CN109166871B - Image sensor and manufacturing method thereof - Google Patents
Image sensor and manufacturing method thereof Download PDFInfo
- Publication number
- CN109166871B CN109166871B CN201810952047.6A CN201810952047A CN109166871B CN 109166871 B CN109166871 B CN 109166871B CN 201810952047 A CN201810952047 A CN 201810952047A CN 109166871 B CN109166871 B CN 109166871B
- Authority
- CN
- China
- Prior art keywords
- color filter
- insulating structure
- image sensor
- photodiode
- semiconductor substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- 239000000758 substrate Substances 0.000 claims abstract description 56
- 239000004065 semiconductor Substances 0.000 claims abstract description 48
- 230000000149 penetrating effect Effects 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 31
- 239000000463 material Substances 0.000 claims description 24
- 230000000694 effects Effects 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 239000007769 metal material Substances 0.000 claims description 5
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 5
- 229910052721 tungsten Inorganic materials 0.000 claims description 5
- 239000010937 tungsten Substances 0.000 claims description 5
- 238000009413 insulation Methods 0.000 claims description 4
- 230000003667 anti-reflective effect Effects 0.000 claims 2
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 238000006243 chemical reaction Methods 0.000 description 11
- 239000000969 carrier Substances 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- CJNBYAVZURUTKZ-UHFFFAOYSA-N hafnium(iv) oxide Chemical compound O=[Hf]=O CJNBYAVZURUTKZ-UHFFFAOYSA-N 0.000 description 4
- 239000012212 insulator Substances 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 239000004925 Acrylic resin Substances 0.000 description 2
- 229920000178 Acrylic resin Polymers 0.000 description 2
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 2
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- KXNLCSXBJCPWGL-UHFFFAOYSA-N [Ga].[As].[In] Chemical compound [Ga].[As].[In] KXNLCSXBJCPWGL-UHFFFAOYSA-N 0.000 description 2
- 229920006026 co-polymeric resin Polymers 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 229910052732 germanium Inorganic materials 0.000 description 2
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 2
- 238000003384 imaging method Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000012860 organic pigment Substances 0.000 description 2
- 229920005990 polystyrene resin Polymers 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- 206010034960 Photophobia Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 208000013469 light sensitivity Diseases 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14603—Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/1462—Coatings
- H01L27/14623—Optical shielding
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14643—Photodiode arrays; MOS imagers
Abstract
The technical scheme of the invention discloses an image sensor and a manufacturing method thereof, wherein the image sensor comprises a semiconductor substrate formed with a photodiode, the semiconductor substrate comprises different pixel areas, and the pixel areas comprise white pixel areas; an insulating structure on the semiconductor substrate; an organic photodiode penetrating the insulating structure and partially covering the white pixel area photodiode; a light shielding film on the insulating structure and partially covering the insulating structure; the color filter layers are positioned on the insulating structure and correspond to different pixels, each color filter layer comprises a white color filter layer, and the shading films isolate the color filter layers of the different pixels; and a micro lens positioned above the color filter layer. The image sensor not only improves the image quality of the image sensor, but also improves the sensitivity of the image sensor.
Description
Technical Field
The invention relates to the field of manufacturing of semiconductor devices, in particular to an image sensor and a manufacturing method thereof.
Background
An image sensor is a device that converts an optical image into an electrical signal. With the development of the computer and communication industries, the demand for high-performance image sensors, which are widely used in various fields such as digital cameras, camcorders, Personal Communication Systems (PCS), game machines, security cameras, medical miniature cameras, and the like, is increasing.
Image Sensors are generally of two types, a Charge Coupled Device (CCD) sensor and a CMOS Image Sensor (CIS). Compared with a CCD (charge coupled device) image sensor, the CMOS image sensor has the advantages of high integration level, low power consumption, low generation cost and the like.
In a conventional CMOS light sensing device, a light sensing diode is located behind a circuit transistor, and the amount of incident light is affected by shading. The back-illuminated CMOS is turned, so that light rays firstly enter the photosensitive diode, the photosensitive quantity is increased, and the shooting effect under the low-illumination condition is obviously improved. The stacked image sensor is formed by placing a signal processing circuit in the original image sensor on the original semiconductor substrate and overlapping the pixel part of the back-illuminated image sensor on the image sensor chip, so that a large number of pixels can be formed on a smaller image sensor chip size, and more pixels can be placed in the vacated space. In addition, the pixel points and the circuits in the sensor are mutually independent, so that the pixel point part can be optimized in higher image quality, and the circuit part can also be optimized in high performance. In addition, the stack type image sensor adds an RGBW coding technology, namely, W (white) pixel points are added into original R (red), G (green) and B (blue) three-primary-color pixel points to improve the image quality, improve the light sensitivity of the sensor and enable the camera to shoot a picture with higher quality in a dark light environment. However, the W pixel is more easily saturated than other pixels, and electrons may overflow into adjacent photodiodes, resulting in a decrease in image quality.
Disclosure of Invention
The technical problem to be solved by the technical scheme of the invention is as follows: aiming at the defect that white light pixels in the existing image sensor are easy to saturate, and electrons overflow into adjacent photodiodes, so that the image quality is reduced, a novel image sensor structure and a manufacturing method thereof are provided, and the imaging quality and the imaging sensitivity of the image sensor under dark light are improved.
To solve the above technical problem, the present invention provides an image sensor, including: a semiconductor substrate on which a photodiode is formed, the semiconductor substrate including different pixel regions including a white pixel region and at least one of a red pixel region, a green pixel region, and a blue pixel region; an insulating structure on the semiconductor substrate; an organic photodiode penetrating the insulating structure and partially covering the white pixel area photodiode; a light shielding film on the insulating structure and partially covering the insulating structure; the color filter layers are positioned on the insulating structure and correspond to different pixels, each color filter layer comprises a white color filter layer, and the shading films isolate the color filter layers of the different pixels; and a micro lens positioned above the color filter layer.
The invention also provides a manufacturing method of the image sensor, which comprises the following steps: providing a semiconductor substrate formed with a photodiode, the semiconductor substrate including different pixel regions including a white pixel region and at least one of a red pixel region, a green pixel region, and a blue pixel region; forming an insulating structure on the semiconductor substrate; forming an organic photodiode penetrating the insulating structure and partially covering the white pixel area photodiode; forming a light shielding film on the insulating structure to partially cover the insulating structure; forming color filter layers corresponding to different pixels on the insulation structure, wherein the color filter layers comprise white color filter layers, and the shading films isolate the color filter layers of the different pixels; and forming a micro lens above the color filter layer at the corresponding position of each pixel region.
Optionally, the light shielding film in the image sensor and the manufacturing method of the image sensor are made of a metal material with a light shielding effect, and further, the light shielding film material is tungsten, aluminum or copper.
Optionally, the insulating structure is a stacked structure formed by multiple dielectric layers, and further, the insulating structure includes one or more of a high dielectric constant material layer, an anti-reflection layer, and an adhesion dielectric layer.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
in the manufacturing method and structure of the image sensor provided by the invention, the organic photodiode partially shields the photodiode in the white pixel area, so that the light inlet quantity of the photodiode in the white pixel area can be reduced, meanwhile, the organic photodiode can absorb white light, the photoelectric conversion efficiency of the white light is improved, the electronic crosstalk of the photodiode is reduced, and under the condition of dark light, the image quality of the image sensor is improved, and the sensitivity of the image sensor is also improved.
Drawings
Fig. 1 to 4 are schematic structural diagrams corresponding to steps of an image sensor forming method according to an embodiment of the invention.
Detailed Description
The present inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the inventive concept are shown. Advantages and features of the inventive concept and methods of accomplishing the same will be apparent from the following more detailed description of exemplary embodiments, which is to be read in connection with the accompanying drawings. However, it should be noted that the inventive concept is not limited to the following exemplary embodiments, but may be implemented in various forms. Accordingly, the exemplary embodiments are provided only for the purpose of disclosing the inventive concept and enabling those skilled in the art to know the scope of the inventive concept. In the drawings, embodiments of the inventive concept are not limited to the specific examples provided herein, and have been enlarged for clarity.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular terms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present.
Similarly, it will be understood that when an element such as a layer, region or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, the term "directly" means that there are no intervening elements. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
In addition, embodiments in the detailed description will be described using cross-sectional views that are idealized exemplary diagrams of the inventive concept. Accordingly, the shapes of the exemplary diagrams may be changed according to manufacturing techniques and/or allowable errors. Accordingly, embodiments of the inventive concept are not limited to the specific shapes shown in the exemplary drawings, but may include other shapes that may be produced according to a manufacturing process. The regions illustrated in the figures are of a general nature and are intended to illustrate the particular shape of an element. Accordingly, this should not be construed as limiting the scope of the inventive concept.
It will be further understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element in some embodiments may be termed a second element in other embodiments without departing from the teachings of the present invention. The same reference numerals or the same reference identifiers denote the same elements throughout the specification.
Further, exemplary embodiments are described by referring to cross-sectional illustrations and/or plan illustrations that are idealized exemplary illustrations. Accordingly, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an etched region shown as a rectangle will typically have rounded or curved features. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of exemplary embodiments.
The technical solution of the present invention will be described in detail below with reference to the embodiments and the accompanying drawings.
Example 1
The method for manufacturing the image sensor comprises the following steps: providing a semiconductor substrate 22 formed with a photodiode 21, the semiconductor substrate 22 comprising different pixel regions 20, the pixel regions 20 comprising white pixel regions; forming an insulating structure on the semiconductor substrate; forming an organic photodiode 28 penetrating the insulating structure and partially covering the white pixel region 20; forming a light shielding film 27 on the insulating structure to partially cover the insulating structure; forming color filter layers 25 corresponding to different pixels on the insulating structure, the color filter layers 25 including a white color filter layer 25W, the light shielding film isolating the color filter layers 25 of the different pixels; a microlens 26 is formed above the color filter layer 25 at a corresponding position of each pixel region.
Referring to fig. 1, a semiconductor substrate 22 formed with photodiodes 21 is first provided, the semiconductor substrate 22 includes different pixel regions 20, and the photodiodes 21 correspond to the different pixel regions 20 and include different pixel units;
in this embodiment, the semiconductor substrate 22 may be a silicon substrate, or may also be germanium, silicon carbide, gallium arsenide, or indium gallium arsenide, or a silicon-on-insulator substrate, or a germanium-on-insulator substrate, or a substrate on which an epitaxial layer is grown. The semiconductor substrate 22 includes a photodiode for converting a received optical signal into an electrical signal. The semiconductor substrate 22 is divided into different pixel regions 20, for example, basic pixel units such as red, green, and blue pixels or other various pixel units such as a white pixel, as needed. When the pixel region is described in this embodiment, any one of the pixel regions may be referred to unless otherwise specified.
As shown in fig. 1, different photodiodes 21 correspond to different pixels, such as basic pixels of red, green, and blue pixels, or other various pixels such as white pixels, according to the division of the pixel region of the semiconductor substrate 22. In fig. 1, a green pixel, a white pixel, and a red pixel region are exemplarily shown for convenience of description.
The photodiodes may be arranged in a Bayer (Bayer) array in the semiconductor substrate 22, or may be arranged in any other array as necessary. In order to meet the requirement of thinning the total thickness of the semiconductor substrate 22, the positions of the respective photodiodes in the semiconductor substrate 22 are generally at substantially the same depth.
Subsequently, an insulating structure including more than one dielectric layer, a stacked structure formed by a plurality of dielectric layers, is formed on the light incident surface of the semiconductor substrate 22. On one hand, the insulating structure may include a high-k material layer for preventing dark current due to surface damage, wherein the high-k material layer has a dielectric constant k greater than 3.9, and the high-k material is, for example, hafnium dioxide; on the other hand, the insulation structure can also comprise an anti-reflection layer for preventing incident light from reflecting to form crosstalk; the insulating structure can also comprise an adhesion dielectric layer, so that the dielectric layers are better adhered; the insulating structure also serves to isolate the semiconductor substrate 22 from a light shielding film 27 formed later.
In fig. 1, an insulating structure formed by a first insulating layer 23 and a second insulating layer 24 is schematically illustrated, wherein the first insulating layer 23 may include any one or more of a high dielectric constant material layer, an anti-reflection layer or an adhesion layer, and the sequence of the layers and the selection of the material may be adjusted according to the requirements of the process design. The second insulating layer 24 may also include any one or more of a high dielectric constant material layer, an anti-reflection layer or an adhesion layer, and the sequence of the layers and the selection of the material may be adjusted according to the requirements of the process design.
Further, the insulating structure may be further stacked on the basis of the first insulating layer 23 and the second insulating layer 24. A process of forming the first insulating layer 23 or the second insulating layer 24 is, for example, a chemical vapor deposition process or the like.
Subsequently, with continued reference to fig. 1, an organic photodiode 28 is formed through the insulating structure and partially covering the white pixel area 20 photodiode. In this embodiment, the organic photodiode 28 partially blocks the photodiode in the white pixel area 20, so that the light entering amount of the corresponding photodiode 21W in the white pixel area 20 can be reduced, and meanwhile, the organic photodiode 28 can also absorb white light, thereby improving the photoelectric conversion efficiency of the white light, and reducing the electronic crosstalk of the photodiode.
The organic photodiode 28 may perform photoelectric conversion on light of a specific wavelength. In the present embodiment, the organic photodiode 28 performs photoelectric conversion on white light.
In this embodiment, the relative position relationship between the organic photodiode 28 and the photodiode of the white pixel region 20 partially shielded by the organic photodiode 28 is not strictly limited, and in an actual process, according to the size of the photodiode area of the white pixel region 20, in the case that sufficient photogenerated carriers are generated according to the full well capacity, the shielding area of the white pixel region 20 by the organic photodiode 28 can be adjusted as required to avoid the overflow phenomenon of the photogenerated carriers.
The processes for forming the organic photodiode 28 are, for example: a mask layer is formed on the insulating structure, and the pattern of the mask layer is defined according to the position of the organic photodiode 28, in this embodiment, the opening position of the mask layer pattern corresponds to the position of the white pixel region, and then the insulating structure is etched until the semiconductor substrate is exposed, and the organic photodiode is manufactured in the insulating structure. The present embodiment does not further limit the specific process for fabricating the organic photodiode, and the fabrication method of the organic photodiode known to those skilled in the art is applicable to the present embodiment. Subsequently, the mask layer is removed.
Referring to fig. 2, a light-shielding film 27 is formed on the second insulating layer 24 constituting the insulating structure, and the light-shielding film 27 may be made of a metal, or a black color filter layer absorbing light, or may be formed of an electrode of an organic photoelectric conversion film. The light shielding film 27 covers the second insulating layer 24 and is disposed at a corresponding position between adjacent pixel regions, so that light from different pixel regions does not enter the photodiodes of other pixel regions.
In the present embodiment, the light shielding film 27 is used to isolate each color filter layer 25 to be formed later, and therefore, the present embodiment has a certain limitation on the thickness thereof, which is close to the thickness of the color filter layer 25 to be formed later, and in a preferred embodiment, the thickness thereof is about 400nm to 1000 nm.
The light shielding film 27 is preferably made of a metal material having a light shielding effect, such as tungsten, aluminum, or copper, and the light shielding film 27 is formed by, for example, chemical vapor deposition of a light shielding film material and selective etching, and then removing a portion of the light shielding film material corresponding to the photodiode position.
In this embodiment, the light shielding film 27 is not positioned to cover the organic photodiode 28.
Referring to fig. 3, a color filter layer 25 corresponding to different pixels is formed on the second insulating layer 24 at a corresponding position of each pixel region, and the color filter layer 25 is isolated by the light shielding film 27; when the color filter layer 25 corresponds to different pixel regions, it may be formed in sequence as needed. In one embodiment of the present invention, a red color filter layer 25R, a white color filter layer 25W, and a green color filter layer 25G are sequentially formed according to the division of the corresponding pixel regions in the semiconductor substrate, respectively.
The color filter layer 25 passes light of a predetermined color corresponding to the pixel region 20, and the color filter layer 25 of the corresponding color is provided for each pixel region 20. That is, as shown in the figure, the red color filter 25R is provided for the red pixel cell region, and the green color filter 25G is provided for the green pixel cell 21G. Each color filter 25 is formed with a resin to which an organic pigment is added inside, and is designed to have a thickness of about 400nm to 1000nm, for example.
In this embodiment, the white color filter layer 25W is located on the organic photodiode 28 and completely covers the organic photodiode 28.
Referring to fig. 4, a microlens 26 is formed on the color filter layer 25 at a corresponding position of each pixel region. In the present embodiment, the relative position of the microlens 26 in the image sensor is schematically shown, which corresponds to the position of the color filter layer 25, and is disposed directly above the color filter layer 25.
The microlens is used to collect light for each pixel unit, and is made of, for example, a polystyrene resin, an acrylic resin, or a copolymer resin of these resins. The process for forming the microlens can be any one of the existing microlens manufacturing processes, and details are not repeated herein.
In actual process, the microlens 26 may also be disposed directly above the color filter layer 25 and directly contact with the color filter layer 25, or may not directly contact with the color filter layer 25, that is, other film layers, such as one or more dielectric layers, may also be disposed between the microlens 26 and the color filter layer 25 as required.
In the method for manufacturing an image sensor according to this embodiment, the organic photodiode partially shields the photodiode in the white pixel region, so that the light incident amount of the photodiode in the white pixel region can be reduced, and the organic photodiode can absorb white light, thereby improving the photoelectric conversion efficiency of the white light, and reducing the electronic crosstalk of the photodiode.
Example 2
Referring to fig. 4, in another embodiment of the present invention, another image sensor structure is provided, including: a semiconductor substrate 22 formed with photodiodes, the semiconductor substrate 22 including different pixel regions 20, wherein the photodiodes correspond to the different pixel regions, and the pixel regions include a white pixel region; an insulating structure on the semiconductor substrate; an organic photodiode 28 penetrating the insulating structure and partially covering the photodiode of the white pixel region; a light shielding film 27 on and partially covering the insulating structure, the light shielding film 27 isolating the different pixel regions 20; the color filter layers 25 are positioned on the insulating structures and correspond to different pixels, the color filter layers comprise white color filter layers, and the shading films isolate the color filter layers of the different pixels; and a microlens 26 positioned over the color filter layer 25.
Referring to fig. 4, a semiconductor substrate 22 formed with photodiodes 21 is first provided, the semiconductor substrate 22 includes different pixel regions 20, and the photodiodes 21 correspond to the different pixel regions 20 and include different pixel units;
in this embodiment, the semiconductor substrate 22 may be a silicon substrate, or may also be germanium, silicon carbide, gallium arsenide, or indium gallium arsenide, or a silicon-on-insulator substrate, or a germanium-on-insulator substrate, or a substrate on which an epitaxial layer is grown. The semiconductor substrate 22 includes a photodiode for converting a received optical signal into an electrical signal. The semiconductor substrate 22 is divided into different pixel regions 20, for example, basic pixel units such as red, green, and blue pixels or other various pixel units such as a white pixel, as needed. When the pixel region is described in this embodiment, any one of the pixel regions may be referred to unless otherwise specified. According to the division of the pixel region of the semiconductor substrate 22, different pixels such as a basic pixel of a red pixel, a green pixel, and a blue pixel or other various pixels such as a white pixel are assigned to different photodiodes 21. In the drawings, a green pixel, a white pixel, and a red pixel region are exemplarily shown for convenience of description.
The photodiodes may be arranged in a Bayer (Bayer) array in the semiconductor substrate 22, or may be arranged in any other array as necessary. In order to meet the requirement of thinning the total thickness of the semiconductor substrate 22, the positions of the respective photodiodes in the semiconductor substrate 22 are generally at substantially the same depth.
The insulating structure comprises more than one dielectric layer and is a stack structure formed by a plurality of dielectric layers. On one hand, the insulating structure may include a high-k material layer for preventing dark current due to surface damage, wherein the high-k material layer has a dielectric constant k greater than 3.9, and the high-k material is, for example, hafnium dioxide; on the other hand, the insulation structure can also comprise an anti-reflection layer for preventing incident light from reflecting to form crosstalk; the insulating structure can also comprise an adhesion dielectric layer, so that the dielectric layers are better adhered; the insulating structure also serves to isolate the semiconductor substrate 22 from a light shielding film 27 formed later.
In fig. 4, an insulating structure formed by a first insulating layer 23 and a second insulating layer 24 is schematically illustrated, wherein the first insulating layer 23 may include any one or more of a high dielectric constant material layer, an anti-reflection layer or an adhesion layer, and the sequence of the layers and the selection of the material may be adjusted according to the requirements of the process design. The second insulating layer 24 may also include any one or more of a high dielectric constant material layer, an anti-reflection layer or an adhesion layer, and the sequence of the layers and the selection of the material may be adjusted according to the requirements of the process design. Further, the insulating structure may be further stacked on the basis of the first insulating layer 23 and the second insulating layer 24. A process of forming the first insulating layer 23 or the second insulating layer 24 is, for example, a chemical vapor deposition process or the like.
With continued reference to fig. 4, the organic photodiode 28 extends through the insulating structure and partially covers the photodiode of the white pixel area 20. In this embodiment, the organic photodiode 28 partially blocks the photodiode in the white pixel area 20, so that the light entering amount of the corresponding photodiode 21W in the white pixel area 20 can be reduced, and meanwhile, the organic photodiode 28 can also absorb white light, thereby improving the photoelectric conversion efficiency of the white light, and reducing the electronic crosstalk of the photodiode.
The organic photodiode 28 may perform photoelectric conversion on light of a specific wavelength. In the present embodiment, the organic photodiode 28 performs photoelectric conversion on white light.
In this embodiment, the relative position relationship between the organic photodiode 28 and the photodiode of the white pixel region 20 partially shielded by the organic photodiode 28 is not strictly limited, and in an actual process, the shielding area of the organic photodiode 28 for the photodiode of the white pixel region 20 may be adjusted as needed to avoid the overflow phenomenon of the photogenerated carriers when sufficient photogenerated carriers are generated according to the size of the photodiode area of the white pixel region 20 and the full well capacity is satisfied.
The processes for forming the organic photodiode 28 are, for example: a mask layer is formed on the insulating structure, and the pattern of the mask layer is defined according to the position of the organic photodiode 28, in this embodiment, the opening position of the mask layer pattern corresponds to the position of the white pixel region, and then the insulating structure is etched until the semiconductor substrate is exposed, and the organic photodiode is manufactured in the insulating structure. The present embodiment does not further limit the specific process for fabricating the organic photodiode, and the fabrication method of the organic photodiode known to those skilled in the art is applicable to the present embodiment. Subsequently, the mask layer is removed.
A light-shielding film 27 is provided on the second insulating layer 24 constituting the insulating structure, and the light-shielding film 27 may be made of a metal, or a black color filter layer absorbing light, or may be constituted by an electrode of an organic photoelectric conversion film. The light shielding film 27 covers the second insulating layer 24 and is disposed at a corresponding position between adjacent pixel regions, so that light from different pixel regions does not enter the photodiodes of other pixel regions.
In the present embodiment, the light shielding film 27 is used to isolate each color filter layer 25 to be formed later, and therefore, the present embodiment has a certain limitation on the thickness thereof, which is close to the thickness of the color filter layer 25 to be formed later, and in a preferred embodiment, the thickness thereof is about 400nm to 1000 nm.
The light shielding film 27 is preferably made of a metal material having a light shielding effect, such as tungsten, aluminum, or copper, and the light shielding film 27 is formed by, for example, chemical vapor deposition of a light shielding film material and selective etching, and then removing a portion of the light shielding film material corresponding to the photodiode position. In this embodiment, the light shielding film 27 is not positioned to cover the organic photodiode 28.
With continued reference to fig. 4, the color filter layers 25 are located on the insulating structure and correspond to different pixels, the color filter layers include white color filter layers, and the light shielding film isolates the color filter layers of the different pixels; when the color filter layer 25 corresponds to different pixel regions, it may be formed in sequence as needed. In one embodiment of the present invention, a red color filter layer 25R, a white color filter layer 25W, and a green color filter layer 25G are sequentially formed according to the division of the corresponding pixel regions in the semiconductor substrate, respectively.
The color filter layer 25 passes light of a predetermined color corresponding to the pixel region 20, and the color filter layer 25 of the corresponding color is provided for each pixel region 20. That is, as shown in the figure, the red color filter 25R is provided for the red pixel cell region, and the green color filter 25G is provided for the green pixel cell 21G. Each color filter 25 is formed with a resin to which an organic pigment is added inside, and is designed to have a thickness of about 400nm to 1000nm, for example.
In this embodiment, the white color filter layer 25W is located on the organic photodiode 28 and completely covers the organic photodiode 28.
Referring to fig. 4, microlenses 26 are disposed on the color filter layer 25 at corresponding positions of each pixel region. In the present embodiment, the relative position of the microlens 26 in the image sensor is schematically shown, which corresponds to the position of the color filter layer 25, and is disposed directly above the color filter layer 25.
The microlens is used to collect light for each pixel unit, and is made of, for example, a polystyrene resin, an acrylic resin, or a copolymer resin of these resins. The process for forming the microlens can be any one of the existing microlens manufacturing processes, and details are not repeated herein.
In actual process, the microlens 26 may also be disposed directly above the color filter layer 25 and directly contact with the color filter layer 25, or may not directly contact with the color filter layer 25, that is, other film layers, such as one or more dielectric layers, may also be disposed between the microlens 26 and the color filter layer 25 as required.
In the method for manufacturing an image sensor according to this embodiment, the organic photodiode partially shields the photodiode in the white pixel region, so that the light incident amount of the photodiode in the white pixel region can be reduced, and the organic photodiode can absorb white light, thereby improving the photoelectric conversion efficiency of the white light, and reducing the electronic crosstalk of the photodiode.
Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make modifications and variations of the present invention without departing from the spirit and scope of the present invention.
Claims (10)
1. An image sensor, comprising:
a semiconductor substrate on which a photodiode is formed, the semiconductor substrate including different pixel regions including a white pixel region and at least one of a red pixel region, a green pixel region, and a blue pixel region;
an insulating structure on the semiconductor substrate;
an organic photodiode penetrating the insulating structure and partially covering the white pixel area photodiode;
a light shielding film on the insulating structure and partially covering the insulating structure;
the color filter layers are positioned on the insulating structure and correspond to different pixels, each color filter layer comprises a white color filter layer, and the shading films isolate the color filter layers of the different pixels;
and a micro lens positioned above the color filter layer.
2. The image sensor according to claim 1, wherein the light shielding film is a metal material having a light shielding effect.
3. The image sensor of claim 1, wherein the light-shielding film material is tungsten, aluminum, or copper.
4. The image sensor of claim 1, wherein the insulating structure is a stacked structure of multiple dielectric layers.
5. The image sensor as in claim 4, wherein the insulating structure comprises one or more of a high-k material layer, an anti-reflective layer, and an adhesion dielectric layer.
6. A method of fabricating an image sensor, comprising:
providing a semiconductor substrate formed with a photodiode, the semiconductor substrate including different pixel regions including a white pixel region and at least one of a red pixel region, a green pixel region, and a blue pixel region;
forming an insulating structure on the semiconductor substrate;
forming an organic photodiode penetrating the insulating structure and partially covering the white pixel area photodiode;
forming a light shielding film on the insulating structure to partially cover the insulating structure;
forming color filter layers corresponding to different pixels on the insulation structure, wherein the color filter layers comprise white color filter layers, and the shading films isolate the color filter layers of the different pixels;
and forming a micro lens above the color filter layer at the corresponding position of each pixel region.
7. The method of claim 6, wherein the light shielding film is a metal material having a light shielding effect.
8. The method for manufacturing an image sensor according to claim 7, wherein the light-shielding film material is tungsten, aluminum, or copper.
9. The method of claim 6, wherein the insulating structure is a stack structure formed by a plurality of dielectric layers.
10. The method of claim 9, wherein the insulating structure comprises one or more of a high-k material layer, an anti-reflective layer, and an adhesion dielectric layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810952047.6A CN109166871B (en) | 2018-08-21 | 2018-08-21 | Image sensor and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810952047.6A CN109166871B (en) | 2018-08-21 | 2018-08-21 | Image sensor and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109166871A CN109166871A (en) | 2019-01-08 |
| CN109166871B true CN109166871B (en) | 2021-07-06 |
Family
ID=64896195
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810952047.6A Active CN109166871B (en) | 2018-08-21 | 2018-08-21 | Image sensor and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109166871B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI676283B (en) * | 2019-01-29 | 2019-11-01 | 同泰電子科技股份有限公司 | Cmos phtosensitive unit, protection glass module thereof and manufaturing method of the same |
| CN110164887A (en) * | 2019-04-30 | 2019-08-23 | 德淮半导体有限公司 | Imaging sensor and forming method thereof |
| CN110098212A (en) * | 2019-05-14 | 2019-08-06 | 德淮半导体有限公司 | A kind of imaging sensor and preparation method thereof |
| CN110233160A (en) * | 2019-07-17 | 2019-09-13 | 德淮半导体有限公司 | Imaging sensor and preparation method thereof |
| CN111263129A (en) * | 2020-02-11 | 2020-06-09 | Oppo广东移动通信有限公司 | Image sensor, camera assembly and mobile terminal |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105009290A (en) * | 2013-03-25 | 2015-10-28 | 索尼公司 | Imaging element and electronic equipment |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009081169A (en) * | 2007-09-25 | 2009-04-16 | Fujifilm Corp | Solid-state image sensor |
| US8629486B2 (en) * | 2010-06-29 | 2014-01-14 | Samsung Electronics Co., Ltd. | CMOS image sensor having anti-absorption layer |
| KR102223515B1 (en) * | 2013-08-07 | 2021-03-04 | 소니 주식회사 | Solid-state imaging device and electronic device |
| KR102491497B1 (en) * | 2015-11-30 | 2023-01-20 | 삼성전자주식회사 | Image sensor and electronic device including the same |
| EP3196953B1 (en) * | 2016-01-19 | 2022-10-12 | Samsung Electronics Co., Ltd. | Optoelectronic device, and image sensor and electronic device including the same |
-
2018
- 2018-08-21 CN CN201810952047.6A patent/CN109166871B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105009290A (en) * | 2013-03-25 | 2015-10-28 | 索尼公司 | Imaging element and electronic equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109166871A (en) | 2019-01-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109166871B (en) | Image sensor and manufacturing method thereof | |
| KR101893325B1 (en) | Solid-state imaging device, method of manufacturing the same, and electronic apparatus | |
| US9111828B2 (en) | Solid-state imaging device, method for manufacturing solid-state imaging device, and electronic apparatus | |
| CN106067469B (en) | Camera head and electronic equipment | |
| CN111491117A (en) | Optical sensor including light blocking pattern and electronic device | |
| US9591242B2 (en) | Black level control for image sensors | |
| US9536915B2 (en) | Image sensor with embedded infrared filter layer | |
| JP2009065098A (en) | Backside irradiation type solid-state imaging device and method of manufacturing the same | |
| JP2006269923A (en) | Photoelectric conversion film-laminate color solid-state image sensor | |
| KR102492595B1 (en) | Solid-state image sensor | |
| US7449359B2 (en) | Fabricating method of CMOS image sensor | |
| CN116884984B (en) | Image sensor and manufacturing method thereof | |
| CN109273480B (en) | Image sensor and manufacturing method thereof | |
| CN105762160B (en) | Back-illuminated global pixel unit structure and preparation method thereof | |
| CN109065564B (en) | Image sensor and forming method thereof | |
| US11538839B2 (en) | Solid-state image sensor including patterned structure for decreasing petal flares | |
| US10586825B2 (en) | Self-alignment of a pad and ground in an image sensor | |
| US20210143206A1 (en) | Image sensor | |
| CN108831901B (en) | Backside illuminated image sensor and manufacturing method thereof | |
| US20230020741A1 (en) | Solid-state image sensor | |
| CN219591401U (en) | Image sensor and electronic device | |
| KR20240029409A (en) | Image sensing device | |
| CN114914255A (en) | Pixel structure of image sensor, preparation method of pixel structure and image sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20230714 Address after: 223001 Room 318, Building 6, east of Zhenda Steel Pipe Company, south of Qianjiang Road, Huaiyin District, Huai'an City, Jiangsu Province Patentee after: Huaian Xide Industrial Design Co.,Ltd. Address before: 223300 no.599, East Changjiang Road, Huaiyin District, Huai'an City, Jiangsu Province Patentee before: HUAIAN IMAGING DEVICE MANUFACTURER Corp. |
|
| TR01 | Transfer of patent right |