Optical filter and preparation method thereof, image sensor and display device

Abstract

The embodiment of the invention provides an optical filter and a preparation method thereof, an image sensor and a display device, and belongs to the technical field of display and sensing, the optical filter comprises a plurality of dielectric film layers which are arranged in a stacked mode, and the preparation method comprises the steps that ions are injected into a plurality of filtering areas of at least one dielectric film layer through an ion injection technology; in the different light filtering areas, ions of different types or different concentrations are injected into the dielectric film layer. According to the optical filter and the preparation method thereof, the image sensor and the display device provided by the embodiment of the invention, the technological process of forming optical filters with different color channels can be simplified, and the cost is reduced.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of display and sensing technologies, and more particularly, to a filter, a method for manufacturing the same, an image sensor, and a display device. Background Art

[0002] Multispectral and hyperspectral imaging technologies are new imaging technologies. They emerged in the 1980s and have since formed a research and development boom, and are still developing rapidly. Because these technologies have advantages such as imaging and spectral detection, they have now been widely applied in multiple military and civilian fields such as remote sensing, pollution monitoring of the atmosphere, soil, and water bodies, medical diagnosis by spectral imaging, detection of food nutrients, military target reconnaissance, detection, and surveillance.

[0003] The principle of multispectral imaging technology is different from that of traditional single-band imaging. It combines imaging and spectral measurement, and then combines with a multi-channel filter at the light channel entrance to obtain spectral information at specific spectral positions. Most of this information not only contains two-dimensional spatial information but also spectral radiation information distributed with wavelengths. By analyzing the detected spectral information combined with the image of the target, the purpose of spectral detection of traditional targets can be achieved.

[0004] In terms of the working area of the spectral channel, spectral imaging technology can be selected according to different needs in the visible / near-infrared region (0.38 μm to 2.5 μm), mid-infrared band (3 μm to 5 μm), and long-wave infrared band (8 μm to 14 μm). Information about surface objects can be detected in the visible / near-infrared region; spectral radiation characteristic information of high-temperature gases such as aircraft tail jet streams and explosions can be detected in the mid-wave infrared region; long-wave infrared is the main working band for realizing day and night reconnaissance, surveillance, identifying false targets, and eliminating background interference, and it is also the region where the chemical characteristic absorption of many substances occurs.

[0005] Traditional multispectral imaging technology is mainly achieved by adding a filter in front of the optical system. Currently, the process flow for forming different color channels by the filter is relatively complex. Summary of the Invention

[0006] Embodiments of the present application aim to provide a filter, a method for manufacturing the same, an image sensor, and a display device, aiming to simplify the process flow of the filter for forming different color channels and reduce costs.

[0007] A first aspect of an embodiment of the present application provides a method for manufacturing a filter. The filter includes a plurality of dielectric film layers stacked on top of each other. The manufacturing method includes:

[0008] Injecting ions into a plurality of filter regions of at least one of the dielectric film layers through an ion implantation process;

[0009] Among them, in different ones of the said light filtering regions, different types or different concentrations of ions are implanted into the dielectric film layer.

[0010] Optionally, the multiple light filtering regions include a first light filtering region, a second light filtering region, and a third light filtering region, and the preparation method includes:

[0011] Using a mask plate to block the first light filtering region, and implanting ions of a first concentration or a first type into the second light filtering region and the third light filtering region through an ion implantation process;

[0012] Using a mask plate to block the first light filtering region and the second light filtering region, and implanting ions of a second concentration or a second type into the third light filtering region through an ion implantation process.

[0013] Optionally, the multiple light filtering regions include a first light filtering region, a second light filtering region, and a third light filtering region, and the preparation method includes:

[0014] Using a mask plate to block the first light filtering region and the third light filtering region, and implanting ions of a first concentration or a first type into the second light filtering region through an ion implantation process;

[0015] Using a mask plate to block the first light filtering region and the second light filtering region, and implanting ions of a second concentration or a second type into the third light filtering region through an ion implantation process.

[0016] Optionally, the multiple light filtering regions include a first light filtering region, a second light filtering region, and a third light filtering region, and the preparation method includes:

[0017] Using a first mask plate to block the first light filtering region, using a second mask plate to block the second light filtering region, using a third mask plate to block the third light filtering region, and implanting ions of a first concentration or a first type into the first light filtering region, the second light filtering region, and the third light filtering region through an ion implantation process;

[0018] Among them, the first mask plate, the second mask plate, and the third mask plate respectively have an opening array with different aperture ratios.

[0019] The second aspect of the embodiments of the present application provides a filter, including:

[0020] Multiple dielectric film layers stacked;

[0021] At least one of the multiple dielectric film layers has multiple light filtering regions;

[0022] Among them, in different ones of the filter regions, different types or different concentrations of ions are doped in the dielectric film layer, and the ions are implanted into the dielectric film layer by an ion implantation process.

[0023] Optionally, the multiple dielectric film layers include a cavity film layer and mirror layers on both sides of the cavity film layer, and the cavity film layer has multiple ones of the filter regions;

[0024] Among them, in different ones of the filter regions, different types or different concentrations of ions are doped in the cavity film layer.

[0025] Optionally, the cavity film layer includes a plurality of sub-film layers arranged in a stacked manner;

[0026] In different ones of the filter regions, different types or different concentrations of ions are doped in each of the sub-film layers.

[0027] Optionally, the refractive indices of two adjacent ones of the plurality of sub-film layers are different.

[0028] Optionally, in different ones of the filter regions, different types or different concentrations of ions are doped in the mirror layer on at least one side of the cavity film layer.

[0029] Optionally, the mirror layer includes a plurality of first film layers and a plurality of second film layers arranged in a stacked manner, the first film layers and the second film layers are arranged in an overlapping manner, and the refractive index of the first film layer is different from the refractive index of the second film layer.

[0030] Optionally, the multiple dielectric film layers include first dielectric film layers and second dielectric film layers arranged alternately, and the refractive index of the first dielectric film layer is different from the refractive index of the second dielectric film layer.

[0031] Optionally, the multiple dielectric film layers include first dielectric film layers, second dielectric film layers and third dielectric film layers arranged alternately, the refractive index of the first dielectric film layer is different from the refractive index of the second dielectric film layer, and the material of the dielectric film layer is a metal material.

[0032] Optionally, the ions include H + 、He + 、Li + 、B + 、N + 、Na + 、Ar + 、Si + and Bi + and at least one of them.

[0033] Optionally, when the ions are H + 、He + 、Li + 、B+ , N + , Na + and Ar + When the ions are, the concentration of the ions is greater than or equal to 0.1×10 16 ions / cm 2 , and less than or equal to 90×10 16 ions / cm 2 ;

[0034] When the ions are Si + and Bi + When the ions are, the concentration of the ions is greater than or equal to 0.1×10 15 ions / cm 2 , and less than or equal to 90×10 15 ions / cm 2 .

[0035] The third aspect of the embodiments of the present application provides an image sensor, including the filter provided in the second aspect of the embodiments of the present application.

[0036] The fourth aspect of the embodiments of the present application provides a display device, including the filter provided in the second aspect of the embodiments of the present application.

[0037] Beneficial effects:

[0038] The present application provides a filter and its preparation method, an image sensor and a display device. By means of an ion implantation process, different types or different concentrations of ions are implanted into different light filtering regions of at least one dielectric film layer of the filter, so that the refractive indexes of different light filtering regions of the dielectric film layer are changed, thereby causing the positions of the light filtering wave peaks of different light filtering regions of the dielectric film layer to shift, and further enabling the filter to form different color channels. At the same time, the preparation method effectively simplifies the process flow, eliminates the need for an etching process, is conducive to the formation of more color channels, and reduces the production cost. Description of the drawings

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 is a schematic structural diagram of a filter proposed in an embodiment of the present application;

[0041] Figure 2 is a schematic structural diagram of a filter including a cavity film layer and a mirror layer proposed in an embodiment of the present application;

[0042] Figure 3 It is a schematic structural diagram of a filter including a cavity film layer with multiple sub-film layers and a mirror layer proposed in an embodiment of the present application;

[0043] Figure 4 It is a schematic structural diagram of a filter including a cavity film layer and a mirror layer, and ions are implanted into the mirror layer on the lower side of the cavity film layer proposed in an embodiment of the present application;

[0044] Figure 5 It is a schematic structural diagram of a filter including a cavity film layer and a mirror layer, and ions are implanted into the mirror layer on the upper side of the cavity film layer proposed in an embodiment of the present application;

[0045] Figure 6 It is a schematic structural diagram of a filter including a cavity film layer and a mirror layer, and ions are implanted into the mirror layers on both sides of the cavity film layer proposed in an embodiment of the present application;

[0046] Figure 7 It is a schematic structural diagram of a filter including multiple first dielectric film layers and second dielectric film layers proposed in an embodiment of the present application;

[0047] Figure 8 It is a schematic structural diagram of a filter including multiple first dielectric film layers, second dielectric film layers and third dielectric film layers proposed in an embodiment of the present application;

[0048] Figure 9 It is a schematic process flow diagram of a method for preparing a filter proposed in an embodiment of the present application;

[0049] Figure 10 It is a schematic diagram of completing ion implantation in the second filter region and the third filter region in a method for preparing a filter proposed in an embodiment of the present application;

[0050] Figure 11 It is a schematic diagram of completing ion implantation in the third filter region in a method for preparing a filter proposed in an embodiment of the present application;

[0051] Figure 12 It is a schematic diagram of completing ion implantation in the second filter region in a method for preparing a filter proposed in an embodiment of the present application;

[0052] Figure 13 It is a schematic diagram of completing ion implantation in the third filter region in a method for preparing a filter proposed in an embodiment of the present application;

[0053] Figure 14 It is a schematic diagram of simultaneously completing ion implantation in the first filter region, the second filter region and the third filter region in a method for preparing a filter proposed in an embodiment of the present application;

[0054] Figure 15 It is a schematic diagram of a first mask plate, a second mask plate, and a third mask plate in a method for preparing a filter according to an embodiment of the present application.

[0055] Explanation of reference numerals: 10, dielectric film layer; 101, first filter region; 102, second filter region; 103, third filter region; 11, cavity film layer; 111, sub-film layer; 12, mirror layer; 121, first film layer; 122, second film layer; 13, first dielectric film layer; 14, second dielectric film layer; 15, third dielectric film layer; 20, mask plate; 21, first mask plate; 22, second mask plate; 23, third mask plate. Specific embodiments

[0056] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0057] In a related art, each color channel of the filter uses a different film layer design. Multiple coating, lithography, and stripping using a metal sacrificial layer are performed on each color channel, and finally a multi-channel narrowband filtering pixel array is formed. The formation of each color channel in this solution requires complex processes, high costs, and is not conducive to the formation of too many color channels. The film layer structures of different color channels are different, which will cause step difference problems and film layer overlap problems after pixelization. This solution can also use an etching process instead of a stripping process, but it is easy to have problems such as damage to the shared film layer or interface, and the problem of a serrated cross-section caused by different etching rates of different film layers.

[0058] In another related art, a design of sharing upper and lower film layers for each color channel of the filter is adopted. Different non-shared film layers in the middle are used for different color channels, and different non-shared film layers of different colors can be cumulatively deposited between different colors. Since this solution requires etching treatment of the non-shared film layer, it is generally easy to have problems such as damage to the shared film layer or interface. Moreover, since the etching process has certain requirements for the coating materials, it may lead to high-quality materials in many optical coatings (such as S4, NbO x 、TiO xProblems such as () cannot be used, ultimately limiting the performance of the dielectric filter film. Since non-shared film layers generally tend to select one material or are limited by the step height limit, only a single cavity or a small number of microcavity designs can be adopted, which is also not conducive to narrowing the full width at half maximum of the filter spectrum of the filter film and eliminating crosstalk colors, ultimately limiting the performance of the dielectric filter film. Similarly, problems such as a zigzag cross-section caused by different etching rates of different film layers will also occur. Moreover, due to different film layer structures in different color channels, step height problems and film layer overlap problems will occur after pixelation.

[0059] In view of this, embodiments of the present application propose a filter, a preparation method thereof, an image sensor, and a display device. Through an ion implantation process, different types or different concentrations of ions are implanted into different filter regions of at least one dielectric film layer of the filter, so that the refractive index of different filter regions of the dielectric film layer changes, thereby causing the filter wave peak positions of different filter regions of the dielectric film layer to shift, and further enabling the filter to form different color channels. At the same time, this preparation method effectively simplifies the process flow, eliminates the need for an etching process, is conducive to the formation of more color channels, and reduces production costs.

[0060] Referring to Figure 1 As shown, a filter disclosed in an embodiment of the present application includes a plurality of dielectric film layers 10 stacked.

[0061] Specifically, at least one of the plurality of dielectric film layers 10 has a plurality of filter regions (exemplarily, including a first filter region 101, a second filter region 102, and a third filter region 103), and in different filter regions, different types or different concentrations of ions are doped in the dielectric film layer 10, and these ions are implanted into the dielectric film layer 10 through an ion implantation process. It should be noted that the ion concentrations or types doped in each filter region are all different, that is, the ion concentrations or types doped in any two filter regions are different. Exemplarily, the ion types doped in any two adjacent filter regions may be the same, but the ion concentrations must be different; or, the ion concentrations doped in any two adjacent filter regions may be the same, but the ion types must be different; or, the ion types and ion concentrations doped in any two adjacent filter regions are both different.

[0062] Ion implantation process is to use an accelerator or an ion implanter to accelerate charged ions into an ion beam with an energy of tens of thousands or even millions of electron volts, and inject it into the surface of a solid material. The implanted ions will cause changes in the surface composition or microstructure of the material. Therefore, the physical, chemical or mechanical properties of the material surface will change after implantation. Among them, when ions are implanted into the material surface, the refractive index of the surface layer (within a certain depth range) of the optical material can be changed, so that different refractive index distributions of the surface layer of the optical material can be prepared by controlling the energy and dose.

[0063] Therefore, after injecting different concentrations or different types of ions into different light filtering regions of the dielectric film layer 10, the equivalent refractive index of different light filtering regions of the dielectric film layer 10 can be changed, thereby changing the optical film thickness of different light filtering regions of the dielectric film layer 10, causing the light filtering peak positions of different light filtering regions of the dielectric film layer 10 to shift, so that the filter forms multiple different color channels.

[0064] And through the ion implantation process, the original characteristics of the implanted material and the smoothness of the surface can be maintained. Ion implantation can make the overall performance of the implanted material unaffected. At the same time, by precisely controlling the number of implanted ions, the degree of damage formed during the implantation process can be controlled; by controlling the energy and type of ions, the depth distribution of ion implantation in the crystal can be controlled. In addition, there are a wide variety of doping ion types available for the ion implantation process, which is not affected by the diffusion coefficient and solid solubility of the material.

[0065] Compared with the solutions in the related art, the filter provided by the embodiment of the present application can effectively avoid the repeated deposition and peeling of dozens or even hundreds of film layers each time for different filter film layers when forming different color channels, which is beneficial to the formation of more color channels and the reduction of costs; and avoid the problem of serrated cross-section caused by different etching rates of different film layers during film layer etching, and avoid the damage problem of the common film layer or interface caused by the etching of non-common film layers; and avoid the step difference problem caused by different film layer structures of different color channels after pixelation, and the film layer overlap problem caused by the separate deposition of different color channel film layers.

[0066] Through the filter provided by the embodiment of the present application, the process flow can be effectively simplified, the etching process is not required, and the finally formed filter is a completely planar structure, which is beneficial to the subsequent semiconductor fine process flow, and the fine bonding with a CMOS (Complementary Metal Oxide Semiconductor) sensor or a silicon-based microdisplay, greatly improving the performance of the product.

[0067] In an alternative embodiment, refer to Figure 2As shown in the figure, an embodiment of the present application further provides a filter. In this filter, a plurality of dielectric film layers 10 include a cavity film layer 11 and mirror layers 12 located on both sides of the cavity film layer 11. The cavity film layer 11 is also the resonant cavity in the filter. The cavity film layer 11 and the mirror layer 12 usually select two materials with different high and low refractive indices as the film materials of the entire filter.

[0068] Specifically, the mirror layer 12 includes a plurality of first film layers 121 and a plurality of second film layers 122 (which can also be called a dielectric film 1 / 4 wave plate stack) arranged in a stacked manner. The first film layers 121 and the second film layers 122 are overlapped, that is, there is a second film layer 122 between two adjacent first film layers 121, and there is a first film layer 121 between two adjacent second film layers 122, and the refractive index of the first film layer 121 is different from that of the second film layer 122. Exemplarily, the first film layer 121 can select a material with a higher refractive index, such as NbO x (where the reference value of x is 2.5), TiO x (where the reference value of x is 5 / 3 or 2), TaO x (where the reference value of x is 2), SiN x (where the reference value of x is 4 / 3 - 1 to 4 / 3), SiN x O y 、SiN x O y C z 、AlO x (where the reference value of x is 1.5), SiC, etc. The second film layer 122 can select a material with a lower refractive index, such as SiO x (where the reference value of x is 2), MgF 2 、LiF、SiN x O y 、SiN x O y C z etc. Here, x, y, z are used to represent the element ratio between different elements in the material during the actual film deposition process. This ratio gives a reference ratio for some materials, but it does not exclude making certain adjustments on this basis to control the actual refractive index of the film-forming material. The cavity film layer 11 is formed by one of the first film layer 121 or the second film layer 122. Of course, the cavity film layer 11 can be formed by a material different from the first film layer 121 and the second film layer 122.

[0069] This filter is generally of the transmissive type. The optical thickness (refractive index * physical thickness) of the cavity film layer 11 determines the center wavelength of the transmission peak. The reference wavelength of the dielectric film 1 / 4-wave plate stack determines the center wavelength of the mirror (the non-transmissive region around the center wavelength of the transmission peak). The refractive index difference between materials with different high and low refractive indices determines the full width at half maximum of the transmission peak and the width of the non-transmissive region around the center wavelength of the transmission peak. This filter can also be of the reflective type, and it can be achieved by appropriately adjusting the combination of the optical thickness of the cavity film layer 11 and the reference wavelength of the dielectric film 1 / 4-wave plate stack.

[0070] Meanwhile, referring to Figure 2 shown, in this embodiment, the cavity film layer 11 has multiple filter regions (exemplarily, including a first filter region 101, a second filter region 102, and a third filter region 103), and in different filter regions, different types or different concentrations of ions are doped in the cavity film layer 11.

[0071] In this way, through the ion implantation process, different concentrations of ions are implanted into different filter regions in the cavity film layer 11 to change the equivalent refractive index of different filter regions, thereby changing the equivalent optical film thickness of different filter regions, and further changing the cavity length of the cavity film layer 11, realizing the position shift of the filter wave peaks in different filter regions of the cavity film layer 11, and then forming multiple different color channels. At this time, ions with a larger implantation depth (the implantation depth refers to the degree to which ions can be implanted into the dielectric film layer 10. The larger the implantation depth, the easier it is for ions to penetrate the dielectric film layer 10) can be selected, such as H + 、He + 、B + 、N + 、Na + 、Ar + 、Si + or Bi + and other light ions with low mass. In addition, in order to achieve a larger implantation depth, a higher acceleration voltage can also be selected when implanting ions.

[0072] For different types of ions, the concentration range of ions is also different. When the ions are H + 、He + 、Li + 、B + 、N + 、Na + and Ar + ,the concentration of ions is greater than or equal to 0.1×10 16 ions / cm 2 ,and less than or equal to 90×10 16 ions / cm 2 . Exemplarily, when the ions are H + 、He +, Li + , B + , N + , Na + and Ar + When the ions are Li, B, N, Na, and Ar, the concentration of the ions can be 0.1×10 16 ions / cm 2 , 10×10 16 ions / cm 2 , 50×10 16 ions / cm 2 , 70×10 16 ions / cm 2 , 90×10 16 ions / cm 2 and so on.

[0073] When the ions are Si + and Bi + , the concentration of the ions is greater than or equal to 0.1×10 15 ions / cm 2 , and less than or equal to 90×10 15 ions / cm 2 ; Exemplarily, when the ions are Si + and Bi + , the concentration of the ions can be 0.1×10 15 ions / cm 2 , 10×10 15 ions / cm 2 , 50×10 15 ions / cm 2 , 70×10 15 ions / cm 2 , 90×10 15 ions / cm 2 and so on.

[0074] Those skilled in the art can select the type and concentration of the ions according to actual needs, so that different light filtering regions of the light filter have different refractive indices.

[0075] Here, the number of light filtering regions is not limited to three. The light filtering regions can be four, five or more. The material of the cavity film layer 11 can be a low refractive index material or a high refractive index material; the mirror layer 12 can include one or more pairs of the first film layer 121 and the second film layer 122, and it can be controlled according to needs which film layer in contact with the substrate first is the first film layer 121 or the second film layer 122, and which is the outermost film layer on the opposite side of the substrate, the first film layer 121 or the second film layer 122.

[0076] In one embodiment, referring to Figure 3As shown, the cavity film layer 11 may include a plurality of sub-film layers 111 arranged in a stacked manner.

[0077] Specifically, the number of the plurality of sub-film layers 111 may be four, five or more. It can be understood that the material of the sub-film layer 111 is also the same as that of the first film layer 121 or the second film layer 122, and the plurality of sub-film layers 111 are also alternately arranged according to the refractive index from high to low. Of course, the sub-film layer 111 may also include other materials different from those of the first film layer 121 and the second film layer 122.

[0078] In this embodiment, each sub-film layer 111 has a plurality of different light-transmitting regions, and in different light-transmitting regions, different types or different concentrations of ions are doped in each sub-film layer 111. It should be noted that each light-transmitting region of each sub-film layer 111 is relatively arranged, and the ion concentration and type doped in the corresponding light-transmitting region of each sub-film layer 111 are the same.

[0079] In one embodiment, referring to Figure 4 、 Figure 5 and Figure 6 As shown, in different light-filtering regions, different types or different concentrations of ions are doped in the mirror layer 12 on at least one side of the cavity film layer 11.

[0080] Specifically, referring to Figure 4 and Figure 5 As shown, ions can be implanted into the mirror layer 12 on any side of the cavity film layer 11 through an ion implantation process, or, referring to Figure 6 As shown, ions are implanted into the mirror layers 12 on both sides of the cavity film layer 11. In this way, it is equivalent to adjusting the equivalent optical film thickness of the cavity film layer 11 and the reference wavelength of the dielectric film 1 / 4-wave plate stack at the same time, thereby realizing the formation of different color channels of the filter.

[0081] In this embodiment, ions with a relatively large implantation depth need to be selected, such as H + 、He + 、B + and other light ions. In addition, in order to achieve a greater implantation depth, a higher acceleration voltage can also be selected when implanting ions.

[0082] In one embodiment, the material of the mirror layer 12 can be selected as a metal material.

[0083] Specifically, the mirror layer 12 can be composed of metal materials such as Ag, Al, and Au, and a film layer of other materials (such as SiO2, etc.) can be formed on the surface of the mirror layer 12 formed by the metal material. This film layer is used to cover the mirror layer 12 formed by the metal material or improve the reflectivity of the mirror layer 12 formed by the metal material. This filter is generally of the transmissive type, and the optical thickness of the cavity film layer 11 determines the central wavelength of the transmission peak. This filter can also be of the reflective type, and only the optical thickness of the cavity film layer 11 needs to be appropriately adjusted.

[0084] In one embodiment, multiple cavity film layers 11 can be provided. That is to say, in this embodiment, the filter has multiple resonant cavities. At this time, the filter can achieve multiple main filter peaks, or be used to improve the filtering performance of a single-resonant-cavity filter (for example, making the filter wave peak wider or narrower, and the cut-off band wider, with less stray light in the cut-off band, or improving the angular response characteristics of the filter).

[0085] In an alternative embodiment, referring to Figure 7 as shown, the embodiment of the present application further provides a filter. In this filter, the multiple dielectric film layers 10 include alternately arranged first dielectric film layers 13 and second dielectric film layers 14, and the refractive index of the first dielectric film layer 13 is different from that of the second dielectric film layer 14.

[0086] Specifically, in this embodiment, the filter does not have a cavity film layer 11. The first dielectric film layer 13 can be understood as the first film layer 121 in the mirror layer 12, and the second dielectric film layer 14 can be understood as the second film layer 122 in the mirror layer 12. Among them, the thickness of each layer of film material has no obvious rule and is completely optimized by a computer algorithm according to the filtering requirements of the transmissive or reflective filter. In practical applications, generally two materials with different high and low refractive indexes are selected as the film material of the entire filter. Of course, it is not limited to two materials with different high and low refractive indexes.

[0087] In one embodiment, referring to Figure 8 as shown, in addition to the first dielectric film layer 13 and the second dielectric film layer 14, the multiple dielectric film layers 10 further include a third dielectric film layer 15.

[0088] Specifically, the first dielectric film layer 13 and the second dielectric film layer 14 are still formed by two materials with different refractive indexes, and the third dielectric film layer 15 is formed by a metal material. And in this filter, the thickness of each layer of film material has no obvious rule and is completely optimized by a computer algorithm according to the filtering requirements of the transmissive or reflective filter. In practical applications, generally two materials with different high and low refractive indexes and a thin metal film material are selected as the film material of the entire filter. Of course, it is not limited to this.

[0089] Figure 9The figure shows a schematic process flow diagram of a method for preparing a filter. Referring to Figure 9 As shown, an embodiment of the present application also discloses a method for preparing a filter, and the preparation method includes:

[0090] Step S01: Inject ions into a plurality of filter regions of at least one dielectric film layer 10 through an ion implantation process; wherein, in different filter regions, different types or different concentrations of ions are implanted into the dielectric film layer 10.

[0091] Specifically, the ion implantation process is to use an accelerator or an ion implanter to accelerate charged ions into an ion beam with an energy of tens of thousands or even millions of electron volts, and inject it into the surface of a solid material. The implanted ions will cause changes in the surface composition or microstructure of the material, so the physical, chemical or mechanical properties of the material surface will change after implantation. Among them, when ions are implanted into the material surface, the refractive index of the surface layer (within a certain depth range) of the optical material can be changed, so that different refractive index distributions of the surface layer of the optical material can be prepared by controlling the energy and dose.

[0092] Therefore, after injecting different concentrations or different types of ions into different filter regions of the dielectric film layer 10, the equivalent refractive index of different filter regions of the dielectric film layer 10 can be changed, thereby changing the optical film thickness of different filter regions of the dielectric film layer 10, so that the filter peak positions of different filter regions of the dielectric film layer 10 shift, so that the filter forms multiple different color channels.

[0093] Next, an embodiment of the present application will use a filter including three filter regions to illustrate three ways of ion implantation in different filter regions. It can be understood that the three filter regions are the first filter region 101, the second filter region 102, and the third filter region 103 respectively.

[0094] In the first method, among the steps of injecting ions into a plurality of filter regions of at least one dielectric film layer 10 through an ion implantation process, the preparation method includes:

[0095] Step S011: Use a mask plate 20 to block the first filter region 101, and inject ions of the first concentration or the first type into the second filter region 102 and the third filter region 103 through an ion implantation process.

[0096] Specifically, the mask plate 20 can be a pixelated photoresist mask formed by multiple times of spin coating, exposure, and development, or a metal (such as Ti, Mo, Cr, etc.) or dielectric pixelated mask formed by multiple times of thin film deposition, spin coating, exposure, development, etching (or stripping).

[0097] After covering the first filter region 101 with the mask plate 20, ions of the first concentration or the first type are implanted into the second filter region 102 and the third filter region 103 through an ion implantation process. At this time, the second filter region 102 and the third filter region 103 are doped with ions of the first concentration or the first type, while the first filter region 101 is not doped with ions, as Figure 10 shown.

[0098] Step S012: Cover the first filter region 101 and the second filter region 102 with the mask plate 20, and implant ions of the second concentration or the second type into the third filter region 103 through an ion implantation process.

[0099] Specifically, after covering the first filter region 101 and the second filter region 102 with the mask plate 20, ions of the second concentration or the second type are implanted into the third filter region 103 through an ion implantation process. At this time, the third filter region 103 is doped with both ions of the first concentration or the first type and ions of the second concentration or the second type, the second filter region 102 is doped with ions of the first concentration or the first type, while the first filter region 101 is not doped with ions, as Figure 11 shown.

[0100] In this way, different types or different concentrations of ions are doped in the first filter region 101, the second filter region 102, and the third filter region 103, so that different color channels can be formed on the filter.

[0101] In the second method, among the steps of implanting ions into multiple filter regions of at least one dielectric film layer 10 through an ion implantation process, the preparation method includes:

[0102] Step S013: Cover the first filter region 101 and the third filter region 103 with the mask plate 20, and implant ions of the first concentration or the first type into the second filter region 102 through an ion implantation process.

[0103] Specifically, after covering the first filter region 101 and the third filter region 103 with the mask plate 20, ions of the first concentration or the first type are implanted into the second filter region 102 through an ion implantation process. At this time, the second filter region 102 is doped with ions of the first concentration or the first type, while the first filter region 101 and the third filter region 103 are not doped with ions, as Figure 12 shown.

[0104] Step S014: Cover the first filter region 101 and the second filter region 102 with the mask plate 20, and implant ions of the second concentration or the second type into the third filter region 103 through an ion implantation process.

[0105] Specifically, after using the mask 20 to block the first filter region 101 and the second filter region 102, ions of the second concentration or the second type are implanted into the third filter region 103 through an ion implantation process. At this time, the third filter region 103 is doped with ions of the second concentration or the second type, the second filter region 102 is doped with ions of the first concentration or the first type, and the first filter region 101 is not doped with ions, as Figure 13 shown.

[0106] In this way, different types or different concentrations of ions are doped in the first filter region 101, the second filter region 102, and the third filter region 103, so that different color channels can be formed on the filter. The main difference between the second method and the first method is that in the third filter region 103, in the first method, the two types of ions are cumulatively shared, while in the second method, the injection is carried out separately.

[0107] In the third method, among the steps of implanting ions into multiple filter regions of at least one dielectric film layer 10 through an ion implantation process, the preparation method includes:

[0108] Step S015: Use the first mask 21 to block the first filter region 101, use the second mask 22 to block the second filter region 102, use the third mask 23 to block the third filter region 103, and implant ions of the first concentration or the first type into the first filter region 101, the second filter region 102, and the third filter region 103 through an ion implantation process.

[0109] Specifically, in the third method, the first mask 21, the second mask 22, and the third mask 23 respectively have an opening array with different opening ratios. That is to say, the control of the ion implantation dose between different filter regions is controlled by the opening ratio of the opening array on the mask 20 corresponding to each filter region in the patterned mask. At this time, all filter regions can be prepared simultaneously through one ion implantation, and there is no need for one more ion implantation for each additional filter region, which simplifies the process flow again, as Figure 14 shown. It can be understood that the first mask 21, the second mask 22, and the third mask 23 can be an integral mask 20.

[0110] Figure 15 Fig. shows an example structure of the patterned mask 20 with an opening array having different opening ratios. The control of the opening ratio of the opening array can be achieved through relevant factors such as the density of the openings, the size of the openings, the shape of the openings, the arrangement pattern of the opening array, and the material of the mask. Here, only the case of the same density, different pore diameters, and square grid arrangement is taken as an example, and the same effect can be achieved for other similar principle cases.

[0111] Based on the same inventive concept, an embodiment of the present application further discloses an image sensor, which includes a sensor body and any one of the filter films as described in the foregoing embodiments of the present application provided on the sensor body.

[0112] Specifically, the sensor body may be a CMOS or a CCD (Charge Coupled Device) image sensor.

[0113] Based on the same inventive concept, an embodiment of the present application further discloses a display device, which includes a display panel and any one of the filter films as described in the foregoing embodiments of the present application provided on the display panel.

[0114] Specifically, the display panel may include an LCD (Liquid Crystal Display) display panel, an LCOS (Liquid Crystal on Silicon) display panel, an OLED (Organic Electroluminescence Display) display panel, an LED (Light-Emitting Diode) display panel, and the like.

[0115] The display device may include a computer monitor, a television, a billboard, a laser printer with a display function, a telephone, a mobile phone, a personal digital assistant (PDA), a laptop computer, a digital camera, a portable video camera, a viewfinder, a vehicle, a large-area wall, a screen in a theater, or a stadium sign, etc.

[0116] It should be noted that the various embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference may be made to each other.

[0117] It should also be noted that in this text, the orientation or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. This is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. In addition, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations, nor can they be construed as indicating or implying relative importance. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or terminal device comprising the element.

[0118] The technical solutions provided by the present application have been introduced in detail above. Specific examples are used in this text to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only for helping to understand the present application, and the content of this specification should not be construed as a limitation to the present application. At the same time, for those of ordinary skill in the art, based on the present application, there will be various forms of changes in the specific implementation manners and application scopes. It is not necessary and impossible to list all the implementation manners here, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for preparing a filter, characterized in that, the filter comprises a plurality of dielectric film layers arranged in a stack, and the preparation method comprises: injecting ions into a plurality of filter regions of at least one of the dielectric film layers through an ion implantation process; wherein, in different filter regions, different types or different concentrations of ions are injected into the dielectric film layer.

2. The method for preparing a filter according to claim 1, characterized in that, the plurality of filter regions include a first filter region, a second filter region and a third filter region, and the preparation method comprises: using a mask plate to block the first filter region, and injecting ions of a first concentration or a first type into the second filter region and the third filter region through an ion implantation process; using a mask plate to block the first filter region and the second filter region, and injecting ions of a second concentration or a second type into the third filter region through an ion implantation process.

3. The method for preparing a filter according to claim 1, characterized in that, the plurality of filter regions include a first filter region, a second filter region and a third filter region, and the preparation method comprises: using a mask plate to block the first filter region and the third filter region, and injecting ions of a first concentration or a first type into the second filter region through an ion implantation process; using a mask plate to block the first filter region and the second filter region, and injecting ions of a second concentration or a second type into the third filter region through an ion implantation process.

4. The method for preparing a filter according to claim 1, characterized in that, the plurality of filter regions include a first filter region, a second filter region and a third filter region, and the preparation method comprises: using a first mask plate to block the first filter region, using a second mask plate to block the second filter region, using a third mask plate to block the third filter region, and injecting ions of a first concentration or a first type into the first filter region, the second filter region and the third filter region through an ion implantation process; wherein, the first mask plate, the second mask plate and the third mask plate respectively have an opening array with different aperture ratios.

5. A filter, characterized in that, comprising: a plurality of dielectric film layers arranged in a stack; at least one of the plurality of dielectric film layers has a plurality of filter regions; wherein, in different filter regions, different types or different concentrations of ions are doped in the dielectric film layer, and the ions are injected into the dielectric film layer through an ion implantation process.

6. The method for preparing a filter according to claim 5, characterized in that: the plurality of dielectric film layers include a cavity film layer and mirror layers located on both sides of the cavity film layer, and the cavity film layer has a plurality of the filter regions; wherein, in different filter regions, different types or different concentrations of ions are doped in the cavity film layer.

7. The filter according to claim 6, characterized in that: the cavity film layer includes a plurality of sub-film layers arranged in a stack; in different filter regions, different types or different concentrations of ions are doped in each sub-film layer.

8. The manufacturing method of the filter according to claim 6, wherein: in different said filter regions, different types or different concentrations of ions are doped in the mirror layer on at least one side of the cavity film layer.

9. The manufacturing method of the filter according to claim 8, wherein: the mirror layer includes a plurality of first film layers and a plurality of second film layers arranged in a stack, the first film layers and the second film layers are arranged in an overlapping manner, and the refractive index of the first film layer is different from that of the second film layer.

10. The filter according to claim 5, wherein: the plurality of dielectric film layers include alternately arranged first dielectric film layers and second dielectric film layers, and the refractive index of the first dielectric film layer is different from that of the second dielectric film layer.

11. The filter according to claim 5, wherein: the plurality of dielectric film layers include alternately arranged first dielectric film layers, second dielectric film layers and third dielectric film layers, the refractive index of the first dielectric film layer is different from that of the second dielectric film layer, and the material of the dielectric film layer is a metal material.

12. The filter according to any one of claims 5-11, wherein: The ions include H + , He + , Li + , B + , N + , Na + , Ar + , Si + and Bi + and at least one of them.

13. The filter according to claim 12, wherein: When the ion is H + , He + , Li + , B + , N + , Na + and Ar + , the concentration of the ion is greater than or equal to 0.1×10 16 ions / cm 2 , and less than or equal to 90×10 16 ions / cm 2 ; When the ions are Si + and Bi + the concentration of the ions is greater than or equal to 0.1×10 15 ions / cm 2 and less than or equal to 90×10 15 ions / cm 2 .

14. An image sensor, wherein, it includes a sensor body and a filter as claimed in any one of claims 5-13 provided on the sensor body.

15. A display device, wherein, it includes a display panel and a filter as claimed in any one of claims 5-13 provided on the display panel.

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