solid-state imaging device

Abstract

To provide a solid-state imaging apparatus capable of improving the phase difference detection characteristic of a phase difference detection pixel.SOLUTION: The solid-state imaging apparatus includes a first imaging pixel which receives a first luminous flux, a phase difference detection pixel which is adjacent to the first imaging pixel and receives a pupil-divided luminous flux, a first imaging microlens which is arranged on the phase difference detection pixel, to be projected from above the first imaging pixel and converges the first luminous flux onto the first imaging pixel, and a phase difference detection microlens which is arranged on the phase difference detection pixel, occupies an area smaller than an area occupied by the first imaging microlens, is connected to the first imaging microlens, and converges the pupil-divided luminous flux onto the phase difference detection pixel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a solid-state imaging device. [Background technology]

[0002] Patent Document 1 discloses a solid-state imaging device. In the solid-state imaging device, a first microlens focuses light on an imaging pixel. A second microlens focuses light on a phase difference detection pixel. The focal length of the second microlens is shorter than the focal length of the first microlens. The focal position of the first microlens is located on the light receiving surface of the photodiode. The focal position of the second microlens is located away from the light receiving surface of the photodiode and on a light-shielding film (paragraphs 0020, 0065 and 0066). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-89432 Summary of the Invention [Problem to be solved by the invention]

[0004] In the solid-state imaging device disclosed in Patent Document 1, the focal length of the second microlens that collects light on the phase difference detection pixel is shorter than the focal length of the first microlens that collects light on the imaging pixel. Therefore, the radius of curvature of the second microlens may be equal to or less than half the diagonal dimension of the phase difference detection pixel. This may result in an area where no microlens is located being formed above the phase difference detection pixel. The area where no microlens is located may cause noise to be superimposed on the phase difference detection signal output by the phase difference detection pixel, degrading the phase difference detection characteristics of the phase difference detection pixel.

[0005] In view of these problems, an object of one aspect of the present disclosure is to provide a solid-state imaging device that can improve the phase difference detection characteristics of a phase difference detection pixel, for example. [Means for solving the problem]

[0006] A solid-state imaging device according to one aspect of the present disclosure includes a first imaging pixel that receives a first light beam; a phase difference detection pixel that is adjacent to the first imaging pixel and receives a pupil-divided light beam; a first imaging microlens that is disposed above the first imaging pixel and extends over the phase difference detection pixel and focuses the first light beam onto the first imaging pixel; and a phase difference detection microlens that is disposed above the phase difference detection pixel, occupies an area smaller than an area occupied by the first imaging microlens, is connected to the first imaging microlens, and focuses the pupil-divided light beam onto the phase difference detection pixel. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a top view schematically illustrating a solid-state imaging device according to a first embodiment. [Figure 2] 2 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of the first embodiment taken along the cutting line aa' in FIG. 1. FIG. [Figure 3] 2 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of the first embodiment taken along the cutting line bb' in FIG. 1. FIG. [Figure 4] 2 is a cross-sectional view schematically illustrating the periphery of a left-eye pixel included in the solid-state imaging device of the first embodiment. FIG. [Figure 5] 2 is a cross-sectional view schematically illustrating the periphery of a right-eye pixel included in the solid-state imaging device of the first embodiment. FIG. [Figure 6] 10 is a graph showing ideal phase difference detection characteristics. [Figure 7] 6 is a graph showing a simulation result of the phase difference detection characteristics of the solid-state imaging device according to the first embodiment. [Figure 8]2 is a cross-sectional view schematically illustrating a state in which incident light is incident on the solid-state imaging device of the first embodiment. FIG. [Figure 9] FIG. 2 is a top view schematically illustrating a solid-state imaging device according to a first reference example. [Figure 10] 10 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of the first reference example taken along the cutting line aa' in FIG. 9. FIG. [Figure 11] 10 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of the first reference example taken along the cutting line bb' in FIG. 9. FIG. [Figure 12] FIG. 10 is a top view schematically illustrating a solid-state imaging device according to a second reference example. [Figure 13] 13 is a cross-sectional view schematically illustrating a cross section of a solid-state imaging device of a second reference example taken along the cutting line aa' in FIG. 12. FIG. [Figure 14] 13 is a cross-sectional view schematically illustrating a cross section of a solid-state imaging device of a second reference example taken along the cutting line bb' in FIG. 12. FIG. [Figure 15] 10 is a cross-sectional view schematically illustrating a state in which incident light is incident on a solid-state imaging device of a second reference example. FIG. [Figure 16] 10 is a graph showing a simulation result of the phase difference detection characteristics of the solid-state imaging device of the second reference example. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0009] 1. First embodiment 1.1 Solid-state imaging device FIG. 1 is a top view that schematically illustrates a solid-state imaging device according to a first embodiment. FIG. 2 is a cross-sectional view that schematically illustrates a cross section of the solid-state imaging device according to the first embodiment, taken along the cutting line a-a' in FIG. 1. FIG. 3 is a cross-sectional view that schematically illustrates a cross section of the solid-state imaging device according to the first embodiment, taken along the cutting line b-b' in FIG. 1. The cutting line a-a' extends in the opposite direction of the solid-state imaging device. Therefore, FIG. 2 is a cross-sectional view in the opposite direction. The cutting line b-b' extends in the diagonal direction of the solid-state imaging device. Therefore, FIG. 3 is a cross-sectional view in the diagonal direction.

[0010] 1, 2, and 3, a solid-state imaging device 1 according to a first embodiment performs imaging and outputs an imaging signal corresponding to a subject image. The solid-state imaging device 1 also performs phase difference detection and outputs a phase difference detection signal corresponding to a defocus direction and a defocus amount. The output phase difference detection signal is used for autofocusing using an image plane phase difference method.

[0011] As shown in FIGS. 1, 2, and 3, the solid-state imaging device 1 includes a plurality of pixels 11, a light-shielding film 12, a planarizing film 13, and a plurality of microlenses .

[0012] Each pixel 11 has a square planar shape. The multiple pixels 11 are arranged in a matrix. The multiple pixels 11 are arranged in a light receiving region that receives light that forms an object image. Each pixel 11 has a light receiving surface 11S. Each pixel 11 photoelectrically converts the light received by the light receiving surface 11S and outputs an electrical signal. As a result, each pixel 11 outputs an electrical signal according to the intensity of the light received by the light receiving surface 11S.

[0013] The light-shielding film 12 has a lattice shape. The light-shielding film 12 covers the vicinity of the boundary between the light-receiving surfaces 11S of adjacent pixels 11. The light-shielding film 12 blocks light that forms an object image. As a result, the light-shielding film 12 prevents the light that forms the object image from being received by the vicinity of the boundary.

[0014] The planarization film 13 is disposed on the light-receiving surfaces 11S of the plurality of pixels 11, overlapping the light-shielding film 12. The planarization film 13 fills in the irregularities formed by the light-shielding film 12 to provide a flat surface 13S. The planarization film 13 transmits light that forms an object image.

[0015] The plurality of microlenses 14 are arranged on the flat surface 13S. The plurality of microlenses 14 are arranged above the plurality of pixels 11, with the flattening film 13 sandwiched therebetween. The microlenses 14 arranged above each pixel 11 focus light onto the light receiving surface 11S of each pixel 11.

[0016] 1.2 Imaging pixels, phase difference detection pixels, imaging microlenses, and phase difference detection microlenses The plurality of pixels 11 include a first imaging pixel 21, a second imaging pixel 22, and a phase difference detection pixel 23.

[0017] The first imaging pixel 21, the second imaging pixel 22, and the phase difference detection pixel 23 are arranged in the same light receiving region. The first imaging pixel 21 is adjacent to the phase difference detection pixel 23 in the direction opposite to the side of the phase difference detection pixel 23. The second imaging pixel 22 is adjacent to the phase difference detection pixel 23 in the diagonal direction of the phase difference detection pixel 23.

[0018] The plurality of microlenses 14 includes a first imaging microlens 31, a second imaging microlens 32, and a phase difference detection microlens 33.

[0019] The first imaging microlens 31 corresponds to the first imaging pixel 21 and is disposed above the first imaging pixel 21. The second imaging microlens 32 corresponds to the second imaging pixel 22 and is disposed above the second imaging pixel 22. The phase difference detection microlens 33 corresponds to the phase difference detection pixel 23 and is disposed above the phase difference detection pixel 23.

[0020] The first imaging microlens 31 focuses the first light beam on the first imaging pixel 21. The first imaging pixel 21 receives the focused first light beam and outputs an electrical signal corresponding to the received first light beam. The first light beam is received by the light receiving surface 11S of the first imaging pixel 21. The electrical signal output by the first imaging pixel 21 constitutes an imaging signal. The second imaging microlens 32 focuses the second light beam on the second imaging pixel 22. The second imaging pixel 22 receives the focused second light beam and outputs an electrical signal corresponding to the received second light beam. The second light beam is received by the light receiving surface 11S of the second imaging pixel 22. The electrical signal output by the second imaging pixel 22 constitutes an imaging signal. The phase difference detection microlenses 33 collect the pupil-divided light beams (hereinafter referred to as "pupil-divided light beams") on the phase difference detection pixels 23. The phase difference detection pixels 23 receive the collected pupil-divided light beams and output electrical signals corresponding to the received pupil-divided light beams. The collected pupil-divided light beams are received by the light receiving surfaces 11S of the phase difference detection pixels 23. The electrical signals output by the phase difference detection pixels 23 constitute phase difference detection signals.

[0021] The pixels 11 and microlenses 14 may have shapes and arrangements different from those illustrated in FIGS.

[0022] 1.3 Curvature of each microlens In the following description, the curvature of each microlens 14 is the curvature of the entrance surface of each microlens 14 in a cross section including the optical axis of each microlens 14.

[0023] Each microlens 14 has rotational symmetry with the optical axis of the microlens 14 as the axis of rotational symmetry. Therefore, the curvature of each microlens 14 in a cross section including the optical axis of the microlens 14 is constant regardless of the cross-sectional direction. Therefore, the curvature of each microlens 14 is constant regardless of the cross-sectional direction in the circumferential direction. This maximizes the light-collecting ability of each microlens 14.

[0024] 1.4 Optimization of imaging microlenses and phase difference detection microlenses In the following description, the incident angle θ of incident light incident on each pixel 11 is the angle between the incident direction of the incident light and the normal to the light receiving surface 11S of each pixel 11.

[0025] What is required of the first imaging pixel 21 and the second imaging pixel 22 is different from what is required of the phase difference detection pixel 23. Therefore, the optimization of the first imaging microlens 31 and the second imaging microlens 32 and the optimization of the phase difference detection microlens 33 are different from each other.

[0026] What is required of the first imaging pixels 21 and the second imaging pixels 22 is that the first imaging pixels 21 and the second imaging pixels 22 have high sensitivity and good oblique incidence characteristics. Therefore, the first imaging microlens 31 and the second imaging microlens 32 are optimized so that the first imaging pixels 21 and the second imaging pixels 22 have high sensitivity and good oblique incidence characteristics. Having good oblique incidence characteristics in the first imaging pixels 21 and the second imaging pixels 22 means that the range of the incident angle θ over which the first imaging pixels 21 and the second imaging pixels 22 have stable sensitivity is wide.

[0027] Therefore, the first imaging microlens 31 and the second imaging microlens 32 have focal points in the photoelectric conversion regions located deeper than the light receiving surfaces 11S of the first imaging pixel 21 and the second imaging pixel 22, respectively, for the following reasons.

[0028] If the distance from the first imaging microlens 31 to the light receiving surface 11S of the first imaging pixel 21 becomes long, the oblique incidence characteristics of the first imaging pixel 21 deteriorate. This is because the light receiving position of incident light having an incident angle θ greater than 0° shifts from the light receiving surface 11S of the first imaging pixel 21 toward the light receiving surface 11S of the pixel 11 adjacent to the first imaging pixel 21, increasing the possibility that the incident light will not be incident on the light receiving surface 11S of the first imaging pixel 21. For example, if refraction by the first imaging microlens 31 is ignored, when the distance increases from 1 μm to 2 μm, the light-receiving position of incident light having an incident angle θ of 30° shifts by approximately 0.6 μm from the light-receiving surface 11S of the first imaging pixel 21 toward the light-receiving surface 11S of the pixel 11 adjacent to the first imaging pixel 21, increasing the likelihood that the incident light will not be incident on the light-receiving surface 11S of the first imaging pixel 21. The same holds true when the distance from the second imaging microlens 32 to the light-receiving surface 11S of the second imaging pixel 22 increases. However, by having the first imaging microlens 31 and the second imaging microlens 32 have focal points on the back side of the light receiving surfaces 11S of the first imaging pixel 21 and the second imaging pixel 22, respectively, the first imaging microlens 31 and the second imaging microlens 32 can be brought closer to the light receiving surfaces 11S of the first imaging pixel 21 and the second imaging pixel 22, respectively. This allows the incident light collected by the first imaging microlens 31 and the second imaging microlens 32 to be received efficiently by the light receiving surfaces 11S of the first imaging pixel 21 and the second imaging pixel 22, respectively. Note that the fact that the first imaging microlens 31 and the second imaging microlens 32 do not have focal points on the light receiving surfaces 11S of the first imaging pixel 21 and the second imaging pixel 22 does not cause any particular problems.

[0029] In contrast, what is required of the phase difference detection pixels 23 is that the phase difference detection pixels 23 have good phase difference detection characteristics. Therefore, the phase difference detection microlenses 33 are optimized so that the phase difference detection pixels 23 have good phase difference detection characteristics. Having good phase difference detection characteristics in the phase difference detection pixels 23 means that the sensitivity of the phase difference detection pixels 23 changes significantly when the incident angle θ changes beyond a specific incident angle. The specific incident angle is, for example, 0°.

[0030] Therefore, the phase difference detection microlens 33 has a focal point on the light receiving surface 11S of the phase difference detection pixel 23. The phase difference detection microlens 33 has a focal point on the light receiving surface 11S of the phase difference detection pixel 23 in both a cross section that includes the optical axis of the phase difference detection microlens 33 and is parallel to the opposite side direction of the phase difference detection pixel 23 as illustrated in Fig. 2 and a cross section that includes the optical axis of the phase difference detection microlens 33 and is parallel to the diagonal direction of the phase difference detection pixel 23 as illustrated in Fig. 3.

[0031] The distance from the phase difference detection microlens 33 to the light receiving surface 11S of the phase difference detection pixel 23 is the same as the distance from the first imaging microlens 31 and the second imaging microlens 32 to the light receiving surface 11S of the first imaging pixel 21 and the second imaging pixel 22. In addition, the phase difference detection microlens 33 has a focal point on the light receiving surface 11S of the phase difference detection pixel 23. In addition, the first imaging microlens 31 and the second imaging microlens 32 have focal points on the back side of the light receiving surfaces 11S of the first imaging pixel 21 and the second imaging pixel 22, respectively. As a result, the phase difference detection microlens 33 has a focal length shorter than the focal lengths of the first imaging microlens 31 and the second imaging microlens 32.

[0032] 1.5 Reducing the gap between the imaging microlens and the phase difference detection microlens In order to make the focal length of the phase difference detection microlens 33 shorter than the focal lengths of the first imaging microlens 31 and the second imaging microlens 32, it is desirable to make the curvature of the phase difference detection microlens 33 smaller than the curvatures of the first imaging microlens 31 and the second imaging microlens 32. When the curvature of the phase difference detection microlens 33 is smaller than the curvatures of the first imaging microlens 31 and the second imaging microlens 32, the diameter of the phase difference detection microlens 33 becomes smaller than the opposite side dimensions and diagonal dimensions of the phase difference detection pixel 23 in a plan view, and becomes smaller than the diameters of the first imaging microlens 31 and the second imaging microlens 32. Therefore, in a plan view, the area occupied by the phase difference detection microlens 33 becomes smaller than the area occupied by the phase difference detection pixel 23, and becomes smaller than the area occupied by the first imaging microlens 31 and the second imaging microlens 32. Therefore, an area where the phase difference detection microlenses 33 are not arranged is formed on the outer periphery of the phase difference detection pixels 23 .

[0033] In the formed region, the outer peripheries of the first imaging microlens 31 and the second imaging microlens 32 are arranged. Therefore, in a plan view, the first imaging microlens 31 is arranged to extend from above the first imaging pixel 21 onto the outer periphery of the phase difference detection pixel 23. Furthermore, in a plan view, the second imaging microlens 32 is arranged to extend from above the second imaging pixel 22 onto the outer periphery of the phase difference detection pixel 23. This makes it possible to prevent the formation of an ineffective region where no microlens is arranged in the region above the phase difference detection pixel 23. Furthermore, the first imaging microlens 31 and the second imaging microlens 32 can condense light incident on the region above the outer periphery of the phase difference detection pixel 23 onto the first imaging pixel 21 and the second imaging pixel 22, respectively.

[0034] Furthermore, in a plan view, the first imaging microlens 31 is connected to the phase difference detection microlens 33. This further prevents an ineffective region, where no microlens is arranged, from being formed in the region above the phase difference detection pixel 23 between the first imaging microlens 31 and the phase difference detection microlens 33. Furthermore, the first imaging microlens 31 can more effectively collect light incident on the region above the outer periphery of the phase difference detection pixel 23 onto the first imaging pixel 21.

[0035] As described above, in the solid-state imaging device 1, the first imaging microlens 31 and the second imaging microlens 32 are given a different radius of curvature from the radius of curvature of the phase difference detection microlens 33. Furthermore, the first imaging microlens 31 and the second imaging microlens 32 are given a planar shape different from the planar shape of the phase difference detection microlens 33, which prevents gaps from being formed between the first imaging microlens 31 and the second imaging microlens 32 and the phase difference detection microlens 33. This enables the phase difference detection characteristics of the phase difference detection pixel 23 to be improved.

[0036] Furthermore, in the solid-state imaging device 1, the first imaging microlens 31 and the second imaging microlens 32 are given the same height as the phase difference detection microlens 33. This makes it possible to suppress the influence on the process after the formation of the multiple microlenses 14.

[0037] 1.6 Boundaries of adjacent microlenses 3 , the solid-state imaging device 1 includes two imaging pixels 43 and 44 that are adjacent to each other in the diagonal direction of the phase difference detection pixel 23. The solid-state imaging device 1 also includes two imaging microlenses 53 and 54 that are arranged above the two imaging pixels 43 and 44, respectively. The two imaging pixels 43 and 44 may include the first imaging pixel 21 or the second imaging pixel 22. The two imaging microlenses 53 and 54 may include the first imaging microlens 31 or the second imaging microlens 32.

[0038] The two imaging microlenses 53 and 54 collect the third and fourth light beams, respectively, onto the two imaging pixels 43 and 44. The two imaging pixels 43 and 44 receive the collected third and fourth light beams, respectively.

[0039] By reducing the diameter of the phase difference detection microlens 33, a height h2 of the phase difference detection microlens 33 and the second imaging microlens 32 at the boundary between the phase difference detection microlens 33 and the second imaging microlens 32 becomes smaller than a height h3 of the two imaging microlenses 53 and 54 at the boundary between the two imaging microlenses 53 and 54. Here, the height h2 is the distance from the light receiving surfaces 11S of the phase difference detection pixel 23 and the second imaging pixel 22 to the incident surfaces of the phase difference detection microlens 33 and the second imaging microlens 32. Furthermore, the height h3 is the distance from the light receiving surfaces 11S of the two imaging pixels 43 and 44 to the incident surfaces of the two imaging microlenses 53 and 54.

[0040] 1.7 Pupil division Fig. 4 is a cross-sectional view schematically illustrating the periphery of a left-eye pixel provided in the solid-state imaging device of the first embodiment. Fig. 5 is a cross-sectional view schematically illustrating the periphery of a right-eye pixel provided in the solid-state imaging device of the first embodiment.

[0041] As a method for causing the phase difference detection pixel 23 to receive the pupil-divided light beam, there is a method in which a part of the light receiving surface 11S of the phase difference detection pixel 23 is shielded from light by a light-shielding film 12. According to this method, as illustrated in Fig. 4, when the right side of the light receiving surface 11S of the phase difference detection pixel 23 is shielded from light by the light-shielding film 12 and the left side of the light receiving surface 11S of the phase difference detection pixel 23 is activated, the phase difference detection pixel 23 becomes a left-eye pixel. On the other hand, as illustrated in Fig. 5, when the left side of the light receiving surface 11S of the phase difference detection pixel 23 is shielded from light by the light-shielding film 12 and the right side of the light receiving surface 11S of the phase difference detection pixel 23 is activated, the phase difference detection pixel 23 becomes a right-eye pixel.

[0042] Fig. 6 is a graph showing ideal phase difference detection characteristics. Fig. 7 is a graph showing simulation results of the phase difference detection characteristics of the solid-state imaging device of the first embodiment. In these graphs, the horizontal axis represents the angle of incidence θ of a light ray to each pixel (light incident angle) of the left eye pixel and the right eye pixel, and the vertical axis represents the sensitivity of each pixel. The sensitivity is normalized so that the maximum value is 100%. Fig. 8 is a cross-sectional view schematically illustrating a state in which incident light is incident on the solid-state imaging device of the first embodiment.

[0043] As shown in Fig. 6, ideal phase difference detection characteristics are those in which the ratio of the sensitivity of the right-eye pixel to the sensitivity of the left-eye pixel is high in the range of incident angles where the light incident angle θ is smaller than 0°, and the ratio of the sensitivity of the left-eye pixel to the sensitivity of the right-eye pixel is high in the range of incident angles where the light incident angle θ is larger than 0°. To obtain desirable phase difference detection characteristics, it is expected that the sensitivity of the left-eye pixel should approach 0% in the former range, and that the sensitivity of the right-eye pixel should approach 0% in the latter range.

[0044] As shown in Fig. 7, the solid-state imaging device 1 has phase difference detection characteristics close to the ideal phase difference detection characteristics shown in Fig. 6. The reason why the solid-state imaging device 1 has such phase difference detection characteristics is that, as shown in Fig. 8, gaps can be prevented from being formed between the first imaging microlens 31 and the second imaging microlens 32 and the phase difference detection pixels 23, and incident light 61 can be prevented from entering the phase difference detection pixels 23 via the formed gaps. This point will become clearer by comparing the second reference example described below with the first embodiment.

[0045] 1.8 Comparison between Reference Example and First Embodiment Fig. 9 is a top view schematically illustrating a solid-state imaging device of Reference Example 1. Fig. 10 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of Reference Example 1 taken along the cutting line a-a' in Fig. 9. Fig. 11 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of Reference Example 1 taken along the cutting line bb' in Fig. 9.

[0046] 9, 10, and 11, the first imaging microlens 31 and the second imaging microlens 32 are given the same height h1 as the height h1 of the phase difference detection microlens 33, and are given the same shape as the phase difference detection microlens 33. For this reason, in the solid-state imaging device 8, it is not possible to independently optimize the first imaging pixel 21 and the second imaging pixel 22 and the phase difference detection pixel 23. For this reason, it is not possible to simultaneously achieve what is required of the first imaging pixel 21 and the second imaging pixel 22 and what is required of the phase difference detection pixel 23.

[0047] Fig. 12 is a top view schematically illustrating a solid-state imaging device of a second reference example. Fig. 13 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of the second reference example taken along the cutting line a-a' in Fig. 12. Fig. 14 is a cross-sectional view schematically illustrating a cross section of the solid-state imaging device of the second reference example taken along the cutting line bb' in Fig. 12. Fig. 15 is a cross-sectional view schematically illustrating a state in which incident light is incident on the solid-state imaging device of the second reference example.

[0048] 12, 13, and 14, the first imaging microlenses 31 and the second imaging microlenses 32 are given shapes different from the shape of the phase difference detection microlenses 33. Therefore, in the solid-state imaging device 9, the first imaging pixels 21 and the second imaging pixels 22 and the phase difference detection pixels 23 can be optimized independently. Therefore, it is possible to achieve both what is required of the first imaging pixels 21 and the second imaging pixels 22 and what is required of the phase difference detection pixels 23.

[0049] However, in the solid-state imaging device 9 of the second reference example, the first imaging microlens 31 and the second imaging microlens 32 are disposed only above the first imaging pixel 21 and the second imaging pixel 22, respectively. Therefore, large gaps are formed between the first imaging microlens 31 and the second imaging microlens 32 and the phase difference detection microlens 33. Therefore, as illustrated in FIG. 15 , a part 62 of the incident light 61 passes through the formed large gap and enters the phase difference detection pixel 23. Therefore, the part 62 of the incident light 61 causes noise to be superimposed on the phase difference detection signal, which prevents the sensitivity of the left-eye pixel from approaching 0% in the range of incident angles where the light incident angle θ is smaller than 0° and prevents the sensitivity of the right-eye pixel from approaching 0% in the range of incident angles where the light incident angle θ is greater than 0°.

[0050] 16 is a graph showing the results of a simulation of the phase difference detection characteristics of the solid-state imaging device of the second reference example. In this graph, the horizontal axis represents the angle of incidence θ of a light ray to each pixel (light ray incident angle) of the left eye pixel and the right eye pixel, and the vertical axis represents the sensitivity of each pixel. The sensitivity is normalized so that the maximum value is 100%.

[0051] 16, in the solid-state imaging device 9 of the second reference example, the sensitivity of the left-eye pixel increases to approximately 40% in the range of incident angles where the light incident angle θ is smaller than 0°, and the sensitivity of the right-eye pixel increases to approximately 40% in the range of incident angles where the light incident angle θ is larger than 0°. Therefore, the solid-state imaging device 9 of the second reference example does not have phase difference detection characteristics close to the ideal phase difference detection characteristics shown in Fig. 6. The reason why the solid-state imaging device 9 does not have such phase difference detection characteristics is that large gaps are formed between the first imaging microlens 31 and the second imaging microlens 32 and the phase difference detection microlens 33, and a portion 62 of the incident light 61 enters the phase difference detection pixel 23 through the formed large gaps.

[0052] 7, in the solid-state imaging device 1 of the first embodiment, the sensitivity of the left-eye pixel decreases to approximately 10% in the range of incident angles where the light incident angle θ is smaller than 0°, and the sensitivity of the right-eye pixel decreases to approximately 10% in the range of incident angles where the light incident angle θ is larger than 0°. Therefore, the solid-state imaging device 1 of the first embodiment has phase difference detection characteristics that are close to the ideal phase difference detection characteristics shown in FIG. 6. The reason why the solid-state imaging device 1 has such phase difference detection characteristics is that gaps are prevented from being formed between the first imaging microlens 31 and the second imaging microlens 32 and the phase difference detection microlens 33, and the incident light 61 is prevented from entering the phase difference detection pixels 23 through the gaps.

[0053] The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0054] 1 solid-state imaging device, 8 solid-state imaging device, 9 solid-state imaging device, 11 pixel, 12 light-shielding film, 13 planarization film, 14 microlens, 11S light-receiving surface, 13S planar surface, 21 first imaging pixel, 22 second imaging pixel, 23 phase difference detection pixel, 31 first imaging microlens, 32 second imaging microlens, 33 phase difference detection microlens, 43 imaging pixel, 44 imaging pixel, 53 imaging microlens, 54 imaging microlens, 61 incident light, 62 part of the incident light.

Claims

1. a first imaging pixel that receives the first light flux; a phase difference detection pixel that is adjacent to the first imaging pixel and receives a pupil-divided light beam; a first imaging microlens that is disposed so as to extend from above the first imaging pixel to above the phase difference detection pixel and that focuses the first light flux onto the first imaging pixel; a phase difference detection microlens that is arranged above the phase difference detection pixel, occupies an area smaller than an area occupied by the first imaging microlens, is connected to the first imaging microlens, and focuses the pupil-divided light beam on the phase difference detection pixel; A solid-state imaging device comprising:

2. The phase difference detection microlens has a focal length shorter than the focal length of the first imaging microlens. The solid-state imaging device according to claim 1 .

3. The curvature of the incident surface of the phase difference detection microlens in a cross section including the optical axis of the phase difference detection microlens is constant regardless of the cross-sectional direction.

3. The solid-state imaging device according to claim 1.

4. a second imaging pixel adjacent to the phase difference detection pixel in a diagonal direction of the phase difference detection pixel and configured to receive a second light flux; a second imaging microlens that focuses the second light flux onto the second imaging pixel; two imaging pixels adjacent to each other in the diagonal direction and configured to receive the third light flux and the fourth light flux, respectively; two imaging microlenses arranged above the two imaging pixels, respectively, to condense the third light flux and the fourth light flux onto the two imaging pixels; Equipped with The height of the phase difference detection microlens and the second imaging microlens at the boundary between the phase difference detection microlens and the second imaging microlens is lower than the height of the two imaging microlenses at the boundary between the two imaging microlenses.

3. The solid-state imaging device according to claim 1.

5. the phase difference detection pixel has a light receiving surface that receives the pupil-divided light beam, The phase difference detection microlens has a focal point on the light receiving surface.

3. The solid-state imaging device according to claim 1.

6. The phase difference detection microlens has a focal point on the light receiving surface in a cross section that includes an optical axis of the phase difference detection microlens and is parallel to an opposite side direction of the phase difference detection pixel, and in a cross section that includes the optical axis and is parallel to a diagonal direction of the phase difference detection pixel. The solid-state imaging device according to claim 5 .

7. the first imaging pixel has a light receiving surface that receives the first light flux, The first imaging microlens has a focal point on the back side of a light receiving surface that receives the first light flux.

3. The solid-state imaging device according to claim 1.

Images