JP5182390B2 - Solid-state imaging device, camera - Google Patents

Description

The present invention relates to a solid-state imaging device having an imaging system lens and a solid-state imaging device chip, and a camera equipped with the solid-state imaging device.

In recent years, pixel miniaturization has been continuously developed in solid-state imaging devices.
Since the number of pixels per chip increases due to pixel miniaturization, an image with higher resolution can be obtained as a result.

  Further, even in a miniaturized pixel, a configuration in which an intralayer lens or an optical waveguide is provided so that a sufficient amount of light is incident on a light receiving portion of each pixel has been proposed (for example, Patent Documents 1 to 5). Reference 3).

JP 2006-332347 A JP 2005-294749 A JP 2007-180208 A

  However, the effect of obtaining the high resolution described above is established in a range where the resolution is smaller than the pixel size. This resolution is determined by the diffraction limit and aberration of the imaging lens provided outside the solid-state imaging device.

At present, optical systems including imaging lenses used in solid-state imaging devices have diffraction limitations and aberrations, so even if a point light source is imaged, the focal point is formed with a width, so the resolution is limited. is there.
For this reason, when the pixel size of the solid-state imaging device is reduced to a certain level, the resolution is not improved even if the pixel size is further reduced.
In other words, in a solid-state image pickup device including a solid-state image pickup element and an optical system such as an imaging lens, improvement in resolution is limited only by devising the configuration of the solid-state image pickup element (semiconductor chip).

In order to solve the above-described problems, the present invention provides a solid-state imaging device capable of improving the resolution and a camera including the solid-state imaging device.

The solid-state imaging device of the present invention includes a chip of a solid-state imaging device, an imaging lens for imaging light onto the solid-state imaging device, and a material having a refractive index greater than 1 disposed between the imaging lens and the chip. The material having a refractive index greater than 1 constitutes an optical component having a flat plate portion and a convex curved portion, and the convex curved portion of the optical component is the outermost portion of the chip. The contact width between the convex curved portion and the uppermost layer of the chip that is in contact with the upper layer is within 800 nm , and incident light becomes near-field light by the convex curved portion and the surface of the chip. Is incident on .
The camera of the present invention includes a solid-state imaging device including a solid-state imaging device, and images are taken. The solid-state imaging device is the configuration of the solid-state imaging device of the present invention.

According to the above-described configuration of the solid-state imaging device of the present invention, since the material having a refractive index larger than 1 is included between the imaging lens and the solid-state imaging device chip, the solid-state imaging device is formed from the imaging lens by this material. It is possible to reduce the resolution by changing the imaging state of the light .
According to the configuration of the camera of the present invention described above, since the solid-state imaging device has the configuration of the solid-state imaging device of the present invention, the resolution of the solid-state imaging device can be reduced.

According to the above-described present invention, since the resolution can be reduced, the resolution can be improved as compared with the conventional case with the same pixel size.
Therefore, according to the present invention, an image with sufficiently high resolution can be obtained even with a fine pixel, exceeding the diffraction limit and aberration limit of the imaging lens.
Also, high resolution can be achieved regardless of the F value of the imaging lens.

1 is a schematic configuration diagram of a first embodiment of a solid-state imaging device of the present invention. It is a schematic sectional drawing in case a solid-state image sensor has an on-chip color filter and an on-chip lens. It is a figure which shows the modification which changed the structure of 1st Embodiment of FIG. 1 partially. A, B It is a schematic block diagram of 2nd Embodiment of the solid-state imaging device of this invention. A, B It is a schematic block diagram of 3rd Embodiment of the solid-state imaging device of this invention. FIGS. 6A to 6D are manufacturing process diagrams illustrating a method for manufacturing the solid-state imaging device of FIG. EH The manufacturing process figure explaining the manufacturing method of the solid-state imaging device of FIG. A and B are manufacturing process diagrams illustrating a method for manufacturing the solid-state imaging device of FIG. FIG. 6 is a manufacturing process diagram illustrating a method for manufacturing the solid-state imaging device of FIG. 5. It is a figure explaining the method of bonding a chip | tip and a glass substrate together using a marker. It is a schematic block diagram of 4th Embodiment of the solid-state imaging device of this invention. A to E are manufacturing process diagrams illustrating a method for manufacturing the solid-state imaging device of FIG. 5. It is an example of the circuit structure of the CMOS type solid-state image sensor to which this invention is applied. It is an example of the circuit structure of the CCD solid-state image sensor to which this invention is applied. It is a schematic block diagram (block diagram) of one embodiment of a camera of the present invention. It is a schematic block diagram (block diagram) of other embodiment of the camera of this invention. It is a schematic block diagram (block diagram) of other embodiment of the camera of this invention. It is a figure explaining a diffraction limit. It is a figure explaining the resolution in case two point light sources exist in the same area. It is a figure which shows the relationship between the coordinate position x of the direction perpendicular | vertical to the optical axis of incident light, and light intensity. It is a figure which shows the relationship between F value and the resolution of A imaging lens. It is a figure explaining the relationship between B resolution and pixel size. It is a figure explaining spherical aberration. A to D are diagrams illustrating aberration characteristics of a general lens. FIGS. 8A to 8C are diagrams comparing the conventional configuration and the configuration of the present invention with the same expected angle from the lens. FIGS. A to C are diagrams comparing the conventional configuration and the configuration of the present invention with equal NA. It is a figure which shows the relationship between the thickness of the laminated material, and the resolution by a diffraction limit. It is a figure which shows the relationship between the thickness of the laminated material, and the blurring amount by an aberration. It is a figure explaining the improvement effect of the resolution by this invention. It is a figure which shows the improvement effect in case the NA and the prospective angle from a lens take an intermediate value. It is a figure explaining the case where the thickness of the material to laminate | stack is below the focal depth of a lens. It is a figure which shows the structure used for A and B wave simulation. AC is a result of simulation of the structure of FIGS. 31A and 31B. It is a figure which shows the structure used for the optical simulation. It is a figure which shows the relationship between a contact width and the breadth of light. It is a figure which shows the structure used for A and B wave simulation. AC is a result of simulation of the structure of FIGS. 35A and 35B.

Hereinafter, the best mode for carrying out the invention (hereinafter referred to as an embodiment) will be described.
The description will be given in the following order.
1. 1. Outline of the present invention First embodiment of solid-state imaging device of the present invention (high refractive index material on chip)
3. Second embodiment of solid-state imaging device of the present invention (use of near-field light; spherical surface or cylindrical surface)
4). Third embodiment of solid-state imaging device of the present invention (use of near-field light and optical waveguide)
5. Fourth embodiment of solid-state imaging device according to the present invention (lamination of plural kinds of high refractive index materials; reduction of chromatic aberration)
6). 6. Example of circuit configuration 7. Modification of solid-state imaging device of the present invention Embodiment of camera of the present invention

<1. Summary of the present invention>
First, prior to description of specific embodiments of the present invention, an outline of the present invention will be described.
The present invention relates to a solid-state imaging device having an imaging lens and a solid-state imaging device chip, and a material having a refractive index larger than 1 (hereinafter referred to as a high refractive index for convenience) between the imaging lens and the chip. The basic structure is to provide a material (sometimes called a material).

  Since the imaging lens has a diffraction limit, even if a point light source is imaged, the focal point is actually formed with a width. This width is called an Airy disk.

FIG. 18 is a diagram for explaining the diffraction limit. As shown in FIG. 18, consider a case where light from one point light source 60 is incident on a solid-state imaging device having an imaging lens 51, a diaphragm 52, and a solid-state imaging device chip 53.
Light from the point light source 60 is focused by the imaging lens 51, passes through the aperture of the diaphragm 52, and is focused near the chip 53. The intensity distribution of light received by the chip 53 at this time is shown on the right side of FIG. As can be seen from the intensity distribution, the light is focused on a circle having a diameter D, and the circle having the diameter D is an Airy disk.
The diameter D of the Airy disk is expressed by the following equation.
D = 1.22λ / NA
Here, λ is the wavelength of light, NA = nsinθ, n is the refractive index of air, and θ is the incident angle of light.

Further, consider the case where the two point light sources 60A and 60B are in substantially the same area as shown in FIG. In this case, the resolution is determined by whether or not the two point light sources 60A and 60B can be resolved as two images. Also in FIG. 19, as in FIG. 18, the intensity distribution of light received by the chip 53 is shown on the right side of FIG.
As shown in FIG. 19, when the two point light sources 60 </ b> A and 60 </ b> B are close to each other, the two Airy disks overlap each other as can be seen from the intensity distribution on the right side. Depending on how the two Airy discs overlap, they cannot be decomposed into two images and become one image.

One that defines the resolution is generally called the Rayleigh limit. This is the limit that the overlap of Airy discs can be disassembled,
Resolution ω = 0.61 × λ / NA
It becomes.
Here, when the F value of the imaging lens 51 is 2.8 and the wavelength λ of the incident light is 0.55 μm (550 nm), the coordinate position x (μm) in the direction perpendicular to the optical axis of the incident light. The relationship between the light intensity and the light intensity (relative value) is shown in FIG. The origin of the coordinate position x is the position of the optical axis of the incident light from one point light source.
In the case shown in FIG. 20, the resolution when F = 2.8 and λ = 0.55 μm is ω = 1.88 μm. The F value here is F = 1 / (2 × NA).

Further, FIG. 21A shows the relationship between the F value of the imaging lens and the resolution ω with the wavelength of incident light fixed at λ = 0.55 μm.
Since ω = 0.61 × λ / NA and F = 1 / (2 × NA), ω = 1.22 × λ × F holds, and when the wavelength λ is constant, F of the imaging lens is satisfied. The value and the resolution ω are proportional.
As shown in FIG. 21A, the smaller the F-number of the imaging lens, the smaller the resolution and the higher the resolution. In the case shown in FIG. 21A, it can be seen that the resolution is 1.88 μm at F = 2.8.

Furthermore, according to the Nyquist theorem, if the pixel size is half the resolution, it can be decomposed to the Rayleigh limit. That is, as shown in FIG. 21B, the pixel size can correspond to each area of light and dark.
Therefore, when an imaging lens with F = 2.8 is used, it can be resolved to the Rayleigh limit with a pixel size of 0.94 μm, which is half the resolution of 1.88 μm. This means that with a pixel size of 0.94 μm or less, the resolution does not increase even if the pixel size is reduced.

Although the diffraction limit has been described above, there is actually an aberration in the lens.
The spherical aberration will be described with reference to FIG.
As shown in FIG. 22, since the focal length differs between the light beam L1 passing near the center of the imaging lens 51 and the light beam L3 passing through the end of the imaging lens 51, spherical aberration occurs. In the case shown in FIG. 22, there are transverse aberration Δy in the direction perpendicular to the optical axis of the incident light and longitudinal aberration Δx in the direction parallel to the optical axis of the incident light. The intermediate lateral aberration Δy.
In this case, the blur amount ε _s corresponding to the resolution is
ε _s = ¼ × Δy
It becomes. In addition to the spherical aberration, the aberration includes chromatic aberration, coma aberration, astigmatism, field curvature, distortion, and the like, and such aberration deteriorates resolution.

Further, the aberration characteristics of a general lens will be described with reference to FIG. 23A to 23D show the F value dependency of the longitudinal aberration Δx described in FIG. 23A to 23D show different lens focal lengths. FIG. 23A shows a case of 20 mm, FIG. 23B shows a case of 75 mm, FIG. 23C shows a case of 70 mm, and FIG.
In any case of FIGS. 23A to 23D, the aberration tends to increase at F <5.6.
In each case, the lateral aberration Δy and the blur amount ε _s were estimated from the maximum longitudinal aberration Δx.
In FIG. 23A (focal length 20 mm), the maximum longitudinal aberration Δx = 0.1 mm, the lateral aberration Δy = 17.9 μm, and the blur amount ε _s = 4.5 μm.
In FIG. 23B (focal length 75 mm), the maximum longitudinal aberration Δx = −0.1 mm, the lateral aberration Δy = 17.9 μm, and the blur amount ε _s = 4.5 μm.
In FIG. 23C (focal length 70 mm), the maximum longitudinal aberration Δx = −0.1 mm, the lateral aberration Δy = 17.9 μm, and the blur amount ε _s = 4.5 μm.
In FIG. 23D (focal length 200 mm), the maximum longitudinal aberration Δx = 0.3 mm, the lateral aberration Δy = 53.5 μm, and the blur amount ε _s = 13.4 μm.
Thus, it can be seen that the value of the blur amount ε _s is larger than the resolution ω = 1.88 μm when F = 2.8. From this, it can be considered that, at F <5.6, the lens aberration is more dominant as a factor determining the resolution than the diffraction limit.

In view of the current situation as described above, the present invention adopts the configuration described below.
That is, a material (high refractive index material) having a refractive index higher than the refractive index (1) of air is disposed in a space between the chip of the solid-state imaging device and the imaging lens.
In the conventional structure, as shown in FIG. 24A, the space between the imaging lens 51 and the chip 53 is air (refractive index n ₀ = 1). On the other hand, for example, as shown in FIG. 24B, a material having a refractive index n ₁ (n ₁ > 1) higher than the refractive index of air (n ₀ = 1) between the imaging lens 51 and the chip 53. 54 is embedded. Thereby, the imaging lens 51 and the chip 53 can be integrated.
In the structure shown in FIG. 24B, the expected angle θ from the imaging lens 51 is made equal (θ ₁ = θ ₀ ) so that the focal length f is equal to the conventional structure shown in FIG. 24A.
Since the expected angles θ from the imaging lens 51 are equal and the refractive index is high, the NA is large and NA ₁ > NA ₀ is satisfied. Here, since the resolution ω = 0.61 × λ / NA, the resolution ω at the diffraction limit decreases as NA increases.
This has the advantage that a high-resolution image can be obtained and the limit of pixel size reduction is further reduced.

Further, in order to obtain the above-described effect, it is not always necessary to embed the entire space between the chip of the solid-state imaging device and the imaging lens with a material having a refractive index higher than that of air.
For example, as shown in FIG. 24C, a material 54 having a high refractive index is embedded in a part of the space between the imaging lens 51 and the chip 53 (in the case of FIG. 24C, the space 53 side). A similar effect can be obtained.

Further, when the expected angle θ from the imaging lens 51 is reduced (θ ₁ <θ ₀ ) so that NA is equal to that of the conventional structure, the spherical aberration is reduced.
A schematic configuration in this case is shown in FIGS. 25B and 25C. FIG. 25A shows the same conventional structure as FIG. 24A. FIG. 25B shows a case where the entire space is filled as in FIG. 24B. FIG. 25C shows a case where a part of the space (chip 53 side) is filled as in FIG. 24C.
In each configuration shown in FIGS. 25B and 25C, the expected angle θ from the imaging lens 51 is made small (θ ₁ <θ ₀ ) so that NA ₀ = NA ₁ .
The amount of blur due to spherical aberration can be expressed by the following equation from the diameter D of the imaging lens 51, the expected angle θ from the imaging lens 51, and the focal length f of the imaging lens 51.

As can be seen from this equation, the amount of blur ε decreases as the expected angle θ from the imaging lens decreases.
The F value of the imaging lens 51 is F = f / D from the diameter D of the imaging lens 51 and the focal length f.

Subsequently, it was estimated how much the resolution was improved by adopting the structure of the present invention described above.
First, when the prospective angles θ from the imaging lens are made equal (see FIG. 24), when the material having the refractive index n ₁ = 1.6 is laminated as the high refractive index material 54, The relationship between the thickness d and the resolution due to the diffraction limit was estimated. The focal length of the imaging lens was f = 5.6 cm. The F value and the diameter D of the imaging lens 51 are changed in three ways: F = 5.6, 1.0 cm, F = 4.2, 1.33 cm, F = 2.8, 2.0 cm, respectively. I investigated. The estimated results are shown in FIG.
When d = 5.6 cm, since the thickness d is equal to the focal length f, the space between the imaging lens 51 and the chip 53 is completely filled with a high refractive index material.

  FIG. 26 shows that the resolution ω decreases as the thickness d of the laminated material increases. As a result, there is an advantage that a high-resolution image can be obtained and the limit of pixel size reduction is reduced.

Next, when a material having a refractive index n ₁ = 1.6 is laminated as the high refractive index material 54 under the condition that the NA is constant in the spherical lens, the thickness d of the laminated material and the blur amount ε due to aberration are Estimated the relationship. The F value and the diameter D of the imaging lens 51 were changed in three ways as in FIG. The estimated result is shown in FIG.

  From FIG. 27, it can be seen that the greater the thickness d of the laminated material, the smaller the blur amount ε due to aberration. As a result, there is an advantage that a high-resolution image can be obtained and the limit of pixel size reduction is reduced.

The resolution improvement effect described above will be conceptually described with reference to FIG.
As shown in FIG. 28, the resolution by the imaging lens depends on the F value of the imaging lens.
In the condition where the expected angles θ from the imaging lens are equal (θ ₀ = θ ₁ , NA ₁ > NA ₀ ), the present invention changes as indicated by the arrow A to improve the resolution due to the diffraction limit.
Next, in the condition where NA is equal (NA ₀ = NA ₁ , θ ₁ <θ ₀ ), the present invention changes as indicated by an arrow B to improve lens aberration such as spherical aberration.
These improvement effects also depend on the F value of the imaging lens.

In order to average the improvement effect over all F values, both NA and θ may take intermediate values.
That is, the effect of improving the resolution can be obtained even under the condition of NA ₁ > NA ₀ and θ ₁ <θ ₀ . In this case, as shown in FIG. 29, the resolution changes as indicated by arrows C and D to improve the resolution ω.

The above results are the same whether the on-chip lens or the on-chip color filter is present or not.
When an on-chip lens or an on-chip color filter exists in the solid-state image sensor, a high refractive index material is formed on these, that is, on the uppermost layer of the chip of the solid-state image sensor.
When neither an on-chip lens nor an on-chip color filter exists in the solid-state imaging device, a high refractive index material is formed on a semiconductor layer such as silicon or an insulating layer including a wiring layer on which a light receiving portion is formed. To do.

In the present invention, an effect of reducing the resolution can be obtained by forming a high refractive index material between the imaging lens and the chip of the solid-state imaging device. Therefore, the effect can be obtained regardless of how the high refractive index material is laminated on the chip of the solid-state imaging device.
For example, it may be stacked on the uppermost layer of the solid-state image sensor or may be stacked on the surface of a package for sealing the solid-state image sensor.

  When the high refractive index material is directly laminated on the on-chip lens on the top layer of the chip, the refractive index of the high refractive index material to be laminated is set to on-chip in order not to lose the lens effect of the on-chip lens. It is better to make it lower than the refractive index of the lens.

In addition, as shown in FIG. 30, when the thickness d of the high refractive index material 54 laminated on the chip 53 is set to be equal to or less than the focal depth of the imaging lens 51, the resolution ω when coupled at the outermost surface of the material 54 is obtained. ′ Determines the overall resolution ω. For this reason, it is considered that the resolution improvement effect is reduced.
Therefore, it is considered that the resolution ω is reduced and a sufficient effect is obtained by laminating a high refractive index material with a thickness equal to or greater than the focal depth of the imaging lens.
That is, if the following conditions are satisfied, sufficient effects are obtained.

In addition, the higher the refractive index n ₁ of the high refractive index material, the greater the effect of reducing the resolution.
For example, if the refractive index of the high refractive index material is n ₁ ≧ 1.6, a sufficient resolution reduction effect can be obtained.

In addition, when a high refractive index material is provided in a part between the imaging lens and the chip, an antireflection is applied to the surface of the high refractive index material in order to prevent light from being reflected on the surface of the high refractive index material. A film may be formed. The refractive index n ₂ of the antireflection film satisfies 1 <n ₂ <n ₁ (an intermediate value between 1 and the refractive index of the high refractive index material), and the thickness d _{2 of the} antireflection film is equal to the wavelength λ of incident light. It is desirable that d ₂ ≦ λ / 4n ₂ be satisfied.

Preferably, a material having a large Abbe number and an Abbe number of 50 or more is used as the high refractive index material in order to reduce chromatic aberration.
In order to further reduce chromatic aberration, a plurality of materials having different Abbe numbers and different wavelength dispersions may be used as the high refractive index material. For example, a material having a large Abbe number and a small wavelength dispersion is formed in a convex shape, and a material having a small Abbe number and a large wavelength dispersion is laminated on the surface.

  Further, when the imaging position is shifted for each color (R, G, B) due to chromatic aberration, correction is performed so that the image of each color is reduced or enlarged so that the image of each color is matched by signal processing. A signal processing program may be set. For example, when a short-wavelength blue B image is shifted outside the image and a long-wavelength red R image is shifted inside the subject, the blue B and red R images are converted into green G images. What is necessary is just to correct | amend by reduction and expansion so that it may match.

  The method of forming the high refractive index material between the chip and the imaging lens is not particularly limited. For example, the high refractive index material is molded in advance, or the imaging lens and the high refractive index material are integrally molded. A method of preparing the prepared product and bonding it to the chip can be considered.

That is, in this invention, it is set as the structure enumerated below.
(1) Solid-state imaging device chip, imaging lens for imaging light onto the solid-state imaging device, and a material having a refractive index greater than 1 (high refractive index material) disposed between the imaging lens and the chip ).
(2) In (1), a layer of a material having a refractive index greater than 1 (high refractive index material) is laminated on the uppermost layer of the chip.
(3) In (1), a layer of a material having a refractive index higher than 1 (high refractive index material) fills the entire space between the imaging lens and the chip. In the case of this configuration, it is possible to integrally form the imaging lens and the high refractive index material.
(4) In (1), a material having a refractive index greater than 1 (high refractive index material) constitutes an optical component having a flat portion and a convex curved portion, and the optical component A convex curved portion is in contact with the top layer of the chip.
(5) In (4), the contact width between the convex curved portion and the top layer of the chip is within 800 nm. Since the contact width is within 1.5 times the wavelength of 540 nm in the vicinity of the center of visible light, the light entering the chip from the curved portion is suppressed from spreading in the semiconductor layer.
(6) In (4), it is configured to further include a waveguide formed between the convex curved portion and the light receiving portion of each pixel of the solid-state imaging device. With the waveguide, light can be efficiently guided to the light receiving unit, and a spot of light incident on the light receiving unit can be reduced.
(7) In (1) to (6), the Abbe number of a material having a refractive index greater than 1 (high refractive index material) is 50 or more. Chromatic aberration can be reduced.
(8) In (1) to (6), a material having a refractive index greater than 1 (high refractive index material) is provided with a plurality of materials having different wavelength dispersions. Chromatic aberration can be reduced by canceling the wavelength dispersion of a plurality of materials.
(9) In (1) to (8), the surface of the imaging lens side of a material having a refractive index larger than 1 (high refractive index material) has an antireflection film, and the refractive index of the antireflection film is 1. It is set as the structure which is an intermediate value with the material (high refractive index material) whose refractive index is larger than one.
(10) When manufacturing a solid-state imaging device including a chip of a solid-state imaging device and an imaging lens for imaging light onto the solid-state imaging device, the refractive index is greater than 1 between the chip and the imaging lens. A material (high refractive index material) is formed.
(11) In the manufacturing method of (10), a material having a refractive index greater than 1 (high refractive index material) is molded to produce an optical component, and this optical component is bonded to the uppermost layer of the chip.
(12) A solid-state imaging device chip, an imaging lens for imaging light onto the solid-state imaging device, and a material having a refractive index greater than 1 (high refractive index material) disposed between the imaging lens and the chip And a solid-state imaging device.

<2. First Embodiment of Solid-State Imaging Device of the Present Invention>
FIG. 1 shows a schematic configuration diagram of the first embodiment of the solid-state imaging device of the present invention.
In the present embodiment, similar to the configuration described with reference to FIGS. 24C and 25C, a portion of the space between the imaging lens 11 and the chip 13 of the solid-state imaging device has a higher refraction than air (refractive index 1). A buried layer 14 made of a material having a ratio (n ₁ > 1) is provided.

The embedded layer 14 is stacked on the chip 13 of the solid-state image sensor.
The space from the surface of the embedded layer 14 to the imaging lens 11 and the diaphragm 12 is a space having nothing as in the conventional configuration.

As the material of the buried layer 14, a material having a high transmittance with respect to light in a wavelength band to be received and detected, preferably a material that is transparent is used.
Examples of the material of the buried layer 14 include oxides such as silicon oxide (SiO ₂ ) and silicon nitride (SiN). The oxide is preferably in a glass state.

As described above, in the present invention, the effect of improving the resolution can be obtained regardless of how the embedded layer is stacked on the chip of the solid-state imaging device.
Therefore, in the present embodiment, even if the embedded layer 14 is stacked on the top layer of the chip 13 of the solid-state image sensor, the embedded layer 14 is stacked on the package for sealing the chip 13 of the solid-state image sensor. Or any of them.

Here, in particular, FIG. 2 shows a schematic cross-sectional view in the case where the embedded layer 14 is laminated on the uppermost layer of the chip of the solid-state imaging device having the on-chip color filter and the on-chip lens.
As shown in FIG. 2, in each pixel, a light receiving portion 22 made of a photodiode is formed on a semiconductor substrate 21, and an on-chip color filter 23 and an on-chip lens 24 are formed above the light receiving portion 22. Yes.
An embedded layer 14 is laminated on the on-chip lens 24, and the unevenness due to the on-chip lens 24 is filled with the embedded layer 14. The buried layer 14 is formed not over each pixel but over the entire chip.
In FIG. 2, the configuration between the light receiving unit 22 and the on-chip color filter 23 is not shown.

  In the configuration shown in FIG. 2, since the embedded layer 14 is directly laminated on the on-chip lens 24, it is desirable that the refractive index of the embedded layer 14 be lower than the refractive index of the on-chip lens 24 as described above. .

  As a method for forming the embedded layer 14, for example, a material obtained by molding the material of the embedded layer 14 or a material in which the imaging lens 11 and the embedded layer 14 are integrally molded is prepared, and this is adhered to the upper surface of the chip 13. There is a way to make it.

  Further, if the high refractive index material constituting the buried layer 14 has an Abbe number of 50 or more, it is advantageous because chromatic aberration is reduced.

According to the configuration of the present embodiment described above, since the embedded layer 14 made of a material having a refractive index greater than 1 is formed between the chip 13 of the solid-state imaging device and the imaging lens 11, the embedded layer 14 This makes it possible to reduce the resolution. Since the resolution can be reduced, it is possible to improve the resolution with the same pixel size as compared with the conventional case.
Therefore, an image with sufficiently high resolution can be obtained even with a fine pixel beyond the diffraction limit or aberration limit of the imaging lens 11.
Also, high resolution can be achieved regardless of the F value of the imaging lens 11.

Subsequently, FIG. 3 shows a modification in which the configuration of the first embodiment described above is partially changed.
As shown in FIG. 3, an antireflection film 15 is formed on the buried layer 14. The refractive index n ₂ of the antireflection film 15 satisfies n ₁ > n ₂ > 1.
Thus, by forming the antireflection film 15 on the buried layer 14, the reflection of incident light on the surface of the buried layer 14 is suppressed, and light is efficiently incident on the light receiving portion in the chip 13. Can do.

More preferably, the antireflection film 15 is formed so that the film thickness d ₂ of the antireflection film 15 satisfies d ₂ = λ / 4n ₂ with respect to the wavelength λ of incident visible light.
Thereby, reflection of incident light on the surface can be suppressed more effectively.

<3. Second Embodiment of Solid-State Imaging Device of the Present Invention>
A schematic configuration diagram of a second embodiment of the solid-state imaging device of the present invention is shown in FIGS. 4A and 4B. 4A is an overall view similar to FIG. 1, and FIG. 4B is an enlarged view of the main part of FIG. 4A.
In the second embodiment, for the purpose of further improving the resolution, a high refractive index material is used as an optical component having a downwardly convex curved surface (spherical surface or cylindrical surface), and a solid-state imaging device chip. The near-field light is used in contact with the surface of the substrate.
That is, as shown in FIG. 4A and FIG. 4B, a high refractive index material is made of a curved surface (spherical surface or cylindrical surface) portion 16A projecting downward on the chip 13 side of the solid-state imaging device and a flat plate on the imaging lens 11 side. The optical part 16 is formed of a portion 16B. Then, the curved surface portion 16 </ b> A of the optical component 16 is brought into contact with the surface of the chip 13.
With this configuration, the space around the curved portion 16A has a lower refractive index than the curved portion 16A. Therefore, as shown in FIG. 4B, the light incident on the curved surface portion 16A travels inside the curved surface, becomes near-field light at the narrowed position, and enters the surface of the chip 13. Thereby, it is possible to avoid the influence of diffraction limit and aberration.

  It is desirable that the curved portion 16A of the optical component 16 is formed so as to correspond to each light receiving portion, that is, each pixel on a one-to-one basis.

According to the configuration of the present embodiment described above, the optical component 16 made of a material having a refractive index larger than 1 is provided between the chip 13 of the solid-state imaging device and the imaging lens 11. 16 makes it possible to reduce the resolution. Since the resolution can be reduced, it is possible to improve the resolution with the same pixel size as compared with the conventional case.
Therefore, an image with sufficiently high resolution can be obtained even with a fine pixel beyond the diffraction limit or aberration limit of the imaging lens 11.
Also, high resolution can be achieved regardless of the F value of the imaging lens 11.

  In addition, according to the configuration of the present embodiment, the optical component 16 includes a curved surface shape 16A portion projecting downward on the chip 13 side and a flat plate portion 16B, and the curved surface portion 16A is formed on the surface of the chip 13. Is in contact with As a result, the incident light becomes near-field light and enters the surface of the chip 13 by the curved portion 16A, so that it is possible to avoid the influence of diffraction limit and aberration.

Here, the effect in the case of a curved surface structure projecting downward as in the second embodiment was confirmed using wave simulation by the FDTD method.
The structure used for the simulation is shown in FIGS. 31A and 31B. FIG. 31A shows a conventional structure, and FIG. 31B shows the structure of the second embodiment of the present invention. In FIGS. 31A and 31B, the imaging lens and the chip are upside down with respect to FIGS.
The diaphragm 52 is disposed on the subject side (the side on which the light 50 is incident) of the imaging lens 51, and the refractive index of the imaging lens 51 is n = 1.8.
The chip of the solid-state imaging device is configured such that a layer 62 having a refractive index n = 1.4 is formed on silicon (n = refractive index 4.1) 61 with a thickness of 2 μm. In FIG. 31B, the layer 62 is in contact with the curved portion of the layer 63 of the high refractive index material.
The layer 63 of the high refractive index material has a refractive index of n = 1.8, the pixel pitch is 1.2 μm, and the radius R of the curved surface protruding below the curved surface portion is 0.5 μm and 0. Two types of 6 μm were used.
The wavelength λ of incident light was 540 nm.
The simulation results are shown in FIGS. 32A to 32C. FIG. 32A shows the case of the conventional structure of FIG. 31A. FIG. 32B shows the case where the radius R of the curved surface is 0.5 μm in FIG. 31B, and FIG. 32C shows the case where the radius of the curved surface is 0.6 μm in FIG. 31B.

From FIG. 32A to FIG. 32C, it can be seen that the spot of light imaged from the imaging lens is narrowed on the surface of the chip in the configuration of the present invention as compared with the conventional structure. For example, in FIG. 32B, as indicated by an arrow A, the spot of light entering the chip is narrowed down.
Therefore, the resolution is improved by employing the configuration of the present invention.

33, the contact width w ₁ between the curved surface (spherical surface or cylindrical surface) portion of the high refractive index material layer 63 and the surface of the layer 62 is changed as shown in FIG. The light spreading width w ₂ was examined by optical simulation. The wavelength λ of incident light was 540 nm.
As a result of the simulation, the relationship between the contact width w ₁ (nm) and the light spreading width w ₂ (nm) is shown in FIG.

As shown in FIG. 34, when λ = 540 nm and the contact width is in the range up to 800 nm, the effect of suppressing the light spreading width in the silicon 61 was confirmed.
Since the spread width of light is proportional to the wavelength λ of light, the allowable value of the contact width is within 1.5 times the wavelength λ.

<4. Third Embodiment of Solid-State Imaging Device of the Present Invention>
FIG. 5 shows a schematic configuration diagram of the third embodiment of the solid-state imaging device of the present invention. 5A is an overall view similar to FIG. 1 and FIG. 4A, and FIG. 5B is an enlarged view of the main part of FIG. 5A.
In the third embodiment, in addition to the configuration of the second embodiment using near-field light shown in FIGS. 4A and 4B, the amount of light incident on the light receiving unit while suppressing the spread of light is reduced. A waveguide is provided for the purpose of improvement.
That is, as shown in FIGS. 5A and 5B, a columnar waveguide 19 is formed in a layer (insulating layer or the like) 18 on the silicon 17 so as to connect the surface to the silicon 17. A material having a refractive index higher than that of the surrounding layer 18 is used inside the waveguide 19 so that light is reflected by the outer wall of the waveguide 19 and guided toward the light receiving portion. The waveguide 19 is formed so as to correspond to each light receiving portion, that is, each pixel on a one-to-one basis.
The shape of the waveguide 19 is, for example, a cylindrical shape, an elliptical column shape, a quadrangular column shape, or the like.

  On the layer 18, an optical component 16 (16A, 16B) having the same configuration as shown in FIGS. 4A and 4B is provided. The curved portion 16A of the optical component 16 has a one-to-one correspondence with the waveguide 19 and has a one-to-one correspondence with each light receiving portion, that is, each pixel.

  Since the waveguide 19 is formed in the layer 18 on the silicon 17, the light incident on the layer 18 travels along the wall surface of the waveguide 19 toward the light receiving unit, and thus enters the silicon 17 on which the light receiving unit is formed. The spread width (spot diameter) of the transmitted light is suppressed to be equal to or smaller than the width of the waveguide 19. Therefore, the spot diameter on the surface of the silicon 17 can be reduced, and a sufficient amount of light can be incident on the light receiving portion of each pixel.

The solid-state imaging device of the present embodiment can be manufactured, for example, as described below.
First, as shown in FIG. 6A, a substrate material 25 to be an optical component 16 is prepared.
Next, as shown in FIG. 6B, a resist 26 is applied to the surface of the substrate material 25.
Next, as shown in FIG. 6C, the resist 26 is exposed and developed to form a trapezoidal cross-sectional shape.
Next, as shown in FIG. 6D, post-baking is performed to dissolve (reflow) the resist 26 to change from a trapezoidal cross-sectional shape to a curved surface shape.
Next, as shown in FIG. 7E, an etching process 27 is performed from above by the RIE (reactive ion etching) method. As a result, the shape of the resist 26 is transferred to the substrate material 25 as shown in FIG. 7F. Finally, as shown in FIG. 7G, the shape of the resist 26 is completely transferred to the substrate material 25, and the optical component 16 having the curved portion 16A is formed.
After that, as shown in FIG. 7H, the optical component 16 is turned upside down, and the waveguide 19 and the optical component 16 are formed on the surface of the chip 13 in which the waveguide 19 is formed inside the layer 18 on the silicon 17. It is attached so as to be aligned with the curved surface portion 16A.
In this way, the solid-state imaging device of the present embodiment can be manufactured.

In addition, the solid-state imaging device of the present embodiment can be manufactured as described below.
For example, as shown in a plan view in FIG. 8A and a cross-sectional view in FIG. 8B, an optical component 16 made of a glass substrate in which a downwardly convex spherical shape 16A is formed for each pixel on a thick flat substrate 16B. Is prepared in advance by injection molding or the like.
Next, as shown in FIG. 9, the optical component 16 is attached to the chip 13 of the solid-state imaging device having the waveguide 19. At this time, for example, the pixel pitch can be 1.2 μm, the radius R of the spherical shape 16A can be 0.5 μm, the thickness of the glass substrate can be 5 cm, and the pitch of the waveguides 19 can be 0.6 μm. In the chip 13 shown in FIG. 9, an on-chip color filter (OCCF) 23 is further formed on the waveguide 19.
When bonding to the chip 13, for example, as shown in FIG. 10, a spherical surface is formed on each pixel of the chip 13 using a marker 29 in a portion 28 </ b> B around the light receiving surface 28 </ b> A of the solid-state imaging device. The shape portion 16A may be aligned by alignment. For bonding the chip 13 and the glass substrate, it is preferable to use an ultraviolet curable material having a refractive index lower than that of the glass substrate.

  Note that the waveguide 19 does not necessarily have to penetrate all of the layer 18, and may be configured to be formed in a partial section of the layer 18 in the depth direction.

  According to the configuration of the present embodiment described above, in addition to the configuration of the second embodiment, the waveguide 19 is formed on the layer 18 between the silicon 17 and the optical component 16 where the light receiving portion is formed. Has been. Thereby, since the spread width (spot diameter) of the light incident on the silicon 17 is suppressed to be equal to or smaller than the width of the waveguide 19, the spot diameter on the surface of the silicon 17 is reduced, and a sufficient amount for the light receiving portion of each pixel Can be incident.

By the way, in the simulation results shown in FIGS. 32B and 32C, the spot is certainly narrowed on the sensor surface, but the spot is widened on the surface of the silicon 61 where the photodiode is formed.
As in the third embodiment of the present invention, a spot on the silicon surface can be reduced by forming a waveguide in each pixel. This was confirmed by simulation.

As shown in FIGS. 35A to 35B, a simulation was performed on a structure in which a waveguide 64 having a refractive index n = 1.6 was provided on the sensor surface in the same manner as FIGS. 31A to 31B. For comparison, a waveguide 64 is also provided in FIG. 35A having a conventional structure. The diameter of the waveguide 64 is 0.6 μm, the refractive index inside the waveguide 64 is n = 1.6, and other conditions are the same as those in FIGS. 31A to 31B.
The results of the simulation are shown in FIGS. 36A to 36C. FIG. 36A is a case of the conventional structure of FIG. 35A. FIG. 36B shows the case where the radius R of the curved surface is 0.5 μm in FIG. 35B, and FIG. 36C shows the case where the radius R of the curved surface is 0.6 μm in FIG.

  From FIG. 36B and FIG. 36C, it can be seen that by providing the waveguide 64, spots are narrowed down on the surface of silicon and inside the silicon. For example, in FIG. 36B, as indicated by an arrow B, the light spot entering the silicon is narrowed. This means that the resolution is further improved.

<5. Fourth Embodiment of Solid-State Imaging Device of the Present Invention>
FIG. 11 shows a schematic configuration diagram of the fourth embodiment of the solid-state imaging device of the present invention.
In the present embodiment, for the purpose of reducing chromatic aberration, a layer of a material having a large wavelength dispersion and a layer of a material having a small wavelength dispersion are laminated, and a buried layer is configured by a plurality of layers.
That is, as shown in FIG. 11, a convex layer 31 made of a material having a large Abbe number (50 or more) and a concave layer 32 made of a material having a small Abbe number (50 or less) are formed. These layers 31 and 32 are stacked to form the buried layer 14.
An antireflection film 15 similar to that shown in FIG. 3 is formed on the buried layer 14.

  Of the buried layer 14, the lower convex-type layer 31 has a small Abbe number and therefore has a small wavelength dispersion. Further, since the upper concave layer 32 has a small Abbe number, the wavelength dispersion is large. By laminating these two layers 31 and 32 having different wavelength dispersions, the chromatic aberration generated in each layer can be canceled and the entire chromatic aberration can be reduced.

As described above, even when the buried layer 14 is formed of one layer, the chromatic aberration is reduced if the Abbe number of the buried layer 14 is 50 or more.
However, when chromatic aberration occurs even when the Abbe number is 50 or more, the chromatic aberration can be further reduced by adopting the configuration of the present embodiment and configuring the embedded layer with a plurality of layers having different wavelength dispersions. .

The solid-state imaging device of the present embodiment can be manufactured, for example, by a process as shown in FIG.
First, as shown in FIG. 12A, a solid-state imaging device chip 13 is prepared.
Next, as shown in FIG. 12B, an optical adhesive 33 that is cured by ultraviolet irradiation is applied to the surface of the chip 13.
On the other hand, as shown in FIG. 12C, a convex-type layer 31 made of a material having an Abbe number of 50 or more and a concave-type layer 32 made of a material having an Abbe number of 50 or less are laminated to form a glass substrate (embedded layer) 14. Configure. Further, an antireflection film 15 is formed on the surface of the glass substrate (embedded layer) 14 by vapor deposition to produce an optical component. The antireflection film 15 can be formed with a refractive index of 1.6 and a thickness of 80 nm, for example.
Next, as shown in FIG. 12D, the optical component is mounted on the optical adhesive 33.
Subsequently, as shown in FIG. 12E , the optical adhesive 33 is cured by the ultraviolet irradiation 34 to bond the optical component and the chip 13 together.
In this way, the solid-state imaging device of the present embodiment can be manufactured.

According to the configuration of the present embodiment described above, since the embedded layer 14 made of a material having a refractive index greater than 1 is formed between the chip 13 of the solid-state imaging device and the imaging lens 11, the embedded layer 14 This makes it possible to reduce the resolution. Since the resolution can be reduced, it is possible to improve the resolution with the same pixel size as compared with the conventional case.
Therefore, an image with sufficiently high resolution can be obtained even with a fine pixel beyond the diffraction limit or aberration limit of the imaging lens 11.
Also, high resolution can be achieved regardless of the F value of the imaging lens 11.

  Further, according to the configuration of the present embodiment, the concave layer 32 having a small Abbe number is stacked on the convex layer 31 having a large Abbe number. Thereby, the lower convex layer 31 has a smaller wavelength dispersion, and the upper concave layer 32 has a larger wavelength dispersion. By laminating these two layers 31 and 32 having different wavelength dispersions, the chromatic aberration generated in each of the layers 31 and 32 can be canceled and the entire chromatic aberration can be reduced.

The plurality of layers having different wavelength dispersions do not necessarily have to be in close contact with each other as shown in FIG. 11 to form a buried layer.
For example, it is possible to adopt a configuration in which a plurality of layers having different wavelength dispersions are arranged between the imaging lens and the solid-state imaging device chip so as to have a space between the layers. Also in this configuration, the effect of reducing chromatic aberration can be obtained as in the configuration shown in FIG.

<6. Example of circuit configuration>
The present invention can be applied to various solid-state image sensors regardless of whether they are CCD solid-state image sensors (CCD image sensors) or CMOS solid-state image sensors (CMOS image sensors).
An example of a circuit configuration of a solid-state imaging device to which the present invention is applied is shown below.

An example of a circuit configuration of a CMOS type solid-state imaging device (CMOS image sensor) to which the present invention is applied is shown in FIG.
As shown in FIG. 13, each pixel has a photodiode PD and a cell amplifier 41 of a light receiving portion. The cell amplifier 41 of each pixel is connected to the vertical signal line 42 and the horizontal signal line 43.
The vertical signal line 42 is connected to the vertical shift register 44.
The horizontal signal line 43 is connected to a horizontal output line 47 via a noise cancellation circuit 45 and a horizontal selection transistor 46. The gate of the horizontal selection transistor 46 is connected to the horizontal shift register 48.
The vertical shift register 44 and the horizontal shift register 48 drive each pixel, and the signal charge accumulated in each pixel is converted into a voltage and read.

An example of a circuit configuration of a CCD solid-state imaging device (CCD image sensor) to which the present invention is applied is shown in FIG.
As shown in FIG. 14, each pixel has a photodiode PD and a read transistor 71 of a light receiving portion. A vertical CCD transfer register 72 is provided in parallel to the pixels of each column, and the read transistor 71 of each pixel is connected to the vertical CCD transfer register 72 of each column. Each vertical CCD transfer register 72 has one end connected to the horizontal CCD transfer register 73. One end of the horizontal CCD transfer register 73 is connected to the output amplifier 74. This circuit configuration is a so-called interline transfer (IT) type CCD solid-state imaging device.
The signal charge accumulated in each pixel is transferred by the read transistor 71, the vertical CCD transfer register 72, and the horizontal CCD transfer register 73, and is output through an output amplifier.

  Further, the present invention can be applied not only to the circuit configurations shown in FIGS. 13 and 14 but also to solid-state imaging devices having other circuit configurations.

<7. Modified Example of Solid-State Imaging Device of the Present Invention>
In each of the above-described embodiments, the case where there is one chip of the solid-state image sensor for one imaging lens has been described. The present invention can also be applied to a configuration having a plurality of solid-state imaging device chips for one imaging lens. That is, the present invention can be applied to a so-called three-plate type using three chips of a solid-state imaging device.
When the present invention is applied to a configuration having a plurality of solid-state imaging device chips, a material having a refractive index higher than 1 is configured in an optical path connecting each chip and the imaging lens. When a material having a refractive index higher than 1 is arranged closer to the imaging lens than the branch point of the optical path to a plurality of chips, only one material is sufficient. When a material having a refractive index higher than 1 is arranged on the chip side with respect to the branch point of the optical path, the same number as the chip is required.

In the above-described fourth embodiment, the chromatic aberration is corrected by providing a plurality of layers having different wavelength dispersions. However, the chromatic aberration can be corrected by other methods.
For example, in order to reduce the color shifts of red R, green G, and blue B due to chromatic aberration, correction by signal processing may be performed.
In general, chromatic aberration is caused when short-wavelength light forms an image on the front side of the imaging system lens, and long-wavelength side light forms an image on the back side of the imaging system lens.
Therefore, for example, when the short wavelength blue B is shifted to the outside of the image and the long wavelength red R is shifted to the inside of the subject, the signal processing here converts the blue B and red R to green G The image is corrected by reduction and enlargement so as to match the image.

<8. Embodiment of Camera of the Present Invention>
The camera of the present invention comprises the above-described solid-state imaging device according to the present invention and constitutes a camera. Examples of the camera of the present invention include a still camera, a video camera, and a portable device with a camera function.
Several embodiments of the camera of the present invention are shown below.

FIG. 15 shows a schematic configuration diagram (block diagram) of an embodiment of the camera of the present invention.
The camera according to the present embodiment includes an optical system (imaging lens) 81, a solid-state imaging device 82, a drive circuit 83, and a signal processing circuit 84. The solid-state image sensor 82 is a CCD solid-state image sensor or a CMOS solid-state image sensor.

  The optical system (imaging lens) 81 forms image light (incident light) from the subject on the imaging surface of the solid-state imaging device 82. Thereby, signal charges are accumulated for a certain period in the light receiving portion (photodiode) of the solid-state imaging device 82. The drive circuit 83 controls driving of the solid-state image sensor 82 such as signal charge accumulation / reading. The signal processing circuit 84 performs various signal processing on the output signal of the solid-state imaging device 82 and outputs the processed signal. The camera according to the present embodiment includes a camera module in which an optical system (imaging lens) 81, a solid-state imaging device 82, a drive circuit 83, and a signal processing circuit 84 are modularized.

  In the camera according to the present embodiment, a material having a higher refractive index than that of the space, such as the embedded layer 14 described above, is disposed in the space between the imaging lens 81 and the solid-state imaging device (chip) 82. Configure.

FIG. 16 shows a schematic configuration diagram (block diagram) of another embodiment of the camera of the present invention. In the camera of the present embodiment, a CCD solid-state image sensor is used as the solid-state image sensor.
This camera includes an imaging lens 101, a CCD 102, an imaging circuit 103, an integration circuit 104, a signal processing circuit 105, an AE (automatic exposure adjustment) arithmetic / control circuit 106, an AWB (automatic white balance) arithmetic / control circuit 107, and timing generation. A container 108 is provided. Further, a display system 109, a recording system 110, a smear detection circuit 111, and a smear amount detection circuit 112 are provided.

Signals are supplied between the units shown in FIG. 16 as follows.
An imaging signal from a CCD (CCD solid-state imaging device) 102 is supplied to an imaging circuit 103. Although not shown, the imaging circuit 103 includes a CDS (double correlation sampling) circuit, an AGC (automatic gain adjuster), an A / D converter, and the like. An output signal (video signal) from the imaging circuit 103 is supplied to the signal processing circuit 105.
The imaging signal from the CCD 102 is also supplied to the smear detection circuit 111 to detect smear, and the smear detection signal from the smear detection circuit 111 is supplied to the smear detection circuit 112 to calculate the smear amount. The The smear detection signal from the smear detection circuit 111 is supplied to the timing generator 108 and the AE calculation / control circuit 106. The smear amount signal from the smear amount detection circuit 112 is supplied to the AE calculation / control circuit 106. An AE control signal from the AE calculation / control circuit 106 is supplied to the imaging lens 101 and the imaging circuit 103. A control signal from the AE calculation / control circuit 106 is supplied to the timing generator 108, and various timing signals are generated in the timing generator 108 and supplied to the CCD 102 and the AE calculation / control circuit 106.
An output signal of the imaging circuit 103 is supplied to the integration circuit 104, and the integration output is supplied to the AWB calculation / control circuit 107. A control signal from the AWB calculation / control circuit 107 is supplied to the signal processing circuit 105, the integration circuit 104, and the smear amount detection circuit 112. A smear amount signal from the smear amount detection circuit 112 is supplied to the AWB calculation / control circuit 107. An integration output from the integration circuit 104 is supplied to the AE calculation / control circuit 106, and a control signal from the AE calculation / control circuit 106 is supplied to the integration circuit 104.
A video signal from the signal processing circuit 105 is supplied to a display system 109 such as an LCD (Liquid Crystal Display) to display an image, and the video signal is supplied to a recording system 110 to be recorded on an external recording medium. The

Hereinafter, the operation of each part of the camera of FIG. 16 will be described more specifically.
The integration circuit 104 generates an automatic exposure adjustment integration value signal for performing automatic exposure adjustment (AE) corresponding to the brightness of the subject, and supplies this signal to the AE calculation / control circuit 106.
Further, the integration circuit 104 generates an automatic white balance control integration value signal for performing automatic white balance control corresponding to the color information of the subject, and supplies this signal to the AWB calculation / control circuit 107.
The AE calculation / control circuit 106 is synchronized with the timing signal from the timing generator 108. Then, the lens aperture value of the lens aperture unit of the imaging lens 101 and the electronic shutter speed of the electronic shutter of the CCD 102 are controlled so that an appropriate brightness and exposure amount are obtained when the recording system 110 performs image recording.
The AE calculation / control circuit 106 also controls the gain control of the AGC circuit in the imaging circuit 103 and the integration operation of the integration circuit 104.
The AWB calculation / control circuit 107 synchronizes with the timing signal from the timing generator 108 and outputs the R (red) signal of the signal processing circuit 105 so as to achieve an appropriate white balance when the recording system 110 performs image recording. Controls the gain and gain of the B (blue) signal.
The smear detection circuit 111 detects smear when the signal level output to the pixel in the smear detection frame provided in the optical black region of the light receiving surface of the CCD solid-state imaging device 102 is within a predetermined threshold. . If it is not within the predetermined threshold, it is considered that smear has not occurred. At the same time, when smear is detected, the smear amount detection circuit 112 is put into an operating state. When the smear is not detected, the smear amount detection circuit 112 is not operated.

  In the camera according to the present embodiment, a material having a higher refractive index than the space, such as the embedded layer 14 described above, is disposed in the space between the imaging lens 101 and the CCD solid-state imaging device (chip) 102. Configure the camera.

FIG. 17 shows a schematic configuration diagram (block diagram) of still another embodiment of the camera of the present invention. Note that the camera of this embodiment also uses a CCD solid-state image sensor as the solid-state image sensor. In FIG. 17, an optical system such as an imaging lens is not shown.
This camera includes a CCD solid-state image sensor 120 and a drive power supply 131, a driver 132, and a timing signal generator 133 as drive control units for driving the CCD solid-state image sensor 120.
In the CCD solid-state imaging device 120, a large number of light receiving portions 121 by photodiodes PD are arranged in a two-dimensional matrix on a semiconductor substrate. A vertical CCD transfer register 123 is formed in parallel with the light receiving unit 121 in each column. Between the light receiving unit 121 and the vertical CCD transfer register 123, a reading gate unit 122 for reading signal charges accumulated in the light receiving unit 121 is formed. A horizontal CCD transfer register 125 is connected to one end of the vertical CCD transfer register 123.
The light receiving unit 121, the read gate unit 122, and the vertical CCD transfer register 123 constitute a unit cell (pixel) 124. Further, a channel stop CS is provided at the boundary portion of each unit cell 124.
In this embodiment, an interline transfer (IT) type CCD solid-state imaging device 120 is driven in six phases or eight phases.

In FIG. 17, a drain voltage V _DD and a reset drain voltage V _RD are applied to the CCD solid-state imaging device 120 from the drive power supply 131, and a predetermined voltage is also supplied to the driver 132.
The vertical CCD transfer register 123 includes a plurality of vertical transfer electrodes 128 (128-1 to 128-6 or 128 per unit cell in this example) corresponding to 6-phase or 8-phase drive. -1 to 128-8).
In this camera, the signal charges stored in the light receiving unit 121 of the CCD solid-state image pickup element 120, by the drive pulse corresponding to the read pulse _{X SG} to read gate 122 is applied, are read out to the vertical CCD transfer register 123 . The vertical CCD transfer register 123 is driven to transfer by drive pulses φV1 to φV6 (φV8) based on 6-phase (8-phase) vertical transfer clocks V1 to V6 (V8). The vertical CCD transfer register 123 transfers the read signal charges in the vertical direction in order corresponding to one scanning line (one line) in a part of the horizontal blanking period.
The horizontal CCD transfer register 125 is driven to be driven by drive pulses φH1 and φH2 based on, for example, two-phase horizontal transfer clocks H1 and H2. The horizontal CCD transfer register 125 sequentially transfers the signal charges for one line transferred from the plurality of vertical CCD transfer registers 123 in the horizontal direction in the horizontal scanning period after the horizontal blanking period. For this reason, a plurality of (two) horizontal transfer electrodes 129 (129-1, 129-2) corresponding to the two-phase driving are provided.
At the end of the transfer destination of the horizontal CCD transfer register 125, for example, a charge / voltage converter 126 having a floating diffusion amplifier (FDA) configuration is provided. The charge-voltage converter 126 sequentially converts the signal charges transferred horizontally by the horizontal CCD transfer register 125 into voltage signals and outputs the voltage signals. This voltage signal is derived as a CCD output (VOUT) corresponding to the amount of incident light from the subject.

The timing signal generator 133 generates various pulse signals (binary of L level and H level) for driving the CCD solid-state imaging device 120. The driver 132 supplies various pulses supplied from the timing signal generator 133 to the CCD solid-state imaging device 120 as drive pulses of a predetermined level.
The timing signal generation unit 133 generates various signals based on, for example, a horizontal synchronization signal (HD) or a vertical synchronization signal (VD) and supplies the generated signals to the driver 132. That is, the readout pulse X _SG for reading the signal charge accumulated in the light receiving unit 121, the vertical transfer clocks V1 to V6 (V8) for driving to transfer the signal charge in the vertical direction, and the horizontal transfer pulse H1 for driving to transfer the signal charge in the horizontal direction. , H2, and a reset pulse RG and the like.
The driver 132 converts the various pulses supplied from the timing signal generation unit 133 into a voltage signal (drive pulse) of a predetermined level, or converts it into another signal and supplies it to the CCD solid-state imaging device 120. For example, the n-phase vertical transfer clocks V 1 to V 6 (V 8) from the timing signal generator 133 are converted into drive pulses φV 1 to φV 6 (φV 8) via the driver 132 and applied to the corresponding predetermined vertical transfer electrodes 128. Is done. Similarly, the two-phase horizontal transfer clocks H1 and H2 are converted into drive pulses φH1 and φH2 via the driver 132 and applied to the corresponding predetermined horizontal transfer electrodes (129-1 and 129-2).

In the camera of the present embodiment, a material having a higher refractive index than the space, such as the embedded layer 14 and the optical component 16 described above, is formed in the space between the imaging lens (not shown) and the chip of the CCD solid-state imaging device 120. Arrange and configure the camera.
The drive control units (131, 132, 133) for driving the CCD solid-state image sensor 120 are provided inside the chip of the CCD solid-state image sensor 120, and are also provided outside the chip of the CCD solid-state image sensor 120. Both configurations are possible.

  The above-described three embodiments of the camera of the present invention may be combined with the first to fourth embodiments of the solid-state imaging device described above, and may be configured as other solid-state imaging devices. good.

  The camera of the present invention is not limited to the embodiments shown in FIGS. 15 to 17 and can employ various other configurations.

  The present invention is not limited to the above-described embodiment, and various other configurations can be taken without departing from the gist of the present invention.

  11, 81, 101 Imaging lens, 12 Aperture, 13 Chip (for solid-state imaging device), 14 Embedded layer, 15 Antireflection film, 16 Optical component, 19 Waveguide, 21 Substrate, 22, 121 Light receiving unit, 23 On-chip Color filter, 24 on-chip lens, 29 marker, 41 cell amplifier, 42 vertical signal line, 43 horizontal signal line, 44 vertical shift register, 45 noise cancel circuit, 46 selection transistor, 47 horizontal output line, 48 horizontal shift register, 71 readout Transistor, 72, 123 Vertical CCD transfer register, 73, 125 Horizontal CCD transfer register, 74 Output amplifier, 82 Solid-state imaging device, 83 Drive circuit, 84 Signal processing circuit, 102 CCD (CCD solid-state imaging device), 103 Imaging circuit, 104 Integration circuit, 105 signals Processing circuit, 106 AE calculation / control circuit, 107 AWB calculation / control circuit, 108 timing generator, 109 display system, 110 recording system, 111 smear detection circuit, 112 smear amount detection circuit, 122 read gate unit, 131 drive power supply, 132 driver, 133 timing signal generator, PD photodiode

Claims (6)

A solid-state imaging device comprising a solid-state imaging device,
A chip of the solid-state image sensor;
An imaging lens for imaging light onto the solid-state imaging device;
A material having a refractive index greater than 1 disposed between the imaging lens and the chip;
The material having a refractive index greater than 1 constitutes an optical component having a flat portion and a convex curved portion, and the convex curved portion of the optical component is the uppermost layer of the chip. The contact width between the convex curved portion and the uppermost layer of the chip that is in contact with the uppermost layer of the chip is within 800 nm , and incident light becomes near-field light by the convex curved portion. Solid-state imaging device that is incident on the surface .   The solid-state imaging device according to claim 1, further comprising a waveguide formed between the convex curved portion and a light receiving portion of each pixel of the solid-state imaging element.   The solid-state imaging device according to claim 1, wherein an Abbe number of a material having a refractive index greater than 1 is 50 or more. A camera that includes a solid-state imaging device including a solid-state imaging device and that captures an image,
The solid-state imaging device chip, an imaging lens for imaging light onto the solid-state imaging device, and a material having a refractive index greater than 1 disposed between the imaging lens and the solid-state imaging device chip And the material having a refractive index greater than 1 constitutes an optical component having a flat portion and a convex curved portion, and the convex curved portion of the optical component is the chip. A contact width between the convex curved portion and the uppermost layer of the chip is within 800 nm , and incident light is converted into near-field light by the convex curved portion. The camera including the solid-state imaging device that is incident on the surface of the chip .   The camera according to claim 4, wherein the solid-state imaging device further includes a waveguide formed between the convex curved portion and a light receiving portion of each pixel of the solid-state imaging device.   The camera according to any one of claims 4 to 5, wherein an Abbe number of a material having a refractive index larger than 1 of the solid-state imaging device is 50 or more.