JP2015200690A - Micro lens substrate, and electro-optic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro lens substrate which can improve light collection efficiency, and an electro-optic device.SOLUTION: A micro lens substrate comprises a first translucent layer 51a formed along a curved face of a micro lens, and a second translucent layer 51b that covers the first translucent layer 51a and has a refractive index different from that of the first translucent layer 51a.

Description

  The present invention relates to a microlens substrate and an electro-optical device.

  As the electro-optical device, for example, an active drive type liquid crystal device including a transistor for each pixel as an element for controlling switching of a pixel electrode is known. The liquid crystal device is used in, for example, a direct view display or a light valve.

  For example, as described in Patent Document 1, such a liquid crystal device includes a microlens substrate provided with a microlens at a position corresponding to each pixel of the liquid crystal device in order to increase the light use efficiency.

  For example, a microlens substrate is manufactured by applying a resist material (resin material) on a base material, patterning the resin material, and then performing reflow by high-temperature baking to form a resist pattern having a convex curved surface. To do. Thereafter, by etching the substrate and the resist pattern using the resist pattern as a mask, a microlens substrate in which the shape of the microlens is transferred to the base material can be formed.

Japanese Patent Laid-Open No. 10-206605

  However, there may be a gap that does not function as a microlens between adjacent microlenses during the manufacturing process of the microlens. Thereby, there exists a subject that the condensing efficiency by a microlens falls.

  An aspect of the present invention has been made to solve at least a part of the above problems, and can be realized as the following forms or application examples.

  Application Example 1 A microlens substrate according to this application example includes a first light-transmitting layer formed along a curved surface of a lens, the first light-transmitting layer, the first light-transmitting layer, And a second translucent layer having a different refractive index.

  According to this application example, the second light-transmitting layer having a different refractive index is arranged to cover the first light-transmitting layer to form the curved surface of the lens, and thus the lens that is not completed in the first light-transmitting layer. This shape can be supplemented by the second translucent layer. Therefore, a microlens close to the curved surface of a regular lens can be provided. Furthermore, since the refractive indexes of the first light transmissive layer and the second light transmissive layer are made different from each other, the light collection efficiency by the microlens can be increased.

  Application Example 2 In the microlens substrate according to the application example, the microlens including the second light-transmitting layer disposed on the first light-transmitting layer may be a convex microlens. preferable.

  According to this application example, since the second light-transmitting layer is disposed so as to cover the first light-transmitting layer, the gap between adjacent convex microlenses is eliminated, and the microscopic surface close to the curved surface of the regular lens is obtained. A lens can be provided.

  Application Example 3 In the microlens substrate according to the application example described above, it is preferable that the refractive index of the first light transmissive layer is larger than the refractive index of the second light transmissive layer.

  According to this application example, since the refractive index of the second light-transmitting layer covering the first light-transmitting layer is smaller, light can be condensed in the convex microlens.

  Application Example 4 In the microlens substrate according to the application example, the convex microlens including the first light-transmitting layer and the second light-transmitting layer are opposed to the concave microlens. It is preferable that they are arranged.

  According to this application example, since the double microlens structure in which the convex microlens and the concave microlens are arranged in a pair is provided, the light can be more easily collected.

  Application Example 5 An electro-optical device according to this application example includes the microlens substrate described above.

  According to this application example, since the microlens substrate is provided, it is possible to provide an electro-optical device capable of increasing the light collection efficiency.

FIG. 2 is a schematic perspective view illustrating a configuration of a liquid crystal device. The schematic perspective view which shows the structure of a microlens board | substrate among liquid crystal devices. The schematic plan view which shows the structure of a liquid crystal panel. FIG. 4 is a schematic cross-sectional view taken along the line H-H ′ of the liquid crystal panel shown in FIG. 3. FIG. 3 is an equivalent circuit diagram illustrating an electrical configuration of the liquid crystal panel. FIG. 2 is a schematic cross-sectional view mainly showing a pixel structure in a liquid crystal panel. FIG. 3 is a schematic cross-sectional view illustrating a structure of a liquid crystal device including a microlens substrate. 5 is a flowchart showing a method for manufacturing a liquid crystal device in the order of steps. The schematic cross section which shows the manufacturing method of a microlens board | substrate among liquid crystal devices in order of a process. The schematic cross section which shows the manufacturing method of a microlens board | substrate among liquid crystal devices in order of a process. The schematic cross section which shows the manufacturing method of a microlens board | substrate among liquid crystal devices in order of a process. Schematic which shows the structure of a projection type display apparatus. FIG. 6 is a schematic cross-sectional view illustrating a configuration of a liquid crystal device including a microlens substrate according to a modification.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  In the following embodiments, for example, when “on the substrate” is described, the substrate is disposed so as to be in contact with the substrate, or is disposed on the substrate via another component, or the substrate. It is assumed that a part is arranged so as to be in contact with each other and a part is arranged via another component.

  In this embodiment, as an example of an electro-optical device, an active matrix liquid crystal device including a thin film transistor (TFT) as a pixel switching element will be described as an example. This liquid crystal device can be suitably used, for example, as a light modulation element (liquid crystal light valve) of a projection display device (liquid crystal projector).

<Configuration of liquid crystal device as electro-optical device and microlens substrate>
FIG. 1 is a schematic perspective view showing the configuration of the liquid crystal device. FIG. 2 is a schematic perspective view showing a configuration of a microlens substrate in the liquid crystal device. Hereinafter, configurations of the liquid crystal device and the microlens substrate will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the liquid crystal device 1 of this embodiment includes a liquid crystal panel 100 and a microlens substrate 50. The liquid crystal panel 100 includes an element substrate 10 and a counter substrate 20 including a part of the microlens substrate 50 disposed on the light incident side of the element substrate 10.

  As shown in FIG. 2, the microlens substrate 50 includes an incident side lens layer 41 disposed on the light incident side, an exit side lens layer 42 disposed on the light exit side, and the incident side lens layer 41 and the exit. A path layer 43 disposed between the side lens layer 42, a first microlens 44 disposed between the incident side lens layer 41 and the path layer 43, and the path layer 43 and the exit side lens layer 42. And a second microlens 51 disposed therebetween.

  The second microlens 51 includes a first light transmissive layer 51 a and a second light transmissive layer 51 b disposed between the first light transmissive layer 51 a and the emission side lens layer 42. .

<Configuration of the liquid crystal panel constituting the liquid crystal device>
FIG. 3 is a schematic plan view showing the configuration of the liquid crystal panel. 4 is a schematic cross-sectional view taken along the line HH ′ of the liquid crystal panel shown in FIG. FIG. 5 is an equivalent circuit diagram showing an electrical configuration of the liquid crystal panel. Hereinafter, the configuration of the liquid crystal panel will be described with reference to FIGS.

  As shown in FIGS. 3 and 4, the liquid crystal panel 100 of the present embodiment includes an element substrate 10 and a counter substrate 20 that are arranged to face each other, and a liquid crystal layer 15 that is sandwiched between the pair of substrates 10 and 20. Have For example, a transparent substrate such as a glass substrate or a quartz substrate is used as the first base material 10a as a substrate constituting the element substrate 10.

  The element substrate 10 is larger than the counter substrate 20, and both the substrates 10, 20 are bonded together via a seal material 14 disposed along the outer periphery of the counter substrate 20. In the element substrate 10, liquid crystal having positive or negative dielectric anisotropy is sealed between the opposing substrates 20 inside the sealing material 14 provided in an annular shape in plan view, thereby forming a liquid crystal layer 15. For the sealing material 14, for example, an adhesive such as a thermosetting or ultraviolet curable epoxy resin is employed. Spacers (not shown) are mixed in the sealing material 14 to keep the distance between the pair of substrates constant.

  A display area E in which a plurality of pixels P are arranged is provided inside the inner edge of the sealing material 14. The display area E may include dummy pixels arranged so as to surround the plurality of pixels P in addition to the plurality of pixels P contributing to display. Although not shown in FIGS. 3 and 4, a light shielding layer (black matrix: BM) that divides a plurality of pixels P in a plane in the display area E is provided on the counter substrate 20.

  A data line driving circuit 22 is provided between the sealing material 14 along one side of the element substrate 10 and the one side. Further, an inspection circuit 25 is provided between the sealing material 14 and the display area E along the other one side facing the one side. Further, a scanning line driving circuit 24 is provided between the sealing material 14 and the display area E along the other two sides that are orthogonal to the one side and face each other. A plurality of wirings 29 connecting the two scanning line driving circuits 24 are provided between the sealing material 14 and the inspection circuit 25 along the other one side facing the one side.

  A light shielding layer 18 (parting part) as a light shielding member is provided between the sealing material 14 arranged in a ring shape on the counter substrate 20 and the display area E. The light shielding layer 18 is made of, for example, a light shielding metal or metal oxide, and the inside of the light shielding layer 18 is a display region E having a plurality of pixels P. Although not shown in FIG. 3, the display region E is also provided with a light shielding layer that divides a plurality of pixels P in a plane.

  Wirings connected to the data line driving circuit 22 and the scanning line driving circuit 24 are connected to a plurality of external connection terminals 35 arranged along the one side. Hereinafter, the direction along the one side will be referred to as the X direction, and the direction along the other two sides orthogonal to the one side and facing each other will be described as the Y direction.

  As shown in FIG. 4, on the surface of the first base material 10a on the liquid crystal layer 15 side, a transparent pixel electrode 27 provided for each pixel P and a thin film transistor (TFT: Thin Film Transistor, which is a switching element) are provided. Hereinafter, it is referred to as “TFT 30”), signal wirings, and an alignment film 28 covering them.

  In addition, a light shielding structure is employed that prevents light from entering the semiconductor layer in the TFT 30 to make the switching operation unstable. The element substrate 10 in the present invention includes at least the pixel electrode 27, the TFT 30, and the alignment film 28.

  On the surface of the counter substrate 20 on the liquid crystal layer 15 side, the light shielding layer 18, the insulating layer 33 formed so as to cover the light shielding layer 18, the counter electrode 31 provided so as to cover the insulating layer 33, and the counter electrode 31 And an alignment film 32 is provided. The counter substrate 20 in the present invention includes at least an insulating layer 33, a counter electrode 31, and an alignment film 32.

  As shown in FIG. 3, the light shielding layer 18 surrounds the display area E and is provided at a position where the scanning line driving circuit 24 and the inspection circuit 25 overlap in a plan view (illustration is simplified). Thus, the light incident on the peripheral circuit including these drive circuits from the counter substrate 20 side is shielded, and the peripheral circuit is prevented from malfunctioning due to the light. Further, unnecessary stray light is shielded from entering the display area E, and high contrast in the display of the display area E is ensured.

  The insulating layer 33 is made of an inorganic material such as silicon oxide, for example, and is provided so as to cover the light shielding layer 18 with light transmittance. As a method of forming such an insulating layer 33, for example, a method of forming a film using a plasma CVD (Chemical Vapor Deposition) method or the like can be cited.

  The counter electrode 31 is made of a transparent conductive film such as ITO, for example, covers the insulating layer 33, and electrically connects the wiring on the element substrate 10 side by the vertical conduction portions 26 provided at the four corners of the counter substrate 20 as shown in FIG. Connected.

  The alignment film 28 covering the pixel electrode 27 and the alignment film 32 covering the counter electrode 31 are selected based on the optical design of the liquid crystal device 1. For example, an inorganic alignment film formed by depositing an inorganic material such as SiOx (silicon oxide) using a vapor deposition method and substantially vertically aligning with liquid crystal molecules having negative dielectric anisotropy can be given.

  Such a liquid crystal device 1 is of a transmissive type, and the transmittance of the pixel P when the voltage is not applied is larger than the transmittance when the voltage is applied, or the transmittance of the pixel P when the voltage is not applied. A normally black mode optical design is employed, which is smaller than the transmittance when a voltage is applied. Polarizing elements are arranged and used according to the optical design on the light incident side and the light exit side, respectively.

  As shown in FIG. 5, the liquid crystal panel 100 includes a plurality of scanning lines 3a and a plurality of data lines 6a that are insulated from each other and orthogonal to each other in at least the display region E, and a capacitor line 3b as a common potential wiring. The direction in which the scanning line 3a extends is the X direction, and the direction in which the data line 6a extends is the Y direction.

  A pixel electrode 27, a TFT 30, and a capacitive element 16 are provided in a region divided by the scanning line 3a, the data line 6a, the capacitive line 3b, and these signal lines, and these constitute a pixel circuit of the pixel P. doing.

  The scanning line 3 a is electrically connected to the gate of the TFT 30, and the data line 6 a is electrically connected to the data line side source / drain region (source region) of the TFT 30. The pixel electrode 27 is electrically connected to the pixel electrode side source / drain region (drain region) of the TFT 30.

  The data line 6a is connected to the data line driving circuit 22 (see FIG. 3), and supplies image signals D1, D2,..., Dn supplied from the data line driving circuit 22 to the pixels P. The scanning line 3a is connected to the scanning line driving circuit 24 (see FIG. 3), and supplies the scanning signals SC1, SC2,..., SCm supplied from the scanning line driving circuit 24 to each pixel P.

  The image signals D1 to Dn supplied from the data line driving circuit 22 to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each of a plurality of adjacent data lines 6a for each group. Good. The scanning line driving circuit 24 supplies the scanning signals SC1 to SCm to the scanning line 3a at a predetermined timing.

  In the liquid crystal panel 100, the TFT 30 serving as a switching element is turned on for a predetermined period by the input of the scanning signals SC1 to SCm, so that the image signals D1 to Dn supplied from the data line 6a are supplied to the pixel electrode 27 at a predetermined timing. It is the structure written in. The predetermined level of the image signals D1 to Dn written to the liquid crystal layer 15 through the pixel electrode 27 is held for a certain period between the pixel electrode 27 and the counter electrode 31 disposed to face the liquid crystal layer 15. The

  In order to prevent the held image signals D1 to Dn from leaking, the capacitive element 16 is connected in parallel with the liquid crystal capacitance formed between the pixel electrode 27 and the counter electrode 31. The capacitive element 16 is provided between the pixel electrode side source / drain region of the TFT 30 and the capacitive line 3b.

<Configuration of pixels constituting liquid crystal panel>
FIG. 6 is a schematic cross-sectional view mainly showing the structure of a pixel in the liquid crystal panel. Hereinafter, the pixel structure of the liquid crystal panel will be described with reference to FIG. FIG. 6 shows the cross-sectional positional relationship of each component, and is represented on a scale that can be clearly shown.

  As shown in FIG. 6, the liquid crystal panel 100 includes an element substrate 10 and a counter substrate 20 disposed to face the element substrate 10. As described above, the first base material 10a configuring the element substrate 10 is configured by, for example, a quartz substrate.

  As shown in FIG. 6, a lower light-shielding layer 3c containing a material such as Al (aluminum), Ti (titanium), Cr (chromium), W (tungsten) is formed on the first base material 10a. ing. The lower light-shielding layer 3c is patterned in a lattice shape in a plane, and defines the opening area of each pixel P. Note that the lower light shielding layer 3c may have conductivity and function as a part of the scanning line 3a. A base insulating layer 11a made of silicon oxide or the like is formed on the first base material 10a and the lower light shielding layer 3c.

  On the base insulating layer 11a, the TFT 30, the scanning line 3a, and the like are formed. The TFT 30 has, for example, an LDD (Lightly Doped Drain) structure, and includes a semiconductor layer 30a made of polysilicon (high-purity polycrystalline silicon), a gate insulating layer 11g formed on the semiconductor layer 30a, A gate electrode 30g made of a polysilicon film or the like formed on the gate insulating layer 11g. The scanning line 3a also functions as the gate electrode 30g.

  The semiconductor layer 30a is formed as an N-type TFT 30 by implanting N-type impurity ions such as phosphorus (P) ions. Specifically, the semiconductor layer 30a includes a channel region 30c, a data line side LDD region 30s1, a data line side source / drain region 30s, a pixel electrode side LDD region 30d1, and a pixel electrode side source / drain region 30d. ing.

  The channel region 30c is doped with P-type impurity ions such as boron (B) ions. The other regions (30s1, 30s, 30d1, 30d) are doped with N-type impurity ions such as phosphorus (P) ions. Thus, the TFT 30 is formed as an N-type TFT.

  A first interlayer insulating layer 11b made of silicon oxide or the like is formed on the gate electrode 30g and the gate insulating layer 11g. A capacitive element 16 is provided on the first interlayer insulating layer 11b. Specifically, the first capacitor electrode 16a as the pixel potential side capacitor electrode electrically connected to the pixel electrode side source / drain region 30d and the pixel electrode 27 of the TFT 30, and the capacitor line 3b (as the fixed potential side capacitor electrode). A part of the second capacitor electrode 16b) is disposed to face the dielectric film 16c, whereby the capacitor element 16 is formed.

  The dielectric film 16c is, for example, a silicon nitride film. The second capacitor electrode 16b (capacitor line 3b) includes at least one of refractory metals such as Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), and Mo (molybdenum). , Metal simple substance, alloy, metal silicide, polysilicide, and a laminate of these. Alternatively, it can be formed from an Al (aluminum) film.

  The first capacitor electrode 16 a is made of, for example, a conductive polysilicon film and functions as a pixel potential side capacitor electrode of the capacitor element 16. However, the first capacitor electrode 16a may be composed of a single layer film or a multilayer film containing a metal or an alloy, like the capacitor line 3b. In addition to functioning as a pixel potential side capacitance electrode, the first capacitance electrode 16a relay-connects the pixel electrode 27 and the pixel electrode side source / drain region 30d (drain region) of the TFT 30 via contact holes CNT1, CNT3, and CNT4. It has the function to do.

  A data line 6a is formed on the capacitive element 16 via the second interlayer insulating layer 11c. The data line 6a is connected to the data line side source / drain of the semiconductor layer 30a through the contact hole CNT2 formed in the gate insulating layer 11g, the first interlayer insulating layer 11b, the dielectric film 16c, and the second interlayer insulating layer 11c. It is electrically connected to the region 30s (source region).

  A pixel electrode 27 is formed on the data line 6a via a third interlayer insulating layer 11d. The third interlayer insulating layer 11d is made of, for example, silicon oxide or nitride, and is subjected to a flattening process for flattening the convex portions on the surface generated by covering the region where the TFT 30 is provided. Examples of the planarization method include chemical mechanical polishing (CMP) and spin coating. A contact hole CNT4 is formed in the third interlayer insulating layer 11d.

  The pixel electrode 27 is electrically connected to the pixel electrode side source / drain region 30d (drain region) of the semiconductor layer 30a by being connected to the first capacitor electrode 16a via the contact holes CNT4 and CNT3. The pixel electrode 27 is formed of a transparent conductive film such as an ITO film, for example.

On the third interlayer insulating layer 11d between the pixel electrode 27 and the adjacent pixel electrode 27, an alignment film 28 obtained by obliquely depositing an inorganic material such as silicon oxide (SiO ₂ ) is provided. On the alignment film 28, a liquid crystal layer 15 in which liquid crystal or the like is sealed in a space surrounded by the sealing material 14 (see FIGS. 3 and 4) is provided.

On the other hand, an insulating layer 33 made of, for example, a PSG film (phosphorus-doped silicon oxide) or the like is provided on the second base material (outgoing side lens layer 42) (on the liquid crystal layer 15 side). On the insulating layer 33, the counter electrode 31 is provided over the entire surface. On the counter electrode 31, an alignment film 32 is formed by obliquely depositing an inorganic material such as silicon oxide (SiO ₂ ). The counter electrode 31 is made of a transparent conductive film such as an ITO film, for example, like the pixel electrode 27 described above.

  The liquid crystal layer 15 takes a predetermined alignment state by the alignment films 28 and 32 in a state where no electric field is generated between the pixel electrode 27 and the counter electrode 31. The sealing material 14 is an adhesive made of, for example, a photo-curing resin or a thermosetting resin for bonding the element substrate 10 and the counter substrate 20, and sets the distance between the element substrate 10 and the counter substrate 20 to a predetermined value. Spacers such as glass fiber or glass beads are mixed.

<Configuration of liquid crystal device as electro-optical device>
FIG. 7 is a schematic cross-sectional view showing the structure of a liquid crystal device including a microlens substrate. Hereinafter, the structure of a liquid crystal device including a microlens substrate will be described with reference to FIG. Note that the liquid crystal device illustrated in FIG. 7 is illustrated by appropriately omitting detailed members of the liquid crystal panel illustrated in FIG.

  As shown in FIG. 7, the liquid crystal device 1 includes a liquid crystal panel 100 and a microlens substrate 50. In the present embodiment, a part of the counter substrate 20 in the liquid crystal panel 100 is configured to overlap with a part of the exit side lens layer 42 of the microlens substrate 50.

  The incident side lens layer 41 is formed with a concave first microlens 44 at the interface with the pass layer 43. The plurality of first microlenses 44 are arranged in a matrix in the incident side lens layer 41. The incident side lens layer 41 is made of, for example, quartz. The refractive index (n) of quartz is 1.46, for example.

  A translucent layer is formed in the concave portion 44a of the incident side lens layer 41 and filled with silicon oxynitride (SiON). The refractive index (n1) of silicon oxynitride (SiON) is about 1.55 to 1.70.

A pass layer 43 is disposed on the incident side lens layer 41 and the first microlens 44 (on the liquid crystal layer 15 side). The pass layer 43 is disposed to adjust the distance between the incident side lens layer 41 and the output side lens layer 42. The material of the pass layer 43 is silicon oxide (SiO ₂ ). The refractive index (n2) of silicon oxide is about 1.46 to 1.52.

  On the pass layer 43 (on the liquid crystal layer 15 side), a first light-transmissive layer 51a that constitutes the second microlens 51 is disposed. There may be a gap that does not have a lens shape between the adjacent first light-transmitting layers 51a. If there is a gap, the light utilization efficiency decreases. The material of the first light transmissive layer 51a is silicon oxynitride (SiON). The refractive index (n3) of silicon oxynitride is about 1.55 to 1.70.

  A second translucent layer 51b that constitutes the second microlens 51 is disposed so as to cover the first translucent layer 51a and the pass layer 43. The second translucent layer 51b is disposed so as to cover the first translucent layer 51a in order to form a shape between the incomplete first translucent layers 51a that does not have a lens shape into a regular lens shape. Has been. The material of the second light transmissive layer 51b is silicon oxynitride (SiON). The refractive index of silicon oxynitride (n4) is about 1.55 to 1.70.

On the second light transmissive layer 51b (on the liquid crystal layer 15 side), an emission side lens layer 42 configured also as a part of the counter substrate 20 is disposed. The material of the exit side lens layer 42 is silicon oxide (SiO ₂ ). The refractive index (n5) of silicon oxide is about 1.46 to 1.52. The relationship between the refractive index n3 of the first translucent layer 51a and the refractive index n4 of the second translucent layer 51b is preferably such that n4 <n3 by adjusting some components to be added.

The relationship between the refractive indexes n, n1, n2, n3, n4, and n5 is as follows.
n5 <n4 <n3
n1 ≠ n3
n1> n2

  The liquid crystal panel 100 described above is disposed on the light exit side of the microlens substrate 50. The light passes through the microlens substrate 50, enters from the counter substrate 20 side of the liquid crystal panel 100, and exits from the element substrate 10 side.

  When the microlens substrate 50 is used, two microlenses (double microlens including the first microlens 44 and the second microlens 51) are arranged so as to correspond to each pixel P of the element substrate 10, for example. The Therefore, the incident light incident on the microlens is condensed toward each pixel P in the element substrate 10 by the refraction action of the microlens.

<Manufacturing method of liquid crystal device (microlens substrate)>
FIG. 8 is a flowchart showing a method of manufacturing the liquid crystal device in the order of steps. 9 to 11 are schematic cross-sectional views illustrating a method of manufacturing a microlens substrate in the liquid crystal device in the order of steps. Hereinafter, a method for manufacturing the liquid crystal device will be described with reference to FIGS.

  First, a manufacturing method on the element substrate 10 side will be described. First, in step S11, the TFT 30 and the like are formed on the first base material 10a made of a quartz substrate or the like. Specifically, it is formed by using a well-known film formation technique, photolithography technique, and etching technique. Hereinafter, the layer in which these are formed will be simply referred to as a circuit layer (not shown).

  In step S12, the pixel electrode 27 is formed. Specifically, the pixel electrode 27 made of ITO or the like is formed on a circuit layer (not shown) including the TFT 30 and the like by using a well-known film formation technique, photolithography technique, and etching technique.

In step S <b> 13, the alignment film 28 is formed so as to cover the pixel electrode 27. As a manufacturing method of the alignment film 28, for example, an oblique deposition method in which an inorganic material such as silicon oxide (SiO ₂ ) is obliquely deposited is used.

  Next, a manufacturing method on the counter substrate 20 side will be described. First, in step S21, the microlens substrate 50 is formed. Specifically, this will be described with reference to FIGS.

  9A, an oxide film 53 (high temperature oxide film, HTO: High Temperature Oxide (for example, annealing at about 700 ° C. to 1100 ° C.) is performed on the second substrate 20a (the liquid crystal layer 15 side). And a polysilicon film 54 is formed on the oxide film 53. For the oxide film 53, for example, silicon oxide formed by a CVD (Chemical Vapor Deposition) method having an etching rate faster than that of the second base material 20a is used. The polysilicon film 54 is used later as a mask.

  In the step shown in FIG. 9B, an opening hole 54 a is formed in the polysilicon film 54. Specifically, using a resist pattern (not shown) as a mask, the polysilicon film 54 at a position corresponding to the pixel P is etched to form a plurality of opening holes 54a. The size of the opening hole 54a is smaller than the opening region of the pixel P because the recess 44a is expanded in a later etching process. Thereby, the mask 54b having the opening hole 54a is completed.

  The mask 54b made of a polysilicon film uses a condition that is not etched. The etchant is, for example, hydrofluoric acid.

  In the step shown in FIG. 9C, the oxide film 53 and the second base material 20a are subjected to the first etching process through the opening hole 54a of the mask 54b to open the oxide film 53, and the second base material. A recess 44a is formed in 20a. The etching process is a dry etching process (anisotropic etching). By adjusting the etching rate as the role of the oxide film 53, the lateral width and depth of the recess 44a formed in the second base material 20a can be changed.

  Next, a second etching process is performed on the oxide film 53 and the second base material 20a through the mask 54b. The second etching process is a wet etching process (isotropic etching). Thereby, the opening hole of the oxide film 53 is widened, and the concave portion 44a of the second base material 20a is isotropically widened. As a result, a lens-shaped recess 44a is formed in the second substrate 20a.

  In the step shown in FIG. 9D, the mask 54b and the oxide film 53 made of the polysilicon film 54 are removed.

  In the step shown in FIG. 10E, the concave portion 44a is filled with a lens layer 44b which is an example of a translucent layer. The lens layer 44b is silicon oxynitride (SiON). As a manufacturing method of the lens layer 44b, it is formed using a CVD method, CMP (Chemical Mechanical Polishing) polishing, or the like. Thereby, the first microlens 44 is completed.

In the step shown in FIG. 10 (f), the pass layer 43 is formed so as to cover the second base material 20 a and the first microlenses 44. The pass layer 43 is used to secure a distance between the first microlens 44 and the second microlens 51. In other words, the distance is adjusted so that light can be collected. The pass layer 43 is silicon oxide (SiO ₂ ). Examples of the method for manufacturing the pass layer 43 include a CVD method.

  In the step shown in FIG. 10G, a precursor layer 51 c is formed on the pass layer 43 in order to form the convex second microlens 51. Thereafter, a resist film 51e is formed on the precursor layer 51c. The material of the precursor layer 51c is silicon oxynitride (SiON). The resist film 51e is, for example, a thermally deformable resist.

  In the step shown in FIG. 10H, a resist pattern 51e1 for forming the second microlens 51 is formed. As a method for forming the resist pattern 51e1, a photolithography technique is used. Thereby, a rectangular resist pattern 51e1 is formed corresponding to the planar position of the first microlens 44.

  In the step shown in FIG. 11I, the resist pattern 51e1 having a curved surface is formed from the resist pattern 51e1 having a square shape. Specifically, since the resist pattern 51e1 is composed of a heat-deformable resist, it can be melted by heating (baking) and reflowed into a substantially hemispherical resist pattern 51e2 by surface tension. The heating temperature is, for example, about 100 ° C to 250 ° C.

  In the step shown in FIG. 11J, the first light-transmitting layer 51a is formed by subjecting silicon oxynitride to dry etching or wet etching using the curved resist pattern 51e2 as a mask. Specifically, as shown in FIG. 11I, when the precursor layer 51c (SiON) is subjected to an etching process, the precursor layer 51c is etched and the thickness thereof is reduced. At this time, the resist pattern 51e2 is also etched.

  At this time, the etching rates of the precursor layer 51c and the resist pattern 51e2 are made the same. Thereby, the shape of the resist pattern 51e2 can be transferred to the precursor layer 51c, and the first light-transmissive layer 51a (microlens) can be formed. At this time, a gap may be generated between adjacent microlenses (first light-transmissive layer 51a). As a result, the light utilization efficiency may be reduced.

  In the step shown in FIG. 11K, the second microlens 51 is formed so as to have a desired shape. Specifically, the second light transmissive layer 51 b is formed so as to cover the first light transmissive layer 51 a and the pass layer 43. The material of the second light transmissive layer 51b is silicon oxynitride (SiON). In addition, the refractive index n3 of the 1st translucent layer 51a and the refractive index n4 of the 2nd translucent layer 51b differ. In this embodiment, it is preferable that n4 <n3.

  As a method for manufacturing the second light transmissive layer 51b, for example, a CVD method can be used. As described above, by forming the second light-transmitting layer 51b so as to cover the first light-transmitting layer 51a and forming a desired lens shape, there is no gap between the adjacent second microlenses 51. Thereby, the utilization efficiency of light can be improved.

In the step shown in FIG. 11L, the emission side lens layer 42 is formed so as to cover the second microlens 51, and the microlens substrate 50 is completed. The material of the exit side lens layer 42 is silicon oxide (SiO ₂ ).

  In step S <b> 22, the counter electrode 31 is formed on the microlens substrate 50 using a well-known film formation technique, photolithography technique, and etching technique. Specifically, it can be formed by sputtering a transparent conductive film such as ITO and etching it.

  In step S <b> 23, the alignment film 32 is formed on the counter electrode 31. The method of manufacturing the alignment film 32 is the same as that of the alignment film 28, and is formed by using, for example, oblique vapor deposition. Thus, the counter substrate 20 side is completed. Next, a method for bonding the element substrate 10 and the counter substrate 20 will be described.

  In step S <b> 31, the sealing material 14 is applied on the element substrate 10. Specifically, the relative positional relationship between the element substrate 10 and, for example, a dispenser (which may be a discharge device) is changed, and the peripheral area of the display area E on the element substrate 10 (so as to surround the display area E). The sealing material 14 is applied.

  Examples of the sealing material 14 include an ultraviolet curable epoxy resin. In addition, it is not limited to photocurable resins, such as an ultraviolet-ray, You may make it use a thermosetting resin. Further, the sealing material 14 includes, for example, a gap material such as a spacer for setting a distance (gap or cell gap) between the element substrate 10 and the counter substrate 20 to a predetermined value.

  In step S <b> 32, the liquid crystal is dropped inside the seal material 14. Specifically, the liquid crystal is dropped onto an area surrounded by the sealing material 14 (ODF (One Drop Fill) method). As a dropping method, for example, an ink jet head can be used. Further, it is desirable that the liquid crystal is dropped on the central portion of the region (display region E) surrounded by the sealing material 14.

  In step S33, the element substrate 10 and the counter substrate 20 are bonded together. Specifically, the element substrate 10 and the counter substrate 20 are bonded together via the sealing material 14 applied to the element substrate 10. More specifically, it is performed while ensuring the positional accuracy in the vertical and horizontal directions of the substrates 10 and 20. Thus, the liquid crystal device 1 is completed.

<Configuration of electronic equipment>
Next, a projection display device including the liquid crystal device will be described with reference to FIG. FIG. 12 is a schematic diagram illustrating a configuration of a projection display device.

  As shown in FIG. 12, the projection display apparatus 1000 according to the present embodiment includes a polarization illumination device 1100 arranged along the system optical axis L, two dichroic mirrors 1104 and 1105 as light separation elements, and three Reflective mirrors 1106, 1107, 1108, five relay lenses 1201, 1202, 1203, 1204, 1205, three transmissive liquid crystal light valves 1210, 1220, 1230 as light modulation means, and a cross dichroic as a light combiner A prism 1206 and a projection lens 1207 are provided.

  The polarized light illumination device 1100 is generally configured by a lamp unit 1101 as a light source composed of a white light source such as an ultra-high pressure mercury lamp or a halogen lamp, an integrator lens 1102, and a polarization conversion element 1103.

  The dichroic mirror 1104 reflects red light (R) and transmits green light (G) and blue light (B) among the polarized light beams emitted from the polarization illumination device 1100. Another dichroic mirror 1105 reflects the green light (G) transmitted through the dichroic mirror 1104 and transmits the blue light (B).

  The red light (R) reflected by the dichroic mirror 1104 is reflected by the reflection mirror 1106 and then enters the liquid crystal light valve 1210 via the relay lens 1205. Green light (G) reflected by the dichroic mirror 1105 enters the liquid crystal light valve 1220 via the relay lens 1204. The blue light (B) transmitted through the dichroic mirror 1105 enters the liquid crystal light valve 1230 via a light guide system including three relay lenses 1201, 1202, 1203 and two reflection mirrors 1107, 1108.

  The liquid crystal light valves 1210, 1220, and 1230 are disposed to face the incident surfaces of the cross dichroic prism 1206 for each color light. The color light incident on the liquid crystal light valves 1210, 1220, and 1230 is modulated based on video information (video signal) and emitted toward the cross dichroic prism 1206.

  In this prism, four right-angle prisms are bonded together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface thereof. The three color lights are synthesized by these dielectric multilayer films, and the light representing the color image is synthesized. The synthesized light is projected on the screen 1300 by the projection lens 1207 which is a projection optical system, and the image is enlarged and displayed.

  The liquid crystal light valve 1210 is one to which the liquid crystal device 1 described above is applied. The liquid crystal device 1 is arranged with a gap between a pair of polarizing elements arranged in crossed Nicols on the incident side and the emission side of colored light. The same applies to the other liquid crystal light valves 1220 and 1230.

  Since the liquid crystal light valves 1210, 1220, and 1230 are used in such a projection display device 1000, high reliability can be obtained.

  As the electronic device on which the liquid crystal device 1 is mounted, in addition to the projection display device 1000, a light receiving element such as a CCD (Charge Coupled Device), a head-up display (HUD), a head-mounted display (HMD), a smartphone, EVF (Electrical View Finder), mobile mini projectors, electronic books, mobile phones, mobile computers, digital cameras, digital video cameras, displays, in-vehicle devices, audio devices, exposure devices, lighting devices, and various other electronic devices.

  As described above in detail, according to the microlens substrate 50 and the liquid crystal device 1 of the present embodiment, the following effects can be obtained.

  (1) According to the microlens substrate 50 of the present embodiment, the second light-transmitting layer 51b having a different refractive index is disposed so as to cover the first light-transmitting layer 51a, thereby forming the curved surface of the microlens. In the first light transmissive layer 51a, the shape of an incomplete microlens can be supplemented by the second light transmissive layer 51b. In other words, the gap between the adjacent second microlenses 51 can be eliminated. Therefore, it is possible to provide the second microlens 51 close to the curved surface of a regular microlens. Furthermore, since the refractive index of the 1st translucent layer 51a and the 2nd translucent layer 51b is varied, the condensing efficiency by the 2nd micro lens 51 can be improved. In addition, since the lens shape can be created when the pixel pitch becomes narrow, high definition can be realized.

  (2) According to the microlens substrate 50 of the present embodiment, since the refractive index of the second light transmissive layer 51b covering the first light transmissive layer 51a is smaller, in the convex second microlens 51, Light can be collected. In addition, since the second microlens 51 having the convex shape and the first microlens 44 having the concave shape are arranged so as to face each other in a pair, the light utilization efficiency can be further increased.

  (3) According to the liquid crystal device 1 of the present embodiment, since the microlens substrate 50 is provided, it is possible to provide the liquid crystal device 1 that can increase the light collection efficiency.

  The aspect of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. It is included in the range. Moreover, it can also implement with the following forms.

(Modification 1)
As described above, the microlens substrate is not limited to the form including the two microlenses (the first microlens 44 and the second microlens 51) arranged to face each other, but the liquid crystal including only the second microlens 51. It may be a device. FIG. 13 is a schematic cross-sectional view illustrating a configuration of a liquid crystal device 101 including a modified microlens substrate 150.

  In the microlens substrate 150 of the modified example, the second microlens 51 having the first light transmissive layer 51a and the second light transmissive layer 51b is disposed on the pass layer 43 (the liquid crystal layer 15 side).

  According to this, although the first microlens 44 is not provided, since the shape of the second microlens 51 is formed close to a regular shape, it is possible to provide the liquid crystal device 101 that can improve the light collection efficiency. .

(Modification 2)
As described above, the present invention is not limited to forming a regular microlens with two layers of convex second microlenses 51; for example, the shape of a regular microlens with two layers of concave microlenses. You may make it build in.

  3a ... scanning line, 3b ... capacitance line, 3c ... lower light shielding layer, CNT1 to CNT4 ... contact hole, 6a ... data line, 10 ... element substrate, 10a ... first substrate, 11a ... underlying insulating layer, 11b ... first DESCRIPTION OF SYMBOLS 1 interlayer insulation layer, 11c ... 2nd interlayer insulation layer, 11d ... 3rd interlayer insulation layer, 11g ... Gate insulation layer, 14 ... Sealing material, 15 ... Liquid crystal layer, 16 ... Capacitance element, 16a ... 1st capacitance electrode, 16b 2nd capacitance electrode 16c Dielectric film 18 Light shielding layer 20 Counter substrate 20a Second substrate 22 Data line drive circuit 24 Scan line drive circuit 25 Inspection circuit 26 Vertical conduction portion, 27... Pixel electrode, 28 and 32... Orientation film, 29 .. wiring, 30... TFT, 30 a... Semiconductor layer, 30 c... Channel region, 30 d. 30g ... 30 s... Data line side source / drain region, 30 s 1... Data line side LDD region, 31 .. Counter electrode, 33 .. Insulating layer, 35 .. External connection terminal, 41. , 43 ... pass layer, 44 ... first microlens, 44a ... recess, 44b ... lens layer, 50 ... microlens substrate, 51 ... second microlens, 51a ... first translucent layer, 51b ... second translucent 51c ... precursor layer, 51e ... resist film, 51e1 ... resist pattern, 51e2 ... resist pattern, 53 ... oxide film, 54 ... polysilicon film, 54a ... open hole, 54b ... mask, 100 ... liquid crystal panel, 101 ... Liquid crystal device, 150 ... Microlens substrate, 1000 ... Projection type display device, 1100 ... Polarized illumination device, 1101 ... Lamp unit, 1102 ... Integral Motor lens 1103 ... polarization conversion element 1104 1105 dichroic mirror 1106 1107 1108 reflection mirror 1201 1202 1203 1204 1205 relay lens 1206 cross dichroic prism 1207 projection lens 1210 1220, 1230 ... Liquid crystal light valve, 1300 ... Screen.

Claims (5)

A first light transmissive layer;
A second translucent layer formed along a lens curved surface of the first translucent layer and having a refractive index different from that of the first translucent layer;
A microlens substrate comprising: The microlens substrate according to claim 1,
The microlens substrate, wherein the microlens including the second translucent layer disposed on the first translucent layer is a convex microlens. The microlens substrate according to claim 1 or 2,
The microlens substrate according to claim 1, wherein a refractive index of the first light transmissive layer is larger than a refractive index of the second light transmissive layer. The microlens substrate according to claim 2 or 3, wherein
A microlens substrate, wherein the convex microlens including the first translucent layer and the second translucent layer is disposed so as to face a concave microlens.   An electro-optical device comprising the microlens substrate according to claim 1.

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