JP2008060464A - Material for microlens, microlens and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the light collection efficiency by enhancing the refractive index of a microlens and decreasing the surface reflectance, at the same time. <P>SOLUTION: As the material for the microlens, a material containing ultrafine particles whose refractive index is 1.6 or higher for binder resin is used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a microlens material, a microlens, and a manufacturing method thereof.

In recent years, the resolution of solid-state image sensors has been increasing, and in order to prevent the reduction in sensitivity associated with this increase in resolution, it is necessary to improve the light collection efficiency of the optical layer that guides incident light to the photoelectric conversion region of each pixel. It has been. For example, a solid-state imaging device has been proposed in which a microlens is formed by a resin lens and a porous layer having an optical void on the resin surface to reduce the surface reflectance (Patent Document 1).
Further, an antireflection film is formed on a transparent substrate facing the microlens (Patent Document 2), and the color filter surface is roughened by wet etching or the like to provide an antireflection function. The thing is also proposed (patent document 3).

JP 2002-261261 A JP 2003-37257 A JP 2005-216897 A

However, in any of the above-described configurations, the refractive index of the microlens is small, the condensing power is insufficient, and therefore the condensing point is blurred, and the condensing efficiency is not sufficient. In addition, the microlens surface has a problem that it cannot avoid reflection of incident light.
In addition, when an antireflection film is separately formed, the number of processes and material types increase accordingly, leading to a cost increase.

  The present invention has been made in view of the above circumstances, and aims to improve the light collection efficiency by increasing the refractive index of the microlens while simultaneously reducing the surface reflectance in a simple process. And

The present invention is a microlens material containing ultrafine particles having a refractive index of 1.6 or more in a binder resin.
According to this configuration, since the microlens is made of a material containing ultrafine particles having a high refractive index, the refractive index can be easily improved and controlled by adjusting the content of the ultrafine particles. Therefore, the light condensing characteristics as a microlens can be easily adjusted, and the reflection characteristics can be adjusted by adjusting the surface state. A lens can be provided.

Further, the present invention includes the above microlens material, wherein the ultrafine particles have a refractive index higher than that of the binder resin by 0.2 or more.
With this configuration, it is possible to make the refractive index higher than in the case of the binder resin alone, and it is possible to improve the light collecting characteristics. That is, by setting the refractive index of ultrafine particles to 1.6 or more, it is intended to make the refractive index of ordinary resins having a refractive index of about 1.6 at most higher than that. More strictly, it is desirable to use ultrafine particles having a refractive index higher than that of the binder resin used. The lens power can be clearly improved by increasing the refractive index of the microlens material by 0.1 or more. For example, when the mixing ratio of the binder resin and the ultrafine particles is 1: 1, in order to increase the refractive index of the microlens material by 0.1 or more, the refractive index of the ultrafine particles is set to be less than the refractive index of the binder resin. Need to be 2 or higher. Thus, the adjustment to the optimum refractive index as a microlens can be easily realized by adjusting the mixing ratio of the binder resin and the ultrafine particles.

In the microlens material according to the present invention, the ultrafine particles are ultrafine particles made of a substantially colorless and transparent inorganic compound.
Here, since the ultrafine particles are a material for forming the microlens, it is preferably colorless and transparent, and may have a refractive index of 1.6 or more.

In the microlens material according to the present invention, the ultrafine particles are ultrafine particles containing any of zinc oxide, zinc hydroxide, zirconium oxide, and titanium oxide.
As the ultrafine particles made of an inorganic compound, there are various materials as described later. From the viewpoint of high refractive index, titanium oxide (rutile type or anatase type) or zirconium oxide is preferable. Further, from the viewpoint that the surface can be roughened by a dissolution method, zinc oxide and zinc hydroxide are easily dissolved in acid and alkali, which is advantageous. In the step of dissolving and removing ultrafine particles, a solvent may be supplied using a spin coater, or the wafer may be immersed in the solvent. Of course, any inorganic compound can be used when dry etching is performed as a method for removing ultrafine particles.
Moreover, when the ultrafine particles made of an inorganic compound have a photocatalytic function, various surface treatments can be applied to the ultrafine particles so that the binder resin constituting the macro lens is not deteriorated by the function.

In the microlens material according to the present invention, the ultrafine particles are ultrafine particles made of an organic compound.
Here, the ultrafine particles only need to be a colorless and transparent organic compound, and a solvent for dissolving the organic compound may be used in the surface roughening treatment. Alternatively, the ultrafine organic compound may be selectively removed by dry etching. As the organic compound having a refractive index of 1.6 or more, for example, a polyimide polymer (refractive index: about 1.75) can be used. Other examples include polypentachlorophenyl methacrylate (refractive index: about 1.608), poly-o-chlorostyrene (refractive index: about 1.6098), poly-α-naphthyl methacrylate (refractive index: about 1.6410), Polyvinyl naphthalene (refractive index: about 1.6818), polyvinyl carbazole (refractive index: about 1.683), polypentabromophenyl methacrylate (refractive index: about 1.71), and the like are also applicable.

  Further, when removing ultrafine particles of an organic compound by a dissolution method, it is convenient that the organic compound is easily dissolved. Therefore, in the case of a polymer, it is desirable to appropriately reduce the degree of polymerization. Alternatively, it is desirable that the molecule of the organic compound is modified so that it is easily dissolved, or that it is a non-curable organic compound. Furthermore, it is desirable to carry out the dissolution removal treatment of the organic compound after the binder resin is cured.

  As a method for forming such ultrafine particles composed of an organic compound, it is necessary to select a substance that does not dissolve in the binder resin. When the binder resin and the organic compound are both dissolved in a solvent that dissolves, a coating film is formed. During the drying process, the organic compound is microphase separated into ultrafine particles. Or you may make it disperse | distribute the fine powder of the organic compound which is not compatible with a binder resin compound in a binder solution (The solvent which does not melt | dissolve an organic compound is used) with a dispersing agent.

  In the microlens material according to the present invention, the ultrafine particles have an average particle size of 10 to 30 nm.

In the microlens material according to the present invention, a volume ratio of the binder resin to the ultrafine particles is 0.9: 0.1 to 0.2: 0.8.
The total refractive index when two materials having different refractive indexes are dispersed and mixed is a weighted average value calculated from the volume mixing ratio of the two materials. Therefore, if even a small amount of high refractive index particles are mixed, the refractive index is improved accordingly. If the refractive index of the ultrafine particles is 1.0 or more higher than that of the binder resin (equivalent to rutile titanium oxide), the refractive index is 1.0 × if the mixing ratio (volume ratio) of the ultrafine particles is 0.1. It is effective that 0.1 = 0.1 or more. This is the lower limit. On the other hand, since it is necessary to stably disperse the ultrafine particles in the binder resin, it is practically impossible to set the ratio of the ultrafine particles to 0.8 or more.

  The microlens of the present invention is arranged so as to face each of a plurality of photoelectric conversion regions constituting the pixel in the microlens material, and collects light incident on the photoelectric conversion region for each pixel. A microlens having a light condensing function is provided, and the microlens contains ultrafine particles having a refractive index of 1.6 or more in a binder resin.

  Further, according to the present invention, in the above microlens, the ultrafine particles include those having a refractive index higher than that of the binder resin by 0.2 or more.

  In the microlens according to the present invention, the ultrafine particles are ultrafine particles made of a substantially colorless and transparent inorganic compound.

  In the microlens according to the present invention, the ultrafine particles are ultrafine particles containing any one of zinc oxide, zinc hydroxide, zirconium oxide, and titanium oxide.

  Further, the present invention includes the above microlens, wherein the ultrafine particles are ultrafine particles made of an organic compound.

  Further, the present invention includes the above microlens, wherein the ultrafine particles have an average particle diameter of 10 to 30 nm.

  The present invention includes the above microlens, wherein the volume ratio of the binder resin to the ultrafine particles is in the range of 0.9: 0.1 to 0.2: 0.8.

  In addition, the present invention includes the above-described microlens that has been subjected to a roughening treatment so that the surface has nano-order irregularities.

Further, the present invention provides a microlens that is disposed so as to face each of a plurality of photoelectric conversion regions constituting a pixel, and has a condensing function for condensing light incident on the photoelectric conversion region for each pixel. A method of supplying a microlens material containing ultrafine particles having a refractive index of 1.6 or more in the binder resin onto a photoelectric conversion region to form a coating film, and the coating film And a shape processing step of processing into a desired shape.
According to this configuration, it is possible to provide a microlens having excellent light collection characteristics.

  In the microlens manufacturing method according to the present invention, the shape processing step includes a step of patterning the coating film and a roughening step of roughening the surface of the microlens.

  In the microlens manufacturing method according to the present invention, the roughening step includes a step of removing the surface of the microlens and the ultrafine particles in the vicinity of the surface.

In the method for manufacturing a microlens, the shape processing step includes a shape processing step of processing the microlens into a desired shape by an etch back method.
In the case of a substance in which ultrafine particles are dissolved in an alkaline aqueous solution, an etch-back method is preferable for patterning the microlens material. This is because, in the process of patterning the microlens material itself by a photolithography method and melting it into a lens shape, the ultrafine particles are dissolved during development, and the desired surface roughening may not be stabilized. When the dissolution rate of the ultrafine particles in the developer is appropriate, the ultrafine particles on the surface are dissolved and removed at the same time as the development, and the traces (recesses) from which the ultrafine particles are removed in the subsequent melt process are crushed and the binder resin A surface layer composed only of is made. In this case as well, the surface reflectance can be reduced and the effect of the present invention can be achieved. However, the reflectance remains at the same level as that of the microlens composed only of the binder resin. “In such a microlens, when it is desired to further reduce the surface reflectance, the ultrafine particle removal treatment can be performed after lightly etching to the extent necessary to expose the surface of the fine particles from the binder resin.

  In the method of manufacturing a microlens, the roughening step includes a step of treating with a solvent that selectively dissolves the ultrafine particles.

  In the method for producing a microlens, the roughening step includes a step of treating the microlens with an acidic or alkaline aqueous solution. For example, when the ultrafine particles are zinc oxide, they may be treated with dilute sulfuric acid.

In the method of manufacturing a microlens, the roughening step includes a step of dry etching the binder resin and the ultrafine particles constituting the microlens at different rates.
In the present invention, the ultrafine particles refer to fine particles having an average particle size of 100 μm or less.

According to the microlens of the present invention, the light collection efficiency can be improved.
That is, it is possible to provide a microlens with high light collection efficiency by configuring the microlens with a material containing ultrafine particles having a large refractive index. Further, the refractive index can be easily controlled by adjusting the volume ratio between the ultrafine particles and the binder resin.
Furthermore, according to the microlens of the present invention, a refractive index gradient can be formed on the surface by post-processing after film formation, and further improvement in light collection efficiency can be achieved. For example, by surface treatment, the outermost surface (surface layer), the vicinity of the surface (intermediate layer), and the inside (core) can be configured so that the refractive index changes, and the light is collected with less surface reflection. A highly efficient microlens can be obtained.

In order to obtain a three-layer structure, it is necessary to remove even the ultrafine particles inside (intermediate layer) rather than the surface. Specifically, it is only necessary that ultrafine particles can be dissolved (intermediate layer) through the binder resin. For example, the binder resin may be such that the dilute sulfuric acid penetrates the binder resin to some extent when it is treated with dilute sulfuric acid. This permeability can also be obtained by adjusting the curing reaction of the binder resin.
If ultrafine particles can be removed to a certain extent from the surface in this way, the deep portion contains ultrafine particles, the middle portion is mainly a binder resin layer, and the surface is a mixed layer of binder resin and air. Is realized. In both the melt method and the etch back method, a thermal process for curing and / or a curing process so as to satisfy both the degree of curing of the binder resin and the degree of curing required in the ultrafine particle removing process required when processing the microlens. It is important to set the UV irradiation process.

In order to minimize the surface reflectance in either the three-layer structure or the two-layer structure, it is preferable to appropriately set the relationship between the refractive indexes of the layers. For example, in the case of a two-layer structure, assuming that the refractive index n0 of air, the refractive index n1 of the surface layer, and the refractive index n2 of the deep part are n1 = (n0 × n2) ^0.5 (Equation 1), the surface reflectance is minimized. can do. n0 is known and n2 is a value determined from the lens power design. On the other hand, assuming that the air mixing ratio = f (vol%) and the refractive index of the binder resin = nb, n1 = nb × (1−f) + “n0 × f (formula 2).
Here, when n0 = 1, nb = 1.49 (acrylic resin), and f = 0.5, n1 = 1.245 is obtained from Equation 2, so that n2 = 1.245 × 1.245 to satisfy Equation 1. = 1.55 is the optimal combination.
Since n2 = 1.55 is the ultrafine particle mixing ratio (assuming the same as the air mixing ratio) = 0.5, the refractive index of the ultrafine particles may be n = 1.61. That is, in the present invention, the range of the refractive index of the ultrafine particles is set to 1.6 or more, but it is understood that this is a preferable range for minimizing the surface reflectance.

  Also, according to the microlens of the present invention, the antireflection film is not separately provided, but the microlens is integrally formed, and thus the process is simpler than the case where the antireflection film is separately formed. Only one type of material is required.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The microlens described in the present embodiment is used for a solid-state image sensor, for example.

(Embodiment 1)
1 is an enlarged schematic cross-sectional view of a microlens according to Embodiment 1 of the present invention, FIG. 2 is a schematic cross-sectional explanatory view of a solid-state imaging device, and FIG. 3 is a schematic plan view (FIG. 2 is an A- (A line cross-sectional schematic diagram). FIG. 4 is a process cross-sectional view illustrating a manufacturing process of the microlens of the solid-state imaging device.

  This solid-state imaging device is composed of a microlens material, zinc oxide ultrafine particles having a particle size of 10 to 30 nm, a refractive index of 1.9 and a true specific gravity of 5.78, an epoxy resin (refractive index of 1.55. Specific gravity of 1.4. ), And other additives are added to adjust the zinc oxide to 40 vol%, and this is applied and formed on a color filter through a flattened film, dried, and made into a microlens shape. The microlens is constructed by roughening the surface by diluting sulfuric acid treatment and dissolving and removing ultrafine zinc oxide particles on the surface.

That is, as shown in the enlarged view of the main part in FIG. 1, the microlens 60 is formed by processing a coating film formed by using a material in which zinc oxide ultrafine particles are dispersed in an epoxy resin, and then performing dilute sulfuric acid treatment. Then, by dissolving and removing the ultrafine zinc oxide particles on the surface and roughening the surface, a microlens core 60a having a refractive index of about 1.69 and a surface layer 60b made of air and an epoxy resin (refractive index 1.33) This is a low-reflective, high-refractive index lens with a surface reflectance of about 3.4%.
In the case of the microlens core constituting the microlens of the above embodiment, the refractive index of the surface layer that minimizes the surface reflectance is n = (1.69 × 1.0) ^0.5 = 1.3.
Since the refractive index of the surface layer can be 1.33, the first embodiment has a substantially optimal structure.

  Although the others have a usual structure, as shown in FIG. 1, this solid-state imaging device corresponds to each photodiode 30 via an intermediate layer 70 above the photodiode 30. A red color filter 50R, a green color filter 50G, and a blue color filter 50B are formed. The upper layer contains a zinc oxide ultrafine particle and a surface roughening process through a planarizing film 61. Thus, the micro lens 60 is formed.

  Then, photodiodes 30 that are photoelectric conversion units are arrayed on the surface of the n-type silicon substrate 1, and charge transfer for transferring signal charges generated in the photodiodes 30 in the column direction (Y direction in FIG. 3). The portion 40 is formed by meandering between a plurality of photodiode columns composed of a plurality of photodiodes 30 arranged in the column direction. Then, the odd-numbered photodiode rows are formed so as to be shifted in the direction of approximately half the array pitch of the photodiodes 30 arranged in the column direction with respect to the even-numbered photodiode rows.

  The charge transfer unit 40 includes a plurality of charge transfer channels 33 formed in the column direction of the surface portion of the silicon substrate 1 corresponding to each of the plurality of photodiode columns, and a charge transfer formed in the upper layer of the charge transfer channel 33. It includes an electrode 3 (first layer electrode 3a, second layer electrode 3b) and a charge readout region 34 for reading out charges generated in the photodiode 30 to the charge transfer channel 33. The charge transfer electrode 3 has a meandering shape extending in the row direction (X direction in FIG. 3) as a whole between a plurality of photodiode rows composed of a plurality of photodiodes 30 arranged in the row direction. .

  As shown in FIG. 2, a p-well layer 1P is formed on the surface of the silicon substrate 1, an n-region 30b forming a pn junction is formed in the p-well layer 1P, and a p-region 30a is formed on the surface. The photodiode 30 is configured, and the signal charge generated in the photodiode 30 is accumulated in the n region 30b. Reference numeral 33 denotes a charge transfer channel, and 34 denotes a readout region 34.

A gate oxide film 2 is formed on the surface of the silicon substrate 1, and a first electrode 3 a and a second electrode 3 b are formed on the charge readout region 34 and the charge transfer channel 33 via the gate oxide film 2. The An interelectrode insulating film 5 is formed between the first electrode 3a and the second electrode 3b. A channel stop 32 made of a p ⁺ region is provided on the right side of the vertical transfer channel 33, and is separated from the adjacent photodiode 30.

  An insulating film 6 such as a silicon oxide film and an antireflection layer 7 are formed on the charge transfer electrode 3, and an intermediate layer 70 is further formed thereon. Of the intermediate layer 70, 71 is a light shielding film, 72 is an insulating film made of BPSG (borophosphosilicate glass), 73 is an insulating film (passivation film) made of P-SiN, and 74 is a flattening film under a filter made of transparent resin or the like. It is. The light shielding film 71 is provided except for the opening of the photodiode 30. Above the intermediate layer 70, the microlens 60 is provided via the color filters 50R, 50G, and 50B and the planarizing film 61.

  In the solid-state imaging device according to the present embodiment, signal charges generated in the photodiode 30 are accumulated in the n region 30b, and the accumulated signal charges are transferred in the column direction by the charge transfer channel 33, and the transferred signals are transferred. The charge is transferred in the row direction by a horizontal charge transfer path (HCCD) (not shown), and a color signal corresponding to the transferred signal charge is output from an amplifier (not shown). In other words, on the silicon substrate 1, a solid-state imaging device unit that is a region including a photoelectric conversion unit, a charge transfer unit, an HCCD, and an amplifier, and a peripheral circuit that is a region where peripheral circuits (PAD unit and the like) of the solid-state imaging device are formed. Are formed to constitute a solid-state imaging device.

Next, the manufacturing process of the above-described solid-state imaging device will be described.
A solid-state imaging device is formed on the silicon substrate 1 and a color filter is formed on the upper layer, but here, the manufacturing steps up to the formation of the color filter are omitted.
After forming the planarizing film 74 under the filter, a color filter is formed. As the planarizing film 74 under the filter, a resist material that is transparent to visible light (for example, C series manufactured by FUJIFILM Electronics Materials Co., Ltd.) is used as in the light-transmitting region.

  Then, color filters for each color are sequentially formed. The red color filter is indicated by “50R”, the green color filter is indicated by “50G”, and the blue color filter is indicated by “50B”.

In this embodiment, after applying an organic resin film as the planarizing film 61, a microlens is formed. A method for forming the microlens will be described below. FIG. 4A shows a state before application of the microlens.
First, when the microlens material is applied on the planarizing film 61, a microlens material containing ultrafine particles having a refractive index of 1.6 or more in a binder resin is used as the coating solution. Furthermore, supplying the microlens material onto the photoelectric conversion region, forming a coating film, performing shape processing, removing the ultrafine particles on the surface and in the vicinity of the surface, and roughening the surface Thus, a microlens having a two-layer structure as described above is formed.

  First, the microlens material is adjusted. This microlens material is adjusted to be thermosetting. As this coating liquid, an epoxy resin (ZnO-350, zinc oxide ultrafine particles having a particle size of 10 to 30 nm (refractive index: 1.9, specific gravity: 5.78: manufactured by Sumitomo Osaka Cement Co., Ltd.) as a binder resin ( The material was dispersed at a refractive index of 1.55 and a specific gravity of 1.4), and a curing agent was added to obtain a microlens material. Here, zinc oxide was adjusted to 40 vol%.

The microlens material thus formed is applied on the wafer on which the planarizing film 61 is formed, and applied and dried so that the dry film thickness becomes 2 μm (FIG. 4B).
Further, after applying a resist and patterning by exposure and development (FIG. 4C), the resist is melted by heating and cured to obtain a lens shape, and then etched back to change the lens shape to the lens. Transferred to material. At that time, the etching rates of the binder resin and the ultrafine particles were made substantially the same (FIG. 4D).

  This was immersed in dilute sulfuric acid, rinsed, and dried at 100 ° C. for 5 minutes. At this time, the ultrafine zinc oxide particles on the surface are removed, and the traces thereof become nano-sized recesses (FIG. 4 (e)). In this way, the surface layer 60c is formed.

  In this way, a microlens having a refractive index of 1.69 for the core and a refractive index of 1.33 for the surface layer could be obtained. The surface reflectance of the microlens thus obtained is 3.4%, which is about half of the reflectance of 6.6% when there is no surface layer, and can reduce the reflection of light on the surface. It turns out that it is possible.

  Note that heat treatment may be performed after the dilute sulfuric acid treatment.

  In the first embodiment, zinc oxide is used as the ultrafine particles. However, zinc hydroxide, zirconium oxide, silicon nitride, silicon carbide, molybdenum disulfide, titanium oxide (rutile type), titanium oxide (anatase type) are also used. ), Barium sulfate, barium carbonate, barium titanate, and the like are also applicable.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.
In this embodiment, rutile titanium oxide (refractive index of 2.7%, specific gravity of 4.2, average particle size of 20 nm is used instead of zinc oxide, and the volume ratio of epoxy resin to titanium oxide is 0.7: 0. A microlens material was prepared in the same manner as in the first embodiment except that it was set to .3).
In the first embodiment, the microlens shape is created in the microlens manufacturing process, and then the surface is roughened by dilute sulfuric acid treatment. However, in this embodiment, the ultrafine particles for surface roughening are used. Is removed by etching. FIG. 5 illustrates this manufacturing process.

The step of roughening the surface is a step of dry etching ultrafine particles earlier than the binder resin.
In this embodiment, the roughening etching time is set to a time for etching 0.03 μm thick titanium oxide because it is only necessary to remove the surface and the titanium oxide in the vicinity of the surface for roughening.

The microlens material was applied and dried on the wafer on which the planarizing film 61 was formed so that the dry film thickness was 2.0 μm (FIG. 5A).
Then, a resist was applied to this upper layer, and patterned by exposure / development to form a resist pattern R (FIG. 5 (b)), then melted and cured by heating to obtain a lens shape (FIG. 5 (c)). ).

Thereafter, the resist pattern R and the microlens material were etched back by about 2.0 μm by dry etching such that the etching rates of the microlens material and the microlens material were substantially equal (FIG. 5 ( d)).
Thereafter, the surface was roughened by slightly performing dry etching under conditions where the etching rate of titanium oxide was faster than the etching rate of resin (FIG. 5E).

In this way, a microlens having an internal refractive index of 1.91 and a surface reflectance of 1.39 could be formed. A desired refractive index can be obtained, and reflection of light from the surface can be reduced.
The surface reflectance of the microlens thus obtained was 5.1%. This is about a half of the reflectance compared to the reflectance of 9.8% when the surface layer is not formed.

In the present embodiment, a solid-state imaging device having a configuration in which photodiodes are arranged in a honeycomb shape has been described. However, the present invention is not limited to this, and a configuration in which a plurality of photodiodes are arranged in a square lattice shape is described. The present invention can also be applied to other solid-state imaging devices.
The present invention is also effective for line sensors. Further, the present invention can be applied regardless of the presence or absence of an in-layer lens or a waveguide. Furthermore, the color filter may be a primary color or a complementary color, and the color filter may also serve as a waveguide, an in-layer lens, or a microlens.

  According to this configuration, since it is possible to form a highly sensitive microlens having excellent light condensing properties, higher sensitivity can be achieved, and it is useful as a solid-state imaging device in an electronic device such as a portable terminal.

1 is a schematic cross-sectional view of a microlens according to Embodiment 1 of the present invention. 1 is a schematic cross-sectional view of a solid-state imaging device according to Embodiment 1 of the present invention. 2 is a schematic plan view of FIG. The figure which shows the manufacturing process of the micro lens of this Embodiment 1. The figure which shows the manufacturing process of the micro lens of this Embodiment 2.

Explanation of symbols

1 n-type silicon substrate 2 gate oxide film 3a first layer electrode 3b second layer electrode 5 interelectrode insulating film 6 insulating film 7 antireflection layer 60 microlens 60a nucleus 60b roughened surface layer 61 flattening film 71 light shielding Film 72 Insulating (BPSG) film 73 Passivation film 74 Flattening film 50B, 50R, 50G Color filter

Claims (22)

  A microlens material containing ultrafine particles having a refractive index of 1.6 or more in a binder resin. The microlens material according to claim 1,
The ultrafine particles are a material for microlenses having a refractive index higher than that of the binder resin by 0.2 or more. The microlens material according to claim 1,
The microlens material is an ultrafine particle made of a substantially colorless and transparent inorganic compound. The microlens material according to claim 3,
The microlens material, wherein the ultrafine particles are ultrafine particles containing any of zinc oxide, zinc hydroxide, zirconium oxide, and titanium oxide. The microlens material according to claim 1,
The microlens material is an ultrafine particle made of an organic compound. The microlens material according to claim 1,
The ultrafine particles are microlens materials having an average particle diameter of 10 to 30 nm. The microlens material according to claim 1,
A microlens material in which the volume ratio of the binder resin to the ultrafine particles is in the range of 0.9: 0.1 to 0.2: 0.8. A microlens that is disposed so as to face each of a plurality of photoelectric conversion regions constituting a pixel and has a condensing function for condensing light incident on the photoelectric conversion region for each pixel,
The microlens is a microlens containing a fine particle having a refractive index of 1.6 or more in a binder resin. The microlens according to claim 8, wherein
The ultrafine particles are microlenses having a refractive index higher than that of the binder resin by 0.2 or more. The microlens according to claim 8, wherein
The microlens is an ultrafine particle made of a substantially colorless and transparent inorganic compound. The microlens according to claim 10,
The microlens is a microlens that is an ultrafine particle containing any one of zinc oxide, zinc hydroxide, zirconium oxide, and titanium oxide. The microlens according to claim 8, wherein
The microlens is an ultrafine particle made of an organic compound. The microlens according to claim 8, wherein
A microlens having an average particle diameter of the ultrafine particles of 10 to 30 nm. The microlens according to claim 8, wherein
A microlens in which the volume ratio of the binder resin to the ultrafine particles is in the range of 0.9: 0.1 to 0.2: 0.8. The microlens according to claim 8, wherein
A microlens that has been roughened so that its surface has nano-order irregularities. A method of manufacturing a microlens that is disposed so as to face each of a plurality of photoelectric conversion regions constituting a pixel and has a condensing function for condensing light incident on the photoelectric conversion region for each pixel. ,
In the binder resin, using a microlens material containing ultrafine particles having a refractive index of 1.6 or more,
Supplying the microlens material onto a photoelectric conversion region, and forming a coating film;
A shape processing step of processing the coating film into a desired shape to form a microlens;
A method for producing a microlens comprising: A method of manufacturing a microlens according to claim 16,
The shape processing step includes a step of patterning the coating film,
A method of manufacturing a microlens including a roughening step of roughening a surface of the microlens after the patterning step. The method of manufacturing a microlens according to claim 17,
The roughening step is a method of manufacturing a microlens including a step of removing the ultrafine particles in the vicinity of the surface of the microlens and the surface. The method of manufacturing a microlens according to claim 17,
The method of manufacturing a microlens, wherein the shape processing step is a shape processing step of processing the microlens into a desired shape by an etch back method. The method of manufacturing a microlens according to claim 18,
The method of manufacturing a microlens, wherein the roughening step includes a step of treating with a solvent that selectively dissolves the ultrafine particles. The method of manufacturing a microlens according to claim 20,
The method of manufacturing a microlens, wherein the roughening step includes a step of treating the microlens with an acidic or alkaline aqueous solution. The method of manufacturing a microlens according to claim 18,
The roughening step is a method of manufacturing a microlens including a step of dry etching the binder resin and the ultrafine particles constituting the microlens at different rates.

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