Optical detection device and electronic apparatus

Abstract

A light detecting device and an electronic apparatus including the same are proposed. The disclosed imaging device can include a first pixel including a first photoelectric converter and a second photoelectric converter arranged in a substrate in a cross-sectional view, a first light blocking film arranged above the first photoelectric converter, and a second light blocking film arranged above the second photoelectric converter, wherein a first area of the first photoelectric converter is greater than a second area of the second photoelectric converter in the cross-sectional view, and wherein a first open area including the first light blocking film is greater than a second open area including the second light blocking film in the cross-sectional view.

Description

[0001] This application is a divisional application of patent application No. 201680060810.3, filed on October 12, 2016, entitled "Imaging Device and Electronic Appliance", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to a light detection device and an electronic appliance. Specifically, the present application relates to a light detection device and an electronic appliance capable of expanding a dynamic range.

[0003] CROSS REFERENCE TO RELATED APPLICATIONS

[0004] This application claims the benefit of Japanese Priority Patent Application No. 2015-209533, filed October 26, 2015, the entire contents of which are incorporated herein by reference. BACKGROUND

[0005] There are techniques to expand the dynamic range of an imaging device in various methods. For example, a time division method is known in which images are acquired using different sensitivities at different times so as to synthesize the images acquired at different times.

[0006] Further, for example, a spatial division method is known in which light receiving elements having different sensitivities are provided in an imaging device so as to respectively synthesize a plurality of images acquired by the light receiving elements, expanding the dynamic range of the imaging device (see, for example, Patent Documents 1 and 2).

[0007] Further, for example, an in-pixel memory method is known in which a memory is provided on each pixel within an imaging device, and the memory accumulates charges overflowing from a photodiode therein so as to increase the amount of charges accumulated during exposure, and such increase expands the dynamic range of the imaging device (see, for example, Patent Document 3).

[0008] LIST OF CITATIONS

[0009] PATENT DOCUMENTS

[0010] Patent Document 1: Japanese Patent No. 3071891

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 2006-253876

[0012] Patent Document 3: Japanese Patent No. 4317115 SUMMARY

[0013] TECHNICAL PROBLEM

[0014] Increasing the number of division times in a time division method or increasing the number of division spaces in a space division method can expand the dynamic range of an imaging device. However, on the other hand, the increase in the number of division times or division spaces deteriorates the image quality due to, for example, the occurrence of artifacts or the reduction in resolution.

[0015] Furthermore, the limitation of memory capacity restricts the dynamic range expansion of the in-pixel memory method.

[0016] In view of the foregoing, it is desirable to expand the dynamic range of an imaging device without deteriorating the image quality.

[0017] Solution to the technical problem

[0018] An imaging device according to an aspect of the present application includes: a pixel array unit; a plurality of unit pixels arranged in the pixel array unit, the unit pixel including a first photoelectric converter and a second photoelectric converter having a lower sensitivity than the sensitivity of the first photoelectric converter, the second photoelectric converter including a light shielding film formed on a side of the second photoelectric converter through which light enters the second photoelectric converter.

[0019] A lens for collecting light entering the second photoelectric converter can not be formed on the second photoelectric converter.

[0020] A light shielding wall for preventing light from leaking from a photoelectric converter into an adjacent photoelectric converter can be provided between the photoelectric converters.

[0021] The light shielding film can have a slit.

[0022] The slit can be different in formation direction on the light shielding film formed on an adjacent second photoelectric converter.

[0023] The imaging device can be a backside-illuminated image sensor.

[0024] The imaging device can be a frontside-illuminated image sensor.

[0025] The light shielding film can be formed on the lower side or the upper side of a wiring layer formed on the second photoelectric converter.

[0026] The light shielding film can be an amorphous silicon film, a polysilicon film, a Ge film, a GaN film, a CdTe film, a GaAs film, an InP film, a CuInSe2 film, a Cu2S film, a CIGS film, a non-conductive carbon film, a black resist film, an organic photoelectric conversion film, or a metal film.

[0027] In the imaging device according to the aspect of the present application, the unit pixel on the pixel array unit on which the plurality of unit pixels are arranged includes a first photoelectric converter and a second photoelectric converter, the second photoelectric converter has a lower sensitivity than a sensitivity of the first photoelectric converter. A light shielding film is formed on a side of the second photoelectric converter through which light enters the second photoelectric converter.

[0028] Advantages of the Invention

[0029] According to the aspect of the present application, it is possible to expand the dynamic range of the imaging device without degrading the image quality.

[0030] According to an embodiment of the present application, an imaging device is presented. The imaging device can include a substrate, a first photoelectric converter having a first area formed in the substrate, and a second photoelectric converter having a second area formed in the substrate, wherein the first area is larger than the second area. Further, a trench extends from a first surface of the substrate such that at least a portion of the trench is between the first photoelectric converter and the second photoelectric converter.

[0031] According to a further embodiment of the present application, an imaging device is presented. The imaging device includes a substrate, a first photoelectric converter, and a second photoelectric converter. The second photoelectric converter has a lower sensitivity than a sensitivity of the first photoelectric converter. Further, a trench extends from the first surface of the substrate such that at least a portion of the trench is between the first photoelectric converter and the second photoelectric converter.

[0032] According to a still further embodiment of the present application, an electronic device is presented. The device includes an optical system, an imaging element that receives light from the optical system, and a digital signal processor that processes a signal received from the imaging element. The imaging element includes a substrate, a first photoelectric converter having a first area formed in the substrate, and a second photoelectric converter having a second area formed in the substrate, wherein the first area is larger than the second area. The imaging element further includes a light shielding wall that extends from a first surface of the substrate, wherein at least a portion of the light shielding wall is between the first photoelectric converter and the second photoelectric converter.

[0033] Note that the effects of the present application are not necessarily limited to the above-mentioned effects, and can be any of the effects described herein. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a schematic system configuration diagram of a CMOS image sensor using an embodiment of the present application.

[0035] Figure 2is a circuit diagram of an exemplary configuration of a unit pixel.

[0036] Figure 3 is an illustrative timing chart of operations when exposure of a unit pixel begins.

[0037] Figure 4 is an illustrative timing chart of operations when a unit pixel is read.

[0038] Figure 5 is an explanatory diagram for explaining properties of light quantity and output of signal processing.

[0039] Figure 6 is an explanatory diagram of a first configuration of a pixel.

[0040] Figure 7 is an explanatory diagram of a second configuration of a pixel.

[0041] Figure 8 is an explanatory diagram of a third configuration of a pixel.

[0042] Figure 9 is an explanatory diagram of a fourth configuration of a pixel.

[0043] Figure 10 is an explanatory diagram of a fifth configuration of a pixel.

[0044] Figure 11 is an explanatory diagram of a sixth configuration of a pixel.

[0045] Figure 12 is an explanatory diagram of a seventh configuration of a pixel.

[0046] Figure 13 is an explanatory diagram of an eighth configuration of a pixel.

[0047] Figure 14 is an explanatory diagram of a ninth configuration of a pixel.

[0048] Figure 15 is an explanatory diagram of a tenth configuration of a pixel.

[0049] Figure 16 is an explanatory diagram of an eleventh configuration of a pixel.

[0050] Figure 17 is an explanatory diagram of a twelfth configuration of a pixel.

[0051] Figure 18 is an explanatory diagram of a thirteenth configuration of a pixel.

[0052] Figure 19 is an explanatory diagram of a fourteenth configuration of a pixel.

[0053] Figure 20 is an explanatory diagram of a fifteenth configuration of a pixel.

[0054] Figure 21 is an explanatory view of a sixteenth configuration of a pixel.

[0055] Figure 22 is an explanatory view of an arrangement of pixels having different sensitivities.

[0056] Figure 23 is an explanatory view of an arrangement of colors.

[0057] Figure 24 is an explanatory view of an arrangement of light-shielding films.

[0058] Figure 25 is a schematic view of an exemplary use of an image pickup device.

[0059] Figure 26 is a schematic view of a configuration of an image pickup device. DETAILED DESCRIPTION

[0060] Embodiments (hereinafter, referred to as examples) of the present application will be described below. Note that the examples will be described in the following order.

[0061] 1. Image pickup device using the present application

[0062] 2. Configuration of a unit pixel (first to sixteenth configurations)

[0063] 3. Arrangement of first and second photoelectric converters

[0064] 4. Exemplary modification

[0065] 5. Exemplary use of an image pickup device

[0066] <IMAGE PICKUP DEVICE USING THE PRESENT INVENTION>

[0067] Figure 1 is a schematic system configuration view of a CMOS image sensor as an image pickup device using the present application, which is, for example, an image pickup device using an X-Y address system. In the present example, the CMOS image sensor is an image sensor that applies or partially uses a CMOS process.

[0068] The CMOS image sensor 10 according to the present exemplary application includes a pixel array unit 11 formed on a semiconductor substrate (chip) (not shown), and a peripheral circuit unit integrated with the pixel array unit 11 formed on the same semiconductor substrate. The peripheral circuit unit includes, for example, a vertical drive unit 12, a column processing unit 13, a horizontal drive unit 14, and a system control unit 15.

[0069] The CMOS image sensor 10 further includes a signal processing unit 18 and a data storage unit 19. The signal processing unit 18 and the data storage unit 19 can be mounted on the same substrate on which the CMOS image sensor 10 is mounted, or can be placed on a substrate different from the substrate on which the CMOS image sensor 10 is mounted. Furthermore, the processing performed by each of the signal processing unit 18 and the data storage unit 19 can be processed by an external signal processing unit (such as a digital signal processor (DSP) circuit or the like) provided on a substrate different from the substrate on which the CMOS image sensor 10 is mounted, or by software.

[0070] In the pixel array unit 11, unit pixels (hereinafter, sometimes simply referred to as "pixels") are arranged in a row direction and a column direction, in other words, are arranged in a two-dimensional matrix. The unit pixels include a photoelectric converter that generates and accumulates electric charges corresponding to an amount of light received by the photoelectric converter. In the present example, the row direction is a direction in which the pixels are arranged in a pixel row (i.e., a horizontal direction), and the column direction is a direction in which the pixels are arranged in a pixel column (i.e., a vertical direction). The specific configuration of the circuit of the unit pixel and the detailed configuration of the unit pixel will be described below.

[0071] In the pixel array unit 11, in the pixel arrangement in a matrix, pixel drive lines 16 are respectively assigned to the pixel rows in the row direction, and vertical signal lines 17 are respectively assigned to the pixel columns in the column direction. The pixel drive lines 16 transmit a drive signal for driving to read a signal from the pixels. Figure 1 The pixel drive lines 16 are illustrated as a wiring line. However, the number of wiring lines is not limited to one. First ends of the pixel drive lines 16 are respectively connected to output terminals of the vertical drive units 12 corresponding to the respective rows.

[0072] The vertical drive unit 12 includes a shift register or an address decoder, and drives the pixels in the pixel array unit 11, for example, simultaneously or row by row. In other words, the vertical drive unit 12 cooperates with a system control unit 15 that controls the vertical drive unit 12, so as to function as a drive unit that controls the operation of each of the pixels in the pixel array unit 11. The illustration of the specific configuration of the vertical drive unit 12 is omitted. However, the vertical drive unit 12 generally includes two scanning systems: a readout scanning system and a drain scanning system.

[0073] The readout scanning system sequentially selects and scans the unit pixels in the pixel array unit 11 row by row, so as to read a signal from the unit pixels. The signal read from the unit pixels is an analog signal. During an exposure period before the readout scanning system reads and scans a certain row in a readout scan, the drain scanning system scans the row in a drain scan.

[0074] The discharge scanning system discharges unnecessary charges from the photoelectric converter of the unit pixel in the read row. This discharge resets the photoelectric converter. Then, the discharge scanning system discharges the unnecessary charges (resets) to cause a so-called electronic shutter operation. In the present example, the electronic shutter operation is an operation in which charges in the photoelectric converter are discharged, and exposure (start of accumulation of charges) is restarted.

[0075] The signal read in the read operation by the read scanning system corresponds to the amount of light received in and after the electronic shutter operation performed before or immediately before the read operation. Therefore, the period between the read timing of the read operation immediately before the present read operation or the discharge timing of the electronic shutter operation immediately before the present read operation and the read timing of the present read operation is the exposure period of the charges in the unit pixel.

[0076] The signal is output from each unit pixel in the pixel row selected and scanned by the vertical drive unit 12. The signal is input to the column processing unit 13 via each vertical signal line 17 pixel by pixel column. The column processing unit 13 processes the signal output from the pixels of the selected row of the pixel array unit 11 via the vertical signal line 17 pixel by pixel column with predetermined signal processing, and temporarily stores the pixel signal after the signal processing.

[0077] Specifically, the column processing unit 13 at least performs a noise removal process, such as a correlated double sampling (CDS) process or a double data sampling (DDS) process, as the signal processing. For example, the CDS process removes reset noise, or pixel-specific fixed pattern noise such as threshold variation of an amplification transistor of the pixel. In addition to the noise removal process, the column processing unit 13 can have, for example, an analog-digital (AD) conversion function so that the column processing unit 13 can convert an analog pixel signal into a digital signal, and output the digital signal.

[0078] The horizontal drive unit 14 includes, for example, a shift register and an address decoder to sequentially select the unit circuits corresponding to the pixel columns of the column processing unit 13. The selection and scanning by the horizontal drive unit 14 sequentially output the pixel signals processed unit circuit by unit circuit in the signal processing of the column processing unit 13.

[0079] The system control unit 15 includes, for example, a timing generator that generates various timing signals to control the drive of, for example, the vertical drive unit 12, the column processing unit 13, and the horizontal drive unit 14 based on the various times generated by the timing generator.

[0080] The signal processing unit 18 includes at least an algorithm processing function to process the pixel signal output from the column processing unit 13 in various signal processing including algorithm processing. The data storage unit 19 temporarily stores data required for the signal processing so that the signal processing unit 18 performs the signal processing.

[0081] <Construction of a circuit with 100 pixels>

[0082] Figure 2 The diagram shows the arrangement in Figure 1 A circuit diagram showing the construction of unit pixels 100 in pixel array unit 11.

[0083] The unit pixel 100 includes a first photoelectric converter 101, a first transmission gate unit 102, a second photoelectric converter 103, a second transmission gate unit 104, a third transmission gate unit 105, a charge accumulation unit 106, a reset gate unit 107, a floating diffusion (FD) unit 108, an amplifying transistor 109, and a selection transistor 110.

[0084] Furthermore, for example, a unit pixel of 100 has multiple driving lines connected pixel by pixel as... Figure 1 The pixel driving line 16 is shown. Then, via the driving line from Figure 1 The vertical drive unit 12 shown supplies various drive signals TGL, TGS, FCG, RST, and SEL. These drive signals are pulse signals that are active when high (e.g., power supply voltage VDD) and inactive when low (e.g., negative potential), because each transistor in the unit pixel 100 is an NMOS transistor.

[0085] The first photoelectric converter 101 includes, for example, a PN junction photodiode. The first photoelectric converter 101 generates and accumulates a charge corresponding to the amount of light received by the first photoelectric converter 101.

[0086] The first transmission gate unit 102 is connected between the first photoelectric converter 101 and the FD unit 108. A drive signal TGL is applied to the gate electrode of the first transmission gate unit 102. When the drive signal TGL becomes active, the first transmission gate unit 102 becomes conductive, so that the charge accumulated in the first photoelectric converter 101 is transferred to the FD unit 108 via the first transmission gate unit 102.

[0087] Similar to the first photoelectric converter 101, the second photoelectric converter 103 includes, for example, a PN junction photodiode. The second photoelectric converter 103 generates and accumulates a charge corresponding to the amount of light received by the second photoelectric converter 103.

[0088] The light-receiving surface of the first photoelectric converter 101 has a larger area and a higher sensitivity than the area and the sensitivity of the second photoelectric converter 103. As described above, the unit pixel 100 includes two photoelectric converters having different sensitivities. In other words, the first photoelectric converter 101 functions as a high-sensitivity pixel, and the second photoelectric converter 103 functions as a low-sensitivity pixel.

[0089] The second transfer gate unit 104 is connected between the charge accumulation unit 106 and the FD unit 108. A drive signal FCG is applied to the gate electrode of the second transfer gate unit 104. When the drive signal FCG becomes an active state, the second transfer gate unit 104 becomes conductive to cause the potential well of the charge accumulation unit 106 and the potential well of the FD unit 108 to be bound to or electrically connected to each other.

[0090] The third transfer gate unit 105 is connected between the second photoelectric converter 103 and the charge accumulation unit 106. A drive signal TGS is applied to the gate electrode of the third transfer gate unit 105. When the drive signal TGS becomes an active state, the third transfer gate unit 105 becomes conductive to cause the electric charge accumulated in the second photoelectric converter 103 to be transferred to the charge accumulation unit 106 via the third transfer gate unit 105, or the region in which the potential well of the charge accumulation unit 106 and the potential well of the FD unit 108 are bound to or electrically connected to each other.

[0091] Further, the potential well is slightly deep at the lower portion of the gate electrode of the third transfer gate unit 105 so as to form an overflow path through which the electric charge that exceeds the amount of electric charge that saturates the second photoelectric converter 103 and overflows from the second photoelectric converter 103 is transferred to the charge accumulation unit 106. Note that the overflow path formed at the lower portion of the gate electrode of the third transfer gate unit 105 is referred to only as the overflow path of the third transfer gate unit 105.

[0092] The charge accumulation unit 106 includes, for example, a capacitor, and is connected between the second transfer gate unit 104 and the third transfer gate unit 105. The counter electrode of the charge accumulation unit 106 is connected between the charge accumulation unit 106 and a power supply VDD that supplies a power supply voltage VDD. The charge accumulation unit 106 accumulates the electric charge transferred from the second photoelectric converter 103.

[0093] The reset gate unit 107 is connected between the power supply VDD and the FD unit 108. A drive signal RST is applied to the gate electrode of the reset gate unit 107. When the drive signal RST becomes an active state, the reset gate unit 107 becomes conductive to cause the potential of the FD unit 108 to be reset to the level of the power supply voltage VDD.

[0094] The FD unit 108 converts the electric charge into a voltage signal in a charge-voltage conversion, and outputs the voltage signal.

[0095] The gate electrode of the amplification transistor 109 is connected to the FD unit 108, and the drain electrode of the amplification transistor 109 is connected to the power supply VDD. The gate electrode and the drain electrode serve as input units of a readout circuit (i.e., a so-called source follower circuit) that reads the electric charge held in the FD unit 108. In other words, the source electrode of the amplification transistor 109 is connected to the vertical signal line 17 via the selection transistor 110, and thus the amplification transistor 109 forms a source follower circuit together with the constant current source 111 connected to the first end of the vertical signal line 17.

[0096] The selection transistor 110 is connected between the source electrode of the amplification transistor 109 and the vertical signal line 17. A selection signal SEL is applied to the gate electrode of the selection transistor 110. When the selection signal SEL becomes an active state, the selection transistor 110 turns on so that the unit pixel 100 is selected. Thus, a pixel signal is output from the amplification transistor 109 to the vertical signal line 17 via the selection transistor 110.

[0097] Note that the fact that each drive signal becomes an active state is also referred to as "each drive signal turning on", and the fact that each drive signal becomes an inactive state is also referred to as "each drive signal turning off". Furthermore, the fact that each gate unit or each transistor turns on is also referred to as "each gate unit or each transistor turning on", and the fact that each gate unit or each transistor turns off is also referred to as "each gate unit or each transistor turning off".

[0098] <Operation of Unit Pixel 100>

[0099] Next, the operation of the unit pixel 100 will be described with reference to the timing charts of FIGS. 12A and 12B. Figure 3 and 4 First, the operation of the unit pixel 100 at the start of exposure will be described with reference to the timing chart of FIG. 12A. This processing is performed in the pixel array unit 11 in a predetermined scan order, for example, pixel row by pixel row or every multiple pixel rows. Note that the timing charts of FIGS. 12A and 12B illustrate the timing charts of the horizontal synchronization signal XHS and the drive signals SEL, RST, TGS, FCG, and TGL. Figure 3 Figure 3 FIG. 12A illustrates the timing charts of the horizontal synchronization signal XHS and the drive signals SEL, RST, TGS, FCG, and TGL.

[0100] First, at time t1, the horizontal synchronization signal XHS is input, and the process of starting the exposure of the unit pixel 100 is started.

[0101] Next, at time t2, the drive signal RST is turned on, and the reset gate unit 107 is turned on. This resets the potential of the FD unit 108 to the level of the power supply voltage VDD.

[0102] ​Next, at time t3, drive signals TGL, FCG, and TGS are activated, and the first transmission gate unit 102, the second transmission gate unit 104, and the third transmission gate unit 105 are also activated. This binds the potential well of the charge accumulation unit 106 to the potential well of the FD unit 108. Furthermore, the charge accumulated in the first photoconverter 101 is transferred via the first transmission gate unit 102 to the bound region where the potential well is bound. The charge accumulated in the second photoconverter 103 is transferred via the third transmission gate unit 105 to the bound region. Then, the bound region is reset.

[0103] Next, at time t4, drive signals TGL and TGS are turned off, and the first transmission gate unit 102 and the third transmission gate unit 105 are also turned off. This begins to accumulate charge in the first photoelectric converter 101 and the second photoelectric converter 103, and the exposure period begins.

[0104] Next, at time t5, the drive signal RST is turned off, and the reset gate unit 107 is turned off.

[0105] Next, at time t6, the drive signal FCG is turned off, and the second transmission gate unit 104 is turned off. This causes the charge accumulation unit 106 to begin accumulating the charge overflowing from the second photoelectric converter 103 and the charge transferred through the overflow path of the third transmission gate unit 105.

[0106] Then, at time t7, the horizontal synchronization signal XHS is input.

[0107] (The operation is for reading out units of 100 pixels)

[0108] Next, refer to Figure 4 The timing diagram illustrates the operations for reading pixel signals for unit pixel 100. For example, since the operation has been performed... Figure 3 The processing shown is performed after a predetermined time period, in a predetermined scanning order, pixel by pixel row or per multiple pixel rows in pixel array unit 11. Note that... Figure 4 The timing diagrams for the horizontal synchronization signal XHS and the drive signals SEL, RST, TGS, FCG, and TGL are shown.

[0109] First, at time t21, the horizontal synchronization signal XHS is input, and the reading period for unit pixel 100 begins.

[0110] At time t22, the selection signal SEL is activated, and the selection transistor 110 is also activated. Therefore, unit pixel 100 is selected.

[0111] Next, at time t23, the drive signal RST is turned on, and the reset gate unit 107 is turned on. Accordingly, the potential of the FD unit 108 is reset to the level of the power supply voltage VDD.

[0112] Next, at time t24, the drive signal RST is turned off, and the reset gate unit 107 is turned off.

[0113] Next, at time t25, the drive signals FCG and TGS are turned on, and the second transfer gate unit 104 and the third transfer gate unit 105 are turned on. This traps the potential well of the charge accumulation unit 106 and the potential well of the FD unit 108, and transfers the charge accumulated in the second photoelectric converter 103 to the trapped region where the potential well is trapped. Accordingly, the charge accumulated in the second photoelectric converter 103 and the charge accumulation unit 106 during the exposure period is accumulated in the trapped region.

[0114] At time t25, the readout of the pixel signal is started, and the exposure period is completed.

[0115] Next, at time t26, the drive signal TGS is turned off, and the third transfer gate unit 105 is turned off. This stops the transfer of the charge from the second photoelectric converter 103.

[0116] Next, at time ta between time t26 and time t27, a signal SL based on the potential in the region where the potential well of the charge accumulation unit 106 and the potential well of the FD unit 108 are trapped is output to the vertical signal line 17 via the amplification transistor 109 and the selection transistor 110. The signal SL is a signal based on the charge generated in the second photoelectric converter 103 and accumulated in the second photoelectric converter 103 and the charge accumulation unit 106 during the exposure period.

[0117] Further, the signal SL is a signal based on the potential in the trapped region where the potential well of the charge accumulation unit 106 and the potential well of the FD unit 108 are trapped when the charge accumulated in the second photoelectric converter 103 and the charge accumulation unit 106 during the exposure period is accumulated in the trapped region. Accordingly, the amount of charge converted in the charge-voltage when the signal SL is read is the total amount of the charge in the charge accumulation unit 106 and the charge of the FD unit 108.

[0118] Note that, hereinafter, the signal SL is also referred to as a low-sensitivity data signal SL.

[0119] Next, at time t27, the drive signal RST is turned on, and the reset gate unit 107 is turned on. This resets the region where the potential well of the charge accumulation unit 106 and the potential well of the FD unit 108 are trapped.

[0120] Next, at time t28, the selection signal SEL is turned off, and the selection transistor 110 is turned off. Thus, the unit pixel 100 is not selected.

[0121] Then, at time t29, the drive signal RST is turned off, and the reset gate unit 107 is turned off.

[0122] Next, at time t30, the selection signal SEL is turned on, and the selection transistor 110 is turned on. Thus, the unit pixel 100 is selected.

[0123] Next, at time tb between time t30 and time t31, a signal NL based on the potential in the region where the potential well of the charge accumulation unit 106 and the potential well of the FD unit 108 are bound is output to the vertical signal line 17 via the amplification transistor 109 and the selection transistor 110. The signal NL is a signal based on the potential in the bound region when the bound region is reset.

[0124] Note that, hereinafter, the signal NL is also referred to as a low-sensitivity reset signal NL.

[0125] Next, at time t31, the drive signal FCG is turned off, and the second transfer gate unit 104 is turned off.

[0126] Next, at time tc between time t31 and time t32, a signal NH based on the potential of the FD unit 108 is output to the vertical signal line 17 via the amplification transistor 109 and the selection transistor 110. The signal NH is a signal based on the potential of the FD unit 108 when the FD unit 108 is reset.

[0127] Note that, hereinafter, the signal NH is also referred to as a high-sensitivity reset signal NH.

[0128] Next, at time t32, the drive signal TGL is turned on, and the first transfer gate unit 102 is turned on. Thus, the charge generated and accumulated in the first photoelectric converter 101 during the exposure period is transferred to the FD unit 108 via the first transfer gate unit 102.

[0129] Next, at time t33, the drive signal TGL is turned off, and the first transfer gate unit 102 is turned off. This stops the transfer of the charge from the first photoelectric converter 101 to the FD unit 108.

[0130] Next, at time td between time t33 and time t34, a signal SH based on the potential of the FD unit 108 is output to the vertical signal line 17 via the amplification transistor 109 and the selection transistor 110. The signal SH is a signal based on the charge generated and accumulated in the first photoelectric converter 101 during the exposure period.

[0131] Further, the signal SH is based on the potential of the FD unit 108 when the charge accumulated in the first photoelectric converter 101 during the exposure period is accumulated in the FD unit 108. Therefore, the amount of charge converted in the charge-voltage conversion when the signal SH is read is the amount of charge in the FD unit 108. This amount of charge is smaller than the amount of charge when the low-sensitivity data signal SL is read at the time ta.

[0132] Note that, hereinafter, the signal SH is also referred to as a high-sensitivity data signal SH.

[0133] Next, at the time t34, the selection signal SEL is turned off, and the selection transistor 110 is turned off. Therefore, the unit pixel 100 is not selected.

[0134] Next, at the time t35, the horizontal synchronization signal XHS is input, and the readout period in which the pixel signal of the unit pixel 100 is read is completed.

[0135] (Explanation of the denoising processing and the algorithm processing)

[0136] The low-sensitivity data signal SL, the low-sensitivity reset signal NL, the high-sensitivity reset signal NH, and the high-sensitivity data signal SH are sequentially output from the unit pixel 100 to the vertical signal line 17. Then, in the signal processing units (for example, the column processing unit 13 and the signal processing unit 18) placed downstream, the low-sensitivity data signal SL, the low-sensitivity reset signal NL, the high-sensitivity reset signal NH, and the high-sensitivity data signal SH are processed with predetermined denoising processing and signal processing. Hereinafter, an exemplary denoising processing performed in the column processing unit 13 placed downstream and an exemplary algorithm processing performed in the signal processing unit 18 placed downstream will be described. Figure 1

[0137] (Denoising processing)

[0138] First, the denoising processing performed by the column processing unit 13 will be described.

[0139] (Exemplary denoising processing)

[0140] First, the exemplary denoising processing will be described.

[0141] The column processing unit 13 generates the low-sensitivity difference signal SNL by obtaining the difference between the low-sensitivity data signal SL and the low-sensitivity reset signal NL. Therefore, it is true that the low-sensitivity difference signal SNL = low-sensitivity data signal SL - low-sensitivity reset signal NL.

[0142] ​Next, the column processing unit 13 generates a high-sensitivity difference signal SNH by taking a difference between the high-sensitivity data signal SH and the high-sensitivity reset signal NH. Thus, it is established that the high-sensitivity difference signal SNH = high-sensitivity data signal SH - high-sensitivity reset signal NH.

[0143] As described above, the low-sensitivity signals SL and NL are processed with DDS processing in which pixel-specific fixed pattern noise (e.g., a difference in threshold value of an amplification transistor in the pixel) is removed but reset noise is not removed. The high-sensitivity signals SH and NH are processed with CDS processing in which reset noise and pixel-specific fixed pattern noise (e.g., a difference in threshold value of an amplification transistor in the pixel) are removed.

[0144] (Exemplary algorithm processing of pixel signals)

[0145] Hereinafter, exemplary algorithm processing of pixel signals will be described.

[0146] When the low-sensitivity difference signal SNL is within a predetermined range, the signal processing unit 18 calculates a ratio of the low-sensitivity difference signal SNL to the high-sensitivity difference signal SNH as a gain on a pixel-by-pixel basis, on a plurality of pixel basis, on a color-by-color basis, or on an average basis in specific pixels or all pixels in a shared pixel unit, and generates a gain table. Then, the signal processing unit 18 calculates a product of the low-sensitivity difference signal SNL and the gain table as a correction value of the low-sensitivity difference signal SNL.

[0147] In the present example, the gain is G, and a value of the corrected low-sensitivity difference signal SNL (hereinafter, referred to as a corrected low-sensitivity difference signal) is SNL'. The gain G and the corrected low-sensitivity difference signal SNL' can be established using the following expressions (1) and (2).

[0148] G = SNH / SNL = (Cfd + Cfc) / Cfd... (1)

[0149] SNL' = G x SNL... (2)

[0150] In the present example, Cfd is a value of the capacitance of the FD unit 108, and Cfc is a value of the capacitance of the charge accumulation unit 106. Thus, the gain G is equal to a ratio of the capacitance of the FD unit 108 to the capacitance of the charge accumulation unit 106.

[0151] Figure 5 The relationship between the amount of incident light and each of the low-sensitivity difference signal SNL, the high-sensitivity difference signal SNH, and the corrected low-sensitivity difference signal SNL' is illustrated.

[0152] Next, the signal processing unit 18 utilizesFigure 5 The predetermined threshold value Vt is set in a region in which the high-sensitivity differential signal SNH does not saturate the signal processing unit 18 before the light response characteristic is linear.

[0153] Then, when the high-sensitivity differential signal SNH does not exceed the predetermined threshold value Vt, the signal processing unit 18 outputs the high-sensitivity differential signal SNH as the pixel signal SN of the pixel to be processed. In other words, when SNH < Vt holds, the pixel signal SN = the high-sensitivity differential signal SNH is maintained.

[0154] On the other hand, when the high-sensitivity differential signal SNH exceeds the predetermined threshold value Vt, the signal processing unit 18 outputs the corrected low-sensitivity differential signal SNL' of the low-sensitivity differential signal SNL as the pixel signal SN of the pixel to be processed. In other words, when Vt < SNH holds, the pixel signal SN = the corrected low-sensitivity differential signal SNL' is maintained.

[0155] Through the above-described algorithm processing, the signal under the weak light condition can be smoothly converted to the signal under the strong light condition.

[0156] Further, the charge accumulation unit 106 is provided in the low-sensitivity second photoelectric converter 103 of the CMOS image sensor 10, and it is possible to increase the level at which the second photoelectric converter 103 is saturated by the low-sensitivity data signal SL. Therefore, it is possible to increase the maximum value of the dynamic range while maintaining the minimum value of the dynamic range. This can expand the dynamic range.

[0157] For example, LED flicker sometimes occurs in a vehicle-mounted image sensor. The LED flicker is a phenomenon in which an image of flicker of an object such as an LED light source is not captured depending on a time of flicker of the object. The LED flicker occurs, for example, because a dynamic range of a previous image sensor is narrow, and an exposure period for each object needs to be adjusted.

[0158] In other words, in order to cope with objects under various light conditions, the previous image sensor increases the exposure period for objects under a weak light condition and decreases the exposure period for objects under a strong light condition. This enables the previous image sensor to cope with objects under various light conditions even when the dynamic range of the image sensor is narrow. On the other hand, the image sensor reads a signal at a constant rate regardless of the length of the exposure period. Therefore, when the exposure period is set to a unit shorter than the period in which the signal is read, light that enters the photoelectric converter other than the exposure period is converted to charges in photoelectric conversion, and is destroyed without being read out.

[0159] On the other hand, the CMOS image sensor 10 is able to expand the dynamic range as described above, and is able to increase the exposure period. This prevents LED flicker from occurring. Furthermore, using the CMOS image sensor 10, it is possible to prevent artifacts that occur when the number of division times in the time division scheme or the number of division spaces in the space division scheme increases, or it is possible to prevent a reduction in resolution.

[0160] <Configuration of unit pixel>

[0161] Next, the configuration of the unit pixel 100 including the high-sensitivity first photoelectric converter 101 and the low-sensitivity second photoelectric converter 103 as described above will also be described. Hereinafter, referring to a cross-sectional view of the unit pixel 100, the configuration of the unit pixel 100 will also be described.

[0162] <First configuration of unit pixel>

[0163] Figure 6 is a cross-sectional view of the unit pixel 100 when the CMOS image sensor 10 is a backside-illuminated image sensor. Hereinafter, the unit pixel 100 illustrated in Figure 6 will be referred to as a unit pixel 100-1 to indicate that the unit pixel 100 illustrated in Figure 6 has the first configuration.

[0164] In the unit pixel 100-1, the on-chip lens 201, the color filter 202, the light-blocking film 203, and the silicon substrate 204 are stacked from the upper portion of the drawing. The first photoelectric converter 101 and the second photoelectric converter 103 are formed in the silicon substrate 204.

[0165] Note that although not illustrated, for example, a glass cover is stacked on the on-chip lens 201, and a wiring layer or a support substrate is stacked under the silicon substrate 204. Hereinafter, illustration and description of other portions will be appropriately omitted while illustration and description of portions required for explanation will be appropriately illustrated and described.

[0166] Figure 6 The first photoelectric converter 101-1, the first photoelectric converter 101-2, and the second photoelectric converter 103 are illustrated. Furthermore, the on-chip lenses 201-1 to 201-3 are formed on the three photoelectric converters, respectively.

[0167] The light-blocking film 203 is formed only on the second photoelectric converter 103. The light-blocking film 203 has a function of absorbing or reflecting light. The light-blocking film 203 can be made of a metal film so that the light-blocking film 203 functions as a film that reflects light. The light-blocking film 203 can be a film that absorbs a part of light and allows a part of light to pass through the film. Alternatively, the light-blocking film 203 can be a light-absorbing film that absorbs light.

[0168] The light-shielding film 203 is, for example, an amorphous silicon film, a polycrystalline silicon film, a germanium (Ge) film, a gallium nitride (GaN) film, a cadmium telluride (CdTe) film, a gallium arsenide (GaAs) film, an indium phosphide (InP) film, a copper indium diselenide (CuInSe2) film, a Cu2S film, a CIGS film, a non-conductive carbon film, a black resist film, or an organic photoelectric conversion film.

[0169] Note that a light-shielding film is formed on the second photoelectric converter 103, and the light-shielding film can be made of the materials described above and in the second to sixteenth constructions below. Note that the materials used to make the light-shielding film are examples. The materials used to make the light-shielding film are not limited to the exemplary materials.

[0170] As described above, a light-shielding film 203 is formed on the low-sensitivity second photoconverter 103, causing the film to absorb light passing through the on-chip lens 201-3 and reduce the amount of light entering the second photoconverter 103. This further reduces the sensitivity of the second photoconverter 103. This improves the performance of the second photoconverter 103 as a low-sensitivity photoconverter. Therefore, the dynamic range can be extended.

[0171] (Second construction per unit pixel)

[0172] Next, the second construction of unit pixel 100 will be explained. Figure 7 It is similar to Figure 6 The diagram shows a cross-sectional view of pixel 100-2 when the CMOS image sensor 10 is a back-illuminated image sensor, representing pixel 100-1.

[0173] Figure 7 The unit pixel 100-2 shown is Figure 6 Compared to unit pixel 100-1, unit pixel 100-2 has the following construction: the on-chip lens 201-3 formed on the second photoelectric converter 103 of unit pixel 100-1 is removed, which differs from unit pixel 100-1, while other parts of unit pixel 100-2 are the same as those in unit pixel 100-1. Hereinafter, similar reference numerals will be given to parts similar to those in unit pixel 100-1, and such descriptions will be omitted where appropriate. Similarly, descriptions of other parts will be omitted where they are similar to those in unit pixel 100-1.

[0174] The unit pixel 100-2 has a configuration in which no on-chip lens 201-3 is formed on the second photoelectric converter 103. Therefore, light is not focused onto the second photoelectric converter 103, and the amount of light entering the second photoelectric converter 103 is reduced. This further reduces the sensitivity of the second photoelectric converter 103 and extends the dynamic range of the low-sensitivity photoelectric converter.

[0175] (Third Configuration of Unit Pixel)

[0176] Next, the third configuration of the unit pixel 100 will be described. Figure 8 is similar to Figure 6 A cross-sectional view of a unit pixel 100-3 of the unit pixel 100-1 shown in FIG. 10 when the CMOS image sensor 10 is a backside illumination type image sensor.

[0177] Figure 8 The unit pixel 100-3 shown in FIG. 11 and Figure 6 The unit pixel 100-3 has a configuration in which a light-blocking wall 231 is added to the configuration of the unit pixel 100-1, unlike the unit pixel 100-1, and other parts of the unit pixel 100-3 are the same as those of the unit pixel 100-1, compared to the unit pixel 100-1 shown in FIG. 10.

[0178] The light-blocking wall 231 is provided between the pixels. In Figure 8 In the unit pixel 100-3 shown in FIG. 11, the light-blocking wall 231 is provided between the first photoelectric converter 101-1 and the second photoelectric converter 103, and between the first photoelectric converter 101-2 and the second photoelectric converter 103. As described above, the light-blocking wall 231 is provided in a pixel separation region that separates the pixels from each other. The light-blocking wall 231 can be formed in a trench or a groove, and can include one or more insulating films extending from the light-receiving surface.

[0179] The light-blocking wall 231 can be formed in a trench by a combination of a negative fixed charge film and an oxide film. The combination can be a combination of a negative fixed charge film, an oxide film, and a metal. Examples of the negative fixed charge film include hafnium oxide and tantalum oxide.

[0180] The light-blocking wall 231 serves to prevent light from leaking from a photoelectric converter into a photoelectric converter that is close to the photoelectric converter. Providing the light-blocking wall 231 can, for example, reduce the occurrence of color mixing. In addition, the light-blocking wall 231 can prevent light from leaking from other pixels into the low-sensitivity pixel 103, and can thus contribute to maintaining the accuracy of the unit pixel output.

[0181] In addition, in the present configuration, the light-blocking film 203 is formed on the low-sensitivity second photoelectric converter 103, causes the light-blocking film 203 to absorb light that passes through the on-chip lens 201-3, and reduces light that enters the second photoelectric converter 103. This further reduces the sensitivity of the second photoelectric converter 103. Thus, it is possible to expand the dynamic range. Providing the light-blocking wall 231 can, for example, reduce the occurrence of color mixing.

[0182] (Fourth Configuration of Unit Pixel)

[0183] Next, the fourth configuration of the unit pixel 100 will be described. Figure 9is similar to Figure 7 is a cross-sectional view of a unit pixel 100-4 when the CMOS image sensor 10 is a backside illumination type image sensor, of the unit pixel 100-2 shown.

[0184] Figure 9 is similar to Figure 7 The unit pixel 100-4 has a configuration in which a light-blocking wall 231 is added to the configuration of the unit pixel 100-2, unlike the unit pixel 100-2, while other parts (for example, the second photoelectric converter 103 in the unit pixel 100-4 on which the on-chip lens 201-3 is not provided) are the same as those of the unit pixel 100-2, compared to the unit pixel 100-2 shown. Figure 8 is the same as the configuration of the unit pixel 100-3 shown.

[0185] Further, in the present configuration, the light-blocking film 203 is formed on the low-sensitivity second photoelectric converter 103, the light-blocking film 203 absorbs light that enters the light-blocking film 203, and the light that enters the second photoelectric converter 103 is reduced. Further, the on-chip lens is not formed. This further reduces the amount of light that enters the second photoelectric converter 103. This further reduces the sensitivity of the second photoelectric converter 103. Thus, it is possible to expand the dynamic range of the low-sensitivity photoelectric converter. The light-blocking wall 231 can reduce, for example, the occurrence of color mixing.

[0186] (Fifth configuration of unit pixel)

[0187] Next, the fifth configuration of the unit pixel 100 will be described. Figure 10 is similar to Figure 6 is a cross-sectional view of a unit pixel 100-5 when the CMOS image sensor 10 is a backside illumination type image sensor, of the unit pixel 100-1 shown.

[0188] Figure 10 is similar to Figure 6 The unit pixel 100-5 has a configuration in which, unlike the unit pixel 100-1, the light-blocking film 251 of the unit pixel 100-5 has a different shape from the light-blocking film 203 of the unit pixel 100-1, while other parts are the same as the corresponding parts of the unit pixel 100-1, compared to the unit pixel 100-1 shown. The light-blocking film 251 of the unit pixel 100-5 has a slit. The light-blocking film 251 can not necessarily be formed on the slit of the light-blocking film 251. Alternatively, the light-blocking film 251 at the slit can be thinner than the light-blocking film 251 at other parts.

[0189] The formation of the slit on the light-blocking film 251 enables the second photoelectric converter 103 to function as a polarization pixel.

[0190] For example, when the second photoelectric converter 103 is mounted on a vehicle and captures an image including the road surface, the light reflected from the road surface is polarized light parallel to the road surface. In order to capture an image with such polarized light removed, a slit is formed on the light-shielding film 251 in a direction parallel to the road surface. This selectively blocks the light reflected from the road surface and allows light from other objects to be received.

[0191] As described above, forming a slit on the light-shielding film 251 can reduce the light entering the second photoelectric converter 103 and also remove unwanted light.

[0192] When the light-shielding film 251 is also used as a polarizer as described above, the light-shielding film 251 can be made of metal, in addition to the materials mentioned above. Note that using a light-shielding film as a polarizer can effectively reduce direct or indirect light compared to using a polarizer made of metal.

[0193] Furthermore, in this configuration, a light-shielding film 251 is formed on the low-sensitivity second photoelectric converter 103 to reduce the amount of light entering the second photoelectric converter 103. Therefore, reducing sensitivity can extend the dynamic range. In addition, forming a slit on the light-shielding film 251 allows the light-shielding film 251 to function as a polarizer in order to remove the influence of unwanted light such as reflected light.

[0194] (The sixth construction per unit pixel)

[0195] Next, the sixth construction of unit pixel 100 will be explained. Figure 11 It is similar to Figure 7 The diagram shows a cross-sectional view of pixel 100-6 when the CMOS image sensor 10 is a back-illuminated image sensor, representing pixel 100-2.

[0196] Figure 11 The unit pixel shown is 100-6 and Figure 7 Compared to unit pixel 100-2, unit pixel 100-6 has the following structure: the light-shielding film 251 of unit pixel 100-6 has a different shape than the light-shielding film 203 of unit pixel 100-2, which is different from unit pixel 100-2, while other parts (e.g., the second photoelectric converter 103 in unit pixel 100-6 without the on-chip lens 201-3) are the same as parts of unit pixel 100-2. Similar to... Figure 10 The light-shielding film 251 shown for unit pixels 100-5 and 100-6 has a slit.

[0197] Similar to unit pixel 100-5 ( Figure 10 A slit is formed on the light-shielding film 251, which can reduce the light entering the second photoelectric converter 103 and also remove unwanted light.

[0198] Furthermore, in this configuration, a light-shielding film 251 is formed on the low-sensitivity second photoconverter 103, which reduces the amount of light entering the second photoconverter 103. Therefore, reducing sensitivity can extend the dynamic range. Additionally, an on-chip lens is not formed on the second photoconverter 103. This further reduces the amount of light entering the second photoconverter 103. Therefore, reducing sensitivity can extend the dynamic range. Furthermore, forming a slit on the light-shielding film 251 allows the film to function as a polarizer, thereby removing unwanted light effects such as reflected light.

[0199] (The seventh construction of a unit pixel)

[0200] Next, the seventh construction of a unit pixel of 100 will be explained. Figure 12 It is similar to Figure 8 The diagram shows a cross-sectional view of pixel 100-7 when the CMOS image sensor 10 is a back-illuminated image sensor, representing pixel 100-3.

[0201] Figure 12 The unit pixels shown are 100-7 and Figure 8 Compared to unit pixel 100-3, unit pixel 100-7 has the following structure: unlike unit pixel 100-3, the light-shielding film 251 has a slit, while other parts (e.g., the light-shielding film 231 disposed between pixels in unit pixel 100-7) are the same as those in unit pixel 100-3.

[0202] Furthermore, in this configuration, forming a light-shielding film 251 on the low-sensitivity second photoelectric converter 103 reduces the amount of light entering the second photoelectric converter 103. Therefore, reducing sensitivity expands the dynamic range. Additionally, forming a slit on the light-shielding film 251 allows it to function as a polarizer, thereby removing unwanted light effects such as reflected light. Providing a light-shielding wall 231 can, for example, reduce color mixing.

[0203] (Eighth construction per unit pixel)

[0204] Next, the eighth construction of unit pixel 100 will be explained. Figure 13 It is similar to Figure 9 The diagram shows a cross-sectional view of pixel 100-8 when the CMOS image sensor 10 is a back-illuminated image sensor, representing pixel 100-4.

[0205] Figure 13 The unit pixel 100-8 shown is Figure 9The unit pixel 100-8 has a configuration in which the light shielding film 251 has a slit, unlike the unit pixel 100-4, compared to the illustrated unit pixel 100-4, and other parts (for example, the light shielding film 231 provided between the pixels in the unit pixel 100-8, and the second photoelectric converter 103 which is not provided with an on-chip lens) are the same as those of the unit pixel 100-4.

[0206] Further, in the present configuration, the light shielding film 251 is formed on the low-sensitivity second photoelectric converter 103, and the light entering the second photoelectric converter 103 can be reduced. Therefore, reducing the sensitivity can expand the dynamic range. Further, the on-chip lens is not formed on the second photoelectric converter 103. This further reduces the light entering the second photoelectric converter 103. Therefore, reducing the sensitivity can expand the dynamic range.

[0207] Further, forming the slit in the light shielding film 251 can cause the light shielding film 251 to function as a polarizer, and thereby remove the influence of unnecessary light such as reflected light. Providing the light shielding wall 231 can, for example, reduce the occurrence of color mixing.

[0208] (Ninth configuration of unit pixel)

[0209] Figure 14 is a cross-sectional view of a unit pixel 100-9 when the CMOS image sensor 10 is a front-side illumination type image sensor.

[0210] In Figure 14 In the illustrated unit pixel 100-9, the on-chip lens 301, the color filter 302, the light shielding film 303, the wiring layer 304, and the silicon substrate 305 are stacked from the upper part of the drawing. The first photoelectric converter 101 and the second photoelectric converter 103 are formed in the silicon substrate 305.

[0211] Note that although not illustrated in the drawing, for example, a glass cover is stacked on the on-chip lens 201. The illustration and the additional explanation of the parts necessary for the explanation will be appropriately illustrated and explained, and the illustration and the explanation of the other parts will be appropriately omitted.

[0212] Figure 14 The first photoelectric converter 101-1, the first photoelectric converter 101-2, and the second photoelectric converter 103 are illustrated. Further, the on-chip lenses 301-1 to 301-3 are formed on the three photoelectric converters, respectively.

[0213] The light-shielding film 303 is formed only on the second photoelectric converter 103. The light-shielding film 303 is, for example, an amorphous silicon film, a polysilicon film, a Ge film, a GaN film, a CdTe film, a GaAs film, an InP film, a CuInSe2 film, a Cu2S film, a CIGS film, a non-conductive carbon film, a black resist film, or an organic photoelectric conversion film. In addition, when the light-shielding film 303 has a slit as described below, the light-shielding film 303 can be made of a metal. Note that the material that makes the light-shielding film is an exemplary material, and the material that makes the light-shielding film is not limited to the exemplary material.

[0214] In addition, in the front-side illumination type image sensor as described above, forming the light-shielding film 303 on the low-sensitivity second photoelectric converter 103 causes the light-shielding film 303 to absorb light that passes through the on-chip lens 301-3, and reduces light that enters the second photoelectric converter 103. This further reduces the sensitivity of the second photoelectric converter 103. Thus, the dynamic range can be expanded.

[0215] (Tenth configuration of unit pixel)

[0216] Next, the tenth configuration of the unit pixel 100 will be described. Figure 15 is a cross-sectional view of the unit pixel 100-10 when the CMOS image sensor 10 is a front-side illumination type image sensor, which is similar to the unit pixel 100-9 shown in Figure 14

[0217] Figure 15 The unit pixel 100-10 has a configuration in which, unlike the unit pixel 100-9, the on-chip lens 301-3 formed on the second photoelectric converter 103 of the unit pixel 100-9 is removed, and other parts of the unit pixel 100-10 are the same as those of the unit pixel 100-9, compared to the unit pixel 100-10 and the unit pixel 100-9 shown in Figure 14

[0218] The on-chip lens 301-3 is not formed on the second photoelectric converter 103. This causes light to enter the second photoelectric converter 103 without being collected. This reduces light that enters the second photoelectric converter 103. Thus, reducing the sensitivity of the second photoelectric converter 103 can expand the dynamic range.

[0219] (Eleventh configuration of unit pixel)

[0220] Next, the eleventh configuration of the unit pixel 100 will be described. Figure 16 is a cross-sectional view of the unit pixel 100-11 when the CMOS image sensor 10 is a front-side illumination type image sensor, which is similar to the unit pixel 100-9 shown in Figure 14

[0221] Figure 16 ​​​The unit pixel 100-11 and Figure 14 In the drawing of the unit pixel 100-9, the light shielding film 303 is formed on the upper side of the wiring layer 304 (this side facing the on-chip lens 301) compared to the unit pixel 100-11 in which the light shielding film is formed on the lower side of the wiring layer 304 (this side facing the silicon substrate 305). The other parts in the unit pixel 100-11 are the same as those in the unit pixel 100-9.

[0222] Referring again to Figure 14 The light shielding film 303 of the unit pixel 100-9 is formed on the upper side of the wiring layer 304 and in the color filter 302. On the other hand, Figure 16 The light shielding film 331 of the unit pixel 100-11 illustrated in FIG. 33 is formed on the lower side of the wiring layer 304 and in the wiring layer 304 on the silicon substrate 305. As described above, the light shielding film can be formed on the upper or lower side of the wiring layer 304.

[0223] As described above, in addition, in the front-side illumination type image sensor, the light shielding film 303 is formed on the low-sensitivity second photoelectric converter 103. This causes the light shielding film 303 to absorb light passing through the on-chip lens 301-3, and reduces light entering the second photoelectric converter 103. This further reduces the sensitivity of the second photoelectric converter 103. Therefore, the dynamic range can be expanded.

[0224] (Twelfth configuration of unit pixel)

[0225] Next, the twelfth configuration of the unit pixel 100 will be described. Figure 17 is similar to Figure 16 is a cross-sectional view of the unit pixel 100-12 of the unit pixel 100-11 illustrated in FIG. 33 when the CMOS image sensor 10 is a front-side illumination type image sensor.

[0226] Figure 17 The unit pixel 100-12 and Figure 16 The unit pixel 100-12 has a configuration in which, unlike the unit pixel 100-11, the on-chip lens 301-3 formed on the second photoelectric converter 103 of the unit pixel 100-11 is removed, compared to the unit pixel 100-11 illustrated in FIG. 33, and the other parts in the unit pixel 100-12 are the same as those in the unit pixel 100-11.

[0227] The on-chip lens 301-3 is not formed on the second photoelectric converter 103. Therefore, light is not concentrated on the second photoelectric converter 103, and light enters the second photoelectric converter 103. This reduces light entering the second photoelectric converter 103, and therefore, reduces the sensitivity of the second photoelectric converter 103 and expands the dynamic range.

[0228] (Thirteenth Configuration of Unit Pixel)

[0229] Next, the thirteenth configuration of the unit pixel 100 will be described. Figure 18 is similar to Figure 14 A cross-sectional view of the unit pixel 100-13 of the unit pixel 100-9 shown in FIG. 10 when the CMOS image sensor 10 is a front-side illumination type image sensor.

[0230] Figure 18 The unit pixel 100-13 shown in FIG. 11 and Figure 14 The unit pixel 100-13 has a configuration in which, unlike the unit pixel 100-9, the light shielding film 351 of the unit pixel 100-13 has a different shape from the light shielding film 303 of the unit pixel 100-9, and other parts of the unit pixel 100-13 are the same as those of the unit pixel 100-9, compared to the unit pixel 100-9 shown in FIG. 10. The light shielding film 351 of the unit pixel 100-13 has a slit shape and is formed in the layer of the color filter 302.

[0231] The slit is formed in the light shielding film 351, which enables the light shielding film 351 to function as a polarizer and the second photoelectric converter 103 to function as a polarization pixel.

[0232] Further, in the present configuration, the light shielding film 351 is formed on the low-sensitivity second photoelectric converter 103, which enables reduction of light entering the second photoelectric converter 103, and thus, reduction of sensitivity, which enables expansion of the dynamic range. Further, the slit is formed in the light shielding film 351, which enables the light shielding film 351 to function as a polarizer, with which the influence of unnecessary light such as reflected light is removed.

[0233] (Fourteenth Configuration of Unit Pixel)

[0234] Next, the fourteenth configuration of the unit pixel 100 will be described. Figure 19 is similar to Figure 18 A cross-sectional view of the unit pixel 100-14 of the unit pixel 100-13 shown in FIG. 10 when the CMOS image sensor 10 is a front-side illumination type image sensor.

[0235] Figure 19 The unit pixel 100-14 shown in FIG. 12 and Figure 18The unit pixel 100-14 has a configuration in which, unlike the unit pixel 100-13, the on-chip lens 301-3 formed on the second photoelectric converter 103 of the unit pixel 100-13 is removed, and other parts of the unit pixel 100-14 are the same as those of the unit pixel 100-13. The light shielding film 351 of the unit pixel 100-14 has a slit, and is formed in a layer of the color filter 302.

[0236] The on-chip lens 301-3 is not formed on the second photoelectric converter 103. Therefore, light is not concentrated on the second photoelectric converter 103, and light enters the second photoelectric converter 103. This reduces light entering the second photoelectric converter 103. This further reduces the sensitivity of the second photoelectric converter 103. Therefore, it is possible to expand the dynamic range. Furthermore, forming a slit in the light shielding film 351 enables the light shielding film 351 to function as a polarizer to thereby remove the influence of unnecessary light such as reflected light.

[0237] (Fifteenth configuration of unit pixel)

[0238] Next, the fifteenth configuration of the unit pixel 100 will be described. Figure 20 is similar to Figure 18 A cross-sectional view of the unit pixel 100-15 of the unit pixel 100-13 when the CMOS image sensor 10 is a front-side illumination type image sensor.

[0239] Figure 20 The unit pixel 100-15 and Figure 18 In the drawing of the unit pixel 100-13, the light shielding film 351 is formed on the upper side of the wiring layer 304, whereas in the drawing of the unit pixel 100-15, the light shielding film 381 is formed on the lower side of the wiring layer 304. Other parts of the unit pixel 100-15 are the same as those of the unit pixel 100-13. In other words, the light shielding film 381 of the unit pixel 100-15 has a slit, and in the drawing of the unit pixel 100-15, the light shielding film 381 is formed on the lower side of the wiring layer 304.

[0240] Furthermore, in the front-side illumination type image sensor having this configuration, the light shielding film 381 is formed on the low-sensitivity second photoelectric converter 103, the light shielding film 381 absorbs light passing through the on-chip lens 301-3, and light entering the second photoelectric converter 103 is reduced. Therefore, the sensitivity of the second photoelectric converter 103 is reduced, which makes it possible to expand the dynamic range. Furthermore, forming a slit in the light shielding film 381 enables the light shielding film 351 to function as a polarizer to thereby remove the influence of unnecessary light such as reflected light.

[0241] (The sixteenth construction per unit pixel)

[0242] Next, the sixteenth construction of unit pixel 100 will be explained. Figure 21 It is similar to Figure 20 The diagram shows a cross-sectional view of unit pixels 100-16 when the CMOS image sensor 10 is a front-illuminated image sensor.

[0243] Figure 21 The unit pixels shown are 100-16 and Figure 20 Compared to unit pixels 100-15, unit pixels 100-16 have the following structure: unlike unit pixels 100-15, the on-chip lens 301-3 formed on the second photoelectric converter 103 of unit pixels 100-15 is removed, while the other parts of unit pixels 100-16 are the same as those in unit pixels 100-15. In other words, the light-shielding film 381 of unit pixels 100-16 has a slit and is formed on the underside of the wiring layer 304.

[0244] No on-chip lens 301-3 is formed on the second photoelectric converter 103. Therefore, light is not focused on the second photoelectric converter 103, and light enters the second photoelectric converter 103. This reduces the amount of light entering the second photoelectric converter 103, thus reducing the sensitivity of the second photoelectric converter 103, which can extend the dynamic range. In addition, a slit is formed on the light-shielding film 381, which enables the light-shielding film 381 to be used as a polarizer to remove unwanted light effects such as reflected light.

[0245] As described in the first through sixteenth configurations, a film with light-absorbing properties is formed on the low-sensitivity second photoconverter 103. This reduces the amount of light entering the second photoconverter 103. Therefore, reducing sensitivity can extend the dynamic range.

[0246] Furthermore, forming slits in the light-shielding film allows it to function as a polarizer. Setting up a polarizer eliminates the effects of reflected light (unwanted light) and simultaneously reduces sensitivity, which expands the dynamic range.

[0247] Compared to using polarizers made of metal, using a light-shielding film as a polarizer can effectively reduce direct or indirect light.

[0248] Arrangement of the first and second photoelectric converters

[0249] For example, such as Figure 22 The arrangement shown includes unit pixels 100, each comprising a first photoelectric converter 101 and a second photoelectric converter 103. Figure 22In this context, a unit pixel is referred to as unit pixel 500. Unit pixel 500 is described as one of units pixel 100-1 to 100-16.

[0250] Figure 22 The illustration shows an example where 16 unit pixels 500-1 to 500-16 (four by four) are arranged. Each unit pixel 500 includes a first photoelectric converter 101 and a second photoelectric converter 103. For example, unit pixel 500-1 includes a first photoelectric converter 101-1 and a second photoelectric converter 103-1.

[0251] Depending on the size of the light-receiving surface, the first photoelectric converter 101 and the second photoelectric converter 103 have different sensitivities. In other words, as... Figure 22 As shown, the light-receiving surface of the first photoelectric converter 101 is larger than the light-receiving surface of the second photoelectric converter 103.

[0252] exist Figure 22 In the example, for instance, the second photoelectric converter 103-1 per unit pixel is placed to the lower right of the first photoelectric converter 101-1 per unit pixel. Although not shown, the second photoelectric converter 103-1 can be placed to the right of the first photoelectric converter 101-1. Alternatively, the positional relationship between the second photoelectric converter 103-1 and the first photoelectric converter 101-1 can be different from that described above. For example, at least a portion of the edge of the second photoelectric converter 103-1 can coincide with or be adjacent to a portion of the edge of the first photoelectric converter 101-1.

[0253] In a unit pixel 500, for example, signal processing circuitry can be placed in the portion where the first photoelectric converter 101 and the second photoelectric converter 103 are not arranged. In other words, arranging the first photoelectric converter 101 and the second photoelectric converter 103 with different light-receiving areas results in excess areas in the unit pixel 500. However, by placing, for example, signal processing circuitry in said excess areas, the excess areas can be utilized effectively.

[0254] The colors of the color filters 202 (302) placed on unit pixel 500 can be arranged, for example, in a Bayer array. Figure 23 As shown in A, pixel 500-1 can be red (R), pixel 500-2 can be green (G), pixel 500-5 can be green (G), and pixel 500-6 can be blue (B).

[0255] In the color array described above, refer again Figure 22 and 23A, for example, in the unit pixel 500-1, the first photoelectric converter 101-1 and the second photoelectric converter 103-1 are arranged, and the color of the color filter 202 (or 302, hereinafter, the color filter 202 is cited as an example for explanation) is red (R). As described above, the first photoelectric converter 101 and the second photoelectric converter 103 arranged in the same unit pixel 500 have the same color of the color filter 202.

[0256] As Figure 23 indicated in B of FIG. 10, the colors can be arranged in a Bayer array in which four pixels have the same color. In Figure 23 B, the unit pixel 500-1, the unit pixel 500-2, the unit pixel 500-5, and the unit pixel 500-6 are red (R); the unit pixel 500-3, the unit pixel 500-4, the unit pixel 500-7, and the unit pixel 500-8 are green (G); the unit pixel 500-9, the unit pixel 500-10, the unit pixel 500-13, and the unit pixel 500-14 are green (G); and the unit pixel 500-11, the unit pixel 500-12, the unit pixel 500-15, and the unit pixel 500-16 are blue (B).

[0257] In the present example, the Bayer array is cited as an example of the color array. However, the present application can be used for other color arrays.

[0258] The light shielding film is formed on the second photoelectric converter 103 as described above. The light shielding film is, for example, a light shielding film 203 (hereinafter, referred to as a solid light shielding film 203) without a slit as indicated in Figure 6 , or a light shielding film 251 with a slit as indicated in Figure 10 .

[0259] Note that, although the solid light shielding film 203 ( Figure 6 ) will be taken as an example of the solid light shielding film for explanation hereinafter, the explanation can be applied to the light shielding film 303 ( Figure 14 ) and the light shielding film 331 ( Figure 16 ). Further, the light shielding film 251 ( Figure 10 ) will be taken as an example of the slit light shielding film for explanation hereinafter. However, the explanation can be applied to the light shielding film 351 ( Figure 18 ) and the light shielding film 381 ( Figure 20 ).

[0260] When the solid light shielding film 203 is formed on the unit pixel, the light shielding film 203 is formed, for example, as indicated in A of FIG. 11. Figure 24 A of FIG. 11 only illustrates Figure 24 the light shielding film 203. Figure 22The top four pixels in the (four by four) 16 unit pixels 500-1 to 500-16 shown. However, the light-shielding film 203 is similarly formed on the other pixels.

[0261] like Figure 24 As shown in Figure A, a solid light-shielding film 203 is formed on the second photoelectric converter 103 in the unit pixel 500. For example, the second photoelectric converter 103 is formed on... Figure 24 The lower right side of unit pixel 500-1 shown in A, and the light-shielding film 203-1 is formed in the area where the second photoelectric converter 103-1 is formed.

[0262] Note that, as Figure 24 As shown in A, the light-shielding film 203 can be formed such that the light-shielding film 203 is connected to a well in the outer peripheral region of the pixel.

[0263] When the slit-shaped light-shielding film 251 is formed on a unit pixel, the light-shielding film 251 is formed, for example, as shown in the figure. Figure 24 As shown in B. Figure 24 As shown in B, the slit light-shielding film 251 is formed on the second photoelectric converter 103 of the unit pixel 500.

[0264] Figure 24 The slit shown in B extends in the lateral direction of the figure, and all four pixels have slits extending in the same direction. As described above, the slits of the light-shielding film 251 disposed on the second photoelectric converter 103 can be formed in the same direction.

[0265] The arrangement direction of the slits on the light-shielding film 251 can be changed according to the pixels. Figure 24 The diagram shows that: light-shielding films 251 are formed on the second photoelectric converter 103 of unit pixel 500, and the slits of the light-shielding films 251 with slits are formed in different directions depending on the pixel.

[0266] Formed in Figure 24 The slit of the light-shielding film 251-1 on the second photoelectric converter 103-1 of unit pixel 500-1, shown in C, is formed in the horizontal direction of the figure. The slit of the light-shielding film 251-2 formed on the second photoelectric converter 103-2 of unit pixel 500-2 is formed in the direction of the left-sloping downward side of the figure.

[0267] The slit of the light-shielding film 251-5 formed on the second photoelectric converter 103-5 of unit pixel 500-5 is formed in the direction of the right-sloping downward side of the figure. The slit of the light-shielding film 251-6 formed on the second photoelectric converter 103-6 of unit pixel 500-6 is formed in the vertical direction of the figure.

[0268] exist Figure 24In the example shown in C, the slits are formed in four directions. Also, in other pixels (not shown), the slits are formed on the light-shielding film 251 so that the slits are formed in four different directions according to the pixels among the (two by two) four pixels. Note that although four directions are cited as an example in the present example, other directions can be added, or for example, the slits can be formed in two or three directions. The number of the directions in which the slits are formed on the light-shielding film 251 is not limited to four.

[0269] As described above, the slits are formed in different directions pixel by pixel, in other words, the direction in which the slits are formed on the light-shielding film 251 formed on the adjacent second photoelectric converter 103 is changed pixel by pixel, and the polarized light from different directions can be blocked.

[0270] Further, when the direction in which the slits are formed is changed according to the pixels as described above, for example, when the slits are formed in different directions respectively among the four pixels shown in C, the four unit pixels can have the same color. In other words, the color can be arranged in a Bayer array in which the four pixels having the same color are arranged as shown in B. Figure 23 Figure 25

[0271] <Example Modification>

[0272] The example in which two photoelectric converters having different sensitivities are arranged in a pixel has been described above. However, three or more photoelectric converters having different sensitivities can be arranged in a pixel. The difference in the sensitivities can be adjusted by changing the material or the thickness of the light-shielding film.

[0273] Further, in the present embodiment, the example in which the present application is applied to the CMOS image sensor having the unit pixels arranged in a matrix has been described. However, the application of the present application is not limited to the application to the CMOS image sensor. In other words, the present application can be applied to all of the imaging devices in which the unit pixels are arranged in a matrix two-dimensionally in an X-Y address scheme.

[0274] Further, the present application can be applied not only to the imaging device that detects the distribution of the visible incident light and takes an image of the light, but also to all of the imaging devices that take an image of the distribution of the incoming infrared rays, X-rays, or particles.

[0275] Note that the imaging device can be formed as a chip, or can be formed as a module having an imaging function in which the imaging unit and the signal processing unit or the optical system are packaged.

[0276] <Example Use of Imaging Device>

[0277] Figure 26 ​​is a schematic diagram of an exemplary use of the imaging device.

[0278] The imaging device can be used for various purposes of sensing light, including visible light, infrared rays, ultraviolet rays, or X-rays, as described below.

[0279] - a device that captures an image for viewing, such as a digital camera or a mobile phone with a camera function, and the like.

[0280] - a device for traffic purposes, such as a vehicle-mounted sensor that captures an image of the front, surroundings, rear, or interior of a car for safe driving including automatic parking and driver state recognition, a surveillance camera that monitors a traveling vehicle or a road, or a distance measuring sensor that measures a distance between a vehicle and another vehicle, and the like.

[0281] - a device for a home appliance including a television (TV), a refrigerator, and an air conditioner. The device captures an image of a user's gesture to control the appliance according to the gesture.

[0282] - a device for medical care or health care, such as an endoscope or an instrument that captures an image of a blood vessel by receiving infrared light, and the like.

[0283] - a device for security, such as a surveillance camera for security or a surveillance camera for personal authentication, and the like.

[0284] - a device for cosmetic purposes, such as a skin condition measuring instrument that captures an image of skin or a microscope that acquires an image of a scalp, and the like.

[0285] - a device for sports, such as an action camera or a wearable camera for sports, and the like.

[0286] - a device for agricultural purposes, such as a camera that monitors a farmland and a crop, and the like.

[0287] Figure 26 is a block diagram of an exemplary configuration of an imaging device (camera device) 1001 as an exemplary electronic device using the present application.

[0288] As shown in ​ , the imaging device 1001 includes, for example, an optical system including a lens group 1011, an imaging element 1012, a DSP 1013 which is a camera signal processing unit, a frame memory 1014, a display device 1015, a recording device 1016, an operation system 1017, and a power supply system 1018. The DSP 1013, the frame memory 1014, the display device 1015, the recording device 1016, the operation system 1017, and the power supply system 1018 are connected to each other via a bus 1019.

[0289] The lens group 1011 takes in incident light (image light) from an object, and forms an image on an image capturing surface of the image capturing element 1012. The image capturing element 1012 converts the amount of incident light by which the lens group 1011 has formed an image on the image capturing surface, pixel by pixel, into an electric signal, so as to output the electric signal as a pixel signal.

[0290] The display device 1015 includes a panel display such as a liquid crystal display or an organic electroluminescence (EL) display, and the like, so as to display a video or a still image captured by the image capturing element 1012. The recording device 1016 records a video or a still image captured by the image capturing element 1012 on a recording medium such as a memory card, a video tape, or a digital versatile disc (DVD), and the like.

[0291] The operating system 1017 issues an instruction for operation of various functions of the image capturing apparatus 1001 under control of a user. The power supply system 1018 appropriately supplies various power sources as power sources for operation of the DSP 1013, the frame memory 1014, the display device 1015, the recording device 1016, and the operating system 1017.

[0292] The image capturing apparatus 1001 described above is applicable to a camcorder or a digital still camera, and to a camera module for a mobile device such as a smartphone or a mobile phone. The image capturing apparatus 1001 can use the image capturing apparatus described in each of the above-described embodiments as the image capturing element 1012. This can improve the image quality of an image captured by the image capturing apparatus 1001.

[0293] Here, a system means the entirety of an apparatus including a plurality of devices.

[0294] Note that the effects described here are merely examples. The effects of the present application are not limited to the described effects, and can include other effects.

[0295] Note that the embodiments of the present application are not limited to the above-described embodiments, and various changes can be made without departing from the essence of the present application.

[0296] Note that the present application can have the following configurations. (1)

[0298] An image capturing apparatus including:

[0299] a pixel array unit in which a plurality of unit pixels are arranged,

[0300] the unit pixel includes:

[0301] a first photoelectric converter, and

[0302] a second photoelectric converter having a lower sensitivity than the sensitivity of the first photoelectric converter,

[0303] The second photoelectric converter includes a light-shielding film formed on a side of the second photoelectric converter into which light enters the second photoelectric converter. (2)

[0305] The imaging device according to (1), wherein a lens for condensing light entering the second photoelectric converter is not formed on the second photoelectric converter. (3)

[0307] The imaging device according to (1) or (2), wherein a light-shielding wall for preventing light from leaking from a photoelectric converter into an adjacent photoelectric converter is provided between the photoelectric converters. (4)

[0309] The imaging device according to any one of (1) to (3), wherein the light-shielding film has a slit. (5)

[0311] The imaging device according to (4), wherein the direction in which the slit is formed on the light-shielding film formed on an adjacent second photoelectric converter is different. (6)

[0313] The imaging device according to any one of (1) to (5), which is a backside-illuminated image sensor. (7)

[0315] The imaging device according to any one of (1) to (5), which is a frontside-illuminated image sensor. (8)

[0317] The imaging device according to (7), wherein the light-shielding film is formed on a lower side or an upper side of a wiring layer formed on the second photoelectric converter. (9)

[0319] The imaging device according to any one of (1) to (8), wherein the light-shielding film is an amorphous silicon film, a polysilicon film, a Ge film, a GaN film, a CdTe film, a GaAs film, an InP film, a CuInSe2 film, a Cu2S film, a CIGS film, a non-conductive carbon film, a black resist film, an organic photoelectric conversion film, or a metal film. (10)

[0321] An imaging device, comprising:

[0322] a substrate;

[0323] a first photoelectric converter having a first region formed in the substrate;

[0324] a second photoelectric converter having a second region formed in the substrate, wherein the first region is larger than the second region;

[0325] a trench extending from a first surface of the substrate, wherein at least a portion of the trench is located between the first photoelectric converter and the second photoelectric converter. (11)

[0327] The imaging device according to (10), wherein the first region and the second region are parallel to the first surface of the substrate. (12)

[0329] The imaging device according to (10) or (11), wherein the first region and the second region respectively correspond to light-receiving surfaces of the first photoelectric converter and the second photoelectric converter. (13)

[0331] The imaging device according to any one of (10) to (12), wherein the first photoelectric converter has a higher sensitivity than the second photoelectric converter. (14)

[0333] The imaging device according to any one of (10) to (13), further comprising a pixel separation region between the first photoelectric converter and the second photoelectric converter, wherein the trench is formed in the pixel separation region. (15)

[0335] The imaging device according to any one of (10) to (14), wherein a light-shielding wall is formed in the trench, and the light-shielding wall includes an insulating film extending from the first surface of the substrate. (16)

[0337] The imaging device according to any one of (10) to (15), wherein a light-shielding wall is formed in the trench, and wherein the light-shielding wall includes at least one of a negative fixed charge film, an oxide film, and a metal. (17)

[0339] The imaging device according to any one of (10) to (16), further comprising a light-shielding film,

[0340] wherein the light-shielding film is formed over at least a portion of the second region of the second photoelectric converter, wherein the light-shielding film absorbs a portion of light incident on the imaging device. (18)

[0342] The imaging device according to any one of (10) to (17), wherein the light shielding film overlaps with the trench. (19)

[0344] The imaging device according to any one of (10) to (18), wherein the light shielding film overlaps with a portion of the first photoelectric converter. (20)

[0346] The imaging device according to any one of (10) to (19), further comprising an on-chip lens formed over the first region of the first photoelectric converter, wherein no on-chip lens is formed over the second region of the second photoelectric converter. (21)

[0348] The imaging device according to any one of (10) to (20), further comprising a color filter, wherein the color filter extends across at least a portion of the first region of the first photoelectric converter. (22)

[0350] The imaging device according to any one of (10) to (21), wherein the color filter extends across the light shielding film. (23)

[0352] The imaging device according to any one of (10) to (22), wherein the light shielding film comprises a slit. (24)

[0354] The imaging device according to any one of (10) to (23), wherein the light shielding film forms a polarizer. (25)

[0356] The imaging device according to any one of (10) to (24), further comprising a plurality of light shielding walls, wherein the first photoelectric converter extends from a first light shielding wall to a second light shielding wall, and the second photoelectric converter extends from the second light shielding wall to a third light shielding wall. (26)

[0358] The imaging device according to any one of (10) to (25), further comprising a plurality of first photoelectric converters, wherein the plurality of first photoelectric converters are arranged in a plurality of rows and a plurality of columns;

[0359] a plurality of second photoelectric converters, wherein the plurality of second photoelectric converters are arranged in a plurality of rows and a plurality of columns, wherein a center line of at least one row of the plurality of first photoelectric converters does not intersect any of the second photoelectric converters, wherein a center line of at least one row of the plurality of second photoelectric converters does not intersect any of the first photoelectric converters, and wherein a diagonal line with respect to at least one row intersects at least one of the first photoelectric converters and at least one of the second photoelectric converters. (27)

[0361] An imaging device comprising:

[0362] a substrate;

[0363] a first photoelectric converter;

[0364] a second photoelectric converter having a lower sensitivity than a sensitivity of the first photoelectric converter;

[0365] a trench extending from a first surface of the substrate, wherein at least a portion of the trench is located between the first photoelectric converter and the second photoelectric converter. (28)

[0367] An electronic apparatus comprising:

[0368] an optical system;

[0369] an image pickup element that receives light from the optical system, the image pickup element comprising:

[0370] a substrate;

[0371] a first photoelectric converter having a first region formed in the substrate;

[0372] a second photoelectric converter having a second region formed in the substrate, wherein the first region is larger than the second region;

[0373] a light-blocking wall extending from a first surface of the substrate, wherein at least a portion of the light-blocking wall is located between the first photoelectric converter and the second photoelectric converter;

[0374] a digital signal processor that processes a signal received from the image pickup element. (29)

[0376] The electronic apparatus according to (28),

[0377] wherein the electronic apparatus is included in a vehicle.

[0378] List of reference signs

[0379] 10 CMOS image sensor

[0380] 11 Pixel array unit

[0381] 12 Vertical drive unit

[0382] 13 Column processing unit

[0383] 14 Horizontal drive unit

[0384] 15 System control unit

[0385] 16 Pixel drive line

[0386] 17 Vertical signal line

[0387] 18 Signal processing unit

[0388] 19 Data storage unit

[0389] 100 Unit pixel

[0390] 101 First photoelectric converter

[0391] 102 First transfer gate unit

[0392] 103 Second photoelectric converter

[0393] 104 Second transfer gate unit

[0394] 105 Third transfer gate unit

[0395] 106 Charge accumulation unit

[0396] 107 Reset gate unit

[0397] 108 FD unit

[0398] 109 Amplification transistor

[0399] 110 Selection transistor

[0400] 203, 251, 303, 331, 351, and 381 Light shielding film

Claims

1. An optical detection device comprising: a first pixel including: a first photoelectric converter and a second photoelectric converter arranged in a substrate in a cross-sectional view; a light shielding film arranged above the second photoelectric converter, wherein, in the cross-sectional view, the light shielding film extends above the second photoelectric converter from one end of the second photoelectric converter to the other end of the second photoelectric converter, wherein, in the cross-sectional view, a first area of the first photoelectric converter is larger than a second area of the second photoelectric converter, wherein the light shielding film above four of the second photoelectric converters in 2x2 has slits formed in different directions from each other.

2. The light detecting device according to claim 1, wherein, the light shielding film is configured to polarize incident light into the second photoelectric converter.

3. The light detecting device according to claim 1, wherein, the first area of the first photoelectric converter and the second area of the second photoelectric converter respectively correspond to a light receiving surface of the first photoelectric converter and a light receiving surface of the second photoelectric converter.

4. The light detecting device of claim 1, wherein, the first photoelectric converter has a higher sensitivity than the second photoelectric converter.

5. The light detecting device according to claim 1, wherein, the direction of formation of the slit includes a lateral direction.

6. The light detecting device of claim 1, wherein, the direction of formation of the slit includes a longitudinal direction.

7. The light detecting device of claim 1, wherein, the direction of formation of the slit includes a diagonal direction. 8.An optical detection device comprising: a first photoelectric converter and a second photoelectric converter arranged in a substrate in a cross-sectional view; a first on-chip lens arranged above the first photoelectric converter in the cross-sectional view; a second on-chip lens arranged above the second photoelectric converter in the cross-sectional view; and a light shielding film arranged between the substrate and the second on-chip lens, wherein, in the cross-sectional view, the light shielding film extends above the second photoelectric converter from one end of the second photoelectric converter to the other end of the second photoelectric converter, wherein the light shielding film above four of the second photoelectric converters in 2x2 has slits formed in different directions from each other.

9. The light detecting device of claim 8, wherein, in the cross-sectional view, a first area of the first photoelectric converter is larger than a second area of the second photoelectric converter.

10. The light detecting device of claim 8, wherein, in the cross-sectional view, an area of the first on-chip lens is larger than an area of the second on-chip lens.

11. The light detecting device of claim 8, wherein, the light shielding film is configured to polarize incident light into the second photoelectric converter.

12. The light detecting device of claim 9, wherein, the first area of the first photoelectric converter and the second area of the second photoelectric converter respectively correspond to a light receiving surface of the first photoelectric converter and a light receiving surface of the second photoelectric converter.

13. The light detecting device of claim 8, wherein, the first photoelectric converter has a higher sensitivity than the second photoelectric converter.

14. The light detecting device of claim 8, wherein, the direction of formation of the slit includes a lateral direction.

15. The light detecting device of claim 8, wherein, the direction of formation of the slit includes a longitudinal direction.

16. The light detecting device of claim 8, wherein, the direction of formation of the slit includes a diagonal direction. 17.An electronic device comprising: an optical system; a light detection device that receives light from the optical system, the light detection device being as claimed in any one of claims 1 to 16; and a digital signal processor that processes signals received from the light detection device.

Images