CN108183116A - Imaging sensor and its manufacturing method - Google Patents

Abstract

This disclosure relates to imaging sensor and its manufacturing method.It is provided with a kind of method for manufacturing imaging sensor, which is characterized in that the method includes：The substrate of formed therein which multiple radiation-sensing elements is provided；The first separating part is formed over the substrate；And form multiple colour filters between first separating part, the multiple colour filter is arranged in correspondence with above the multiple radiation-sensing element, and first separating part is used to prevent the crosstalk of the radiation between the multiple colour filter, wherein, it forms first separating part and includes：Dielectric components are formed over the substrate；And form the first metal layer on the side wall of the dielectric components.

Description

Image sensor and manufacturing method thereof

technical field

The present disclosure relates generally to the field of semiconductors, and in particular, to image sensors and methods of manufacturing the same.

Background technique

In an image sensor, a plurality of radiation sensing elements and a correspondingly arranged plurality of color filters may be included. Accordingly, the image sensor may further include partitions disposed between the radiation sensing elements and partitions disposed between the color filters. With the shrinking of semiconductor process nodes, the manufacturing process of the spacers is becoming more and more complicated and difficult to realize.

Therefore, there is a need for new techniques.

Contents of the invention

An object of the present disclosure is to provide a novel image sensor and a method of manufacturing the same.

According to a first aspect of the present disclosure, there is provided a method for manufacturing an image sensor, characterized in that the method includes: providing a substrate in which a plurality of radiation sensing elements are formed; forming first partitions; and forming a plurality of color filters between the first partitions, the plurality of color filters being correspondingly disposed above the plurality of radiation sensing elements, and the first partitions part for preventing crosstalk of radiation between the plurality of color filters, wherein the first partition part includes: a dielectric part formed on the substrate; and a first metal layer formed on the on the sidewall of the dielectric part.

According to a second aspect of the present disclosure, there is provided an image sensor, characterized in that the image sensor includes: a substrate in which a plurality of radiation sensing elements are formed; a first partition formed in on the substrate; a plurality of color filters formed between the first partitions, wherein the plurality of color filters are correspondingly arranged above the plurality of radiation sensing elements, and the first A partition for preventing crosstalk of radiation between the plurality of color filters; and wherein the first partition includes: a dielectric member formed on the substrate; and a first metal layer formed on the sidewall of the dielectric component.

Other features of the present disclosure and advantages thereof will become apparent through the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, which constitute a part of this specification, illustrate the embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

The present disclosure can be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

FIG. 1A illustrates a flowchart of a manufacturing method 100 of an image sensor according to an exemplary embodiment of the present disclosure.

FIG. 1B illustrates a flowchart of step 120 in the method 100 for manufacturing an image sensor according to an exemplary embodiment of the present disclosure.

FIGS. 2A-2F illustrate device cross-sectional views at various steps of a specific example 200 of the manufacturing method 100 of the image sensor shown in FIGS. 1A and 1B according to an exemplary embodiment of the present disclosure.

FIG. 3 is a diagram schematically showing one example of a transmission path of light at an interface when light is incident from a radiation sensing element to a second partition.

FIGS. 4A-4F illustrate device cross-sectional views at various steps of a specific example 300 of the manufacturing method 100 of the image sensor shown in FIGS. 1A and 1B according to an exemplary embodiment of the present disclosure.

FIGS. 5A-5C illustrate device cross-sectional views at various steps of a specific example 400 of the manufacturing method 100 of the image sensor shown in FIGS. 1A and 1B according to an exemplary embodiment of the present disclosure.

Note that in the embodiments described below, the same reference numerals are sometimes used commonly between different drawings to denote the same parts or parts having the same functions, and repeated descriptions thereof are omitted. In this specification, similar reference numerals and letters are used to refer to similar items, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

In order to facilitate understanding, the position, size, range, etc. of each structure shown in the drawings and the like may not represent the actual position, size, range, and the like. Therefore, the disclosed invention is not limited to the positions, dimensions, ranges, etc. disclosed in the drawings and the like.

Detailed ways

In an image sensor, a plurality of radiation sensing elements may be included, and the plurality of radiation sensing elements are usually arranged in an array in a substrate. In order to improve imaging performance, multiple radiation sensing elements must not only have good radiation sensing performance, but also be able to effectively isolate each other. Since radiation sensing elements involve converting radiation into electrical signals, effective electrical isolation and effective radiation isolation are required between multiple radiation sensing elements to avoid performance loss caused by crosstalk. Here, the term "radiation" includes, but is not limited to, optical radiation such as visible light, infrared rays, ultraviolet rays, and the like.

On one side of the radiation sensing element of the image sensor for sensing radiation, a color filter for screening radiation may also be provided. For example, color filters for sensing radiation in different frequency bands may be disposed above each radiation sensing element. In an array composed of a plurality of radiation sensing elements, there may also be groups formed by different color filter arrangements. Take the commonly used Bayer grouping as an example: four radiation sensing elements arranged in a two-by-two matrix form a grouping, where two radiation sensing elements on a diagonal line in each grouping are provided with A color filter for passing green light, and a color filter for passing red light and a color filter for passing blue light are respectively arranged above the other two radiation sensing elements. Since adjacent color filters are generally used to transmit radiation of different frequency bands, it is necessary to provide a partition between each color filter to prevent radiation crosstalk between adjacent color filters.

With the continuous shrinking of semiconductor process technology nodes, higher requirements are placed on the performance of the partitions between the radiation sensing elements and the partitions between the color filters, which also makes the process flow for manufacturing these partitions change. more complicated.

In this regard, the inventors of the present application hope to improve the structure and process flow of the partition in the image sensor, thereby improving the structure and manufacturing method of the image sensor.

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and in no way intended as any limitation of the disclosure, its application or uses.

Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered part of the Authorized Specification.

In all examples shown and discussed herein, any specific values should be construed as exemplary only, and not as limitations. Therefore, other examples of the exemplary embodiment may have different values.

FIG. 1A shows a flowchart of a manufacturing method 100 of an image sensor according to an exemplary embodiment of the present disclosure.

Specifically, as shown in FIG. 1A , the image sensor manufacturing method 100 includes: providing a substrate in which a plurality of radiation sensing elements are formed (step 110 ).

In some embodiments, other semiconductor device components may also be formed in the substrate. Herein, there is no particular limitation on the substrate as long as it is suitable for forming a radiation sensing structure for sensing radiation therein. In some embodiments, the substrate may include a unitary semiconductor material (such as silicon or germanium, etc.) or a compound semiconductor material (such as silicon carbide, silicon germanium, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, and/or or indium antimonide) or a combination thereof.

In some embodiments, radiation sensing structures may include structures capable of photoelectric conversion, including but not limited to photodiodes or others.

The manufacturing method 100 of the image sensor further includes: forming first partitions on the substrate (step 120), and forming a plurality of color filters between the first partitions, wherein the plurality of color filters are correspondingly arranged in a plurality of above the radiation sensing element, and the first partition is used to prevent crosstalk of radiation between the plurality of color filters (step 130).

As described above, the first partition is formed between a plurality of color filters for preventing crosstalk of radiation between adjacent color filters. Therefore, the first partition needs to include a material capable of preventing transmission of radiation, and the height of the first partition is not lower than the color filter. In some embodiments, the first partition may include a metallic material, and preferably may include tungsten.

The function of the color filter includes enabling only radiation in a specific frequency band to pass through the color filter to reach the radiation sensing element in the substrate, so each color filter can be correspondingly disposed above each radiation sensing element. In some embodiments, methods of forming color filters include, but are not limited to, deposition, photolithography, and etching, and repetitions of these steps. In some embodiments, color filters for transmitting different colors of light are formed in different steps.

FIG. 1B illustrates a flowchart of step 120 in the method 100 for manufacturing an image sensor according to an exemplary embodiment of the present disclosure. As shown in FIG. 1B, in the manufacturing method 100 of the image sensor, forming the first partition may include: forming a dielectric component on the substrate (step 122), and forming a metal layer on the sidewall of the dielectric component (step 124).

In some embodiments, methods of forming dielectric features include, but are not limited to, deposition, photolithography, and etching. Materials for the dielectric components include, but are not limited to, silicon oxide, silicon nitride, and the like.

In some embodiments, a metal layer may also be formed on top of the dielectric component. In some embodiments, methods of forming a metal layer on the sidewalls and/or top of a dielectric feature include, but are not limited to, deposition, polishing, photolithography, and etching. The thickness of the metal layer should ensure that radiation can be prevented from passing through, so that radiation crosstalk between adjacent color filters can be effectively prevented.

The image sensor manufacturing method 100 can realize a novel image sensor structure, wherein the dielectric component in the first partition can increase the height of the first partition while reducing the complexity and cost of the related manufacturing process, and, The metal layer in the first partition can prevent crosstalk, increase quantum efficiency, and improve color separation. In addition, compared with the traditional metal grid, the metal material in the first partition realized by the manufacturing method 100 is reduced, which can not only reduce the risk of metal contamination, but also help to simplify the manufacturing process and reduce the cost.

FIGS. 2A-2F illustrate device cross-sectional views at various steps of a specific example 200 of the manufacturing method 100 of the image sensor shown in FIGS. 1A and 1B according to an exemplary embodiment of the present disclosure. Note that this example is not intended to limit the invention. What has been described above in connection with FIGS. 1A and 1B may also apply to corresponding features.

As shown in FIG. 2A, a substrate 210 having a plurality of radiation sensing elements 220 formed therein is provided. Although only two radiation sensing elements are schematically shown in the figure, those skilled in the art will understand that in the substrate 210, the structure, quantity and arrangement of the radiation sensing elements 220 are not the same. It is specifically limited, but may include any suitable structure, number and arrangement. In some embodiments, a plurality of photodiodes arranged in a matrix may be disposed in the substrate 210 .

Next, as shown in FIG. 2B , trenches 212 are formed between the radiation sensing elements 220 in the substrate 210 .

In some embodiments, methods of forming trench 212 include, but are not limited to, photolithography and etching. In addition, although the depth of the groove 212 shown in the figure is consistent with the depth of the radiation sensing element 220, those skilled in the art will understand that the depth of the groove 212 may be less than, equal to or greater than the depth of the radiation sensing element 220 .

Next, as shown in FIG. 2C , a dielectric material layer 214 is deposited on the substrate 210 and in the trench 212 . Wherein, the dielectric material deposited in the trench 212 may be used to form the second partition. Since the deposited dielectric material layer 214 can not only be used to form the second partition, but also can be used to form the dielectric components of the first partition on the substrate 210, the dielectric material layer 214 should fill the trench 212 and its The thickness of the portion higher than the upper surface of the substrate 210 should not be smaller than the height of the dielectric member of the first partition to be formed later.

In some embodiments, the dielectric material layer 214 may be formed using a deposition process including, but not limited to, using molecular beam epitaxy (MBE), chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD), Physical vapor deposition (PVD), chemical solution deposition, blanket deposition, and other possible deposition processes are used to deposit the dielectric material on substrate 210 and in trenches 212 .

In some embodiments, after the dielectric material layer 214 is formed on the substrate 210 and in the trench 212 , the dielectric material layer 214 may be planarized using a suitable process such as chemical mechanical planarization (CMP).

Next, as shown in FIG. 2D , the part of the dielectric material layer 214 on the substrate 210 is removed, and the part of the remaining dielectric material layer higher than the upper surface of the substrate 210 is used as the dielectric member 240 of the first partition, and the remaining A portion of the dielectric material layer lower than the upper surface of the substrate 210 serves as the second partition 230 . The second partition 230 is formed between the plurality of radiation sensing elements 220 for electrically isolating the plurality of radiation sensing elements 220 , and the second partition 230 is correspondingly disposed under the first partition.

Although the width of the dielectric member 240 of the first partition in FIG. 2D (the width in the direction parallel to the paper and parallel to the upper surface of the substrate 210) is smaller than the corresponding width of the second partition 230, the art Those skilled in the art understand that the width of the dielectric member 240 of the first partition can be smaller than, equal to or larger than the corresponding width of the second partition 230 . Preferably, the dielectric member 240 of the first partition is adapted to enable alignment of a color filter to be formed later with the radiation sensing element 220 in the substrate 210 .

In some embodiments, methods of removing portions of the dielectric material layer 214 include, but are not limited to, photolithography and etching.

As described above, through the steps shown in FIGS. 2C and 2D , the dielectric member 240 of the first partition and the second partition 230 contain the same material and are formed in the same step, which can effectively simplify the manufacturing process. Thereby reducing costs.

In some embodiments, the refractive index of the radiation sensing element 220 may be greater than that of the material of the dielectric material layer 214 , so that the refractive index of the radiation sensing element 220 may be greater than that of the second partition 230 . This can effectively improve the photosensitive efficiency of the radiation sensing element 220 . FIG. 3 is a diagram schematically showing one example of a transmission path of light at an interface when light is incident from the radiation sensing element 220 in FIG. 2D to the second partition 230 . Wherein, the solid line with the arrow indicates the transmission path of light in the two transmission media, the dotted line indicates the normal line, and the dotted line is the extension line of the transmission direction of the incident light. Since the refractive index of the radiation sensing element 220 is greater than the refractive index of the second partition 230, the light incident from the radiation sensing element 220 to the second partition 230 enters the optically thinner medium from the optically denser medium, and its refraction angle r is greater than Incidence angle i, so that the transmission path of light is changed to be deflected outward, so that more light remains in the radiation sensing element 220 instead of being refracted into the second partition 230, thereby improving the radiation sensing element 220 Photosensitivity.

In some embodiments, the second partition 230 may be formed including a plurality of dielectric layers. The materials of the multiple dielectric layers can be the same or different. In some embodiments, the dielectric layer of the plurality of dielectric layers that is in contact with the radiation sensing element 220 has a refractive index smaller than that of the radiation sensing element 220 . In some embodiments, the refractive index of the dielectric layer farther from the radiation sensing element 220 among the plurality of dielectric layers is smaller than or equal to the refractive index of the dielectric layer closer to the radiation sensing element 220 . The material of the plurality of dielectric layers may be the same as or different from the material of the dielectric member 240 of the first partition. In some embodiments, the material of the dielectric layer located in the middle of the plurality of dielectric layers can be the same as the material of the dielectric member 240 of the first partition, so the middle position of the plurality of dielectric layers can be formed in the same step. The dielectric layer of the portion and the dielectric member 240 of the first partition are formed in steps similar to those described with reference to FIGS. layer while retaining the trenches for forming the dielectric layer in between, and then repeat the flow of FIGS. 2C and 2D .

In some embodiments, in the case that the second partition 230 includes a plurality of dielectric layers and the refractive index of the dielectric layer in contact with the radiation sensing element 220 among the plurality of dielectric layers is smaller than the refractive index of the radiation sensing element 220, As described with reference to FIG. 3 , the light refracted from the radiation sensing element 220 into the second partition 230 (that is, refracted into the dielectric layer in contact with it) undergoes an optical path from the optically denser medium to the optically thinner medium, so the The transmission path is changed to be deflected outward, so that more light stays in the radiation sensing element 220 instead of being refracted into the second partition 230 , thereby improving the light-sensing efficiency of the image sensor. Further, when the refractive index of the dielectric layer farther away from the radiation sensing element 220 among the plurality of dielectric layers is less than or equal to the refractive index of the dielectric layer closer to the radiation sensing element 220, the radiation sensing element The interfaces through which light propagates from 220 to the second partition 230 are from the optically denser medium to the optically thinner medium or adjacent media with the same refractive index, so the transmission path of the light is changed to be deflected outward or not deflected, thereby More light stays in the radiation sensing element 220 instead of being refracted into the second partition 230 , which effectively improves the light-sensing efficiency of the image sensor.

Next, as shown in FIG. 2E , a first anti-reflection layer 250 is formed on the substrate 210 , and then a metal layer 242 is formed on the sidewall and top of the dielectric member 240 . So far, the first partition composed of the dielectric member 240 and the metal layer 242 is formed. The first partition is used to isolate the radiation between the color filters 260 that will be formed later, so the height of the first partition composed of the height of the dielectric member 240 and the height of the metal layer 242 should not be less than slightly The height of the color filter 260 to be formed later, and the material and thickness of the metal layer 242 should ensure that light cannot pass through the metal layer, thereby effectively avoiding crosstalk between adjacent color filters.

In some embodiments, the metal layer may be formed only on the sidewalls of the dielectric member 240 without forming the metal layer on the top of the dielectric member 240 . In this case, the height of the dielectric member 240 should not be smaller than that of a color filter to be formed later.

The width of the first partition in a direction parallel to the plane of the paper and parallel to the upper surface of the substrate 210 is composed of the width of the dielectric member 240 and the thickness of the metal layer 242 . Although the width of the first partition in FIG. 2E is substantially equal to the corresponding width of the second partition 230, those skilled in the art understand that the width of the first partition may be smaller than, equal to, or greater than the corresponding width of the second partition 230. . Preferably, the widths of the first spacer and the second spacer should not only meet the requirements of their respective isolation functions, but also be suitable for the alignment of the color filter to be formed later with the radiation sensing element 220 in the substrate 210 .

Referring again to FIG. 2E , after forming the metal layer 242 , a second anti-reflection layer 252 may also be formed on top of the first partition.

Next, as shown in FIG. 2F , a plurality of color filters 260 are formed between the first partitions. A plurality of color filters 260 are correspondingly disposed above the plurality of radiation sensing elements 220 , so that only radiation of a specific frequency band can pass through the color filters 260 to reach the radiation sensing elements 220 .

Methods of forming the color filter 260 include, but are not limited to, depositing a layer of color filter material and then removing portions of the layer of color filter material. The color filter 260 for transmitting light of different colors may be formed by repeating the above steps. In some embodiments, the color filter material layer may be formed by any of the following coating techniques, including but not limited to suspension coating, brush coating, spray coating, electrostatic spray coating, 3D printing, and any combination of techniques thereof. Removing the part of the color filter material layer can be accomplished through an etching process, including but not limited to dry etching and wet etching. Those skilled in the art understand that the above process steps for forming the color filter 260 are optional and not limiting, and the color filter 260 of the present invention can be formed by any suitable process steps.

Next, continuing to refer to FIG. 2F , a plurality of microlenses 262 may be correspondingly disposed above the plurality of color filters 260 .

Those skilled in the art understand that the above steps do not limit the solutions of the present invention, but can be modified or modified arbitrarily according to actual applications.

In the above specific embodiment, in the image sensor obtained by the image sensor manufacturing method 200, firstly, the dielectric member 240 in the first partition can increase the height of the first partition while reducing the thickness of the metal material. use, reduce the complexity of related manufacturing processes and reduce costs; second, the metal layer 242 in the first partition can prevent crosstalk, increase quantum efficiency and improve color separation; third, through the refractive index of the second partition 230 The arrangement of can effectively reduce the light refracted from the radiation sensing element 220 into the second partition 230 , thereby improving the photosensitive efficiency of the radiation sensing element 220 . In addition, in the manufacturing method 200 of the image sensor, the dielectric member 240 of the first partition and the second partition 230 are formed in the same step, which can reduce the complexity of the manufacturing process, thereby reducing the manufacturing cost.

According to an exemplary embodiment of the present disclosure, an image sensor is provided, which may be as shown in FIG. 2F . The image sensor may include: a substrate 210 in which a plurality of radiation sensing elements 220 are formed; first partitions formed on the substrate 210; a plurality of color filters 260 formed between the first partitions, wherein , a plurality of color filters 260 are correspondingly disposed above the plurality of radiation sensing elements 220, and the first partition is used to prevent crosstalk of radiation between the plurality of color filters 260; and wherein the first partition includes: The dielectric part 240 is formed on the substrate 210 ; and the metal layer 242 is formed on the sidewall of the dielectric part 210 .

In some embodiments, metal layer 242 may also be formed on top of dielectric member 240 .

In some embodiments, the image sensor shown in FIG. 2F may further include a first anti-reflection layer 250 formed between the bottom of the metal layer 242 and the plurality of color filters 260 and the substrate 210. .

In some embodiments, the image sensor as shown in FIG. 2F may further include a second anti-reflection layer 252 disposed on top of the first partition.

In some embodiments, the image sensor as shown in FIG. 2F may further include a second partition 230 formed between the plurality of radiation sensing elements 220 for electrically isolating the plurality of radiation sensing elements. 220, and the second partition 230 is correspondingly disposed below the first partition.

In some embodiments, the dielectric member 240 of the first partition is made of the same material as the second partition 230 and is formed in the same step.

In some embodiments, the refractive index of the radiation sensing element 220 is greater than that of the second partition 230 .

In some embodiments, the second partition 230 may include a plurality of dielectric layers, a dielectric layer in contact with the radiation sensing element 220 having a refractive index smaller than that of the radiation sensing element 220 among the plurality of dielectric layers. In some embodiments, the refractive index of the dielectric layer farther from the radiation sensing element 220 among the plurality of dielectric layers is smaller than or equal to the refractive index of the dielectric layer closer to the radiation sensing element 220 .

FIGS. 4A-4F illustrate device cross-sectional views at various steps of a specific example 300 of the manufacturing method 100 of the image sensor shown in FIGS. 1A and 1B according to an exemplary embodiment of the present disclosure. Note that this example is not intended to limit the invention. What has been described above in connection with FIGS. 1A-1B or 2A-2F may also apply to corresponding features.

As shown in FIG. 4A , a substrate 310 is provided in which a plurality of radiation sensing elements 320 are formed, and then trenches 312 are formed between the radiation sensing elements 320 in the substrate 310 . The steps shown in FIG. 4A are similar to those described above with reference to FIGS. 2A and 2B , and thus will not be described again.

Next, as shown in FIG. 4B , a first dielectric layer 330 covering the sidewalls of the trench 312 is formed.

In some embodiments, the method of forming the first dielectric layer 330 covering the sidewall of the trench 312 includes, but is not limited to: depositing or growing the first dielectric layer 330 on the sidewall of the trench 312, or filling the trench with a dielectric material. Trenches 312 are then photolithographically and etched away to remove portions of the dielectric material in trenches 312 leaving a first dielectric layer 330 covering the sidewalls.

In some embodiments, the refractive index of the radiation sensing element 320 can be greater than the refractive index of the first dielectric layer 330, so the light incident from the radiation sensing element 320 to the first dielectric layer 330 enters the optically thinner medium from the optically denser medium. , the transmission path thereof is changed to be deflected outward, so that more light remains in the radiation sensing element 320 instead of being refracted into the first dielectric layer 330 , thereby improving the photosensitive efficiency of the radiation sensing element 320 .

In some embodiments, the first dielectric layer 330 covering the sidewalls of the trench 312 may be a multilayer structure. Specifically, a plurality of dielectric layers may be formed on the sidewall of the trench as the first dielectric layer 330 , and the materials of the plurality of dielectric layers may be the same or different. Preferably, the refractive index of the dielectric layer in contact with the radiation sensing element 320 among the plurality of dielectric layers is smaller than the refractive index of the radiation sensing element 320 . Further, the refractive index of the dielectric layer farther from the radiation sensing element 320 among the plurality of dielectric layers is smaller than or equal to the refractive index of the dielectric layer closer to the radiation sensing element 320 .

When the refractive index of the dielectric layer in contact with the radiation sensing element 320 among the plurality of dielectric layers is smaller than the refractive index of the radiation sensing element 320, refraction from the radiation sensing element 320 to the first dielectric layer 330 (that is, refraction The light in the dielectric layer in contact with it goes through the optical path from the optically denser medium to the optically thinner medium, and the transmission path of the light is changed to be deflected outward, thereby improving the photosensitive efficiency of the image sensor.

In the case where the refractive index of the dielectric layer farther from the radiation sensing element 320 among the plurality of dielectric layers is less than or equal to the refractive index of the dielectric layer closer to the radiation sensing element 320 , from the radiation sensing element 320 to the second The interfaces through which light propagates through a dielectric layer 330 are all from an optically denser medium to an optically thinner medium or a medium with the same refractive index, so that the transmission path of the light is changed to be deflected outward or not deflected, so that more light stays in the The radiation sensing element 320 is not refracted into the first dielectric layer 330, effectively improving the photosensitive efficiency of the image sensor.

Next, as shown in FIG. 4C , two metal layers 332 are formed on the first dielectric layer 330 covering the sidewalls of the trench 312 , and the two metal layers 332 are arranged symmetrically and do not contact the radiation sensing element 320 .

The two metal layers 332 are used to prevent radiation crosstalk between the radiation sensing elements 320 . For opaque media, the greater the refractive index, the greater the reflectivity. In some embodiments, the refractive index of the opaque metal layer is greater than that of the radiation sensing element 320, and thus the reflectivity is correspondingly high. Therefore, the light incident on the first dielectric layer 330 from the radiation sensing element 320 will be reflected at the metal layer 332, and thus reflected back into the radiation sensing element 320, so that the photosensitive efficiency of the radiation sensing element 320 is further improved . In some embodiments, the surface of the metal layer 332 facing the radiation sensing element 320 is smooth to better reflect incident light. The thickness of the metal layer 332 is preferably set to prevent light from passing through. In some embodiments, a silicon nitride layer may be disposed around the metal layer 332 to effectively prevent metal contamination.

Next, as shown in FIG. 4D , similar to FIG. 2C , a dielectric material layer 314 is deposited between the two metal layers 332 and on the substrate 310 .

The dielectric material deposited between the two metal layers 332 is used to form the second dielectric layer. Since the deposited dielectric material layer 314 is not only used to form the second dielectric layer, but also used to form the dielectric components of the first partition on the substrate 310, the dielectric material layer should fill the space between the two metal layers 332. The gap, and the thickness of the dielectric material layer 314 above the upper surface of the substrate 310 should not be smaller than the height of the dielectric part of the first partition to be formed later.

Next, as shown in FIG. 4E, the part of the dielectric material layer 314 on the substrate 310 is removed, and the part of the remaining dielectric material layer higher than the upper surface of the substrate 310 is used as the dielectric member 340 of the first partition, and the remaining The portion of the dielectric material layer lower than the upper surface of the substrate 310 serves as the second dielectric layer 334 between the two metal layers 332 . So far, the second partition part composed of the first dielectric layer 330 , the metal layer 332 and the second dielectric layer 334 is formed. A second partition is formed between the plurality of radiation sensing elements 320 for electrically isolating the plurality of radiation sensing elements 320, and the second partition is correspondingly disposed under the first partition.

As described above, through the steps shown in FIG. 4D and FIG. 4E, the dielectric member 340 of the first partition and the second dielectric layer 334 between the two metal layers 332 contain the same material and are formed in the same step. , which can effectively simplify the manufacturing process and reduce costs.

Next, as shown in FIG. 4F , a first anti-reflection layer 350 is formed on the substrate 310 , and then a metal layer 342 is formed on the sidewall and top of the dielectric member 340 . So far, the first partition composed of the dielectric member 340 and the metal layer 342 is formed. In some embodiments, the metal layer 342 may be formed only on the sidewalls of the dielectric member 340 and not on the top thereof.

Continuing to refer to FIG. 4F , after forming the metal layer 342 , a second anti-reflection layer 352 may also be formed on top of the first partition. Next, a plurality of color filters 360 may be formed between the first partitions. A plurality of color filters 360 may be correspondingly disposed above the plurality of radiation sensing elements 320 for allowing only radiation of a specific frequency band to pass through the color filters and reach the radiation sensing elements 320 . In addition, a plurality of microlenses 362 may be correspondingly disposed above the plurality of color filters 360 . The above steps are similar to those described with reference to FIGS. 2E-2F , and will not be repeated here.

Note that although the width of the first partition in FIG. 4F is substantially equal to the corresponding width of the second partition, those skilled in the art understand that the width of the first partition may be smaller than, equal to, or greater than the corresponding width of the second partition. . Preferably, the widths of the first partition and the second partition should be suitable for realizing the alignment of the color filter 360 and the radiation sensing element 320 in the substrate 310 in addition to meeting the requirements of their respective isolation functions.

In the above specific embodiment, in the image sensor obtained by the manufacturing method 300 of the image sensor, firstly, the dielectric member 340 in the first partition can increase the height of the first partition and at the same time reduce the density of the metal material. use, reduce the complexity of related manufacturing processes and reduce costs; second, the metal layer 342 in the first partition can prevent crosstalk, increase quantum efficiency and improve color separation; third, by adjusting the refractive index of the second partition Setting, and/or disposing a metal layer in the second partition can effectively reduce the light refracted from the radiation sensing element 320 into the second partition, thereby improving the photosensitive efficiency of the radiation sensing element 320 . In addition, in the manufacturing method 300 of the image sensor, the dielectric member 340 of the first partition and the dielectric layer (the second dielectric layer 334 between the two metal layers 332 ) located in the middle of the second partition are placed on the Formed in the same step, the complexity of the manufacturing process can be reduced, thereby saving the manufacturing cost.

According to an exemplary embodiment of the present disclosure, an image sensor is provided, which may be as shown in FIG. 4F . The image sensor may include: a substrate 310 in which a plurality of radiation sensing elements 320 are formed; first partitions formed on the substrate 310; a plurality of color filters 360 formed between the first partitions, wherein , a plurality of color filters 360 are correspondingly disposed above the plurality of radiation sensing elements 320, and the first partition is used to prevent crosstalk of radiation between the plurality of color filters 360; and wherein the first partition includes: The dielectric part 340 is formed on the substrate 310 ; and the metal layer 342 is formed on the sidewall of the dielectric part 310 .

In some embodiments, metal layer 342 may also be formed on top of dielectric member 340 .

In some embodiments, the image sensor shown in FIG. 4F may further include a first anti-reflection layer 350 formed between the bottom of the metal layer 342 and the plurality of color filters 360 and the substrate 310. .

In some embodiments, the image sensor as shown in FIG. 4F may further include a second anti-reflection layer 352 disposed on top of the first partition.

In some embodiments, the image sensor as shown in FIG. 4F may further include a second partition formed between the plurality of radiation sensing elements 420 for electrically isolating the plurality of radiation sensing elements 420, And the second partition is correspondingly arranged below the first partition.

In some embodiments, the first dielectric layer 330 covering the sidewalls of the trench 312 may be a multilayer structure. Preferably, among the plurality of dielectric layers included in the first dielectric layer 330 , the dielectric layer in contact with the radiation sensing element 320 has a refractive index smaller than that of the radiation sensing element 320 . Further, among the plurality of dielectric layers included in the first dielectric layer 330 , the refractive index of the dielectric layer farther away from the radiation sensing element 320 is smaller than or equal to the refractive index of the dielectric layer closer to the radiation sensing element 320 .

In some embodiments, two metal layers 332 are formed on the first dielectric layer 330 covering the sidewall of the trench 312, the two metal layers 332 are arranged symmetrically and do not contact the radiation sensing element 320, and the two metal layers 332 Dielectric layer 334 is formed between 332 . That is, in the image sensor shown in FIG. 4F , the second partition between the radiation sensing elements 320 includes not only the first dielectric layer 330 but also two metal layers 332 and a dielectric between the two metal layers 332. Layer 334. The metal layer 332 can effectively prevent the transmission of light, so that the light incident on the radiation sensing element 320 will not be absorbed by the second partition, effectively improving the photosensitive efficiency of the image sensor.

In some embodiments, the material of the dielectric member 340 and the dielectric layer 334 between the two third metal layers 332 is the same.

FIGS. 5A-5C illustrate device cross-sectional views at various steps of a specific example 400 of the manufacturing method 100 of the image sensor shown in FIGS. 1A and 1B according to an exemplary embodiment of the present disclosure. Note that this example is not intended to limit the invention. What was described above in connection with FIGS. 1A-1B , 2A-2F or 4A-4F may also apply to corresponding features.

As shown in FIG. 5A , a substrate 410 is provided in which a plurality of radiation sensing elements 420 are formed, and then trenches 412 are formed between the radiation sensing elements 420 in the substrate 410 . The steps shown in FIG. 5A are similar to those described with reference to FIGS. 2A and 2B , and thus will not be described again.

Next, as shown in FIG. 5B , a dielectric layer 430 is formed on the sidewalls of the trenches 412 , and trenches 432 are formed between the dielectric layers 430 .

In some embodiments, a dielectric material can be deposited in the trench 412 first, and then the trench 432 can be formed by steps such as photolithography and trench etching. However, those skilled in the art understand that the above process steps for forming the dielectric layer 430 and the trench 432 are only optional and not limiting, and the dielectric layer 430 and the trench 432 of the present invention can be formed by any suitable process steps .

In some embodiments, the refractive index of the dielectric layer 430 can be smaller than the refractive index of the radiation sensing element 420, so that the light incident into the radiation sensing element 420 is less likely to be refracted into the dielectric layer 430, thereby improving the radiation sensing element. photosensitive efficiency.

Then, as shown in FIG. 5C , a metal layer 434 is first formed in the trench 412 , and the metal layer 434 is not in contact with the radiation sensing element 420 . So far, the second partition including the metal layer 434 and the dielectric layer 430 is formed. Next, a first anti-reflection layer 450 may be formed over the substrate 410 . Dielectric feature 440 may then be formed on substrate 412 .

In some embodiments, metal layer 434 is used to prevent crosstalk of radiation between radiation sensing elements 420 . For opaque media, the greater the refractive index, the greater the reflectivity. In some embodiments, the refractive index of the opaque metal layer 434 may be greater than that of the radiation sensing element 420, and thus the reflectivity is correspondingly high. Therefore, the light incident on the dielectric layer 430 from the radiation sensing element 420 can be reflected at the metal layer 434 and return to the radiation sensing element 420 , so that the light-sensing efficiency of the radiation sensing element 420 is improved. In some embodiments, the surfaces on both sides of the metal layer 434 are smooth to better reflect incident light. The thickness of the metal layer 434 is preferably set to prevent the transmission of radiation. In some embodiments, a silicon nitride layer may be disposed around the metal layer 434 to effectively prevent metal contamination.

Continuing to refer to FIG. 5C , next, a metal layer 442 , a second anti-reflection layer 452 , a plurality of color filters 460 and a lens 462 may be formed. These steps are similar to those described with reference to FIGS. 2E-2F or FIG. 4F , and thus will not be described again.

In the above specific embodiment, in the image sensor obtained by the manufacturing method 400 of the image sensor, firstly, the dielectric member 440 in the first partition can increase the height of the first partition while reducing the density of the metal material. use, reduce the complexity of the related manufacturing process and reduce costs; second, the metal layer 442 in the first partition can prevent crosstalk, increase quantum efficiency and improve color separation; third, by adjusting the refractive index of the second partition Setting, and by disposing the metal layer 434 in the second partition, can effectively reduce the light refracted from the radiation sensing element 420 into the second partition, thereby improving the photosensitive efficiency of the radiation sensing element 420 .

According to an exemplary embodiment of the present disclosure, an image sensor is provided, which may be as shown in FIG. 5C . The image sensor may include: a substrate 410 in which a plurality of radiation sensing elements 420 are formed; first partitions formed on the substrate 410; a plurality of color filters 460 formed between the first partitions, wherein , a plurality of color filters 460 are correspondingly disposed above the plurality of radiation sensing elements 420, and the first partition is used to prevent crosstalk of radiation between the plurality of color filters 460; and wherein the first partition includes: The dielectric part 440 is formed on the substrate 410 ; and the metal layer 442 is formed on the sidewall of the dielectric part 410 .

In some embodiments, metal layer 442 may also be formed on top of dielectric member 440 .

In some embodiments, the image sensor as shown in FIG. 5C may further include a first anti-reflection layer 450 formed between the first partition and color filter 460 and the substrate 410 .

In some embodiments, the image sensor as shown in FIG. 5C may further include a second anti-reflection layer 452 formed on top of the first partition.

In some embodiments, the image sensor as shown in FIG. 5C may further include a second partition formed between the plurality of radiation sensing elements 420 for electrically isolating the plurality of radiation sensing elements 420, And the second partition is correspondingly arranged below the first partition. In the image sensor shown in FIG. 5C , the second partition includes a dielectric layer 430 and a metal layer 434 , wherein the metal layer 434 is not in contact with the radiation sensing element 420 . The refractive index of the metal layer 434 is greater than that of the radiation sensing element 420, which can effectively prevent the transmission of light, so that the light incident into the radiation sensing element 420 is not absorbed by the second partition, thereby improving the performance of the image sensor. Photosensitivity.

In some embodiments, the dielectric layer 430 may be a multilayer structure. Preferably, among the plurality of dielectric layers included in the dielectric layer 430 , the dielectric layer in contact with the radiation sensing element 420 has a refractive index smaller than that of the radiation sensing element 420 . In some embodiments, the refractive index of the dielectric layer farther from the radiation sensing element 420 among the plurality of dielectric layers included in the dielectric layer 430 is smaller than or equal to the refractive index of the dielectric layer closer to the radiation sensing element 420 .

According to an aspect of the present disclosure, there is provided a method for manufacturing an image sensor, the method including: providing a substrate in which a plurality of radiation sensing elements are formed; forming a first partition on the substrate and forming a plurality of color filters between the first partitions, the plurality of color filters are correspondingly disposed above the plurality of radiation sensing elements, and the first partitions are used to prevent the crosstalk of radiation between the plurality of color filters, wherein forming the first partition includes: forming a dielectric member on the substrate; and forming a first metal on a sidewall of the dielectric member Floor.

In one embodiment, the first metal layer is also formed on top of the dielectric component.

In one embodiment, the method further includes forming a first anti-reflection layer, wherein the first anti-reflection layer is formed between the bottom of the first metal layer and the plurality of color filters and the substrate between.

In one embodiment, the method further includes forming a second anti-reflection layer, wherein the second anti-reflection layer is formed on top of the first partition.

In one embodiment, the method further comprises forming a second partition formed between the plurality of radiation sensing elements for electrically isolating the plurality of radiation sensing elements, and The second partitions are correspondingly arranged below the first partitions.

In one embodiment, the dielectric member of the first partition and the second partition are made of the same material.

In one embodiment, said dielectric member of said first partition and said second partition are formed in the same step.

In one embodiment, the dielectric member of the first partition and the second partition are formed by: forming a trench between the plurality of radiation sensing elements; Neutralize and deposit a dielectric material layer on the substrate; remove the part of the dielectric material layer on the substrate, and use the part of the remaining dielectric material layer higher than the upper surface of the substrate as the first partition part of the dielectric member, and the remaining part of the dielectric material layer lower than the upper surface of the substrate serves as a second partition.

In one embodiment, the radiation sensing element has a refractive index greater than that of the second partition.

In one embodiment, the second partition includes a plurality of dielectric layers, wherein the dielectric layer in the plurality of dielectric layers that is in contact with the radiation sensing element has a refractive index smaller than that of the radiation sensing element. refractive index.

In one embodiment, the refractive index of the dielectric layer farther from the radiation sensing element among the plurality of dielectric layers is smaller than or equal to the refractive index of the dielectric layer closer to the radiation sensing element.

In one embodiment, the second partition further includes a second metal layer, and the second metal layer is not in contact with the radiation sensing element.

In one embodiment, the refractive index of the second metal layer is greater than the refractive index of the radiation sensing element.

In one embodiment, the second partition further includes two third metal layers arranged symmetrically, wherein the two third metal layers are not in contact with the radiation sensing element, and the two third metal layers A dielectric layer is formed between the third metal layers.

In one embodiment, the dielectric component of the first partition is made of the same material as the dielectric layer between the two third metal layers.

In one embodiment, the dielectric part of the first partition is formed in the same step as the dielectric layer between the two third metal layers.

In one embodiment, the dielectric layer between the dielectric part of the first partition and the two third metal layers is formed by the following steps: between the two third metal layers and the Deposit a dielectric material layer on the substrate; remove the part of the dielectric material layer on the substrate, and use the remaining part of the dielectric material layer higher than the upper surface of the substrate as the dielectric of the first partition electrical components, and the portion of the remaining dielectric material layer below the upper surface of the substrate serves as a dielectric layer between the two third metal layers.

According to another aspect of the present disclosure, there is provided an image sensor including: a substrate in which a plurality of radiation sensing elements are formed; a first partition formed in the substrate above; a plurality of color filters formed between the first partitions, wherein the plurality of color filters are correspondingly arranged above the plurality of radiation sensing elements, and the first partitions are used to prevent crosstalk of radiation between the plurality of color filters; and wherein the first partition includes: a dielectric member formed on the substrate; and a first metal layer formed on the dielectric on the side walls of electrical components.

In one embodiment, the first metal layer is also formed on top of the dielectric component.

In one embodiment, the image sensor further includes a first anti-reflection layer formed between the bottom of the first metal layer and the plurality of color filters and the substrate .

In one embodiment, the image sensor further includes a second anti-reflection layer formed on top of the first partition.

In one embodiment, the image sensor further includes a second partition formed between the plurality of radiation sensing elements for electrically isolating the plurality of radiation sensing elements, and The second partitions are correspondingly arranged below the first partitions.

In one embodiment, the dielectric member of the first partition and the second partition are made of the same material.

In one embodiment, the radiation sensing element has a refractive index greater than that of the second partition.

In one embodiment, the second partition includes a plurality of dielectric layers, wherein the dielectric layer in the plurality of dielectric layers that is in contact with the radiation sensing element has a refractive index smaller than that of the radiation sensing element. refractive index.

In one embodiment, the refractive index of the dielectric layer farther from the radiation sensing element among the plurality of dielectric layers is smaller than or equal to the refractive index of the dielectric layer closer to the radiation sensing element.

In one embodiment, the second partition further includes a second metal layer, and the second metal layer is not in contact with the radiation sensing element.

In one embodiment, the refractive index of the second metal layer is greater than the refractive index of the radiation sensing element.

In one embodiment, the second partition further includes two third metal layers arranged symmetrically, wherein the two third metal layers are not in contact with the radiation sensing element, and the two third metal layers A dielectric layer is formed between the third metal layers.

In one embodiment, the dielectric component of the first partition is made of the same material as the dielectric layer between the two third metal layers.

In the specification and claims, the words "front", "rear", "top", "bottom", "above", "under", etc., if present, are used for descriptive purposes and not necessarily to describe a constant relative position. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. Orientation operation.

As used herein, the word "exemplary" means "serving as an example, instance, or illustration" rather than as a "model" to be exactly reproduced. Any implementation described illustratively herein is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or specific examples.

As used herein, the word "substantially" is meant to include any minor variations due to defects in design or manufacturing, device or component tolerances, environmental influences, and/or other factors. The word "substantially" also allows for differences from a perfect or ideal situation due to parasitic effects, noise, and other practical considerations that may exist in an actual implementation.

The above description may refer to elements or nodes or features being "connected" or "coupled" together. As used herein, unless expressly stated otherwise, "connected" means that one element/node/feature is directly connected (or electrically, mechanically, logically, or otherwise) to another element/node/feature. direct communication). Similarly, unless expressly stated otherwise, "coupled" means that one element/node/feature can be directly or indirectly mechanically, electrically, logically or otherwise connected to another element/node/feature to Interactions are allowed even though the two features may not be directly connected. That is, "coupled" is intended to encompass both direct and indirect couplings of elements or other features, including connections utilizing one or more intervening elements.

In addition, certain terms may also be used in the following description for reference purposes only, and thus are not intended to be limiting. For example, the words "first," "second," and other such numerical terms referring to structures or elements do not imply a sequence or order unless clearly indicated by the context.

It should also be understood that when the word "comprises/comprises" is used herein, it indicates the presence of indicated features, integers, steps, operations, units and/or components, but does not exclude the presence or addition of one or more other features, whole, steps, operations, units and/or components and/or combinations thereof.

In this disclosure, the term "provide" is used broadly to cover all ways of obtaining an object, thus "provide something" includes, but is not limited to, "purchase", "preparation/manufacture", "arrangement/setup", "installation/ Assembly", and/or "Order" objects, etc.

Those skilled in the art will appreciate that the boundaries between the above-described operations are merely illustrative. Multiple operations may be combined into a single operation, a single operation may be distributed among additional operations, and operations may be performed with at least partial overlap in time. Furthermore, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be altered in other various embodiments. However, other modifications, changes and substitutions are also possible. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only, rather than limiting the scope of the present disclosure. The various embodiments disclosed herein can be combined arbitrarily without departing from the spirit and scope of the present disclosure. Those skilled in the art will also appreciate that various modifications may be made to the embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims (10)

1. A method for manufacturing an image sensor, characterized in that the method comprises: providing a substrate having a plurality of radiation sensing elements formed therein; forming a first partition on the substrate; and A plurality of color filters are formed between the first partitions, the plurality of color filters are correspondingly disposed above the plurality of radiation sensing elements, and the first partitions are used to prevent the multiple radiation crosstalk between color filters, Wherein, forming the first partition includes: forming a dielectric feature on the substrate; and A first metal layer is formed on sidewalls of the dielectric member. 2. The method of claim 1, wherein the first metal layer is also formed on top of the dielectric component. 3. The method according to claim 1, further comprising forming a first anti-reflection layer, wherein the first anti-reflection layer is formed on the bottom of the first metal layer and the plurality of between the color filter and the substrate. 4. The method of claim 1, further comprising forming a second anti-reflection layer, wherein the second anti-reflection layer is formed on top of the first partition. 5. The method of claim 1, further comprising forming a second partition formed between the plurality of radiation sensing elements for electrically isolating the plurality of radiation sensing elements. the plurality of radiation sensing elements, and the second partitions are correspondingly disposed below the first partitions. 6. The method of claim 5, wherein the dielectric member of the first partition and the second partition are made of the same material. 7. The method of claim 6, wherein the dielectric member of the first partition and the second partition are formed in the same step. 8. The method according to claim 7, wherein the dielectric member of the first partition and the second partition are formed by the following steps: forming trenches between the plurality of radiation sensing elements; depositing a layer of dielectric material in the trench and on the substrate; removing a portion of the dielectric material layer on the substrate, the remaining portion of the dielectric material layer higher than the upper surface of the substrate serves as the dielectric member of the first partition, and the remaining dielectric A portion of the material layer lower than the upper surface of the substrate serves as a second partition. 9. The method of claim 5, wherein a refractive index of the radiation sensing element is greater than a refractive index of the second partition. 10. The method according to claim 5, wherein the second partition comprises a plurality of dielectric layers, wherein the refractive index of the dielectric layer in contact with the radiation sensing element among the plurality of dielectric layers The index is less than the refractive index of the radiation sensing element.