TWI425629B - Solid state image pickup device, method of manufacturing the same, image pickup device, and electronic device - Google Patents

Description

Solid-state image pickup device and manufacturing method thereof, image pickup device and electronic device

The present invention relates to a solid-state image pickup device, a method of manufacturing the solid-state image pickup device, an image pickup device, and an electronic device including the solid-state image pickup device, such as a camera.

The solid-state image pickup device includes an amplifying solid-state image pickup device, which is represented by, for example, a metal oxide semiconductor (MOS) image sensor, such as a complementary metal oxide semiconductor (CMOS). The solid-state image pickup device includes a charge-switching solid-state image pickup device, which is represented by a charge coupled device (CCD) image sensor. The types of such solid-state image pickup devices have been widely used in digital still cameras and digital video recorders. Since the supply voltage and power consumption of the MOS solid-state image pickup device are low, the solid-state image pickup device is often used in a mobile device such as a mobile phone provided with a camera and a personal digital assistant (PDA).

A typical MOS solid-state image pickup device includes a plurality of unit pixels arranged in an array, each unit pixel having a group of photodiodes as photoelectric converters, and a plurality of pixel transistors. In recent years, the miniaturization of pixel sizes has continued to advance. In order to reduce the number of pixel transistors per unit pixel and increase the area of the photodiode, a MOS solid-state image pickup device is developed in which unit pixels are arranged in an array, and each unit pixel cluster has one pixel shared by a plurality of pixels. Crystals (see Japanese Unexamined Patent Application Publication No. Publication No. No. 2006-54276 and No. 2009-135319).

Further, a solid-state image pickup device is proposed in which a waveguide guides incident light to a corresponding photodiode to improve sensitivity characteristics (see Japanese Unexamined Patent Application Publication No. Publication No. 2008-166677). Further, a solid-state image pickup device is proposed in which a pupil correction is performed on a lens on a wafer to correct shading (Japanese Patent No. 2600250).

The solid-state image pickup device comprises a waveguide and an on-wafer lens, and the waveguide is disposed on the photodiode of the photoelectrically converted incident light, and the lens on the wafer guides the incident light to the waveguide. In addition, a color filter layer is formed between the lens on the wafer and the waveguide. The color filter layer divides incident light into, for example, colored light including red (R) light, green (G) light, and blue (B) light. In order to reduce the chromatic aberration effect, the radius of curvature of the wafer lens for RGB color is adjusted. Further, the pupil correction amount at the high image height position of the lens on the wafer and the color filter is determined to be smaller than the lens main ray angle (CRA) to reduce the chromatic aberration effect.

For example, when a wafer-on-wafer lens having a high main ray angle (for example, 25°) is used, chromatic aberration at a high image height position causes shading (a difference between image focus positions (depth)), and color mixing occurs.

When a method of adjusting the radius of curvature of a lens on a wafer according to color is used, similar to the prior art, the number of steps of manufacturing a lens on a wafer is increased. As the pixel is further miniaturized, the radius of curvature of the lens on the wafer increases. This makes it difficult to adjust the radius of curvature according to the color.

In the high incident angle portion, the center of image formation (including F light) is diverted from the center of the photodiode to the optical center (for example, toward the center of the pixel portion). Therefore, shading and color mixing are produced. In the prior art, if the radius of curvature of the lens on the wafer is not adjusted according to the color, the illumination diameter of the incident light at one end of the incident light of the waveguide may change with the color due to the chromatic aberration. As the pixels shrink more, it is more difficult to implement corrections to obtain balanced positions for all colors. If the amount of pupil correction for the lens and color filter layer on the wafer changes with color, a gap or overlap will occur. Therefore, shading and color mixing are produced. Therefore, pupil correction is performed on the on-wafer lens and the color filter layer to effectively concentrate uniform oblique light. Unfortunately, such a structure causes brightness shading, in which the sensitivity is reduced at the periphery of the angular range, and color shading occurs due to the difference in shape of the shading of the individual colors.

A technique for guiding a waveguide to incident light to a photoelectric converter even when the incident angle of incident light is large is disclosed. With this technique, the angular extent is divided into four quarter-sectors, and the tapered position of the waveguide is varied according to the position in the four quarter-sectors so that the waveguide can direct incident light at different angles of incidence (eg, See Japanese Unexamined Patent Application Publication No. 2005-175234.

However, even if a portion of the waveguide is tapered, the inventors have found that light entering the waveguide vertically is reflected by the inclined surface of the tapered waveguide, thus reducing sensitivity. Therefore, since the tapered shape causes a decrease in sensitivity, a part of the waveguide should not be tapered. Further, in order to form a waveguide having a tapered portion, the number of processes and the number of masks are increased as compared with the formation of a general waveguide. Further, since this technique divides only the angular range into four quarter-sectors and changes the shape of the waveguide, this technique cannot reduce the shading characteristics.

1 shows an example of a MOS solid-state image pickup device 1 of a two-pixel sharing type according to the prior art, in which two pixels share a floating diffusion, an amplifier transistor, and a selection transistor. The solid-state image pickup device 1 includes a unit pixel cluster 2 of a two-pixel sharing type in which two pixels share a floating diffusion, an amplifier transistor, and a selection transistor. The unit pixel cluster 2 includes two photodiodes PD1 and PD2, two conversion transistors Tr11 and Tr12, one floating diffusion FD, one reset transistor Tr2, and one amplifier transistor Tr3. In this example, a color filter with a Bayer pattern is used. The unit pixel cluster 2 of the two-pixel sharing type is arranged such that the first green pixel Gb is adjacent to the blue pixel B, and the second green pixel Gr is adjacent to the red pixel R. In FIG. 1, a unit pixel cluster 2 of a two-pixel sharing type including a red pixel R and a first green pixel Gb, and a unit pixel cluster 2 of a two-pixel sharing type including a blue pixel B and a second green pixel Gr are repeatedly arranged. .

The conversion transistors Tr11 and Tr12 respectively include a conversion gate 3 made of a polymer germanium, individual photodiodes PD (PD1, PD2), and a floating diffusion FD. The reset transistor Tr2 includes a reset gate 4 made of a polymer germanium, a floating diffusion FD, and a source region 5. The amplifier transistor Tr3 includes an amplifier gate 6, a source region 7, and a drain region 8 made of a polymer. The floating diffusion FD and the amplifier gate 6 are connected to each other by a wiring portion 9. The source region 7 of the amplifier transistor Tr3 is connected to a vertical signal line (not shown).

In the solid-state image pickup device 1, the layout of the switching gate 3 of the first green pixel Gb is symmetrical to the layout of the switching gate 3 of the second green pixel Gr. These layouts cause a difference in sensitivity between the first and second green pixels Gb and Gr. For example, the difference between the base layer layout caused by the switching gate 3 causes a difference in the amount of incident light that illuminates the green pixels Gb and Gr, because a portion of the obliquely incident light is converted by one of the green pixels. The gate is shielded. In the MOS solid-state image pickup device, the sensitivity difference between the two pixels becomes more and more obvious as the pixel miniaturization progresses. The difference in sensitivity is a bottleneck for miniaturization.

2, there is shown a solid-state image pickup device 10 in which a unit pixel cluster 2 of two pixel sharing type (where two pixels share a floating diffusion, an amplifier transistor, and a selection transistor) are arranged in an interlaced manner. . Since the unit pixel clusters 2 of the two-pixel sharing type are arranged in a staggered manner in the solid-state image pickup device 10, the layouts of the switching gates of the first and second green pixels Gb and Gr are symmetrical with each other. Therefore, the sensitivity difference between the green pixels Gb and Gr is reduced.

The difference in sensitivity between the first and second green pixels Gb and Gr may cause noise, such as the occurrence of grid noise, and may also cause color shading. The desire is to eliminate the difference between the sensitivity.

Meanwhile, in the solid-state image pickup device 10 shown in FIG. 2, the layout of the pixel transistors and the layout of the floating diffusion FD are restricted to maintain the symmetrical layout of the switching gates of the first and second green pixels Gb and Gr. This limitation is the bottleneck of miniaturization. For example, the unit pixel cluster 2 only achieves two pixel sharing, so the number of pixel transistors and floating diffusion is twice the number of pixel transistors and floating diffusion in a four pixel shared layout. Therefore, the area of the photodiode PD for photoelectric conversion is reduced. A reduction in the area of the photodiode PD results in a loss of sensitivity. Further, in the solid-state image pickup device 10, the layout of the switching gates 3 of the green pixels Gb and Gr is asymmetrical to the layout of the switching gates 3 of the red pixel R and the blue pixel B. Therefore, it is difficult to prevent the occurrence of color shading.

As described above, since there is an asymmetrically disposed base layer with respect to a boundary between predetermined adjacent pixels, optical asymmetry occurring between pixels is caused.

According to the situation, the device is a solid-state image pickup device and an electronic device including the solid-state image pickup device, such as a camera, which can improve the optical asymmetry between pixels caused by the asymmetry of the base layer. And wiring parts.

A solid-state image pickup device according to an embodiment of the present invention includes a pixel portion in which pixels are arranged in an array; a base layer formed under a light incident surface of the cluster with a plurality of pixels clustered, and the base layer has a layout including electrodes and wiring The layout is asymmetrical with respect to a boundary between predetermined adjacent pixels; and an adjustment mechanism for making the optical asymmetry between the pixels caused by the base layer optically symmetrical.

As a preferred embodiment of the solid-state image pickup device, the pixel portion may include a plurality of unit pixel clusters, each unit pixel cluster having a plurality of pixels sharing a single predetermined transistor. The base layer may be a base layer including a gate and a wiring portion of the pixel transistor.

With the solid-state image pickup device of this embodiment, the effect of the base layer on the incident light is reduced in accordance with the adjustment direction and the adjustment amount of the positional displacement of the adjustment mechanism. The incident efficiency of the incident light of the photoelectric converter of the individual pixels can be equivalent.

With the solid-state image pickup device of the preferred embodiment, the pixel portion can include a cluster of unit pixels of a plurality of pixel sharing types. Thus, the incident efficacy of incident light on a photoelectric converter of at least one common color pixel (the same color signal is output from the color pixel) can be equivalent in a pixel unit cluster, or in a plurality of adjacent unit pixel clusters Is equivalent.

An electronic device according to an embodiment of the present invention includes a solid-state image pickup device, an optical system that directs incident light to a photoelectric converter of the solid-state image pickup device, and a signal processing circuit for processing a signal output from the solid-state image pickup device. The solid-state image pickup device is any of the above-described solid-state image pickup devices.

With the electronic device in this embodiment, since the solid-state image pickup device is used, the performance of the base layer for incident light is reduced or eliminated. The incident efficiency of the incident light of the photoelectric converter of the individual pixels can be equivalent.

A disadvantage of the prior art is that as further pixels are miniaturized, since the illumination diameter of the incident light at one end of the light incident side of the waveguide changes with the chromatic aberration of the color, it is difficult to perform correction to reach the balance for all colors. position. Moreover, if the amount of pupil correction of the lens and the color filter layer on the wafer changes with color, voids or overlapping portions may occur. Therefore, shading and color mixing are produced.

The device does not perform pupil correction on the on-wafer lens and color filter layer depending on the color of the incident light transmitted through the color filter layer, but performs pupil correction based on the reference color of the incident light. Therefore, even when the illumination diameter of the incident light changes with the chromatic aberration of the color, the incident light can be efficiently irradiated on one end of the light incident side of the waveguide.

A solid-state image pickup device according to an embodiment of the present invention includes a pixel portion which is formed by arranging unit pixels in a row and column direction of a semiconductor substrate. Each unit pixel includes a photoelectric converter, a waveguide, and a microlens. The photoelectric converter is formed on the semiconductor substrate and converts the incident light into a signal charge. The waveguide is formed on the photoelectric converter and guides the incident light to the photoelectric converter. A lens is formed over the waveguide and directs the incident light to one end of the light incident side of the waveguide. The waveguide has a cylindrical body, and its cross section is kept constant from the light incident side to the light exit side, and is arranged such that the center of the incident light of the incident light of the microlens at one end of the light incident side of the waveguide is aligned with the central axis of the waveguide. .

With the solid-state image pickup device of this embodiment, the cylindrical body of the waveguide has a constant cross section from one end of the light incident side to one end of the light exit side. The light incident perpendicularly to one end of the light incident side of the waveguide is not reflected by the sidewall of the waveguide but is transmitted through the waveguide 16. Therefore, the reduction in sensitivity is limited. Further, the center of the light incident on one end of the light incident side of the waveguide is aligned with the central axis of the waveguide. Therefore, pupil correction can be performed on the waveguide. Therefore, incident light incident from the microlens can be efficiently guided to the waveguide.

A method of manufacturing a solid-state image pickup device according to an embodiment of the present invention includes the steps of: forming a waveguide hole in a wiring layer, the waveguide hole guiding incident light onto a photoelectric converter, and the photoelectric converter converts incident light into a signal charge, The photoelectric converter is formed in the semiconductor substrate, the wiring layer is formed in the semiconductor substrate and includes an interlayer insulating film having a plurality of layer connection portions; the waveguide hole is filled with the waveguide material film, and the refractive index of the waveguide material film is higher than the refractive index of the interlayer insulating film And forming a waveguide in the waveguide hole; forming a color filter layer on the waveguide material film, and a flat insulating film interposed therebetween; and forming a microlens on the color filter layer, the microlens guiding the incident light to the photoelectric converter on. A plurality of unit pixels each having a photoelectric converter are arrayed in a row and column direction of a semiconductor substrate to form a pixel portion. The waveguide formed corresponding to the photoelectric converter has a cylindrical body whose cross section is kept constant from one end on the light incident side to one end on the light exit side, and is configured to make incident light incident on one end of the light incident side of the waveguide The center of the light is aligned with the central axis of the waveguide.

With the manufacturing method of the solid-state image pickup device of this embodiment, the cross section of the cylindrical body of the waveguide is constant from one end of the light incident side to one end of the light exit side. Light incident perpendicularly to one end of the light incident side of the waveguide is not reflected by the sidewall of the waveguide but is transmitted through the waveguide 16. Therefore, the reduction in sensitivity can be limited. Further, the center of the light incident from one end of the light incident side of the waveguide is aligned with the central axis of the waveguide. Therefore, pupil correction can be performed for the waveguide. Therefore, light incident from the lens can be efficiently guided to the waveguide.

An image pickup apparatus according to an embodiment of the present invention includes a light concentrating optical unit that collects incident light, an image pickup unit including a solid-state image pickup device, and the solid-state image pickup device receives light collected by the light concentrating optical unit and photoelectricizes the light And a signal processing unit that processes signals obtained by photoelectric conversion of the solid-state image pickup device. The solid-state image pickup device includes a pixel portion formed of unit pixels arranged in an array in the row and column directions of the semiconductor substrate. The unit pixel cluster includes a photoelectric converter formed on the semiconductor substrate and converting incident light to signal charges; a waveguide formed over the photoelectric converter and guiding the incident light to the photoelectric converter; and a microlens formed on the waveguide Above and directed incident light to one end of the light incident side of the waveguide. The waveguide has a cylindrical body whose cross section is kept constant from one end on the light incident side to one end on the light exit side. And being arranged such that the center of the light incident from the microlens at one end of the light incident side of the waveguide is aligned with the central axis of the waveguide.

With the image pickup apparatus of this embodiment, since the solid-state image pickup device described above is used, the reduction in sensitivity can be restricted, and the light incident from the microlens can be efficiently guided to the waveguide.

Since the pupil correction is performed even for the waveguide of the solid-state image pickup device, the incident light of the individual colors is completely collected to the waveguide. Therefore, color unevenness (color shading) due to wavelength can be reduced. Since the shading is reduced, the sensitivity can be increased when the sensitivity is defined as the average of the output of the overall screen. For example, exposure time can be reduced and images can be captured in dark environments.

With the manufacturing method of the solid-state image pickup device, since the pupil correction is performed even for the waveguide, the incident light of the individual colors can be completely collected to the waveguide. Therefore, color unevenness (color shading) of shading depending on the wavelength can be reduced. Because of the reduced shading, sensitivity is increased when sensitivity is defined as the average output of the overall screen. For example, exposure time can be reduced and image capture can be performed in a dark environment. Therefore, the chromatic aberration effect can be reduced without increasing the number of processes.

Further, in the miniaturized pixel, the light that does not enter the waveguide can be reduced by adjusting the pupil correction amount of each color. Reduces shading and color mixing.

Since the image pickup apparatus according to this embodiment uses the solid-state image pickup device described above, color unevenness (color shading) due to shading of wavelength can be reduced. The sensitivity can be increased, so that a high quality image can be obtained.

With the solid-state image pickup device, the incident efficiency of incident light to an individual photoelectric converter can be equivalent. The photoelectric converter of individual pixels can achieve optical symmetry. For example, if a pixel-shared type solid-state image pickup device is used, the effect of the asymmetric base layer can be reduced or eliminated, and the difference between the sensitivity of the shared color pixels (the same color signal is output from the color pixel) can be reduced. In addition, color shading can be reduced.

With the electronic device, optical symmetry can be provided in an individual pixel photoelectric converter of a solid-state image pickup device. It can increase the quality of electronic devices and improve their image quality.

Embodiments of the invention will be described below.

1. First embodiment First exemplary structure of solid-state image pickup device

An exemplary configuration of the first embodiment of the solid-state image pickup device according to the present invention will be described with reference to the schematic cross-sectional views of 3A to 3C and the plan layout. 3A shows a unit pixel located at the center of the angular range, FIG. 3B shows a unit pixel located at the edge of the angular range, and FIG. 3C shows a pixel portion including a plurality of unit pixels.

Hereinafter, reference numeral 1 denotes a solid-state image pickup device, 11 denotes a semiconductor substrate, 12 denotes a photoelectric converter, 14 denotes an interlayer insulating film, 16 denotes a waveguide, 17 denotes a color filter layer, 18 denotes a microlens, 19 denotes a waveguide hole, and 20 denotes The pixel portion, 21 indicates a unit pixel, 53 indicates a waveguide material film, 200 indicates an image pickup device, 201 indicates an image pickup unit, 202 indicates a light collecting optical unit, 203 indicates a signal processing unit, and 210 (1) indicates a solid-state image pickup device.

Referring to FIGS. 3A to 3C, the photoelectric converter 12 is formed on the surface of the semiconductor substrate 11 (light incident side). The photoelectric converter 12 converts the incident light into a signal charge. The semiconductor substrate 11 uses a germanium substrate. Alternatively, the semiconductor substrate 11 uses a germanium (SOI) substrate on an insulator. In this case, the photoelectric converter 12 is formed on the ruthenium layer on the SOI substrate. The wiring layer 13 is formed over the photoelectric converter 12. For example, the wiring layer 13 is formed so that a plurality of layers including the wiring portion 15 are formed in the interlayer insulating film 14. The wiring portion 15 is not formed in a region above the photoelectric converter 12. The surface of the interlayer insulating layer 14 is planarized.

Further, the waveguide 16 is formed in the wiring layer 13 of the region above the photoelectric converter 12. The waveguide 16 directs incident light to the photoelectric converter 12. The waveguide 16 is formed such that the waveguide hole is formed in the interlayer insulating film 14 in the region above the photoelectric converter 12, and the waveguide hole is filled with the light refraction material having a refractive index higher than that of the interlayer insulating film 14. The material is, for example, a tantalum nitride film, a diamond film or a resin material.

A microlens 18 (also referred to as an on-wafer lens) is formed over the interlayer insulating film 14 in a region above the waveguide 16, and a color filter layer 17 is interposed therebetween. The color filter layer 17 separates the incident light. The microlens 18 guides the incident light emitted from the color filter layer 17 to one end of the light incident side of the waveguide 16. The microlens 18 and color filter layer 17 accept pupil correction to effectively concentrate uniform oblique rays. From the center of the angular range (for example, the center of the phase portion) toward the edge of the angular range, the amount of pupil correction is getting larger and larger. The color filter layer 17 divides the incident light into, for example, red light, green light, and blue light. Therefore, a color filter for individual colors is set. Microlens 18 is also referred to as an on-wafer lens. The microlens 18 has a convex lens shape and is disposed on the uppermost layer.

The photoelectric converter 12, the waveguide 16, the color filter layer 17, the microlens 18, the switching gate (not shown), and the like form a unit pixel 21. A plurality of unit pixels 21 are arranged in a row and a column direction of the semiconductor substrate 11 to form a pixel portion 20. A pixel amplification unit (not shown, also referred to as a pixel transistor unit) is provided for each unit pixel, or every two unit pixels, or every four unit pixels. The pixel amplifying unit amplifies the signal charge read by the switching gate and outputs the amplified signal charge.

Waveguides 16 are formed in the pixel portion 20 to correspond to the photoelectric converter 12, respectively. Each of the waveguides 16 has a cylindrical body whose cross section is constant from one end on the light incident side to one end on the light exit side. For example, a cylindrical body having a constant cross section may be a cylinder or an oval cylinder (including an elliptical cylinder). Alternatively, the waveguide 16 is a crucible having rounded corners. The center of light LC of the incident light incident from one end of the light incident side of the waveguide 16 is aligned with the central axis C of the waveguide 16.

In this case, in the unit pixel 21 (see FIG. 3A) at the center of the angular range, the incident light is incident on the microlens 18 in the central axis direction. The incident light collected by the microlens 18 is transmitted and separated by the color filter layer 17, and is incident on one end of the light incident side of the waveguide 16. Incident light is guided along the central axis C of the waveguide 16 and exits from one end of the waveguide 16 on the light exit side. Light is emitted to the center of the photoelectric converter 12. That is, the incident light transmitted through the microlens 18 is transmitted along the center of the color filter layer 17 and the central axis C of the waveguide 16, and is emitted to the center of the photoelectric converter 12. Therefore, pupil correction is not performed for the waveguide 16.

In the unit pixel 21 (see FIG. 3B) located at the center of the off-angle range, as described above, the microlens 18 and the color filter layer 17 receive pupil correction to effectively gather uniform oblique light. Further, the waveguide 16 is disposed such that the center LC of the incident light incident from the one end of the light incident side of the waveguide 16 is aligned with the central axis C of the waveguide 16. That is, pupil correction is performed on the waveguide 16.

In the photoelectric converter 12 having the incident light of the same wavelength incident thereon, the displacement amount of the central axis C of each waveguide 16 with respect to the center of the corresponding photoelectric converter 12 follows the photoelectric converter at the center of the pixel portion 20. 12 is getting bigger and bigger towards the outside. That is, the incident angle of the incident light collected by the microlens 18 is larger and larger from the center of the pixel portion 20 toward the outside. Although the pupil correction has been performed for the microlens 18, the amount of correction is not sufficient. Therefore, for incident light having an equal wavelength, the amount of displacement of the central axis of the waveguide 16 with respect to the center of the photoelectric converter 12 is increased, and thus the center of the light incident from the microlens 18 is aligned with the central axis C of the waveguide 16.

The diameter of the waveguide 16 allows light generated from one end of the light exit side of the waveguide 16 to be emitted into a region of the surface of the photoelectric converter 12. Therefore, unlike the waveguide of the prior art, the size of the waveguide 16 is not equal to the size of the surface of the photoelectric converter 12. The diameter of the waveguide 16 is preferably larger than the diameter of the incident light transmitted through the color filter layer 17 to the light incident side of the waveguide 16. The illumination diameter changes with the wavelength of the incident light. For example, when the color filter layer 17 separates incident light into red light, green light, and blue light, the light diameter of the red light is the largest, the light diameter of the green light is smaller than the light diameter of the red light, and the light diameter of the blue light is smaller than the green light. The diameter of the illumination. If the diameter of the waveguide 16 is determined by the color, the layout is complicated. In some cases, the waveguide 16 can reach the junction 15 of the wiring layer 13. For example, the diameter of the waveguide 16 is determined based on green light having an intermediate wavelength range of incident light. Alternatively, if there is room between the waveguide 16 and the connection portion 15 of the wiring layer 13, the diameter of the waveguide 16 can be determined based on the red light.

As described above, the margin of pupil correction can be increased by reducing the diameter of the waveguide 16 to be smaller than the diameter of the waveguide of the prior art. Furthermore, the margin of pupil correction of the waveguide 16 can be further increased by reducing the width of the wiring portion 15 disposed around the waveguide 16. For example, the line width of the wiring portion can be reduced in a range, and the processing can be considered, which avoids the clock delay caused by increasing the impedance of the wiring layer 15 by reducing the line width. For example, if the line width of the wiring portion 15 is reduced by 10 nm, the room for pupil correction can be increased by 10 nm.

The solid-state image pickup device 1 (1A) is configured as described above.

Exemplary calculation of pupil correction

Next, an exemplary method of calculating the pupil correction amount of the solid-state image pickup device 1 will be described with reference to the schematic cross-sectional views of FIGS. 4A and 4B. Figure 4A shows a unit pixel located at the center of the angular range. Figure 4B shows the unit pixels at the edges of the angular range.

Referring to FIG. 4A, in the unit pixel 21 located at the center of the angular range, the incident light is incident on the microlens 18 in the central axis direction. The incident light collected by the microlens 18 is transmitted and separated by the color filter layer 17, and is incident on one end of the light incident side of the waveguide 16. The incident light is guided along the central axis C of the waveguide 16, and it exits from one end of the waveguide 16 on the light exit side. Light is emitted to the center of the photoelectric converter 12. That is, the incident light transmitted through the center of the microlens 18 is transmitted along the center of the color filter layer 17 and the central axis C of the waveguide 16, and is emitted to the center of the photoelectric converter 12. Therefore, pupil correction is not performed for the waveguide 16.

In contrast, in the unit pixel 21 located at the edge of the angular range, referring to FIG. 4B, the pupil angle correction amount when the incident angle θ1 of the incident light incident on the microlens 18 is, for example, θ1=25° is calculated.

The refractive index n of the microlens 18 is n = 1.5.

If the refractive index n0 of the atmosphere around the microlens 18 is n0=1, and the refractive index n1 of the microlens 18 is n1=1.6, the following relationship can be established:

Sin θ2=(n0/n1)×sinθ1

If θ1=25°, the result is as follows

Θ2=sin-1{(n0/n1)×sinθ1}=sin-1{(1/1.6)×sin25}=15.3°

For example, when one end of the light incident side of the waveguide 16 serves as a reference position (reference level), the height h1 represents the height from the reference position to the plane in which the microlens 18 is formed, and the height h2 represents the position from the reference position to the color filter layer 17. The height of the incident plane.

For example, assume that h1 = 2 μm and h2 = 1.5 μm. In this case, the difference X_OCL' between the central axis C of the waveguide 16 and the central axis LC of the microlens 18 is as follows

X_OCL'=h1×tanθ 2+X_WG=2×tan 15.3°+X_WG=0.547μm+X_WG

Where X_WG is the difference between the photoelectric converter 12 and the central axis C of the waveguide 16.

Further, the difference X_CF' between the central axis C of the waveguide 16 and the central axis FC of the color filter layer 17 is as follows:

X_CF'=h2×tanθ 2+X_WG=1.5×tan 15.3°+X_WG=0.411μm +X_WG

If the diffraction angle θ3 at one end of the light exit side of the waveguide 16 is θ3 = 13.0°, the diffusion width w to the surface of the photoelectric converter 12 is as follows

W=h3×tanθ3

If the distance h3 from the photoelectric converter 12 to one end of the light exit side of the waveguide 16 is, for example, h3 = 0.5 μm, the result is as follows

W=h3×tanθ3=0.5×tan 13.0°=0.115μm

For example, if the width PD of the photoelectric converter is PD = 1.1 μm, and the diameter WG ^' of the waveguide 16 is WG ^' = 0.6 μm, from the diffracted light to the semiconductor substrate 11 formed on the switching gate of the adjacent photoelectric converter 12 The distance α of the projection position is expressed by

(PD-WG ^' )/2>W+α

Using the above formula, the value becomes as follows

(1.1-0.6)/2>0.11+α

Therefore, the pupil correction X _{_} WG can be provided until the condition becomes the following:

α<0.25-0.115=0.135μm

Next, a method of calculating the diffraction angle θ3 will be described.

Based on the Young's experiment, if d is the pixel pitch × 2, n is 1 (first-order diffracted light), and λ is the wavelength of the incident light, the following formula can be provided.

d×sin θ=nλ

Therefore, the results are as follows

θ=sin-1(nλ/d)

For example, if d=1.4μm×2=2.80μm and n=1, and if the wavelength λ of the red light is λ=630 nm (red), the diffraction angle θ of the red light is as follows

θ=sin-1(0.63/2.8)=13.00°

For reference, if the wavelength λblue of the blue light is λblue=450 nm (blue), the diffraction angle of the blue light is as follows

Θblue=sin-1(0.45/2.8)=9.25°

Further, if the wavelength λgreen of the green light is λgreen=550 nm (green), the diffraction angle of the green light is as follows

Θgreen=sin-1(0.55/2.8)=11.33°

Next, the structure of the solid-state image pickup device according to the prior art will be described as a comparative example with reference to the schematic cross-sectional views of FIGS. 5A and 5B. Figure 5A shows the unit pixels at the center of the angular range. Figure 5B shows the unit pixels at the edges of the angular range.

Referring to FIGS. 5A and 5B, in the unit pixel 21, the photoelectric converter 12 is formed on the surface of (on the light incident side of) the semiconductor substrate 11. The photoelectric converter 12 converts the incident light into a signal charge. The wiring layer 13 is formed over the photoelectric converter 12. For example, the wiring layer 13 is formed such that a plurality of layers including the wiring portion 15 are formed in the interlayer insulating film 14. The wiring portion 15 is not formed in the upper region of the photoelectric converter 12. The surface of the interlayer insulating film 14 is planarized.

Further, the waveguide 16 is formed in the wiring layer 13 in the region above the photoelectric converter 12. The waveguide 16 directs incident light to the photoelectric converter 12. A microlens 18 (also referred to as an on-wafer lens) is formed over the interlayer insulating film 14 in the region above the waveguide 16, with the color filter layer 17 interposed therebetween. The color filter layer 17 separates the incident light. The microlens 18 guides the incident light emitted from the color filter layer 17 to one end of the light incident side of the waveguide 16. The color filter layer 17 separates incident light into, for example, red light, green light, and blue light. Therefore, a color filter for individual colors is set. Microlens 18 is also referred to as an on-wafer lens. The microlens 18 has a convex lens shape and is disposed on the uppermost layer.

Referring to FIG. 5A, in the unit pixel 21 at the center of the angular range, the incident light is incident on the microlens 18 in the central axis direction. The incident light collected by the microlens 18 is transmitted and separated by the color filter layer 17, and is incident on one end of the light incident side of the waveguide 16. Incident light is directed along the central axis C of the waveguide 16, and it exits from the light exit side of the waveguide 16. Light is emitted to the center of the photoelectric converter 12. That is, the incident light transmitted through the center of the microlens 18 is transmitted along the center of the color filter layer 17 and the central axis C of the waveguide 16, and is emitted to the center of the photoelectric converter 12. Therefore, pupil correction is not performed on the microlens 18 or the color filter layer 17.

In contrast, referring to FIG. 5B, in the unit pixel 21 at the center of the off-angle range, the microlens 18 and the color filter layer 17 receive pupil correction to effectively collect uniform oblique light. The pupil correction amount is increased from the center of the angular range toward the edge of the angular range.

Next, a method of calculating the pupil correction amount according to the comparative example will be described with reference to the schematic cross-sectional views of FIGS. 6A and 6B. Figure 6A shows a unit pixel at the center of the angular range. Figure 6B shows the unit pixels at the edges of the angular range.

Referring to FIG. 6A, in the unit pixel 21 at the center of the angular range, incident light is incident on the microlens 18 in the central axis direction. The incident light collected by the microlens 18 is transmitted and separated by the color filter layer 17, and is incident on one end of the light incident side of the waveguide 16. Incident light is directed along the central axis C of the waveguide 16, and it exits from one end of the waveguide 16 on the light exit side. Light is emitted to the center of the photoelectric converter 12. That is, the incident light transmitted through the center of the microlens 18 is transmitted along the center of the color filter layer 17 and the central axis C of the waveguide 16, and is emitted to the center of the photoelectric converter 12. Therefore, pupil correction is not performed for the waveguide 16.

In contrast, referring to FIG. 6B, in the solid-state image pickup device of the prior art, the pupil correction is not performed on the waveguide 16 even for the unit pixel 21 of the edge of the angular range. Here, for example, the pupil correction amount of the incident light incident on the microlens 18 at the position where the incident angle θ1 is θ1=25° with respect to the microlens 18 and the color filter layer 17 is calculated.

For example, the F number of the microlens 18 is F = 2.8, and the refractive index n of the microlens 18 is n = 1.5.

Further, the angle θ3 of the edge light is θ3 = 6.8°.

If the refractive index n0 of the atmosphere around the microlens 18 is n0=1, and the refractive index n1 of the microlens 18 is n1=1.6, the following relationship can be established.

Sin θ2=(n0/n1)×sinθ1

If θ1=25°, the result is as follows

Θ2=sin-1{(n0/n1)×sinθ1}=sin-1{(1/1.6)×sin25}=15.3°

For example, when one end of the light incident side of the waveguide 16 serves as a reference position (reference level), the height h1 represents the height from the reference position to the formation plane of the microlens 18, and the height h2 represents the reference position to the color filter layer 17 The height of the incident plane.

For example, assume that h1 = 2 μm and h2 = 1.5 μm. In this case, the difference X_OCL between the central axis C of the waveguide 16 (the center of the photoelectric converter) and the central axis LC of the microlens 18 is as follows

X_OCL=h1×tanθ2=2×tan15.3°=0.547μm

Moreover, the difference X_CF between the central axis C of the waveguide 16 and the central axis FC of the color filter layer 17 is as follows

X_CF=h2×tanθ2=1.5×tan15.3°=0.411μm

In this embodiment, pupil correction is not performed for the waveguide 16. Therefore, the problems described with reference to FIGS. 3A to 3C may occur.

In the solid-state image pickup device 1, the waveguide 16 has a cylindrical body whose cross section is kept constant from one end on the light incident side to one end on the light exit side. The light incident perpendicularly to the light incident side of the waveguide 16 is not reflected by the side wall of the waveguide 16, but is transmitted through the waveguide 16. Since the light is not reflected by the side walls of the waveguide 16, the reduction in sensitivity can be limited. Further, since the center of the light incident on one end of the light incident side of the waveguide 16 is aligned with the central axis of the waveguide 16, the incident light can be efficiently guided to the waveguide 16. That is, the pupil correction is performed even on the waveguide 16.

Since even the pupil 16 in the solid-state image pickup device 1 is subjected to pupil correction, the incident light of the individual colors can be completely collected to the waveguide 16. Therefore, color unevenness (color shading) due to shading of the wavelength can be reduced.

Further, the distance from the surface of the photoelectric converter 12 to one end of the light exit side of the waveguide 16 should be a predetermined distance to avoid occurrence of white spots. For example, if the interlayer insulating film 14 formed between the photoelectric converter 12 and the waveguide 16 is made of yttria, the predetermined distance from the photoelectric converter 12 to the waveguide 16 is, for example, about 500 nm.

The diameter of the waveguide 16 is determined such that incident light having a diffusion characteristic emitted from one end of the light exit side of the waveguide 16 and having a diffusion characteristic due to diffraction is emitted into a region of the surface of the photoelectric converter 12. Therefore, since the diffusion portion of the light emitted from the waveguide 16 is also emitted onto the photoelectric converter 12, the sensitivity can be increased.

Since the shading is reduced, when the sensitivity is defined as the output average of the overall screen, the sensitivity can be increased and the exposure time can be reduced. The actual result is that the sensitivity of green light can be increased by 4%, the sensitivity of red light can be increased by 3%, and the sensitivity of blue light can be increased by 2%.

In the prior art, the size of the waveguide 16 can be increased as much as possible in the range of the room relative to the wiring portion 15 to increase the sensitivity. Incident light emitted from one end of the light exit side of the waveguide 16 is diffused and emitted by diffraction. Therefore, if the diameter of the waveguide 16 is as large as possible equal to the size of the surface of the photoelectric converter 12, the diffused portion of the outward light is not emitted to the photoelectric converter 12. This diffusion site will cause a decrease in sensitivity.

Next, the diameter reduction of the waveguide 16 will be described. As described above, the diameter of the waveguide 16 allows incident light from one end of the light exit side of the waveguide 16 to be emitted into the region of the surface of the photoelectric converter 12. Therefore, unlike the waveguide of the prior art, the size of the waveguide 16 is not equal to the size of the surface of the photoelectric converter 12. In addition, the diameter of the waveguide is reduced. For example, although the structure is similar to the prior art, in which the space between the wiring portion 15 and the waveguide 16 is only a cover, the pupil 16 can be corrected by reducing the diameter of the waveguide 16. For example, assume that the waveguide 16 of the prior art has a diameter of 1.5 μm. By reducing the diameter of the waveguide 16 to 1 μm, the diameter of each side can be reduced by 0.25 μm each. In this way, a pupil correction of 0.25 μm can be performed. As described above, the diameter of the waveguide 16 is preferably the diameter of the incident light transmitted to the one end of the light incident side of the waveguide 16 through the color filter layer 17. For example, the diameter of the waveguide 16 is determined based on green light having an intermediate wavelength range of incident light. Alternatively, if there is room for the connection between the waveguide 16 and the connection portion 15 of the wiring layer 13, the diameter of the waveguide 16 can be determined based on the red light.

In the case of the aforementioned miniaturized pixel, the pupil correction amount is determined based on the distance from the waveguide 16 to the connection portion 15. For example, the diameter of the waveguide 16 is reduced to an expected value such that it is larger than the illumination diameter of the incident light incident on the waveguide 16. The amount to be reduced is determined to achieve the desired amount of pupil correction. However, if the pupil correction amount is insufficient, as described above, the line width of the wiring 15 is reduced to increase the pupil correction amount. The pupil correction of the waveguide 16 in this embodiment of the invention is not only implemented for a waveguide 16 having a structure as in the prior art, but also provides a pupil correction amount for the waveguide 16, for example, by reducing the diameter of the waveguide 16 or The line width of the wiring portion 15 is reduced. Therefore, an adequate amount of pupil correction can be provided. Color shading can be significantly reduced. The ratio of the pupil correction amount of the waveguide 16 is constant as compared with the pupil correction amount of the microlens 18 or the color filter layer 17. For example, the pupil correction amount of the waveguide 16 is 0.2 times the pupil correction amount of the microlens 18.

In the solid-state image pickup device 1 described in the first exemplary example, the idea of the waveguide 16 of the prior art is largely changed. Specifically, in the prior art, the diameter of the waveguide 16 is increased as much as possible within the range of the margin with respect to the wiring portion 15 to increase the sensitivity. In contrast, in the above-described solid-state image pickup device 1, as long as the diameter of the waveguide 16 is larger than the illumination diameter of the incident light at one end on the light incident side, the diameter of the waveguide 16 (the diameter of one end on the light incident side) is as large as possible. The reduction is such that all of the outward light rays emitted from the waveguide 16 are emitted onto the photoelectric converter 12. This is a major difference from the previous technology. Moreover, as noted above, another important point is that the pupil correction for the waveguide 16 is also significantly different from prior art waveguides.

The solid-state image pickup device 1 preferably has different pupil correction amounts for the waveguide 16 depending on the color of the incident light separated by the color filter layer 17. This point will be explained with reference to the schematic cross-sectional views of Figs. 7A to 7C. 7A to 7C show unit pixels of the color filter layer 17 having an equal distance from the center of the angular range (for example, the center of the pixel portion) and having different colors. FIG. 7A shows a unit pixel of blue, FIG. 7B shows a unit pixel of green, and FIG. 7C shows a unit pixel of red.

In the solid-state image pickup device 1, referring to FIGS. 7A to 7C, in the photoelectric converter 12 in which light of equal wavelength is incident, in the pixel portion 20, the central axis C of each waveguide 16 is opposed to the center of the corresponding photoelectric converter 12. The displacement amount of the shaft FC gradually becomes larger as the photoelectric converter 12 located at the center of the pixel portion 20 moves outward. In other words, considering the photoelectric converter 12 located at an equal distance from the center of the pixel portion 20, the displacement amount of the central axis C of each waveguide 16 with respect to the central axis FC of the corresponding photoelectric converter 12 follows the color filter layer 17 The wavelength of the light that is separated and incident on the photoelectric converter 12 becomes larger and becomes smaller.

More specifically, when the pitch of the photoelectric converter 12 of the solid-state image pickup device 1 is 1 to 3 μm and the diameter of the waveguide 16 is about 0.5 to 2.5 μm, the pupil correction amount of the waveguide 16 satisfies the following relationship "blue light (B) <Green light (G) <Red light (R). It should be noted that in order to simplify the planar layout, the waveguide 16 is smaller than the photoelectric converter 12. For example, a pupil correction of about 20 to 50 nm is performed for the waveguide 16 on which the blue light is incident, and a pupil correction of about 50 to 80 nm is performed for the waveguide 16 on which the green light is incident, for the waveguide 16 on which the red light is incident. Pupil correction of approximately 80 to 110 nm. Therefore, the shading of each of the waveguides 16 can be optimized.

Typically, the incident angle of the incident light collected by the microlens 18 may increase as the position deviates from the center of the pixel portion 20 toward the outside. The pupil correction is performed for the microlens 18, however, this pupil correction amount is not sufficient. Therefore, as described above, for incident light having the same wavelength, the distance of the central axis of each waveguide 16 with respect to the center of the corresponding photoelectric converter 12 is increased so that the center of the light generated from the microlens 18 is aligned with the waveguide 16. Central axis.

In general, the microlens 18 and the color filter layer 17 receive pupil correction so that the incident light is incident on the photoelectric converter 12 in the central axis direction. For example, pupil correction is performed on the microlens 18 and the color filter layer 17 having incident light of a reference wavelength (e.g., green light). In this case, referring to FIG. 7A, since the blue light is easily bent by the microlens 18, the incident angle of the blue light is large when incident on one end of the light incident side of the waveguide 16. Therefore, even when the microlens 18 and the color filter layer 17 largely deviate from the center of the pixel portion with respect to the central axis FC of the photoelectric converter 12 by the pupil correction, the light emitted from the color filter layer 17 is incident on the light of the waveguide 16. One end of the side is close to the position of the central axis FC of the photoelectric converter 12. Therefore, almost all of the incident light of one end of the light incident side of the waveguide 16 is guided to the waveguide 16. In this case, the position of the waveguide 16 is corrected such that the central axis LC of the light of the incident light incident on one end of the light incident side of the waveguide 16 is aligned with the central axis C of the waveguide 16.

In contrast, referring to FIG. 7C, since the microlens 18 is difficult to bend red light compared to the blue light, when the red light is incident on one end of the light incident side of the waveguide 16, the incident angle is smaller than the incident angle of the blue light. Further, since the microlens 18 and the color filter layer 17 have largely deviated from the center of the pixel portion with respect to the central axis FC of the photoelectric converter 12 by pupil correction, the light emitted from the color filter layer 17 is incident on the light of the waveguide 16. One end of the incident side is at a position away from the central axis FC of the photoelectric converter 12. In some cases, the light is incident such that a major portion of the light protrudes from one end of the light incident side of the waveguide 16. However, in this embodiment of the invention, the position of the waveguide 16 is corrected such that the central axis LC of the incident light incident on one end of the light incident side of the waveguide 16 is aligned with the central axis C of the waveguide 16. Therefore, almost all of the incident light emitted from the color filter layer 17 is incident on one end of the light incident side of the waveguide 16, and is guided to the waveguide 16.

Further, referring to FIG. 7B, it is difficult for the microlens 18 to bend green light compared to the blue light, and the microlens 18 is likely to bend green light compared to the red light. The incident angle of the incident light incident on the light incident side of the waveguide 16 is smaller than the incident angle of the blue light, but larger than the incident angle of the red light. Since the microlens 18 and the color filter layer 17 have been deviated from the center of the angular range of the photoelectric converter 12 by the pupil correction, the light emitted from the color filter layer 17 is incident on one end of the light incident side of the waveguide 16, At a distance from the central axis FC of the photoelectric converter 12. However, in this embodiment of the invention, the position of the waveguide 16 is corrected such that the central axis LC of the incident light of the incident light incident on the light incident side of the waveguide 16 is aligned with the central axis C of the waveguide 16. Therefore, almost all of the incident light emitted from the color filter layer 17 is incident on one end of the light incident side of the waveguide 16 and guided to the waveguide 16.

As described above, the offset amount of the central axis C of each of the waveguides 16 with respect to the center of the corresponding photoelectric converter 12 becomes smaller as the wavelength of the light separated by the color filter layer 17 becomes smaller. Therefore, even when the wavelengths of the incident light at one end of the light incident side of the waveguide 16 are different, the waveguide 16 can be separately provided according to the wavelength, and the sensitivity of the unit pixel 21 is the same, and color shading does not occur.

Second exemplary structure of solid-state image pickup device

A second exemplary configuration of the solid-state image pickup device of the first embodiment of the present invention will be described with reference to the plan view of FIG. 8 and the cross-sectional views of FIGS. 9A to 9C. In FIGS. 8 and 9A to 9C, for example, four pixels share one pixel transistor unit. Four unit pixels form a unit pixel cluster.

Referring to FIGS. 8, 9A to 9C, the unit pixel cluster 22 includes, for example, two first unit pixels 21 (21G), a single second unit pixel 21 (21B), and a single third unit pixel 21 (21R). The first unit pixel 21G includes a photoelectric converter 12 (12G) on which light of a first wavelength (for example, green light G) separated by the color filter layer 17 (17G) is incident. The second unit pixel 21B includes a photoelectric converter 12B on which light of a second wavelength (blue light B) separated by the color filter layer 17B is incident. The second wavelength is less than the first wavelength (green light). The third unit pixel 21R includes a photoelectric converter 12R on which light of a third wavelength (red light R) separated by the color filter layer 17R is incident. The third wavelength is greater than the first wavelength.

Considering the amount of displacement of the central axis C of each waveguide 16 with respect to the central axis FC of the corresponding photoelectric converter 12 within the unit pixel cluster 22, the amount of displacement of the central axis C of the waveguide 16 with respect to the center of the photoelectric converter 12 is The wavelength of the light separated by the color filter layer 17 becomes smaller and smaller. Further, the displacement amount of the central axis C of each waveguide 16 with respect to the central axis FC of the corresponding photoelectric converter 12 is larger toward the center of the pixel portion 20. In other words, from the center of the angular range (for example, the center of the pixel portion) toward the edge of the angular range, the amount of displacement becomes larger and larger, and the direction deviated from the photoelectric converter 12 is toward the center of the angular range.

The solid-state image pickup device 1 (1B) is organized as described above. It should be noted that the first unit pixel 21G, the second unit pixel 21B, and the third unit pixel 21R each have a structure similar to that of the first exemplary configuration of the solid-state image pickup device 1.

The solid-state image pickup device 1B is a so-called majority pixel sharing type (four-pixel sharing type) which shares a floating diffusion, an amplifier transistor, and a selection transistor for a plurality of (or four) pixels. The displacement amount of the central axis of each waveguide 16 with respect to the center of the corresponding photoelectric converter 12 gradually increases as the wavelength of incident light incident on one end of the light incident side of the waveguide 16 becomes smaller. In such four pixel sharing types, four pixels (unit pixel 21) are considered, and the displacement amount (the pupil correction amount) of the waveguide 16 of the third unit pixel 21R is larger than that of the first unit pixel 21G, and the second unit The displacement amount (the pupil correction amount) of the waveguide 16 of the pixel 21B is smaller than that of the first unit pixel 21G.

Typically, the microlens 18 and the color filter layer 17 are subjected to pupil correction such that the incident light is incident on the photoelectric converter 12 in the central axis direction. For example, pupil correction is performed on the microlens 18 and the color filter layer 17 having incident light of a reference wavelength (e.g., green light). In this case, since the blue light is easily bent by the microlens 18, when incident on one end of the light incident side of the waveguide 16, the incident angle of the blue light becomes large. Even when the microlens 18 and the color filter layer 17 are largely deviated from the center of the angular range with respect to the central axis FC of the photoelectric converter 12 by the pupil correction (for example, the center of the pixel portion), the light emitted from the color filter layer 17 is incident on the light. The end of the light incident side of the waveguide 16 is close to the position of the central axis FC of the photoelectric converter 12. Therefore, almost all of the incident light of one end of the light incident side of the waveguide 16 is guided to the waveguide 16. In contrast, since red light is hard to be bent by the microlens 18 than blue light, when incident on one end of the light incident side of the waveguide 16, the incident angle of the red light is smaller than the incident angle of the blue light. Since the microlens 18 and the color filter layer 17 have deviated from the center of the pixel portion with respect to the central axis FC of the photoelectric converter 12 by pupil correction, the light emitted from the color filter layer 17 is incident on the light incident side of the waveguide 16. One end is at a distance from the central axis FC of the photoelectric converter 12. In some cases, the light is incident such that a major portion of the light protrudes from one end of the light incident side of the waveguide 16. However, in this embodiment of the invention, the position of the waveguide 16 is corrected such that the central axis LC of the light of the incident light at one end of the light incident side of the waveguide 16 is aligned with the central axis C of the waveguide 16. Therefore, the incident light emitted from the color filter layer 17 is incident on one end of the light incident side of the waveguide 16, and is guided to the waveguide 16. Further, the green light is hard to be bent by the microlens 18 than the blue light, but the green light is easily bent by the microlens 18 than the red light. The incident light of one end of the light incident side of the waveguide 16 is smaller than the incident angle of the blue light, but larger than the incident angle of the red light. Since the microlens 18 and the color filter layer 17 have deviated from the center of the angular range with respect to the central axis FC of the photoelectric converter 12 by pupil correction, the light emitted from the color filter layer 17 is incident on the light incident side of the waveguide 16. One end is at a distance from the central axis FC of the photoelectric converter 12. However, with the present embodiment, the position of the waveguide 16 is corrected such that the center of the ray of the incident light at one end of the light incident side of the waveguide 16 is aligned with the central axis C of the waveguide 16. The incident light emitted from the color filter layer 17 is incident on one end of the light incident side of the waveguide 16 and guided to the waveguide 16. As described above, considering the waveguide 16 within the unit pixel cluster 22, the displacement amount of the central axis C of each waveguide 16 with respect to the central axis FC of the corresponding photoelectric converter 12 becomes smaller as the wavelength separated by the color filter layer 17 becomes smaller. small. Therefore, even when the wavelengths of the incident light at one end of the light incident side of the waveguide 16 are different from each other, the waveguides 16 can be respectively arranged according to the wavelength, and the sensitivity of the unit pixels 21 is equal, and color shading does not occur.

The third exemplary structure of solid-state image pickup device

A third exemplary configuration of the solid-state image pickup device according to the first embodiment of the present invention will be described below with reference to cross-sectional views of Figs. 10A to 10D. Referring to FIGS. 10A to 10D, in addition to the configuration of the waveguide 16, the solid-state image pickup device of the third example has a configuration similar to that of the solid-state image pickup device 1 of the first example.

Referring to FIGS. 10A and 10B, the unit pixel 21 includes a waveguide 16 having a first waveguide 16A and a second waveguide 16B. The first waveguide 16A forms a peripheral portion of the waveguide 16. The second waveguide 16B is formed within the first waveguide 16A and has a lower refractive index than the first waveguide 16A. The first waveguide 16A may also be formed at a bottom portion of the second waveguide 16B. Fig. 10A shows the unit pixel 21 at the center of the angular range. FIG. 10B shows the unit pixel 21 located at a distance from the center of the angular range and near the edge of the angular range. Similar to the solid-state image pickup device 1 of the first example, pupil correction is performed on the waveguide 16 as the waveguide 16 is closer to the edge of the angular range.

For example, referring to Fig. 11, there is shown a structure in which the waveguide 16 having the photoelectric converter 12 (e.g., photodiode) having a size of 2 μm has a diameter of 1 μm. This configuration can be designed to perform a 0.45 μm pupil correction for the portion of the braid that is closest to the angular extent. The first waveguide 16A is formed within the first waveguide 16A to form a sidewall of the waveguide 16 by using a film having a refractive index n1 of about 1.8 (for example, a film formed of a material selected from nitride). The second waveguide 16B is formed of a film selected from a resin and having a refractive index n2 of about 1.4. Therefore, the two side walls of the first waveguide 16A have a thickness of 100 nm. Therefore, the thickness of both sides of the side wall of the first waveguide 16 is 200 nm. The second waveguide 16B has a diameter of 800 nm. If the film of the first waveguide 16A is formed of a material film (for example, a tantalum nitride film) selected from a nitride, the film has the effect of a passivation film.

Next, an optical path of incident light will be described with reference to FIGS. 10C and 10D. Fig. 10C shows the unit pixel 21 at the central portion of the angular range. Figure 10D shows a unit pixel 21 located at a distance from the center of the angular range and near the edge of the angular extent. Referring to FIG. 10C, incident light transmitted through the microlens 18 and the color filter layer 17 is mainly concentrated on the first waveguide 16A as a side wall portion, because in the waveguide 16 at the center of the angular range, the first waveguide 16A in the side wall portion has The refractive index is higher than the refractive index of the second waveguide 16B at the center portion.

In contrast, referring to FIG. 10D, when pupil correction is performed for the waveguide 16, although the waveguide 16 is located at a position close to the edge of the angular range (the refractive index satisfies the above n1>n2), the microlens 18 and the color filter layer 17 are transmitted. The transmitted light of the incident light can be directed to the center of the photoelectric converter 12. In particular, oblique incident light entering the first waveguide 16A from the second waveguide 16B and incident on the waveguide 16 is reflected within the first waveguide 16A having a refractive index higher than that of the second waveguide 16B, which is emitted to One end of the light exit side is emitted to the photoelectric converter 12. Since the light is guided through the waveguide 16, it is reasonable to determine the refractive index of the material of the waveguide 16 (the first waveguide 16A) to be higher than the refractive index of other materials around the waveguide 16. In particular, the pupil 16 at the edge of the angular range is subjected to pupil correction such that the central axis C of the waveguide 16 is aligned with the central axis LC of the incident light of one end of the light incident side of the waveguide 16. Therefore, the central axis C of the waveguide 16 is offset toward the center of the angular range with respect to the center of the photoelectric converter 12. Therefore, even if incident light incident on one end of the light incident side of the waveguide 16 is incident on the second waveguide 16B, the light enters the first waveguide 16A having a higher refractive index than that of the second waveguide 16B. Light is transmitted within the first waveguide 16A and is directed from the transmitting end to the photoelectric converter 12. Further, since the incident light is emitted toward a position close to the edge of the angular range from a position close to the center of the angular range, the incident light is incident obliquely into the second waveguide 16B toward the edge of the angular range. Therefore, light is transmitted through the edge portion close to the angular range of the first waveguide 16A. That is, since the portion near the edge of the angular range of the first waveguide 16A is close to the center of the photoelectric converter 12, the incident light incident on the second waveguide 16B is transmitted through the first waveguide 16A, and is efficiently transmitted to the photoelectric converter. 12 on.

Since the waveguide 16 has a structure including the first waveguide 16A and the second waveguide 16B, the amount of light leakage from the bottom of the waveguide 16 to the photoelectric converter 12 can be minimized. Even if the polymerized germanium electrode 61 or the like is disposed close to the photoelectric converter 12, the light is incident on the center of the photoelectric converter 12 or near the center, and the amount of the element shielded by the polymerized electrode 61 can be reduced. If the waveguide 16 having the foregoing structure is made of a single material, the amount of light blocked by the polymerized germanium electrode 61 can be reduced by reducing the diameter of the waveguide 16.

Further, pupil correction can be performed on the wiring portion 15 of the photoelectric converter 12, the pixel transistor (not shown), and the wiring layer 13 (not shown). Therefore, the amount of light blocked by the pixel transistor can be reduced, and color shading can be reduced.

2. Second Embodiment First exemplary method of manufacturing a solid-state image pickup device

Next, a first exemplary manufacturing method of a solid-state image pickup device according to a second embodiment of the present invention will be described with reference to Figs.

Referring to Fig. 12, a photoelectric converter 12 is formed on the surface (light incident side) of the semiconductor substrate 11. The photoelectric converter 12 converts the incident light into a signal charge. Further, a switching gate 31 is formed on the semiconductor substrate 11. The switching gate 31 reads the signal charge that receives the photoelectric conversion of the photoelectric converter 12. Further, although not shown, the pixel transistor and the peripheral circuit unit can be formed on the surface of the semiconductor substrate 11. The pixel transistor amplifies and outputs a signal charge that is subjected to photoelectric conversion by the photoelectric converter 12. The surrounding circuit unit processes the amplified and output signals. As the semiconductor substrate 11, for example, a germanium substrate is used. Alternatively, a germanium (SOI) substrate on an insulator may be used for the semiconductor substrate 11. In this case, the photoelectric converter 12, the switching gate 31, and the like are formed on the germanium layer of the SOI substrate.

A plurality of unit pixels 21 each having the photoelectric converter 12 are arranged in the row and column directions of the semiconductor substrate 11 to form the pixel portion 20.

An insulating film is formed on the semiconductor substrate 11 to cover the photoelectric converter 12, the switching gate 31, the pixel transistor, the surrounding circuit unit, and the like, thereby forming the wiring layer 13. For example, the wiring layer 13 is formed such that a plurality of layers including the wiring portions 15 are formed in the interlayer insulating film 14. A barrier metal layer 141 is formed around the wiring portion 15. In the interlayer insulating film 14, for example, a tantalum carbide (SiC) film is formed as the diffusion preventive film 142, which prevents diffusion of metal or the like from the wiring portion 15. The interlayer insulating film 14 may be formed of a yttrium oxide (SiO ₂ ) film. The surface of the interlayer insulating film 14 is planarized. The wiring portion 15 is not formed in a region above the photoelectric converter 12.

Next, referring to Fig. 13, a photoresist film 51 is formed on the interlayer insulating film 14 on the top of the wiring layer 13 by a typical photoresist treatment. With the lithography technique, an opening 52 is formed in the photoresist film 51 in a region where the waveguide is to be formed. When the layout of the opening 52 is obtained, the pupil correction as explained with reference to Figs. 3A to 3C, 4A and 4B and the like is performed for the waveguide. Specifically, the opening 52 is formed such that the central axis of the waveguide to be formed under the opening 52 is aligned with the center of the light of the incident light incident on one end of the light incident side of the waveguide.

Next, referring to Fig. 14, a waveguide hole 19 for forming a waveguide is formed in the interlayer insulating film 14 of the wiring layer 13 by dry etching using the photoresist film 51 as an etching mask. At this time, the waveguide holes 19 are formed such that the side walls of the waveguide holes 19 are vertical, and the waveguide holes 19 have a depth of about 4 to 5 μm. Further, the waveguide hole 19 has a constant cross section from the opening toward the bottom portion. The shape of the opening may be a circle, an oval (including an ellipse), or the like. Alternatively, the shape of the opening of the waveguide hole 19 may be a rectangle, for example, a square having rounded corners.

Next, referring to FIG. 15, the photoresist film 51 (see FIG. 14) is removed to allow the interlayer insulating film 14 in the wiring layer 13 to be exposed.

Next, referring to Fig. 16, the waveguide hole 19 is filled with the waveguide material film 53.

For the waveguide material, a material having a refractive index higher than that of the interlayer insulating film 14 in the wiring layer 13 is selected. For example, when the interlayer insulating film 14 is a film made of a material selected from cerium oxide and has a refractive index of 1.4, the waveguide material film 53 is a film having a refractive index of 1.4 or higher. The waveguide material film 53 is made of a material selected from a nitride and having a refractive index of about 1.8. For example, a tantalum nitride film can be used. A waveguide material film 53 is also formed over the interlayer insulating film 14. The waveguide material film 53 can be formed by coating, chemical vapor deposition, or the like. Therefore, the waveguide 16 is formed with the waveguide material film 53 filling the waveguide holes 19.

Next, referring to FIG. 17, a flat insulating film 54 for planarizing the surface of the waveguide material film 53 is formed. The flat insulating film 54 is formed of, for example, a resin layer.

Next, referring to FIG. 18, a color filter layer 17 is formed on the flat insulating film 54. The color filter layer 17 is formed by applying a color filter material and then patterning by exposure, development, or the like. The color filter layer 17 uses, for example, a red color filter, a green color filter, and a blue color filter to correspond to colors to be sensed by the individual photoelectric converters 12. The layout of the color filter layer 17 also accepts pupil correction.

Next, referring to Fig. 19, a lens forming film 55 is formed on the color filter layer 17. The lens forming film 55 is a material for a microlens (also referred to as a lens on a wafer). The lens forming film 55 is formed of, for example, a light-transmitting resin film.

Next, referring to FIG. 20, a photoresist pattern 56 for a microlens is formed on the lens forming film 55. The layout of the photoresist pattern 56 accepts pupil correction. Then, although not shown, the photoresist pattern 56 is molded to have a lens shape. Then, the resist pattern 56 having a lens shape of the mold is transferred to the lens forming film 55 by etch back.

Therefore, referring to FIG. 21, a micro-permeable layer 18 is formed on the lens forming film 55.

In the above manufacturing method, the waveguide 16 has a constant cross-sectional shape from one end on the light incident side to one end on the light exit side. Light rays incident perpendicularly to one end of the light incident side of the waveguide 16 are not reflected by the side walls of the waveguide 16, but are transmitted through the waveguide 16. Therefore, the reduction in sensitivity can be limited. Further, since the center of the ray of the incident light at one end of the light incident side of the waveguide 16 is aligned with the central axis of the waveguide 16, the incident light is efficiently guided to the waveguide 16. Therefore, the solid-state image pickup device 1 (1A) can be manufactured, which provides effects and advantages similar to those provided by the solid-state image pickup device of the first example in the first embodiment.

Second exemplary manufacturing method of solid-state image pickup device

Next, a second exemplary manufacturing method of the solid-state image pickup device according to the second embodiment of the present invention will be described with reference to Figs.

Referring to FIG. 22, a waveguide hole 19 is formed in the wiring layer 13 in a manner similar to the first exemplary manufacturing method. Then, a first waveguide material film 57 for the first waveguide 16A is formed inside the waveguide hole 19. The first waveguide material film 57 is also formed on the interlayer insulating film 14. The first waveguide material film 57 is made of a material having a refractive index higher than that of the interlayer insulating film 14. For example, the first waveguide material film 57 may be made of a material selected from nitride. For example, the film may be a tantalum nitride (SiN) film or a hafnium oxynitride film. Further, when the first waveguide material film 57 is formed of a tantalum nitride film, the film serves as a passivation film. Although the material of the first waveguide material film 57 is not limited to the material selected from the nitride, a tantalum nitride film having a high refractive index such as n = 1.8 may be used. Considering the film thickness, for example, the sidewall portion may have a thickness of about 100 nm. The film thickness of the first waveguide material film 57 is preferably determined such that a second waveguide formed later can be formed within the first waveguide 16A. The film formation method may be coating. Of course, the film formation method can be other methods such as chemical vapor deposition.

Next, referring to Fig. 23, the waveguide hole 19 in which the first waveguide material film 57 is formed is filled with the second waveguide material film 58, whereby the second waveguide 16B can be formed. The second waveguide material film 58 is a material having a refractive index lower than that of the first waveguide material film 57. For example, a resin film having a refractive index of about 1.4 (for example, a resin having good light transmittance, such as PMMA) or a film made of a material selected from cerium oxide is used. A waveguide material film 53 is also formed over the interlayer insulating film 14. Each of the above waveguide material films can be formed by coating, chemical vapor deposition, or the like. In this manner, the first waveguide 16A made of the first waveguide material film 57 may be formed inside the waveguide hole 19, and the second waveguide 16B formed of the second waveguide material film 58 may be formed on the first waveguide 16A. Inside.

Next, referring to FIG. 24, a flat insulating film 54 for planarizing the surface of the second waveguide material film 58 is formed. The flat insulating film 54 is formed of, for example, a resin layer.

Next, referring to FIG. 25, a color filter layer 17 is formed over the flat insulating film 54. The color filter layer 17 is formed by applying a color filter material and then patterning by exposure, development, or the like. The color filter layer 17 uses, for example, a red color filter, a green color filter, and a blue color filter to correspond to colors to be sensed by the individual photoelectric converters 12. The layout of the color filter layer 17 also accepts pupil correction.

Next, referring to Fig. 26, a lens forming film 55 is formed on the color filter layer 17. The lens forming film 55 is a material for a microlens (also referred to as a lens on a wafer). The lens forming film 55 is formed of, for example, a light-transmitting resin film.

Next, referring to FIG. 27, a photoresist pattern 56 for a microlens is formed on the lens forming film 55. The layout of the photoresist pattern 56 accepts pupil correction. Then, even if not shown, the photoresist pattern 56 is molded to have a lens shape. Then, the mold is transferred to the lens forming film 55 by etch back in the shape of the photoresist pattern 56 having a lens shape.

Therefore, referring to Fig. 28, a microlens 18 is formed on the lens forming film 55. The height h1 from the surface of the second waveguide material film 58 to the bottom portion of the microlens 18 is, for example, 1 to 3 μm. Further, the height h2 from the surface of the second waveguide material film 58 to the surface of the color filter layer 17 is, for example, 0.5 to 2.5 μm. Further, the height h3 of one end from the surface of the photoelectric converter 12 to the light exit side of the incident light of the waveguide 16 is, for example, 0.3 to 2 μm.

With the second manufacturing method, the waveguide 16 is formed such that the second waveguide 16B is formed inside the first waveguide 16A, while the first waveguide 16A having a relatively high refractive index is formed around the second waveguide 16B. Light entering the first waveguide 16A from the second waveguide 16B is transmitted through the first waveguide 16A and is emitted therefrom.

Therefore, the solid-state image pickup device 1 (1B) can provide the effects and advantages provided by the solid-state image pickup device as described in the first example of the first embodiment.

3. Third Embodiment Example organization of image pickup device

Next, an exemplary configuration of an image pickup apparatus according to a third embodiment of the present invention will be described with reference to FIG. This image pickup device uses a solid-state image pickup device according to an embodiment of the present invention.

Referring to FIG. 29, the image pickup apparatus 200 includes an image pickup unit and a solid-state image pickup device 210. The light concentrating optical unit 202 is disposed on the light collecting side of the image pickup unit 201. The image pickup unit 201 is connected to the signal processing unit 203. The signal processing unit 203 includes a driving circuit that drives the image pickup unit 201, and a signal processing circuit that processes a signal that is subjected to photoelectric conversion by the solid-state image pickup device 210 to become an image. The image signal processed by the signal processing unit 203 can be stored in an image storage unit (not shown). In such an image pickup apparatus 200, the solid-state image pickup apparatus 210 can use the solid-state image pickup apparatus 1 according to the foregoing embodiment.

Since the image pickup device 200 according to the present embodiment uses the solid-state image pickup device 1 according to the foregoing embodiment, color unevenness (color shading) due to shading of wavelengths in the solid-state image pickup device 1 can be reduced. Sensitivity can be increased, so that images with high quality can be obtained.

The image pickup device 200 can be formed as a wafer or a module in which the image pickup unit and the signal processing unit or the optical system are packaged, thereby having an image pickup function. The image pickup device 200 is, for example, a camera or a mobile device having an image pickup function. Moreover, "image pickup" includes not only obtaining images during normal shooting of the camera, but also detecting fingerprints in a broad sense.

4. Fourth Embodiment Exemplary organization of solid-state image pickup device

30 to 32 each show a solid-state image pickup device according to a fourth embodiment of the present invention. The solid-state image pickup device of this embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. Figure 30 is a plan view showing a pixel portion in which a plurality of unit pixel clusters of a four-pixel sharing type are two-dimensionally arranged. 31A and 31B are plan views showing a cluster of unit pixels showing the center of the angular range of the pixel portion and a cluster of unit pixels of the pixel cluster at the edge of the angular range of the pixel portion. Figure 32 is a cross-sectional view taken along line XXXII-XXXII of Figure 31A.

Hereinafter, reference numeral 40 denotes a pixel portion, 38 denotes a solid-state image pickup device, 42 denotes a unit pixel cluster, PD (PD1 to PD4) denotes a photoelectric converter, Tr11 to Tr14, Tr2, Tr3 and Tr4 denote a pixel transistor, and 43 denotes a conversion Gate, 48 indicates reset gate, 49 indicates amplifier gate, 151 indicates selection gate, 152 indicates waveguide, 154 indicates interlayer insulation film, 155 indicates wiring part, 155a indicates protruding part, 150 indicates wiring layer, 157 indicates color The filter layer, 158 indicates the microlens, and L indicates the incident light.

First, in order to facilitate understanding of the fourth embodiment, a comparative example before the improvement is explained with reference to Figs. 62 and 63. This comparative example is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share a floating diffusion, an amplifier transistor, and a selection transistor. The MOS solid-state image pickup device 113 of the comparative example includes a pixel portion in which a plurality of unit pixel clusters are arranged in an array. In each unit pixel cluster, a plurality of pixels share a single pixel transistor. In particular, the MOS solid-state image pickup device 113 includes a unit pixel cluster 114 of a four-pixel sharing type in which four photodiodes PD as a photoelectric converter share a single pixel transistor unit. More specifically, the unit pixel cluster 114 includes four photodiodes PD (PD1 to PD4), four conversion transistors Tr (Tr11 to Tr14), and a single floating diffusion FD. Further, the unit pixel cluster 114 includes a single worm transistor Tr2, an amplifier transistor Tr3, and a selection transistor Tr4. A switching gate 115 made of a polymer germanium is disposed between the floating diffusion FD and the photodiodes PD1 to PD4 located at the center of the unit pixel cluster 114. Therefore, four conversion transistors Tr11 to Tr14 for the four photodiodes PD are formed.

The reset transistor Tr2, the amplifier transistor Tr3, and the selection transistor Tr4 are continuously horizontally disposed under the photodiodes PD1 to PD4. The reset transistor Tr2 includes a diffusion region 116, a diffusion region 117, and a reset gate 120. The amplifier transistor Tr3 includes a diffusion region 117, a diffusion region 118, and an amplifier gate 121. The selection transistor Tr4 includes a diffusion region 118, a diffusion region 119, and a selection gate 122. In the unit pixel cluster 114, the base layer including the gates made of the polymer germanium has an asymmetric configuration with respect to the boundaries of adjacent pixels. In particular, the pixel transistor including the reset transistor Tr2, the amplifier transistor Tr3, and the selection transistor Tr4 is asymmetrically arranged with respect to the pixels Gb and R, and the boundary between the pixels Gr and B. Further, the switching gates 115 of the pixels Gr, R, Gb, and B are asymmetrically arranged with respect to the boundary between the pixels Gr, R, Gb, and B.

A waveguide 23 is formed for each of the photodiodes PD1 to PD4. In this example, a Bayer pattern color filter layer is used. In this layer, a plurality of unit pixel clusters 114 of a four-pixel sharing type are repeatedly arranged, wherein four pixels share a floating diffusion, an amplifier transistor, and a selection transistor. Each unit pixel cluster 114 includes a red pixel R, a first green pixel Gb, a blue pixel B, and a second green pixel Gr.

Fig. 63 is a cross-sectional view taken along line LXIII-LXIII of Fig. 62 passing through the second pixel Gr. Referring to Fig. 64, a photodiode PD4 as a photoelectric converter is formed on the surface of the semiconductor substrate 24, and a plurality of layers including the wiring portion 26 are formed on the semiconductor substrate 24 with an interlayer insulating film 25 interposed therebetween. The waveguide 23 is formed on the photodiode PD4 so that the waveguide 23 is embedded in the interlayer insulating film 25. A color filter layer 28 is formed over the waveguide 23. Microlenses 29 (also referred to as on-wafer lenses) are formed over color filter layer 28. Further, the amplifier gate 121 is formed close to the photodiode PD4. The gate insulating film 27 is provided between the amplifier gate 121 and the photodiode PD4.

In the solid-state image pickup device 113 of the comparative example, the incident light L is transmitted through the microlens 29 and the waveguide 23, and is incident on the photodiode PD of each pixel. At this time, in the second green pixel Gr, a portion of the incident light L transmitted through the waveguide 23 is shielded from the amplifier gate 121 having a large gate length close to the second green pixel Gr, as shown in FIGS. 62 and 63. The circle c is shown. In the first green pixel Gb, the incident light L transmitted through the waveguide 23 is incident on the photodiode PD1 without being affected by the reset gate 120 or the amplifier gate 121. Therefore, as shown in the wavelength of Fig. 64 and the output diagram, the sensitivity of the second green pixel Gr (see curve r1) is lower than the sensitivity of the first green pixel Gb (see curve b1). Therefore, a sensitivity difference occurs between the green pixels Gr and Gb.

In contrast, the solid-state image pickup device according to the fourth embodiment can control the sensitivity such that the sensitivity of the first and second green pixels Gb and Gr is equal within a unit pixel cluster of a four-pixel sharing type, wherein four pixels A floating diffusion, an amplifier transistor, and a selection transistor are shared.

Referring to Fig. 31, the solid-state image pickup device 38 according to the fourth embodiment includes pixel portions in which a plurality of unit pixel clusters 42 are arranged in an array. In each unit pixel cluster 42, a plurality of pixels share a single pixel transistor. In particular, the solid-state image pickup device 38 includes a unit pixel cluster 42 of a four-pixel sharing type in which four pixels share a floating diffusion, an amplifier transistor, and a selection transistor, wherein four photodiodes are used as photoelectric converters. The body PDs share a single pixel transistor unit. More specifically, the unit pixel cluster 42 includes four photodiodes PD (PD1 to PD4), four conversion transistors Tr (Tr11 to Tr14), and a single floating diffusion FD. Further, the unit pixel cluster 42 includes a single reset transistor Tr2, an amplifier transistor Tr3, and a selection transistor Tr4. The floating diffusion FD is disposed at the center of the four photodiodes PD1 to PD4 of the 2 × 2 array. A gate electrode 43 formed of a polymerized germanium is disposed between the floating diffusion FD and the photodiodes PD1 to PD4. Therefore, four conversion transistors Tr11 to Tr14 for the four photodiodes PD are formed.

The reset transistor Tr2, the amplifier transistor Tr3, and the selection transistor Tr4 are continuously horizontally disposed under the four photodiodes PD1 to PD4. The reset transistor Tr2 includes a diffusion region 44, a diffusion region 45, and a reset gate 48. The amplifier transistor Tr3 includes a diffusion region 45, a diffusion region 46, and an amplifier gate 49. The selection transistor Tr4 includes a diffusion region 46, a diffusion region 47, and a selection gate 151.

The waveguide 152 is formed for the photodiodes PD1 to PD4, respectively. In this embodiment, the color filter layer 157 uses the Bayer pattern color filter 101 shown in FIG. Therefore, in this embodiment, referring to FIG. 30, a plurality of unit pixel clusters 42 of a four-pixel sharing type are repeatedly arranged, wherein four pixels share a floating diffusion, an amplifier transistor, and a selection transistor, thereby forming a pixel portion. 40. Each unit pixel cluster 42 includes a red pixel R, a first green pixel Gb, a blue pixel B, and a second green pixel Gr.

The pixels R, Gb, B, and Gr have a basic structure similar to that shown in FIG. In particular, the semiconductor substrate 153 of the pixels R, Gb, B, and Gr each has a photodiode PD as a photoelectric converter. The wiring layer 150 is formed on the semiconductor substrate 153. In the wiring layer 150, a plurality of layers including the wiring portion 155 are provided and the interlayer insulating film 154 is interposed therebetween in a region other than above the photodiode PD. The waveguide 152 is formed over the photodiode PD such that the waveguide 152 is embedded in the interlayer insulating film 154. The waveguide 152 directs incident light to the photodiode PD. The surface of the interlayer insulating film 154 is planarized. A color filter layer 157 for separating incident light to correspond to the waveguide 152 is formed on the planarized surface. A microlens 158 (also referred to as an on-wafer lens) is formed over the color filter layer 157. Gates 43, 48, 49, and 151 of a pixel transistor made of a polymerized germanium are formed, and the gate insulating film 131 is interposed therebetween. Referring to the cross-sectional view of Fig. 32, the amplifier gate 49 is formed close to the photodiode PD4. The gate insulating film 131 is provided between the amplifier gate 121 and the photodiode PD4.

The waveguide 152 formed to correspond to the photodiode PD has a cylindrical body whose cross section is constant from one end on the light incident side to one end on the light exit side. For example, the cylindrical body can be a cylinder or an oval cylinder (including an elliptical cylinder). The diameter (width) of the waveguide 152 is smaller than the width of the photodiode PD and the opening width of the wiring portion 155 for the photodiode PD, so that the waveguide 152 can be adjusted by displacement explained later. The waveguide 152 has a tapered cylindrical shape whose cross section gradually decreases from one end on the light incident side to one end on the light exit side.

In the unit pixel cluster 42, the base layer disposed under the light incident surface has an asymmetrical configuration. In this embodiment, the base layer including the switching gate 43 and formed under the waveguide 152 has an asymmetrical configuration with respect to the boundary between the adjacent pixels Gr, R, Gb, and B. That is, the switching gates 43 of the pixels Gr, R, Gb, and B are asymmetrically arranged in the unit pixel cluster 42. Further, in the unit pixel cluster 42, the pixel transistor unit including the reset transistor Tr2, the amplifier transistor Tr3, and the selection transistor Tr4 is asymmetrically arranged with respect to the boundary between the pixels Gb, R and the pixels Gr and B. .

In a state before the waveguide 152 of the predetermined pixel is adjusted by the displacement (equivalent to the state of the comparative example of FIG. 62), the waveguide 152 is disposed in the entire region of the pixel portion 40 at regular intervals, and the photodiode PD The positional relationship with the waveguide 152 is the same throughout the pixel portion 40. For example, one case is where the center of the photodiode PD is slightly offset from the central axis of the waveguide 152, in which case the center of the photodiode PD is aligned with the central axis of the waveguide 152. In either case, the positional relationship between the center of the photodiode PD and the waveguide 152 is the same throughout the pixel portion 40.

The color filter layer 157 and the microlens 158 of the respective colors can accept pupil correction or do not accept pupil correction. If pupil correction is performed on the color filter layer 157 and the microlens 158, pupil correction is performed such that the center of the color filter layer 157 or the displacement amount of the microlens 158 with respect to the photodiode PD is gradually changed from the center of the pixel portion 40 toward the periphery. Big.

In this embodiment, the waveguide 152 acts as an adjustment mechanism to obtain optical symmetry of the photodiode PD in the unit pixel cluster 42. In this embodiment, the waveguide 152 of the second green pixel Gr is away from the amplifier gate 49 from the reference position, and the waveguide 152 of the pixel is disposed at a regular interval in the entire area of the pixel portion 40 at the reference position. In this case, the adjustment direction of the displacement and the adjustment amount are determined such that the sensitivity of the second green pixel Gr is equal to the sensitivity of the first green pixel Gb. In this embodiment, the waveguide 152 of the second green pixel Gr is moved to the upper left side of the tilt, as shown by the arrow B in FIGS. 31A and 31B, and the distance d1 of the initial state or the reference state is made (see the comparative example of FIG. 62). ) becomes a distance d2 greater than the distance d1. In the entire pixel portion including the waveguide 152 located at the edge of the angular range, the displacement adjustment direction (displacement direction) and the adjustment amount (displacement amount) of the waveguide 152 of the second green pixel Gr are equal. The positions of the other red pixel R, the blue pixel B, and the waveguide 152 of the first green pixel Gb are not changed from the initial state.

Therefore, the waveguide 152 of the second green pixel Gr of the unit pixel cluster 42 of the four-pixel sharing type (four pixels sharing one floating diffusion, one amplifier transistor and one selection transistor) is opposite to the second green pixel Gr and other red The boundary between the pixel R, the blue pixel B, and the first green pixel Gb is a waveguide 152 that is asymmetric with respect to the other red pixel R, the blue pixel B, and the first green pixel Gb.

The overall layout of the waveguide 152 of the unit pixel cluster 42 in the exposure mask is provided in advance for the waveguide 152 that forms the displacement position of the waveguide 152 of the intended second green pixel Gr. Therefore, by using the exposure mask, the waveguide 152 in which only the second green pixel Gr is formed is intentionally displaced in the unit pixel cluster 42 by a predetermined distance in a predetermined direction, compared to the waveguides 152 of the other pixels Gb, R, and B.

With the solid-state image pickup device 38 according to the fourth embodiment, only the waveguide 152 of the second green pixel Gr is deliberately deviated from the amplifier gate 49 made of polymerized germanium in the base layer. Therefore, the incident light L can be prevented from being blocked by the amplifier gate 49. Therefore, the sensitivity difference between the first and second green pixels Gb and Gr can be reduced or eliminated, and thus optical symmetry between the green pixels Gb and Gr can be obtained. Referring to the wavelengths and output curves r2 and b2 shown in FIG. 33, the first and second green pixels Gb and Gr have the same sensitivity. Therefore, by reducing the sensitivity difference between the first and second green pixels Gb and Gr, noise (for example, grid noise) can be reduced, and a solid-state image pickup device having high image quality can be provided.

5. Fifth embodiment Exemplary organization of solid-state image pickup device

34A and 34B each show a solid-state image pickup device according to a fifth embodiment of the present invention. The solid-state image pickup device of this embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share a floating diffusion, an amplifier transistor, and a selection transistor. 34A and 34B are unit pixel clusters showing a cluster of unit pixels at the center of the angular range and edges at angular ranges of the pixel portion.

The amount of displacement as the adjustment amount of the waveguide 152 is determined based on the distance from the opening width corresponding to the wiring portion 155 of the photodiode PD. Therefore, the amount of displacement is limited. Because of this limitation, even if the waveguide 152 of the second green pixel Gr is displaced, the sensitivity difference between the first and second green pixels Gb and Gr may not be reduced. The fifth embodiment improves this point.

In the solid-state image pickup device 161 according to the fifth embodiment, similarly to the fourth embodiment, the waveguide 152 of the second green pixel Gr is displaced toward the upper right side of the tilt, away from the amplifier gate 49 by a predetermined distance, as shown in FIGS. 34A and 34B. The arrow shows. At the same time, the waveguide 152 of the first green pixel Gb is displaced toward the upper right side of the tilt shown by the arrow C of FIGS. 34A and 34B to be closer to the reset gate 48 by a predetermined distance d3. The layout of the waveguides 152 in the unit pixel cluster 42 is the same throughout the pixel portion 40. In this embodiment, the waveguide 152 of the first green pixel Gb is displaced in the same direction as the displacement direction of the second pixel Gr, as indicated by an arrow C. The displacement directions of the first and second green pixels Gb and Gr are not limited thereto. The optimum direction is determined depending on the layout of the pixel transistors Tr11 to Tr14.

Other configurations are similar to those described in accordance with the fourth embodiment. Like reference numerals refer to like numerals in FIGS. 31A and 31B.

With the solid-state image pickup device 161 according to the fifth embodiment, the sensitivity of the second green pixel Gr is increased by moving the waveguide 152 of the second green pixel Gr away from the amplifier gate 49 in the base layer, and by moving the first The waveguide 152 of the green pixel Gb deliberately reduces the sensitivity of the first green pixel Gb toward the reset gate 48 in the base layer. Therefore, optical symmetry may be obtained for the first and second green pixels Gb and Gr. That is, the sensitivity difference between the first and second green pixels Gb and Gr can be further reduced or eliminated. The sensitivity of the two green pixels Gb and Gr can be equal. Therefore, by reducing the difference in sensitivity between the first and second green pixels Gb and Gr, noise (for example, grid noise) can be reduced and a solid-state image pickup device with high image quality can be provided.

6. Sixth embodiment Exemplary organization of solid-state image pickup device

35, 36A and 36B each show a solid-state image pickup device according to a sixth embodiment of the present invention. The solid-state image pickup device of this embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. Fig. 35 is a diagram showing a unit pixel cluster in the last state according to the sixth embodiment. 36A and 36B are schematic plan views showing a cluster of unit pixels at the center of the angular range and a cluster of unit pixels at the edges of the angular extent of the pixel portion to provide an improvement in oblique incident light.

The solid-state image pickup device according to the sixth embodiment can provide color shading control in addition to the sensitivity difference between the green pixels Gb and Gr.

First, in order to facilitate understanding of the sixth embodiment, a comparative example before improvement will be described with reference to Figs. 65A and 65B. The comparative example in Figures 65A and 65B is similar to the comparative example shown in Figure 62 above. Like reference numerals refer to like elements. As shown in Fig. 65A, at the center of the angular range, the incident light L is incident in a direction perpendicular to the drawing (in the figure, the incident light L enters downward from above for convenience of explanation). The waveguides 23 of the pixels R, Gr, Gb, and B are disposed close to the corresponding switching gates 115. Therefore, as indicated by the circle f, part of the incident light L transmitted through the waveguide 23 may be blocked by the switching gate 115. In contrast, as shown in FIG. 65B, at the edge of the angular range (in the figure, the pixel portion of the left edge is taken as an example), the incident light L enters the left obliquely from the right. Since the photodiodes PD1 and PD2 are blocked by the switching gate 115, as indicated by a circle g, a portion of the incident light L incident on the first green pixel Gb and the red pixel R is blocked by the switching gate 115. As indicated by the circle f, incident light incident on the second green pixel Gr and the blue pixel B may also be blocked by the switching gate 115. Further, at the center and the edge of the angular range, the waveguides 23 of the second green pixel Gr and the blue pixel B are disposed close to the amplifier gate 121. As indicated by the circle e, part of the incident light L is blocked by the amplifier gate 121. Therefore, a sensitivity difference is generated between the first and second green pixels Gb and Gr, and color shading occurs.

With the solid-state image pickup device 63 according to the sixth embodiment, the center of the angular range shown in FIG. 36A and the edge of the angular range shown in FIG. 36B, the waveguides of the pixels R, Gr, Gb, and B in the unit pixel cluster 42 are used. 152 is displaced horizontally away from the individual switching gates 43, as indicated by arrow X. Therefore, among the pixels R, Gr, Gb, and B, the oblique incident light L and the partially perpendicular incident light L at the center of the angular range are hardly blocked by the switching gate 43. Therefore, the shading of the incident light L caused by the switching gate 43 can be reduced or eliminated.

Again, similar to the description of the fourth embodiment, the waveguide 152 of the second green pixel Gr is displaced away from the amplifier gate 49, and the waveguide 152 of the blue pixel B is displaced away from the amplifier gate 159.

Therefore, referring to Fig. 35, the solid-state image pickup device 63 according to the sixth embodiment is displaced by a predetermined displacement amount in the direction indicated by the arrow. In particular, the waveguide 152 of the second green pixel Gr exits the switching gate 43 and the amplifier gate 49 toward the upper right side of the tilt (as indicated by arrow Y). The waveguide 152 of the blue pixel B is displaced toward the lower right side of the tilt (as indicated by arrow Z) to be symmetric with the waveguide 152 of the second green pixel Gr. The waveguide 152 of the first green pixel Gb and the red pixel R is displaced leftward in the horizontal direction away from the switching gate 43. The layout of the waveguides 152 in the unit pixel cluster 42 is the same throughout the pixel portion 40.

Other configurations are similar to those described in accordance with the fourth embodiment. In Figures 35, 36A and 36B, like reference numerals refer to elements similar to those of Figures 31A and 31B.

With the solid-state image pickup device 63 according to the sixth embodiment, the sensitivity difference between the first and second green pixels Gb and Gr can be reduced or eliminated. Noise (such as grille noise) can be reduced. In addition, the sensitivity of the red pixel R and the blue pixel B can be controlled. The sensitivity variation in the pixel portion 40 can be reduced, and color shading can be reduced. Since the sensitivity variation in the pixel portion 40 is reduced, the correction circuit can be reduced and the circuit size can be reduced.

7. Seventh embodiment Exemplary organization of solid-state image pickup device

Figure 37 shows a solid-state image pickup device according to a seventh embodiment of the present invention. The solid-state image pickup device of this embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. Figure 37 is a cross-sectional view showing a second green pixel Gr in a unit pixel cluster.

The asymmetric configuration in the base layer occurs not only in the gates made of the polymer but also in the wiring pattern. The solid-state image pickup device according to the seventh embodiment can obtain optical symmetry of the wiring portion 155 of the base layer.

First, in order to facilitate understanding of the seventh embodiment, a comparative example before improvement will be described with reference to FIG. 38 is a cross-sectional view showing a second green pixel Gr in a unit pixel cluster of a four-pixel sharing type in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. In the solid-state image pickup device 33 of the comparative example, referring to FIG. 38, a photodiode PD4 as a photoelectric converter is formed on the surface of the semiconductor substrate 24, and a plurality of layers including the wiring portion 26 are formed on the semiconductor substrate 24, The interlayer insulating film 25 is interposed therebetween. The waveguide 23 is formed over the photodiode PD4 so that the waveguide 23 is embedded in the interlayer insulating film 25. A color filter layer 28 is formed over the waveguide 23. Microlenses 29 (also referred to as on-wafer lenses) are formed over color filter layer 28. In this example, the waveguide 23 is disposed over the junction 26 in the bottom layer. A portion of the wiring portion 26 in the bottom layer protrudes into the region above the photodiode PD4, and the bottom layer including the wiring portion 26 has an asymmetrical configuration in the unit pixel cluster. Although not shown, in other pixels (including the first green pixel Gb, the red pixel R, and the blue pixel B), the wiring portion 26 in the underlayer below the waveguide 23 does not protrude to the photodiodes PD1, PD2, PD3. In the area above.

In the solid-state image pickup device 33 of the comparative example, as shown by a circle h in FIG. 38, a portion of the incident light L incident on the second green pixel Gr is blocked by the wiring portion 26 in the underlayer, resulting in the second green pixel Gr. The sensitivity is reduced. Therefore, a difference in sensitivity between the first and second green pixels Gb and Gr may occur. If a portion of the wiring portion 26 in the bottom layer extends over the photodiode of another color pixel, and if the layout of the bottom layer including the wiring portion 26 is symmetrical, color shading may occur.

In the solid-state image pickup device 65 according to the seventh embodiment, the photodiode PD4 as a photoelectric converter is formed on the surface of the semiconductor substrate 153, and a plurality of layers including the wiring portion 155 are formed over the semiconductor substrate 153 with interlayer An insulating film 154 is interposed therebetween. The wiring portion 155 is substantially open in a region corresponding to the photodiode PD4. The waveguide 152 is formed over the photodiode PD4 such that the waveguide 152 is embedded in the interlayer insulating film 154. The waveguide 152 directs incident light to the photodiode PD. The surface of the interlayer insulating film 154 is planarized. A color filter layer 157 is formed on the surface of the interlayer insulating film 154. A microlens 158 (also referred to as an on-wafer lens) is formed over the color filter layer 157. In this embodiment, the waveguide 152 is disposed over the wiring portion 155 of the bottom layer, and a portion of the wiring portion 155 in the bottom layer protrudes to a region above the photodiode PD4. Although not shown, in other pixels (including the first green pixel Gb, the red pixel R, and the blue pixel B), the wiring portion 155 in the underlayer below the waveguide 152 does not protrude to the photodiodes PD1, PD2. In the area above PD3. Thus, the layout of the bottom layer containing the wiring locations 155 has an asymmetrical configuration in the unit pixel cluster 42.

In this embodiment, the waveguide 152 of the second green pixel Gr is displaced away from the wiring portion 155 protruding to the photodiode PD4. The waveguides 152 of the other color pixels R, Gb, and B are disposed at the same position with respect to the individual photodiodes. Since only the waveguide 152 of the second green pixel Gr is displaced away from the initial state, the waveguide 152 of the second green pixel Gr in the unit pixel cluster 42 is relative to the second green pixel Gr and other adjacent pixels Gb, R, and B. The boundary between the two is a waveguide 152 that is asymmetrical to the other color pixels Gb, R, and B. The layout of the waveguides 152 in the unit pixel cluster 42 is the same throughout the pixel portion 40.

The other configurations of the four-pixel sharing type in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor are similar to those according to the fourth embodiment. Omit redundant instructions.

With the solid-state image pickup device 65 according to the seventh embodiment, the waveguide 152 of the second green pixel Gr is displaced away from the wiring portion 155 protruding to the region above the photodiode PD4. Therefore, the incident light L is not blocked by the wiring portion 155 and is incident on the photodiode PD4 so that the sensitivity of the second green pixel Gr can be increased. Therefore, the difference in sensitivity between the first and second green pixels Gb and Gr can be reduced or eliminated. The sensitivity of the green pixels Gb and Gr can be equal. Therefore, by reducing the difference in sensitivity between the first and second green pixels Gb and Gr, noise (for example, grid noise) can be reduced and a solid-state image pickup device with high image quality can be provided.

If a portion of the wiring portion 155 in the bottom layer protrudes into a region above the PD of another color pixel, the waveguide of the pixel is displaced. With this configuration, incident light is not blocked by the wiring portion 155, and color shading can be reduced.

8. Eighth embodiment Exemplary organization of solid-state image pickup device

39A and 39B show a solid-state image pickup device according to an eighth embodiment of the present invention. The solid-state image pickup device of this embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. 39A and 39B are schematic block diagrams showing a unit pixel cluster of the unit pixel cluster at the center of the angular range in the final state and the edge of the angular range according to the eighth embodiment.

The solid-state image pickup device according to this embodiment reduces the sensitivity difference between the green pixels Gr and Gb by combining the waveguide displacement according to any of the fourth to seventh embodiments described above and the pupil correction of the waveguide, and Reduce color shading.

First, the pupil correction for the waveguide will be described with reference to Figs. 40A to 43. In the cross-sectional views of Figs. 40A to 43, the pixel transistor is not shown for convenience of explanation. Figure 40A shows pixels located at the center of the angular extent. Figure 40B shows the pixels at the end of the angular range. Referring to FIGS. 40A and 40B, in the pixels of the solid-state image pickup device, a photodiode PD as a photoelectric converter is formed on the surface of the semiconductor substrate 153, and a plurality of layers including the wiring layer 155 are formed on the semiconductor substrate 153 except for the light two. In the region other than the polar body PD, the interlayer insulating film 154 is interposed therebetween. The waveguide 152 is formed over the photodiode PD such that the waveguide 152 is embedded in the interlayer insulating film 154. The waveguide 152 directs incident light to the photodiode PD. The surface of the interlayer insulating film 154 is planarized. A color filter layer 157 corresponding to the waveguide 152 is formed on the planarized surface. Microlenses 158 (also referred to as on-wafer lenses) are formed on color filter layer 157.

The waveguide 152 is formed such that a waveguide hole is formed in the interlayer insulating film 154 over the photodiode PD, and the waveguide hole is filled with a light transmissive material having a refractive index higher than that of the interlayer insulating film 154. The material is, for example, a tantalum nitride film, a diamond film or a resin material. The microlens 158 and color filter layer 157 accept pupil correction to effectively concentrate uniform oblique light. The pupil correction is made larger from the center of the angular range (for example, the center of the pixel portion) toward the edge of the angular range.

The waveguide 152 of the photodiode PD formed in the corresponding pixel portion 40 has a cylindrical body whose cross section is constant from one end on the light incident side to one end on the light exit side, as described above. For example, a cylindrical body having a constant cross section is a cylinder, a crucible, or an oval cylinder (including an elliptical cylinder). The center LC of the incident ray incident on one end of the light incident side of the waveguide 152 is aligned with the central axis C of the waveguide 152.

In this case, in the pixel at the center of the angular range of FIG. 40A, incident light is incident on the microlens 158 in the central axis direction. The incident light collected by the microlens 158 is transmitted and separated by the color filter layer 157, and is incident on one end of the light incident side of the waveguide 152. The incident light is guided along the central axis C of the waveguide 152 and exits from the light exit side of the waveguide 152. Light is emitted to the center of the photodiode PD. That is, the incident light transmitted through the center of the microlens 158 is transmitted along the center of the color filter layer 157 and the central axis C of the waveguide 152, and is emitted to the center of the photodiode PD. Therefore, pupil correction is not performed on the waveguide 152.

In the pixels displaced from the center of the angular range, or in the pixels at the edges of the angular range in the drawing, pupil correction is performed on the microlens 158 and the color filter layer 157 to effectively gather uniform oblique light, As above. Further, the center LC of the incident light incident on one end of the light incident side of the waveguide 152 is aligned with the central axis C of the waveguide 152. That is, pupil correction is performed on the waveguide 152.

In the photodiode PD on which the incident light of the same wavelength is incident, in the pixel portion 40, the displacement amount of the central axis C of each waveguide 152 with respect to the center of the corresponding photodiode PD is from the center of the pixel portion 40. The polar body PD is outward and gradually enlarged. The pupil correction is performed on the microlens 158 from the center of the pixel portion 40 toward the outside, however, the amount of correction is insufficient. Therefore, for incident light having the same wavelength, the amount of displacement of the central axis of the waveguide 152 with respect to the center of the photodiode PD is increased so that the center of the light generated from the center of the microlens 158 is aligned with the central axis C of the waveguide 152. .

The diameter of the waveguide 152 can allow incident light from one end of the light exit side of the waveguide 152 to be irradiated into the surface area of the photodiode PD. Therefore, unlike the waveguide of the prior art, the size of the waveguide 152 is not equal to the surface size of the photodiode PD. The diameter of the waveguide 152 is preferably larger than the diameter of the incident light of the color filter layer 157 which is transmitted through one end of the light incident side of the waveguide 152. The illumination diameter changes with the wavelength of the incident light. For example, when the color filter layer 157 separates the incident light into red light, green light, and blue light, the red light has the largest diameter, the green light has a smaller diameter than the red light, and the blue light has a smaller diameter than the green light. Illumination diameter. If the diameter of the waveguide 152 changes with color, the layout becomes complicated. For example, the diameter of the waveguide 152 is determined based on green light having an intermediate wavelength range of incident light. Alternatively, if a space is provided between the waveguide 152 and the connection portion 155 of the wiring layer 150, the diameter of the waveguide 152 can be determined based on the red light.

The margin correction can be increased by reducing the diameter of the waveguide 152 to be smaller than the diameter of the waveguide of the prior art. Further, the pupil correction margin of the waveguide 152 can be further increased by reducing the width of the wiring portion 155 provided around the waveguide 152.

Referring to FIGS. 41A to 41C, in the photodiode PD on which incident light having the same wavelength is incident, in the pixel portion 40, the displacement amount of the central axis C of each waveguide 152 with respect to the center of the corresponding photodiode PD is It is enlarged outward from the center of the pixel portion 40. In other words, considering the photodiode PD at the same distance from the center of the pixel portion 40, the displacement amount of the central axis C of each waveguide 152 with respect to the central axis FC of the corresponding photodiode PD is incident on the photodiode PD. The wavelength of light on the surface increases and increases. The pupil correction amount of the waveguide 152 satisfies the relationship of "blue light (B) < green light (G) < red light (R)". In order to facilitate the layout of the plan view, the waveguide 152 is smaller than the photodiode PD. Therefore, the shading can be optimized by the respective waveguides 152.

In general, the incident angle of the incident light collected by the microlens 158 gradually increases as the position deviates from the pixel portion 20 toward the outside. The pupil correction is performed for the microlens 158, however, the pupil correction amount is insufficient. Therefore, as described above, for incident light having the same wavelength, the amount of displacement of the central axis of the waveguide 16 with respect to the center of the photodiode is increased so that the center of the light generated from the microlens 158 is aligned with the central axis of the waveguide 16. C.

In general, the microlens 158 and the color filter layer 157 receive pupil correction so that the incident light is incident on the photodiode PD in the central axis direction. For example, pupil correction is performed on the microlens 158 and the color filter layer 157 having incident light of a reference wavelength (e.g., green light). In this case, referring to FIG. 41A, since the blue light is easily bent by the microlens 158, when incident on one end of the light incident side of the waveguide 152, the incident angle of the blue light becomes large. Therefore, the microlens 158 and the color filter layer 157 are largely displaced toward the center of the pixel portion with respect to the central axis FC of the photodiode PD by pupil correction. However, even when the microlens 158 and the color filter layer 157 are largely moved, the light emitted from the color filter layer 157 is incident on the position of the one end of the light incident side of the waveguide 152 which is close to the central axis FC of the photodiode PD. Therefore, almost all of the incident light of one end of the light incident side of the waveguide 152 is guided to the waveguide 152. In this case, the position of the waveguide 152 is corrected such that the central axis LC of the incident light of the incident light incident on the light incident side of the waveguide 152 is aligned with the central axis C of the waveguide 152.

Referring to FIG. 41C, since red light is hard to be bent by the microlens 158 than blue light, when incident on one end of the light incident side of the waveguide 152, the incident angle of the red light is smaller than the incident angle of the blue light. Further, the microlens 158 and the color filter layer 157 are largely displaced toward the center of the pixel portion with respect to the central axis FC of the photodiode PD by pupil correction. Therefore, the light emitted from the color filter layer 157 is incident on the position of the one end of the light incident side of the waveguide 152 away from the central axis FC of the photodiode PD. In some cases, light may be incident such that a major portion of the light protrudes from one end of the light incident side of the waveguide 152. However, in this embodiment of the invention, the position of the waveguide 152 is corrected such that the central axis LC of the incident light incident on one end of the light incident side of the waveguide 152 is aligned with the central axis C of the waveguide 152. Therefore, almost all of the incident light emitted from the color filter layer 157 is incident on one end of the light incident side of the waveguide 152, and is guided to the waveguide 152.

Further, referring to FIG. 41B, green light is less likely to be bent by the microlens 158 than blue light, but is easily bent by the microlens 158 than red light. The incident angle of the incident light incident on one end of the waveguide 152 is smaller than the incident angle of the blue light, but larger than the incident angle of the red light. Since the microlens 158 and the color filter layer 157 are displaced toward the center of the pixel portion with respect to the central axis FC of the photodiode PD by pupil correction, the light emitted from the color filter layer 157 is trapped on the light incident side of the waveguide 152. The position of one end away from the central axis FC of the photodiode PD. However, in this embodiment of the invention, the position of the waveguide 152 is corrected such that the central axis LC of the incident light of the incident light incident on the light incident side of the waveguide 152 is aligned with the central axis C of the waveguide 152. Therefore, almost all of the incident light emitted from the color filter layer 157 is incident on one end of the light incident side of the waveguide 152, and is guided to the waveguide 152.

As described above, the displacement amount of the central axis C of each of the waveguides 152 with respect to the center of the corresponding photodiode PD becomes smaller as the wavelength of the light separated by the color filter layer 157 is smaller. Therefore, even when the wavelength of the incident light at one end of the light incident side of the waveguide 152 is different, the waveguide 152 can be separately provided according to the wavelength so that the sensitivity of the pixels is the same without generating color shading.

42A, 42B and 43 each show a four-pixel sharing type solid-state image pickup device in which four pixels share a floating diffusion, an amplifier transistor, and a selection transistor, wherein pupil correction is performed for the waveguide. Figure 42A shows a layout of a waveguide 152 of a unit pixel cluster 42 in a four pixel sharing type in which four pixels share a floating diffusion, an amplifier transistor, and a selection transistor, which is located as shown in Figure 43. The center of the angular extent of the pixel portion 40. Figure 42B shows a layout of a waveguide 152 of a unit pixel cluster 42 in a four pixel sharing type in which four pixels share a floating diffusion, an amplifier transistor, and a selection transistor, which is located as shown in Figure 43. The upper right edge of the angular extent of the pixel portion 40. The layout of the waveguide 152 of the unit pixel cluster 42 of the four-pixel sharing type is symmetric with respect to the layout of the waveguide 152 shown in FIG. 42B at the lower right edge and the lower left edge of the angular range of the pixel portion 40 with respect to the center of the angular range.

The solid-state image pickup device 67 according to the eighth embodiment is constructed by the layout in which the layout of the second green pixel Gr according to the fourth embodiment is added only to the pupil-corrected waveguide 152 implemented as shown in FIGS. 40A to 43.

Since the solid-state image pickup device 67 according to the eighth embodiment has a structure in which pupil correction is performed for the waveguide 152, color shading can be reduced. Further, the sensitivity difference between the first and second green pixels Gb and Gr can be reduced, and a solid-state image pickup device having high image quality can be provided.

Alternatively, the eighth embodiment may have a configuration in which any one of the fifth to seventh embodiments is combined with the pupil correction performed on the waveguide described with reference to FIGS. 40A to 43.

9. Ninth Embodiment Exemplary organization of solid-state image pickup device

Figure 44 shows a solid-state image pickup device according to a ninth embodiment of the present invention. The solid-state image pickup device of this embodiment is a two-pixel sharing type MOS solid-state image pickup device in which two pixels share a floating diffusion, an amplifier transistor, and a selection transistor.

First, in order to facilitate the understanding of the ninth embodiment, a comparative example of the two-pixel sharing type solid-state image pickup device 34 will be described with reference to FIG. 45, in which two pixels share one floating diffusion, one amplifier transistor, and one selection transistor. The solid-state image pickup device 34 has an exemplary configuration including a waveguide 111. The solid-state image pickup device 34 is constructed by adding the waveguide 111 to each pixel of the solid-state image pickup device 1 shown in FIG. 1 described above. Other configurations are similar to those described with reference to FIG. In FIG. 45, like reference numerals refer to elements similar to those in FIG. 1. In the solid-state image pickup device 34, in the unit pixel cluster 2 of the two-pixel sharing type, two of the pixels share a floating diffusion, an amplifier transistor, and a selection transistor, and the switching gate 3 is opposed to the adjacent pixel. The boundaries are asymmetrical. In particular, the switching gates 3 of the pixels B and Gr are asymmetric with respect to the boundary between the pixels B and Gr, and the boundary between the switching gates 3 of the pixels Gb and R with respect to the pixels Gb and R is not Symmetrical. It is assumed that a cluster of four pixels including the red pixel R, the first and second green pixels Gb and Gr, and the blue pixel B has a Bayer pattern, and since the layout of the switching gates 3 is asymmetric with respect to each other in the base layer, green is generated. The sensitivity difference between the pixels Gb and Gr, and color shading occurs.

Referring to FIG. 44, the solid-state image pickup device 69 according to the ninth embodiment has a pixel portion in which a unit pixel cluster 71 of a two-pixel sharing type in which two pixels share one floating diffusion, one amplifier transistor, and one selection transistor is The repeated two-dimensional arrays. Each unit pixel cluster 71 of the two-pixel sharing type includes two photodiodes PD1 and PD2 (or PD3 and PD4), two conversion transistors Tr11 and Tr12, a floating diffusion FD, a reset transistor Tr2, and an amplifier. Transistor Tr3. A waveguide 78 is formed for each of the photodiodes PD1 and PD2 (or PD3 and PD4). In this embodiment, since the color filter having the Bayer pattern is used, the unit pixel cluster 71 including the red pixel R and the first green pixel Gb of the two-pixel sharing type and the blue pixel of the two-pixel sharing type are repeatedly disposed. B and a unit pixel cluster 71 of the second green pixel Gr. The adjacent two unit pixel clusters 71 of the two-pixel sharing type form a cluster of four pixels Gr, R, Gb, and B.

The conversion transistors Tr11 and Tr12 respectively include a switching gate 70 made of a polymer germanium, photodiodes PD (PD1, PD2, PD3, PD4) and a floating diffusion FD. The reset transistor Tr2 includes a reset gate 72 made of a polymer germanium, a floating diffusion FD, and a source region 73. The amplifier transistor Tr3 includes an amplifier gate 74, a source region 75, and a drain region 76 made of a polymer germanium. The floating diffusion FD and the amplifier gate 74 are connected to each other by a wiring portion 77. The source region 75 of the amplifier transistor Tr3 is connected to a vertical signal line (not shown).

In this embodiment, the waveguides 78 in the individual pixels R, G, Gr, and B are displaced in a direction in which the base layer has an asymmetric layout, that is, in this embodiment, it is difficult to include the switching gate 70 made of a polymer germanium. The waveguide 78 is affected. In this embodiment, the waveguides 78 of the first green pixel Gb and the blue pixel B are horizontally displaced to the right, and the waveguides 78 of the second green pixel Gr and the red pixel R are vertically displaced downward. The direction of displacement in this embodiment is merely an example. Any direction of displacement can be selected depending on the asymmetric configuration of the base layer. The configuration according to any of the fourth to eighth embodiments may also be selected. When the four pixels R, Gb, Gr, and B form a cluster, the layout of the waveguides 78 in each cluster is the same throughout the pixel portion.

With the solid-state image pickup device 69 according to the ninth embodiment, the waveguides 78 of the individual pixels are separated from the transfer gates 70 that affect the waveguides 78. Therefore, the sensitivity difference between the green pixels Gb and Gr and the color shading can be reduced. Optical symmetry can be provided to the pixels separately, and a solid-state image pickup device with high image quality can be provided.

10. Tenth Embodiment Exemplary organization of solid-state image pickup device

46, 47A and 47B each show a solid-state image pickup device according to a tenth embodiment of the present invention. The solid-state image pickup device according to the present embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. Figure 47A is a schematic cross-sectional view taken along line XLVIIA-XLVIIA of Figure 46. Figure 47B is a schematic cross-sectional view taken along line XLVIIB-XLVIIB of Figure 46.

This embodiment does not use a waveguide as an adjustment mechanism, but uses a wiring portion to adjust the amount of light, thereby obtaining optical symmetry.

First, in order to facilitate the understanding of the tenth embodiment, a comparative example of a four-pixel sharing type solid-state image pickup device 35 will be described with reference to FIGS. 48, 49A and 49B, in which four pixels share one floating diffusion, one amplifier transistor, and one selection power. Crystal. The unit pixel cluster 114 of the solid-state image pickup device 35 of the comparative example is similar to the configuration shown in FIG. 62 except that the solid-state image pickup device 35 does not have a waveguide over the region of the photodiode PD (PD1 to PD4). In the plan view shown in Fig. 48, the wiring portion 26 is added. The wiring portion 26 is disposed so as not to be positioned above the photodiode PD. Referring to Figures 48, 49A and 49B, like reference numerals in Figures 62, 63A and 63B refer to like elements, and redundant description is omitted.

In the unit pixel cluster 114 of the solid-state image pickup device 35 of the comparative example, referring to the cross-sectional view taken along line XLIXA-XLIXA of FIG. 49A of FIG. 49A, part of the incident light incident on the second green pixel Gr is The amplifier gate 121 in the base layer is hidden and placed close to the photodiode PD4. In contrast, referring to the cross-sectional view taken along line XLIXB-XLIXB of FIG. 49B of FIG. 49B, the light incident on the first green pixel Gb is not blocked by the gate in the base layer, and is incident on the photodiode. Body PD1. The incident light incident on the blue pixel B is blocked by the amplifier gate 121. The incident light incident on the first green pixel Gb is not blocked by the amplifier gate 121. Therefore, the amount of light incident on the green pixel Gr is different from the amount of light incident on the green pixel Gb. Therefore, a difference in sensitivity occurs. Further, a difference in incident light amount occurs between the pixels Gr and B and between the pixels Gb and R. This produces an optical asymmetry.

Referring to FIGS. 46, 47A and 47B, the solid-state image pickup device 81 according to the tenth embodiment is similar to the waveguide and the wiring portion, and the configuration of the unit pixel cluster 42 of the four-pixel sharing type is similar to that shown in FIGS. 31A, 31B and 32. The fabric of the fourth embodiment, wherein four pixels share a floating diffusion, an amplifying transistor, and a selection transistor. In particular, referring to FIG. 46, the solid-state image pickup device 81 according to the tenth embodiment includes a unit pixel cluster 42 of a four-pixel sharing type in which four pixels share a floating diffusion, an amplifier transistor, and a selection transistor, wherein A single pixel transistor unit shares four photodiodes PD as photoelectric converters. More specifically, the unit pixel cluster 42 includes four photodiodes PD (PD1 to PD4), four conversion transistors Tr (Tr11 to Tr14), and a single floating diffusion FD. Further, the unit pixel cluster 42 includes a single reset transistor Tr2, an amplifier transistor Tr3, and a selection transistor Tr4. The waveguide is not formed on the photodiode of each pixel.

The floating diffusion FD is disposed at the center of the four photodiodes PD1 to PD4 of the 2 × 2 array. A switching gate 43 made of a polymer germanium is disposed between the floating diffusion FD and the photodiodes PD1 to PD4. Therefore, four conversion transistors Tr11 to Tr14 for four PDs are formed. The reset transistor Tr2, the amplifier transistor Tr3, and the selection transistor Tr4 are continuously horizontally disposed under the four photodiodes PD1 to PD4.

As shown in FIGS. 47A and 47B, in each of the pixels R, Gr, Gb, and B, a photodiode PD as a photoelectric converter is formed on the surface of the semiconductor substrate 153, and the wiring layer 150 is formed on the semiconductor substrate 153. The interlayer insulating film 154 is interposed therebetween. Wiring layer 150 includes a plurality of layers of wiring locations 155. Further, a color filter layer 157 and a microlens 158 (also referred to as a wafer on-wafer) are layered on the wiring layer 150.

This embodiment uses the wire portion 155 as an adjustment mechanism for obtaining optical symmetry. In this embodiment, the protruding portion 155a protrudes from the wiring layer 155 in the upper layer. The protruding portion 155a shields the partial photodiodes PD1 and PD2 of the first green pixel Gb and the red pixel R which are not affected by the amplifier gate in the base layer. The adjustment amount of the incident light of the protruding portion 155a, that is, the portion where the protruding portion 155a overlaps with the respective photodiodes PD1 and PD2, is determined such that the incident light amount of each of the photodiodes PD1 and PD2 is equal to the incidence of the other photodiodes PD3 and PD4. The amount of light. The layout of the protruding portions 155a of the wiring portion 155 is the same for the unit pixel cluster 42 in the entire pixel portion 40.

Other configurations are similar to those described with reference to Figures 31A, 31B and 32. Referring to Figures 46, 47A and 47B, like reference numerals refer to like elements in Figures 31A, 31B and 32, and redundant description is omitted.

With the solid-state image pickup device 81 according to the tenth embodiment, the amount of protrusion of the protruding portion 155a of the wiring portion 155 of the pixel not affected by the amplifier gate 49 is adjusted, which is the first green pixel Gb and the red pixel R in this embodiment. Thereby, the amount of incident light can be adjusted. Therefore, the sensitivity difference between the first and second green pixels Gb and Gr can be reduced or eliminated and the incident light amounts of the individual pixels R, Gr, Gb, and B can be made equal. In addition, color shading can be reduced. Therefore, optical symmetry can be obtained, and a solid-state image pickup device with high image quality can be provided.

11. Eleventh Embodiment Exemplary organization of solid-state image pickup device

50, 51A, and 51B each show a solid-state image pickup device according to an eleventh embodiment of the present invention. The solid-state image pickup device according to this embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. This embodiment does not use a waveguide, but uses an analog electrode made of a polymerized crucible as an adjustment mechanism to obtain optical symmetry.

First, in order to facilitate the understanding of the eleventh embodiment, a comparative example before the improvement of the four-pixel sharing type solid-state image pickup device 36 will be described with reference to FIGS. 52, 53A, and 53B, in which four pixels share one floating diffusion and no waveguide. An amplifier transistor and a selection transistor. The unit pixel cluster 114 of the solid-state image pickup device 36 of the comparative example is similar to that of FIGS. 48, 49A, and 49B except that the solid-state image pickup device 36 does not have a waveguide in a region above the photodiode PD (PD1 to PD4). The display, and the layout of the waveguide and the wiring portion are omitted. In the solid-state image pickup device 36, the layout of the wiring portion 26 is asymmetrical. In this example, in the unit pixel cluster 114, the formation wiring portion 26 has overlapped with a portion of the blue pixel B and the second green pixel Gr. Referring to Figures 52, 53A and 53B, like reference numerals refer to like elements in Figures 48, 49A and 49B, and redundant description is omitted.

As described with reference to the solid-state image pickup device 36 of the comparative example, if the wiring portion 26 is necessarily asymmetrical, part of the incident light incident on the blue pixel B and the second green pixel Gr is blocked by the wiring portion 26. The amount of incident light can vary with the pixel, making it impossible to provide optical symmetry.

The solid-state image pickup device 83 according to the eleventh embodiment has a pixel portion 40 in which a unit pixel cluster 42 of a four-pixel sharing type is organized in a manner similar to that described in the tenth embodiment, wherein four pixels share a floating diffusion An amplifier transistor having no waveguide above the photodiode PD and a selection transistor. The layout of the wiring locations 155 is asymmetrical, similar to the manner of the comparative examples of Figures 52, 53A, and 53B. In particular, the wiring portion 155 is formed to overlap the portion of the blue pixel B and the second green pixel Gr.

This embodiment uses an analog electrode 84 made of polymeric tantalum and used as an adjustment mechanism to obtain optical symmetry. The analog electrode 84 is formed simultaneously with the gate of the pixel transistor. That is, in this embodiment, the dummy electrode 84 is formed near the photodiodes PD1 and PD2 of the first green pixel Gb and the red pixel R which are not affected by the wiring portion 155. Each of the analog electrodes 84 is formed at a position where a part of the incident light is blocked by the dummy electrode 84. The adjustment amount of the incident light of the analog electrode 84, that is, the length of the photodiodes PD1 and PD2, is determined such that the light incident amount of each of the photodiodes PD1 and PD2 is equal to the light incident amount of the other photodiodes PD3 and PD4. The layout of the analog electrodes 84 is the same in the unit pixel cluster 42 throughout the pixel portion 40.

Other configurations are similar to those described with reference to Figures 46, 47A and 47B. Referring to Figures 50, 51A and 51B, like reference numerals refer to like elements in Figures 46, 47A and 47B, and redundant description is omitted.

With the solid-state image pickup device 83 according to the eleventh embodiment, referring to FIG. 51A, part of the incident light L incident on the second green pixel Gr is blocked by the protruding wiring portion 155, and therefore, the amount of incident light for the second green pixel Gr cut back. Similarly, a part of the incident light L incident on the blue pixel B is blocked by the protruding portion 155a of the wiring portion 155, resulting in a decrease in the amount of incident light of the blue pixel B. In contrast, referring to FIG. 51B, considering the first green pixel Gb that is not affected by the wiring portion 155, a portion of the incident light L incident on the first green pixel Gb is blocked by the dummy electrode 84, resulting in the first green pixel Gb. The amount of incident light is reduced. The amount of decrease in the amount of incident light can be controlled to be equal by controlling the size of the analog electrode 84.

With the solid-state image pickup device 83 according to the eleventh embodiment, if the wiring portion 155 is necessarily asymmetrical in the unit pixel cluster 42, the dummy electrode 84 can be disposed in the base layer near the position of the pixel not affected by the wiring portion 155. . Therefore, optical symmetry can be obtained. That is, the difference in sensitivity between the first and second green pixels Gb and Gr can be reduced or eliminated. Further, the amount of incident light to the individual pixels R, Gr, Gb, and B can be equal. In addition, color shading can be reduced.

12. Twelfth embodiment Exemplary organization of solid-state image pickup device

Figures 54, 55A and 55B each show a solid-state image pickup device according to a twelfth embodiment of the present invention. The solid-state image pickup device of this embodiment is a four-pixel sharing type MOS solid-state image pickup device in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor. This embodiment does not use a waveguide, but uses a microlens as an adjustment mechanism to obtain optical symmetry.

First, a comparative example of a solid-state image pickup device 37 of a four-pixel sharing type before improvement will be described with reference to FIGS. 56, 57A and 57B, in which four pixels share one floating crystal, one amplifier transistor without a waveguide, and one selection. Transistor. The unit pixel cluster 114 of the solid-state image pickup device 37 of the comparative example is similar to that shown in FIGS. 48, 49A, and 49B except that the solid-state image pickup device 37 does not have a waveguide in a region above the photodiode PD (PD1 to PD4). The organization. Referring to Figures 56, 57A and 57B, like reference numerals refer to like elements in Figures 48, 49A and 49B, and redundant description is omitted.

In the unit pixel cluster 114 of the solid-state image pickup device 37 of the comparative example, referring to the cross-sectional view shown in FIG. 57A taken along the line LVIIA-LVIIA of FIG. 56, the portion incident on the second green pixel Gr is incident. The light is blocked by the amplifier gate 121 disposed in the base layer near the photodiode PD4. In contrast, referring to the cross-sectional view shown in FIG. 57B taken along the line LVIIB-LVIIB of FIG. 56, the incident light incident on the first green pixel Gb is not blocked by the gate in the base layer, and is incident. On the photodiode PD1. The incident light incident on the blue pixel B is blocked by the amplifier gate 121. The incident light incident on the first green pixel Gb is not blocked by the amplifier gate 121. Therefore, the amount of incident light on the first green pixel Gr is different from the amount of incident light of the green pixel Gb. Therefore, a difference in sensitivity is generated. Further, when the pixels Gr and B and the pixels Gb and R have a difference in the amount of incident light, optical asymmetry occurs.

Referring to FIGS. 54, 55A and 55B, the solid-state image pickup device 85 according to the twelfth embodiment includes a unit pixel cluster 42 of a four-pixel sharing type in which four pixels share one floating diffusion and no waveguide on the photodiode PD. An amplifier transistor and a selection transistor. A plurality of unit pixel clusters 42 of a four pixel sharing type are arrayed to form pixel locations 40. As described above, the unit pixel cluster 42 includes four photodiodes PD (PD1 to PD4), four conversion transistors Tr (Tr11 to Tr14), and a single floating diffusion FD. Further, the unit pixel cluster 42 includes a single reset transistor Tr2, an amplifier transistor Tr3, and a selection transistor Tr4.

As shown in FIGS. 55A and 55B, each of the pixels R, Gr, Gb, B, and a photodiode PD as a photoelectric converter are formed on the surface of the semiconductor substrate 153, and the wiring layer 150 is formed on the surface of the semiconductor substrate 153. The interlayer insulating film 154 is interposed therebetween. The wiring layer 150 includes a plurality of layers formed by the wiring portions 155. Further, a color filter layer 157 and microlenses 158 (also referred to as on-wafer lenses) are stacked on the wiring layer 150.

The solid-state image pickup device 85 in this embodiment uses the microlens 158 as an adjustment mechanism that obtains optical symmetry. In this embodiment, only the microlens 158 of the second green pixel Gr and the blue pixel B (which are not affected by the amplifier gate 49) are displaced to the incident light L transmitted through the microlens 158 without being blocked by the gate. s position. In particular, the focus of the microlens 158 of the second green pixel Gr and the blue pixel B is displaced away from the amplifier gate 49. In the unit pixel cluster 42 of the entire pixel portion 40, the layout of the microlenses 158 in the unit pixel cluster 42 is the same.

In the twelfth embodiment, as shown in Fig. 55A, the microlens 158 of the second green pixel Gr is displaced away from the amplifier gate. Therefore, the incident light L of the second green pixel Gr is not blocked by the amplifier gate 49 and is incident on the photodiode PD4. Also, the microlens 158 of the blue pixel B is displaced in a manner similar to the second pixel Gr. In contrast, the microlens 158 of the first green pixel Gb is not displaced, and the incident light is incident on the photodiode PD1 without being affected by the gate as the base layer. Further, in a manner similar to the first green pixel Gb, the incident light is incident on the red pixel R without being affected by the gate as the base layer.

With the solid-state image pickup device 85 according to the twelfth embodiment, the amount of light can be adjusted by the displacement of the microlenses 158 of the pixels Gr and B. Therefore, the sensitivities of the first and second green pixels Gb and Gr can be made equal. Further, the amounts of incident light of the individual pixels R, Gr, Gb, and B can be made equal. In addition, color shading can be reduced. Optical symmetry is thus obtained.

13. Thirteenth Embodiment Exemplary organization of solid-state image pickup device

Figures 58, 59A and 59B each show a solid-state image pickup device according to a thirteenth embodiment of the present invention. The solid-state image pickup device of this embodiment is a four-pixel sharing type MOS solid-state image pickup device. This embodiment provides an improvement when sufficient adjustment of the sensitivity difference is still not achieved according to the light amount adjustment provided by the twelfth embodiment.

The solid-state image pickup device 87 according to the thirteenth embodiment includes a unit pixel cluster 42 of a four-pixel sharing type in which four pixels share one floating diffusion, one amplifier transistor, and one selection transistor, wherein the second green pixel Gr and blue The microlens 158 of the color pixel B is displaced away from the amplifier gate 49 in the base layer. Further, the microlenses 158 of the first green pixel Gb and the red pixel R are displaced toward the wiring portion 155 in the base layer.

With the solid-state image pickup device 87 according to the thirteenth embodiment, the microlenses 158 of the second green pixel Gr and the blue pixel B are displaced away from the amplifier gate 49 to move the focus. Therefore, the loss of the amount of incident light can be limited, and the sensitivity can be increased. In contrast, the microlens 158 of the first green pixel Gb and the red pixel R are displaced toward the wiring portion 155 to perform adjustment to reduce the amount of incident light caused by the wiring portion 155. Therefore, the sensitivity is reduced. Therefore, the sensitivity difference between the first and second green pixels Gb and Gr is reduced. The incident light amounts of the individual pixels R, Gr, Gb, and B may be equal. In addition, color shading can be reduced. Therefore, optical symmetry can be obtained.

14. Fourteenth Embodiment Exemplary organization of solid-state image pickup device

Although not shown, the solid-state image pickup device having the configuration for obtaining an optical symmetry as described in any of the fourth to thirteenth embodiments can be applied to a CCD solid-state image pickup device. Even when such a configuration is applied to a CCD solid-state image pickup device, the light amount adjustment as described above can be performed, and optical symmetry can be obtained for individual pixels.

In the above embodiment, the fabric can be applied to a two-pixel sharing type solid-state image pickup device in which two pixels share a floating diffusion, an amplifier transistor and a selection transistor, or are applied to a four-pixel sharing type. Four of the pixels share a floating diffusion, an amplifier transistor, and a selection transistor. However, the configuration can be applied to another number of pixel-sharing type solid-state image pickup devices in which another number of pixels share a floating diffusion, an amplifier transistor, and a selection transistor.

In the above embodiment, the configuration is applied to a solid-state image pickup device having a color filter 101 of a Bayer pattern. However, the configuration can be applied to a solid-state image pickup device having a color filter layer 102 of a honeycomb pattern of an oblique array as shown in FIG.

In the above embodiment, the fabric is applied to a color solid-state image pickup device. However, the fabric can be applied to a solid-state image pickup device of a single color (for example, black and white). In this case, a waveguide, a wiring portion, an analog electrode, a lens on a wafer, or the like can be used as the adjustment mechanism.

15. Fifteenth Embodiment Exemplary organization of electronic devices

The solid-state image pickup device according to any of the foregoing embodiments can be applied to an electronic device such as a camera system such as a digital camera or a video recorder; a mobile phone having an image pickup function; or another device having an image pickup function.

Fig. 66 shows a fifteenth embodiment in which a solid-state image pickup device is applied to a camera as an example of an electronic device. The camera in this embodiment is, for example, a video recorder that can obtain still images or motion pictures. The camera 91 in this embodiment includes a solid-state image pickup device 92, an optical system 93 (which guides incident light to a light sensor of the solid-state image pickup device 92), and a shutter device 94. Further, the camera 91 includes a drive circuit 95 and a signal processing circuit 96 that processes an output signal of the solid-state image pickup device 92.

The solid-state image pickup device 92 may be a solid-state image pickup device according to any of the above embodiments. The optical system (optical lens) 93 causes the image light (incident light) generated by the object to be focused on the image pickup surface of the solid-state image pickup device 92. Therefore, signal charges are accumulated in the solid-state image pickup device 92 for a while. Optical system 93 can be an optical lens system that includes a plurality of optical lenses. The shutter device 94 controls the lighting time and the shading time of the solid-state image pickup device 92. The drive circuit 95 supplies a drive signal to control the switching operation of the solid-state image pickup device 92 and the shutter operation of the shutter device 94. In response to the drive signal (timing signal) supplied from the drive circuit 95, the signal generated by the solid-state image pickup device is converted. Signal processing circuit 96 performs various signal processing. The video signal after signal processing is stored in a storage medium (such as a memory) or output to a screen.

With the electronic device according to the fifteenth embodiment, for example, a camera, for example, optical symmetry can be obtained so that the sensitivity of the green pixels Gb and Gr of the solid-state image pickup device 92 can be equal, and thus the image quality can be improved. Therefore, a reliable electronic device can be provided.

Another embodiment can be applied to any of the foregoing embodiments. In this way, optical symmetry can be obtained.

The present application contains the subject matter of Japanese Priority Patent Application No. 2009-081100, filed on Jan. 30, 2009, and the Japanese Patent Application No. 2009-081100, filed on Jan. Priority Patent Application No. 2009-240774. The entire contents of this document are hereby incorporated by reference.

It will be appreciated by those skilled in the art that, depending upon design requirements and other factors, there may be various modifications, combinations, sub-combinations and alterations, which are still within the scope of the appended claims or their equivalents. in.

1. . . MOS solid state image pickup device

1A. . . Solid-state image pickup device

1B. . . Solid-state image pickup device

2. . . Unit pixel cluster

3. . . Switching gate

4. . . Reset gate

5. . . Source area

6. . . Amplifier gate

7. . . Source area

8. . . Bungee area

9. . . Wiring part

10. . . Solid-state image pickup device

11. . . Semiconductor substrate

12. . . Photoelectric converter

13. . . Wiring layer

14. . . Interlayer insulating film

15. . . Wiring part

16. . . waveguide

16A. . . First waveguide

16B. . . Second waveguide

17. . . Color filter layer

18. . . Microlens

19. . . Waveguide hole

20. . . Pixel part

twenty one. . . Unit pixel

twenty two. . . Unit pixel cluster

twenty three. . . waveguide

twenty four. . . Semiconductor substrate

25. . . Interlayer insulating film

26. . . Wiring part

27. . . Gate insulating film

28. . . Color filter layer

29. . . Microlens

31. . . Switching gate

33. . . Solid-state image pickup device

34. . . Solid-state image pickup device

35. . . Solid-state image pickup device

36. . . Solid-state image pickup device

37. . . Solid-state image pickup device

38. . . Solid-state image pickup device

40. . . Pixel part

42. . . Unit pixel cluster

43. . . Switching gate

44. . . Diffusion zone

45. . . Diffusion zone

46. . . Diffusion zone

47. . . Diffusion zone

48. . . Reset gate

49. . . Amplifier gate

51. . . Photoresist film

52. . . Opening

53. . . Waveguide material film

54. . . Flat insulating film

55. . . Lens forming film

56. . . Resistive pattern

57. . . First waveguide material film

58. . . Second waveguide material film

61. . . Polymeric germanium electrode

63. . . Solid-state image pickup device

65. . . Solid-state image pickup device

67. . . Solid-state image pickup device

69. . . Solid-state image pickup device

70. . . Switching gate

71. . . Unit pixel cluster

72. . . Reset gate

73. . . Source area

74. . . Amplifier gate

75. . . Source area

76. . . Bungee area

77. . . Wiring part

78. . . waveguide

81. . . Solid-state image pickup device

83. . . Solid-state image pickup device

84. . . Analog electrode

85. . . Solid-state image pickup device

87. . . Solid-state image pickup device

91. . . camera

92. . . Solid-state image pickup device

93. . . Optical system

94. . . Shutter device

95. . . Drive circuit

96. . . Signal processing circuit

101. . . Bayer pattern color filter

102. . . Color filter layer

111. . . waveguide

113. . . MOS solid state image pickup device

114. . . Unit pixel cluster

115. . . Switching gate

116. . . Diffusion zone

117. . . Diffusion zone

118. . . Diffusion zone

119. . . Diffusion zone

120. . . Reset gate

121. . . Amplifier gate

122. . . Select gate

131. . . Gate insulating film

141. . . Barrier metal layer

142. . . Anti-diffusion film

150. . . Wiring layer

151. . . Select gate

152. . . waveguide

153. . . Semiconductor substrate

154. . . Interlayer insulating film

155. . . Wiring part

155a. . . Protruding part

157. . . Color filter layer

158. . . Microlens

161. . . Solid-state image pickup device

200. . . Image pickup device

201. . . Image pickup unit

202. . . Light concentrating optical unit

203. . . Signal processing unit

210. . . Solid-state image pickup device

1 is a schematic block diagram showing a main portion of an exemplary solid-state image pickup device of a two-pixel sharing type according to the prior art, wherein two pixels share a floating diffusion, an amplifier transistor, and a selection transistor;

2 is a schematic block diagram showing a main portion of an exemplary solid-state image pickup device of another two-pixel sharing type according to the prior art, wherein two pixels share a floating diffusion, an amplifier transistor, and a selection transistor;

3A to 3C are schematic cross-sectional views and plan layout views showing a first exemplary configuration of a solid-state image pickup device according to a first embodiment of the present invention;

4A and 4B are schematic cross-sectional views showing an exemplary method of calculating a pupil correction amount, in accordance with an embodiment of the present invention;

5A and 5B are schematic cross-sectional views showing an exemplary configuration of a solid-state image pickup device according to the prior art;

6A and 6B are schematic cross-sectional views showing an exemplary method of calculating a pupil correction amount according to the prior art;

7A to 7C are pupil corrections showing a schematic cross-sectional view of a waveguide of an individual color;

Figure 8 is a plan layout view showing a second exemplary configuration of a solid-state image pickup device according to a first embodiment of the present invention;

9A to 9C are schematic cross-sectional views showing a second exemplary configuration of a solid-state image pickup device according to a first embodiment of the present invention;

10A to 10D are schematic cross-sectional views showing a third exemplary configuration of a solid-state image pickup device according to a first embodiment of the present invention;

Figure 11 is a schematic cross-sectional view showing a third exemplary configuration of a solid-state image pickup device according to a first embodiment of the present invention;

Figure 12 is a cross-sectional view showing the manufacturing steps of the first exemplary manufacturing method of the solid-state image pickup device according to the second embodiment of the present invention;

Figure 13 is a cross-sectional view showing a manufacturing step in a first exemplary manufacturing method of the solid-state image pickup device;

Figure 14 is a cross-sectional view showing a manufacturing step in a first exemplary manufacturing method of the solid-state image pickup device;

Figure 15 is a cross-sectional view showing a manufacturing step in a first exemplary manufacturing method of the solid-state image pickup device;

Figure 16 is a cross-sectional view showing the manufacturing steps of the first exemplary manufacturing method of the solid-state image pickup device;

Figure 17 is a cross-sectional view showing a manufacturing step of a first exemplary manufacturing method of the solid-state image pickup device;

Figure 18 is a cross-sectional view showing the manufacturing steps of the first exemplary manufacturing method of the solid-state image pickup device;

Figure 19 is a cross-sectional view showing the manufacturing steps of the first exemplary manufacturing method of the solid-state image pickup device;

Figure 20 is a cross-sectional view showing a manufacturing step of a first exemplary manufacturing method of the solid-state image pickup device;

21 is a cross-sectional view showing a manufacturing step of a first exemplary manufacturing method of the solid-state image pickup device;

Figure 22 is a cross-sectional view showing a manufacturing step of a second exemplary manufacturing method of the solid-state image pickup device;

Figure 23 is a cross-sectional view showing a manufacturing step of a second exemplary manufacturing method of the solid-state image pickup device;

Figure 24 is a cross-sectional view showing a manufacturing step of a second exemplary manufacturing method of the solid-state image pickup device;

Figure 25 is a cross-sectional view showing a manufacturing step of a second exemplary manufacturing method of the solid-state image pickup device;

Figure 26 is a cross-sectional view showing a manufacturing step of a second exemplary manufacturing method of the solid-state image pickup device;

Figure 27 is a cross-sectional view showing a manufacturing step of a second exemplary manufacturing method of the solid-state image pickup device;

28 is a cross-sectional view showing a manufacturing step of a second exemplary manufacturing method of the solid-state image pickup device;

Figure 29 is a block diagram showing an exemplary image pickup apparatus according to a third embodiment of the present invention;

Figure 30 is a diagram showing a schematic configuration of a pixel portion in a solid-state image pickup device according to a fourth embodiment of the present invention;

31A and 31B are schematic diagrams showing the main components of a solid-state image pickup device according to a fourth embodiment of the present invention;

Figure 32 is a cross-sectional view taken along line XXXII-XXXII in Figure 31A;

Figure 33 is a diagram showing wavelengths and outputs of green pixels Gb and Gr according to the fourth embodiment shown in Figures 31A and 31B;

34A and 34B are schematic diagrams showing the main components of a solid-state image pickup device according to a fifth embodiment of the present invention;

Figure 35 is a schematic block diagram showing the main part of a solid-state image pickup device according to a sixth embodiment of the present invention;

36A and 36B are views showing a configuration of a main portion of a solid-state image pickup device according to a sixth embodiment to explain the movement of the waveguide;

37 is a schematic block diagram showing the main part of a solid-state image pickup device according to a seventh embodiment of the present invention;

38 is a block diagram showing a main part of a solid-state image pickup device according to a comparative example to explain a seventh embodiment;

39A and 39B are schematic block diagrams showing the main parts of a solid-state image pickup device according to an eighth embodiment of the present invention;

40A to 40C are cross-sectional views showing main parts of a solid-state image pickup device according to an eighth embodiment to explain pupil correction of a waveguide;

41A to 41C are cross-sectional views showing main parts of a solid-state image pickup device according to an eighth embodiment to explain pupil correction of a waveguide;

42A and 42B are plan views showing main parts of a solid-state image pickup device according to an eighth embodiment to explain pupil correction of a waveguide;

43 is a plan view showing a pixel portion of a solid-state image pickup device according to an eighth embodiment to explain pupil correction of a waveguide;

Figure 44 is a schematic block diagram showing the main part of a solid-state image pickup device according to a ninth embodiment of the present invention;

45 is a block diagram showing a main part of a solid-state image pickup device according to a comparative example to explain a ninth embodiment;

Figure 46 is a schematic block diagram showing the main part of a solid-state image pickup device according to a tenth embodiment of the present invention;

47A and 47B are schematic cross-sectional views taken along line XLVIIA-XLVIIA and line XLVIIB-XLVIIB in Fig. 46A;

48 is a block diagram showing a main part of a solid-state image pickup device according to a comparative example to explain a tenth embodiment;

49A and 49B are schematic cross-sectional views taken along the line XLIXA-XLIXA and the line XLIXB-XLIXB in Fig. 48, respectively;

Figure 50 is a schematic block diagram showing the main part of a solid-state image pickup device according to an eleventh embodiment of the present invention;

51A and 51B are schematic cross-sectional views taken along line LIA-LIA and line LIB-LIB in Fig. 50, respectively;

Figure 52 is a block diagram showing the main part of a solid-state image pickup device according to a comparative example to explain the eleventh embodiment;

53A and 53B are schematic cross-sectional views taken along line LIIIA-LIIIA and line LIIIB-LIIIB in Fig. 52, respectively;

Figure 54 is a schematic block diagram showing the main part of a solid-state image pickup device according to a twelfth embodiment of the present invention;

55A and 55B are schematic cross-sectional views taken along line LVA-LVA and line LVB-LVB in Fig. 54, respectively;

Figure 56 is a block diagram showing the main part of a solid-state image pickup device according to a comparative example to explain the twelfth embodiment;

57A and 57B are schematic cross-sectional views taken along line LVIIA-LVIIA and line LVIIB-LVIIB in Fig. 56, respectively;

Figure 58 is a schematic block diagram showing the main part of a solid-state image pickup device according to a thirteenth embodiment of the present invention;

59A and 59B are schematic cross-sectional views taken along line LIXA-LIXA and line LIBB-LIXB in Fig. 58, respectively;

Figure 60 is a diagram showing a schematic composition of a color filter layer having a Bayer pattern as an exemplary color filter of a solid-state image pickup device according to a fourteenth embodiment of the present invention;

Figure 61 is a diagram showing a schematic configuration of a color filter having a honeycomb pattern as another exemplary color filter of a solid-state image pickup device according to a fourteenth embodiment of the present invention;

62 is a schematic block diagram showing a main part of a solid-state image pickup device according to a comparative example;

Figure 63 is a cross-sectional view taken along line LXIII-LXIII of Figure 62;

64 is a graph showing wavelengths and outputs of green pixels Gb and Gr according to the comparative example shown in FIG. 62;

65A and 65B are schematic diagrams showing the main components of a solid-state image pickup device according to a comparative example; and

Figure 66 is a schematic block diagram showing an electronic device according to a fifteenth embodiment of the present invention.

12. . . Photoelectric converter

15. . . Wiring part

16. . . waveguide

17. . . Color filter layer

18. . . Microlens

twenty one. . . Unit pixel

Claims (16)

A solid-state image pickup device comprising: a pixel portion formed by unit pixels arranged in an array in a row and column direction of a semiconductor substrate, wherein the unit pixel cluster comprises a first unit pixel, including a photoelectric converter having a light having a first wavelength incident thereon, the light being separated by the color filter layer, a second unit pixel comprising the photoelectric converter on which light having a second wavelength is incident, the light being Separating the color filter layer, the second slope length is smaller than the first wavelength, and a third unit pixel includes the photoelectric converter on which light having a third wavelength is incident, and the light is separated by the color filter layer. The third wavelength is greater than the first wavelength, and wherein for the photoelectric converter in the unit pixel cluster, a displacement amount of a central axis of each of the waveguides relative to a center of the corresponding photoelectric converter follows The wavelength of the light separated by the color filter layer is smaller and smaller, and each of the unit pixels includes a photoelectric converter formed on the semiconductor substrate and inserted into Converting light into signal charge, a waveguide formed on the photoelectric converter and guiding the incident light to the photoelectric converter, and a microlens formed on the waveguide and guiding the incident light to the waveguide One end of the side, and Wherein the waveguide has a cylindrical body having a constant cross section from the end on the light incident side to the one end on the light exit side, and is disposed such that the incident light center from the end of the light incident side of the waveguide is incident from the microlens It is aligned to a central axis of the waveguide. The solid-state image pickup device of claim 1, further comprising: a color filter layer formed between the waveguide and the microlens and separating the incident light, wherein the microlens and the color filter layer are based on the incident A pupil correction is performed with a reference color of light. The solid-state image pickup device of claim 1, wherein, for the photoelectric converter having incident light of the same wavelength incident on the pixel portion, the central axis of each of the waveguides is opposite to the corresponding photoelectric converter A displacement amount of the center gradually increases as it goes outward from a center of the pixel portion. The solid-state image pickup device of claim 1, wherein for the photoelectric converter having the same distance from a center of the pixel portion, the central axis of each of the waveguides is opposite to a center of the corresponding photoelectric converter The amount of displacement is gradually reduced as the wavelength of the light is longer, and the light is separated by the color filter layer and incident on the photoelectric converter. A solid-state image pickup device according to claim 1, wherein the diameter of the waveguide allows the incident light from the end of the light exit side of the waveguide to be emitted into a region of a surface of the photoelectric converter. A solid-state image pickup device as claimed in claim 1 The waveguide includes a first waveguide defining a surrounding portion of the waveguide, and a second waveguide formed within the first waveguide and having a refractive index lower than a refractive index of the first waveguide. An image pickup device comprising: a light collecting optical unit for collecting incident light; and an image pickup unit comprising a solid-state image pickup device, the solid-state image pickup device receiving the light collected by the light collecting optical unit and implementing the light And a signal processing unit for processing a signal obtained by the photoelectric conversion of the solid-state image pickup device, wherein the solid-state image pickup device comprises a pixel portion arranged in an array in a row and a column direction of the semiconductor substrate Formed by a unit pixel, a unit pixel cluster, wherein the unit pixel cluster includes a first unit pixel, including the photoelectric converter on which light having a first wavelength is incident, the light is separated by the color filter layer, a two-unit pixel including the photoelectric converter on which light having a second wavelength is incident, the light is separated by the color filter layer, the second slope length is smaller than the first wavelength, and a third unit pixel includes a photoelectric converter having a light having a third wavelength incident thereon, the light being passed by the color filter layer From the third wave length is greater than the first wavelength, and Wherein, for the photoelectric converter in the unit pixel cluster, a displacement of a central axis of each waveguide relative to a center of the corresponding photoelectric converter is smaller with a wavelength of light separated by the color filter layer. Increasingly, wherein the unit pixel comprises a photoelectric converter formed on the semiconductor substrate and converting incident light into a signal charge, a waveguide formed on the photoelectric converter and guiding the incident light to the photoelectric conversion And a microlens formed on the waveguide and guiding the incident light to one end of the light incident side of the waveguide, and wherein the waveguide has a cylindrical body having the end from the light incident side to the light exit A constant cross section of one end of the side is disposed such that an incident ray center line from the end of the microlens incident on the light incident side of the waveguide is aligned with a central axis of the waveguide. A solid-state image pickup device comprising: a pixel portion, wherein a plurality of pixels are arranged in an array; a base layer is formed at a position of a plurality of pixels below a light incident surface of the group, and the layout of the base layer comprises an electrode And wiring, the layout being asymmetric with respect to a boundary between predetermined adjacent pixels; and adjusting mechanism for making optical asymmetry between the pixels caused by the base layer optically symmetrical, wherein the adjusting mechanism An adjustment direction of a displacement and an adjustment amount are the same in the entire pixel portion. Such as the solid-state image pickup device of claim 8 of the patent scope, And comprising: a color filter layer formed on the photoelectric converter of the pixel and separating incident light; a wafer upper lens located on the color filter layer; and a base layer formed under the color filter layer. The solid-state image pickup device of claim 9, wherein the pixel portion comprises a plurality of unit pixel clusters, each of the unit pixel clusters having a plurality of pixels, the plurality of pixels sharing a single predetermined transistor, and the asymmetry thereof The base layer is a base layer including a gate and a connection portion of the pixel transistor. The solid-state image pickup device of claim 10, wherein the adjustment mechanism is a waveguide of each pixel, wherein the color filter layer is formed above the waveguide, wherein the base layer is located below the waveguide and includes the gate And a base layer of the wiring portion, and wherein a state in which the waveguide is disposed in the entire pixel portion at a regular interval is used as a reference state, a waveguide of at least one specific pixel is clustered in the unit pixel or in a plurality of In a neighboring unit pixel cluster, offset from a position of the reference state. The solid-state image pickup device of claim 11, wherein at least one waveguide of the first common color pixel is displaced from a gate of a common pixel transistor adjacent to the waveguide, and the same color is output from the common color pixel. Signal to make the unit pixel cluster or the majority The sensitivity difference between the common color pixels in adjacent unit pixel clusters is the same. The solid-state image pickup device of claim 12, wherein a waveguide of at least one second common color pixel is displaced from the waveguide of the common color pixel toward a gate of a common pixel transistor such that the unit pixel The difference in sensitivity between the cluster or the common color pixel in the majority of the adjacent unit pixel clusters is the same. The solid-state image pickup device of claim 10, wherein for the photoelectric converter located at the same distance from a center of the pixel portion, waveguide pupil correction is performed such that the central axis of the waveguide is opposite to the photoelectric A shift amount of the center of the converter is gradually increased as the wavelength is longer, and the light is separated by the color filter layer and incident on the photoelectric converter. The solid-state image pickup device of claim 8, wherein the adjustment mechanism is a protruding portion of the connection portion, and wherein the unit pixel cluster or the plurality of adjacent unit pixel clusters The protruding portion protrudes to an area above a photoelectric converter that does not affect the base layer. An electronic device comprising: a solid-state image pickup device; an optical system for guiding incident light to a photoelectric converter of the solid-state image pickup device; and a signal processing circuit for processing an output signal of the solid-state image pickup device, wherein The solid-state image pickup device is based on the first patent application scope A solid-state image pickup device of any of the four items.