JP2016152265A - Solid-state image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-state image pickup device that can reduce noise caused by crosstalk.SOLUTION: A solid-state image pickup device includes a photoelectric conversion film and plural photoelectric conversion elements. The photoelectric conversion film is provided over plural pixels at one surface side of a p-type monocrystal Si substrate, absorbs and photoelectrically converts light of any first and second color wavelength areas in the three elementary colors of light, and transmits light of a third color wavelength area therethrough. The photoelectric conversion elements are provided in the p-type monocrystal Si substrate so as to correspond to the plural pixels, and all the photoelectric conversion elements absorb and photoelectrically convert the light of the third color wavelength area transmitted through the photoelectric conversion film.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a solid-state imaging device.

  In recent years, a stacked solid-state imaging device has attracted attention from the viewpoint of improving light utilization efficiency. However, since such a solid-state imaging device includes a plurality of photodiodes that absorb light in different wavelength ranges, noise due to crosstalk may increase.

JP 2007-31550 A

  The problem to be solved by the present invention is to provide a solid-state imaging device capable of reducing noise due to crosstalk.

  The solid-state imaging device of the embodiment has a photoelectric conversion film and a plurality of photoelectric conversion devices. The photoelectric conversion film is provided over a plurality of pixels on one surface side of the p-type single crystal Si substrate, and absorbs light in the wavelength regions of arbitrary first and second colors in the three primary colors of light. While performing photoelectric conversion, light in the wavelength region of the third color is transmitted. The photoelectric conversion element is provided in the p-type single crystal Si substrate so as to correspond to a plurality of pixels, and all of them photoelectrically convert the light in the third color wavelength range that has passed through the photoelectric conversion film.

FIG. 3 is a cross-sectional view schematically showing the configuration of the solid-state image sensor according to the first embodiment. FIG. 3 is a schematic plan view showing an arrangement of color filters when the solid-state imaging device of the first embodiment is viewed from the light receiving surface side. FIG. 3 is a schematic plan view illustrating an arrangement of colors to be detected when the solid-state imaging device according to the first embodiment is viewed from the light receiving surface side. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. Sectional drawing which shows the manufacturing method of the solid-state image sensor of 1st Embodiment. FIG. 3 is a perspective view illustrating an example of a CMOS image sensor to which the solid-state imaging element according to the first embodiment is applied. The perspective view which shows the other example of the CMOS image sensor to which the solid-state image sensor of 1st Embodiment is applied. The top view which shows an example of a vehicle provided with the camera carrying a CMOS image sensor. The top view which shows the other example of a vehicle provided with the camera carrying a CMOS image sensor. The top view which shows a smart phone provided with the camera carrying a CMOS image sensor. The top view which shows a tablet provided with the camera carrying a CMOS image sensor. Sectional drawing which shows the structure of the solid-state image sensor of 2nd Embodiment typically. The plane schematic diagram which shows the arrangement | sequence of a color filter when the solid-state image sensor of 2nd Embodiment is seen from the light-receiving surface side. The plane schematic diagram which shows the arrangement | sequence of the color detected when the solid-state image sensor of 2nd Embodiment is seen from the light-receiving surface side. The plane schematic diagram which shows the arrangement | sequence of a color filter when the solid-state image sensor of 3rd Embodiment is seen from the light-receiving surface side. The plane schematic diagram which shows the arrangement | sequence of the color detected when the solid-state image sensor of 3rd Embodiment is seen from the light-receiving surface side. Sectional drawing which shows the structure of the solid-state image sensor of 4th Embodiment typically.

Hereinafter, a solid-state imaging device according to an embodiment will be described with reference to the drawings.
In the drawings used in the following description, in order to make each component easy to see, the scale of the size may be changed depending on the component. In addition, the materials, dimensions, and the like exemplified in the following description are examples, and the embodiment is not necessarily limited thereto, and can be implemented with appropriate modifications.

(First embodiment)
FIG. 1 is a cross-sectional view schematically showing the configuration of the solid-state imaging device 1 of the first embodiment. As shown in FIG. 1, the solid-state imaging device 1 includes adjacent pixels 2a and 2b. In the solid-state imaging device 1 shown in FIG. 1, only two pixels 2a and 2b are drawn. However, in the solid-state imaging device 1 of the first embodiment, a plurality of pixels are arranged two-dimensionally.

The solid-state imaging device 1 according to the first embodiment includes a support substrate 3, a wiring unit 4, a first photoelectric conversion unit 5, a second photoelectric conversion unit 6, a color filter unit 7, and a microlens 8. .
The solid-state imaging device 1 of the first embodiment is a backside illumination type, and detects light incident on the light receiving surface 1a. The solid-state imaging device 1 is not limited to the backside illumination type, and may be a frontside illumination type.

  The support substrate 3 is a substrate for supporting the wiring part 4. As the support substrate 3, for example, a silicon (Si) wafer or the like can be used.

  The wiring part 4 is provided on the light receiving surface 1 a side of the support substrate 3. The wiring part 4 and the support substrate 3 are laminated via an adhesive layer 9. The wiring unit 4 includes an insulating layer 10, a multilayer wiring 11, and a reading transistor 12.

The insulating layer 10 is provided adjacent to the adhesive layer 9 and the first photoelectric conversion unit 5. Examples of the material of the insulating layer 10 include silicon oxide (SiO ₂ ).

  The multilayer wiring 11 is provided inside the insulating layer 10 for each of the pixels 2a and 2b, and is connected to the reading transistor 12, the storage diode 16, and a peripheral circuit (not shown). The multilayer wiring 11 can output the electric charges accumulated in the photoelectric conversion elements 13a and 13b and the storage diode 16 as an electric signal to a peripheral circuit (not shown). The material of the multilayer wiring 11 is not particularly limited as long as it is a conductive material. Specifically, for example, a refractory metal such as copper (Cu), titanium (Ti), molybdenum (Mo), tungsten (W), etc. , And refractory metal silicides such as titanium silicide (TiSi), molybdenum silicide (MoSi), tungsten silicide (WSi), and the like.

  The readout transistor 12 is provided for each of the pixels 2 a and 2 b on the surface of the wiring unit 4 on the first photoelectric conversion unit 5 side. The reading transistor 12 controls the movement of charges accumulated in the photoelectric conversion elements 13a and 13b.

  The first photoelectric conversion unit 5 is provided adjacent to the wiring unit 4 and the second photoelectric conversion unit 6. The first photoelectric conversion unit 5 includes photoelectric conversion elements 13 a and 13 b, a transparent insulating layer 14, a contact plug 15, and a storage diode 16.

  The photoelectric conversion elements 13a and 13b are provided in the p-type single crystal Si substrate 17 so as to correspond to the pixels 2a and 2b arranged in an array. The photoelectric conversion elements 13a and 13b absorb and photoelectrically convert light in a wavelength region of one of the three primary colors of light that has passed through the photoelectric conversion film 23 described later.

  Here, “three primary colors of light” are three colors of “blue”, “green”, and “red”. The wavelength range of blue light (light in the blue wavelength range) is 400 to 500 nm, the wavelength range of green light (light in the green wavelength range) is 500 to 600 nm, and red light (light in the red wavelength range). The wavelength region is 600 to 700 nm.

In the solid-state imaging device 1 of the first embodiment, all the photoelectric conversion elements including the photoelectric conversion elements 13a and 13b are arranged to absorb light in the same wavelength range.
For example, when the photoelectric conversion elements 13a and 13b absorb red light, all the other photoelectric conversion elements are also arranged to absorb red light.

  Examples of the photoelectric conversion elements 13a and 13b include an n-type impurity diffusion region 18 provided in the p-type single crystal Si substrate 17. A PN junction surface is formed between the p-type single crystal Si substrate 17 and the n-type impurity diffusion region 18. In the first embodiment, the photoelectric conversion elements 13a and 13b are not limited to the n-type impurity diffusion region provided in the p-type single crystal Si substrate, but are provided in the n-type single crystal Si substrate. Alternatively, it may be a p-type impurity diffusion region.

  A p-type single crystal Si substrate (substrate) 17 is provided adjacent to the wiring portion 4 and the transparent insulating layer 14. As the p-type single crystal Si substrate 17, for example, Si doped with a p-type impurity such as boron can be used. Examples of the n-type impurity diffusion region 18 include a material in which an n-type impurity such as phosphorus is ion-implanted into Si.

The transparent insulating layer 14 is provided adjacent to the p-type single crystal Si substrate 17 and the second photoelectric conversion unit 6. The transparent insulating layer 14 insulates the photoelectric conversion film 23 and the p-type single crystal Si substrate 17 while transmitting light. Examples of the material of the transparent insulating layer 14 include SiO ₂ .

  The contact plug 15 is provided so as to penetrate the p-type single crystal Si substrate 17 and electrically connects the wiring portion 4 and the second photoelectric conversion portion 6. In addition, the contact plug 15 is arranged for each of the pixels 2a and 2b so as to be located in a region surrounded on all sides by the photoelectric conversion elements 13a and 13b.

  The contact plug 15 is electrically connected to the lower transparent electrode 21 and the storage diode 16, and can transmit the charges collected by the lower transparent electrode 21 to the storage diode 16. The contact plug 15 includes a conductive film 19 and an insulating film 20. The material of the conductive film 19 is not particularly limited as long as it is a conductive material, but specific examples include Si and the like. Further, the material of the insulating film 20 is not particularly limited as long as it is an insulating material, and specific examples include silicon nitride (SiN).

  The storage diode 16 is provided at the end of the contact plug 15 on the wiring part 4 side. The storage diode 16 temporarily accumulates the charges collected by the lower transparent electrode 21. The floating diffusion (not shown) is provided in the p-type single crystal Si substrate 17. The accumulated electric charge is sent from the storage diode 16 to a floating diffusion (not shown) and converted into an electric signal.

  The second photoelectric conversion unit 6 is provided adjacent to the first photoelectric conversion unit 5 and the color filter unit 7. The second photoelectric conversion unit 6 includes a lower transparent electrode 21, an upper transparent electrode 22, a photoelectric conversion film 23, and an inorganic protective film 24.

  The lower transparent electrode 21 is provided for each of the pixels 2a and 2b on the surface of the transparent insulating layer 14 on the light receiving surface 1a side. Further, the peripheral edge portion of the projection region formed by projecting the lower transparent electrode 21 onto the p-type single crystal Si substrate 17 overlaps the light receiving surfaces of the photoelectric conversion elements 13a and 13b in plan view. Examples of the material of the lower transparent electrode 21 include a transparent conductive material such as indium tin oxide (ITO).

The upper transparent electrode 22 is provided as a sheet on the surface of the photoelectric conversion film 23 on the light receiving surface 1a side so as to cover the plurality of photoelectric conversion elements 13a and 13b. A bias voltage supplied from the outside can be applied to the photoelectric conversion film 23 by the upper transparent electrode 22.
Due to the bias voltage, the charges generated in the photoelectric conversion film 23 can be collected in each lower transparent electrode 21. Examples of the material of the upper transparent electrode 22 include a transparent conductive material such as indium tin oxide (ITO).

  The photoelectric conversion film 23 is provided as a sheet across the plurality of pixels 2 a and 2 b so as to be adjacent between the lower transparent electrode 21 and the upper transparent electrode 22. The photoelectric conversion film 23 absorbs light in any two color wavelength ranges of the three primary colors of light and performs photoelectric conversion, and transmits light in the remaining one color wavelength range. For example, when blue light and green light are absorbed by the photoelectric conversion film 23, red light is transmitted. The transmitted red light is absorbed by the photoelectric conversion elements 13a and 13b.

  Hereinafter, the light of the two color wavelength ranges absorbed by the photoelectric conversion film 23 is referred to as “light of the first color wavelength range” and “light of the second color wavelength range”, and the wavelength of the remaining one color that is transmitted. The light in the region is referred to as “light in the third color wavelength region”. That is, the above-described photoelectric conversion elements 13a and 13b absorb light in the third color wavelength range.

  As a material for the photoelectric conversion film 23, when absorbing blue light, for example, at least one of a porphyrin cobalt complex, a coumarin derivative, a fullerene, a fullerene derivative, a fluorene compound, a pyrazole derivative, and the like can be selected. it can.

  When green light is absorbed, at least one of quinacridone derivatives, perylene bisimide derivatives, oligothiophene derivatives, subphthalocyanine derivatives, rhodamine compounds, ketocyanine derivatives, and the like can be selected.

When red light is absorbed, at least one of phthalocyanine derivatives, squarylium derivatives, subnaphthalocyanine derivatives, and the like can be selected.
Since the above materials have high light absorptance, the thickness of the photoelectric conversion film 23 can be reduced. Further, crosstalk between pixels can be suppressed.

The inorganic protective film 24 is provided as a single sheet on the surface of the upper transparent electrode 22 on the light receiving surface 1a side. Examples of the material of the inorganic protective film 24 include aluminum oxide (Al ₂ O ₃ ).

  The color filter unit 7 is provided adjacent to the second photoelectric conversion unit 6 and the microlens 8. The color filter unit 7 includes a planarization layer 25 and a plurality of first color filters 26a and second color filters 26b.

  The planarization layer 25 is provided adjacent to the second photoelectric conversion unit 6 and the microlens 8. As a material for the planarization layer 25, for example, a polythiophene derivative is doped with polystyrene sulfonic acid. Specifically, a poly (3,4-ethylenedioxythiophene): poly (styrene sulfonic acid) mixture ( PEDOT: PSS) and the like.

  A plurality of first color filters 26a and second color filters 26b are provided in the planarization layer 25 and are provided so as to face the photoelectric conversion elements 13a and 13b. The first color filter 26a absorbs light in the wavelength band of the first color and transmits light in the wavelength bands of the second and third colors. The second color filter 26b absorbs light in the wavelength band of the second color and transmits light in the wavelength bands of the first and third colors.

  For example, the first color filter 26a absorbs blue (first color) light and transmits green (second color) light and red (third color) light. On the other hand, the second color filter 26b absorbs green (second color) light and transmits blue (first color) light and red (third color) light.

  By appropriately selecting the wavelength range of light absorbed by the first color filter 26a and the second color filter 26b, the wavelength range of light absorbed by the photoelectric conversion film 23 can be selected.

  FIG. 2 is a schematic plan view showing the arrangement of the first color filter 26a and the second color filter 26b when the solid-state imaging device 1 of the first embodiment is viewed from the light receiving surface 1a side. As shown in FIG. 2, the first color filter 26a and the second color filter 26b are alternately provided for each of the pixels 2a, 2b, 2c, and 2d.

  The microlens 8 is provided on the light receiving surface 1a side of the color filter portion 7 at a position facing the photoelectric conversion elements 13a and 13b. The micro lens 8 can be, for example, a circular lens in a plan view, and incident light can be collected by the micro lens 8. The optical center of each microlens 8 is at the center of the light receiving surface of each photoelectric conversion element 13a, 13b. The planar view area of the microlens 8 is larger than the areas of the light receiving surfaces of the photoelectric conversion elements 13a and 13b.

Next, an outline of the operation of the solid-state imaging device 1 of the embodiment will be described with reference to FIG. Here, the operation of the pixel 2a will be described.
First, of the light incident from the microlens 8, the first color filter 26a absorbs light in the first color wavelength range and transmits light in the second and third color wavelength ranges. The transmitted light in the wavelength regions of the second and third colors reaches the photoelectric conversion film 23.

  Next, the photoelectric conversion film 23 absorbs light in the wavelength region of the second color and performs photoelectric conversion to generate charges. At this time, the amount of charge generated varies with the amount of incident light. The generated charge is stored in the storage diode 16.

  Next, the photoelectric conversion element 13a absorbs light in the wavelength region of the third color and performs photoelectric conversion to generate and accumulate charges. At this time, the amount of charge generated varies with the amount of incident light.

  Next, the electric charges accumulated in the storage diode 16 and the photoelectric conversion element 13a are sent to a floating diffusion (not shown). The electric charge sent to the floating diffusion is converted into an electric signal and sent to a peripheral circuit (not shown) via the multilayer wiring 11. As described above, the pixel 2a can separately detect light in the wavelength regions of two types of colors. Further, the wavelength range of the light to be detected can be selected by selecting the wavelength range of the light that can be transmitted by the first color filter 26a.

  FIG. 3 is a schematic plan view illustrating an arrangement of colors to be detected when the solid-state imaging device 1 according to the first embodiment is viewed from the light receiving surface 1a side. FIG. 3 shows an array of colors to be detected for four adjacent 2 × 2 pixels. In addition, one square represents one pixel 2a, 2b, 2c, and 2d. The color above the diagonal line in the square is the color in the wavelength range of light that is photoelectrically converted by the photoelectric conversion film, and the color below is photoelectric. The color of the wavelength range of the light photoelectrically converted by the conversion element is shown. “B” indicates blue of the three primary colors, “G” indicates green, and “R” indicates red.

  Here, as an example, blue (first color) light and green (second color) light are photoelectrically converted by the photoelectric conversion film, and red (third color) light is photoelectrically converted by the photoelectric conversion element. The case will be shown. The pixels 2a and 2d are provided with a first color filter 26a that absorbs blue (first color) light and transmits green (second color) light and red (third color) light. It has been. On the other hand, the pixels 2b and 2c are provided with a second color filter 26b that absorbs green (second color) light and transmits blue (first color) light and red (third color) light. It has been.

  As shown in FIG. 3, in the pixels 2a and 2d, since the green light and the red light are transmitted by the first color filter 26a, the green light is photoelectrically converted in the photoelectric conversion film. Moreover, the red light which permeate | transmitted the photoelectric converting film is photoelectrically converted in a photoelectric conversion element. On the other hand, in the pixels 2b and 2c, since the blue light and the red light are transmitted by the second color filter 26b, the blue light is photoelectrically converted in the photoelectric conversion film. Moreover, the red light which permeate | transmitted the photoelectric converting film is photoelectrically converted in a photoelectric conversion element.

  Next, a method for manufacturing the solid-state imaging device 1 according to the first embodiment will be described with reference to FIGS. 4-12 is sectional drawing which shows the manufacturing method of the solid-state image sensor 1 of 1st Embodiment.

  First, as shown in FIG. 4, a p-type single crystal Si substrate 17 is formed by epitaxially growing a Si layer doped with a p-type impurity such as boron on a semiconductor substrate 31 such as a Si wafer.

  Next, for example, n-type impurities such as phosphorus are ion-implanted into the p-type single crystal Si substrate 17 for each of the pixels 2a and 2b, and an annealing process is performed. A type impurity diffusion region 18 is disposed. Thus, in the solid-state imaging device 1, photoelectric conversion elements 13a and 13b, which are photodiodes, are formed by a PN junction between the p-type single crystal Si substrate 17 and the n-type impurity diffusion region 18.

  Next, another n-type impurity diffusion region such as the storage diode 16 is formed on the inner surface of the p-type single crystal Si substrate 17 by performing ion implantation of an n-type impurity such as phosphorus and annealing. . Further, if necessary, a pixel isolation region or the like (not shown) can be formed by ion-implanting a p-type impurity such as boron and performing an annealing process.

  Next, the insulating layer 10 is formed on the p-type single crystal Si substrate 17 together with the multilayer wiring 11 and the reading transistor 12. Specifically, after forming the readout transistor 12 and the like on the upper surface of the p-type single crystal Si substrate 17, a step of forming an Si oxide layer, a step of forming a predetermined wiring pattern on the Si oxide layer, and a wiring pattern The process of embedding Cu or the like inside is repeated. As a result, the insulating layer 10 in which the multilayer wiring 11 and the reading transistor 12 are provided is formed.

  Next, an adhesive is applied to the upper surface of the insulating layer 10 to provide an adhesive layer 9, and a support substrate 3 such as a Si wafer is attached to the upper surface of the adhesive layer 9. Note that the insulating layer 10 and the support substrate 3 are bonded by polishing by CMP (Chemical Mechanical Polishing) or the like so that the surface of the insulating layer 10 is flat and smooth instead of bonding with an adhesive. It is also possible to directly bond to the substrate 3.

Next, the surface of the Si wafer having the photoelectric conversion elements 13a and 13b on the opposite side of the support substrate 3 is thinned to a predetermined thickness by a grinding device such as a grinder. Thereafter, the surface of the semiconductor substrate is polished by a polishing apparatus such as CMP, and the damaged layer on the surface of the semiconductor substrate is removed by wet etching or the like. As a result, the light receiving surface of the p-type single crystal Si substrate 17 is exposed as shown in FIG. Thereafter, a transparent insulating layer 14 made of a transparent insulating material such as SiO ₂ is formed on the upper surface of the p-type single crystal Si substrate 17.

  Next, as shown in FIG. 6, the transparent insulating layer 14 and the p-type single crystal Si substrate 17 at positions surrounded by the respective photoelectric conversion elements are bonded to the upper end of the storage diode 16 by, for example, RIE (Reactive Ion Etching). Remove until. Thereby, the trench 32 is formed. An insulating film 20 made of an insulating material such as SiN is formed on the inner surface of the trench 32 by, for example, a CVD (Chemical Vapor Deposition) method.

  Next, as shown in FIG. 7, a conductive film 19 made of a conductive material such as Si is embedded in the trench 32 whose inner surface is covered with the insulating film 20 by, for example, a CVD method. Note that the conductive film 19 is subjected to annealing after ion-implanting n-type impurities such as phosphorus before and after the step of forming an impurity diffusion region such as the storage diode 16 instead of the above-described method. It is also possible to form a diffusion region and use the n-type impurity diffusion region as the conductive film 19.

  Next, as shown in FIG. 8, a conductive layer 33 made of a transparent conductive material such as ITO is formed on the upper surface of the transparent insulating layer 14 and the exposed upper surface of the contact plug 15.

  Next, as shown in FIG. 9, for example, a resist is applied to the upper surface of the conductive layer 33, and a portion of the resist where the lower transparent electrode 21 is to be formed is left by photolithography, and the other resist is removed. Using the remaining resist 34 as a mask, for example, RIE is performed to remove a portion of the conductive layer not covered with the resist, and the lower transparent electrode 21 is formed as shown in FIG. Thereafter, the resist 34 used as a mask is removed.

  Next, as shown in FIG. 11, the photoelectric conversion film 23 is formed on the upper surface of the lower transparent electrode 21 by, for example, a vacuum deposition method. The photoelectric conversion film 23 is made of, for example, a material having a property of selectively absorbing green light and blue light and transmitting red light. Specifically, the photoelectric conversion film 23 is formed by selecting one material each for selectively absorbing light in two desired wavelength ranges and co-depositing them.

Next, the upper transparent electrode 22 made of a transparent conductive material such as ITO is formed on the upper surface of the photoelectric conversion film 23 by, for example, a sputtering method. Thereafter, an inorganic protective film 24 made of, for example, Al ₂ O ₃ is formed on the upper transparent electrode 22 by, eg, sputtering. Thereafter, a planarizing layer 25 made of a transparent resin is formed on the inorganic protective film 24 as shown in FIG.

  Next, at the positions of the planarization layer 25 facing the light receiving surfaces of the photoelectric conversion elements 13a and 13b, for example, the first and first photolithography is performed by photolithography using a color filter pigment or dye that transmits green and red. Two color filters 26a and 26b are formed. Then, a planarizing layer 25 made of a transparent resin is further formed so as to cover the first and second color filters 26a and 26b. As a result, the first and second color filters 26 a and 26 b are embedded in the planarization layer 25.

  Finally, a microlens 8 made of, for example, an acrylic organic compound is covered on the upper surface of the planarizing layer 25 at a position facing the light receiving surface of each of the photoelectric conversion elements 13a and 13b in plan view. Form in size. As described above, the solid-state imaging device 1 of the first embodiment is manufactured.

  As described above, according to the solid-state imaging device 1 of the first embodiment, the photoelectric conversion elements 13a and 13b of each pixel photoelectrically convert light in the same wavelength range, so that noise due to crosstalk is reduced. Can do.

  Further, according to the solid-state imaging device 1 of the first embodiment, since the photoelectric conversion film 23 is used, it is not necessary to focus on the photoelectric conversion film 23. Therefore, the installation area of the microlens 8 can be increased, and the amount of light incident on the light receiving surfaces of the photoelectric conversion elements 13a and 13b can be greatly increased.

  Moreover, according to the solid-state image sensor 1 of 1st Embodiment, the photoelectric converting film 23 can absorb the light of the wavelength range of two colors among three primary colors of light. For this reason, the degree of freedom in selecting a material used for the photoelectric conversion film 23 is high.

  Further, according to the solid-state imaging device 1 of the first embodiment, green light having the highest relative luminous efficiency is detected in all pixels by changing the light absorbed by the photoelectric conversion elements 13a and 13b to green light. Therefore, the luminance S / N can be improved.

FIG. 13 is a perspective view illustrating an example of a CMOS image sensor 41 to which the solid-state imaging device 1 of the first embodiment is applied. The CMOS image sensor 41 is a Full HD (1080p) type CMOS image sensor. The CMOS image sensor 41 includes the solid-state imaging device 1 and a mold resin 42.
The mold resin 42 is provided so as to cover other than the light receiving surface 1 a of the solid-state imaging device 1. By integrating the solid-state imaging device 1 and the mold resin 42, the solid-state imaging device 1 can be protected from external stress, moisture, and contaminants.

  The CMOS image sensor 41 is used in various mobile terminals such as a digital camera and a mobile phone (including a smartphone), an imaging device such as a monitoring camera and a web camera using the Internet.

FIG. 14 is a perspective view showing another example of the CMOS image sensor 51 to which the solid-state imaging device 1 of the first embodiment is applied. The CMOS image sensor 51 is a VGA type CMOS image sensor. The CMOS image sensor 51 includes a solid-state imaging device 1 and a mold resin 52.
The mold resin 52 is provided so as to cover other than the light receiving surface 1 a of the solid-state imaging device 1. By integrating the solid-state imaging device 1 and the mold resin 52, the solid-state imaging device 1 can be protected from external stress, moisture, and contaminants.

  The CMOS image sensor 51 is used in various mobile terminals such as a digital camera and a mobile phone (including a smartphone), an imaging device such as a surveillance camera and a web camera using the Internet.

  FIG. 15 is a plan view showing an example of a car 61 including a camera 62 on which the above-described CMOS image sensor 41 or CMOS image sensor 51 is mounted. The car 61 includes a camera 62 and a display 63. The camera 62 is provided at the front end of the car 61 and can photograph the front of the car 61. The display 63 is provided in front of the driver's seat of the car 61 and can display an image taken by the camera 62. By confirming the image photographed by the camera 62 on the display 63, the blind spot can be confirmed at the time of parking, for example.

  FIG. 16 is a plan view showing another example of a car 71 including a camera 72 equipped with the CMOS image sensor 41 or the CMOS image sensor 51 described above. The car 71 includes a camera 72 and a display 73. The camera 72 is provided at the rear end of the car 71 and can photograph the rear of the car 71. The display 73 is provided in front of the driver's seat of the car 71 and can display an image taken by the camera 72. By confirming the image photographed by the camera 72 on the display 73, the rear side can be confirmed.

  FIG. 17 is a plan view showing a smartphone 81 including a camera on which the above-described CMOS image sensor 41 or CMOS image sensor 51 is mounted. The smartphone 81 includes a camera (not shown) and a touch panel 82. For example, when the camera is provided in the upper front portion of the smartphone 81, the camera can photograph the front surface of the smartphone 81. The touch panel 82 is provided in the center of the front of the smartphone and can display an image taken by the camera.

  FIG. 18 is a plan view showing a tablet 91 including a camera equipped with the CMOS image sensor 41 or the CMOS image sensor 51 described above. The tablet 91 includes a camera (not shown) and a touch panel 92. For example, when the camera is provided in the upper front portion of the tablet 91, the front of the tablet 91 can be photographed. The touch panel 92 is provided in the center of the front of the tablet and can display an image taken by the camera.

(Second Embodiment)
FIG. 19 is a cross-sectional view schematically showing the configuration of the solid-state imaging device 101 of the second embodiment.
The solid-state imaging device 101 according to the second embodiment includes a support substrate 3, a wiring unit 4, a first photoelectric conversion unit 5, a second photoelectric conversion unit 6, a color filter unit 7, a microlens 8, Is provided. That is, the solid-state imaging device 101 of the second embodiment is the same as that of the first embodiment except that some of the pixels do not include the color filter 103, and description of similar parts is omitted.

  FIG. 20 is a schematic plan view showing the arrangement of the color filters 103 when the solid-state imaging device 101 according to the second embodiment is viewed from the light receiving surface 1a side. As shown in FIG. 20, the pixels 102a and 102d provided with the color filter 103 and the pixels 102b and 102c not provided with the color filter 103 are alternately provided.

  FIG. 21 is a schematic plan view illustrating an arrangement of colors to be detected when the solid-state imaging device 101 according to the second embodiment is viewed from the light receiving surface 1a side. FIG. 21 shows an arrangement of colors to be detected for four adjacent 2 × 2 pixels, as in FIG. 3. Further, one square represents one pixel 102a, 102b, 102c, and 102d. The color above the diagonal line in the square is the color in the wavelength range of the light photoelectrically converted by the photoelectric conversion film 23, and the color below is the color. The color of the wavelength range of the light photoelectrically converted by the photoelectric conversion element is shown. “G” indicates green among the three primary colors, “B” indicates blue, and “R” indicates red.

  Here, as an example, the color filter 103 absorbs blue (first color) light and transmits green (second color) light and red (third color) light. The photoelectric conversion film photoelectrically converts blue (first color) light and green (second color) light, and the photoelectric conversion element photoelectrically converts red (third color) light. In the solid-state imaging device 101 according to the second embodiment, a blend color composed of two colors of blue and green is detected by the photoelectric conversion film in the pixels 102b and 102c where the color filter 103 is not provided.

  In the method of manufacturing the solid-state imaging device 101 according to the second embodiment, after forming the inorganic protective film 24 as shown in FIG. 11 described above, the color filters 103 are formed every other pixel. Thereafter, the solid-state imaging device 101 of the second embodiment can be manufactured in the same manner as the solid-state imaging device 1 of the first embodiment.

  According to the solid-state imaging device 101 of the second embodiment, since the number of color filters is halved compared to the first embodiment, the material cost can be suppressed.

(Third embodiment)
The solid-state imaging device 111 according to the third embodiment includes a support substrate 3, a wiring unit 4, a first photoelectric conversion unit 5, a second photoelectric conversion unit 6, a color filter unit 7, and a microlens 8. . In the third embodiment, the color filter 103 is provided in three arbitrarily selected pixels among four adjacent 2 × 2 pixels, and the arrangement of the color filters 103 is the same as that in the second embodiment. Different. Other than that, the second embodiment is the same as the second embodiment, and the description of the same parts is omitted.

  FIG. 22 is a schematic plan view illustrating the arrangement of the color filters 103 when the solid-state imaging device 111 according to the third embodiment is viewed from the light receiving surface 1a side. As shown in FIG. 22, the color filter 103 is provided in three arbitrarily selected pixels 112a, 112c, and 112d out of four adjacent 2 × 2 pixels 112a, 112b, 112c, and 112d.

  FIG. 23 is a schematic plan view illustrating an arrangement of colors to be detected when the solid-state imaging device 111 according to the third embodiment is viewed from the light receiving surface 1a side. FIG. 23 shows an array of colors to be detected for four adjacent 2 × 2 pixels, as in FIG. 3. In addition, one pixel 112a, 112b, 112c, and 112d is shown by one square, and the color above the diagonal line in the square is the color in the wavelength range of the light that is photoelectrically converted by the photoelectric conversion film 23, and the color below is The color of the wavelength range of the light photoelectrically converted by the photoelectric conversion element is shown. “G” indicates green among the three primary colors, “B” indicates blue, and “R” indicates red.

  Here, as an example, the color filter 103 absorbs blue (first color) light and transmits green (second color) light and red (third color) light. The photoelectric conversion film photoelectrically converts blue (first color) light and green (second color) light, and the photoelectric conversion element photoelectrically converts red (third color) light. In the solid-state imaging device 111 according to the third embodiment, in the pixel 102b where the color filter 103 is not provided, the photoelectric conversion film detects a blend color composed of two colors of blue and green.

  According to the solid-state imaging device 111 of the third embodiment, when green light is detected by the photoelectric conversion film, the green sampling point having the highest specific luminous efficiency is 1.5 times that of the first embodiment. Therefore, the luminance S / N can be improved.

(Fourth embodiment)
FIG. 24 is a cross-sectional view schematically showing the configuration of the solid-state imaging device 121 of the fourth embodiment.
The solid-state imaging device 121 according to the fourth embodiment includes a support substrate 3, a wiring unit 4, a first photoelectric conversion unit 5, a second photoelectric conversion unit 6, a color filter unit 7, and a microlens 8. And a planarization layer 122. That is, the solid-state imaging device 121 of the fourth embodiment is the same as that of the first embodiment except that the flattening layer 122 is provided, and the description of the same parts is omitted.

  The planarizing layer 122 is provided adjacent to the lower transparent electrode 21 and the transparent insulating layer 14 and the photoelectric conversion film 23, and smoothes the irregularities on the surfaces of the lower transparent electrode 21 and the transparent insulating layer 14. Can do. Examples of the material of the planarizing layer 122 include polymethyl methacrylate.

  As shown in FIG. 10 described above, after the lower transparent electrode 21 is formed, the planarizing layer 122 is coated with a transparent resin on the lower transparent electrode 21 and the transparent insulating layer 14 by a coating process such as spin coating. Can be formed. After the planarization layer 122 is formed, the photoelectric conversion film 23 is applied on the planarization layer 122, and thereafter, the solid-state imaging device 1 of the first embodiment is used, and then the solid-state of the fourth embodiment. The imaging element 121 can be manufactured.

  According to the solid-state imaging device 121 of the fourth embodiment, the influence of the surface irregularities of the lower transparent electrode 21 and the transparent insulating layer 14 on the photoelectric conversion film 23 is reduced, and the upper transparent electrode 22 and the lower transparent electrode 21 are short-circuited. Can be prevented. As a result, dark current (current flowing through the photoelectric conversion film 23 during light shielding) is reduced, and S / N can be improved.

  In the fourth embodiment, the planarizing layer 122 is provided so as to be adjacent to the lower transparent electrode 21 and the transparent insulating layer 14 and the photoelectric conversion film 23. However, in the other embodiments, the planarizing layer is similarly provided. 122 may be provided. Thereby, also in other embodiments, dark current (current flowing through the photoelectric conversion film 23 during light shielding) is reduced, and S / N can be improved.

  According to at least one embodiment described above, noise due to crosstalk can be reduced by having the photoelectric conversion film 23 and the plurality of photoelectric conversion elements 13a and 13b.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1, 101, 111, 121 ... Solid-state image sensor, 1a ... Light-receiving surface, 2a, 2b, 2c, 2d ... Pixel, 3 ... Support substrate, 4 ... Wiring part, 5 ... 1st photoelectric conversion part, 6 ... 2nd 7 ... color filter part, 8 ... microlens, 9 ... adhesive layer, 10 ... insulating layer, 11 ... multilayer wiring, 12 ... read transistor, 13a, 13b ... photoelectric conversion element, 14 ... transparent insulating layer , 15 ... contact plug, 16 ... storage diode, 17 ... p-type single crystal Si substrate (substrate), 18 ... n-type impurity diffusion region, 19 ... conductive film, 20 ... insulating film, 21 ... lower transparent electrode, 22 ... upper part Transparent electrode, 23 ... photoelectric conversion film, 24 ... inorganic protective film, 25 ... flattening layer, 26a ... first color filter, 26b ... second color filter, 31 ... semiconductor substrate, 32 ... trench, 33 ... conductive layer , 34 ... Strike, 41, 51 ... CMOS image sensor, 42, 52 ... mold resin, 61, 71 ... car, 62, 72 ... camera, 63, 73 ... display, 81 ... smartphone, 82 ... touch panel, 91 ... tablet, 92 ... touch panel , 102a, 102b, 102c, 102d ... pixel, 103 ... color filter, 112a, 112b, 112c, 112d ... pixel, 122 ... flattening layer

Claims (11)

Provided across a plurality of pixels on one surface side of the substrate, absorbs light in the wavelength regions of any of the first and second colors in the three primary colors of light and performs photoelectric conversion, and A photoelectric conversion film that transmits light in the wavelength range;
A plurality of photoelectric conversion elements which are provided in the substrate so as to correspond to the plurality of pixels and which absorb and photoelectrically convert light in the wavelength region of the third color transmitted through the photoelectric conversion film;
A solid-state imaging device. It is provided so as to face any of the photoelectric conversion elements across the photoelectric conversion film, and absorbs light in the wavelength range of the first color and emits light in the wavelength range of the second and third colors. A first color filter to transmit;
It is provided so as to face any of the photoelectric conversion elements across the photoelectric conversion film, and absorbs light in the wavelength region of the second color and emits light in the wavelength region of the first and third colors. A second color filter to transmit;
The solid-state imaging device according to claim 1, comprising:   The solid-state imaging device according to claim 2, wherein a pixel provided with the first color filter and a pixel provided with the second color filter are alternately provided.   It is provided so as to face any of the photoelectric conversion elements across the photoelectric conversion film, and absorbs light in the wavelength range of the first color and emits light in the wavelength range of the second and third colors. The solid-state imaging device according to claim 1, further comprising a color filter that transmits light.   The solid-state imaging device according to claim 4, wherein a pixel provided with the color filter and a pixel not provided with the color filter are alternately provided.   The solid-state imaging device according to claim 4, wherein the color filter is provided in three arbitrarily selected pixels among four adjacent 2 × 2 pixels.   The photoelectric conversion film has at least one of a porphyrin cobalt complex, a coumarin derivative, a fullerene, a fullerene derivative, a fluorene compound, and a pyrazole derivative as a material that absorbs light in the blue wavelength region of the three primary colors of light. The solid-state image sensor of Claim 1 containing this.   The photoelectric conversion film is a material that absorbs light in the green wavelength region of the three primary colors of light. The solid-state imaging device according to claim 1, comprising at least one.   The photoelectric conversion film includes at least one of a phthalocyanine derivative, a squarylium derivative, and a subnaphthalocyanine derivative as a material that absorbs light in a red wavelength region of the three primary colors of light. Solid-state image sensor. A plurality of lower transparent electrodes provided on the light-receiving surface side of the substrate;
A planarization layer provided between the photoelectric conversion film and the lower transparent electrode;
The solid-state imaging device according to claim 1, comprising:   The solid-state image sensor of Claim 1 whose light absorbed by the said photoelectric conversion element is light of a green wavelength range.

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