JP2006190958A - Method and device for acquiring physical information and manufacturing method of semiconductor device for detecting physical quantity distribution with a plurality of unit constituent elements arranged therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To independently and simultaneously obtain a color image and an infrared ray image with one image sensor. <P>SOLUTION: In a physical information acquiring method, a wiring layer constituting a signal line for reading an image signal from an in-pixel amplifier is formed on a semiconductor element where a photodiode and the in-pixel amplifier or the like are formed, and there is formed on the wiring layer a laminate film 1 that includes a structure where a plurality of layers having different refractive indexes between adjacent layers and having different predetermined thicknesses, and that has a characteristic where infrared rays IR are reflected and visible light VL is passed. For a plurality of pixels constituting a unit pixel matrix 12 infrared light is cut or is not cut for every pixel. Color filters 14R, 14G, and 14B for color imaging are formed on the laminate film 1 correspondingly to color pixels 12R, 12G, 12B. A color image is obtained on the basis of a pixel signal from the pixels 12R, 12G, and 12B where the laminate film 1 is formed. An infrared ray image is obtained on the basis of a pixel signal from a pixel 12IR where no laminate film 1 is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a physical information acquisition method, a physical information acquisition device, and a method for manufacturing a semiconductor device for physical quantity distribution detection in which a plurality of unit components are arranged. More specifically, for example, a plurality of unit components that are sensitive to electromagnetic waves input from the outside such as light and radiation are arranged, and the physical quantity distribution converted into an electric signal by the unit components is converted into an electric signal. The present invention relates to a signal acquisition technique suitable for application to a solid-state imaging device or the like using a semiconductor device capable of detecting a physical quantity distribution that can be read as. In particular, the present invention relates to an imaging apparatus that enables imaging using wavelength components other than visible light (for example, infrared light).

  There are various physical quantity distribution detection semiconductor devices in which a plurality of unit components (for example, pixels) that are sensitive to changes in physical quantity such as light and radiation input from the outside such as electromagnetic waves are arranged in a line or matrix form. Used in the field.

  For example, in the field of video equipment, a CCD (Charge Coupled Device) type, a MOS (Metal Oxide Semiconductor) type, or a CMOS (Complementary Metal-oxide Semiconductor) type solid that detects changes in light (an example of an electromagnetic wave) that is an example of a physical quantity. An imaging device is used. These read out, as an electrical signal, a physical quantity distribution converted into an electrical signal by a unit component (a pixel in a solid-state imaging device).

  For example, in a solid-state imaging device, a photodiode that is a photoelectric conversion element (light receiving element; photosensor) provided in an imaging unit (pixel unit) of a device unit receives electromagnetic waves input from outside such as light and radiation. The signal charges are detected and generated and accumulated, and the accumulated signal charges (photoelectrons) are read out as image information.

  Recently, a mechanism for capturing an image by visible light and an image by infrared light has been proposed (see, for example, Patent Documents 1 to 7). For example, by preparing an infrared light emitting point in advance and tracking it, the position of the infrared light emitting point in the visible light image can be detected. In addition, a clear image can be obtained by irradiating infrared light and taking an image even at night, for example, without visible light. Furthermore, sensitivity can be improved by incorporating infrared light in addition to visible light.

JP 2004-103964 A Japanese Patent Laid-Open No. 10-210486 JP 2002-369049 A Japanese Patent Laid-Open No. 06-121325 JP 09-166493 A Japanese Patent Laid-Open No. 09-130678 JP 2002-142228 A

  The mechanism described in Patent Document 1 is a single plate type that utilizes the difference in absorption coefficient depending on the wavelength in the depth direction of the semiconductor.

  In addition, the mechanisms described in Patent Documents 2 to 4 use a wavelength separation optical system such as a wavelength separation mirror or prism as an input optical system, and receive visible light and infrared light with separate imaging elements. It is.

  The mechanism described in Patent Document 5 is a single-plate type that uses a rotary wavelength resolving optical system as an input optical system and receives visible light and infrared light with the same imaging device. For example, when an infrared light cut filter is inserted / extracted as a rotating mechanism and an infrared light cut filter is inserted, a visible color image that is not affected by near infrared light or infrared light is displayed in red. When the external light cut filter is extracted, an image obtained by adding the light intensities of visible light and near infrared light is output.

  The mechanism described in Patent Document 6 uses a stop optical system having a wavelength resolving function as an input optical system, and receives visible light and infrared light with the same imaging device.

  Further, the mechanism described in Patent Document 7 is a system in which four types of color filters having separate filter characteristics are regularly arranged in each pixel of an image sensor having sensitivity to visible light and near-infrared light. A visible light color image and a near-infrared light image are obtained independently by performing a matrix operation on the output of each pixel provided with a color filter.

  53A and 53B are diagrams for explaining the mechanism of the sensor described in Patent Document 1, in which FIG. 53A shows the light absorption spectrum characteristics of the semiconductor layer, and FIG. 53B shows the cross-sectional structure of the device. It is a schematic diagram.

  In this mechanism, the light absorption coefficient of the Si (silicon) semiconductor decreases in the order of blue, green, red, and infrared light as shown in FIG. 53A, that is, blue light and green contained in the incident light L1. With respect to light, red light, and infrared light, as shown in FIG. 53 (B), by taking advantage of the location dependence depending on the wavelength in the depth direction of the semiconductor, the depth direction from the surface of the Si semiconductor. Layers for detecting each color light of visible light (blue, green, red) and infrared light are sequentially provided.

  However, the mechanism described in Patent Document 1 using the difference in absorption coefficient depending on the wavelength does not decrease the amount of light that can be detected theoretically, but the layer that detects blue light absorbs to some extent when red light or green light passes through. In order to receive, those lights will be detected as blue light. For this reason, even if a blue signal is not originally present, if a green or red signal is input, a blue signal is also generated and a false signal is generated, so that sufficient color reproducibility cannot be obtained.

  In order to avoid this, it is necessary to perform correction by signal processing by calculation for all three primary colors, and a circuit necessary for the calculation is separately required. Therefore, the circuit configuration is complicated and large in size, and the cost is increased. Become expensive. Further, for example, when one of the three primary colors is saturated, the original value of the saturated light is not known, resulting in a calculation error. As a result, the signal is processed differently from the original color. .

  As shown in FIG. 53A, most semiconductors have absorption sensitivity to infrared light. Therefore, for example, in a solid-state imaging device (image sensor) using Si semiconductor, for example, it is usually necessary to put an infrared cut filter made of glass as an example of a color reduction filter in front of the sensor.

  Therefore, in order to receive only infrared light, or visible light and infrared light as signals, it is necessary to remove the infrared cut filter or reduce the rate of infrared light cut.

  However, in this case, infrared light is mixed with visible light and incident on the photoelectric conversion element, so that the color of the visible light image is different from the original one. Therefore, it is difficult to obtain an appropriate image by dividing a visible light image and infrared light alone (or a mixture of infrared light and visible light) simultaneously.

  In addition to the above-described problems, the use of an infrared cut filter as in a normal solid-state imaging device also reduces the sensitivity because some of the visible light is cut. Further, the use of an infrared cut filter increases the cost.

  Further, the mechanisms described in Patent Documents 2 to 4 require a large input optical system because of a wavelength resolving optical system such as a wavelength separating mirror or prism.

  In addition, the mechanism described in Patent Document 5 is an infrared light cut filter insertion / extraction mechanism, so that the apparatus becomes large, and the operation of the infrared light cut filter cannot be performed automatically.

  Further, since the mechanism described in Patent Document 6 is an aperture optical system having a wavelength resolving function, the apparatus becomes large. In addition, although both an infrared image and a visible light image can be obtained simultaneously, the image sensor can output only an electric signal obtained by synthesizing the visible light image and the infrared image, and only the visible light image or only the infrared image can be output. Cannot output.

  On the other hand, since the mechanism described in Patent Document 7 performs wavelength separation by arranging four types of color filters, there is no problem that the input optical system as in Patent Documents 2 to 6 becomes large. There is a problem with arithmetic processing. In other words, the mechanism described in Patent Document 7 performs a matrix operation on the output of each pixel in which four types of color filters having different filter characteristics are arranged, so that a visible light color image and a near-infrared light image are independent of each other. Although the visible light image and the infrared image can be output individually and simultaneously, when obtaining the visible light image, it is necessary to perform an arithmetic process with the infrared light component. Become significant.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a new mechanism capable of solving at least one of the above-described problems and a method of manufacturing an apparatus used for the mechanism.

  As an example, an imaging apparatus having a new mechanism for independently obtaining a visible light color image and a near-infrared light image with the same image sensor is provided.

  As another example, when the same image sensor captures both visible light and infrared light simultaneously, it solves the problem that the hue caused by removing the infrared light cut filter differs from the original one. The present invention provides a mechanism capable of simultaneously capturing an image with visible light and an image with infrared light or ultraviolet light with accurate hue.

  As another example, there is provided a mechanism capable of solving the high cost due to the use of a thick glass infrared cut filter as in a normal image sensor.

  The physical information acquisition method and apparatus according to the present invention uses a laminated film having a structure in which a plurality of layers having different refractive indexes are laminated to separate wavelengths of a reflected wavelength region component and a reflected wavelength region component. It is characterized in that signals are acquired independently or simultaneously by individual detection units.

  That is, the physical information acquisition method according to the present invention includes a detection unit that detects electromagnetic waves and a unit signal generation unit that generates and outputs a corresponding unit signal based on the amount of electromagnetic waves detected by the detection unit. A physical information acquisition method for acquiring physical information for a predetermined purpose based on a unit signal using an apparatus for detecting a physical quantity distribution in which unit components are arranged on the same substrate in a predetermined order. The detector has a structure in which a plurality of layers having different refractive indexes between adjacent layers and having a predetermined thickness are stacked, and has a characteristic of reflecting a predetermined wavelength region component of electromagnetic waves and passing the remaining components. It is provided on the incident surface side on which the electromagnetic wave is incident.

  Then, the detection unit detects the passing wavelength region component that has passed through the laminated member, and thereby acquires physical information for a predetermined purpose based on the unit signal of the passing wavelength region component obtained from the unit signal generation unit.

  The “remaining” does not mean all the wavelength components except the reflected wavelength region component to be reflected, and may be at least one that does not substantially include the reflected wavelength region component. “The reflection wavelength region component is substantially not included” means that the reflection wavelength region component is hardly affected at all, and may be slightly affected. This is because it is only necessary to obtain a signal that can ignore the influence of the reflection wavelength region on the passing wavelength side. As for the reflection wavelength region, it is only necessary to obtain a signal that can ignore the influence of the passing wavelength region component.

  The physical information acquisition device according to the present invention is a device suitable for carrying out the physical information acquisition method according to the present invention, and is arranged between adjacent layers arranged on the incident surface side where the electromagnetic wave of the detection unit is incident. A laminated member having a structure in which a plurality of layers having different refractive indexes and having a predetermined thickness are laminated, reflecting a predetermined wavelength region component of electromagnetic waves, and allowing the remainder to pass through, and a laminate detected by a detection unit And a signal processing unit that acquires physical information for a predetermined purpose based on a unit signal of a passing wavelength region component obtained from a unit signal generation unit based on a passing wavelength region component that has passed through the member. The laminated member may be a separate member from the detection unit, but is preferably configured integrally with the detection unit.

  The method for manufacturing a semiconductor device according to the present invention is a method suitable for manufacturing the device according to the present invention, wherein a semiconductor element layer having a detection unit and a unit signal generation unit is formed on a semiconductor substrate. A step of forming a wiring layer that forms a signal line for reading a unit signal from the unit signal generator on the semiconductor element layer, and a refractive index is different between adjacent layers on the wiring layer and has a predetermined thickness. And a step of forming a laminated film having a structure in which a plurality of layers are laminated and having a characteristic of reflecting a predetermined wavelength region component of electromagnetic waves and allowing the remainder to pass therethrough.

  In addition, in order to make the configuration capable of detecting the reflected wavelength region component, a step of regularly removing a part of the laminated film by aligning the plurality of detection units with the detection units corresponding to the respective wavelengths is further provided. Thus, the passing wavelength region component that has passed through the laminated film is detected on one side of the plurality of detection units, and the reflected wavelength region component that does not pass through the laminated film is detected on the other side of the plurality of detection units. Also good. The laminated film is preferably configured integrally with the detection unit rather than separately from the detection unit, in that a part is regularly removed by aligning with the detection unit corresponding to each wavelength.

  In addition, in the case of color imaging applications, there is further provided a step of forming, on the laminated film, a wavelength-specific optical member that allows a predetermined wavelength component in the passing wavelength region component to pass through and is aligned with the wavelength corresponding pixel. May be. In terms of forming a wavelength-specific optical member by aligning with the detection unit corresponding to each wavelength, the wavelength-specific optical member is configured integrally with the laminated film and the detection unit rather than separately from the laminated film and the detection unit. Is preferred.

  The inventions described in the dependent claims define further advantageous specific examples of the present invention.

  For example, in order to obtain an image related to a reflected wavelength region component such as infrared light with respect to a passing wavelength region component such as visible light, a laminated member is not provided on the incident surface side where the electromagnetic wave of the detection unit for the reflected wavelength region component is incident. In addition, the reflected wavelength region component may be detected by the detection unit, and thereby the second physical information for the predetermined purpose may be acquired based on the unit signal of the reflected wavelength region component obtained from the unit signal generation unit. .

  In addition, either one of the first physical information based on the unit signal of the passing wavelength region component and the second physical information based on the unit signal of the reflected wavelength region component is selected and output, or both are output simultaneously. It is good to do.

  In addition, an optical member that separates the inside of the passing wavelength region component into different wavelength region components is provided on the incident surface side of the plurality of detecting portions that detect the passing wavelength region component, and each of the detecting portions receives different passing wavelength region components In this way, one piece of physical information related to the pass wavelength region component may be acquired by combining each unit signal of the different pass wavelength region components obtained from the unit signal generation unit. For example, as an optical member, a primary color system color filter in which transmitted light in the visible region is a wavelength component of three primary colors is used for three detection units, or transmitted light in the visible region is a complementary color for each of the three primary colors. A color image is captured by using a complementary color filter.

  In addition, regarding the signal acquisition of the reflected wavelength region component, not only the reflected wavelength region component but also all or a part of the passing wavelength region component (for example, any one of the three primary colors) is simultaneously captured by the detection unit, By the difference calculation process, a signal of only the reflected wavelength region component that can ignore the influence of the passing wavelength region component may be acquired. Alternatively, the detection unit for the reflected wavelength region component is provided with an optical member that transmits the reflected wavelength region component and blocks the transmitted wavelength region component on the incident surface side so that the transmitted wavelength region component does not enter in advance. Also good.

  In addition, when it is set as the structure which also acquires the signal of a reflection wavelength region component, and produces | generates the image, the reflection wavelength region component is partly compared with the conventional arrangement | positioning aspect of the detection part which detects a passage wavelength region component. The pixel arrangement structure must be replaced with the detection unit to be detected, and the resolution may be affected by how each detection unit is arranged.

  In this regard, for example, when importance is attached to the resolution of a normal color image based on a passing wavelength region component, a certain wavelength component is detected among a plurality of color-specific detection elements that contribute to normal color image generation. It is preferable that the pixels (a typical example is a pixel for G color) have a checkered pattern. On the other hand, when importance is attached to the resolution of an image based on the reflected wavelength region component (typically, an infrared light image), it is preferable to arrange the detection units that contribute to the image generation in a checkered pattern.

  In addition, when these pixels are arranged in a two-dimensional lattice shape, a predetermined angle (typical example) is provided rather than a square lattice shape that is parallel and orthogonal to the reading directions in the vertical direction and the horizontal direction. Are arranged in an oblique lattice shape rotated by approximately 45 degrees), the density of each pixel in the vertical direction and the horizontal direction is increased, and the resolution in that direction can be further increased.

  According to the present invention, the wavelength component of the pass wavelength region component and the reflected wavelength region component are separated by using a laminated film having a structure in which a plurality of layers having different refractive indexes are laminated, and the component signals of both are detected by individual detection units. I tried to do it.

  As a result, it is possible to acquire physical information related to the passing wavelength region component in which the influence of the reflected wavelength region component can be ignored with a single semiconductor device (for example, an image sensor). At this time, for example, an expensive glass-made optical member for cutting infrared rays as in the prior art that cuts infrared light that is a reflected wavelength region component with respect to visible light, which is an example of a passing wavelength region component, becomes unnecessary. The difference in absorption coefficient due to the wavelength in the depth direction of the semiconductor is not utilized, and the problem of color reproducibility due to this does not occur.

  In addition, when the transmission wavelength region component and the reflection wavelength region component are separately detected and the signal output of both components is acquired simultaneously, the reflection wavelength region component is cut in advance by the laminated film for the transmission wavelength region component. Unlike the mechanism described in Japanese Patent Application Laid-Open No. 2002-142228, when obtaining a signal of a passing wavelength region component that is hardly affected by the reflected wavelength region component, there is no need to perform an arithmetic process with the reflected wavelength region component. is there.

  Of course, since the signals of the passing wavelength region component and the reflected wavelength region component can be detected separately and simultaneously, for example, by using a structure that separately detects infrared light, ultraviolet light, and visible light, the image of visible light and red Images from external light and ultraviolet light can be taken simultaneously. At this time, the visible light is further divided into the three primary color signal components and detected so that an image of visible light with an accurate hue and an image of infrared light or ultraviolet light can be simultaneously captured. Become.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<< Concept of Dielectric Multilayer Image Sensor >>
FIG. 1 is a diagram for explaining the concept of a demultiplexing image sensor that separates electromagnetic waves for each predetermined wavelength using a dielectric laminated film. Here, a spectral image sensor that separates light, which is an example of electromagnetic waves, for each predetermined wavelength will be described as an example.

  As shown in FIG. 1, the dielectric laminated film 1 is a layer having a predetermined thickness dj in which the refractive index nj (j is a positive integer of 2 or more; the same shall apply hereinafter) differs between adjacent layers (refractive index difference Δn). Is a laminated member having a structure in which a plurality of layers are laminated. As a result, as described later, it has a characteristic of reflecting a predetermined wavelength region component of the electromagnetic wave and passing the rest.

  The number of layers of each dielectric layer 1_j forming the dielectric laminated film 1 is counted without counting the thick layers (n0th layer 1_0 and kth layer 1_k) on both sides as the number of layers, for example, the first layer To the k-th layer side. Substantially, the dielectric laminated film 1 is configured except for the thick layers (the 0th layer 1_0 and the kth layer 1_k) on both sides.

  When light is incident on the dielectric multilayer film 1 having such a structure, the reflectance (or transmittance) has a certain dependency on the wavelength λ due to interference in the dielectric multilayer film 1. The effect increases as the refractive index difference Δn of light increases.

  In particular, when this dielectric laminated film 1 has a periodic structure and certain conditions (for example, conditions d to λ / 4n of the thickness d of each layer), when incident light L1 such as white light is incident, a certain specific Only the reflectance of light in the wavelength range (specific wavelength range light) is effectively increased to make most of the reflected light component L2, that is, the transmittance is reduced, and the reflectance of light in other wavelength ranges is increased. By making it low, most of the transmitted light component L3 can be obtained, that is, the transmittance can be increased.

  Here, the wavelength λ is the center wavelength in a certain wavelength range, and n is the refractive index of the layer. In the present embodiment, the spectral filter 10 is realized by utilizing the wavelength dependency of the reflectance (or transmittance) of the dielectric multilayer film 1.

<Basic configuration of demultiplexing image sensor using dielectric multilayer film>
FIG. 2 is a conceptual diagram illustrating a basic configuration of a demultiplexing image sensor using a dielectric laminated film. Here, FIG. 2 shows an example in which infrared light IR (InfraRed) and visible light VL (Visible Light) are split. The dielectric laminated film 1 is formed so as to have a high reflectance with respect to infrared light IR having a wavelength λ (mainly longer wavelength than 780 nm) in the infrared region which is longer than visible light VL. Thus, the infrared light IR can be transmitted by cutting the infrared light IR and not forming such a dielectric laminated film 1.

  The members (layer materials) of each dielectric layer 1_j constituting the dielectric laminated film 1 are at least two types because the dielectric laminated film 1 is composed of a plurality of layers. Any of the body layers 1_j may be made of different layer materials, or two (or more) layers may be laminated alternately or in any order. Further, the dielectric laminated film 1 may be configured with basic first and second layer materials, and a part thereof may be replaced with a third (or more) layer material. This will be specifically described below.

<Configuration of multi-wavelength demultiplexing image sensor using dielectric laminated film>
FIG. 3 is a diagram illustrating a configuration example in which the basic configuration of the spectral image sensor 11 using the spectral image sensor 10 illustrated in FIG. 2 is applied to a plurality of wavelength separation configurations.

  As described with reference to FIG. 2, the infrared light IR can be cut or transmitted depending on whether or not the dielectric laminated film 1 is formed. By applying this, for a plurality of detection units (for example, photodiodes) constituting the unit pixel matrix 12, a part of the laminated film is regularly removed by aligning with the detection units corresponding to each wavelength, that is, For each pixel (cell), infrared light is cut or not, so that only visible light VL and infrared light IR are picked up, or only visible light VL is picked up and infrared light IR and visible. Imaging in which the light VL is mixed can be performed simultaneously.

  It is not affected by the infrared light IR when capturing a monochrome image or a color image in the daytime, and can be imaged with the infrared light IR at night. If necessary, the other image can be output simultaneously. Even in that case, an image of only the infrared light IR that is not affected by the visible light VL can be obtained in the daytime.

  That is, the spectral image sensor 11 that supports multi-wavelength demultiplexing includes the dielectric layered film 1 that can reflect the infrared light IR as described above, and each pixel constituting the unit pixel matrix 12 in which the pixels are regularly arranged. By forming it on the photodiode that forms the main part of the infrared ray, it is possible to reflect infrared light IR, and based on the pixel signal obtained from this pixel, only visible light VL that is hardly affected by infrared light IR. Monochrome image can be obtained. Unlike the mechanism described in Japanese Patent Application Laid-Open No. 2002-142228, when obtaining a monochrome image of visible light VL that is hardly affected by infrared light IR, there is no need to perform arithmetic processing with components of infrared light IR. It is.

  Further, a color filter 14 having a predetermined wavelength transmission characteristic in the visible light VL region is provided as an example of an optical member for separating the wavelength region component into a predetermined wavelength region component on the photodiode on which the dielectric laminated film 1 is formed. By providing, an image of only a specific wavelength region in the visible light VL region that is hardly affected by the infrared light IR can be obtained.

  In addition, the color filters 14x having different wavelength transmission characteristics in the visible light VL region are integrally aligned with the photodiodes corresponding to each wavelength (color-specific) on the plurality of photodiodes constituting the unit pixel matrix 12. By arranging regularly, the visible light VL region can be separated by wavelength (by color), and by performing synthesis processing based on each pixel signal obtained from these pixels by color, A color image (visible light color image) of only visible light VL that is hardly affected by infrared light IR is obtained. Unlike the mechanism described in Japanese Patent Application Laid-Open No. 2002-142228, when obtaining a color image of visible light VL that is hardly affected by infrared light IR, there is no need to perform arithmetic processing with components of infrared light IR. It is.

  Further, in the same image pickup device (spectral image sensor 11), for example, by providing pixels in the unit pixel matrix 12 that do not partially form the dielectric multilayer film 1, by performing matrix calculation on the output of each pixel, It is always possible to independently obtain a monochrome image or color image of visible light VL and an image of infrared light IR. Further, a part of the dielectric multilayer film 1 integrally formed on the photodiode is not partially formed so that the dielectric multilayer film 1 is partially formed. Unlike the case where a separate optical member having no dielectric laminated film 1 is provided on the image pickup device, the problem of alignment does not occur.

  For example, imaging with only visible light VL (monochrome imaging or color imaging) that is almost completely unaffected by infrared light IR and imaging that mixes infrared light IR and visible light VL are performed simultaneously. Can do. In addition, the effect of visible light VL is achieved by combining (specifically, differential processing) a component that includes only visible light VL (monochrome image component or color image component) and a component that mixes infrared light IR and visible light VL. It is also possible to perform imaging using only infrared light IR that does not receive substantially any of the above.

  In the above, “substantially unaffected” means that the human visual sense is ultimately taken into account. Generally, if a clear difference cannot be recognized by human visual sense, It may be “received”. In other words, it is only necessary to obtain an infrared image (an example of physical information) that can ignore the influence of the pass wavelength region (visible light VL) on the infrared light IR side, and a reflected wavelength region component (infrared) on the visible light VL side. It is only necessary to obtain a normal image (an example of physical information) that can ignore the influence of (light IR).

  The color filter 14 includes a blue component B (for example, a transmittance of about 1 at a wavelength λ = 400 to 500 nm and a transmission rate of about 1 for other wavelengths) that is the three primary colors of visible light VL (wavelength λ = 380 to 780 nm), and a green component G. (For example, the transmittance is approximately 1 at a wavelength λ = 500 to 600 nm, and approximately zero at others), and the primary color filter centering on a red component R (for example, the transmittance is approximately 1 at a wavelength λ = 600 to 700 nm and approximately zero at others). It may be.

  Alternatively, yellow Ye (for example, transmittance is approximately zero at wavelength λ = 400 to 500 nm, approximately 1 for others), magenta Mg (for example, transmittance is approximately zero at wavelength λ = 500 to 600 nm, approximately 1 for others), cyan Cy It may be a complementary color filter having substantially zero transmittance for the three primary color components of visible light, such as (for example, the wavelength λ = 600 to 700 nm and the transmittance is substantially zero, otherwise approximately 1).

  Since the complementary color filter is more sensitive than the primary color filter, the sensitivity of the imaging apparatus can be increased by using a complementary color filter in which the transmitted light in the visible region is the complementary color of each of the three primary colors. it can. On the other hand, the use of a primary color filter has an advantage that the color signal of the primary color can be acquired without performing the difference processing, and the signal processing is simplified.

  Note that the transmittance of “approximately 1” means an ideal state, and the transmittance in the wavelength region is much larger than the transmittance in other wavelength regions. That's fine. Some of them may have “transmittance other than“ 1. ”Also, the transmittance is“ nearly zero ”, which is also an ideal state, and the transmittance in that wavelength region. May be much smaller than the transmittance in other wavelength regions, and some may have “non-zero” transmittance.

  In addition, both the primary color system and the complementary color system need only pass the wavelength region component of a predetermined color (primary color or complementary color) in the visible light VL region, which is a transmission wavelength region component, and are reflected wavelength region components. It does not matter whether the infrared light IR region is transmitted, that is, the transmittance for the infrared light IR. This is because the infrared light IR component is cut by the dielectric laminated film 1.

  For example, as shown in FIG. 3, the dielectric multilayer film 1 is not formed only on one pixel 12IR in a unit pixel matrix 12 composed of four pixels (cells), and other red (R), green ( While forming the dielectric laminated film 1 on the pixels 12R, 12G, and 12B for the three colors G) and blue (B), the corresponding red (R), green (G), and blue (B) 3 Primary color filters 14R, 14G, and 14B are provided.

  Further, in order to increase sensitivity, as shown in FIG. 3, in the pixel 12IR in which the dielectric laminated film 1 is not formed, the color filter so that not only the infrared light IR but also the visible light VL simultaneously contributes to the signal. Do not put 14C. By doing so, the infrared light pixel 12IR can substantially function as a pixel that serves not only for the infrared light IR but also for the infrared light IR and the visible light VL.

  In particular, by dividing the unit pixel matrix 12 composed of four pixels into the pixels 12R, 12G, 12B, and 12IR in this way, the entire configuration of the image sensor (spectral image sensor 11) can be arranged without any gap, so that the design can be improved. It becomes easy.

  In this way, by combining one image based on each color component of red (R), green (G), and blue (B) obtained from the three pixels 12R, 12G, and 12B, infrared light can be synthesized. A color image of visible light VL that is almost unaffected by IR (so-called normal color image) is obtained, and at the same time, infrared light based on a component that mixes infrared light IR and visible light VL obtained from the pixel 12IR. It is possible to take images related to IR.

  Here, “image related to infrared light IR” means an image of only infrared light IR that is not substantially affected by visible light VL, or an image in which infrared light IR and visible light VL are mixed. . In order to obtain an image of only the infrared light IR that is hardly affected by the visible light VL with the configuration shown in FIG. 3, for example, a component in which the infrared light IR obtained from the pixel 12IR and the visible light VL are mixed, It is preferable to take a difference from each color component of red (R), green (G), and blue (B) obtained from the three pixels 12R, 12G, and 12B. Even without providing a green filter 14G or a black filter 14BK, which will be described later, blue, red, and green obtained from the output of the pixel 12IR that receives visible light VL and infrared light IR by the three pixels 12R, 12G, and 12B. This is because the intensity of the infrared light IR can be obtained by reducing the intensity of.

  In addition, when considering applications such as optical communication applications and applications that detect the position by tracking infrared emission points, such as applications that simultaneously capture infrared IR images that are not substantially affected by visible light VL, On the pixel 12IR, a color filter 14C that transmits at least the infrared light IR that is the reflected wavelength region component and the predetermined wavelength component of the visible light VL that is the transmitted wavelength region component may be inserted.

  For example, by providing a green filter 14G that transmits infrared light IR and green light G as the color filter 14C, a mixed component of infrared light IR and green visible light LG can be obtained from the pixel 12IR. By taking the difference from the green component of only the visible light VL obtained from the pixel 12G, an image of only the infrared light IR that is hardly affected by the visible light VL (here, the green light G) is obtained. Although it is necessary to provide the green filter 14G, the process becomes simpler than the case of reducing the blue, red, and green intensities obtained by the three pixels 12R, 12G, and 12B without providing the green filter 14G.

  Alternatively, when the black filter 14BK that passes the infrared light IR and absorbs only the visible light VL is provided as the color filter 14C, the visible light VL is absorbed by the black filter 14BK, so that the infrared light is transmitted from the pixel 12IR. A component of only the light IR is obtained, and an image of only the infrared light IR that is hardly affected by the visible light VL can be obtained without performing the difference processing.

  It should be noted that R, G, and B color filters that are generally used at present are highly transmissive with respect to each of R, G, and B in the visible light band, for example, other colors (for example, G and B for R). ) Is low, but the transmittance outside the visible light band is not specified, and is usually higher than the transmittance of other colors (for example, G or B for R). It has sensitivity in the region and has light transmission in the infrared region. However, in this embodiment, even such a characteristic having a high transmittance outside the visible light band is not affected.

<< Design method of dielectric laminated film; Infrared light cut example >>
<Design method of thickness dj>
4-6 is a figure explaining the basic concept of the method of designing the dielectric laminated film 1. FIG. Here, a design example will be described in which the dielectric laminated film 1 is composed of basic first and second layer materials and selectively reflects infrared light IR.

As shown in the structural diagram of FIG. 4, the dielectric laminated film 1 used in the present embodiment has thick silicon oxide SiO ₂ on both sides (hereinafter, the light incident side is referred to as the 0th layer and the opposite side is referred to as the kth layer). A plurality of dielectric layers 1_j made of first and second layer materials are stacked between each other (hereinafter referred to as SiO2). In the illustrated example, a general material is used for both the first and second layer materials forming the dielectric layer 1_j, and silicon nitride Si ₃ N ₄ (hereinafter referred to as SiN) is used as the first layer material. These are alternately laminated by using two kinds of silicon oxide SiO2 as the second layer material. In addition, the structure of the dielectric laminated film 1 assumes that there are sufficiently thick silicon oxide SiO2 layers above and below (d0 = dk = ∞).

  Such a dielectric laminated film 1 can effectively increase the reflectance by satisfying the condition of the following formula (1).

  Here, dj (j is the layer number; hereinafter the same) is the thickness of each dielectric layer 1_j constituting the dielectric multilayer film 1, nj is the refractive index of each dielectric layer 1_j, and λ0 is the reflection The center wavelength in the wavelength region (hereinafter referred to as the reflection center wavelength).

  The number of layers of each dielectric layer 1_j constituting the dielectric laminated film 1 is counted, for example, in order from the first layer to the k-th layer side without counting the thick silicon oxide SiO2 on both sides as the number of layers. , SiN layer / SiO 2 layer / SiN layer 3 layers, SiN layer / SiO 2 layer / SiN layer / SiO 2 layer / SiN layer 5 layers. FIG. 4 shows a seven-layer structure.

  Further, the refractive index nα = 2.03 of the silicon nitride SiN forming the odd-numbered layer, the zeroth-numbered, even-numbered and k-th layers, with the reflection center wavelength λ0 = 900 nm of the infrared light IR being the reflection wavelength region. The refractive index nβ = 1.46 of the silicon oxide SiO2 forming the refractive index difference Δn is 0.57.

  Further, according to the above formula (1), the silicon nitride SiN thickness dα (= d1, d3,..., J = odd) is 111 nm, and the silicon oxide SiO2 layer thickness dβ (= d2, d4,..., J = even). Is 154 nm.

  FIG. 5 shows the result (reflection spectrum diagram) of the reflectance R calculated by the effective Fresnel coefficient method for the structure of FIG. 4 using a general material while changing the number of layers. You can see the number dependent properties.

  From the results of FIG. 5, it can be seen that as the number of layers increases, the reflectance R increases with the reflection center wavelength λ0 = 900 nm of the infrared light IR as the center. Furthermore, it can be seen that the infrared light IR and the visible light VL are substantially separated by selecting the wavelength 900 nm as the reflection center wavelength λ0 in this way. Here, it can be seen that the reflectivity R is 0.5 or more by using 5 layers or more, and particularly the reflectivity exceeds 0.7 by using 7 layers or more.

  FIG. 6 is a diagram illustrating the variation dependency (relationship with variation) of the thickness of the dielectric layer 1_j. Here, the result (reflection spectrum diagram) calculated by changing the thickness dj of each dielectric layer 1_j by ± 10% is shown by taking the case of seven layers as an example.

  Conditional expression (1) is an ideal calculated value by the Fresnel coefficient method, but in reality, the condition of expression (1) is gentle and wide. For example, it has been found by calculation using the Fresnel coefficient method that the reflectivity can be effectively increased even if there is an error in the thickness dj of ± 10%.

  For example, as shown in FIG. 6, it has been found that the reflectance R can be effectively increased even if the thickness dj varies. For example, a sufficient reflectance R of 0.5 or more is obtained at the reflection center wavelength λ0 = 900 nm of the infrared light IR, and the entire infrared light IR (mainly longer wavelength side than 780 nm) is obtained. However, it turns out that reflection is strong. Therefore, in practice, if the thickness dj of the dielectric layer 1_j is in the range of the following formula (2), taking into account variations, a sufficient effect can be obtained in effectively increasing the reflectance. Become.

<Design method of reflection center wavelength λ0>
7 to 9 are diagrams for explaining conditions of the reflection center wavelength λ0. The numerical condition of the thickness dj depends on the bandwidth ΔλIR of the infrared reflection region of the spectrum. As shown in FIG. 7A showing the concept of the reflection spectrum, when the bandwidth ΔλIR of the infrared reflection region is wide, reflection with visible light VL is remarkable unless the center wavelength λ0 is provided on the long wavelength side. Become. On the contrary, as shown in FIG. 7B showing the concept of the reflection spectrum, when the bandwidth ΔλIR of the infrared reflection region is narrow, it is close to the visible light VL unless the center wavelength λ0 is provided on the short wavelength side. Reflection in the infrared region does not occur.

  By the way, if the infrared light IR in the range of 0.78 μm ≦ λ ≦ 0.95 μm is reflected in the infrared region from the graph of the absorption spectrum of silicon Si shown in FIG. As you can see it will be enough. This is because light having a wavelength longer than the wavelength of 0.95 μm is hardly absorbed inside the silicon Si and is not photoelectrically converted. Therefore, the reflection center wavelength λ0 may be selected so that infrared light IR having a wavelength in the range of 0.78 μm ≦ λ ≦ 0.95 μm can be reflected.

  Further, even in the visible light VL, it may be considered that the light in the range of 640 to 780 nm in the red (R) region does not particularly affect the performance of the image sensor even if it is reflected or not because of low visibility. . Therefore, there is no problem even if reflection occurs in the wavelength region of 640 to 780 nm.

  Further, the bandwidth ΔλIR of the infrared reflection region becomes wider when the refractive index difference Δn of the dielectric laminated film 1 is large, and conversely becomes narrower when the refractive index difference Δn is small. Therefore, the bandwidth λIR of the infrared reflection region is narrow in the case of the SiN / SiO 2 multilayer film and wide in the case of the Si / SiO 2 multilayer film.

  From these facts, in the case of a SiN / SiO 2 multilayer film (refractive index difference Δn = 0.57), 780 nm ≦ λ0 ≦ 950 nm is calculated from the reflection center wavelengths λ0 of 780 nm and 950 nm shown in the reflection spectrum diagram of FIG. If it is in the range, it can be seen that the above-mentioned conditions are substantially satisfied. Incidentally, FIG. 8 has a laminated structure as shown in FIG. 13 described later, and is calculated by changing only the film thickness dj of the dielectric layer 1_j so that λ0 = 780 nm and λ0 = 950 nm.

  Similarly, in the case of a Si / SiO 2 multilayer film (refractive index difference Δn = 2.64), as shown in the reflection spectrum diagram of FIG. 9, the above condition is substantially satisfied if it is in the range of 900 nm ≦ λ0 ≦ 1100 nm.

  From the above, in the combination of silicon nitride SiN or silicon Si and silicon oxide SiO2, the following formula (3-1) should be satisfied as the reflection center wavelength λ0. Preferably, the following formula (3-2) is satisfied. These mean that it is ideal that the vicinity of 900 nm be the reflection center wavelength λ0.

  Of course, the materials shown above are only examples, and the effects as described above are not necessarily limited to the combination of silicon oxide SiO2 and silicon nitride SiN layer, and the refractive index difference is 0.3 or more, more preferably It was estimated by calculation that a similar effect can be obtained by selecting a material having 0.5 or more.

For example, the composition of the SiN film may vary slightly depending on the manufacturing conditions. Further, as the dielectric layer 1_j constituting the dielectric laminated film 1, alumina Al ₂ O ₃ , zirconia ZrO ₂ (refractive index 2.05), titanium oxide TiO _{2 in} addition to silicon oxide SiO 2 and silicon nitride SiN. (Refractive index 2.3 to 2.55), oxides such as magnesium oxide MgO and zinc oxide ZnO (refractive index 2.1), polycarbonate PC (refractive index 1.58), and acrylic resin PMMA (refractive index 1.49). ) And other semiconductor materials such as silicon carbide SiC (refractive index 2.65) and germanium Ge (refractive index 4 to 5.5) can also be used.

  By using a polymer material, an optical filter having characteristics not found in conventional glass can be configured. That is, it can be made of plastic and is lightweight and excellent in durability (high temperature, high humidity, impact).

<< Demultiplexing Image Sensor Using Dielectric Multilayer Film; First Embodiment >>
10 to 14 are diagrams for explaining a first embodiment of a spectral image sensor 11 that uses the dielectric laminated film 1 and supports single wavelength demultiplexing. The first embodiment is configured using a basic design method of a demultiplexing image sensor using a dielectric laminated film. Here, the spectral image sensor 11 is designed to receive the visible light VL component by cutting the infrared light IR by using the dielectric laminated film 1 that selectively reflects the infrared light IR. An example is given.

  4 to 6 is a semiconductor element layer in which the refractive index of the sensing element such as a silicon (Si) photodetector formed on the dielectric laminated film 1 is larger than each dielectric layer 1_j forming the dielectric laminated film 1 In manufacturing the above, the distance from the semiconductor element layer to the dielectric laminated film 1, that is, the thickness dk of the silicon oxide SiO2 layer forming the kth dielectric layer 1_k is important.

  As shown in the structural diagram of FIG. 10, this is due to an interference effect with the reflected light L4 from the surface of the silicon substrate 1_ω, which is the surface of a semiconductor element layer (photodetector, etc.) made of silicon Si (refractive index 4.1), for example. This means that the spectrum of the total reflected light LRtotal changes.

  FIG. 11 is a reflection spectrum diagram for explaining the dependence of the total reflected light LRtotal on the variation of the thickness dk of the silicon oxide SiO2 layer forming the dielectric layer 1_k. Here, the calculation result of the dielectric multilayer film 1 having the seven-layer structure shown in FIG. 4 while changing the thickness dk of the dielectric layer 1_k is shown. In each figure in FIG. 11, the horizontal axis is the wavelength λ (μm), and the vertical axis is the reflectance R.

  As can be seen from each diagram in FIG. 11, when the thickness is dk = 0.154 μm, that is, when the reflection center wavelength λ0 of the infrared light IR is a value satisfying the conditional expression (1), the reflection spectrum is almost the same. It can be seen that infrared light IR (wavelength λ ≧ 780 nm) is strongly reflected without being affected. On the other hand, it can be seen that another vibration occurs in the spectrum of thickness dk = 0.3 to 50 μm, compared to the reflection spectrum of thickness dk = ∞. As a result, it can be seen that there is a wavelength region in which the reflection in the infrared is dip-shaped.

  However, when the thickness dk = 2.5 μm or more, the half width of the infrared dip becomes 30 nm or less, and particularly when the thickness dk = 5.0 μm or more, the half width becomes 20 nm or less. On the other hand, since the half width is sufficiently narrowed, the averaged reflectance is obtained. Furthermore, it can also be seen that the reflectance with visible light VL is high with respect to a spectrum having a thickness dk = 0.3 to 1.0 μm. From these facts, it can be said that the thickness dk = 0.154 μm, that is, the value satisfying the conditional expression (1) is optimal.

  FIG. 12 is a reflection spectrum diagram illustrating the variation dependency of the thickness dk of the silicon oxide SiO2 layer forming the dielectric layer 1_k, and is calculated by changing the value of the thickness dk, particularly in the vicinity of the thickness dk = 0.154 μm. The results are shown. In each figure in FIG. 12, the horizontal axis is the wavelength λ (μm), and the vertical axis is the reflectance R.

  As can be seen from this result, reflection with visible light VL can be suppressed if the thickness dk = 0.154 to 0.16 μm with the thickness dk = 0.154 μm satisfying the conditional expression (1) as the center. I understand.

  From the above, the optimum structure of the spectroscopic image sensor 11 is, as shown in the structural diagram of FIG. 13, substantially the dielectric layered film 1A having an eight-layer structure including the kth dielectric layer 1_k. The calculation result of the reflection spectrum is as shown in the reflection spectrum diagram of FIG. In other words, the dielectric laminated film 1A has a structure in which a layer made of silicon oxide SiO2 that is the second layer material is provided for four periods on the silicon substrate 1_ω.

<< Demultiplexing Image Sensor Using Dielectric Multilayer Film; Second Embodiment >>
FIGS. 15 to 18 are diagrams illustrating a second embodiment of the spectral image sensor 11 that supports single wavelength demultiplexing using the dielectric laminated film 1. The second embodiment is configured by applying a modification (No. 1) of the design method of the first embodiment, and is based on the method described in FIGS. 10 to 14 in the visible light region. It is modified so as to reduce reflection.

  In the first modification, the refractive index nk of the kth dielectric layer 1_k and the refractive index nω of the silicon substrate 1_ω (= 4) are provided between the kth dielectric layer 1_k and the silicon substrate 1_ω. .1) is characterized in that a third layer material having an intermediate refractive index is added.

  Corresponding to this deformation, in the constant design of the first to seventh layers of the dielectric laminated film 1, the reflection center wavelength λ0 of the infrared light IR is changed to 852 nm on the lower side instead of 900 nm. The thickness dα (= d1, d3,..., J = odd) of silicon nitride SiN is 105 nm, and the thickness dβ (= d2, d4,..., J = even) of the silicon oxide SiO2 layer is 146 nm. This is because the reflectance of visible light is reduced by newly inserting a thin SiN layer (30 nm), and at the same time, the reflectance near the boundary between visible light and infrared light is reduced to 780 nm. This is to compensate for this decrease by shifting to, that is, to efficiently cut infrared light near the boundary. Of course, the reflection center wavelength λ0 of the infrared light IR may be kept at 900 nm.

  Specifically, in the structure of the first modified example shown in FIG. 15, a third silicon nitride SiN layer 1_γ having a relatively thin thickness dγ is provided between the silicon oxide SiO2 of the kth layer and the silicon substrate 1_ω. It has a laminated structure as a layer material. Here, the thickness dγ = 0.030 μm. The calculation result of the reflection spectrum is as shown in FIG.

  The third layer material added in the first modification is the same as the silicon nitride SiN that is the first layer material, but any member having a refractive index larger than that of the silicon substrate 1_ω may be used. Other members may be used.

  The spectral image sensor 11 having the dielectric multilayer film 1 of the modification of the first example is substantially composed of a seven-layer dielectric multilayer film 1, a k-th dielectric layer 1_k (silicon oxide SiO2 layer), and Including the two layers of the silicon nitride SiN layer 1_γ, the dielectric multilayer film 1B having a nine-layer structure as a whole is provided.

  In the structure of the second modification example shown in FIG. 17, the third layer material added in the first modification example and the silicon substrate 1_ω have a refractive index smaller than that of the third layer material. The fourth layer material is laminated. Specifically, a silicon oxide SiO2 layer 1_δ is used as a fourth layer material between a silicon nitride SiN layer 1_γ having a thickness dγ and a silicon substrate 1_ω, and the thickness dδ = It is 0.010 μm. The calculation result of the reflection spectrum is as shown in FIG.

  The fourth layer material added in the second modification is the same as the second layer material, silicon oxide SiO2, but is smaller than the third layer material (silicon nitride SiN in this example). Any member having a refractive index may be used, and other members may be used.

  The spectral image sensor 11 having the dielectric multilayer film 1 according to the modification of the second example substantially includes a seven-layer dielectric multilayer film 1 and a k-th dielectric layer 1_k (silicon oxide SiO2 layer). A dielectric laminated film 1C having a 10-layer structure as a whole is provided, including three layers of the silicon nitride SiN layer 1_γ and the silicon oxide SiO2 layer 1_δ. In other words, the dielectric multilayer film 1C has a structure in which five layers of silicon oxide SiO2 that is the second layer material are provided on the silicon substrate 1_ω.

  In the first example and the second example, there is a difference in the presence or absence of the silicon oxide SiO 2 layer 1_δ, but as can be seen from FIGS. 16 and 18, the reflectance with visible light VL is sufficiently lowered. Moreover, the effect which can reduce a dark current is acquired by adding silicon oxide SiO2 layer 1_delta like a 2nd example. It should be noted that the relationship between the thicknesses of both layers is preferably dδ << dγ so that the effect of adding the silicon nitride SiN layer 1_γ is not reduced by adding the silicon oxide SiO 2 layer 1_δ.

  In this way, an intermediate refractive index nγ (= nSiN) between the refractive index nk (= nSiO2) and the refractive index nω (= nSi) between the silicon oxide SiO2 of the kth layer and the silicon substrate 1_ω. By adding a thin silicon nitride SiN layer 1_γ as an intermediate layer as an intermediate member, reflection by visible light VL can be suppressed. This is understood when considered as follows.

  First, when the wavelength of visible light VL is λVL, the intermediate refractive index of the layer is Nm, and the thickness of the layer is dm, the conditional expression (4) is obtained from the theory of the low reflection film similar to the conditional expression (1). When the conditional expression (4) is satisfied, a sufficient effect is exhibited.

  Here, since the wavelength λVL indicates the entire visible light VL, the wavelength range is given by Expression (5).

  In each modification of the first example and the second example, the silicon nitride SiN layer 1_γ is added as an intermediate layer, and the refractive index is nγ (= nSiN = Nm). Can be transformed as shown in the equation (6) showing the thickness dm of the intermediate layer, that is, the thickness dγ of the silicon nitride SiN layer 1 — γ.

  Although it is ideal that the thickness dm of the intermediate layer satisfies the expression (6), it may be slightly deviated from that, and according to an experiment, there is a margin especially for the thinner one. As can be seen from FIG. 18, as an example, it was confirmed that there was an effect even when dm = 30 nm. Of course, since an intermediate layer (third layer material) is added between the silicon oxide SiO2 of the kth layer and the silicon substrate 1_ω, the thinner one is larger than 0 nm (not including 0 nm). Needless to say. That is, when an intermediate layer is added between the kth silicon oxide SiO2 and the silicon substrate 1_ω, the thicknesses dm and dγ of the intermediate layer only need to satisfy Expression (7).

<< Demultiplexing Image Sensor Using Dielectric Multilayer Film; Third Embodiment >>
FIGS. 19 to 24 are diagrams illustrating a third embodiment of the spectral filter 10 and the spectral image sensor 11 compatible with single wavelength demultiplexing using the dielectric laminated film 1. Here, FIGS. 19 to 22 are diagrams for explaining the dielectric multilayer film 1 constituting the spectral filter 10 of the third embodiment, and FIGS. 23 to 24 are diagrams of the dielectric multilayer film 1 of the third embodiment. It is a figure explaining the spectral image sensor 11 corresponding to a single wavelength demultiplexing using the.

  The third embodiment is configured by applying a modification (No. 2) of the design method of the first embodiment, in that the number of dielectric layers 1_j forming the dielectric multilayer film 1 is reduced. Has characteristics. In reducing the number of layers, a member (layer material) having a refractive index larger than that of the basic first and second layer materials constituting the dielectric multilayer film 1 is added in the dielectric multilayer film 1. Characterized by points.

  In adding this member having a large refractive index, the larger one of the basic two layer materials may be replaced with the fifth layer material having a larger refractive index. The dielectric laminated film 1 of this modified example (No. 2) is substantially a dielectric laminated film 1D having a structure including the fifth layer material 1_η. In other words, the dielectric multilayer film 1D has a structure in which a layer made of silicon oxide SiO2 that is the second layer material is provided for N periods on the silicon substrate 1_ω.

  Regarding the thickness dη of the fifth layer material, when the refractive index is nη, the conditional expression (8) is obtained from the theory of the low reflection film similar to the conditional expression (1), and the conditional expression (8) When satisfied, it will show a sufficient effect.

  For example, in the example shown in the structural diagram of FIG. 19, a silicon nitride layer having a refractive index = 4.1 higher than silicon nitride SiN and silicon oxide SiO 2 and having a thickness dη = 61 nm is used as the fifth layer material. Instead of SiN, only one layer is added (in place of the intermediate third dielectric layer 1_3). The calculation result of the reflection spectrum is as shown in the reflection spectrum diagram shown in FIG.

  Here, FIG. 22 shows the calculation result when the total number of layers is changed when the silicon nitride SiN forming the middle layer of the dielectric multilayer film 1 having an odd total number of layers is changed to silicon Si. ing.

  In FIG. 19, in the constant design of each layer of the dielectric laminated film 1, the reflection center wavelength λ0 of the infrared light IR is changed to 1000 nm instead of 900 nm, and the thickness dα (= d1, d3) of the silicon nitride SiN is changed. ,...; J = odd) is 123 nm, and the thickness dβ (= d2, d4,...; J = even) of the silicon oxide SiO 2 layer is 171 nm.

  Further, in the example shown in the structural diagram of FIG. 21, in the constant design of each layer of the dielectric laminated film 1, the reflection center wavelength λ0 of the infrared light IR is set to 900 nm, and the thickness dα of silicon nitride SiN (= d1, .., j = odd) is 111 nm, the thickness dβ (= d2, d4,...; j = even) of the silicon oxide SiO 2 layer is 154 nm, and a silicon Si layer having a thickness dη = 55 nm is used as the fifth layer material. Instead of silicon nitride SiN, only one layer is added. The calculation result of the reflection spectrum is as shown in the reflection spectrum diagram shown in FIG.

  The fifth layer material added in the second modification is the same as the silicon substrate 1_ω that forms the semiconductor element layer, but is larger than the dielectric layer 1_j other than the fifth layer material that forms the dielectric multilayer film 1. Any member having a refractive index may be used, and other members may be used.

  As can be seen from the calculation results of the reflection spectra shown in FIGS. 20 and 22, a layer material having a refractive index larger than that of the dielectric layer 1_j other than the fifth layer material forming the dielectric multilayer film 1 is added. Thus, sufficient reflectance can be obtained with a small number of layers. In particular, in the case of five layers, it can be seen that the bandwidth in the visible light VL is sufficiently wide and is optimal for separating the visible light VL and the infrared light IR.

  As described with reference to FIGS. 10 to 12 in the first embodiment, when the dielectric multilayer film 1D is formed on the semiconductor element layer (silicon substrate 1_ω), the dielectric multilayer film 1D is formed from the semiconductor element layer. Distance, that is, the thickness dk of the silicon oxide SiO2 layer forming the kth dielectric layer 1_k is important.

  As shown in the structural diagram of FIG. 23, this is due to an interference effect with the reflected light LR from the surface of the silicon substrate 1_ω, which is the surface of a semiconductor element layer (such as a photodetector) made of silicon Si (refractive index 4.1), for example. This means that the spectrum of the total reflected light LRtotal changes.

  FIG. 24 is a reflection spectrum diagram for explaining the dependence of the total reflected light LRtotal on the thickness dk of the silicon oxide SiO2 layer forming the dielectric layer 1_k in the five-layered dielectric laminated film 1D shown in FIG. It is. In each figure in FIG. 24, the horizontal axis is the wavelength λ (μm), and the vertical axis is the reflectance R.

  As can be seen from each figure in FIG. 24, when the thickness dk = 0.15 μm, that is, when the reflection center wavelength λ0 of the infrared light IR satisfies the value dk = 0.154 μm that satisfies the conditional expression (1). Further, it can be seen that the reflection spectrum is hardly affected, and the infrared light IR (wavelength λ ≧ 780 nm) is strongly reflected. On the other hand, it can be seen that another vibration occurs in the spectrum of thickness dk = 0.3 to 50 μm, compared to the reflection spectrum of thickness dk = ∞. As a result, it can be seen that there is a wavelength region in which the reflection in the infrared is dip-shaped. This is the same as described with reference to FIGS. 11 and 12 in the first embodiment.

<< Demultiplexing Image Sensor Using Dielectric Multilayer Film; Fourth Embodiment >>
FIG. 25 and FIG. 26 are diagrams for explaining a fourth embodiment of the spectral image sensor 11 compatible with single wavelength demultiplexing using the dielectric laminated film 1.

  The fourth embodiment is a modification of the third embodiment in which the number of dielectric layers 1_j forming the dielectric multilayer film 1 is reduced, and is characterized in that the number of layers is further reduced. Have. Specifically, in reducing the number of layers, a plurality of members (layers) having a refractive index larger than the basic first and second layer materials constituting the dielectric multilayer film 1 in the dielectric multilayer film 1. It is characterized by the addition of material. In adding a plurality of members having a large refractive index, the larger one of the basic two layer materials may be replaced with a fifth layer material having a larger refractive index. . The dielectric multilayer film 1 of this modification is substantially a dielectric multilayer film 1E having a structure including a plurality of fifth layer materials 1_η.

  The plurality of fifth layer materials 1_η may be members having a refractive index larger than that of the dielectric layer 1_j other than the fifth layer material forming the base dielectric multilayer film 1 as in the third embodiment. That's fine. Further, all of the plurality of members may be the same member or different members.

  Regarding the thickness dηp of the plurality of fifth layer materials, when the refractive index is nηp, the conditional expression (9) is obtained from the theory of the low reflection film similar to the conditional expression (1), and the conditional expression (9 ) Will be fully effective.

  For example, in the example shown in the structural diagram of FIG. 25, a dielectric laminated film 1E having a three-layer structure is formed, and a thickness dη = 61 nm having a refractive index = 4.1 higher than that of silicon nitride SiN and silicon oxide SiO2. Two layers of silicon Si layers are provided as a fifth layer material in place of silicon nitride SiN. The calculation result of the reflection spectrum is as shown in the reflection spectrum diagram shown in FIG. In other words, the dielectric laminated film 1E has a structure in which a layer made of silicon oxide SiO2 that is the second layer material is provided for two periods on the silicon substrate 1_ω.

  In the constant design of each layer of the dielectric laminated film 1, the reflection center wavelength λ0 of the infrared light IR is set to 1000 nm, and the thickness dη (= d1, d3) of the silicon Si layer as the fifth layer material is 61 nm. The thicknesses dβ (= d2) and dk of the silicon oxide SiO 2 layer are 171 nm.

<< Demultiplexing Image Sensor Using Dielectric Multilayer Film; Fifth Embodiment >>
FIGS. 27 and 28 are diagrams for explaining a fifth embodiment of the spectral image sensor 11 compatible with single wavelength demultiplexing using the dielectric laminated film 1.

  In the fifth embodiment, the spectral image sensor 11 of the third or fourth embodiment is modified so as to reduce reflection in the visible light region, as in the second embodiment.

  In the example shown in the structural diagram of FIG. 27, with respect to the dielectric multilayer film 1E of the fourth embodiment shown in FIG. 25, the k-th layer is provided between the k-th dielectric layer 1_k and the silicon substrate 1_ω. A third layer material having an intermediate refractive index is added to the refractive index nk of the dielectric layer 1_k of the eye and the refractive index nω (= 4.1) of the silicon substrate 1_ω. Unlike the second embodiment, the reflection center wavelength λ0 of the infrared light IR is kept at 1000 nm. Of course, as in the second embodiment, the reflection center wavelength λ0 of the infrared light IR may be changed to a lower side instead of 1000 nm.

  Specifically, in the structure shown in FIG. 27, as in the first modification of the second embodiment, silicon having a relatively thin thickness dγ between the silicon oxide SiO2 in the k-th layer and the silicon substrate 1_ω. The nitride SiN layer 1_γ is stacked as a third layer material. Here, the thickness dγ = 0.030 μm. The calculation result of the reflection spectrum is as shown in the reflection spectrum diagram shown in FIG. The spectral image sensor 11 having the dielectric multilayer film 1 of this modification is substantially composed of a three-layer dielectric multilayer film 1, a kth dielectric layer 1_k (silicon oxide SiO2 layer), and silicon nitride. As a whole, including the two layers of the SiN layer 1_γ, the dielectric laminated film 1F having a five-layer structure is provided.

  The third layer material added in this modification is the same as the silicon nitride SiN that is the first layer material, but any member having a higher refractive index than the silicon substrate 1_ω may be used. It may be a member.

  Although not shown, like the second modification example in the second embodiment, a refractive index smaller than that of the third layer material is provided between the third layer material added in this modification example and the silicon substrate 1_ω. It is also possible to have a structure in which a fourth layer material having a thickness is laminated.

  In any case, as in the second embodiment, the reflectance in the visible light VL region can be reduced, and in particular, the reflectance in the blue B component (wavelength near 420 nm) and the green G component (wavelength near 520 nm) is slightly higher. Although increasing, the reflectance in the red R component (wavelength near 600 nm) can be sufficiently lowered, and is suitable for separation from infrared light IR.

<Imaging device with spectral image sensor; CCD compatible>
29 and 30 are circuit diagrams when the spectral image sensor 11 described in the above embodiment is applied to an image pickup apparatus using an interline transfer type CCD solid-state image pickup device (IT_CCD image sensor). The imaging apparatus 100 is an example of a physical information acquisition apparatus according to the present invention.

  Here, FIG. 29 shows a structure in which the infrared light IR is detected while dividing the visible light VL band into R, G, and B color components as in FIG. The light B, the green light G, the red light R, and the infrared light IR are each independently detected, and the pixels (photoelectric conversion elements) 12B for each wavelength in one unit pixel matrix 12 substantially. , 12G, 12R, and the pixel 12IR that does not have the dielectric laminated film 1.

  For example, as shown in FIG. 29A, the CCD solid-state imaging device 101 is provided with a plurality of vertical transfer CCDs 122 arranged in the vertical transfer direction in addition to the unit pixel matrix 12. The charge transfer direction of the vertical transfer CCD 122, that is, the readout direction of the pixel signal is the vertical direction (X direction in the figure).

  Further, between the vertical transfer CCD 122 and each unit pixel matrix 12, a MOS transistor forming a readout gate 124 (124B, 124G, 124R, 124IR for each wavelength) is interposed, and the boundary of each unit cell (unit component). The part is provided with a channel stop (not shown).

  As can be seen from FIG. 29, one unit pixel matrix 12 has a structure in which the blue light B, the green light G, the red light B, and the infrared light IR are independently detected. In the pixel matrix 12, pixels 12B, 12G, 12R, and 12IR are formed for each wavelength (color). An imaging area is provided by a plurality of vertical transfer CCDs 122 that are provided for each vertical column of the sensor units 112 configured to include these unit pixel matrices 12 and vertically transfer the signal charges read from the sensor units by the read gate 124. 110 is configured.

  Here, as the arrangement of the color filters 14, for example, blue, green, red, IR, blue, green, red, IR,... In the vertical direction (X direction) of the vertical transfer CCD 122 on the light receiving surface side of the silicon substrate 1_ω. In the same row direction (Y direction) of the plurality of vertical transfer CCDs 122, the order is blue, green, red, IR, blue, green, red, IR,.

  The signal charges accumulated in the unit pixel matrix 12 (each pixel 12B, 12G, 12R, 12IR) of the sensor unit 112 are applied to the readout gate 124 by applying a drive pulse φROG corresponding to the readout pulse ROG to the same vertical column. To the vertical transfer CCD 122. The vertical transfer CCD 122 is driven to transfer by a drive pulse φVx based on a vertical transfer clock Vx such as 3 phase to 8 phase, for example, and the read signal charge is one scanning line (one line) in a part of the horizontal blanking period. Are transferred in the vertical direction one by one in order. This vertical transfer for each line is called a line shift.

  Further, the CCD solid-state imaging device 101 includes a horizontal transfer CCD 126 extending in a predetermined (for example, left and right) direction adjacent to each transfer destination side end of the plurality of vertical transfer CCDs 122, that is, the vertical transfer CCD 122 in the last row. (H register unit, horizontal transfer unit) are provided for one line. The horizontal transfer CCD 126 is driven by, for example, drive pulses φH 1 and φH 2 based on the two-phase horizontal transfer clocks H 1 and H 2, and the signal charge for one line transferred from the plurality of vertical transfer CCDs 122 is transferred to the horizontal blanking period. The data is sequentially transferred in the horizontal direction in the subsequent horizontal scanning period. For this reason, a plurality of (two) horizontal transfer electrodes corresponding to two-phase driving are provided.

  At the end of the transfer destination of the horizontal transfer CCD 126, for example, an output amplifier 128 having a charge-voltage conversion unit having a floating diffusion amplifier (FDA) configuration is provided. The output amplifier 128 is an example of a physical information acquisition unit. In the charge-voltage conversion unit, the signal charge horizontally transferred by the horizontal transfer CCD 126 is sequentially converted into a voltage signal, amplified to a predetermined level, and output. From this voltage signal, a pixel signal is derived as a CCD output (Vout) corresponding to the amount of incident light from the subject. The interline transfer type CCD solid-state imaging device 11 is configured as described above.

  The pixel signal derived from the output amplifier 128 as the CCD output (Vout) is input to the image signal processing unit 140 shown in FIG. The image signal processing unit 140 receives an image switching control signal from an image switching control unit 142 which is an example of a signal switching control unit. The CCD solid-state imaging device 101 is driven by a drive pulse from a drive control unit (an example of a drive unit) 146.

  The image switching control unit 142 outputs the output of the image signal processing unit 140 to a monochrome image or a color image of visible light VL that is hardly affected by infrared light IR, and infrared light that is hardly affected by visible light VL. Command to switch to either one of IR images, or both of them, or a mixed image of visible light VL and infrared light IR, that is, a pseudo-monochrome image or a pseudo-color image in which the brightness of infrared light IR is added To do. That is, simultaneous imaging output and switching imaging output of an image of visible light VL and an image related to infrared light IR are controlled.

  This command may be an external input for operating the imaging device, or the image switching control unit 142 may command switching by an automatic process based on visible light luminance without infrared light IR of the image signal processing unit 140.

  Here, the image signal processing unit 140, for example, a synchronization process that simultaneously synchronizes the imaging data R, G, B, and IR of each pixel, and a vertical stripe noise correction process that corrects a vertical stripe noise component caused by a smear phenomenon or a blooming phenomenon. , WB control processing for controlling white balance (WB) adjustment, gamma correction processing for adjusting the gradation degree, and dynamic range expansion processing for expanding the dynamic range using pixel information of two screens having different charge accumulation times Alternatively, YC signal generation processing for generating luminance data (Y) and color data (C) is performed. As a result, a visible light VL band image (so-called normal image) based on imaging data (R, G, B, and IR pixel data) of primary colors of red (R), green (G), and blue (B) is obtained. It is done.

  Further, the image signal processing unit 140 generates an image related to the infrared light IR using the pixel data of the infrared light IR. For example, in the pixel 12IR in which the dielectric laminated film 1 is not formed, when not including the color filter 14C so that not only the infrared light IR but also the visible light VL simultaneously contributes to the signal, the pixel data from the pixel 12IR By using, a highly sensitive image can be obtained. Alternatively, when the green filter 14G is inserted as the color filter 14C, a mixed image of the infrared light IR and the green visible light LG is obtained from the pixel 12IR, but the difference from the green component obtained from the pixel 12G is obtained. By taking it, an image of only infrared light IR can be obtained. Alternatively, when the black filter 14BK is provided as the color filter 14C, an image of only the infrared light IR can be obtained by using pixel data from the pixel IR.

  Each image generated in this manner is sent to a display unit (not shown) and presented to the operator as a visible image, or stored and stored in a storage device such as a hard disk device as it is, or to other functional units. Sent as processed data.

  FIG. 30 shows a structure for independently detecting visible light VL (blue light, green light, and red light) and infrared light IR. Although the detailed description is omitted, the basic configuration is the same as that shown in FIG. 29, and the visible light VL pixel 12W is formed in one unit pixel matrix 12 (photodiode group) substantially. However, the pixel 12IR does not have the dielectric laminated film 1. Basically, the arrangement of the color filter 14 is different, and the other points are the same as those in FIG.

  Here, the arrangement of the color filters 14 is, for example, visible light VL, infrared light IR, visible light VL, infrared light IR in the vertical direction (X direction) of the vertical transfer CCD 122 on the light receiving surface side of the silicon substrate 1_ω. In this order, visible light VL, infrared light IR, visible light VL, infrared light IR,... Are also arranged in the same row direction (Y direction) of the plurality of vertical transfer CCDs 122. .

<Image sensor using spectral image sensor; CMOS compatible>
31 and 32 are circuit diagrams when the spectral image sensor 11 described in the above embodiment is applied to an imaging apparatus using a CMOS solid-state imaging device (CMOS image sensor). The imaging apparatus 100 is an example of a physical information acquisition apparatus according to the present invention.

  Here, like FIG. 3, FIG. 31 shows a structure in which infrared light IR is detected while dividing the visible light VL band into R, G, B color components, and the blue light in the visible light VL is shown. The light B, the green light G, the red light R, and the infrared light IR are each independently detected, and the pixels (photoelectric conversion elements) 12B for each wavelength in one unit pixel matrix 12 substantially. , 12G, 12R, and the pixel 12IR that does not have the dielectric laminated film 1.

  FIG. 32 shows a structure in which visible light VL (blue light, green light, and red light) and infrared light IR are independently detected, and substantially one unit pixel matrix 12 (photodiode group). In this structure, a pixel 12W for visible light VL is formed, and a pixel 12IR that does not have the dielectric laminated film 1 is provided. Basically, only the arrangement of the color filters 14 is different (similar to FIG. 30), and the other points are the same as those of FIG.

  When the spectral image sensor is applied to the COMS, each cell (photoelectric conversion element) 12B, 12G, 12R, 12IR in the unit pixel matrix 12 has one cell amplifier. Therefore, in this case, the structure is as shown in FIG. The pixel signal is amplified by a cell amplifier and then output through a noise cancellation circuit or the like.

  For example, the CMOS solid-state imaging device 201 includes a pixel unit in which a plurality of pixels including a light receiving element (an example of a charge generation unit) that outputs a signal corresponding to the amount of incident light is arranged in rows and columns (that is, in a two-dimensional matrix). The signal output from each pixel is a voltage signal, and a CDS (Correlated Double Sampling) processing function unit, a digital conversion unit (ADC), and the like are provided in parallel in a column. It is a so-called typical column type.

  Specifically, as shown in FIG. 31, the CMOS solid-state imaging device 201 includes a pixel unit (imaging unit) 210 in which a plurality of pixels 12 are arranged in rows and columns, and a drive provided outside the pixel unit 210. A control unit 207, a column processing unit 226, and an output circuit 228 are provided.

  Note that an AGC (Auto Gain Control) circuit having a signal amplification function or the like may be provided in the same semiconductor region as the column processing unit 226, if necessary, before or after the column processing unit 226. When AGC is performed before the column processing unit 226, analog amplification is performed. When AGC is performed after the column processing unit 226, digital amplification is performed. If the n-bit digital data is simply amplified, the gradation may be lost. Therefore, it is preferable to perform digital conversion after amplification by analog.

  The drive control unit 207 has a control circuit function for sequentially reading signals from the pixel unit 210. For example, the drive control unit 207 includes a horizontal scanning circuit (column scanning circuit) 212 that controls column addresses and column scanning, a vertical scanning circuit (row scanning circuit) 214 that controls row addresses and row scanning, And a communication / timing control unit 220 having functions such as an inter-interface function and an internal clock generation function.

  The horizontal scanning circuit 212 has a function of a reading scanning unit that reads a count value from the column processing unit 226. Each element of these drive control units 207 is formed integrally with a pixel unit 210 in a semiconductor region such as single crystal silicon using a technique similar to a semiconductor integrated circuit manufacturing technique, and is an example of a solid-state imaging that is an example of a semiconductor system It is configured as an element (imaging device).

  In FIG. 31, for the sake of simplicity, some of the rows and columns are omitted, but in reality, tens to thousands of pixels 12 are arranged in each row and each column. The pixel 12 typically includes an intra-pixel amplifier (cell amplifier; pixel signal generation unit) 205 (color) having a unit pixel matrix 12 as a light receiving element (charge generation unit) and an amplification semiconductor element (for example, a transistor). Separately, 205B, 205G, 205R).

  Further, as can be seen from FIG. 31, one unit pixel matrix 12 has a structure for independently detecting blue light B, green light G, red light R, and infrared light IR, and substantially one unit. In the pixel matrix 12, pixels 12B, 12G, 12R, and 12IR are formed for each wavelength (color).

  Here, the arrangement of the color filters 14 is, for example, blue, green, red, IR, blue, green, red, IR,... In the X direction on the light receiving surface side of the silicon substrate 1_ω, and orthogonal to the X direction. Also in the Y direction, the order is blue, green, red, IR, blue, green, red, IR,.

  As the intra-pixel amplifier 205, for example, a floating diffusion amplifier configuration is used. As an example, with respect to the charge generation unit, a read selection transistor that is an example of a charge readout unit (transfer gate unit / read gate unit), a reset transistor that is an example of a reset gate unit, a vertical selection transistor, and a floating diffusion As a CMOS sensor having a source follower-amplifying transistor, which is an example of a detection element for detecting a change in potential, a sensor composed of four general-purpose transistors can be used.

  Alternatively, as described in Japanese Patent No. 2708455, an amplifying transistor connected to a drain line (DRN) and an in-pixel amplifier for amplifying a signal voltage corresponding to the signal charge generated by the charge generating unit It is also possible to use a transistor composed of three transistors, including a reset transistor for resetting 205 and a read selection transistor (transfer gate portion) scanned from a vertical shift register via a transfer wiring (TRF). it can.

  The pixels 12 are connected to the vertical scanning circuit 214 via a row control line 215 for row selection and to the column processing unit 226 via a vertical signal line 219, respectively. Here, the row control line 215 indicates the entire wiring that enters the pixel from the vertical scanning circuit 214. As an example, the row control line 215 is arranged in a direction parallel to the long scatterer 3.

  The horizontal scanning circuit 212 and the vertical scanning circuit 214 include, for example, a shift register and a decoder, and start an address selection operation (scanning) in response to a control signal given from the communication / timing control unit 220. Yes. Therefore, the row control line 215 includes various pulse signals (for example, a reset pulse RST, a transfer pulse TRF, a DRN control pulse DRN, etc.) for driving the pixels 12.

  Although not shown, the communication / timing control unit 220 is a master via a functional block of a timing generator TG (an example of a read address control device) that supplies a clock signal necessary for the operation of each unit and a pulse signal of a predetermined timing, and a terminal 220a. A communication interface functional block for receiving a clock CLK0, receiving data DATA for instructing an operation mode or the like via a terminal 220b, and outputting data including information of the CMOS solid-state imaging device 201 via a terminal 220c.

  For example, the horizontal address signal is output to the horizontal decoder and the vertical address signal is output to the vertical decoder, and each decoder receives it and selects the corresponding row or column, and the pixel 12 and the column processing unit 226 via the drive circuit. Drive.

  At this time, since the pixels 12 are arranged in a two-dimensional matrix, an analog pixel signal generated by the in-pixel amplifier (pixel signal generation unit) 205 and output in the column direction via the vertical signal line 219 is row-by-row. (Column parallel) to access and capture (vertical) scan reading, and then access the row direction, which is the arrangement direction of the vertical columns, and read out pixel signals (for example, digitized pixel data) to the output side (horizontal ) It is preferable to speed up reading of pixel signals and pixel data by performing scanning reading. Of course, not only scanning reading but also random access for reading out only necessary pixel 12 information by directly addressing the pixel 12 to be read out is possible.

  In the communication / timing control unit 220, a clock CLK1 having the same frequency as the master clock (master clock) CLK0 input via the terminal 220a, a clock obtained by dividing the clock CLK1, and a low-speed clock obtained by further dividing the clock are used as devices. For example, a horizontal scanning circuit 212, a vertical scanning circuit 214, a column processing unit 226, and the like.

  The vertical scanning circuit 214 selects a row of the pixel portion 210 and supplies a necessary pulse to the row. For example, a pulse is supplied to a vertical decoder that defines a readout row in the vertical direction (selects a row of the pixel unit 210) and a row control line 215 for the pixel 12 on the readout address (in the row direction) defined by the vertical decoder. And a vertical drive circuit for driving. Note that the vertical decoder selects a row for electronic shutter in addition to a row from which a signal is read.

  The horizontal scanning circuit 212 sequentially selects column circuits (not shown) in the column processing unit 226 in synchronization with the low-speed clock CLK2, and guides the signal to a horizontal signal line (horizontal output line) 218. For example, a horizontal decoder that defines a read column in the horizontal direction (selects individual column circuits in the column processing unit 226), and a read address defined by the horizontal decoder, the selection switch 227 causes the column processing unit 226 to A horizontal drive circuit for guiding each signal to a horizontal signal line 218. For example, if the horizontal signal line 218 corresponds to the number of bits n (n is a positive integer) handled by the column AD circuit, for example, 10 (= n) bits, 10 horizontal signal lines 218 are arranged corresponding to the number of bits.

  In the CMOS solid-state imaging device 201 having such a configuration, the pixel signal output from the pixel 12 is supplied to the column circuit of the column processing unit 226 via the vertical signal line 219 for each vertical column. Here, the signal charges accumulated in the unit pixel matrix 12 (the respective pixels 12B, 12G, 12R, and 12IR) are read out through the vertical signal lines 219 in the same vertical column.

  Each column circuit of the column processing unit 226 receives a pixel signal for one column and processes the signal. For example, each column circuit has an ADC (Analog Digital Converter) circuit that converts an analog signal into, for example, 10-bit digital data using, for example, a low-speed clock CLK2.

  In addition, by devising the circuit configuration, the signal level (noise level) immediately after pixel reset and the true signal (depending on the amount of received light) for the voltage mode pixel signal input via the vertical signal line 219 A process for obtaining a difference from the level Vsig can be performed. Thereby, it is possible to remove a noise signal component called fixed pattern noise (FPN) or reset noise.

  The analog pixel signal (or digital pixel data) processed by the column circuit is transmitted to the horizontal signal line 218 via the horizontal selection switch 217 driven by the horizontal selection signal from the horizontal scanning circuit 212, and further output. Input to the circuit 228. Note that 10 bits is an example, and other bit numbers such as less than 10 bits (for example, 8 bits) and more than 10 bits (for example, 14 bits) may be used.

  With such a configuration, pixel signals are sequentially output for each vertical column for each row from the pixel unit 210 in which the unit pixel matrix 12 (pixels 12B, 12G, 12R, and 12IR) as the charge generation unit is arranged in a matrix. Is done. Then, one image corresponding to the pixel unit 210 in which the light receiving elements are arranged in a matrix, that is, a frame image, is shown as a set of pixel signals of the entire pixel unit 210.

  The output circuit 228 corresponds to the output amplifier 128 in the CCD solid-state image sensor 101, and in the subsequent stage, as shown in FIG. 140 is provided. As in the case of the CCD solid-state imaging device 101, the image signal processing unit 140 receives an image switching control signal from the image switching control unit 142.

  As a result, the red (R), green (G), and blue (B) primary color imaging data (R, G, B, and IR pixel data) or the visible light VL band based on the visible light VL pixel data can be obtained. An image (so-called normal image) can be obtained, and an image related to the infrared light IR can be obtained by using the pixel data of the infrared light IR.

  Although illustration is omitted, the visible light VL band is divided into R, G, and B color components by removing the infrared light IR pixel 12IR while using FIG. 29 and FIG. 31 as basic configurations. It is also possible to adopt a structure that detects the above.

  As the arrangement of the color filters 14, for example, blue, green, red, green, blue, green, red, green, blue,... In the vertical direction (X direction) of the vertical transfer CCD 122 on the light receiving surface side of the silicon substrate 1_ω. Also, the same row direction (Y direction) of the plurality of vertical transfer CCDs 122 is arranged in the order of blue, green, red, green, blue, green, red, green, blue,. Alternatively, a so-called Bayer arrangement in which two G colors and one R color and B color are arranged in the unit pixel matrix 12 of 2 rows and 2 columns may be employed. Further, the color reproduction range may be extended by adding a fourth color (for example, emerald) to the three colors B, G, and R.

  In these cases, only the visible light VL region is imaged, but it is not necessary to place an infrared cut filter in front of the sensor as an example of a color reduction filter. Costs can be significantly reduced by eliminating the need for expensive infrared cut filters. Further, by eliminating the need for an infrared cut filter having a thickness or weight, the optical system can be made light and compact. Of course, an infrared cut filter insertion / extraction mechanism is not required, and the apparatus does not become large.

  Of course, this is advantageous in terms of cost, for example, because the existing infrared filter cut out of glass is replaced with a dielectric laminated film, and the imaging sensor and the dielectric laminated film are separated (detection). This is also true even if the portion and the dielectric laminated film are not integrated.

  For example, it is advantageous in terms of cost as compared with the case of using an existing infrared cut filter made of glass, and can provide an imaging device such as a digital camera that is compact and excellent in portability.

  Further, in the configuration in which the infrared cut filter is placed in front of the sensor, the glass substrate is placed in front of an image sensor such as a CCD or CMOS, so that an air / glass interface is generated in the middle of the optical path. Therefore, even visible light desired to be transmitted is reflected at the interface, which causes a problem of lowering sensitivity. Further, since the number of such interfaces increases, the angle of refraction at oblique incidence (within the glass) varies depending on the wavelength, causing defocus due to a change in the optical path. On the other hand, by using a dielectric laminated film, there is an advantage that the defocus due to such a wavelength is eliminated.

<< Specific Example of Manufacturing Process >>
FIG. 33 is a diagram showing a specific process example for manufacturing the spectral image sensor having the sensor structure described in the above embodiment. FIG. 33 shows an example of a manufacturing process of a spectral image sensor including a light receiving unit for infrared light IR and a light receiving unit for visible light VL.

  In manufacturing this structure, a general CCD or CMOS structure circuit as shown in FIG. 29 and FIG. 30 or FIG. 31 and FIG. 32 is first formed (FIG. 33A). Thereafter, an SiO 2 film and SiN are sequentially stacked on the Si photodiode by using, for example, CVD (Chemical Vapor Deposition) (FIG. 33B).

  Thereafter, for example, only one of the four pixels is etched by using an RIE (Reactive Ion Etching) method or the like, so that an opening reaching the lowermost SiO2 film is provided in the light receiving part for infrared light IR ( FIG. 33 (E)).

  Thereafter, in order to protect the dielectric laminated film 1 and the like, an SiO 2 film is laminated again on the dielectric laminated film 1 having an opening partly by using, for example, CVD (FIG. 33F). . Of course, this process is not essential.

  At this time, a photoresist in which an opening is provided in a light receiving portion for infrared light IR may be used so that the three pixels (for R, G, and B components) for visible light VL are not etched. (FIGS. 33 (C) and (D)). In this case, it is necessary to remove the photoresist before laminating the SiO 2 film on the dielectric laminated film 1 (FIG. 33 (D) → (E)).

  Although not shown in the figure, color filters and microlenses may be formed thereon so as to correspond to the pixels.

  Further, when some infrared light IR leaks and enters a photoelectric conversion element (photodiode or the like) for visible light VL, a weak infrared cut filter may be inserted in the whole. For example, if an infrared cut filter of 50% or less is inserted, the infrared light IR will be reduced in the infrared light IR photoelectric conversion element (photodiode, etc.) even if it is cut to a level where there is almost no problem with the visible light VL. Condensation is sufficient to provide sufficient sensitivity.

  In such a manufacturing process, etching is performed up to the surface of the Si substrate, that is, an opening reaching the lowermost SiO2 film is provided in the light receiving portion for infrared light IR (FIG. 33E), and thus damage caused by etching. May be a problem. In this case, it is also possible to reduce the damage by increasing the thickness d of the SiO2 layer immediately above the Si substrate.

  Here, when dk = 2.5 μm or more, the half-value width of the dip in the infrared IR region of the reflection spectrum becomes narrow as shown in FIG. 11, so the reflectance averaged for general broad natural light. Therefore, infrared light can be reflected. Therefore, the thickness dk of the kth dielectric layer 1_k is preferably 2.5 μm or more. More desirably, the thickness is 5 μm or more.

  Further, a pixel wiring as a unit signal is read out from an imaging unit (detection region) from a metal wiring for a photodiode, an amplifier in a pixel, etc. formed on the silicon substrate 1_ω, that is, an amplifier in a pixel as a unit signal generation unit. When the wiring layer forming the signal line for forming the dielectric layer 1 is formed immediately above the silicon substrate 1_ω, the dielectric layered film 1 is located at a certain distance on the silicon substrate 1_ω rather than the structure in which the dielectric layer film 1 is provided directly on the silicon substrate 1_ω. By forming the dielectric laminated film 1 above the metal wiring, the process can be facilitated, and the merit of reducing the cost can be obtained. As will be described in detail later, a good result can be obtained to some extent by increasing the number of layers forming the dielectric laminated film 1. Hereinafter, a spectral image sensor considering metal wiring will be described.

<< Demultiplexing Image Sensor Using Dielectric Multilayer Film; Sixth Embodiment >>
34 to 40 are views for explaining a sixth embodiment of the spectral image sensor 11 compatible with single wavelength demultiplexing using the dielectric laminated film 1. In the sixth embodiment, based on the method described with reference to FIGS. 10 to 14, in consideration of metal wiring, the dielectric multilayer film 1 is placed on the silicon substrate 1_ω on the upper side that is a certain distance away from the silicon substrate 1_ω. It is characterized in that it is formed integrally with a detector such as a photodiode.

  For example, when considering a CMOS structure as shown in FIG. 34, when one wiring layer is provided on a semiconductor element layer on which a detection unit such as a photodiode is formed and the thickness thereof is about 0.7 μm, the photodiode When the multilayer film structure is integrally formed on approximately 0.7 μm above the silicon substrate 1_ω on which the dielectric layer is formed, the dielectric laminated film 1 may be formed after the process of the first wiring layer. In this way, a wiring layer can be provided in the kth layer having a thickness dk≈0.7 μm.

  Further, as shown in FIG. 35, when three wiring layers are provided on the semiconductor element layer and the total thickness thereof is about 3.2 μm, it is approximately 3.2 μm than the silicon substrate 1_ω on which the photodiode and the like are formed. When the multilayer film structure is integrally formed thereon, the dielectric laminated film 1 may be formed after the process of the uppermost third wiring layer. In this way, a wiring layer can be provided in the kth layer having a thickness dk = 3.2 μm.

  Here, “approximately 3.2 μm” is described, as shown in the figure, in this example, a SiO 2 layer (δ layer) having a thickness of about 10 nm is provided on the silicon substrate 1_ω, and the thickness is 65 nm. This is because an approximately SiN layer (γ layer) is provided, and “3.2 μm” means the thickness of the k layer excluding these γ and δ layers.

  The color filter 14 and the microlens may be formed after the dielectric laminated film 1 is formed.

  As the spectral image sensor 11 corresponding to these, for example, in FIG. 36, the seven-layer structure of the second embodiment shown in FIG. 17 is used, while the kth dielectric layer 1_k (silicon oxide SiO2 layer) and silicon nitride. The thickness of the dielectric layer 1_k of the kth layer is set to 700 nm based on the dielectric laminated film 1C having three layers of the SiN layer 1_γ and the silicon oxide SiO2 layer 1_δ. In addition, a relatively thin silicon nitride SiN layer 1_γ having a thickness dγ = 65 nm or 100 nm is stacked as a third layer material between the silicon oxide SiO2 of the kth layer and the silicon substrate 1_ω. A dielectric laminated film 1C in which a silicon oxide SiO 2 layer 1_δ as a fourth layer material having a refractive index smaller than that of the third layer material is laminated with a thickness dδ = 10 nm between the layer material 3 and the silicon substrate 1_ω. I have to.

  In FIG. 37, the basic dielectric multilayer film 1 has a nine-layer structure, and the thickness of the kth dielectric layer 1_k is set to 700 nm or 3.2 μm. Further, a relatively thin silicon nitride SiN layer 1_γ having a thickness dγ = 65 nm is laminated as a third layer material between the kth layer silicon oxide SiO2 and the silicon substrate 1_ω, and this additional third layer is added. A dielectric laminated film 1C in which a silicon oxide SiO 2 layer 1_δ as a fourth layer material having a refractive index smaller than that of the third layer material is laminated with a thickness dδ = 10 nm between the layer material and the silicon substrate 1_ω. Yes.

  The calculation results of these reflection spectra are as shown in FIGS. As can be seen from FIGS. 37 and 36, the wiring process is facilitated by forming the dielectric laminated film 1 on the upper side of the silicon substrate 1_ω by about 0.7 μm or 3.2 μm. To be precise, since the SiO2 layer as the fourth layer material and the SiN layer as the third layer material have thicknesses of 10 nm and 65 nm (or 100 nm), respectively, immediately above the silicon substrate 1_ω. On the top.

  Here, in the dielectric laminated film 1 having the SiN film and the SiO 2 film, the case of 7 layers and the case of 9 layers have been shown. However, as can be seen from FIG. It can be seen that when the number of layers of the structure is increased, the reflectance R in the infrared IR region exceeds 0.9 and becomes sufficient.

  As can be seen from FIG. 40, in the seven-layer structure in which the thickness dk of the kth dielectric layer 1_k is 3.2 μm, the dip in the infrared light reflection region is large, and as a result, the reflection is greatly reduced. I understand. However, it can also be seen that when the number of layers is increased to 9 layers, these dips become smaller and reflection in the infrared light IR region becomes sufficient.

  Further, as can be seen from FIG. 38, when the thickness dγ of the SiN layer as the third layer material is thick, the reflection in the visible light VL region becomes high. This is because, as described in the second embodiment, the third layer material provided as the intermediate layer is intended to reduce reflection in the visible light region, and the dielectric layer provided as the intermediate layer. It is ideal that the thickness dγ of 1_γ satisfies the formula (6), and it is considered that the thinner one has a sufficient margin but the larger one has a smaller margin.

  As described above, after the conventional wiring process is performed, the formation of the dielectric laminated film 1 is easier to manufacture, and it is unnecessary to examine a new process, which is good in terms of cost. That is, by producing a CMOS structure as shown in FIG. 35, the process can be facilitated and an effective effect can be obtained. If the wiring process is performed after the dielectric laminated film 1 is formed, it is a big difference from the fact that the process becomes difficult, for example, the dielectric laminated film 1 is removed.

<Color Separation Filter Array; First Example>
FIG. 41 is a diagram illustrating a first specific example (hereinafter referred to as a first specific example) of the color separation filter arrangement. The first specific example is characterized in that, in addition to a detection region for capturing a visible light color image, a detection region that excludes visible light and receives and detects only infrared light is provided.

  As shown in FIG. 41A, a basic color filter having a so-called Bayer arrangement in which filters of respective colors are arranged in a mosaic pattern is used. First, unit pixels arranged in a square lattice pattern are red ( In order to correspond to the three color filters of R), green (G), and blue (B), the repeating unit of the color separation filter is arranged by 2 pixels × 2 pixels to constitute the pixel portion. Further, one of the two green (G) is replaced with a black filter BK in order to provide a detection unit (detection region) that excludes visible light and receives and detects only infrared light. That is, for a visible light color image, a filter for three wavelength regions (color components) of primary color filters R, G, and B and a black filter BK for infrared light different from the primary color filters R, G, and B components are used. Four kinds of color filters having different filter characteristics are regularly arranged.

  For example, a first color pixel for sensing a first color (red; R) is arranged in even rows and odd columns, and a second color (green; G) is sensed in odd rows and odd columns. The second color pixels are arranged, the third color pixels for sensing the third color (blue; B) are arranged in the odd rows and even columns, and the infrared light IR is arranged in the even rows and even columns. A fourth color pixel (in this case, a black correction pixel) for sensing is arranged, and different G / B or R / BK pixels are arranged in a checkered pattern for each row. In the basic color filter of such a Bayer arrangement, two colors of G / B or R / BK are repeated every two in the row direction and the column direction.

  A visible light color image can be picked up by detecting with a corresponding detection unit through primary color filters R, G, B, and an infrared light image is a visible light color image by detecting with a corresponding detection unit through black filter BK. Images can be taken independently and simultaneously. The detection unit (detection element) in which the primary color filters R, G, and B are arranged is for detecting the visible light region, which is the pass wavelength region, by further wavelength separation.

  In the above example, the primary color filters 14R, 14G, and 14B are used as the color filter 14 for capturing a visible light color image. However, complementary color filters Cy, Mg, and Ye can be used. The detection unit (detection element) in which the complementary color filters Cy, Mg, and Ye are arranged is for detecting the visible light region, which is a passing wavelength region, by further wavelength separation. In this case, for example, as shown in FIG. 41B, the primary color filter 14R may be replaced with yellow Ye, the primary color filter 14G may be replaced with magenta Mg, and the primary color filter 14B may be replaced with cyan Cy. Then, a black filter BK as a correction pixel is arranged on one of the magenta Mg that is present on the diagonal.

  The dielectric laminated film 1 is formed on the pixels 12Cy, 12Mg, and 12Ye excluding the pixel on which the black filter is disposed, and the complementary color filters 14Cy, 14Mg, and 14Ye are further provided thereon, and the complementary color filters 14Cy, 14Mg, and 14Ye are provided. The corresponding cyan Cy, magenta Mg, and yellow Ye of the visible light VL are received through the light. That is, by forming the dielectric laminated film on the detection portion of a pixel having a complementary color filter, a function capable of effectively cutting infrared light is provided.

  Further, not only a combination of only Cy, Mg, and Ye complementary color filters, but also a black filter BK forming a correction pixel for a combination of a green filter G or a white filter W, which is one of the primary color filters, with a complementary color filter. These pixels can also be provided. For example, as shown in FIG. 41C, in a field storage frequency interleave method in which two complementary color filters of Cy and Mg and a primary color filter of G are combined, two primary color filters G existing in four pixels. One of them may be replaced with a black filter BK as a correction pixel.

<Specific example 1 of sensor structure; compatible with CCD>
42 and 43 show a CCD solid-state imaging device having the arrangement of the color separation filter shown in FIG. 41 and capable of separately capturing two wavelength components of only infrared light IR and visible light VL as images simultaneously. It is a figure explaining. Here, FIG. 42 is a sketch (perspective view) showing a structural example. FIG. 43 is a cross-sectional structure diagram in the vicinity of the substrate surface. Here, an application example to the CCD solid-state imaging device 101 using the dielectric laminated film 1 is shown.

  In the structure of the CCD solid-state imaging device 101 shown in FIG. 42, only the unit pixel matrix 12 composed of four pixels is shown, but in actuality, this is repeated in the horizontal direction and further repeated in the vertical direction. .

  Of the four pixels of the periodic arrangement forming the unit pixel matrix 12, the dielectric laminated film 1 is not formed on one pixel 12IR, but the black filter 14BK is provided, and the infrared light IR is passed through the black filter 14BK. Only light is received. That is, by using the black filter 14BK as the color filter 14 on the pixel 12IR of the infrared light IR, the visible light VL is cut and only the infrared light IR can be received. The pixel 12IR provided with the black filter 14BK is also referred to as a black pixel 12BK.

  On the other hand, the dielectric laminated film 1 is formed on the other three pixels 12B, 12G, and 12R, and further, primary color filters 14R, 14G, and 14B are provided thereon, and visible through the primary color filters 14R, 14G, and 14B. Among the light VL, the corresponding three primary colors of blue B, green G, and red R are received. That is, by forming the dielectric laminated film on the detection portion of the pixel having the three primary color filters, a function capable of effectively cutting infrared light is provided. The circuit configuration shown in FIG. 29 was adopted.

  FIG. 43 showing a cross-sectional structure near the substrate surface shows a pixel that receives only visible light VL. The pixel 12IR that receives the infrared light IR has a structure without the dielectric laminated film 1 and the black filter 14BK. That is, after the SiN layer and the SiO 2 layer are sequentially laminated by the CVD method with the structure shown in FIG. 13 as in the manufacturing process steps described in FIG. 33, infrared light IR is applied by the lithography technique and the RIE method. It is removed only at the pixels that receive light. Thereafter, the SiO2 layer was laminated again and planarized.

  It was found that a visible light color image based on the three primary color components and an image of only the infrared light IR can be picked up simultaneously by using the image pickup device manufactured with such a structure. That is, when the black filter 14BK that absorbs only the visible light VL is provided as the color filter 14C, the visible light VL can be absorbed by the black filter 14BK, and the image data from the pixel 12IR of the infrared light IR is added. Based on this, an image of only infrared light IR is obtained.

<Color separation filter arrangement; second example>
FIG. 44 is a diagram showing a second specific example (hereinafter referred to as a second specific example) of the color separation filter arrangement. This second specific example is characterized in that, in addition to a detection region for capturing a visible light color image, a detection region for receiving and detecting all wavelengths of visible light as well as infrared light is provided.

  As shown in FIG. 44A, a basic color filter having a so-called Bayer arrangement is used. First, unit pixels arranged in a square lattice are red (R), green (G), and blue (B). In order to correspond to these three color filters, the repeating unit of the color separation filter is arranged by 2 pixels × 2 pixels to constitute a pixel portion. Further, one of the two green (G) is replaced with a white filter W in order to provide a detection unit (detection region) that receives and detects all wavelength components of visible light together with infrared light. That is, for a visible light color image, a filter for three wavelength regions (color components) of primary color filters R, G, and B, and a white filter W for infrared light that is different from the primary color filters R, G, and B components. Four kinds of color filters having different filter characteristics are regularly arranged.

  Note that the white pixel on which the white filter W is arranged passes all wavelength components from visible light to infrared light (particularly near-infrared light). The structure which does not provide can be taken.

  For example, a first color pixel for sensing a first color (red; R) is arranged in even rows and odd columns, and a second color (green; G) is sensed in odd rows and odd columns. The second color pixels are arranged, the third color pixels for sensing the third color (blue; B) are arranged in the odd rows and even columns, and the infrared light IR is arranged in the even rows and even columns. A fourth color pixel (in this case, a white pixel) is provided for sensing, and different G / B or R / W pixels are arranged in a checkered pattern for each row. In the color arrangement of the basic color filter of such a Bayer arrangement, two colors of G / B or R / W are repeated every two in both the row direction and the column direction.

  A visible color image can be taken by detecting the corresponding color through the primary color filters R, G, and B, and an infrared image or infrared light or visible by detecting the corresponding color through the white filter W. The mixed image of light can be taken independently and simultaneously with the visible light color image. For example, by using the pixel data from the pixel 12IR that receives the mixed component of the infrared light IR and the visible light VL as they are, an image of the mixed component of the infrared light IR and the visible light VL can be obtained, and the sensitivity is increased. can do. Further, an image of visible light VL is obtained together with an image of a mixed component of infrared light IR and visible light VL. By taking the difference between the two, an image of only infrared light IR can be obtained.

  In the above example, the primary color filters 14R, 14G, and 14B are used as the color filter 14 for capturing a visible light color image. However, complementary color filters Cy, Mg, and Ye can be used. In this case, for example, as shown in FIG. 44B, the primary color filter 14R may be replaced with yellow Ye, the primary color filter 14G may be replaced with magenta Mg, and the primary color filter 14B may be replaced with cyan Cy. Then, a white filter W for acquiring an infrared light image is arranged on one of magenta Mg that will exist at two diagonals.

  The dielectric laminated film 1 is formed on the pixels 12Cy, 12Mg, and 12Ye excluding the pixel on which the white filter is disposed, and the complementary color filters 14Cy, 14Mg, and 14Ye are further provided thereon, and the complementary color filters 14Cy, 14Mg, and 14Ye are provided. The corresponding cyan Cy, magenta Mg, and yellow Ye of the visible light VL are received through the light. That is, by forming the dielectric laminated film on the detection portion of a pixel having a complementary color filter, a function capable of effectively cutting infrared light is provided.

  Further, not only a combination of only Cy, Mg, and Ye complementary color filters, but also a white filter W pixel that forms a correction pixel is provided for a combination of a green filter G that is one of the primary color filters and a complementary color filter. You can also. For example, as shown in FIG. 44C, in a field accumulation frequency interleave method in which two complementary color filters of Cy and Mg and a primary color filter of G are combined, two primary color filters G existing in four pixels. One of them may be replaced with a white filter W as a correction pixel.

  By the way, since the white correction pixel 12W has sensitivity in a wide wavelength region from visible light VL to infrared light IR, the signal is compared with a pixel for imaging a visible light color image (here, a primary color pixel provided with a primary color filter). Is easily saturated, and this saturation phenomenon can be a problem particularly in imaging in a bright environment. Specifically, an appropriate infrared light image cannot be acquired in a bright environment.

  In order to eliminate this saturation problem, the drive control unit 146 may control the detection time of the detection unit provided with the white filter W. For example, in imaging in a bright environment, it is preferable to perform imaging at high speed using exposure control using a shutter function (including not only a mechanical shutter but also an electronic shutter). For example, the image sensor may be exposed with a short cycle, and a pixel signal may be read from the image sensor (specifically, a detection unit) and sent to the image signal processing unit 140.

  In this case, for example, exposure and signal readout are performed at a rate higher than 60 frames / second, thereby increasing the effect on saturation. Alternatively, it is only necessary that the signal can be read out in a time shorter than 0.01667 seconds (accumulation time). In this case, for example, the accumulation of charges in an effectively short time may be read by discharging the charge signal to the substrate side using overflow.

  More preferably, the effect on saturation can be further improved by performing exposure and signal readout at a rate higher than 240 frames / second. Alternatively, it is only necessary that the signal can be read out in a time shorter than 4.16 milliseconds (accumulation time).

  Note that the target pixel from which charges are read out in a short time (accumulation time) so as not to be saturated in this way may be only the white correction pixel 12W, or another pixel for capturing a visible light color image (here, a primary color filter is arranged). All the pixels including the primary color pixels).

  Further, by integrating the signals read with a shorter exposure time twice or more, the weak signal in the dark portion may be converted into a strong signal, and the S / N ratio may be increased. For example, in this way, appropriate sensitivity and a high S / N ratio can be obtained and the dynamic range can be widened even when imaged in a dark environment or imaged in a bright environment. That is, it is difficult to cause saturation at the white correction pixel 12W by imaging at a high speed, and a wide dynamic range can be obtained by integrating the signals.

<Specific example 2 of sensor structure; compatible with CCD>
FIG. 45 is a diagram for explaining a CCD solid-state imaging device having the arrangement of the color separation filter shown in FIG. 44 and capable of separately capturing two wavelength components of infrared light IR and visible light VL as images simultaneously. is there. Here, FIG. 45 is a sketch (perspective view) showing a structural example. Here, an example of application to a CCD solid-state imaging device 101 using a dielectric laminated film is shown. The cross-sectional structure near the substrate surface is the same as FIG.

  In the structure of the CCD solid-state imaging device 101 shown in FIG. 45, only the unit pixel matrix 12 consisting of four pixels is shown. However, this is actually a structure in which this is repeated in the horizontal direction and further repeated in the vertical direction. .

  Of the four pixels of the periodic arrangement forming the unit pixel matrix 12, the dielectric laminated film 1 is not formed on one pixel 12IR, the color filter 14 is not provided, and the infrared rays are not passed through the color filter 14. Light IR is received. In this case, the pixel 12IR can receive a mixed component of the infrared light IR and the visible light VL. The pixel 12IR not provided with the color filter 14 is referred to as a white pixel 12W or an all-pass pixel.

  As described above, in the pixel 12IR in which the dielectric laminated film 1 is not formed, the color filter 14 is not inserted in the white pixel 12W so that not only the infrared light IR but also the visible light VL simultaneously contributes to the signal. By doing so, the infrared light pixel 12IR can substantially function as a pixel that serves not only for the infrared light IR but also for the infrared light IR and the visible light VL.

  On the other hand, the dielectric laminated film 1 is formed on the other three pixels 12B, 12G, and 12R, and further, primary color filters 14R, 14G, and 14B are provided thereon, and the primary color filters 14R, 14G, and 14B are passed through. Of the visible light VL, corresponding three primary colors of blue B, green G, and red R are received. That is, by forming the dielectric laminated film on the detection portion of the pixel having the three primary color filters, a function capable of effectively cutting infrared light is provided. As the primary color filters 14R, 14G, and 14B used in the second specific example, those similar to the first specific example shown in FIG. 64A can be used. The circuit configuration shown in FIG. 29 was adopted.

  Capable of simultaneously capturing visible light color images based on the three primary color components and an infrared light IR-only image or a mixture of infrared light IR and visible light VL by using an image sensor manufactured with such a structure. I understood. For example, by using the pixel data from the pixel 12IR that receives the mixed component of the infrared light IR and the visible light VL as they are, an image of the mixed component of the infrared light IR and the visible light VL can be obtained, and the sensitivity is increased. can do. Further, an image of visible light VL is obtained together with an image of a mixed component of infrared light IR and visible light VL. By taking the difference between the two, an image of only infrared light IR can be obtained.

  Although not shown, the white color filter 14W passes the G color component and the infrared light component in the visible light region and blocks the rest (the B color component and the R color component in the visible light region). A configuration in which a detection region for receiving and detecting a specific wavelength component in visible light as well as infrared light is provided, such as replacement with a green filter.

  Even in this case, by using the pixel data from the pixel 12IR that receives a certain wavelength component of the infrared light IR and the visible light VL as they are, a mixed component of the certain wavelength component of the infrared light IR and the visible light VL is used. Image can be obtained, and the sensitivity can be increased. An image of the visible light VL is obtained together with the image of the mixed component, and an image of only the infrared light IR is obtained by taking a difference from the certain wavelength component in the image of the visible light VL.

<Other arrangement examples of the color separation filter>
46 to 52 are diagrams for explaining pixel arrangements in consideration of a decrease in resolution. Regarding the pixel arrangement, when the arrangement structure as shown in FIGS. 41 and 44 is applied, the infrared light (or the conventional RGB primary color filter or the CyMgYe complementary color filter (or the primary color filter G) is applied to the visible light pixel. Pixels for detection) (mixture of infrared light and visible light) are added.

  For example, a green pixel G or a magenta color pixel Mg for imaging a visible light color image is originally replaced with a black color correction pixel, a white color pixel, a green color correction pixel, or a magenta color correction pixel. Any of the images may cause a reduction in resolution. For example, when one pixel of G in the conventional RGB Bayer array is replaced with an infrared pixel, the resolution decreases. However, by devising the arrangement of the correction pixel and the wavelength component pixel (for example, the green pixel G) that greatly contributes to the resolution, it is possible to solve this resolution reduction problem.

  In this case, what is important is that when a color separation filter structure in which filters of each color are arranged in a mosaic pattern is adopted as in the prior art, there is a certain pixel for infrared light (or a mixture of infrared light and visible light). And a mosaic pattern with a certain grid spacing, and a mosaic pattern with a primary grid of RGB or complementary color CyMgYe pixels of visible light. It is.

  Here, “to make a mosaic pattern” means that when attention is paid to a certain color pixel, they are arranged in a grid pattern with a certain grid interval. The color pixels are not necessarily required to be adjacent to each other. As a typical example of the arrangement mode in which the color pixels are adjacent to each other, an arrangement mode in which a square pattern (checkered pattern) in which squares of infrared light pixels and other color pixels are arranged alternately is arranged. is there. Alternatively, there is an arrangement mode in which a square pattern (checkered pattern) is formed by alternately arranging squares of one pixel of the primary color RGB or complementary color CyMgYe pixels of visible light and the other color pixels.

<Application example to primary color filter>
For example, in order to suppress the degradation of the resolution of the visible light color image while using the RGB primary color filter, the arrangement density of the G pixels in the visible light region is maintained, and the remaining R or B pixels in the visible light region are corrected. Replace with black, white, or green pixels. For example, as shown in FIG. 46, in the unit pixel matrix 12 of 2 rows and 2 columns, first, color pixels G for sensing the green component of the visible light region are arranged in the odd rows and odd columns and even rows and even columns, Correction black pixels (FIG. 46A), white pixels (FIG. 46B), and green pixels (not shown) are arranged in even rows and odd columns.

  In the odd-numbered unit pixel matrix 12 in the column direction, color pixels B for sensing the blue component of the visible light region are arranged in the odd-numbered and even-numbered columns in the odd-numbered unit pixel matrix 12 in the row direction. Color pixels R for sensing the red component of the visible light region are arranged in odd rows and even columns in the even-numbered unit pixel matrix 12 in the direction. In the even number in the column direction of the unit pixel matrix 12, the arrangement of the color pixels B and the color pixels R is reversed. As a whole, the repetition cycle of the color filter 14 is completed with the 2 × 2 unit pixel matrix 12.

  In the case of the arrangement form as shown in FIG. 46, a checkerboard arrangement mode in which squares of one pixel G of the primary color RGB pixels of the visible light and the other color pixels are alternately arranged is used. Since the arrangement density of the color pixels G that greatly contribute to the resolution in the color image can be made the same as that of the Bayer array, the resolution of the visible light color image is not lowered.

  However, since the arrangement density of the color pixels R and B is ½ of the Bayer arrangement, the color resolution is lowered. However, the human visual sensitivity regarding the color may be considered not to be a big problem because red B and blue B are inferior to green G. On the other hand, regarding the infrared light image using the correction pixels, the arrangement density of the correction pixels is ½ that of the color pixels G for sensing the green component in the visible light region, so that the resolution is visible light color. Inferior to image.

  For example, using a black filter 14BK exhibiting transmission spectrum characteristics as shown in FIG. 47, the black correction pixels are arranged in an arrangement manner as shown in FIG. The cross-sectional structure diagram corresponding to the light-receiving pixel is shown in FIG. 35). A CMOS solid-state imaging device (pixel circuit configuration is FIG. 31) is manufactured as shown in FIG. It was found that a high-resolution color image of visible light and an image of infrared light having a relatively high resolution but a lower resolution than a color image can be simultaneously captured.

  In addition, a CMOS solid-state imaging device (shown in FIG. 35 is a cross-sectional structure diagram corresponding to a pixel that receives visible light) in which white pixels are arranged in an arrangement mode as shown in FIG. The pixel circuit configuration shown in FIG. 31) was manufactured in the same manner as the manufacturing process shown in FIG. 33, and an experiment was conducted. As a result, a high-resolution color image of three primary colors of visible light was compared with a lower resolution than a color image. Image with a mixture of high-resolution infrared light and visible light at the same time, and by reducing the intensities of blue, red, and green detected by the visible light pixels R, G, and B of the three primary colors, infrared It was found that a light-only image can be taken simultaneously.

  In order not to saturate, all the pixels are exposed in a short time, the charge signal is read out, and the signal read in a shorter time is integrated twice or more, so that it can be converted into a large signal. It was confirmed that appropriate sensitivity was obtained and the dynamic range was widened even if the image was taken or in a bright environment.

  Further, the structure in which the black correction pixel and the multilayer film are combined as shown in FIG. 46A and the structure in which the white pixel and the multilayer film are combined as shown in FIG. A similar effect was confirmed even when a CCD structure as shown in FIG. 43 was fabricated.

  In order to suppress the resolution reduction of the infrared light image, for example, as shown in FIG. 48, the color pixel G for detecting the green component in the visible light region shown in FIG. 46 and the black pixel for correction (FIG. 48). (A)), white pixels (FIG. 48B), and green pixels (not shown) may be interchanged. In this case, a checkered pattern arrangement mode in which squares of infrared light pixels and other color pixels are alternately arranged as correction pixels is adopted, and the correction pixel arrangement density can be the same as in the Bayer array, The resolution of the infrared light image is not reduced. However, since the arrangement density of the color pixels G that greatly contributes to the resolution in the visible light color image is ½ that of the correction pixel, the visible light color image is inferior to the resolution of the infrared light image. The color resolution is the same as in FIG.

  For example, a CCD solid-state imaging device in which black correction pixels are arranged in an arrangement mode as shown in FIG. 48A using a black filter 14BK exhibiting transmission spectrum characteristics as shown in FIG. The cross-sectional structure diagram corresponding to the pixel that receives visible light is shown in FIG. 43), and an experiment was conducted. As a result, a high-resolution infrared image and a relatively high resolution image that is lower in resolution than the infrared image. It was found that a visible color light image with a resolution could be taken simultaneously.

  In addition, a CCD solid-state imaging device in which white pixels are arranged as shown in FIG. 46B (a pixel circuit configuration is shown in FIG. 29, and a cross-sectional structure diagram corresponding to a pixel receiving visible light is shown in FIG. 43) is manufactured. As a result of experiments, it was possible to simultaneously capture an image in which high-resolution infrared light and visible light were mixed, and to detect the intensities of blue, red, and green detected by the three primary colors of visible light pixels R, G, and B. It was found that the image of only the high-resolution infrared light can be taken by reducing the image quality, and at the same time, the visible light color image having a relatively high resolution can be taken although the resolution is lower than that of the infrared light image.

  In any case, the color reproduction is good even if an infrared light cut-off filter is not used or an image is picked up in an environment with infrared light. It has also been confirmed that the sensitivity of visible color images can be increased independently of color reproducibility by correcting the luminance signal obtained based on the visible light pixels of the three primary colors using light components. It was.

  In order not to saturate, it is possible to convert only a white pixel into a large signal by reading out the charge in a short time using overflow, and integrating the signals read in a shorter time twice or more. It was confirmed that appropriate sensitivity was obtained and the dynamic range was widened even if the camera was picked up with a lens or in a bright environment.

  Further, the structure combining the black correction pixel and the multilayer film as shown in FIG. 48A and the structure combining the white pixel and the multilayer film as shown in FIG. Similar effects were confirmed even when fabricated with a CMOS solid-state imaging device structure.

  FIG. 49 is a diagram for explaining another pixel arrangement in the case of providing pixels for acquiring an infrared light image independently of a visible light color image. This modification is characterized in that a plurality of color filter colors arranged on the infrared light image acquisition pixel are combined. For example, in the example shown in FIG. 49, the first specific example and the second specific example are combined, and the black filter 14BK and the white filter 14W are alternately arranged with respect to the unit pixel matrix 12 as pixels for acquiring the infrared light image. Is arranged. 49A is a combination of FIGS. 41 and 44, FIG. 49B is a combination of FIGS. 46A and 46B, and FIG. 49C is a combination of FIGS. ).

  By adopting such a combination arrangement, for example, the white pixel 12W can be used mainly for high sensitivity, and the black pixel 12BK can be used for normal illuminance or high illuminance. Also, by combining the outputs of both, a reproduction range from a low illuminance level to a high illuminance level can be obtained, and the dynamic range can be expanded.

<Application to complementary color filter>
In order to suppress the reduction in the resolution of the visible light color image while using the CyMgYe complementary color filter, the arrangement density of the Mg pixels in the visible light region is maintained, and the remaining R or B pixels in the visible light region are replaced with infrared light. It may be replaced with black pixels, white pixels, or green pixels for image acquisition. For example, as shown in FIG. 50, in the unit pixel matrix 12 of 2 rows and 2 columns, first, the color pixels Mg for sensing the magenta color component in the visible light region are arranged in the odd rows and odd columns and even rows and even columns. In the even rows and odd columns, black pixels (FIG. 50A), white pixels (FIG. 50B), and magenta pixels (not shown) for acquiring an infrared light image are arranged. One of the magenta colors Mg can be replaced with green G.

  In this case, a checkered pattern arrangement in which one pixel Mg of the complementary color CyMgYe pixels of visible light and the squares of the other color pixels are alternately arranged is adopted, and the color greatly contributes to the resolution in the visible light color image. Since the arrangement density of the pixels Mg can be made the same as that of the Bayer array, the resolution of the visible light color image is not lowered.

  In addition, since the arrangement density of the color pixels Cy and the color pixels Ye is ½ that of the arrangement of the color pixels Mg, the color resolution is lowered. Good. In addition, regarding the infrared light image using the correction pixel, the arrangement density of the correction pixels (infrared light pixels) is ½ of the color pixel Mg for detecting the magenta color component in the visible light region. Therefore, the resolution is inferior to that of a visible light color image.

  Further, in order to suppress the reduction in the resolution of the infrared light image, for example, as shown in FIG. 51, the color pixel Mg for sensing the magenta color component in the visible light region and the black pixel for obtaining the infrared light image (FIG. 51 (A)), white pixels (FIG. 51A), and magenta color pixels (not shown) may be replaced. In this case, a checkered pattern arrangement mode in which squares of infrared light pixels and other color pixels are alternately arranged as correction pixels is adopted, and the correction pixel arrangement density can be the same as in the Bayer array, The resolution of the infrared light image is not reduced. However, since the arrangement density of the color pixels Mg that greatly contributes to the resolution in the visible light color image is ½ that of the correction pixel, the visible light color image is inferior to the resolution of the infrared light image. The color resolution is the same as in FIG.

  In the above arrangement example for suppressing the reduction in resolution, the pixels of green G or magenta color Mg are arranged in a mosaic pattern (checkered pattern as a standard example) at as high a density as possible. Even if the pixels of the colors (R, B or Cy, Ye) are arranged in a checkered pattern, substantially the same effect can be obtained. Of course, in order to increase the resolution and the color resolution, it is preferable to arrange the color component filters having high visibility so as to form a mosaic pattern with as high a density as possible.

<Example of application to diagonal arrangement>
In the above example, the case where the color filters are arranged in a square lattice shape has been described. However, the color filters may be arranged in an oblique lattice shape. For example, the arrangement mode shown in FIG. 52A is a pixel arrangement in a state where the arrangement mode shown in FIG. 46B is rotated clockwise by approximately 45 degrees. The arrangement form shown in FIG. 52B is a pixel arrangement in a state where the arrangement form shown in FIG. 48B is rotated by approximately 45 degrees clockwise. As described above, when arranged in an oblique lattice shape, the pixel density in the vertical direction and the horizontal direction increases, and the resolution in that direction can be further increased.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which such changes or improvements are added are also included in the technical scope of the present invention.

  Further, the above embodiments do not limit the invention according to the claims (claims), and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Absent. The embodiments described above include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. Even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, as long as an effect is obtained, a configuration from which these some constituent requirements are deleted can be extracted as an invention.

  The structure described above shows an embodiment of the present invention, and as described above, has a structure in which a plurality of layers having different refractive indexes and a predetermined thickness are stacked between adjacent layers, Other similar structures can be used to enable wavelength separation using a laminated member (dielectric laminated film) having a characteristic of reflecting a predetermined wavelength region component of electromagnetic waves and allowing the remainder to pass therethrough.

  Furthermore, the above-described technique is not necessarily limited to visible light and infrared light spectroscopy. For example, spectroscopy and detection of visible light and ultraviolet light are possible, and ultraviolet light as well as visible light can be detected and imaged simultaneously. In addition, the visible light detected at the same time is not limited to detecting a monochrome image without splitting, and the visible light band is split into, for example, three primary color components using the color filters for each color as described above. Can also detect color images.

  Accordingly, it is possible to simultaneously acquire image information of ultraviolet light that cannot be seen by the eye, corresponding to an image image (monochrome image or color image) of visible light that can be seen by the eye. This expands the application as a key device for new information systems such as photosynthetic surveillance cameras.

  For example, the visible light VL and the visible light VL are obtained by using the dielectric laminated film 1 in which the visible light VL is a reflected wavelength region component and the passing wavelength region component is a lower wavelength side (for example, ultraviolet light) than the visible light VL. It is also possible to perform spectroscopy and detection on the lower wavelength side (for example, ultraviolet light).

  For example, although not shown, in FIG. 41, the dielectric laminated film 1 that reflects a wavelength component of visible light VL or more is formed on one pixel 12IR out of four pixels of the periodic array forming the unit pixel matrix 12. Thus, only the wavelength lower than the visible light VL (ultraviolet light) is received, the dielectric laminated film 1 is not formed on the other three pixels 12B, 12G, and 12R, and the color filter 14 (14R, 14B, 14B), the corresponding three primary colors of blue B, green G and red R in the visible light VL are received together with the low wavelength side (ultraviolet light).

  In order to obtain a visible light VL signal as a reflected wavelength region component that is substantially unaffected by the transmitted wavelength region component, an arithmetic process with the ultraviolet light component that is the transmitted wavelength region component may be performed. If the color filter 14 (14R, 14B, 14B) has a characteristic that the transmittance with respect to the ultraviolet light component, which is a passing wavelength region component, is substantially zero, a wavelength lower than the visible light VL (ultraviolet light). ) Is removed by the color filter 14 (14R, 14B, 14B), so this calculation process is not necessary.

It is a figure explaining the concept of the demultiplexing image sensor which separates electromagnetic waves for every predetermined wavelength using a dielectric laminated film. It is a conceptual diagram explaining the basic composition of the demultiplexing image sensor using a dielectric laminated film. FIG. 3 is a diagram illustrating a configuration example in which the basic configuration of the spectral image sensor illustrated in FIG. 2 is applied to a plurality of wavelength separation configurations. It is a structure figure explaining the basic concept of the method of designing a laminated film. It is a reflection spectrum figure explaining the basic concept of the method of designing a laminated film. It is a reflection spectrum figure explaining the basic concept of the method of designing a laminated film. It is a figure explaining the conditions of reflection center wavelength (lambda) (the figure which showed the concept of the reflection spectrum). It is a reflection spectrum figure explaining the conditions of reflection center wavelength (lambda). It is a reflection spectrum figure explaining the conditions of reflection center wavelength (lambda). 1 is a structural diagram illustrating a first embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. FIG. It is a reflection spectrum figure explaining 1st Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a figure (reflection spectrum figure; details) explaining 1st Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. 1 is a structural diagram illustrating a first embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. FIG. It is a reflection spectrum figure explaining 1st Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. FIG. 5 is a structural diagram illustrating a second embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 2nd Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. FIG. 5 is a structural diagram illustrating a second embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 2nd Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. FIG. 6 is a structural diagram illustrating a third embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 3rd Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. FIG. 6 is a structural diagram illustrating a third embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 3rd Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. FIG. 6 is a structural diagram illustrating a third embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 3rd Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a structure figure explaining 4th Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 4th Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a structure figure explaining 5th Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 5th Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a circuit diagram (R, G, B, infrared light IR correspondence) at the time of applying a laminated film to an IT_CCD image sensor. FIG. 6 is a circuit diagram (corresponding to visible light VL and infrared light IR) when a laminated film is applied to an IT_CCD image sensor. It is a circuit diagram (R, G, B, infrared light IR correspondence) at the time of applying a laminated film to a CMOS solid-state image sensor. FIG. 6 is a circuit diagram (corresponding to visible light VL and infrared light IR) when a laminated film is applied to a CMOS solid-state imaging device. It is a figure which shows the example of a process which manufactures a spectral image sensor. FIG. 11 is a structural diagram illustrating a sixth embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. FIG. 11 is a structural diagram illustrating a sixth embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. FIG. 11 is a structural diagram illustrating a sixth embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. FIG. 11 is a structural diagram illustrating a sixth embodiment of a spectral image sensor that supports single wavelength demultiplexing using a laminated film. It is a figure explaining 6th Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 6th Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a reflection spectrum figure explaining 6th Embodiment of the spectral image sensor corresponding to a single wavelength demultiplexing using a laminated film. It is a figure which shows arrangement | positioning of the 1st specific example of a color separation filter. FIG. 42 is a diagram (perspective view) for explaining a configuration example of a CCD solid-state imaging device having the color separation filter arrangement shown in FIG. 41. It is a figure (sectional structure figure) explaining the structural example of the CCD solid-state image sensor which enabled it to image two wavelength components of infrared light and visible light separately as an image simultaneously. It is a figure which shows arrangement | positioning of the 2nd specific example of a color separation filter. FIG. 45 is a diagram (perspective view) illustrating a configuration example of a CCD solid-state imaging device having the color separation filter arrangement illustrated in FIG. 44. FIG. 6 is a diagram (part 1) for explaining a pixel arrangement in consideration of resolution reduction. It is a figure which shows an example of the transmission spectrum characteristic of a black filter. FIG. 6 is a diagram (part 2) for explaining a pixel arrangement in consideration of a reduction in resolution. FIG. 6 is a third diagram illustrating a pixel arrangement in consideration of a resolution reduction. It is FIG. (4) explaining the pixel arrangement which considered the resolution fall. It is FIG. (5) explaining the pixel arrangement which considered the resolution fall. It is FIG. (6) explaining the pixel arrangement | sequence which considered the resolution fall. It is a figure explaining the mechanism of the sensor given in patent documents 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Dielectric laminated film, 10 ... Spectral filter, 11 ... Spectral image sensor, 12 ... Unit pixel matrix, 100 ... Imaging device, 101 ... CCD solid-state image sensor, 122 ... Vertical transfer CCD, 124 ... Reading gate, 126 ... Horizontal Transfer CCD, 128 ... output amplifier, 140 ... image signal processing unit, 142 ... image switching control unit, 146 ... drive control unit, 201 ... CMOS solid-state imaging device, 205 ... in-pixel amplifier, 207 ... drive control unit, 219 ... vertical Signal line, 226 ... Column processing section

Claims (39)

The unit component includes a detection unit that detects electromagnetic waves and a unit signal generation unit that generates and outputs a corresponding unit signal based on the amount of electromagnetic waves detected by the detection unit, and the unit components are in a predetermined order. A physical information acquisition method for acquiring physical information for a predetermined purpose based on the unit signal, using a device for detecting a physical quantity distribution arranged on the same substrate,
The detecting unit has a structure in which a plurality of layers having different refractive indexes between adjacent layers and having a predetermined thickness are stacked, and has a characteristic of reflecting a predetermined wavelength region component of the electromagnetic wave and passing the remaining component. Provided on the incident surface side on which the electromagnetic wave is incident,
The passing wavelength region component that has passed through the laminated member is detected by the detection unit, thereby acquiring physical information for the predetermined purpose based on the unit signal of the passing wavelength region component obtained from the unit signal generation unit. Characteristic physical information acquisition method. Without detecting the laminated wavelength member on the incident surface side where the electromagnetic wave is incident on the other detection unit different from the one detection unit for the transmission wavelength region component, the detection wavelength unit detects the reflection wavelength region component, 2. The physical information acquisition method according to claim 1, wherein the second physical information for a predetermined purpose is acquired based on a unit signal of the reflected wavelength region component obtained from the unit signal generator. Either one of the first physical information based on the unit signal of the passing wavelength region component and the second physical information based on the unit signal of the reflected wavelength region component is selected and output, or both are output simultaneously The physical information acquisition method according to claim 2, wherein: An optical member that separates the inside of the passing wavelength region component into different wavelength region components, respectively, on the incident surface side on which the electromagnetic waves of the plurality of detection units that detect the passing wavelength region component are incident,
The plurality of detection units detect different pass wavelength region components, and thereby, by combining each unit signal of the different pass wavelength region components obtained from the unit signal generation unit, one unit related to the pass wavelength region component is obtained. The physical information acquisition method according to claim 1, wherein the physical information is acquired. 5. The physical information acquisition method according to claim 4, wherein primary optical color filters in which transmitted light in the visible region is wavelength components of three primary colors are used for the three detection units as the optical member. 5. The physical information acquisition method according to claim 4, wherein, as the optical member, a complementary color type color filter in which transmitted light in the visible region is a complementary color for each of the three primary colors is used for the three detection units. Physical information capable of ignoring the influence of the passing wavelength region component is obtained as the second physical information by performing differential processing between the unit signal of the reflected wavelength region component and the unit signal of the passing wavelength region component. The physical information acquisition method according to claim 2. An optical member that allows a predetermined wavelength component in the passing wavelength region component to pass through is provided on the incident surface side on which the electromagnetic wave is incident on one of the detection units that detects the passing wavelength region component,
An optical member that allows the reflected wavelength region component and the predetermined wavelength component in the passing wavelength region component to pass through is provided on the incident surface side where the electromagnetic wave is incident on the other detection unit that detects the reflected wavelength region component. ,
The predetermined wavelength component in the passing wavelength region component, the reflected wavelength region component, and the combined component of the predetermined wavelength component in the passing wavelength region component are detected by respective detection units, thereby the unit signal. The physical information capable of ignoring the influence of the passing wavelength region component is acquired as the second physical information by differential processing of each unit signal of different wavelength region components obtained from the generation unit. 8. The physical information acquisition method according to 7. An optical member that transmits the reflected wavelength region component and blocks the transmitted wavelength region component is provided on the incident surface side on which the electromagnetic wave of the other detection unit that detects the reflected wavelength region component is incident,
The second physical information is detected by a unit signal of the reflected wavelength region component obtained from the unit signal generation unit by detecting the reflected wavelength region component from which the passing wavelength region component is blocked by the other detection unit. The physical information acquisition method according to claim 2, further comprising: acquiring physical information that can ignore an influence of the passing wavelength region component. The unit component includes a detection unit that detects electromagnetic waves and a unit signal generation unit that generates and outputs a corresponding unit signal based on the amount of electromagnetic waves detected by the detection unit, and the unit components are in a predetermined order. A physical information acquisition device that acquires physical information for a predetermined purpose based on the unit signal using an apparatus for physical quantity distribution detection arranged on the same substrate,
The detection unit has a structure in which a plurality of layers having different refractive indexes and different thicknesses are disposed between adjacent layers disposed on the incident surface side on which the electromagnetic wave is incident, and a predetermined wavelength region component of the electromagnetic wave A laminated member with the property of reflecting and allowing the rest to pass,
Signal processing for acquiring physical information for the predetermined purpose based on a unit signal of a passing wavelength region component obtained from the unit signal generation unit based on a passing wavelength region component that has passed through the laminated member detected by the detection unit And a physical information acquisition device. The physical information acquisition apparatus according to claim 10, wherein the laminated member is configured integrally with the detection unit. The signal processing unit is obtained from the unit signal generation unit based on a reflected wavelength region component that does not pass through the laminated member detected by the other detection unit different from the one detection unit for the transmission wavelength region component The physical information acquisition apparatus according to claim 11, wherein the second physical information for a predetermined purpose is acquired based on a unit signal of a reflected wavelength region component. Either one of the first physical information based on the unit signal of the passing wavelength region component and the second physical information based on the unit signal of the reflected wavelength region component is selected and output, or both are output simultaneously The physical information acquisition apparatus according to claim 12, further comprising: a signal switching control unit that controls the signal processing unit. An optical member that separates each of the passing wavelength region components into different wavelength region components is provided on the incident surface side on which the electromagnetic waves of the plurality of detection units that detect the passing wavelength region components are incident,
The signal processing unit is configured to detect different pass wavelength region components by the plurality of detection units, and thereby combine the unit wavelengths of the different pass wavelength region components obtained from the unit signal generation unit, thereby combining the pass wavelengths. The physical information acquisition apparatus according to claim 12, wherein one piece of physical information related to a region component is acquired. The physical information acquiring apparatus according to claim 14, wherein the optical member is a primary color filter in which visible light transmitted through the three detection units is a wavelength component of three primary colors. The physical information acquisition apparatus according to claim 14, wherein the optical member is a complementary color system color filter in which transmitted light in the visible region is a complementary color for each of the three primary colors with respect to three detection units. The signal processing unit is physical information that can ignore the influence of the passing wavelength region component as the second physical information by performing differential processing between the unit signal of the reflected wavelength region component and the unit signal of the passing wavelength region component. The physical information acquisition apparatus according to claim 12, wherein the physical information acquisition apparatus acquires the physical information. An optical member that allows a predetermined wavelength component in the passing wavelength region component to pass on an incident surface side on which the electromagnetic wave of the detection unit that detects the passing wavelength region component is incident,
An optical member that allows the reflected wavelength region component and the predetermined wavelength component in the passing wavelength region component to pass on an incident surface side on which the electromagnetic wave is incident of the other detection unit that detects the reflected wavelength region component. ,
The signal processing unit includes a unit signal of the predetermined wavelength component obtained from the unit signal generation unit based on the predetermined wavelength component in the passing wavelength region component, and within the reflected wavelength region component and the passing wavelength region component. By performing a difference process with the unit signal of the synthesized component obtained from the unit signal generation unit based on the synthesized component of the predetermined wavelength component, as the second physical information, The physical information acquisition apparatus according to claim 17, wherein physical information whose influence can be ignored is acquired. The reflected wavelength region component is passed through the incident surface side on which the electromagnetic wave is incident of the other detection unit that detects the reflected wavelength region component different from the one detection unit for the transmitted wavelength region component, and the passing wavelength An optical member for blocking region components;
The signal processing unit uses, as the second physical information, a unit signal of the reflected wavelength region component obtained from the unit signal generation unit based on the reflected wavelength region component from which the passing wavelength region component is blocked. The physical information acquisition apparatus according to claim 12, wherein physical information capable of ignoring the influence of the passing wavelength region component is acquired. The member of the jth layer constituting the laminated member satisfies the following conditional expression (A), where nj is the refractive index, dj is the thickness, and λ0 is the center wavelength of the reflection wavelength region component. The physical information acquisition apparatus according to claim 10.
0.9 × λ0 / 4n ≦ dj ≦ 1.1 × λ0 / 4n (A) The physical information acquisition apparatus according to claim 10, wherein a central wavelength λ0 of the reflected wavelength region component satisfies the following conditional expression (B).
780 nm ≦ λ0 ≦ 1100 nm (B) The physical information acquisition apparatus according to claim 21, wherein a central wavelength λ0 of the reflection wavelength region component is approximately 900 nm. When the refractive index is nγ, the thickness is dγ, and the passing wavelength region λ1 is the following conditional expression (C1), the member of the γ layer on the detection unit side constituting the laminated member is the following conditional expression (C2) The physical information acquisition apparatus according to claim 10, wherein:
380 nm ≦ λ1 ≦ 780 nm (C1)
0 nm <dγ ≦ 96 nm (C2) The physical information acquisition apparatus according to claim 23, wherein the member of the γ layer satisfies the following conditional expression (C3).
47 nm ≦ dγ ≦ 96 nm (C3) The laminated member may be an oxide such as silicon nitride, silicon oxide, alumina, zirconia, titanium oxide, magnesium oxide, and zinc oxide, or a polymer material such as polycarbonate or acrylic resin, or a semiconductor material such as silicon carbide or germanium Ge. The physical information acquisition apparatus according to claim 10, comprising at least two of the above as layer materials. The physical information according to claim 25, wherein the laminated member has a structure in which silicon nitride is used as a first layer material and silicon oxide is used as a second layer material, and these are alternately laminated. Acquisition device. The laminated member includes a wiring layer that forms a signal line for reading the unit signal from the unit signal generation unit on the detection unit side, and a plurality of layers having different refractive indexes between adjacent layers and having a predetermined thickness are laminated. The physical information according to claim 11, wherein a laminated film having a structure and having a characteristic of reflecting a predetermined wavelength region component of the electromagnetic wave and allowing the remainder to pass therethrough is formed on the wiring layer. Acquisition device. The laminated film has silicon nitride as the first layer material and silicon oxide as the second layer material, and the first layer material is arranged on both sides, and alternately, nine or more layers are laminated alternately. Has a structure,
28. The physical information acquisition apparatus according to claim 27, wherein a distance between the laminated film and the detection unit is approximately 700 nm. The laminated film has silicon nitride as the first layer material and silicon oxide as the second layer material, and the first layer material is arranged on both sides, and alternately, nine or more layers are laminated alternately. Has a structure,
28. The physical information acquisition apparatus according to claim 27, wherein a distance between the laminated film and the detection unit is approximately 3.2 nm. The physical information acquisition apparatus according to claim 12, further comprising a drive unit that controls a detection time of the other detection unit. The signal processing unit integrates the unit signal of the reflected wavelength region component detected by the other detection unit a plurality of times, and uses the unit signal of the reflected wavelength region component after the integration to perform the second predetermined purpose. The physical information acquisition apparatus according to claim 12, wherein the physical information is acquired. The physical unit according to claim 12, wherein the detection unit that detects the passing wavelength region component and the detection unit that detects the reflected wavelength region component are periodically arranged with a certain number ratio. Information acquisition device. The physical information acquisition apparatus according to claim 32, wherein one detection unit that detects the reflected wavelength region component is arranged for a plurality of detection units that detect the plurality of pass wavelength region components. The physical information acquisition apparatus according to claim 12, wherein a detection unit that detects the passing wavelength region component and a detection unit that detects the reflected wavelength region component are arranged one-to-one. The detection unit for detecting the pass wavelength region component is composed of a combination of a plurality of detection elements for detecting the pass wavelength region by further wavelength separation,
The plurality of detection elements of the detection unit that detects the passing wavelength region component and the detection unit that detects the reflection wavelength region component are arranged in a two-dimensional lattice pattern, and are among the plurality of detection elements The physical information acquisition apparatus according to claim 12, wherein the components that detect the wavelength components are arranged in a checkered pattern. The detection unit for detecting the pass wavelength region component is composed of a combination of a plurality of detection elements for detecting the pass wavelength region by further wavelength separation,
Detection in which the plurality of detection elements of the detection unit for detecting the passing wavelength region component and the detection unit for detecting the reflection wavelength region component are arranged in a two-dimensional lattice pattern and detect the reflection wavelength region component The physical information acquisition apparatus according to claim 12, wherein the parts are arranged in a checkered pattern. The unit component includes a detection unit that detects electromagnetic waves and a unit signal generation unit that generates and outputs a corresponding unit signal based on the amount of electromagnetic waves detected by the detection unit, and the unit components are in a predetermined order. A method of manufacturing a semiconductor device for physical quantity distribution detection arranged on the same semiconductor substrate,
Forming a semiconductor element layer having the detection unit and the unit signal generation unit on the semiconductor substrate;
Forming a wiring layer forming a signal line for reading the unit signal from the unit signal generation unit on the semiconductor element layer;
A layer having a structure in which a plurality of layers having different refractive indexes and different thicknesses between adjacent layers are laminated on the wiring layer, and having a characteristic of reflecting a predetermined wavelength region component of the electromagnetic wave and passing the rest. A method for manufacturing a semiconductor device, comprising: forming a film. 38. The method of manufacturing a semiconductor device according to claim 37, further comprising a step of aligning the plurality of detection units with detection units corresponding to each wavelength and removing a part of the laminated film. . 38. The method of claim 37, further comprising: forming, on the laminated film, an optical member that allows a predetermined wavelength component in the passing wavelength region component to pass through and is aligned with a detection unit corresponding to each wavelength. The manufacturing method of the semiconductor device as described in any one of Claims 1-3.