WO2021149350A1 - Imaging element and imaging device - Google Patents

Imaging element and imaging device Download PDF

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Publication number
WO2021149350A1
WO2021149350A1 PCT/JP2020/044033 JP2020044033W WO2021149350A1 WO 2021149350 A1 WO2021149350 A1 WO 2021149350A1 JP 2020044033 W JP2020044033 W JP 2020044033W WO 2021149350 A1 WO2021149350 A1 WO 2021149350A1
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Prior art keywords
region
semiconductor substrate
image pickup
pickup device
photoelectric conversion
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PCT/JP2020/044033
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French (fr)
Japanese (ja)
Inventor
純 井手渕
昭一 廣岡
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ソニーセミコンダクタソリューションズ株式会社
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Publication of WO2021149350A1 publication Critical patent/WO2021149350A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/76—Making of isolation regions between components
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144—Devices controlled by radiation
    • H01L27/146—Imager structures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/70—SSIS architectures; Circuits associated therewith
    • H04N25/76—Addressed sensors, e.g. MOS or CMOS sensors

Definitions

  • the present disclosure relates to an image pickup device and an image pickup device. More specifically, the present invention relates to an image pickup device having a separation region for separating pixels and an image pickup device using the image pickup device.
  • an image sensor configured by arranging a plurality of pixels for generating an image signal.
  • a photoelectric conversion unit that performs photoelectric conversion of incident light is arranged in the pixel, and an image signal is generated based on the electric charge generated by the photoelectric conversion.
  • the photoelectric conversion unit of these a plurality of pixels is arranged on the semiconductor substrate. Therefore, the photoelectric conversion unit of each pixel is arranged adjacent to the semiconductor substrate. Further, in the semiconductor substrate, a separation region is arranged at the boundary between adjacent pixels. This is to insulate image signals and the like for each pixel.
  • this separation region a separation region formed by filling a groove (trench) formed in a semiconductor substrate with an insulating material is used. Since grooves are formed on the semiconductor substrate, higher insulation resistance can be obtained as compared with the method of separating using a pn junction.
  • an interface state is formed on the surface of the groove formed on the semiconductor substrate. The current based on the capture of electric charge by the interface state and the emission of electric charge from the interface state is called a dark current, which causes noise in the image signal. In order to reduce this noise, it is necessary to prevent the transfer of electric charge with respect to the interface state. This can be done by pinning the interface state. This pinning limits the transfer of charge by terminating the electric field from the interface state. Specifically, pinning can be performed by arranging a semiconductor region having a relatively high impurity concentration around the separated region having a groove. This semiconductor region can be formed by injecting a high concentration of impurities into the semiconductor substrate around the separation region.
  • Impurities can be implanted by ion implantation.
  • ion implantation When a relatively deep groove is formed in the separation region, it becomes difficult to implant impurities by ion implantation. This is because high implantation energy is required and it is necessary to form a thick resist to be used as a mask for ion implantation.
  • the injection of high-energy ions also causes a problem that a large number of lattice defects are generated in the semiconductor substrate.
  • This solid phase diffusion is a method of diffusing impurities into a semiconductor substrate by depositing a solid thin film containing a large amount of impurities on the semiconductor substrate and heating the solid thin film.
  • a thin film containing impurities is placed on the inner wall of the grooves and heated to a temperature of several hundred to 1000 degrees Celsius to form a semiconductor region having a high impurity concentration around the grooves. Can be done.
  • the solid phase diffusion method it is necessary to form a groove on the surface side of the semiconductor substrate before forming the wiring region to perform solid phase diffusion. This is because a heating process is required.
  • a groove penetrating the semiconductor substrate In order to improve the separation ability of the separation region, it is necessary to form a groove penetrating the semiconductor substrate. This can be done by forming a groove and a wiring region on the front surface side of the semiconductor substrate, and then grinding the back surface of the semiconductor substrate to thin the semiconductor substrate until the bottom of the groove is exposed.
  • a solid-state image sensor in which p-type and n-type diffusion layers are formed by solid-phase diffusion on the side wall of a trench formed between pixels has been proposed (for example, Patent Document 1). reference.).
  • the above-mentioned conventional technique has a problem that the strength of the semiconductor substrate is lowered.
  • the back surface side of the semiconductor substrate is ground to expose the bottom of the groove formed from the front surface side of the semiconductor substrate, the region of the semiconductor substrate of each pixel is separated by the groove. Therefore, the strength of the semiconductor substrate is lowered, which causes a problem that the semiconductor substrate separated in the grinding process is detached and damaged.
  • the present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to reduce a decrease in the strength of an image sensor in which a semiconductor substrate is separated for each pixel.
  • the present disclosure has been made in order to solve the above-mentioned problems, and the first aspect thereof is on a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of incident light, and on the surface side of the semiconductor substrate.
  • a plurality of pixels having a wiring region in which wiring for transmitting the signal of the photoelectric conversion unit is arranged, a separation region for separating the semiconductor substrate between the plurality of pixels, and a gap formed in the separation region.
  • It is an image pickup device including a non-separable region formed of the above-mentioned semiconductor substrate.
  • the separation region may be arranged in a recess formed on the surface side of the semiconductor substrate.
  • the separation region may be arranged in the recess that penetrates the semiconductor substrate.
  • the separation region may be arranged in the recess formed by the circular opening.
  • the separation region may be formed by arranging a metal in the recess.
  • the separation region may be configured by arranging polycrystalline silicon in the recess.
  • the separation region may include a side wall film having a shape that covers the surface of the semiconductor substrate in the recess.
  • the non-separable region may be formed in a conductive type different from the semiconductor region constituting the photoelectric conversion unit.
  • the non-separable region may be formed in the conductive type by impurities diffused from a member containing impurities arranged in a recess formed in the semiconductor substrate.
  • the non-separable region may be composed of the semiconductor substrate in the gap portion of 2 times or less the diffusion distance of the impurities.
  • the non-separable region may be composed of the semiconductor substrate in the gap portion having a width of 1/4 of the wavelength of the incident light.
  • the non-separable region may be arranged on the back surface side of the semiconductor substrate.
  • a semiconductor region which is formed in a conductive type different from the semiconductor region constituting the photoelectric conversion unit and is arranged between the separation region and the photoelectric conversion unit may be further provided. ..
  • a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of incident light and wiring arranged on the surface side of the semiconductor substrate to transmit signals of the photoelectric conversion unit are arranged.
  • the region of the semiconductor substrate is left in the gap portion of the separation region arranged at the boundary of the pixels.
  • FIG. 1 is a diagram showing a configuration example of an image sensor according to an embodiment of the present disclosure.
  • the image sensor 1 in the figure includes a pixel array unit 10, a vertical drive unit 20, a column signal processing unit 30, and a control unit 40.
  • the pixel array unit 10 is configured by arranging the pixels 100 in a two-dimensional grid pattern.
  • the pixel 100 generates an image signal according to the irradiated light.
  • the pixel 100 has a photoelectric conversion unit that generates an electric charge according to the irradiated light.
  • the pixel 100 further has a pixel circuit. This pixel circuit generates an image signal based on the electric charge generated by the photoelectric conversion unit. The generation of the image signal is controlled by the control signal generated by the vertical drive unit 20 described later.
  • the signal lines 11 and 12 are arranged in the pixel array unit 10 in an XY matrix.
  • the signal line 11 is a signal line that transmits a control signal of the pixel circuit in the pixel 100, is arranged for each line of the pixel array unit 10, and is commonly wired to the pixel 100 arranged in each line.
  • the signal line 12 is a signal line for transmitting an image signal generated by the pixel circuit of the pixel 100, is arranged in each row of the pixel array unit 10, and is commonly wired to the pixel 100 arranged in each row.
  • NS These photoelectric conversion units and pixel circuits are formed on a semiconductor substrate.
  • the vertical drive unit 20 generates a control signal for the pixel circuit of the pixel 100.
  • the vertical drive unit 20 transmits the generated control signal to the pixel 100 via the signal line 11 in the figure.
  • the column signal processing unit 30 processes the image signal generated by the pixel 100.
  • the column signal processing unit 30 processes the image signal transmitted from the pixel 100 via the signal line 12 in the figure.
  • the processing in the column signal processing unit 30 corresponds to, for example, analog-to-digital conversion that converts an analog image signal generated in the pixel 100 into a digital image signal.
  • the image signal processed by the column signal processing unit 30 is output as an image signal of the image sensor 1.
  • the control unit 40 controls the entire image sensor 1.
  • the control unit 40 controls the image sensor 1 by generating and outputting a control signal for controlling the vertical drive unit 20 and the column signal processing unit 30.
  • the control signal generated by the control unit 40 is transmitted to the vertical drive unit 20 and the column signal processing unit 30 by the signal lines 41 and 42, respectively.
  • the image sensor 1 is an example of the image sensor described in the claims. Further, the image sensor 1 is an example of the image pickup device described in the claims. In this case, the pixel array unit 10 is an example of the image pickup device described in the claims, and the column signal processing unit 30 is an example of the processing circuit described in the claims.
  • FIG. 2 is a diagram showing a configuration example of an image sensor according to the embodiment of the present disclosure.
  • FIG. 6 is a schematic cross-sectional view showing a configuration example of the image sensor 1.
  • the image pickup device 1 in the figure includes a pixel 100, a separation region 140, and a non-separation region 150.
  • the pixel 100 includes a semiconductor substrate 110, a wiring region 120, a protective film 160, a color filter 170, a light-shielding film 171 and an on-chip lens 180.
  • the semiconductor substrate 110 is a semiconductor substrate on which a diffusion layer of elements such as pixels 100 is formed.
  • a substrate made of silicon (Si) can be used for the semiconductor substrate 110.
  • the element of the pixel 100 can be formed in the well region formed on the semiconductor substrate 110.
  • the semiconductor substrate 110 in the figure is assumed to be configured in a p-type well region. By arranging the n-type semiconductor region in the p-type well region, the diffusion layer of the device can be formed.
  • the photoelectric conversion unit 101, the charge holding unit 102, and the charge transfer unit 103 are shown as examples of the device.
  • the photoelectric conversion unit 101 is composed of an n-type semiconductor region 111 arranged in a p-type well region of the semiconductor substrate 110. Specifically, the photodiode composed of the pn junction formed between the n-type semiconductor region 111 and the surrounding p-type well region corresponds to the photoelectric conversion unit 101.
  • the photoelectric conversion unit 101 holds electrons in the electric charge generated by the photoelectric conversion of the incident light in the n-type semiconductor region 111.
  • the charge holding unit 102 and the charge transfer unit 103 are elements included in the pixel circuit described above.
  • the charge holding unit 102 holds the electric charge generated by the photoelectric conversion of the photoelectric conversion unit 101.
  • the charge holding portion 102 is composed of an n-type semiconductor region 112 arranged in a p-type well region of the semiconductor substrate 110.
  • the charge transfer unit 103 transfers the charge generated by the photoelectric conversion unit 101 to the charge holding unit 102.
  • the charge transfer unit 103 transfers the charge held in the n-type semiconductor region 111 of the photoelectric conversion unit 101 to the n-type semiconductor region 112 of the charge holding unit 102.
  • the charge transfer unit 103 can be configured by a MOS transistor. Specifically, the charge transfer unit 103 has n-type semiconductor regions 111 and 112 as source regions and drain regions, respectively, and channels are formed in p-type well regions between n-type semiconductor regions 111 and 112. It is composed of MOS transistors. As shown in the figure, the n-type semiconductor region 111 is arranged on the back surface side of the semiconductor substrate 110, and the n-type semiconductor substrate 112 is arranged on the front surface side of the semiconductor substrate 110.
  • the gate electrode 113 of the charge transfer unit 103 is configured to be embedded in the surface side of the semiconductor substrate 110, and is arranged adjacent to the n-type semiconductor regions 111 and 112 via a gate insulating film (not shown).
  • a MOS transistor having such a shape is called a vertical transistor, and is a transistor that transfers electric charges in a direction perpendicular to the surface of the semiconductor substrate 110.
  • the image signal can be generated and output as follows. First, the photoelectric conversion unit 101 performs photoelectric conversion during the exposure period, and holds the generated electric charge in the n-type semiconductor region 111. After the lapse of this exposure period, the charge transfer unit 103 transfers the charge held in the n-type semiconductor region 111 to the charge holding unit 102. An image signal corresponding to the transferred charge is generated by a MOS transistor (not shown) and output from the pixel 100.
  • the wiring area 120 is an area in which wiring for transmitting a signal to an element such as a pixel 100 is formed.
  • the wiring region 120 is arranged adjacent to the surface side of the semiconductor substrate 110.
  • the wiring area 120 includes a wiring layer 122 and an insulating layer 121.
  • the wiring layer 122 is wiring that transmits a signal to an element such as a pixel 100.
  • the wiring layer 122 can be made of a metal such as copper (Cu) or aluminum (Al).
  • the insulating layer 121 insulates the wiring layer 122.
  • the insulating layer 121 can be made of, for example, an insulating material such as silicon oxide (SiO 2).
  • the wiring layer 122 in the figure shows the wiring connected to the gate electrode 113 of the charge transfer unit 103 as an example.
  • the wiring layer 122 and the gate electrode 113 are connected via a contact plug 123.
  • the contact plug 123 is made of columnar metal and connects a semiconductor region and wiring.
  • the protective film 160 is arranged on the back surface side of the semiconductor substrate 110 to protect the back surface of the semiconductor substrate 110.
  • the protective film 160 can be made of, for example, SiO 2 .
  • the color filter 170 is an optical filter that transmits light of a predetermined wavelength among the incident light.
  • the color filter 170 is arranged for each pixel 100.
  • a color filter 170 that transmits any of red light, green light, and blue light can be used.
  • one of these three types of color filters 170 is arranged in the pixel 100.
  • the color filter 170 can be made of, for example, a resin in which a dye or a pigment is dispersed.
  • the light-shielding film 171 is a film that blocks incident light.
  • the light-shielding film 171 is arranged at the boundary of the pixel 100 and blocks the light transmitted through the color filter 170 of the adjacent pixel 100. This makes it possible to prevent color mixing.
  • the light-shielding film 171 can be composed of a metal film or a resin film in which a material having a light-shielding property is dispersed.
  • the on-chip lens 180 is a lens that is arranged adjacent to the color filter 170 and collects incident light.
  • the on-chip lens 180 is configured in a hemispherical shape, and collects incident light on a photoelectric conversion unit 101 of a semiconductor substrate 110.
  • the on-chip lens 180 can be made of an inorganic material such as silicon nitride (SiN) or an organic material such as an acrylic resin.
  • the image sensor 1 in the figure represents an example of a back-illuminated image sensor that images the incident light emitted on the back surface side of the semiconductor substrate 110.
  • the separation region 140 is arranged on the semiconductor substrate 110 at the boundary of the pixel 100 to separate the pixel 100.
  • the separation region 140 is arranged in a recess 130 formed on the surface of the semiconductor substrate 110.
  • the recess 130 in the figure is configured to penetrate the semiconductor substrate 110.
  • the separation region 140 in the figure is composed of the side wall membrane 141 and the filling membrane 142.
  • the side wall film 141 is a film that is arranged on the side wall of the recess 130 and insulates the semiconductor substrate 110 on the side wall of the recess 130.
  • the side wall film 141 can be made of, for example, SiO 2 or SiN.
  • the side wall film 141 can also be formed of a fixed charge film.
  • This fixed charge film is a film having a fixed charge for pinning the interface of the semiconductor substrate 110.
  • This fixed charge film can be composed of, for example, hafnium oxide (HfO 2 ), tantalum oxide (Ta 2 O 5 ) and aluminum oxide (Al 2 O 3 ).
  • the filling film 142 is a film that is filled in the recess 130, and is a film that is embedded inside the side wall film 141.
  • the packing film 142 can also be made of, for example, a metal such as tungsten (W).
  • the packed membrane 142 can also be made of polycrystalline silicon or polycrystalline silicon doped with impurities.
  • a solid phase diffusion region 119 is arranged on the semiconductor substrate 110 around the separation region 140.
  • the solid phase diffusion region 119 is a semiconductor region formed by diffusing impurities into the semiconductor substrate 110 by the solid phase diffusion method, and is a conductive type different from the n-type semiconductor region 111 and the like constituting the photoelectric conversion unit 101. It is a semiconductor area to be composed.
  • the solid phase diffusion region 119 in the figure shows an example of being formed in a p-type.
  • the p-type solid phase diffusion region 119 forms a pn junction with the n-type semiconductor region 111, and electrically separates the photoelectric conversion unit 101 of the pixel 100. That is, the pixel 100 is electrically separated from the adjacent pixel 100 by the separation region 140 and the solid phase diffusion region 119.
  • the solid phase diffusion region 119 can be configured to have a higher impurity concentration than the p-type well region.
  • the solid phase diffusion region 119 can be formed by the solid phase diffusion method. Specifically, a solid thin film containing a large amount of impurities is placed on the side wall of the recess 130 before the side wall film 141 and the filling film 142 are placed and heated. As a result, impurities of the solid thin film can be diffused into the semiconductor substrate 110, and a solid phase diffusion region 119 can be formed in the semiconductor substrate 110 around the recess 130.
  • a SiO 2 film containing a large amount of impurities can be used.
  • boron (B) which is an acceptor, can be used as an impurity in the solid thin film.
  • phosphorus (P) which is a donor, is contained in the solid thin film. After that, the solid thin film arranged in the recess 130 is removed, and the side wall film 141 and the filling film 142 are arranged.
  • the non-separable region 150 is a region formed by the semiconductor substrate 110 in the gap portion formed in the separated region 140.
  • the non-separable region 150 is an region in which the pixels 100 are connected to each other by the semiconductor substrate 110.
  • the above-mentioned solid phase diffusion region 119 can be arranged in the non-separated region 150.
  • FIG. 3 is a plan view showing a configuration example of the image sensor according to the first embodiment of the present disclosure.
  • FIG. 3 is a plan view showing a configuration example of pixels 100 arranged in the pixel array unit 10.
  • the broken line rectangle in the figure represents the area of pixel 100.
  • the n-type semiconductor region 111 constituting the photoelectric conversion unit 101 is described in the pixel 100.
  • a solid phase diffusion region 119 is arranged around the n-type semiconductor region 111.
  • a separation region 140 is arranged at the boundary between the pixels 100. Further, the non-separation region 150 is arranged in the gap portion of the separation region 140.
  • FIG. 2 corresponds to a cross-sectional view of the pixel 100 along the line AA'in the figure.
  • the separated region 140 has a shape surrounding the semiconductor substrate 110 of the pixel 100, and the island-shaped semiconductor substrate 110 is arranged in the pixel 100.
  • the recess 130 of the separation region 140 is filled with the filling membrane 142.
  • the filling film 142 is a film laminated on the side wall film 141 of the recess 130, the recess 130 cannot be completely filled in the case of a relatively deep recess 130. Therefore, a gap may be formed in the central portion of the recess 130.
  • the strength of the semiconductor substrate 110 is reduced. When grinding from the back surface side of the semiconductor substrate 110 in which the separation region 140 is arranged is performed, the gap in the central portion of the recess 130 may be crushed, and the island-shaped semiconductor substrate 110 may be displaced and damaged.
  • the non-separation area 150 is arranged in a part of the separation area 140.
  • the regions of the semiconductor substrate 110 of the adjacent pixels 100 are connected to each other. Thereby, the decrease in the strength of the semiconductor substrate 110 can be reduced.
  • a solid phase diffusion region 119 is formed around the separation region 140.
  • the width of the gap of the separation region 140 in which the non-separation region 150 is arranged can be twice or less the width of the solid phase diffusion region 119.
  • the solid phase diffusion region 119 is arranged in the entire non-separation region 150 by forming a gap of the separation region 140 in a width of twice or less the diffusion distance of impurities in the above-mentioned solid phase diffusion method. Can be done.
  • the semiconductor substrates 110 of the adjacent pixels 100 can be electrically separated from each other in the non-separable region 150.
  • FIG. 4 are diagrams showing an example of a method for manufacturing an image sensor according to the first embodiment of the present disclosure.
  • 4 to 6 are views showing an example of a manufacturing process of the image sensor 1.
  • a p-type well region is formed on the semiconductor substrate 110.
  • an n-type semiconductor region 111 or the like is formed in the p-type well region. These can be done by ion implantation (A in FIG. 4).
  • the recess 130 is formed on the surface side of the semiconductor substrate 110. At this time, the recess 130 is not formed in the region 302, which is the region where the non-separable region 150 is arranged (B in FIG. 4).
  • a solid thin film 303 containing B is placed on the inner wall of the recess 130. This can be done, for example, by CVD (Chemical Vapor Deposition) (C in FIG. 4).
  • CVD Chemical Vapor Deposition
  • the semiconductor substrate 110 is heated to perform solid phase diffusion, whereby a solid phase diffusion region 119 is formed around the recess 130.
  • a solid phase diffusion region 119 is also formed in the region 302 forming the non-separation region 150 (D in FIG. 5).
  • the side wall film 141 is arranged on the inner wall of the recess 130. This can be done, for example, by forming a film of SiO 2 by CVD (F in FIG. 5).
  • the filling film 142 is laminated on the side wall film 141 of the inner wall of the recess 130. This can be done, for example, by forming a film of W by CVD (G in FIG. 6).
  • the wiring region 120 is formed on the surface side of the semiconductor substrate 110 (H in FIG. 6).
  • the back surface side of the semiconductor substrate 110 is ground. This can be done, for example, by mechanically polishing with a grinder. Further, for example, it can be performed by chemical mechanical polishing (CMP). As a result, the semiconductor substrate 110 is thinned, and a separated region 140 and a non-separated region 150 that penetrate the semiconductor substrate 110 can be formed (I in FIG. 6).
  • CMP chemical mechanical polishing
  • the image sensor 1 can be manufactured by arranging the protective film 160, the light-shielding film 171, the color filter 170, and the on-chip lens 180.
  • the configuration of the image sensor 1 according to the first embodiment of the present disclosure is not limited to this example.
  • a semiconductor region formed by a method other than solid phase diffusion can be used instead of the solid phase diffusion region 119 around the separation region 140.
  • the decrease in the intensity of the image pickup device 1 is reduced by arranging the non-separation region 150 in the gap of the separation region 140 at the boundary of the pixels. can do.
  • Second Embodiment> In the image sensor 1 of the first embodiment described above, the separated region 140 and the non-separated region 150 are arranged at the boundary of the pixel 100. On the other hand, in the image sensor 1 of the second embodiment of the present disclosure, variations in the shapes of the separated region 140 and the non-separated region 150 are proposed.
  • FIG. 7 is a plan view showing a configuration example of the image sensor according to the second embodiment of the present disclosure.
  • FIG. 3 is a plan view showing a configuration example of a separated region 140 and a non-separated region 150 of the pixel 100.
  • a in the figure is a diagram showing an example in which the non-separable region 150 is arranged at the corner of the pixel 100.
  • the separation region 140 arranged in the horizontal direction in the drawing A in the figure is commonly arranged with respect to the pixels 100 adjacent in the horizontal direction.
  • B in the figure is a diagram showing an example in which the separation region 140 is finely divided and many non-separation regions 150 are arranged. Since many non-separable regions 150 are arranged, the strength of the pixel 100 can be further improved. Further, by periodically arranging the separated region 140 and the non-separated region 150, the incident light obliquely incident from the adjacent pixel 100 can be deflected and attenuated. As a result, crosstalk can be reduced. At this time, it is preferable to configure the width of the gap d between the separation regions 140 to be 1/4 of the wavelength of the incident light. This is because the incident light from the adjacent pixel 100 can be further attenuated.
  • FIG. 8 is a plan view showing another configuration example of the image pickup device according to the second embodiment of the present disclosure.
  • the figure is a diagram showing a separation region 140 formed in a circular shape in a plan view.
  • the separation region 140 in the figure is a separation region 140 in which the opening is arranged in the concave portion 130 having a circular shape.
  • the solid-phase diffusion region 119 By arranging the solid-phase diffusion region 119 around the circular separation region 140, the solid-phase diffusion region 119 having a shape between the photoelectric conversion unit 101 and the photoelectric conversion unit 101 in a plan view is formed by connecting arcs. Can be done.
  • the end of the joined arc has a shape that enters the non-separable region 150 side, and the region of the photoelectric conversion unit 101 can be expanded.
  • the amount of charge that can be stored in the photoelectric conversion unit 101 can be increased, and the dynamic range can be improved.
  • FIG. 9 is a cross-sectional view showing a configuration example of the image sensor according to the second embodiment of the present disclosure.
  • the figure is a cross-sectional view showing a configuration example of a separated region 140 and a non-separated region 150.
  • FIG. A in the figure is a diagram showing an example of a separation region 140 formed in a shape perpendicular to the surface of the semiconductor substrate 110.
  • the non-separable region 150 is also configured to have a shape perpendicular to the surface of the semiconductor substrate 110.
  • B in the figure is a diagram showing an example of a separation region 140 having different widths on the surface and the central portion of the semiconductor substrate 110. As shown in B in the figure, it is also possible to form a shape in which adjacent separation regions 140 are in contact with each other in the central portion of the semiconductor substrate 110. In this case, the non-separable region 150 is arranged near the front and back surfaces of the semiconductor substrate.
  • the non-separable region 150 is arranged on the back surface side of the semiconductor substrate 110, and the decrease in strength at the time of grinding on the back surface side of the semiconductor substrate 110 can be reduced.
  • the non-separable region 150 on the back surface side of the semiconductor substrate 110 can be configured to have a depth corresponding to the variation in thickness when grinding the back surface of the semiconductor substrate 110.
  • the cross-sectional shape of the separation region 140 can be configured to have a tapered shape in which the opening area on the front surface side of the semiconductor substrate 110 is larger than that on the back surface side.
  • the image sensor 1 of the second embodiment of the present disclosure can reduce the decrease in the intensity of the pixel 100 even when the shapes of the separated region 140 and the non-separated region 150 are changed. can.
  • the technology according to the present disclosure can be applied to various products.
  • the present technology may be realized as an image pickup device mounted on an image pickup device such as a camera.
  • FIG. 10 is a block diagram showing a schematic configuration example of a camera which is an example of an imaging device to which the present technology can be applied.
  • the camera 1000 in the figure includes a lens 1001, an image pickup element 1002, an image pickup control unit 1003, a lens drive unit 1004, an image processing unit 1005, an operation input unit 1006, a frame memory 1007, a display unit 1008, and the like.
  • a recording unit 1009 is provided.
  • the lens 1001 is a photographing lens of the camera 1000.
  • the lens 1001 collects light from the subject and causes the light to be incident on the image pickup device 1002 described later to form an image of the subject.
  • the image sensor 1002 is a semiconductor element that captures light from a subject focused by the lens 1001.
  • the image sensor 1002 generates an analog image signal corresponding to the irradiated light, converts it into a digital image signal, and outputs the signal.
  • the image pickup control unit 1003 controls the image pickup in the image pickup device 1002.
  • the image pickup control unit 1003 controls the image pickup device 1002 by generating a control signal and outputting the control signal to the image pickup device 1002. Further, the image pickup control unit 1003 can perform autofocus on the camera 1000 based on the image signal output from the image pickup device 1002.
  • the autofocus is a system that detects the focal position of the lens 1001 and automatically adjusts it.
  • a method (image plane phase difference autofocus) in which the image plane phase difference is detected by the phase difference pixels arranged in the image sensor 1002 to detect the focal position can be used. It is also possible to apply a method (contrast autofocus) of detecting the position where the contrast of the image is highest as the focal position.
  • the image pickup control unit 1003 adjusts the position of the lens 1001 via the lens drive unit 1004 based on the detected focus position, and performs autofocus.
  • the image pickup control unit 1003 can be configured by, for example, a DSP (Digital Signal Processor) equipped with firmware.
  • DSP Digital Signal Processor
  • the lens driving unit 1004 drives the lens 1001 based on the control of the imaging control unit 1003.
  • the lens driving unit 1004 can drive the lens 1001 by changing the position of the lens 1001 using a built-in motor.
  • the image processing unit 1005 processes the image signal generated by the image sensor 1002. This processing includes, for example, demosaic to generate an image signal of a color that is insufficient among the image signals corresponding to red, green, and blue for each pixel, noise reduction to remove noise of the image signal, and coding of the image signal. Applicable.
  • the image processing unit 1005 can be configured by, for example, a microcomputer equipped with firmware.
  • the operation input unit 1006 receives the operation input from the user of the camera 1000.
  • a push button or a touch panel can be used for the operation input unit 1006.
  • the operation input received by the operation input unit 1006 is transmitted to the image pickup control unit 1003 and the image processing unit 1005. After that, processing according to the operation input, for example, processing such as imaging of the subject is activated.
  • the frame memory 1007 is a memory that stores a frame that is an image signal for one screen.
  • the frame memory 1007 is controlled by the image processing unit 1005 and holds frames in the process of image processing.
  • the display unit 1008 displays the image processed by the image processing unit 1005.
  • a liquid crystal panel can be used.
  • the recording unit 1009 records the image processed by the image processing unit 1005.
  • a memory card or a hard disk can be used for the recording unit 1009.
  • the cameras to which this disclosure can be applied have been described above.
  • the present technology can be applied to the image pickup device 1002 among the configurations described above.
  • the image pickup device 1 described with reference to FIG. 1 can be applied to the image pickup device 1002.
  • the image processing unit 1005 is an example of the processing circuit described in the claims.
  • the camera 1000 is an example of the image pickup apparatus described in the claims.
  • the present technology can have the following configurations.
  • (1) A plurality of wiring regions formed on a semiconductor substrate for performing photoelectric conversion of incident light and wiring regions arranged on the surface side of the semiconductor substrate to transmit signals of the photoelectric conversion unit.
  • pixels A separation region that separates the semiconductor substrate between the plurality of pixels, and An image pickup device including a non-separable region formed of the semiconductor substrate in a gap portion formed in the separated region.
  • (2) The image pickup device according to (1), wherein the separation region is arranged in a recess formed on the surface side of the semiconductor substrate.
  • (3) The image pickup device according to (2), wherein the separation region is arranged in the recess that penetrates the semiconductor substrate.
  • the image pickup device according to any one of (1) to (10), wherein the non-separable region is composed of the semiconductor substrate in the gap portion having a width of 1/4 of the wavelength of the incident light. (12) The image pickup device according to any one of (1) to (11), wherein the non-separable region is arranged on the back surface side of the semiconductor substrate. (13) The above (1) to (12), which are configured in a conductive type different from the semiconductor region constituting the photoelectric conversion unit and further include a semiconductor region arranged between the separation region and the photoelectric conversion unit. The image pickup device according to any one. (14) A plurality of wiring regions formed on a semiconductor substrate for performing photoelectric conversion of incident light and wiring regions arranged on the surface side of the semiconductor substrate to transmit signals of the photoelectric conversion unit.
  • pixels A separation region that separates the semiconductor substrate between the plurality of pixels, and The non-separable region formed by the semiconductor substrate in the gap portion formed in the separated region and the non-separable region
  • An imaging device including a processing circuit that processes an image signal generated based on the photoelectric conversion.

Abstract

According to the present invention, any reduction of strength is mitigated in an imaging element in which semiconductor substrates are separated for each pixel.　An imaging element comprising a plurality of pixels, separation regions, and non-separated regions. Each of the pixels comprises: a photoelectric conversion unit that is formed on a semiconductor substrate and performs photoelectric conversion of incident light; and a wiring region that is positioned on the obverse-surface side of the semiconductor substrate, the wiring region being configured so that wiring for transmitting signals of the photoelectric conversion unit is positioned thereon. The separation regions separate the semiconductor substrates of the plurality of pixels. The non-separated regions are configured from the semiconductor substrates in gap portions that are formed in the separation regions.

Description

撮像素子および撮像装置Image sensor and image sensor
　本開示は、撮像素子および撮像装置に関する。詳しくは、画素を分離する分離領域を有する撮像素子および当該撮像素子を使用する撮像装置に関する。 The present disclosure relates to an image pickup device and an image pickup device. More specifically, the present invention relates to an image pickup device having a separation region for separating pixels and an image pickup device using the image pickup device.
　従来、画像信号を生成する複数の画素が配置されて構成された撮像素子が使用されている。画素には入射光の光電変換を行う光電変換部が配置され、光電変換により生成された電荷に基づいて画像信号が生成される。これら複数の画素の光電変換部は半導体基板に配置される。このため、半導体基板には、各画素の光電変換部が隣接して配置されることとなる。また、半導体基板は、隣接する画素同士の境界に分離領域が配置される。画像信号等を画素毎に絶縁するためである。 Conventionally, an image sensor configured by arranging a plurality of pixels for generating an image signal has been used. A photoelectric conversion unit that performs photoelectric conversion of incident light is arranged in the pixel, and an image signal is generated based on the electric charge generated by the photoelectric conversion. The photoelectric conversion unit of these a plurality of pixels is arranged on the semiconductor substrate. Therefore, the photoelectric conversion unit of each pixel is arranged adjacent to the semiconductor substrate. Further, in the semiconductor substrate, a separation region is arranged at the boundary between adjacent pixels. This is to insulate image signals and the like for each pixel.
　この分離領域として半導体基板に形成された溝（トレンチ）に絶縁材料を詰め込んで構成された分離領域が使用されている。半導体基板に溝を形成するため、ｐｎ接合を使用して分離する方式と比較して高い絶縁抵抗を得ることができる。一方、半導体基板に形成された溝の表面には界面準位が形成される。この界面準位による電荷の捕獲や界面準位からの電荷の放出に基づく電流は暗電流と称され、画像信号のノイズの原因となる。このノイズを低減するためには、界面準位に対する電荷の移動を防ぐ必要がある。これは、界面準位をピニングすることにより行うことができる。このピニングは、界面準位からの電界を終端することにより電荷の移動を制限するものである。具体的には、溝を有する分離領域の周囲に比較的高い不純物濃度の半導体領域を配置することにより、ピニングを行うことができる。この半導体領域は、分離領域の周囲の半導体基板に高い濃度の不純物を注入することにより行うことができる。 As this separation region, a separation region formed by filling a groove (trench) formed in a semiconductor substrate with an insulating material is used. Since grooves are formed on the semiconductor substrate, higher insulation resistance can be obtained as compared with the method of separating using a pn junction. On the other hand, an interface state is formed on the surface of the groove formed on the semiconductor substrate. The current based on the capture of electric charge by the interface state and the emission of electric charge from the interface state is called a dark current, which causes noise in the image signal. In order to reduce this noise, it is necessary to prevent the transfer of electric charge with respect to the interface state. This can be done by pinning the interface state. This pinning limits the transfer of charge by terminating the electric field from the interface state. Specifically, pinning can be performed by arranging a semiconductor region having a relatively high impurity concentration around the separated region having a groove. This semiconductor region can be formed by injecting a high concentration of impurities into the semiconductor substrate around the separation region.
　不純物の注入は、イオン注入により行うことができる。しかし、分離領域に比較的深い溝を形成する際には、イオン注入による不純物の注入が困難になる。高い注入エネルギーが必要になり、イオン注入のマスクとして使用するレジストを厚く形成する必要があるためである。また、高エネルギーのイオンの注入により、半導体基板に多数の格子欠陥が生成されるという問題も生じる。 Impurities can be implanted by ion implantation. However, when a relatively deep groove is formed in the separation region, it becomes difficult to implant impurities by ion implantation. This is because high implantation energy is required and it is necessary to form a thick resist to be used as a mask for ion implantation. In addition, the injection of high-energy ions also causes a problem that a large number of lattice defects are generated in the semiconductor substrate.
　このようなイオン注入に替えて、固相拡散により高い不純物濃度の半導体領域を形成することも可能である。この固相拡散は、不純物を多量に含んだ固体薄膜を半導体基板に堆積させて加熱することにより不純物を半導体基板中に拡散させる方法である。上述の溝が形成された半導体基板では、溝の内壁に不純物を含む薄膜を配置し、数１００乃至１０００度の温度に加熱することにより、高い不純物濃度の半導体領域を溝の周囲に形成することができる。固相拡散法を適用する場合には、配線領域を形成する前の半導体基板の表面側に溝を形成し、固相拡散を行う必要がある。加熱の工程が必要となるためである。 Instead of such ion implantation, it is also possible to form a semiconductor region with a high impurity concentration by solid phase diffusion. This solid phase diffusion is a method of diffusing impurities into a semiconductor substrate by depositing a solid thin film containing a large amount of impurities on the semiconductor substrate and heating the solid thin film. In the above-mentioned semiconductor substrate in which the grooves are formed, a thin film containing impurities is placed on the inner wall of the grooves and heated to a temperature of several hundred to 1000 degrees Celsius to form a semiconductor region having a high impurity concentration around the grooves. Can be done. When the solid phase diffusion method is applied, it is necessary to form a groove on the surface side of the semiconductor substrate before forming the wiring region to perform solid phase diffusion. This is because a heating process is required.
　分離領域の分離能力を向上させるためには、半導体基板を貫通する溝を形成する必要がある。これは、半導体基板の表面側に溝および配線領域を形成した後に、半導体基板の裏面を研削して溝の底部が露出するまで半導体基板を薄肉化することにより行うことができる。このような溝を有する撮像素子として、例えば、画素間に形成したトレンチの側壁にｐ型およびｎ型の拡散層を固相拡散により形成する固体撮像素子が提案されている（例えば、特許文献１参照。）。 In order to improve the separation ability of the separation region, it is necessary to form a groove penetrating the semiconductor substrate. This can be done by forming a groove and a wiring region on the front surface side of the semiconductor substrate, and then grinding the back surface of the semiconductor substrate to thin the semiconductor substrate until the bottom of the groove is exposed. As an image sensor having such a groove, for example, a solid-state image sensor in which p-type and n-type diffusion layers are formed by solid-phase diffusion on the side wall of a trench formed between pixels has been proposed (for example, Patent Document 1). reference.).
特開２０１８－１４８１１６号公報Japanese Unexamined Patent Publication No. 2018-148116
　上述の従来技術では、半導体基板の強度が低下するという問題がある。半導体基板の裏面側を研削して半導体基板の表面側から形成された溝の底部を露出される際、各画素の半導体基板の領域が溝により分離された状態になる。このため、半導体基板の強度が低下し、研削の工程において分離された半導体基板が脱離して破損するという問題を生じる。 The above-mentioned conventional technique has a problem that the strength of the semiconductor substrate is lowered. When the back surface side of the semiconductor substrate is ground to expose the bottom of the groove formed from the front surface side of the semiconductor substrate, the region of the semiconductor substrate of each pixel is separated by the groove. Therefore, the strength of the semiconductor substrate is lowered, which causes a problem that the semiconductor substrate separated in the grinding process is detached and damaged.
　本開示は、上述した問題点に鑑みてなされたものであり、画素毎に半導体基板が分離される撮像素子の強度の低下を軽減することを目的としている。 The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to reduce a decrease in the strength of an image sensor in which a semiconductor substrate is separated for each pixel.
　本開示は、上述の問題点を解消するためになされたものであり、その第１の態様は、半導体基板に形成されて入射光の光電変換を行う光電変換部および上記半導体基板の表面側に配置されて上記光電変換部の信号を伝達する配線が配置される配線領域を備える複数の画素と、上記複数の画素同士の上記半導体基板を分離する分離領域と、上記分離領域に形成される間隙部分の上記半導体基板により構成される非分離領域とを具備する撮像素子である。 The present disclosure has been made in order to solve the above-mentioned problems, and the first aspect thereof is on a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of incident light, and on the surface side of the semiconductor substrate. A plurality of pixels having a wiring region in which wiring for transmitting the signal of the photoelectric conversion unit is arranged, a separation region for separating the semiconductor substrate between the plurality of pixels, and a gap formed in the separation region. It is an image pickup device including a non-separable region formed of the above-mentioned semiconductor substrate.
　また、この第１の態様において、上記分離領域は、上記半導体基板の表面側に形成される凹部に配置されてもよい。 Further, in this first aspect, the separation region may be arranged in a recess formed on the surface side of the semiconductor substrate.
　また、この第１の態様において、上記分離領域は、上記半導体基板を貫通する上記凹部に配置されてもよい。 Further, in this first aspect, the separation region may be arranged in the recess that penetrates the semiconductor substrate.
　また、この第１の態様において、上記分離領域は、円形状の開口部に構成される上記凹部に配置されてもよい。 Further, in this first aspect, the separation region may be arranged in the recess formed by the circular opening.
　また、この第１の態様において、上記分離領域は、上記凹部に金属が配置されて構成されてもよい。 Further, in the first aspect, the separation region may be formed by arranging a metal in the recess.
　また、この第１の態様において、上記分離領域は、上記凹部に多結晶シリコンが配置されて構成されてもよい。 Further, in this first aspect, the separation region may be configured by arranging polycrystalline silicon in the recess.
　また、この第１の態様において、上記分離領域は、上記凹部における上記半導体基板の表面を覆う形状の側壁膜を備えてもよい。 Further, in this first aspect, the separation region may include a side wall film having a shape that covers the surface of the semiconductor substrate in the recess.
　また、この第１の態様において、上記非分離領域は、上記光電変換部を構成する半導体領域とは異なる導電型に構成されてもよい。 Further, in this first aspect, the non-separable region may be formed in a conductive type different from the semiconductor region constituting the photoelectric conversion unit.
　また、この第１の態様において、上記非分離領域は、上記半導体基板に形成される凹部に配置される不純物を含む部材から拡散した不純物により上記導電型に構成されてもよい。 Further, in this first aspect, the non-separable region may be formed in the conductive type by impurities diffused from a member containing impurities arranged in a recess formed in the semiconductor substrate.
　また、この第１の態様において、上記非分離領域は、上記不純物の拡散の距離の２倍以下の上記間隙部分の上記半導体基板により構成されてもよい。 Further, in this first aspect, the non-separable region may be composed of the semiconductor substrate in the gap portion of 2 times or less the diffusion distance of the impurities.
　また、この第１の態様において、上記非分離領域は、上記入射光の波長の１／４の幅の上記間隙部分の上記半導体基板により構成されてもよい。　 Further, in this first aspect, the non-separable region may be composed of the semiconductor substrate in the gap portion having a width of 1/4 of the wavelength of the incident light.
　また、この第１の態様において、上記非分離領域は、上記半導体基板の裏面側に配置されてもよい。 Further, in this first aspect, the non-separable region may be arranged on the back surface side of the semiconductor substrate.
　また、この第１の態様において、上記光電変換部を構成する半導体領域とは異なる導電型に構成されて上記分離領域および上記光電変換部の間に配置される半導体領域をさらに具備してもよい。 Further, in this first aspect, a semiconductor region which is formed in a conductive type different from the semiconductor region constituting the photoelectric conversion unit and is arranged between the separation region and the photoelectric conversion unit may be further provided. ..
　また、本開示の第２の態様は、半導体基板に形成されて入射光の光電変換を行う光電変換部および上記半導体基板の表面側に配置されて上記光電変換部の信号を伝達する配線が配置される配線領域を備える複数の画素と、上記複数の画素同士の上記半導体基板を分離する分離領域と、上記分離領域に形成される間隙部分の上記半導体基板により構成される非分離領域と、上記光電変換に基づいて生成される画像信号の処理を行う処理回路とを具備する撮像装置である。 Further, in the second aspect of the present disclosure, a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of incident light and wiring arranged on the surface side of the semiconductor substrate to transmit signals of the photoelectric conversion unit are arranged. A plurality of pixels having a wiring region to be formed, a separation region for separating the semiconductor substrate between the plurality of pixels, a non-separation region composed of the semiconductor substrate in a gap portion formed in the separation region, and the above. It is an image pickup apparatus including a processing circuit that processes an image signal generated based on photoelectric conversion.
　本開示の態様により、画素の境界に配置される分離領域の間隙部分に半導体基板の領域が残されるという作用をもたらす。 According to the aspect of the present disclosure, the region of the semiconductor substrate is left in the gap portion of the separation region arranged at the boundary of the pixels.
本開示の実施の形態に係る撮像素子の構成例を示す図である。It is a figure which shows the structural example of the image sensor which concerns on embodiment of this disclosure. 本開示の実施の形態の変形例に係る撮像素子の構成例を示す図である。It is a figure which shows the structural example of the image sensor which concerns on the modification of embodiment of this disclosure. 本開示の第１の実施の形態に係る撮像素子の構成例を示す平面図である。It is a top view which shows the structural example of the image pickup device which concerns on 1st Embodiment of this disclosure. 本開示の第１の実施の形態に係る撮像素子の製造方法の一例を示す図である。It is a figure which shows an example of the manufacturing method of the image pickup device which concerns on 1st Embodiment of this disclosure. 本開示の第１の実施の形態に係る撮像素子の製造方法の一例を示す図である。It is a figure which shows an example of the manufacturing method of the image pickup device which concerns on 1st Embodiment of this disclosure. 本開示の第１の実施の形態に係る撮像素子の製造方法の一例を示す図である。It is a figure which shows an example of the manufacturing method of the image pickup device which concerns on 1st Embodiment of this disclosure. 本開示の第２の実施の形態に係る撮像素子の構成例を示す平面図である。It is a top view which shows the structural example of the image pickup device which concerns on 2nd Embodiment of this disclosure. 本開示の第２の実施の形態に係る撮像素子の他の構成例を示す平面図である。It is a top view which shows the other structural example of the image pickup device which concerns on 2nd Embodiment of this disclosure. 本開示の第２の実施の形態に係る撮像素子の構成例を示す断面図である。It is sectional drawing which shows the structural example of the image pickup device which concerns on 2nd Embodiment of this disclosure. 本技術が適用され得る撮像装置の一例であるカメラの概略的な構成例を示すブロック図である。It is a block diagram which shows the schematic configuration example of the camera which is an example of the image pickup apparatus to which this technology can be applied.
　次に、図面を参照して、本開示を実施するための形態（以下、実施の形態と称する）を説明する。以下の図面において、同一または類似の部分には同一または類似の符号を付している。また、以下の順序で実施の形態の説明を行う。
　１．第１の実施の形態
　２．第２の実施の形態
　３．カメラへの応用例 Next, a mode for carrying out the present disclosure (hereinafter, referred to as an embodiment) will be described with reference to the drawings. In the drawings below, the same or similar parts are designated by the same or similar reference numerals. In addition, the embodiments will be described in the following order.
1. 1. First Embodiment 2. Second embodiment 3. Application example to camera
　＜１．第１の実施の形態＞
　［撮像素子の構成］
　図１は、本開示の実施の形態に係る撮像素子の構成例を示す図である。同図の撮像素子１は、画素アレイ部１０と、垂直駆動部２０と、カラム信号処理部３０と、制御部４０とを備える。 <1. First Embodiment>
[Structure of image sensor]
FIG. 1 is a diagram showing a configuration example of an image sensor according to an embodiment of the present disclosure. The image sensor 1 in the figure includes a pixel array unit 10, a vertical drive unit 20, a column signal processing unit 30, and a control unit 40.
　画素アレイ部１０は、画素１００が２次元格子状に配置されて構成されたものである。ここで、画素１００は、照射された光に応じた画像信号を生成するものである。この画素１００は、照射された光に応じた電荷を生成する光電変換部を有する。また画素１００は、画素回路をさらに有する。この画素回路は、光電変換部により生成された電荷に基づく画像信号を生成する。画像信号の生成は、後述する垂直駆動部２０により生成された制御信号により制御される。画素アレイ部１０には、信号線１１および１２がＸＹマトリクス状に配置される。信号線１１は、画素１００における画素回路の制御信号を伝達する信号線であり、画素アレイ部１０の行毎に配置され、各行に配置される画素１００に対して共通に配線される。信号線１２は、画素１００の画素回路により生成された画像信号を伝達する信号線であり、画素アレイ部１０の列毎に配置され、各列に配置される画素１００に対して共通に配線される。これら光電変換部および画素回路は、半導体基板に形成される。 The pixel array unit 10 is configured by arranging the pixels 100 in a two-dimensional grid pattern. Here, the pixel 100 generates an image signal according to the irradiated light. The pixel 100 has a photoelectric conversion unit that generates an electric charge according to the irradiated light. Further, the pixel 100 further has a pixel circuit. This pixel circuit generates an image signal based on the electric charge generated by the photoelectric conversion unit. The generation of the image signal is controlled by the control signal generated by the vertical drive unit 20 described later. The signal lines 11 and 12 are arranged in the pixel array unit 10 in an XY matrix. The signal line 11 is a signal line that transmits a control signal of the pixel circuit in the pixel 100, is arranged for each line of the pixel array unit 10, and is commonly wired to the pixel 100 arranged in each line. The signal line 12 is a signal line for transmitting an image signal generated by the pixel circuit of the pixel 100, is arranged in each row of the pixel array unit 10, and is commonly wired to the pixel 100 arranged in each row. NS. These photoelectric conversion units and pixel circuits are formed on a semiconductor substrate.
　垂直駆動部２０は、画素１００の画素回路の制御信号を生成するものである。この垂直駆動部２０は、生成した制御信号を同図の信号線１１を介して画素１００に伝達する。カラム信号処理部３０は、画素１００により生成された画像信号を処理するものである。このカラム信号処理部３０は、同図の信号線１２を介して画素１００から伝達された画像信号の処理を行う。カラム信号処理部３０における処理には、例えば、画素１００において生成されたアナログの画像信号をデジタルの画像信号に変換するアナログデジタル変換が該当する。カラム信号処理部３０により処理された画像信号は、撮像素子１の画像信号として出力される。制御部４０は、撮像素子１の全体を制御するものである。この制御部４０は、垂直駆動部２０およびカラム信号処理部３０を制御する制御信号を生成して出力することにより、撮像素子１の制御を行う。制御部４０により生成された制御信号は、信号線４１および４２により垂直駆動部２０およびカラム信号処理部３０に対してそれぞれ伝達される。 The vertical drive unit 20 generates a control signal for the pixel circuit of the pixel 100. The vertical drive unit 20 transmits the generated control signal to the pixel 100 via the signal line 11 in the figure. The column signal processing unit 30 processes the image signal generated by the pixel 100. The column signal processing unit 30 processes the image signal transmitted from the pixel 100 via the signal line 12 in the figure. The processing in the column signal processing unit 30 corresponds to, for example, analog-to-digital conversion that converts an analog image signal generated in the pixel 100 into a digital image signal. The image signal processed by the column signal processing unit 30 is output as an image signal of the image sensor 1. The control unit 40 controls the entire image sensor 1. The control unit 40 controls the image sensor 1 by generating and outputting a control signal for controlling the vertical drive unit 20 and the column signal processing unit 30. The control signal generated by the control unit 40 is transmitted to the vertical drive unit 20 and the column signal processing unit 30 by the signal lines 41 and 42, respectively.
　なお、撮像素子１は、請求の範囲に記載の撮像素子の一例である。また、撮像素子１は、請求の範囲に記載の撮像装置の一例である。この場合、画素アレイ部１０は請求の範囲に記載の撮像素子の一例であり、カラム信号処理部３０は請求の範囲に記載の処理回路の一例である。 The image sensor 1 is an example of the image sensor described in the claims. Further, the image sensor 1 is an example of the image pickup device described in the claims. In this case, the pixel array unit 10 is an example of the image pickup device described in the claims, and the column signal processing unit 30 is an example of the processing circuit described in the claims.
　［画素の構成］
　図２は、本開示の実施の形態に係る撮像素子の構成例を示す図である。同図は、撮像素子１の構成例を表す模式断面図である。同図の撮像素子１は、画素１００と、分離領域１４０と、非分離領域１５０とを備える。また、画素１００は、半導体基板１１０と、配線領域１２０と、保護膜１６０と、カラーフィルタ１７０と、遮光膜１７１と、オンチップレンズ１８０とを備える。 [Pixel composition]
FIG. 2 is a diagram showing a configuration example of an image sensor according to the embodiment of the present disclosure. FIG. 6 is a schematic cross-sectional view showing a configuration example of the image sensor 1. The image pickup device 1 in the figure includes a pixel 100, a separation region 140, and a non-separation region 150. Further, the pixel 100 includes a semiconductor substrate 110, a wiring region 120, a protective film 160, a color filter 170, a light-shielding film 171 and an on-chip lens 180.
　半導体基板１１０は、画素１００等の素子の拡散層が形成される半導体の基板である。この半導体基板１１０には、例えば、シリコン（Ｓｉ）により構成された基板を使用することができる。画素１００の素子は、半導体基板１１０に形成されたウェル領域に形成することができる。便宜上、同図の半導体基板１１０は、ｐ型のウェル領域に構成されるものと想定する。このｐ型のウェル領域にｎ型の半導体領域を配置することにより、素子の拡散層を形成することができる。同図には、光電変換部１０１、電荷保持部１０２および電荷転送部１０３を素子の例として記載した。 The semiconductor substrate 110 is a semiconductor substrate on which a diffusion layer of elements such as pixels 100 is formed. For the semiconductor substrate 110, for example, a substrate made of silicon (Si) can be used. The element of the pixel 100 can be formed in the well region formed on the semiconductor substrate 110. For convenience, the semiconductor substrate 110 in the figure is assumed to be configured in a p-type well region. By arranging the n-type semiconductor region in the p-type well region, the diffusion layer of the device can be formed. In the figure, the photoelectric conversion unit 101, the charge holding unit 102, and the charge transfer unit 103 are shown as examples of the device.
　光電変換部１０１は、半導体基板１１０のｐ型のウェル領域に配置されたｎ型の半導体領域１１１により構成される。具体的には、ｎ型の半導体領域１１１と周囲のｐ型のウェル領域との間に形成されるｐｎ接合部により構成されるフォトダイオードが光電変換部１０１に該当する。光電変換部１０１は、入射光の光電変換により生成された電荷のうちの電子をｎ型の半導体領域１１１に保持する。　 The photoelectric conversion unit 101 is composed of an n-type semiconductor region 111 arranged in a p-type well region of the semiconductor substrate 110. Specifically, the photodiode composed of the pn junction formed between the n-type semiconductor region 111 and the surrounding p-type well region corresponds to the photoelectric conversion unit 101. The photoelectric conversion unit 101 holds electrons in the electric charge generated by the photoelectric conversion of the incident light in the n-type semiconductor region 111.
　電荷保持部１０２および電荷転送部１０３は、前述の画素回路に含まれる素子である。電荷保持部１０２は、光電変換部１０１の光電変換により生成された電荷を保持するものである。この電荷保持部１０２は、半導体基板１１０のｐ型のウェル領域に配置されたｎ型の半導体領域１１２により構成される。電荷転送部１０３は、光電変換部１０１により生成された電荷を電荷保持部１０２に転送するものである。この電荷転送部１０３は、光電変換部１０１のｎ型の半導体領域１１１に保持された電荷を電荷保持部１０２のｎ型の半導体領域１１２に転送する。 The charge holding unit 102 and the charge transfer unit 103 are elements included in the pixel circuit described above. The charge holding unit 102 holds the electric charge generated by the photoelectric conversion of the photoelectric conversion unit 101. The charge holding portion 102 is composed of an n-type semiconductor region 112 arranged in a p-type well region of the semiconductor substrate 110. The charge transfer unit 103 transfers the charge generated by the photoelectric conversion unit 101 to the charge holding unit 102. The charge transfer unit 103 transfers the charge held in the n-type semiconductor region 111 of the photoelectric conversion unit 101 to the n-type semiconductor region 112 of the charge holding unit 102.
　電荷転送部１０３は、ＭＯＳトランジスタにより構成することができる。具体的には、電荷転送部１０３は、ｎ型の半導体領域１１１および１１２をそれぞれソース領域およびドレイン領域とし、ｎ型の半導体領域１１１および１１２の間のｐ型のウェル領域にチャネルが形成されるＭＯＳトランジスタにより構成される。同図に表したように、ｎ型の半導体領域１１１は半導体基板１１０の裏面側に配置され、ｎ型の半導体基板１１２は半導体基板１１０の表面側に配置される。電荷転送部１０３のゲート電極１１３は、半導体基板１１０の表面側に埋め込まれた形状に構成され、不図示のゲート絶縁膜を介してｎ型の半導体領域１１１および１１２に隣接して配置される。このような形状のＭＯＳトランジスタは、縦型トランジスタと称され、半導体基板１１０の表面に対して垂直方向に電荷を転送するトランジスタである。 The charge transfer unit 103 can be configured by a MOS transistor. Specifically, the charge transfer unit 103 has n- type semiconductor regions 111 and 112 as source regions and drain regions, respectively, and channels are formed in p-type well regions between n- type semiconductor regions 111 and 112. It is composed of MOS transistors. As shown in the figure, the n-type semiconductor region 111 is arranged on the back surface side of the semiconductor substrate 110, and the n-type semiconductor substrate 112 is arranged on the front surface side of the semiconductor substrate 110. The gate electrode 113 of the charge transfer unit 103 is configured to be embedded in the surface side of the semiconductor substrate 110, and is arranged adjacent to the n- type semiconductor regions 111 and 112 via a gate insulating film (not shown). A MOS transistor having such a shape is called a vertical transistor, and is a transistor that transfers electric charges in a direction perpendicular to the surface of the semiconductor substrate 110.
　画像信号の生成および出力は、次のように行うことができる。まず、露光期間に光電変換部１０１が光電変換を行い、生成した電荷をｎ型の半導体領域１１１に保持する。この露光期間の経過後に、電荷転送部１０３がｎ型の半導体領域１１１に保持された電荷を電荷保持部１０２に転送する。この転送された電荷に応じた画像信号が不図示のＭＯＳトランジスタにより生成され、画素１００から出力される。 The image signal can be generated and output as follows. First, the photoelectric conversion unit 101 performs photoelectric conversion during the exposure period, and holds the generated electric charge in the n-type semiconductor region 111. After the lapse of this exposure period, the charge transfer unit 103 transfers the charge held in the n-type semiconductor region 111 to the charge holding unit 102. An image signal corresponding to the transferred charge is generated by a MOS transistor (not shown) and output from the pixel 100.
　配線領域１２０は、画素１００等の素子に信号を伝達する配線が形成される領域である。この配線領域１２０は、半導体基板１１０の表面側に隣接して配置される。配線領域１２０は、配線層１２２および絶縁層１２１を備える。配線層１２２は、画素１００等の素子に信号を伝達する配線である。この配線層１２２は、銅（Ｃｕ）やアルミニウム（Ａｌ）等の金属により構成することができる。絶縁層１２１は、配線層１２２を絶縁するものである。この絶縁層１２１は、例えば、酸化シリコン（ＳｉＯ２）等の絶縁物により構成することができる。同図の配線層１２２は、電荷転送部１０３のゲート電極１１３に接続される配線を例として表したものである。この配線層１２２およびゲート電極１１３は、コンタクトプラグ１２３を介して接続される。コンタクトプラグ１２３は、柱状の金属により構成され、半導体領域および配線を接続するものである。 The wiring area 120 is an area in which wiring for transmitting a signal to an element such as a pixel 100 is formed. The wiring region 120 is arranged adjacent to the surface side of the semiconductor substrate 110. The wiring area 120 includes a wiring layer 122 and an insulating layer 121. The wiring layer 122 is wiring that transmits a signal to an element such as a pixel 100. The wiring layer 122 can be made of a metal such as copper (Cu) or aluminum (Al). The insulating layer 121 insulates the wiring layer 122. The insulating layer 121 can be made of, for example, an insulating material such as silicon oxide (SiO 2). The wiring layer 122 in the figure shows the wiring connected to the gate electrode 113 of the charge transfer unit 103 as an example. The wiring layer 122 and the gate electrode 113 are connected via a contact plug 123. The contact plug 123 is made of columnar metal and connects a semiconductor region and wiring.
　保護膜１６０は、半導体基板１１０の裏面側に配置され、半導体基板１１０の裏面を保護するものである。この保護膜１６０は、例えば、ＳｉＯ２により構成することができる。 The protective film 160 is arranged on the back surface side of the semiconductor substrate 110 to protect the back surface of the semiconductor substrate 110. The protective film 160 can be made of, for example, SiO 2 .
　カラーフィルタ１７０は、入射光のうち所定の波長の光を透過させる光学的なフィルタである。このカラーフィルタ１７０は、画素１００毎に配置される。カラーフィルタ１７０として、例えば、赤色光、緑色光および青色光の何れかを透過させるカラーフィルタ１７０を使用することができる。この場合、これら３種類のカラーフィルタ１７０のうちの１つが画素１００に配置される。カラーフィルタ１７０は、例えば、染料や顔料を分散した樹脂により構成することができる。 The color filter 170 is an optical filter that transmits light of a predetermined wavelength among the incident light. The color filter 170 is arranged for each pixel 100. As the color filter 170, for example, a color filter 170 that transmits any of red light, green light, and blue light can be used. In this case, one of these three types of color filters 170 is arranged in the pixel 100. The color filter 170 can be made of, for example, a resin in which a dye or a pigment is dispersed.
　遮光膜１７１は、入射光を遮光する膜である。この遮光膜１７１は、画素１００の境界に配置され、隣接する画素１００のカラーフィルタ１７０を透過した光を遮光する。これにより、混色を防止することができる。遮光膜１７１は、金属膜や遮光性を有する材料を分散した樹脂膜により構成することができる。 The light-shielding film 171 is a film that blocks incident light. The light-shielding film 171 is arranged at the boundary of the pixel 100 and blocks the light transmitted through the color filter 170 of the adjacent pixel 100. This makes it possible to prevent color mixing. The light-shielding film 171 can be composed of a metal film or a resin film in which a material having a light-shielding property is dispersed.
　オンチップレンズ１８０は、カラーフィルタ１７０に隣接して配置され、入射光を集光するレンズである。このオンチップレンズ１８０は、半球形状に構成され、半導体基板１１０の光電変換部１０１に入射光を集光する。オンチップレンズ１８０は、窒化シリコン（ＳｉＮ）等の無機材料やアクリル樹脂等の有機材料により構成することができる。 The on-chip lens 180 is a lens that is arranged adjacent to the color filter 170 and collects incident light. The on-chip lens 180 is configured in a hemispherical shape, and collects incident light on a photoelectric conversion unit 101 of a semiconductor substrate 110. The on-chip lens 180 can be made of an inorganic material such as silicon nitride (SiN) or an organic material such as an acrylic resin.
　同図の撮像素子１は、半導体基板１１０の裏面側に照射された入射光の撮像を行う裏面照射型の撮像素子の例を表したものである。 The image sensor 1 in the figure represents an example of a back-illuminated image sensor that images the incident light emitted on the back surface side of the semiconductor substrate 110.
　分離領域１４０は、画素１００の境界の半導体基板１１０に配置されて画素１００を分離するものである。この分離領域１４０は、半導体基板１１０の表面に形成された凹部１３０に配置される。同図の凹部１３０は、半導体基板１１０を貫通する形状に構成される。 The separation region 140 is arranged on the semiconductor substrate 110 at the boundary of the pixel 100 to separate the pixel 100. The separation region 140 is arranged in a recess 130 formed on the surface of the semiconductor substrate 110. The recess 130 in the figure is configured to penetrate the semiconductor substrate 110.
　同図の分離領域１４０は、側壁膜１４１および充填膜１４２により構成される。側壁膜１４１は、凹部１３０の側壁に配置されて凹部１３０の側壁の半導体基板１１０を絶縁する膜である。この側壁膜１４１は、例えば、ＳｉＯ２やＳｉＮにより構成することができる。また、側壁膜１４１は、固定電荷膜により構成することもできる。この固定電荷膜は、半導体基板１１０の界面のピニングを行う固定電荷を有する膜である。この固定電荷膜は、例えば、酸化ハフニウム（ＨｆＯ２）、酸化タンタル（Ｔａ２Ｏ５）および酸化アルミニウム（Ａｌ２Ｏ３）により構成することができる。充填膜１４２は、凹部１３０に充填される膜であり、側壁膜１４１の内側に埋め込まれる膜である。充填膜１４２は、例えば、タングステン（Ｗ）等の金属により構成することもできる。また、充填膜１４２は、多結晶シリコンや不純物がドーピングされた多結晶シリコンにより構成することもできる。 The separation region 140 in the figure is composed of the side wall membrane 141 and the filling membrane 142. The side wall film 141 is a film that is arranged on the side wall of the recess 130 and insulates the semiconductor substrate 110 on the side wall of the recess 130. The side wall film 141 can be made of, for example, SiO 2 or SiN. Further, the side wall film 141 can also be formed of a fixed charge film. This fixed charge film is a film having a fixed charge for pinning the interface of the semiconductor substrate 110. This fixed charge film can be composed of, for example, hafnium oxide (HfO 2 ), tantalum oxide (Ta 2 O 5 ) and aluminum oxide (Al 2 O 3 ). The filling film 142 is a film that is filled in the recess 130, and is a film that is embedded inside the side wall film 141. The packing film 142 can also be made of, for example, a metal such as tungsten (W). The packed membrane 142 can also be made of polycrystalline silicon or polycrystalline silicon doped with impurities.
　なお、分離領域１４０の周囲の半導体基板１１０には、固相拡散領域１１９が配置される。この固相拡散領域１１９は、固相拡散法により半導体基板１１０に不純物を拡散させて形成された半導体領域であり、光電変換部１０１を構成するｎ型の半導体領域１１１等とは異なる導電型に構成される半導体領域である。同図の固相拡散領域１１９は、ｐ型に構成される例を表したものである。ｐ型に構成された固相拡散領域１１９は、ｎ型の半導体領域１１１とｐｎ接合を形成し、画素１００の光電変換部１０１を電気的に分離する。すなわち、画素１００は、分離領域１４０および固相拡散領域１１９により隣接する画素１００から電気的に分離される。固相拡散領域１１９は、ｐ型のウェル領域より高い不純物濃度に構成することができる。 A solid phase diffusion region 119 is arranged on the semiconductor substrate 110 around the separation region 140. The solid phase diffusion region 119 is a semiconductor region formed by diffusing impurities into the semiconductor substrate 110 by the solid phase diffusion method, and is a conductive type different from the n-type semiconductor region 111 and the like constituting the photoelectric conversion unit 101. It is a semiconductor area to be composed. The solid phase diffusion region 119 in the figure shows an example of being formed in a p-type. The p-type solid phase diffusion region 119 forms a pn junction with the n-type semiconductor region 111, and electrically separates the photoelectric conversion unit 101 of the pixel 100. That is, the pixel 100 is electrically separated from the adjacent pixel 100 by the separation region 140 and the solid phase diffusion region 119. The solid phase diffusion region 119 can be configured to have a higher impurity concentration than the p-type well region.
　上述のように、固相拡散領域１１９は、固相拡散法により形成することができる。具体的には、側壁膜１４１および充填膜１４２を配置する前の凹部１３０の側壁に不純物を多量に含んだ固体薄膜を配置して加熱する。これにより、固体薄膜の不純物を半導体基板１１０に拡散させ、凹部１３０の周囲の半導体基板１１０に固相拡散領域１１９を形成することができる。固体薄膜には、不純物を多量に含んだＳｉＯ２の膜を使用することができる。また、固体薄膜の不純物には、アクセプタであるホウ素（Ｂ）を使用することができる。なお、ｎ型の固相拡散領域１１９を形成する際には、ドナーであるリン（Ｐ）を固体薄膜に含有させる。その後、凹部１３０に配置した固体薄膜を除去し、側壁膜１４１および充填膜１４２を配置する。 As described above, the solid phase diffusion region 119 can be formed by the solid phase diffusion method. Specifically, a solid thin film containing a large amount of impurities is placed on the side wall of the recess 130 before the side wall film 141 and the filling film 142 are placed and heated. As a result, impurities of the solid thin film can be diffused into the semiconductor substrate 110, and a solid phase diffusion region 119 can be formed in the semiconductor substrate 110 around the recess 130. As the solid thin film, a SiO 2 film containing a large amount of impurities can be used. Further, boron (B), which is an acceptor, can be used as an impurity in the solid thin film. When forming the n-type solid phase diffusion region 119, phosphorus (P), which is a donor, is contained in the solid thin film. After that, the solid thin film arranged in the recess 130 is removed, and the side wall film 141 and the filling film 142 are arranged.
　非分離領域１５０は、分離領域１４０に形成される間隙部分の半導体基板１１０により構成される領域である。非分離領域１５０は、画素１００同士が半導体基板１１０により繋げられた領域である。この非分離領域１５０には、上述の固相拡散領域１１９を配置することができる。 The non-separable region 150 is a region formed by the semiconductor substrate 110 in the gap portion formed in the separated region 140. The non-separable region 150 is an region in which the pixels 100 are connected to each other by the semiconductor substrate 110. The above-mentioned solid phase diffusion region 119 can be arranged in the non-separated region 150.
　［画素の平面構成］
　図３は、本開示の第１の実施の形態に係る撮像素子の構成例を示す平面図である。同図は、画素アレイ部１０に配列される画素１００の構成例を表す平面図である。同図の破線の矩形が画素１００の領域を表す。この画素１００には、光電変換部１０１を構成するｎ型の半導体領域１１１を記載した。このｎ型の半導体領域１１１の周囲に固相拡散領域１１９が配置される。画素１００同士の境界には、分離領域１４０が配置される。また、分離領域１４０の間隙部分に非分離領域１５０が配置される。同図は、画素１００を囲繞する形状の分離領域１４０の辺の部分に非分離領域１５０が配置される例を表したものである。なお、図２は、同図のＡ－Ａ’線に沿う画素１００の断面図に該当する。 [Pixel plane configuration]
FIG. 3 is a plan view showing a configuration example of the image sensor according to the first embodiment of the present disclosure. FIG. 3 is a plan view showing a configuration example of pixels 100 arranged in the pixel array unit 10. The broken line rectangle in the figure represents the area of pixel 100. The n-type semiconductor region 111 constituting the photoelectric conversion unit 101 is described in the pixel 100. A solid phase diffusion region 119 is arranged around the n-type semiconductor region 111. A separation region 140 is arranged at the boundary between the pixels 100. Further, the non-separation region 150 is arranged in the gap portion of the separation region 140. The figure shows an example in which the non-separable region 150 is arranged on the side portion of the separated region 140 having a shape surrounding the pixel 100. Note that FIG. 2 corresponds to a cross-sectional view of the pixel 100 along the line AA'in the figure.
　同図に表した非分離領域１５０を配置しない構成にすると、分離領域１４０が画素１００の半導体基板１１０を囲繞する形状となり、画素１００には島状の半導体基板１１０が配置されることとなる。前述のように、分離領域１４０の凹部１３０は、充填膜１４２により埋められる。しかし、充填膜１４２は凹部１３０の側壁膜１４１に積層される膜であるため、比較的深い凹部１３０の場合には、凹部１３０を完全に埋めることができない。このため、凹部１３０の中央部に空隙が形成される場合がある。半導体基板１１０の強度が低下する。このような分離領域１４０が配置された半導体基板１１０の裏面側からの研削を行うと、凹部１３０の中央部の空隙が押しつぶされ、島状の半導体基板１１０がずれて破損する場合がある。 If the non-separable region 150 shown in the figure is not arranged, the separated region 140 has a shape surrounding the semiconductor substrate 110 of the pixel 100, and the island-shaped semiconductor substrate 110 is arranged in the pixel 100. As described above, the recess 130 of the separation region 140 is filled with the filling membrane 142. However, since the filling film 142 is a film laminated on the side wall film 141 of the recess 130, the recess 130 cannot be completely filled in the case of a relatively deep recess 130. Therefore, a gap may be formed in the central portion of the recess 130. The strength of the semiconductor substrate 110 is reduced. When grinding from the back surface side of the semiconductor substrate 110 in which the separation region 140 is arranged is performed, the gap in the central portion of the recess 130 may be crushed, and the island-shaped semiconductor substrate 110 may be displaced and damaged.
　そこで、分離領域１４０の一部に非分離領域１５０を配置する。画素１００の境界の半導体基板１１０の一部を残すことにより、隣接する画素１００の半導体基板１１０の領域同士を連結する。これにより、半導体基板１１０の強度の低下を軽減することができる。 Therefore, the non-separation area 150 is arranged in a part of the separation area 140. By leaving a part of the semiconductor substrate 110 at the boundary of the pixel 100, the regions of the semiconductor substrate 110 of the adjacent pixels 100 are connected to each other. Thereby, the decrease in the strength of the semiconductor substrate 110 can be reduced.
　また、分離領域１４０の周囲には、固相拡散領域１１９が形成される。非分離領域１５０が配置される分離領域１４０の間隙の幅を固相拡散領域１１９の幅の２倍以下にすることにより、非分離領域１５０に固相拡散領域１１９を形成することができる。具体的には、前述の固相拡散法における不純物の拡散距離の２倍以下の幅に分離領域１４０の間隙を構成することにより、非分離領域１５０の全体に固相拡散領域１１９を配置することができる。非分離領域１５０において隣接する画素１００の半導体基板１１０同士を電気的に分離することができる。 Further, a solid phase diffusion region 119 is formed around the separation region 140. By setting the width of the gap of the separation region 140 in which the non-separation region 150 is arranged to be twice or less the width of the solid phase diffusion region 119, the solid phase diffusion region 119 can be formed in the non-separation region 150. Specifically, the solid phase diffusion region 119 is arranged in the entire non-separation region 150 by forming a gap of the separation region 140 in a width of twice or less the diffusion distance of impurities in the above-mentioned solid phase diffusion method. Can be done. The semiconductor substrates 110 of the adjacent pixels 100 can be electrically separated from each other in the non-separable region 150.
　［画素の製造方法］
　図４乃至６は、本開示の第１の実施の形態に係る撮像素子の製造方法の一例を示す図である。図４乃至６は、撮像素子１の製造工程の一例を表した図である。まず、半導体基板１１０にｐ型のウェル領域を形成する。次に、ｐ型のウェル領域にｎ型の半導体領域１１１等を形成する。これらは、イオン注入により行うことができる（図４におけるＡ）。 [Pixel manufacturing method]
4 to 6 are diagrams showing an example of a method for manufacturing an image sensor according to the first embodiment of the present disclosure. 4 to 6 are views showing an example of a manufacturing process of the image sensor 1. First, a p-type well region is formed on the semiconductor substrate 110. Next, an n-type semiconductor region 111 or the like is formed in the p-type well region. These can be done by ion implantation (A in FIG. 4).
　次に、半導体基板１１０の表面側に凹部１３０を形成する。この際、非分離領域１５０を配置する領域である領域３０２には、凹部１３０を形成しない（図４におけるＢ）。 Next, the recess 130 is formed on the surface side of the semiconductor substrate 110. At this time, the recess 130 is not formed in the region 302, which is the region where the non-separable region 150 is arranged (B in FIG. 4).
　次に、凹部１３０の内壁にＢを含んだ固体薄膜３０３を配置する。これは、例えば、ＣＶＤ（Chemical Vapor Deposition）により行うことができる（図４におけるＣ）。 Next, a solid thin film 303 containing B is placed on the inner wall of the recess 130. This can be done, for example, by CVD (Chemical Vapor Deposition) (C in FIG. 4).
　次に、半導体基板１１０を加熱して固相拡散を行う、これにより、凹部１３０の周囲に固相拡散領域１１９が形成される。また、非分離領域１５０を形成する領域３０２にも固相拡散領域１１９が形成される（図５におけるＤ）。　 Next, the semiconductor substrate 110 is heated to perform solid phase diffusion, whereby a solid phase diffusion region 119 is formed around the recess 130. In addition, a solid phase diffusion region 119 is also formed in the region 302 forming the non-separation region 150 (D in FIG. 5).
　次に、固体薄膜３０３を除去する（図５におけるＥ）。これにより、以降の工程における固相拡散を防止することができる。 Next, the solid thin film 303 is removed (E in FIG. 5). This makes it possible to prevent solid phase diffusion in the subsequent steps.
　次に、凹部１３０の内壁に側壁膜１４１を配置する。これは、例えば、ＳｉＯ２の膜をＣＶＤにより成膜することにより行うことができる（図５におけるＦ）。 Next, the side wall film 141 is arranged on the inner wall of the recess 130. This can be done, for example, by forming a film of SiO 2 by CVD (F in FIG. 5).
　次に、凹部１３０の内壁の側壁膜１４１に充填膜１４２を積層する。これは、例えば、Ｗの膜をＣＶＤにより成膜することにより行うことができる（図６におけるＧ）。 Next, the filling film 142 is laminated on the side wall film 141 of the inner wall of the recess 130. This can be done, for example, by forming a film of W by CVD (G in FIG. 6).
　次に、半導体基板１１０の表面側に配線領域１２０を形成する（図６におけるＨ）。 Next, the wiring region 120 is formed on the surface side of the semiconductor substrate 110 (H in FIG. 6).
　次に、半導体基板１１０の裏面側を研削する。これは、例えば、グラインダを使用して機械的に研磨することにより行うことができる。また、例えば、化学的機械的研磨（ＣＭＰ：Chemical Mechanical Polishing）により行うこともできる。これにより、半導体基板１１０が薄肉化され、半導体基板１１０を貫通する分離領域１４０および非分離領域１５０を形成することができる（図６におけるＩ）。 Next, the back surface side of the semiconductor substrate 110 is ground. This can be done, for example, by mechanically polishing with a grinder. Further, for example, it can be performed by chemical mechanical polishing (CMP). As a result, the semiconductor substrate 110 is thinned, and a separated region 140 and a non-separated region 150 that penetrate the semiconductor substrate 110 can be formed (I in FIG. 6).
　その後、保護膜１６０、遮光膜１７１、カラーフィルタ１７０およびオンチップレンズ１８０を配置することにより、撮像素子１を製造することができる。 After that, the image sensor 1 can be manufactured by arranging the protective film 160, the light-shielding film 171, the color filter 170, and the on-chip lens 180.
　なお、本開示の第１の実施の形態の撮像素子１の構成は、この例に限定されない。例えば、分離領域１４０の周囲の固相拡散領域１１９の代わりに固相拡散以外の方法により形成された半導体領域を使用することもできる。 The configuration of the image sensor 1 according to the first embodiment of the present disclosure is not limited to this example. For example, a semiconductor region formed by a method other than solid phase diffusion can be used instead of the solid phase diffusion region 119 around the separation region 140.
　以上説明したように、本開示の第１の実施の形態の撮像素子１は、画素の境界の分離領域１４０の間隙に非分離領域１５０を配置することにより、撮像素子１の強度の低下を軽減することができる。 As described above, in the image pickup device 1 of the first embodiment of the present disclosure, the decrease in the intensity of the image pickup device 1 is reduced by arranging the non-separation region 150 in the gap of the separation region 140 at the boundary of the pixels. can do.
　＜２．第２の実施の形態＞
　上述の第１の実施の形態の撮像素子１は、画素１００の境界に分離領域１４０および非分離領域１５０が配置されていた。これに対し、本開示の第２の実施の形態の撮像素子１では、この分離領域１４０および非分離領域１５０の形状のバリエーションについて提案する。 <2. Second Embodiment>
In the image sensor 1 of the first embodiment described above, the separated region 140 and the non-separated region 150 are arranged at the boundary of the pixel 100. On the other hand, in the image sensor 1 of the second embodiment of the present disclosure, variations in the shapes of the separated region 140 and the non-separated region 150 are proposed.
　［画素の平面構成］
　図７は、本開示の第２の実施の形態に係る撮像素子の構成例を示す平面図である。同図は、画素１００の分離領域１４０および非分離領域１５０の構成例を表す平面図である。 [Pixel plane configuration]
FIG. 7 is a plan view showing a configuration example of the image sensor according to the second embodiment of the present disclosure. FIG. 3 is a plan view showing a configuration example of a separated region 140 and a non-separated region 150 of the pixel 100.
　同図におけるＡは、画素１００の隅部に非分離領域１５０が配置される例を表した図である。同図におけるＡの図面の横方向に配置される分離領域１４０は、横方向に隣接する画素１００に対して共通に配置される。 A in the figure is a diagram showing an example in which the non-separable region 150 is arranged at the corner of the pixel 100. The separation region 140 arranged in the horizontal direction in the drawing A in the figure is commonly arranged with respect to the pixels 100 adjacent in the horizontal direction.
　同図におけるＢは、分離領域１４０が細かく分断されて、非分離領域１５０が多く配置される例を表した図である。非分離領域１５０が多く配置されるため、画素１００の強度をさらに向上させることができる。また、分離領域１４０および非分離領域１５０を周期的に配置することにより、隣接する画素１００から斜めに入射する入射光を偏向させることができ、減衰させることがでる。これにより、クロストークを低減することがでる。この際、分離領域１４０同士の間隙ｄの幅を入射光の波長の１／４の幅に構成すると好適である。隣接する画素１００からの入射光をさらに減衰させることができるためである。　 B in the figure is a diagram showing an example in which the separation region 140 is finely divided and many non-separation regions 150 are arranged. Since many non-separable regions 150 are arranged, the strength of the pixel 100 can be further improved. Further, by periodically arranging the separated region 140 and the non-separated region 150, the incident light obliquely incident from the adjacent pixel 100 can be deflected and attenuated. As a result, crosstalk can be reduced. At this time, it is preferable to configure the width of the gap d between the separation regions 140 to be 1/4 of the wavelength of the incident light. This is because the incident light from the adjacent pixel 100 can be further attenuated.
　［画素の平面の他の構成］
　図８は、本開示の第２の実施の形態に係る撮像素子の他の構成例を示す平面図である。同図は、平面視において円形状に構成される分離領域１４０を表した図である。同図の分離領域１４０は、開口部が円形状の凹部１３０に配置される分離領域１４０である。この円形状の分離領域１４０の周囲に固相拡散領域１１９を配置することにより、平面視における光電変換部１０１との間の形状が円弧をつなぎ合わせた形状の固相拡散領域１１９を構成することができる。つなぎ合わされた円弧の端部が非分離領域１５０の側に入り込んだ形状となり、光電変換部１０１の領域を拡張することができる。光電変換部１０１に蓄積可能な電荷量を増加させることができ、ダイナミックレンジを向上させることができる。 [Other configurations of pixel plane]
FIG. 8 is a plan view showing another configuration example of the image pickup device according to the second embodiment of the present disclosure. The figure is a diagram showing a separation region 140 formed in a circular shape in a plan view. The separation region 140 in the figure is a separation region 140 in which the opening is arranged in the concave portion 130 having a circular shape. By arranging the solid-phase diffusion region 119 around the circular separation region 140, the solid-phase diffusion region 119 having a shape between the photoelectric conversion unit 101 and the photoelectric conversion unit 101 in a plan view is formed by connecting arcs. Can be done. The end of the joined arc has a shape that enters the non-separable region 150 side, and the region of the photoelectric conversion unit 101 can be expanded. The amount of charge that can be stored in the photoelectric conversion unit 101 can be increased, and the dynamic range can be improved.
　［画素の断面の構成］
　図９は、本開示の第２の実施の形態に係る撮像素子の構成例を示す断面図である。同図は、分離領域１４０および非分離領域１５０の構成例を表す断面図である。同図におけるＡは、半導体基板１１０の表面に対して垂直な形状に構成される分離領域１４０の例を表した図である。この場合、非分離領域１５０も半導体基板１１０の表面に対して垂直な形状に構成される。 [Structure of pixel cross section]
FIG. 9 is a cross-sectional view showing a configuration example of the image sensor according to the second embodiment of the present disclosure. The figure is a cross-sectional view showing a configuration example of a separated region 140 and a non-separated region 150. FIG. A in the figure is a diagram showing an example of a separation region 140 formed in a shape perpendicular to the surface of the semiconductor substrate 110. In this case, the non-separable region 150 is also configured to have a shape perpendicular to the surface of the semiconductor substrate 110.
　同図におけるＢは、半導体基板１１０の表面と中央部とにおいて異なる幅に構成される分離領域１４０の例を表した図である。同図におけるＢに表したように、半導体基板１１０の中央部において隣接する分離領域１４０同士が接する形状に構成することもできる。この場合、非分離領域１５０は、半導体基板の表側および裏側の表面の近傍に配置される。 B in the figure is a diagram showing an example of a separation region 140 having different widths on the surface and the central portion of the semiconductor substrate 110. As shown in B in the figure, it is also possible to form a shape in which adjacent separation regions 140 are in contact with each other in the central portion of the semiconductor substrate 110. In this case, the non-separable region 150 is arranged near the front and back surfaces of the semiconductor substrate.
　また、半導体基板１１０の表側の表面の近傍においても隣接する分離領域１４０同士が接する形状に構成することもできる。この場合においても半導体基板１１０の裏面側には非分離領域１５０が配置され、半導体基板１１０の裏面側の研削の際の強度の低下を軽減することができる。なお、半導体基板１１０の裏面側の非分離領域１５０は、半導体基板１１０の裏面の研削の際の厚さのばらつきに応じた深さに構成することができる。 Further, it is also possible to form a shape in which adjacent separation regions 140 are in contact with each other even in the vicinity of the front surface of the semiconductor substrate 110. Even in this case, the non-separable region 150 is arranged on the back surface side of the semiconductor substrate 110, and the decrease in strength at the time of grinding on the back surface side of the semiconductor substrate 110 can be reduced. The non-separable region 150 on the back surface side of the semiconductor substrate 110 can be configured to have a depth corresponding to the variation in thickness when grinding the back surface of the semiconductor substrate 110.
　また、分離領域１４０の断面の形状を半導体基板１１０の表面側における開口面積が裏面側より大きいテーパ形状に構成することもできる。 Further, the cross-sectional shape of the separation region 140 can be configured to have a tapered shape in which the opening area on the front surface side of the semiconductor substrate 110 is larger than that on the back surface side.
　これ以外の撮像素子１の構成は本開示の第１の実施の形態において説明した撮像素子１の構成と同様であるため、説明を省略する。 Since the other configurations of the image sensor 1 are the same as the configurations of the image sensor 1 described in the first embodiment of the present disclosure, the description thereof will be omitted.
　以上説明したように、本開示の第２の実施の形態の撮像素子１は、分離領域１４０および非分離領域１５０の形状を変更した場合であっても画素１００の強度の低下を軽減することができる。 As described above, the image sensor 1 of the second embodiment of the present disclosure can reduce the decrease in the intensity of the pixel 100 even when the shapes of the separated region 140 and the non-separated region 150 are changed. can.
　＜３．カメラへの応用例＞
　本開示に係る技術（本技術）は、様々な製品に応用することができる。例えば、本技術は、カメラ等の撮像装置に搭載される撮像素子として実現されてもよい。 <3. Application example to camera>
The technology according to the present disclosure (the present technology) can be applied to various products. For example, the present technology may be realized as an image pickup device mounted on an image pickup device such as a camera.
　図１０は、本技術が適用され得る撮像装置の一例であるカメラの概略的な構成例を示すブロック図である。同図のカメラ１０００は、レンズ１００１と、撮像素子１００２と、撮像制御部１００３と、レンズ駆動部１００４と、画像処理部１００５と、操作入力部１００６と、フレームメモリ１００７と、表示部１００８と、記録部１００９とを備える。 FIG. 10 is a block diagram showing a schematic configuration example of a camera which is an example of an imaging device to which the present technology can be applied. The camera 1000 in the figure includes a lens 1001, an image pickup element 1002, an image pickup control unit 1003, a lens drive unit 1004, an image processing unit 1005, an operation input unit 1006, a frame memory 1007, a display unit 1008, and the like. A recording unit 1009 is provided.
レンズ１００１は、カメラ１０００の撮影レンズである。このレンズ１００１は、被写体からの光を集光し、後述する撮像素子１００２に入射させて被写体を結像させる。 The lens 1001 is a photographing lens of the camera 1000. The lens 1001 collects light from the subject and causes the light to be incident on the image pickup device 1002 described later to form an image of the subject.
　撮像素子１００２は、レンズ１００１により集光された被写体からの光を撮像する半導体素子である。この撮像素子１００２は、照射された光に応じたアナログの画像信号を生成し、デジタルの画像信号に変換して出力する。 The image sensor 1002 is a semiconductor element that captures light from a subject focused by the lens 1001. The image sensor 1002 generates an analog image signal corresponding to the irradiated light, converts it into a digital image signal, and outputs the signal.
　撮像制御部１００３は、撮像素子１００２における撮像を制御するものである。この撮像制御部１００３は、制御信号を生成して撮像素子１００２に対して出力することにより、撮像素子１００２の制御を行う。また、撮像制御部１００３は、撮像素子１００２から出力された画像信号に基づいてカメラ１０００におけるオートフォーカスを行うことができる。ここでオートフォーカスとは、レンズ１００１の焦点位置を検出して、自動的に調整するシステムである。このオートフォーカスとして、撮像素子１００２に配置された位相差画素により像面位相差を検出して焦点位置を検出する方式（像面位相差オートフォーカス）を使用することができる。また、画像のコントラストが最も高くなる位置を焦点位置として検出する方式（コントラストオートフォーカス）を適用することもできる。撮像制御部１００３は、検出した焦点位置に基づいてレンズ駆動部１００４を介してレンズ１００１の位置を調整し、オートフォーカスを行う。なお、撮像制御部１００３は、例えば、ファームウェアを搭載したＤＳＰ（Digital Signal Processor）により構成することができる。 The image pickup control unit 1003 controls the image pickup in the image pickup device 1002. The image pickup control unit 1003 controls the image pickup device 1002 by generating a control signal and outputting the control signal to the image pickup device 1002. Further, the image pickup control unit 1003 can perform autofocus on the camera 1000 based on the image signal output from the image pickup device 1002. Here, the autofocus is a system that detects the focal position of the lens 1001 and automatically adjusts it. As this autofocus, a method (image plane phase difference autofocus) in which the image plane phase difference is detected by the phase difference pixels arranged in the image sensor 1002 to detect the focal position can be used. It is also possible to apply a method (contrast autofocus) of detecting the position where the contrast of the image is highest as the focal position. The image pickup control unit 1003 adjusts the position of the lens 1001 via the lens drive unit 1004 based on the detected focus position, and performs autofocus. The image pickup control unit 1003 can be configured by, for example, a DSP (Digital Signal Processor) equipped with firmware.
　レンズ駆動部１００４は、撮像制御部１００３の制御に基づいて、レンズ１００１を駆動するものである。このレンズ駆動部１００４は、内蔵するモータを使用してレンズ１００１の位置を変更することによりレンズ１００１を駆動することができる。 The lens driving unit 1004 drives the lens 1001 based on the control of the imaging control unit 1003. The lens driving unit 1004 can drive the lens 1001 by changing the position of the lens 1001 using a built-in motor.
　画像処理部１００５は、撮像素子１００２により生成された画像信号を処理するものである。この処理には、例えば、画素毎の赤色、緑色および青色に対応する画像信号のうち不足する色の画像信号を生成するデモザイク、画像信号のノイズを除去するノイズリダクションおよび画像信号の符号化等が該当する。画像処理部１００５は、例えば、ファームウェアを搭載したマイコンにより構成することができる。 The image processing unit 1005 processes the image signal generated by the image sensor 1002. This processing includes, for example, demosaic to generate an image signal of a color that is insufficient among the image signals corresponding to red, green, and blue for each pixel, noise reduction to remove noise of the image signal, and coding of the image signal. Applicable. The image processing unit 1005 can be configured by, for example, a microcomputer equipped with firmware.
　操作入力部１００６は、カメラ１０００の使用者からの操作入力を受け付けるものである。この操作入力部１００６には、例えば、押しボタンやタッチパネルを使用することができる。操作入力部１００６により受け付けられた操作入力は、撮像制御部１００３や画像処理部１００５に伝達される。その後、操作入力に応じた処理、例えば、被写体の撮像等の処理が起動される。 The operation input unit 1006 receives the operation input from the user of the camera 1000. For example, a push button or a touch panel can be used for the operation input unit 1006. The operation input received by the operation input unit 1006 is transmitted to the image pickup control unit 1003 and the image processing unit 1005. After that, processing according to the operation input, for example, processing such as imaging of the subject is activated.
　フレームメモリ１００７は、１画面分の画像信号であるフレームを記憶するメモリである。このフレームメモリ１００７は、画像処理部１００５により制御され、画像処理の過程におけるフレームの保持を行う。 The frame memory 1007 is a memory that stores a frame that is an image signal for one screen. The frame memory 1007 is controlled by the image processing unit 1005 and holds frames in the process of image processing.
　表示部１００８は、画像処理部１００５により処理された画像を表示するものである。この表示部１００８には、例えば、液晶パネルを使用することができる。 The display unit 1008 displays the image processed by the image processing unit 1005. For this display unit 1008, for example, a liquid crystal panel can be used.
　記録部１００９は、画像処理部１００５により処理された画像を記録するものである。この記録部１００９には、例えば、メモリカードやハードディスクを使用することができる。 The recording unit 1009 records the image processed by the image processing unit 1005. For example, a memory card or a hard disk can be used for the recording unit 1009.
　以上、本開示が適用され得るカメラについて説明した。本技術は以上において説明した構成のうち、撮像素子１００２に適用され得る。具体的には、図１において説明した撮像素子１は、撮像素子１００２に適用することができる。なお、画像処理部１００５は、請求の範囲に記載の処理回路の一例である。カメラ１０００は、請求の範囲に記載の撮像装置の一例である。 The cameras to which this disclosure can be applied have been described above. The present technology can be applied to the image pickup device 1002 among the configurations described above. Specifically, the image pickup device 1 described with reference to FIG. 1 can be applied to the image pickup device 1002. The image processing unit 1005 is an example of the processing circuit described in the claims. The camera 1000 is an example of the image pickup apparatus described in the claims.
　最後に、上述した各実施の形態の説明は本開示の一例であり、本開示は上述の実施の形態に限定されることはない。このため、上述した各実施の形態以外であっても、本開示に係る技術的思想を逸脱しない範囲であれば、設計等に応じて種々の変更が可能であることは勿論である。 Finally, the description of each embodiment described above is an example of the present disclosure, and the present disclosure is not limited to the above-described embodiment. Therefore, it goes without saying that various changes can be made according to the design and the like as long as the technical idea according to the present disclosure is not deviated from the above-described embodiments.
　また、本明細書に記載された効果はあくまで例示であって限定されるものでは無い。また、他の効果があってもよい。 In addition, the effects described in this specification are merely examples and are not limited. It may also have other effects.
　また、上述の実施の形態における図面は、模式的なものであり、各部の寸法の比率等は現実のものとは必ずしも一致しない。また、図面相互間においても互いの寸法の関係や比率が異なる部分が含まれることは勿論である。 Further, the drawings in the above-described embodiment are schematic, and the dimensional ratios of each part do not always match the actual ones. In addition, it goes without saying that parts of the drawings having different dimensional relationships and ratios are included.
　なお、本技術は以下のような構成もとることができる。
（１）半導体基板に形成されて入射光の光電変換を行う光電変換部および前記半導体基板の表面側に配置されて前記光電変換部の信号を伝達する配線が配置される配線領域を備える複数の画素と、
　前記複数の画素同士の前記半導体基板を分離する分離領域と、
　前記分離領域に形成される間隙部分の前記半導体基板により構成される非分離領域と
を具備する撮像素子。
（２）前記分離領域は、前記半導体基板の表面側に形成される凹部に配置される前記（１）に記載の撮像素子。
（３）前記分離領域は、前記半導体基板を貫通する前記凹部に配置される前記（２）に記載の撮像素子。
（４）前記分離領域は、円形状の開口部に構成される前記凹部に配置される前記（２）から（３）の何れかに記載の撮像素子。
（５）前記分離領域は、前記凹部に金属が配置されて構成される前記（２）から（４）の何れかに記載の撮像素子。
（６）前記分離領域は、前記凹部に多結晶シリコンが配置されて構成される前記（２）から（４）の何れかに記載の撮像素子。
（７）前記分離領域は、前記凹部における前記半導体基板の表面を覆う形状の側壁膜を備える前記（２）から（６）の何れかに記載の撮像素子。
（８）前記非分離領域は、前記光電変換部を構成する半導体領域とは異なる導電型に構成される前記（１）から（７）の何れかに記載の撮像素子。
（９）前記非分離領域は、前記半導体基板に形成される凹部に配置される不純物を含む部材から拡散した不純物により前記導電型に構成される前記（８）に記載の撮像素子。
（１０）前記非分離領域は、前記不純物の拡散の距離の２倍以下の前記間隙部分の前記半導体基板により構成される前記（９）に記載の撮像素子。
（１１）前記非分離領域は、前記入射光の波長の１／４の幅の前記間隙部分の前記半導体基板により構成される前記（１）から（１０）の何れかに記載の撮像素子。
（１２）前記非分離領域は、前記半導体基板の裏面側に配置される前記（１）から（１１）の何れかに記載の撮像素子。
（１３）前記光電変換部を構成する半導体領域とは異なる導電型に構成されて前記分離領域および前記光電変換部の間に配置される半導体領域をさらに具備する前記（１）から（１２）の何れかに記載の撮像素子。
（１４）半導体基板に形成されて入射光の光電変換を行う光電変換部および前記半導体基板の表面側に配置されて前記光電変換部の信号を伝達する配線が配置される配線領域を備える複数の画素と、
　前記複数の画素同士の前記半導体基板を分離する分離領域と、
　前記分離領域に形成される間隙部分の前記半導体基板により構成される非分離領域と、
　前記光電変換に基づいて生成される画像信号の処理を行う処理回路と
を具備する撮像装置。 The present technology can have the following configurations.
(1) A plurality of wiring regions formed on a semiconductor substrate for performing photoelectric conversion of incident light and wiring regions arranged on the surface side of the semiconductor substrate to transmit signals of the photoelectric conversion unit. With pixels
A separation region that separates the semiconductor substrate between the plurality of pixels, and
An image pickup device including a non-separable region formed of the semiconductor substrate in a gap portion formed in the separated region.
(2) The image pickup device according to (1), wherein the separation region is arranged in a recess formed on the surface side of the semiconductor substrate.
(3) The image pickup device according to (2), wherein the separation region is arranged in the recess that penetrates the semiconductor substrate.
(4) The image pickup device according to any one of (2) to (3), wherein the separation region is arranged in the recess formed in a circular opening.
(5) The image pickup device according to any one of (2) to (4) above, wherein the separation region is formed by arranging a metal in the recess.
(6) The image pickup device according to any one of (2) to (4) above, wherein the separation region is formed by arranging polycrystalline silicon in the recess.
(7) The image pickup device according to any one of (2) to (6) above, wherein the separation region includes a side wall film having a shape that covers the surface of the semiconductor substrate in the recess.
(8) The image pickup device according to any one of (1) to (7), wherein the non-separable region is formed in a conductive type different from the semiconductor region constituting the photoelectric conversion unit.
(9) The image pickup device according to (8), wherein the non-separable region is formed into a conductive type by impurities diffused from a member containing impurities arranged in a recess formed in the semiconductor substrate.
(10) The image pickup device according to (9), wherein the non-separable region is composed of the semiconductor substrate in the gap portion which is twice or less the diffusion distance of the impurities.
(11) The image pickup device according to any one of (1) to (10), wherein the non-separable region is composed of the semiconductor substrate in the gap portion having a width of 1/4 of the wavelength of the incident light.
(12) The image pickup device according to any one of (1) to (11), wherein the non-separable region is arranged on the back surface side of the semiconductor substrate.
(13) The above (1) to (12), which are configured in a conductive type different from the semiconductor region constituting the photoelectric conversion unit and further include a semiconductor region arranged between the separation region and the photoelectric conversion unit. The image pickup device according to any one.
(14) A plurality of wiring regions formed on a semiconductor substrate for performing photoelectric conversion of incident light and wiring regions arranged on the surface side of the semiconductor substrate to transmit signals of the photoelectric conversion unit. With pixels
A separation region that separates the semiconductor substrate between the plurality of pixels, and
The non-separable region formed by the semiconductor substrate in the gap portion formed in the separated region and the non-separable region
An imaging device including a processing circuit that processes an image signal generated based on the photoelectric conversion.
　１、１００２　撮像素子
　１０　画素アレイ部
　３０　カラム信号処理部
　１００　画素
　１０１　光電変換部
　１１０　半導体基板
　１１９　固相拡散領域
　１２０　配線領域
　１３０　凹部
　１４０　分離領域
　１４１　側壁膜
　１４２　充填膜
　１５０　非分離領域
　１０００　カメラ
　１００５　画像処理部 1, 1002 Image sensor 10 Pixel array unit 30 Column signal processing unit 100 pixels 101 Photoelectric conversion unit 110 Semiconductor substrate 119 Solid phase diffusion area 120 Wiring area 130 Recessed 140 Separation area 141 Side wall film 142 Filling film 150 Non-separation area 1000 Camera 1005 Image Processing unit

Claims (14)

  1. 　半導体基板に形成されて入射光の光電変換を行う光電変換部および前記半導体基板の表面側に配置されて前記光電変換部の信号を伝達する配線が配置される配線領域を備える複数の画素と、
    　前記複数の画素同士の前記半導体基板を分離する分離領域と、
    　前記分離領域に形成される間隙部分の前記半導体基板により構成される非分離領域と
    を具備する撮像素子。     A plurality of pixels having a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of incident light, and a wiring region arranged on the surface side of the semiconductor substrate and arranging a wiring for transmitting a signal of the photoelectric conversion unit.
    A separation region that separates the semiconductor substrate between the plurality of pixels, and
    An image pickup device including a non-separable region formed of the semiconductor substrate in a gap portion formed in the separated region.
  2. 　前記分離領域は、前記半導体基板の表面側に形成される凹部に配置される請求項１記載の撮像素子。 The image pickup device according to claim 1, wherein the separation region is arranged in a recess formed on the surface side of the semiconductor substrate.
  3. 　前記分離領域は、前記半導体基板を貫通する前記凹部に配置される請求項２記載の撮像素子。 The image pickup device according to claim 2, wherein the separation region is arranged in the recess that penetrates the semiconductor substrate.
  4. 　前記分離領域は、円形状の開口部に構成される前記凹部に配置される請求項２記載の撮像素子。 The image pickup device according to claim 2, wherein the separation region is arranged in the recess formed by a circular opening.
  5. 　前記分離領域は、前記凹部に金属が配置されて構成される請求項２記載の撮像素子。 The image pickup device according to claim 2, wherein the separation region is formed by arranging a metal in the recess.
  6. 　前記分離領域は、前記凹部に多結晶シリコンが配置されて構成される請求項２記載の撮像素子。 The image pickup device according to claim 2, wherein the separation region is formed by arranging polycrystalline silicon in the recess.
  7. 　前記分離領域は、前記凹部における前記半導体基板の表面を覆う形状の側壁膜を備える請求項２記載の撮像素子。 The image pickup device according to claim 2, wherein the separation region includes a side wall film having a shape that covers the surface of the semiconductor substrate in the recess.
  8. 　前記非分離領域は、前記光電変換部を構成する半導体領域とは異なる導電型に構成される請求項１記載の撮像素子。 The image pickup device according to claim 1, wherein the non-separable region is formed in a conductive type different from the semiconductor region constituting the photoelectric conversion unit.
  9. 　前記非分離領域は、前記凹部に配置される不純物を含む部材から拡散した不純物により前記導電型に構成される請求項８記載の撮像素子。 The image pickup device according to claim 8, wherein the non-separable region is formed into a conductive type by impurities diffused from a member containing impurities arranged in the recess.
  10. 　前記非分離領域は、前記不純物の拡散の距離の２倍以下の前記間隙部分の前記半導体基板により構成される請求項９記載の撮像素子。 The image pickup device according to claim 9, wherein the non-separable region is composed of the semiconductor substrate in the gap portion which is twice or less the diffusion distance of the impurities.
  11. 　前記非分離領域は、前記入射光の波長の１／４の幅の前記間隙部分の前記半導体基板により構成される請求項１記載の撮像素子。 The image pickup device according to claim 1, wherein the non-separable region is formed of the semiconductor substrate in the gap portion having a width of 1/4 of the wavelength of the incident light.
  12. 　前記非分離領域は、前記半導体基板の裏面側に配置される請求項１記載の撮像素子。 The image pickup device according to claim 1, wherein the non-separable region is arranged on the back surface side of the semiconductor substrate.
  13. 　前記光電変換部を構成する半導体領域とは異なる導電型に構成されて前記分離領域および前記光電変換部の間に配置される半導体領域をさらに具備する請求項１記載の撮像素子。 The imaging device according to claim 1, further comprising a semiconductor region that is formed in a conductive type different from the semiconductor region constituting the photoelectric conversion unit and is arranged between the separation region and the photoelectric conversion unit.
  14. 　半導体基板に形成されて入射光の光電変換を行う光電変換部および前記半導体基板の表面側に配置されて前記画素の信号を伝達する配線が配置される配線領域を備える複数の画素と、
    　前記複数の画素同士の前記半導体基板を分離する分離領域と、
    　前記分離領域に形成される間隙部分の前記半導体基板により構成される非分離領域と、
    　前記光電変換に基づいて生成される画像信号の処理を行う処理回路とを具備する撮像装置。     A plurality of pixels having a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of incident light, and a wiring region arranged on the surface side of the semiconductor substrate and arranging wirings for transmitting signals of the pixels.
    A separation region that separates the semiconductor substrate between the plurality of pixels, and
    A non-separable region formed of the semiconductor substrate in the gap portion formed in the separated region, and a non-separable region.
    An image pickup apparatus including a processing circuit that processes an image signal generated based on the photoelectric conversion.
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