WO2021241243A1 - Dispositif d'imagerie à semi-conducteurs et procédé de photodétection - Google Patents

Dispositif d'imagerie à semi-conducteurs et procédé de photodétection Download PDF

Info

Publication number
WO2021241243A1
WO2021241243A1 PCT/JP2021/018175 JP2021018175W WO2021241243A1 WO 2021241243 A1 WO2021241243 A1 WO 2021241243A1 JP 2021018175 W JP2021018175 W JP 2021018175W WO 2021241243 A1 WO2021241243 A1 WO 2021241243A1
Authority
WO
WIPO (PCT)
Prior art keywords
photoelectric conversion
conversion layer
solid
light
layer
Prior art date
Application number
PCT/JP2021/018175
Other languages
English (en)
Japanese (ja)
Inventor
遥之 中川
Original Assignee
ソニーセミコンダクタソリューションズ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ソニーセミコンダクタソリューションズ株式会社 filed Critical ソニーセミコンダクタソリューションズ株式会社
Publication of WO2021241243A1 publication Critical patent/WO2021241243A1/fr

Links

Images

Classifications

    • 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
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices 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; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0232—Optical elements or arrangements associated with the device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices 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; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices 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; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/10—Semiconductor devices 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; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors

Definitions

  • the present disclosure relates to a solid-state image sensor and a photodetection method.
  • Patent Document 1 discloses a solid-state image pickup device including a photoelectric conversion unit (photodiode) formed on a silicon semiconductor substrate.
  • One aspect of the present disclosure makes it possible to improve the light detection sensitivity while suppressing an increase in the substrate thickness.
  • the solid-state image pickup device includes a pixel array including a plurality of pixels, each of the plurality of pixels provided on a semiconductor substrate, and includes a first photoelectric conversion layer and a second photoelectric conversion layer.
  • the second photoelectric conversion layer includes a photoelectric conversion unit and a transfer transistor that reads out and transfers the charge accumulated in the photoelectric conversion unit, and the second photoelectric conversion layer is a photonic crystal layer.
  • the photodetection method is a photodetection method for detecting light using a photoelectric conversion unit, wherein the photoelectric conversion unit includes a first photoelectric conversion layer and a second photoelectric conversion layer provided on a semiconductor substrate.
  • the second photoelectric conversion layer includes a photoelectric conversion layer, and the second photoelectric conversion layer is a photonic crystal layer, and the photodetection method reads out the charge generated in the first photoelectric conversion layer and the charge generated in the second photoelectric conversion layer.
  • FIG. 1 It is a figure which shows the example of the schematic structure of the solid-state image pickup apparatus which concerns on embodiment. It is a figure which shows the example of the circuit structure of a pixel. It is sectional drawing which shows the example of the schematic structure of a pixel. It is a perspective view which shows the example of the schematic structure of the photonic crystal layer. It is sectional drawing which shows the example of the schematic structure of a pixel. It is sectional drawing which shows the example of the schematic structure of a pixel. It is sectional drawing which shows the example of the schematic structure of a pixel. It is a block diagram which shows an example of the schematic structure of a vehicle control system. It is explanatory drawing which shows an example of the installation position of the vehicle exterior information detection unit and the image pickup unit.
  • the substrate thickness for example, the film thickness of silicon
  • the rare earth iron garnet RIG: Rare earth
  • Iron Garnet Iron Garnet
  • the disclosed technology is the detection sensitivity of infrared light while suppressing the increase in substrate thickness and avoiding the introduction of RIG, etc. by introducing a photonic crystal into which a refractive index distribution is periodically introduced. To improve.
  • FIG. 1 is a diagram showing an example of a schematic configuration of a solid-state image sensor according to an embodiment.
  • the illustrated solid-state imaging device 1 includes a pixel region 2, a vertical drive circuit 3, a horizontal drive circuit 4, a control circuit 5, a column signal processing circuit 6, and an output circuit 7.
  • the pixel area 2 is a pixel array in which a plurality of pixels 20 are arranged in a two-dimensional array.
  • the pixel 20 includes a photoelectric conversion unit (for example, a photodiode).
  • a pixel transistor or the like is included in the pixel 20.
  • An example of the pixel transistor is the transfer transistor 25 of FIG. 2, which will be described later.
  • the vertical drive circuit 3 drives the pixel 20 in row units.
  • the vertical drive circuit 3 is composed of, for example, a shift register.
  • the vertical drive circuit 3 selects the pixel drive wiring and supplies the drive signal (for example, a pulse) of the pixel 20.
  • the vertical drive circuit 3 selectively scans each pixel 20 in the pixel region 2 in a row-by-row manner in the vertical direction, and a pixel signal based on the signal charge generated in the photoelectric conversion unit of each pixel 20 according to the amount of light received. Is supplied to the column signal processing circuit 6 via the vertical signal line 8.
  • the horizontal drive circuit 4 drives the column signal processing circuit 6 in column units.
  • the horizontal drive circuit 4 is composed of, for example, a shift register.
  • the horizontal drive circuit 4 sequentially outputs each of the column signal processing circuits 6 by sequentially outputting horizontal scanning pulses, and outputs pixel signals from each of the column signal processing circuits 6 via the horizontal signal line 9. Output to circuit 7.
  • the control circuit 5 controls the entire solid-state image sensor 1.
  • the control circuit 5 receives an input clock and data for instructing an operation mode and the like, and outputs data such as internal information of the solid-state image pickup device 1. That is, the control circuit 5 outputs a clock signal, a control signal, etc., which is a reference for the operation of the vertical drive circuit 3, the column signal processing circuit 6, the horizontal drive circuit 4, etc., based on the vertical synchronization signal, the horizontal synchronization signal, and the master clock. Generate. Then, these signals are input to the vertical drive circuit 3, the column signal processing circuit 6, the horizontal drive circuit 4, and the like.
  • the column signal processing circuit 6 is arranged for each column of the pixel 20, for example, and performs signal processing such as noise removal for each pixel column for the signal output from the pixel 20 for one row.
  • the column signal processing circuit 6 performs signal processing such as CDS (Correlated Double Sampling), signal amplification, and AD (Analog to Digital) conversion for removing fixed pattern noise peculiar to the pixel 20.
  • a horizontal selection switch (not shown) is connected to the output stage of the column signal processing circuit 6 between the horizontal signal line 9 and the horizontal selection switch.
  • the output circuit 7 performs signal processing on the signals sequentially supplied from each of the column signal processing circuits 6 through the horizontal signal line 9, and outputs an image signal. At that time, the output circuit 7 buffers the signal from the column signal processing circuit 6.
  • the output circuit 7 may perform black level adjustment, column variation correction, various digital signal processing, and the like on the signal from the column signal processing circuit 6.
  • FIG. 2 is a diagram showing an example of a pixel circuit configuration.
  • the pixel 20 includes a PD 24, a transfer transistor 25, an FD 26, a reset transistor 27, an amplification transistor 28, and a selection transistor 29.
  • the transfer transistor 25, the reset transistor 27, the amplification transistor 28, and the selection transistor 29 (pixel transistor) are n-type MOS transistors.
  • a transfer signal line For the pixel 20, three signal lines of a transfer signal line, a reset signal line, and a selection signal line are provided in the row direction, and a vertical signal line 8 is provided in the column direction.
  • a power supply voltage Vdd is supplied to the drains of the reset transistor 27 and the amplification transistor 28.
  • the PD24 is a photodiode (photoelectric conversion unit) that generates an electric charge according to the incident light.
  • the anode of PD24 is grounded.
  • the transfer transistor 25 is a transistor that transfers the electric charge generated in the PD 24.
  • the transfer transistor 25 is provided between the cathode of the PD 24 and the FD 26.
  • the transfer transistor 25 is turned on when a high-level signal is input from the vertical drive circuit 3 to the gate via the transfer signal line, and the charge photoelectrically converted in the PD 24 is transferred to the FD 26.
  • the FD 26 is a floating diffusion region that converts the charge transferred by the transfer transistor 25 into a voltage signal.
  • the voltage signal of the FD 26 is connected to the drain of the reset transistor 27 and the gate of the amplification transistor 28.
  • the reset transistor 27 is a transistor for resetting the voltage of the FD 26.
  • the reset transistor 27 is provided between the power supply voltage Vdd and the FD 26.
  • the reset transistor 27 is turned on when a high-level signal is input from the vertical drive circuit 3 to the gate to the reset signal line, and resets the potential of the FD 26 to the power supply voltage Vdd.
  • the amplification transistor 28 is a transistor that amplifies the voltage signal of the FD 26.
  • the gate of the amplification transistor 28 is connected to the FD 26.
  • the drain of the amplification transistor 28 is connected to the power supply voltage Vdd, and the source of the amplification transistor 28 is connected to the vertical signal line 8 via the selection transistor 29.
  • the amplification transistor 28 amplifies the voltage signal of the FD 26 and outputs the amplified signal as a pixel signal to the selection transistor 29.
  • the selection transistor 29 is a transistor for selecting the pixel 20.
  • the selection transistor 29 is provided between the amplification transistor 28 and the vertical signal line 8.
  • the selection transistor 29 is turned on when a high-level signal is input from the vertical drive circuit 3 to the gate to the selection signal line, and the voltage signal amplified by the amplification transistor 28 is output to the vertical signal line 8.
  • a memory unit that temporarily holds the electric charge generated by the PD 24 before being transferred to the FD 26 may be provided between the PD 24 and the transfer transistor 25 and the FD 26.
  • another transfer transistor may be provided in which the memory unit holds the electric charge and transfers the electric charge to the FD 26.
  • One of the features of the solid-state image sensor 1 described above is the PD24 of the pixel 20. This will be described with reference to FIGS. 3 and later.
  • FIG. 3 is a cross-sectional view showing an example of a schematic configuration of pixels.
  • the semiconductor substrate on which the pixels 20 are formed is referred to as a semiconductor substrate 100 and is illustrated.
  • the front surface and the back surface of the semiconductor substrate 100 are referred to as a substrate surface 100a and a substrate back surface 100b and are shown.
  • the XYZ coordinate system is shown.
  • the Z-axis direction corresponds to the thickness direction of the semiconductor substrate 100.
  • the X-axis direction and the Y-axis direction correspond to the plane direction of the semiconductor substrate 100.
  • FIG. 3 shows an example of a cross-sectional view of the pixel 20 when viewed in the Y-axis direction.
  • the light from the subject is indicated by an arrow pointing in the positive direction of the Z axis.
  • the light from the subject is incident on the back surface 100b of the semiconductor substrate 100.
  • the solid-state image sensor 1 is a back-illuminated solid-state image sensor.
  • An example of the material of the semiconductor substrate 100 is silicon.
  • the semiconductor substrate 100 may be a p-type semiconductor substrate.
  • the pixel 20 includes an on-chip lens 21, a light-shielding film 22, an element separation unit 23, a PD 24, and a transfer transistor 25.
  • the on-chip lens 21 is provided on the back surface 100b of the semiconductor substrate 100.
  • the light from the subject is incident on the back surface 100b of the semiconductor substrate 100 via the on-chip lens 21.
  • the on-chip lens 310 is formed of, for example, a resin-based material such as a styrene-based resin, an acrylic-based resin, a styrene-acrylic copolymer resin, or a siloxane-based resin.
  • the light-shielding film 22 separates adjacent pixels.
  • the light-shielding film 22 is formed in a region between pixels in the vicinity of the back surface 100b of the semiconductor substrate 100.
  • the material of the light-shielding film 22 may be any material that shields light, and for example, tungsten (W), aluminum (Al), copper (Cu), or the like can be used.
  • the element separation unit 23 has a structure (DTI: Deep Trench Isolation) in which a groove structure 23a is dug into the semiconductor substrate 100.
  • the groove structure 23a is covered with an oxide film and is filled with, for example, a metal material. It is desirable that the metal material has a high light shielding ability to block diffracted light.
  • a metal material for example, tungsten (W), aluminum (Al), copper (Cu), or a metal alloy thereof can be used as a main component.
  • the groove structure 23a may be filled with a dielectric such as SiO2 having a relatively low refractive index with respect to silicon. Filling with a metal material having a high light shielding ability has the effect of suppressing optical color mixing and improving the resolution, but filling with a dielectric may improve the light detection sensitivity.
  • the PD 24 is a photoelectric conversion unit partitioned by the element separation unit 23 and formed on the semiconductor substrate 100.
  • the PD 24 is formed as an n-type impurity region sandwiched by a p-type semiconductor region, for example, in the Z-axis direction.
  • the PD 24 includes a photoelectric conversion layer 241 (first photoelectric conversion layer), a photoelectric conversion layer 242 (second photoelectric conversion layer), and an additional layer 243.
  • the photoelectric conversion layer 241 and the photoelectric conversion layer 242 are provided (via the additional layer 243) in order from the incident side of the light to the PD 24 (in the positive direction of the Z axis).
  • the photoelectric conversion layer 241 absorbs light in a wavelength band (first wavelength band) corresponding to the material of the semiconductor substrate 100 and performs photoelectric conversion.
  • the photoelectric conversion layer 241 mainly absorbs light in the wavelength band of visible light, and generates and stores charges according to the amount of light.
  • the layer thickness (length in the Z-axis direction) of the photoelectric conversion layer 241 may be about 10 ⁇ m.
  • the photoelectric conversion layer 242 is a photonic crystal layer. This will be described with reference to FIG.
  • FIG. 4 is a perspective view showing an example of the schematic configuration of the photonic crystal layer.
  • the photoelectric conversion layer 242, which is a photonic crystal layer, has a plurality of discontinuous portions D.
  • the discontinuous portion D is a portion having a refractive index different from that of the material (for example, silicon) of the semiconductor substrate 100.
  • the refractive index of the discontinuous portion D may be smaller than the refractive index of the material of the semiconductor substrate 100.
  • the discontinuous portion D is a hole formed in the semiconductor substrate 100.
  • the holes penetrate the photoelectric conversion layer 242 in the substrate thickness direction (Z-axis direction).
  • the photoelectric conversion layer 242 is basically provided with discontinuous portions D side by side at regular intervals (provided periodically). However, in this structure, there is a region R in which the discontinuous portion D is not provided. The portion of the region R where the discontinuous portion D is not provided is indicated by a broken line.
  • the photoelectric conversion layer 242 is a component of the PD 24, in the photoelectric conversion layer 242, charges are generated and accumulated according to the amount of light confined in the photoelectric conversion layer 242.
  • the light to be confined may be light in a wavelength band (second wavelength band) different from the light in the first wavelength band absorbed by the photoelectric conversion layer 241.
  • An example of light to be confined is infrared light.
  • the opening shape of the hole (discontinuous portion D) is circular
  • the diameter of the hole may be 1 ⁇ m or less.
  • the distance between adjacent holes (distance between centers) may be 1 ⁇ m or less.
  • the shape of the hole (opening shape) may be a shape other than the circular shape, and the size of the opening in that case may be determined so as to have an area similar to the area in the case of the circular shape described above. Examples of other shapes are elliptical, triangular, polygonal and the like.
  • the pores may be voids or may be filled with some material.
  • the material is different from the material of the semiconductor substrate 100 (for example, silicon), and is, for example, SiO 2 .
  • the number of holes may be determined as appropriate.
  • the positions of the holes may also be appropriately adjusted so that the light confinement effect can be easily obtained (enhanced).
  • the layer thickness (length in the Z-axis direction) of the photoelectric conversion layer 242 is, for example, 1 ⁇ m or less. This layer thickness can be smaller (eg, 10% or less) than the layer thickness of the photoelectric conversion layer 241.
  • the photoelectric conversion layer 241 absorbs the light to be photoelectrically converted (for example, visible light) by having a certain layer thickness, whereas the photoelectric conversion layer 242 is not the layer thickness but the photoelectric conversion by the arrangement of the discontinuous portion D. This is because it traps the target light (for example, infrared light).
  • the additional layer 243 is provided between the photoelectric conversion layer 241 and the photoelectric conversion layer 242.
  • the material of the additional layer 243 is different from the material of the semiconductor substrate 100.
  • the additional layer 243 may have an insulating property, in which case the additional layer 243 may be an insulating film (for example, SiO 2 ).
  • the additional layer 243 may be an insulating film (for example, SiO 2 ).
  • the transfer transistor 25 reads out and transfers the electric charge generated and accumulated by the photoelectric conversion in the PD 24.
  • the transfer transistor 25 has a gate VG.
  • the gate VG is provided on the substrate surface 100a of the semiconductor substrate 100 (on the photoelectric conversion layer 242 in this example), and extends from there in the stacking direction (Z-axis direction) of the photoelectric conversion layer 241 and the photoelectric conversion layer 242. ..
  • the gate VG extending in the Z-axis direction in this way is also referred to as a vertical gate or the like.
  • the gate VG of the transfer transistor 25 passes through the photoelectric conversion layer 242 and the additional layer 243 in order from the substrate surface 100a of the semiconductor substrate 100, and reaches the photoelectric conversion layer 241.
  • a filter for example, a color filter
  • resin or the like may be provided between the substrate back surface 100b of the semiconductor substrate 100 and the on-chip lens 21.
  • the photoelectric conversion operation (light detection method using PD24) in PD24 will be described.
  • the light incident on the substrate back surface 100b of the semiconductor substrate 100 reaches the photoelectric conversion layer 241 of the PD 24.
  • the photoelectric conversion layer 241 absorbs at least a part of the reached light, specifically, light in the first wavelength band (for example, visible light). Charges are generated and accumulated according to the amount of absorbed light.
  • the light not absorbed by the photoelectric conversion layer 241 reaches the photoelectric conversion layer 242.
  • the photoelectric conversion layer 242 at least a part of the reached light, specifically the light in the second wavelength band (for example, infrared light) is confined. Charges are generated and accumulated according to the amount of confined light.
  • the photoelectric conversion (charge generation and accumulation) in the photoelectric conversion layer 241 and the photoelectric conversion layer 242 described above is reflected not only by the light incident on the substrate back surface 100b and toward the substrate surface 100a but also by the substrate surface 100a. Then, the light is directed toward the back surface 100b of the substrate, and further, the light reflected by the back surface 100b of the substrate and directed toward the front surface 100a of the substrate is also emitted.
  • the electric charge accumulated in the photoelectric conversion layer 241 and the photoelectric conversion layer 242 is read out by the transfer transistor 25 and transferred.
  • the transferred charge is converted into a pixel signal as described above with reference to FIGS. 1 and 2.
  • the light detection sensitivity can be improved by the amount that the PD24 of the pixel 20 includes the photoelectric conversion layer 242. Since the photoelectric conversion layer 242 is a photonic crystal, the layer thickness of the photoelectric conversion layer 242 can be made smaller than, for example, the layer thickness of the photoelectric conversion layer 241. As a result, an increase in the thickness of the PD 24 and, by extension, the substrate thickness of the semiconductor substrate 100 (for example, the film thickness of the silicon bulk) is suppressed, and the potential design is simplified.
  • FIG. 5 is a cross-sectional view showing an example of a schematic configuration of pixels.
  • the illustrated pixel 20A is different from the pixel 20 (FIG. 3) in that the PD 24A is provided in place of the PD 24 and the transfer transistor 25A is provided in place of the transfer transistor 25.
  • PD24A differs from PD24 in that it does not contain an additional layer 243.
  • the photoelectric conversion layer 242 is directly provided on the photoelectric conversion layer 241. Since there is no additional layer between the photoelectric conversion layer 241 and the photoelectric conversion layer 242, the electric charge generated in the photoelectric conversion layer 241 can be transferred to the photoelectric conversion layer 242.
  • the transfer transistor 25A is different from the transfer transistor 25 in that it does not have a gate VG.
  • the gate of the transfer transistor 25A is provided only on the substrate surface 100a of the semiconductor substrate 100 (in this example, on the photoelectric conversion layer 242).
  • the photoelectric conversion operation (light detection method using PD24A) in PD24A is the same as PD24, so the description is not repeated.
  • FIG. 6 is a cross-sectional view showing an example of a schematic configuration of pixels.
  • the illustrated pixel 20B differs from the pixel 20A (FIG. 4) in that it comprises a PD24B in place of the PD24A.
  • PD24B includes a photoelectric conversion layer 241B and a photoelectric conversion layer 242B.
  • the photoelectric conversion layer 242B and the photoelectric conversion layer 241B are provided in order from the incident side of the light on the PD 24B (in the positive direction of the Z axis).
  • the gate VG of the transfer transistor 25 passes through the photoelectric conversion layer 241B and reaches the photoelectric conversion layer 242B.
  • the photoelectric conversion operation (light detection method using PD24B) in PD24B will be described.
  • the light incident on the back surface 100b of the semiconductor substrate 100 reaches the photoelectric conversion layer 242B of the PD 24B.
  • the photoelectric conversion layer 242B At least a part of the reached light, specifically, light in the second wavelength band (for example, infrared light) is confined. Charges are generated and accumulated according to the amount of confined light.
  • the light not confined by the photoelectric conversion layer 242B reaches the photoelectric conversion layer 241B.
  • the photoelectric conversion layer 241B absorbs at least a part of the reached light, specifically, light in the first wavelength band (for example, visible light). Charges are generated and accumulated according to the amount of absorbed light.
  • the charges accumulated in the photoelectric conversion layer 241B and the photoelectric conversion layer 242B are read out by the transfer transistor 25 and transferred.
  • the PD includes a first photoelectric conversion layer and a second photoelectric conversion layer one by one, that is, two photoelectric conversion layers has been described.
  • the PD may include three or more photoelectric conversion layers. This will be described with reference to FIG.
  • FIG. 7 is a cross-sectional view showing an example of a schematic configuration of pixels.
  • the illustrated pixel 20C differs from the pixel 20A (FIG. 5) in that it comprises a PD24C in place of the PD24A.
  • the PD 24C includes a plurality of photoelectric conversion layers 241C and a plurality of photoelectric conversion layers 242C.
  • a plurality of photoelectric conversion layers 241C are illustrated as photoelectric conversion layers 241C1, photoelectric conversion layers 241C2, and photoelectric conversion layers 242C3 with different reference numerals.
  • a plurality of photoelectric conversion layers 242C are shown as the photoelectric conversion layer 242C1 and the photoelectric conversion layer 242C2 with different reference numerals.
  • the photoelectric conversion layer 241C and the photoelectric conversion layer 242C are alternately provided in the stacking direction (Z-axis direction).
  • the photoelectric conversion layer 241C1, the photoelectric conversion layer 242C1, the photoelectric conversion layer 241C2, the photoelectric conversion layer 242C2, and the photoelectric conversion layer 241C3 are provided in order from the incident side of the light on the PD 24C (in the positive direction of the Z axis).
  • the photoelectric conversion layer 241C1, the photoelectric conversion layer 241C2, and the photoelectric conversion layer 241C3 may have the same layer thickness or may have different layer thicknesses.
  • the amount of light absorbed increases by the number of layers, so that the light detection sensitivity is improved.
  • these photoelectric conversion layers have different layer thicknesses, they are absorbed by the photoelectric conversion layer 241C by absorbing light in different wavelength bands (some wavelengths in the band may overlap). The wavelength band of light (first wavelength band) is widened.
  • the photoelectric conversion layer 242C1 and the photoelectric conversion layer 242C2 may have the same structure or may have different structures.
  • the amount of light confined by the number of layers increases, so that the light detection sensitivity is improved.
  • the photoelectric conversion layers have different structures, the light confined in the photoelectric conversion layer 242C by confining light in different wavelength bands (some wavelengths in the band may overlap).
  • the wavelength band (second wavelength band) is widened.
  • the number of photoelectric conversion layers 241C and the number of photoelectric conversion layers 242C shown in FIG. 6 are merely examples.
  • the PD24C may include three or more photoelectric conversion layers in which the photoelectric conversion layers 241C and the photoelectric conversion layers 242C are alternately laminated.
  • the material of the semiconductor substrate 100 is mainly silicon
  • the material of the semiconductor substrate 100 is not limited to silicon.
  • the photoelectric conversion layer 242 which is a photonic crystal layer, has a structure for confining infrared light
  • the photonic crystal may be arranged (tuned) so as to have a structure that traps light other than infrared light.
  • the solid-state image pickup device 1 includes a pixel region 2 (pixel array) including a plurality of pixels 20.
  • pixel region 2 pixel array
  • each of the plurality of pixels 20 includes a PD 24 and a transfer transistor 25.
  • the PD 24 is a photoelectric conversion unit including a photoelectric conversion layer 241 and a photoelectric conversion layer 242 provided on the semiconductor substrate 100.
  • the transfer transistor 25 reads out the electric charge stored in the PD 24 and transfers it.
  • the photoelectric conversion layer 242 is a photonic crystal layer.
  • the light detection sensitivity can be improved by the amount that the PD24 of the pixel 20 includes the photoelectric conversion layer 242. Since the photoelectric conversion layer 242 is a photonic crystal, the layer thickness of the photoelectric conversion layer 242 can be made smaller than, for example, the layer thickness of the photoelectric conversion layer 241. Therefore, it is possible to improve the light detection sensitivity while suppressing an increase in the thickness of the PD 24 and, by extension, the substrate thickness of the semiconductor substrate 100. Since the substrate thickness of the semiconductor substrate 100 (for example, the film thickness of the silicon bulk) is suppressed, the potential design is simplified.
  • the photoelectric conversion layer 242 may include a discontinuous portion D having a refractive index different from that of the material (for example, silicon) of the semiconductor substrate 100.
  • the discontinuous portion D may have a refractive index smaller than the refractive index of the material of the semiconductor substrate 100.
  • the discontinuous portion D may be a hole provided in the photoelectric conversion layer 242.
  • the holes may be filled with a material having a refractive index different from that of the material of the semiconductor substrate 100.
  • the photoelectric conversion layer 242 can function as a photonic crystal layer.
  • the discontinuity portion D may be provided so as to confine the light in the wavelength band of infrared light in the photoelectric conversion layer 242. This makes it possible to improve the detection sensitivity of infrared light.
  • the photoelectric conversion layer 242 may have a layer thickness smaller than that of the photoelectric conversion layer 241.
  • the photoelectric conversion layer 242 may have a layer thickness of 1 ⁇ m or less.
  • the photoelectric conversion layer 241 and the photoelectric conversion layer 242 may be provided in order from the incident side of the light on the PD 24 (in the positive direction of the Z axis). In this case, at least a part of the light not absorbed by the photoelectric conversion layer 241 is confined in the photoelectric conversion layer 242. By combining the light absorption effect of the photoelectric conversion layer 241 and the light confinement effect of the photoelectric conversion layer 242, the wavelength band of the detectable light can be widened.
  • the photoelectric conversion layer 242B and the photoelectric conversion layer 241B may be provided in order from the incident side of the light on the PD 24B (in the positive direction of the Z axis). In this case, at least a part of the light not confined in the photoelectric conversion layer 242B is absorbed by the photoelectric conversion layer 241B.
  • the wavelength band of the detectable light can be widened.
  • the PD 24C includes three or more photoelectric conversion layers in which a photoelectric conversion layer 241C and a photoelectric conversion layer 242C are alternately laminated, for example, a photoelectric conversion layer 241C1, a photoelectric conversion layer 242C1, and a photoelectric.
  • the conversion layer 241C2, the photoelectric conversion layer 242C2, and the photoelectric conversion layer 241C3 may be included.
  • the transfer transistor 25 may have a gate VG extending in the stacking direction (Z-axis direction) of the photoelectric conversion layer 241 and the photoelectric conversion layer 242.
  • the PD 24 includes an additional layer 243 provided between the photoelectric conversion layer 241 and the photoelectric conversion layer 242, and the gate VG of the transfer transistor 25 may pass through the additional layer 243.
  • light from the subject may be incident on the back surface 100b of the semiconductor substrate 100.
  • a back-illuminated solid-state image sensor for example, it is possible to suppress the obstruction of light by the wiring of the transfer transistor 25 provided on the substrate surface 100a side of the semiconductor substrate 100, and to reduce the light detection sensitivity. Can be improved.
  • a photodetection method for detecting light using PD24 is also one aspect of the present disclosure. That is, the photodetection method includes reading out the charge generated in the photoelectric conversion layer 241 and the charge generated in the photoelectric conversion layer 242 (photonic crystal layer). According to such a light detection method, it is possible to improve the light detection sensitivity as in the solid-state image sensor 1 described above.
  • the technology according to the present disclosure can be applied to various products.
  • the technology according to the present disclosure is realized as a device mounted on a moving body of any kind such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, and a robot. You may.
  • FIG. 8 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technique according to the present disclosure can be applied.
  • the vehicle control system 12000 includes a plurality of electronic control units connected via the communication network 12001.
  • the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside information detection unit 12030, an in-vehicle information detection unit 12040, and an integrated control unit 12050.
  • a microcomputer 12051, an audio image output unit 12052, and an in-vehicle network I / F (Interface) 12053 are shown as a functional configuration of the integrated control unit 12050.
  • the drive system control unit 12010 controls the operation of the device related to the drive system of the vehicle according to various programs.
  • the drive system control unit 12010 has a driving force generator for generating the driving force of the vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to the wheels, and a steering angle of the vehicle. It functions as a control device such as a steering mechanism for adjusting and a braking device for generating braking force of the vehicle.
  • the body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs.
  • the body system control unit 12020 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as headlamps, back lamps, brake lamps, turn signals or fog lamps.
  • the body system control unit 12020 may be input with radio waves transmitted from a portable device that substitutes for the key or signals of various switches.
  • the body system control unit 12020 receives inputs of these radio waves or signals and controls a vehicle door lock device, a power window device, a lamp, and the like.
  • the outside information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000.
  • the image pickup unit 12031 is connected to the vehicle outside information detection unit 12030.
  • the vehicle outside information detection unit 12030 causes the image pickup unit 12031 to capture an image of the outside of the vehicle and receives the captured image.
  • the vehicle outside information detection unit 12030 may perform object detection processing or distance detection processing such as a person, a vehicle, an obstacle, a sign, or a character on the road surface based on the received image.
  • the image pickup unit 12031 is an optical sensor that receives light and outputs an electric signal according to the amount of the light received.
  • the image pickup unit 12031 can output an electric signal as an image or can output it as distance measurement information. Further, the light received by the image pickup unit 12031 may be visible light or invisible light such as infrared light.
  • the in-vehicle information detection unit 12040 detects the in-vehicle information.
  • a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040.
  • the driver state detection unit 12041 includes, for example, a camera that images the driver, and the in-vehicle information detection unit 12040 determines the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041. It may be calculated, or it may be determined whether the driver has fallen asleep.
  • the microcomputer 12051 calculates the control target value of the driving force generator, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and the drive system control unit.
  • a control command can be output to 12010.
  • the microcomputer 12051 realizes ADAS (Advanced Driver Assistance System) functions including vehicle collision avoidance or impact mitigation, follow-up driving based on inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane deviation warning, and the like. It is possible to perform cooperative control for the purpose of.
  • ADAS Advanced Driver Assistance System
  • the microcomputer 12051 controls the driving force generating device, the steering mechanism, the braking device, and the like based on the information around the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040. It is possible to perform coordinated control for the purpose of automatic driving that runs autonomously without depending on the operation.
  • the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the vehicle outside information detection unit 12030.
  • the microcomputer 12051 controls the headlamps according to the position of the preceding vehicle or the oncoming vehicle detected by the outside information detection unit 12030, and performs cooperative control for the purpose of anti-glare such as switching the high beam to the low beam. It can be carried out.
  • the audio image output unit 12052 transmits an output signal of at least one of audio and an image to an output device capable of visually or audibly notifying information to the passenger or the outside of the vehicle.
  • an output device an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified.
  • the display unit 12062 may include, for example, at least one of an onboard display and a head-up display.
  • FIG. 9 is a diagram showing an example of the installation position of the image pickup unit 12031.
  • the image pickup unit 12031 has image pickup units 12101, 12102, 12103, 12104, and 12105.
  • the image pickup units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as, for example, the front nose, side mirrors, rear bumpers, back doors, and the upper part of the windshield in the vehicle interior of the vehicle 12100.
  • the image pickup unit 12101 provided in the front nose and the image pickup section 12105 provided in the upper part of the windshield in the vehicle interior mainly acquire an image in front of the vehicle 12100.
  • the image pickup units 12102 and 12103 provided in the side mirror mainly acquire images of the side of the vehicle 12100.
  • the image pickup unit 12104 provided in the rear bumper or the back door mainly acquires an image of the rear of the vehicle 12100.
  • the image pickup unit 12105 provided on the upper part of the windshield in the vehicle interior is mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.
  • FIG. 9 shows an example of the shooting range of the imaging units 12101 to 12104.
  • the imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose
  • the imaging ranges 12112 and 12113 indicate the imaging range of the imaging units 12102 and 12103 provided on the side mirrors, respectively
  • the imaging range 12114 indicates the imaging range.
  • the imaging range of the imaging unit 12104 provided on the rear bumper or the back door is shown. For example, by superimposing the image data captured by the image pickup units 12101 to 12104, a bird's-eye view image of the vehicle 12100 can be obtained.
  • At least one of the image pickup units 12101 to 12104 may have a function of acquiring distance information.
  • at least one of the image pickup units 12101 to 12104 may be a stereo camera including a plurality of image pickup elements, or may be an image pickup element having pixels for phase difference detection.
  • the microcomputer 12051 has a distance to each three-dimensional object in the image pickup range 12111 to 12114 based on the distance information obtained from the image pickup unit 12101 to 12104, and a temporal change of this distance (relative speed with respect to the vehicle 12100).
  • a predetermined speed for example, 0 km / h or more
  • the microcomputer 12051 can set an inter-vehicle distance to be secured in advance in front of the preceding vehicle, and can perform automatic brake control (including follow-up stop control), automatic acceleration control (including follow-up start control), and the like. In this way, it is possible to perform coordinated control for the purpose of automatic driving or the like in which the vehicle travels autonomously without depending on the operation of the driver.
  • the microcomputer 12051 converts three-dimensional object data related to a three-dimensional object into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, electric poles, and other three-dimensional objects based on the distance information obtained from the image pickup units 12101 to 12104. It can be classified and extracted and used for automatic avoidance of obstacles. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines the collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or higher than the set value and there is a possibility of collision, the microcomputer 12051 via the audio speaker 12061 or the display unit 12062. By outputting an alarm to the driver and performing forced deceleration and avoidance steering via the drive system control unit 12010, driving support for collision avoidance can be provided.
  • At least one of the image pickup units 12101 to 12104 may be an infrared camera that detects infrared rays.
  • the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured image of the imaging unit 12101 to 12104.
  • pedestrian recognition is, for example, a procedure for extracting feature points in an image captured by an image pickup unit 12101 to 12104 as an infrared camera, and pattern matching processing is performed on a series of feature points indicating the outline of an object to determine whether or not the pedestrian is a pedestrian. It is done by the procedure to determine.
  • the audio image output unit 12052 determines the square contour line for emphasizing the recognized pedestrian.
  • the display unit 12062 is controlled so as to superimpose and display. Further, the audio image output unit 12052 may control the display unit 12062 so as to display an icon or the like indicating a pedestrian at a desired position.
  • the above is an example of a vehicle control system to which the technology according to the present disclosure can be applied.
  • the technique according to the present disclosure can be applied to, for example, the image pickup unit 12031 among the configurations described above.
  • the solid-state image sensor 1 of FIG. 1 can be applied to the image pickup unit 12031.
  • the present technology can also have the following configurations.
  • (1) Equipped with a pixel array containing multiple pixels Each of the plurality of pixels
  • a photoelectric conversion unit provided on the semiconductor substrate and including a first photoelectric conversion layer and a second photoelectric conversion layer, A transfer transistor that reads out and transfers the electric charge stored in the photoelectric conversion unit, and Including
  • the second photoelectric conversion layer is a photonic crystal layer.
  • the second photoelectric conversion layer includes a discontinuous portion having a refractive index different from that of the material of the semiconductor substrate.
  • the discontinuity has a refractive index smaller than that of the material of the semiconductor substrate.
  • the discontinuous portion is a hole provided in the second photoelectric conversion layer.
  • the holes are filled with a material having a refractive index different from that of the material of the semiconductor substrate.
  • the discontinuous portion is provided so as to confine the light in the wavelength band of infrared light in the second photoelectric conversion layer.
  • the second photoelectric conversion layer has a layer thickness smaller than that of the first photoelectric conversion layer.
  • the second photoelectric conversion layer has a layer thickness of 1 ⁇ m or less.
  • the first photoelectric conversion layer and the second photoelectric conversion layer are provided in order from the side of light incident on the photoelectric conversion unit.
  • the solid-state image sensor according to any one of (1) to (8).
  • the second photoelectric conversion layer and the first photoelectric conversion layer are provided in order from the side of light incident on the photoelectric conversion unit.
  • the photoelectric conversion unit includes three or more photoelectric conversion layers in which the first photoelectric conversion layer and the second photoelectric conversion layer are alternately laminated.
  • the transfer transistor has a gate extending in the stacking direction of the first photoelectric conversion layer and the second photoelectric conversion layer.
  • the solid-state image sensor according to any one of (1) to (11).
  • the photoelectric conversion unit includes an additional layer provided between the first photoelectric conversion layer and the second photoelectric conversion layer. The gate of the transfer transistor passes through the additional layer.
  • Light from the subject is incident on the back surface of the semiconductor substrate.
  • It is a photodetection method that detects light using a photoelectric conversion unit.
  • the photoelectric conversion unit includes a first photoelectric conversion layer and a second photoelectric conversion layer provided on the semiconductor substrate.
  • the second photoelectric conversion layer is a photonic crystal layer.
  • the light detection method is It comprises reading out the charge generated in the first photoelectric conversion layer and the charge generated in the second photoelectric conversion layer. Light detection method.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Solid State Image Pick-Up Elements (AREA)

Abstract

Un dispositif d'imagerie à semi-conducteurs (1) comprend un réseau de pixels (2) qui comprend une pluralité de pixels (20). Chacun de la pluralité de pixels (20) comprend un élément de conversion photoélectrique (24) qui est disposé sur un substrat semi-conducteur (100) et comprend une première couche de conversion photoélectrique (241) et une seconde couche de conversion photoélectrique (242), et un transistor de transfert (25) qui lit et transfère une charge stockée dans la partie de conversion photoélectrique (24). La seconde couche de conversion photoélectrique (242) est une couche de cristal photonique.
PCT/JP2021/018175 2020-05-29 2021-05-13 Dispositif d'imagerie à semi-conducteurs et procédé de photodétection WO2021241243A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020094625 2020-05-29
JP2020-094625 2020-05-29

Publications (1)

Publication Number Publication Date
WO2021241243A1 true WO2021241243A1 (fr) 2021-12-02

Family

ID=78723409

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/018175 WO2021241243A1 (fr) 2020-05-29 2021-05-13 Dispositif d'imagerie à semi-conducteurs et procédé de photodétection

Country Status (1)

Country Link
WO (1) WO2021241243A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005072097A (ja) * 2003-08-20 2005-03-17 Sony Corp 光電変換装置及びその駆動方法、並びにその製造方法、固体撮像装置及びその駆動方法、並びにその製造方法
JP2013093553A (ja) * 2011-10-04 2013-05-16 Canon Inc 光電変換装置及びその製造方法、並びに光電変換システム
JP2016136584A (ja) * 2015-01-23 2016-07-28 株式会社東芝 固体撮像装置および固体撮像装置の製造方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005072097A (ja) * 2003-08-20 2005-03-17 Sony Corp 光電変換装置及びその駆動方法、並びにその製造方法、固体撮像装置及びその駆動方法、並びにその製造方法
JP2013093553A (ja) * 2011-10-04 2013-05-16 Canon Inc 光電変換装置及びその製造方法、並びに光電変換システム
JP2016136584A (ja) * 2015-01-23 2016-07-28 株式会社東芝 固体撮像装置および固体撮像装置の製造方法

Similar Documents

Publication Publication Date Title
JP7395650B2 (ja) 撮像素子および電子機器
WO2018216477A1 (fr) Élément de capture d'image à semi-conducteur et appareil électronique
US10840284B2 (en) Imaging element with a first and second converging portion for converging light between a first and second signal extraction portion of adjacent pixels
JP7044107B2 (ja) 光センサ、及び、電子機器
KR102103128B1 (ko) 애벌란시 포토 다이오드 센서
WO2021100675A1 (fr) Dispositif d'imagerie semi-conducteur et dispositif électronique
WO2020195825A1 (fr) Dispositif d'imagerie et appareil électronique
WO2019188043A1 (fr) Dispositif d'imagerie et procédé de fabrication de dispositif d'imagerie
WO2020045142A1 (fr) Dispositif d'imagerie et instrument électronique
JPWO2020105634A1 (ja) 固体撮像装置および電子機器
WO2021095668A1 (fr) Élément d'imagerie à semi-conducteur et son procédé de fabrication
WO2022249575A1 (fr) Élément d'imagerie à semi-conducteurs, procédé de production d'élément d'imagerie à semi-conducteurs et dispositif électronique
WO2021241243A1 (fr) Dispositif d'imagerie à semi-conducteurs et procédé de photodétection
WO2020021826A1 (fr) Élément d'imagerie à semi-conducteurs, dispositif d'imagerie et procédé de commande d'élément d'imagerie à semi-conducteurs
WO2022269997A1 (fr) Dispositif d'imagerie à semi-conducteurs et appareil électronique
WO2023127512A1 (fr) Dispositif d'imagerie et appareil électronique
WO2023248388A1 (fr) Dispositif de détection de lumière et appareil électronique
WO2022004445A1 (fr) Élément d'imagerie, dispositif d'imagerie et équipement électronique
WO2021153030A1 (fr) Dispositif d'imagerie à semi-conducteur et son procédé de fabrication
WO2023013493A1 (fr) Dispositif d'imagerie et dispositif électronique
WO2023095491A1 (fr) Élément récepteur de lumière et dispositif électronique
WO2023013178A1 (fr) Dispositif d'imagerie à semi-conducteurs et appareil électronique
WO2022172642A1 (fr) Élément d'imagerie à semi-conducteur, procédé d'imagerie et dispositif électronique
WO2021241191A1 (fr) Dispositif de télémétrie
WO2021171717A1 (fr) Élément d'imagerie à semi-conducteur, dispositif d'imagerie, et procédé de commande d'élément d'imagerie à semi-conducteur

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21812555

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21812555

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP