Spectrometric imaging chip structure

Abstract

The present application provides a kind of spectral imaging chip structure, which includes pixel photosensitive unit, matching layer, narrow-band filter film, transition layer, first, second and third cut-off filter film, the matching layer is integrally deposited and grown on the pixel photosensitive unit, the narrow-band filter film is integrally deposited and grown on the matching layer, the transition layer is integrally deposited and grown on the narrow-band filter film, the first cut-off filter film is integrally deposited and grown on the transition layer, the transition layer is used to transition narrow-band filter film and the first cut-off filter film, the second cut-off filter film is pasted on the first cut-off filter film, the third cut-off filter film is pasted on the second cut-off filter film, and the matching layer is used to transition the optical admittance between the photosensitive unit and the narrow-band filter film, the transition layer, the first, the second and the third cut-off filter film to improve the central wavelength peak transmittance. The technical scheme of the present application is used to solve the technical problems of low spectral transmittance and low quantum efficiency of the chip structure in the prior art.

Description

Technical Field

[0001] This invention relates to the field of spectral imaging technology, and in particular to a spectral imaging chip structure. Background Technology

[0002] Hyperspectral Imaging (HSI) systems can acquire three-dimensional spectral images with "image-spectrum integration" characteristics, which are composed of two-dimensional spatial image information and one-dimensional spectral information. It can observe both the two-dimensional spatial information and the spectral information of each pixel.

[0003] Spatial information in an image reflects external features such as the size, shape, and defects of the target object, while spectral information reflects the physical and chemical composition of the target object. Therefore, by analyzing and processing spectral information, we can identify the physical and chemical information such as the material, texture, and components of a substance. Furthermore, we can quickly and intuitively identify the relevant location and range through the spatial information of the image.

[0004] In classic HSI systems, since the system is based on a single discrete device, in order to ensure spatial and spectral resolution, optical devices such as objectives, apertures, collimators, and various lenses must be introduced. At the same time, the focusing and collimation problems between various devices must be considered. This results in traditional HSI systems being very complex, large in size, and expensive, which greatly limits their application range.

[0005] Furthermore, in order to filter out the target's characteristic spectral bands and achieve target differentiation, a narrowband filter is integrated onto the spectral imaging chip, which allows for tunable filtering at the center of the desired band (e.g., ...). Figure 6 As shown, the center wavelength of a narrowband filter is tunable within a certain range. However, due to the limitations of existing high and low refractive indices, the spectral bandwidth cannot cover the entire spectrum (e.g., Figure 6 As shown, the cutoff bandwidth is less than 200nm, and there is interference from other band signals, such as... Figure 7 As shown, in addition to the required band, other bands have an impact. An external cutoff filter (such as...) is needed. Figure 8 As shown, this is the cutoff interference band. Existing external cutoff filters, which are deposited separately and then bonded to the image sensor, reduce spectral transmittance, leading to decreased quantum efficiency and affecting imaging performance. Summary of the Invention

[0006] This invention provides a spectral imaging chip structure that can solve the technical problems of low spectral transmittance and low quantum efficiency in existing chip structures.

[0007] This invention provides a spectral imaging chip structure with an integrated cutoff filter film, comprising: a pixel photosensitive unit for image acquisition and data readout; a matching layer integrally deposited on the pixel photosensitive unit; a narrowband filter integrally deposited on the matching layer for tunability at the center wavelength of a desired band; a transition layer integrally deposited on the narrowband filter; and a first cutoff filter integrally deposited on the transition layer for cutting off a first interference band, and the transition layer for transitioning the narrowband filter... The system comprises two film systems: a light-sensitive film and a first cutoff filter film; a second cutoff filter film, which is adhered to the first cutoff filter film and is used to cut off a second interference band, which is different from the first interference band; and a third cutoff filter film, which is adhered to the second cutoff filter film and is used to cut off a third interference band, which is different from both the first and second interference bands. A matching layer is used to transition the optical admittance between the photosensitive unit and the narrowband filter film, the transition layer, the first cutoff filter film, the second cutoff filter film, and the third cutoff filter film to improve the peak transmittance of the center wavelength.

[0008] Furthermore, the film structure of the spectral imaging chip is Sub|HL H(LH)^S12nL(HL)^S1 HL n1(W1)^S2n2(W2)^S3n3(W3)^S4|Air, where HL is the film structure of the matching layer, and H(LH)^S12nL(HL)^S1 H represents the film structure of the narrowband filter, L represents the film structure of the transition layer, n1(W1)^S2 represents the film structure of the first cutoff filter, n2(W2)^S3 represents the film structure of the second cutoff filter, and n3(W3)^S4 represents the film structure of the third cutoff filter. W1, W2, and W3 all include high-refractive-index materials and low-refractive-index materials. H represents high-refractive-index materials, L represents low-refractive-index materials, S1, S2, S3, and S4 represent the number of stacking operations, n represents the film thickness adjustment coefficient of the narrowband filter, n1 represents the film thickness adjustment coefficient of the first cutoff filter, n2 represents the film thickness adjustment coefficient of the second cutoff filter, and n3 represents the film thickness adjustment coefficient of the third cutoff filter.

[0009] Furthermore, in the membrane structure of the first cutoff filter membrane, W1 includes (0.5LH0.5L) or (0.5HL0.5H); in the second cutoff filter membrane, W2 includes (0.5LH0.5L) or (0.5HL0.5H); and in the third cutoff filter membrane, W3 includes (0.5LH0.5L) or (0.5HL0.5H).

[0010] Furthermore, the first cutoff filter film, the second cutoff filter film, and the third cutoff filter film are all prepared by alternating deposition of high refractive index materials and low refractive index materials. The high refractive index materials of the first cutoff filter film, the second cutoff filter film, and the third cutoff filter film all include Ta2O5, Ti3O5, TiO2, Si3N4, or Nb2O5, and the low refractive index materials of the first cutoff filter film, the second cutoff filter film, and the third cutoff filter film all include at least one of SiO2, MgF2, and Al2O3.

[0011] Furthermore, the narrowband filter includes multiple FP cavity structures, all of which are formed in one step using semiconductor technology. Each FP cavity structure includes a first reflector, a light-transmitting layer, and a second reflector stacked sequentially from bottom to top. The multiple FP cavity structures are distributed in a line scan pattern. The light-transmitting layer heights of the multiple FP cavity structures along any column of the narrowband filter are the same, while the light-transmitting layer heights of the multiple FP cavity structures along any row of the narrowband filter are different.

[0012] Furthermore, the spectral imaging chip structure is a line-scanning chip in the range of 400nm to 510nm, and the film system structure of the spectral imaging chip structure is Sub|HL H(LH)^52nL(HL)^5H L 1.28(0.5LH0.5L)^10 1.6(0.5LH0.5L)^10 1.99(0.5LH0.5L)^10|Air, where HL is the film structure of the matching layer, H(LH)^52nL(HL)^5H is the film structure of the narrowband filter, n=0.573-1.344, L is the film structure of the transition layer, 1.28(0.5LH0.5L)^10 is the film structure of the first cutoff filter, 1.6(0.5LH0.5L)^10 is the film structure of the second cutoff filter, and 1.99(0.5LH0.5L)^10 is the film structure of the third cutoff filter; or, the spectral imaging chip structure is a line scan chip in the range of 510nm to 630nm, and the film structure of the spectral imaging chip structure is Sub|HL H(LH)^52nL(HL)^5H L 0.79(0.5HL0.5H)^101.3(0.5LH0.5L)^101.6(0.5LH0.5L)^10|Air, where HL is the film structure of the matching layer, H(LH)^52nL(HL)^5H is the film structure of the narrowband filter, n=0.64-1.336, L is the film structure of the transition layer, 0.79(0.5HL0.5H)^10 is the film structure of the first cutoff filter, 1.3(0.5LH0.5L)^10 is the film structure of the second cutoff filter, and 1.6(0.5LH0.5L)^10 is the film structure of the third cutoff filter.

[0013] Furthermore, the film thickness adjustment coefficient can be obtained according to the following steps: determine the cutoff spectral band of the cutoff filter; calculate the center wavelength of the cutoff spectral band based on the first boundary threshold and the second boundary threshold of the cutoff spectral band; determine the film thickness adjustment coefficient of the cutoff filter based on the center wavelength of the cutoff spectral band and the center wavelength of the narrowband filter.

[0014] Furthermore, the center wavelength of the spectral band to be cut off can be determined according to... To obtain, where λ0 is the center wavelength of the spectral band to be cut off, λ1 is the first boundary threshold of the spectral band to be cut off, and λ2 is the second boundary threshold of the spectral band to be cut off.

[0015] Furthermore, the center wavelength of the spectral band to be cut off can be determined according to... To obtain, where λ0 is the center wavelength of the spectral band to be cut off, λ1 is the first boundary threshold of the spectral band to be cut off, and λ2 is the second boundary threshold of the spectral band to be cut off.

[0016] Furthermore, the film thickness adjustment coefficient n of the cutoff filter film can be based on... To obtain, where λ is the center wavelength of the narrowband filter, and n = n1, n2, or n3.

[0017] The present invention provides a spectral imaging chip structure. This structure integrally deposits a matching layer onto the pixel photosensitive unit, a narrowband filter onto the matching layer, a transition layer onto the narrowband filter, and a first cutoff filter onto the transition layer. There are no gaps between the first cutoff filter, the transition layer, the narrowband filter, the matching layer, and the pixel photosensitive unit, resulting in high spectral transmittance, reduced energy loss, and a single-stage fabrication process that is unaffected by external environmental contamination, offering better robustness, higher fabrication efficiency, and higher integration. Attaching a second cutoff filter onto the first cutoff filter and a third cutoff filter onto the second cutoff filter effectively simplifies the manufacturing process and broadens the cutoff range for interference bands. Furthermore, since the narrowband filter and the cutoff filter have different equivalent refractive indices, direct superposition would affect peak transmittance. By placing a transition layer between the narrowband filter and the cutoff filter, the peak transmittance of the spectral imaging chip structure can be effectively improved. Furthermore, during the growth of the narrowband filter, the refractive index difference between the film material and the pixel photosensitive unit material of the image sensor is significant. Direct growth leads to refractive index mismatch and a decrease in the peak transmittance at the center wavelength, resulting in low quantum efficiency of the spectral imaging system and affecting imaging performance. Therefore, by setting a matching layer between the pixel photosensitive unit and the narrowband filter, the problem of refractive index mismatch and decreased peak transmittance at the center wavelength can be effectively overcome, effectively improving the peak transmittance at the center wavelength of the spectral imaging chip structure. Compared with the existing externally bonded cutoff filter film, the spectral imaging chip structure provided by this invention integrates the first cutoff filter film and the narrowband filter film into the spectral imaging chip structure, and attaches the third cutoff filter film onto the second cutoff filter film, greatly improving quantum efficiency and spectral transmittance. By attaching the second cutoff filter film onto the first cutoff filter film, the processing technology can be effectively simplified, and the cutoff range of the interference band can be widened. The introduction of a transition layer can effectively improve the peak transmittance of the spectral imaging chip structure. The introduction of a matching layer can effectively improve the peak transmittance at the center wavelength of the spectral imaging chip structure. Attached Figure Description

[0018] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0019] Figure 1A partial structural schematic diagram of a spectral imaging chip structure (only one FP cavity structure is shown for the narrowband filter) provided according to a specific embodiment of the present invention is illustrated.

[0020] Figure 2 A schematic diagram of a narrowband filter film plus a first cutoff filter film for a line scan chip in the range of 400nm to 510nm provided according to a specific embodiment of the present invention is shown.

[0021] Figure 3a A schematic diagram of the filtering of the second cutoff filter film of a line scan chip in the range of 400nm to 510nm provided according to a specific embodiment of the present invention is shown;

[0022] Figure 3b A schematic diagram of the filtering of the third cutoff filter film of a line scan chip in the range of 400nm to 510nm provided according to a specific embodiment of the present invention is shown.

[0023] Figure 4 A schematic diagram of a narrowband filter film plus a first cutoff filter film for a line scan chip in the 510nm to 630nm range provided according to a specific embodiment of the present invention is shown.

[0024] Figure 5a A schematic diagram of the filtering of the second cutoff filter film of a line scan chip in the range of 510nm to 630nm provided according to a specific embodiment of the present invention is shown.

[0025] Figure 5b A schematic diagram of the filtering of the third cutoff filter film of a line scan chip in the range of 510nm to 630nm provided according to a specific embodiment of the present invention is shown.

[0026] Figure 6 A schematic diagram of a narrowband filter film provided according to a specific embodiment of the present invention is shown;

[0027] Figure 7 A schematic diagram of a narrowband filter subject to interference from other band signals is shown according to a specific embodiment of the present invention;

[0028] Figure 8 A schematic diagram of a cutoff filter membrane according to a specific embodiment of the present invention is shown;

[0029] Figure 9 A schematic diagram of a narrowband filter film plus a cutoff filter film provided according to a specific embodiment of the present invention is shown;

[0030] Figure 10 The diagram shows the filtering effect of a spectral imaging chip structure without a cutoff filter film in the first comparative example provided by the thirteenth embodiment of the present invention.

[0031] Figure 11 A filtering effect diagram of a spectral imaging chip structure with a cutoff filter film determined according to the film thickness adjustment coefficient determination method of the present invention added in the second comparative example provided by the thirteenth embodiment of the present invention is shown.

[0032] Figure 12 The diagram shows the filtering effect of a spectral imaging chip structure with a randomly determined cutoff filter film added in the third comparative example according to the thirteenth embodiment of the present invention.

[0033] The above figures include the following reference numerals:

[0034] 10. Pixel photosensitive unit; 20. Narrowband filter film; 30. First cutoff filter film; 40. Transition layer; 50. Matching layer; 60. Second cutoff filter film; 70. Third cutoff filter film. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] As a first embodiment of the present invention, such as Figure 1 As shown, a spectral imaging chip structure is provided according to a specific embodiment of the present invention. This spectral imaging chip structure includes a pixel photosensitive unit 10, a narrowband filter 20, a first cutoff filter 30, a transition layer 40, a matching layer 50, a second cutoff filter 60, and a third cutoff filter 70. The pixel photosensitive unit 10 is used for image acquisition and data readout. The matching layer 50 is integrally deposited and grown on the pixel photosensitive unit 10. The narrowband filter 20 is integrally deposited and grown on the matching layer 50, and is used to achieve tunability at the center wavelength of the desired band. The transition layer 40 is integrally deposited and grown on the narrowband filter 20. The first cutoff filter 30 is integrally deposited and grown on the transition layer 40, and is used to cut off... The first interference band is blocked. The transition layer 40 is used to transition between the two film systems, the narrowband filter film 20 and the first cutoff filter film 30. The second cutoff filter film 60 is attached to the first cutoff filter film 30 and is used to block the second interference band, which is different from the first interference band. The third cutoff filter film 70 is attached to the second cutoff filter film 60 and is used to block the third interference band, which is different from both the first and second interference bands. The matching layer 50 is used to transition the optical admittance between the photosensitive unit and the narrowband filter film 20, the transition layer 40, the first cutoff filter film 30, the second cutoff filter film 60, and the third cutoff filter film 70 to improve the peak transmittance of the center wavelength.

[0039] In a first embodiment of the present invention, a spectral imaging chip structure is provided. This structure integrally deposits a matching layer on a pixel photosensitive unit, an integrally deposits a narrowband filter on the matching layer, an integrally deposits a transition layer on the narrowband filter, and an integrally deposits a first cutoff filter on the transition layer. There are no gaps between the first cutoff filter, the transition layer, the narrowband filter, the matching layer, and the pixel photosensitive unit, resulting in high spectral transmittance, reduced energy loss, and a single-stage fabrication process that is unaffected by external environmental contamination, offering better robustness, higher fabrication efficiency, and higher integration. Attaching a second cutoff filter to the first cutoff filter and a third cutoff filter to the second cutoff filter effectively simplifies the manufacturing process and broadens the cutoff range of the interference band. Furthermore, since the narrowband filter and the cutoff filter have different equivalent refractive indices, direct superposition would affect the peak transmittance. By providing a transition layer between the narrowband filter and the cutoff filter, the peak transmittance of the spectral imaging chip structure can be effectively improved. Furthermore, during the growth of the narrowband filter, the refractive index difference between the film material and the pixel photosensitive unit material of the image sensor is significant. Direct growth leads to refractive index mismatch and a decrease in the peak transmittance at the center wavelength, resulting in low quantum efficiency of the spectral imaging system and affecting imaging performance. Therefore, by setting a matching layer between the pixel photosensitive unit and the narrowband filter, the problem of refractive index mismatch and decreased peak transmittance at the center wavelength can be effectively overcome, effectively improving the peak transmittance at the center wavelength of the spectral imaging chip structure. Compared with the existing externally bonded cutoff filter film, the spectral imaging chip structure provided by this invention integrates the first cutoff filter film and the narrowband filter film into the spectral imaging chip structure, greatly improving quantum efficiency and spectral transmittance. By bonding the second cutoff filter film onto the first cutoff filter film and the third cutoff filter film onto the second cutoff filter film, the processing technology can be effectively simplified, and the cutoff range of the interference band can be widened. The introduction of a transition layer can effectively improve the peak transmittance of the spectral imaging chip structure. The introduction of a matching layer can effectively improve the peak transmittance at the center wavelength of the spectral imaging chip structure.

[0040] As a second embodiment of the present invention, a spectral imaging chip structure is provided. This spectral imaging chip structure is based on the first embodiment, but the film structure of the spectral imaging chip structure is further defined. In this second embodiment, the film structure of the spectral imaging chip structure is configured as Sub|HL H(LH)^S12nL(HL)^S1 H Ln1(W1)^S2n2(W2)^S3n3(W3)^S4|Air, where HL is the film structure of the matching layer 50, and H(LH)^S12nL(HL)^S1 H represents the film structure of the narrowband filter 20, L represents the film structure of the transition layer 40, n1(W1)^S2 represents the film structure of the first cutoff filter 30, n2(W2)^S3 represents the film structure of the second cutoff filter 60, and n3(W3)^S4 represents the film structure of the third cutoff filter 70. W1, W2, and W3 all include high-refractive-index materials and low-refractive-index materials. H represents a high-refractive-index material, L represents a low-refractive-index material, S1, S2, S3, and S4 represent the number of stacking operations, n represents the film thickness adjustment coefficient of the narrowband filter 20, n1 represents the film thickness adjustment coefficient of the first cutoff filter 30, n2 represents the film thickness adjustment coefficient of the second cutoff filter 60, and n3 represents the film thickness adjustment coefficient of the third cutoff filter 70. In the second embodiment of the present invention, by configuring the specific model structure of the spectral imaging chip, tunable filtering at the center of the desired wavelength band and prevention of stray light interference can be achieved. In this invention, the film thickness adjustment coefficients n1, n2, and n3 of the cutoff filter film are determined using two methods. The first method involves obtaining them through software simulation. This method uses software to simulate various filter curves and determines the optimal film thickness adjustment coefficients by analyzing the performance differences of the tuned filter curves obtained with different parameters. The second method involves determining the spectral band to be cut off by the cutoff filter film; calculating the center wavelength of the spectral band to be cut off based on the first and second boundary thresholds; and determining the film thickness adjustment coefficients of the cutoff filter film based on the center wavelength of the spectral band to be cut off and the center wavelength of the narrowband filter film. This method uses numerical calculation to obtain the film thickness adjustment coefficients, which is simple and can achieve effective cutoff in a specific band. In practical applications, the appropriate coefficient can be selected according to actual needs.

[0041] As a third embodiment of the present invention, a spectral imaging chip structure is provided, which is the same as the spectral imaging chip structure of the second embodiment. In this spectral imaging chip structure, S1 = 5-7, S2, S3, S4 = 8-13, n1, n2, n3 = 0.5-2.5. Sub represents the substrate Si, Air represents air, H represents high refractive index materials Ta2O5, Ti3O5, TiO2, Si3N4, and Nb2O5; L represents one or a mixture of low refractive index materials SiO2, MgF2, and Al2O3.

[0042] As a fourth embodiment of the present invention, a spectral imaging chip structure is provided, which further defines the cutoff filter film based on the first to fourth embodiments. In this embodiment, the first cutoff filter film is integrally deposited and grown on the narrowband filter film using semiconductor technology. The first cutoff filter film uses a material compatible with semiconductor technology, thereby further improving spectral transmittance and reducing energy loss. In the film system structure of the first cutoff filter film 30, W1 includes (0.5LH0.5L) or (0.5HL0.5H). The second cutoff filter film 60 is attached to the first cutoff filter film 30. In the film system structure of the second cutoff filter film 60, W2 includes (0.5LH0.5L) or (0.5HL0.5H). The third cutoff filter film 70 is attached to the second cutoff filter film 60. In the film system structure of the third cutoff filter film 70, W3 includes (0.5LH0.5L) or (0.5HL0.5H).

[0043] As a fifth embodiment of the present invention, a spectral imaging chip structure is provided, which further defines the cutoff filter film based on the fourth embodiment. The first cutoff filter film 30, the second cutoff filter film 60, and the third cutoff filter film 70 are all prepared by alternating deposition of high-refractive-index and low-refractive-index materials. The high-refractive-index materials of the first cutoff filter film 30, the second cutoff filter film 60, and the third cutoff filter film 70 all include Ta2O5, Ti3O5, TiO2, Si3N4, or Nb2O5, and the low-refractive-index materials of the first cutoff filter film 30, the second cutoff filter film 60, and the third cutoff filter film 70 all include at least one of SiO2, MgF2, and Al2O3. By defining the cutoff filter film, quantum efficiency and spectral transmittance can be greatly improved.

[0044] As a sixth embodiment of the present invention, a spectral imaging chip structure is provided, which further defines the structure of the narrowband filter film based on the first to fifth embodiments. In this embodiment, the narrowband filter film 20 includes multiple FP cavity structures, all of which are formed in one step using semiconductor technology. Each FP cavity structure includes a first reflector, a light-transmitting layer, and a second reflector stacked sequentially from bottom to top. The multiple FP cavity structures are arranged in a line scan pattern. The light-transmitting layer height of the multiple FP cavity structures along any column of the narrowband filter film 20 is the same, while the light-transmitting layer height of the multiple FP cavity structures along any row of the narrowband filter film 20 is different.

[0045] In the sixth embodiment of the present invention, by configuring the structure of the narrowband filter film, the structural complexity of the chip structure can be effectively reduced, the structural volume can be reduced, and the cost can be lowered. The narrowband filter film includes multiple FP cavity structures, and the pixel photosensitive unit includes multiple pixel photosensitive areas. The multiple FP cavity structures are configured one-to-one with the multiple pixel photosensitive areas. Each FP cavity structure includes a first reflector, a light-transmitting layer, and a second reflector stacked sequentially from bottom to top. The multiple FP cavity structures are distributed in a line scan pattern. All multiple FP cavity structures are formed in one step using semiconductor technology. The first reflector, the light-transmitting layer, the second reflector, and the pixel photosensitive areas are all made of semiconductor-compatible materials and are strictly aligned vertically without any post-lamination bonding. This method utilizes advanced semiconductor (CMOS) process technology to directly fabricate the traditional spectral splitting system onto the pixel photosensitive units of the photoelectric sensor. Due to the close connection, stray light is reduced, and photon utilization is improved, thus achieving a speed of hundreds of frames per second and realizing spectral video functionality. Its size and weight are no different from ordinary RGB chips, enabling an imaging system the size of a finger. CMOS technology brings unparalleled integration to the spectral imaging chip structure, allowing for highly integrated connections with any circuit, such as embedding it in a mobile phone.

[0046] As a seventh embodiment of the present invention, a spectral imaging chip structure is provided. This integrated growth cutoff filter film is based on the first to sixth embodiments, with further definition of the first and second reflectors. In this embodiment, the first reflector is an upper reflector, and the second reflector is a lower reflector. The upper reflector is fabricated by alternating layers of high-reflectivity and low-reflectivity materials to form a Bragg reflector, which overlaps multiple times, achieving a reflectivity of over 99%, serving as the cavity mirror of the FP cavity structure. The lower reflector has the same structure and materials as the upper reflector and is located between the light-transmitting layer and the pixel photosensitive area, also exhibiting high reflectivity.

[0047] As an eighth embodiment of the present invention, a spectral imaging chip structure is provided. This spectral imaging chip structure is based on the first to eighth embodiments, but specifies a chip structure within a specific wavelength range of 400–510 nm. The spectral imaging chip structure is a line-scan chip within the 400–510 nm range. Figure 2 A schematic diagram of a narrowband filter film plus a first cutoff filter film is shown. Figure 3a A schematic diagram of the second cutoff filter membrane is shown. Figure 3bA schematic diagram of the third cutoff filter film is shown. In this embodiment, the spectral imaging chip structure is a line scan chip in the range of 400nm to 510nm. The film system structure of the spectral imaging chip structure is Sub|HL H(LH)^5 2nL(HL)^5H L 1.28(0.5LH0.5L)^10 1.6(0.5LH0.5L)^101.99(0.5LH0.5L)^10|Air, where HL is the film system structure of the matching layer, H(LH)^52nL(HL)^5H is the film system structure of the narrowband filter film 20, L is the film system structure of the transition layer 40, 1.28(0.5LH 0.5L)^10 is the film system structure of the first cutoff filter film 30, 1.6(0.5LH 0.5L)^10 is the film system structure of the second cutoff filter film 60, and 1.99(0.5LH 0.5L)^10 is the film system structure of the second cutoff filter film 60. 0.5L)^10 represents the film structure of the third cutoff filter film 70. The center wavelength of this spectral imaging chip structure is 460 nm, n = 0.573-1.344, the narrowband spacer layer thickness is 90 nm-211 nm, and the narrowband peak value is tunable within the range of 407 nm-507 nm. In this embodiment, the film thickness adjustment coefficient of the cutoff filter film is obtained through software simulation. Alternatively, as another embodiment of the present invention, the film thickness adjustment coefficient of the cutoff filter film can also be determined based on the center wavelength of the spectral band to be cut off and the center wavelength of the narrowband filter film. This is not limited here, and other methods can also be used to determine the film thickness adjustment coefficient of the cutoff filter film.

[0048] As a ninth embodiment of the present invention, a spectral imaging chip structure is provided. This spectral imaging chip structure is based on the first to sixth embodiments, but specifies a chip structure within a specific wavelength range of 510nm to 630nm. The spectral imaging chip structure is a line-scan chip within the 510nm to 630nm range. Figure 4 A schematic diagram of a narrowband filter film plus a first cutoff filter film is shown. Figure 5a A schematic diagram of the second cutoff filter membrane is shown. Figure 5bA schematic diagram of the third cutoff filter membrane is shown. In this embodiment, the spectral imaging chip structure is a line scan chip in the range of 510nm to 630nm. The film structure of the spectral imaging chip structure is Sub|HL H(LH)^5 2nL(HL)^5H L 0.79(0.5HL0.5H)^101.3(0.5LH0.5L)^101.6(0.5LH0.5L)^10|Air, where HL is the film structure of the matching layer, H(LH)^52nL(HL)^5H is the film structure of the narrowband filter 20, L is the film structure of the transition layer 40, 0.79(0.5HL0.5H)^10 is the film structure of the first cutoff filter 30, 1.3(0.5LH0.5L)^10 is the film structure of the second cutoff filter 60, and 1.6(0.5LH0.5L)^10 is the film structure of the third cutoff filter 70. The center wavelength of this spectral imaging chip structure is 570 nm, n = 0.64-1.336, the narrowband spacer layer thickness is 125 nm-261 nm, and the narrowband peak value is tunable within the range of 513 nm-622 nm. In this embodiment, the film thickness adjustment coefficient of the cutoff filter film is obtained by software simulation. Alternatively, as another embodiment of the present invention, the film thickness adjustment coefficient of the cutoff filter film can also be determined based on the center wavelength of the spectral band to be cut off and the center wavelength of the narrowband filter film. This is not limited here, and other methods can also be used to determine the film thickness adjustment coefficient of the cutoff filter film.

[0049] As a tenth embodiment of the present invention, a spectral imaging chip structure is provided, which further defines the film thickness adjustment coefficient of the cutoff filter film based on the above embodiments. This embodiment describes in detail a second method for obtaining the film thickness adjustment coefficient of the cutoff filter film. In this embodiment, the film thickness adjustment coefficient can be obtained according to the following steps: determining the spectral band to be cut off by the cutoff filter film; calculating the center wavelength of the spectral band to be cut off based on a first boundary threshold and a second boundary threshold; and determining the film thickness adjustment coefficient of the cutoff filter film based on the center wavelength of the spectral band to be cut off and the center wavelength of the narrowband filter film.

[0050] In the tenth embodiment of the present invention, by optimizing the design of the cutoff filter film, that is, by designing the film thickness adjustment coefficient of the cutoff filter film, specifically by calculating the center wavelength of the spectral band to be cut off based on the first boundary threshold and the second boundary threshold, the film thickness adjustment coefficient of the cutoff filter film is determined by the center wavelength of the spectral band to be cut off and the center wavelength of the narrowband filter film. In this way, when the cutoff filter film with the film thickness adjustment coefficient is integrally deposited on the narrowband filter film, the leakage light outside the free spectrum range can be greatly suppressed, the interference band can be cut off, the side mode suppression ratio of the spectral filter is greatly improved, and the spectral imaging performance of the spectral imaging chip structure is improved.

[0051] As an eleventh embodiment of the present invention, a spectral imaging chip structure is provided, which, based on the above embodiments, defines the center wavelength of the spectral band to be cut off. In this embodiment, the center wavelength of the spectral band to be cut off can be determined according to... To obtain; or, the center wavelength of the spectral band to be cut off can be obtained according to The above describes two methods for obtaining the center wavelength of the spectral band to be cut off, where λ0 is the center wavelength, λ1 is the first boundary threshold of the spectral band to be cut off, and λ2 is the second boundary threshold of the spectral band to be cut off. This method obtains the center wavelength of the spectral band to be cut off, resulting in higher calculation accuracy and better assurance of suppressing light leakage outside the free spectral range (compared to the formula). (Obtain the center wavelength of the spectral band to be cut off).

[0052] As a twelfth embodiment of the present invention, a spectral imaging chip structure is provided, which, based on the above embodiments, limits the film thickness adjustment coefficient of the cutoff filter film. In this embodiment, the film thickness adjustment coefficient n of the cutoff filter film can be determined according to... The wavelength λ is obtained by using the method described above, where λ is the center wavelength of the narrowband filter, and n = n1, n2, or n3. This method of determining the film thickness adjustment coefficient of the cutoff filter film can significantly suppress light leakage outside the free spectral range, effectively cut off interference bands, greatly improve the side-mode suppression ratio of the spectral filter, and enhance the spectral imaging performance of the spectral imaging chip structure.

[0053] As a thirteenth embodiment of the present invention, a spectral imaging chip structure is provided. This spectral imaging chip structure, based on the foregoing embodiments, illustrates the role of the film thickness adjustment coefficient determination method in suppressing light leakage. Taking λ as a center wavelength of 600nm as an example, the first comparative example is without adding a cutoff filter film, and the filtering effect is as follows. Figure 10As shown, narrowband filtering was only achieved in the 530nm–696nm range, while severe light leakage occurred in the 400nm–520nm and 700nm–1000nm spectral bands. This is a very serious light leakage problem for SI-based detectors responding to the 400nm–1000nm spectral range, and these two spectral bands need to be suppressed.

[0054] In the second comparative example of the thirteenth embodiment, based on the leakage spectral ranges of 400nm–520nm and 700nm–1000nm, a first cutoff filter film is integrally deposited on the narrow-band filter film. A second cutoff filter film is then bonded onto the first cutoff filter film, and a third cutoff filter film is bonded onto the second cutoff filter film. The first cutoff filter film is used to suppress leakage light in the 400nm–520nm range, with a center wavelength of [missing information]. The center wavelength is determined to be 452nm; the corresponding film thickness adjustment coefficient α1 is 452nm / 600nm = 0.75; similarly, the second cutoff filter film suppresses light leakage in the 700nm–780nm range, with a center wavelength of... The center wavelength was determined to be 738 nm; the corresponding film thickness adjustment coefficient α2 was 738 nm / 600 nm = 1.23; the third cutoff filter film suppressed light leakage in the 780–1000 nm range, with a center wavelength of... The center wavelength was determined to be 876nm; the corresponding film thickness adjustment factor α3 was 876nm / 600nm = 1.46.

[0055] In the third comparative example, the only difference from the second comparative example is that the coefficients α1, α2 and α3 are taken as 0.7, 1.1 and 1.4 respectively. These coefficients are randomly obtained, that is, the film thickness adjustment coefficients are not determined according to the method of the embodiments of the present invention.

[0056] Figure 11 The filtering effect diagram of the spectral imaging chip structure provided for the second comparative example. Figure 12 The filtering effect diagram of the spectral imaging chip structure provided for the third comparative example shows that the cutoff filter film, with the film thickness adjustment coefficient determined according to the embodiment of the present invention, can greatly suppress light leakage outside the free spectral range. Conversely, if the film thickness adjustment coefficient is not determined according to the method of the embodiment of the present invention, even if a cutoff filter film is added and the coefficient difference is very small, it is difficult to effectively suppress light leakage outside the free spectral range, or even solve the light leakage problem.

[0057] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0058] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A spectral imaging chip structure, characterized by, The spectral imaging chip structure of the integrated growth cutoff filter film includes: A pixel photosensitive unit (10) is used to realize image acquisition and data readout; A matching layer (50) is integrally deposited and grown on the pixel photosensitive unit (10); Narrowband filter (20), which is integrally deposited and grown on the matching layer (50), is used to achieve tunability at the center wavelength of the desired band; A transition layer (40) is integrally deposited and grown on the narrow band filter film (20); The first cutoff filter film (30) is integrally deposited and grown on the transition layer (40). The first cutoff filter film (30) is used to cut off the first interference band. The transition layer (40) is used to transition between the two film systems, the narrowband filter film (20) and the first cutoff filter film (30). The second cutoff filter film (60) is attached to the first cutoff filter film (30). The second cutoff filter film (60) is used to cut off the second interference band, which is different from the first interference band. The third cutoff filter film (70) is attached to the second cutoff filter film (60). The third cutoff filter film (70) is used to cut off the third interference band, which is different from the first interference band and the second interference band. The matching layer (50) is used to transition the optical admittance between the photosensitive unit (10) and the narrowband filter film (20), the transition layer (40), the first cutoff filter film (30), the second cutoff filter film (60) and the third cutoff filter film (70) to improve the peak transmittance of the center wavelength. The film system structure of the spectral imaging chip structure is Sub|HL H(LH)^S12nL(HL)^S1 HL n1(W1)^S2n2(W2)^S3n3(W3)^S4|Air, where HL is the film system structure of the matching layer (50) and H(LH)^S12nL(HL)^S1 H represents the film structure of the narrowband filter (20), L represents the film structure of the transition layer (40), n1(W1)^S2 represents the film structure of the first cutoff filter (30), n2(W2)^S3 represents the film structure of the second cutoff filter (60), and n3(W3)^S4 represents the film structure of the third cutoff filter (70). W1, W2, and W3 all include high-refractive-index materials and low-refractive-index materials. H represents a high-refractive-index material, L represents a low-refractive-index material, and S1 represents a low-refractive-index material. S2, S3, and S4 represent the number of stacking operations; n is the film thickness adjustment coefficient of the narrowband filter film (20); n1 is the film thickness adjustment coefficient of the first cutoff filter film (30); n2 is the film thickness adjustment coefficient of the second cutoff filter film (60); and n3 is the film thickness adjustment coefficient of the third cutoff filter film (70). The spectral imaging chip structure is a line scan chip in the range of 400nm to 510nm. The film system structure of the spectral imaging chip structure is Sub|HL H(LH)^5 2nL(HL)^5H L 1.28(0.5LH0.5L)^10 1.6(0.5LH0.5L)^10 1.99(0.5LH0.5L)^10|Air, where HL is the film system structure of the matching layer (50). H(LH)^5 2nL (HL)^5 H is the film structure of the narrowband filter film (20), n=0.573-1.344, L is the film structure of the transition layer (40), 1.28(0.5LH0.5L)^10 is the film structure of the first cutoff filter film (30), 1.6(0.5LH0.5L)^10 is the film structure of the second cutoff filter film (60), and 1.99(0.5 LH 0.5L)^10 is the film structure of the third cutoff filter film (70); or, the spectral imaging chip structure is a line scan chip in the range of 510nm to 630nm, and the film structure of the spectral imaging chip structure is Sub|HL H(LH)^5 2nL (HL)^5 HL 0.79(0.5HL0.5H)^10 1.3(0.5LH0.5L)^10 1.6(0.5LH0.5L)^10|Air, where HL is the membrane structure of the matching layer (50), H(LH)^5 2nL (HL)^5 H is the film structure of the narrowband filter (20), n=0.64-1.336, L is the film structure of the transition layer (40), 0.79(0.5HL0.5H)^10 is the film structure of the first cutoff filter (30), 1.3(0.5LH0.5L)^10 is the film structure of the second cutoff filter (60), and 1.6(0.5LH0.5L)^10 is the film structure of the third cutoff filter (70). The film thickness adjustment coefficient can be obtained according to the following steps: determine the cutoff spectral band of the cutoff filter; calculate the center wavelength of the cutoff spectral band according to the first boundary threshold and the second boundary threshold of the cutoff spectral band; determine the film thickness adjustment coefficient of the cutoff filter according to the center wavelength of the cutoff spectral band and the center wavelength of the narrowband filter. The center wavelength of the cutoff spectral band can be obtained according to the following steps: determine the cutoff spectral band of the cutoff filter; calculate the center wavelength of the cutoff spectral band according to the first boundary threshold and the second boundary threshold of the cutoff spectral band; determine the film thickness adjustment coefficient of the cutoff filter according to the center wavelength of the cutoff spectral band and the center wavelength of the narrowband filter. To obtain, among which, The center wavelength of the spectral band to be cut off. The first boundary threshold of the spectral band to be cut off. The second boundary threshold of the spectral band to be cut off; or the center wavelength of the spectral band to be cut off can be determined according to... To obtain, among which, The center wavelength of the spectral band to be cut off. The first boundary threshold of the spectral band to be cut off. The second boundary threshold of the spectral band to be cut off; the film thickness adjustment coefficient n of the cutoff filter film can be based on To obtain, among which, The center wavelength of the narrowband filter film. In the film system structure of the first cut-off filter film (30), W1 includes (0.5LH0.5L) or (0.5HL0.5H); in the second cut-off filter film (60), W2 includes (0.5LH0.5L) or (0.5HL0.5H); in the third cut-off filter film (70), W3 includes (0.5LH0.5L) or (0.5HL0.5H).

2. The spectral imaging chip structure according to claim 1, characterized in that, The first cutoff filter film (30), the second cutoff filter film (60), and the third cutoff filter film (70) are all prepared by alternating deposition of high-refractive-index materials and low-refractive-index materials. The high-refractive-index materials of the first cutoff filter film (30), the second cutoff filter film (60), and the third cutoff filter film (70) all include Ta2O5, Ti3O5, TiO2, Si3N4, or Nb2O5. The low-refractive-index materials of the first cutoff filter film (30), the second cutoff filter film (60), and the third cutoff filter film (70) all include at least one of SiO2, MgF2, and Al2O3.

3. The spectral imaging chip structure according to any one of claims 1 to 2, characterized in that, The narrowband filter (20) includes multiple FP cavity structures, each of which is formed in one step using semiconductor technology. Each FP cavity structure includes a first reflector, a light-transmitting layer, and a second reflector stacked sequentially from bottom to top. The multiple FP cavity structures are arranged in a line scan pattern. The light-transmitting layer height of the multiple FP cavity structures along any column of the narrowband filter (20) is the same, while the light-transmitting layer height of the multiple FP cavity structures along any row of the narrowband filter (20) is different.

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