JP2007150260A - Solid-state imaging device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for realizing a solid-state imaging device without image noise to uniformly and evenly apply a coating, when a material is applied to a microlens of the solid-state imaging device, using a spin coating method. <P>SOLUTION: As the solid-state imaging device 1, in a dicing region 5X between adjoining imaging regions 9, a barrier pattern 7 having a rectangular sectional form is so formed, as a step alleviating structure, as to surround each imaging region 9. By the barrier pattern 7, a antireflection coating 8 on the microlens 6 is applied more uniformly, as compared with conventional manner, in an antireflection coating forming process by the spin coating method. As a result, the effect of applying uniform, compared with the conventional manner, is acquired at the manufacturing process, and the antireflection coating 8 on the microlens 6 presents satisfactory imaging performance. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device, and more particularly to an improved technique for eliminating coating unevenness when forming an antireflection film on a microlens and improving yield efficiency.

A solid-state imaging device in which a plurality of light receiving elements such as photodiodes are formed on a semiconductor substrate has excellent features such as small size, light weight, long life, low afterimage, and low power consumption. The use of still cameras as light receiving elements is rapidly expanding.
A large number of solid-state imaging devices are formed at a time on a single semiconductor substrate (wafer) as in Patent Documents 1 and 2, for example, and separated by dicing. The size of each solid-state imaging device has been miniaturized, and in the manufacturing process, microlenses are stacked on each light-receiving element on the wafer for the purpose of collecting light to obtain sufficiently high sensitivity. Is done.

The microlens is generally formed of a transparent resin such as an acrylic resin or polystyrene, but has a reflectance of about 10%, and thus it is necessary to apply an antireflection film to suppress this.
For example, as shown in FIGS. 14 to 16, the antireflection film is composed of a hydrophilic group 1072 that maintains a solid film state by applying pressure from the side surface by the pulley means 104 to 106 on the surface of the water 102 put in the water tank 101. A monomolecular film 107 having a hydrophobic group 1072 is formed by the LB (Langmuir-Blodgett) method in which the film 107 is scooped up several times on the substrate P (M1, M2, M3) (Patent Document 3). In addition, a method of forming a film by a water surface casting method or a so-called spin coating method can also be employed. The spin coating method is a method in which an antireflection film material is dropped on a wafer, the wafer is rotated at a predetermined rotation speed, and the antireflection film material is diffused to form a thin film.
JP-A-2005-223130 JP 2002-176156 A JP-A-4-275459 JP-A-5-55371

However, in the antireflection film forming step using the spin coating method, the centrifugal force applied during the spin coating basically works along the wafer surface, so that each of the microlenses provided so as to protrude from the wafer surface. It is difficult to apply a uniform coating on the surface of the film, and there is a problem that uneven coating tends to occur.
That is, since there are fine irregularities due to the shape of the microlens on the semiconductor substrate, the coating material diffused on the wafer surface at a high speed by the spin coat method is difficult to reach the top of the lens, and as a result, each microlens Uneven film thickness, coating unevenness, and image spots may occur between lenses. Such a problem is also described in Patent Document 1, which is a conventional problem.

  With respect to such a problem, in the countermeasure described in Patent Document 4 (FIG. 17), a so-called square dummy pattern is formed as a barrier pattern (step relief structure) at the intersection of dicing lines of the semiconductor device, and this is used as a barrier. Attempts have been made to prevent coating unevenness by adjusting the flow rate of the coating material on the wafer surface during spin coating. However, this technique originally considers the material application on the wafer surface itself, and is insufficient as a measure for improving the application unevenness and the non-uniform film thickness of the microlenses provided protruding from the wafer surface.

Thus, at present, there is still room for improvement in the process of coating on the microlens.
The present invention has been made in view of the above problems. In the case of applying a material on a microlens of a solid-state imaging device using a spin coating method, the coating film is formed uniformly and without uneven application, It is an object of the present invention to provide a method for manufacturing a solid-state imaging device capable of realizing a solid-state imaging device without an object.

  In order to solve the above-described problems, the present invention provides a group of light receiving elements mounted on one surface of a semiconductor substrate, a microlens is stacked on each light receiving element, and an image is transferred to the group of light receiving elements through the microlens. The imaging region to be imaged is a solid-state imaging device arranged to have four corners on the substrate surface, and the one side of the semiconductor substrate has a barrier pattern so as to surround at least the four corners of the imaging region. It was set as the structure formed.

Here, the barrier pattern may be disposed so as to surround the imaging region in a square shape at least once.
Further, the barrier pattern may be arranged so as to surround the imaging region in a circular shape over one or more layers.
Further, the height of the barrier pattern along the thickness direction of the semiconductor substrate may be formed so as to gradually decrease as the distance from the imaging region surrounded by the barrier pattern increases.

Here, the barrier pattern may have a top portion inclined so as to gradually decrease from the imaging region with respect to the planar direction of the semiconductor substrate.
The barrier pattern may be formed by forming a plurality of microlenses similar to the microlenses stacked on each light receiving element in the imaging region.

  Furthermore, the present invention provides a barrier pattern forming step of forming a barrier pattern on the outer edge of the imaging region on the surface of the semiconductor substrate on which the microlens is disposed, and an antireflection film on the microlens surface after the barrier pattern forming step. A method of manufacturing a solid-state imaging device through an antireflection film forming step to form, wherein in the barrier pattern forming step, the substrate thickness direction of the imaging region by a photolithography method using a reduction projection optical system and a gray scale mask A barrier pattern as a step-relief structure is formed so as to surround the imaging region higher than the height.

  Here, in the barrier pattern forming step, an original image formed by printing on a transparent sheet or the like as a gray scale mask as a gray pattern representing a density pattern of black pixels is used to form an image of each pixel of the original image using a reduction projection optical system. It is also possible to use a photocopy material copied at a magnification that is blurred and averaged with the image of adjacent pixels and cannot be resolved.

  According to the solid-state imaging device of the present invention having the above characteristics, since the barrier pattern is arranged so as to surround the four corners of the imaging region, when the coating material is applied on the microlens, the coating material Is prevented from flowing away immediately, and a certain coating material can be stored in a region surrounded by the barrier pattern. Therefore, even when applying on the microlens by the spin coat method, the stored application material is effectively utilized, and the material related to the application is prevented from being insufficient, and the upper part of each microlens belonging to the imaging region is provided. The coating material can be supplied sufficiently. As a result, it is possible to uniformly apply the microlenses belonging to the imaging region, and it is possible to suppress the occurrence of problems such as image spots.

Here, the present invention is characterized in that a barrier pattern is provided around the imaging region of the solid-state imaging device. The “imaging region” referred to here indicates a certain microlens assembly, and “periphery of the imaging region”. And between adjacent microlens assemblies.
In addition, as a cross-sectional shape of the barrier pattern, not only a single rectangular shape but also a slope shape or a shape whose height changes to a step shape can be taken. In this case, the height of the barrier pattern needs to be the lowest at the midpoint of the interval between the adjacent microlens assemblies in the slope shape and the shape whose height changes stepwise.

Embodiments and examples of the present invention will be described below, but the present invention is naturally not limited to these forms, and may be appropriately modified and implemented without departing from the technical scope of the present invention. be able to.
(Embodiment 1)
<Configuration of solid-state imaging device 1>
FIG. 1 is a schematic partial enlarged cross-sectional view of the solid-state imaging device 1 according to the first embodiment. FIG. 2 is a schematic partial top view of the apparatus.

In the solid-state imaging device 1 shown in FIG. 1, a group of light receiving parts 2 made of light receiving elements (photodiodes) are mounted in a matrix on one side of a substrate 10, and transfer electrodes 3 are arranged between the light receiving parts 2 at predetermined intervals. It is arranged. Each transfer electrode 3 is covered with a light-shielding insulating film 4 and is devised so that detection of external light of the light receiving unit 2 is not hindered by the metallic luster of the transfer electrode 3.
A flattening film 5 made of a transparent acrylic resin is formed on the substrate 10 so as to cover all of the light receiving unit 2, the transfer electrode 3, and the light-shielding insulating film 4, and thus the flattening film 5 is provided. A semiconductor substrate 11 (wafer) is formed.

On the surface of the planarizing film 5, a microlens 6 made of an acrylic positive photosensitive resin is further formed at a position corresponding to the light receiving portion 2.
Thus, in the solid-state imaging device 1, the light receiving unit 2 and the microlens 6 are stacked on the substrate 10 in the same order, and one unit formed in a matrix is configured as the imaging unit 9X. When the imaging unit 9x is looked down from the upper surface of the semiconductor substrate, the imaging unit 9x is recognized as the imaging region 9 corresponding to the collective region of the microlenses. In FIG. 2, the pattern from the upper surface direction of the imaging region 9 is a pattern in which the microlenses 6 are gathered in a matrix shape. However, the pattern is not limited to the matrix shape, and may be other patterns such as a honeycomb shape.

  Here, the solid-state imaging device 1 according to the first embodiment is characterized in that the barrier pattern 7 is a dummy pattern having a square cross-sectional shape so as to surround each imaging region 9 in the dicing region 5X between the adjacent imaging regions 9. Is the point where is formed. With this barrier pattern 7, the antireflection film 8 on the microlens 6 is applied more uniformly than in the prior art in the antireflection film forming process described below, and good imaging performance is exhibited.

The manufacturing method of the solid-state imaging device 1 can be performed by sequentially performing a microlens formation step, a barrier pattern formation step, and an antireflection film formation step as follows.
A microlens is formed on each light receiving portion 2 disposed on one side of the substrate 10 using an acrylic positive photosensitive resin (microlens forming step).
Thereafter, a barrier pattern is formed on the outer edge of the imaging region 9 on the surface of the semiconductor substrate on which the microlenses are arranged. (Barrier pattern forming step).

Here, as an example of the formation process of the barrier pattern 7, about 3 to 5 cc of a positive photosensitive material is first dropped on the wafer surface on which the microlens 6 is formed. Then, the spin coater is main rotated at 1500 to 3000 rpm to form a coating.
Subsequently, the solvent in the dropped positive photosensitive material is heated at a temperature of 80 ° C. to 100 ° C. for about 30 seconds to 80 seconds to volatilize it. In this state, ultraviolet exposure and development are performed using a photomask having a pattern that shields areas other than the imaging area 9.

Here, the “region other than the imaging region 9” is a region other than the imaging region 9 including not only the peripheral circuit but also the scribe position.
Through the above steps, the rectangular barrier pattern 7 can be formed in a region other than the imaging region 9.
Thereafter, a predetermined coating material is applied on the microlens 6 to form an antireflection film (antireflection film forming step).

<About the effect at the time of an antireflection film formation process>
Next, the effect of the antireflection film forming process of the present invention will be described together with consideration of coating defects occurring in the prior art.
FIG. 18 is a cross-sectional view showing a form of application on the microlens 6, where the left side of the drawing shows a uniform film thickness, and the right side of the drawing shows a non-uniform film thickness but a smooth surface. On the other hand, FIG. 19 is a cross-sectional view schematically showing how the coating unevenness 8Y occurs.

As shown in FIG. 19, the degree of coating unevenness 8Y that occurs when the coating material 8X is applied to the microlens 6 during spin coating appears macroscopically as the roughness of the material surface that covers the microlens 6. In other words, the state of “no coating unevenness” refers to a state in which a film having a smooth surface is formed on the microlens 6 by the coating material 8X as shown on the right side of FIG.
Specifically, “unevenness of application” is a difference in the thickness of the unevenness on the surface of the coating material on the microlens 6. In the coating material arranged on the surface, it appears as a groove having a certain length.

  In general, in a solid-state imaging device, the microlens 6 is about 0.5 to 2 μm higher than the surface of the surrounding semiconductor substrate due to the overall thickness of the microlens 6 and the like, so that the entire substrate has an uneven cross-sectional shape. It has a shape in which a large number of the grooves are present. Even if the wafer is spun on such a substrate surface based on a normal spin coating method, the centrifugal force due to the spin only extends along the wafer surface, so the degree of diffusion of the coating material in the microlens 6 is small. It tends to vary in that part.

In other words, due to the structure of the microlens, the surface area is large at the bottom of the microlens, and the surface area decreases as it approaches the top. Even if the lower part of the microlens can be satisfactorily applied, it is difficult to uniformly apply to the top part under the same conditions.
Based on the above principle, even if the material dropped on the wafer is spin-coated on the entire microlens as it is, the coating material does not reach the top of the microlens well, and coating unevenness and uneven film thickness occur. Due to this problem, the image characteristics of the solid-state imaging device may eventually deteriorate such that a streak-like image (so-called “image spot”) appears in the captured image.

Therefore, in the first embodiment, the periphery of the imaging region 9 is surrounded by the barrier pattern 7. Here, more preferably, by setting the barrier pattern 7 higher than the height of the microlens 6 in the imaging region 9, problems such as coating unevenness can be reduced.
The “peripheral portion” specifically means a region other than the location where the microlenses 6 are integrated, and includes peripheral circuits other than the microlenses 6, OB portions, pads, and dicing (scribe) positions.

That is, according to the present invention, the effect of the present invention can be obtained by the following steps at the time of application by spin coating.
1. When the coating material is dropped on the wafer surface, first, the coating material is stored in the barrier pattern 7. Thereby, sufficient coating material for coating on the top of the microlens 6 is stored in the vicinity of the microlens 6 in the barrier pattern 7.

2. Thereafter, when the wafer is spun, a centrifugal force acts on the stored coating material along the wafer plane, and the coating material is moved horizontally to lift up the top of the microlens 6. . For this reason, the coating material is diffused well over the entire surface of the microlens 6 without depending on the shape of the microlens 6 even by spin coating.
3. By the above principle, it is possible to apply the coating uniformly over the entire microlens 6.

Note that the height of the barrier pattern 7 is more preferably equal to or higher than the height of the microlens 6 in order to satisfactorily store the coating material and achieve a lift-up effect.
In the first embodiment, the case where a positive resist is applied to the microlens 6 has been described. However, in the negative resist, a similar structure can be formed by appropriately selecting a light shielding region using a photomask. .
(Embodiments 2 and 3)
Hereinafter, the second embodiment will be described focusing on differences from the first embodiment. 3 and 4 are a cross-sectional view and a top view, respectively, of the solid-state imaging device 1a of the second embodiment.

As shown in FIG. 3, the solid-state imaging device 1a is characterized in that the cross-sectional shape of the barrier pattern 7a surrounding each imaging region 9 is a substantially right triangle, and its slope (slope) height gradually decreases in a direction away from the imaging region 9. It is in the point configured to do. Further, the barrier pattern 7a is not disposed in the dicing region 5X. The height of the barrier pattern 7a is the same as in the first embodiment.
The barrier pattern 7a is composed of the same photosensitive material as in the first embodiment, but unlike the formation of the slope, the barrier pattern 7a has a continuous transmittance distribution between 0% and 100%. Use the gray scale mask.

  Specifically, based on a so-called photolithography method, a photosensitive material is disposed in a region other than the microlens 6, and exposure is performed through a gray scale mask in which the transmittance is adjusted by the aperture area ratio of the fine pattern. The photosensitive material can be exposed with a photosensitivity that is continuously changed between 0% and 100% of the transmittance. As a result, formation of the slope-shaped barrier pattern 7a can be formed. The angle of the slope can be freely controlled by previously adjusting the transmittance of the gray scale mask, and the thickness of the photosensitive material can be easily adjusted according to the viscosity of the coating material and the solvent type.

The gray scale mask can be manufactured as follows. First, an original image is printed on a transparent sheet or the like as a light and shade pattern expressed by the density of black pixels. The original image is copied onto a photographic material at a magnification at which the image of each pixel of the original image is blurred and averaged with the image of adjacent pixels using a reduction projection optical system and cannot be resolved. Thus, the gray scale mask is formed.
In the solid-state imaging device 1a of the second embodiment having the above-described configuration, in addition to the effect of being able to perform coating with less coating unevenness, as in the first embodiment, a barrier pattern having a substantially right triangle cross-sectional shape Since the volume of the barrier pattern 7a is smaller than that of the barrier pattern 7 having the square cross-sectional shape, there is an advantage that less material is required for forming the barrier pattern 7a.

In the solid-state imaging device 1a of the second embodiment, the rectangular barrier pattern 7a is seen from the top, but the present invention is not limited to this, and the solid-state imaging device 1b according to the third embodiment of FIG. As shown, a circular or elliptical barrier pattern 7b may be used. If the barrier pattern has such a cornerless shape, excess coating material can quickly flow away in the dicing region 5X during spin coating, and can be recovered satisfactorily. Therefore, improvement in coating efficiency can be expected.
(Embodiments 4 and 5)
Hereinafter, the fourth embodiment will be described focusing on the feature points. FIG. 6 is a sectional view of the fourth embodiment of the present invention, and FIG. 7 is a top view thereof.

The feature of the solid-state imaging device 1c of the fourth embodiment is based on the second embodiment, and by arranging multiple narrow ring-shaped bodies around the imaging region 9 at regular intervals, The barrier pattern 7c is configured. Each ring-shaped body in the barrier pattern 7c is set lower as the distance from the imaging region 9 increases.
Also in the solid-state imaging device 1c of the fourth embodiment having such a barrier pattern 7c, substantially the same effect as the second embodiment is exhibited. In addition, when the spin coating is performed, the coating material that flows radially from the center of the substrate surface is adjusted in speed and quantity by the ring-shaped body when flowing into the imaging region 9, and the occurrence of problems such as scattering is suppressed. Such an effect can be expected.

In the fourth embodiment, as shown in FIG. 8, in the barrier pattern 7c ′, it is also possible to form a slope-like top portion that is inclined so as to gradually decrease from the imaging region with respect to the planar direction of the wafer. With this configuration, as in the third embodiment, there is an advantage that the material used for the pattern can be reduced when the barrier pattern 7c ′ is formed.
In Embodiment 4, the barrier pattern 7c has a square shape when viewed from above, but the present invention is not limited to this, as shown in the solid-state imaging device 1d of Embodiment 5 in FIG. An elliptical barrier pattern 7d may be used. In this way, as in the third embodiment, by forming the barrier pattern in such a shape having no corners, excess coating material quickly flows off from the wafer surface in the dicing region 5X during spin coating. Can hope to improve.
(Embodiment 6)
Hereinafter, the sixth embodiment will be described focusing on the feature points. A sectional view of the sixth embodiment of the present invention is shown in FIG. 10, and a top view thereof is shown in FIG.

The solid-state imaging device 1e according to the sixth embodiment has a feature in which the barrier pattern 7e is provided only at the four corners of the rectangular imaging region 9 based on the second embodiment. The barrier pattern 7e can be manufactured using a photosensitive material using a gray scale mask as in the second embodiment.
Also in the solid-state imaging device 1e of the sixth embodiment having such a configuration, the following effects can be expected in addition to the coating effect with almost the same coating unevenness as in the second embodiment.

That is, for example, when the viscosity of the coating material is somewhat high, the coating material dropped in the spin coating method is difficult to diffuse immediately, so even in such a configuration of the barrier pattern 7e, the coating material is somewhat within the imaging region 9. It can be stored.
In general, since the microlens assembly is arranged in a square pattern, the corner (any one of the four corners) of the microlens assembly is close to the center of the wafer. Here, the main coating unevenness occurs due to uneven material supply due to the shape of the microlenses 6 that are close to each other. Therefore, it is necessary to provide a partial slope near the corner. On the other hand, in the sixth embodiment, the barrier pattern 7e has an inclined surface as in the second embodiment, so that the coating material follows the slope of the barrier pattern 7e from the lowest position on the wafer surface. Therefore, the effect of lifting up to the top of the microlens 6 can also be expected. Due to this effect, it is possible to reduce coating non-uniformity in the vicinity of the four corners of the imaging region 9.

Furthermore, since the coating material tends to concentrate at the four corners of the rectangular imaging area 9 by spin force during spin coating, if the coating material can be reliably supported at least at the four corners of the imaging area 9, it can be lifted up to the top of the microlens 6. It is expected to be applied almost certainly.
It should be noted that the height of the barrier pattern 7e is preferably equal to or higher than the height of the microlens 6 as in the first embodiment.
(Embodiment 7)
FIG. 12 is a cross-sectional view of the solid-state imaging device 1f according to the seventh embodiment, and FIG. 13 is a top view of the device 1f.

The feature of the seventh embodiment is that a microlens is disposed on the entire wafer surface, and the microlens located in the dicing area is a dummy lens 6a. The imaging area 9 is formed in a matrix like the first embodiment. In the drawing, for convenience, the microlenses 6 and 6a are illustrated so as to be distinguished from each other, but there is actually no difference in appearance.
According to such a configuration, since the coating material dropped on the wafer surface during spin coating is uniformly diffused over the entire area of the wafer surface, the coating conditions for the microlenses 6 and 6a are the same. Can be. As a result, it is possible to suppress coating unevenness that occurs for each of the microlenses 6 and 6a.
(Other matters)
The barrier pattern referred to in each embodiment in the present invention is mainly used for coating on the microlens 6, but the barrier pattern itself is conventionally used as a dummy pattern in wafer processing. May be used for other purposes. Therefore, the barrier pattern used in the present invention may be devised so as to be shared with the conventional dummy pattern. In this case, it is more rational than using the dummy pattern twice separately, and it is advantageous because an effect of reducing the manufacturing cost can be expected.

  Specifically, for example, instead of the conventionally used hollow package structure, direct pasting in which a translucent plate material is directly pasted with a translucent adhesive on a semiconductor substrate on which a light receiving portion and a floating diffusion portion are formed. In the case of using the structure, an adhesive adhesion preventing dummy pattern may be used in the dam portion in order to prevent the translucent adhesive from being covered on the floating diffusion portion. In such a case, the adhesive adhesion preventing dummy pattern and the barrier pattern of the present invention can be shared.

  INDUSTRIAL APPLICABILITY The present invention can be used for a solid-state imaging device formed using a semiconductor substrate, and in particular in the manufacturing process, a liquid substance can be uniformly applied on the upper part of the microlens structure. This is useful in that it can contribute to added value. Note that the microlens is not limited to the solid-state imaging device but is used in a liquid crystal projector or an optical communication connector, and thus is effective in this field.

1 is a cross-sectional view illustrating a configuration of a solid-state imaging device according to a first embodiment of the present invention. 1 is a top view showing a configuration of a solid-state imaging apparatus according to Embodiment 1 of the present invention. FIG. 5 is a cross-sectional view illustrating a configuration of a solid-state imaging device according to a second embodiment of the present invention. FIG. 5 is a top view showing a configuration of a solid-state imaging device according to a second embodiment of the present invention. FIG. 6 is a top view showing a configuration of a solid-state imaging apparatus according to Embodiment 3 of the present invention. FIG. 6 is a cross-sectional view showing a configuration of a solid-state imaging apparatus according to Embodiment 4 of the present invention. FIG. 6 is a top view showing a configuration of a solid-state imaging device according to a fourth embodiment of the present invention. FIG. 10 is a cross-sectional view showing a configuration of a solid-state imaging device according to a modification of Embodiment 4 of the present invention. FIG. 10 is a top view showing a configuration of a solid-state imaging device according to a fifth embodiment of the present invention. FIG. 10 is a cross-sectional view illustrating a configuration of a solid-state imaging device according to a sixth embodiment of the present invention. FIG. 10 is a top view showing a configuration of a solid-state imaging device according to a sixth embodiment of the present invention. FIG. 10 is a cross-sectional view showing a configuration of a solid-state imaging device according to a seventh embodiment of the present invention. FIG. 10 is a top view showing a configuration of a solid-state imaging device according to a seventh embodiment of the present invention. It is a figure which shows typically the outline | summary of the film-forming by LB method. It is a figure which shows typically the outline | summary of the film-forming by LB method. It is a figure which shows typically the outline | summary of the film-forming by LB method. . It is a top view of the solid-state imaging device which shows the conventional dummy pattern shape. It is a figure which shows the application | coating form (sectional drawing) on the conventional microlens. It is sectional drawing which represents typically a mode that the coating nonuniformity generate | occur | produced on the micro lens.

Explanation of symbols

1 Semiconductor substrate (wafer)
2 Receiver
3 Transfer electrode
4 Light-shielding insulating film
5 Planarization film
5X dicing area
6 Micro lens
7, 7a-7e, 7c 'Barrier pattern (dummy pattern)
8 Anti-reflective coating
9 Imaging area

Claims (8)

A group of light receiving elements is mounted on one surface of the semiconductor substrate, a microlens is stacked on each of the light receiving elements, and an imaging region in which one image is captured by the group of light receiving elements through the microlens is formed on the surface of the substrate. A solid-state imaging device arranged to have four corners,
A barrier pattern is formed on the one surface of the semiconductor substrate so as to surround at least four corners of the imaging region. 2. The solid-state imaging device according to claim 1, wherein the barrier pattern is arranged so as to surround the imaging region in a square shape at least once. 2. The solid-state imaging device according to claim 1, wherein the barrier pattern is arranged so as to surround the imaging region in a circular shape at least once. 4. The solid-state imaging device according to claim 1, wherein the height of the barrier pattern along the thickness direction of the semiconductor substrate gradually decreases as the distance from the imaging region surrounded by the barrier pattern increases. 5. The solid-state imaging device according to claim 1, wherein the barrier pattern has a top portion that is inclined so as to gradually decrease from the imaging region with respect to a planar direction of the semiconductor substrate. 6. The solid according to claim 1, wherein the barrier pattern is formed by a plurality of microlenses similar to the microlenses stacked on each light receiving element in the imaging region. Imaging device. A barrier pattern forming step for forming a barrier pattern on the outer edge of the imaging region on the surface of the semiconductor substrate on which the microlens is arranged, and an antireflection film for forming an antireflection film on the microlens surface after the barrier pattern forming step A manufacturing method of a solid-state imaging device through a forming step,
In the barrier pattern forming step, a barrier as a step relaxation structure is formed by a photolithography method using a reduction projection optical system and a gray scale mask so as to surround the imaging region higher than the height of the imaging region in the substrate thickness direction. A method of manufacturing a solid-state imaging device, comprising forming a pattern. In the barrier pattern forming step, an original image formed by printing on a transparent sheet or the like as a gray scale mask as a gray scale pattern expressed by the density of black pixels is blurred using a reduction projection optical system, and an image of each pixel of the original image is blurred. 8. The method for manufacturing a solid-state imaging device according to claim 7, wherein the image is copied to a photographic material at a magnification that cannot be resolved by averaging with an image of adjacent pixels.

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