Reduced color crosstalk and infrared image sensor

Abstract

Various embodiments of the present disclosure relate to an image sensor device including first and second image sensor elements disposed within a substrate. An interconnect structure is disposed along a front side surface of the substrate and includes a plurality of conductive wiring lines, a plurality of vias, and a first absorption structure. The first image sensor element is configured to generate electrical signals from electromagnetic radiation in a first wavelength range. The second image sensor element is configured to generate electrical signals from electromagnetic radiation in a second wavelength range, the second wavelength range being different from the first wavelength range. The second image sensor element is laterally adjacent to the first image sensor element. Further, the first image sensor element overlies the first absorption structure and is laterally spaced between opposing side walls of the first absorption structure.

Description

Technical Field

[0001] This disclosure relates to a device, a chip, and a method, and more particularly to an image sensor device, a chip, and a method for forming an image sensor device. Background Technology

[0002] Integrated circuits (ICs) with image sensors are used in various modern electronic devices. In recent years, complementary metal-oxide-semiconductor (CMOS) image sensors (CIS) have begun to be widely used, greatly replacing charge-coupled device (CCD) image sensors. Compared with CCD image sensors, CIS is increasingly favored due to its low power consumption, small size, fast data processing, direct data output, and low manufacturing cost. Summary of the Invention

[0003] This disclosure provides an image sensor device. The image sensor device includes: a substrate having a front surface opposite a rear surface; an interconnect structure disposed along the front surface of the substrate, wherein the interconnect structure includes a plurality of conductive wires, a plurality of vias, and a first absorption structure; a first image sensor element disposed within the substrate and configured to generate an electrical signal from electromagnetic radiation in a first wavelength range; and a second image sensor element disposed within the substrate and configured to generate an electrical signal from electromagnetic radiation in a second wavelength range different from the first wavelength range, wherein the second image sensor element is laterally adjacent to the first image sensor element; wherein the first image sensor element is overlaid on the first absorption structure and laterally spaced between opposing sidewalls of the first absorption structure.

[0004] This disclosure provides an integrated chip, comprising: a substrate including a front surface opposite to a rear surface; a plurality of pixel devices disposed on the front surface of the substrate; an interconnect structure disposed along the front surface of the substrate, wherein the interconnect structure includes a plurality of conductive wires and a plurality of vias, the plurality of conductive wires and the plurality of vias being disposed within the interconnect dielectric structure and electrically coupled to the plurality of pixel devices; a plurality of pixel sensors disposed within the substrate, wherein the plurality of pixel sensors respectively include a first image sensor element and a second image sensor element, wherein the first image sensor element is configured to generate an electrical signal from infrared (IR) radiation and the second image sensor element is configured to generate an electrical signal from visible light; and a plurality of absorption structures disposed within the interconnect dielectric structure and located below the plurality of pixel sensors, wherein the first image sensor elements are spaced apart laterally between opposing sidewalls of corresponding absorption structures, and wherein the second image sensor elements are laterally offset from the plurality of absorption structures by a non-zero distance.

[0005] This disclosure provides a method for forming an image sensor device, the method comprising: forming a first image sensor element in a substrate, wherein the first image sensor element is configured to generate an electrical signal from electromagnetic radiation in a first wavelength range; forming a second image sensor element laterally adjacent to the first image sensor element in the substrate, wherein the second image sensor element is configured to generate an electrical signal from electromagnetic radiation in a second wavelength range different from the first wavelength range; forming an interconnect structure on the first image sensor element and the second image sensor element, wherein the interconnect structure includes a plurality of conductive wires, a plurality of vias, and an absorption structure, wherein the absorption structure comprises a conductive material configured to interact with the first wavelength range; and wherein the absorption structure is directly overlaid on the first image sensor element such that the first image sensor element is laterally spaced between opposing sidewalls of the absorption structure. Attached Figure Description

[0006] A thorough understanding of the various aspects of this disclosure is best achieved by reading the following detailed description in conjunction with the accompanying drawings. It should be noted that, in accordance with standard practice in the industry, the features are not drawn to scale. In fact, the dimensions of the features may be arbitrarily increased or decreased for clarity of explanation.

[0007] Figures 1A to 1C Various views illustrating some embodiments of an image sensor device including multiple pixel sensors, each of the multiple pixel sensors including a first image sensor element, a second image sensor element, and an absorption structure configured to reduce crosstalk between the first image sensor element and the second image sensor element.

[0008] Figures 2A to 2B Until 4A Figure 4B illustrate Figures 1A to 1C Top view of some alternative embodiments of the image sensor device.

[0009] Figures 5A to 5C The illustration includes cross-sectional views of various embodiments of an image sensor device comprising a first image sensor element, a second image sensor element, and an absorption structure configured to reduce crosstalk between the first and second image sensor elements.

[0010] Figures 6A to 12 Various views illustrating some embodiments of a method for forming an image sensor device including a first image sensor element, a second image sensor element, and an absorption structure, wherein the absorption structure is configured to reduce crosstalk between the first image sensor element and the second image sensor element.

[0011] Figure 13 A method is illustrated in flowchart format, which illustrates some embodiments of forming an image sensor device including a first image sensor element, a second image sensor element, and an absorption structure configured to reduce crosstalk between the first image sensor element and the second image sensor element. Detailed Implementation

[0012] This disclosure provides numerous different embodiments or instances for implementing various features of this disclosure. Specific examples of components and arrangements are described below to simplify this disclosure. Of course, these are merely examples and not intended to be limiting. For example, in the following description, forming a first feature on or over a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which an additional feature may be formed between the first and second features such that the first and second features are not in direct contact. Furthermore, reference numerals and / or letters may be repeated in various instances of this disclosure. Such repetition is for the sake of brevity and clarity and does not in itself imply a relationship between the various embodiments and / or configurations discussed.

[0013] Furthermore, for ease of explanation, spatially relative terms such as “beneath,” “below,” “lower,” “above,” and “upper” are used herein to describe the relationship between one element or feature illustrated in the figures and another element or feature. In addition to the orientations shown in the figures, these spatially relative terms are also intended to encompass different orientations of the device in use or operation. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein can be interpreted accordingly.

[0014] Furthermore, for ease of explanation, the terms "first," "second," "third," etc., may be used herein to distinguish different elements within a figure or series of figures. "First," "second," "third," etc., are not intended to describe corresponding elements but are merely general identifiers. For example, "first dielectric layer" as described in conjunction with the first figure may not necessarily correspond to "first dielectric layer" as described in some embodiments, but may correspond to "second dielectric layer" in other embodiments.

[0015] Some complementary metal-oxide-semiconductor (CIS) sensors include multiple image sensor elements (e.g., photodiodes) disposed in a semiconductor substrate. Pixel devices (e.g., transistors) are disposed along the front surface of the semiconductor substrate and configured to process electrical signals generated by the multiple image sensor elements. An interconnect structure including multiple conductive wirings and multiple vias is disposed along the front surface of the semiconductor substrate. Furthermore, a filter array having multiple filters (e.g., multiple color filters, multiple infrared (IR) filters, any combination of the aforementioned devices, etc.) is disposed along the rear surface of the semiconductor substrate.

[0016] One challenge of the aforementioned CIS is crosstalk between laterally adjacent image sensor elements configured for different wavelengths. For example, the plurality of image sensor elements may include a first image sensor element and a second image sensor element laterally adjacent to the first image sensor element. The first image sensor element (e.g., a first photodiode) is configured to generate an electrical signal from electromagnetic radiation within a first wavelength range (e.g., a first wavelength range including infrared (IR) radiation), and the second image sensor element (e.g., a second photodiode) is configured to generate an electrical signal from electromagnetic radiation within a second wavelength range (e.g., a second wavelength range including visible light), which differs from the first wavelength range. During operation of the CIS, electromagnetic radiation from the first wavelength range can be reflected to the second image sensor element from conductive features (e.g., conductive wiring and / or conductive traces) in the interconnect structure. This can reduce the signal-to-noise ratio (SNR) of the image sensor element (e.g., the second image sensor element) configured to generate an electrical signal from the second wavelength range, thereby degrading the performance of the CIS.

[0017] In another example, a 2x2 image sensor may be arranged in a Bayer pattern consisting of a red pixel sensor, a blue pixel sensor, a first green pixel sensor, and a second green pixel sensor. Each of the color pixel sensors in the Bayer pattern includes at least one IR image sensor element directly adjacent to the corresponding color image sensor element in the lateral direction. For example, the red pixel sensor includes a first image sensor element configured to generate an electrical signal from electromagnetic radiation (e.g., IR radiation) in a first wavelength range, which is directly adjacent in the lateral direction to a second image sensor element configured to generate an electrical signal from electromagnetic radiation (e.g., red visible light) in a second wavelength range. The IR image sensors within the 2x2 image sensor may be laterally offset from each other by the corresponding color image sensor elements. Due to this arrangement of the plurality of image sensor elements, electromagnetic radiation from the first wavelength range can travel to the laterally adjacent color image sensor elements, further increasing crosstalk among the plurality of image sensor elements. This can further reduce the SNR of the image sensor element configured to generate an electrical signal from the second wavelength range (e.g., the second image sensor element), thereby further degrading the performance of the CIS.

[0018] In some embodiments, this application relates to an image sensor device having an interconnect structure and an image sensor element layout that configures a plurality of image sensor elements to reduce crosstalk between the plurality of image sensor elements. For example, the image sensor device includes a plurality of image sensor elements disposed within a semiconductor substrate. A plurality of pixel devices (e.g., transistors) are disposed along a front surface of the semiconductor substrate, and the interconnect structure is disposed along the front surface of the semiconductor substrate. The interconnect structure includes a plurality of conductive wirings and a plurality of vias configured to provide electrical connections between devices (e.g., pixel devices) disposed on and / or on the semiconductor substrate. Furthermore, the plurality of image sensor elements includes: a first image sensor element configured to generate an electrical signal from electromagnetic radiation (e.g., IR radiation) in a first wavelength range; and a second image sensor element configured to generate an electrical signal from electromagnetic radiation (e.g., visible light radiation) in a second wavelength range. The interconnect structure includes an absorption structure located directly beneath the first image sensor element. Due to the size of the absorption structure and the conductive material (e.g., titanium nitride, tantalum nitride, tungsten, etc.), the absorption structure is configured to prevent electromagnetic radiation (e.g., IR radiation) in the first wavelength range from being reflected to adjacent image sensor elements (e.g., a second image sensor element). This reduces crosstalk between adjacent image sensor elements and increases the SNR of the second image sensor element, thereby enhancing the performance of the image sensor device.

[0019] Additionally, the image sensor elements can be arranged in one or more Bayer patterns (e.g., a 2x2 layout) consisting of a red pixel sensor, a blue pixel sensor, a first green pixel sensor, and a second green pixel sensor. Each of the color pixel sensors in the Bayer pattern includes at least one IR image sensor element directly adjacent to the corresponding color image sensor element in the lateral direction. Furthermore, the IR image sensor elements in the 2x2 layout are arranged to be laterally adjacent to each other, thereby reducing crosstalk between the color image sensor elements and the IR image sensor elements. Therefore, the layout of the plurality of image sensor elements is configured to further reduce crosstalk between adjacent image sensor elements and increase the SNR between color image sensor elements, thereby further enhancing the performance of the image sensor device.

[0020] Figures 1A to 1C The illustration shows various views of some embodiments of an image sensor device 100 including multiple pixel sensors 144a to 144d, which include multiple image sensor elements 120a to 120b disposed within a substrate 116. Figure 1A Along some embodiments illustrating the image sensor device 100 Figure 1BThe sectional view obtained by line A-A'. Furthermore, Figure 1B Along some embodiments illustrating the image sensor device 100 Figure 1A The top view obtained by drawing line A-A'. Furthermore, Figure 1C A top view taken along line B-B' illustrating some embodiments of the image sensor device 100.

[0021] like Figure 1A As illustrated in the cross-sectional view, the image sensor device 100 includes an interconnect structure 102 disposed along the front surface 116f of the substrate 116. A plurality of pixel devices 110 are disposed along the front surface 116f of the substrate 116. Furthermore, the plurality of image sensor elements 120a to 120b include a first image sensor element 120a and a second image sensor element 120b. The first image sensor element 120a and the second image sensor element 120b are configured to convert electromagnetic radiation (e.g., photons) into electrical signals (i.e., to generate electron-hole pairs from the electromagnetic radiation). In some embodiments, the electromagnetic radiation is back-side illuminated (BSI) on the image sensor device 100 (e.g., the electromagnetic radiation is disposed on the back surface 116b of the substrate 116). The first image sensor element 120a is configured to generate an electrical signal from electromagnetic radiation within a first wavelength range, while the second image sensor element 120b is configured to generate an electrical signal from electromagnetic radiation within a second wavelength range, which differs from the first wavelength range. In some embodiments, the first wavelength range may be, for example, infrared (IR) radiation (e.g., electromagnetic radiation with wavelengths ranging from approximately 700 nanometers (nm) to approximately 2.5 millimeters (mm), near IR (NIR) radiation (e.g., electromagnetic radiation with wavelengths ranging from approximately 700 nm to approximately 1.1 mm), etc. In other embodiments, the second wavelength range may be, for example, visible light (e.g., electromagnetic radiation with wavelengths ranging from approximately 400 nm to approximately 700 nm).

[0022] First image sensor element 120a and second image sensor element 120b are disposed within substrate 116. In some embodiments, substrate 116 may be, for example, a semiconductor material (e.g., silicon, crystalline silicon, monocrystalline silicon, bulk silicon, epitaxial silicon, another semiconductor material, or any combination thereof) and / or have a first doping type (e.g., p-type doping). First image sensor element 120a and second image sensor element 120b may respectively include intrinsic regions and / or doped regions of semiconductor material. First image sensor element 120a includes a first photodetector region 118. In some embodiments, the first photodetector region 118 may include, for example, a photodetector region and / or layer configured to convert electromagnetic radiation (e.g., photons) from a first wavelength range into electrical signals and / or facilitate the readout of electrical signals, such as a charge storage region, floating node, surface pinning region, contact region, guard ring, etc. (not shown). In some other embodiments, the first photodetector region 118 may be or comprise a second semiconductor material (e.g., germanium) that is different from a semiconductor material (e.g., silicon) configured to increase the quantum efficiency (QE) of electromagnetic radiation in the first wavelength range. Additionally, the second image sensor element 120b includes a second photodetector region 122, which may be or comprise a semiconductor material (e.g., silicon) including a second doping type opposite to the first doping type (e.g., n-type doping). In some other embodiments, the first doping type may be p-type and the second doping type may be n-type, or vice versa. In some embodiments, the first image sensor element 120a may be referred to as a first photodetector or a first photodiode, and the second image sensor element 120b may be referred to as a second photodetector or a second photodiode.

[0023] Additionally, the plurality of pixel devices 110 may include a gate structure 112 and a sidewall spacer structure 114 that laterally surrounds the gate structure 112. The plurality of pixel devices 110 may be configured to facilitate readout of electrical signals generated by the plurality of image sensor elements 120a to 120b. In some embodiments, the pixel device 110 may be, for example, a transfer transistor, a source follower transistor, a row select transistor, a reset transistor, another suitable pixel device, or any combination of the aforementioned transistors. Furthermore, the interconnect structure 102 includes an interconnect dielectric structure 104, a plurality of conductive wirings 106, a plurality of vias 108, and a plurality of absorption structures 107. The interconnect structure 102 is configured to electrically couple semiconductor devices (e.g., pixel devices 110) to each other or to other semiconductor devices. An isolation structure 124 extends from the rear surface 116b of the substrate 116 to the front surface 116f of the substrate 116. The isolation structure 124 may include a passivation layer 126 and a trench layer 128, wherein the passivation layer 126 is disposed between the substrate 116 and the trench layer 128. In some embodiments, the isolation structure 124 may be configured as a back-side trench isolation (BTI) structure, a back-side deep trench isolation (BDTI) structure, or another suitable isolation structure.

[0024] An upper passivation layer 130 is disposed along the rear surface 116b of the substrate 116. Furthermore, a grid structure 132 is disposed above the upper passivation layer 130 and may include a dielectric grid structure and / or a metal grid structure. An upper dielectric structure 134 is disposed above the upper passivation layer 130 and the grid structure 132. The plurality of image sensor elements 120a to 120b are laterally spaced between the sidewalls of the grid structure 132. A filter array 136 is overlaid on the grid structure 132 and includes a plurality of filters 136a to 136b. In some embodiments, the plurality of filters 136a to 136b includes a first filter 136a and a second filter 136b. The first filter 136a is overlaid on the first image sensor element 120a and, in some embodiments, is configured to allow wavelengths within a first wavelength range to pass through while blocking other wavelengths different from the first wavelength range. Furthermore, a second filter 136b is overlaid on the second image sensor element 120b and, in some embodiments, is configured to allow wavelengths within a second wavelength range to pass through while blocking other wavelengths different from the second wavelength range. In other embodiments, the second filter 136b includes a color filter 142 overlaid on the bandpass filter 140. Additionally, a plurality of microlenses 138 are overlaid on the filter array 136 and configured to direct electromagnetic radiation toward the underlying image sensor elements 120a to 120b.

[0025] An absorption structure 107 is located below the first image sensor element 120a. In some embodiments, the absorption structure 107 may be part of the plurality of conductive wirings 106 and may be referred to as the first conductive wirings. In these embodiments, the absorption structure 107 may be configured as conductive wirings 106 and electrically couple semiconductor devices together. In some embodiments, the first width w1 of the absorption structure 107 is greater than the second width w2 of the first image sensor element 120a. In other embodiments, the area of ​​the absorption structure 107 is greater than the area of ​​the first image sensor element 120a when viewed from above. Furthermore, the absorption structure 107 comprises a conductive material (e.g., titanium nitride, tantalum nitride, tungsten, etc.) configured to interact with electromagnetic radiation in a first wavelength range (e.g., absorb electromagnetic radiation in the first wavelength range). Therefore, during operation of the image sensor device 100, electromagnetic radiation may pass from the rear surface 116b of the substrate 116 through the first image sensor element 120a to reach the interconnect structure 102. Because the absorption structure 107 contains a conductive material and has a relatively large area (e.g., larger than the area of ​​the first image sensor element 120a), electromagnetic radiation within the first wavelength range can interact with the absorption structure 107 (e.g., be absorbed by the absorption structure 107) and prevent reflection towards the second image sensor element 120b. This partially reduces crosstalk between the first image sensor element 120a and the second image sensor element 120b and increases the signal-to-noise ratio (SNR) of the second image sensor element 120b. Therefore, the reliability of the image sensor device 100 is increased, and the accuracy of the images generated from the image sensor device 100 is increased.

[0026] In addition, such as Figure 1BAs illustrated in the top view, the image sensor device 100 includes the plurality of pixel sensors 144a to 144d. In some embodiments, the image sensor device 100 is configured as a 2x2 image sensor, the 2x2 image sensors being arranged in a Bayer pattern including a first pixel sensor 144a, a second pixel sensor 144b, a third pixel sensor 144c, and a fourth pixel sensor 144d. The plurality of pixel sensors 144a to 144d each include a first image sensor element 120a configured to generate an electrical signal from a first wavelength range (e.g., IR radiation) and a second image sensor element 120b configured to generate an electrical signal from a second wavelength range (e.g., visible light). In other embodiments, the first pixel sensor 144a is configured as a first green pixel sensor, the second pixel sensor 144b is configured as a blue pixel sensor, the third pixel sensor 144c is configured as a red pixel sensor, and the fourth pixel sensor 144d is configured as a second green pixel sensor. Furthermore, in some embodiments, the plurality of pixel sensors 144a to 144d are arranged such that the first image sensor element 120a of each pixel sensor 144a to 144d is directly adjacent to each other in the lateral direction. This partially reduces electromagnetic radiation from the first wavelength range traveling to the second image sensor element 120b of each pixel sensor 144a to 144d, thereby reducing crosstalk and further increasing the SNR of the second image sensor element 120b. Therefore, the reliability of the image sensor device 100 is further increased. Additionally, the second filter 136b of each pixel sensor 144a to 144d extends from the first sidewall of the corresponding first filter 136a to the second sidewall of the corresponding first filter 136a, wherein the first sidewall is perpendicular to the second sidewall.

[0027] In addition, such as Figure 1C As illustrated in the top view, the first image sensor element 120a of each pixel sensor 144a to 144d is laterally aligned with the corresponding absorption structure 107. In some embodiments, the absorption structure 107 is a single conductive structure extending laterally across each pixel sensor 144a to 144d. Because the area of ​​the absorption structure 107 is larger than the area of ​​the corresponding first image sensor element 120a, electromagnetic radiation in a first wavelength range can be prevented from traveling to the second image sensor element 120b of the plurality of pixel sensors 144a to 144d.

[0028] Figures 2A to 2B illustrate Figures 1A to 1C Top view of some alternative embodiments of the image sensor device 100. Figure 2A Explaining some embodiments of the image sensor device 100 Figure 1A The top view is obtained by using the line A-A' of the sectional view. Figure 2BVarious embodiments of the image sensor device 100 are described below. Figure 1A Another top view is obtained by taking the line B-B' of the sectional view.

[0029] In some embodiments, each pixel sensor 144a to 144d includes a first image sensor element 120a and a second image sensor element 120b. In one embodiment, a second filter 136b extends continuously from a first sidewall of the first filter 136a to a second sidewall of the first filter 136a, wherein the first sidewall is perpendicular to the second sidewall. In some embodiments, the first filter 136a of the first pixel sensor 144a and the first filter 136a of the second pixel sensor 144b are laterally separated by the second filter 136b of the second pixel sensor 144b. In other embodiments, the absorption structure 107 of the first pixel sensor 144a and the absorption structure 107 of the second pixel sensor 144b are laterally separated by the second image sensor element 120b of the second pixel sensor 144b.

[0030] Figures 3A to 3B illustrate Figures 1A to 1C Top view of some alternative embodiments of the image sensor device 100. Figure 3A Explaining some embodiments of the image sensor device 100 Figure 1A The top view is obtained by using the line A-A' of the sectional view. Figure 3B Various embodiments of the image sensor device 100 are described below. Figure 1A Another top view is obtained by taking the line B-B' of the sectional view.

[0031] In some embodiments, each pixel sensor 144a to 144d includes a plurality of first image sensor elements 120a and a plurality of second image sensor elements 120b, wherein the first image sensor elements 120a are diagonally spaced apart from each other. Furthermore, a first filter 136a is applied to each first image sensor element 120a and a second filter 136b is applied to each second image sensor element 120b. In other embodiments, the first filter 136a of the first pixel sensor 144a and the first filter 136a of the second pixel sensor 144b are laterally separated by the second filter 136b of the second pixel sensor 144b. Additionally, in various embodiments, each first image sensor element 120a is laterally spaced between opposing sidewalls of the corresponding absorption structure 107.

[0032] Figures 4A to 4B illustrate Figures 1A to 1C Top view of some alternative embodiments of the image sensor device 100. Figure 4A Explaining some embodiments of the image sensor device 100 Figure 1AThe top view is obtained by using the line A-A' of the sectional view. Figure 4B Various embodiments of the image sensor device 100 are described below. Figure 1A Another top view is obtained by taking the line B-B' of the sectional view.

[0033] In some embodiments, each pixel sensor 144a to 144d includes a first image sensor element 120a and a second image sensor element 120b. In some embodiments, the area of ​​the first image sensor element 120a and / or the area of ​​the first filter 136a are equal to the area of ​​the second image sensor element 120b and / or the area of ​​the second filter 136b, respectively. Furthermore, the first image sensor element 120a of the first pixel sensor 144a is directly laterally adjacent to the first image sensor element 120a of the second pixel sensor 144b, thereby reducing crosstalk between the first image sensor elements 120a and the second image sensor elements 120b of the pixel sensors 144a to 144d. This partially increases the SNR of the second image sensor elements 120b of each pixel sensor 144a to 144d and reduces crosstalk across the plurality of pixel sensors 144a to 144d, thereby enhancing the performance of the image sensor device 100. In still other embodiments, each first image sensor element 120a includes elements directly laterally adjacent to each other and / or accessible through an isolation structure ( Figure 1A At least two IR image sensor elements 124) are separated from each other. In these embodiments, each second image sensor element 120b includes elements directly adjacent to each other in the lateral direction and / or accessible through an isolation structure ( Figure 1A (124) At least two visible light image sensor elements separated from each other.

[0034] Figure 5A Explanation based on Figure 1A Cross-sectional views of some alternative embodiments of the image sensor device 100 and some embodiments of the image sensor device 500.

[0035] Image sensor device 500 includes an interconnect structure 102 disposed along the front surface 116f of a substrate 116. In some embodiments, the substrate 116 may be, for example, or include a bulk substrate (e.g., a bulk silicon substrate), a silicon-on-insulator (SOI) substrate, crystalline silicon, p-type doped silicon, or another suitable semiconductor material. The interconnect structure 102 includes a plurality of conductive wirings 106, a plurality of vias 108, an interconnect dielectric structure, and an absorption structure 107. In some embodiments, the interconnect dielectric structure includes a plurality of inter-level dielectric (ILD) layers 506 and a plurality of etch stop layers 504. The plurality of conductive wirings 106 and the plurality of vias 108 are disposed within the interconnect dielectric structure and configured to electrically couple semiconductor devices disposed within the image sensor device 500 to each other and / or to another integrated circuit (IC) (not shown). In some embodiments, the absorption structure 107 and the plurality of conductive wirings 106 may each include a conductive body 502 and a conductive pad 503. The conductive pad 503 may be disposed along the top surface of each conductive body 502. In some other embodiments, the conductive pad 503 may extend along the bottom surface and opposite sidewalls of the conductive body 502 (not shown).

[0036] In some embodiments, the conductive pad 503 may comprise a conductive material, such as (for example) titanium, tantalum, titanium nitride, tantalum nitride, tungsten, another material, or any combination of the foregoing. In other embodiments, the conductive body 502 may be, for example, aluminum, copper, ruthenium, another material, or any combination of the foregoing. In other embodiments, the plurality of ILD layers 506 may be, for example, or comprise a low-k dielectric material, an extremely low-k dielectric material, silicon dioxide, another dielectric material, or any combination of the foregoing. In still other embodiments, the plurality of etch stop layers 504 may be, for example, silicon nitride, silicon carbide, silicon oxynitride, silicon oxycarbide, another dielectric material, or any combination of the foregoing.

[0037] Furthermore, the plurality of pixel devices 110 are disposed along the front surface 116f of the substrate 116 and may include a gate structure 112 and a sidewall spacer structure 114. In some embodiments, the plurality of pixel devices 110 may be, for example, a transfer transistor, a source follower transistor, a row select transistor, a reset transistor, another suitable pixel device, or any combination of the aforementioned transistors. The plurality of pixel devices 110 may be electrically coupled to conductive wiring 106 and vias 108. A first image sensor element 120a is disposed within the substrate 116, and a second image sensor element 120b is disposed within the substrate 116 and laterally adjacent to the first image sensor element 120a. In some embodiments, the first image sensor element 120a is configured to generate an electrical signal from electromagnetic radiation within a first wavelength range, while the second image sensor element 120b is configured to generate an electrical signal from electromagnetic radiation within a second wavelength range, the second wavelength range being different from the first wavelength range. In some embodiments, the first wavelength range may be, for example, infrared (IR) radiation (e.g., electromagnetic radiation with wavelengths ranging from approximately 700 nanometers (nm) to approximately 2.5 millimeters (mm), near-IR (NIR) radiation (e.g., electromagnetic radiation with wavelengths ranging from approximately 700 nm to approximately 1.1 mm), etc. It will be understood that a first wavelength range including other wavelength values ​​is also within the scope of this disclosure. In other embodiments, the second wavelength range includes visible light (e.g., electromagnetic radiation with wavelengths ranging from approximately 400 nm to approximately 700 nm), etc. It will be understood that a second wavelength range including other wavelength values ​​is also within the scope of this disclosure. A first image sensor element 120a includes a first photodetector region 118, and a second image sensor element 120b includes a second photodetector region 122. In some embodiments, the first photodetector region 118 and the second photodetector region 122 each include a doped region of a semiconductor material (e.g., silicon) constituting the substrate 116. In some other embodiments, the first photodetector region 118 includes a layer of another semiconductor material (e.g., germanium) and the second photodetector region 122 includes the semiconductor material (e.g., silicon), wherein the other semiconductor material is configured to increase the absorption of electromagnetic radiation in the first wavelength range.

[0038] Furthermore, the isolation structure 124 extends from the rear surface 116b of the substrate 116 to the front surface 116f of the substrate 116. In some embodiments, the isolation structure 124 continuously surrounds the first image sensor element 120a and the second image sensor element 120b laterally. Therefore, the isolation structure 124 is configured to electrically and / or optically isolate the first image sensor element 120a and the second image sensor element 120b from each other, and / or electrically and / or optically isolate the first image sensor element 120a and the second image sensor element 120b from other devices disposed on / within the substrate 116. The isolation structure 124 may include a passivation layer 126 and a trench layer 128. In some embodiments, the passivation layer 126 may be, for example, silicon dioxide, silicon oxynitride, silicon carbide, another dielectric material, or any combination of the foregoing materials. Furthermore, the passivation layer 126 may extend continuously along the rear surface 116b of the substrate 116. The passivation layer 126 is disposed between the substrate 116 and the trench layer 128. In some embodiments, the trench layer 128 may be, for example, aluminum, tungsten, copper, another material, or any combination of the foregoing materials. In other embodiments, the isolation structure 124 may be configured to guide electromagnetic radiation toward the first image sensor element 120a and / or the second image sensor element 120b. In these embodiments, electromagnetic radiation may be reflected from the sidewalls of the trench layer 128 to the first image sensor element 120a or the second image sensor element 120b. Furthermore, this mitigates the travel of electromagnetic radiation in a first wavelength range directly disposed on the first image sensor element 120a to the second image sensor element 120b. Therefore, the isolation structure 124 can reduce crosstalk between adjacent image sensor elements, thereby enhancing the performance of the image sensor device 500.

[0039] An upper passivation layer 130 is overlaid on the isolation structure 124. In some embodiments, the upper passivation layer 130 may be configured as an anti-reflection coating (ARC) layer to prevent electromagnetic radiation from being reflected from the rear surface 116b of the substrate 116. A grid structure 132 is overlaid on the upper passivation layer 130. The grid structure 132 may include, for example, a metal grid structure and / or a dielectric grid structure. The grid structure 132 is configured to guide electromagnetic radiation to the first image sensor element 120a and / or the second image sensor element 120b. In some embodiments, when the grid structure 132 includes a metal grid structure (e.g., the grid structure 132 comprises aluminum, copper, tungsten, another material, or any combination of the foregoing materials), electromagnetic radiation may be reflected from the sidewalls of the metal grid structure to the underlying first image sensor element 120a or second image sensor element 120b instead of traveling to an adjacent image sensor element (not shown). This further reduces crosstalk between adjacent image sensor elements, thereby further enhancing the performance of the image sensor device 500. An upper dielectric structure 134 is overlaid on the grid structure 132 and the upper passivation layer 130. In some embodiments, the upper dielectric structure 134 may comprise, for example, an oxide (e.g., silicon dioxide), another dielectric material, or any combination of the aforementioned materials.

[0040] Additionally, the filter array 136 is overlaid on the upper dielectric structure 134 and includes a plurality of filters 136a to 136b. In some embodiments, the plurality of filters 136a to 136b includes a first filter 136a and a second filter 136b. The first filter 136a is overlaid on the first image sensor element 120a and, in some embodiments, is configured to allow wavelengths within a first wavelength range to pass through while blocking other wavelengths different from the first wavelength range (e.g., blocking wavelengths within a second wavelength range). In still other embodiments, the first filter 136a is configured as an all-pass filter that does not block electromagnetic radiation within the wavelength range. Furthermore, the second filter 136b is overlaid on the second image sensor element 120b and, in some embodiments, is configured to allow electromagnetic radiation with wavelengths within the second wavelength range to pass through while blocking other wavelengths different from the second wavelength range (e.g., blocking wavelengths within the first wavelength range). In other embodiments, the second filter 136b includes a color filter 142 and a bandpass filter 140. In some embodiments, the color filter 142 may be configured as a red filter, a blue filter, a green filter, etc. In other embodiments, the bandpass filter 140 is configured to allow electromagnetic radiation within a second wavelength range to pass through while blocking other wavelengths different from the second wavelength range (e.g., blocking wavelengths within a first wavelength range). The plurality of microlenses 138 are overlaid on the filter array 136 and configured to direct electromagnetic radiation toward the first image sensor element 120a and / or the second image sensor element 120b.

[0041] The absorption structure 107 is located below the first image sensor element 120a. In some embodiments, the absorption structure 107 is located directly below the first image sensor element 120a. In other embodiments, when viewed from above, the area of ​​the absorption structure 107 is larger than the area of ​​the first image sensor element 120a (e.g., see...). Figure 1B , Figure 2B , Figure 3B and / or Figure 4B During operation of the image sensor device 500, electromagnetic radiation can pass from the rear surface 116b of the substrate 116 through the first image sensor element 120a to the absorption structure 107. Since the absorption structure 107 includes a conductive pad 503 comprising a conductive material (e.g., titanium nitride, tantalum nitride, tungsten, etc.), the absorption structure 107 is configured to interact with electromagnetic radiation in a first wavelength range (e.g., absorb electromagnetic radiation in the first wavelength range). This prevents electromagnetic radiation in the first wavelength range from being reflected toward the second image sensor element 120b, thereby reducing crosstalk between the first and second image sensor elements and increasing the SNR of the second image sensor element 120b. Therefore, the performance of the image sensor device 500 is enhanced.

[0042] Figure 5B illustrate Figure 5A A cross-sectional view of some alternative embodiments of the image sensor device 500, wherein the absorption structure 107 is electrically isolated from the plurality of conductive wirings 106, the plurality of vias 108, and / or the plurality of pixel devices 110. In some embodiments, the etch stop layer 504 directly contacts the bottom surface of the absorption structure 107 across the entire bottom surface. In other embodiments, the ILD layer 506 directly contacts the top surface of the absorption structure 107 across the entire top surface. The bottom and top surfaces of the absorption structure 107 are defined between a first outer sidewall and a second outer sidewall of the absorption structure 107, wherein the first outer sidewall and the second outer sidewall are opposite each other. In still other embodiments, the ILD layer 506 and the etch stop layer 504 extend laterally along an uninterrupted path from the first outer sidewall to the second outer sidewall of the absorption structure 107, respectively. In these embodiments, the plurality of vias 108 are laterally offset from the top and bottom surfaces of the absorption structure 107, respectively, so that the absorption structure 107 is completely separated from the plurality of vias 108 and the plurality of conductive wires 106. It should be understood that, although Figure 5B The cross-sectional view illustrates a single absorbing structure 107, but Figure 1B , Figure 2B , Figure 3B and / or Figure 4B The absorption structure 107 can be configured as follows: Figure 5B The absorption structure 107 described and / or explained herein.

[0043] Figure 5C illustrate Figure 5B A cross-sectional view of some alternative embodiments of the image sensor device 500, wherein the absorption structure 107 is disposed in the vertical direction between the front surface 116f of the substrate 116 and the plurality of conductive wirings 106. In some embodiments, the absorption structure 107 comprises a conductive material (e.g., titanium nitride, tantalum nitride, tungsten, or any combination thereof) and is disposed in a first ILD layer 506. In still other embodiments, the first ILD layer 506 directly contacts the entire bottom and top surfaces of the absorption structure 107, respectively. It should be understood that, although Figure 5C The cross-sectional view illustrates a single absorbing structure 107, but Figure 1B , Figure 2B , Figure 3B and / or Figure 4B The absorption structure 107 can be configured as follows: Figure 5C The described and / or illustrated absorption structure 107.

[0044] Figures 6A to 12Various views 600a to 1200 illustrate some embodiments of a method for forming an image sensor device according to the present disclosure, the image sensor device including a first image sensor element, a second image sensor element, and an absorption structure configured to reduce crosstalk between the first image sensor element and the second image sensor element. Although Figures 6A to 12 The various views 600a to 1200 shown are illustrated with reference to the method of illustration, but it will be understood that... Figures 6A to 12 The structure shown is not limited to the method described, but can exist independently of it. Furthermore, although... Figures 6A to 12 The actions are described as a series of actions, but it will be understood that these actions are not limited to this, because the order of the actions can be changed in other embodiments, and the disclosed method is also applicable to other structures. In other embodiments, some of the described and / or illustrated actions may be omitted, in whole or in part.

[0045] like Figure 6A and Figure 6B As illustrated in the various views, a substrate 116 is provided and a plurality of pixel sensors 144a to 144d are formed within the substrate 116. Figure 6A A cross-sectional view 600a illustrates some embodiments of the plurality of pixel sensors 144a to 144d. Additionally, Figure 6B illustrate Figure 6A Top view 600b obtained along line C-C' of some embodiments of the sectional view 600a shown.

[0046] Each pixel sensor 144a to 144d includes a plurality of image sensor elements 120a to 120b. The plurality of image sensor elements 120a to 120b include a first image sensor element 120a and a second image sensor element 120b that are laterally adjacent. In some embodiments, the substrate 116 may be, for example, a bulk substrate (e.g., a bulk silicon substrate), a silicon-on-insulator (SOI) substrate, or some other suitable substrate; and / or include a first doping type (e.g., p-type doping). In some embodiments, the first image sensor element 120a forms a first photodetector region 118, and the second image sensor element 120b forms a second photodetector region 122. In some embodiments, the first photodetector region 118 may include, for example, a photodetector region and / or layer configured to convert electromagnetic radiation (e.g., photons) from a first wavelength range into an electrical signal and / or facilitate the readout of the electrical signal, such as a charge storage region, floating node, surface pinning region, contact region, guard ring, etc. (not shown). Additionally, the second image sensor element 120b includes a second photodetector region 122, which may be, for example, a semiconductor material (e.g., silicon) comprising a second doping type (e.g., n-type doping) opposite to the first doping type. In yet other embodiments, the first doping type may be p-type and the second doping type may be n-type, or vice versa. In yet other embodiments, the first image sensor element 120a and / or the second image sensor element 120b may be formed by one or more selective ion implantation processes.

[0047] In some embodiments, the first photodetector region 118 may be, for example, a second semiconductor material (e.g., germanium) different from the semiconductor material (e.g., silicon). In these embodiments, the process for forming the first image sensor element 120a may include: selectively etching the substrate 116 to form an opening within the substrate 116; depositing the second semiconductor material (e.g., germanium) in the opening (e.g., by molecular-beam epitaxy (MBE), vapor phase epitaxy (VPE), liquid phase epitaxy (LPE), some other suitable epitaxial processes, chemical vapor deposition (CVD), physical vapor deposition (PVD), or some other suitable deposition or growth processes); performing a planarization process on the second semiconductor material (e.g., chemical mechanical polishing (CMP)); and performing one or more selective ion implantation processes to form the photodetector region within the first photodetector region 118. In some embodiments, a first image sensor element 120a is configured to generate an electrical signal from electromagnetic radiation (e.g., IR radiation) within a first wavelength range, while a second image sensor element 120b is configured to generate an electrical signal from electromagnetic radiation (e.g., visible light) within a second wavelength range, which is different from the first wavelength range.

[0048] In some embodiments, the second image sensor element 120b is formed such that the second image sensor element 120 extends from a first sidewall of the first image sensor element 120a to a second sidewall of the first image sensor element 120a. In other embodiments, each pixel sensor 144a to 144d includes a first image sensor element 120a and a second image sensor element 120b. Because the first image sensor element 120a of the first pixel sensor 144a is positioned laterally adjacent to the first image sensor element 120a of the second pixel sensor 144b, crosstalk between the first image sensor element 120a and the second image sensor element 120b can be reduced. This partially enhances the performance of the image sensor device.

[0049] like Figure 7 As illustrated in cross-sectional view 700, a thinning process is performed on the rear surface 116b of substrate 116. In some embodiments, the thickness of substrate 116 is reduced from an initial thickness Ti to a thickness Ts. In other embodiments, the thinning process includes performing a CMP process, a mechanical polishing process, another thinning process, or any combination of the foregoing processes.

[0050] like Figure 8A and Figure 8B As illustrated in the various views, a plurality of pixel devices 110 are formed on the front surface 116f of the substrate 116. Figure 8A A cross-sectional view 800a illustrating some embodiments of forming the plurality of pixel devices 110 is provided. Additionally, Figure 8B illustrate Figure 8A A top view 800b is obtained along line D-D' of some embodiments of the sectional view 800a.

[0051] In some embodiments, each pixel device 110 includes a gate structure 112 and a sidewall spacer structure 114 laterally surrounding the gate structure 112. In other embodiments, the gate structure 112 includes a gate electrode overlaid on a substrate 116 and a gate dielectric layer disposed between the substrate 116 and the gate electrode. Subsequently, as Figure 8A and Figure 8B As described, an interconnect dielectric structure 104 is formed on substrate 116, and multiple conductive wirings 106, multiple vias 108, and multiple absorption structures 107 are formed within the interconnect dielectric structure 104. In some embodiments, the interconnect dielectric structure 104 can be formed by, for example, CVD, PVD, ALD, another suitable growth or deposition process, or any combination of the foregoing processes. Furthermore, the interconnect dielectric structure 104 may include multiple interlayer dielectric (ILD) layers and / or multiple etch stop layers (e.g., see [reference needed]). Figure 5A ).

[0052] In other embodiments, the plurality of conductive wires 106 and the plurality of absorption structures 107 may each include a conductive body 502 and a conductive pad 503. In still other embodiments, the absorption structure 107 is directly overlaid on the corresponding first image sensor element 120a. In still other embodiments, the plurality of conductive wires 106, the plurality of vias 108, and / or the plurality of absorption structures 107 may be formed by a single damascene process, a dual damascene process, or another suitable forming process. In some embodiments, the conductive pad 503 may comprise a conductive material, such as (for example) titanium, tantalum, titanium nitride, tantalum nitride, tungsten, another material, or any combination of the foregoing materials. In other embodiments, the conductive body 502 may be, for example, aluminum, copper, ruthenium, another material, or any combination of the foregoing materials. In still other embodiments, the plurality of absorption structures 107 are formed simultaneously with the plurality of conductive wires 106.

[0053] In addition, such as Figure 8BAs described, the absorption structures 107 are formed such that the area of ​​each absorption structure 107 is larger than the area of ​​the corresponding first image sensor element 120a. During the operation of the first image sensor element 120a and the second image sensor element 120b, electromagnetic radiation can be disposed on the rear surface 116b of the substrate 116, and the electromagnetic radiation travels through the substrate 116 and the first image sensor element 120a to reach the absorption structure 107. Since the absorption structure 107 has a conductive pad 503 comprising a conductive material (e.g., titanium nitride, tantalum nitride, tungsten, etc.) and has a relatively large area (e.g., larger than the area of ​​the first image sensor element 120a), the absorption structure 107 is configured to interact with electromagnetic radiation in the first wavelength range (e.g., absorb electromagnetic radiation in the first wavelength range). This prevents electromagnetic radiation in the first wavelength range from being reflected toward the second image sensor element 120b, thereby reducing crosstalk between the first image sensor element 120a and the second image sensor element 120b and increasing the SNR of the second image sensor element 120b. In some embodiments, Figure 2B , Figure 3B and / or Figure 4B Explanation Figure 8A Some alternative embodiments of the cross-sectional view 800a along Figure 8A The top view obtained by the line D-D'.

[0054] like Figure 9 As illustrated in cross-sectional view 900, one or more additional layers of conductive wiring 106 and one or more additional layers of vias 108 are formed on substrate 116, thereby forming an interconnect structure 102 on the front surface 116f of substrate 116. In some embodiments, the one or more additional layers of conductive wiring 106 and vias 108 may be formed by a single damascene process, a dual damascene process, or another suitable forming process.

[0055] Figure 10 As illustrated in the cross-sectional view 1000, an isolation structure 124 is formed within a substrate 116. In some embodiments, the isolation structure 124 includes a passivation layer 126 and a trench layer 128, wherein the passivation layer 126 is disposed between the substrate 116 and the trench layer 128. In some embodiments, a method for forming the isolation structure 124 includes: selectively etching the substrate 116 to form an isolation structure opening within the substrate 116; depositing (e.g., by CVD, PVD, ALD, etc.) the passivation layer 126 on the substrate 116 to pad the isolation structure opening; depositing (e.g., by CVD, PVD, ALD, etc.) the trench layer 128 on the passivation layer 126; and performing a planarization process on the passivation layer 126 and / or the trench layer 128 to form the isolation structure 124.

[0056] like Figure 11 As illustrated in the cross-sectional view 1100, an upper passivation layer 130 is formed on the rear surface 116b of the substrate 116. In some embodiments, the upper passivation layer 130 is formed by, for example, CVD, PVD, ALD, or another suitable deposition or growth process. Furthermore, a gate structure 132 and an upper dielectric structure 134 are formed on the upper passivation layer 130. In other embodiments, the gate structure 132 and / or the upper dielectric structure 134 may be formed by, for example, CVD, PVD, ALD, or another suitable deposition or growth process.

[0057] like Figure 12 As illustrated in the cross-sectional view 1200, a filter array 136 is formed on the upper dielectric structure 134, and a plurality of microlenses 138 are formed on the filter array 136. In some embodiments, the filter array 136 includes a first filter 136a overlaid on the first image sensor element 120a and a second filter 136b overlaid on the second image sensor element 120b. In other embodiments, the second filter 136b includes a color filter 142 and a bandpass filter 140. In some embodiments, the first filter 136a and the second filter 136b may be formed, for example, by CVD, PVD, ALD, or another suitable growth or deposition process. Furthermore, the plurality of microlenses 138 may be formed by, for example, CVD, PVD, ALD, or another suitable growth or deposition process.

[0058] Figure 13 This description describes a method 1300 for forming an image sensor device including a first image sensor element, a second image sensor element, and an absorption structure according to some embodiments of the present disclosure, wherein the absorption structure is configured to reduce crosstalk between the first image sensor element and the second image sensor element. Although method 1300 is described and / or illustrated as a series of actions or events, it should be understood that method 1300 is not limited to the described order or actions. Therefore, in some embodiments, the actions may be performed in a different order than described, and / or simultaneously. Furthermore, in some embodiments, the described actions or events may be subdivided into multiple actions or events that may be performed at separate times or simultaneously with other actions or sub-actions. In some embodiments, some described actions or events may be omitted, and other undescribed actions or events may be included.

[0059] At operation 1302, a plurality of pixel sensors are formed within the substrate, wherein each pixel sensor includes a first image sensor element and a second image sensor element that are laterally adjacent. The first image sensor element is configured to generate an electrical signal from electromagnetic radiation in a first wavelength range, and the second image sensor element is configured to generate an electrical signal from electromagnetic radiation in a second wavelength range different from the first wavelength range. Figure 6A and Figure 6B Various views 600a and 600b are shown corresponding to some embodiments of action 1302.

[0060] At action 1304, an interconnect structure is formed on the front surface of the substrate, wherein the interconnect structure includes multiple conductive wires, multiple vias, and multiple absorption structures. Each absorption structure contains a conductive material (e.g., titanium nitride, tantalum nitride, tungsten, etc.) and is overlaid on the corresponding first image sensor element. Figure 8A , Figure 8B and Figure 9 Various views 800a, 800b and 900 corresponding to some embodiments of action 1304 are described.

[0061] At action 1306, an isolation structure is formed in the rear surface of the substrate. Figure 10 Explanation of some embodiments of action 1306, corresponding to sectional view 1000.

[0062] At action 1308, a grid structure and an upper dielectric structure are formed on the rear surface of the substrate. Figure 11 Explanation of some embodiments of action 1308, corresponding to sectional view 1100.

[0063] At action 1310, a filter array is formed on the upper dielectric structure, and multiple microlenses are formed on the filter array. Figure 12 Explaining some embodiments of action 1310. A cross-sectional view 1200 corresponding to this.

[0064] Therefore, in some embodiments, this disclosure relates to an image sensor device including a first image sensor element and a second image sensor element. The first image sensor element is configured to generate an electrical signal from electromagnetic radiation within a first wavelength range, and the second image sensor element is configured to generate an electrical signal from a second wavelength range different from the first wavelength range. The interconnect structure is disposed along the front surface of a substrate and includes an absorption structure located below the first image sensor element.

[0065] In some embodiments, this application provides an image sensor device, the image sensor device comprising: a substrate having a front surface opposite a rear surface; an interconnect structure disposed along the front surface of the substrate, wherein the interconnect structure includes a plurality of conductive wires, a plurality of vias, and a first absorption structure; a first image sensor element disposed within the substrate and configured to generate an electrical signal from electromagnetic radiation in a first wavelength range; and a second image sensor element disposed within the substrate and configured to generate an electrical signal from electromagnetic radiation in a second wavelength range different from the first wavelength range, wherein the second image sensor element is laterally adjacent to the first image sensor element; wherein the first image sensor element is overlaid on the first absorption structure and laterally spaced between opposing sidewalls of the first absorption structure.

[0066] In a related embodiment, when viewed from above, the area of ​​the first absorption structure is larger than the area of ​​the first image sensor element.

[0067] In related embodiments, the image sensor device further includes: a third image sensor element disposed within the substrate and configured to generate an electrical signal from the electromagnetic radiation within the first wavelength range, wherein the third image sensor element is laterally adjacent to the first image sensor element; and a second absorption structure located below the third image sensor element, wherein the sidewall of the second absorption structure is adjacent to the sidewall of the first absorption structure.

[0068] In a related embodiment, the first absorption structure is configured to interact with the electromagnetic radiation within the first wavelength range, wherein the first wavelength range includes near-infrared (NIR) radiation.

[0069] In related embodiments, the first absorption structure comprises titanium nitride, tantalum nitride, and / or tungsten.

[0070] In a related embodiment, the top surface of the first absorption structure is aligned with the top surface of the first layer of the plurality of conductive wirings.

[0071] In related embodiments, the first absorption structure and the plurality of conductive wires respectively include a conductive pad and a conductive body.

[0072] In a related embodiment, the first absorption structure is disposed between the plurality of conductive wires and the front surface of the substrate.

[0073] In some embodiments, this application provides an integrated chip, the integrated chip comprising: a substrate including a front surface opposite to a rear surface; a plurality of pixel devices disposed on the front surface of the substrate; an interconnect structure disposed along the front surface of the substrate, wherein the interconnect structure includes a plurality of conductive wires and a plurality of vias, the plurality of conductive wires and the plurality of vias being disposed within the interconnect dielectric structure and electrically coupled to the plurality of pixel devices; a plurality of pixel sensors disposed within the substrate, wherein the plurality of pixel sensors respectively include a first image sensor element and a second image sensor element, wherein the first image sensor element is configured to generate an electrical signal from infrared (IR) radiation and the second image sensor element is configured to generate an electrical signal from visible light; and a plurality of absorption structures disposed within the interconnect dielectric structure and located below the plurality of pixel sensors, wherein the first image sensor elements are laterally spaced between opposing sidewalls of the corresponding absorption structures, and wherein the second image sensor elements are laterally offset from the plurality of absorption structures by a non-zero distance.

[0074] In a related embodiment, the plurality of pixel sensors includes a first pixel sensor and a second pixel sensor, wherein the first image sensor element of the first pixel sensor is laterally adjacent to the first image sensor element of the second pixel sensor.

[0075] In a related embodiment, the second image sensor element extends continuously from a first sidewall of the first image sensor element to a second sidewall of the first image sensor element, wherein the first sidewall is perpendicular to the second sidewall.

[0076] In related embodiments, the plurality of absorption structures are electrically coupled to the plurality of pixel devices through the plurality of vias.

[0077] In a related embodiment, the plurality of absorption structures are spaced apart in the vertical direction between the plurality of pixel sensors and the plurality of conductive wirings.

[0078] In a related embodiment, the interconnecting dielectric structure directly contacts the bottom surface across the entire bottom surface of each of the plurality of absorption structures and directly contacts the top surface across the entire top surface of each of the plurality of absorption structures.

[0079] In a related embodiment, the integrated chip further includes: an isolation structure disposed from the rear surface of the substrate to a point located below the rear surface, wherein the isolation structure is laterally disposed between the first image sensor element and the second image sensor element of each of the plurality of pixel sensors; and wherein the absorption structures extend laterally between corresponding opposite sidewalls of the isolation structure.

[0080] In related embodiments, the isolation structure includes a passivation layer and a trench layer, wherein the passivation layer is disposed between the trench layer and the substrate, and wherein the trench layer contains a conductive material.

[0081] In related embodiments, the integrated chip further includes: a filter array disposed on the front surface of the substrate, wherein the filter array includes a first filter covered on the first image sensor element and a second filter covered on the second image sensor element, wherein the first filter is configured to allow infrared radiation to pass through and block visible light, and wherein the second filter is configured to allow visible light to pass through and block infrared radiation.

[0082] In related embodiments, the second filter includes a color filter overlaid on a bandpass filter.

[0083] In some embodiments, this application provides a method for forming an image sensor device, the method comprising: forming a first image sensor element in a substrate, wherein the first image sensor element is configured to generate an electrical signal from electromagnetic radiation in a first wavelength range; forming a second image sensor element laterally adjacent to the first image sensor element in the substrate, wherein the second image sensor element is configured to generate an electrical signal from electromagnetic radiation in a second wavelength range different from the first wavelength range; forming an interconnect structure on the first image sensor element and the second image sensor element, wherein the interconnect structure includes a plurality of conductive wires, a plurality of vias, and an absorption structure, wherein the absorption structure comprises a conductive material configured to interact with the first wavelength range; and wherein the absorption structure is directly overlaid on the first image sensor element such that the first image sensor element is laterally spaced between opposing sidewalls of the absorption structure.

[0084] In a related embodiment, the method further includes: forming a third image sensor element within the substrate, wherein the third image sensor element is configured to generate an electrical signal from the electromagnetic radiation within the first wavelength range, and wherein the third image sensor element is adjacent to the first image sensor element.

[0085] The foregoing has outlined features of several embodiments to enable those skilled in the art to better understand various aspects of this disclosure. Those skilled in the art will understand that this disclosure can be readily used as a basis for designing or modifying other processes and structures to achieve the same purposes and / or realize the same advantages as the embodiments described herein. Those skilled in the art will also recognize that these equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made thereto without departing from the spirit and scope of this disclosure.

[0086] [Explanation of Symbols]

[0087] 100, 500: Image sensor devices

[0088] 102: Internal Structure

[0089] 104: Internal dielectric structure

[0090] 106: Conductive wiring

[0091] 107: Absorption Structure

[0092] 108: Through hole

[0093] 110: Pixel device

[0094] 112: Gate structure

[0095] 114: Sidewall spacer structure

[0096] 116: Substrate

[0097] 116b: Rear side surface

[0098] 116f: Front surface

[0099] 118: First photodetector area

[0100] 120a: Image sensor element / First image sensor element / Subordinate image sensor element

[0101] 120b: Image sensor element / Second image sensor element / Subordinate image sensor element

[0102] 122: Second photodetector area

[0103] 124: Isolation Structure

[0104] 126: Passivation layer

[0105] 128: Trench layer

[0106] 130: Upper passivation layer

[0107] 132: Grid structure

[0108] 134: Upper dielectric structure

[0109] 136: Filter array

[0110] 136a: Filter / First Filter

[0111] 136b: Filter / Second Filter

[0112] 138: Microlens

[0113] 140: Bandpass filter

[0114] 142: Color Filter

[0115] 144a: Pixel sensor / First pixel sensor

[0116] 144b: Pixel sensor / Second pixel sensor

[0117] 144c: Pixel sensor / Third pixel sensor

[0118] 144d: Pixel sensor / Fourth pixel sensor

[0119] 502: Conductive body

[0120] 503: Conductive pad

[0121] 504: Etching Stop Layer

[0122] 506: Interlayer Dielectric (ILD) Layer / First ILD Layer

[0123] 600a, 700, 800a, 900, 1000, 1100, 1200: Views / Sectional Views

[0124] 600b, 800b: Top view / view

[0125] 1300: Method

[0126] 1302, 1304, 1306, 1308, 1310: Actions

[0127] A-A', B-B', C-C', D-D': Line Ti: Initial thickness

[0128] Ts: Thickness

[0129] w1: First width

[0130] w2: Second width.

Claims

1. An image sensor device, comprising: The substrate has a front surface opposite to the rear surface; An interconnect structure is provided along the front surface of the substrate, wherein the interconnect structure includes multiple conductive wires, multiple vias, and a first absorption structure; A first image sensor element is disposed within the substrate and configured to generate an electrical signal from electromagnetic radiation within a first wavelength range; as well as A second image sensor element is disposed within the substrate and configured to generate an electrical signal from electromagnetic radiation in a second wavelength range, which is different from the first wavelength range, wherein the second image sensor element is laterally adjacent to the first image sensor element. The first image sensor element is coated on the first absorption structure and has a gap between it and the opposite sidewall of the first absorption structure in the lateral direction. The first absorption structure is configured to prevent electromagnetic radiation within the first wavelength range from being reflected to the second image sensor element.

2. The image sensor device according to claim 1, wherein when viewed from above, the area of ​​the first absorption structure is larger than the area of ​​the first image sensor element.

3. The image sensor device according to claim 1, further comprising: A third image sensor element is disposed within the substrate and configured to generate an electrical signal from the electromagnetic radiation within the first wavelength range, wherein the third image sensor element is laterally adjacent to the first image sensor element. as well as A second absorption structure is located below the third image sensor element, wherein the sidewall of the second absorption structure is adjacent to the sidewall of the first absorption structure.

4. The image sensor device of claim 1, wherein the first absorption structure is configured to interact with the electromagnetic radiation within the first wavelength range, and wherein the first wavelength range includes near-infrared radiation.

5. The image sensor device according to claim 1, wherein the first absorption structure comprises titanium nitride, tantalum nitride, and / or tungsten.

6. The image sensor device according to claim 1, wherein the top surface of the first absorption structure is aligned with the top surface of the first layer of the plurality of conductive wirings.

7. The image sensor device according to claim 1, wherein both the first absorption structure and the plurality of conductive wires include a conductive pad and a conductive body.

8. The image sensor device according to claim 1, wherein the first absorption structure is disposed between the plurality of conductive wires and the front surface of the substrate.

9. An integrated chip, comprising: The substrate includes a front surface opposite to the rear surface; Multiple pixel devices are disposed on the front surface of the substrate; An interconnect structure is provided along the front surface of the substrate, wherein the interconnect structure includes multiple conductive wires and multiple vias, the multiple conductive wires and the multiple vias are disposed within the interconnect dielectric structure and electrically coupled to the multiple pixel devices; Multiple pixel sensors are disposed within the substrate, wherein the multiple pixel sensors respectively include a first image sensor element and a second image sensor element, wherein the first image sensor element is configured to generate an electrical signal from infrared radiation and the second image sensor element is configured to generate an electrical signal from visible light; as well as Multiple absorption structures are disposed within the interconnecting dielectric structure and located below the multiple pixel sensors. The first image sensor element is spaced laterally from the opposite sidewall of its corresponding absorption structure. The second image sensor element is laterally offset from the multiple absorption structures by a non-zero distance. The plurality of absorption structures are configured to prevent infrared radiation from being reflected to the second image sensor element.

10. The integrated chip of claim 9, wherein the plurality of pixel sensors includes a first pixel sensor and a second pixel sensor, wherein the first image sensor element of the first pixel sensor is laterally adjacent to the first image sensor element of the second pixel sensor.

11. The integrated chip of claim 9, wherein the second image sensor element extends continuously from a first sidewall of the first image sensor element to a second sidewall of the first image sensor element, wherein the first sidewall is perpendicular to the second sidewall.

12. The integrated chip of claim 9, wherein the plurality of absorption structures are electrically coupled to the plurality of pixel devices through the plurality of vias.

13. The integrated chip of claim 9, wherein the plurality of absorption structures are spaced apart in the vertical direction from the plurality of pixel sensors and the plurality of conductive wirings.

14. The integrated chip of claim 9, wherein the interconnect dielectric structure directly contacts the bottom surface across the entire bottom surface of each of the plurality of absorption structures and directly contacts the top surface across the entire top surface of each of the plurality of absorption structures.

15. The integrated chip according to claim 9, further comprising: An isolation structure is provided from the rear surface of the substrate to a point located below the rear surface, wherein the isolation structure is laterally disposed between the first image sensor element and the second image sensor element of each of the plurality of pixel sensors; and The absorption structures extend laterally between corresponding opposite sidewalls of the isolation structure.

16. The integrated chip of claim 15, wherein the isolation structure includes a passivation layer and a trench layer, wherein the passivation layer is disposed between the trench layer and the substrate, and wherein the trench layer comprises a conductive material.

17. The integrated chip according to claim 9, further comprising: A filter array is disposed on the front surface of the substrate, wherein the filter array includes a first filter covered on the first image sensor element and a second filter covered on the second image sensor element, wherein the first filter is configured to allow infrared radiation to pass through and block visible light, and wherein the second filter is configured to allow visible light to pass through and block infrared radiation.

18. The integrated chip of claim 17, wherein the second filter comprises a color filter overlaid on a bandpass filter.

19. A method for forming an image sensor device, comprising: A first image sensor element is formed in a substrate, wherein the first image sensor element is configured to generate an electrical signal from electromagnetic radiation in a first wavelength range; A second image sensor element is formed laterally adjacent to the first image sensor element within the substrate, wherein the second image sensor element is configured to generate an electrical signal from electromagnetic radiation in a second wavelength range, which is different from the first wavelength range; An interconnect structure is formed on the first image sensor element and the second image sensor element, wherein the interconnect structure includes multiple conductive wires, multiple vias and an absorption structure, wherein the absorption structure includes a conductive material configured to interact with the first wavelength range; and The absorption structure is directly coated on the first image sensor element, such that the first image sensor element is spaced apart laterally from the opposite sidewall of the absorption structure. The absorption structure is configured to prevent electromagnetic radiation within the first wavelength range from being reflected to the second image sensor element.

20. The method of claim 19, further comprising: A third image sensor element is formed within the substrate, wherein the third image sensor element is configured to generate an electrical signal from the electromagnetic radiation within the first wavelength range, and wherein the third image sensor element is adjacent to the first image sensor element.

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