A spectral chip

Abstract

The application relates to a spectrum chip. The spectrum chip comprises a silicon-based substrate comprising a photoelectric sensing layer, wherein the photoelectric sensing layer comprises a plurality of pixels; a spectrum modulation layer arranged on the photoelectric sensing layer, wherein the spectrum modulation layer comprises periodically arranged light filtering units, each light filtering unit is composed of a plurality of light filtering sub-units, and each light filtering sub-unit has a different transmittance curve; and a first protective film layer arranged on the spectrum modulation layer, wherein the first protective film layer comprises a plurality of sub-protective film layers, and at least two light filtering sub-units in the same light filtering unit are covered by the same sub-protective film layer. The protective film layer is arranged above the photoelectric sensing layer and the light filtering sub-units, so that the thickness of the light filtering sub-units is prevented from being reduced to less than a preset thickness range in a subsequent cleaning process, the ideal preset transmittance curve cannot be obtained, and the photoelectric sensing layer and the completed light filtering sub-units are prevented from being damaged due to environmental factors in the step of preparing the to-be-completed light filtering sub-units.

Description

Technical Field

[0001] This application relates to the field of spectral modulation technology, specifically to a spectral chip. Background Technology

[0002] Spectral imaging has seen rapid development in recent years, enriching traditional imaging methods and providing unprecedented detail of objects. As a high-dimensional perception method, it plays an increasingly important role in fields such as precision agriculture, food safety inspection, environmental monitoring, and medical imaging.

[0003] During the fabrication of the filter unit of the spectral chip, each filter subunit is formed one by one. However, the formed filter subunits are often damaged during the fabrication process of the filter subunits to be formed, causing the spectral chip to fail to meet its preset performance requirements. For example, the thickness of the formed filter subunits is easily reduced to less than its preset thickness during the cleaning process, thus failing to obtain the ideal transmittance curve. In other words, the formed filter subunits may be damaged due to mechanical, chemical, environmental or improper operation factors, making them unable to meet the stability and functionality requirements of the filter subunits. Summary of the Invention

[0004] To overcome the above-mentioned defects, this patent proposes to add a protective film layer to the filter sub-unit during the fabrication process of the spectral chip, so as to effectively prevent the completed filter sub-unit from being damaged in subsequent fabrication processes, and at the same time ensure that the thickness of the completed filter sub-unit will not be reduced due to subsequent cleaning steps, thereby ensuring the ideal fabrication effect of the final spectral modulation layer.

[0005] The first aspect of this application provides a spectral chip, comprising,

[0006] A silicon-based substrate, including a photoelectric sensing layer, wherein the photoelectric sensing layer includes a plurality of pixels;

[0007] A spectral modulation layer is disposed on the photoelectric sensing layer, wherein the spectral modulation layer includes periodically arranged filter units, each filter unit is composed of multiple filter sub-units, and each filter sub-unit has a different transmittance curve.

[0008] A first protective film layer is disposed on the spectral modulation layer, wherein the first protective film layer includes a plurality of sub-protective film layers, and at least two filter sub-units in the same filter unit are covered by the same sub-protective film layer.

[0009] Optionally, the thickness of the first protective film layer ranges from 10 to 500 nm.

[0010] Optionally, at least two adjacent filter sub-units in the same filter unit are covered by the same sub-protective film layer.

[0011] Optionally, the filtering unit consists of M rows and N columns of filtering sub-units.

[0012] The first protective film layer includes M sub-protective film layers, where the m-th sub-protective film layer covers the N filter sub-units in the m-th row, where m traverses from 1 to M, and M and N are both natural numbers greater than or equal to 2.

[0013] Optionally, the filter unit includes 3*3 filter sub-units C1-C9, wherein the first row along the first direction consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9.

[0014] The first protective film layer includes three sub-protective film layers, wherein the first sub-protective film layer covers C1-C3, the second sub-protective film layer covers C4-C6, and the third sub-protective film layer covers C7-C9.

[0015] Optionally, the filtering unit consists of M rows and N columns of filtering sub-units.

[0016] The first protective film layer includes N sub-protective film layers, where the nth sub-protective film layer covers the M filter sub-units in the nth column, where n traverses from 1 to N, and M and N are both natural numbers greater than or equal to 2.

[0017] Optionally, the filter unit includes 3*3 filter sub-units C1-C9, wherein the first row along the first direction consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9.

[0018] The first protective film layer includes three sub-protective film layers, wherein the first sub-protective film layer covers C1, C4 and C7, the second sub-protective film layer covers C2, C5 and C8, and the third sub-protective film layer covers C3, C6 and C9.

[0019] Optionally, at least two non-adjacent filter sub-units in the same filter unit are covered by the same sub-protective film layer.

[0020] Optionally, the filtering unit consists of M rows and N columns of filtering sub-units.

[0021] The first protective film layer includes a first sub-protective film layer and a second sub-protective film layer, wherein the first sub-protective film layer covers the even-numbered filter sub-units, and the second sub-protective film layer covers the odd-numbered filter sub-units, wherein the odd and even numbers are calculated from the first row and first column to the M-th row and N-th column.

[0022] Optionally, the filter unit includes 3*3 filter sub-units C1-C9, wherein the first row along the first direction contains C1-C3, the second row contains C4-C6, and the third row contains C7-C9.

[0023] The first sub-protective film layer covers the C2, C4, C6, and C8 filter sub-units, and the second sub-protective film layer covers the C1, C3, C5, C7, and C9 filter sub-units.

[0024] Optionally, the chip further includes a second protective film layer disposed between the spectral modulation layer and the photoelectric sensing layer.

[0025] Optionally, the thickness of the second protective film layer ranges from 10 to 500 nm.

[0026] Optionally, the spectral chip further includes a base material layer disposed between the photoelectric sensing layer and the spectral modulation layer, wherein the optical signal incident on the spectral chip is modulated by the spectral modulation layer and the base material layer.

[0027] Optionally, the base material layer is disposed between the spectral modulation layer and the second protective film layer.

[0028] Optionally, the base material layer has a first transmittance curve, wherein the shape of the first transmittance curve is designed such that the response of the final transmittance curve obtained by the optical signal in each spectral modulation channel is more sensitive within the preset wavelength range than the response outside the preset wavelength range.

[0029] Optionally, the transmittance of the first transmittance curve within a preset wavelength range is higher than the transmittance outside the preset wavelength range.

[0030] Optionally, if the waveform of the filter subunit within the preset wavelength range is plateau-shaped, the final transmittance curve after modulation will exhibit a peak within the preset wavelength range; or

[0031] If the waveform of the filter subunit has a peak within the preset wavelength range, and the final transmittance curve after modulation still shows a peak within the preset wavelength range, the full width at half maximum (FWHM) of the modulated peak is smaller than that of the peak before modulation; or

[0032] If the waveform of the filter subunit is concave within the preset wavelength range, the final transmittance curve after modulation will show a peak within the preset wavelength range.

[0033] Optionally, the base material layer is a colloidal curable film composed of a mixture of resin material, photoinitiator material, and solvent material; and / or

[0034] The filter subunit is a colloidal cured film composed of resin material, photoinitiator material, pigment, and solvent material.

[0035] Optionally, the base material layer is a single-layer structure.

[0036] Optionally, throughout the entire spectral chip, the sum of the thicknesses of each filter subunit and its corresponding base material layer in projection relation is equal; and

[0037] Within the same filter unit, the thickness of the base material layer corresponding to different filter sub-units is stepped.

[0038] Optionally, the base material layer includes:

[0039] A grid structure formed of a dielectric material, wherein the orthographic projection of each mesh of the grid structure onto the photoelectric sensing layer is aligned with the orthographic projection of one or more filter subunits onto the photoelectric sensing layer;

[0040] The base material is filled into the mesh, wherein the base material is the same in each mesh.

[0041] Optionally, the base material in each mesh of the mesh structure corresponds to a filter sub-unit, wherein the sum of the thicknesses of the base materials in all meshes and their corresponding filter sub-units is equal throughout the entire spectral chip; and within the same filter unit, the thicknesses of the base materials corresponding to different filter sub-units are stepped.

[0042] Optionally, the thickness of the filter subunit is in the range of 500-1000 nm, and the thickness of the base material layer is in the range of 50-500 nm.

[0043] Optionally,

[0044] The preset wavelength range is 500-650nm;

[0045] The transmittance of the first transmittance curve satisfies the following constraints: peak transmittance wavelength is 500-640nm, T(400nm-490nm)≥70%, T(585nm-620nm)≥90%, T(650nm-900nm)≥70%.

[0046] The filter unit comprises 3*3 filter sub-units C1-C9, and the transmittance curve of each filter sub-unit satisfies the following constraints:

[0047] TC1: Valley transmittance wavelength is 420-465nm, T(420nm-465nm)≤20%, T(515nm-900nm)≥80%;

[0048] TC2: Valley transmittance wavelength is 470-500nm, T(470nm-500nm)≤10%, T(525nm-900nm)≥90%;

[0049] TC3: Valley transmittance wavelength is 510-560nm, T(400nm-450nm)≥80%, T(510nm-560nm)≤20%; T(580nm-900nm)≥85%;

[0050] TC4: Valley transmittance wavelength is 585-615nm, T(415nm-480nm)≥80%, T(585nm-615nm)≤10%; T(650nm-900nm)≥75%;

[0051] TC5: Valley transmittance wavelength is 620-645nm, T(300nm-540nm)≥80%, T(620nm-645nm)≤10%; T(675nm-900nm)≥85%;

[0052] TC6: Valley transmittance wavelength is 625-660nm, T(400nm-535nm)≥80%, T(625nm-660nm)≤10%; T(690nm-900nm)≥85%;

[0053] TC7: Valley transmittance wavelength is 655-700nm; T(400nm-545nm)≥80%; T(655nm-700nm)≤20%; T(740nm-900nm)≥85%;

[0054] TC8: Valley transmittance wavelength is 685-730nm, T(400nm-565nm)≥80%, T(685nm-730nm)≤10%; T(780nm-900nm)≥85%;

[0055] TC9: Valley transmittance wavelength is 700-745nm, T(470nm-590nm)≥80%, T(700nm-745nm)≤40%; T(790nm-900nm)≥80%;

[0056] The transmittance of the final transmittance curves obtained by the optical signal on each spectral modulation channel A1-A9 satisfies the following constraints:

[0057] TA1: Peak transmittance wavelength is 500nm-650nm, T(430nm-460nm)≤10%, T(500nm-650nm)≥60%, T(650nm-900nm)≥55%;

[0058] TA2: Peak transmittance wavelength is 550-620nm, T(460nm-500nm)≤10%, T(550nm-620nm)≥80%, T(650nm-900nm)≥65%;

[0059] TA3: Peak transmittance wavelength is 575-635nm, T(510nm-550nm)≤15%, T(575nm-635nm)≥70%, T(650nm-900nm)≥60%;

[0060] TA4: Valley transmittance wavelength is 550-620nm, T(400nm-540nm)≥20%, T(550nm-620nm)≤20%, T(640nm-900nm)≥55%;

[0061] TA5: Valley transmittance wavelength is 615-650nm, T(300nm-565nm)≥60%, T(615nm-650nm)≤20%, T(675nm-900nm)≥60%;

[0062] TA6: Valley transmittance wavelength is 600-670nm, T(400nm-560nm)≥60%, T(600nm-670nm)≤20%, T(700nm-900nm)≥60%;

[0063] TA7: Valley transmittance wavelength is 630-700nm, T(400nm-575nm)≥60%, T(630nm-700nm)≤20%, T(735nm-900nm)≥60%;

[0064] TA8: Valley transmittance wavelength is 635-735nm, T(400nm-590nm)≥60%, T(635nm-735nm)≤20%, T(780nm-900nm)≥60%;

[0065] TA9: Peak transmittance wavelength is 500-625nm, T(300nm-480nm)≤60%, T(500nm-625nm)≥60%, T(685nm-750nm)≤40%, T(810nm-900nm)≥60%.

[0066] Optionally, there is at least one inclined overlap region relative to the silicon substrate between each filter subunit and its adjacent filter subunit, the orthographic projection of the inclined overlap region on the silicon substrate spanning two adjacent pixels.

[0067] Optionally, the filter subunit is frustum-shaped.

[0068] Optionally, two adjacent filter subunits are respectively a regular square frustum and an inverted square frustum.

[0069] Optionally, the angle between the beveled overlap area and the silicon substrate is between 60 degrees and 90 degrees.

[0070] Optionally, the thickness of the filter subunit is in the range of 500-1000 nm.

[0071] Optionally, the filter subunit is a colloidal cured film composed of resin material, photoinitiator material, pigment and solvent material.

[0072] Optionally, each filter unit includes 3*3 filter subunits C1-C9, wherein the first row along the first direction consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9, wherein C2, C4, C6 and C8 are regular square frustums, and C1, C3, C5, C7 and C9 are inverted square frustums.

[0073] Optionally, the transmittance curve of the light incident on the multispectral chip after being modulated by the spectral modulation layer satisfies the following constraint:

[0074] TC1: Valley transmittance wavelength is 400-550nm; T(430nm-495nm)≤10%; T(550nm-900nm)≥70%;

[0075] TC2: Valley transmittance wavelength is 400-575nm; T(420nm-550nm)≤15%; T(585nm-900nm)≥65%;

[0076] TC3: Valley transmittance wavelength is 400-580nm; T(455nm-550nm)≤15%; T(600nm-900nm)≥75%;

[0077] TC4: Valley transmittance wavelength is 500-680nm; T(400nm-500nm)≥65%; T(580nm-645nm)≤10%; T(700nm-900nm)≥65%;

[0078] TC5: Valley transmittance wavelength is 500-675nm; T(400nm-500nm)≥50%; T(550nm-650nm)≤10%; T(700nm-900nm)≥60%;

[0079] TC6: Valley transmittance wavelength is 550-700nm; T(400nm-535nm)≥65%; T(600nm-665nm)≤10%; T(700nm-900nm)≥75%;

[0080] TC7: Valley transmittance wavelength is 550-750nm; T(400nm-550nm)≥65%; T(630nm-725nm)≤10%; T(800nm-900nm)≥75%;

[0081] TC8: Valley transmittance wavelength is 550-750nm; T(460nm-545nm)≥55%; T(625nm-740nm)≤10%; T(775nm-900nm)≥55%;

[0082] TC9: Valley transmittance wavelength is 600-700nm; T(465nm-540nm)≥70%; T(680nm-745nm)≤10%; T(785nm-900nm)≥70%.

[0083] In this application, by setting a protective film layer on the completed filter sub-units and photoelectric sensing layer, the problem of damage to these units during subsequent fabrication is solved. More importantly, the thickness of the completed filter sub-units has a significant impact on transmittance. Setting a protective film layer on them prevents the thickness from decreasing during subsequent cleaning, thus ensuring the performance of the spectral chip. Furthermore, this reduces the complexity of adjusting various parameters (such as curing time) during subsequent fabrication and effectively prevents mutual interference between filter sub-units, ensuring the fabrication quality of each spectral material layer and resulting in more stable and ideal performance of the multi-channel spectral chip. Attached Figure Description

[0084] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Furthermore, similar numbers in the drawings are used to denote similar components, wherein:

[0085] Figure 1 This is a schematic diagram of the structure of a spectral chip according to an embodiment of this application;

[0086] Figure 2 This is a schematic diagram of a preferred structure of a spectral chip according to an embodiment of this application;

[0087] Figure 3 It is based on the light transmittance curve of a 9-channel spectral chip using existing technology;

[0088] Figure 4 This is a light transmittance curve of the base material layer according to an embodiment of this application;

[0089] Figure 5 This is a light transmittance curve of a structure having a base material layer according to an embodiment of this application after modulation;

[0090] Figure 6 (a) and (b) are schematic diagrams of a preferred structure of a spectral chip according to an embodiment of this application;

[0091] Figure 7 Is Figure 3 The diagram shown illustrates the presence of an aliasing region in the light transmittance curve.

[0092] Figure 8 Is Figure 5 The diagram shown illustrates the presence of an aliasing region in the light transmittance curve.

[0093] Figure 9 (a) and (b) are schematic diagrams of a preferred structure of a spectral chip according to yet another embodiment of this application;

[0094] Figure 10 It is based on Figure 9 A partial schematic diagram of the structure of the multispectral chip shown;

[0095] Figure 11 The light transmittance curve is a structure of a filter subunit having a regular square truncated pyramid shape and an inverted square truncated pyramid shape according to another embodiment of this application after modulation.

[0096] Figure 12 The light transmittance curve is a structure modulated according to another embodiment of this application, which has a base material layer and filter subunits with regular and inverted square pyramid shapes.

[0097] Figure 13 This is a flowchart of the spectral chip fabrication method;

[0098] Figures 14 to 19 This is a schematic flowchart of a method for fabricating a spectral chip according to an embodiment of this application. Detailed Implementation

[0099] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0100] In the description of this application, for ease of description, spatial relative terms such as "below," "under," "below," "above," and "on" may be used to describe the relationship between one element and another. When an element or layer is referred to as "on," "adjacent to," or "connected to" other elements or layers, it may be directly on, adjacent to, or connected to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," or "directly connected to" other elements or layers, there are no intervening elements or layers.

[0101] It should also be understood that, for ease of description, the term "A and / or B" refers to all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and may include only A, only B, or A and B. The singular forms of the terms "a" or "this" may also include plural forms.

[0102] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0103] During the fabrication of spectral chips, technicians have discovered that the process of fabricating the spectral modulation layer becomes increasingly complex as the number of spectral modulation channels increases. Taking the structure disclosed in existing technology CN113497065A as an example, the filter film includes N periods, each period including T1, T2...Tn units. The specific process includes: firstly, a first type of filter film material is coated on the photoelectric conversion substrate using a standard spraying or spin coating method, followed by an etching layer. Based on the correspondence with the pixels of the photoelectric conversion substrate, the required areas are retained, and the unnecessary areas are etched away. Then, a second type of filter film material is coated, followed by another etching layer. Based on the correspondence with the pixels of the photoelectric conversion substrate, the required areas are retained, and the unnecessary areas are etched away. This process is repeated until all N types of filter film materials are coated onto the photoelectric conversion substrate. After each of the N types of filter film materials is coated and etched, a complete filter film with N periods is finally formed.

[0104] In this process, the etching during the fabrication of the subsequent filter film material can easily damage the already fabricated filter film. Furthermore, cleaning is typically required after each etching step, all of which reduce the thickness of the subsequent filter film, preventing it from reaching the preset thickness and thus failing to obtain the desired transmittance profile. Technicians often try to improve this by adjusting various preparation parameters (such as curing time); however, as the number of spectral modulation channels increases, the number of factors requiring coordination grows, eventually becoming impossible to balance simultaneously.

[0105] To solve the above-mentioned technical problems, the inventors have proposed the solution in this application.

[0106] One embodiment of this application provides a spectral chip, the spectral chip comprising:

[0107] A silicon-based substrate includes a photosensitive layer comprising a plurality of pixels. In a specific example, the photosensitive layer is a CMOS image sensor or a CCD image sensor.

[0108] A spectral modulation layer is disposed on the photoelectric sensing layer, wherein the spectral modulation layer includes periodically arranged filter units, and each filter unit includes multiple filter sub-units. Figure 1 In the example shown, the filter unit includes 3*3 filter sub-units C1-C9, where the first row along the first direction (from left to right in the figure) consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9. Each filter sub-unit has a different transmittance curve.

[0109] A first protective film layer is disposed on the spectral modulation layer. This first protective film layer includes multiple sub-protective film layers, with at least two filter sub-units within the same filter unit being covered by the same sub-protective film layer. Figure 1 In the example shown, the first protective film layer of the spectral chip includes three sub-protective film layers. The first sub-protective film layer is disposed on filter sub-units C1-C3, the second sub-protective film layer is disposed on filter sub-units C4-C6, and the third sub-protective film layer is disposed on filter sub-units C7-C9. The first, second, and third sub-protective film layers together constitute the first protective film layer. In fact, the first, second, and third sub-protective film layers are located in the same layer, but are implemented in different process steps (see the method described later).

[0110] Understandably, in the entire spectral chip, the filter subunits C1-C3 in each periodic unit (filter unit) are fabricated sequentially first, and a first sub-protective film layer is applied to them. Then, C4-C6 in each periodic unit are fabricated, and a second sub-protective film layer is applied to them. Finally, C7-C9 in each periodic unit are fabricated, and a third sub-protective film layer is applied to them. During the fabrication of filter subunits C4-C9, the surface of filter subunits C1-C3 is not damaged, nor is the thickness of filter subunits C1-C3 reduced during the cleaning process. Furthermore, the impact on filter subunits C1-C3 does not need to be considered when setting parameters in subsequent fabrication processes, thus greatly reducing the complexity of parameter setting during chip fabrication. Similarly, after applying the second sub-protective film layer to filter subunits C4-C6, the complexity of parameter setting for fabricating filter subunits C7-C9 is also greatly reduced, while ensuring the integrity and functionality of filter subunits C4-C6. Those skilled in the art will understand that this example is a case of creating line by line. Of course, it is also possible to create from right to left within the same line, for example, creating C3, C2, and C1 sequentially in the first line.

[0111] In another alternative embodiment, the filters can be fabricated column by column. That is, filter sub-units C1, C4, and C7 are fabricated sequentially, and a first sub-protective film layer is placed on them; then C2, C5, and C8 are fabricated sequentially, and a second sub-protective film layer is placed on them; finally, C3, C7, and C9 are fabricated, and a third sub-protective film layer is placed on them.

[0112] The above two embodiments are examples of sequential fabrication of filter sub-units. In another alternative embodiment, the order of fabricating filter sub-units is as follows: first, fabricate the even-numbered filter sub-units, then fabricate the odd-numbered filter sub-units, where odd and even numbers are calculated from row 1, column 1 to row 3, column 3. For example, C2, C4, C6, and C8 are fabricated first, and a first sub-protective film is placed on them; then C1, C3, C5, C7, and C9 are fabricated, and a second sub-protective film is placed on them. Alternatively, the odd-numbered filter sub-units are fabricated first, then the even-numbered filter sub-units are fabricated. In this case, the first sub-protective film is placed on C1, C3, C5, C7, and C9, and the second sub-protective film is placed on C2, C4, C6, and C8. This approach can be applied to the following descriptions. Figure 9 The structure shown.

[0113] In the above example, each filter unit is a 3*3 array structure. However, it is not limited to this. It can also be a 4*4, 5*5, or even an M*N array structure.

[0114] In one embodiment, the spectral chip filter unit is a 4*4 array structure, with the first sub-protective film layer disposed on filter sub-units C1-C4, the second sub-protective film layer disposed on filter sub-units C5-C8, the third sub-protective film disposed on C9-C12, and the fourth sub-protective film disposed on C13-C16.

[0115] In one embodiment, the spectral chip filter unit is a 5*5 array structure, with the first sub-protective film layer disposed on filter sub-units C1-C5, the second sub-protective film layer disposed on filter sub-units C6-C10, the third sub-protective film disposed on C11-C15, the fourth sub-protective film disposed on C16-C20, and the fifth sub-protective film disposed on C21-C25.

[0116] In the example where the filter unit consists of M rows and N columns of filter sub-units, the first protective film layer includes M sub-protective film layers, where the m-th sub-protective film layer covers the m-th row and N filter sub-units, where m traverses from 1 to M, and M and N are both natural numbers greater than or equal to 2.

[0117] In another example where the filter unit consists of M rows and N columns of filter sub-units, the first protective film layer includes N sub-protective film layers, where the nth sub-protective film layer covers the M filter sub-units in the nth column, where n ranges from 1 to N, and M and N are both natural numbers greater than or equal to 2.

[0118] In another example where a filter unit consists of M rows and N columns of filter sub-units, the first protective film layer includes a first sub-protective film layer and a second sub-protective film layer, wherein the first sub-protective film layer covers the even-numbered filter sub-units and the second sub-protective film layer covers the odd-numbered filter sub-units, wherein the odd and even numbers are calculated from the first row and first column to the M-th row and N-th column.

[0119] By setting up protective films, it is possible to effectively ensure that each filter unit will not interfere with each other after it is fabricated, making the performance of the spectral chip more stable and ideal.

[0120] More broadly, those skilled in the art, guided by the above teachings, can achieve the aforementioned technical effect by fabricating two or more filter sub-units (whether adjacent or spaced apart) and then adding a sub-protective film layer during the fabrication process. Alternatively, a sub-protective film layer can be added after fabricating a single filter sub-unit, although this increases the complexity and cost of the process; in actual fabrication, both the process and the protective effect must be considered.

[0121] Those skilled in the art will understand that the thickness of the protective film layer has a significant impact on the intensity of transmitted light. If the protective film layer is too thick, the incident light will not achieve the desired intensity after passing through the spectral modulation layer; if the protective film layer is too thin, it will not provide any protective effect. Based on experimental data, the inventors have determined that a thickness range of 10-500 nm for the first protective film layer is optimal.

[0122] In this application, the material of the protective film is not limited, as long as it can achieve high transmittance within the wavelength range of interest in the application. In other words, within this wavelength range, the transmittance of the protective film can be regarded as a straight line, for example, a transmittance of more than 95%.

[0123] In one embodiment, since the spectral modulation layer is disposed on the photoelectric sensing layer, to avoid damaging the photoelectric sensing layer during the fabrication process, such as... Figure 2 As shown, a second protective film layer can be disposed on the photoelectric sensing layer, and the spectral modulation layer is disposed on the second protective film layer. The material and thickness of the second protective film layer are within the same range as those of the first protective film layer.

[0124] In one embodiment of this application, the material of the photofilter subunit is a colloidal cured film composed of resin material, photoinitiator material, pigment, and solvent material.

[0125] The resin materials include soluble resins, such as phenolic resins, polyurethane resins, polyvinyl alcohol resins, and maleic anhydride resins; and photocurable resins, such as polyimide resins, polyvinyl alcohol resins, epoxy resins, and styrene resins.

[0126] Photoinitiator materials include benzophenones, alkyl phenyl ketones, benzoin and its derivatives, iodonium salts, and iron aromatics.

[0127] Pigments include aniline pigments, phthalocyanine pigments, azo pigments, and pyrrole pigments.

[0128] Solvent-based materials include ethylene glycol methyl ethers, propylene glycol methyl ether acetates, triethylene glycol methyl ethers, and ethyl 3-ethoxypropionate.

[0129] By selecting and proportioning these materials, the transmittance curves of each of the aforementioned filter sub-units can be obtained.

[0130] In some applications, due to limitations inherent in the material itself, the transmittance curve of the modulation channel (e.g.) Figure 3As shown, in a spectral chip with a 3*3 array structure of filter units, the 9 spectral modulation channels are made of different spectral modulation materials. The 9 spectral modulation materials have the transmittance curves shown in the figure. In certain key wavelength ranges (key bands, such as those used in cameras for visible light imaging, which are usually 500-650nm), the linear response of such a structure cannot be better. During color reproduction, the response of such a structure to the key band will be affected by the interference of bands outside the band, especially under low light conditions, and it cannot provide accurate spectral capture effect.

[0131] Therefore, in a preferred embodiment of this application, the spectral chip further includes a base material layer disposed between the photoelectric sensing layer and the spectral modulation layer, wherein the linear shape of the first transmittance curve is designed such that the transmittance curve of the light incident on the multispectral chip, after being modulated by the spectral modulation layer and the base material layer, is more sensitive in a preset wavelength range than in a response outside the preset wavelength range.

[0132] Unlike existing technologies, this application adds a base material layer, and the incident light is modulated sequentially by the spectral modulation layer and the base material layer.

[0133] It is worth noting that since the base material layer can also provide protection in addition to its light modulation function, a second protective film layer is not necessary in this case.

[0134] The inventors introduced a base material layer into the original structure and designed the shape of its transmittance curve (hereinafter referred to as the first transmittance curve). This makes the transmittance curve of the incident light after being modulated by the spectral modulation layer and the base material layer more sensitive in the preset wavelength range than in the range outside the preset wavelength range. Essentially, this makes the transmittance of the multispectral chip higher for light in the key band (which, from a design perspective, can also be called the preset wavelength range) than for light outside that range.

[0135] In a preferred embodiment, the transmittance of the first transmittance curve within a preset wavelength range is higher than the transmittance outside the preset wavelength range.

[0136] Figure 4 The figure shows the first transmittance curve designed for the visible light band of 500-650nm. Specifically, the transmittance of the first transmittance curve satisfies the following constraints: peak transmittance wavelength is 500-640nm, T(400nm-490nm)≥70%, T(585nm-620nm)≥90%, and T(650nm-900nm)≥70%.

[0137] The process of modulating the transmittance curves of each filter unit using the first transmittance curve is mathematically equivalent to multiplying the transmittances of the two units at the same wavelength as a new transmittance, thus obtaining a wavelength-transmittance function. Alternatively, it can be described as using the transmittance on the first transmittance curve as a modulation factor to modulate the transmittance on the transmittance curves of each filter unit. This design of the first transmittance curve allows for the following: Figure 3 The transmittance curve shown is modulated within a preset wavelength range, which can improve or alleviate situations where some modulation channels plateau or even dip within that wavelength range.

[0138] Specifically, if the waveform of the filter subunit within the preset wavelength range is plateau-shaped, the modulated transmittance curve within the preset wavelength range will exhibit a peak; if the waveform of the filter subunit within the preset wavelength range has a peak, the modulated transmittance curve within the preset wavelength range will still exhibit a peak, and the full width at half maximum (FWHM) of the modulated peak will be smaller than that of the peak before modulation; if the waveform of the filter subunit within the preset wavelength range is concave-shaped, the modulated transmittance curve within the preset wavelength range will exhibit a peak.

[0139] by Figure 3 Taking C1-C9 as an example, the transmittance curves of each filter sub-unit satisfy the following constraints:

[0140] TC1: Valley transmittance wavelength is 420-465nm, T(420nm-465nm)≤20%, T(515nm-900nm)≥80%;

[0141] TC2: Valley transmittance wavelength is 470-500nm, T(470nm-500nm)≤10%, T(525nm-900nm)≥90%;

[0142] TC3: Valley transmittance wavelength is 510-560nm, T(400nm-450nm)≥80%, T(510nm-560nm)≤20%; T(580nm-900nm)≥85%;

[0143] TC4: Valley transmittance wavelength is 585-615nm, T(415nm-480nm)≥80%, T(585nm-615nm)≤10%; T(650nm-900nm)≥75%;

[0144] TC5: Valley transmittance wavelength is 620-645nm, T(300nm-540nm)≥80%, T(620nm-645nm)≤10%; T(675nm-900nm)≥85%;

[0145] TC6: Valley transmittance wavelength is 625-660nm, T(400nm-535nm)≥80%, T(625nm-660nm)≤10%; T(690nm-900nm)≥85%;

[0146] TC7: Valley transmittance wavelength is 655-700nm; T(400nm-545nm)≥80%; T(655nm-700nm)≤20%; T(740nm-900nm)≥85%;

[0147] TC8: Valley transmittance wavelength is 685-730nm, T(400nm-565nm)≥80%, T(685nm-730nm)≤10%; T(780nm-900nm)≥85%;

[0148] TC9: Valley transmittance wavelength is 700-745nm, T(470nm-590nm)≥80%, T(700nm-745nm)≤40%; T(790nm-900nm)≥80%.

[0149] Sutra Figure 4 Modulation of the first transmittance curve shown yields the following result: Figure 5 The line shape shown:

[0150] The transmittance curves of light incident on the spectral chip, after being modulated by the spectral modulation layer and the base material layer, satisfy the following constraints:

[0151] TA1: Peak transmittance wavelength is 500nm-650nm, T(430nm-460nm)≤10%, T(500nm-650nm)≥60%, T(650nm-900nm)≥55%;

[0152] TA2: Peak transmittance wavelength is 550-620nm, T(460nm-500nm)≤10%, T(550nm-620nm)≥80%, T(650nm-900nm)≥65%;

[0153] TA3: Peak transmittance wavelength is 575-635nm, T(510nm-550nm)≤15%, T(575nm-635nm)≥70%, T(650nm-900nm)≥60%;

[0154] TA4: Valley transmittance wavelength is 550-620nm, T(400nm-540nm)≥20%, T(550nm-620nm)≤20%, T(640nm-900nm)≥55%;

[0155] TA5: Valley transmittance wavelength is 615-650nm, T(300nm-565nm)≥60%, T(615nm-650nm)≤20%, T(675nm-900nm)≥60%;

[0156] TA6: Valley transmittance wavelength is 600-670nm, T(400nm-560nm)≥60%, T(600nm-670nm)≤20%, T(700nm-900nm)≥60%;

[0157] TA7: Valley transmittance wavelength is 630-700nm, T(400nm-575nm)≥60%, T(630nm-700nm)≤20%, T(735nm-900nm)≥60%;

[0158] TA8: Valley transmittance wavelength is 635-735nm, T(400nm-590nm)≥60%, T(635nm-735nm)≤20%, T(780nm-900nm)≥60%;

[0159] TA9: Peak transmittance wavelength is 500-625nm, T(300nm-480nm)≤60%, T(500nm-625nm)≥60%, T(685nm-750nm)≤40%, T(810nm-900nm)≥60%.

[0160] In this application, by introducing a base material layer with a transmittance curve designed for a preset wavelength range, the transmittance curve of the original filter subunit is modulated. This optimizes the response of the spectral camera to the preset wavelength range, improves image quality, reduces interference from other bands (the presence of the base material layer reduces the transmittance of light outside the preset wavelength range), and ensures accurate color reproduction during shooting. Even if the application scenario changes (the key wavelength changes), only the transmittance curve of a single base layer needs to be designed for the new target wavelength, rather than adjusting the transmittance curves of multiple filter subunits in a coordinated manner.

[0161] The following explains how to achieve the transmittance curve designed for the base material layer. The inventor's idea is to make it compatible with the materials and processes of the filter subunit.

[0162] In this application, the material of the filter subunit is a colloidal cured film composed of resin material, photoinitiator material, pigment and solvent material.

[0163] The resin materials include soluble resins, such as phenolic resins, polyurethane resins, polyvinyl alcohol resins, and maleic anhydride resins; and photocurable resins, such as polyimide resins, polyvinyl alcohol resins, epoxy resins, and styrene resins.

[0164] Photoinitiator materials include benzophenones, alkyl phenyl ketones, benzoin and its derivatives, iodonium salts, and iron aromatics.

[0165] Pigments include aniline pigments, phthalocyanine pigments, azo pigments, and pyrrole pigments.

[0166] Solvent-based materials include ethylene glycol methyl ethers, propylene glycol methyl ether acetates, triethylene glycol methyl ethers, and ethyl 3-ethoxypropionate.

[0167] Therefore, the base material layer is made of a colloidal curable film composed of resin material, photoinitiator material and solvent material.

[0168] In a specific example, the base material layer is a monolithic structure, meaning it is deposited as a single layer on top of and covers the photosensitive layer. However, in this case, when light exits from a certain filter unit and enters the base material layer, it can be scattered to areas outside the corresponding region of the base material layer, resulting in crosstalk. This is particularly pronounced when the base material layer is thick.

[0169] Therefore, this application provides another preferred structure. Specifically, the base material layer includes:

[0170] A grid structure formed of a dielectric material, wherein the orthographic projection of each mesh of the grid structure onto the photoelectric sensing layer is aligned with the orthographic projection of one or more filter subunits onto the photoelectric sensing layer;

[0171] The base material is filled into the mesh, wherein the base material is the same in each mesh.

[0172] The medium material is preferably a light-absorbing material, such as the black matrix commonly used in the display panel industry.

[0173] As those skilled in the art can anticipate, the addition of a base material layer reduces the energy utilization of light, a situation that is further highlighted in embodiments with a grid structure formed by light-absorbing materials.

[0174] Typically, the solution that comes to mind is to reduce the thickness of the base material layer. However, if the base layer is too thin, it will be impossible to effectively modulate the key bands.

[0175] Therefore, in one embodiment, experiments revealed that the thickness of the base layer ranges from 50 to 500 nm, and the thickness of the modulation layer ranges from 500 to 1000 nm. Within this range, the spectral modulation channels of the base layer and modulation layer are advantageous for fabrication and can achieve better spectral modulation performance. A base layer thickness exceeding 500 nm increases the optical path length of the modulation channel, leading to spectral crosstalk between adjacent pixels in the photoelectric sensing layer. For the modulation layer, if its thickness is less than 500 nm, it loses its broadband modulation capability and cannot achieve the ideal modulation line shape; while if the modulation layer thickness exceeds 1000 nm, it makes the fabrication process difficult and, in addition to increasing spectral crosstalk, also reduces the transmittance of the modulation line.

[0176] However, this overall adjustment method does not take into account the differences in materials of different filter sub-units (e.g., different wavelengths of light scatter the same material to different degrees). A more preferred embodiment is given below.

[0177] In embodiments where the base material layer is a monolithic structure, within the entire spectral chip, and within the same filter unit, the thickness of the base material layer corresponding to different filter subunits exhibits a stepped appearance. For example, such as... Figure 6 As shown, where Figure 6 (a) is a top view of the spectral chip, and (b) is a cross-sectional view along the dashed line in the figure. From Figure 6 As shown in (b), the thickness of the base material region corresponding to C1 is greater than that corresponding to C2, C3, C4, C5, C6, C7, C8, and C9. The overall base material layer is stepped.

[0178] As will be discussed in the process section later, the thickness varies depending on which filter sub-unit is fabricated first; the thickness of the corresponding base material region fabricated first is greater than that of the corresponding base material region fabricated later. Of course, the overall thickness of the base layer can still be controlled within the range of 50-500nm.

[0179] In the specific process, filter sub-units corresponding to wavelength ranges insensitive to scattering by the base layer material can be selected as C1 (made first), and filter sub-units corresponding to wavelength ranges sensitive to scattering by the base layer material can be selected as C9 (made later). This takes into account the crosstalk problem. At the same time, for the subsequent device flatness, the sum of the thickness of each filter sub-unit and the thickness of its corresponding base material layer region in the projection relationship is equal. Of course, the thickness of the modulation layer can still be controlled within 500-1000nm. In this way, with the total thickness being the same, the thickness ratio of each filter sub-unit to the corresponding base layer material can be varied, which is equivalent to the material ratio in the vertical direction being varied in each channel. This increases the means to adjust the transmittance curve shape, thereby enabling a more refined obtaining of the desired curve shape.

[0180] In the above-described mesh structure implementation, the above concept can also be realized. In the entire spectral chip, the sum of the thickness of the base material in all meshes and the thickness of the corresponding filter sub-units are equal; and in the same filter unit, the thickness of the base material corresponding to different filter sub-units is stepped.

[0181] On the other hand, regardless of the transmittance curve of the spectral chip without a base material layer ( Figure 3 The transmittance curve of the spectral chip after adding a base material layer is also shown. Figure 5 All of these exhibit aliasing in at least some channels within certain wavelength ranges. This aliasing becomes more severe as the number of channels increases.

[0182] Figure 7 and Figure 8 In respectively Figure 3 and Figure 5 The corresponding aliasing region is shown on the basis (this phenomenon exists even in the above-mentioned preset wavelength region after the addition of the base material layer), which leads to low spectral resolution, making it difficult to accurately identify and modulate the spectral signal, and limiting the application of the spectral chip in complex environments.

[0183] Typically, when fabricating each filter subunit, the desired ideal morphology is vertical or nearly vertical. Researchers have explored various methods for fabricating vertical or near-vertical filter subunits. However, the inventors of this application have discovered through experimentation that when the edges of the filter subunits are inclined, meaning that adjacent filter subunits have an overlap area (inclined interface), Figure 7 or Figure 8 The waveform in the aliasing region shown will demix, which gives the inventors a new idea to further optimize the transmittance curve.

[0184] Therefore, in one embodiment of this application, there is at least one inclined overlap region relative to the silicon substrate between each filter subunit and its adjacent filter subunit, the orthographic projection of the inclined overlap region on the silicon substrate bridging two adjacent pixels on the photoelectric sensing layer.

[0185] In a preferred embodiment, such as Figure 9 As shown, Figure 9 (a) is a top view of the spectral chip, and (b) is a cross-sectional view along the dashed line in the figure. From Figure 9 As can be seen in (b), C2, C4, C6 and C8 are regular trapezoids (corresponding to a regular square frustum in the concept of solid geometry), while C1, C3, C5, C7 and C9 are inverted trapezoids (corresponding to an inverted square frustum in the concept of solid geometry).

[0186] Please note that "regular" and "inverted" are relative concepts. In this application, a regular square truncated pyramid refers to a surface whose area is larger than the area of ​​the surface away from the photoelectric sensing layer, meaning that the filter subunit is smaller at the top and larger at the bottom relative to the photoelectric sensing layer. An inverted square truncated pyramid refers to a surface whose area is smaller than the area of ​​the surface away from the photoelectric sensing layer, meaning that the filter subunit is larger at the top and smaller at the bottom relative to the photoelectric sensing layer.

[0187] Such a structure can achieve such a modulation effect, such as Figure 10 As shown, taking C1-C3 as an example, the light entering pixel P1 is modulated by C1 and C2 (the R1 region to the left of the dashed line L1) (and also by the underlying base material layer below, the same below); the light entering pixel P3 is modulated by C3 and C2 (the R2 region to the right of the dashed line L2); the light entering pixel P2 is modulated by C1 (the R3 region to the right of the dashed line L3), C2, and C3 (the R4 region to the left of the dashed line L4).

[0188] The above examples use regular and inverted square truncated pyramids as illustrations; however, this application is not limited to these. Any truncated pyramid structure is acceptable. That is, a common modulation effect can be achieved when a filter subunit and its adjacent filter subunits have at least one beveled overlap area. For example, C1 and C2, C4 each have beveled overlap areas. Those skilled in the art, guided by the teachings of this application, can adjust the area and slope of the overlap area to ensure that the light entering each pixel is modulated by at least two different modulation subunits, thereby finely adjusting the linearity of the light transmittance curve entering the pixel and alleviating aliasing at certain wavelengths.

[0189] Furthermore, although the frustum-shaped filter unit coexists with the base material layer in the example above, this application is not limited to this. The frustum-shaped filter unit can be used independently (i.e., the filter unit is frustum-shaped in a spectral chip structure without a base material layer) to achieve its own effect. Specifically, the linearity of the transmittance curve of each channel can be more finely adjusted by adjusting the area and slope of the overlap area, thereby alleviating the aliasing of the transmittance curve at certain wavelengths.

[0190] In a preferred example, the angle between the beveled overlap area and the surface of the spectral modulation layer is between 60 and 90 degrees.

[0191] Figure 11 The figure shows the transmittance curve of light incident on the multispectral chip after being modulated by the spectral modulation layer in the case of a spectral chip structure without a base material layer, which satisfies the following constraints:

[0192] TC1: Valley transmittance wavelength is 400-550nm; T(430nm-495nm)≤10%; T(550nm-900nm)≥70%;

[0193] TC2: Valley transmittance wavelength is 400-575nm; T(420nm-550nm)≤15%; T(585nm-900nm)≥65%;

[0194] TC3: Valley transmittance wavelength is 400-580nm; T(455nm-550nm)≤15%; T(600nm-900nm)≥75%;

[0195] TC4: Valley transmittance wavelength is 500-680nm; T(400nm-500nm)≥65%; T(580nm-645nm)≤10%; T(700nm-900nm)≥65%;

[0196] TC5: Valley transmittance wavelength is 500-675nm; T(400nm-500nm)≥50%; T(550nm-650nm)≤10%; T(700nm-900nm)≥60%;

[0197] TC6: Valley transmittance wavelength is 550-700nm; T(400nm-535nm)≥65%; T(600nm-665nm)≤10%; T(700nm-900nm)≥75%;

[0198] TC7: Valley transmittance wavelength is 550-750nm; T(400nm-550nm)≥65%; T(630nm-725nm)≤10%; T(800nm-900nm)≥75%;

[0199] TC8: Valley transmittance wavelength is 550-750nm; T(460nm-545nm)≥55%; T(625nm-740nm)≤10%; T(775nm-900nm)≥55%;

[0200] TC9: Valley transmittance wavelength is 600-700nm; T(465nm-540nm)≥70%; T(680nm-745nm)≤10%; T(785nm-900nm)≥70%.

[0201] Compare Figure 11 and Figure 7 It is evident that the combination of regular and inverted square truncated pyramid shapes helps to separate partially overlapping transmittance curves, thereby improving the distinction between different spectra and enhancing the effect of spectral modulation.

[0202] Figure 12 The figure shows the transmittance curve of light incident on the multispectral chip after being modulated by the spectral modulation layer and the base material layer in the case of a spectral chip structure with a base material layer, which satisfies the following constraints:

[0203] TA1: Peak transmittance wavelength is 520-640nm; T(420nm-495nm)≤10%; T(580nm-625nm)≥55%; T(670nm-900nm)≥50%;

[0204] TA2: Peak transmittance wavelength is 570-645nm; T(425nm-550nm)≤10%; T(600nm-630nm)≥70%; T(670nm-900nm)≥55%;

[0205] TA3: Peak transmittance wavelength is 575-645nm; T(460nm-555nm)≤15%; T(580nm-620nm)≥70%; T(660nm-900nm)≥55%;

[0206] TA4: Valley transmittance wavelength is 550-650nm; T(400nm-500nm)≥45%; T(580nm-645nm)≤10%; T(700nm-900nm)≥50%;

[0207] TA5: Valley transmittance wavelength is 550-675nm; T(425nm-500nm)≥35%; T(550nm-665nm)≤10%; T(700nm-900nm)≥45%;

[0208] TA6: Valley transmittance wavelength is 500-650nm; T(350nm-450nm)≤40%; T(485nm-615nm)≥50%; T(800nm-900nm)≥60%;

[0209] TA7: Valley transmittance wavelength is 575-750nm; T(400nm-570nm)≥45%; T(630nm-730nm)≤10%; T(775nm-900nm)≥50%;

[0210] TA8: Valley transmittance wavelength is 600-750nm; T(460nm-565nm)≥40%; T(620nm-745nm)≤10%; T(800nm-900nm)≥45%;

[0211] TA9: Valley transmittance wavelength is 600-760nm; T(460nm-580nm)≥50%; T(635nm-645nm)≤15%; T(800nm-900nm)≥50%.

[0212] Compare Figure 12 and Figure 8 It is evident that the combination of regular and inverted square truncated pyramid shapes not only helps to separate transmittance curves that are partially overlapped outside the preset wavelength range, but also helps to separate transmittance curves that are partially overlapped within the preset wavelength range, thereby improving the distinguishability between different spectra and enhancing the effect of spectral modulation.

[0213] Furthermore, by combining regular and inverted square truncated pyramid shapes, the transmittance of the spectral chip within the preset wavelength range is also relatively improved.

[0214] In summary, this structure not only optimizes spectral discrimination but also improves the accuracy of spectral modulation, enabling the spectral chip to perform effective modulation and identification over a wider wavelength range. Through this structural optimization, the overall performance of the spectral chip is enhanced, allowing it to better handle complex spectral signal modulation requirements.

[0215] As mentioned earlier, it is often difficult to form a perfect cube or cuboid structure in the ideal filter unit film layer in the process. There will always be a slight slope. The inventors of this application have taken advantage of this defect and amplified it by deliberately making it into the shape of a regular square truncated pyramid and an inverted square truncated pyramid to form an overlapping area. This is easier to achieve in the process preparation, thereby further improving the preparation accuracy and quality.

[0216] Furthermore, the above examples use 500-650nm as the key wavelength band; however, this application is not limited to this. For example, if considering applications in the ultraviolet band spectral imaging field, such as surface defect detection, fluorescence imaging, forensic medicine and security (e.g., bloodstain and fingerprint recognition), and cultural relic identification and restoration, the key wavelength band is between 200-400nm. If considering applications in the infrared band spectral imaging field, such as agriculture, food inspection, medical imaging, security monitoring, and material sorting, the key wavelength band is between 800-1700nm. Based on the teachings of this application, the transmittance curves of the corresponding basic material layers can be designed for the corresponding wavelength bands.

[0217] The second aspect of this application provides a method for fabricating a spectral chip, such as... Figure 13 As shown, it includes:

[0218] S10. A photoelectric sensing layer is formed on a silicon substrate, wherein the photoelectric sensing layer includes a plurality of pixels;

[0219] S15. A spectral modulation layer and a first protective film layer are formed on the photoelectric sensing layer, wherein the spectral modulation layer includes periodically arranged filter units, each filter unit is composed of multiple filter sub-units, and each filter sub-unit has a different transmittance curve; and wherein the first protective film layer includes multiple sub-protective film layers, and at least two filter sub-units in the same filter unit are covered by the same sub-protective film layer.

[0220] In a specific example, the filter unit consists of M rows and N columns of filter sub-units.

[0221] The first protective film layer includes M sub-protective film layers, where the m-th sub-protective film layer covers the N filter sub-units in the m-th row, where m traverses from 1 to M, and M and N are both natural numbers greater than or equal to 2.

[0222] In another specific example, the filter unit consists of M rows and N columns of filter sub-units.

[0223] The first protective film layer includes N sub-protective film layers, where the nth sub-protective film layer covers the M filter sub-units in the nth column, where n traverses from 1 to N, and M and N are both natural numbers greater than or equal to 2.

[0224] In yet another specific example, the filter unit consists of M rows and N columns of filter sub-units.

[0225] The first protective film layer includes a first sub-protective film layer and a second sub-protective film layer, wherein the first sub-protective film layer covers the even-numbered filter sub-units, and the second sub-protective film layer covers the odd-numbered filter sub-units, wherein the odd and even numbers are calculated from the first row and first column to the M-th row and N-th column.

[0226] Next Figure 1 The structure shown is used as an example for specific explanation. Figure 1 In the structure shown, the filter unit includes 3*3 filter sub-units C1-C9, wherein the first row along the first direction (from left to right) consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9.

[0227] Step S15 includes:

[0228] S150, C1-C3 of each filter unit are sequentially formed on the photoelectric sensing layer, such as Figure 14 As shown. Specific process methods for forming the filter sub-unit can be found in CN113497065A;

[0229] S151, Form the first sub-protective film material layer.

[0230] S152. Pattern the first sub-protective film material layer to obtain the first sub-protective film layer, which only covers C1-C3, such as... Figure 15 As shown.

[0231] S153, C4-C6 of each filter unit are sequentially formed on the photoelectric sensing layer, such as Figure 16 As shown.

[0232] S154, Forming a second sub-protective film material layer;

[0233] S155. Pattern the second sub-protective film material layer to obtain the second sub-protective film layer, which only covers C4-C6, as shown. Figure 17 As shown.

[0234] S156. C7-C9 of each filter unit are sequentially formed on the photoelectric sensing layer, such as Figure 18 As shown;

[0235] S157, Forming the third sub-protective film material layer;

[0236] S158. Pattern the third sub-protective film material layer to obtain the third sub-protective film layer, which only covers C4-C6, such as... Figure 19 As shown.

[0237] In another embodiment, still as Figure 1 Taking the structure shown as an example, the filter unit includes 3*3 filter sub-units C1-C9, where the first row along the first direction contains C1-C3, the second row contains C4-C6, and the third row contains C7-C9.

[0238] The formation of a spectral modulation layer and a first protective film layer on the photoelectric sensing layer includes:

[0239] C1, C4 and C7 of each filter unit are sequentially formed on the photoelectric sensing layer;

[0240] Form the first sub-protective film material layer;

[0241] Pattern the first sub-protective film material layer to obtain the first sub-protective film layer, which only covers C1, C4 and C7;

[0242] C2, C5 and C8 of each filter unit are sequentially formed on the photoelectric sensing layer;

[0243] Forming a second protective film material layer;

[0244] The second sub-protective film material layer is patterned to obtain the second sub-protective film layer, which only covers C2, C5 and C8;

[0245] C3, C6 and C9 of each filter unit are sequentially formed on the photoelectric sensing layer;

[0246] Forming a third protective film material layer;

[0247] The third sub-protective film material layer is patterned to obtain a third sub-protective film layer that only covers C3, C6 and C9.

[0248] In yet another embodiment, still using Figure 1 Taking the structure shown as an example, the filter unit includes 3*3 filter sub-units C1-C9, where the first row along the first direction consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9.

[0249] The formation of a spectral modulation layer and a first protective film layer on the photoelectric sensing layer includes:

[0250] C2, C4, C6 and C8 of each filter unit are sequentially formed on the photoelectric sensing layer;

[0251] Form the first sub-protective film material layer;

[0252] Patterning the first sub-protective film material layer yields the first sub-protective film layer, which only covers C2, C4, C6, and C8;

[0253] C1, C3, C5, C7 and C9 of each filter unit are sequentially formed on the photoelectric sensing layer;

[0254] Forming a second protective film material layer;

[0255] The second sub-protective film material layer is patterned to obtain the second sub-protective film layer, which only covers C1, C3, C5, C7 and C9.

[0256] The above description has been given for illustrative and descriptive purposes. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, additions, and sub-combinations therein.

[0257] It should be noted that although the steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effect of this application, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders, and these variations are all within the scope of protection of this application.

[0258] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A spectral chip, characterized in that, The spectral chip includes: A silicon-based substrate, including a photoelectric sensing layer, wherein the photoelectric sensing layer includes a plurality of pixels; A spectral modulation layer is disposed on the photoelectric sensing layer, wherein the spectral modulation layer includes periodically arranged filter units, each filter unit is composed of multiple filter sub-units, and each filter sub-unit has a different transmittance curve. A first protective film layer is disposed on the spectral modulation layer, wherein the first protective film layer includes a plurality of sub-protective film layers, and at least two filter sub-units in the same filter unit are covered by the same sub-protective film layer.

2. The spectral chip according to claim 1, characterized in that, At least two adjacent filter sub-units within the same filter unit are covered by the same sub-protective film layer.

3. The spectral chip according to claim 2, characterized in that, The filtering unit consists of M rows and N columns of filtering sub-units. The first protective film layer includes M sub-protective film layers, where the m-th sub-protective film layer covers the N filter sub-units in the m-th row, where m traverses from 1 to M, and M and N are both natural numbers greater than or equal to 2.

4. The spectral chip according to claim 3, characterized in that, The filter unit includes 3*3 filter subunits C1-C9, wherein the first row along the first direction consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9. The first protective film layer includes three sub-protective film layers, wherein the first sub-protective film layer covers C1-C3, the second sub-protective film layer covers C4-C6, and the third sub-protective film layer covers C7-C9.

5. The spectral chip according to claim 2, characterized in that, The filtering unit consists of M rows and N columns of filtering sub-units. The first protective film layer includes N sub-protective film layers, where the nth sub-protective film layer covers the M filter sub-units in the nth column, where n traverses from 1 to N, and M and N are both natural numbers greater than or equal to 2.

6. The spectral chip according to claim 5, characterized in that, The filter unit includes 3*3 filter subunits C1-C9, wherein the first row along the first direction consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9. The first protective film layer includes three sub-protective film layers, wherein the first sub-protective film layer covers C1, C4 and C7, the second sub-protective film layer covers C2, C5 and C8, and the third sub-protective film layer covers C3, C6 and C9.

7. The spectral chip according to claim 1, characterized in that, At least two non-adjacent filter sub-units within the same filter unit are covered by the same sub-protective film layer.

8. The spectral chip according to claim 7, characterized in that, The filtering unit consists of M rows and N columns of filtering sub-units. The first protective film layer includes a first sub-protective film layer and a second sub-protective film layer, wherein the first sub-protective film layer covers the even-numbered filter sub-units, and the second sub-protective film layer covers the odd-numbered filter sub-units, wherein the odd and even numbers are calculated from the first row and first column to the M-th row and N-th column.

9. The spectral chip according to claim 8, characterized in that, The filtering unit includes 3*3 filtering subunits C1-C9, wherein the first row along the first direction contains C1-C3, the second row contains C4-C6, and the third row contains C7-C9. The first sub-protective film layer covers the C2, C4, C6, and C8 filter sub-units, and the second sub-protective film layer covers the C1, C3, C5, C7, and C9 filter sub-units.

10. The spectral chip according to claim 1, characterized in that, It also includes a second protective film layer disposed between the spectral modulation layer and the photoelectric sensing layer.

11. The spectral chip according to claim 1, characterized in that, The spectral chip also includes a base material layer disposed between the photoelectric sensing layer and the spectral modulation layer, wherein the optical signal incident on the spectral chip is modulated by the spectral modulation layer and the base material layer.

12. The spectral chip according to claim 11, characterized in that, The first transmittance curve shows that the transmittance within the preset wavelength range is higher than the transmittance outside the preset wavelength range.

13. The spectral chip according to claim 12, characterized in that, The waveform of the filter subunit within the preset wavelength range is plateau-shaped, while the final transmittance curve after modulation shows a peak within the preset wavelength range. or If the waveform of the filter subunit has a peak in the preset wavelength range, the final transmittance curve after modulation still shows a peak in the preset wavelength range, and the full width at half maximum (FWHM) of the peak after modulation is smaller than that of the peak before modulation. or If the waveform of the filter subunit is concave within the preset wavelength range, the final transmittance curve after modulation will show a peak within the preset wavelength range.

14. The spectral chip according to claim 1 or 11, characterized in that, There is at least one inclined overlap region between each filter subunit and its adjacent filter subunit, the inclined overlap region being projected onto the silicon substrate and spanning two adjacent pixels.

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