outside the recess formed continuously from the inside of the recess is formed on the surface of the first film 220. Is formed. The first film 220 may be left on the upper surface of the transparent plate member 210 in the region where the microlens 500 is not formed, in addition to the vicinity of the edge of each microlens 500.

  As shown in FIG. 2A, FIG. 3A, and FIG. 3B, at the edge of each microlens 500, the curved surface is relative to the surface of the cover glass 200 or the surface of the transparent plate member 210. Steeply sharp. Further, as shown in FIGS. 3A and 3B, the lens curved surface in the transparent plate member 210 is an aspherical surface because it is manufactured by a manufacturing method unique to the present invention as described later. More specifically, as shown in FIG. 3B, the slope of the lens curved surface in the transparent plate member 210 is gentle from the vicinity of the edge of the microlens 500 toward the top of the lens curved surface, that is, the bottom of the recess. Therefore, the tangent line of the lens curved surface of the microlens 500 is inclined from the tangent line A and the tangent line A having a relatively large inclination from the vicinity of the edge of the microlens 500 toward the top of the lens curved surface, as shown in FIG. The tangent line B is smaller and the tangent line C is smaller than the tangent line B.

  In this embodiment, the lens curved surface of the microlens 500 is changed from a gentle slope to a steep slope from the vicinity of the edge of the microlens 500 to the top of the lens curved surface by the manufacturing method unique to the present invention. It is also possible to form. That is, in the present embodiment, it is possible to control the shape of the curved surface of the recess. Accordingly, the lens curved surface of the microlens 500 can be aspherical, and the curved surface of the microlens 500 can be designed with a high degree of freedom. Therefore, an optically optimal shape can be obtained.

  When used, the microlens array plate 20 is arranged so that each microlens 500 corresponds to each pixel of an electro-optical device such as a liquid crystal device described later. As shown in FIG. 4, as a modification of the present embodiment, the microlens array plate 20 is provided with a light shielding film 23 that at least partially defines a non-opening region in the electro-optical device to which the microlens array plate 20 is attached. May be. More specifically, the light shielding film 23 having a lattice-like plane pattern may be configured so as to define a lattice-like non-opening region independently. Or you may comprise the light shielding film 23 which has a striped planar pattern so that a grid | lattice-like non-opening area | region may be prescribed | regulated in cooperation with another light shielding film. Further, a light shielding film for defining such a non-opening region alone or partially is formed as a light shielding film built in a TFT array substrate disposed opposite to a microlens array plate 20 as a counter substrate as will be described later. May be.

  If configured as shown in FIG. 4, the non-opening region of each pixel can be more reliably defined, and light leakage between the pixels can be prevented. Furthermore, it is ensured that light is incident on electronic elements such as TFTs and TFDs that are formed in the non-opening region of the electro-optical device and have characteristics that change when a light leaks due to photoelectric effect. It is also possible to prevent it.

  In FIG. 4, a counter electrode 21 and an alignment film as described later may be formed on the light shielding film 23. In addition, an R (red), G (green), or B (blue) color filter is formed in the aperture region of each pixel partitioned by the light shielding film 23 with respect to the microlens array plate as shown in FIG. It is also possible.

<1-2: Electro-optical device>
Next, the overall configuration of the electro-optical device according to the first embodiment of the invention will be described with reference to FIGS. FIG. 5 is a plan view of the TFT array substrate as viewed from the above-described microlens array plate used as a counter substrate together with each component formed on the TFT array substrate. FIG. It is H 'sectional drawing. Here, a TFT active matrix driving type liquid crystal device with a built-in driving circuit, which is an example of an electro-optical device, is taken as an example.

  5 and 6, in the electro-optical device according to this embodiment, a TFT array substrate 10 and a microlens array plate 20 used as a counter substrate are disposed to face each other. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the microlens array plate 20, and the TFT array substrate 10 and the microlens array plate 20 are provided in a seal region positioned around the image display region 10a. They are bonded to each other by a sealing material 52.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. Further, a gap material such as glass fiber or glass bead is dispersed in the sealing material 52 to set the distance between the TFT array substrate 10 and the microlens array plate 20 (inter-substrate gap) to a predetermined value. That is, the electro-optical device according to the present embodiment is suitable for a small and enlarged display for a projector light valve.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display region 10a is provided on the microlens array plate 20 side in parallel with the inside of the seal region where the sealing material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  Of the peripheral regions located around the image display region 10 a, the data line driving circuit 101 and the external circuit connection terminal 102 are arranged on one side of the TFT array substrate 10 in the region located outside the seal region where the sealing material 52 is disposed. It is provided along. The scanning line driving circuit 104 is provided along two sides adjacent to the one side so as to be covered with the frame light shielding film 53. Further, in order to connect the two scanning line driving circuits 104 provided on both sides of the image display area 10a in this way, the TFT array substrate 10 is covered with the frame light shielding film 53 along the remaining side. A plurality of wirings 105 are provided.

  In addition, at the four corners of the microlens array plate 20, vertical conductive members 106 functioning as vertical conductive terminals between the two substrates are disposed. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region facing these corner portions. As a result, electrical conduction can be established between the TFT array substrate 10 and the microlens array plate 20.

  In FIG. 6, on the TFT array substrate 10, an alignment film is formed on the pixel electrode 9a after the pixel switching TFT, the scanning line, the data line and the like are formed. On the other hand, although a detailed configuration will be described later, on the microlens array plate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an alignment film are formed in the uppermost layer portion. Further, the liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  On the TFT array substrate 10 shown in FIGS. 5 and 6, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, the image signal on the image signal line is sampled and supplied to the data line. Sampling circuit, precharge circuit for supplying a precharge signal of a predetermined voltage level to a plurality of data lines in advance of the image signal, for inspecting the quality, defects, etc. of the electro-optical device during production or at the time of shipment An inspection circuit or the like may be formed.

  Next, the circuit configuration and operation of the electro-optical device configured as described above will be described with reference to FIG. FIG. 7 shows an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms the image display area of the electro-optical device.

  In FIG. 7, each of the plurality of pixels formed in a matrix that forms the image display region 10 a of the electro-optical device according to the present embodiment includes a pixel electrode 9 a and a TFT 30 for switching control of the pixel electrode 9 a. The data line 6 a formed and supplied with an image signal is electrically connected to the source of the TFT 30. The image signals S1, S2,..., Sn written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. Good.

  Further, the gate electrode 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are pulse-sequentially applied in this order to the scanning line 11a and the gate electrode 3a at a predetermined timing. It is comprised so that it may apply. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6a is obtained by closing the switch of the TFT 30 as a switching element for a certain period. Write at a predetermined timing.

  A predetermined level of the image signals S1, S2,..., Sn written in the liquid crystal as an example of the electro-optical material via the pixel electrode 9a is between the counter electrode 21 formed on the microlens array plate 20 for a certain period. Retained. The liquid crystal modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The light transmittance is increased, and light having a contrast corresponding to the image signal is emitted from the electro-optical device as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. The storage capacitor 70 is provided side by side along the scanning line 11a, and includes a capacitor electrode 300 including a fixed potential side capacitor electrode and fixed at a constant potential.

  The function of the microlens array plate 20 provided in the above-described electro-optical device will be described with reference to FIGS. FIG. 8 is a plan view schematically showing the configuration of the light shielding film 23 in the microlens array plate 20, and FIG. 9 is a diagram showing in more detail the configuration of the cross section shown in FIG. 6 for a plurality of pixels. FIG. 6 is a cross-sectional view for explaining the function of each microlens 500.

  As described with reference to FIG. 4, in the microlens array plate 20, the light shielding film 23 having a lattice-like planar pattern as shown in FIG. 8 is formed on the cover glass 200. In the microlens array plate 20, a non-opening area is defined by the light shielding film 23, and an area delimited by the light shielding film 23 is an opening area 700. The light shielding film 23 is formed in a stripe shape, and the non-opening region is defined by the light shielding film 23 and various components such as the capacitor electrode 300 and the data line 6a provided on the TFT array substrate 10 side. Also good.

  Each microlens 500 is arranged so as to correspond to each pixel. More specifically, as shown in FIG. 9, in the microlens array plate 20, the microlens is formed in an area at least partially including an opening area 700 and a non-opening area located around the opening area 700 for each pixel. 500 is formed.

  In FIG. 9, a counter electrode 21 made of a transparent conductive film is formed on the cover glass 200 so as to cover the light shielding film 23. Further, an alignment film (not shown in FIG. 9) is formed on the counter electrode 21.

  On the other hand, in FIG. 9, pixel electrodes 9 a are formed in regions corresponding to the respective opening regions 700 on the TFT array substrate 10. In addition, the pixel switching TFT 30, the various wirings such as the scanning line 11a and the data line 6a for driving the pixel electrode 9a, and the electronic elements such as the storage capacitor 70 are formed in the non-opening region. With this configuration, the pixel aperture ratio in the electro-optical device can be maintained relatively large. Further, although not shown in FIG. 9, an alignment film is provided on the pixel electrode 9a.

  In FIG. 9, light such as projection light incident on the microlens array plate 20 is collected by each microlens 500. In FIG. 9, the appearance of light collected by the microlens 500 is schematically shown by an alternate long and short dash line. Then, the light collected by each microlens 500 is transmitted through the liquid crystal layer 50 to be applied to the pixel electrode 9a, passes through the pixel electrode 9a, and is emitted from the TFT array substrate 10 as display light. Therefore, the light directed to the non-opening region among the light incident on the microlens array plate 20 can also be made incident on the opening region 700 by the condensing action of the microlens 500, so that the effective aperture ratio in each pixel is increased. Can do. That is, it is possible to display a brighter image by increasing the light utilization efficiency.

  Further, as described above, the shape of the lens curved surface of the microlens 500 can be controlled and formed. Therefore, the microlens 500 can disperse light incident on each pixel, and can prevent a situation where light is concentrated and irradiated at one point in each pixel. As a result, the life of the electro-optical device can be extended. Further, the light transmittance and contrast in each pixel can be improved, and as a result, high-quality image display can be performed. In addition, when the above-described electro-optical device is used as a light valve of a liquid crystal projector, matching with an optical system can be performed relatively easily.

  In addition, since the antireflection film 240 is formed in each concave portion in the microlens array plate 20 as described above, the light utilization efficiency in each microlens 500 can be further improved. Here, the function of the antireflection film 240 will be described with reference to FIGS. 10 (a) and 10 (b). FIG. 10A shows a table for explaining an example of the configuration of the microlens array plate 20 when the antireflection film 240 is provided, and FIG. 10B shows the configuration of FIG. As a comparative example, a table for explaining the configuration of the microlens array plate 20 when the antireflection film 240 is not provided is shown. In the tables shown in FIGS. 10A and 10B, the material, refractive index (n), and layer thickness [nm] of each layer of the microlens array plate 20 shown in FIG. 1 are shown.

10A, the lowermost layer, that is, the tenth layer of the microlens array plate 20 shown in FIG. 1 is composed of a transparent plate-like member 210 having a thickness of 50000 [nm]. The layers are constituted by the antireflection film 240 formed in each recess. The antireflection film 240 is formed by alternately laminating an aluminum oxide (Al ₂ O ₃ ) film having a film thickness of 24 [nm] and a silicon oxide film having a film thickness of 9 [nm]. Further, the fifth layer is constituted by a microlens 500 having a thickness of 50000 nm.

  In this embodiment, although not shown in FIGS. 2A, 4, and 9, the antireflection film 240 is provided between the cover glass 200 and each microlens 500 in FIG. 2A, for example. May be provided. In this case, the fourth layer to the first layer are constituted by an antireflection film 240 formed by alternately laminating an aluminum oxide film and a silicon oxide film as in the ninth layer to the sixth layer.

  As described above, when the microlens array plate 20 is provided in the electro-optical device, the cover glass 200 serves as an incident layer for projection light or the like. In the table shown in FIG. 10A, specific values for the thickness of the incident layer are omitted.

  When the microlens array plate 20 is configured in this way, the reflectance of the microlens 500 can be 0.006 [%]. That is, the reflection of light in the microlens 500 can be suppressed, and as a result, the light utilization efficiency can be dramatically improved.

  On the other hand, according to the configuration of the microlens array plate 20 represented by the table shown in FIG. 10B, the ninth to sixth layers and the fourth to first layers are as described above. The point that the antireflection film 240 is not provided is different from the configuration described with reference to FIG. In this case, the reflectance of the microlens 500 is about 0.412 [%], and the light use efficiency is lowered.

<1-3: Microlens array manufacturing method>
Next, a method for manufacturing the microlens array plate 20 according to the present embodiment will be described with reference to FIGS.

  FIG. 11, FIG. 13 and FIG. 14 are process diagrams schematically showing the cross-sectional configuration of the microlens array plate 20 in each step of the manufacturing process.

  First, in each lens formation region, a first film 220a made of a plurality of films each having a different etching rate for a predetermined type of etchant such as hydrofluoric acid is formed on one surface of a transparent plate member 210a such as a quartz plate. Each step relating to the formation of the first film 220 will be described with reference to FIG. Here, it is assumed that the first film 220a is composed of three types of films having different etching rates. FIG. 12 schematically shows the shapes of the three types of films formed by the respective steps described with reference to FIG. 11 in order.

In FIG. 11A, the first type film 810 is formed on the transparent plate member 210a. The first type film 810 is formed from a transparent silicon oxide film by, for example, CVD using silane (SiH ₄ ) and nitrogen monoxide (N ₂ O) as a source gas, for example. Note that FIGS. 11A to 11D specifically show one lens formation region 800.

  As shown in FIG. 12A, after the first type film 810 is formed, it is formed as a small disk-like pattern in the lens formation region 800 by patterning using a photolithography method and etching.

  Subsequently, in FIG. 11B, the first type film 810 is embedded, and the second type film 820 is formed on the transparent plate member 210a as a silicon oxide film in the same manner as the first type film 810. .

  Thereafter, in FIG. 11C, the second type film 820 is patterned in the same manner as the first type film 810, and as shown in FIG. 12B, the first type film 810 is formed in the lens formation region 800. As a larger disc-shaped pattern, it is formed coaxially with respect to the first type film 810.

  Subsequently, in FIG. 11D, the first-type and second-type films 810 and 820 are embedded, and the third-type film 830 is oxidized on the transparent plate member 210a in the same manner as the second-type film 820. It is formed as a silicon film. The third type film 830 is patterned in the same manner as the second type film 820 and has a disk-like shape larger than the first type and second type film 820 in the lens formation region 800 as shown in FIG. The pattern is formed so as to be coaxial with the first and second type films 810 and 820.

  The first-type, second-type, and third-type films 810, 820, and 830 are not limited to being formed as disk-shaped patterns, but may be formed as rectangular patterns, for example. Further, the first-type, second-type, and third-type films 810, 820, and 830 are not limited to being arranged coaxially.

  Here, the etching rate of each of the first-type, second-type, and third-type films 810, 820, and 830 is controlled by any one of the film formation temperature, the film formation speed, and the film formation pressure, for example. Is done. More specifically, when the deposition temperature is increased, a denser film is formed, and the etching rate in the film is decreased. Conversely, when the deposition temperature is decreased, the etching rate is increased. On the other hand, when the film formation rate is increased, the etching rate in the formed film is increased. Conversely, when the film formation rate is decreased, a denser film is formed and the etching rate is decreased. Furthermore, the etching rate of each film can be controlled by changing the film formation pressure by controlling the gas flow rate.

  Alternatively, the first-type, second-type, and third-type films 810, 820, and 830 are formed by CVD, and the etching rate of each film is controlled by the composition ratio of the source gas. It may be.

  In this embodiment, the etching rate is controlled in this way, and the etching rate decreases in the order of the first type film 810, the second type film 820, and the third type film 830, and The value of the etching rate in the first type film 810, the second type film 820, and the third type film 830 is greater than that of the transparent plate member 210a.

  Through the steps described above, as shown in FIG. 11D, the first film 220a in which the etching rate changes concentrically within a plane along one surface of the transparent plate member 210a is formed in the lens forming region 800. Is done. In addition, according to each process demonstrated with reference to FIG. 11, the patterning of each film | membrane which comprises the 1st film | membrane 220a can be performed comparatively easily. At that time, it is possible to prevent a situation in which the shape of the film already formed is damaged by over-etching in patterning of the film formed after the film. In addition, for example, when the first-type, second-type, and third-type films 810, 820, and 830 are not arranged coaxially, the etching rate is one surface of the transparent plate member 210a in the lens formation region 800. The first film 220a that changes in an eccentric circular shape in a plane along the line is formed.

  Subsequently, in FIG. 13A, a mask 900 is formed from a polysilicon film on the first film 220a by, for example, CVD, sputtering, or the like.

  Next, in FIG. 13B, a hole 902 is formed at a position corresponding to the center of the microlens 500 to be formed by patterning using photolithography and etching on the mask 900. At this time, the diameter of the hole 902 is set to be smaller than the diameter of the microlens 500 to be formed.

  Subsequently, in FIG. 13C, the first film 220a and the transparent plate member 210a are wet-etched with an etchant such as hydrofluoric acid through the mask 900 having such holes 902 formed therein. Then, in the first film 220a of the lens formation region 800, the etching proceeds isotropically from the upper layer, that is, from the third type film 830 to the first type film 810, and this isotropic property is obtained. By etching, an opening 222 reaching the surface of the transparent plate member 210a from the surface of the third type film 830 is formed.

  The etching rate for the etchant used here is a value controlled as described above for the first-type film 810, the second-type film 820, and the third-type film 830 constituting the first film 220a. ing. Therefore, after the opening as described above is formed, the first type film 810 is etched earlier than the third type film 830, the second type film 820, and the transparent plate member 210a. When the first type film 810 is completely etched, the second type film 820 is etched earlier than the third type film 830 and the transparent plate member 210a, and when the second type film 820 is all etched, The third type film 830 is etched faster than the transparent plate member 210a.

  In the wet etching, the degree of etching of the first-type film 810 among the first-type film 810, the second-type film 820, and the third-type film 830 is the highest with respect to the transparent plate member 210a. growing. While the first type film 810 is etched, a concave portion is dug in the transparent plate member 210a, and a curved surface on a cone having the smallest angle with the transparent plate member 210a in cross section is formed in the concave portion. Subsequently, a curved surface having the second largest cross-sectional angle is formed in the recess dug into the transparent plate member 210a while the second type film 820 is etched, and then the third type film 830 is etched. A curved surface having the largest cross-sectional angle is formed in the recessed portion that is further dug during the process.

  Thereafter, as shown in FIG. 13D, the etching is finished when a recess having a size corresponding to the microlens 500 is dug by time management or the like. At this time, the concave portion having the curved surface of the microlens 500 as described with reference to FIG. 3 is formed. Then, the unique structure of the present invention is obtained in which the first film 220 is left in the vicinity of the edge of the recess and on the upper surface of the transparent plate member 210.

  Next, in 14 (a), the mask 900 is removed by an etching process. If the film thickness of the mask 900 is set so that the mask 900 is completely removed by the etching in the process of FIG. 13C, the process of FIG. 14A can be omitted.

  Subsequently, in FIG. 14B, an antireflection film 240 covering the surface in each recess is continuously formed from the inside of the recess to the outside of the recess.

  After that, in FIG. 14C, a thermosetting transparent adhesive is applied to the surface of the antireflection film 240 in each recess, and the cover glass 200 made of neoceram, quartz, or the like is pressed against the transparent plate member 210. Harden. Thereby, the microlens 500 in which the adhesive layer 230 is filled in each concave portion dug in the transparent plate member 210 is completed. At this time, by forming the adhesive layer 230 having a higher refractive index than that of the transparent plate member 210, the aspherical microlenses 500 each formed of a convex lens can be formed relatively easily.

  Therefore, according to the method for manufacturing the microlens array plate 20 as described above, the lens forming region 800 is formed on the transparent plate member 210a by changing the etching rate in the first film 220a as described above. It becomes possible to control the shape of the curved surface of each recess.

  In the present embodiment, as described above, in each lens formation region 800, the etching rate of the first film 220a is concentrically within a plane along one surface of the transparent plate member 210a. The first film 220a may be formed so as to increase from the center of the lens forming region 800 toward the outside, without being limited to the case where it decreases from the center to the outside.

  In addition, the first film 220a is not limited to the structure composed of three kinds of films, and may be composed of two kinds or more kinds of films. Then, by controlling the etching rates of the plurality of films constituting the first film 220a as described above, the curved surface of the recess can be made to have a shape different from the shape shown in FIG. Therefore, the microlens 500 having a lens curved surface having an optimal shape can be formed.

  In addition, according to the present embodiment, as shown in FIG. 11D, in the lens formation region 800, the first film 220a has a flat surface along the one surface of the transparent plate member 210a in addition to the etching rate. It is formed so as to change concentrically. In FIG. 13B, the hole 902 in the mask 900 is opened so that the film thickness of the first film 220a decreases concentrically from the center toward the outside as viewed in a plan view. In this way, in the wet etching described with reference to FIG. 13C, in addition to the above-described change in the etching rate in the first film 220a, the first film 220a is also formed by the change in the film thickness. The degree of etching and the degree of etching of the transparent plate member 210a can be equal to or different from each other. As a result, the shape of the curved surface of the recess can be controlled.

<1-4: Modification>
A modification of the method for manufacturing the microlens array plate 20 of the present embodiment will be described. In the present modification, the manufacturing process of the first film 220a described with reference to FIG. 11 is different. Therefore, the manufacturing process of the first film 220a in this modification will be described in detail with reference to FIGS. FIG. 15 is a process diagram for explaining each process related to the formation of the first film 220a in the present modification, and schematically shows the configuration of the cross section of the microlens array plate 20 in each process in order. It is process drawing shown. FIG. 16 schematically shows the shapes of the three types of films formed by the respective steps described with reference to FIG. 15 in order. FIG. 15 shows a cross-sectional configuration of the microlens array plate 20 in one lens formation region 800.

  First, in FIG. 15A, a third type film 830a is formed on the transparent plate member 210a. The third type film 830a is patterned after film formation, and is formed as a large ring-shaped pattern along the outer periphery of the lens formation region 800, as shown in FIG.

  Subsequently, in FIG. 15B, the second type film 820 is formed by embedding the third type film 830a. Next, in FIG. 15C, the second type film 820 is patterned, and as shown in FIG. 16B, holes smaller in size than holes formed in the ring-shaped third type film 830a are formed. The ring-shaped pattern 820a has a coaxial arrangement with respect to the third type film 830a.

  Thereafter, in FIG. 15D, the second-type and third-type films 820a and 830a are embedded to form the first-type film 810a. The first type film 810a is patterned after film formation, and as shown in FIG. 16C, the second type film 810a is formed as a disk-like pattern having the same size as the second type and third type films 820a and 830a. And the third type films 820a and 830a. Therefore, the hole of the ring-shaped second type film 820a is embedded by the first type film 810a.

  Therefore, according to this modification as well, as described with reference to FIG. 11D, the first film 220a in which the etching rate changes concentrically in a plane along one surface of the transparent plate member 210a is formed. be able to.

<2: Second Embodiment>
A second embodiment according to the method for manufacturing a microlens of the present invention will be described. In the second embodiment, the manufacturing process of the first film in the first embodiment is different. Therefore, the manufacturing process of the first film in the second embodiment will be described in detail with reference to FIGS. 17 and 18 only for the differences from the first embodiment. FIG. 17 is a process diagram for describing each process related to the formation of the first film in the second embodiment, and schematically shows the configuration of the cross section of the microlens array plate in each process in order. It is process drawing. FIG. 18 schematically shows the shapes of the three types of films formed by the steps described with reference to FIG. 17 in order. In FIG. 17 and FIG. 18, common parts with the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  First, in FIG. 17A, a silicon oxide film 805 is formed on the transparent plate member 210a as a precursor film of the first film 220a by CVD or the like.

  Next, in FIG. 17B, a first mask 910a is formed on the precursor film 805 from a polysilicon film, for example, by CVD, sputtering, or the like. Then, patterning using photolithography and etching is performed on the first mask 910a to form first openings 912a in regions corresponding to the lens formation regions 800 in the first mask 910a. Thereafter, a first type of ion implantation is performed on a disk-shaped region corresponding to the first opening 912 a in the precursor film 805. More specifically, for example, ionized boron (B) is implanted into the surface of the precursor film 805 exposed in the first opening 912a. After the first-type ion implantation is completed, the first mask 910a is peeled off. As a result, in the precursor film 805, a first type film 810 having a small disk-like pattern as shown in FIG. 18A is formed.

  Subsequently, in FIG. 17C, a second mask 910b is formed on the precursor film 805 similarly to the first mask 910a. Then, the second mask 910b is patterned in the same manner as the first mask 910a, and ring-shaped second openings 912b are formed in regions corresponding to the lens formation regions 800 in the second mask 910b. Form. At this time, in the precursor film 805, the surface of the first type film 810 is covered with the second mask 910b, and the surface of the ring-shaped region adjacent to the first type film 810 is the second opening portion. It is exposed in 912b. A second type of ion implantation is performed on the surface of the precursor film 805 exposed in the second opening 912b. The second type of ion implantation is performed with an ion implantation amount of boron (B) less than that of the first type of ion implantation. After the second-type ion implantation is completed, the second mask 910b is peeled off. As a result, in the precursor film 805, the second type film 820b is formed as a ring-shaped pattern arranged side by side and coaxially with the first type film 810 as shown in FIG.

  Thereafter, in FIG. 17D, a third mask 910c is formed on the precursor film 805 in the same manner as the second mask 910b. Then, the third mask 910c is patterned in the same manner as the second mask 910b, and ring-shaped third openings 912c are formed in regions corresponding to the lens formation regions 800 in the third mask 910c. Form. At this time, in the precursor film 805, the surfaces of the first-type and second-type films 810 and 820b are covered by the third mask 910c, and the surface of the ring-shaped region adjacent to the second-type film 820b is The third opening 912c is exposed. A third type of ion implantation is performed on the surface of the precursor film 805 exposed in the third opening 912c. The third type of ion implantation is performed with an ion implantation amount of boron (B) being smaller than that of the first and second types of ion implantation. After the third-type ion implantation is completed, the third mask 910c is peeled off. As a result, the third-type film 830b is arranged side by side and coaxially with the second-type film 820b as shown in FIG. 18C, and a ring-shaped pattern along the outer periphery of the lens forming region 800. Formed as.

  As described above, by performing three types of ion implantations with different ion implantation amounts, the etching rate is controlled, and the first-type film 810, the second-type film 820b, and the third-type film are controlled. In the order of 830b, the etching rate decreases, and the etching rate values of the first type film 810, the second type film 820b, and the third type film 830b become larger than those of the transparent plate member 210a. Accordingly, in the lens formation region 800, the first film 220a in which the etching rate changes concentrically within a plane along one surface of the transparent plate member 210a is formed. In the second embodiment, as shown in FIGS. 17D and 18C, the first film 220a having a flat surface can be formed.

  In FIG. 17A, the precursor film 805 may be formed as a film having a different etching rate from the transparent plate member 210a. In this way, the first film 220a can be more easily formed by reducing the types of ion implantation performed on the precursor film 805 as described above.

<2-1: Modification>
A method for manufacturing the microlens array plate 20 of the second embodiment will be described with reference to FIG. 19 in addition to FIG. FIG. 19 is a process diagram for describing each process related to the formation of the first film 220a in the present modification, and schematically shows the configuration of the cross section of the microlens array plate 20 in each process in order. It is process drawing shown. FIG. 19 shows a cross-sectional configuration of the microlens array plate 20 in one lens formation region 800.

  In this modification, first, in FIG. 19A, the first type film 810 is formed by patterning after film formation by the CVD method or the like, as in the first embodiment. As a result, the first type film 810 is formed on the transparent plate member 210a as a small disk-shaped pattern as shown in FIG.

  Subsequently, in FIG. 19B, the second type film 820c is patterned after film formation in the same manner as the first type film 810. As a result, the second type film 820c is formed as a ring-shaped pattern arranged side by side and coaxially with the first type film 810 in substantially the same manner as the second type film 820b shown in FIG. It is formed. As shown in FIG. 19B, if the second type film 820c is left thin on the surface of the first type film 810, the first type film 830c will be described later when patterning the third type film 830c. Overetching in the film 810 can be prevented.

  Subsequently, in FIG. 19C, the third type film 830c is patterned after film formation in the same manner as the second type film 820c, so that the third type film 830b shown in FIG. In general, the ring-shaped pattern is formed along the outer periphery of the lens forming region 800 by being arranged side by side and coaxially on the second type film 820c.

  Thereafter, in FIG. 19D, a planarization process using a chemical mechanical polishing (CMP) method or the like is performed on the first type film 810, the second type film 820c, and the third type film 830c. As a result, the first film 220a having a planarized surface can be formed.

  In this modification, it is preferable that the etching rates of the first-type, second-type, and third-type films 810, 820c, and 830c are controlled in the same manner as in the first embodiment.

<3: Electronic equipment>
Next, an overall configuration, particularly an optical configuration, of an embodiment of a projection color display device as an example of an electronic apparatus using the above-described electro-optical device as a light valve will be described. FIG. 20 is a schematic cross-sectional view of the projection type color display device.

  In FIG. 20, a liquid crystal projector 1100, which is an example of a projection type color display device, prepares three liquid crystal modules including a liquid crystal device having a drive circuit mounted on a TFT array substrate, and RGB light valves 100R, 100G, and The projector is configured as 100B. In the liquid crystal projector 1100, when projection light is emitted from a lamp unit 1102 of a white light source such as a metal halide lamp, the light components R, G, and R corresponding to the three primary colors of RGB are obtained by three mirrors 1106 and two dichroic mirrors 1108. The light is divided into B and led to the light valves 100R, 100G and 100B corresponding to the respective colors. In particular, the B light is guided through a relay lens system 1121 including an incident lens 1122, a relay lens 1123, and an exit lens 1124 in order to prevent light loss due to a long optical path. Light components corresponding to the three primary colors modulated by the light valves 100R, 100G, and 100B are synthesized again by the dichroic prism 1112 and then projected as a color image on the screen via the projection lens 1114.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the invention or the concept that can be read from the entire claims and the specification, and the microlens with such a change can be changed. A manufacturing method, a microlens manufactured by the manufacturing method, an electro-optical device including the microlens, and an electronic apparatus including the electro-optical device are also included in the technical scope of the present invention.

It is a schematic perspective view of a micro lens array board. FIG. 2A is a partially enlarged cross-sectional view of a microlens array plate, and FIG. 2B is a partially enlarged plan view showing an enlarged portion related to four microlenses in the microlens array plate. . FIG. 3A and FIG. 3B are partial enlarged cross-sectional views showing an enlarged portion related to one microlens. It is a partial expanded sectional view of the micro lens array board in a modification. It is a top view which shows the whole structure of an electro-optical apparatus. It is H-H 'sectional drawing of FIG. 2 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixel portions formed in a matrix that forms an image display region of an electro-optical device. It is a top view which shows typically the structure of the light shielding film in a micro lens array board. It is sectional drawing for demonstrating the function of each micro lens. FIG. 10A is a diagram showing a table for explaining an example of the configuration of the microlens array plate, and FIG. 10B is a table for explaining the configuration of the microlens array plate of the comparative example. FIG. It is manufacturing process sectional drawing (the 1) which shows the manufacturing method of the micro lens array board which concerns on 1st Embodiment later on. It is a figure which shows roughly the order of the shape of three types of films | membranes formed by each process concerning formation of a 1st film later on. FIG. 6 is a manufacturing process cross-sectional view (part 2) illustrating the manufacturing method of the microlens array plate according to the first embodiment in order. It is manufacturing process sectional drawing (the 3) which shows the manufacturing method of the micro lens array board which concerns on 1st Embodiment later on. It is process drawing for demonstrating each process which concerns on formation of the 1st film | membrane in the modification of 1st Embodiment. In the modification of 1st Embodiment, it is a figure which shows roughly the order of the shape of three types of films | membranes formed by each process concerning formation of a 1st film later on. It is process drawing for demonstrating each process which concerns on formation of the 1st film | membrane in 2nd Embodiment. In 2nd Embodiment, it is a figure which shows roughly the order of the shape of three types of films | membranes formed by each process which concerns on formation of a 1st film later on. It is process drawing for demonstrating each process which concerns on formation of the 1st film | membrane in the modification of 2nd Embodiment. 1 is a schematic cross-sectional view showing a color liquid crystal projector as an example of a projection type color display device which is an embodiment of an electronic apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Micro lens array board 200 ... Cover glass 210, 210a ... Transparent board member 220, 220a ... 1st film | membrane 230 ... Adhesion layer 240 ... Antireflection film 500 ... Micro lens 800 ... Lens formation area

Claims (20)

Forming a first film on one surface of the substrate, including a portion in each lens forming region of the one surface that has a portion in which an etching rate with respect to a predetermined type of etchant changes in a contour line in a plane along the one surface;
Forming on the first film a mask having a hole in a location corresponding to the approximate center of a microlens to be formed in the lens formation region;
A method of manufacturing a microlens, comprising: performing a wet etching through the mask to dig an aspherical concave portion defining a curved surface of the microlens into the substrate. 2. The microlens according to claim 1, wherein the first film is formed so as to include a portion where the etching rate changes concentrically in a plane along the one surface in each lens formation region. Production method. 3. The microlens according to claim 1, wherein the first film is formed so as to include a portion where the film thickness changes in a contour line in a plane along the one surface in each lens formation region. Manufacturing method. 4. The microlens manufacturing method according to claim 3, wherein the first film is formed so as to include a portion where the film thickness changes concentrically in a plane along the one surface in each lens formation region. Method. The step of forming the first film includes a step of forming, in each lens forming region, a plurality of films having different etching rates, which are arranged in contour lines on the one surface, respectively. The manufacturing method of the microlens as described in any one of 1-4.   6. The method of manufacturing a microlens according to claim 5, wherein each of the plurality of films is formed in a disk shape.   6. The method of manufacturing a microlens according to claim 5, wherein each of the plurality of films is formed in a substantially square shape. 8. The micro of any one of claims 5 to 7, wherein the step of forming the first film includes a step of stacking the plurality of films on the one surface in ascending order or in descending order. Lens manufacturing method.   The method for manufacturing a microlens according to any one of claims 5 to 8, wherein an etching rate of each of the films is controlled by a film forming temperature, a film forming speed, or a film forming pressure.   9. The method of manufacturing a microlens according to claim 5, wherein each of the films is formed by a CVD method, and an etching rate of each of the films is controlled by a composition ratio of a source gas. . In the step of forming the first film, in each lens forming region, a plurality of films having different etching rates are formed on the one surface, and at least the second and subsequent films from the center are respectively in a ring shape and mutually. The method of manufacturing a microlens according to any one of claims 1 to 4, further comprising a step of forming a coaxial arrangement. The method of manufacturing a microlens according to claim 11, wherein the step of forming the first film includes a step of forming the plurality of films side by side in the plane. The step of forming the first film includes forming a precursor film of the first film on the one surface,
Dividing the precursor film into a plurality of processing regions in the ring shape or substantially disk shape in the lens forming region, and performing a plurality of types of ion implantation on the plurality of processing regions. The manufacturing method of the microlens of Claim 11 or 12.   The method of manufacturing a microlens according to claim 13, wherein the precursor film is formed so that the etching rate has a value different from that of the substrate. Forming a first film on one surface of the substrate including a portion where the film thickness changes in a contour line in a plane along the one surface in each lens forming region of the one surface;
Forming on the first film a mask having a hole in a location corresponding to the approximate center of a microlens to be formed in the lens formation region;
A method of manufacturing a microlens, comprising: performing a wet etching through the mask to dig an aspherical concave portion defining a curved surface of the microlens into the substrate.   16. The method according to claim 1, further comprising a step of forming an antireflection film so as to cover the surface of the recess using at least one transparent member in at least the recess of the substrate. The method for producing a microlens according to one item.   17. The micro of claim 1, further comprising a step of placing a transparent medium having a refractive index higher than that of the transparent substrate into the concave portion. Lens manufacturing method.   The microlens manufactured by the manufacturing method of the microlens as described in any one of Claim 1 to 17. A microlens according to claim 18,
A display electrode facing the microlens;
An electro-optical device comprising: at least one of a wiring and an electronic element connected to the display electrode. An electronic apparatus comprising the electro-optical device according to claim 19.

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