JP2019103129A - Solid state imaging apparatus, method of driving solid state imaging apparatus, and electronic equipment - Google Patents

Abstract

To provide a solid state imaging apparatus capable of providing a visible light image such as RGB and an infrared image such as NIR (near-infrared), and holding high light receiving sensitivity with respect to an infrared light, and a method of driving the solid state imaging apparatus, and electronic equipment.SOLUTION: The solid state imaging apparatus includes: a pixel part 20 in which a unit pixel group performing a photoelectric conversion and including at least a plurality of pixels for a visible light, is arranged; a read-out part 70 reading out a pixel signal from the pixel part. The plurality of pixels for the visible light has light receiving sensitivity with respect to an infrared light, and the read-out part 70 can add a signal of the infrared light read out from the plurality of pixels for the visible light in an infrared light reading mode.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a solid-state imaging device, a method of driving a solid-state imaging device, and an electronic device.

As a solid-state imaging device (image sensor) using a photoelectric conversion element that detects light and generates electric charge, a complementary metal oxide semiconductor (CMOS) image sensor is put to practical use.
CMOS image sensors are widely applied as a part of various electronic devices such as digital cameras, video cameras, surveillance cameras, medical endoscopes, personal computers (PCs), mobile terminal devices such as mobile phones (mobile devices), etc. There is.

  The CMOS image sensor has an FD amplifier having a photodiode (photoelectric conversion element) and a floating diffusion layer (FD: Floating Diffusion) for each pixel, and its readout selects one row in the pixel array In addition, a column parallel output type in which they are read simultaneously in the column direction is the mainstream.

  For each pixel of the CMOS image sensor, for example, for one photodiode, a transfer transistor as a transfer gate, a reset transistor as a reset gate, a source follower transistor as a source follower gate (amplifying gate), and a selection gate Four elements of the selection transistor are included as active elements (see, for example, Patent Document 1).

  Generally, a CMOS image sensor captures a color image using three primary color filters of red (R), green (G) and blue (B) and four complementary colors of cyan, magenta, yellow and green.

  Generally, in a CMOS image sensor, pixels are individually provided with filters. The filter is a pixel group in which four of a red (R) filter that mainly transmits red light, a green (Gr, Gb) filter that mainly transmits green light, and a blue (B) filter that mainly transmits blue light are squarely arranged Are arranged two-dimensionally as a unit RGB pixel group.

Also, incident light to the CMOS image sensor is received by the photodiode through the filter. The photodiode receives light in a wavelength range (380 nm to 1100 nm) wider than human visible range (about 380 nm to 780 nm) to generate a signal charge, which causes an error for the infrared light, and thus color reproduction Sex is reduced.
For this reason, it is common to remove infrared light by an infrared cut filter (IR cut filter) in advance.
However, since the IR cut filter attenuates visible light by about 10% to about 20%, the sensitivity of the solid-state imaging device is lowered, and the image quality is deteriorated.

Therefore, a CMOS image sensor (solid-state imaging device) not using an IR cut filter has been proposed (see, for example, Patent Document 2).
This CMOS image sensor mainly includes red (R) filters that transmit red light, green (G) filters that mainly transmit green light, and blue (B) filters that transmit blue light. A group of pixels including four B pixels and a dedicated near infrared (NIR) pixel for receiving infrared light are two-dimensionally arranged as a unit RGBIR pixel group.
This CMOS image sensor functions as an NIR-RGB sensor capable of obtaining so-called NIR images and RGB images.

  In this CMOS image sensor, high color reproduction is achieved without using an IR cut filter by correcting the output signals of pixels that received red, green, and blue light using the output signals of pixels that received infrared light. Can be realized.

  In addition, in a CMOS image sensor provided with a unit RGBIR pixel group or a unit RGB pixel group, the floating diffusion FD, the reset transistor RST-Tr, the source follower transistor SF-Tr, and the selection transistor SEL are four pixels of the unit pixel group. -Tr may be shared.

  Further, as an infrared (IR, NIR) sensor, an infrared (IR, NIR) sensor is known in which four pixels of a unit pixel group are formed by one large NIR light reception dedicated pixel.

FIG. 1 is a plan view schematically showing an exemplary arrangement of components of a solid-state imaging device (CMOS image sensor) formed as an NIR-RGB sensor having unit RGBIR pixel groups.
In the example of FIG. 1, each pixel PXL of a unit RGBIR pixel group has the same size, and so-called RGB images and NIR images can be obtained.

FIG. 2 is a plan view schematically showing an exemplary arrangement of components of a solid-state imaging device (CMOS image sensor) formed as an NIR sensor.
In the example of FIG. 2, the pixel dedicated to NIR light reception is formed to be larger in pixel size than the NIR-RGB sensor.

JP 2005-223681 A JP, 2017-139286, A

A CMOS image sensor configured as a conventional NIR-RGB sensor as shown in FIG. 1 has the advantage of being able to obtain RGB and NIR images with one sensor.
However, at the time of infrared light reception, the resolution is equivalent to that of RGB pixels, but there is a disadvantage that the NIR sensitivity is low (about 1⁄4 of usual).

  Although the CMOS image sensor formed as a conventional NIR sensor as shown in FIG. 2 has high NIR sensitivity (approximately 4 times), it has a disadvantage that it can not obtain a visible light color image such as RGB. is there.

  The present invention can obtain a visible light image such as RGB and an infrared image such as NIR, and further can maintain a high light receiving sensitivity to infrared light, a method of driving the solid image pickup device, and It is in providing an electronic device.

  According to a first aspect of the present invention, there is provided a solid-state imaging device, which performs photoelectric conversion, and a pixel unit in which a unit pixel group including at least a plurality of visible light pixels is arranged; and reading out pixel signals from the pixel unit. A plurality of the pixels for visible light have photosensitivity to infrared light, and the readout unit reads out from the plurality of pixels for visible light in the infrared readout mode It is possible to add the signals of the infrared light.

  According to a second aspect of the present invention, there is provided a pixel section in which a unit pixel group including at least a plurality of pixels for visible light is disposed, which performs photoelectric conversion, the plurality of pixels for visible light being infrared A method of driving a solid-state imaging device having a light receiving sensitivity to light, comprising: reading out infrared light signals from the plurality of pixels for visible light and adding the read out infrared light signals in an infrared reading mode .

  An electronic apparatus according to a third aspect of the present invention includes a solid-state imaging device, and an optical system for forming an object image on the solid-state imaging device, the solid-state imaging device performs photoelectric conversion, at least visible light. Pixel unit in which a unit pixel group including a plurality of pixels for pixels is arranged, and a reading unit for reading a pixel signal from the pixel unit, and the plurality of pixels for visible light are infrared light In the infrared readout mode, the readout unit can add infrared light signals read out from the plurality of pixels for visible light.

  According to the present invention, it is possible to obtain a visible light image such as RGB and an infrared image such as NIR, and it is possible to maintain high light receiving sensitivity to infrared light.

FIG. 2 is a plan view schematically showing a schematic arrangement example of components of a solid-state imaging device (CMOS image sensor) formed as an NIR-RGB sensor having unit RGBIR pixel groups. FIG. 2 is a plan view schematically illustrating an exemplary arrangement of components of a solid-state imaging device (CMOS image sensor) formed as a NIR sensor. It is a block diagram showing an example of composition of a solid-state imaging device concerning a 1st embodiment of the present invention. FIG. 6 is a circuit diagram showing an example in which one floating diffusion is shared by four pixels in a pixel section of the solid-state imaging device according to the first embodiment. It is a figure which shows the structural example of the column signal processing circuit in the read-out circuit which concerns on this embodiment. FIG. 2 is a plan view schematically showing a schematic arrangement example of components of a solid-state imaging device (CMOS image sensor) having unit RGB pixel groups according to the first embodiment. It is a simplified sectional view showing typically the example of composition of the unit pixel group in the solid imaging device concerning a 1st embodiment of the present invention. FIG. 7 is a diagram for describing the read operation in the first mode and the read operation in the second mode in the solid-state imaging device according to the first embodiment. FIG. 12 is a plan view schematically showing a schematic arrangement example of components of a solid-state imaging device (CMOS image sensor) having a unit pixel group according to the second embodiment. FIG. 13 is a plan view schematically showing a schematic example of arrangement of components of a solid-state imaging device (CMOS image sensor) having a unit pixel group according to a third embodiment. FIG. 18 is a diagram for describing the read operation in the first mode and the read operation in the second mode in the solid-state imaging device according to the third embodiment. It is a flowchart for demonstrating the switching control of the 1st-4th pixel signal readout mode at the time of the infrared readout mode in the readout part which concerns on the 3rd embodiment. It is a simplified sectional view showing an example of rough composition of a solid-state imaging device (CMOS image sensor) concerning a 4th embodiment. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 4th embodiment, and an optical filter. It is a simplified sectional view showing an example of rough composition of a solid-state imaging device (CMOS image sensor) concerning a 5th embodiment. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 5th embodiment, and an optical filter. It is a figure for demonstrating the method to determine the cutoff wavelength of a light-shielding wavelength band end, when optically shielding between the visible light wavelength band which is between light wavelength bands and between infrared light wavelength bands. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 6th embodiment, and an optical filter. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 6th embodiment, and an optical filter. It is a simplified sectional view showing an example of rough composition of a solid-state imaging device (CMOS image sensor) concerning a 7th embodiment. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 7th embodiment, and an optical filter. It is a simplified sectional view showing an example of rough composition of a solid-state imaging device (CMOS image sensor) concerning the 8th embodiment. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 8th embodiment, and an optical filter. It is a simplified sectional view showing an example of rough composition of a solid-state imaging device (CMOS image sensor) concerning a 9th embodiment. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 9th embodiment, and an optical filter. FIG. 21 is a simplified cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to a tenth embodiment. It is a figure which shows the transmission characteristic of the color filter array which concerns on the 10th embodiment, and an optical filter. It is a figure showing an example of composition of electronic equipment with which a solid imaging device concerning an embodiment of the present invention is applied.

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

First Embodiment
FIG. 3 is a block diagram showing a configuration example of the solid-state imaging device according to the first embodiment of the present invention.
In the present embodiment, the solid-state imaging device 10 is configured of, for example, a CMOS image sensor.

As shown in FIG. 3, the solid-state imaging device 10 includes a pixel unit 20 as an imaging unit, a vertical scanning circuit (row scanning circuit) 30, a readout circuit (column readout circuit) 40, and a horizontal scanning circuit (column scanning circuit) 50. And a timing control circuit 60 as a main component.
Further, among these components, for example, the vertical scanning circuit 30, the reading circuit 40, the horizontal scanning circuit 50, and the timing control circuit 60 constitute a pixel signal reading unit 70.

In the first embodiment, the solid-state imaging device 10 can obtain a visible light image such as RGB and an infrared image such as NIR, and can further maintain high light receiving sensitivity to infrared light. In addition, the pixel unit 20 performs photoelectric conversion, and a unit pixel group including a plurality of visible light pixels (also referred to as color pixels) is disposed, and a plurality of visible light pixels (color pixels) The light receiving sensitivity to light is provided, and the reading unit 70 can add infrared light signals read from a plurality of color pixels in the infrared reading mode MIRRD.
In the first embodiment, the wavelength of infrared light is 800 nm or more.
Further, each color pixel may be able to read out simultaneously a color pixel signal in the visible region and an infrared pixel signal in the infrared region by the readout unit 70 in parallel.

  In the first embodiment, the unit pixel group has a function of photoelectrically converting light incident from one side, and includes a plurality of photoelectric conversion units corresponding to a plurality of visible light wavelength bands (colors). The photoelectric conversion unit of the present invention includes a red (R) photoelectric conversion unit corresponding to a red (R) region, a first green (Gb) photoelectric conversion unit corresponding to a green (Gb, Gr) region, and a second green (Gr) The photoelectric conversion unit includes a blue (B) photoelectric conversion unit corresponding to the blue (B) region.

In the first mode MOD1, the readout unit 70 performs the first green (Gb) photoelectric conversion unit, the blue (B) photoelectric conversion unit, the red (R) photoelectric conversion unit, and the second green (Gr) photoelectric conversion unit. The signal read out from the conversion unit can be output as it is, and in the second mode MOD2 including the infrared readout mode, the first green (Gb) photoelectric conversion unit, blue (B) photoelectric conversion unit, red (R) It is possible to add the signals read from the photoelectric conversion unit and the second green (Gr) photoelectric conversion unit.
In the first embodiment, basically, the first mode MOD1 is a red (R) green (G) blue (B) image acquisition mode, and the second mode MOD2 is infrared (IR, NIR) ) It is an image acquisition mode.
In the first embodiment, the unit pixel group is formed as a unit RGB pixel group.

  Hereinafter, after describing the configuration and function of each part of the solid-state imaging device 10, the specific configuration, arrangement, and the like of the pixel will be described in detail.

(Configuration of Pixel Unit 20 and Pixel PXL)
In the pixel unit 20, a plurality of pixels including a photodiode (photoelectric conversion unit) and an in-pixel amplifier are arranged in a two-dimensional matrix (matrix) of N rows × M columns.

  FIG. 4 is a circuit diagram showing an example in which one floating diffusion is shared by four pixels in the pixel section of the solid-state imaging device according to the first embodiment.

  In the pixel unit 20 of FIG. 4, four pixels PXL11, PXL12, PXL21, and PXL22 are arranged in a 2 × 2 square.

  The pixel PXL11 is configured to include a photodiode PD11 and a transfer transistor TG11-Tr.

  The pixel PXL12 is configured to include a photodiode PD12 and a transfer transistor TG12-Tr.

  The pixel PXL21 is configured to include a photodiode PD21 and a transfer transistor TG21-Tr.

  The pixel PXL22 is configured to include a photodiode PD22 and a transfer transistor TG22-Tr.

  The pixel unit 20 includes four pixels PXL11, PXL12, PXL21, and PXL22. The floating diffusion FD (Floating Diffusion; floating diffusion layer) 11, a reset transistor RST11-Tr, a source follower transistor SF11-Tr, and a selection transistor SEL11-. Tr is shared.

In such a four-pixel sharing configuration, when the unit pixel group has a Bayer arrangement, the pixel PXL11 is formed as a Gb pixel, the pixel PXL12 is formed as a B pixel, PXL21 is formed as an R pixel, and the pixel PXL22 is a Gr pixel It is formed as
For example, the photodiode PD11 of the pixel PXL11 functions as a first green (Gb) photoelectric conversion unit, the photodiode PD12 of the pixel PXL12 functions as a blue (B) photoelectric conversion unit, and the photodiode PD21 of the pixel PXL21 is red ( R) Functions as a photoelectric conversion unit, and the photodiode PD22 of the pixel PXL22 functions as a second green (Gr) photoelectric conversion unit.

Generally, the sensitivity to saturation of the photodiode PD of each pixel is different for each color (light wavelength band).
For example, the sensitivities of the photodiodes PD11 and PD22 of the G pixel are higher than the sensitivities of the photodiode PD12 of the B pixel and the photodiode PD21 of the R pixel.

For example, a buried photodiode (PPD) is used as the photodiodes PD11, PD12, PD21 and PD22.
Since surface states due to defects such as dangling bonds exist on the substrate surface forming the photodiodes PD11, PD12, PD21, and P22, a large amount of charge (dark current) is generated by thermal energy, and the correct signal can be read out. It will be gone.
In the embedded photodiode (PPD), it is possible to reduce the mixing of dark current into a signal by embedding the charge storage portion of the photodiode PD in the substrate.

The photodiodes PD11, PD12, PD21, and PD22 generate and accumulate signal charges (here, electrons) according to the amount of incident light.
Hereinafter, the case where the signal charge is an electron and each transistor is an n-type transistor will be described. However, the signal charge may be a hole or each transistor may be a p-type transistor.

The transfer transistors TG11 to Tr are connected between the photodiode PD11 and the floating diffusion FD11, and are controlled through a control line (or control signal) TG11.
The transfer transistor TG11-Tr is turned on when the control line TG11 is selected during a high level (H) period of a predetermined level under the control of the reading unit 70, and the charge photoelectrically converted and stored by the photodiode PD11 (electron ) To the floating diffusion FD11.

The transfer transistor TG12-Tr is connected between the photodiode PD12 and the floating diffusion FD11, and is controlled through a control line (or control signal) TG12.
The transfer transistor TG12-Tr is turned on when the control line TG12 is selected during a high level (H) of a predetermined level under the control of the reading unit 70, and the charge photoelectrically converted and stored by the photodiode PD12 (electron ) To the floating diffusion FD11.

The transfer transistor TG21-Tr is connected between the photodiode PD21 and the floating diffusion FD11, and is controlled through a control line (or control signal) TG21.
The transfer transistor TG21-Tr is turned on when the control line TG21 is selected during a high level (H) of a predetermined level under the control of the reading unit 70, and the charge photoelectrically converted and stored by the photodiode PD21 (electron ) To the floating diffusion FD11.

The transfer transistor TG22-Tr is connected between the photodiode PD22 and the floating diffusion FD11, and is controlled through a control line (or control signal) TG22.
The transfer transistor TG22-Tr is turned on when the control line TG22 is selected during a high level (H) of a predetermined level under the control of the reading unit 70, and the charge photoelectrically converted and stored by the photodiode PD22 (electron ) To the floating diffusion FD11.

As shown in FIG. 4, the reset transistors RST11 to Tr are connected between the power supply line VDD (or power supply potential) and the floating diffusion FD11, and are controlled through a control line (or control signal) RST11.
The reset transistors RST11 to Tr may be connected between a power supply line VRst different from the power supply line VDD and the floating diffusion FD, and may be configured to be controlled through a control line (or control signal) RST11.
Under the control of the read unit 70, for example, at the time of read scan, the reset transistor RST11-Tr is selected during the period when the control line RST11 is at H level and becomes conductive, causing the floating diffusion FD11 to be at the potential of the power supply line VDD (or VRst). Reset.

The source follower transistor SF11-Tr and the selection transistor SEL11-Tr are connected in series between the power supply line VDD and the vertical signal line LSGN.
The floating diffusion FD11 is connected to the gate of the source follower transistor SF11-Tr, and the selection transistor SEL11-Tr is controlled through the control line (or control signal) SEL11.
The selection transistor SEL11-Tr is selected during a period in which the control line SEL11 is at H level and becomes conductive. Thereby, the source follower transistor SF11-Tr outputs the read voltage (signal) VSL (PIXOUT) of the column output obtained by converting the charge of the floating diffusion FD11 into a voltage signal with a gain corresponding to the charge amount (potential) to the vertical signal line LSGN Do.

In the pixel section 20, since the pixels PXL are arranged in N rows × M columns, there are N control lines SEL, RST, and TG, and M vertical signal lines LSGN.
In FIG. 3, each control line (or control signal) SEL, RST, and TG is represented as one row scanning control line.

The vertical scanning circuit 30 drives the pixels through the row scanning control line in the shutter row and the readout row according to the control of the timing control circuit 60.
Further, the vertical scanning circuit 30 outputs a row selection signal of a row address for reading out the signal and a row address of the shutter row for resetting the charge accumulated in the photodiode PD in accordance with the address signal.

  In a normal pixel readout operation, shutter scanning is performed by driving of the readout unit 70 by the vertical scanning circuit 30, and then readout scanning is performed.

  The readout circuit 40 includes a plurality of column signal processing circuits (not shown) arranged corresponding to the respective column outputs of the pixel unit 20, and even if column parallel processing is possible by the plurality of column signal processing circuits. Good.

  The readout circuit 40 can be configured to include a correlated double sampling (CDS) circuit, an ADC (analog digital converter; AD converter), an amplifier (AMP, amplifier), a sample hold (S / H) circuit, etc. It is.

As described above, the readout circuit 40 may include an ADC 41 that converts the readout signal VSL of each column output of the pixel unit 20 into a digital signal, as shown in FIG. 5A, for example.
Alternatively, in the readout circuit 40, for example, as shown in FIG. 5B, an amplifier (AMP) 42 that amplifies the readout signal VSL of each column output of the pixel unit 20 may be disposed.
Further, as shown in FIG. 5C, for example, a sample and hold (S / H) circuit 43 may be arranged to sample and hold the read signal VSL of each column output of the pixel unit 20 in the read out circuit 40.

  The horizontal scanning circuit 50 scans the signals processed by the plurality of column signal processing circuits such as the ADC of the reading circuit 40, transfers the signals in the horizontal direction, and outputs the signals to a signal processing circuit (not shown).

  The timing control circuit 60 generates timing signals necessary for signal processing of the pixel unit 20, the vertical scanning circuit 30, the reading circuit 40, the horizontal scanning circuit 50, and the like.

The outline of the configuration and function of each part of the solid-state imaging device 10 has been described above.
Next, a specific configuration of the pixel arrangement according to the first embodiment will be described.

  FIG. 6 is a plan view schematically showing a schematic arrangement example of each component of a solid-state imaging device (CMOS image sensor) having a unit pixel group according to the first embodiment.

The pixel unit 20 of FIG. 6 is shown by planarizing the circuit of FIG. 4, and four pixels PXL11, PXL12, PXL21, and PXL22 are arranged in a 2 × 2 square.
More specifically, arrangement areas AR11, AR12, AR21, AR22 in which four pixels PXL11, PXL12, PXL21, PXL22 are respectively arranged in the rectangular arrangement area AR10 are allocated to a square of 2 × 2.

  The pixel unit 20 in FIG. 6 shows a configuration in the case of square arrangement in a 4-pixel sharing configuration, in which the pixel PXL11 is formed as a Gb pixel, the pixel PXL12 is formed as a B pixel, and the pixel PXL21 is formed as an R pixel The pixel PXL22 is formed as a Gr pixel.

  In the pixel unit 20, the floating diffusion FD11, the reset transistor RST11-Tr, the source follower transistor SF11-Tr, and the selection transistor SEL11-Tr are shared by the four pixels PXL11, PXL12, PXL21, and PXL22.

FIG. 7 is a simplified cross-sectional view schematically showing a configuration example of a unit pixel group in the solid-state imaging device according to the first embodiment of the present invention.
In FIG. 7, for ease of understanding, each first green (Gb) pixel PXL11, blue (B) pixel PXL12, red (R) pixel PXL 21 and second green (Gr) are conveniently used. The components of the pixel PXL 22 are shown arranged in a line.

  The unit RGB pixel group 200 includes a microlens array 210, a color filter array 220, a photodiode array 230 as a photoelectric conversion unit, and a flat layer 240 as main components.

The color filter array 220 includes a first green (Gb) filter area 221, a blue (B) filter area 222, a red (R) filter area 223, and a second green (Gr) to form each color pixel. A filter area 224 is divided.
On the light incident side of each first green (Gb) filter area 221, blue (B) filter area 222, red (R) filter area 223, and second green (Gr) filter area 224, a microlens array 210 is provided. Micro lens MCL is arranged.

  The photodiodes PD11, PD12, PD21, and PD22 as the photoelectric conversion units are provided to the semiconductor substrate 250 having the first substrate surface 251 side and the second substrate surface 252 side opposite to the first substrate surface 251 side. It is formed to be embedded, and is formed to have a photoelectric conversion function and a charge storage function of the received light.

In the photodiodes PD11, PD12, PD21, and PD22 of the photodiode array 230, the color filter array 220 is disposed on the first substrate surface 251 side (rear surface side) with the flat layer 240 interposed therebetween.
Output units 231, 232, 233, and 234 each including an output transistor or the like that outputs a signal corresponding to the charge that has been photoelectrically converted and accumulated on the second substrate surface 252 side (front surface side) of the photodiode PD11, PD12, PD21, PD22. Is formed.

  Each color pixel in the unit RGB pixel group 200 having the above-described configuration not only has an inherent specific response in the visible range (400 nm to 700 nm), but also in the near infrared (NIR) region (800 nm to 1000 nm) It has high responsiveness.

  In the color filter array 220 according to the first embodiment, the color (visible light) region is a range up to the start region (for example, 850 nm) of the near infrared region, and the red filter, the green filter, and the blue filter have different transmittances. And has a large transmittance of 90% or more in the near infrared region.

  That is, in the first embodiment, the photodiode PD11 that is the first green (Gb) photoelectric conversion unit, the photodiode PD12 that is the blue (B) photoelectric conversion unit, and the photodiode that is the red (R) photoelectric conversion unit The PD 21 and the photodiode PD22, which is a second green (Gr) photoelectric conversion unit, also have a function as an infrared (NIR) photoelectric conversion unit.

  FIGS. 8A and 8B are diagrams for explaining the read operation in the first mode and the read operation in the second mode in the solid-state imaging device 10 according to the first embodiment.

  In the first mode MOD1 (RGB image acquisition mode), as shown in FIG. 8A under the control of the reading unit 70, the photodiode PD11, which is the first green (Gb) photoelectric conversion unit, blue (B) A signal read out from the photodiode PD12 that is a photoelectric conversion unit, the photodiode PD21 that is a red (R) photoelectric conversion unit, and the photodiode PD22 that is a second green (Gr) photoelectric conversion unit is output as it is.

  In the second mode MOD2 (NIR image acquisition mode), as shown in FIG. 9B under the control of the reading unit 70, the photodiode PD11, which is the first green (Gb) photoelectric conversion unit, blue (B (B)) ) A plurality (for example, all) of the signals read out from the photodiode PD12 which is a photoelectric conversion unit, the photodiode PD21 which is a red (R) photoelectric conversion unit, and the photodiode PD22 which is a second green (Gr) photoelectric conversion unit It is possible.

  As described above, in the solid-state imaging device 10 according to the first embodiment, an RGB image and an NIR image can be obtained, and moreover, it is possible to keep the NIR sensitivity high.

As described above, according to the first embodiment, in the solid-state imaging device 10, the pixel unit 20 performs photoelectric conversion, and a unit RGB pixel group 200 including a plurality of color pixels for visible light is arranged. The red (RGB) pixel has a light receiving sensitivity to infrared light, and the reading unit 70 can add infrared light signals read out from a plurality of color pixels in the infrared reading mode MIRRD.
For example, in the first mode MOD1 (RGB image acquisition mode), under the control of the reading unit 70, the Gb pixel PXL11 including the photodiode PD11 which is the first green (Gb) photoelectric conversion unit, blue (B) photoelectric conversion Pixel PXL12 including a photodiode PD12 that is a part, R pixel PXL21 that includes a photodiode PD21 that is a red (R) photoelectric conversion part, and Gb pixel that includes a photodiode PD22 that is a second green (Gr) photoelectric conversion part The signal read out from the PXL 22 is output as it is.
In the second mode MOD2 (NIR image acquisition mode) including the infrared readout mode MIRRD, under control of the readout unit 70, the Gb pixel PXL11 including the photodiode PD11 that is the first green (Gb) photoelectric conversion unit, blue (B) B pixel PXL12 including a photodiode PD12 which is a photoelectric conversion unit, R pixel PXL21 including a photodiode PD21 which is a red (R) photoelectric conversion unit, and a photodiode which is a second green (Gr) photoelectric conversion unit It is possible to add a plurality of (for example, all) signals read out from the Gb pixel PXL 22 including the PD 22.

According to the first embodiment having such a configuration, a visible light image such as RGB and an infrared image such as NIR can be obtained, and moreover, it is possible to maintain high light receiving sensitivity to infrared light. Become.
For example, in a surveillance camera or the like, desired characteristics with higher sensitivity in the near infrared (NIR) region can be obtained.
Further, in the near infrared (NIR) region having a wavelength of 800 nm or more, a high sensitivity NIR image can be acquired without degrading the resolution of the pixel.

Second Embodiment
FIG. 9 is a diagram for explaining the read operation in the second mode in the solid-state imaging device according to the second embodiment.

The difference between the second embodiment and the first embodiment is as follows.
In the second embodiment, the readout unit 70 includes the Gb pixel PXL11 including the photodiode PD11 that is the first green (Gb) photoelectric conversion unit, and the B pixel that includes the photodiode PD12 that is the blue (B) photoelectric conversion unit. A color pixel signal (RGB in the visible region from PXL12, an R pixel PXL21 including a photodiode PD21 that is a red (R) photoelectric conversion unit, and a Gr pixel PXL22 that includes a photodiode PD22 that is a second green (Gr) photoelectric conversion unit And infrared pixel signals (NIR) in the infrared region can be read out (acquired) simultaneously and in parallel.

  The solid-state imaging device 10A according to the second embodiment includes pixel signals in a visible region and a near-infrared (NIR) region of 800 nm or less, for example, by Gb pixel PXL11, B pixel PXL12, R pixel PXL21, and Gr pixel PXL22. And a color image including near infrared (NIR) regions.

  The reading unit 70 simultaneously and parallelly reads a color pixel signal (G) and an infrared pixel signal (NIR) in the infrared region from the Gb pixel PXL11 including the photodiode PD11 that is the first green (Gb) photoelectric conversion unit. (G + NIR).

  The reading unit 70 simultaneously reads out a color pixel signal (B) and an infrared pixel signal (NIR) in the infrared region from the BG element PXL12 including the photodiode PD12 which is a blue (B) photoelectric conversion unit (B + NIR) .

  The reading unit 70 simultaneously reads out a color pixel signal (R) and an infrared pixel signal (NIR) in the infrared region from the R pixel PXL21 including the photodiode PD21 that is a red (R) photoelectric conversion unit (R + NIR) .

  The readout unit 70 simultaneously and parallelly reads out a color pixel signal (G) and an infrared pixel signal (NIR) in the infrared region from the Gr pixel PXL22 including the photodiode PD22 which is a second green (Gr) photoelectric conversion unit. (G + NIR).

According to the second embodiment, it is possible not only to obtain the same effect as that of the first embodiment described above but also to obtain a colored NIR image, so that, for example, veins and arteries can be distinguished. .
That is, in the solid-state imaging device 10A, since it is possible to acquire colored infrared images, for example, veins and arteries of human beings can be imaged with different colors in this region, so that the accuracy is high and the security level is high. Biometric authentication (palm, retina, etc.) becomes possible.
Therefore, the solid-state imaging device 10A according to the second embodiment is effective for biometrics technology such as vein and artery or iris authentication.

Third Embodiment
FIG. 10 is a plan view schematically showing a schematic arrangement example of each component of a solid-state imaging device (CMOS image sensor) having a unit pixel group according to the third embodiment.
FIG. 11 is a diagram for explaining the read operation in the first mode and the read operation in the second mode in the solid-state imaging device according to the third embodiment.

The difference between the third embodiment and the first embodiment is as follows.
In the unit pixel group 200B of the third embodiment, the filter of the pixel PXL22 disposed in the placement area AR22 is replaced with green (Gr), and red including an infrared (NIR) photoelectric conversion unit that receives infrared light. The outer dedicated pixel PXL 22 B is disposed and formed as a unit RGBIR pixel group.

In the first mode MOD1, the readout unit 70 is a G pixel PXL11 including a photodiode PD11 as a green photoelectric conversion unit, a B pixel PXL12 including a photodiode PD12 as a blue photoelectric conversion unit, and a photo as a red photoelectric conversion unit. It is possible to output the pixel signal read out from the R pixel PXL21 including the diode PD21 as it is.
Alternatively, in the first mode MOD1, the reading unit 70 includes a G pixel PXL11 including a photodiode PD11 as a green photoelectric conversion unit and a B pixel including a photodiode PD12 as a blue photoelectric conversion unit under the control of the reading unit 70. Adding a signal read out from the infrared dedicated pixel PXL22B including the photodiode PD22 as an infrared (NIR) photoelectric conversion unit to a signal read out from the R pixel PXL21 including the PXL12 and the photodiode PD21 as a red photoelectric conversion unit Is possible.
In the second mode MOD2 including the infrared readout mode MIRRD, the readout unit 70, as shown in FIG. 11, the G pixel PXL11 including the photodiode PD11 as a green photoelectric conversion unit, and the photodiode as a blue photoelectric conversion unit Adding pixel signals read out from the B pixel PXL12 including the PD12, the R pixel PXL21 including the photodiode PD21 as the red photoelectric conversion unit, and the infrared dedicated pixel PXL22B including the photodiode PD22 as the infrared photoelectric conversion unit It is possible.

In the third embodiment, the infrared readout mode MIRRD includes a first pixel signal readout mode MIRRD1, a second pixel signal readout mode MIRRD2, a third pixel signal readout mode MIRRD3, and a fourth pixel signal readout mode. Includes MIRRD4.
In the first pixel signal readout mode MIRRD1, an infrared pixel signal is read out from the infrared only pixel PXL22B.
In the second pixel signal readout mode MIRRD2, infrared pixel signals are read out from the infrared dedicated pixel PXL22B and the G pixel PXL11, the B pixel PXL12, and the R pixel PXL21 which are color pixels.
In the third pixel signal readout mode MIRRD3, infrared pixel signals are read out from the G pixel PXL11, the B pixel PXL12, and the R pixel PXL21 which are color pixels.
In the fourth pixel signal readout mode MIRRD4, the infrared pixel signals read out from the infrared only pixel PXL22B and the G pixel PXL11, the B pixel PXL12, and the R pixel PXL21 which are color pixels are added.

  In the third embodiment, the readout unit 70 is configured to perform the first pixel signal readout mode MIRRD1, the second pixel signal readout mode MIRRD2, the third pixel signal readout mode M, and the fourth pixel signal readout mode MIRRD4. Among them, at least two pixel signal readout modes can be switched to perform readout of pixel signals according to the mode.

  FIG. 12 is a flowchart for describing switching control of the first to fourth pixel signal readout modes in the infrared readout mode in the readout unit according to the third embodiment.

The reading unit 70 receives the mode signal MOD from the control system (not shown) (ST1), and the received mode signal is the first pixel signal reading mode MIRRD1 of the infrared reading mode MIRRD in the second mode signal MOD2. It is determined (ST2).
When it is determined in step ST2 that the read out unit 70 is the first pixel signal read out mode MIRRD1 of the infrared read out mode MIRRD, the read out portion 70 reads out the infrared pixel signal from the infrared only pixel PXL22B (ST3).

If it is determined in step ST2 that the first pixel signal readout mode MIRRD1 of the infrared readout mode MIRRD is not set, the readout unit 70 determines whether or not the second pixel signal readout mode MIRRD2 is selected (ST4).
When the reading unit 70 determines in step ST4 that the second pixel signal reading mode MIRRD2 of the infrared reading mode MIRRD is selected, the infrared dedicated pixel PXL22B, and the G pixel PXL11, the B pixel PXL12, and the R pixel which are color pixels. An infrared pixel signal is read out from PXL 21 (ST5).

If it is determined in step ST4 that the second pixel signal readout mode MIRRD2 of the infrared readout mode MIRRD is not set, the readout unit 70 determines whether or not the third pixel signal readout mode MIRRD3 is selected (ST6).
When the reading unit 70 determines that the third pixel signal reading mode MIRRD3 of the infrared reading mode MIRRD is in step ST6, the infrared pixel signal is output from the G pixel PXL11, the B pixel PXL12, and the R pixel PXL21 which are color pixels. Read out (ST7).

If it is determined in step ST6 that the third pixel signal readout mode MIRRD3 of the infrared readout mode MIRRD is not selected, the readout unit 70 determines whether or not the fourth pixel signal readout mode MIRRD4 is selected (ST8).
When it is determined in step ST8 that the fourth pixel signal readout mode MIRRD4 of the infrared readout mode MIRRD is selected, the readout unit 70 determines that the infrared dedicated pixel PXL22B and the G pixels PXL11, B pixels PXL12, and R pixels which are color pixels. The infrared pixel signal read out from PXL 21 is added (ST 9).

  If it is determined in step ST8 that the fourth pixel signal readout mode MIRRD4 of the infrared readout mode MIRRD is not selected, the readout unit 70 returns to, for example, the process of step ST1, and repeats the above-described series of operations.

  According to the third embodiment, it is possible to further improve the NIR sensitivity as well as to obtain the same effects as the effects of the first embodiment described above.

Fourth Embodiment
FIG. 13 is a simplified cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to the fourth embodiment.
FIG. 14 is a diagram showing transmission characteristics of the color filter array and the optical filter according to the fourth embodiment.

The difference of the fourth embodiment from the third embodiment is as follows.
In the fourth embodiment, the photodiode PD11C that is a red (R) photoelectric conversion unit, the photodiode PD12C that is a green (G) photoelectric conversion unit, and the photodiode PD21C that is a blue (B) photoelectric conversion unit The photodiodes are arranged in the above order and have a function as a photodiode which is an infrared (NIR) photoelectric conversion unit, and the photodiode PD22 which is an infrared (NIR) photoelectric conversion unit is not provided.

In the fourth embodiment, the unit pixel group 200C is configured to include an optical filter group 260 including a plurality of optical filters capable of receiving visible light and infrared light of a specific wavelength.
The optical filter group 260 includes the first optical filter 261 disposed on the light incident side of each of the red filter FLR-R, the green filter FLT-G, and the blue filter FLT-B, and the color filter array 220C. Red filter FLR-R, green filter FLT-G, and blue filter FLT-B, a photodiode PD11C that is a red (R) photoelectric conversion unit, a photodiode PD12C that is a green (G) photoelectric conversion unit, And a second optical filter 262 formed of a selective infrared (selective IR) cut material, which is disposed between the first and second sides of the photodiode PD21C which is a blue (B) photoelectric conversion unit.

  The arrangement position of the color filter array 220C and the second optical filter 262 is not limited to the example of FIG. 13, and the second optical filter 262 is arranged on the microlens array 210 side, and the photodiode PD11C, The color filter array 220C may be disposed on one side of the PD 12C and PD 21C.

  A solid-state imaging device 10C according to the fourth embodiment includes a first optical filter 261 such as an IR filter in an optical system, and is a selective infrared (selective IR) filter on an on chip. The optical filter 262 is included.

In the fourth embodiment, the plurality of optical filters are formed by, for example, band pass filters (band pass filters).
In the example of FIG. 14, the transmission (transmission) wavelength band of the first optical filter 261 is, for example, a wavelength band of 380 nm to 1100 nm wider than the visible region of about 380 nm to about 780 nm.
The transmission (transmission) wavelength band of the second optical filter 262 is, for example, in the visible region of about 380 nm to 780 nm and 900 nm or more, and the second optical filter 262 blocks the transmission of the wavelength band of 780 nm to 900 nm. . Thus, it is possible that the second optical filter 262 is a selective infrared (IR) cut filter.

In the fourth embodiment, at least one of the plurality (two in the fourth embodiment) of the optical filters 261 and 262 can switch the light reception wavelength.
The second optical filter 262 includes a photodiode PD11C that is a red (R) photoelectric conversion unit, a photodiode PD12C that is a green (G) photoelectric conversion unit, and a photodiode PD21C that is a blue (B) photoelectric conversion unit. It is disposed on one side (light incident side).
However, the plurality of (two in the fourth embodiment) optical filters 261 and 262 may be disposed on the optical system, the package, and the pixel.

In FIG. 14, the curve indicated by the broken line TC1 indicates the transmission characteristic of the first optical filter 261, and the curve indicated by the thick solid line TC2 indicates the transmission characteristic of the second optical filter 262.
In the fourth embodiment, as shown in FIG. 14, the first optical filter 261 and the second optical filter 262 have a portion where the passing wavelength band is shifted (the cutoff wavelength is shifted).

As shown in FIG. 14, the solid-state imaging device 10C including the optical filter group 260 can transmit visible light such as RGB and infrared light of a specific wavelength and can receive light at the photoelectric conversion unit.
In the fourth embodiment, the specific infrared wavelength is 800 nm to 1000 nm, more preferably 850 nm to 950 nm.

  For example, in the case of an image sensor that receives infrared light with a wavelength of 800 to 1000 nm for ordinary visible light image and biometric authentication, if unnecessary 650 to 800 nm or 1000 nm or more infrared light can be cut by the optical filter group 260 It is possible to obtain a good RGB visible light image and an NIR image with less color mixing.

  According to the fourth embodiment, it is possible not only to obtain the same effect as that of the first embodiment described above but also to acquire an RGB image and an NIR image without crosstalk.

Fifth Embodiment
FIG. 15 is a simplified cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to the fifth embodiment.
FIG. 16 is a view showing the transmission characteristics of the color filter array and the optical filter according to the fifth embodiment.
In FIG. 16, a curve indicated by a thick solid line TC11 indicates the transmission characteristic of the first optical filter 261D.

The difference of the fifth embodiment from the fourth embodiment is as follows.
In the fourth embodiment described above, the transmission (transmission) wavelength band of the first optical filter 261 is, for example, one wavelength band of 380 nm to 1100 nm wider than the visible region of about 380 nm to 780 nm.

On the other hand, in the fifth embodiment, a plurality of (2 in the fifth embodiment) light wavelength bands are formed as the transmission (transmission) wavelength bands of the first optical filter 261D. There is.
Specifically, in the first optical filter 261D, a first transmission (transmission) region TWB11 having at least one visible light wavelength band (visible region) of about 380 to 700 nm as a transmission (transmission) wavelength band and infrared light, It is formed to have two regions of a second transmission (transmission) region TWB 12 of about 850 to 1000 nm in a light wavelength band (infrared region).
That is, the first optical filter 261D functions as an on lid dual band pass filter and as an infrared (IR) filter.

  FIG. 17 is a diagram for describing a method of determining the cutoff wavelength of the light shielding wavelength band end when optically blocking light between the visible light wavelength band and the infrared light wavelength band, which are between the light wavelength bands. .

  When optically shielding light between a plurality of light wavelength bands, specifically, between a visible light wavelength band and an infrared light wavelength band as shown in FIG. 17, the cutoff wavelengths of the light shielding wavelength band ends TSWBV and TSWBIR are set. It is determined by an infrared filter forming the first optical filter 261D or a selective infrared filter forming the second optical filter 262D on an on-chip.

According to the fifth embodiment, the light wavelength band desired to be imaged can be selected with the minimum number of optical filters (IR filters).
For example, in the case of imaging a visible light band and an infrared light band, imaging can be performed with one sheet by using an IR filter having a transmittance as shown in FIG.

  In addition, when the cutoff wavelength is determined by the selective IR filter, crosstalk can be suppressed strongly even in the angle dependency.

Sixth Embodiment
FIG. 18 is a simplified cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to the sixth embodiment.
FIG. 19 is a view showing the transmission characteristics of the color filter array and the optical filter according to the sixth embodiment.

The sixth embodiment is different from the fifth embodiment in the following points.
In the fifth embodiment described above, a plurality of (2 in the fifth embodiment) light wavelength bands are formed as the transmission (transmission) wavelength bands of the first optical filter 261D.
Specifically, in the first optical filter 261E, a first transmission (transmission) region TWBI1 of at least one visible light wavelength band (visible region) of about 380 to 700 nm as a transmission (transmission) wavelength band, and an infrared It is formed to have two regions of a second transmission (transmission) region TWB 12 of about 850 to 1000 nm in a light wavelength band (infrared region).

In the sixth embodiment, the passband (passband) can be further selected.
As shown in FIG. 19, when the band A is selected, the optical filter 261E functions as an IR filter capable of imaging only the first passing (transmission) region TWBI1 in the visible light wavelength band (visible region) of about 380 to 700 nm. .
When the band B is selected, only the second transmission (transmission) area TWB 12 having an infrared light wavelength band (infrared area) of about 850 to 1000 nm functions as an IR filter that can be imaged.
When the band C1 is selected, a first transmission (transmission) region TWBI1 of about 380 to 700 nm in a visible light wavelength band (visible region) and a second transmission (transmission of about 850 to 1000 nm in an infrared light wavelength band (infrared region) ) Functions as an IR filter capable of simultaneously imaging the region TWB12.

  According to the sixth embodiment, the light wavelength band to be imaged can be selected with the minimum number of optical filters (IR filters).

Seventh Embodiment
FIG. 20 is a simplified cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to the seventh embodiment.
FIG. 21 is a diagram showing the transmission characteristics of the color filter array and the optical filter according to the seventh embodiment.

  In FIG. 21, the horizontal axis indicates the wavelength, and the vertical axis indicates the QE (quantization efficiency). Further, in FIG. 21, TC21 indicates the transmission characteristics of the first optical filter 261F that functions as an on lid dual band pass filter and as an infrared (IR) filter. TC22 shows the transmission characteristic of the 2nd optical filter 262F which functions as an on-chip IR cut filter.

The seventh embodiment is different from the sixth embodiment in the following points.
In the seventh embodiment, the second optical filter 262F, which is a selective infrared filter, is formed of a selective infrared (IR) cut filter that blocks transmission of the infrared light wavelength band.

  According to the seventh embodiment, the configuration in which the IR filter of the optical system and the IR cut filter of the on-chip are combined can be realized as R, G, B pixels, and the optical filter (IR It can be selected by the number of filters).

Eighth Embodiment
FIG. 22 is a simplified cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to the eighth embodiment.
FIG. 23 is a view showing the transmission characteristics of the color filter array and the optical filter according to the eighth embodiment.

  In FIG. 23, the horizontal axis indicates the wavelength, and the vertical axis indicates the QE (quantization efficiency). Also, in FIG. 23, TC 31 indicates the transmission characteristics of the first optical filter 261G that functions as an on lid dual band pass filter and as an infrared (IR) filter. TC32 shows the transmission characteristic of the 2nd optical filter 262G which functions as an on-chip IR pass filter.

The eighth embodiment is different from the sixth embodiment in the following points.
In the eighth embodiment, the second optical filter 262G, which is a selective infrared filter, is formed of a selective infrared (IR) pass filter that transmits the infrared light wavelength band.
In addition, according to the eighth embodiment, each FLT of the filter array 220G is formed of a clear filter FLT-C that transmits the entire visible wavelength band.

  According to the eighth embodiment, the configuration in which the IR filter of the optical system and the on-chip IR pass filter are combined can be realized as NIR pixels, and the number of optical filters (IR filters) having a minimum light wavelength band desired to be captured Can be selected.

Ninth Embodiment
FIG. 24 is a simplified cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to the ninth embodiment.
FIG. 25 is a diagram showing transmission characteristics of the color filter array and the optical filter according to the ninth embodiment.

  In FIG. 25, the horizontal axis indicates the wavelength, and the vertical axis indicates the QE (quantization efficiency). Further, in FIG. 25, the TC 41 functions as an on lid dual band pass filter and shows the transmission characteristic of the first optical filter 261 H functioning as an infrared (IR) filter. There is.

The difference of the ninth embodiment from the sixth embodiment is as follows.
In the ninth embodiment, each FLT of the second optical filter 262H that is a selective infrared filter and the filter array 220H is formed of a clear filter FLT-C that transmits the entire visible wavelength band. There is.

  According to the ninth embodiment, a configuration combining an IR filter of an optical system and an IR pass filter of an on-chip can be realized as a black and white pixel and an NIR pixel, and an optical filter (IR filter having a minimum light wavelength band desired to be imaged) Can be selected by the number of

Tenth Embodiment
FIG. 26 is a schematic cross-sectional view showing a schematic configuration example of a solid-state imaging device (CMOS image sensor) according to the tenth embodiment.
FIG. 27 is a view showing the transmission characteristics of the color filter array and the optical filter according to the tenth embodiment.

The tenth embodiment is different from the fourth embodiment in the following points.
In the tenth embodiment, in the optical filter group 260I, the third optical filter 263 is disposed on the light incident side of each of the red filter FLR-R, the green filter FLT-G, and the blue filter FLT-B. It is possible.
For example, a second infrared cut filter 262I is formed on the on-chip of a CMOS image sensor (CIS), and the first optical filter 261 or (/ and) the third of the CIS glass lid or the optical lens system is formed. Optical filter 263 is formed.

In FIG. 27, the curve indicated by the broken line TC1 indicates the transmission characteristic of the first optical filter 261, the curve indicated by the thick solid line TC2 indicates the transmission characteristic of the second optical filter 262, and the curve indicated by the thick solid line TC3 is the third. The transmission characteristics of the optical filter 263 of FIG.
In the example of FIG. 27, the passing wavelength band of the third optical filter 263 is, for example, a wavelength band of about 380 nm to 950 nm which is wider than the visible region of about 380 nm to 780 nm.

  In the tenth embodiment, a first light receiving mode for receiving only visible light by switching light receiving wavelengths of a plurality of optical filters (for example, by switching a combination of a plurality of optical filters) and infrared light It is possible to switch to a second light receiving mode capable of receiving incident light including light.

In the tenth embodiment, for example, in the first light receiving mode in which only visible light is received, imaging by the second optical filter 262 and the third optical filter 263 is performed.
In the second light receiving mode capable of receiving incident light including infrared light, imaging with the first optical filter 261 and the second optical filter 262 is performed.

  According to the tenth embodiment, it is possible not only to obtain the same effect as that of the fourth embodiment described above, but also to obtain an RGB image and an NIR image without crosstalk.

  The solid-state imaging devices 10, 10A to 10I described above can be applied as imaging devices to electronic devices such as digital cameras, video cameras, portable terminals, surveillance cameras, and medical endoscope cameras.

  FIG. 28 is a view showing an example of the configuration of an electronic apparatus equipped with a camera system to which the solid-state imaging device according to the embodiment of the present invention is applied.

As illustrated in FIG. 28, the electronic device 100 includes a CMOS image sensor 110 to which the solid-state imaging device 10 according to the present embodiment can be applied.
Further, the electronic device 100 has an optical system (lens or the like) 120 for guiding incident light to the pixel area of the CMOS image sensor 110 (forming an object image).
The electronic device 100 includes a signal processing circuit (PRC) 130 that processes an output signal of the CMOS image sensor 110.

The signal processing circuit 130 performs predetermined signal processing on the output signal of the CMOS image sensor 110.
The image signal processed by the signal processing circuit 130 can be displayed as a moving image on a monitor including a liquid crystal display or the like, or can be output to a printer, or can be recorded directly on a recording medium such as a memory card. Is possible.

As described above, by mounting the solid-state imaging devices 10 and 10A to 10I described above as the CMOS image sensor 110, it is possible to provide a high-performance, small-sized, low-cost camera system.
And, electronic equipment such as surveillance cameras, medical endoscope cameras, etc. used for applications where restrictions on the mounting size, number of connectable cables, cable length, installation height etc. are required for camera installation requirements Can be realized.

  10, 10A to 10I: solid-state imaging device, 20: pixel portion, PXL11, PXL12, PXL21, PXL22: pixel, PD11, PD12, PD21, PD22: photodiode, 200, 200A, 200C 200I: unit RGB pixel group, 200B: unit RGBIR pixel group, 210: microlens array, 220: color filter array, 220G, 220H: filter array, 230: photodiode array 240: flat layer 250: semiconductor substrate 260: optical filter group 261, 261D to 261I: first optical filter 262, 262D to 262I: second optical filter , 263 ... third optical filter, 30 ... vertical scanning circuit, 40 · · Horizontal scanning circuit, 50 · · · readout circuit, 60 · · · timing control circuit, 70 · · · readout unit, 100 · · · electronic equipment, 110 · · · · CMOS image sensor, 120 · · · optical system, 130: Signal processing circuit (PRC).

Claims (25)

A pixel unit in which a unit pixel group including at least a plurality of pixels for visible light which performs photoelectric conversion is disposed;
And a reading unit for reading a pixel signal from the pixel unit.
The plurality of pixels for visible light have photosensitivity to infrared light,
The reading unit is
In the infrared readout mode, it is possible to add signals of infrared light read out from the plurality of pixels for visible light. Solid-state imaging device. The solid-state imaging device according to claim 1, wherein a wavelength of the infrared light is 800 nm or more. The reading unit is
The solid-state imaging device according to claim 1, wherein a color pixel signal in a visible region and an infrared pixel signal in an infrared region can be simultaneously read out in parallel from the pixels for visible light. The solid-state imaging device according to claim 3, wherein the infrared pixel signal is a signal in a near-infrared region having a wavelength of 800 nm or less. The pixel unit is
A unit pixel group including a plurality of pixels for visible light is disposed;
The unit pixel group is
It has a function of photoelectrically converting light incident from one side, and includes a plurality of photoelectric conversion units corresponding to the plurality of visible light wavelength bands,
The plurality of photoelectric conversion units are
A red photoelectric conversion unit corresponding to a red region, a green photoelectric conversion unit corresponding to a green region, and a blue photoelectric conversion unit corresponding to a blue green region;
The reading unit is
In the first mode, it is possible to output the signals read from the red photoelectric conversion unit, the green photoelectric conversion unit, and the blue photoelectric conversion unit as they are,
In the second mode including the infrared readout mode, the signals read from the red photoelectric conversion unit, the green photoelectric conversion unit, and the blue photoelectric conversion unit can be added. The solid-state imaging device according to claim 1. The pixel unit is
A unit pixel group including the plurality of pixels for visible light and an infrared dedicated pixel for receiving infrared light;
The infrared readout mode is
A first pixel signal readout mode for reading out an infrared pixel signal from the infrared dedicated pixel;
A second pixel signal readout mode for reading out an infrared pixel signal from the infrared dedicated pixel and the pixel for visible light;
A third pixel signal readout mode for reading out an infrared pixel signal from the pixel for visible light;
The solid-state imaging device according to claim 1, further comprising: a fourth pixel signal readout mode in which an infrared pixel signal read out from the infrared dedicated pixel and the pixel for visible light is added. The reading unit is
At least two pixel signal readout modes are switched among the first pixel signal readout mode, the second pixel signal readout mode, the third pixel signal readout mode, and the fourth pixel signal readout mode. The solid-state imaging device according to claim 6, wherein it is possible to read out a pixel signal according to. The unit pixel group is
It has a function of photoelectrically converting light incident from one side, and includes a plurality of photoelectric conversion units corresponding to the plurality of visible light wavelength bands,
The plurality of photoelectric conversion units are
A red photoelectric conversion unit corresponding to a red region, a green photoelectric conversion unit corresponding to a green region, a blue photoelectric conversion unit corresponding to a blue-green region, and an infrared photoelectric conversion unit corresponding to an infrared region;
The reading unit is
In the first mode, it is possible to output the signals read from the red photoelectric conversion unit, the green photoelectric conversion unit, and the blue photoelectric conversion unit as they are,
In the second mode including the infrared readout mode, it is possible to add the signals read from the red photoelectric conversion unit, the green photoelectric conversion unit, the blue photoelectric conversion unit, and the infrared photoelectric conversion unit. The solid-state imaging device according to claim 6. The unit pixel group is
The solid-state imaging device according to any one of claims 1 to 5, comprising a plurality of optical filters capable of receiving visible light and infrared light of a specific wavelength. The solid-state imaging device according to claim 9, wherein the specific infrared wavelength is 800 nm to 1000 nm. The solid-state imaging device according to claim 9, wherein at least one optical filter among the plurality of optical filters is capable of switching a light reception wavelength. The solid-state imaging device according to any one of claims 9 to 11, wherein at least one optical filter among the plurality of optical filters is disposed on the light incident side of a photoelectric conversion unit that performs photoelectric conversion. By switching the light receiving wavelength of the plurality of optical filters, it is possible to switch between a first light receiving mode that receives only visible light and a second light receiving mode that can receive incident light including infrared light. Item 13. The solid-state imaging device according to any one of items 9 to 12. The solid-state imaging device according to any one of claims 9 to 13, wherein the plurality of optical filters are shifted in passing wavelength band. The unit pixel group is
A filter array in which a plurality of filters for visible light are arranged;
It has a function of photoelectrically converting light transmitted through the filters disposed on one side, and includes a plurality of visible light photoelectric conversion units corresponding to the plurality of filters,
The optical filter is
A first optical filter disposed on the light incident side of the color filter;
The solid-state imaging device according to any one of claims 9 to 14, comprising: a second optical filter disposed on a light incident side of the plurality of photoelectric conversion units. The first optical filter is formed by an infrared filter.
The second optical filter is formed by an on-chip selective infrared filter,
The solid-state imaging device according to claim 15, wherein the infrared filter forming the first optical filter transmits a plurality of light wavelength bands. The solid-state imaging device according to claim 16, wherein at least one of the plurality of light wavelength bands is a visible light wavelength band or an infrared light wavelength band. When optically shielding between the plurality of light wavelength bands, an infrared filter forming the first optical filter or a second optical filter on the on-chip is formed at the cutoff wavelength of the light shielding wavelength band end The solid-state imaging device according to claim 16 or 17, which is determined by the selective infrared filter. The solid-state imaging device according to any one of claims 16 to 18, wherein the selective infrared filter is formed by a selective infrared cut filter that blocks transmission of an infrared light wavelength band. The selective infrared filter is formed by a selective infrared pass filter transmitting an infrared light wavelength band,
The solid-state imaging device according to any one of claims 16 to 18, wherein the filters of the filter array are formed by a clear filter that transmits at least the entire visible wavelength band. The solid-state imaging device according to any one of claims 16 to 18, wherein the selective infrared filter and the filter of the filter array are formed by a clear filter that transmits at least an entire visible wavelength band. The plurality of optical filters are
Further including a third optical filter disposed on the light incident side of the color filter,
In a first light reception mode for receiving only visible light, imaging is performed by the second optical filter and the third optical filter,
The solid-state imaging device according to claim 15, wherein in the second light receiving mode capable of receiving incident light including infrared light, imaging with the first optical filter and the second optical filter is performed. The plurality of photoelectric conversion units are
A red photoelectric conversion unit corresponding to a red region, a green photoelectric conversion unit corresponding to a green region, and a blue photoelectric conversion unit corresponding to a blue green region;
The solid-state imaging device according to any one of claims 15 to 19, 22. It has a pixel section in which a unit pixel group including at least a plurality of pixels for visible light to be subjected to photoelectric conversion is disposed,
The plurality of pixels for visible light may have a light receiving sensitivity to infrared light.
In the infrared readout mode, signals of infrared light are read out from the plurality of pixels for visible light, and the read out signals of infrared light are added. A solid-state imaging device,
An optical system for forming an object image on the solid-state imaging device;
The solid-state imaging device is
A pixel unit in which a unit pixel group including at least a plurality of pixels for visible light which performs photoelectric conversion is disposed;
And a reading unit for reading a pixel signal from the pixel unit.
The plurality of pixels for visible light have photosensitivity to infrared light,
The reading unit is
In the infrared readout mode, it is possible to add infrared light signals read out from the plurality of pixels for visible light.

Images