KR20150118885A - Unit pixel of an image sensor and image sensor including the same - Google Patents

Abstract

A unit pixel of an image sensor includes a visible light detection pixel and an infrared light detection pixel. The visible light detection pixel transforms visible light irradiated from the outside into a first charge by using a photoelectric conversion device and generates a first electrical signal corresponding to the first charge deposition. The infrared light detection pixel transforms infrared light irradiated from the outside into a second charge by using an infrared light detection layer including infrared light detection materials between an upper electrode and a lower electrode. At this time, the infrared light adsorption amount of the infrared light detection layer is adjusted based on a bias by a first voltage applied to the upper electrode and a second voltage applied to the lower electrode.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a unit pixel of an image sensor,

The present invention relates to an image sensor, and more particularly, to a unit pixel of an image sensor capable of detecting visible light and infrared rays, and an image sensor including the unit pixel.

An image sensor is a semiconductor device that detects light reflected by a subject and converts the light into an electrical signal, and is widely used in electronic devices such as digital cameras and mobile phones. Such an image sensor is divided into a charge coupled device (CCD) image sensor and a complementary metal oxide semiconductor (CMOS) image sensor. The image sensor is low in manufacturing cost, consumes less power, This easy-to-use CMOS image sensor is getting more attention. In recent years, efforts have been made to generate not only image signals in the visible light region but also image signals in the infrared region using one image sensor.

It is an object of the present invention to provide a method and apparatus for generating an image signal in a visible light region with a visible light detection pixel and an image signal in an infrared light region (or near infrared region) The unit pixel of the image sensor capable of determining whether the infrared detection pixel is activated or not and capable of adjusting the sensitivity of the infrared detection pixel.

Another object of the present invention is to provide an image sensor capable of outputting a high-quality image by including the unit pixel.

In order to accomplish one object of the present invention, a unit pixel of an image sensor according to embodiments of the present invention converts a visible light incident from the outside into a first charge using a photoelectric conversion element, And an infrared detection layer including an infrared detection material between the upper electrode and the lower electrode to convert the incident infrared rays into a second electric charge, And an infrared detection pixel for generating a second electrical signal corresponding to an accumulated amount of two charges. At this time, the infrared absorption amount of the infrared detection layer may be adjusted based on a bias by a first voltage applied to the upper electrode and a second voltage applied to the lower electrode.

According to an embodiment, the photoelectric conversion element may correspond to a photodiode.

According to one embodiment, the infrared detecting material may include an organic material, a quantum dot, or a III-V compound.

According to an embodiment, the visible light detection pixel and the infrared detection pixel may be disposed adjacent to each other within the unit pixel.

According to an embodiment, the infrared detection pixels in the unit pixel may be stacked on top of the visible light detection pixels.

According to an embodiment, the infrared detection pixel may operate as an infrared cut filter for the visible light detection pixel.

According to an embodiment, if the bias is greater than a predetermined mode switching reference value, the infrared detection pixel is activated, and if the bias is below the mode switching reference value, the infrared detection pixel may be inactivated.

According to an embodiment, when the bias is larger than the mode switching reference value, the infrared absorption amount increases as the bias increases, and the infrared absorption amount decreases as the bias decreases.

According to an embodiment, when the bias is larger than the mode switching reference value, a visible light image may be generated by a sum of the first electrical signal and the second electrical signal.

According to an embodiment, when the bias is less than or equal to the mode switching reference value, the visible light image may be generated based only on the first electrical signal.

According to another aspect of the present invention, there is provided an image sensor comprising: a pixel array including a plurality of unit pixels each having a visible ray detection pixel and an infrared ray detection pixel whose infrared ray absorption amount is adjusted; An analog-to-digital converter section for converting an analog signal, which is an electrical signal outputted from the analog-digital converter, into a digital signal, a digital signal processor section for performing digital signal processing on the digital signal to output an image signal, A converter unit and a controller for controlling the digital signal processor unit.

According to one embodiment, the visible light detection pixel may convert visible light into a first electrical charge using a photoelectric conversion element, and generate a first electrical signal corresponding to an accumulation amount of the first electrical charge. The infrared detecting pixel includes an infrared detecting layer including an infrared detecting material between an upper electrode and a lower electrode and converts infrared rays into a second electric charge using the infrared detecting layer, A corresponding second electrical signal can be generated. Furthermore, the infrared absorption amount may be adjusted based on a bias by a first voltage applied to the upper electrode and a second voltage applied to the lower electrode.

According to an embodiment, the photoelectric conversion element corresponds to a photodiode, and the infrared detecting material may include an organic material, a quantum dot, or a III-V compound. .

According to an embodiment, in each of the unit pixels, the visible light detection pixel and the infrared detection pixel may be disposed adjacent to each other.

According to an embodiment, in each of the unit pixels, the infrared detection pixels may be stacked on top of the visible light detection pixels.

According to an embodiment, the infrared detection pixel may operate as an infrared cut filter for the visible light detection pixel.

According to an embodiment, if the bias is greater than a predetermined mode switching reference value, the infrared detection pixel is activated, and if the bias is below the mode switching reference value, the infrared detection pixel may be inactivated.

According to an embodiment, when the bias is larger than the mode switching reference value, the infrared absorption amount increases as the bias increases, and the infrared absorption amount decreases as the bias decreases.

According to an embodiment, when the bias is larger than the mode switching reference value, a visible light image is generated by a sum of the first electrical signal and the second electrical signal, and when the bias is equal to or less than the mode switching reference value, The visible light image may be generated based only on the first electrical signal.

According to an embodiment, if the external illuminance is greater than a predetermined reference illuminance, the bias is set to be equal to or less than the mode change reference value, and if the external illuminance is less than the reference illuminance, the bias can be set to be larger than the mode change reference value .

The unit pixel of the image sensor according to the embodiments of the present invention generates an image signal in a visible light region with a visible light detection pixel and generates an image signal in an infrared region with an infrared detection pixel, The infrared detection pixel can be inactivated in the dual mode of the image sensor and the sensitivity of the infrared detection pixel can be adjusted in the dual mode of the image sensor.

An image sensor according to embodiments of the present invention can provide a high-quality image (e.g., a visible light image) to a user by including the unit pixel.

It should be understood, however, that the effects of the present invention are not limited to the above-described effects, but may be variously modified without departing from the spirit and scope of the present invention.

1 is a block diagram illustrating an image sensor in accordance with embodiments of the present invention.
2 is a view showing an example of a unit pixel included in the image sensor of FIG.
3 is a cross-sectional view of the unit pixel of FIG. 2 taken along line A'-A '.
4 is a view showing another example of the unit pixel included in the image sensor of FIG.
5 is a cross-sectional view of the unit pixel of FIG. 4 taken along the line B'-B ''.
6 is a diagram showing another example of the unit pixel included in the image sensor of FIG.
FIG. 7 is a cross-sectional view of the unit pixel of FIG. 6 taken along line C'-C ''.
8 is a view showing another example of the unit pixel included in the image sensor of FIG.
FIG. 9 is a cross-sectional view of the unit pixel of FIG. 8 taken along line D'-D ".
10A is a circuit diagram showing subpixels in a unit pixel included in the image sensor of FIG.
10B is a cross-sectional view showing an example in which the subpixel of FIG. 10A is a visible light detection pixel.
10C is a cross-sectional view showing an example in which the subpixel of FIG. 10A is an infrared detection pixel.
11 is a flowchart showing an example in which unit pixels included in the image sensor of FIG. 1 generate a first electrical signal and a second electrical signal.
12 is a circuit diagram showing an example in which subpixels in a unit pixel included in the image sensor of FIG. 1 are provided with signal generating circuits, respectively.
13 is a flowchart showing another example in which unit pixels included in the image sensor of FIG. 1 generate a first electrical signal and a second electrical signal.
14 is a circuit diagram showing an example in which subpixels share a signal generation circuit in a unit pixel included in the image sensor of FIG.
15 is a view showing an operation mode of the image sensor of FIG.
16 is a diagram showing an example in which a bias is applied to an infrared detection pixel in a unit pixel included in the image sensor of FIG.
FIG. 17 is a graph illustrating an example in which an infrared ray absorption amount (or an infrared ray light reception amount) is adjusted based on a bias applied to an infrared ray detection pixel in a unit pixel included in the image sensor of FIG.
FIG. 18 is a flowchart showing an example in which the image sensor of FIG. 1 determines an operation mode according to external illuminance.
19 and 20 are graphs showing the principle of improving the sensitivity of a unit pixel included in the image sensor of FIG. 1 in the dual mode of the image sensor.
21 is a flowchart illustrating an infrared noise removing method for an image sensor according to embodiments of the present invention.
22 is a diagram showing a pixel array of an image sensor to which the infrared noise removing method of FIG. 21 is applied.
23 is a diagram showing a filter structure of a unit pixel included in the pixel array of Fig.
FIG. 24 is a graph showing the operation of the dual bandpass filter in the filter structure of FIG. 23. FIG.
25A is a graph showing the operation of the visible light blocking filter in the filter structure of FIG. 23. FIG.
FIG. 25B is a graph showing the operation of the infrared cut filter in the filter structure of FIG. 23. FIG.
26 is a block diagram showing an electronic apparatus according to embodiments of the present invention.
27 is a diagram showing an example in which the electronic device of Fig. 26 is implemented as a smart phone.
FIG. 28 is a flowchart showing an example in which an image sensor provided in the electronic apparatus of FIG. 26 detects infrared rays.
29 is a flowchart showing another example in which the image sensor provided in the electronic apparatus of Fig. 26 detects infrared rays.
30 is a block diagram showing an example of an interface used in the electronic apparatus of Fig.

For the embodiments of the invention disclosed herein, specific structural and functional descriptions are set forth for the purpose of describing an embodiment of the invention only, and it is to be understood that the embodiments of the invention may be practiced in various forms, The present invention should not be construed as limited to the embodiments described in Figs.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms may be used for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprise", "having", and the like are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be construed as meaning consistent with meaning in the context of the relevant art and are not to be construed as ideal or overly formal in meaning unless expressly defined in the present application .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same constituent elements in the drawings, and redundant description of the same constituent elements will be omitted.

1 is a block diagram illustrating an image sensor in accordance with embodiments of the present invention.

1, the image sensor 100 includes a pixel array 120, an analog-to-digital converter (ADC) unit 140, a digital signal processor (DSP) unit 160, And a controller 180 for controlling them.

The pixel array 120 may include row and column lines connected to the unit pixels 122 and the unit pixels 122. For example, the unit pixels 122 may be arranged in a matrix form in the pixel array 120 as the row lines and the column lines are wired crossing each other. At this time, each of the unit pixels 122 has a structure in which an infrared detection layer is stacked on top of the visible light detection layer, so that the image signal in the visible light region and the infrared region (or near infrared region) The image signal in the wavelength region of m or more can be generated without mutual crosstalk. That is, each of the unit pixels 122 may have a laminated structure in which a visible light detecting pixel and an infrared detecting pixel are stacked and arranged. Depending on the embodiment, the row lines and column lines in the pixel array 120 may be provided separately for the visible light detection pixels and the infrared detection pixels, and may be shared by the visible light detection pixels and the infrared detection pixels. The visible light detection pixel may include a photoelectric conversion portion and may include a signal generation circuit that generates an electrical signal corresponding to an amount of accumulated charge of the visible light. At this time, the photoelectric conversion portion of the visible light detection pixel may be a photoelectric conversion element or a visible light detection layer made of a visible light detection material and a charge storage element connected thereto. Further, the infrared detection pixel may include a photoelectric conversion section and may include a signal generation circuit which generates an electrical signal corresponding to an accumulation amount of the electric charges converted by the infrared rays. At this time, the photoelectric conversion unit of the infrared detection pixel may be an infrared detection layer made of an infrared ray detection material and a charge storage element connected thereto.

In one embodiment, the visible light detection pixel and the infrared detection pixel may each comprise a signal generation circuit. In this case, the visible light detection pixel and the infrared light detection pixel can respectively generate an electrical signal corresponding to the accumulated amount of the electric charges converted by the visible light and an electric signal corresponding to the accumulation amount of the infrared-converted electric charge. Accordingly, an electrical signal corresponding to the accumulated amount of the electric charges converted by the visible light and an electric signal corresponding to the accumulated amount of the electric charges converted by the infrared light can be generated simultaneously or sequentially. In another embodiment, the visible light detection pixel and the infrared detection pixel may share a signal generation circuit. In this case, the visible light detection pixel and the infrared light detection pixel can sequentially generate an electrical signal corresponding to the accumulated amount of the electric charge converted by the visible light and an electric signal corresponding to the accumulated amount of the infrared-converted electric charge.

As described above, each of the unit pixels 122 may have a structure in which an infrared detection layer is stacked on the upper portion of the visible light detection layer. In one embodiment, each of the unit pixels 122 may include a visible light detection layer including a color filter layer and a silicon layer, and an infrared detection layer stacked on top of the visible light detection layer. The visible light detection layer can convert visible light incident from the outside through the color filter layer into a first electric charge using a photoelectric conversion element formed on the silicon layer. For example, the photoelectric conversion element may be a photodiode. The infrared detecting layer includes an infrared detecting material between the upper electrode and the lower electrode, and infrared rays incident from the outside can be converted into a second electric charge using an infrared detecting material. For example, the infrared detection material may comprise an organic material, a quantum dot or a III-V compound. At this time, the silicon layer may include a charge storage element electrically connected to the infrared detection layer through the color filter layer in the periphery of the photoelectric conversion element. For example, the charge storage device may be an n + doped region within a p-type silicon region. In accordance with an embodiment, each of the unit pixels 122 may further include a microlens layer stacked on top of the infrared detection layer and guiding infrared and visible light to the infrared detection layer and the visible light detection layer. On the other hand, when the image sensor 100 employs a Bayer pattern technique, the color filter layer includes a first color filter, a second color filter, and a third color filter, and the first color filter, And the third color filter may be disposed in the form of a Bayer pattern on the color filter layer. In one embodiment, the first color filter corresponds to a green filter, the second color filter corresponds to a red filter, and the third color filter may correspond to a blue filter. In another embodiment, the first color filter corresponds to a magenta filter, the second color filter corresponds to a yellow filter, and the third color filter may correspond to a cyan filter.

In another embodiment, each of the unit pixels 122 includes a first visible light detection layer that includes a color filter layer and a silicon layer, a second visible light detection layer that is layered on top of the first visible light detection layer, And an infrared ray detection layer laminated on the light ray detection layer. Specifically, the first visible light detection layer can convert the first visible light incident from the outside through the color filter layer into the first electric charge by using the photoelectric conversion element formed on the silicon layer. For example, the photoelectric conversion element may be a photodiode. The second visible light detecting layer may include a visible light detecting material between the upper electrode and the lower electrode and convert a second visible light incident from the outside into a second electric charge using a visible light detecting material. For example, the visible light detection material may comprise an organic material, a quantum dot or a Group 3-5 compound. The infrared detecting layer includes an infrared detecting material between the upper electrode and the lower electrode, and infrared rays incident from the outside can be converted into a third electric charge using an infrared detecting material. For example, the infrared detection material may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the silicon layer passes through the color filter layer and the first charge storage element electrically connected to the second visible light detection layer around the photoelectric conversion element, and passes through the color filter layer and the second visible light detection layer, And a second charge storage element coupled to the second charge storage element. For example, the first and second charge storage elements may be n + doped regions within the p-type silicon region. According to an embodiment, each of the unit pixels 122 is stacked on top of an infrared detection layer and infrared rays, a first visible light and a second visible light are transmitted through the infrared detection layer, the first visible light detection layer and the second visible light detection layer And a microlens layer guiding the microlenses.

In another embodiment, each of the unit pixels 122 includes a first visible light detection layer, a second visible light detection layer that is deposited on top of the first visible light detection layer, and a second visible light detection layer that is layered on top of the second visible light detection layer A third visible light detection layer, an infrared detection layer stacked on top of the third visible light detection layer, and a silicon layer. Specifically, the first visible light detecting layer includes a first visible light detecting material between the upper electrode and the lower electrode, and converts a first visible light incident from the outside into a first electric charge by using a first visible light detecting material can do. For example, the first visible light detecting material may comprise an organic material, a quantum dot or a Group 3-5 compound. The second visible light detection layer may include a second visible light detection material between the upper electrode and the lower electrode and convert a second visible light incident from the outside into a second charge using a second visible light detection material . For example, the second visible light detecting material may comprise an organic material, a quantum dot or a Group 3-5 compound. The third visible light detection layer may include a third visible light detection material between the upper electrode and the lower electrode and may convert a third visible light incident from the outside into a third charge using a third visible light detection material . For example, the third visible light detecting material may comprise an organic material, a quantum dot or a Group 3-5 compound. The infrared detecting layer includes an infrared detecting material between the upper electrode and the lower electrode, and the infrared rays incident from the outside can be converted into the fourth electric charges using the infrared detecting material. For example, the infrared detection material may comprise an organic material, a quantum dot or a Group 3-5 compound. The silicon layer includes a first charge storage element electrically connected to the first visible light detection layer, a second charge storage element electrically connected to the second visible light detection layer through the first visible light detection layer, And a third charge storage element electrically connected to the third visible light detection layer through the second visible light detection layer and a second charge storage element electrically connected to the third visible light detection layer through the first visible light detection layer, the second visible light detection layer, and the third visible light detection layer And a fourth charge storage element electrically connected to the infrared detection layer. For example, the first through fourth charge storage elements may be n + doped regions within a p-type silicon region. According to the embodiment, each of the unit pixels 122 is stacked on top of the infrared detection layer, and the infrared light, the first visible light, the second visible light and the third visible light are reflected by the infrared detection layer, the first visible light detection layer, And a microlens layer guiding the first visible light ray detection layer, the second visible ray detection layer and the third visible ray detection layer.

The analog-to-digital converter unit 140 may convert an analog signal, which is an electrical signal output from the pixel array 120, into a digital signal. To this end, the analog-to-digital converter unit 140 may include a plurality of analog-to-digital converters. The analog-to-digital converter unit 140 can convert an electrical signal, i.e., a first analog signal, corresponding to an accumulated amount of charges converted by the visible light output from the pixel array 120 into a first digital signal, The second analog signal corresponding to the accumulation amount of the electric charges converted by the infrared ray outputted from the infrared sensor 120 may be converted into the second digital signal. In one embodiment, the analog-to-digital converter 140 sequentially receives a first analog signal corresponding to the accumulated amount of charge converted by the visible light and a second analog signal corresponding to the accumulated amount of the infrared- Signal and a second digital signal (i.e., labeled as a sequential ADC). In another embodiment, the analog-to-digital converter section 140 includes a first analog-to-digital converter section for converting a first analog signal corresponding to a stored amount of charge of the visible light into a first digital signal, And a second analog-to-digital converter unit for converting the second analog signal corresponding to the accumulation amount of the first digital signal into the second digital signal, thereby generating the first digital signal and the second digital signal, respectively, . According to an embodiment, the analog-to-digital converter unit 140 may include a correlated double sampling (CDS) unit for extracting a valid signal component. In one embodiment, the correlated double sampling unit may perform analog double sampling, which extracts the valid signal components based on the difference between the reset output signal representing the reset component and the analog signal representing the signal component. In another embodiment, the correlated double sampling unit may perform digital double sampling, which converts the reset output signal and the analog signal into digital signals, respectively, and then extracts the difference between the two digital signals as an effective signal component . In yet another embodiment, the correlated double sampling unit may perform dual correlated double sampling, which performs both analog double sampling and digital double sampling.

The digital signal processor 160 may perform digital signal processing on the digital signal to output an image signal. That is, the digital signal processor unit 160 may receive the digital signal from the analog-to-digital converter unit 140 and perform digital signal processing on the digital signal. For example, the digital signal processor 160 may perform image interpolation, color correction, white balance, gamma correction, color conversion, and the like . According to an embodiment, the digital signal output from the analog-to-digital converter unit 140 may be amplified by an amplifier circuit and then provided to the digital signal processor unit 160. [ In one embodiment, the digital signal processor portion 160 performs digital signal processing on the first digital signal associated with the stored amount of charge of the visible light to output a first image signal, and stores the accumulated amount of charge And output the second image signal by performing digital signal processing on the second digital signal associated with the second digital signal. That is, the digital signal processor 160 may separately output the first image signal and the second image signal. In this case, the second image signal output from the image sensor 100 may be used for a predetermined purpose (for example, iris recognition, etc.). In another embodiment, the digital signal processor 160 may compensate for the first digital signal associated with the accumulated amount of charge that the visible light has converted based on the second digital signal associated with the accumulated amount of charge of the infrared-converted charge. For example, the digital signal processor 160 may remove the infrared noise from the first digital signal associated with the stored amount of charge of the converted visible light based on the second digital signal associated with the accumulated amount of charge of the infrared- The image quality of the image outputted from the image sensor 100 can be improved by compensating the first digital signal related to the accumulation amount of the charge of the visible light converted into the second digital signal related to the accumulated amount of the infrared converted infrared light. Although the digital signal processor unit 160 is shown in FIG. 1 as being included in the image sensor 100, according to an embodiment, the digital signal processor unit 160 may be located outside the image sensor 100 have.

The controller 180 may control the pixel array 120, the analog-to-digital converter section 140 and the digital signal processor section 160 (i.e., denoted CTL1, CTL2, CTL3). To this end, the controller 180 may generate various signals such as a clock signal, a timing control signal, etc. required for the operation of the pixel array 120, the analog-digital converter section 140 and the digital signal processor section 160 . However, the controller 180 is schematically shown in Fig. For example, the controller 180 includes a vertical scanning circuit for controlling the row address and row scan of the pixel array 120, a column address of the pixel array 120, A horizontal scanning circuit for controlling a column scan, a voltage generating circuit for generating a plurality of voltages used in the analog-to-digital converter 140 (for example, a logic control circuit, a phase locked loop (Phase Lock Loop (PLL) circuit, a timing control circuit, a communication interface circuit, etc.). As such, the image sensor 100 includes a unit pixel 122 having a structure in which an infrared ray detection layer is stacked on top of the visible ray detection layer, thereby providing a high quality image (i.e., a visible ray image and / or an infrared image) Can be provided. In this regard, the structure of each unit pixel 122 included in the image sensor 100 will be described later in detail with reference to FIG. 2 to FIG.

FIG. 2 is a view showing an example of the unit pixel included in the image sensor of FIG. 1, and FIG. 3 is a sectional view of the unit pixel of FIG. 2 taken along line A'-A ".

Referring to FIGS. 2 and 3, a unit pixel 122a included in the image sensor 100 is shown. Specifically, the unit pixel 122a may include an infrared detection layer IDL stacked on the visible light detection layer VDL and the visible light detection layer VDL. At this time, as shown in FIG. 2, the unit pixel 122a may be divided into a first planar region to a fourth planar region.

In recent years, efforts have been made to detect infrared rays with an image sensor to perform various functions (for example, iris recognition, tomography, color image dynamic range improvement, etc.). To this end, a Back-Side Illuminated (BSI) CMOS image sensor has been used in the past, but the infrared sensor has not been able to efficiently detect infrared rays due to its small amount of infrared absorption. To overcome this problem, if the infrared detection region of the image sensor is widened, it is difficult to realize the high resolution of the image sensor due to the size restriction. If the thickness of the epitaxial layer is increased, the image sensor may not operate normally. Accordingly, the unit pixel 122a has a structure in which the infrared ray detection layer IDL is laminated on the upper portion of the visible light detection layer VDL, thereby reducing the problem (i.e., the amount of infrared absorption in the silicon layer is small) Problems). Specifically, the unit pixel 122a is formed by stacking an infrared detection layer (IDL) including an organic material, a quantum dot, or a Group 3-5 compound that causes photoelectric conversion in the infrared region, on the upper portion of the visible light detection layer VDL And the first to third color filters are arranged in a Bayer pattern in a color filter layer (CFL) included in the visible light detection layer (VDL). Thus, the presence of the infrared detection layer IDL in the unit pixel 122a does not give any influence (for example, area reduction) to the visible light detection layer VDL, so that the unit pixel 122a is visible in the visible light region And the image signal in the infrared region can be generated without mutual crosstalk. Thus, the unit pixel 122a can maximize the light receiving area by having the structure in which the infrared ray detection layer IDL is laminated on the upper portion of the visible light detection layer VDL, thereby allowing the image sensor 100 to have a high It is possible to output a visible light image having a resolution and an infrared image having a high resolution. On the other hand, since the infrared detection layer IDL laminated on the upper part of the visible light detection layer VDL has a high infrared absorption amount, the infrared detection layer IDL in the unit pixel 122a can be used for the visible light detection layer VDL It can be used as an IR cut filter. As a result, the unit pixel 122a does not need to have a separate infrared cutoff filter for the visible light detection layer VDL. Hereinafter, the unit pixel 122a will be described in detail with reference to FIGS. 2 and 3. FIG.

The visible light detection layer VDL includes a color filter layer CFL and a silicon layer SIL and a visible light incident from outside through the color filter layer CFL is formed on the photoelectric conversion element PD formed on the silicon layer SIL. The first charge can be converted into the first charge. For example, the photoelectric conversion element PD may be a photodiode. 3, the insulating layer BL may be disposed on the silicon layer SIL in the visible light detecting layer VDL, and the color filter layer CFL may be disposed on the insulating layer BL have. For example, the insulating layer BL may include oxide or may include oxide and nitride. The color filter layer CFL may also include a planarizing layer PL disposed on top of the color filters B-CF and G-CF and the color filters B-CF and G-CF. For example, the planarizing layer PL may comprise an acrylic or epoxy material. However, this is merely an example, and the structure of the visible light detecting layer VDL is not limited to the structure shown in Fig. The visible light detection layer VDL includes a first color filter for detecting a visible light incident through the first color filter of the color filter layer CFL, a visible light detection area for detecting visible light incident through the second color filter of the color filter layer CFL, A second color filter for detecting visible light, and a third color filter visible light detecting area for detecting visible light incident through the third color filter of the color filter layer (CFL). At this time, the first color filter visible light detection area is arranged in two planar areas out of the first planar area to the fourth planar area of the unit pixel 122a, and the second color filter visible light detection area is arranged in the unit pixel 122a ), And the third color filter visible light detection area is arranged in one planar area out of the first planar area to the fourth planar area of the unit pixel 122a . 2, the visible light detection layer VDL includes a blue light detection area 126-1 for detecting a visible light (i.e., blue light) incident through a blue filter of the color filter layer CFL, Green light detection areas 126-2 and 126-3 for detecting visible light (that is, green light) incident through the green filter of the color filter layer CFL and visible light rays And a red light detection area 126-4 for detecting red light (i.e., red light). That is, the green light detection areas 126-2 and 126-3 correspond to the visible light detection area of the first color filter, the blue light detection area 126-1 and the red light detection area 126-4 correspond to the visible light detection area, And may correspond to the light detection area and the visible light detection area of the third color filter, respectively. 2, the green light detection areas 126-2 and 126-3 occupy 50% of the total area of the unit pixels 122a in consideration of the visual characteristic that human eyes are most sensitive to green, The area 126-1 and the red light detection area 126-4 occupy 25% of the total area of the unit pixel 122a. However, the first through third The arrangement of the color filter visible light detection areas is not limited to the arrangement shown in Fig.

The infrared detection layer (IDL) may be laminated on top of the visible light detection layer (VDL). The infrared detecting layer IDL includes an infrared detecting material IRM between the upper electrode FE and the lower electrode SE and converts infrared rays incident from the outside into a second electric charge using an infrared detecting material IRM can do. For example, an infrared detection material (IRM) may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the infrared ray absorbing amount of the infrared ray detecting layer IDL can be adjusted based on the bias by the first voltage applied to the upper electrode FE and the second voltage applied to the lower electrode SE. As shown in FIG. 2, the infrared detection layer IDL includes a first infrared detection area 124-1, a second infrared detection area 124-2, a third infrared detection area 124-3, And an infrared detection area 124-4. The first infrared detection area 124-1, the second infrared detection area 124-2, the third infrared detection area 124-3, and the fourth infrared detection area 124-4 are unit pixels The second planar region, the third planar region, and the fourth planar region of the first planar region 122a. For example, the first infrared detection region 124-1 may be disposed in the first planar region of the unit pixel 122a and disposed above the blue light detection region 126-1, and may be disposed in the second infrared detection region 124-2 may be disposed in the second planar region of the unit pixel 122a and disposed above the green light detection region 126-2 and the third infrared detection region 124-3 may be disposed in the unit pixel 122a, And the fourth infrared detection area 124-4 may be disposed in the fourth planar area of the unit pixel 122a and may be disposed in the third planar area of the unit pixel 122a to be located above the green light detection area 126-3, May be disposed on top of the region 126-4. The silicon layer SIL may include a charge storage element SD electrically connected to the infrared detection layer IDL through the color filter layer CFL in the periphery of the photoelectric conversion element PD. For example, the charge storage device SD may be an n + doped region in the p-type silicon region SM. 3, the infrared detection layer IDL is divided into the first infrared detection area 124-1, the second infrared detection area 124-2, the third infrared detection area 124-3, The charge storage element SD is distributed and arranged in the first planar region, the second planar region, the third planar region, and the fourth planar region of the unit pixel 122a, The first infrared detection area 124-1, the second infrared detection area 124-2, the third infrared detection area 124-3, and the fourth infrared detection area 124-4, respectively.

In one embodiment, the silicon layer (SIL) comprises a first signal generation circuit coupled to the photoelectric conversion device (PD) to generate a first electrical signal corresponding to an accumulated amount of the first charge converted by the visible light and a second signal generation circuit SD), and generates a second electrical signal corresponding to an accumulation amount of the second electrical charge converted by the infrared ray. In this case, the first signal generation circuit and the second signal generation circuit may be respectively connected to the photoelectric conversion element PD and the charge storage element SD to generate the first electrical signal and the second electrical signal, respectively. Accordingly, the second electrical signal corresponding to the accumulation amount of the first electrical signal corresponding to the accumulation amount of the first charge converted by the visible light and the second electrical charge converted by the infrared light can be generated simultaneously or sequentially. In another embodiment, the silicon layer (SIL) comprises a first electrical signal coupled in common to the photoelectric conversion element (PD) and the charge storage element (SD) to provide a first electrical signal corresponding to the accumulated amount of the first electrical charge converted by the visible light, And a signal generating circuit for sequentially generating a second electrical signal corresponding to the accumulated amount of the second charge. In this case, the signal generating circuit generates a first electrical signal corresponding to the accumulation amount of the first charge converted by the visible light, and then generates a second electrical signal corresponding to the accumulation amount of the second electrical charge converted by the infrared light, A second electrical signal corresponding to the accumulated amount of the second charge may be generated and then a first electrical signal corresponding to the accumulation amount of the first charge converted by the visible light may be generated.

According to an embodiment, the unit pixel 122a may further include a microlens layer MLL for guiding infrared rays and visible rays to the infrared ray detection layer IDL and the visible ray detection layer VDL. At this time, the microlens layer MLL includes a plurality of microlenses ML and may be stacked on top of the infrared detection layer IDL. However, if it is not necessary to guide the infrared rays to the infrared detection layer IDL in the unit pixel 122a, the microlens layer MLL may be positioned below the infrared detection layer IDL. As described above, since the unit pixel 122a has a structure in which the infrared ray detection layer IDL and the visible light detection layer VDL are laminated, the unit pixel 122a can prevent the image sensor 100 from generating a visible light image with high resolution, To output an infrared image having an infrared ray. For example, in a conventional unit pixel having a structure in which infrared detection pixels and visible light detection pixels are arranged on the same layer, one infrared detection area, one red light detection area, one green light detection area, and one blue light detection area However, in the unit pixel 122a, there may exist four infrared detection regions, one red light detection region, two green light detection regions, and one blue light detection region. As a result, the unit pixel 122a can generate more image information than the conventional unit pixel.

FIG. 4 is a view showing another example of the unit pixel included in the image sensor of FIG. 1, and FIG. 5 is a sectional view of the unit pixel of FIG. 4 taken along line B'-B ''.

Referring to FIGS. 4 and 5, a unit pixel 122b included in the image sensor 100 is shown. Specifically, the unit pixel 122b may include an infrared detection layer IDL stacked on the visible light detection layer VDL and the visible light detection layer VDL. At this time, as shown in FIG. 4, the unit pixel 122b may be divided into a first planar area to a fourth planar area.

The visible light detection layer VDL includes a color filter layer CFL and a silicon layer SIL and a visible light incident from outside through the color filter layer CFL is formed on the photoelectric conversion element PD formed on the silicon layer SIL. The first charge can be converted into the first charge. For example, the photoelectric conversion element PD may be a photodiode. 5, the insulating layer BL may be disposed on the silicon layer SIL in the visible light detecting layer VDL and the color filter layer CFL may be disposed on the insulating layer BL have. For example, the insulating layer BL may include an oxide or may include an oxide and a nitride. In addition, the color filter layer CFL may include a planarizing layer PL disposed on top of the color filters R-CF and the color filters R-CF. For example, the planarizing layer PL may comprise an acrylic or epoxy material. However, this is merely an example, and the structure of the visible light detection layer (VDL) is not limited to the structure shown in Fig. The visible light detection layer VDL includes a first color filter for detecting a visible light incident through the first color filter of the color filter layer CFL, a visible light detection area for detecting visible light incident through the second color filter of the color filter layer CFL, A second color filter for detecting visible light, and a third color filter visible light detecting area for detecting visible light incident through the third color filter of the color filter layer (CFL). At this time, the first color filter visible light detection area is arranged in one planar area from the first planar area to the fourth planar area of the unit pixel 122b, and the second color filter visible light detection area is arranged in the unit pixel 122b, And the third color filter visible light detection area is disposed in one planar area out of the first planar area to the fourth planar area of the unit pixel 122b . 4, the visible light detection layer VDL includes a blue light detection area 127-1 for detecting visible light (i.e., blue light) incident through the blue filter of the color filter layer CFL, A green light detection area 127-2 for detecting a visible light (that is, green light) incident through the green filter of the color filter layer CFL, and a visible light (that is, red light And a red light detection area 127-3 that detects the red light detection area 127-3. In other words, the blue light detection area 127-1, the green light detection area 127-2, and the red light detection area 127-3 are arranged in such a manner that the first color filter visible light detection area, the second color filter visible light detection area, Color filter visible light detection area, respectively. However, the arrangement of the first to third color filter visible light detection areas included in the visible light detection layer (VDL) is not limited to the arrangement shown in Fig.

The infrared detection layer (IDL) may be laminated on top of the visible light detection layer (VDL). The infrared detecting layer IDL includes an infrared detecting material IRM between the upper electrode FE and the lower electrode SE and converts infrared rays incident from the outside into a second electric charge using an infrared detecting material IRM can do. For example, an infrared detection material (IRM) may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the infrared ray absorbing amount of the infrared ray detecting layer IDL can be adjusted based on the bias by the first voltage applied to the upper electrode FE and the second voltage applied to the lower electrode SE. 4, the infrared detection layer IDL includes one infrared detection area 124, and one infrared detection area 124 includes a first planar area of the unit pixel 122b, And may be disposed throughout the planar region. The silicon layer SIL may include a charge storage element SD electrically connected to the infrared detection layer IDL through the color filter layer CFL in the periphery of the photoelectric conversion element PD. For example, the charge storage device SD may be an n + doped region in the p-type silicon region SM. 4, when the infrared detection layer IDL includes one infrared detection area 124, the charge storage element SD is divided into a first planar area to a fourth planar area of the unit pixel 122b, And may be electrically connected to the infrared detection region 124. [0034] FIG. That is, since the second charge generated in the infrared detection region 124 having an area corresponding to the entire area of the unit pixel 122b must be stored, the size of the charge storage element SD must be relatively large. Therefore, one planar region out of the first to fourth planar regions of the unit pixel 122b is allocated to the dedicated region 127-4 (IRC) for the charge storage element SD. In one embodiment, the silicon layer (SIL) comprises a first signal generation circuit coupled to the photoelectric conversion device (PD) to generate a first electrical signal corresponding to an accumulated amount of the first charge converted by the visible light and a second signal generation circuit SD), and generates a second electrical signal corresponding to an accumulation amount of the second electrical charge converted by the infrared ray. In another embodiment, the silicon layer (SIL) comprises a first electrical signal coupled in common to the photoelectric conversion element (PD) and the charge storage element (SD) to provide a first electrical signal corresponding to the accumulated amount of the first electrical charge converted by the visible light, And a signal generating circuit for sequentially generating a second electrical signal corresponding to the accumulated amount of the second charge.

According to an embodiment, the unit pixel 122b may further include a microlens layer MLL for guiding infrared rays and visible rays to the infrared ray detection layer IDL and the visible ray detection layer VDL. At this time, the microlens layer MLL includes a plurality of microlenses ML and may be stacked on top of the infrared detection layer IDL. However, when it is not necessary to guide the infrared rays to the infrared detection layer IDL in the unit pixel 122b, the microlens layer MLL may be positioned below the infrared detection layer IDL. Thus, the unit pixel 122b has a structure in which the infrared ray detection layer IDL is laminated on the visible light detection layer VDL, so that the image signal in the visible light region and the image signal in the infrared region are transmitted to each other It can be generated without crosstalk. Since the unit pixel 122b has a structure in which the infrared detection layer IDL and the visible light detection layer VDL are laminated, the influence of the presence of the infrared detection layer IDL on the visible light detection layer VDL For example, area reduction, etc.), the image sensor 100 can generate a visible light image with high resolution and an infrared image with high resolution. On the other hand, since the infrared detection layer IDL laminated on the upper part of the visible light detection layer VDL has a high infrared absorption amount, the infrared detection layer IDL in the unit pixel 122b has a high absorption coefficient for the visible light detection layer VDL It can be used as an infrared cut filter. Therefore, the unit pixel 122b does not need to have a separate infrared cut-off filter for the visible light detection layer VDL.

FIG. 6 is a view showing another example of the unit pixel included in the image sensor of FIG. 1, and FIG. 7 is a sectional view of the unit pixel of FIG. 6 taken along the line C'-C ".

Referring to FIGS. 6 and 7, the unit pixel 122c included in the image sensor 100 is shown. Specifically, the unit pixel 122c includes a first visible light detection layer (VDL1), a second visible light detection layer (VDL2) stacked on top of the first visible light detection layer (VDL1), and a second visible light detection layer And an infrared detection layer (IDL) laminated on the upper portion of the second electrode layer (VDL2). At this time, as shown in FIG. 6, the unit pixel 122c may be divided into a first planar area to a fourth planar area.

The first visible light detection layer VDL1 includes a color filter layer CFL and a silicon layer SIL and forms a first visible light incident from outside through the color filter layer CFL through a photoelectric conversion It can be converted into the first electric charge by using the element PD. For example, the photoelectric conversion element PD may be a photodiode. 7, the insulating layer BL1 is disposed on the upper portion of the silicon layer SIL in the first visible light detecting layer VDL1, the color filter layer CFL is disposed on the upper portion of the insulating layer BL1, . For example, the insulating layer BL1 may include an oxide or may include an oxide and a nitride. The color filter layer CFL may also include a planarizing layer PL disposed on top of the color filters B-CF and R-CF and the color filters B-CF and R-CF. For example, the planarizing layer PL may comprise an acrylic or epoxy material. However, this is an example, and the structure of the first visible light detection layer VDL1 is not limited to the structure shown in Fig. The first visible light detection layer VDL1 includes a first color filter for detecting a first visible light incident through the first color filter of the color filter layer CFL and a second color filter for detecting visible light incident on the second color filter And a second color filter visible light detection area that detects a first visible light incident through the first color filter. At this time, the first color filter visible light detection area is arranged in two planar areas out of the first planar area to the fourth planar area of the unit pixel 122c, and the second color filter visible light detection area is arranged in the unit pixel 122c Of the first planar region to the fourth planar region of the first planar region. 6, the first visible light detection layer VDL1 includes a blue light detection area (for example, blue light detection area) for detecting a first visible light (i.e., blue light) incident through a blue filter of the color filter layer CFL 132-1 and 132-4 that detect the first visible light (i.e., red light) incident through the red filter of the color filter layer CFL, and the red light detection areas 132-2 and 132-3 that detect the first visible light . In other words, the blue light detection areas 132-1 and 132-4 and the red light detection areas 132-2 and 132-3 correspond to the visible light detection area of the first color filter and the visible light detection area of the second color filter, respectively . However, the arrangement of the first and second color filter visible light detection regions included in the first visible light detection layer VDL1 is not limited to the arrangement shown in Fig.

The second visible light detecting layer VDL2 is laminated on the first visible light detecting layer VDL1 and includes a visible light detecting material GM between the upper electrode FE1 and the lower electrode SE1, The second visible light can be converted into the second electric charge by using the visible light detection material GM. For example, the visible light detection material (GM) may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the visible light absorption amount of the visible light detection layer VDL2 can be adjusted based on the bias by the first voltage applied to the upper electrode FE1 and the second voltage applied to the lower electrode SE1. As shown in FIG. 6, the second visible light detection layer VDL2 includes a first non-color filter visible light detection area 130-1, a second non-color filter visible light detection area 130-2, Color filter visible light detection area 130-3 and a fourth non-color filter visible light detection area 130-4, wherein the first non-color filter visible light detection area 130-1, the second non- The filter visible light detection area 130-2, the third non-color filter visible light detection area 130-3 and the fourth non-color filter visible light detection area 130-4 are arranged in the first plane of the unit pixel 122c Region, the second planar region, the third planar region, and the fourth planar region, respectively. The silicon layer SIL may include a first charge storage element SD1 electrically connected to the second visible light detection layer VDL2 through the color filter layer CFL in the periphery of the photoelectric conversion element PD have. For example, the first charge storage element SD1 may be an n + type doped region in the p-type silicon region SM. As shown in Fig. 6, the second visible light detection layer VDL2 is divided into the first non-color filter visible light detection region 130-1, the second non-color filter visible light detection region 130-2, Color filter visible light detection area 130-3 and a fourth non-color filter visible light detection area 130-4, the first charge storage element SD1 is divided into a first plane Color filter visible light detection area 130-1, the second non-color filter visible light detection area 130-2, and the second non-color filter visible light distribution area 130-1 dispersed in the first planar area, the second planar area, the third planar area, The third non-color filter visible light detection area 130-3 and the fourth non-color filter visible light detection area 130-4, respectively.

The infrared detection layer IDL may be laminated on the second visible light detection layer VDL2. An insulating layer BL2 may be disposed between the infrared detection layer IDL and the second visible light detection layer VDL2. For example, the insulating layer BL2 may include an oxide or may include an oxide and a nitride. The infrared detecting layer IDL includes an infrared detecting material IRM between the upper electrode FE2 and the lower electrode SE2 and converts infrared rays incident from the outside into a third electric charge using an infrared detecting material IRM can do. For example, an infrared detection material (IRM) may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the infrared absorption amount of the infrared detection layer IDL can be adjusted based on the bias by the first voltage applied to the upper electrode FE2 and the second voltage applied to the lower electrode SE2. As shown in Fig. 6, the infrared detection layer IDL includes a first infrared detection area 124-1, a second infrared detection area 124-2, a third infrared detection area 124-3, And an infrared detection area 124-4. The first infrared detection area 124-1, the second infrared detection area 124-2, the third infrared detection area 124-3, The second planar region 124-4 may be respectively disposed in the first planar region, the second planar region, the third planar region, and the fourth planar region of the unit pixel 122c. For example, the first infrared detection region 124-1 may be disposed in the first planar region of the unit pixel 122c, and the second infrared detection region 124-2 may be disposed in the second planar region of the unit pixel 122c. The third infrared detection area 124-3 may be disposed in the third planar area of the unit pixel 122c and the fourth infrared detection area 124-4 may be disposed in the planar area and the unit pixel 122c In the fourth planar region of FIG. On the other hand, the silicon layer (SIL) includes a second charge storage element (IDL) electrically connected to the infrared detection layer (IDL) through the color filter layer (CFL) and the second visible light detection layer (VDL2) (SD2). For example, the second charge storage element SD2 may be an n + type doped region in the p-type silicon region SM. As shown in FIG. 6, the infrared detection layer IDL includes the first infrared detection area 124-1, the second infrared detection area 124-2, the third infrared detection area 124-3, The second charge storage element SD2 is distributed and arranged in the first planar region, the second planar region, the third planar region, and the fourth planar region of the unit pixel 122c, Can be electrically connected to the first infrared detection area 124-1, the second infrared detection area 124-2, the third infrared detection area 124-3 and the fourth infrared detection area 124-4, respectively. have.

According to the embodiment, the unit pixel 122c may be formed by a combination of infrared rays, a first visible light ray and a second visible light ray as the infrared ray detection layer IDL, the first visible light ray detection layer VDL1 and the second visible light ray detection layer VDL2 And may further include a micro lens layer (MLL) for guiding light. At this time, the microlens layer MLL includes a plurality of microlenses ML and may be stacked on top of the infrared detection layer IDL. However, when it is not necessary to guide the infrared ray to the infrared detection layer IDL in the unit pixel 122c, the microlens layer MLL may be positioned below the infrared detection layer IDL. Thus, the unit pixel 122c has a structure in which the infrared detection layer IDL is laminated on the first and second visible light detection layers VDL1 and VDL2, so that the image signal in the visible light region and the infrared light The image signal in the region can be generated without mutual crosstalk. Since the unit pixel 122c has a structure in which the infrared detection layer IDL and the first and second visible light detection layers VDL1 and VDL2 are laminated, (E.g., area reduction, etc.) to the second visible light detection layers VDL1 and VDL2, the image sensor 100 generates a visible light image with high resolution and an infrared image with high resolution can do. On the other hand, in FIG. 6, the green light detection areas 132-1, ..., and 132-4 correspond to the blue light detection areas 124-1 and 124-4 in consideration of the visual characteristic that human eyes are most sensitive to green, And the red light detection areas 124-2 and 124-3, the structure of the unit pixel 122c is not limited to the structure shown in FIG. Although the first and second charge storage elements SD1 and SD2 are shown as being distributed in the first to fourth planar regions of the unit pixel 122c in FIG. 6, the unit pixels 122c, A portion of the first to fourth planar regions of the first charge storage element SD1 and / or the second charge storage element SD2 may be allocated as a dedicated region for the first charge storage element SD1 and / or the second charge storage element SD2.

FIG. 8 is a view showing another example of the unit pixel included in the image sensor of FIG. 1, and FIG. 9 is a sectional view of the unit pixel of FIG. 8 taken along line D'-D ".

8 and 9, a unit pixel 122d included in the image sensor 100 is shown. Specifically, the unit pixel 122d includes a first visible light detection layer VDL1, a second visible light detection layer VDL2 stacked on top of the first visible light detection layer VDL1, a second visible light detection layer A third visible light detection layer VDL3 stacked on the third visible light detection layer VDL2 and an infrared detection layer IDL stacked on the third visible light detection layer VDL3.

The first visible light detection layer VDL1 may be stacked on top of the silicon layer SIL. An insulating layer BL1 may be disposed between the silicon layer SIL and the first visible light detection layer VDL1. For example, the insulating layer BL1 may include an oxide or may include an oxide and a nitride. The first visible light detection layer VDL1 includes a first visible light detection material RM between the upper electrode FE1 and the lower electrode SE1 and the first visible light incident from the outside is referred to as a first visible light detection Can be converted to the first charge using the material RM. For example, the first visible light detection material RM may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the visible light absorption amount of the first visible light detection layer VDL1 can be adjusted based on the bias by the first voltage applied to the upper electrode FE1 and the second voltage applied to the lower electrode SE1 . The second visible light detection layer (VDL2) may be laminated on the first visible light detection layer (VDL1). An insulating layer BL2 may be disposed between the first visible light detection layer VDL1 and the second visible light detection layer VDL2. For example, the insulating layer BL2 may include an oxide or may include an oxide and a nitride. The second visible light detection layer VDL2 includes a second visible light detection material BM between the upper electrode FE2 and the lower electrode SE2 and a second visible light incident from the outside is referred to as a second visible light detection Can be converted into a second charge using a material (BM). For example, the second visible light detecting material (BM) may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the visible light absorption amount of the second visible light detection layer VDL2 can be adjusted based on the bias by the first voltage applied to the upper electrode FE2 and the second voltage applied to the lower electrode SE2 . And the third visible light detection layer VDL3 may be laminated on the second visible light detection layer VDL2. An insulating layer BL3 may be disposed between the second visible light detection layer VDL2 and the third visible light detection layer VDL3. For example, the insulating layer BL3 may include an oxide or may include an oxide and a nitride. The third visible light detection layer VDL3 includes a third visible light detection material GM between the upper electrode FE3 and the lower electrode SE3 and the third visible light incident from the outside is referred to as a third visible light detection Can be converted to a third charge using a material (GM). For example, the third visible light detection material (GM) may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the visible light absorption amount of the third visible light detection layer VDL3 can be adjusted based on the bias by the first voltage applied to the upper electrode FE3 and the second voltage applied to the lower electrode SE3 . As described above, in the unit pixel 122d, the first through third visible light detection layers VDL1, VDL2, and VDL3 are formed by using the organic material, the quantum dot, or the 3-5 group compound, not the photoelectric conversion element, It is possible to detect visible rays, respectively.

The infrared detection layer (IDL) may be laminated on the third visible light detection layer (VDL3). An insulating layer BL4 may be disposed between the third visible light detection layer VDL3 and the infrared detection layer IDL. For example, the insulating layer BL4 may include oxides or may include oxides and nitrides. The infrared detecting layer IDL includes an infrared detecting material IRM between the upper electrode FE4 and the lower electrode SE4 and converts infrared rays incident from the outside into a fourth electric charge by using an infrared detecting material IRM can do. For example, an infrared detection material (IRM) may comprise an organic material, a quantum dot or a Group 3-5 compound. At this time, the infrared absorption amount of the infrared detection layer IDL can be adjusted based on the bias by the first voltage applied to the upper electrode FE4 and the second voltage applied to the lower electrode SE4. The silicon layer SIL includes a first charge storage element SD1 electrically connected to the first visible light detection layer VDL1 and a second charge storage element SD1 electrically connected to the second visible light detection layer VDL1 through the first visible light detection layer VDL1. A second charge storage element SD2 electrically connected to the third visible light detection layer VDL3 through the first visible light detection layer VDL1 and the second visible light detection layer VDL2, 3 electrically connected to the infrared detection layer IDL through the charge storage element SD3 and the first visible light detection layer VDL1, the second visible light detection layer VDL2 and the third visible light detection layer VDL3 And a fourth charge storage element SD4. For example, the first to fourth charge storage elements SD1, SD2, SD3, SD4 may be n + type doped regions in the p-type silicon region SM, respectively.

According to an embodiment, the unit pixel 122d may include infrared light, a first visible light, a second visible light, and a third visible light to an infrared detection layer IDL, a first visible light detection layer VDL1, Layer MLL that guides the light to the third visible light detection layer VDL2 and the third visible light detection layer VDL3. At this time, the microlens layer MLL includes a plurality of microlenses ML and may be stacked on top of the infrared detection layer IDL. However, when it is not necessary to guide the infrared ray to the infrared detection layer IDL in the unit pixel 122d, the microlens layer MLL may be positioned below the infrared detection layer IDL. Thus, the unit pixel 122d has a structure in which the infrared detection layer IDL is laminated on the first to third visible light detection layers VDL1, VDL2 and VDL3, so that the image signal in the visible light region And the image signals in the infrared region can be generated without mutual crosstalk. In addition, since the unit pixel 122d has a structure in which the infrared detection layer IDL and the first through third visible light detection layers VDL1, VDL2 and VDL3 are laminated, the presence of the infrared detection layer IDL (E.g., area reduction, etc.) to the first through third visible light detection layers VDL1, VDL2, and VDL3, the image sensor 100 can detect both the high resolution visible light image signal and the high resolution infrared Images can be generated. 9, the first through third visible light detection layers VDL1, VDL2, and VDL3 are each used to detect the first through third visible rays using an organic material, a quantum dot, or a Group 3-5 compound However, according to the embodiment, a portion of the first through third visible light detection layers VDL1, VDL2, and VDL3 includes a color filter layer, so that the first through third visible light beams .

10A is a circuit diagram showing subpixels in a unit pixel included in the image sensor of FIG.

10A, a sub-pixel 200 (i.e., an infrared detection pixel and a visible light detection pixel) within a unit pixel 122 includes a photoelectric conversion unit LECD and a plurality of transistors TX, RX, DX, SX ). The subpixel 200 may have a 1-transistor structure, a 3-transistor structure, a 4-transistor structure, or a 5-transistor structure depending on the number of transistors. For convenience of description, Transistor structure will be described.

The plurality of transistors TX, RX, DX and SX may comprise a transfer transistor TX, a reset transistor RX, a sensing transistor DX and a selection transistor SX. Further, a floating diffusion node FD may be formed by a capacitor (not shown) at a second terminal of the transfer transistor TX. Specifically, the transfer transistor TX has a gate terminal to which a transfer signal TG is input, a first terminal to which a photoelectric conversion section LECD is connected, and a second terminal to which a floating diffusion node FD is connected. The reset transistor RX has a gate terminal connected to a reset signal RS and a first terminal connected to the floating diffusion node FD and a second terminal connected to the high voltage VDD. The sensing transistor DX may have a gate terminal connected to the floating diffusion node FD and a first terminal connected to the second terminal of the selection transistor SX and a second terminal connected to the high voltage VDD . The selection transistor SX may have a row selection signal SEL input to its gate terminal, a first terminal connected to the output terminal OUT and a second terminal connected to the first terminal of the sensing transistor DX. The photoelectric conversion unit LECD may correspond to a photoelectric conversion element (for example, a photodiode) when the subpixel 200 is a visible light detection pixel, and the infrared detection layer And a charge storage element electrically connected thereto. On the other hand, the photoelectric conversion unit LECD may be located between the transfer transistor TX and the low power supply voltage GND.

In operation of the sub-pixel 200, the photoelectric conversion unit LECD can convert visible light or infrared light into electric charges and accumulate them. The transfer transistor TX can be turned on based on the transfer signal TG input to the gate terminal, thereby transferring the accumulated charge to the floating diffusion node FD. At this time, the reset transistor RX maintains the turn-off state, and the potential of the floating diffusion node FD, that is, the gate potential of the sensing transistor DX, can be changed by the accumulated charge. The change in the gate potential of the sensing transistor DX changes the bias of the first terminal of the sensing transistor DX or the second terminal of the selection transistor SX and changes the bias of the row selection signal SEL The electrical signal corresponding to the accumulated charge can be output to the output terminal OUT. The reset transistor RX can be turned on based on the reset signal RS after the electric signal corresponding to the accumulated charge is outputted, thereby enabling the floating diffusion node FD to be initialized. However, the structure and operation of the subpixel 200 are illustrative, and the structure and operation of the subpixel 200 may be variously changed according to the conditions required for the image sensor 100. [

On the other hand, the operation of the subpixel 200 may be different depending on whether the subpixel 200 is an infrared detection pixel or a visible light detection pixel. For example, the operation of the transfer transistor TX in the operation of the sub-pixel 200 may be omitted. Specifically, the sub-pixel 200 may be driven by a so-called 4-transistor operation including the operation in which the transfer transistor TX is turned on or turned off, and the so-called three-transistor operation in which the transfer transistor TX is always turned on - It may be driven by transistor operation. In one embodiment, the subpixel 200 may be driven in a so-called 4-transistor operation if it is an infrared detection pixel and may be driven in a so-called 4-transistor operation if the subpixel 200 is a visible light detection pixel. In another embodiment, the subpixel 200 may be driven in a so-called 3-transistor operation if it is an infrared detection pixel and in a so-called 4-transistor operation if the subpixel 200 is a visible light detection pixel. In yet another embodiment, the subpixel 200 may be driven in a so-called 4-transistor operation if it is an infrared detection pixel and be driven in a so-called 3-transistor operation if the subpixel 200 is a visible light detection pixel. In yet another embodiment, the subpixel 200 may be driven with a so-called 3-transistor operation if it is an infrared detection pixel and a so-called 3-transistor operation if the subpixel 200 is a visible light detection pixel.

10B is a cross-sectional view showing an example in which the subpixel in FIG. 10A is a visible light detection pixel, and FIG. 10C is a sectional view showing an example in which the subpixel in FIG. 10A is an infrared detection pixel.

10B and 10C, active isolation regions 210a and 210b are formed in isolation regions of the semiconductor substrate 280 corresponding to p-type silicon regions in the sub-pixel 200, have. In one embodiment, when the subpixel 200 is a visible light detection pixel, a photoelectric conversion element PD (e.g., a photodiode) may be formed in the semiconductor substrate 280, as shown in FIG. 10B. have. In this case, the photoelectric conversion element PD may be composed of an n-type doped region 263 and a p-type doped region 264. [ In another embodiment, as shown in FIG. 10C, when the sub-pixel 200 is an infrared detection pixel, a charge storage element SD may be formed in the semiconductor substrate 280. In this case, the charge storage element SD may be configured as an n + -type doped region and may be electrically connected to the infrared detection layer IDL of the unit pixel 122. Also, a first n + -type doped region 265, which is a floating diffusion node FD for sensing the accumulated charge, is formed at a position spaced apart from the photoelectric conversion element PD or the charge storage element SD by a predetermined distance . A gate terminal of the transfer transistor TX may be formed on the semiconductor substrate 280 between the photoelectric conversion element PD or the charge storage element SD and the first n + doped region 265, The gate terminal of the reset transistor RX may be formed on the semiconductor substrate 280 between the n + doped region 265 and the second n + doped region 267. Further, a gate terminal of the sensing transistor DX may be formed on the semiconductor substrate 280 between the second n + -type doped region 267 and the third n + -type doped region 269, A gate terminal of the selection transistor SX may be formed on the semiconductor substrate 280 between the region 269 and the fourth n + -type doped region 271. 10A to 10C, a transfer signal TG may be input to the gate terminal of the transfer transistor TX and a reset signal RS may be input to the gate terminal of the reset transistor RX . The gate terminal of the sensing transistor DX may be connected to the first n + doped region 265 which is the floating diffusion node FD and the row select signal SEL may be input to the gate terminal of the select transistor SX .

FIG. 11 is a flowchart showing an example in which a unit pixel included in the image sensor of FIG. 1 generates a first electrical signal and a second electrical signal. FIG. And a signal generating circuit, respectively.

11 and 12, the subpixels 200 of the unit pixel 122, that is, the visible light detection pixel 220 and the infrared detection pixel 240 may each include a signal generation circuit. Specifically, when the unit pixel 122 is exposed to the visible light and infrared rays, the visible light detection pixel 220 and the infrared detection pixel 240 can detect the visible light and the infrared light, respectively (S120). The visible light detection pixel 220 may then output a first electrical signal corresponding to the detected visible light S140 and the infrared detection pixel 240 may output a second electrical signal corresponding to the detected infrared light S160). Since the visible light detection pixel 220 and the infrared light detection pixel 240 each include a signal generation circuit at this time, the visible light detection pixel 220 and the infrared light detection pixel 240 are separated from each other by the first charge The second electrical signal corresponding to the accumulation amount of the first electrical signal corresponding to the accumulation amount of the infrared ray and the second electrical charge converted by the infrared ray, simultaneously or sequentially. The operation of the transfer transistors TX1 and TX2 in the operation of the sub pixel 200 may be omitted depending on whether the sub pixel 200 is the visible light detection pixel 220 or the infrared light detection pixel 240 have. In one embodiment, the visible light detection pixel 220 is driven in a so-called 4-transistor operation, and the infrared detection pixel 240 may be driven in a so-called 4-transistor operation. In another embodiment, the visible light detection pixel 220 is driven in so-called 3-transistor operation, and the infrared detection pixel 240 may be driven in a so-called 4-transistor operation. In yet another embodiment, the visible light detection pixel 220 is driven in a so-called 4-transistor operation, and the infrared detection pixel 240 may be driven in a so-called 3-transistor operation. In yet another embodiment, the visible light detection pixel 220 is driven in a so-called three-transistor operation, and the infrared detection pixel 240 can be driven in a so-called three-transistor operation.

FIG. 13 is a flowchart showing another example in which a unit pixel included in the image sensor of FIG. 1 generates a first electrical signal and a second electrical signal. FIG. And a signal generating circuit are shared.

13 and 14, the subpixels 200 of the unit pixel 122, that is, the visible light detection pixels 222 and 262 and the infrared detection pixels 242 and 262 share the signal generation circuit 262 can do. Specifically, when the unit pixels 122 are exposed to the visible light and infrared rays, the visible light detection pixels 222 and 262 and the infrared detection pixels 242 and 262 can detect the visible light and the infrared light, respectively (S220). Thereafter, the visible light detection pixels 222 and 262 output a first electrical signal corresponding to the detected visible light (S240), and the infrared detection pixels 242 and 262 detect a second electrical signal corresponding to the detected infrared light Output (S260). At this time, since the visible light detection pixels 222 and 262 and the infrared detection pixels 242 and 262 share the signal generation circuit 262, the visible light detection pixels 222 and 262 and the infrared detection pixels 242 and 262 May sequentially generate a second electrical signal corresponding to an accumulation amount of the first electrical signal corresponding to the accumulation amount of the first charge converted by the visible light and the accumulation amount of the second electrical charge converted by the infrared light. In the above description, after the visible light detection pixels 222 and 262 output the first electrical signal corresponding to the detected visible light (S240), the infrared detection pixels 242 and 262 detect the infrared rays corresponding to the detected infrared rays The infrared ray detection pixels 242 and 262 output the second electrical signal corresponding to the detected infrared ray S260 after the infrared ray detection pixels 242 and 262 output the second electrical signal S260. And output a first electrical signal corresponding to the detected visible light (S240). As described above, the operation of the transfer transistors TX1 and TX2 in the operation of the subpixel 200 according to whether the subpixel 200 is the visible light detection pixel 222 or 262 or the infrared detection pixel 242 or 262 Can be omitted. In one embodiment, the visible light detection pixels 222 and 262 are driven in a so-called 4-transistor operation, and the infrared detection pixels 242 and 262 may be driven in a so-called 4-transistor operation. In another embodiment, the visible light detection pixels 222 and 262 may be driven in so-called three-transistor operation and the infrared detection pixels 242 and 262 may be driven in a so-called four-transistor operation. In yet another embodiment, the visible light detection pixels 222 and 262 are driven in so-called 4-transistor operation, and the infrared detection pixels 242 and 262 may be driven in a so-called 3-transistor operation. In yet another embodiment, the visible light detection pixels 222 and 262 are driven in so-called three-transistor operation, and the infrared detection pixels 242 and 262 may be driven in a so-called three-transistor operation.

FIG. 15 is a view showing an operation mode of the image sensor of FIG. 1, FIG. 16 is a diagram showing an example in which a bias is applied to an infrared detection pixel in a unit pixel included in the image sensor of FIG. 1, (Or infrared light receiving amount) is adjusted based on a bias applied to an infrared detection pixel inside a unit pixel included in the image sensor of FIG.

15 to 17, the image sensor 100 may operate in a single mode 320 or a dual mode 340. [ Specifically, the operation of the image sensor 100 in the single mode 320 means that the image sensor 100 produces a color image (i.e., a visible light image) based only on the image signal in the visible light region, The fact that the image sensor 100 operates in the dual mode 340 means that the image sensor 100 generates a color image (i.e., a visible light image) based on the image signal in the visible light region and the image signal in the infrared region . Accordingly, in the single mode 320 of the image sensor 100, the visible light detection pixels of the unit pixel 122 can be activated (i.e., visible light is detected) and the infrared detection pixels of the unit pixel 122 are deactivated That is, does not detect infrared rays). On the other hand, in the dual mode 340 of the image sensor 100, the visible light detection pixel of the unit pixel 122 can be activated (i.e., the visible light is detected), and the infrared detection pixel of the unit pixel 122 can also be activated (I.e., detecting infrared rays).

The unit pixel 122 converts a visible light incident from the outside through the color filter layer CFL into a first charge using a photoelectric conversion element formed in the silicon layer and outputs a first electrical signal corresponding to the accumulation amount of the first charge And a visible light ray detection pixel to be converted and an infrared ray incident from outside are converted into a second electric charge by using an infrared ray detection layer IDL including an infrared ray detection material IRM between the upper electrode FE and the lower electrode SE And an infrared detection pixel for generating a second electrical signal corresponding to an accumulation amount of the second charge. For example, an infrared detection material (IRM) may comprise an organic material, a quantum dot or a Group 3-5 compound. 16, the infrared ray absorbing amount of the infrared ray detecting layer IDL is determined by the first voltage V1 applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE, And the sensitivity of the infrared detection pixel can be adjusted accordingly. On the other hand, the visible light detection pixels may be arranged in the Bayer pattern in the unit pixel 122. [ In one embodiment, within the unit pixel 122, the visible light detection pixel and the infrared detection pixel may be disposed next to each other. That is, it may be a structure in which one visible light detection pixel (for example, G sub-pixel) is replaced with an infrared detection pixel in a conventional unit pixel (i.e., R-G-G-B subpixel combination) consisting only of a visible light detection pixel. In another embodiment, the infrared detection pixels within the unit pixel 122 may be stacked on top of the visible light detection pixels. That is, a structure in which an infrared detection pixel is inserted in the upper portion of a visible light detection pixel in a conventional unit pixel (i.e., an R-G-G-B subpixel combination) consisting only of a visible light detection pixel may be used. In this case, since the infrared detection pixels are stacked on top of the visible light detection pixels, they can operate as an infrared cut filter for visible light detection pixels.

The bias voltage BIAS applied by the first voltage V1 applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE may be set to a predetermined mode switching reference value The infrared detection pixel of the unit pixel 122 can be activated (i.e., indicated by ON-STATE) and the first voltage V1 applied to the upper electrode FE and the first voltage V2 applied to the lower electrode SE The infrared detection pixel of the unit pixel 122 may be deactivated (i.e., indicated as OFF-STATE) if the bias BIAS by the applied second voltage V2 is less than or equal to the predetermined mode switching reference value PMCV. Therefore, when the bias BIAS due to the first voltage V1 applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE is less than or equal to the predetermined mode switching reference value PMCV, The sensor 100 may generate a color image based only on the visible light detected by the visible light detection pixels. That is, the image sensor 100 operates in the single mode 320. On the other hand, when the bias BIAS due to the first voltage V1 applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE is greater than the predetermined mode switching reference value PMCV , The image sensor 100 can generate a color image based on the visible light detected by the visible light detection pixels and the infrared light detected by the infrared detection pixels. That is, the image sensor 100 operates in the dual mode 340. Particularly when the bias BIAS due to the first voltage V1 applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE is greater than the predetermined mode switching reference value PMCV, The greater the amount of bias BIAS due to the first voltage V1 applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE, the more the infrared absorption amount of the infrared detection layer IDL increases, The smaller the bias BIAS caused by the first voltage V1 applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE becomes, the smaller the IR absorption amount of the infrared detection layer IDL becomes . Therefore, when the image sensor 100 is operated in the dual mode 320, the infrared ray absorbing amount (i.e., the infrared ray absorbing amount) of the infrared ray detecting layer IDL is changed according to the conditions (e.g., external illuminance, etc.) required for the image sensor 100 , The sensitivity of the infrared detection pixel) can be adjusted (i.e., indicated as ADJUSTABLE).

As described above, since the conventional unit pixel has the structure including the IR pass filter for the infrared detection pixel, the infrared transmittance of the infrared pass filter can not be controlled. That is, conventional unit pixels can not adjust the sensitivity of the infrared detection pixels or activate and deactivate the infrared detection pixels. On the other hand, in the unit pixel 122, an infrared detection pixel is provided between the upper electrode FE and the lower electrode SE by infrared detection (IRM) including an IRM (i.e., an organic material, a quantum dot or a 3- The bias voltage BIAS applied to the upper electrode FE and the second voltage V2 applied to the lower electrode SE can be adjusted by adjusting the bias voltage BIAS applied to the lower electrode SE, It is possible to adjust the sensitivity of the infrared detection pixels or to activate and deactivate the infrared detection pixels. Therefore, the unit pixel 122 can obtain a color image in which color mixing, noise, and the like are improved by using up to infrared information (that is, an image signal in the infrared region) in generating a color image (i.e., a visible light image). For example, when the external illuminance is relatively high (for example, outdoor or daytime), by deactivating the infrared detection pixel, a high-quality color image can be obtained only by the image signal in the visible light region, and the external illuminance is relatively low A high quality color image can be obtained based on the image signal in the visible light region and the image signal in the infrared region by activating the infrared detection pixel in the case (for example, indoor or night). At this time, the sensitivity of the infrared detection pixel can be adjusted by adjusting the infrared absorption amount of the infrared detection layer (IDL) inside the infrared detection pixel (that is, displayed as ADJUSTABLE). In the above description, the single mode 320 and the dual mode 340 of the image sensor 100 for generating a color image have been described. However, as described with reference to FIGS. 1 to 14, To produce a color image and an infrared image, respectively. For example, when the image sensor 100 operates in an individual mode, an infrared ray image is generated by activating infrared ray detection pixels at the time of infrared ray imaging (for example, iris recognition), and infrared ray detection pixels It may be disabled to not generate an infrared image.

FIG. 18 is a flowchart showing an example in which the image sensor of FIG. 1 determines the operation mode according to the external illuminance, FIGS. 19 and 20 show the sensitivity of the unit pixel included in the image sensor of FIG. 1 in the dual mode of the image sensor These graphs show the principle of improvement.

18 to 20, it is shown that the image sensor 100 determines the operation mode according to external illuminance. Specifically, the image sensor 100 may measure the external illuminance (S310), and then determine whether the external illuminance is greater than a predetermined reference illuminance (S320). At this time, if the external illuminance is greater than the predetermined reference illuminance, the image sensor 100 may operate in a single mode (S330) for generating a color image based on only the image signal in the visible light region. That is, the image sensor 100 may deactivate the infrared detection pixel of the unit pixel 122. [ On the other hand, when the external illuminance is smaller than the preset reference illuminance, the image sensor 100 operates in a dual mode for generating a color image based on the image signal in the visible light region and the image signal in the infrared region (S340) . That is, the image sensor 100 can activate the infrared detection pixel of the unit pixel 122. [ The image sensor 100 may then generate (S350) a color image (i.e., a visible light image) based on the image signal in the visible light region or the image signal in the visible region and the image region in the infrared region . In this way, the image sensor 100 deactivates the infrared detection pixel if the external illuminance is greater than the predetermined reference illuminance, and activates the infrared detection pixel when the external illuminance is smaller than the predetermined reference illuminance (for example, stray light) A clear color image can be obtained. That is, the image sensor 100 can adjust the bias (BIAS) applied to the infrared detection layer IDL in the infrared detection pixel according to the external illuminance, thereby ensuring the optimum imaging condition.

Meanwhile, FIGS. 19 and 20 show the principle that the image sensor 100 obtains a clearer color image by activating the infrared detection pixels when the external illuminance is smaller than the preset reference illuminance. Specifically, when the external illuminance is smaller than the predetermined reference illuminance, the light amount of the visible light is not sufficient, so that the image signal SPS (i.e., the image signal in the visible light region) output from the visible light detection pixel is relatively weak. At this time, when the image sensor 100 generates a color image based only on the image signal SPS in the visible light region, a high-quality color image can not be obtained due to color mixing, noise, or the like. On the other hand, the image signal OPS (i.e., the image signal in the infrared region) output from the infrared detection pixels is not generated at a constant level regardless of the light amount of the visible light, even if the light intensity of the visible light is insufficient because the external illuminance is smaller than the preset reference illuminance Lt; / RTI > Therefore, when the image sensor 100 generates a color image based on the image signal SPS in the visible light region and the image signal OPS in the infrared region, the sum of the image signals SPS and OPS, that is, Since the final image signal (OPS + SPS) becomes considerably strong, a color image with improved color mixing, noise, and the like can be obtained. As described above, if the external illuminance is smaller than the predetermined reference illuminance, the image sensor 100 can improve the sensitivity of the unit pixels 122 by activating the infrared detection pixels. Further, the image sensor 100 adjusts the bias (BIAS) applied to the infrared detection layer IDL of the infrared detection pixel in a state in which the infrared detection pixels of the unit pixel 122 are activated, Can be finely adjusted. For example, as shown in FIG. 20, the bias (BIAS) applied to the infrared detection layer IDL of the infrared detection pixel in the state in which the infrared detection pixels of the unit pixel 122 are activated is VA, VB, The sensitivity of the infrared detection pixel may be increased, and thus the sensitivity of the unit pixel 122 may also be increased.

FIG. 21 is a flowchart showing an infrared noise removing method for an image sensor according to embodiments of the present invention, FIG. 22 is a view showing a pixel array of an image sensor to which the infrared noise removing method of FIG. 21 is applied, 22 is a diagram showing a filter structure of a unit pixel included in the pixel array of Fig. 22. Fig.

21 to 23, in the infrared noise removing method of FIG. 21, the dual bandpass filter 410 is commonly located on the infrared light detecting pixels 440 and the visible light detecting pixels 450, May be applied to the pixel array 400 having a configuration in which the visible ray blocking filter 420 is disposed on the upper portion of the display panel 440 and the infrared ray blocking filter 430 is disposed on the upper portion of the visible ray detecting pixels 450 . Specifically, the infrared noise removing method of FIG. 21 detects infrared components in the infrared detecting pixels IRk (k is an integer equal to or greater than 1) (S420) and detects infrared components detected in the infrared detecting pixels IRk (S440) infrared ray components at visible light detection pixels Ri, Bi, Gi (where i is an integer equal to or greater than 1) based on interpolation with respect to the calculated infrared rays, (S460), it is possible to subtract the value applied with the correction constant from the light component detected in the visible light detection pixels Ri, Bi, Gi (S480). 21, the infrared ray blocking filter 430 does not completely block the infrared ray component, so that the infrared ray component mixed in the light component detected by the visible ray detecting pixels Ri, Bi, Gi is detected by the infrared ray detecting pixel (I.e., an image signal in the infrared region) output from the light source IRk.

The infrared noise removing method of FIG. 21 can detect infrared components in the infrared detecting pixels IRk (S420). 23, a dual bandpass filter 410 and a visible ray blocking filter 420 may be disposed on the infrared detecting pixels 440. [ Although the dual bandpass filter 410 is shown as being located above the visible light blocking filter 420 in Figure 23, the dual bandpass filter 410 may be located below the visible blocking filter 420 . That is, after the visible light component and the infrared component of the incident light are passed by the dual bandpass filter 410, the visible light component can be blocked by the visible light blocking filter 420. Therefore, only the infrared ray component reaches the infrared ray detection pixel 440, so that the infrared ray detection pixel 440 can accurately detect only the infrared ray component. Thereafter, infrared components in the visible light detection pixels Ri, Bi, Gi may be calculated (S440) based on the interpolation of the infrared components detected in the infrared detection pixels IRk. For example, when interpolation is performed on the infrared component detected in one infrared detection pixel IR1 and the infrared component detected in the other infrared detection pixel IR2, the infrared detection pixels IR1, The infrared component in the visible light detection pixel B1 located between the visible light detection pixel B1 and the visible light detection pixel B1 can be calculated. In one embodiment, the infrared component at a particular visible light detection pixel Ri, Bi, Gi may be applied to the infrared components detected at the infrared detection pixels IRk adjacent to the particular visible light detection pixel Ri, Bi, Can be calculated as the interpolation. In another embodiment, the infrared component in the specific visible light detection pixel Ri, Bi, Gi is detected in the infrared detection pixels IRk within a predetermined distance from the specific visible light detection pixel Ri, Bi, Gi Can be computed as an interpolation of the infrared components. However, this is an example, and the range for performing the interpolation may be variously changed. Also, according to the embodiment, noise reduction through kernel ring can be performed at the same time when the interpolation is performed.

Next, the infrared noise removing method of FIG. 21 may apply a correction constant to the calculated infrared components (S460). 23, the dual band-pass filter 410 and the infrared cut-off filter 430 may be disposed on the upper portion of the visible light detection pixels 450. Although the dual bandpass filter 410 is shown as being located above the IR cut filter 430 in FIG. 23, the dual bandpass filter 410 may be located below the IR cut filter 430. That is, after the visible light component and the infrared component of the incident light are transmitted by the dual bandpass filter 410, the infrared component can be blocked by the infrared cut filter 430. Therefore, only the visible light component reaches the visible light detection pixel 450, so that the visible light detection pixel 450 can accurately detect only the visible light component. However, the visible light blocking filter 420 can completely block the visible light component, while the infrared blocking filter 430 can not completely block the infrared component. Therefore, the infrared noise removing method of FIG. 21 applies a correction constant to the calculated infrared components to compensate for the fact that the infrared cut filter 430 does not completely block the infrared component.

The infrared noise removing method of FIG. 21 further includes a step of removing the light component detected in the visible light detection pixels Ri, Bi, Gi (that is, visible light component and the infrared light blocking filter 430) (I.e., a part of the infrared component generated due to the correction factor) (S480). Thus, the infrared noise removing method of FIG. 21 can accurately remove the infrared component, that is, the infrared noise, from the light components detected by the visible light detecting pixels Ri, Bi, Gi. On the other hand, the infrared noise removing method of FIG. 21 can be expressed by the following equation (1).

[Equation 1]

R = (R with IRrc) ?? [f (IRref) * coeff_r]

G = (G with IRgc) ?? [f (IRref) * coeff_g]

B = (B with IRbc) ?? [f (IRref) * coeff_b]

(R with IRrc), (G with IRgc), and (B with IRbc), where R, G, and B are the red light component from which infrared noise is removed, the green light component from which infrared noise is removed, and the blue light component from which infrared noise is removed. ) Is a light component detected by the red light detecting pixel, a light component detected by the green light detecting pixel, and a light component detected by the blue light detecting pixel, IRref is the infrared component detected by the infrared detecting pixel, f is the infrared component detected by the infrared detecting pixel Coeff_r, coeff_g, and coeff_b are correction constants for the red light detection pixels, correction constants for the green light detection pixels, and correction constants for the blue light detection pixels).

In this way, when the image sensor 100 generates the visible light image and the infrared image, due to the performance problem of the infrared cut filter located above the visible light detection pixels Ri, Bi, Gi, (IR) contamination may occur. Therefore, the infrared noise removing method of FIG. 21 eliminates the infrared noise affecting the visible light image based on the information output from the infrared detecting pixel IRk (i.e., the image signal in the infrared region) It is possible to effectively improve the color mixture, noise and the like.

FIG. 24 is a graph showing the operation of the dual bandpass filter in the filter structure of FIG. 23, FIG. 25A is a graph showing the operation of the visible light blocking filter in the filter structure of FIG. 23, And Fig.

24 to 25B, the dual bandpass filter 410, the visible light blocking filter 420, and the infrared blocking filter 430 included in the pixel array 400 to which the infrared noise removing method of FIG. Operation is shown. As described above, the dual bandpass filter 410 and the visible ray blocking filter 420 may be disposed on the infrared detecting pixels 440. 24 and 25A, after the visible light component and the infrared component of the incident light are transmitted by the dual bandpass filter 410, the visible light component is blocked by the visible light blocking filter 420 . As a result, only the infrared component can reach the infrared detection pixel 440. In addition, a dual bandpass filter 410 and an infrared cutoff filter 430 may be disposed on the upper portion of the visible light detection pixels 450. 24 and 25B, after the visible light component and the infrared component of the incident light are transmitted by the dual bandpass filter 410, the infrared component can be blocked by the infrared cut filter 430 . As a result, only the visible light component can reach the visible light detection pixel 450. However, as shown in FIGS. 25A and 25B, the visible light blocking filter 420 can completely block the visible light component, while the infrared blocking filter 430 can not completely block the infrared component. For this reason, in performing the infrared noise removing method of FIG. 21, a correction constant for compensating for the fact that the infrared cut filter 430 can not completely block the infrared component (that is, represented by MPT) is used.

FIG. 26 is a block diagram illustrating an electronic device according to an embodiment of the present invention, and FIG. 27 is a diagram illustrating an example in which the electronic device of FIG. 26 is implemented as a smartphone.

26 and 27, the electronic device 500 includes a processor 510, a memory device 520, a storage device 530, an input / output device 540, a power supply 550, and an image sensor 560 . At this time, the image sensor 560 may correspond to the image sensor 100 of Fig. Further, the electronic device 500 may further include a plurality of ports capable of communicating with a video card, a sound card, a memory card, a USB device, or the like, or communicating with other electronic devices. Meanwhile, as shown in FIG. 27, the electronic device 500 may be implemented as a smart phone.

The processor 510 may perform certain calculations or tasks. The processor 510 may be a microprocessor, a central processing unit (CPU), an application processor (AP), or the like. The processor 510 may be coupled to other components via an address bus, a control bus, and a data bus. In accordance with an embodiment, the processor 510 may also be coupled to an expansion bus, such as a Peripheral Component Interconnect (PCI) bus. The memory device 520 may store data necessary for the operation of the electronic device 500. For example, the memory device 520 may be an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, (PRAM) device, a Resistance Random Access Memory (RRAM) device, a Nano Floating Gate Memory (NFGM) device, a Polymer Random Access Memory (PoRAM) device, a Magnetic Random Volatile memory devices and / or dynamic random access memory (DRAM) devices such as MRAM, Ferroelectric Random Access Memory (MRAM) DRAM devices, and the like. The storage device 530 may include a solid state drive (SSD), a hard disk drive (HDD), a CD-ROM, and the like.

The input / output device 540 may include input means such as a keyboard, a keypad, a touchpad, a touch screen, a mouse, etc., and output means such as a display, a speaker, The power supply 550 can supply power necessary for the operation of the electronic device 500. The image sensor 560 may be coupled to other components via the buses or other communication links. As described above, the image sensor 560 includes a pixel array having unit pixels having a stacked structure in which a visible light detecting pixel and an infrared detecting pixel are stacked and arranged, and an analog signal, which is an electrical signal output from the pixel array, A digital signal processor unit for performing digital signal processing on the digital signal to output an image signal, and a controller for controlling the pixel array, the analog-to-digital converter unit, and the digital signal processor unit. At this time, each of the unit pixels may have a structure in which an infrared detection layer is stacked on an upper portion of the visible light detection layer. As a result, since each of the unit pixels can generate the image signal in the visible light region and the image signal in the infrared region (for example, 0.7 m or more wavelength region) without mutual crosstalk, Can produce high quality visible light images and high quality infrared images. However, since this has been described above, a duplicate description thereof will be omitted.

As described above, the image sensor 560 can operate in a separate mode that basically produces a color image and an infrared image, respectively. However, according to an embodiment, the image sensor 560 may operate in a single mode that produces a color image (i.e., a visible light image) based only on the image signal in the visible light region, And may operate in a dual mode that generates a color image based on the image signal in the infrared region. Therefore, in the single mode of the image sensor 560, the visible light detection pixels inside the unit pixel are activated, and the infrared detection pixels inside the unit pixel can be inactivated. On the other hand, in the dual mode of the image sensor 560, the visible light detection pixels inside the unit pixel are activated, and the infrared detection pixels inside the unit pixels can also be activated (i.e., infrared rays are detected). Further, the image sensor 560 operates in a dual mode that generates a color image based on the image signal in the visible light region and the image signal in the infrared region, so that the infrared light absorption amount of the infrared light detection layer included in the infrared light detection pixel The sensitivity of the infrared detection pixel can be adjusted. In addition, the image sensor 560 solves the problem of mixing color due to infrared noise in the visible light image due to the performance problem of the infrared cut filter located above the visible light detection pixel in generating the visible light image and the infrared image. Noise by affecting crosstalk of an infrared component by removing infrared noise affecting the visible light image on the basis of the information output from the infrared detection pixel (i.e., the image signal in the infrared region) . However, since this has been described above, a duplicate description thereof will be omitted.

Meanwhile, the image sensor 560 can be implemented in various types of packages. For example, at least some configurations of the image sensor 560 may include package on package (PoP), ball grid arrays (BGAs), chip scale packages (CSPs), plastic leaded chip carriers (PDIP), Die in Waffle Pack, Die in Wafer Form, Chip On Board (COB), Ceramic Dual In-Line Package (CERDIP), Plastic Metric Quad Flat Pack (MQFP), Thin Quad Flatpack (TQFP) SOIC), Shrink Small Outline Package (SSOP), Thin Small Outline (TSOP), Thin Quad Flatpack (TQFP), System In Package (SIP), Multi Chip Package (MCP), Wafer-level Fabricated Package Level Processed Stack Package (WSP) and the like. Depending on the embodiment, the image sensor 560 may be integrated on one chip with the processor 510, or may be integrated on different chips, respectively. 27, the electronic device 500 is implemented as a smart phone, but the implementation of the electronic device 500 is not limited thereto. That is, the electronic device 500 should be interpreted as any electronic device using the image sensor 560. [ For example, the electronic device 500 may be implemented as a mobile phone, a smart phone, a smart pad, a personal digital assistant (PDA), a portable multimedia player (PMP), or the like.

FIG. 28 is a flowchart showing an example in which an image sensor provided in the electronic apparatus shown in FIG. 26 detects infrared rays; and FIG. 29 is a flowchart showing another example in which an image sensor provided in the electronic apparatus shown in FIG. 26 detects infrared rays.

Referring to FIGS. 28 and 29, infrared rays are detected by the image sensor 560 provided in the electronic device 500. FIG. As shown in FIG. 28, the image sensor 560 provided in the electronic device 500 can irradiate the subject with infrared rays (S520). To this end, the image sensor 560 provided in the electronic device 500 or the electronic device 500 may include an infrared ray irradiating device for irradiating the subject with infrared rays. The image sensor 560 provided in the electronic device 500 may detect the infrared ray reflected from the subject in step S540 and generate an infrared image based on the detected infrared ray in step S560. As described above, the image sensor 560 provided in the electronic device 500 can detect the infrared ray irradiated to the subject, and this method can be performed under a light amount condition that is insufficient for generating an infrared image, for example. A method of detecting infrared rays irradiated to a subject may be iris recognition, tomography, or the like. Further, even when the image sensor 560 is used as a depth sensor for measuring a predetermined distance (i.e., depth), the image sensor 560 can operate in a manner that detects infrared rays irradiated to the object. 29, the image sensor 560 provided in the electronic device 500 can detect infrared rays from the outside (S620) and generate an infrared image based on the detected infrared rays (S640) have. Such a method can be performed under a light amount condition sufficient to generate an infrared image, for example. However, the above-described methods are merely exemplary and the manner in which the image sensor 560 provided in the electronic device 500 detects infrared rays is not limited thereto.

30 is a block diagram showing an example of an interface used in the electronic apparatus of Fig.

30, the electronic device 1000 may be implemented as a data processing device (e.g., a mobile phone, a PDA, a GMP, a smart phone, etc.) capable of using or supporting a MIPI interface, An image sensor 1140, a display 1150, and the like. The CSI host 1112 of the application processor 1110 can perform serial communication with the CSI device 1141 of the image sensor 1140 through a camera serial interface (CSI). In one embodiment, the CSI host 1112 may include an optical deserializer (DES), and the CSI device 1141 may include an optical serializer (SER). The DSI host 1111 of the application processor 1110 can perform serial communication with the DSI device 1151 of the display 1150 through a display serial interface (DSI). In one embodiment, the DSI host 1111 may include an optical serializer (SER), and the DSI device 1151 may include an optical deserializer (DES). Furthermore, the electronic device 1000 may further include an RF (Radio Frequency) chip 1160 capable of performing communication with the application processor 1110. The PHY 1113 of the electronic device 1000 and the PHY 1161 of the RF chip 1160 can perform data transmission and reception according to a Mobile Industry Processor Interface (MIPI) DigRF. In addition, the application processor 1110 may further include a DigRF MASTER 1114 for controlling data transmission / reception according to the MIPI DigRF of the PHY 1161. The electronic device 1000 may include a Global Positioning System (GPS) 1120, a storage 1170, a microphone 1180, a DRAM device 1185, and a speaker 1190. In addition, the electronic device 1000 may use an Ultra Wide Band (UWB) 1210, a Wireless Local Area Network (WLAN) 1220, and a Worldwide Interoperability for Microwave Access (WIMAX) So that communication can be performed. However, the structure and the interface of the electronic device 1000 are not limited thereto.

The present invention can be variously applied to an image sensor and an electronic device including the same. For example, the present invention can be applied to a computer, a notebook, a digital camera, a mobile phone, a smart phone, a smart pad, a tablet PC, a PDA, a PMP, a car navigation system,

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the following claims. It can be understood that it is possible.

100: image sensor 122: unit pixel
120: pixel array 140: analog-to-digital converter section
160: Digital Signal Processor Unit 180: Controller
500: Electronic device

Claims (20)

A visible light detection pixel for converting a visible light incident from the outside into a first charge using a photoelectric conversion element and generating a first electrical signal corresponding to an accumulation amount of the first charge; And
An infrared detection unit which converts an infrared ray incident from the outside into a second electric charge between an upper electrode and a lower electrode using an infrared ray detection layer including an infrared ray detecting material and generates a second electric signal corresponding to an accumulation amount of the second electric charge, Pixels,
Wherein an infrared absorption amount of the infrared detection layer is adjusted based on a bias by a first voltage applied to the upper electrode and a second voltage applied to the lower electrode. 2. The unit pixel of claim 1, wherein the photoelectric conversion element corresponds to a photodiode. The unit pixel of an image sensor according to claim 1, wherein the infrared detecting material comprises an organic material, a quantum dot, or a III-V compound. The unit pixel of claim 1, wherein the visible light detection pixel and the infrared detection pixel are disposed adjacent to each other within the unit pixel. The unit pixel of an image sensor according to claim 1, wherein the infrared detection pixels in the unit pixel are stacked on top of the visible light detection pixel. 6. The unit pixel of claim 5, wherein the infrared detection pixel operates as an infrared cut filter for the visible light detection pixel. The unit pixel of an image sensor according to claim 1, wherein the infrared detection pixel is activated when the bias is greater than a predetermined mode switching reference value, and the infrared detection pixel is inactivated when the bias is below the mode switching reference value. 8. The unit pixel of claim 7, wherein when the bias is larger than the mode switching reference value, the infrared absorption amount increases as the bias increases, and the infrared absorption amount decreases as the bias decreases. 9. The unit pixel of claim 8, wherein a visible light image is generated by a sum of the first electrical signal and the second electrical signal when the bias is greater than the mode switching reference value. 10. The unit pixel of claim 9, wherein the visible light image is generated based only on the first electrical signal when the bias is less than or equal to the mode switching reference value. A pixel array including a plurality of unit pixels including a visible light detection pixel and an infrared detection pixel whose infrared absorption is adjusted;
An analog-to-digital converter for converting an analog signal, which is an electrical signal outputted from the pixel array, into a digital signal;
A digital signal processor for performing digital signal processing on the digital signal and outputting an image signal; And
And a controller for controlling the pixel array, the analog-to-digital converter section, and the digital signal processor section. 12. The method of claim 11, wherein the visible light detection pixel converts visible light into a first electrical charge using a photoelectric conversion element, generates a first electrical signal corresponding to an accumulation amount of the first electrical charge,
Wherein the infrared detection pixel includes an infrared detection layer including an infrared detection material between an upper electrode and a lower electrode and converts infrared rays into a second electric charge using the infrared detection layer, Generating a second electrical signal,
Wherein the infrared absorption amount is adjusted based on a bias by a first voltage applied to the upper electrode and a second voltage applied to the lower electrode. The method of claim 12, wherein the photoelectric conversion element corresponds to a photodiode, and the infrared detecting material includes an organic material, a quantum dot, or a III-V compound Contains image sensors. 13. The image sensor according to claim 12, wherein in each of the unit pixels, the visible light detection pixel and the infrared detection pixel are disposed adjacent to each other. 13. The image sensor according to claim 12, wherein in each of the unit pixels, the infrared detection pixels are stacked on top of the visible light detection pixels. 16. The image sensor of claim 15, wherein the infrared detection pixels act as an infrared cut filter for the visible light detection pixels. 13. The image sensor according to claim 12, wherein the infrared detection pixel is activated when the bias is larger than a predetermined mode switching reference value, and the infrared detection pixel is inactivated when the bias is below the mode switching reference value. 18. The image sensor according to claim 17, wherein when the bias is larger than the mode switching reference value, the infrared absorption amount increases as the bias increases, and the infrared absorption amount decreases as the bias decreases. 19. The method of claim 18, wherein when the bias is greater than the mode switching reference value, a visible light image is generated by a sum of the first electrical signal and the second electrical signal, Wherein the visible light image is generated based only on a first electrical signal. The method of claim 17, wherein if the external illuminance is greater than a predetermined reference illuminance, the bias is set to be equal to or less than the mode change reference value, and if the external illuminance is less than the reference illuminance, sensor.

Images