Image sensor

Abstract

To provide an image sensor.SOLUTION: A image sensor includes: a substrate which includes a first PD region and a second PD region arranged adjacent to the first PD region; a first PD having a first area arranged in the first PD region; a second PD having a second area smaller than the first area which is arranged in the second PD region; a microlens which is arranged on the substrate, and covers the first PD region; and an optical splitter which is interposed between the substrate and the microlens, and includes a substance having a refraction index different from the microlens, where the optical splitter can extend from a position above the first PD region to a position above the second PD region.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an image sensor, and more particularly to an image sensor having a split PD (Photo Diode) structure. [Background technology]

[0002] The image sensor is a semiconductor-based sensor that receives light and generates an electrical signal, and may include a pixel array having a plurality of pixels, a circuit for driving the pixel array to generate an image, etc. The plurality of pixels may include a PD that generates an electric charge in response to external light, and a pixel circuit that converts the electric charge generated by the PD into an electric signal, etc. Image sensors may be widely applied to smartphones, tablet PCs, laptop computers, televisions, automobiles, etc. in addition to cameras for taking photos and videos. Recently, research is being conducted to improve the performance of image sensors having a divided PD structure in order to improve the dynamic range of the image sensor. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an image sensor having improved image quality.

[0004] Furthermore, the problems to be solved by the technical idea of ​​the present invention are not limited to the problems described above, and other problems will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0005] In order to solve the above problem, an image sensor according to the technical concept of the present invention includes a substrate including a first PD region and a second PD region disposed adjacent to the first PD region; a first PD having a first area disposed in the first PD region; a second PD having a second area smaller than the first area disposed in the second PD region; a microlens disposed on the substrate and covering the first PD region; and an optical splitter interposed between the substrate and the microlens and including a material having a refractive index different from that of the microlens; and the optical splitter may extend from above the first PD region to above the second PD region.

[0006] In addition, an image sensor according to the technical concept of the present invention includes a substrate having a first PD region and a second PD region defined therein; a first PD having a first area disposed within the substrate in the first PD region; a second PD having a second area smaller than the first area disposed within the substrate in the second PD region; a color filter on the substrate; and an optical splitter disposed between the substrate and the color filter or on the color filter; the optical splitter includes a material having a refractive index different from that of the color filter, and the optical splitter may overlap at least a portion of the first PD region and at least a portion of the second PD region in a vertical direction.

[0007] In addition, an image sensor according to the technical idea of ​​the present invention includes a substrate including a first PD region and a second PD region adjacent to the first PD region; a first PD having a first area disposed in the first PD region; a second PD having a second area smaller than the first area disposed in the second PD region; a deep trench isolation (DTI) penetrating the substrate to separate the first PD region and the second PD region from each other; a microlens disposed on the substrate and covering the first PD region; a color filter interposed between the substrate and the microlens; an optical splitter interposed between the substrate and the color filter or between the color filter and the microlens; and a wiring layer disposed under the substrate and including an insulating film and conductive wiring in the insulating film; wherein the optical splitter overlaps at least a portion of the first PD region and at least a portion of the second PD region in a vertical direction, and the optical splitter has a refractive index different from that of the microlens and the color filter. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram illustrating a simplified image processing device including an image sensor according to an embodiment of the present invention; [Diagram 2] 1 is a simplified perspective view of an image processing device including an image sensor according to an embodiment of the present invention; [Diagram 3] 1 is a simplified perspective view of an image processing device including an image sensor according to an embodiment of the present invention; [Figure 4] 2 is a circuit diagram illustrating a pixel circuit included in an image sensor according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 6] 6 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line AA' of FIG. 5. [Figure 7] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 8]FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 9] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 10] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 11] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 12] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 13] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 14] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 15] 15 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line BB' of FIG. 14. [Figure 16] 6 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line AA' of FIG. 5. [Figure 17] 6 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line AA' of FIG. 5. [Figure 18] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 19] 19 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line CC' of FIG. 18. [Figure 20] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 21] 21 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line DD' of FIG. 20. [Figure 22] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Diagram 23] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 24] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Diagram 25] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 26] 26 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line EE' of FIG. 25. [Figure 27] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Figure 28] 28 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line FF' of FIG. 27. [Figure 29] FIG. 2 is a plan view of an image sensor according to an embodiment of the present invention. [Diagram 30] FIG. 30 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line GG' of FIG. 29. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The same components in the drawings are designated by the same reference numerals, and duplicated descriptions thereof will be omitted.

[0010] FIG. 1 is a block diagram showing a simplified image processing apparatus including an image sensor according to an embodiment of the present invention.

[0011] 1, an image processing device 1 of the present embodiment may include an image sensor 10 and an image processor 20. The image sensor 10 may include a pixel array 11, a row driver 12, a column driver 13, a readout circuit 14, a timing controller 15, and the like.

[0012] The image sensor 10 operates according to a control command received from the image processor 20, and may convert light reflected from a subject to be photographed into an electrical signal and output the signal to the image processor 20. A pixel array 11 included in the image sensor 10 includes a plurality of pixels PX, and each of the plurality of pixels PX may include a photodiode (Photo-Diode: PD) that receives light and generates an electric charge. In one embodiment, each of the plurality of pixels PX may include two or more PDs.

[0013] Meanwhile, each of the multiple pixels PX may include a pixel circuit for generating an electrical signal from the charge generated by the PD. For example, the pixel circuit may include a pixel TR such as a transfer transistor (TR), a driving TR, a select TR, and a reset TR. When one pixel PX has two or more PDs, each pixel PX may include a pixel circuit for processing the charge generated by each of the two or more PDs. That is, when one pixel PX has two or more PDs, the pixel circuit may include two or more of at least one of the transfer TR, driving TR, select TR, and reset TR.

[0014] In the image processing device 1 of this embodiment, one pixel PX may include two PDs. Thus, the pixel PX has a split PD structure. In addition, in the image processing device 1 of this embodiment, the pixel PX may include a first pixel circuit that processes charges generated in one PD and a second pixel circuit that processes charges generated in another PD. Each of the first pixel circuit and the second pixel circuit may include a plurality of semiconductor elements. The first pixel circuit may generate and output a first pixel signal from charges generated in one PD, and the second pixel circuit may generate and output a second pixel signal from charges generated in the other PD. Each of the first pixel signal and the second pixel signal may include a reset voltage and a pixel voltage.

[0015] The row driver 12 may drive the pixel array 11 on a row-by-row basis. For example, the row driver 12 may generate a transfer control signal that controls a transfer TR of each pixel PX, a reset control signal that controls a reset TR, a selection control signal that controls a selection TR, and the like.

[0016] The column driver 13 may include a correlated double sampler (CDS), an analog-to-digital converter (ADC), etc. The CDS may perform correlated double sampling to obtain pixel signals through column lines connected to pixels PX included in a row selected by a row selection signal supplied by the row driver 12. The ADC may convert an output of the correlated double sampler into a digital signal and transmit the digital signal to the readout circuit 14.

[0017] The readout circuit 14 may include a latch or buffer circuit for temporarily storing a digital signal, an amplifier circuit, etc. Also, the readout circuit 14 may process a digital signal received from the column driver 13 to generate image data. Operation timings of the row driver 12, the column driver 13, and the readout circuit 14 may be determined by a timing controller 15. The timing controller 15 may operate according to a control command transmitted from the image processor 20. The image processor 20 may process image data output from the readout circuit 14 and output the processed image data to a display device or store the processed image data in a storage device such as a memory. Also, when the image processing device 1 of the present embodiment is mounted on an autonomous vehicle, the image processor 20 may process image data and transmit the processed image data to a main controller for controlling the autonomous vehicle.

[0018] 2 and 3 are simplified perspective views of an image processing device including an image sensor according to an embodiment of the present invention.

[0019] 2, the image processing device 2 of the present embodiment may include multiple stacked chips. For example, the image processing device 2 may include an upper chip 40 having a sensing region SA, a middle chip 50 having a logic circuit region LC, and a lower chip 60 having a memory region MC and a dummy region DC. In some embodiments, the upper chip 40 and the middle chip 50 may be stacked together at the wafer level, and the lower chip 60 may be attached to the lower part of the middle chip 50 at the chip level.

[0020] The upper chip 40 may include a sensing area SA in which a plurality of pixels PX are arranged, and a first pad area PA1 around the sensing area SA. A plurality of upper pads PAD may be arranged in the first pad area PA1. The plurality of upper pads PAD may be connected to pads arranged in a second pad area PA2 of the middle chip 50 through vias or the like, and may be connected to a logic circuit in a logic circuit area LC.

[0021] Each of the pixels PX may include a PD that receives light and generates charges, a pixel circuit that converts the charges generated by the PD into an electrical signal, etc. The PD may include an organic PD or a semiconductor PD, etc. In some embodiments, each of the pixels PX may include a plurality of semiconductor PDs. The pixel circuit may include a plurality of pixels TR for converting the charges generated by the PD into an electrical signal.

[0022] The middle chip 50 may include a logic circuit region LC in which a logic circuit is arranged, and a second pad region PA2 around the logic circuit region LC. The logic circuit in the logic circuit region LC may include circuits for driving pixel circuits arranged in the upper chip 40, such as a row driver, a column driver, and a timing controller. The logic circuit in the logic circuit region LC may be connected to the pixel circuits through pads and vias in the first and second pad regions PA1 and PA2.

[0023] The lower chip 60 may include a memory region MC and a dummy region DC. In some embodiments, the dummy region DC may be omitted. In some embodiments, the lower chip 60 has a package structure. For example, the memory region MC and the dummy region DC are each manufactured as a chip and sealed together with a sealant, so that the lower chip 60 has a package structure including two chips. A memory element such as a dynamic random access memory (DRAM) element or a static random access memory (SRAM) element may be disposed in the memory region MC. However, the memory element disposed in the memory region MC is not limited to a DRAM element or an SRAM element. No memory element is disposed in the dummy region DC. The dummy region DC does not function to store data, but functions to support the upper chips 50 and 60. The memory element in the memory region MC may be electrically connected to at least a part of the logic circuit in the logic circuit region LC of the middle chip 50 via a bump, a through electrode, or the like.

[0024] 3, the image processing device 3 of the present embodiment may include an upper chip 70 and a lower chip 80. The upper chip 70 may include a sensing region SA in which a plurality of pixels PX are provided, a logic circuit region LC in which elements for driving the plurality of pixels PX are provided, and a pad region PA around the sensing region SA and the logic circuit region LC. A plurality of upper pads PAD are arranged in the pad region PA, and the plurality of upper pads PAD may be connected to memory elements of a memory region MC provided in the lower chip 80 through vias or the like. The lower chip 80 may include a memory region MC and a dummy region DC. The lower chip 80 may be substantially the same as the lower chip 60 of the image processing device 2 of FIG. 2. Therefore, detailed description of the lower chip 80 will be omitted.

[0025] FIG. 4 is a circuit diagram showing a pixel circuit included in an image sensor according to an embodiment of the present invention.

[0026] Referring to FIG. 4, the pixel circuit of the image sensor 100 of this embodiment may include a first PD LPD, a second PD SPD, a first transfer TR TX1, a second transfer TR TX2, a first floating diffusion FD1, a second FD FD2, a first switch SW1, a second switch SW2, a reset TR RX, a drive TR DX, a selection TR SX, a metal capacitor Mcap, a capacitor EXC, and a dual conversion gain TR DCG.

[0027] The first PD LPD and the second PD SPD are also photodiodes including an n-type impurity region and a p-type impurity region. According to the pixel circuit of the image sensor 100, an electric signal can be output using the charges generated in the first PD LPD and the second PD SPD. The first PD LPD has a size several to several tens of times larger than that of the second PD SPD, for example. Here, the size means a horizontal area. Therefore, as can be seen from FIG. 5 and FIG. 6, the first PD LPD has a light receiving area several to several tens of times larger than that of the second PD SPD.

[0028] The first PD LPD may be connected to the first FD FD1 via the first transfer TR TX1. The first transfer TR TX1 may transfer charges accumulated in the first PD LPD to the first FD FD1 based on a transfer control signal transferred from the row driver. The first PD LPD may generate electrons as the main charge carriers.

[0029] The second PD SPD may be connected to the second FD FD2 via the second transfer TR TX2. The second transfer TR TX2 may transfer the charge accumulated in the second PD SPD to the second FD FD2 based on a transfer control signal transferred from the row driver. The second PD SPD may also generate electrons as the main charge carriers. Specifically, the charge generated in the second PD SPD may be transferred to the second FD FD2 when the second transfer TR TX2 is turned on. The second PD SPD generates charge in response to light while the second transfer TR TX2 is turned off, and the charge generated in the second PD SPD may be transferred to and accumulated in the second FD FD2 every time the second transfer TR TX2 is turned on.

[0030] In one embodiment, the first switch SW1 and the second FD FD2 may be used to adjust the conversion gain (CG) of the charge generated in the first PD LPD or the capacitance of the pixel. The first switch SW1 may be embodied as a TR. For example, by turning on the first switch SW1 and combining the first FD FD1 and the second FD FD2, the capacitance of the pixel may be increased, the dynamic range (DR) may be increased, and the CG may be changed. That is, the image sensor 100 of this embodiment may have a double CG structure.

[0031] Also, the charge generated in the second PD SPD may be stored in the metal capacitor Mcap. A second switch SW2 may be disposed between the metal capacitor Mcap and the second FD FD2. The second switch SW2 may also be implemented as a TR like the first switch SW1. Thus, the metal capacitor Mcap may store charge in response to the operation of the second transfer TR TX2 and the second switch SW2. In one embodiment, the second switch SW2 is not provided. In another embodiment, when the second switch SW2 is not provided, the metal capacitor Mcap may store charge in response to the operation of the second transfer TR TX2.

[0032] Meanwhile, a first switch SW1 and a second switch SW2 may be disposed between the metal capacitor Mcap and the first FD FD1. Thus, the charge of the metal capacitor Mcap may be transferred to the first FD FD1 by the on / off operation of the first switch SW1 and the second switch SW2. As described above, the second PD SPD has a relatively small light receiving area compared to the first PD LPD, and the charge of the second PD SPD may be transferred to and stored in the metal capacitor Mcap, thereby preventing saturation of the second PD SPD.

[0033] In the image sensor 100 of this embodiment, the second PD SPD can be used to improve the dynamic range of the image sensor, that is, the metal capacitor Mcap can be used to store and output charges without being saturated even under high illuminance.

[0034] The driving TR DX may operate as a source follower buffer amplifier according to the charge accumulated in the first FD FD1. The driving TR DX may amplify the charge accumulated in the first FD FD1 and transmit a signal to the selection TR SX. Specifically, the first FD FD1 may be connected to the gate of the driving TR DX, and a power supply voltage VDD may be connected to the reset TR RX and the source of the driving TR DX. A column line may be connected to the drain of the selection TR SX to output a voltage Vout. The selection TR SX may operate according to a selection control signal input from a row driver and perform switching and addressing operations. When the selection control signal is applied from the row driver to the gate of the selection TR SX, a voltage Vout may be output through a column line connected to the selection TR SX. The voltage Vout may be detected by a column driver and a readout circuit connected to the column line.

[0035] The column driver and readout circuit may detect a reset voltage when no charge is stored in the first FD FD1, and may detect a pixel voltage when charge is stored in the first FD FD1. The image sensor 100 of the present embodiment may generate image data by calculating a difference between the reset voltage and the pixel voltage using, for example, a CDS included in the column driver 13 illustrated in FIG.

[0036] The dual conversion gain TR DCG may be connected to the capacitor EXC. The first FD FD1 is connected to or not connected to the capacitor EXC depending on the on or off state of the dual conversion gain TR DCG. This allows the capacitance of the first FD FD1 to be adjusted. When the dual conversion gain TR DCG is turned off, the capacitance of the first FD FD1 decreases and the CG increases, thereby improving the performance of the image sensor 100 in low light conditions. Meanwhile, when the dual conversion gain TR DCG is turned on, the capacitance of the first FD FD1 increases and the full well capacity increases, thereby improving the performance of the image sensor 100 in high light conditions. In this way, the dual conversion gain TR DCG may perform a function of improving the image quality of the image sensor 100 by dynamically adjusting on / off from low light and high light conditions.

[0037] The first PD LPD and the second PD SPD may share a column line. Thus, while a first pixel voltage corresponding to a charge of the first PD LPD is output through the column line, the second PD SPD may be isolated from the column line. For example, while the first pixel voltage is output to the column line, at least one of the second transfer TR TX2 and the first switch SW1 may be turned off to isolate the second PD SPD from the column line. To generate a first pixel voltage using the charge of the first PD LPD and output it to the column line, the first transfer TR TX1 may be turned on, and the charge generated in the first PD LPD may be stored in the first FD FD1.

[0038] Similarly, the first PD LPD may be isolated from the column line while outputting a second pixel voltage corresponding to the charge of the second PD SPD to the column line. For example, the first transfer TR TX1 may be turned off to isolate the first PD LPD from the column line while the second pixel voltage is output to the column line. In order to generate a second pixel voltage using the charge of the second PD SPD and output it to the column line, the second transfer TR TX2 and the first switch SW1 may be turned on to connect the first FD FD1 and the second FD FD2 to each other. The charge of the second PD SPD may be stored in the first FD FD1 and the second FD FD2 and converted into a voltage by the driving TR DX.

[0039] 5 is a plan view of an image sensor according to an embodiment of the present invention, and FIG 6 is a cross-sectional view of the image sensor according to an embodiment of the present invention taken along line AA' in FIG 5.

[0040] 5 and 6, the image sensor 100 may include a substrate 101, a first PD LPD, a second PD SPD, a deep trench isolation (DTI) 130, a metal grating 172, a color filter 170, a light splitter LS, a microlens 180, and a wiring layer 200.

[0041] The substrate 101 may include silicon. However, the material of the substrate 101 is not limited to silicon. For example, the substrate 101 may include a single element semiconductor such as germanium (Ge) or a compound semiconductor such as silicon carbide (SiC), gallium arsenide (GaAs), indium arsenide (InAs), or indium phosphide (InP).

[0042] A plurality of unit pixels PXu may be arranged in a two-dimensional array structure along a first direction X and a second direction Y. In this specification, the first direction X is defined as a direction parallel to the top surface of the substrate 101, and the second direction Y is defined as a direction parallel to the top surface of the substrate 101 and perpendicular to the first direction X.

[0043] Each of the plurality of unit pixels PXu may include one first PD region AR1 and one second PD region AR2 corresponding to the one first PD region AR1. For example, the unit pixel PXu may include one first PD region AR1 and one second PD region AR2 disposed at the upper left side of the one first PD region AR1. The plurality of unit pixels PXu may be separated from each other by a DTI 130 structure. The first PD region AR1 and the second PD region AR2 may be separated from each other by a DTI 130 structure.

[0044] In one embodiment, a plurality of unit pixels PXu may be separated from each other by a Front-DTI structure.

[0045] In a plan view, the first PD region AR1 has an octagonal shape, and the second PD region AR2 has a rectangular shape. Meanwhile, the second PD region AR2 may be disposed between four adjacent first PD regions AR1. More specifically, one second PD region AR2 is surrounded by four first PD regions AR1. Also, four second PD regions AR2 may be disposed alternately adjacent to each other on four of the eight sides of the first PD region AR1.

[0046] The embodiment in which the first PD region AR1 has an octagonal shape and the second PD region AR2 has a rectangular shape has been described above. However, in the image sensor 100 of this embodiment, the shapes of the first PD region AR1 and the second PD region AR2 constituting each of the plurality of unit pixels PXu are not limited to the above-mentioned shapes. For example, the first PD region AR1 has a rectangular shape or a hexagonal shape. Meanwhile, the second PD region AR2 may also have a rectangular shape. However, the second PD region AR2 may be disposed inside the first PD region AR1. In that case, the second PD region AR2 may have various shapes such as a circle, an ellipse, or a polygon other than a rectangle. The shapes of the first PD region AR1 and the second PD region AR2 may differ depending on the design of the image sensor 100 to be implemented.

[0047] In the first PD region AR1, a first PD LPD may be disposed in the substrate 101, and in the second PD region AR2, a second PD SPD may be disposed in the substrate 101. Meanwhile, the first PD region AR1 and the second PD region AR2 may be separated from each other by the DTI 130.

[0048] The DTI 130 may penetrate the substrate 101 in a vertical direction. Since the DTI 130 is formed in a structure penetrating the substrate 101, crosstalk between pixels due to light incident at an angle may be prevented. In addition, the first PD LPD and the second PD SPD are each formed approximately adjacent to the DTI 130, thereby increasing the light receiving area and improving the fill factor.

[0049] The DTI 130 may include a conductive layer 132 and an insulating layer 134. The conductive layer 132 may include, for example, polysilicon or polysilicon doped with impurities. However, the material of the conductive layer 132 is not limited to the above materials. For example, the conductive layer 132 may include a metal, a metal silicide, a metal-containing conductive material, etc. The insulating layer 134 may surround an exterior of the conductive layer 132 and insulate the conductive layer 132 from the substrate 101. The insulating layer 134 may include, for example, an oxide or nitride, such as silicon oxide, silicon nitride, and silicon oxynitride. However, the material of the insulating layer 134 is not limited to the above materials.

[0050] A color filter 170 may be disposed on the upper surface of the substrate 101. The color filter 170 covers the upper surface of the substrate 101. The color filter 170 may include any one of a red filter, a blue filter, and a green filter. In one embodiment, the color filter 170 may be omitted. When the color filter 170 is omitted, another transparent structure that transmits light may be included in the position where the color filter 170 was. When the color filter 170 is omitted, the image sensor 100 may be used as an infrared sensor.

[0051] A metal grating 172 may be disposed between the substrate 101 and the color filter 170. The metal grating 172 may overlap the DTI 130 in the vertical direction. The vertical thickness of the metal grating 172 is thinner than the vertical thickness of the color filter 170. However, the present invention is not limited thereto, and the vertical thickness of the metal grating 172 may be the same as the vertical thickness of the color filter 170. The vertical thickness refers to the thickness in a direction perpendicular to the upper surface of the substrate 101.

[0052] The metal grid 172 separates the color filters 170. The metal grid 172, together with the DTI 130, may prevent light incident on the color filters 170 from being transmitted to the PD of the adjacent unit pixel PXu. This may reduce crosstalk between the unit pixels PXu of the image sensor 100. The metal grid 172 may include a conductive material such as a metal and / or a metal nitride. For example, the metal grid 172 may include tungsten (W), titanium (Ti), and / or titanium nitride (TiN). However, the material of the metal grid 172 is not limited to W, Ti, and TiN. A grid structure made of a low refractive index material may be further formed on the metal grid 172.

[0053] An optical splitter LS may be disposed on the color filter 170. In a plan view, the optical splitter LS has a rectangular shape. In a plan view, the optical splitter LS has a long axis extending in a direction from the center of the first PD area AR1 toward the center of the second PD area AR2. The splitter LS may extend from the first PD LPD to the second PD SPD without any interruption. The optical splitter LS may overlap at least a portion of the first PD LPD in the vertical direction and overlap at least a portion of the second PD SPD in the vertical direction.

[0054] The light splitter LS may include a material having a refractive index different from that of the color filter 170 and the microlens 180. For example, the light splitter LS may include a material having a refractive index different from that of the color filter 170 and the microlens 180. 2 , SiO 2 , SiN, and / or amorphous silicon.

[0055] On the color filter 170, the microlens 180 may overlap the first PD region AR1 in the vertical direction. The microlens 180 may overlap the entire first PD region AR1 in the vertical direction and may overlap a part of the second PD region AR2 in the vertical direction. Another part of the second PD region AR2 is not overlapped by the microlens 180 in the vertical direction.

[0056] On the first PD region AR1, the microlens 180 covers the color filter 170 and the light splitter LS. On the second PD region AR2, the microlens 180 may cover at least a part of the color filter 170 and at least a part of the light splitter LS. Therefore, a part of the upper surface of the color filter 170 and a part of the upper surface of the light splitter LS may be exposed to the outside from the microlens 180. Alternatively, on the second PD region AR2, the microlens 180 may cover the entire light splitter LS. This depends on the design of the image sensor 100 to be implemented. The microlens 180 has a dome shape or a hemispherical shape.

[0057] In one embodiment, on the second PD area AR2, the microlens 180 completely covers the color filter 170 and the light splitter LS, or does not cover at least a portion of the color filter 170 and the light splitter LS, respectively. The horizontal area of ​​the microlens 180 may vary depending on the design of the image sensor 100 to be implemented.

[0058] The microlenses 180 may be transparent and may transmit light. The microlenses 180 may comprise an organic material, such as a polymer. For example, the microlenses 180 may comprise a photoresist material or a thermosetting resin.

[0059] External light may pass through the microlens 180. The light passing through the microlens 180 may go to the first PD LPD via the color filter 170 or may be incident on the optical splitter LS. A portion of the light that has reached the optical splitter LS may be repeatedly reflected at the interface between the optical splitter LS and the microlens 180 and the interface between the optical splitter LS and the color filter 170. In this manner, a portion of the light that has reached the optical splitter LS may travel from the first PD LPD to the second PD SPD. The light that has traveled to the second PD SPD may be incident on the second PD SPD via the optical splitter LS. That is, the optical splitter LS may perform a function of distributing the light incident on the first PD region AR1 to the second PD region AR2, as its name suggests.

[0060] If the optical splitter LS is not provided and the microlens 180 covering the first PD region AR1 and the microlens 180 covering the second PD region AR2 are provided separately, the heights of the two microlenses 180 will be different from each other. This is because the microlenses 180 have a dome shape or a hemisphere shape. In this case, when the angle of light incident on the two microlenses 180 with respect to the direction perpendicular to the upper surface of the substrate 101 increases, the degree of vignetting occurring in the first PD region AR1 and the second PD region AR2 will be different, and the relative illumination in the first PD LPD and the second PD SPD may be different. In addition, considering that the first PD LPD and the second PD SPD form one unit pixel PXu in the image sensor 100, a problem occurs in which the optical centers do not match due to the position difference between the first PD LPD and the second PD SPD. The mismatch of the optical centers may cause color separation between the first PD LPD and the second PD SPD. In addition, if the heights of the two microlenses 180 are different, the microlenses of the first PD LPD may shield the microlenses of the second PD SPD as the angle of the incident light increases, which may cause a problem of different optical characteristics depending on the angle between the first PD LPD and the second PD SPD.

[0061] The image sensor 100 according to the concept of the present invention may include a substrate 101 including a first PD LPD and a second PD SPD, an optical splitter LS on the substrate 101, and a microlens 180 on the optical splitter LS. The optical splitter LS may include a material having a different refractive index from that of the microlens 180. Thus, light incident on the first PD LPD may be incident on the optical splitter LS through the microlens 180, and may be incident on the second PD SPD through the optical splitter LS. Therefore, since only one microlens 180 can be disposed in the unit pixel PXu, problems caused by differences in height between a plurality of microlenses 180 may be solved. For the above reasons, the image quality of the image sensor 100 may be improved.

[0062] A pixel circuit may be disposed under the substrate 101. Pixel circuits not shown may be disposed in an inner or outer portion in a direction perpendicular to the paper plane of FIG. 6. To explain only the illustrated pixel circuits in more detail, a gate TG1 of a first transfer TR (TX1 in FIG. 4) and a first FD FD1 may be disposed under the substrate 101 in the first PD region AR1. A gate TG2 of a second transfer TR (TX2 in FIG. 4) and a second FD FD2 may be disposed under the substrate 101 in the second PD region AR2.

[0063] The gate TG1 of the first transfer TR (TX1 in FIG. 4) and the gate TG2 of the second transfer TR (TX2 in FIG. 4) have a vertical structure. Thus, the gate TG1 of the first transfer TR (TX1 in FIG. 4) may extend vertically through the bottom of the substrate 101 to be connected to the first PD LPD. The gate TG2 of the second transfer TR (TX2 in FIG. 4) may extend vertically through the bottom of the substrate 101 to be connected to the second PD SPD. The gate TG1 of the first transfer TR (TX1 in FIG. 4) and the gate TG2 of the second transfer TR (TX2 in FIG. 4) may be made of a conductive material such as doped silicon.

[0064] Although not shown, the gate of the reset TR (RX in FIG. 4), the gate of the drive TR (DX in FIG. 4), and the gate of the selection TR (SX in FIG. 4) have a horizontal structure, whereby the gates of the horizontal structure can be disposed on the lower surface of the substrate 101.

[0065] Meanwhile, a plurality of heavily doped regions 140 may be disposed on the lower surface portion of the substrate 101. The plurality of heavily doped regions 140 may include a first FD FD1, a second FD FD2, and source / drain regions of the pixel TR. For example, the heavily doped region 140 on the side of the gate TG1 of the first transfer TR (TX1 in FIG. 4) may constitute the first FD FD1. Similarly, the heavily doped region 140 on the side of the gate TG2 of the second transfer TR (TX2 in FIG. 4) may constitute the second FD FD2. Although not shown, the heavily doped regions 140 on both sides of the gate of the driving TR (DX in FIG. 4) and the gate of the selection TR (SX in FIG. 4) may constitute the source / drain regions of the driving TR (DX in FIG. 4) and the selection TR (SX in FIG. 4).

[0066] A wiring layer 200 may be disposed on the lower surface of the substrate 101. The wiring layer 200 may include an insulating layer 202 and a conductive wiring 204 in the insulating layer 202. The conductive wiring 204 may be connected to a gate TG1 of a first transfer TR (TX1 in FIG. 4), a gate TG2 of a second transfer TR (TX2 in FIG. 4), a first FD FD1, and a second FD FD2. The conductive wiring 204 may also be connected to a pixel circuit not shown in FIG. 6.

[0067] 7 to 13 are plan views of an image sensor according to an embodiment of the present invention. Hereinafter, descriptions that overlap with those described with reference to FIGS. 5 and 6 will be omitted, and only differences will be described in detail.

[0068] 7 to 13, the planar shape of the optical splitter LS may be modified in various ways. Referring to FIG. 7, the horizontal area of ​​the optical splitter LS1 of the image sensor 100a on the second PD region AR2 is larger than the horizontal area on the edge portion of the first PD region AR1. The edge portion of the first PD region AR1 may be a portion surrounding the center of the first PD region AR1. In an embodiment, the optical splitter LS1 may cover the entire second PD region AR2. When the horizontal area of ​​the optical splitter LS1 on the second PD region AR2 is larger than the horizontal area on the edge portion of the first PD region AR1, the ratio of light incident on the second PD region AR2 to the second PD SPD may increase. Therefore, the efficiency of light transmission to the second PD SPD may increase, and the sensitivity of the second PD SPD may be improved.

[0069] 8 and 9, the horizontal area of ​​the optical splitters LS2 and LS3 of the image sensors 100b and 100c on the second PD area AR2 is larger than the horizontal area on the edge portion of the first PD area AR1. The edge portion of the first PD area AR1 may be a portion surrounding the center of the first PD area AR1. In one embodiment, the optical splitters LS2 and LS3 may cover the entire second PD area AR2.

[0070] Also, the horizontal area of ​​the optical splitters LS2 and LS3 on the center of the first PD region AR1 is larger than the horizontal area on the edge of the first PD region AR1. For example, the optical splitters LS2 and LS3 have a rectangular planar shape on the center of the first PD region AR1. In this case, the corner direction of the rectangle can be variously modified. As shown in FIG. 8, the horizontal side of the rectangle may be parallel to the first direction X or the second direction Y. Or, as shown in FIG. 9, the horizontal side of the rectangle may be parallel to the top surface of the substrate (101 in FIG. 6) and parallel to any direction intersecting the first direction X and the second direction Y. In one embodiment, as shown in FIG. 9, the rectangle has a rhombus. However, the present invention is not limited thereto, and the optical splitters LS2 and LS3 on the center of the first PD region AR1 have various planar shapes such as a circle, an ellipse, and a polygon.

[0071] In this case, the amount of light incident on the optical splitters LS2 and LS3 increases, and the ratio of the light incident on the first PD area AR1 that goes to the second PD area AR2 increases, thereby improving the sensitivity of the second PD SPD.

[0072] Referring to FIG. 10, the image sensor 100d may include an optical splitter LS4. The horizontal area of ​​the optical splitter LS4 on the center of the first PD area AR1 is larger than the horizontal area of ​​the optical splitter LS4 on the edge portion of the first PD area AR1. The edge portion of the first PD area AR1 may be a portion surrounding the center of the first PD area AR1. As described in FIG. 5, the optical splitter LS4 may overlap a portion of the second PD area AR2 in the vertical direction. The optical splitter LS4 does not cover at least a portion of the second PD area AR2. For example, the optical splitter LS4 has a rectangular planar shape on the center of the first PD area AR1. However, the present invention is not limited thereto, and the optical splitter LS4 may have various planar shapes such as a circle, an ellipse, and a polygon on the center of the first PD area AR1.

[0073] 11 and 12, the thickness TT of the optical splitters LS5 and LS6 of the image sensor 100e may vary in a direction from the center of the first PD area AR1 toward the center of the second PD area AR2.

[0074] 11, the thickness TT of the optical splitter LS5 of the image sensor 100e increases from the center of the first PD region AR1 to the center of the second PD region AR2. The thickness TT of the optical splitter LS5 is parallel to the top surface of the substrate (101 in FIG. 6) and refers to the thickness in a direction perpendicular to the direction from the center of the first PD region AR1 to the center of the second PD region AR2. In one embodiment, the thickness TT of the optical splitter LS5 increases uniformly from the center of the first PD region AR1 to the center of the second PD region AR2. Although the sidewall of the optical splitter LS5 is illustrated as a straight line in FIG. 11, the present invention is not limited thereto. The sidewall of the optical splitter LS5 may have a curved shape.

[0075] 12, the thickness TT of the optical splitter LS6 of the image sensor 100f may decrease from the center of the first PD region AR1 to the center of the second PD region AR2. The thickness TT of the optical splitter LS6 is parallel to the top surface of the substrate (101 in FIG. 6) and refers to the thickness in a direction perpendicular to the direction from the center of the first PD region AR1 to the center of the second PD region AR2. In one embodiment, the thickness TT of the optical splitter LS6 may decrease uniformly from the center of the first PD region AR1 to the center of the second PD region AR2. Although the sidewall of the optical splitter LS6 is illustrated as a straight line in FIG. 12, the present invention is not limited thereto. The sidewall of the optical splitter LS6 may have a curved shape.

[0076] 13, the optical splitter LS7 of the image sensor 100g may cover the entire second PD area AR2. The thickness TT of the optical splitter LS7 is constant from the center of the first PD area AR1 to the center of the second PD area AR2. The thickness TT of the optical splitter LS7 is parallel to the top surface of the substrate (101 in FIG. 6) and refers to the thickness in a direction perpendicular to the direction from the center of the first PD area AR1 to the center of the second PD area AR2.

[0077] Figure 14 is a plan view of an image sensor according to an embodiment of the present invention. Figure 15 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line BB' in Figure 14. Hereinafter, description will be omitted that overlaps with that described with reference to Figures 5 and 6, and only differences will be described in detail.

[0078] 14 and 15, at least a portion of the metal grating 172 at the boundary between the first PD region AR1 and the second PD region AR2 of the image sensor 100h may be omitted. The metal grating 172 may be omitted in a portion that overlaps with the optical splitter LS in the vertical direction. Meanwhile, in a plan view, the metal grating 172 may be separated from the optical splitter LS. In that case, even if the height of the metal grating 172 is high, light may smoothly travel onto the second PD region AR2 through the optical splitter LS. Therefore, the sensitivity of the second PD SPD may be improved.

[0079] Figure 16 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line A-A' in Figure 5. Figure 17 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line A-A' in Figure 5. Hereinafter, description will be omitted that overlaps with what has been described with reference to Figures 5 and 6, and only differences will be described in detail.

[0080] 16, the light splitter LS of the image sensor 100i may be interposed between the substrate 101 and the color filter 170. The light splitter LS may directly cover the upper surface of the substrate 101. The light splitter LS may cover at least a portion of the metal grating 172 at the boundary between the first PD region AR1 and the second PD region AR2. The microlens 180 and the light splitter LS may be spaced apart from each other. The color filter 170 may cover the upper and side surfaces of the light splitter LS. In this case, at least a portion of the metal grating 172 at the boundary between the first PD region AR1 and the second PD region AR2 may be omitted to facilitate smooth light propagation through the light splitter LS.

[0081] 17, the image sensor 100j may include a first metal grating 173 and a second metal grating 174 instead of the metal grating 172 of the image sensor 100 in FIG. 6. The first metal grating 173 may correspond to a portion of the metal grating 172 in FIG. 6 that is disposed on the boundary surface between the first PD region AR1 and the second PD region AR2. The second metal grating 174 may be a remaining portion of the metal grating 172 in FIG. 6 excluding the first metal grating 173. The first metal grating 173 is a portion that is covered by the optical splitter LS, and the second metal grating 174 is a portion that is not covered by the optical splitter LS. However, the second metal grating may include a first portion 175 and a second portion 176, different from the metal grating 172 in FIG. 6. The first portion 175 and the second portion 176 may include materials having different refractive indices. The first metal grating 173 may include the same material as the first portion 175. The second portion 176 may be a non-metallic, low refractive index insulating or semiconductor material.

[0082] The light splitter LS of the image sensor 100j may be interposed between the substrate 101 and the color filter 170, like the light splitter LS of the image sensor 100i in FIG. 16. The light splitter LS may directly cover the top surface of the substrate 101. The light splitter LS may cover at least a portion of the first metal grating 173. The microlens 180 and the light splitter LS may be spaced apart from each other. The color filter 170 may cover the top and side surfaces of the light splitter LS.

[0083] The optical splitter LS may include the same material as the second portion 176. This allows the optical splitter LS to be formed together with the first metal grating 173 and the second metal grating 174. That is, the manufacturing process of the image sensor 100j is simplified.

[0084] Figure 18 is a plan view of an image sensor according to an embodiment of the present invention. Figure 19 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line CC' in Figure 18. Hereinafter, description will be omitted that overlaps with that described with reference to Figures 5 and 6, and only differences will be described in detail.

[0085] 18 and 19, the image sensor 100k may further include a filler 178 and a light-shielding film LSF on the second PD region AR2. The filler 178 may be disposed on the upper surface of the substrate 101. The filler 178 may be disposed on a side of the light splitter LS. The filler 178 may be interposed between the light-shielding film LSF and the substrate 101. The filler 178 may include an insulating material such as silicon oxide, silicon nitride, and / or silicon oxynitride. Alternatively, the filler may include the same material as the color filter 170.

[0086] A light shielding film LSF may be disposed on the light splitter LS and the filler 178. The light shielding film LSF may cover the second PD area AR2. The vertical level of the upper surface of the light shielding film LSF may be the same as, lower than, or higher than the vertical level of the upper surface of the color filter 170. The microlens 180 may cover a portion of the light shielding film LSF. The light shielding film LSF may include a metal such as W, Al, and / or Cu.

[0087] Since the light blocking film LSF can prevent direct light from entering the second PD SPD, the color filter 170 can be provided only on the first PD region AR1, which can more effectively adjust the amount of light transmitted to the second PD region AR2, making it easier to adjust the sensitivity of the second PD SPD.

[0088] Figure 20 is a plan view of an image sensor according to an embodiment of the present invention. Figure 21 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line D-D' in Figure 20. Hereinafter, description will be omitted that overlaps with that described with reference to Figures 5 and 6, and only differences will be described in detail.

[0089] 20 and 21, the microlens 180 of the image sensor 100l may include an opening 180H. In a plan view, the opening 180H may be formed in the center of the microlens 180 (or in the center of the first PD region AR1). The microlens 180 has a donut shape. In a plan view, the microlens 180 has an annular shape. At least a portion of the optical splitter LS on the first PD region AR1 may be exposed to the outside through the opening 180H. Meanwhile, at least a portion of the optical splitter LS on the first PD region AR1 may overlap with the opening 180H in the vertical direction.

[0090] The cross-sectional shape of the microlens 180, excluding the opening 180H, may be a portion of a circle. In one embodiment, the cross-sectional shape of the microlens 180 may be a semicircle.

[0091] The opening 180H is formed in the center of the first PD region AR1, so that the amount of light incident on the first PD region AR1 to the optical splitter LS can be reduced. In other words, the opening 180H can be formed to adjust the amount of light transmitted to the second PD SPD.

[0092] Fig. 22 is a plan view of an image sensor according to an embodiment of the present invention. Fig. 23 is a plan view of an image sensor according to an embodiment of the present invention. Fig. 24 is a plan view of an image sensor according to an embodiment of the present invention. Hereinafter, the description will be omitted with reference to Figs. 20 and 21, and only the differences will be described in detail.

[0093] 22, 23, and 24, the position of the opening 180H formed in the microlens 180 of the image sensors 100m, 100n, and 100o may be changed in various ways. For example, as shown in FIG. 22, the opening 180H of the microlens 180 may be formed closer to the second PD region AR2 than the center of the first PD region AR1. Or, as shown in FIG. 23, the opening 180H of the microlens 180 may be formed away from the center of the first PD region AR1 in a direction away from the second PD region AR2. This increases or decreases the area of ​​the optical splitter LS that vertically overlaps with the opening 180H. Or, as shown in FIG. 24, the length of the optical splitter LS may be reduced, and the planar position of the opening 180H may also vertically overlap at least a portion of the optical splitter LS. By determining the position of the aperture 180H and adjusting the distance of the optical splitter LS as described above, the amount of light transmitted to the second PD SPD can be adjusted.

[0094] Figure 25 is a plan view of an image sensor according to an embodiment of the present invention. Figure 26 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line E-E' in Figure 25. Hereinafter, description will be omitted that overlaps with what has been described with reference to Figures 5 and 6, and only differences will be described in detail.

[0095] 25 and 26, the image sensor 100p may include a first splitter portion LS8 and a second splitter portion LS9 instead of the optical splitter LS in FIGS. 5 and 6. The first splitter portion LS8 may be interposed between the substrate 101 and the color filter 170 on the first PD region AR1. The second splitter portion LS9 may be interposed between the substrate 101 and the color filter 170 on the second PD region AR2. The first splitter portion LS8 has a triangular cross-sectional shape. The second splitter portion LS9 has a shape such as a circular cylinder, an elliptical cylinder, a rectangular prism, or a polygonal prism. The first splitter portion LS8 performs the function of a prism. That is, the light incident on the first PD region AR1 is transmitted to the first splitter portion LS8, and the light is reflected and refracted inside the first splitter portion LS8 and transmitted to the second splitter portion LS9 on the second PD region AR2. The light transmitted to the second splitter portion LS9 is reflected and refracted and transmitted to the second PD SPD. The first splitter portion LS8 and the second splitter portion LS9 may contain the same material as the material contained in the optical splitter LS in FIGS. 5 and 6.

[0096] Figure 27 is a plan view of an image sensor according to an embodiment of the present invention. Figure 28 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line F-F' in Figure 27. Hereinafter, description will be omitted that overlaps with what has been described with reference to Figures 5 and 6, and only differences will be described in detail.

[0097] 27 and 28, the optical splitter LS of the image sensor 100q may include mesa-shaped structures LSa, LSb, LSc, and LSd. In this case, the image sensor 100q does not include a microlens 180. The mesa shape refers to a figure shape with a flat top surface and right-angled or steep sides. For example, the mesa shape may include a cylinder. In FIG. 26, the planar shapes of the structures LSa, LSb, LSc, and LSd are illustrated as circles, but are not limited thereto. The structures LSa, LSb, LSc, and LSd may have various shapes such as an ellipse, a triangle, a square, and / or a polygon. Thus, the mesa shape may have various shapes such as an elliptical cylinder, a triangular prism, a quadrangular prism, and / or a polygonal prism.

[0098] The structures LSa, LSb, LSc, and LSd may be spaced apart from each other. The distance between the structures LSa, LSb, LSc, and LSd may be freely adjusted. The horizontal area of ​​each of the structures LSa, LSb, LSc, and LSd may also be freely adjusted. By adjusting the distance between the structures LSa, LSb, LSc, and LSd and the horizontal area of ​​each of the structures LSa, LSb, LSc, and LSd, the light incident on the first PD area AR1 may be transmitted to the second PD area AR2 through reflection and refraction. That is, by adjusting the shape and distance of the structures LSa, LSb, LSc, and LSd, the light splitter LS of the image sensor 100q may perform a function (light distribution function) similar to that of the light splitter LS in FIGS. 5 and 6.

[0099] The structures LSa, LSb, LSc, and LSd of the optical splitter LS of the image sensor 100q may include the same material as the optical splitter LS of the image sensor 100 in FIGS.

[0100] Figure 29 is a plan view of an image sensor according to an embodiment of the present invention. Figure 30 is a cross-sectional view of an image sensor according to an embodiment of the present invention taken along line G-G' in Figure 29. Hereinafter, description will be omitted that overlaps with what has been described with reference to Figures 5 and 6, and only differences will be described in detail.

[0101] 29 and 30, the light splitter LS of FIGS. 5 and 6 may be omitted. Instead, a void VD may be formed inside the microlens 180 of the image sensor 100r. The void VD may be an empty space inside the microlens 180. In one embodiment, the void VD may include an air gap. The void VD may include gas atoms or molecules. The refractive index of the void VD may be different from the refractive index of the microlens 180 and the color filter 170.

[0102] Light incident on the microlens 180 is incident inside the void VD, and the light may be repeatedly reflected at the interface between the void VD and the microlens 180 and the interface between the void VD and the color filter 170, and may proceed from the first PD LPD to the second PD SPD. The light that has proceeded to the second PD SPD may pass through the void VD and be incident on the second PD SPD. Thus, the void VD of the image sensor 100r performs a function similar to the light splitter LS in Figures 5 and 6. That is, the void VD of the image sensor 100r performs a function of distributing the light incident on the first PD area AR1 to the second PD area AR2.

[0103] The shape of the void VD may be various. In Fig. 29 and Fig. 30, the planar and cross-sectional shapes of the void VD are shown as rectangular, but the present invention is not limited thereto. The planar and / or cross-sectional shapes of the void VD may be changed to various shapes such as a circle, an ellipse, and a polygon. For example, the void VD may be hemispherical. This also depends on the design of the image sensor 100r to be implemented.

[0104] Although the present invention has been described above based on the embodiments shown in the drawings, these are merely illustrative, and a person skilled in the art will understand that various modifications and equivalent embodiments are possible. Therefore, the true technical scope of the present invention should be determined by the technical ideas of the claims. [Explanation of symbols]

[0105] 100 Image Sensor 101 Substrate 130 Deep element isolation (deep trench isolation) 170 Color Filter 172 Metal Lattice 180 Micro Lens 200 wiring layers LS Optical Splitter PXu Unit pixel LPD 1st PD SPD Second PD AR1 First PD region AR2 Second PD region

Claims

1. a substrate including a first photodiode (PD) region and a second PD region disposed adjacent to the first PD region; a first PD having a first area disposed in the first PD region; a second PD having a second area smaller than the first area and disposed in the second PD region; a microlens disposed on the substrate and covering the first PD region; an optical splitter interposed between the substrate and the microlens and including a material having a refractive index different from that of the microlens; The optical splitter extends from above the first PD region to above the second PD region.

2. the first PD region includes a central portion and an edge portion surrounding the central portion, The image sensor of claim 1 , wherein a horizontal area of ​​the light splitter over the second PD region is greater than a horizontal area of ​​the first PD region over the edge portion.

3. the first PD region includes a central portion and an edge portion surrounding the central portion, The image sensor of claim 1 , wherein a horizontal area of ​​the first PD region of the light splitter on the center portion is greater than a horizontal area of ​​the first PD region on the edge portion.

4. The optical splitter is made of TiO ２ , SiO ２ 10. The image sensor of claim 1, comprising at least one of the following: SiO.sub.2, SiN, and amorphous silicon.

5. A direction parallel to an upper surface of the substrate and extending from a center of the first PD region to a center of the second PD region is defined as a first direction; A direction parallel to the upper surface of the substrate and perpendicular to the first direction is defined as a second direction; The image sensor of claim 1 , wherein the light splitter has a variable thickness in the second direction as it moves in the first direction.

6. Further including a deep trench isolation (DTI) that separates the first PD region and the second PD region from each other, The image sensor of claim 1 , wherein the light splitter overlaps at least a portion of the DTI in a vertical direction.

7. the microlens includes an opening exposing at least a portion of the light splitter over the first PD region; The image sensor according to claim 1 , wherein the microlens has an annular shape in a plan view.

8. a substrate having a first PD region and a second PD region defined thereon; a first PD of a first area disposed within the substrate in the first PD region; a second PD disposed within the substrate in the second PD region and having a second area smaller than the first area; a color filter on the substrate; a light splitter disposed between the substrate and the color filter or on the color filter; the optical splitter includes a material having a refractive index different from that of the color filter; The image sensor, wherein the light splitter is overlapped with at least a portion of the first PD area and at least a portion of the second PD area in a vertical direction.

9. The image sensor of claim 8 , wherein the light splitter is disposed over the color filter.

10. The image sensor of claim 8 , wherein the light splitter is interposed between the substrate and the color filter.

Images