Image sensor and preparation method thereof

Abstract

The invention relates to an image sensor and a preparation method thereof. The image sensor comprises a first photosensitive chip, a first supporting wall and a light-transmitting cover plate, the first photosensitive chip comprises a photosensitive area and a non-photosensitive area, the non-photosensitive area surrounds the photosensitive area, the photosensitive area is provided with N photosensitive elements, the N photosensitive elements are respectively used for sensing light of different target wavebands, and the N different target wavebands are not overlapped with each other, the first supporting enclosing wall is located on the non-photosensitive area and surrounds the space above the photosensitive area, the light-transmitting cover plate is located on the side, away from the first photosensitive chip, of the first supporting enclosing wall, the light-transmitting cover plate comprises a working area, the projection of the photosensitive area on the light-transmitting cover plate is located in the working area, and the working area comprises N light-transmitting sub-areas, the positions of the N light-transmitting sub-regions are in one-to-one correspondence with the positions of the N photosensitive elements, and the N light-transmitting sub-regions are respectively used for only allowing light of different target wavebands to transmit. According to the technical scheme, the optical signal crosstalk of the image sensor can be reduced.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and more specifically to an image sensor and its fabrication method. Background Technology

[0002] In related technologies, color filters, including red, green, and blue filters, are set on the photosensitive side of the photosensitive element in an image sensor. Due to the transmittance characteristics of the red, green, and blue filters, their output quantum efficiency (QE) exhibits a normal distribution, resulting in high optical signal crosstalk between the red, green, and blue channels. During the operation of the image sensor, crosstalk often negatively impacts image quality, reducing image sharpness and accuracy. Summary of the Invention

[0003] The purpose of this application is to provide an image sensor and its fabrication method, which can reduce optical signal crosstalk in the image sensor and improve the clarity and accuracy of imaging.

[0004] According to a first aspect of the embodiments of this application, an image sensor is provided, comprising:

[0005] The first photosensitive chip includes a photosensitive area and a non-photosensitive area, the non-photosensitive area surrounding the photosensitive area; the photosensitive area is provided with N photosensitive elements, where N is an integer greater than 1, and the N photosensitive elements are adjacent to each other; the N photosensitive elements are respectively used to sense light of different target wavelength bands; the different target wavelength bands do not overlap with each other;

[0006] The first supporting wall is located on the non-photosensitive area and surrounds the space above the photosensitive area;

[0007] A light-transmitting cover plate is located on the side of the first supporting wall away from the first photosensitive chip; the light-transmitting cover plate includes a working area and a non-working area; the non-working area surrounds the working area, the projection of the non-working area on the first photosensitive chip is located within the non-photosensitive area, and the projection of the photosensitive area on the light-transmitting cover plate is located within the working area; the working area includes N light-transmitting sub-regions, the positions of the N light-transmitting sub-regions correspond one-to-one with the positions of the N photosensitive elements, and the N light-transmitting sub-regions are respectively used to allow light of different target wavelength bands to pass through; for the corresponding light-transmitting sub-regions and the photosensitive elements, the projection of the photosensitive element on the light-transmitting cover plate is located within the light-transmitting sub-region.

[0008] In one embodiment, the light-transmitting cover plate includes a first transparent cover plate and a selectively light-transmitting film;

[0009] The first transparent cover is located on the side of the first supporting wall away from the first photosensitive chip, and is located in the working area and the non-working area; the selective light-transmitting film is located on the side of the first transparent cover away from the first photosensitive chip, and is located in the working area;

[0010] The selective light-transmitting film includes N light-transmitting sub-films, each located in a different light-transmitting sub-region. Each of the N light-transmitting sub-films is used to allow light of a different target wavelength band to pass through. For the light-transmitting sub-films and the photosensitive element corresponding to the position, the projection of the photosensitive element on the first transparent cover is located within the projection of the light-transmitting sub-film on the first transparent cover.

[0011] In one embodiment, N is 4; the selective light-transmitting film includes a first light-transmitting sub-film, a second light-transmitting sub-film, a third light-transmitting sub-film, and a fourth light-transmitting sub-film;

[0012] The first light-transmitting sub-film is used to allow only light of the first target wavelength band to pass through, the second light-transmitting sub-film is used to allow only light of the second target wavelength band to pass through, the third light-transmitting sub-film is used to allow only light of the third target wavelength band to pass through, and the fourth light-transmitting sub-film is used to allow only light of the fourth target wavelength band to pass through. The first target wavelength band, the second target wavelength band, the third target wavelength band, and the fourth target wavelength band do not overlap with each other.

[0013] In one embodiment, the first target band is the near-infrared band, the second target band is the red light band, the third target band is the green light band, and the fourth target band is the blue light band.

[0014] In one embodiment, the wavelength range of the near-infrared band is 800-1000nm, the wavelength range of the red band is 600-700nm, the wavelength range of the green band is 500-599nm, and the wavelength range of the blue band is 400-499nm.

[0015] In one embodiment, the material of the selective light-transmitting film is an inorganic material.

[0016] In one embodiment, the first transparent cover is clear glass with a transmittance greater than or equal to 95%.

[0017] In one embodiment, a first light-shielding barrier is provided between the space above the photosensitive area and the space above the non-photosensitive area. The bottom of the first light-shielding barrier is located on the first photosensitive chip, and the top of the first light-shielding barrier is in contact with the light-transmitting cover plate. The first light-shielding barrier is used to prevent light from the non-working area that passes through the light-transmitting cover plate from entering the photosensitive area of ​​the first photosensitive chip.

[0018] In one embodiment, the material of the first light-shielding barrier is epoxy resin.

[0019] In one embodiment, a second light-shielding barrier is provided between the spaces above adjacent photosensitive elements. The bottom of the second light-shielding barrier is located on the first photosensitive chip, and the top of the second light-shielding barrier is in contact with the light-transmitting cover plate. The second light-shielding barrier is used to isolate light that passes through two adjacent light-transmitting sub-regions.

[0020] In one embodiment, the material of the second light-shielding barrier is epoxy resin.

[0021] In one embodiment, the image sensor further includes an adhesive frame located between the first supporting wall and the light-transmitting cover plate, for bonding the first supporting wall and the light-transmitting cover plate together.

[0022] According to a second aspect of the embodiments of this application, a method for manufacturing an image sensor is provided, the method comprising:

[0023] A first photosensitive chip is fabricated; the first photosensitive chip includes a photosensitive area and a non-photosensitive area, the non-photosensitive area surrounding the photosensitive area; the photosensitive area is provided with N photosensitive elements, where N is an integer greater than 1, and the N photosensitive elements are adjacent to each other; the N photosensitive elements are respectively used to sense light of different target wavelength bands; the different target wavelength bands do not overlap with each other;

[0024] Prepare a first supporting wall; the first supporting wall is located on the non-photosensitive area and surrounds the space above the photosensitive area;

[0025] Prepare a light-transmitting cover plate; the light-transmitting cover plate includes a working area and a non-working area; the non-working area surrounds the working area, and the working area includes N light-transmitting sub-regions, each of the N light-transmitting sub-regions being used to allow light of different target wavelength bands to pass through only;

[0026] The light-transmitting cover plate is fixed to the first supporting wall; the light-transmitting cover plate is located on the side of the first supporting wall away from the first photosensitive chip; the projection of the non-working area on the first photosensitive chip is located within the non-photosensitive area, and the projection of the photosensitive area on the light-transmitting cover plate is located within the working area; the positions of the N light-transmitting sub-regions correspond one-to-one with the positions of the N photosensitive elements, and for the corresponding light-transmitting sub-region and the photosensitive element, the projection of the photosensitive element on the light-transmitting cover plate is located within the light-transmitting sub-region.

[0027] In one embodiment, the light-transmitting cover plate includes a first transparent cover plate and a selectively light-transmitting film; the first transparent cover plate is located between the working area and the non-working area, and the selectively light-transmitting film is located in the working area; the selectively light-transmitting film is made of an inorganic material.

[0028] The selective light-transmitting film includes N light-transmitting sub-films, each located in a different light-transmitting sub-region, and each of the N light-transmitting sub-films is used to allow light of only different target wavelength bands to pass through.

[0029] The preparation of the light-transmitting cover plate includes:

[0030] In preparing each of the phototransparent sub-films, a target mask is placed on the first transparent cover plate; the target mask includes a first cutout area, the pattern of the first cutout area is the same as the pattern of the phototransparent sub-film, and the first cutout area is used to expose the phototransparent sub-film;

[0031] The phototransparent membrane is prepared in the phototransparent region using a deposition process, and the pattern of the phototransparent membrane is the same as the pattern of the first hollowed-out region; or

[0032] The preparation of the light-transmitting cover plate includes:

[0033] During the preparation of each of the light-transmitting sub-films, a first photosensitive material layer is formed on the first transparent cover plate;

[0034] The first photosensitive material layer is exposed and developed using a photolithography machine to obtain a second photosensitive material layer; the second photosensitive material layer includes a second hollow area, and the pattern of the second hollow area is the same as the pattern of the phototransparent sub-area.

[0035] A first inorganic material layer is prepared, the first inorganic material layer comprising a phototransparent sub-film and an ineffective film layer, the phototransparent sub-film covering the second hollow area, the ineffective film layer covering the second photosensitive material layer;

[0036] Remove the second photosensitive material layer and the invalid film layer to obtain the light-transmitting sub-film.

[0037] In one embodiment, fixing the light-transmitting cover to the first supporting wall includes:

[0038] A frame is prepared on the side of the first transparent cover plate away from the selective light-transmitting film;

[0039] The first transparent cover plate is fixed to the first supporting wall by the adhesive frame; the adhesive frame is located between the first supporting wall and the light-transmitting cover plate, and is used to bond the first supporting wall and the light-transmitting cover plate; the first transparent cover plate is located on the side of the first supporting wall away from the first photosensitive chip, and the selective light-transmitting film is located on the side of the first transparent cover plate away from the first photosensitive chip. For the light-transmitting sub-film and the photosensitive element corresponding to the position, the projection of the photosensitive element on the first transparent cover plate is located within the projection of the light-transmitting sub-film on the first transparent cover plate.

[0040] In one embodiment, before fixing the light-transmitting cover to the first supporting wall, the method further includes:

[0041] A first light-shielding barrier and a second light-shielding barrier are prepared. The first light-shielding barrier is located between the space above the photosensitive area and the space above the non-photosensitive area. The bottom of the first light-shielding barrier is located on the first photosensitive chip, and the top of the first light-shielding barrier is used to contact the light-transmitting cover plate. The first light-shielding barrier is used to prevent light passing through the non-working area of ​​the light-transmitting cover plate from entering the photosensitive area of ​​the first photosensitive chip. The second light-shielding barrier is located between the spaces above adjacent photosensitive elements. The bottom of the second light-shielding barrier is located on the first photosensitive chip, and the top of the second light-shielding barrier is used to contact the light-transmitting cover plate. The second light-shielding barrier is used to isolate light passing through two adjacent light-transmitting sub-regions.

[0042] Compared with the prior art, the beneficial effects of this application are as follows: Since the image sensor includes a first photosensitive chip, a first supporting wall, and a light-transmitting cover, and the first photosensitive chip includes a photosensitive area and a non-photosensitive area, with the non-photosensitive area surrounding the photosensitive area, and the photosensitive area is provided with N photosensitive elements, where N is an integer greater than 1, the N photosensitive elements are adjacent, and the N photosensitive elements are respectively used to sense light of different target wavelengths, with the N different target wavelengths not overlapping each other. The first supporting wall is located on the non-photosensitive area and surrounds the space above the photosensitive area. The light-transmitting cover is located on the side of the first supporting wall away from the first photosensitive chip, and the light-transmitting cover includes a working area and a non-working area, with the non-working area surrounding the working area. The projection of the non-working area onto the first photosensitive chip... Located within the non-photosensitive area, the projection of the photosensitive area onto the light-transmitting cover plate lies within the working area. The working area comprises N light-transmitting sub-regions, each corresponding to one of the positions of N photosensitive elements. Each of the N light-transmitting sub-regions is used to allow only light of different target wavelengths to pass through. For the corresponding light-transmitting sub-region and photosensitive element, the projection of the photosensitive element onto the light-transmitting cover plate lies within the light-transmitting sub-region. In this way, only one target wavelength is allowed to pass through the same light-transmitting sub-region on the light-transmitting cover plate, while light of other wavelengths is prohibited from passing through. The wavelengths of light transmitted through the N light-transmitting sub-regions on the light-transmitting cover plate do not overlap, thus reducing optical signal crosstalk of the image sensor and improving the clarity and accuracy of the image.

[0043] Furthermore, since the selective light-transmitting film is made of inorganic materials, the quantum efficiency of the output of N light-transmitting sub-films can be significantly improved. On this basis, the limitation on the wavelength of light transmitted through each light-transmitting sub-film can be greatly reduced, thereby enabling the wavelengths of light transmitted through the N light-transmitting sub-films to not overlap. This reduces crosstalk of optical signals in the various channels of the image sensor.

[0044] Furthermore, since a second light-shielding barrier is provided between the spaces above adjacent photosensitive elements, the second light-shielding barrier is used to isolate the light that passes through the two adjacent phototransmitting sub-regions. Therefore, it can prevent the light signal of one channel from entering other channels and causing light signal crosstalk. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of an image sensor based on related technologies.

[0046] Figure 2 This is a schematic diagram of the structure of a color filter based on relevant technologies.

[0047] Figures 3-6 It is the preparation Figure 1 The diagram shows the structure of the intermediate structure generated during the image sensor process.

[0048] Figure 7 yes Figure 2The diagram shows the quantum efficiency of the color filter.

[0049] Figure 8 This is a schematic diagram of the structure of an image sensor according to an exemplary embodiment.

[0050] Figure 9 This is a schematic diagram of the structure of a light-transmitting cover plate according to an exemplary embodiment.

[0051] Figure 10 This is a schematic diagram illustrating the quantum efficiency of an image sensor according to an exemplary embodiment.

[0052] Figure 11 This is a flowchart illustrating a method for fabricating an image sensor according to an exemplary embodiment.

[0053] Figures 12-14 It is the preparation Figure 8 The diagram shows the structure of the intermediate structure generated during the image sensor process.

[0054] Figure 15 This is a flowchart illustrating a method for fabricating an image sensor according to another exemplary embodiment.

[0055] Figure 16 This is a flowchart illustrating the preparation of a light-transmitting cover plate according to an exemplary embodiment.

[0056] Figures 17-20 This is a schematic diagram of an intermediate structure produced during the fabrication of a light-transmitting cover plate, according to an exemplary embodiment.

[0057] Figure 21 This is a flowchart illustrating the preparation of a light-transmitting cover plate according to another exemplary embodiment.

[0058] Figures 22-25 This is a schematic diagram of an intermediate structure produced during the fabrication of a light-transmitting cover plate, according to another exemplary embodiment. Detailed Implementation

[0059] Unless otherwise defined, the technical or scientific terms used in this specification and claims should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. Specific embodiments of the invention will be described below with reference to the accompanying drawings. It should be noted that, in order to provide a concise description, this specification cannot provide a detailed description of all features of the actual embodiments. Without departing from the spirit and scope of the invention, those skilled in the art can make modifications and substitutions to the embodiments of the invention, and the resulting embodiments are also within the protection scope of the invention.

[0060] In related technologies, such as Figure 1 As shown, the line scan image sensor includes a second photosensitive chip 11, a second supporting wall 12 and a second transparent cover plate 13. The second photosensitive chip 11 includes a first photosensitive element PD-1, a second photosensitive element PD-2, a third photosensitive element PD-3, a fourth photosensitive element PD-4 and a color filter 111.

[0061] The first photosensitive element PD-1, the second photosensitive element PD-2, the third photosensitive element PD-3, and the fourth photosensitive element PD-4 are the same, used to sense light signals, and can sense the same wavelength range.

[0062] like Figure 1 and Figure 2 As shown, the color filter 111 includes a near-infrared filter LN, a red filter LR, a green filter LG, and a blue filter LB. The near-infrared filter LN, red filter LR, green filter LG, and blue filter LB are respectively located on the first photosensitive element PD-1, the second photosensitive element PD-2, the third photosensitive element PD-3, and the fourth photosensitive element PD-4. The near-infrared filter LN allows only near-infrared light to pass through, the red filter LR allows only red light to pass through, the green filter LG allows only green light to pass through, and the blue filter LB allows only blue light to pass through. The second supporting wall 12 is a glued wall, surrounding the near-infrared filter LN, the red filter LR, the green filter LG, and the blue filter LB. A second transparent cover plate 13 covers the second supporting wall 12.

[0063] In related technologies, at the color filter site, a near-infrared filter (LN), a red filter (LR), a green filter (LG), and a blue filter (LB) are sequentially fabricated using coating, exposure, and development techniques. The materials used for the near-infrared filter (LN), red filter (LR), green filter (LG), and blue filter (LB) are organic materials. The fabrication method for the color filter 111 is as follows: First, as... Figure 3 As shown, a first material layer L1 is formed on the first photosensitive element PD-1, the second photosensitive element PD-2, the third photosensitive element PD-3, and the fourth photosensitive element PD-4. Then, as... Figure 4 As shown, a first mask 41 is placed on a first material layer L1. The first mask 41 includes a first light-blocking area 411 and a third cutout area 412. The pattern of the first light-blocking area 411 is the same as the pattern of the near-infrared filter LN. Then, ultraviolet light (UV) is used to illuminate the first mask 41 and the first material layer L1. The area of ​​the first material layer L1 illuminated by UV light forms a second material layer L2, and the area of ​​the first material layer L1 not illuminated by UV light forms the near-infrared filter LN. Then, as... Figure 5As shown, the second material layer L2 is removed. Then, a red filter LR, a green filter LG, and a blue filter LB are prepared sequentially. The preparation methods of the red filter LR, the green filter LG, and the blue filter LB are similar to those of the near-infrared filter LN, and will not be described in detail here.

[0064] After fabricating the color filter 111, the second photosensitive chip 11 is encapsulated. The encapsulation process can be carried out by applying adhesive to bond the second photosensitive chip 11 to the second transparent cover plate 13, thus completing the encapsulation.

[0065] like Figure 7 As shown, since the red filter LR, green filter LG, and blue filter LB are made of organic materials, their transmittance characteristics cause their output quantum efficiency (QE) to exhibit a normal distribution. Specifically, the first quantum efficiency curve 71, the second quantum efficiency curve 72, the third quantum efficiency curve 73, and the fourth quantum efficiency curve 74 are the quantum efficiency curves of the red filter LR, the green filter LG, the blue filter LB, and the near-infrared filter LN, respectively. This results in high crosstalk among the red, green, and blue channels and a decrease in overall response. Especially when the near-infrared band of the incident image sensor exceeds 850nm, the optical paths of the red, green, and blue channels often cause image distortion.

[0066] The inventors of this invention discovered that using inorganic materials for the red filter LR, green filter LG, and blue filter LB can improve their output quantum efficiency (QE). However, due to the uneven surface of the second photosensitive chip 11 and limitations in the manufacturing process, only organic materials can be used for the red filter LR, green filter LG, and blue filter LB, and inorganic materials cannot be used. The specific reasons are as follows: Due to the uneven surface of the second photosensitive chip 11, the red filter LR, green filter LG, and blue filter LB on the second photosensitive chip 11 can only be prepared using photolithography and cannot be prepared using inorganic layer preparation processes such as plasma-enhanced chemical vapor deposition (PECVD) or lift-off processes. This is because PECVD is not as precise as photolithography, and the film prepared using inorganic layer preparation processes has poor flatness and large coating thickness deviation. Moreover, the uneven surface of the second photosensitive chip will lead to material residue and low yield when using inorganic layer preparation processes. For example, after preparing the red filter LR on the second photosensitive element PD-2, the material of the red filter LR may remain on the third photosensitive element PD-3 and the fourth photosensitive element PD-4.

[0067] During the operation of an image sensor, crosstalk often has a negative impact on image quality, reducing the clarity and accuracy of the image.

[0068] To address the aforementioned technical problems, this application proposes an image sensor and its fabrication method, which can reduce optical signal crosstalk in the image sensor and improve the clarity and accuracy of imaging.

[0069] One embodiment of this application provides an image sensor. This image sensor can be applied to electronic devices with camera functions, such as cameras, mobile phones, tablets, and laptops. See also... Figure 8 The image sensor includes: a first photosensitive chip 81, a first supporting wall 82, and a light-transmitting cover plate 83.

[0070] like Figure 8 As shown, the first photosensitive chip 81 includes a photosensitive area A1 and a non-photosensitive area A2. The non-photosensitive area A2 surrounds the photosensitive area A1. The photosensitive area A1 is provided with N photosensitive elements PD-5, PD-6, PD-7, and PD-8, where N is an integer greater than 1, and the N photosensitive elements PD-5, PD-6, PD-7, and PD-8 are adjacent to each other. The N photosensitive elements PD-5, PD-6, PD-7, and PD-8 are used to sense light of different target wavelengths. The different target wavelengths do not overlap.

[0071] In this embodiment, N can be 4. For example... Figure 8 As shown, the photosensitive area A1 is provided with four photosensitive elements: a fifth photosensitive element PD-5, a sixth photosensitive element PD-6, a seventh photosensitive element PD-7, and an eighth photosensitive element PD-8. These four photosensitive elements are arranged sequentially. In other embodiments, N can be 2, 3, 5, 6, 8, or 9, or any other integer greater than 1.

[0072] The fifth photosensitive element PD-5 is used to sense light in the first target wavelength band, the sixth photosensitive element PD-6 is used to sense light in the second target wavelength band, the seventh photosensitive element PD-7 is used to sense light in the third target wavelength band, and the eighth photosensitive element PD-8 is used to sense light in the fourth target wavelength band. The first, second, third, and fourth target wavelength bands do not overlap.

[0073] In this embodiment, the first target wavelength band is the near-infrared band, with a wavelength range of 800-1000 nm. The second target wavelength band is the red light band, with a wavelength range of 600-700 nm. The third target wavelength band is the green light band, with a wavelength range of 500-599 nm. The fourth target wavelength band is the blue light band, with a wavelength range of 400-499 nm. There is a 100 nm interval between the wavelength ranges of the near-infrared band and the red light band. This avoids near-infrared light interfering with the optical paths of the red, green, and blue channels, thus preventing image distortion and further reducing crosstalk.

[0074] like Figure 8 As shown, the first supporting wall 82 is located on the non-photosensitive area A2 and surrounds the space above the photosensitive area A1. The first supporting wall 82 may be located on the edge of the non-photosensitive area A2 away from the photosensitive area A1.

[0075] In this embodiment, the first supporting wall 82 is opaque. The material of the first supporting wall 82 can be a black organic material. For example, the material of the first supporting wall 82 can be epoxy resin. The first supporting wall 82 can be prepared by 3D printing, which is a highly efficient method and provides good morphological control. In other embodiments, the first supporting wall 82 can be prepared by applying a coating material.

[0076] like Figure 8 As shown, the light-transmitting cover plate 83 is located on the side of the first supporting wall 82 away from the first photosensitive chip 81. The light-transmitting cover plate 83 includes a working area B1 and a non-working area B2. The non-working area B2 surrounds the working area B1, and the projection of the non-working area B2 on the first photosensitive chip 81 is located within the non-photosensitive area A2. The projection of the photosensitive area A1 on the light-transmitting cover plate 83 is located within the working area B1.

[0077] like Figure 8 As shown, the working area B1 includes N light-transmitting sub-regions B11, B12, B13, and B14, which are used to allow light of different target wavelengths to pass through. The positions of the N light-transmitting sub-regions B11, B12, B13, and B14 correspond one-to-one with the positions of the N photosensitive elements PD-5, PD-6, PD-7, and PD-8. For the corresponding light-transmitting sub-region and photosensitive element, the projection of the photosensitive element on the light-transmitting cover plate 83 is located within the light-transmitting sub-region.

[0078] In this embodiment, as Figure 8As shown, the working area B1 may include a first light-transmitting sub-region B11, a second light-transmitting sub-region B12, a third light-transmitting sub-region B13, and a fourth light-transmitting sub-region B14. The first light-transmitting sub-region B11, the second light-transmitting sub-region B12, the third light-transmitting sub-region B13, and the fourth light-transmitting sub-region B14 are arranged sequentially. The first light-transmitting sub-region B11 is used to allow only light of a first target wavelength band to pass through; the second light-transmitting sub-region B12 is used to allow only light of a second target wavelength band to pass through; the third light-transmitting sub-region B13 is used to allow only light of a third target wavelength band to pass through; and the fourth light-transmitting sub-region B14 is used to allow only light of a fourth target wavelength band to pass through.

[0079] In this embodiment, as Figure 8 As shown, the position of the first light-transmitting sub-region B11 corresponds to the position of the fifth photosensitive element PD-5, and the projection of the fifth photosensitive element PD-5 on the light-transmitting cover plate 83 is located within the first light-transmitting sub-region B11.

[0080] In this embodiment, as Figure 8 As shown, the position of the second light-transmitting sub-region B12 corresponds to the position of the sixth photosensitive element PD-6, and the projection of the sixth photosensitive element PD-6 on the light-transmitting cover plate 83 is located within the second light-transmitting sub-region B12.

[0081] In this embodiment, as Figure 8 As shown, the position of the third phototransparent sub-region B13 corresponds to the position of the seventh photosensitive element PD-7, and the projection of the seventh photosensitive element PD-7 on the light-transmitting cover plate 83 is located within the third phototransparent sub-region B13.

[0082] In this embodiment, as Figure 8 As shown, the position of the fourth phototransparent sub-region B14 corresponds to the position of the eighth photosensitive element PD-8, and the projection of the eighth photosensitive element PD-8 on the light-transmitting cover plate 83 is located within the fourth phototransparent sub-region B14.

[0083] In this embodiment, only one target wavelength band of light is allowed to pass through the same light-transmitting sub-region on the light-transmitting cover plate 83, and light of wavelength bands other than the target wavelength band is prohibited from passing through. The wavelength bands of light transmitted through the N light-transmitting sub-regions on the light-transmitting cover plate 83 do not overlap with each other. In this way, crosstalk of optical signals of the image sensor can be reduced, and the clarity and accuracy of imaging can be improved.

[0084] In this embodiment, as Figure 8 As shown, the light-transmitting cover 83 includes a first transparent cover 831 and a selectively light-transmitting film 832.

[0085] In this embodiment, as Figure 8As shown, the first transparent cover plate 831 is located on the side of the first supporting wall 82 away from the first photosensitive chip 81, and is located between the working area B1 and the non-working area B2. The selective light-transmitting film 832 is located on the side of the first transparent cover plate 831 away from the first photosensitive chip 81, and is located in the working area B1.

[0086] In this embodiment, as Figure 8 As shown, the selective light-transmitting film 832 may include N light-transmitting sub-films 8321, 8322, 8323, and 8324. The N light-transmitting sub-films 8321, 8322, 8323, and 8324 are located in different light-transmitting sub-regions B11, B12, B13, and B14, respectively, and are used to allow only light of different target wavelengths to pass through. For the corresponding light-transmitting sub-films and photosensitive elements, the projection of the photosensitive element on the first transparent cover plate 831 lies within the projection of the light-transmitting sub-film onto the first transparent cover plate 831.

[0087] In this embodiment, as Figure 8 As shown, the selective light-transmitting film 832 includes a first light-transmitting sub-film 8321, a second light-transmitting sub-film 8322, a third light-transmitting sub-film 8323, and a fourth light-transmitting sub-film 8324. The first light-transmitting sub-film 8321 is located in a first light-transmitting sub-region B11, the second light-transmitting sub-film 8322 is located in a second light-transmitting sub-region B12, the third light-transmitting sub-film 8323 is located in a third light-transmitting sub-region B13, and the fourth light-transmitting sub-film 8324 is located in a fourth light-transmitting sub-region B14. The first light-transmitting sub-film is used to allow only light of a first target wavelength band to pass through, the second light-transmitting sub-film is used to allow only light of a second target wavelength band to pass through, the third light-transmitting sub-film is used to allow only light of a third target wavelength band to pass through, and the fourth light-transmitting sub-film is used to allow only light of a fourth target wavelength band to pass through.

[0088] In this embodiment, as Figure 8As shown, the position of the first phototransparent membrane 8321 corresponds to the position of the fifth photosensitive element PD-5, and the projection of the fifth photosensitive element PD-5 on the first transparent cover plate 831 lies within the projection of the first phototransparent membrane 8321 on the first transparent cover plate 831. The position of the second phototransparent membrane 8322 corresponds to the position of the sixth photosensitive element PD-6, and the projection of the sixth photosensitive element PD-6 on the first transparent cover plate 831 lies within the projection of the second phototransparent membrane 8322 on the first transparent cover plate 831. The position of the third phototransparent membrane 8323 corresponds to the position of the seventh photosensitive element PD-7, and the projection of the seventh photosensitive element PD-7 on the first transparent cover plate 831 lies within the projection of the third phototransparent membrane 8323 on the first transparent cover plate 831. The position of the fourth phototransparent membrane 8324 corresponds to the position of the eighth photosensitive element PD-8, and the projection of the eighth photosensitive element PD-8 on the first transparent cover plate 831 lies within the projection of the fourth phototransparent membrane 8324 on the first transparent cover plate 831.

[0089] In this embodiment, the first transparent cover plate 831 is clear glass with a transmittance of 95%. In other embodiments, the transmittance of the first transparent cover plate 831 may be greater than 95%, for example, the transmittance of the first transparent cover plate 831 may be 96%, 98%, or 99%.

[0090] In this embodiment, the light transmission channels from the first translucent sub-film 8321 to the fifth photosensitive element PD-5 are near-infrared light channels, from the second translucent sub-film 8322 to the sixth photosensitive element PD-6 are red light channels, from the third translucent sub-film 8323 to the seventh photosensitive element PD-7 are green light channels, and from the fourth translucent sub-film 8324 to the eighth photosensitive element PD-8 are blue light channels. Since each translucent sub-film only allows light of one target wavelength band to pass through and prohibits light of other wavelength bands from passing through, the wavelengths of light transmitted through the four translucent sub-films on the light-transmitting cover plate 83 do not overlap. This reduces crosstalk between the optical signals of the various channels of the image sensor, improving the clarity and accuracy of the image.

[0091] In this embodiment, the selective light-transmitting film 832 is made of an inorganic material. Because the selective light-transmitting film 832 is made of an inorganic material, the quantum efficiency of the N light-transmitting sub-films can be significantly improved. Based on this, the limitation on the wavelength of light transmitted through each light-transmitting sub-film can be greatly reduced, thereby enabling the wavelengths of light transmitted through the N light-transmitting sub-films to not overlap. This reduces crosstalk of optical signals in different channels of the image sensor.

[0092] In this embodiment, as Figure 8As shown, a first light-shielding barrier 84 is disposed between the space above the photosensitive area A1 and the space above the non-photosensitive area A2. The bottom of the first light-shielding barrier 84 is located on the first photosensitive chip 81, and the top of the first light-shielding barrier 84 contacts the light-transmitting cover plate 83, specifically, the top of the first light-shielding barrier 84 contacts the first transparent cover plate 831. The first light-shielding barrier 84 is used to prevent light passing through the non-working area B2 of the light-transmitting cover plate 83 from entering the photosensitive area A1 of the first photosensitive chip 81. In this way, interference can be reduced and image quality can be improved.

[0093] In this embodiment, the material of the first light-shielding barrier 84 can be a black organic material, such as epoxy resin, but is not limited thereto. The first light-shielding barrier 84 can be prepared by 3D printing, which is highly efficient and provides good morphological control. In other embodiments, the first light-shielding barrier 84 can be prepared by applying adhesive.

[0094] In this embodiment, as Figure 8 As shown, a second light-shielding barrier 85 is respectively disposed between the spaces above adjacent photosensitive elements. The bottom of the second light-shielding barrier 85 is located on the first photosensitive chip 81, and the top of the second light-shielding barrier 85 contacts the light-transmitting cover plate 83. The second light-shielding barrier 85 is used to isolate light passing through two adjacent light-transmitting sub-regions. In some embodiments, when the distance between the first photosensitive chip 81 and the light-transmitting cover plate 83 is relatively small, the second light-shielding barrier 85 may not be disposed between the spaces above adjacent photosensitive elements. In some embodiments, when the distance between the first photosensitive chip 81 and the light-transmitting cover plate 83 is relatively large, and crosstalk is easily caused by the refraction of the first transparent cover plate 831, the second light-shielding barrier 85 may be disposed between the spaces above adjacent photosensitive elements.

[0095] In this embodiment, as Figure 8 As shown, a second light-shielding barrier 85 is provided between the space above the fifth photosensitive element PD-5 and the space above the sixth photosensitive element PD-6 to isolate the light from the near-infrared light channel and the red light channel. A second light-shielding barrier 85 is provided between the space above the sixth photosensitive element PD-6 and the space above the seventh photosensitive element PD-7 to isolate the light from the red light channel and the green light channel. A second light-shielding barrier 85 is provided between the space above the seventh photosensitive element PD-7 and the space above the eighth photosensitive element PD-8 to isolate the light from the green light channel and the blue light channel.

[0096] In this embodiment, the material of the second light-shielding barrier 85 can be a black organic material, such as epoxy resin, but is not limited thereto. The second light-shielding barrier 85 can be prepared by 3D printing, which is highly efficient and provides good morphological control. In other embodiments, the second light-shielding barrier 85 can be prepared by applying adhesive.

[0097] Since a second light-shielding barrier 85 is provided between the spaces above adjacent photosensitive elements to isolate the light passing through the two adjacent light-transmitting sub-regions, it can prevent the light signal of one channel from entering other channels and causing light signal crosstalk.

[0098] In this embodiment, the image sensor also includes an adhesive frame located between the first supporting wall 82 and the light-transmitting cover plate 83, for bonding the first supporting wall 82 and the light-transmitting cover plate 83. Specifically, the adhesive frame is located on the side of the first transparent cover plate 831 away from the selective light-transmitting film 832, and can be manufactured by screen printing.

[0099] In this embodiment, the image sensor can be a line-scan image sensor. The photosensitive surfaces of the fifth photosensitive element PD-5, the sixth photosensitive element PD-6, the seventh photosensitive element PD-7, and the eighth photosensitive element PD-8 are rectangular. In other embodiments, the image sensor can also be other types of image sensors, not limited to line-scan image sensors.

[0100] In this embodiment, the first light-transmitting sub-region B11, the second light-transmitting sub-region B12, the third light-transmitting sub-region B13, and the fourth light-transmitting sub-region B14 of the light-transmitting cover plate 83 can be rectangular.

[0101] In this embodiment, as Figure 9 As shown, the first light-transmitting sub-membrane 8321, the second light-transmitting sub-membrane 8322, the third light-transmitting sub-membrane 8323 and the fourth light-transmitting sub-membrane 8324 of the light-transmitting cover plate 83 are rectangular.

[0102] The QE performance of the image sensor in this embodiment is as follows: Figure 10 As shown. Figure 10 In the figure, the fifth quantum efficiency curve 91, the sixth quantum efficiency curve 92, the seventh quantum efficiency curve 93, and the eighth quantum efficiency curve 94 are the quantum efficiency curves of the first phototransparent membrane 8321, the second phototransparent membrane 8322, the third phototransparent membrane 8323, and the fourth phototransparent membrane 8324, respectively.

[0103] Will Figure 10 and Figure 7 In comparison, the quantum efficiency of the image sensor in this embodiment is improved. The wavelengths of light transmitted through the first, second, third, and fourth phototransmitting sub-films 8321, 8322, 8323, and 8324 do not overlap, effectively reducing crosstalk. Furthermore, the sixth, seventh, and eighth photosensitive elements PD-6, PD-7, and PD-8 do not respond to near-infrared light above 700nm, representing near-infrared cutoff, while the fifth photosensitive element PD-5 responds to near-infrared light in the 800–1000nm range, representing near-infrared enhancement. Therefore, the image sensor in this embodiment achieves both infrared cutoff and near-infrared enhancement functions.

[0104] Another embodiment of this application also provides a method for fabricating an image sensor. Please refer to [link to relevant documentation]. Figure 11 The method for manufacturing this image sensor may include the following steps 1101 to 1104:

[0105] Step 1101: Prepare the first photosensitive chip.

[0106] In this step, the first photosensitive chip 81 is prepared as follows: Figure 12 As shown. The first photosensitive chip 81 includes a photosensitive area A1 and a non-photosensitive area A2, with the non-photosensitive area A2 surrounding the photosensitive area A1; the photosensitive area A1 is provided with N photosensitive elements PD-5, PD-6, PD-7 and PD-8, where N is an integer greater than 1, and the N photosensitive elements are adjacent; the N photosensitive elements are used to sense light of different target wavelengths; the different target wavelengths do not overlap.

[0107] In this embodiment, N can be 4. For example... Figure 12 As shown, the photosensitive area A1 is provided with four photosensitive elements: the fifth photosensitive element PD-5, the sixth photosensitive element PD-6, the seventh photosensitive element PD-7, and the eighth photosensitive element PD-8. The four photosensitive elements are arranged sequentially.

[0108] In this embodiment, the fifth photosensitive element PD-5 is used to sense light in the first target wavelength band, the sixth photosensitive element PD-6 is used to sense light in the second target wavelength band, the seventh photosensitive element PD-7 is used to sense light in the third target wavelength band, and the eighth photosensitive element PD-8 is used to sense light in the fourth target wavelength band. The first, second, third, and fourth target wavelength bands do not overlap.

[0109] In this embodiment, the first target wavelength band is the near-infrared band, with a wavelength range of 800-1000 nm. The second target wavelength band is the red light band, with a wavelength range of 600-700 nm. The third target wavelength band is the green light band, with a wavelength range of 500-599 nm. The fourth target wavelength band is the blue light band, with a wavelength range of 400-499 nm. There is a 100 nm interval between the wavelength ranges of the near-infrared band and the red light band.

[0110] Step 1102: Prepare the first supporting wall 82, the first light-shielding wall 84, and the second light-shielding wall 85.

[0111] In this step, after preparing the first supporting wall 82, the first light-shielding wall 84, and the second light-shielding wall 85, the resulting intermediate structure is as follows: Figure 13 As shown.

[0112] like Figure 13 As shown, the first supporting wall 82 is located on the non-photosensitive area A2 and surrounds the space above the photosensitive area A1. The first supporting wall 82 may be located on the edge of the non-photosensitive area A2 away from the photosensitive area A1.

[0113] The first light-shielding barrier 84 is located between the space above the photosensitive area A1 and the space above the non-photosensitive area A2. The bottom of the first light-shielding barrier 84 is located on the first photosensitive chip 81, and the top of the first light-shielding barrier 84 is used to contact the light-transmitting cover plate 83. The first light-shielding barrier 84 is used to prevent light passing through the non-working area B2 of the light-transmitting cover plate 83 from entering the photosensitive area A1 of the first photosensitive chip 81.

[0114] The second light-shielding barrier 85 is located between the spaces above adjacent photosensitive elements. The bottom of the second light-shielding barrier 85 is located on the first photosensitive chip 81, the top of the second light-shielding barrier 85 is used to contact the light-transmitting cover plate 83, and the second light-shielding barrier 85 is used to isolate light that passes through two adjacent light-transmitting sub-regions.

[0115] In this embodiment, the materials of the first supporting wall 82, the second light-shielding wall 85, and the first light-shielding wall 84 can be the same, all being black organic materials, such as epoxy resin. This allows the first supporting wall 82, the first light-shielding wall 84, and the second light-shielding wall 85 to be fabricated using 3D printing, which is highly efficient and provides good morphological control of the adhesive walls. In other embodiments, the first supporting wall 82, the first light-shielding wall 84, and the second light-shielding wall 85 can be fabricated using a paint-on method.

[0116] Step 1103: Prepare the light-transmitting cover plate 83.

[0117] In this step, the light-transmitting cover plate 83 is prepared as follows: Figure 14 As shown. The light-transmitting cover plate 83 includes a working area B1 and a non-working area B2; the non-working area B2 surrounds the working area B1, and the working area B1 includes N light-transmitting sub-regions B11, B12, B13 and B14, which are used to allow light of different target wavelengths to pass through.

[0118] In this embodiment, the working area B1 may include a first light-transmitting sub-region B11, a second light-transmitting sub-region B12, a third light-transmitting sub-region B13, and a fourth light-transmitting sub-region B14. The first light-transmitting sub-region B11, the second light-transmitting sub-region B12, the third light-transmitting sub-region B13, and the fourth light-transmitting sub-region B14 are arranged sequentially. The first light-transmitting sub-region B11 is used to allow only light of a first target wavelength band to pass through; the second light-transmitting sub-region B12 is used to allow only light of a second target wavelength band to pass through; the third light-transmitting sub-region B13 is used to allow only light of a third target wavelength band to pass through; and the fourth light-transmitting sub-region B14 is used to allow only light of a fourth target wavelength band to pass through.

[0119] In this embodiment, as Figure 14 As shown, the light-transmitting cover 83 may include a first transparent cover 831 and a selective light-transmitting film 832. The selective light-transmitting film 832 may include a first light-transmitting sub-film 8321, a second light-transmitting sub-film 8322, a third light-transmitting sub-film 8323, and a fourth light-transmitting sub-film 8324. The first light-transmitting sub-film 8321 is located in a first light-transmitting sub-region B11, the second light-transmitting sub-film 8322 is located in a second light-transmitting sub-region B12, the third light-transmitting sub-film 8323 is located in a third light-transmitting sub-region B13, and the fourth light-transmitting sub-film 8324 is located in a fourth light-transmitting sub-region B14. The first light-transmitting sub-film 8321 is used to allow only light of a first target wavelength band to pass through, the second light-transmitting sub-film 8322 is used to allow only light of a second target wavelength band to pass through, the third light-transmitting sub-film 8323 is used to allow only light of a third target wavelength band to pass through, and the fourth light-transmitting sub-film 8324 is used to allow only light of a fourth target wavelength band to pass through.

[0120] In this embodiment, the first transparent cover plate 831 is clear glass with a transmittance of 95%. In other embodiments, the transmittance of the first transparent cover plate 831 may be greater than 95%, for example, the transmittance of the first transparent cover plate 831 may be 96%, 98%, or 99%.

[0121] In this embodiment, the selective light-transmitting film 832 is made of an inorganic material. Because the selective light-transmitting film 832 is made of an inorganic material, the quantum efficiency of the N light-transmitting sub-films can be significantly improved. Based on this, the limitation on the wavelength of light transmitted through each light-transmitting sub-film can be greatly reduced, thereby enabling the wavelengths of light transmitted through the N light-transmitting sub-films to not overlap. This reduces crosstalk of optical signals in different channels of the image sensor.

[0122] Step 1104: Fix the light-transmitting cover plate to the first supporting wall.

[0123] In this step, after fixing the light-transmitting cover plate 83 to the first supporting wall 82, the following is obtained: Figure 8 The image sensor shown.

[0124] like Figure 8As shown, the light-transmitting cover plate 83 is located on the side of the first supporting wall 82 away from the first photosensitive chip 81. The top of the first supporting wall 82, the top of the first light-shielding wall 84, and the top of the second light-shielding wall 85 are in contact with the light-transmitting cover plate 83. Specifically, the top of the first light-shielding wall 84 and the top of the second light-shielding wall 85 are in contact with the first transparent cover plate 831.

[0125] The projection of the non-working area B2 onto the first photosensitive chip 81 is located within the non-photosensitive area A2, and the projection of the photosensitive area A1 onto the light-transmitting cover plate 83 is located within the working area B1; the positions of the N light-transmitting sub-regions correspond one-to-one with the positions of the N photosensitive elements, and for the corresponding light-transmitting sub-regions and photosensitive elements, the projection of the photosensitive element onto the light-transmitting cover plate 83 is located within the light-transmitting sub-region.

[0126] In this embodiment, as Figure 8 As shown, the position of the first light-transmitting sub-region B11 corresponds to the position of the fifth photosensitive element PD-5, and the projection of the fifth photosensitive element PD-5 onto the light-transmitting cover plate 83 is located within the first light-transmitting sub-region B11. The position of the second light-transmitting sub-region B12 corresponds to the position of the sixth photosensitive element PD-6, and the projection of the sixth photosensitive element PD-6 onto the light-transmitting cover plate 83 is located within the second light-transmitting sub-region B12. The position of the third light-transmitting sub-region B13 corresponds to the position of the seventh photosensitive element PD-7, and the projection of the seventh photosensitive element PD-7 onto the light-transmitting cover plate 83 is located within the third light-transmitting sub-region B13. The position of the fourth light-transmitting sub-region B14 corresponds to the position of the eighth photosensitive element PD-8, and the projection of the eighth photosensitive element PD-8 onto the light-transmitting cover plate 83 is located within the fourth light-transmitting sub-region B14.

[0127] In this embodiment, as Figure 15 As shown, step 1104 may include the following steps:

[0128] Step 1501: Prepare a frame on the side of the first transparent cover away from the selective light-transmitting film.

[0129] In this step, the adhesive frame can be prepared by screen printing on the side of the first transparent cover plate 831 away from the selective light-transmitting film 832.

[0130] Step 1502: Fix the first transparent cover plate to the first supporting wall using a plastic frame.

[0131] In this embodiment, after the first transparent cover plate 831 is fixed to the first supporting wall 82 by a glue frame, the glue frame is located between the first supporting wall 82 and the first transparent cover plate 831 to bond the first supporting wall 82 and the first transparent cover plate 831. The first transparent cover plate 831 is located on the side of the first supporting wall 82 away from the first photosensitive chip 81, and the selective light-transmitting film 832 is located on the side of the first transparent cover plate 831 away from the first photosensitive chip 81. For the light-transmitting sub-film and the photosensitive element corresponding to the position, the projection of the photosensitive element on the first transparent cover plate 831 is located within the projection of the light-transmitting sub-film on the first transparent cover plate 831.

[0132] Another exemplary embodiment of this application provides a method for fabricating an image sensor. In this embodiment, the light-transmitting cover plate 83 includes a first transparent cover plate 831 and a selectively light-transmitting film 832, the selectively light-transmitting film 832 being made of an inorganic material. The selectively light-transmitting film 832 includes N light-transmitting sub-films, each located in a different light-transmitting sub-region. In this embodiment, the light-transmitting cover plate 83 is fabricated using plasma-enhanced chemical vapor deposition (PECVD) and a photomask. Figure 16 As shown, in this embodiment, step 1103 may include the following steps 1601 to 1602:

[0133] Step 1601: When preparing each transparent sub-film, the target mask is placed on the first transparent cover plate.

[0134] The target mask includes a first cutout area, the pattern of which is the same as the pattern of the phototransmitter area, and the first cutout area is used to expose the phototransmitter area.

[0135] Step 1602: A phototransparent membrane is prepared in the phototransparent region using a deposition process. The pattern of the phototransparent membrane is the same as the pattern of the first hollowed-out region.

[0136] In this embodiment, when preparing each phototransparent membrane, a target mask can be placed on the first transparent cover plate 831. Then, a plasma-enhanced chemical vapor deposition process is used to prepare the phototransparent membrane in the phototransparent region.

[0137] Because the surface of the first transparent cover plate 831 is smooth and has good flatness, the light-transmitting membrane prepared on the first transparent cover plate 831 has good consistency and there is no material residue problem.

[0138] Even if the precision of plasma-enhanced chemical vapor deposition is lower than that of photolithography, resulting in the length and width of the phototransparent subfilm being greater than the specified length and width or deviations in position, it can be adjusted through subsequent processes (e.g., removing excess material, cutting the edge of the first transparent cover plate 831 to align the phototransparent subfilm with the photosensitive element) to compensate for the deficiencies of the deposition process, and there is no material residue problem.

[0139] For example, such as Figure 17 As shown, when preparing the first phototransparent membrane 8321, a corresponding target mask 171 is placed on the first transparent cover plate 831. The pattern of the first cutout area 1711 of the target mask 171 is the same as the pattern of the first phototransparent region B11, and the first cutout area 1711 is used to expose the first phototransparent region B11. Then, the first phototransparent membrane 8321 can be prepared in the first phototransparent region B11 using a plasma-enhanced chemical vapor deposition process. The pattern of the first phototransparent membrane 8321 is the same as the pattern of the first cutout area of ​​the target mask 171 and the pattern of the first phototransparent region B11.

[0140] like Figure 18 As shown, in preparing the second phototransparent membrane 8322, a corresponding target mask 181 is placed on the first transparent cover plate 831. The pattern of the first cutout region 1811 of the target mask 181 is the same as the pattern of the second phototransparent region B12. The first cutout region 1811 is used to expose the second phototransparent region B12. Then, the second phototransparent membrane 8322 can be prepared in the second phototransparent region B12 using a plasma-enhanced chemical vapor deposition process. The pattern of the second phototransparent membrane 8322 is the same as the pattern of the first cutout region 1811 and the pattern of the second phototransparent region B12.

[0141] like Figure 19 As shown, in preparing the third phototransparent membrane 8323, a corresponding target mask 191 is placed on the first transparent cover plate 831. The pattern of the first cutout region 1911 of the target mask 191 is the same as the pattern of the third phototransparent region B13. The first cutout region 1911 is used to expose the third phototransparent region B13. Then, the third phototransparent membrane 8323 can be prepared in the third phototransparent region B13 using a plasma-enhanced chemical vapor deposition process. The pattern of the third phototransparent membrane 8323 is the same as the pattern of the first cutout region 1911 and the pattern of the third phototransparent region B13.

[0142] like Figure 20As shown, in preparing the fourth phototransparent sub-film 8324, a corresponding target mask 201 is placed on a first transparent cover plate 831. The pattern of the first cutout region 2011 of the target mask 201 is the same as the pattern of the fourth phototransparent sub-region B14, and the first cutout region 2011 is used to expose the fourth phototransparent sub-region B14. Then, the fourth phototransparent sub-film 8324 can be prepared in the fourth phototransparent sub-region B14 using a plasma-enhanced chemical vapor deposition process. The pattern of the fourth phototransparent sub-film 8324 is the same as the pattern of the first cutout region 2011 and the pattern of the fourth phototransparent sub-region B14.

[0143] In this embodiment, a first phototransparent membrane 8321, a second phototransparent membrane 8322, a third phototransparent membrane 8323, and a fourth phototransparent membrane 8324 can be prepared sequentially to obtain the following: Figure 14 The light-transmitting cover plate 83 shown.

[0144] In this embodiment, a plasma-enhanced chemical vapor deposition process and a photomask are used to prepare the transparent cover plate, which is relatively simple and efficient.

[0145] Another exemplary embodiment of this application provides a method for fabricating an image sensor. In this embodiment, the light-transmitting cover plate 83 includes a first transparent cover plate 831 and a selectively light-transmitting film 832, the selectively light-transmitting film 832 being made of an inorganic material. The selectively light-transmitting film 832 includes N light-transmitting sub-films, each located in a different light-transmitting sub-region. In this embodiment, the light-transmitting cover plate 83 is fabricated using a coating, exposure, and development lift-off process. Figure 21 As shown, in this embodiment, step 1103 may include the following steps 2101 to 2102:

[0146] Step 2101: When preparing each photosensitive membrane, a first photosensitive material layer is formed on the first transparent cover plate.

[0147] Step 2102: The first photosensitive material layer is exposed and developed using a photolithography machine to obtain the second photosensitive material layer.

[0148] The second photosensitive material layer includes a second hollow area, the pattern of which is the same as the pattern of the phototransparent area.

[0149] Step 2103: Prepare a first inorganic material layer, which includes a phototransparent membrane and an ineffective membrane layer. The phototransparent membrane covers the second hollow area, and the ineffective membrane layer covers the second photosensitive material layer.

[0150] Step 2104: Remove the second photosensitive material layer and the invalid film layer to obtain a phototransparent sub-film.

[0151] The following section will take the preparation of the first phototransparent membrane 8321 as an example.

[0152] like Figure 22 As shown, during the fabrication of the first photosensitive film 8321, a first photosensitive material layer 221 is formed on the first transparent cover plate 831. The material of the first photosensitive material layer 221 is photoresist.

[0153] Then, as Figure 23 As shown, a photolithography machine is used to expose and develop the first photosensitive material layer 221 to obtain the second photosensitive material layer 222. Specifically, the photolithography machine transfers the pattern of the target mask onto the photosensitive material to obtain the second photosensitive material layer 222. The second photosensitive material layer 222 includes a second cutout region 223, the pattern of which is the same as the pattern of the first phototransparent sub-region B11. The first phototransparent sub-region B11 is determined using a photolithography process with high precision.

[0154] Then, as Figure 24 As shown, a first inorganic material layer 224 is prepared using a deposition process. The first inorganic material layer 224 includes a first transparent sub-film 8321 and a non-transparent film layer 2241. The first transparent sub-film 8321 covers the second hollow area 223, and the non-transparent film layer 2241 covers the second photosensitive material layer 222. In other embodiments, the first inorganic material layer can also be prepared using a sputtering process.

[0155] Then, as Figure 25 As shown, the second photosensitive material layer 222 and the invalid film layer 2241 are removed to obtain the first phototransparent sub-film 8321.

[0156] The above describes a method for preparing the first phototransparent membrane 8321 using a peel-and-strip process. After preparing the first phototransparent membrane 8321, the second phototransparent membrane 8322, the third phototransparent membrane 8323, and the fourth phototransparent membrane 8324 can be prepared sequentially using the peel-and-strip process.

[0157] Because the surface of the first transparent cover plate 831 is smooth and has good flatness, the light-transmitting membrane prepared on the first transparent cover plate 831 has good consistency and there is no material residue problem.

[0158] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0159] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. An image sensor, characterized in that, include: The first photosensitive chip includes a photosensitive area and a non-photosensitive area, the non-photosensitive area surrounding the photosensitive area; the photosensitive area is provided with N photosensitive elements, where N is an integer greater than 1, and the N photosensitive elements are adjacent to each other; the N photosensitive elements are respectively used to sense light of different target wavelength bands; the different target wavelength bands do not overlap with each other; The first supporting wall is located on the non-photosensitive area and surrounds the space above the photosensitive area; A light-transmitting cover plate is located on the side of the first supporting wall away from the first photosensitive chip; the light-transmitting cover plate includes a working area and a non-working area; the non-working area surrounds the working area, the projection of the non-working area on the first photosensitive chip is located within the non-photosensitive area, and the projection of the photosensitive area on the light-transmitting cover plate is located within the working area; the working area includes N light-transmitting sub-regions, the positions of the N light-transmitting sub-regions correspond one-to-one with the positions of the N photosensitive elements, and the N light-transmitting sub-regions are respectively used to allow light of different target wavelength bands to pass through; for the corresponding light-transmitting sub-regions and the photosensitive elements, the projection of the photosensitive element on the light-transmitting cover plate is located within the light-transmitting sub-region.

2. The image sensor as described in claim 1, characterized in that, The light-transmitting cover plate includes a first transparent cover plate and a selectively light-transmitting film; The first transparent cover is located on the side of the first supporting wall away from the first photosensitive chip, and is located in the working area and the non-working area; the selective light-transmitting film is located on the side of the first transparent cover away from the first photosensitive chip, and is located in the working area; The selective light-transmitting film includes N light-transmitting sub-films, each located in a different light-transmitting sub-region. Each of the N light-transmitting sub-films is used to allow light of a different target wavelength band to pass through. For the light-transmitting sub-films and the photosensitive element corresponding to the position, the projection of the photosensitive element on the first transparent cover is located within the projection of the light-transmitting sub-film on the first transparent cover.

3. The image sensor as described in claim 2, characterized in that, N is 4; the selective light-transmitting film includes a first light-transmitting sub-film, a second light-transmitting sub-film, a third light-transmitting sub-film, and a fourth light-transmitting sub-film; The first light-transmitting sub-film is used to allow only light of the first target wavelength band to pass through, the second light-transmitting sub-film is used to allow only light of the second target wavelength band to pass through, the third light-transmitting sub-film is used to allow only light of the third target wavelength band to pass through, and the fourth light-transmitting sub-film is used to allow only light of the fourth target wavelength band to pass through. The first target wavelength band, the second target wavelength band, the third target wavelength band, and the fourth target wavelength band do not overlap with each other.

4. The image sensor as described in claim 3, characterized in that, The first target band is the near-infrared band, the second target band is the red light band, the third target band is the green light band, and the fourth target band is the blue light band.

5. The image sensor as described in claim 4, characterized in that, The wavelength range of the near-infrared band is 800-1000nm, the wavelength range of the red band is 600-700nm, the wavelength range of the green band is 500-599nm, and the wavelength range of the blue band is 400-499nm.

6. The image sensor as described in claim 2, characterized in that, The material of the selective light-transmitting film is an inorganic material.

7. The image sensor as described in claim 2, characterized in that, The first transparent cover is made of clear glass with a transmittance of 95% or higher.

8. The image sensor as claimed in claim 1, characterized in that, A first light-shielding barrier is provided between the space above the photosensitive area and the space above the non-photosensitive area. The bottom of the first light-shielding barrier is located on the first photosensitive chip, and the top of the first light-shielding barrier is in contact with the light-transmitting cover plate. The first light-shielding barrier is used to prevent light from the non-working area that passes through the light-transmitting cover plate from entering the photosensitive area of ​​the first photosensitive chip.

9. The image sensor as claimed in claim 8, characterized in that, The first light-shielding barrier is made of epoxy resin.

10. The image sensor as claimed in claim 1, characterized in that, A second light-shielding barrier is provided between the spaces above adjacent photosensitive elements. The bottom of the second light-shielding barrier is located on the first photosensitive chip, and the top of the second light-shielding barrier is in contact with the light-transmitting cover plate. The second light-shielding barrier is used to isolate light that passes through two adjacent light-transmitting sub-regions.

11. The image sensor as claimed in claim 10, characterized in that, The material of the second light-shielding barrier is epoxy resin.

12. The image sensor as claimed in claim 1, characterized in that, It also includes a frame, which is located between the first supporting wall and the light-transmitting cover plate, and is used to bond the first supporting wall and the light-transmitting cover plate together.

13. A method for fabricating an image sensor, characterized in that, The method includes: A first photosensitive chip is fabricated; the first photosensitive chip includes a photosensitive area and a non-photosensitive area, the non-photosensitive area surrounding the photosensitive area; the photosensitive area is provided with N photosensitive elements, where N is an integer greater than 1, and the N photosensitive elements are adjacent to each other; the N photosensitive elements are respectively used to sense light of different target wavelength bands; the different target wavelength bands do not overlap with each other; Prepare a first supporting wall; the first supporting wall is located on the non-photosensitive area and surrounds the space above the photosensitive area; Prepare a light-transmitting cover plate; the light-transmitting cover plate includes a working area and a non-working area; the non-working area surrounds the working area, and the working area includes N light-transmitting sub-regions, each of the N light-transmitting sub-regions being used to allow light of different target wavelength bands to pass through only; The light-transmitting cover plate is fixed to the first supporting wall; the light-transmitting cover plate is located on the side of the first supporting wall away from the first photosensitive chip; the projection of the non-working area on the first photosensitive chip is located within the non-photosensitive area, and the projection of the photosensitive area on the light-transmitting cover plate is located within the working area; the positions of the N light-transmitting sub-regions correspond one-to-one with the positions of the N photosensitive elements, and for the corresponding light-transmitting sub-region and the photosensitive element, the projection of the photosensitive element on the light-transmitting cover plate is located within the light-transmitting sub-region.

14. The method for fabricating an image sensor as described in claim 13, characterized in that, The light-transmitting cover plate includes a first transparent cover plate and a selectively light-transmitting film; the first transparent cover plate is located in the working area and the non-working area, and the selectively light-transmitting film is located in the working area; the material of the selectively light-transmitting film is an inorganic material; The selective light-transmitting film includes N light-transmitting sub-films, each located in a different light-transmitting sub-region, and each of the N light-transmitting sub-films is used to allow light of only different target wavelength bands to pass through. The preparation of the light-transmitting cover plate includes: In preparing each of the phototransparent sub-films, a target mask is placed on the first transparent cover plate; the target mask includes a first cutout area, the pattern of the first cutout area is the same as the pattern of the phototransparent sub-film, and the first cutout area is used to expose the phototransparent sub-film; The phototransparent membrane is prepared in the phototransparent region using a deposition process, and the pattern of the phototransparent membrane is the same as the pattern of the first hollowed-out region; or The preparation of the light-transmitting cover plate includes: During the preparation of each of the light-transmitting sub-films, a first photosensitive material layer is formed on the first transparent cover plate; The first photosensitive material layer is exposed and developed using a photolithography machine to obtain a second photosensitive material layer; the second photosensitive material layer includes a second hollow area, and the pattern of the second hollow area is the same as the pattern of the phototransparent sub-area. A first inorganic material layer is prepared, the first inorganic material layer comprising a phototransparent sub-film and an ineffective film layer, the phototransparent sub-film covering the second hollow area, the ineffective film layer covering the second photosensitive material layer; Remove the second photosensitive material layer and the invalid film layer to obtain the light-transmitting sub-film.

15. The method for fabricating an image sensor as described in claim 14, characterized in that, The step of fixing the light-transmitting cover to the first supporting wall includes: A frame is prepared on the side of the first transparent cover plate away from the selective light-transmitting film; The first transparent cover plate is fixed to the first supporting wall by the adhesive frame; the adhesive frame is located between the first supporting wall and the light-transmitting cover plate, and is used to bond the first supporting wall and the light-transmitting cover plate; the first transparent cover plate is located on the side of the first supporting wall away from the first photosensitive chip, and the selective light-transmitting film is located on the side of the first transparent cover plate away from the first photosensitive chip. For the light-transmitting sub-film and the photosensitive element corresponding to the position, the projection of the photosensitive element on the first transparent cover plate is located within the projection of the light-transmitting sub-film on the first transparent cover plate.

16. The method for fabricating an image sensor as described in claim 13, characterized in that, Before fixing the light-transmitting cover to the first supporting wall, the method further includes: A first light-shielding barrier and a second light-shielding barrier are prepared. The first light-shielding barrier is located between the space above the photosensitive area and the space above the non-photosensitive area. The bottom of the first light-shielding barrier is located on the first photosensitive chip, and the top of the first light-shielding barrier is used to contact the light-transmitting cover plate. The first light-shielding barrier is used to prevent light passing through the non-working area of ​​the light-transmitting cover plate from entering the photosensitive area of ​​the first photosensitive chip. The second light-shielding barrier is located between the spaces above adjacent photosensitive elements. The bottom of the second light-shielding barrier is located on the first photosensitive chip, and the top of the second light-shielding barrier is used to contact the light-transmitting cover plate. The second light-shielding barrier is used to isolate light passing through two adjacent light-transmitting sub-regions.

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