Spectrometric imaging chip structure

Abstract

The present application provides a kind of spectral imaging chip structure, which includes pixel photosensitive unit, narrowband filter film, cut-off filter film and first matching layer, pixel photosensitive unit is used to realize image acquisition and data readout, first matching layer is integrally deposited and grown on pixel photosensitive unit, narrowband filter film is integrally deposited and grown on first matching layer, narrowband filter film is used to realize the tunable of the center wavelength in the required waveband, and first matching layer is used to transition the optical admittance between narrowband filter film and pixel photosensitive unit to improve the center wavelength peak transmittance. The technical scheme of the present application is used to solve the technical problems of low center wavelength transmittance and low quantum efficiency of the chip structure in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of spectral imaging technology, and particularly relates to a spectral imaging chip structure. BACKGROUND

[0002] Hyper Spectral Imaging (HSI) can obtain a three-dimensional spectral image with the characteristics of "integration of image and spectrum", which is composed of two-dimensional spatial image information and one-dimensional spectral information. It can not only observe the spatial information of two-dimensional distribution, but also observe the spectral information of each pixel point.

[0003] The image spatial information reflects the external characteristics of the target object such as size, shape and defects, and the spectral information can reflect the physical and chemical composition of the target object. Therefore, the physical and chemical information such as material, material and composition can be identified by analyzing and processing the spectral information, and the relevant position and range can be quickly and intuitively identified through the image spatial information.

[0004] In the classical HSI system, since the system is based on a single discrete device, in order to ensure the spatial resolution and spectral resolution, optical devices such as objective lens, diaphragm, collimator and various lenses must be introduced, and the focusing and collimation problems between various devices must be considered, which leads to high complexity, large volume and high cost of the traditional HSI system, and the application range is greatly limited.

[0005] In the prior art, in order to realize the lightness and miniaturization of the spectral imaging system, a FP structure narrow band filter film is integrally grown on the image sensor. In the growth process, the refractive index difference between the film layer material and the image sensor material is large, and direct growth will lead to refractive index mismatch, center wavelength peak transmittance drop, which will lead to low quantum efficiency of the spectral imaging system and affect the imaging effect. SUMMARY

[0006] The present application provides a spectral imaging chip structure, which can solve the technical problems of low center wavelength peak transmittance and low quantum efficiency of the chip structure in the prior art.

[0007] According to one aspect of the present application, a spectral imaging chip structure integrally grown with a cutoff filter film is provided, which includes: a pixel photosensitive unit, the pixel photosensitive unit is used for realizing image acquisition and data readout; a first matching layer, the matching layer is integrally deposited and grown on the pixel photosensitive unit; a narrow band filter film, the narrow band filter film is integrally deposited and grown on the first matching layer, and the narrow band filter film is used for realizing tunable at the center wavelength of the required waveband, and the first matching layer is used for transitioning the optical admittance between the narrow band filter film and the pixel photosensitive unit to improve the center wavelength peak transmittance.

[0008] Further, the spectral imaging chip structure further comprises a second matching layer, the second matching layer is integrally deposited and grown on the narrow-band filter film, and the second matching layer is used to improve the central wavelength transmittance of the spectral imaging chip structure.

[0009] Further, the film system structure of the spectral imaging chip structure is Sub|Q1(HL)^S1 H 2nL H(LH)^S2|Air, wherein Q1 is the film system structure of the first matching layer, (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band filter film, n is the film layer thickness adjustment coefficient of the narrow-band filter film, H is a high refractive index material, L is a low refractive index material, and S1 and S2 are both superposition numbers.

[0010] Further, in the film system structure of the first matching layer, Q1 comprises L or HL.

[0011] Further, the film system structure of the spectral imaging chip structure is Sub|Q1(HL)^S1 H 2nL H(LH)^S2Q2|Air, wherein Q1 is the film system structure of the first matching layer, (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band filter film, n is the film layer thickness adjustment coefficient of the narrow-band filter film, Q2 is the film system structure of the second matching layer, H is a high refractive index material, L is a low refractive index material, and S1 and S2 are both superposition numbers.

[0012] Further, in the film system structure of the first matching layer, Q1 comprises HL or LHL; in the film system structure of the second matching layer, Q2 comprises LH or LHL, when Q1 is HL, Q2 is LHL; when Q1 is LHL, Q2 is LH.

[0013] Further, the narrow-band filter film comprises a plurality of FP cavity structures, the plurality of FP cavity structures are formed by a semiconductor process at one time, any FP cavity structure comprises a first reflector, a light transmission layer and a second reflector which are stacked from bottom to top, the plurality of FP cavity structures are distributed in a mosaic manner, the light transmission layer heights of the plurality of FP cavity structures along any one column of the narrow-band filter film are all different, and the light transmission layer heights of the plurality of FP cavity structures along any one row of the narrow-band filter film are all different; or the plurality of FP cavity structures are distributed in a line scanning manner, the light transmission layer heights of the plurality of FP cavity structures along any one column of the narrow-band filter film are all same, and the light transmission layer heights of the plurality of FP cavity structures along any one row of the narrow-band filter film are all different.

[0014] Further, the half-wave width of the spectral imaging chip structure can be obtained according to , wherein λ is the central wavelength, x represents the total number of high refractive index layers of the multilayer reflection film, m represents the interference order, n H is the refractive index of the high refractive index material, and n L is the refractive index of the low refractive index material.

[0015] Further, the half-wave width of the spectral imaging chip structure can be obtained according to wherein λ is the center wavelength, m represents the interference order, n H is the refractive index of the high refractive material, and n L is the refractive index of the low refractive material.

[0016] According to another aspect of the present application, a spectral imaging chip structure is provided, comprising: a pixel photosensitive unit for realizing image acquisition and data readout; a narrow-band filter film integrally deposited and grown on the pixel photosensitive unit, the narrow-band filter film being used for realizing tunable center wavelength in a required waveband; and a third matching layer integrally deposited and grown on the narrow-band filter film, the third matching layer being used for improving the center wavelength transmittance of the spectral imaging chip structure.

[0017] Further, the film system structure of the spectral imaging chip structure is Sub|(HL)^S1 H 2nL H(LH)^S2 Q3|Air, wherein (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band filter film, n is the film layer thickness adjustment coefficient of the narrow-band filter film, Q3 is the film system structure of the third matching layer, H is a high refractive material, L is a low refractive material, and S1 and S2 are both superposition numbers.

[0018] Further, the half-wave width of the spectral imaging chip structure can be obtained according to wherein λ is the center wavelength, x represents the total number of high refractive layers of the multilayer reflective film, m represents the interference order, n H is the refractive index of the high refractive material, and n L is the refractive index of the low refractive material.

[0019] The technical scheme of the present application provides a spectral imaging chip structure, which is integrally formed by integrally depositing a matching layer on a pixel photosensitive unit and integrally depositing a narrow-band light filter film on the matching layer, and has no gap among the narrow-band light filter film, the matching layer and the pixel photosensitive unit, so that the spectral transmittance is high, the energy loss is reduced, the preparation process is integrally formed at one time, the external environment pollution is avoided, the firmness is better, and the preparation efficiency and the integration degree are higher. In the present application, because the refractive index difference between the film layer material and the pixel photosensitive unit material of the image sensor is large during the growth of the narrow-band light filter film, direct growth will cause the refractive index mismatch, the central wavelength peak transmittance will decrease, the quantum efficiency of the spectral imaging system will be low, and the imaging effect will be affected. Therefore, by arranging the matching layer between the pixel photosensitive unit and the narrow-band light filter film, the problem of refractive index mismatch and central wavelength peak transmittance decrease can be effectively overcome, the central wavelength peak transmittance of the spectral imaging chip structure can be effectively improved, the transmittance can be increased while the bandwidth is reduced, more spectral bands can be prepared within the fixed cutoff range, more spectral lines can be obtained, the adjacent spectral band overlap is less, and the data processing is better distinguished. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings included to provide a further understanding of the embodiments of the present application, constitute a part of the specification and illustrate the embodiments of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 A partial structure schematic diagram of a spectral imaging chip structure (a narrow-band light filter film is only shown as an FP cavity structure) provided according to a specific embodiment of the present application is shown;

[0022] Figure 2 Central wavelength peak transmittance schematic diagrams of a matching layer and a non-matching layer provided according to a specific embodiment of the present application are shown;

[0023] Figure 3 Central wavelength peak transmittance schematic diagrams of a non-matching layer, a substrate side matching layer and an air side matching layer provided according to a specific embodiment of the present application are shown;

[0024] Figure 4 Central wavelength peak transmittance schematic diagrams of a non-matching layer, an L matching layer and an HL matching layer provided according to a specific embodiment of the present application are shown.

[0025] Among the above drawings, the following reference signs are included:

[0026] 10, pixel photosensitive unit; 20, narrow-band light filter film; 50, first matching layer. DETAILED DESCRIPTION

[0027] It should be noted that the embodiments and features of the present application can be combined with each other, as long as there is no conflict. The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0028] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0029] Unless specifically stated otherwise, the relative arrangements of the components and steps illustrated in these embodiments and the numerical expressions and values set forth herein are not limiting. It should be understood that the various parts of the drawings are not necessarily drawn to scale, and that, for the purpose of convenience and clarity, not all components and steps can be shown in the drawings. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the description of the present application. In all examples shown and discussed herein, any specific value should be interpreted as merely an example, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values. It should be noted that like reference numerals and letters refer to like items in the following drawings, and thus, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0030] As a first embodiment of the present application, as Figure 1 and Figure 2As shown, the specific embodiment according to the present application provides a spectral imaging chip structure, which includes a pixel photosensitive unit 10, a narrow-band light filtering film 20 and a first matching layer 50, the pixel photosensitive unit 10 is used for image acquisition and data readout, the first matching layer 50 is integrally deposited and grown on the pixel photosensitive unit 10, the narrow-band light filtering film 20 is integrally deposited and grown on the first matching layer 50, the narrow-band light filtering film 20 is used for tunable center wavelength in the required waveband, and the first matching layer is used for transition of optical admittance between the narrow-band light filtering film 20 and the pixel photosensitive unit 10 to improve the center wavelength peak transmittance.

[0031] In the first embodiment of the present application, the spectral imaging chip structure is integrally formed by integrally depositing the first matching layer on the pixel photosensitive unit, and integrally depositing and growing the narrow-band light filtering film on the first matching layer, there is no gap between the narrow-band light filtering film, the first matching layer and the pixel photosensitive unit, the spectral transmittance is high, the energy loss is reduced, the one-time preparation process is integrally formed, is not polluted by the external environment, has better firmness, and has higher preparation efficiency and integration. In the present application, since the refractive index difference between the film layer material and the pixel photosensitive unit material of the image sensor is large during the growth of the narrow-band light filtering film, direct growth will cause refractive index mismatch and center wavelength peak transmittance drop, which will cause low quantum efficiency of the spectral imaging system and affect the imaging effect. Therefore, by arranging the matching layer between the pixel photosensitive unit and the narrow-band light filtering film, the problem of refractive index mismatch and center wavelength peak transmittance drop can be effectively overcome, the center wavelength peak transmittance of the spectral imaging chip structure is effectively improved, the transmittance is increased while the bandwidth is reduced, more spectral bands can be prepared within the fixed cutoff range, more spectral lines can be obtained, the adjacent spectral band overlap is less, and the data processing is better distinguished.

[0032] As a second embodiment of the present application, a spectral imaging chip structure is provided, which is further limited to the film system structure of the spectral imaging chip structure on the basis of the first embodiment. In the second embodiment, the film system structure of the spectral imaging chip structure is configured as Sub|Q1(HL)^S1 H 2nL H(LH)^S2|Air, wherein Q1 is the film system structure of the first matching layer 50, (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band light filtering film 20, n is the film layer thickness adjustment coefficient of the narrow-band light filtering film 20, H is a high refractive index material, L is a low refractive index material, and S1 and S2 are both superposition times. In the second embodiment of the present application, by configuring the specific model structure of the spectral imaging chip structure, tunable center filtering in the required waveband and improved center wavelength peak transmittance can be realized.

[0033] As a third embodiment of the present invention, a spectral imaging chip structure is provided, which further defines the film structure of the first matching layer based on the first embodiment. In this third embodiment, the film structure Q1 of the first matching layer 50 includes L or HL, where H represents a high refractive index material and L represents a low refractive index material.

[0034] Specifically, in this third embodiment, any spectral imaging chip structure can be represented by an equivalent interface, whose reflection, transmission, and phase characteristics are determined by the combined admittance of the incident medium and the equivalent interface. Essentially, the effect of any thin film layer can be viewed as altering the admittance of the equivalent interface, thereby changing the optical properties of the thin film system. Optical admittance is the ratio of electric field strength to magnetic field strength; in the optical band, optical admittance is numerically equal to the refractive index.

[0035] On the substrate (refractive index n) s When the beam has only one thin film (i.e., any H or L, a single-layer thin film), its characteristic matrix is ​​as follows when the beam is incident perpendicularly from air (n0 = 1):

[0036]

[0037] The above formula contains all the useful parameters of the thin film, where, B is the electric field strength, C is the magnetic field strength, δ1 is the phase thickness of the first thin film, n1 is the refractive index of the first thin film, d1 is the film thickness of the first thin film, λ is the center wavelength, θ1 is the incident angle of the first thin film, η1 is the tilt optical admittance of the first thin film, and η s The tilted optical admittance is the base, and i is a complex number.

[0038] Depend on From the expression of the matrix, we can see that when the effective optical thickness of the thin film is an integer multiple of 1 / 4 wavelength, that is...

[0039]

[0040] Where n is the refractive index, d is the film thickness, and θ is the incident angle.

[0041] or its phase thickness is Integer multiples of, i.e.

[0042]

[0043] Where δ is the phase thickness of the film;

[0044] The characteristic matrix of the thin film is

[0045]

[0046]

[0047] R = [(η0-η s ) / (η0+η s )] 2

[0048] where Y represents optical admittance, R is reflectivity, η0is optical admittance at the center wavelength λ, and the characteristic matrix of the thin film is a unit matrix, which has no effect on the reflection or transmission characteristics of the film system at the reference wavelength λ. This thin film is called a dummy layer.

[0049] Taking the currently designed spectral imaging chip structure as an example, the narrow-band filter film corresponds to a dummy layer, which does not affect the spectral transmittance. The film system structure is

[0050] Sub|(HL)^3H 2nL H(LH)^3|Air

[0051] At the center wavelength λ, the middle cavity layer is an even multiple of λ / 4, which has no effect on the transmittance at the center wavelength and can be removed. In the remaining structure, the two adjacent high refractive index film layers form a λ / 2 layer, which can also be removed. In this way, all the film layers are removed, and finally become a structure of Sub|Air.

[0052] Due to the difference between the substrate refractive index and the air refractive index, there is a residual reflectivity at the center wavelength. The transmittance at the center wavelength can be improved by adding a matching layer. The concept of dummy layer is introduced, and the design problem of matching layer is converted into the design of antireflection film related to the substrate. For Sub|Air, a thick low refractive index layer can be added near the substrate side or the air side to act as a matching layer.

[0053] For the case of low refractive index spacer layer (i.e. 2nL), the half-wave width is represented by the following formula,

[0054]

[0055] where x represents the total number of high refractive index layers of the multilayer reflective film, and when there is no matching layer, the multilayer reflective film refers to the upper Bragg mirror; when there is a matching layer, it refers to the multilayer film before the 2L spacer layer, including the high refractive index layers in the spacer layer. When the film system structure is Sub|(HL)^3H 2L H(LH)^3|Air, X = 4, and when the film system structure is Sub|HL(HL)^3H 2L H(LH)^3LHL|Air, X = 5, m represents the interference order, n H is the refractive index of the high refractive index material, and n L is the refractive index of the low refractive index material.

[0056] According to formula (1), the half-wave width of the film system before adding the matching layer is

[0057]

[0058] The half-wave width of the film system after adding a low-refractive matching layer on the substrate side is

[0059]

[0060] According to the half-wave width after adding the matching layer on the substrate side, the addition of the matching layer improves the transmittance of the filter while changing the half-wave width, and the change of the half-wave width affects the resolution. Adding the matching layer on the side close to the substrate can improve the transmittance of the filter while reducing the half-wave width. The reduction of the half-wave width can produce more spectral bands in a limited stop range, reduce the overlapping range of adjacent spectral bands, and better identify the characteristics of different spectral bands. However, too narrow half-wave width is not conducive to signal recognition, so the half-wave width can be adjusted according to the actual number of spectral bands and the signal recognition rate requirement.

[0061] As a fourth embodiment of the present application, a spectral imaging chip structure is provided, which is the same as the spectral imaging chip structure of the second embodiment. In the spectral imaging chip structure, Sub is a substrate Si, Air is air, H represents one of high-refractive materials Ta2O5, Ti3O5, TiO2, Si3N4, and Nb2O5, and L represents one of low-refractive materials SiO2, MgF2, and Al2O3 or a mixture thereof.

[0062] As a fifth embodiment of the present application, a spectral imaging chip structure is provided, which is based on the spectral imaging chip structure provided in the first embodiment and introduces a second matching layer. The second matching layer is integrally deposited and grown on the narrow-band filter film 20, and the second matching layer is used to improve the central wavelength peak transmittance of the spectral imaging chip structure. In this fifth embodiment, a first matching layer is arranged on the substrate side and a second matching layer is arranged on the air side, and the addition of the first matching layer and the second matching layer improves the transmittance of the filter while changing the half-wave width. As shown in Figure 3 , the matching layer added on the substrate side can reduce the half-wave width, and the matching layer added on the air side can increase the half-wave width. In order to make the bandwidth with the matching layer close to the bandwidth without the matching layer, the matching layer can be added on the substrate side and the air side at the same time, so as to ensure that the half-wave width does not change.

[0063] As a sixth embodiment of the present application, a spectral imaging chip structure is provided, which is based on the fifth embodiment and further defines the film stack structure of the spectral imaging chip structure. In this embodiment, the film stack structure is Sub|Q1(HL)^S1H 2nL H(LH)^S2Q2|Air, where Q1 is the film stack structure of the first matching layer 50, (HL)^S1H 2nL H(LH)^S2 is the film stack structure of the narrow-band filter film 20, n is the film layer thickness adjustment coefficient of the narrow-band filter film 20, Q2 is the film stack structure of the second matching layer, H is a high refractive index material, L is a low refractive index material, and S1 and S2 are both the number of superpositions.

[0064] As a seventh embodiment of the present application, a spectral imaging chip structure is provided, which is based on the sixth embodiment and further defines the first matching layer and the second matching layer. In this embodiment, the film stack structure is Sub|HL(HL)^3H 2nL H(LH)^3LHL|Air, and the half-wave width is where λ is the center wavelength, m represents the interference order, n H is the refractive index of the high refractive index material, n L is the refractive index of the low refractive index material, and η s is the tilted optical admittance of the substrate. As a specific embodiment of the present application, the half-wave width of the spectral imaging chip structure is

[0065] As an eighth embodiment of the present application, a spectral imaging chip structure is provided, which is based on the first embodiment and further defines the film stack structure of the spectral imaging chip structure. In this embodiment, the film stack structure with a low refractive index layer added on the substrate side is Sub|L(HL)^3H 2nL H(LH)^3|Air. The film stack structure with a high refractive index layer and a low refractive index layer added on the substrate side is Sub|HL(HL)^3H 2nL H(LH)^3|Air. The transmittance curve is shown in Figure 4 After adding the matching layer L, the transmittance at the center wavelength is 92.78%; after adding the matching layer HL, the transmittance at the center wavelength is 94.68%, and the transmittance is higher.

[0066] As a ninth embodiment of the present application, a spectral imaging chip structure is provided, which comprises a pixel photosensitive unit 10, a narrow-band filter film 20 and a third matching layer, the pixel photosensitive unit 10 is used to realize image acquisition and data readout, the narrow-band filter film 20 is integrally deposited and grown on the pixel photosensitive unit 10, the narrow-band filter film 20 is used to realize tunable at a required waveband center wavelength, and the third matching layer is integrally deposited and grown on the narrow-band filter film 20, and the third matching layer is used to improve the center wavelength peak transmittance of the spectral imaging chip structure.

[0067] In the ninth embodiment of the present application, considering that the refractive index difference between the film layer material and the pixel photosensitive unit material of the image sensor is large during the growth of the narrow-band filter film, direct growth will cause refractive index mismatch, the center wavelength peak transmittance will decrease, the quantum efficiency of the spectral imaging system will be low, and the imaging effect will be affected, therefore, by integrally growing the third matching layer on the narrow-band filter film, the problem of refractive index mismatch and the decrease of the center wavelength peak transmittance can be effectively overcome, and the center wavelength peak transmittance of the spectral imaging chip structure can be effectively improved.

[0068] As a tenth embodiment of the present application, a spectral imaging chip structure is provided, which is based on the ninth embodiment and limits the film system structure of the spectral imaging chip. The film system structure of the spectral imaging chip structure is Sub|(HL)^S1 H 2nL H(LH)^S2 Q3|Air, wherein (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band filter film 20, n is the film layer thickness adjustment coefficient of the narrow-band filter film 20, Q3 is the film system structure of the third matching layer, H is a high refractive index material, L is a low refractive index material, and S1 and S2 are both the number of superpositions.

[0069] Specifically, in the present application, the film system structure selection of the matching layer of the spectral imaging chip structure is shown in Table 1. Q1 and Q2 have a corresponding relationship, Q1 is L, and there is no Q2; Q2 is L, and there is no Q1; Q1 is HL, and there is no Q2 or Q2 is LHL; Q1 is LHL, and Q2 is LH.

[0070] Table 1: Matching layer film system structure selection

[0071] Q1 Q2 corresponds to L Sub|L|Air (base side) ​ L Sub|L|Ai r (air side) ​ HL Sub|HL|Air (base side) ​ HL LHL Sub|L|Air (air side) LHL LH Sub|L|Air (base side) ​

[0072] As an eleventh embodiment of the present application, a spectral imaging chip structure is provided, which is based on the ninth embodiment and limits how to determine the half-wave width of the spectral imaging chip structure. In this embodiment, the half-wave width of the spectral imaging chip structure can be determined according to to obtain, where λ is the center wavelength, x represents the total number of high refractive layers of the multilayer reflective film, m represents the interference order, n H is the refractive index of the high refractive material. L is the refractive index of the low refractive material.

[0073] As a twelfth embodiment of the present application, a spectral imaging chip structure is provided, which is based on the above-mentioned embodiments and further limits the structure of the narrow-band filter film. In this embodiment, the narrow-band filter film 20 includes a plurality of FP cavity structures, each of which is formed by a semiconductor process in one step. Any FP cavity structure includes a first mirror, a light transmission layer, and a second mirror, which are stacked in order from bottom to top. The plurality of FP cavity structures are distributed in a mosaic pattern. The heights of the light transmission layers of the plurality of FP cavity structures along any one column of the narrow-band filter film 20 are all different. The heights of the light transmission layers of the plurality of FP cavity structures along any one row of the narrow-band filter film 20 are all different. Alternatively, the narrow-band filter film can also adopt other structure types. The plurality of FP cavity structures are distributed in a line scanning pattern. The heights of the light transmission layers of the plurality of FP cavity structures along any one column of the narrow-band filter film 20 are all the same. The heights of the light transmission layers of the plurality of FP cavity structures along any one row of the narrow-band filter film 20 are all different. In the present application, the narrow-band filter film can adopt various structure forms without limitation.

[0074] In the twelfth embodiment of the present application, by setting the structure of the narrow-band filter film, the structural complexity of the chip structure can be effectively reduced, the structural volume can be reduced, and the cost can be reduced. The narrow-band filter film includes a plurality of FP cavity structures, and the pixel photosensitive unit includes a plurality of pixel photosensitive sites. The plurality of FP cavity structures and the plurality of pixel photosensitive sites are set in one-to-one correspondence. Any FP cavity structure includes a first mirror, a light transmission layer, and a second mirror, which are stacked in order from bottom to top. The plurality of FP cavity structures are distributed in a mosaic pattern or a line scanning pattern. The plurality of FP cavity structures are all formed by a semiconductor process in one step. The first mirror, the light transmission layer, the second mirror, and the pixel photosensitive site all adopt materials compatible with the semiconductor process, and are strictly aligned vertically without a later bonded part. In this way, by means of advanced semiconductor (CMOS) process technology, the traditional light splitting system is directly processed on the pixel photosensitive unit of the photosensor. Since they are closely connected, stray light is reduced, the photon utilization rate is improved, the speed can reach hundreds of frames per second, the spectral video function is realized, the volume and weight are the same as those of ordinary RGB chips, the imaging system of the size of a finger is realized, and the CMOS technology brings unparalleled integration to the spectral imaging chip structure, which can be connected to any circuit at a high integration level, such as embedded in a mobile phone.

[0075] As a thirteenth embodiment of the present application, a spectral imaging chip structure is provided, and the integrated growth cutoff filter film is further limited to the first mirror and the second mirror based on the above-mentioned embodiments. In this embodiment, the first mirror is an upper mirror, and the second mirror is a lower mirror. The upper mirror is prepared by alternately arranging a plurality of high-refractive materials and a plurality of low-refractive materials, forming a Bragg mirror, and the plurality of high-refractive materials and the plurality of low-refractive materials are overlapped with each other multiple times, and the reflectivity is greater than 99%, serving as a cavity mirror of an FP cavity structure. The lower mirror has the same structure and material as the upper mirror, is located between the light transmission layer and the pixel photosensitive site, and also has a high reflection effect.

[0076] For the convenience of description, spatial relative terms such as "above", "upper", "top", "up", etc. can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0077] In addition, it should be noted that the use of the terms "first", "second", etc. to define parts only facilitates the distinction of the corresponding parts, and the above terms have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0078] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A spectral imaging chip structure, characterized by, The spectral imaging chip structure comprises: A pixel photosensitive unit (10) is used to realize image acquisition and data readout; A first matching layer (50) is integrally deposited and grown on the pixel photosensitive unit (10); A narrow-band filter film (20) is integrally deposited on the first matching layer (50), which is used to achieve tunable center wavelength in the required waveband, and the first matching layer (50) is used to transition the optical admittance between the narrow-band filter film (20) and the pixel photosensitive unit (10) to improve the center wavelength peak transmittance. The film system structure of the spectral imaging chip structure is Sub|Q1(HL)^S1 H 2nL H(LH)^S2|Air, wherein Q1 is the film system structure of the first matching layer (50), (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band filter film (20), n is the film layer thickness adjustment coefficient of the narrow-band filter film (20), H is a high refractive index material, L is a low refractive index material, and S1 and S2 are both the number of superpositions; the half-wave width of the spectral imaging chip structure can be obtained according to wherein λ is the center wavelength, x represents the number of high refractive index layers before the 2nL spacer layer, m represents the interference order, n H is the refractive index of the high refractive index material, n L is the refractive index of the low refractive index material, n s is the substrate refractive index, S1 and S2 are equal, and in the film system structure of the first matching layer (50), Q1 includes L or HL.

2. A spectral imaging chip structure, characterized by The spectral imaging chip structure comprises: A pixel photosensitive unit (10) is used to realize image acquisition and data readout; A first matching layer (50) is integrally deposited and grown on the pixel photosensitive unit (10); A narrow-band filter film (20) is integrally deposited on the first matching layer (50), and is used to achieve tunable center wavelength in a desired waveband; the first matching layer (50) is used to transition optical admittance between the narrow-band filter film (20) and the pixel photosensitive unit (10) to improve the center wavelength peak transmittance; the spectral imaging chip structure further comprises a second matching layer, which is integrally deposited on the narrow-band filter film (20) and is used to improve the center wavelength transmittance of the spectral imaging chip structure; the film system structure of the spectral imaging chip structure is Sub|Q1(HL)^S1 H 2nL H(LH)^S2 Q2|Air, wherein Q1 is the film system structure of the first matching layer (50), (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band filter film (20), n is the film layer thickness adjustment coefficient of the narrow-band filter film (20), Q2 is the film system structure of the second matching layer, H is a high refractive index material, L is a low refractive index material, S1 and S2 are both the number of superpositions; the half-wave width of the spectral imaging chip structure can be obtained according to wherein λ is the center wavelength, m represents the interference order, n H is the refractive index of the high refractive index material, n L is the refractive index of the low refractive index material, x represents the number of high refractive index layers before the 2nL spacer layer, including the high refractive index layer in the spacer layer, n s is the substrate refractive index, S1 and S2 are equal, in the film system structure of the first matching layer (50), Q1 includes HL or LHL; in the film system structure of the second matching layer, Q2 includes LH or LHL, when Q1 is HL, Q2 is LHL; when Q1 is LHL, Q2 is LH.

3. The spectral imaging chip structure according to claim 1 or 2, characterized in that The narrow-band filter film (20) comprises a plurality of FP cavity structures, each of which is formed by a semiconductor process at one time, any one of which comprises a first reflector, a light transmission layer and a second reflector which are stacked in turn from bottom to top, the plurality of FP cavity structures are distributed in a mosaic manner, the heights of the light transmission layers of the plurality of FP cavity structures along any one column of the narrow-band filter film (20) are all different, and the heights of the light transmission layers of the plurality of FP cavity structures along any one row of the narrow-band filter film (20) are all different; or the plurality of FP cavity structures are distributed in a line scanning manner, the heights of the light transmission layers of the plurality of FP cavity structures along any one column of the narrow-band filter film (20) are all the same, and the heights of the light transmission layers of the plurality of FP cavity structures along any one row of the narrow-band filter film (20) are all different.

4. A spectral imaging chip structure, characterized by The spectral imaging chip structure comprises: A pixel photosensitive unit (10) is used to realize image acquisition and data readout; A narrow-band filter film (20) is integrally deposited on the pixel photosensitive unit (10), and is used to achieve tunable center wavelength in a required waveband; a third matching layer is integrally deposited on the narrow-band filter film (20), and is used to improve the center wavelength transmittance of the spectral imaging chip structure, and the film system structure of the spectral imaging chip structure is Sub|(HL)^S1 H 2nL H(LH)^S2 Q3|Air, wherein (HL)^S1 H 2nL H(LH)^S2 is the film system structure of the narrow-band filter film (20), n is the film layer thickness adjustment coefficient of the narrow-band filter film (20), Q3 is the film system structure of the third matching layer, H is a high refractive index material, L is a low refractive index material, S1 and S2 are both the number of superpositions, and the half-wave width of the spectral imaging chip structure can be obtained according to wherein λ is the center wavelength, x represents the total number of high refractive index layers of the multilayer reflective film, m represents the interference order, n H is the refractive index of the high refractive index material, n L is the refractive index of the low refractive index material, x represents the number of high refractive index layers in the multilayer film before the 2nL spacer layer, including the high refractive index layers in the spacer layer, n s is the substrate refractive index, S1 and S2 are equal, and Q3 is L.

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