Image sensor including separated structure

Abstract

To provide an image sensor for improving resolution.SOLUTION: An image sensor includes: a substrate 106; an isolation structure 141 that penetrates the substrate; photoelectric conversion element domains PD separated from each other by the isolation structure in the substrate; a color filter 160 on a second surface 106s2 of the substrate; and a micro-lens 170 on the color filter. The isolation structure includes a lower separation pattern 115 and an upper separation pattern 138. In a plan view, the isolation structure includes first line parts extending in a first horizontal direction and second line parts crossing perpendicularly the first line parts and extending in parallel with each other. In a cross section structure obtained by cutting one first line part in the first horizontal direction, at least one of an upper surface of the lower separation pattern and a lower surface of the upper separation pattern has a wavy shape or sawtooth shape. In a crossing domain in which two line parts crossing each other, a vertical length of either one of the lower separation pattern and the upper separation pattern is about two to about ten times larger than that of the other.SELECTED DRAWING: Figure 2a

Description

Technical Field

[0001] The present invention relates to an image sensor, and particularly to an image sensor including a separation structure.

Background Art

[0002] An image sensor that captures an image and converts it into an electrical signal is used not only in electronic devices for general consumers such as digital cameras, mobile phone cameras, and portable video cameras, but also in cameras attached to automobiles, security devices, robots, and the like. Since such image sensors are required to be miniaturized and have high resolution, various studies have been conducted to meet these requirements.

Summary of the Invention

Problems to be Solved by the Invention

[0003] One of the technical problems to be solved by the technical idea of the present invention is to provide an image sensor capable of increasing the resolution.

Means for Solving the Problems

[0004] The present invention provides an image sensor according to one embodiment of the technical concept of the present invention. This image sensor includes a substrate having a first surface and a second surface opposite to each other, a separation structure penetrating the substrate, photoelectric conversion element regions separated from each other by the separation structure within the substrate, a color filter on the second surface of the substrate, and a microlens on the color filter. The separation structure includes a lower separation pattern and an upper separation pattern on the lower separation pattern. In plan view, the separation structure includes a first line portion extending parallel to each other in a first horizontal direction and a second line portion extending parallel to each other and perpendicularly intersecting the first line portion. The cross-sectional structure obtained by cutting one of the first line portions of the separation structure along the first horizontal direction includes a wavy shape in which concave and convex portions are repeatedly and alternately arranged in the first horizontal direction, and in the intersection region where the first line portion and the second line portion intersect each other, the vertical length of either the lower separation pattern or the upper separation pattern is approximately 2 to 10 times greater than the vertical length of the other.

[0005] The present invention provides an image sensor according to one embodiment of the technical concept of the present invention. This image sensor includes a first chip structure and a second chip structure on the first chip structure. The first chip structure includes a first substrate, a first circuit element and a first wiring structure on the first substrate, and a first insulating layer covering the first circuit element and the first wiring structure on the first substrate. The second chip structure includes a second substrate having a first surface facing the first chip structure and a second surface opposite to the first surface; a second circuit element and a second wiring structure disposed between the first surface of the second substrate and the first chip structure; a second insulating layer covering the second circuit element and the second wiring structure between the first surface of the second substrate and the first chip structure; a separation structure within the second substrate; photoelectric conversion element regions separated from each other by the separation structure within the second substrate; an insulating structure on the second surface of the second substrate; a color filter on the insulating structure; and a microlens on the color filter. The separation structure includes a lower separation pattern having a first vertical length and an upper surface within the second substrate, and an upper separation pattern having a second vertical length smaller than the first vertical length and a lower surface within the second substrate, wherein at least a portion of the upper surface of the lower separation pattern is in contact with at least a portion of the lower surface of the upper separation pattern, and in plan view, the separation structure includes first line portions extending parallel to each other in a first horizontal direction and second line portions extending parallel to each other and perpendicularly intersecting the first line portions, and each of the first line portions is arranged alternately in the first horizontal direction. The invention includes an in region and an intersection region, wherein the intersection region of the first line portion is the region of the first line portion that intersects with the second line portion, and the cross-sectional structure is obtained by cutting one of the first line portions along the first horizontal direction, the upper surface of the lower separation pattern has a wavy shape in which concave and convex portions are arranged alternately in the first horizontal direction, the vertical length of the lower separation pattern in the intersection region is greater than the vertical length of the upper separation pattern, and the first height difference between the upper surface of the lower separation pattern and the first surface of the substrate in the intersection region is approximately 1.5 μm to approximately 10 μm.

[0006] The present invention provides an image sensor according to one embodiment of the technical concept of the present invention. This image sensor includes a first chip structure and a second chip structure on the first chip structure. The first chip structure includes a first substrate, a first circuit element and a first wiring structure on the first substrate, and a first insulating layer covering the first circuit element and the first wiring structure on the first substrate. The second chip structure includes a second substrate having a first surface facing the first chip structure and a second surface opposite to the first surface, a separation structure within the second substrate, a second circuit element and a second wiring structure disposed between the first surface of the second substrate and the first chip structure, a second insulating layer covering the second circuit element and the second wiring structure between the first surface of the second substrate and the first chip structure, a photoelectric conversion element region within the second substrate, an insulating structure on the second surface of the second substrate, a color filter on the insulating structure, and a microlens on the color filter. The separation structure includes a lower separation pattern and an upper separation pattern on the lower separation pattern. In plan view, the separation structure includes a first line portion extending parallel to each other in a first horizontal direction and a second line portion extending parallel to each other and perpendicularly intersecting the first line portion. Each of the first line portions includes line regions and intersection regions arranged alternately in the first horizontal direction. In the first line portion, the intersection region is the region of the first line portion that intersects with the second line portion. In the cross-sectional structure obtained by cutting one of the first line portions along the first horizontal direction, at least one of the upper surface of the lower separation pattern and the lower surface of the upper separation pattern has a wavy shape. In the intersection region, the vertical length of either the lower separation pattern or the upper separation pattern is approximately 2 to 10 times greater than the vertical length of the other. [Effects of the Invention]

[0007] According to an embodiment of the technical concept of the present invention, an image sensor can be provided that includes a separation structure comprising a lower separation pattern and an upper separation pattern on the lower separation pattern. The vertical length of either the lower separation pattern or the upper separation pattern can be greater than the vertical length of the other, and at least one of the upper surface of the lower separation pattern and the lower surface of the upper separation pattern can have a wavy shape in which concave and convex portions are repeatedly and alternately arranged in a certain horizontal direction. Such a separation structure can improve dark current characteristics and prevent crosstalk, thereby improving the signal noise of the image sensor and increasing the resolution of the image sensor.

[0008] The diverse yet significant advantages and effects of the present invention are not limited to those described above and can be more easily understood in the process of describing specific embodiments of the present invention. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic drawing showing an image sensor according to one embodiment of the present invention. [Figure 2a] This is a schematic cross-sectional view showing an image sensor according to one embodiment of the present invention. [Figure 2b] This is a schematic cross-sectional view showing an image sensor according to one embodiment of the present invention. [Figure 2c] This is a schematic cross-sectional view showing an image sensor according to one embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view showing an image sensor according to one embodiment of the present invention. [Figure 4] This is a schematic partially enlarged cross-sectional view showing a modified example of an image sensor according to one embodiment of the present invention. [Figure 5a] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 5b] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 5c] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 6a] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 6b] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 7] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 8a] This is a schematic cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 8b] This is a schematic cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 9a] This is a schematic cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 9b] This is a schematic cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 9c] This is a schematic cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 10a] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 10b] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 11a] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 11b] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 12] This is a schematic partially enlarged cross-sectional view showing another modified example of the image sensor according to one embodiment of the present invention. [Figure 13]It is a schematic partial enlarged cross-sectional view showing another modification of the image sensor according to an embodiment of the present invention. [Figure 14] It is a cross-sectional view schematically showing a method of forming an image sensor according to an embodiment of the present invention. [Figure 15] It is a cross-sectional view schematically showing a method of forming an image sensor according to an embodiment of the present invention. [Figure 16a] It is a cross-sectional view schematically showing a method of forming an image sensor according to an embodiment of the present invention. [Figure 16b] It is a cross-sectional view schematically showing a method of forming an image sensor according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0010] Hereinafter, terms such as "upper", "upper part", "upper surface", "lower", "lower part", "lower surface", "side surface", "upper end", and "lower end" can be understood to refer based on the drawing, unless otherwise indicated by reference numerals and separately named.

[0011] First, referring to FIG. 1, an exemplary example of an image sensor according to an embodiment of the present invention will be described. FIG. 1 is an exploded perspective view for explaining an image sensor according to an embodiment of the present invention, and the partially enlarged area indicated by "A" in FIG. 1 can show an enlarged planar shape of a part of the image sensor shown in the exploded perspective view.

[0012] Referring to FIG. 1, an image sensor 1 according to an embodiment can include a first chip structure 3 and a second chip structure 103 on the first chip structure 3. The first chip structure 3 can be a logic chip, and the second chip structure 103 can be an image sensor chip including a plurality of pixel regions PX. In other examples, the first chip structure 3 can be a stacked chip structure including a logic chip and a memory chip.

[0013] The second chip structure 103 of the image sensor 1 may include a first region CA, a second region EA, and a third region PA.

[0014] The third region PA can be located on at least one side of the central region which includes the first region CA and the second region EA. For example, the third region PA can be located on both sides of the central region which includes the first region CA and the second region EA, or it can be located so as to surround the central region. The second region EA can be located on at least one side of the first region CA. For example, the second region EA can be located on either side of the first region CA, on both sides of the first region CA, or it can be located so as to surround the first region CA.

[0015] The first region CA may include the Active Pixel Sensor Array region, the second region EA may include the Optical Black Region OB and the Inter-chip Connecting Region CB, and the third region PA may include the Pad Region where the Input / Output Pads are located. The third region PA may be referred to as the Pad Region.

[0016] The first region CA may be an active pixel sensor array region into which light is incident, the optical black region OB of the second region EA may be a region into which light is not incident, and the inter-chip connecting region CB of the second region EA may be a region that electrically connects the wiring structure of the first chip structure 3 and the wiring structure of the second chip structure 103. In the embodiment, the optical black region OB and the inter-chip connecting region CB can be arranged in various ways.

[0017] The second chip structure 103 may include multiple pixel regions. These multiple pixel regions PX can be shown in Figure 1 as a planar area indicated by "A," which is an enlarged view of a portion of the second chip structure 103, and are denoted by the drawing reference numeral "PX." The pixel regions PX can be arranged in the first region CA, i.e., the Active Pixel Sensor Array region.

[0018] As shown in "A" in Figure 1, in a plan view, the second chip structure 103 may further include separation structures 141 positioned between each pixel region PX.

[0019] As shown in "A" in Figure 1, in a plan view, the separation structure 141 may include a first line portion 141_1 and a second line portion 141_2 that are parallel to each other. The second line portion 141_2 may intersect the first line portion 141_1 perpendicularly. Each of the first line portions 141_1 may extend in a first horizontal direction Y, and each of the second line portions 141_2 may extend in a second horizontal direction X that is perpendicular to the first horizontal direction Y.

[0020] Each of the first and second line portions 141_1 and 141_2 may include line regions and intersection regions. In the first and second line portions 141_1 and 141_2, the intersection region may be the region where the first line portion 141_1 and the second line portion 141_2 intersect each other. For example, each of the first line portion 141_1 may include line regions 141ia and intersection regions 141ca arranged alternately in the first horizontal direction Y. Similarly, each of the second line portions 141_2 may include line regions and intersection regions arranged alternately in the second horizontal direction X.

[0021] Next, with reference to Figures 2a to 2c, an exemplary example of the image sensor 1 described with reference to Figure 1 will be explained. Figure 2a is a cross-sectional view showing the region taken along the line I-I' in Figure 1, Figure 2b is a partially enlarged cross-sectional view of the region indicated by "B" in Figure 2a, and Figure 2c is a cross-sectional view showing the region taken along the line II-II' in Figure 1, from the first height level L1 in Figure 2b to the second height level L2 which is higher than the first height level L1.

[0022] Referring to Figures 1 and 2a-2c, the first chip structure 3 of the image sensor 1 may include a first substrate 6, an element isolation film 9s that defines an active region 9a on the first substrate 6, a first circuit element 12 and a first wiring structure 15 on the first substrate 6, and a first insulating layer 18 that covers the first circuit element 12 and the first wiring structure 15 on the first substrate 6. The first substrate 6 may be a semiconductor substrate. For example, the first substrate 6 may be a semiconductor substrate formed of a semiconductor material, such as a single-crystal silicon substrate. The circuit element 12 may include elements such as a transistor, which includes a gate 12a and a source / drain 12b.

[0023] The second chip structure 103 may include a second substrate 106 having a first surface 106s1 and a second surface 106s2 opposite to each other, an element isolation film 109 disposed on the first surface 106s1 of the second substrate 106 to limit the active region, a second circuit element 124 and a second wiring structure 127 disposed between the first surface 106s1 of the second substrate 106 and the first chip structure 3, and a second insulating layer 130 covering the second circuit element 124 and the second wiring structure 127 between the first surface 106s1 of the second substrate 106 and the first chip structure 3. The second chip structure 103 may further include an isolation structure 141 and a photoelectric conversion element region PD within the second substrate 106. The first surface 106s1 of the second substrate 106 may face the first chip structure 3. The second substrate 106 may be a semiconductor substrate. For example, the second substrate 206 can be a semiconductor substrate formed of a semiconductor material, such as a single-crystal silicon substrate.

[0024] The second circuit element 124 may include a transfer gate TG, a floating diffusion region FD, and a circuit transistor 121. The circuit transistor 121 may include a gate 121a and a source / drain 121b. The transfer gate TG can transfer charge from an adjacent photoelectric conversion element region PD to an adjacent floating diffusion region FD. The circuit transistor 121 may be at least one of a source follower transistor, a reset transistor, and a selection transistor. The transfer gate TG may be a vertical transfer gate including a portion extending from the first surface 106s1 of the second substrate 106 into the interior of the second substrate 106. The second wiring structure 127 may include multilayer wiring located at different height levels and vias that electrically connect the multilayer wiring to electrically connect the multilayer wiring to the second circuit element 124.

[0025] The first insulating layer 18 and the second insulating layer 130 can be in contact and bonded together. Each of the first and second insulating layers 18 and 130 can be formed as a multilayer containing different types of insulating layers. For example, the second insulating layer 130 can be formed as a multilayer containing at least two types of layers: a silicon oxide layer, a low-k dielectric layer, and a silicon nitride layer.

[0026] The photoelectric conversion element regions PD can be formed inside the second substrate 106 and separated from each other by separation structures 141. A pixel region PX can be defined as a region containing the photoelectric conversion element regions PD. For example, each pixel region PX may contain one photoelectric conversion element region PD. The photoelectric conversion element regions PD can generate and store charge corresponding to incident light. For example, the photoelectric conversion element regions PD may include photodiodes, phototransistors, photogates, pinned photodiodes (PPDs), and combinations thereof.

[0027] The isolation structure 141 can be positioned to surround each photoelectric conversion element region PD. The isolation structure 141 can be positioned within an isolation trench 135 that penetrates the second substrate 106. At least a portion of the isolation structure 141 can penetrate the second substrate 106. The isolation structure 141 can be connected to a portion of the element isolation film 109. For example, the isolation structure 141 can penetrate the element isolation film 109. The element isolation film 109 can be formed of an insulating material such as silicon oxide.

[0028] The isolation trench 135 may include a lower isolation trench 112 extending into the interior of the second substrate 106 from the first surface 106s1 of the second substrate 106 and an upper isolation trench 133 extending into the interior of the second substrate 106 from the second surface 106s2 of the second substrate 106. In one example, at least a portion of the lower isolation trench 112 and at least a portion of the upper isolation trench 133 may be in communication with each other. In one example, the lower isolation trench 112 may extend into the interior of the second substrate 106 while penetrating the element isolation film 109.

[0029] The separation structure 141 may include a lower separation pattern 115 that can be placed in the lower separation trench 112 and an upper separation pattern 138 that can be placed in the upper separation trench 133. The upper separation pattern 138 can be placed on top of the lower separation pattern 115. The upper surface of the lower separation pattern 115 and the lower surface of the upper separation pattern 138 can be placed within the second substrate 106.

[0030] In one example, in the separation structure 141, the lower separation pattern 115 can improve the dark current characteristics of the image sensor 1, and the upper separation pattern 138 can prevent crosstalk of the image sensor 1. Therefore, the separation structure 141 can improve the signal noise of the image sensor 1 and increase the resolution of the image sensor 1.

[0031] In one example, the lower surface of the lower separation pattern 115 can be coplane with the first surface 106s1 of the second substrate 106. In one example, the upper surface of the upper separation pattern 138 can be coplane with the second surface 106s2 of the second substrate 106. In one example, at least a portion of the upper surface of the lower separation pattern 115 can be in contact with at least a portion of the lower surface of the upper separation pattern 138. For example, the entire upper surface of the lower separation pattern 115 can be in contact with the entire lower surface of the upper separation pattern 138. The upper surface of the lower separation pattern 115 and the lower surface of the upper separation pattern 138 can be indicated by the drawing reference numeral "SR" in Figure 2c.

[0032] In a cross-sectional structure obtained by cutting one of the first line portions (141_1 in Figure 1) of the separation structure 141 along the first horizontal direction Y, for example, in a cross-sectional structure as shown in Figure 2c, at least one of the upper surface of the lower separation pattern 115 and the lower surface of the upper separation pattern 138 located inside the second substrate 106 may have a wavy shape in which concave and convex portions are alternately arranged in the first horizontal direction Y, or a sawtooth shape in which upwardly sloped line segments and downwardly sloped line segments are alternately arranged in the first horizontal direction Y. In the sawtooth shape, a horizontal line segment may be arranged between the upwardly sloped line segments and the downwardly sloped line segments. For example, the upper surface SR of the lower separation pattern 115 may have a wavy shape in which recessed portions P1b and convex portions P1a are alternately arranged in the first horizontal direction Y.

[0033] In the embodiments, the term "recessed portion" can mean a downward concave shape when viewed from the drawing, and the term "convex portion" can mean an upward convex shape when viewed from the drawing.

[0034] The upper end portion of the convex portion P1a of the upper surface SR of the lower separation pattern 115 can be located within the intersection region 141ca, and the lower end portion of the concave portion P1b of the upper surface SR of the lower separation pattern 115 can be located within the line region 141ia.

[0035] In a cross-sectional structure obtained by cutting one of the first line portions 141_1 of the separation structure 141 along the second horizontal direction X, for example, a cross-sectional structure as shown in Figure 2b, the upper surface of the lower separation pattern 115 can be convex.

[0036] In one example, in the intersection region (141ca in Figures 1 and 2c) where the first line portion (141_1 in Figure 1) and the second line portion (141_2 in Figure 1) intersect each other, the vertical length of either the lower separation pattern 115 or the upper separation pattern 138 can be approximately 2 to 10 times greater than the vertical length of the other. For example, in the intersection region 141ca of the separation structure 141 for improving the dark current characteristics of the image sensor 1, i.e., reducing dark current and preventing crosstalk, the first vertical length D1a of the lower separation pattern 115 can be approximately 2 to 10 times greater than the second vertical length D2a of the upper separation pattern 138. In one example, in the intersection region 141ca, the first vertical length D1a of the lower separation pattern 115 can be approximately 3 to 9 times greater than the second vertical length D2a of the upper separation pattern 138.

[0037] In one example, the first vertical length D1a of the lower separation pattern 115 in the crossover region 141ca can be approximately 1.5 μm to approximately 10 μm.

[0038] In one example, the first vertical length D1a of the lower separation pattern 115 in the crossover region 141ca can be approximately 2 μm to approximately 9 μm.

[0039] In the intersection region 141ca, the first vertical length D1a can be described as the "first height difference" between the upper surface of the lower separation pattern 115 and the first surface 106s1 of the second substrate 106. In the intersection region 141ca, the second vertical length D2a can be described as the "second height difference" between the lower surface of the upper separation pattern 138 and the second surface 106s2 of the second substrate 106.

[0040] In one example, the lower separation pattern 115 can have a minimum vertical length D1b in the line region (141ia in Figures 1 and 2c) and a maximum vertical length in the intersection region (141ca in Figures 1 and 2c). The maximum vertical length can be the first vertical length D1a described above.

[0041] In one example, the upper separation pattern 138 may have a maximum vertical length D2b in the line region (141ia in Figures 1 and 2c) and a minimum vertical length in the intersection region (141ca in Figures 1 and 2c). The minimum vertical length may be the second vertical length D2a described above.

[0042] The height difference D3 between the lower end portion of the recessed portion P1b and the upper end portion of the convex portion P1a can be the difference between the maximum vertical length D1a and the minimum vertical length D1b of the lower separation pattern 115. The height difference D3 between the lower end portion of the recessed portion P1b and the upper end portion of the convex portion P1a can be the same as the difference between the maximum vertical length D2b and the minimum vertical length D2a of the upper separation pattern 138.

[0043] In one example, the height difference D3 between the lowest end of a recessed portion P1b and the highest end of a convex portion P1a in a recessed portion P1b and a convex portion P1a that are adjacent to each other can be equal to or less than the second vertical length D2a.

[0044] In one example, the lower separation pattern 115 may include a lower material pattern 114b and a lower material layer 114a that covers at least the sides of the lower material pattern 114b. The lower material layer 114a may surround the sides of the lower material pattern 114b and cover the upper surface of the lower material pattern 114b.

[0045] The lower separation pattern 115 may include a conductive material to which a negative bias can be applied in order to improve the dark current characteristics of the image sensor 1. For example, in the lower separation pattern 115, the lower material pattern 114b may include polysilicon to which a negative bias can be applied, and the lower material layer 114a may be formed of an insulating material. For example, the lower material layer 114a may include at least one of silicon oxide and a high-k dielectric. For example, the lower material layer 114a may be formed of silicon oxide. The high-k dielectric may be a dielectric having a dielectric constant higher than the dielectric constant of silicon oxide.

[0046] In one example, the upper separation pattern 138 can be formed from an insulating material. For example, the upper separation pattern 138 can be formed from silicon oxide. In another example, the upper separation pattern 138 can be formed from multiple insulating layers, including a silicon oxide layer and a high-k dielectric layer. The upper separation pattern 138, which can be formed from an insulating material, can prevent crosstalk of the image sensor 1.

[0047] In one example, when viewed with reference to the first surface 106s1 of the second substrate 106, the upper surface SR of the lower separation pattern 115 located within the second substrate 106 can be positioned at a higher level than the upper surface of the element separation film 109 located within the second substrate 106.

[0048] The second chip structure 103 may further include an insulating structure 145 disposed on the second surface 106s2 of the second substrate 106. The insulating structure 145 may cover the isolation structure 141. The insulating structure 145 may include an anti-reflective layer that can be provided by adjusting the refractive index so that incident light can proceed to the photoelectric conversion element region PD with high transmittance.

[0049] The insulating structure 145 may include a plurality of sequentially laminated insulating layers. For example, the plurality of insulating layers of the insulating structure 145 may include a silicon oxide layer and a high-k dielectric layer. For example, the insulating structure 145 may include at least two layers of an aluminum oxide layer, a hafnium oxide layer, a silicon oxynitride layer, a silicon oxide layer, and a silicon nitride layer. For example, the insulating structure 145 may include a first layer 145a, a second layer 145b, a third layer 145c, and a fourth layer 145d, sequentially laminated. The first layer 145a may be an aluminum oxide layer, the second and fourth layers 145b and 145d may each be hafnium oxide layers, and the third layer 145c may be a silicon oxide layer. In one example, the thickness of the first layer 145a may be substantially the same as the thickness of the fourth layer 145d. In one example, the thickness of the second layer 145b may be greater than the thickness of the first layer 145a and the fourth layer 145d, respectively. For example, the thickness of the second layer 145b can be approximately 5 to 7 times greater than the thickness of the first layer 145a. In one example, the thickness of the third layer 145c can be greater than the thickness of the second layer 145b. The thickness of the third layer 145c can be approximately 6 to 8 times greater than the thickness of the first layer 145a.

[0050] The second chip structure 103 may further include a grid pattern structure 150 and a color filter 160 on the insulating structure 145.

[0051] The grid pattern structure 150 can overlap the separation structure 141 in the perpendicular Z direction. The grid pattern structure 150 may include a first grid layer 150a and a second grid layer 150b that are stacked in order. The thickness of the second grid layer 150b may be greater than the thickness of the first grid layer 150a. The first grid layer 150a and the second grid layer 150b may be made of different materials. For example, the first grid layer 150a may be made of a conductive material containing at least one metal or metal nitride. For example, the first grid layer 150a may include at least one of Ti, Ta, TiN, TaN, or W. The second grid layer 150b may include an insulating material. The second grid layer 150b may be made of a low refractive index (LRI) material. For example, the second grid layer 150b may be made of a low refractive index material whose refractive index can be in the range of about 1.1 to about 1.8. The second grid layer 150b may contain an oxide or nitride containing Si, Al, or a combination thereof. For example, the second grid layer 150b may contain porous silicon oxide or network silica nanoparticles.

[0052] The first grid layer 150a within the grid pattern structure 150 can be formed of a conductive material to serve as a charge path for removing charge, thereby improving the optical crosstalk phenomenon of the image sensor 1.

[0053] The color filter 160 can be configured to allow light of a specific wavelength to pass through to the photoelectric conversion element region PD. For example, the color filter 160 can be formed from a material obtained by mixing a pigment containing metal or a metal oxide with a resin. The thickness of each color filter 160 can be greater than the thickness of the grid pattern structure 150. The color filter 160 can cover the grid pattern structure 150 on the insulating structure 145. The color filter 160 can cover the side and top surfaces of the grid pattern structure 150 on the insulating structure 145. The color filter 160 may include a green filter, a red filter, and a blue filter.

[0054] In one example, each of the color filters 160 can be placed in multiple pixel regions PX. For example, the color filters 160 may include a first color filter 160a and a second color filter 160b of different colors, and one first color filter 160a can be placed in multiple pixel regions PX. By placing one of the color filters 160, for example, one first color filter 160a, overlapping with multiple photoelectric conversion element regions PD in multiple pixel regions PX, the sensitivity of the same color, for example, the color of the first color filter 160a, for example, green, can be improved in the image sensor 1. Similarly, the sensitivity of red and blue can also be improved for the same reasons as green.

[0055] The second chip structure 103 may further include microlenses 170 on the color filter 160. In one example, multiple microlenses 170 can be arranged on any one of the color filters 160. For example, multiple microlenses 170 can be arranged on one first color filter 160a and multiple microlenses 170 can be arranged on one second color filter 160b.

[0056] Each microlens 170 can overlap with each photoelectric element region PD in the direction Z perpendicular to it. Each microlens 170 can be convex in the direction away from the first chip structure 3, for example, away from the second substrate 106. The microlens 170 can focus incident light into the photoelectric element region PD. The microlenses 170 can be formed from a transparent photoresist material or a transparent thermosetting resin material. For example, the microlenses 170 can be formed from TMR series resins (Tokyo Ohka Kogo, Co. products) or MFR series resins (Japan Synthetic Rubber Corporation products), but are not limited to these materials.

[0057] Next, with reference to Figure 3, an exemplary example of the cross-sectional structure of the image sensor 1, including the optical black region OB described in Figure 1, will be described. Figure 3 is a cross-sectional view showing the region taken along the line III-III' in Figure 1. In describing the exemplary example of the cross-sectional structure of the image sensor 1 with reference to Figure 3 below, explanations of the components described with reference to Figures 1 to 2c and components that can be easily understood from the content described with reference to Figures 1 to 2c will be omitted.

[0058] Referring to Figure 3 along with Figures 1 to 2c, the region where the photoelectric conversion element region PD' is formed in the optical black region OB of the second chip structure 103, similar to the photoelectric conversion element region PD described above, can be defined by the first reference region, and the region NPD where the photoelectric conversion element region PD is not formed can be defined by the second reference region.

[0059] In the following, in the cross-sectional structure of Figure 3, the area indicated by drawing reference numeral PD' is defined as the first reference region, and the area indicated by drawing reference numeral NPD is defined as the second reference region.

[0060] The first reference region PD' and the second reference region NPD can be placed within the substrate 106 and separated by a separation structure 141, as described with reference to Figures 1 to 2c. That is, the separation structure 141 can surround the sides of the first reference region PD' and the second reference region NPD, respectively. The second reference region NPD can be a comparison region that does not include the photoelectric conversion element region PD or a comparison region of the photoelectric conversion element region PD that does not include the photodiode.

[0061] Within the optical black region OB of the second region EA of the image sensor 1, the second chip structure 103 may include the aforementioned insulating structure 145, which is disposed on the second surface 106s2 of the second substrate 106.

[0062] Within the optical black region OB of the second region EA of the image sensor 1, the second chip structure 103 may further include light-shielding conductive layers 147, 148, a light-shielding color filter layer 162, and an upper capping layer 175, which are sequentially stacked on the insulating structure 145.

[0063] The light-shielding conductive layers 147, 148 and the light-shielding color filter layer 162 can constitute a light-shielding pattern that blocks light. These light-shielding patterns can block light from entering the first reference region PD' and the second reference region NPD. The light-shielding conductive layers 147, 148 may include sequentially stacked metal nitride layers 147 and metal layer 148. The metal nitride layer 147 may contain materials such as TiN or WN, and the metal layer 148 may contain materials such as Ti, W, Cu, Al, Cu, or Ag.

[0064] The light-shielding color filter layer 162 may include a blue filter. The upper capping layer 175 may contain the same material as the microlens 170.

[0065] The optical black region OB can be used to remove noise signals due to dark current. For example, with light blocked by the light-shielding conductive layers 147, 148 and the light-shielding color filter layer 162, the first reference region PD' including a photodiode can be used as a reference pixel for noise removal by the photodiode. Also, with light blocked by the light-shielding conductive layers 147, 148 and the light-shielding color filter layer 162, the second reference region NPD, which does not include a photodiode, can be a region for checking process noise for noise removal by other components instead of a photodiode.

[0066] In this embodiment, the image sensor 1 is located within a via hole that penetrates a portion of the second chip structure 103 and extends into the first chip structure 3 within the inter-chip connecting region CB of the second region EA, and may further include a connecting conductive layer that electrically connects the first chip structure 3 and the second chip structure 103.

[0067] In the embodiment, the image sensor 1 may further include an input / output conductive layer located in a via hole that penetrates a portion of the second chip structure 103 and extends into the first chip structure 3 within the third region PA, and an input / output pad electrically connected to the input / output conductive layer.

[0068] The following describes various modifications of the image sensor 1 described above, with reference to Figures 4 to 13. In describing the modifications of the image sensor 1 below, the focus will be on the components that can be modified or replaced from the components described above, and the components that cannot be modified from the components described above will either be directly cited and explained, or their explanation will be omitted.

[0069] Referring to Figure 4, a modified example of the separation structure 141 described in Figures 1 to 3 will be explained. Figure 4 is a partially enlarged cross-sectional view corresponding to the cross-sectional structure of Figure 2c, and can show a separation structure that can replace the separation structure 141 in Figure 2c. Therefore, referring to Figure 4, the modified portion of the separation structure 141 in Figure 2c will be explained in detail.

[0070] In a modified example, referring to Figure 4, similar to that described in Figure 2c, the separation structure 141a may include a lower separation pattern 115a and an upper separation pattern 138a on the lower separation pattern 115a, and the upper surface SR' of the lower separation pattern 115a located inside the second substrate 106 in the separation structure 141a may have a wavy shape in which recessed portions P1b' and convex portions P1a are alternately arranged in the first horizontal direction Y. The lower separation pattern 115a may have a minimum vertical length D1b' in the line region (141ia in Figures 1 and 4) and a maximum vertical length D1a in the intersection region (141ca in Figures 1 and 4). The upper separation pattern 138a may have a maximum vertical length D2b' in the line region (141ia in Figures 1 and 4) and a minimum vertical length D2a in the intersection region (141ca in Figures 1 and 4).

[0071] Among the recessed portion P1b' and the convex portion P1a, the height difference D3' between the lowest end of the recessed portion P1b' and the highest end of the convex portion P1a in adjacent recessed portion P1b' and convex portion P1a can be greater than the minimum vertical length D2a. Here, the minimum vertical length D2a can be the same as the distance between the highest end of the convex portion P1a and the second surface 106s2 of the second substrate 106.

[0072] Next, a modified example of the image sensor 1 will be described with reference to Figures 5a to 5c. Figures 5a to 5c are partially enlarged cross-sectional views corresponding to the cross-sectional structure of Figure 2c.

[0073] In a modified example, referring to Figure 5a along with Figures 1 to 2b, the image sensor 1 may include a separation structure 141b that can replace the separation structure in Figure 2c (141 in Figure 2c). The separation structure 141b may include a lower separation pattern 115b and an upper separation pattern 138b on the lower separation pattern 115b. The lower separation pattern 115b may have the same cross-sectional structure as the lower separation pattern in Figure 2c (115 in Figure 2c) or the lower separation pattern in Figure 4 (115 in Figure 4). For example, the upper surfaces SR1 and SR2 of the lower separation pattern 115b located inside the second substrate 106 in the separation structure 141b may have a wavy shape in which recessed portions P1b and convex portions P1a are alternately arranged in the first horizontal direction Y. The upper surfaces SR1 and SR2 of the lower separation pattern 115b may have a first upper surface SR1 that is separated from the upper separation pattern 138b and a second upper surface SR2 that is in contact with the upper separation pattern 138b. The lower surfaces SR3 and SR2 of the upper separation pattern 138b located inside the second substrate 106 in the separation structure 141b may have a first lower surface SR3 that is separated from the lower separation pattern 115b and a second lower surface SR2 that is in contact with the lower separation pattern 115b. The second upper surface SR2 of the lower separation pattern 115b may be in contact with the second lower surface SR2 of the upper separation pattern 138b. Since the second upper surface SR2 of the lower separation pattern 115b and the second lower surface SR2 of the upper separation pattern 138b are in contact with each other, they may be represented by a single reference numeral "SR2".

[0074] The first upper surface SR1 of the lower separation pattern 115b may be an upper surface including a recessed portion P1b, and the second upper surface SR2 of the lower separation pattern 115b may be an upper surface including a convex portion P1a.

[0075] The image sensor 1 may further include a semiconductor region 106a positioned between the first upper surface SR1 of the lower separation pattern 115b and the first lower surface SR3 of the upper separation pattern 138b. The semiconductor region 106a can be in contact with the first upper surface SR1 of the lower separation pattern 115b and the first lower surface SR3 of the upper separation pattern 138b. The semiconductor region 106a can be formed from the same material as the semiconductor material of the second substrate 106, for example, single-crystal silicon.

[0076] The upper surface of the semiconductor region 106a can be positioned at a higher level than the upper end portion of the protruding portion P1a of the upper surfaces SR1 and SR2 of the lower separation pattern 115b.

[0077] In a modified example, referring to Figure 5b along with Figures 1 to 2b, the image sensor 1 may include a separation structure 141c that can replace the separation structure in Figure 5a (141b in Figure 5a). For example, the separation structure 141c may include a lower separation pattern 115c having substantially the same structure as the lower separation pattern in Figure 5a (115b in Figure 5a), and may include an upper separation pattern 138c that can replace the upper separation pattern in Figure 5a (138b in Figure 5a). For example, the lower surfaces SR3' and SR2 of the upper separation pattern 138c located inside the second substrate 106 in the separation structure 141c may have a first lower surface SR3' that is separated from the lower separation pattern 115c and a second lower surface SR2 that is in contact with the lower separation pattern 115c, and the first lower surface SR3' of the upper separation pattern 138c may have a substantially flat shape. Similar to Figure 5a, the image sensor 1 may further include a semiconductor region 106b positioned between the first upper surface SR1 of the lower separation pattern 115c and the first lower surface SR3' of the upper separation pattern 138c. The upper surface of the semiconductor region 106c in contact with the first lower surface SR3' of the upper separation pattern 138c may be substantially flat.

[0078] In a modified example, referring to Figure 5c along with Figures 1 to 2b, the image sensor 1 may include a separation structure 141d that can replace the separation structure in Figure 5b (141c in Figure 5b). For example, the separation structure 141d may include a lower separation pattern 115d that is substantially identical to the lower separation pattern in Figure 5b (115c in Figure 5b), and may include an upper separation pattern 138d that can replace the upper separation pattern in Figure 5b (138c in Figure 5b). For example, the lower surfaces SR3'' and SR2 of the upper separation pattern 138d located inside the second substrate 106 in the separation structure 141d may have a first lower surface SR3'' that is separated from the lower separation pattern 115d and a second lower surface SR2 that is in contact with the lower separation pattern 115d. The first lower surface SR3'' of the upper separation pattern 138d may have a curved shape that is bent downwards.

[0079] Similar to Figure 5a, the image sensor 1 may further include a semiconductor region 106c positioned between the first upper surface SR1 of the lower separation pattern 115d and the first lower surface SR3" of the upper separation pattern 138d. The upper surface of the semiconductor region 106c in contact with the first lower surface SR3" of the upper separation pattern 138d may be concave.

[0080] Next, with reference to Figure 6a, a modified example of the insulating structure 145 and the upper separation pattern 138 of the separation structure 141 described above will be explained. Figure 6a is a partially enlarged cross-sectional view corresponding to Figure 2b, and can show a modified example of the insulating structure 145 and the upper separation pattern 138 shown in Figure 2b.

[0081] In the modified example, referring to Figure 6a along with Figures 1 and 2a, the upper separation pattern (138 in Figure 2b) described in Figure 2b can be formed by extending at least some of the layers 145a, 145b, 145c, and 145d of the insulating structure 145 described in Figure 2b. Therefore, at least some of the layers 145a, 145b, 145c, and 145d of the insulating structure 145 can be formed integrally with the upper separation pattern 138e. For example, the first and second layers 145a and 145b of the insulating structure 145 can be extended to fill the upper separation trench 133 described above. Of the multiple layers 145a, 145b, 145c, and 145d of the insulating structure 145, the portions 145a' and 145b' of the first and second layers 145a and 145b that extend into the upper separation trench 133 and fill the upper separation trench 133 can constitute the upper separation pattern 138e.

[0082] The cross-sectional structure of separation structure 141e can be deformed in the same way as any one of the separation structures described in Figures 2c, 4, and 5a to 5c.

[0083] Next, with reference to Figure 6b, a modified example of the upper separation pattern 138 of the separation structure 141 described above will be explained. As a partially enlarged cross-sectional view corresponding to Figure 2b, Figure 6b can show a modified example of the separation structure 141 shown in Figure 2b.

[0084] In the modified examples, referring to Figure 6b along with Figures 1 and 2a, the upper separation pattern 138 shown in Figure 2b can be replaced by an upper separation pattern 138f, which includes an upper material pattern 137b and an upper material layer 137a covering the sides of the upper material pattern 137b. The lower separation pattern 115 shown in Figure 2b can be replaced by a lower separation pattern 115f, which includes a lower material pattern 114b' in contact with the upper material pattern 137b and a lower material layer 114a covering the sides of the lower material pattern 114b'. Therefore, the separation structure 141 in Figure 2b can be replaced by a separation structure 141f, which includes a lower separation pattern 115f and an upper separation pattern 138f. At least one of the lower material pattern 114b' and the upper material pattern 137b can be made of polysilicon. At least one of the lower material layer 114a' and the upper material layer 137a can include at least one of silicon oxide or a high-k dielectric. For example, the lower material layer 114a' and the upper material layer 137a can be formed from silicon oxide.

[0085] The cross-sectional structure of the separation structure 141f can be deformed in the same way as any one of the separation structures described in Figures 2c, 4, and 5a to 5c.

[0086] Next, with reference to Figure 7, a modified example of the lower separation pattern 115 of the separation structure 141 described above will be explained. Figure 7 can be shown as a partially enlarged cross-sectional view corresponding to Figure 2b, illustrating a modified example of the separation structure 141 shown in Figure 2b.

[0087] In a modified example, referring to Figure 7 along with Figures 1 and 2a, the lower separation pattern 115 shown in Figure 2b can be replaced by a lower separation pattern 115g, which includes a first lower material pattern 114b'', a lower material layer 114a'' covering at least the sides of the first lower material pattern 114b'', and a second lower material pattern 114c positioned below the first lower material pattern 114b''. Thus, the separation structure 141 shown in Figure 2b can be replaced by a separation structure 141g, which includes the lower separation pattern 115g along with the upper separation pattern 138.

[0088] The lower surface of the second lower material pattern 114c can be coplane with the first surface 106s1 of the second substrate 106.

[0089] The first and second lower material patterns 114b'' and 114c can have the same cross-sectional structure as the lower material pattern described above, for example, the lower material pattern 114b in Figure 2b.

[0090] The vertical length of the first lower material pattern 114b" can be greater than the vertical length of the second lower material pattern 114c.

[0091] The first and second lower material patterns 114b'' and 114c can be formed from different materials. For example, the first lower material pattern 114b'' can be formed from polysilicon, and the second lower material pattern 114c can be formed from an insulating material. For example, the second lower material pattern 114c can include at least one of silicon oxide and a high-k dielectric.

[0092] The cross-sectional structure of separation structure 141g can be deformed in the same way as any one of the separation structures described in Figures 2c, 4, and 5a to 5c.

[0093] Next, a modified example of the image sensor 1 according to one embodiment of the present invention will be described with reference to Figures 8a and 8b. Figure 8a can be a cross-sectional view showing a cross-sectional structure corresponding to the cross-sectional structure of Figure 2a, and Figure 8b is a partially enlarged view of the portion indicated by "C" in Figure 8a, and can be a cross-sectional view showing a cross-sectional structure corresponding to the cross-sectional structure of Figure 2b.

[0094] In the modified example, referring to Figures 8a and 8b, of the element isolation film 109 in Figures 2a and 2b, the element isolation film that comes into contact with the lower isolation pattern 115 of the isolation structure 141 in Figures 2a and 2b (109 in Figures 2a and 2b) is omitted, and the remaining element isolation film 109 can remain. Therefore, the isolation structure 141 is separated from the element isolation film 109 and can penetrate the second substrate 106.

[0095] Next, a modified example of the image sensor 1 according to one embodiment of the present invention will be described with reference to Figures 9a, 9b, and 9c. Figure 9a can be a cross-sectional view showing a cross-sectional structure corresponding to the cross-sectional structure of Figure 2a, Figure 9b is a partially enlarged view of the portion indicated by "D" in Figure 9a and can be a cross-sectional view showing a cross-sectional structure corresponding to the cross-sectional structure of Figure 2b, and Figure 9c can be a cross-sectional view showing a cross-sectional structure corresponding to the cross-sectional structure of Figure 2c.

[0096] In a modified example, referring to Figures 1 and 9a-9c, the separation structure 241 may include a lower separation pattern 215 that can replace the lower separation pattern 115 described in Figures 2a and 2b, and an upper separation pattern 238 that can replace the upper separation pattern 138 described in Figures 2a and 2b. The separation structure 241 may be placed within a separation trench 235 that penetrates the second substrate 106. In the separation structure 241, the lower separation pattern 215 may be placed within the lower separation trench 212, and the upper separation pattern 238 may be placed within the upper separation trench 233.

[0097] The planar shape of the separation structure 241 can be the same as the planar shape of the separation structure 141 described in Figure 1. Therefore, the separation structure 241 can include the first and second line portions (141_1 and 141_2 in Figure 1) described in Figure 1, and can include the line region 141ia and the intersection region 141ca described in Figure 1.

[0098] In one example, the lower surface of the lower separation pattern 215 can be in contact with the first surface 106s1 of the second substrate 106, and the upper surface of the upper separation pattern 238 can be in contact with the second surface 106s2 of the second substrate 106.

[0099] In one example, at least a portion of the upper surface SRa of the lower separation pattern 215 can come into contact with at least a portion of the lower surface of the upper separation pattern 238.

[0100] In a cross-sectional structure obtained by cutting one of the first line portions (141_1 in Figure 1) of the separation structure 241 along the first horizontal direction Y, for example, in a cross-sectional structure as shown in Figure 9c, at least one of the upper surface SRa of the lower separation pattern 215 and the lower surface of the upper separation pattern 238 located inside the second substrate 106 may have a wavy shape in which recessed portions and convex portions are alternately arranged in the first horizontal direction Y. For example, the upper surface SRa of the lower separation pattern 215 may have a wavy shape in which recessed portions P2b and convex portions P2a are alternately arranged in the first horizontal direction Y.

[0101] In one example, the upper end portion of the convex portion P2a of the upper surface SRa of the lower separation pattern 215 can be located within the intersection region 141ca, and the lower end portion of the concave portion P2b of the upper surface SRa of the lower separation pattern 215 can be located within the line region 141ia.

[0102] In one example, a cross-sectional structure obtained by cutting one of the first line portions 141_1 of the separation structure 141 along the second horizontal direction X, for example, a cross-sectional structure as shown in Figure 9b, can have a convex upper surface of the lower separation pattern 215.

[0103] In one example, in the intersection region (141ca in Figures 1 and 9c) where the first line portion (141_1 in Figure 1) and the second line portion (141_2 in Figure 1) intersect each other, the vertical length D2aa of the upper separation pattern 238 can be approximately 2 to 10 times larger than the vertical length D1aa of the lower separation pattern 215.

[0104] In one example, the vertical length D2aa of the upper separation pattern 238 in the intersection region 141ca can be approximately 3 to 9 times larger than the vertical length D1aa of the lower separation pattern 215.

[0105] In one example, the vertical length D2aa of the upper separation pattern 238 in the crossing region 141ca can be approximately 1.5 μm to approximately 10 μm.

[0106] In one example, the vertical length D2aa of the upper separation pattern 238 in the crossing region 141ca can be approximately 2 μm to approximately 9 μm.

[0107] In one example, the lower separation pattern 215 can have a minimum vertical length D1bb in the line region (141ia in Figures 1 and 9c) and a maximum vertical length D1aa in the intersection region (141ca in Figures 1 and 9c).

[0108] In one example, the upper separation pattern 238 may have a maximum vertical length D2bb in the line region (141ia in Figures 1 and 9c) and a minimum vertical length D2aa in the intersection region (141ca in Figures 1 and 9c).

[0109] In one example, the lower separation pattern 215 may include a lower material pattern 214b and a lower material layer 214a covering at least the sides of the lower material pattern 214b. The lower material layer 214a may surround the sides of the lower material pattern 214b and cover the upper surface of the lower material pattern 214b. The lower material pattern 214b may contain polysilicon, and the lower material layer 214a may be formed of an insulating material. For example, the lower material layer 214a may include at least one of silicon oxide and a high-k dielectric. In one example, the upper separation pattern 238 may be formed of an insulating material. For example, the upper separation pattern 238 may be formed of silicon oxide. In another example, the upper separation pattern 238 may be formed of multiple insulating layers, including a silicon oxide layer and a high-k dielectric layer.

[0110] In one example, when viewed with reference to the first surface 106s1 of the second substrate 106, the upper surface SRa of the lower isolation pattern 215 located within the second substrate 106 can be positioned at a higher level than the upper surface of the element isolation film 109 located within the second substrate 106.

[0111] Next, a modified example of the separation structure 241 will be described with reference to Figures 10a and 10b. Figure 10a can be a cross-sectional view showing a cross-sectional structure corresponding to the cross-sectional structure of Figure 9b, and Figure 10b can be a cross-sectional view showing a cross-sectional structure corresponding to the cross-sectional structure of Figure 9c.

[0112] In a modified example, referring to Figures 10a and 10b, the separation structure 241a may include a lower separation pattern 215a that can replace the lower separation pattern 215 described in Figures 9b and 9c, and an upper separation pattern 238a that can replace the upper separation pattern 238 described in Figures 9b and 9c.

[0113] The planar shape of the separation structure 241a can be the same as the planar shape of the separation structure 141 described in Figure 1. Therefore, the separation structure 241a can include the first and second line portions (141_1 and 141_2 in Figure 1) described in Figure 1, and can include the line region 141ia and the intersection region 141ca described in Figure 1.

[0114] The lower separation pattern 215a may include a lower material pattern 214b and a lower material layer 214a covering the sides of the lower material pattern 214b, and the upper separation pattern 238a may be in contact with at least the lower material pattern 214b. The lower material pattern 214b may contain polysilicon, and the lower material layer 214a may be formed of an insulating material. The upper separation pattern 238a may be formed of an insulating material.

[0115] In one example, at least a portion of the upper surface SRb of the lower separation pattern 215a can come into contact with at least a portion of the lower surface of the upper separation pattern 238.

[0116] In a cross-sectional structure obtained by cutting one of the first line portions (141_1 in Figure 1) of the separation structure 241a along the first horizontal direction Y, for example, in a cross-sectional structure like that in Figure 10b, at least one of the upper surface SRb of the lower separation pattern 215a and the lower surface of the upper separation pattern 238a located inside the second substrate 106 may have a wavy shape in which recessed portions and convex portions are alternately arranged in the first horizontal direction Y. For example, the upper surface SRb of the lower separation pattern 215a may have a wavy shape in which recessed portions P2aa and convex portions P2bb are alternately arranged in the first horizontal direction Y.

[0117] In one example, the upper end portion of the convex portion P2bb of the upper surface SRb of the lower separation pattern 215a can be located within the line region 141ia, and the lower end portion of the concave portion P2aa of the upper surface SRb of the lower separation pattern 215a can be located within the intersection region 141ca.

[0118] In one example, a cross-sectional structure obtained by cutting one of the first line portions 141_1 of the separation structure 241a along the second horizontal direction X, for example, a cross-sectional structure as shown in Figure 10a, can have a concave upper surface of the lower separation pattern 215a.

[0119] In one example, in the intersection region (141ca in Figures 1 and 9c) where the first line portion (141_1 in Figure 1) and the second line portion (141_2 in Figure 1) intersect, the vertical length D2ab of the upper separation pattern 238a can be approximately 2 to 10 times larger than the vertical length D1ab of the lower separation pattern 215a. In another example, in the intersection region 141ca, the vertical length D2ab of the upper separation pattern 238a can be approximately 3 to 9 times larger than the vertical length D1ab of the lower separation pattern 215a.

[0120] In one example, the vertical length D2ab of the upper separation pattern 238a in the crossing region 141ca can be approximately 1.5 μm to approximately 10 μm.

[0121] In one example, the vertical length D2ab of the upper separation pattern 238a in the crossing region 141ca can be approximately 2 μm to approximately 9 μm.

[0122] In one example, the lower separation pattern 215a may have a maximum vertical length D1bc in the line region (141ia in Figures 1 and 10b) and a minimum vertical length D1ab in the intersection region (141ca in Figures 1 and 10b).

[0123] In one example, the upper separation pattern 238a can have a minimum vertical length D2bc in the line region (141ia in Figures 1 and 10b) and a maximum vertical length D2ab in the intersection region (141ca in Figures 1 and 10b).

[0124] In one example, the lower separation pattern 215a may include a lower material pattern 214b and a lower material layer 214a covering at least the sides of the lower material pattern 214b. The lower material layer 214a may cover the sides of the lower material pattern 214b. The lower material pattern 214b may contain polysilicon, and the lower material layer 214a may be formed of an insulating material.

[0125] In one example, the upper separation pattern 238a can be formed of an insulating material. For example, the upper separation pattern 238a can be formed of silicon oxide. In another example, the upper separation pattern 238a can be formed of multiple insulating layers, including a silicon oxide layer and a high-k dielectric layer.

[0126] In one example, the upper separation pattern 238a can come into contact with the lower material pattern 214b.

[0127] Next, with reference to Figure 11a, a modified example of the upper separation pattern 238a of the separation structure 241b will be described. Figure 11a can be shown as a partially enlarged cross-sectional view corresponding to Figure 10a, illustrating a modified example of the upper separation pattern 238b shown in Figure 10a.

[0128] In a modified example, referring to Figure 11a, the upper separation pattern described in Figure 10a (238a in Figure 10a) can be replaced by an upper separation pattern 238b formed by extending at least some of the multiple layers 145a, 145b, 145c, and 145d of the insulating structure 145 described in Figure 2b. Therefore, the separation structure 241b can include the upper separation pattern 238b and a lower separation pattern 215b having a structure substantially identical to the lower separation pattern 215a in Figure 10a.

[0129] At least some of the layers 145a, 145b, 145c, and 145d of the insulating structure 145 can be formed integrally with the upper separation pattern 238b. The upper separation pattern 238b can consist of at least some of the layers 145a, 145b, 145c, and 145d of the insulating structure 145, for example, material layers 145a'' and 145b'' formed by extending the first and second layers 145a and 145b. Similarly, the upper separation pattern 238 in Figure 9b can consist of material layers formed by extending at least some of the layers 145a, 145b, 145c, and 145d of the insulating structure 145.

[0130] Next, with reference to Figure 11b, a modified example of the upper separation pattern 238a of the separation structure 241b will be described. Figure 11b can be shown as a partially enlarged cross-sectional view corresponding to Figure 10a, illustrating a modified example of the upper separation pattern 238b shown in Figure 10a.

[0131] In the modified example, referring to Figure 11b along with Figures 1 and 2a, the upper separation pattern described in Figure 10a (238a in Figure 10a) can be replaced by an upper separation pattern 238c, which includes an upper material pattern 237b and an upper material layer 237a covering the sides of the upper material pattern 237b. Thus, the separation structure 241c can include the upper separation pattern 238c and a lower separation pattern 215c having a structure substantially identical to the lower separation pattern 215a in Figure 10a. At least one of the lower material pattern 214b and the upper material pattern 237b can be formed of polysilicon. At least one of the lower material layer 214a and the upper material layer 237a can include at least one of silicon oxide or a high-k dielectric.

[0132] Next, various examples of the side profiles of the separation structure described above will be explained with reference to Figures 12 and 13, respectively. Figures 12 and 13 are partially enlarged cross-sectional views showing the cross-sectional structure corresponding to the partially enlarged cross-sectional structure in Figure 2b.

[0133] First, referring to Figure 12, the separation structure 341 located within the separation trench 335 in the second substrate 106 may include a lower separation pattern 315 that can be located within the lower separation trench 312 and an upper separation pattern 338 that can be located within the upper separation trench 333. The upper separation pattern 338 can be in contact with the lower separation pattern 315 on the lower separation pattern 315.

[0134] In one example, the lower separation pattern 315 may include a lower material pattern 314b and a lower material layer 314a covering at least the sides of the lower material pattern 314b. The lower material pattern 314b may be formed of polysilicon, and at least one of the lower material layers 314a may include at least one silicon oxide or a high-k dielectric.

[0135] In one example, the upper separation pattern 338 may include at least one of silicon oxide or a high-k dielectric.

[0136] The lower separation pattern 315 may have sides that are sloped such that they become narrower from bottom to top. The upper separation pattern 338 may have sides that are sloped such that they become narrower from top to bottom. For example, the lower separation pattern 315 may have sides with a positive slope, and the upper separation pattern 338 may have sides with a negative slope.

[0137] The lower separation patterns described above (115 in Figures 2b, 6a, and 8b, 115f in Figure 6b, 115g in Figure 7, 215 in Figure 9b, 215a in Figure 10a, 215b in Figure 11a, and 215c in Figure 11c) can have substantially vertical sides. In exemplary embodiments, at least one of the lower separation patterns (2b, 6a, 115 in Figure 8b, 115f in Figure 6b, 115g in Figure 7, 215 in Figure 9b, 215a in Figure 10a, 215b in Figure 11a, and 215c in Figure 11c) can be modified to have sides with a positive incline, similar to the lower separation pattern 315.

[0138] The upper separation patterns described above (Figures 2b, 7, 8b, 6a, 6b, 6b, 9b, 138a, 10a, 11a, 11b, and 11b) can have substantially vertical sides. In exemplary embodiments, at least one of the upper separation patterns (Figures 2b, 7, 8b, 6a, 6b, 6b, 9b, 10a, 11a, 11b, and 11b) can have sides with a negative slope, similar to the upper separation pattern 338.

[0139] Referring to Figure 13, the isolation structure 441 located within the isolation trench 435 in the second substrate 106 may include a lower isolation pattern 415 that can be located within the lower isolation trench 412 and an upper isolation pattern 438 that can be located within the upper isolation trench 433. The upper isolation pattern 438 may be in contact with the lower isolation pattern 415 on the lower isolation pattern 415.

[0140] In one example, the lower separation pattern 415 may include a lower material pattern 414b and a lower material layer 414a covering at least the sides of the lower material pattern 414b. The lower material pattern 414b may be formed of polysilicon, and at least one of the lower material layers 414a may include at least one silicon oxide or a high-k dielectric.

[0141] In one example, the upper separation pattern 438 may include at least one of silicon oxide or a high-k dielectric.

[0142] In the separation structure 441, the central axis between the two sides of the lower separation pattern 415 may not be aligned perpendicular to the central axis between the two sides of the upper separation pattern 438 in the Z direction.

[0143] The central axes of the lower separation patterns described above (115 in Figures 2b, 6a, and 8b, 115f in Figure 6b, 115g in Figure 7, 215 in Figure 9b, 215a in Figure 10a, 215b in Figure 11a, and 215c in Figure 11b) can be aligned perpendicular to the Z direction with the central axis of the corresponding upper separation patterns (138 in Figures 2b, 7, and 8b, 138e in Figure 6a, 138f in Figure 6b, 238 in Figure 9b, 238a in Figure 10a, 238b in Figure 11a, and 238c in Figure 11b).

[0144] In the exemplary embodiment, similar to the separation structure 441, the central axes of the lower separation patterns described above (115 in Figures 2b, 6a, and 8b, 115f in Figure 6b, 115g in Figure 7, 215 in Figure 9b, 215a in Figure 10a, 215b in Figure 11a, and 215c in Figure 11b) may not be aligned in the vertical Z direction with the central axis of the corresponding upper separation patterns (138 in Figures 2b, 7, and 8b, 138e in Figure 6a, 138f in Figure 6b, 238 in Figure 9b, 238a in Figure 10a, 238b in Figure 11a, and 238c in Figure 11b).

[0145] Next, an exemplary example of a method for forming an image sensor according to one embodiment of the present invention will be described. Figures 14, 15, 16a, and 16b are schematic cross-sectional views showing a region taken along the line I-I' in Figure 1 to illustrate the method for forming an image sensor according to one embodiment of the present invention.

[0146] Referring to Figure 14, the first chip structure 3 can be formed. Forming the first chip structure 3 may include preparing a first substrate 6, forming an element isolation film 9s that limits the active region 9a on the first substrate 6, forming a first circuit element 12 on the first substrate 6, forming a first wiring structure 15 that is electrically connected to the first circuit element 12 on the first substrate 6, and forming a first insulating layer 18 that covers the first circuit element 12 and the first wiring structure 15.

[0147] Referring to Figure 15, a second chip 103a can be formed. Forming the second chip 103a may include preparing a second substrate 106 having a first surface 106s1 and a second surface 106s2 opposite to each other, forming a lower isolation pattern 115 and a photoelectric conversion element region PD within the second substrate 106, forming an element isolation film 109 that limits the active region on the first surface 106s1 of the second substrate 106, forming a second circuit element 124 on the first surface 106s1 of the second substrate 106, forming a second wiring structure 127 and a second insulating layer 130 that covers the second circuit element 124 and the second wiring structure 127 on the first surface 106s1 of the second substrate 106. The order in which the lower isolation pattern 115, the photoelectric conversion element region PD, and the element isolation film 109 are formed can be varied in many ways.

[0148] In one example, forming the lower separation pattern 115 may include forming a lower separation trench 112 that penetrates the element separation film 109 and extends into the interior of the second substrate 106, forming a lower material layer 114a that covers the inner wall of the lower separation trench 112, and forming a lower material pattern 114b on the lower material layer 114a that fills the lower separation trench 112.

[0149] Referring to Figure 16a, the wafer bonding process to join the two wafers can be carried out to join the first chip structure 3 and the second chip (103a in Figure 15). The first insulating layer 18 of the first chip structure 3 and the second insulating layer 130 of the second chip 103a can be joined.

[0150] Referring to Figure 16b, in one example, a grinding process can be performed to reduce the thickness of the second substrate 106 of the second chip 103a. An upper separation pattern 138 can be formed within the second substrate 106 whose thickness has been reduced. The upper separation pattern 138 and the lower separation pattern 115 can constitute a separation structure 141.

[0151] In one example, forming the upper separation pattern 138 may include etching the second substrate 106 to form an upper separation trench 133 that exposes at least a portion of the lower separation pattern 115, and filling the upper separation trench 133 with material for forming the upper separation pattern 138. Thus, the upper separation pattern 138 can be formed within the upper separation trench 133.

[0152] Referring again to Figure 2a, an insulating structure 145 can be formed on the second surface 106s2 of the second substrate 106. A grid pattern structure 150 can be formed on the insulating structure 145. A color filter 160 covering the grid pattern structure 150 and a microlens 170 can be formed on the insulating structure 145.

[0153] While embodiments of the present invention have been described above with reference to the attached drawings, those with ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without altering its technical idea or essential features. Therefore, the embodiments described above should be understood to be illustrative and not limiting in all respects. [Explanation of Symbols]

[0154] 1 Image sensor 3. First chip structure 6. First substrate 12 First Circuit Element 15 1st wiring structure 18. First insulating layer 103 Second chip structure 106 Second board 106s1 Page 1 106s2 Page 2 PD (Photoelectric Detector) Photoelectric Converter Region 135 Separation Trench 141 Separation Structure 115 Lower separation pattern 115a Lower material pattern 115b Lower material layer 138 Upper separation pattern 141_1 First line section 141_2 Second line section 141i line area 141ca Cross-region 145 Insulating Structures 150 Grid Pattern Structures 160 Color Filters 170 Microlenses

Claims

1. A substrate having a first surface and a second surface opposite to each other, A separation structure that penetrates the aforementioned substrate, Photoelectric conversion element regions separated from each other by the separation structure within the substrate, The color filter on the second surface of the substrate, The color filter includes a microlens, The separation structure includes a lower separation pattern and an upper separation pattern on the lower separation pattern. In a plan view, the separation structure includes a first line portion extending parallel to each other in a first horizontal direction and a second line portion extending parallel to each other and perpendicular to the first line portion. A cross-sectional structure obtained by cutting one of the first line portions of the separation structure along the first horizontal direction, wherein at least one of the upper surface and the lower surface of the lower separation pattern has a wavy shape or a sawtooth shape. An image sensor in which, in the intersection region where the first line portion and the second line portion intersect each other, the vertical length of either the lower separation pattern or the upper separation pattern is 2 to 10 times greater than the vertical length of the other.

2. The image sensor according to claim 1, wherein in the intersection region, the first height difference between the level of the upper surface of the lower separation pattern and the level of the first surface of the substrate is three to nine times greater than the second height difference between the level of the upper surface of the lower separation pattern and the level of the second surface of the substrate.

3. In the aforementioned intersection region, the vertical length of the lower separation pattern is greater than the vertical length of the upper separation pattern. The image sensor according to claim 1, wherein in the intersection region, the first height difference between the level of the upper surface of the lower separation pattern and the level of the first surface of the substrate is 1.5 μm to 10 μm.

4. The image sensor according to claim 1, wherein the lower separation pattern includes a lower material pattern and a lower material layer covering at least the sides of the lower material pattern.

5. The aforementioned lower material pattern includes polysilicon, The lower material layer comprises silicon oxide, as described in claim 4, for the image sensor.

6. The upper separation pattern comprises an insulating material, as described in claim 4 or 5, for the image sensor.

7. The present invention further includes an insulating structure between the second surface of the substrate and the color filter, The insulating structure includes multiple layers stacked in sequence, The image sensor according to any one of claims 1 to 6, wherein the plurality of layers include a silicon oxide layer and a high-k dielectric layer.

8. The image sensor according to claim 7, wherein at least some of the layers of the plurality of layers of the insulating structure are formed integrally with the upper separation pattern.

9. The semiconductor region between the lower separation pattern and the upper separation pattern further includes The upper surface of the lower separation pattern has a first upper surface that contacts the upper separation pattern and a second upper surface that is separated from the upper separation pattern. The image sensor according to claim 1, wherein the semiconductor region is disposed between the second upper surface of the lower separation pattern and the upper separation pattern.

10. The semiconductor region has an upper surface that contacts the upper separation pattern and a lower surface that contacts the lower separation pattern. The image sensor according to claim 9, wherein the upper surface of the semiconductor region is convex.

11. The semiconductor region has an upper surface that contacts the upper separation pattern and a lower surface that contacts the lower separation pattern. The image sensor according to claim 9, wherein the upper surface of the semiconductor region is concave.

12. The element isolation film further includes an element isolation film that extends from the first surface of the substrate into the substrate and has an upper surface located within the substrate, The image sensor according to any one of claims 1 to 11, wherein, when viewed with reference to the first surface of the substrate, the upper surface of the lower separation pattern is positioned at a higher level than the upper surface of the element separation film.

13. An image sensor according to any one of claims 1 to 12, wherein one of the first line portions of the separation structure is cut along a second horizontal direction perpendicular to the first horizontal direction, and the upper surface of the lower separation pattern is convex.

14. A first chip structure comprising a first substrate, a first circuit element and a first wiring structure on the first substrate, and a first insulating layer covering the first circuit element and the first wiring structure on the first substrate, Including a second chip structure on the first chip structure, The second chip structure is, A second substrate having a first surface facing the first chip structure and a second surface opposite to the first surface, A second circuit element and a second wiring structure are disposed between the first surface of the second substrate and the first chip structure, Between the first surface of the second substrate and the first chip structure, a second insulating layer is provided that covers the second circuit element and the second wiring structure. The separation structure within the second substrate, Within the second substrate, photoelectric conversion element regions separated from each other by the separation structure, The insulating structure on the second surface of the second substrate, The color filter on the insulating structure, The color filter includes a microlens, The separation structure includes a lower separation pattern having an upper surface within the second substrate and an upper separation pattern having a lower surface within the second substrate. At least a portion of the upper surface of the lower separation pattern is in contact with at least a portion of the lower surface of the upper separation pattern. In a plan view, the separation structure includes a first line portion extending parallel to each other in a first horizontal direction and a second line portion extending parallel to each other and perpendicular to the first line portion. Each of the first line portions includes line regions and intersection regions that are arranged alternately and repeatedly in the first horizontal direction. The intersection region of the first line portion is the region of the first line portion that intersects with the second line portion. A cross-sectional structure obtained by cutting one of the first line portions along the first horizontal direction, wherein the upper surface of the lower separation pattern has a wavy shape or a sawtooth shape. In the aforementioned intersection region, the vertical length of the lower separation pattern is greater than the vertical length of the upper separation pattern. In the aforementioned intersection region, the first height difference between the level of the upper surface of the lower separation pattern and the level of the first surface of the second substrate is 1.5 μm to 10 μm, in the image sensor.

15. The wavy shape of the upper surface of the lower separation pattern includes alternately repeated recessed and convex portions. The upper end portion of the convex portion on the upper surface of the lower separation pattern is located within the intersection region. The lower end portion of the recess on the upper surface of the lower separation pattern is located within the line region. A cross-sectional structure obtained by cutting one of the first line portions of the separation structure along a second horizontal direction perpendicular to the first horizontal direction, wherein the upper surface of the lower separation pattern is convex. The lower separation pattern includes a lower material pattern, a lower material layer covering the side and upper surfaces of the lower material pattern, The aforementioned lower material pattern includes polysilicon, The lower material layer contains silicon oxide, The upper separation pattern comprises an insulating material, as described in claim 14.

16. The image sensor according to claim 14, wherein in the intersection region, the first height difference between the level of the upper surface of the lower separation pattern and the level of the first surface of the second substrate is 2 to 10 times greater than the second height difference between the level of the upper surface of the lower separation pattern and the level of the second surface of the second substrate.

17. The semiconductor region between the lower separation pattern and the upper separation pattern further includes The upper surface of the lower separation pattern has a first upper surface that contacts the upper separation pattern and a second upper surface that is separated from the upper separation pattern. The lower surface of the upper separation pattern has a first lower surface that contacts the first upper surface of the lower separation pattern and a second lower surface that is separated from the lower separation pattern. The image sensor according to claim 14, wherein the semiconductor region is disposed between the second upper surface of the lower separation pattern and the second lower surface of the upper separation pattern.

18. A first chip structure comprising a first substrate, a first circuit element and a first wiring structure on the first substrate, and a first insulating layer covering the first circuit element and the first wiring structure on the first substrate, Including a second chip structure on the first chip structure, The second chip structure is, A second substrate having a first surface facing the first chip structure and a second surface opposite to the first surface, The separation structure within the second substrate, A second circuit element and a second wiring structure are disposed between the first surface of the second substrate and the first chip structure, Between the first surface of the second substrate and the first chip structure, a second insulating layer is provided that covers the second circuit element and the second wiring structure. The photoelectric conversion element region within the second substrate, The insulating structure on the second surface of the second substrate, The color filter on the insulating structure, The color filter includes a microlens, The separation structure includes a lower separation pattern and an upper separation pattern on the lower separation pattern. In a plan view, the separation structure includes a first line portion extending parallel to each other in a first horizontal direction and a second line portion extending parallel to each other and perpendicular to the first line portion. Each of the first line portions includes line regions and intersection regions that are arranged alternately and repeatedly in the first horizontal direction. In the first line portion, the intersection region is the region of the first line portion that intersects with the second line portion. A cross-sectional structure obtained by cutting one of the first line portions along the first horizontal direction, wherein at least one of the upper surface and the lower surface of the lower separation pattern has a wavy shape. An image sensor in which, in the aforementioned intersection region, the vertical length of either the lower separation pattern or the upper separation pattern is 2 to 10 times greater than the vertical length of the other.

19. The image sensor according to claim 18, wherein one of the lower separation pattern and the upper separation pattern includes a polysilicon pattern and an insulating layer covering the side surface of the polysilicon pattern.

20. In the aforementioned intersection region, the vertical length of the lower separation pattern is greater than the vertical length of the upper separation pattern. The image sensor according to claim 18, wherein the vertical length of the lower separation pattern is 1.5 μm to 10 μm.

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