Image sensor including grid structure

Abstract

An image sensor includes: a photoelectric conversion device disposed in a substrate including a first surface and a second surface; a first photoelectric conversion element and a second photoelectric conversion element in the substrate; a first separation structure and a second separation structure in the substrate; and a first grid structure and a second grid structure on the first separation structure and the second separation structure. The second photoelectric conversion element is disposed between the first separation structure and the second separation structure. The first grid structure and the second grid structure vertically overlap the first separation structure and the second separation structure. The first lattice structure includes an air gap and N layers on an outer side surface of the air gap. Each of the N layers extends in a first direction. The second lattice structure includes M layers on an outer side surface of the second lattice structure and extending in the first direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims the benefit of priority from Korean Patent Application No. 10-2023-0134527 filed on October 10, 2023 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] The inventive concept relates to an image sensor and a method of forming the same, and particularly, to an image sensor including a grid structure and a method of forming the same. Background Art

[0003] The image sensor may be a semiconductor-based sensor that receives light and generates an electrical signal. The image sensor may include a pixel array having a plurality of pixels, and a logic circuit for driving the pixel array and generating an image. Each of the plurality of pixels may include a photodiode and a pixel circuit that converts the charge generated by the photodiode into an electrical signal. Summary of the invention

[0004] According to an aspect of the inventive concept, there is provided an image sensor including a lattice structure including an air gap.

[0005] According to one aspect of the present disclosure, an image sensor is provided, comprising: a substrate, comprising a first surface and a second surface opposite to the first surface; a first photoelectric conversion element, in the substrate; a second photoelectric conversion element, in the substrate; a first separation structure, in the substrate and between the first photoelectric conversion element and the second photoelectric conversion element; a second separation structure, in the substrate; a first color filter, arranged on the first photoelectric conversion element; a second color filter, arranged on the second photoelectric conversion element; and a first grid structure, on the first separation structure and between the first color filter and the second color filter; and a second grid structure, on the second separation structure, wherein the second photoelectric conversion element is arranged between the first separation structure and the second separation structure, wherein the first grid structure vertically overlaps with the first separation structure, and the second grid structure vertically overlaps with the second separation structure, wherein the first grid structure includes an air gap and N layers on the outer side surface of the air gap, wherein each of the N layers extends in a first direction, Wherein the second grid structure includes M layers on an outer surface of the second grid structure and extending in a first direction, wherein N and M are integers, wherein N is different from M, and wherein the image sensor is configured to receive light from the second surface.

[0006] According to one aspect of the present disclosure, an image sensor is provided, comprising: a substrate, comprising a first surface and a second surface opposite to the first surface; a first group of photoelectric conversion elements, comprising a first photoelectric conversion element in the substrate; at least four microlenses on the first group of photoelectric conversion elements; a second group of photoelectric conversion elements, comprising a second photoelectric conversion element in the substrate; at least four microlenses on the second group of photoelectric conversion elements; a first separation structure, between the first photoelectric conversion element and the second photoelectric conversion element; a second separation structure, between the first group of photoelectric conversion elements; a first grid structure, on the first separation structure, and vertically overlapping with the first separation structure; and a second grid structure, on the second separation structure, and vertically overlapping with the second separation structure; wherein the first grid structure comprises an air gap and N layers on an outer surface of the air gap, wherein each of the N layers extends in a first direction, wherein the second grid structure comprises M layers on an outer surface of the second grid structure and extending in the first direction, wherein N and M are integers, wherein N is different from M, and wherein the image sensor is configured to receive light from the second surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The above and other aspects, features and advantages of the present inventive concept will be more clearly understood from the following detailed description in conjunction with the accompanying drawings, in which:

[0008] Figure 1 is a schematic block diagram illustrating an image sensor according to example embodiments;

[0009] Figure 2A and Figure 2B is a schematic diagram showing an example of a pixel circuit of an image sensor according to example embodiments;

[0010] Figure 3 is a schematic plan view of an image sensor according to example embodiments;

[0011] Figure 4 yes Figure 3 an enlarged view of the image sensor shown;

[0012] Figure 5 yes Figure 4 A vertical cross-sectional view of the image sensor shown taken along line II';

[0013] Figure 6 yes Figure 5 an enlarged view of the image sensor shown;

[0014] Fig. 7A , Figure 7B , Fig. 8A , Figure 8B , Fig.9A , Fig. 9B , Fig. 10A , Fig. 10B and Fig.11 are plan views and cross-sectional views in a process sequence for describing a method of manufacturing an image sensor according to example embodiments;

[0015] Fig.12 is a vertical cross-sectional view of an image sensor according to example embodiments;

[0016] Figures 13 to 17 is a vertical cross-sectional view of an image sensor according to example embodiments;

[0017] Fig.18A is a plan view of an image sensor according to example embodiments;

[0018] Fig.18B yes Fig.18A A vertical cross-sectional view of the image sensor shown taken along line II-II'; and

[0019] Figures 19 to 21 is a plan view of an image sensor according to example embodiments. DETAILED DESCRIPTION

[0020] Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings.

[0021] The following detailed description is provided to help the reader obtain a comprehensive understanding of the method, device and / or system described herein. However, after understanding the disclosure of the application, various changes, modifications and equivalents of the method, device and / or system described herein will be apparent. For example, except for the operations that must be performed in a certain order, the order of operations described herein is only an example, and is not limited to those order of operations set forth in this article, but can be changed as will be apparent after understanding the disclosure of the application. In addition, for greater clarity and brevity, the description of features known after understanding the disclosure of the application can be omitted.

[0022] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein, which will be apparent after understanding the disclosure of the present application.

[0023] Throughout the specification, when a component is described as being "connected to" or "coupled to" another component, it may be directly "connected to" or "coupled to" the other component, or there may be one or more other components interposed therebetween. Conversely, when an element is described as being "directly connected to" or "directly coupled to" another element, there may be no other elements interposed therebetween. Similarly, similar expressions such as "between" and "directly between", and "adjacent to" and "immediately adjacent to" are also understood in the same manner. As used herein, the term "and / or" includes any one of the items listed in the association and any combination of any two or more.

[0024] Although terms such as "first", "second", and "third" may be used herein to describe various components, assemblies, regions, layers, or portions, these components, assemblies, regions, layers, or portions should not be limited by these terms. Instead, these terms are only used to distinguish one component, component, region, layer, or portion from another component, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first component, component, region, layer, or portion mentioned in the examples may also be referred to as the second component, component, region, layer, or portion.

[0025] Hereinafter, terms such as “top”, “upper”, “upper surface”, “above”, “bottom”, “lower”, “lower surface”, “below” and “side surface” may be understood with reference to the accompanying drawings. However, the present disclosure is not limited thereto.

[0026] The terms used herein are only used to describe various examples, and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the articles "one", "an" and "the" are intended to include plural forms. The terms "comprise", "include" and "have" represent the presence of the features, quantities, operations, components, elements and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof. As used herein, the expression "at least one" after the element list modifies the entire element list, and does not modify the single element in the list. For example, the expression "at least one of a, b and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b and c.

[0027] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those of ordinary skill in the art to which the present disclosure belongs, and as understood based on the understanding of the disclosure of the present application. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant technology and the disclosure of the present application, and should not be interpreted as an ideal or overly formal meaning unless explicitly defined as such herein. In this article, the use of the term "may" with respect to examples or embodiments (e.g., with respect to what an example or embodiment may include or implement) indicates that there is at least one example or embodiment that includes or implements such features, and all examples or embodiments are not limited thereto.

[0028] The embodiments of the present disclosure are example embodiments, and therefore, the present disclosure is not limited thereto and may be implemented in various other forms. As is common in the art, embodiments may be described and illustrated around blocks (as shown in the figures) that perform the functions described. These blocks (which may be referred to herein as units or modules, etc., or named as devices, logic, circuits, counters, comparators, generators, converters, etc.) may be physically implemented by analog and / or digital circuits including one or more of logic gates, integrated circuits, microprocessors, microcontrollers, storage circuits, passive electronic components, active electronic components, optical components, etc., and may also be implemented or driven by software and / or firmware (configured to perform the functions or operations described herein).

[0029] Figure 1 is a schematic block diagram illustrating an image sensor according to example embodiments of the inventive concept.

[0030] refer to Figure 1 , the image sensor 1 may include a pixel array 10 and a logic circuit 20. The pixel array 10 may include a plurality of pixels PX. The plurality of pixels PX may be arranged in an array form along a plurality of rows and a plurality of columns. Each of the plurality of pixels PX may include at least one photoelectric conversion device and a pixel circuit. At least one photoelectric conversion device may be configured to generate a charge based on light incident on at least one photoelectric conversion device. The pixel circuit may be configured to generate a pixel signal corresponding to the charge generated by the photoelectric conversion device. The photoelectric conversion device may include, but is not limited to, a photodiode formed of a semiconductor material or an organic photodiode formed of an organic material. According to an embodiment, the photoelectric conversion device may be referred to as a photoelectric conversion element or a photoelectric converter.

[0031] According to an embodiment, the pixel circuit may include a floating diffusion region, a transfer transistor, a reset transistor, a drive transistor, and a selection transistor. The configuration of the pixel PX may vary according to various example embodiments. For example, each pixel PX may include an organic photodiode containing an organic material, or may be implemented as a digital pixel. In the example case where the pixel PX is implemented as a digital pixel, each pixel PX may include an analog-to-digital converter for outputting a digital pixel signal.

[0032] The logic circuit 20 may include a circuit for controlling the pixel array 10. For example, the logic circuit 20 may include, but is not limited to, a row driver 21, a readout circuit 22, a column driver 23, and a control logic 24. The row driver 21 may drive the pixel array 10 on a row line basis. For example, the row driver 21 may generate a transfer control signal for controlling a transfer transistor of a pixel circuit, a reset control signal for controlling a reset transistor, and a selection control signal for controlling a selection transistor, and may input a signal into the pixel array 10 according to the row line. For example, the row driver 21 may input a signal into the pixel array 10 on a row line basis.

[0033] The readout circuit 22 may include, but is not limited to, a correlated double sampler CDS, an analog-to-digital converter ADC, etc. The correlated double sampler may be connected to the pixel PX through a column line. The correlated double sampler may read a pixel signal from a pixel PX connected to a row line selected by a row line selection signal of the row driver 21 through a column line. The analog-to-digital converter may convert the pixel signal detected by the correlated double sampler into a digital pixel signal, and send the digital pixel signal to the column driver 23.

[0034] The column driver 23 may include, but is not limited to, a latch or buffer circuit configured to temporarily store a digital pixel signal, or an amplifier circuit, and may process the digital pixel signal received from the readout circuit 22. The control logic 24 may control the row driver 21, the readout circuit 22, and the column driver 23. For example, the control logic 24 may control one or more operations of the row driver 21, the readout circuit 22, and the column driver 23. The control logic 24 may include, but is not limited to, a timing controller for controlling the operation timing of the row driver 21, the readout circuit 22, and the column driver 23.

[0035] In the pixel array 10, among the plurality of pixels PX, two or more pixels PX arranged in the same column of the pixel array in the vertical direction may share the same column line. In an example, two or more pixels PX arranged in the same row of the pixel array in the horizontal direction may be selected by the row driver 21 at the same time, and pixel signals may be output through the column lines. In an example, the readout circuit 22 may simultaneously obtain pixel signals from the pixels PX selected by the row driver 21 through the column lines. The pixel signal may include a reset voltage and a pixel voltage, and the pixel voltage may be a voltage in which the charge generated in response to light in each pixel PX is reflected in the reset voltage.

[0036] Figure 2A and Figure 2B is a schematic diagram illustrating an example of a pixel circuit of an image sensor according to example embodiments.

[0037] In the example, refer to Figure 1 and Figure 2A , each of the plurality of pixels PX may include a photodiode PD and a pixel circuit, and the pixel circuit may include a transfer transistor TX, a reset transistor RX, a selection transistor SX, and a drive transistor DX.

[0038] The photodiode PD may generate and accumulate charges in response to external incident light. The pixel circuit may further include a floating diffusion region FD that accumulates the charges generated by the photodiode PD.

[0039] In some example embodiments, the photodiode PD may be replaced by a phototransistor, a photogate, or a pinned photodiode. The photodiode PD may be referred to and described as a "photoelectric conversion device". Accordingly, the photoelectric conversion device may be a photodiode, a phototransistor, a photogate, or a pinned photodiode.

[0040] The transfer transistor TX may move the charges generated by the photodiode PD to the floating diffusion region FD. The floating diffusion region FD may store the charges generated by the photodiode PD. The voltage output by the drive transistor DX may vary according to the amount of charges accumulated in the floating diffusion region FD.

[0041] The reset transistor RX may reset the voltage of the floating diffusion region FD by removing the charge accumulated in the floating diffusion region FD. The drain electrode of the reset transistor RX may be connected to the floating diffusion region FD, and the source electrode of the reset transistor RX may be connected to the power supply voltage VDD. In the example case where the reset transistor RX is turned on, the power supply voltage VDD connected to the source electrode of the reset transistor RX may be applied to the floating diffusion region FD, and the charge accumulated in the floating diffusion region FD may be removed.

[0042] The drive transistor DX may be used as a source follower buffer amplifier. The drive transistor DX may amplify a voltage change in the floating diffusion region FD, and may output the amplified voltage change to one of the column lines COL1 and COL2. The selection transistor SX may select a pixel PX to be read on a row basis. In the example case where the selection transistor SX is turned on, the voltage of the drive transistor DX may be output to one of the column lines COL1 and COL2. In the example case where the selection transistor SX is turned on, a reset voltage or a pixel voltage may be output through the column lines COL1 and COL2.

[0043] exist Figure 2A In the illustrated example embodiment, each of the plurality of pixels PX includes a photodiode PD and a transfer transistor TX, as well as a reset transistor RX, a selection transistor SX, and a drive transistor DX, but example embodiments of the inventive concept are not limited thereto and may be modified as follows: Figure 2B As shown.

[0044] According to another embodiment, reference Figure 1 and Figure 2B Two or more pixels adjacent to each other may share at least a portion of transistors included in the pixel circuit. For example, four pixels adjacent to each other may share a floating diffusion region FD, a reset transistor RX, first and second drive transistors DX1 and DX2, and a select transistor SX.

[0045] In the example, the first photodiode PD1 and the first transfer transistor TX1 of the first pixel can be connected to the floating diffusion region FD. Similarly, the second photodiode PD2 of the second pixel can be connected to the floating diffusion region FD through the second transfer transistor TX2, the third photodiode PD3 of the third pixel can be connected to the floating diffusion region FD through the third transfer transistor TX3, and the fourth photodiode PD4 of the fourth pixel can be connected to the floating diffusion region FD through the fourth transfer transistor TX4.

[0046] In an example, floating diffusion regions FD respectively included in pixels may be connected to each other using an interconnection line pattern or the like, so that the first to fourth transfer transistors TX1 to TX4 may be commonly connected to one floating diffusion region FD.

[0047] In another example, the floating diffusion regions FD respectively included in the pixels may be formed as one floating diffusion region FD in a substrate which may be formed of a semiconductor material.

[0048] The pixel circuit may include a reset transistor RX, a first drive transistor DX1 and a second drive transistor DX2, and a selection transistor SX. The reset transistor RX may be controlled by a reset control signal RG, and the selection transistor SX may be controlled by a selection control signal SEL. For example, each of the four pixels may further include a transistor other than the transfer transistor TX. In the pixel array 10, among the four transistors included in the four pixels, two transistors may be connected in parallel to each other and be set as the first drive transistor DX1 and the second drive transistor DX2, and one of the remaining two transistors may be set as the selection transistor SX, and the other may be set as the reset transistor RX.

[0049] refer to Figure 2B The pixel circuit described is only an example and is not necessarily limited to this form. For example, among the four transistors, one transistor can be designated as a drive transistor, and one transistor can be designated as a selection transistor. In addition, the remaining two transistors can be connected in series with each other and designated as a first reset transistor and a second reset transistor, thereby realizing an image sensor configured to adjust the conversion gain of the pixel. Alternatively, the pixel circuit can vary according to the number of transistors included in each pixel. Therefore, reference Figure 2A and Figure 2B The described pixel circuits are merely examples for implementing an image sensor according to example embodiments of the inventive concepts, and example embodiments of the inventive concepts are not limited thereto.

[0050] Figures 3 to 5 is a schematic diagram illustrating an image sensor according to example embodiments. Figure 3 is a schematic plan view of an image sensor according to example embodiments, Figure 4 yes Figure 3 A schematic enlarged view of the image sensor shown, and Figure 5 yes Figure 4 The image sensor shown is a vertical cross-sectional view taken along line II'.

[0051] refer to Figures 3 to 5 , the image sensor 1 according to the example embodiment may have a multi-layer chip structure. For example, the multi-layer chip structure may include at least two chips. Figure 5 As shown, the image sensor 1 may include a first chip structure 103 and a second chip structure 203 on the first chip structure 103. The first chip structure 103 may be a logic chip, and the second chip structure 203 may be an image sensor chip. In another example, the first chip structure 103 may be a multi-layer chip structure including a logic chip and a memory chip.

[0052] The first chip structure 103 of the image sensor 1 may include a first substrate 106, an isolation film 109s on the first substrate 106, a first circuit device 112 and a first interconnection line structure 115 on the first substrate 106, and a first insulating structure 118 on the first substrate 106. According to an embodiment, the isolation film 109s may define an active region 109a in the first substrate 106. According to an embodiment, the first insulating structure 118 may cover the first circuit device 112 and the first interconnection line structure 115. For example, the first insulating structure 118 may contact one or more sides of the first circuit device 112 and the first interconnection line structure 115. For example, the first insulating structure 118 may surround the first circuit device 112 and the first interconnection line structure 115.

[0053] The first substrate 106 may be a semiconductor substrate. For example, the first substrate 106 may be a substrate formed of a semiconductor material. For example, the semiconductor material may include, but is not limited to, single crystal silicon. The first circuit device 112 may include a device such as a transistor including a gate 112a and a source / drain 112b. Here, the source / drain 112b may include a source region and a drain region.

[0054] The second chip structure 203 may include a second substrate 206 having a first surface 206s1 and a second surface 206s2 facing each other, an isolation film 218 disposed on the first surface 206s1 of the second substrate 206, a second circuit device 224 and a second interconnection line structure 227 disposed between the first surface 206s1 of the second substrate 206 and the first chip structure 103, and a second insulating structure 230 between the first surface 206s1 of the second substrate 206 and the first chip structure 103. According to an embodiment, the isolation film 218 may define an active region. According to an embodiment, the second insulating structure 230 may cover the second circuit device 224 and the second interconnection line structure 227. For example, the second insulating structure 230 may contact one or more sides of the second circuit device 224 and the second interconnection line structure 227. For example, the second insulating structure 230 may surround the second circuit device 224 and the second interconnection line structure 227.

[0055] The first surface 206s1 of the second substrate 206 may face the first chip structure 103. For example, the first surface 206s1 of the second substrate 206 may be arranged to face the first chip structure 103. The isolation film 218 may be formed of an insulating material. The insulating material may include, but is not limited to, silicon oxide. In an example embodiment, the isolation film 218 may be formed by doping p-type impurities in the first surface 206s1 of the second substrate 206. In an example embodiment, the isolation film 218 may be formed by forming a shallow trench on the first surface 206s1 of the second substrate 206 and then filling the shallow trench with an insulating material (e.g., silicon oxide). The second circuit device 224 and the second interconnect structure 227 disposed below the first surface 206s1 of the second substrate 206 may form a circuit interconnect structure. Accordingly, the circuit interconnect structure may be disposed below the first surface 206s1 of the second substrate 206.

[0056] The second substrate 206 may be a semiconductor substrate. For example, the second substrate 206 may be a substrate formed of a semiconductor material. The semiconductor material may include, but is not limited to, single crystal silicon.

[0057] The photoelectric conversion device PD can generate and accumulate charges corresponding to the incident light. For example, the photoelectric conversion device PD may include a photodiode, a phototransistor, a photogate, a pinned photodiode PPD, or a combination thereof. Each photoelectric conversion device PD may be a photodiode that may be formed in the second substrate 206. The photoelectric conversion device (PD) may be configured to detect light. In one embodiment, at least two of the photoelectric conversion devices PD may be configured to detect light of different wavelengths. For example, among the photoelectric conversion devices PD, the first photoelectric conversion device PD may be configured to detect light of a first wavelength, and the second photoelectric conversion device PD may be configured to detect light of a second wavelength different from the first wavelength.

[0058] The second chip structure 203 may further include a separation structure 215. The separation structure 215 may be arranged to surround each photoelectric conversion device PD. The separation structure 215 may vertically pass through at least a portion of the second substrate 206. For example, the separation structure 215 may vertically pass through the second substrate 206. The separation structure 215 may be arranged in a pixel isolation groove 212 vertically passing through the second substrate 206. The separation structure 215 may be connected to an isolation film 218. Accordingly, the separation structure 215 may pass through the second substrate 206 between the isolation film 218 and the second surface 206s2 of the second substrate 206. The separation structure 215 may have a substantially vertical side surface. In an embodiment, the isolation film 218 may be formed by forming a pixel isolation groove 212 penetrating the first surface 206s1 and the second surface 206s2 of the substrate, forming a shallow groove overlapping the pixel isolation groove 212 on the first surface 206s1, and then filling the shallow groove with an insulating material (e.g., silicon oxide).

[0059] The separation structure 215 may include a separation pattern 213b and a separation insulating layer 213a. The separation insulating layer 213a may be disposed on one side of the separation pattern 213b. For example, the separation insulating layer 213a may be disposed to cover the side surface of the separation pattern 213b. For example, the separation insulating layer 215a may include but is not limited to silicon oxide, and the separation pattern 213b may include but is not limited to polysilicon. The separation pattern 213b may also be referred to as a silicon pattern or a polysilicon pattern. The separation insulating layer 213a may be formed of a single material layer.

[0060] The separation pattern 213b may be formed of a material configured to perform the following operations: a voltage is applied to the separation pattern 213b so as to minimize or prevent interference or influence between the photoelectric conversion devices PD. For example, the separation pattern 213b may include a conductive material. The conductive material may include, but is not limited to, doped polysilicon. In an example, the separation pattern 213b may be formed of doped polysilicon having an N-type conductivity type. In another example, the separation pattern 213b may be formed of doped polysilicon having a P-type conductivity type.

[0061] The second circuit device 224 may include a transmission gate TG and an active device 221. The active device 221 may be a transistor including a gate 221a and a source / drain 221b. The transmission gate TG may transfer charges from an adjacent photoelectric conversion device PD to an adjacent floating diffusion region. The active device 221 may include, but is not limited to, a reference Figure 2A and Figure 2B The various transistors of the pixel circuit are described. For example, the active device 221 may include a drive transistor, a reset transistor, and a select transistor.

[0062] The transfer gate TG may be a vertical transfer gate including a portion extending from the first surface 206 s 1 of the second substrate 206 into the second substrate 206 .

[0063] The second interconnection line structure 227 may include a plurality of multilayer interconnections and a plurality of vias. The plurality of multilayer interconnections may be located at different height levels. The plurality of vias may electrically connect the multilayer interconnections to each other and electrically connect the multilayer interconnections to the second circuit device 224.

[0064] The first insulating structure 118 and the second insulating structure 230 may contact each other. For example, the first insulating structure 118 and the second insulating structure 230 may be bonded to each other while contacting each other. Each of the first insulating structure 118 and the second insulating structure 230 may be formed by multiple layers. According to an embodiment, the multiple layers may include different types of insulating layers. For example, the second insulating structure 230 may be formed by multiple layers including at least two types of layers. For example, the at least two types of layers may include two or more of a silicon oxide layer, a low-κ dielectric layer, and a silicon nitride layer. However, the present disclosure is not limited thereto, and therefore, other types of layers may be provided. In addition, according to another embodiment, the multiple layers may include the same type of insulating layers.

[0065] The second chip structure 203 may further include an insulating structure 240 disposed on the second surface 206s2 of the second substrate 206. The insulating structure 240 may cover the separation structure 215.

[0066] The insulating structure 240 may include an anti-reflection layer that may be configured to prevent light reflection, which may occur due to a sudden change in the refractive index of the second surface 206s2 of the second substrate 206 that may be formed of silicon. The insulating structure 240 may include an anti-reflection layer that is configured to adjust the refractive index to allow incident light to pass through the photoelectric conversion device PD with high transmittance. The insulating structure 240 may also be referred to as an anti-reflection structure or an anti-reflection layer.

[0067] The insulating structure 240 may have transparency at visible light wavelengths and may include a material having a negative charge to prevent charges caused by dangling bonds of the second surface 206s2 of the substrate 206. In addition, the insulating structure 240 may include a material configured to adjust a peak transmittance by adjusting a thickness. The insulating structure 240 may include at least one of silicon oxide, aluminum oxide, and hafnium oxide. The insulating structure 240 may be formed of a single layer or multiple layers.

[0068] The second chip structure 203 may include a color filter CF. For example, the color filter CF may include a plurality of color filters configured to filter light of different colors. For example, the color filter CF may include at least one of a green filter, a blue filter, a red filter, a white filter, and a yellow filter.

[0069] The color filter CF may be disposed on the insulating structure 240. The color filter CF may vertically overlap the photoelectric conversion devices PD corresponding thereto respectively. The color filter CF may allow light having a specific wavelength to pass through and reach the photoelectric conversion device PD. For example, the color filter CF may be formed of a material obtained by mixing a resin with a pigment including a metal or a metal oxide.

[0070] In an example embodiment, the plurality of color filters CF may include a plurality of first color filters CF1, a plurality of second color filters CF2, and a plurality of third color filters CF3. In an example embodiment, the first color filters CF1, the second color filters CF2, and the third color filters CF3 may be respectively arranged in a 2×2 array. In some example embodiments, the plurality of first color filters CF1, the plurality of second color filters CF2, and the plurality of third color filters CF3 may be respectively arranged in a 1×1 array or a 3×3 array. In an example embodiment, the plurality of color filters CF may have a rectangular shape in a plan view.

[0071] For example, among a plurality of first color filters CF1, first color filters CF1 disposed adjacent to each other may form a first color filter group FG1. For example, among a plurality of second color filters CF2, second color filters CF2 disposed adjacent to each other may form a second color filter group FG2. For example, among a plurality of third color filters CF3, third color filters CF3 disposed adjacent to each other may form a third color filter group FG3. For example, the first color filter group FG1, the second color filter group FG2, and the third color filter group FG3 may include four first color filters CF1, four second color filters CF2, and four third color filters CF3, respectively. Different color filter groups FG may be configured to filter different colors. For example, Figure 5 The illustrated color filters CF1 and CF2 may be different types of color filters. The photoelectric conversion devices PD corresponding to the first, second, and third color filter groups FG1, FG2, and FG3 may form first, second, and third groups of photoelectric conversion devices PD, respectively.

[0072] The second chip structure 203 may further include a grid structure 250. The grid structure 250 may be disposed on the insulating structure 240. In an example embodiment, the grid structure 250 may vertically overlap the separation structure 215. In an example embodiment, the grid structure 250 may have a first width different from the second width of the separation structure 215. For example, the first width of the grid structure 250 may be greater than the second width of the separation structure 215. The grid structure 250 may extend in a horizontal direction between a plurality of color filters CF. For example, the grid structure 250 may separate the color filters CF from each other. For example, the grid structure 250 may extend in a horizontal direction between adjacent color filters CF to separate adjacent color filters CF from each other.

[0073] The grid structure 250 may include a first grid structure 260 and a plurality of second grid structures 270. In an example embodiment, the first grid structure 260 may extend in the X direction and the Y direction between different color filter groups FG. In a plan view, the first grid structure 260 may have a rectangular grid shape. For example, Figure 4 As shown, the first grid structure 260 may surround the first color filter group FG1, and the four first color filters CF1 of the first color filter group FG1 may be surrounded by the first grid structure 260. The second color filter group FG2 and the third color filter group FG3 may also be surrounded by the first grid structure 260. For example, the first grid structure 260 may be disposed between the first color filter CF1 of the first color filter group FG1 and the second color filter CF2 of the second color filter group FG2 adjacent thereto.

[0074] In an example embodiment, the plurality of second grid structures 270 may extend in the X direction and the Y direction between the color filters CF included in the same color filter group FG. In a plan view, the plurality of second grid structures 270 may have a cross shape. For example, Figure 4 As shown, each of the plurality of second grid structures 270 may be disposed in the first grid structure 260. For example, among the plurality of second grid structures 270, the second grid structure 270 disposed in the first color filter group FG1 may extend in the X direction and the Y direction between the first color filters CF1. The first color filters CF1 disposed in the first color filter group FG1 may be spaced apart from each other by the second grid structure 270. The length of each of the plurality of second grid structures 270 may be greater than the horizontal width of each of the plurality of color filters CF. The "length" of the second grid structure 270 may refer to the width in the direction in which the second grid structure 270 extends.

[0075] In an example embodiment, the second grid structure 270 may include a first line portion 270a and a second line portion 270b. The first line portion 270a may be disposed between the first group of color filters CF and extend in the X direction, and the second line portion 270b may be disposed between the second group of color filters CF and extend in the Y direction. The first line portion 270a may intersect with the second line portion 270b. According to an embodiment, the first line portion 270a may be formed integrally with the second line portion 270b.

[0076] In example embodiments, at least one color filter CF among the plurality of color filters CF may be surrounded by the first grid structure 260 and / or one of the plurality of second grid structures 270. For example, a side surface of at least one color filter CF among the plurality of color filters CF may be in contact with the first grid structure 260 and one of the plurality of second grid structures 270 in a plan view.

[0077] Figure 6 yes Figure 5 An enlarged view of portion "B" of the image sensor is shown.

[0078] refer to Figure 6 , the first grid structure 260 may include an air gap AG, N layers on the outer side surface of the air gap AG, and L layers on the air gap AG, where N and L are different integers. In an example embodiment, the N layers may extend in a first direction, and the L layers may extend in a second direction perpendicular to the first direction. The N layers on the outer side surface of the air gap AG may include a first layer in contact with the air gap AG and a second layer in contact with the first layer. The first layer may include a first material, and the second layer may include a second material different from the first material. In an example embodiment, the first grid structure 260 may include a spacer layer 262, a capping layer 264, and a barrier layer 266. The N layers on the outer side surface of the air gap AG may include a spacer layer 262 and a capping layer 264. In a cross-sectional view, two spacer layers 262 may be spaced apart from each other in a first direction that intersects with a second direction in which the first grid structure 260 extends. The spacer layer 262 may include an inner surface 262a and an outer surface 262b. Adjacent spacer layers 262 may be arranged so that inner surfaces 262a of adjacent spacer layers 262 face each other. The spacer layer 262 may extend in the X direction and the Y direction along the first grid structure 260. The spacer layer 262 may include, but is not limited to, at least one of silicon oxide, silicon nitride, and silicon carbonitride. In example embodiments, the spacer layer 262 and the capping layer 264 may each be composed of a plurality of layers.

[0079] The capping layer 264 may be disposed on the side surface and the upper surface of the spacer layer 262. For example, the capping layer 264 may be disposed to cover the side surface and the upper surface of the spacer layer 262. For example, the spacer layer 262 may be disposed in the capping layer 264, and the capping layer 264 may be in contact with the outer surface 262b of the spacer layer 262. The capping layer 264 may have an arch shape. The capping layer 264 may surround the spacer layer 262. The upper surface of the capping layer 264 may be located at a first level higher than a second level of the upper surface of the spacer layer 262.

[0080] For example, the capping layer 264 may include a vertical portion 264a, a horizontal portion 264b, and a protrusion 264c. The vertical portion 264a may refer to a portion of the capping layer 264 that is lower than the upper surface of the spacer layer 262, and the horizontal portion 264b may refer to a portion of the capping layer 264 that is higher than the upper surface of the spacer layer 262. The vertical portion 264a may be disposed on the outer side of the spacer layer 262 relative to the central portion of the first grid structure 260, and may be disposed on the side surface of the spacer layer 262. For example, the vertical portion 264a may cover the side surface of the spacer layer 262. The horizontal portion 264b may be disposed on the vertical portion 264a, and may be disposed on the upper surface of the spacer layer 262. For example, the vertical portion 264a may cover the spacer layer 262. The protrusion 264c may be disposed on the lower surface of the horizontal portion 264b, and may be disposed between the spacer layers 262. The protrusion 264c may protrude below the upper surface of the spacer layer 262. For example, the lower end of the protrusion 264c may be located at a level lower than the level of the upper surface of the spacer layer 262. In example embodiments, the protrusion 264c may have a tapered shape with a horizontal width decreasing downward, and the lower surface of the protrusion 264c may have a sharp point. However, the present disclosure is not limited thereto, and therefore, the protrusion 264c may have different shapes. The capping layer 264 may include, but is not limited to, at least one of silicon oxide and silicon nitride.

[0081] In example embodiments, the barrier layer 266 may be disposed between adjacent spacer layers 262. In example embodiments, the barrier layer 266 may include a conductive material. For example, the barrier layer 266 may be formed of a conductive material (including but not limited to at least one of a metal or a metal nitride). For example, the barrier layer 266 may include but not limited to at least one of Ti, Ta, TiN, TaN, or W. In the case where the second surface 206s2 of the substrate 206 is charged, the barrier layer 266 formed of a conductive material may be used as a charge path for removing the charge. The lower surface of the barrier layer 266 may be coplanar with the lower surface of the spacer layer 262 and the lower surface of the capping layer 264. The lower surface of the barrier layer 266 may be in contact with the upper surface of the insulating structure 240. In some example embodiments, the barrier layer 266 may be omitted.

[0082] In example embodiments, the first grid structure 260 may include an air gap AG. For example, the air gap AG may be formed between the spacer layers 262. For example, the air gap AG may be defined by the spacer layer 262, the capping layer 264, and the barrier layer 266. For example, the air gap AG may be defined by the space between the spacer layer 262, the capping layer 264, and the barrier layer 266. For example, the upper limit of the air gap AG may be defined by the capping layer 264, and the lower limit of the air gap AG may be defined by the barrier layer 266. The lateral limit of the air gap AG may be defined by the spacer layer 262. For example, the outer side surface of the air gap AG may be defined by the spacer layer 262, the top surface of the air gap AG may be defined by the capping layer 264, and the bottom surface of the air gap AG may be defined by the barrier layer 266. The air gap AG may be sealed in the first grid structure 260. For example, the air gap AG may be sealed or filled by the spacer layer 262, the capping layer 264, and the barrier layer 266. The first grid structure 260 may have an air gap AG having a refractive index of 1, thereby preventing or reducing an optical crosstalk phenomenon of the image sensor 1 .

[0083] In a plan view, each of the plurality of capping layers 264 of the first grid structure 260 may surround a corresponding one of the plurality of color filter groups FG. For example, each of the plurality of capping layers 264 may have a rectangular shape. Each of the plurality of spacer layers 262 may surround a corresponding one of the plurality of color filter groups FG, and may surround the corresponding capping layer 264.

[0084] In example embodiments, the horizontal width of the spacer layer 262 may be about 20 nm to about 50 nm. The horizontal width of the air gap AG may be about 30 nm to about 60 nm. The horizontal width of the first grid structure 260 may be about 80 nm to about 150 nm. Here, the "horizontal width" may refer to a width in a first direction that is perpendicular to a second direction in which the spacer layer 262, the air gap AG, and the first grid structure 260 extend. The distance from the top surface of the air gap AG to the second surface 206s2 of the second substrate 206 may be greater than the distance from the bottom surface of the air gap AG to the second surface 206s2. In example embodiments, the horizontal width of the bottom surface of the air gap AG may be equal to or greater than half of the horizontal width of the bottom surface of the first grid structure 260.

[0085] The second grid structure 270 and the capping layer 264 may include the same material. For example, the second grid structure 270 and the capping layer 264 may be formed of the same material. For example, the second grid structure 270 may include silicon oxide. However, the second grid structure 270 may not include components such as the spacer layer 262, the air gap AG, and the barrier layer 266 of the first grid structure 260. In example embodiments, the second grid structure 270 may also include a barrier layer in contact with the upper surface of the insulating structure 240. In example embodiments, the barrier layer may include a conductive material. For example, the barrier layer may be formed of a conductive material including but not limited to at least one of a metal or a metal nitride. For example, the barrier layer may include but is not limited to at least one of Ti, Ta, TiN, TaN, or W. In example embodiments, the second grid structure 270 may have the same horizontal width, but the inventive concept is not limited thereto. For example, the horizontal width of the bottom surface of the second grid structure 270 may be substantially the same as the horizontal width of the bottom surface of the first grid structure 260. In some example embodiments, the horizontal width of the first grid structure 260 may be greater than the horizontal width of the second grid structure 270. In example embodiments, the horizontal width of the second grid structure 270 may be about 50 nm to about 150 nm. In example embodiments, at least one of the first grid structure 260 and the second grid structure 270 may not include a layer containing a metal material between a bottom surface thereof and the second surface 206s2 of the second substrate 206. In example embodiments, a distance from a top surface of the first grid structure 260 to the second surface 206s2 of the second substrate 206 may be substantially the same as a distance from a top surface of the second grid structure 270 to the second surface 206s2.

[0086] In example embodiments, the second grid structure 270 includes M layers on an outer side surface of the second grid structure 270 and extending in the first direction.

[0087] In example embodiments, the capping layer 264 of the first grid structure 260 may be in contact with the second grid structure 270 and may be integrally formed with the second grid structure 270. For example, in a plan view, in the same color filter group FG, the capping layer 264 of the first grid structure 260 may be connected to the second grid structure 270, and the capping layer 264 and the second grid structure 270 may be materially continuous.

[0088] In an example embodiment, the grid structure 250 may be disposed between the color filters CF. The thickness of each color filter CF may be greater than the thickness of the grid structure 250. A portion of the color filter CF may be disposed on the insulating structure 240 and adjacent to the grid structure 250. For example, a portion of the color filter CF may cover the grid structure 250. For example, the color filter CF may be disposed on the side surface and the upper surface of the grid structure 250. For example, the color filter CF may cover the side surface and the upper surface of the grid structure 250 on the insulating structure 240.

[0089] In an example embodiment, the first grid structure 260 including the air gap AG may be disposed between different color filter groups FG, and thus may be disposed between color filters CF configured to filter different colors. Accordingly, an optical crosstalk phenomenon occurring between different color filters CF may be prevented or reduced. In addition, the first grid structure 260 may be disposed between color filters CF filtering different colors, thereby improving the light sensitivity of the image sensor 1.

[0090] In example embodiments, a passivation layer 280 may be further provided between the grid structure 250 and the color filter CF, and between the insulating structure 240 and the color filter CF. The passivation layer 280 may be conformally formed along the surfaces of the insulating structure 240 and the grid structure 250. The passivation layer 280 may include, but is not limited to, at least one of silicon oxide, aluminum oxide, and hafnium oxide. In example embodiments, the passivation layer 280 may be included in N layers on the outer surface of the air gap AG.

[0091] The second chip structure 203 may further include a micro lens ML on the color filter CF.

[0092] The microlens ML may vertically overlap with each color filter CF, respectively. In an example embodiment, each microlens ML may vertically overlap with one color filter CF. Alternatively, the microlenses ML may vertically overlap with a plurality of color filter groups FG, respectively. For example, one microlens among the microlenses ML may vertically overlap with one color filter group among the plurality of color filter groups FG. Accordingly, the microlenses ML may vertically overlap with a plurality of color filters CF, respectively. For example, one microlens among the microlenses ML may vertically overlap with four color filters CF among the plurality of color filters CF. In an example embodiment, at least four microlenses ML may be disposed on each group of photoelectric conversion devices. In an example embodiment, a single microlens ML may be disposed on each group of photoelectric conversion devices.

[0093] Each microlens ML may have a convex shape in a direction away from the first chip structure 103. The microlens ML may converge incident light into the photoelectric conversion device PD. The microlens ML may be formed of a transparent photoresist material or a transparent thermosetting resin material. However, the material of the microlens ML is not limited to the above materials, and therefore, the microlens ML may be formed of other materials.

[0094] Fig. 7A , Figure 7B , Fig. 8A , Figure 8B , Fig.9A , Fig. 9B , Fig. 10A , Fig. 10B and Fig.11 1 is a plan view and a cross-sectional view for describing a process sequence of a method for manufacturing an image sensor according to an example embodiment. For example, Fig. 7A , Fig. 8A , Fig.9A and Fig. 10A is with Figure 4 The corresponding floor plan, and Figure 7B , Figure 8B , Fig. 9B and Fig. 10B They are Fig. 7A , Fig. 8A , Fig.9A and Fig. 10A A vertical cross-sectional view taken along line II'.

[0095] refer to Fig. 7A and Figure 7B , a blocking layer 266 and a sacrificial layer 261 may be formed on the insulating structure 240. The blocking layer 266 and the sacrificial layer 261 may be formed by stacking a blocking material and a sacrificial material on the insulating structure 240, and then patterning the blocking material and the sacrificial material to surround each color filter group FG. In example embodiments, the sacrificial layer 261 may include, but is not limited to, at least one of silicon oxide, silicon nitride, and polysilicon. In example embodiments, the sacrificial layer 261 may include, but is not limited to, an organic material.

[0096] In some example embodiments, the barrier layer 266 may be omitted, and a lower surface of the sacrificial layer 261 may be in contact with the insulating structure 240 .

[0097] refer to Fig. 8A and Figure 8B, a spacer material layer 262P may be formed. For example, the spacer material layer 262P may be disposed on the insulating structure 240, the barrier layer 266, and the sacrificial layer 261. For example, the spacer material layer 262P may cover the insulating structure 240, the barrier layer 266, and the sacrificial layer 261. For example, the spacer material layer 262P may be conformally formed along the surfaces of the insulating structure 240, the barrier layer 266, and the sacrificial layer 261. The spacer material layer 262P may include a material having an etching selectivity relative to the sacrificial layer 261. For example, the spacer material layer 262P may include at least one of silicon oxide, silicon nitride, and silicon carbonitride.

[0098] refer to Fig.9A and Fig. 9B , the sacrificial layer 261 may be removed. First, a spacer layer 262 may be formed by etching a portion of the spacer material layer 262P by performing an anisotropic etching process. The spacer layer 262 may extend in a horizontal direction while covering the side surface of the sacrificial layer 261. The upper surface of the sacrificial layer 261 may be exposed using an etching process. Thereafter, the sacrificial layer 261 may be selectively removed to expose the side surface of the spacer layer 262 and the upper surface of the barrier layer 266.

[0099] refer to Fig. 10A and Fig. 10B , a capping material layer 264P may be formed. The capping material layer 264P may cover the insulating structure 240 and the spacer layer 262. The capping material layer 264P may include a material having a low gap filling capability. Accordingly, the capping material layer 264P may not be filled between the spacer layers 262, and an air gap AG may be formed between the spacer layers 262.

[0100] refer to Fig.11 , a mask layer M may be formed on the capping material layer 264P, and the first grid structure 260 and a plurality of second grid structures 270 may be formed by etching the capping material layer 264P using the mask layer M as an etching mask using an etching process.

[0101] Fig.12 is a vertical cross-sectional view of an image sensor according to example embodiments.

[0102] refer to Fig.12 , the image sensor 1a may include a grid structure 250 including a first grid structure 260 and a plurality of second grid structures 270. In example embodiments, the horizontal width of the first grid structure 260 may be greater than the horizontal width of each of the plurality of second grid structures 270. For example, the air gap AG of the first grid structure 260 of the image sensor 1a may be formed to be larger than Figure 5 The air gap AG is shown to be wider.

[0103] Figures 13 to 17is a vertical cross-sectional view of an image sensor according to example embodiments.

[0104] refer to Fig.13 , the image sensor 1b may include a first grid structure 260 disposed between the color filters CF, the first grid structure 260 including the air gap AG. In example embodiments, an upper portion of the spacer layer 262 of the first grid structure 260 may have a horizontal width that decreases upward. For example, in a cross-sectional view, an upper portion of the spacer layer 262 may have an arc-shaped cross-section.

[0105] refer to Fig.14 , the image sensor 1c may include a first grid structure 260 disposed between the color filters CF, the first grid structure 260 including an air gap AG. Figure 6 Unlike the first grid structure 260 of the image sensor shown, the barrier layer 266 may be omitted in example embodiments. An air gap AG may be defined by the insulating structure 240, the spacer layer 262, and the capping layer 264.

[0106] refer to Fig.15 , the image sensor 1d may include a first grid structure 260 disposed between the color filters CF, the first grid structure 260 including the air gap AG. In example embodiments, the protrusion 264c of the capping layer 264 of the first grid structure 260 may have a downwardly protruding shape. In addition, the horizontal width of the protrusion 264c may decrease downward, and the lower end of the protrusion 264c may be located at a level lower than that of the upper surface of the spacer layer 262.

[0107] refer to Fig.16 , the image sensor 1e may include a first grid structure 260 disposed between the color filters CF, the first grid structure 260 including an air gap AG. In example embodiments, the protrusion 264c of the capping layer 264 of the first grid structure 260 may have a downwardly concave shape. For example, the upper portion of the air gap AG may have an upwardly convex shape.

[0108] refer to Fig.17 , the image sensor 1f may include a first grid structure 260 disposed between the color filters CF, the first grid structure 260 including the air gap AG. In example embodiments, the horizontal width of the first grid structure 260 may increase downward. For example, the horizontal width of the vertical portion 264a of the capping layer 264 may increase downward, and one side surface of the vertical portion 264a may become farther downward from the spacer layer 262.

[0109] Fig.18A is a plan view of an image sensor according to example embodiments, and Fig.18B yes Fig.18A The image sensor is shown in a vertical cross-sectional view taken along line II-II'.

[0110] refer to Fig.18A and Fig.18B , the image sensor 1g may include a first grid structure 260 disposed between the color filters CF, the first grid structure 260 including an air gap AG. Figure 4 The grid structure 250 of the image sensor shown is different, and the second grid structure 270 can be omitted in the example embodiment. For example, the first grid structure 260 can extend in the X direction and the Y direction to surround each of the multiple color filters CF. In a plan view, each of the multiple capping layers 264 of the first grid structure 260 can surround a corresponding color filter CF among the multiple color filters CF. Each of the multiple spacer layers 262 can surround a corresponding color filter CF among the multiple color filters CF, and can surround the corresponding capping layer 264. For example, the first grid structure 260 can extend between the first color filter CF1 included in the first color filter group FG1, and between the second color filter CF2 included in the second color filter group FG2. The first grid structure 260 can also extend between different color filter groups FG. In example embodiments, the blocking layer 266 of the first grid structure 260 may be omitted in at least one region between different color filter groups FG (e.g., between the first color filter CF1 and the second color filter CF2) and within the same color filter group FG (e.g., within the second color filter group FG2).

[0111] Figures 19 to 21 is a plan view of an image sensor according to example embodiments.

[0112] refer to Fig.19 , the image sensor 1h may include a grid structure 250 disposed between the color filters CF, the grid structure 250 including a first grid structure 260 and a plurality of second grid structures 270. In an example embodiment, the first grid structure 260 may extend in the X direction and the Y direction between the color filters CF included in the same color filter group FG. For example, the first grid structure 260 may extend between the first color filters CF1 included in the first color filter group FG1. The first grid structure 260 may also extend between different color filter groups FG. In a plan view, the color filters CF disposed in the first grid structure 260 may be included in different color filter groups FG. For example, two first color filters CF1, one second color filter CF2, and one third color filter CF3 disposed in the first grid structure 260 may be included in different color filter groups FG, respectively.

[0113] In an example embodiment, each of the plurality of second grid structures 270 may be disposed between different color filter groups FG. The plurality of second grid structures 270 may have a cross shape in a plan view. For example, each of the plurality of second grid structures 270 may be disposed in the first grid structure 260. For example, each of the plurality of second grid structures 270 may be disposed between color filters CF included in different color filter groups FG.

[0114] For example, the second grid structure 270 may be disposed between the first color filter CF1 of the first color filter group FG1 and the second color filter CF2 of the second color filter group FG2 adjacent thereto. The first color filters CF1 of the first color filter group FG1 may be spaced apart from each other by the first grid structure 260 .

[0115] refer to Fig. 20 , the image sensor 1i may include a plurality of color filters CF. In an example embodiment, in a plan view, the plurality of color filters CF may have an octagonal shape or a rectangular shape. For example, the color filters CF having an octagonal shape may be arranged in a grid form in the X direction and the Y direction, and the color filters CF having a rectangular shape may be arranged between the color filters CF having an octagonal shape.

[0116] For example, the first color filter CF1, the second color filter CF2, and the third color filter CF3 having an octagonal shape may be arranged in a grid form in the X direction and the Y direction. The first color filter CF1, the second color filter CF2, and the third color filter CF3 having a rectangular shape may be arranged between the first color filter CF1, the second color filter CF2, and the third color filter CF3 having an octagonal shape. As described above, the color filters CF included in the same color filter group FG may filter the same color.

[0117] The image sensor 1i may further include a grid structure 250 disposed between the color filters CF, the grid structure 250 including a first grid structure 260 and a second grid structure 270. In example embodiments, the first grid structure 260 may extend between different color filter groups FG in the X direction, the Y direction, and a direction between the X direction and the Y direction. Fig. 20 As shown, the first grid structure 260 may be disposed between color filters CF included in different color filter groups FG.

[0118] In example embodiments, a plurality of second grid structures 270 may be disposed between color filters CF included in the same color filter group FG. Fig. 20 As shown, the octagonal first color filter CF1 and the rectangular first color filter CF1 may be adjacent to each other, and the second grid structure 270 may be disposed between the octagonal first color filter CF1 and the rectangular first color filter CF1.

[0119] refer to Fig.21 , the image sensor 1j may include a grid structure 250 disposed between the color filters CF, the grid structure 250 including a first grid structure 260 and a second grid structure 270. In an example embodiment, the first grid structure 260 may be disposed to surround one color filter group FG among a plurality of color filter groups FG. For example, the first grid structure 260 may be disposed to surround a third color filter CF3 included in a third color filter group FG3. In an example embodiment, the first grid structure 260 may extend between the third color filter groups FG3 to connect adjacent third color filter groups FG3 to each other. For example, as Fig.21 As shown, the first grid structure 260 may extend along the first color filter CF1 disposed between the third color filter groups FG3.

[0120] The first grid structure 260 may be disposed to surround the color filter group FG including the color filter CF configured to filter a specific color, thereby improving light sensitivity of a desired color and preventing an optical crosstalk phenomenon with an adjacent color filter group FG or a different type color filter group FG.

[0121] According to example embodiments of the inventive concept, the grid structure may include an air gap, thereby preventing or reducing an optical crosstalk phenomenon. In addition, the grid structure may be disposed to surround each color filter group, thereby improving the light sensitivity of the image sensor.

[0122] While example embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations may be made without departing from the scope of the inventive concept as defined by the appended claims.

Claims

1. An image sensor, comprising: A substrate comprising a first surface and a second surface opposite to the first surface; a first photoelectric conversion element, in the substrate; a second photoelectric conversion element, in the substrate; a first separation structure in the substrate and between the first photoelectric conversion element and the second photoelectric conversion element; a second separation structure in the substrate; A first color filter is disposed on the first photoelectric conversion element; A second color filter is disposed on the second photoelectric conversion element; a first grid structure on the first separation structure and between the first color filter and the second color filter; as well as a second grid structure, on the second separation structure, wherein the second photoelectric conversion element is disposed between the first separation structure and the second separation structure, wherein the first grid structure vertically overlaps the first separation structure, and the second grid structure vertically overlaps the second separation structure, wherein the first grid structure comprises an air gap and N layers on an outer surface of the air gap, Each of the N layers extends in a first direction, wherein the second grid structure includes M layers on an outer surface of the second grid structure and extending in the first direction, Where N and M are integers, where N is different from M, and Wherein, the image sensor is configured to receive light from the second surface.

2. The image sensor according to claim 1, further comprising: a third photoelectric conversion element, in the substrate; a third separation structure, in the substrate; as well as a third grid structure on the third separation structure; The third photoelectric conversion element is disposed between the second separation structure and the third separation structure. wherein the third grid structure vertically overlaps the third separation structure, and The third grid structure includes M layers on an outer surface of the third grid structure and extending in the first direction.

3. The image sensor according to claim 2, wherein: The first photoelectric conversion element is configured to detect light of a first wavelength, and The second photoelectric conversion element and the third photoelectric conversion element are configured to detect light of a second wavelength different from the first wavelength.

4. The image sensor according to claim 2, wherein: The first grid structure further comprises L layers on the air gap, wherein a distance from a top surface of the air gap to the second surface is greater than a distance from a bottom surface of the air gap to the second surface, wherein each of the L layers on the top surface of the air gap extends in a second direction perpendicular to the first direction, and Among them, L is different from N.

5. The image sensor according to claim 4, wherein: N is greater than L.

6. The image sensor according to claim 2, wherein: The N layers on the outer side surface of the air gap include a first layer and a second layer, wherein the first layer is in contact with the air gap, and the second layer is in contact with the first layer, and The first layer includes a first material, and the second layer includes a second material different from the first material.

7. The image sensor according to claim 6, further comprising a passivation layer on the second surface, and in, The N layers on the outer side surface of the air gap include the passivation layer, and Wherein, the M layers on the outer surface of the second grid structure include the passivation layer.

8. The image sensor according to claim 7, wherein: The first grid structure includes a barrier layer between the second surface and the air gap.

9. The image sensor according to claim 7, wherein: The first grid structure has a top surface and a bottom surface opposite to the top surface, wherein a distance from a top surface of the first grid structure to the second surface is greater than a distance from a bottom surface of the first grid structure to the second surface, wherein the bottom surface of the air gap has a first width in a second direction perpendicular to the first direction, wherein the bottom surface of the first grid structure has a second width in the second direction, and Wherein, the first width is equal to or greater than half of the second width.

10. The image sensor according to claim 9, wherein: The second grid structure has a top surface and a bottom surface opposite to the top surface, wherein a distance from a top surface of the second grid structure to the second surface is greater than a distance from a bottom surface of the second grid structure to the second surface, wherein the bottom surface of the second grid structure has a third width in the second direction, and The third width is the same as the second width.

11. The image sensor according to claim 10, wherein: The first separation structure penetrates the substrate.

12. An image sensor, comprising: A substrate comprising a first surface and a second surface opposite to the first surface; a first group of photoelectric conversion elements, including a first photoelectric conversion element in the substrate; at least four micro lenses on the first group of photoelectric conversion elements; a second group of photoelectric conversion elements, including a second photoelectric conversion element in the substrate; at least four micro lenses on the second group of photoelectric conversion elements; a first separation structure between the first photoelectric conversion element and the second photoelectric conversion element; a second separation structure between the first group of photoelectric conversion elements; a first grid structure on the first separated structure and vertically overlapping the first separated structure; as well as a second grid structure on and vertically overlapping the second separated structure; wherein the first grid structure comprises an air gap and N layers on an outer surface of the air gap, Each of the N layers extends in a first direction, wherein the second grid structure includes M layers on an outer surface of the second grid structure and extending in the first direction, Where N and M are integers, where N is different from M, and Wherein, the image sensor is configured to receive light from the second surface.

13. The image sensor according to claim 12, wherein: The first photoelectric conversion element is configured to detect light of a first wavelength, and The second photoelectric conversion element is configured to detect light of a second wavelength different from the first wavelength.

14. The image sensor according to claim 13, further comprising: A first single color filter is disposed on the first group of photoelectric conversion elements; as well as A second single color filter is disposed on the second group of photoelectric conversion elements.

15. The image sensor according to claim 13, wherein: The first grid structure also includes a barrier layer between the air gap and the second surface.

16. The image sensor according to claim 15, wherein: The barrier layer of the first grid structure includes a metallic material.

17. The image sensor according to claim 15, wherein: The second grid structure has a top surface and a bottom surface opposite to the top surface, wherein a distance from a top surface of the second grid structure to the second surface is greater than a distance from a bottom surface of the second grid structure to the second surface, and The second grid structure does not include a metal-containing material layer between a bottom surface of the second grid structure and the second surface.

18. The image sensor according to claim 15, wherein: The first grid structure has a top surface and a bottom surface opposite to the top surface, wherein a distance from a top surface of the first grid structure to the second surface is greater than a distance from a bottom surface of the first grid structure to the second surface, and The distance from the top surface of the first grid structure to the second surface is the same as the distance from the top surface of the second grid structure to the second surface.

19. The image sensor according to claim 15, wherein: The at least four microlenses on the first group of photoelectric conversion elements are arranged in one of a 2×2, 3×3 or 4×4 matrix.

20. The image sensor of claim 18, further comprising a passivation layer on the second surface, and in, The N layers on the first grid structure include the passivation layer, and Wherein, the M layers on the second grid structure include the passivation layer.

Images