Spectral filter, and image sensor and electronic device comprising the same

Abstract

A spectral filter, a method of manufacturing the spectral filter, and an image sensor and an electronic device each including the spectral filter are provided. The spectral filter includes a plurality of first reflective layers disposed apart from each other, and a plurality of cavities disposed between the plurality of first reflective layers. The cavities have different thicknesses according to center wavelengths. Each of the cavities includes a plurality of etch stop layers having a constant total thickness according to the center wavelengths, and at least one dielectric layer having a total thickness that varies according to the center wavelengths, wherein the etch stop layers include a material having an etch selectivity different from that of the dielectric layer.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2020-0089857, filed on July 20, 2020, Korean Patent Application No. 10-2021-0060948, filed on May 11, 2021, and Korean Patent Application No. 10-2021-0071713, filed on June 2, 2021, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to spectral filters and image sensors and electronic devices that include said spectral filters. Background Technology

[0004] Image sensors using spectral filters are among the most important optical instruments in the field of optics. However, image sensors, which incorporate various optical components according to relevant technologies, are often large and bulky. Recently, driven by the demand for miniaturization of image sensors, research has been conducted on simultaneously implementing integrated circuits and optical elements on a single semiconductor chip. Summary of the Invention

[0005] A spectral filter is provided, as well as an image sensor and an electronic device that both include the spectral filter.

[0006] Additional aspects will be set forth in part in the description which follows, and will become clear in part from the description, or may be learned by practice of exemplary embodiments of this disclosure.

[0007] According to one aspect of this disclosure, a spectral filter may include: a plurality of first reflective layers spaced apart from and facing each other; and at least a first cavity and a second cavity disposed between the plurality of first reflective layers, wherein the first cavity has a different thickness than the second cavity, the thickness of the first cavity being determined according to a first center wavelength, and the thickness of the second cavity being determined according to a second center wavelength, wherein each of the first cavity and the second cavity includes a plurality of etch stop layers having a constant total thickness, the first cavity including one or more dielectric layers having a first total thickness, and the second cavity including one or more dielectric layers having a second total thickness, wherein the first total thickness and the second total thickness are different from each other according to the first center wavelength of the first cavity and the second center wavelength of the second cavity.

[0008] The spectral filter may further include a third cavity, wherein the first cavity, the second cavity, and the third cavity are arranged in a two-dimensional manner between the plurality of first reflective layers.

[0009] The difference between the refractive index of the material included in the one or more dielectric layers and the refractive index of the material included in the etch stop layer may be less than or equal to 2.5. The difference between the refractive index of the material included in the one or more dielectric layers and the refractive index of the material included in the etch stop layer may be less than or equal to 1.

[0010] The spectral filter may have one or more dielectric layers comprising silicon, silicon oxide, or silicon nitride. The etch stop layer comprises silicon oxide, titanium oxide, or hafnium oxide, and wherein the etch stop layer comprises a material whose etch selectivity differs from that of the one or more dielectric layers by a factor of 5 or greater.

[0011] The one or more dielectric layers and the etch stop layer respectively include: silicon nitride and hafnium oxide, silicon nitride and titanium oxide, silicon oxide and hafnium oxide, silicon oxide and titanium oxide, or silicon and silicon oxide.

[0012] The first reflective layer includes a metallic reflective layer. The metallic reflective layer includes Al, Cu, Ag, Au, or TiN. The first reflective layer also includes a Bragg reflective layer.

[0013] The spectral filter may have: a first transmission dielectric layer disposed below the lower first reflection layer of the plurality of first reflection layers for improving transmittance, and a second transmission dielectric layer disposed above the upper first reflection layer of the plurality of first reflection layers.

[0014] The first and second transmission dielectric layers each have a thickness that varies according to the center wavelength of the first and second cavities, respectively.

[0015] The spectral filter may further include: a plurality of second reflective layers disposed on one side of the plurality of first reflective layers in the lateral direction; and at least a third cavity and a fourth cavity disposed between the plurality of second reflective layers, wherein the third cavity has a different thickness than the fourth cavity, wherein each of the third cavity and the fourth cavity includes the plurality of etch stop layers, and the third cavity and the fourth cavity include the one or more dielectric layers.

[0016] At least one of the third cavity and the fourth cavity also includes at least one spacer for adjusting the thickness.

[0017] The second reflective layer includes a metallic reflective layer or a Bragg reflective layer.

[0018] A first transmission dielectric layer for improving transmittance is disposed below the lower second reflective layer of the plurality of second reflective layers, and a second transmission dielectric layer is disposed above the upper second reflective layer of the plurality of second reflective layers.

[0019] A method for manufacturing a spectral filter may include: sequentially forming a first etch stop layer and a first dielectric layer on a lower reflective layer; etching a portion of the first dielectric layer to expose a portion of the first etch stop layer; sequentially forming a second etch stop layer and a second dielectric layer on the exposed portion of the first etch stop layer and on the first dielectric layer; etching a portion of the second dielectric layer to expose a portion of the second etch stop layer; wherein at least the top of the second dielectric layer and the top of the exposed portion of the second etch stop layer form respective boundaries of a first cavity and a second cavity having different thicknesses; and forming an upper reflective layer on the first cavity and the second cavity.

[0020] The method may further include: after etching the portion of the second dielectric layer to expose the portion of the second etch stop layer, sequentially forming a third etch stop layer and a third dielectric layer on the exposed portion of the second etch stop layer and on the second dielectric layer; and etching a portion of the third dielectric layer to expose a portion of the third etch stop layer.

[0021] The difference between the refractive index of the materials included in the first and second dielectric layers and the refractive index of the materials included in the first and second etch stop layers is less than or equal to 2.5. The difference between the refractive index of the materials included in the first and second dielectric layers and the refractive index of the materials included in the first and second etch stop layers is less than or equal to 1.

[0022] The first dielectric layer and the second dielectric layer comprise silicon, silicon oxide, or silicon nitride, and wherein the first etch stop layer and the second etch stop layer comprise materials whose etch selectivity differs from that of the first dielectric layer and the second dielectric layer by a factor of 5 or greater.

[0023] The first etch stop layer and the second etch stop layer comprise silicon oxide, titanium oxide, or hafnium oxide.

[0024] The method may further include forming at least one spacer in at least one of the first cavity and the second cavity for adjusting the thickness.

[0025] Each of the lower reflective layer and the upper reflective layer includes a metallic reflective layer or a Bragg reflective layer.

[0026] Each of the lower reflective layer and the upper reflective layer includes a first metal reflective layer and a second metal reflective layer arranged on a plane.

[0027] Each of the lower reflective layer and the upper reflective layer includes a metallic reflective layer and a Bragg reflective layer arranged on a plane.

[0028] The method may further include: forming a first transmission dielectric layer for improving transmittance below the lower reflective layer and forming a second transmission dielectric layer above the upper reflective layer.

[0029] The first transmission dielectric layer, used to improve transmittance, is formed to have a different thickness depending on the center wavelength.

[0030] An image sensor may include: a spectral filter; and a pixel array for receiving light transmitted through the spectral filter, wherein the spectral filter includes: a plurality of first reflective layers spaced apart from and facing each other; and at least a first cavity and a second cavity disposed between the plurality of first reflective layers, wherein the first cavity has a different thickness than the second cavity, the thickness of the first cavity being determined according to a first center wavelength, and the thickness of the second cavity being determined according to a second center wavelength, wherein each of the first cavity and the second cavity includes a plurality of etch stop layers having a constant total thickness, the first cavity including one or more dielectric layers having a first total thickness, and the second cavity including one or more dielectric layers having a second total thickness, wherein the first total thickness and the second total thickness are different from each other according to the first center wavelength of the first cavity and the second center wavelength of the second cavity.

[0031] The difference between the refractive index of the material included in the one or more dielectric layers and the refractive index of the material included in the etch stop layer is less than or equal to 2.5. The difference between the refractive index of the material included in the one or more dielectric layers and the refractive index of the material included in the etch stop layer is less than or equal to 1.

[0032] The one or more dielectric layers include silicon, silicon oxide, or silicon nitride.

[0033] The etch stop layer comprises silicon oxide, titanium oxide, or hafnium oxide, and wherein the etch stop layer comprises a material whose etch selectivity differs from that of the one or more dielectric layers by a factor of 5 or greater.

[0034] The first reflective layer includes a metallic reflective layer or a Bragg reflective layer.

[0035] The image sensor may have a spectral filter that further includes a plurality of second reflective layers and at least a third cavity and a fourth cavity, wherein the plurality of second reflective layers are disposed on one side of the plurality of first reflective layers in the lateral direction, the third cavity and the fourth cavity are disposed between the plurality of second reflective layers, wherein the third cavity has a different thickness than the fourth cavity, and wherein each of the third cavity and the fourth cavity includes the plurality of etch stop layers, and the third cavity and the fourth cavity include the one or more dielectric layers.

[0036] At least one of the third cavity and the fourth cavity also includes at least one spacer for adjusting the thickness.

[0037] The second reflective layer includes a metallic reflective layer or a Bragg reflective layer.

[0038] The image sensor may further include one or more processors configured to operate as a timing controller, a line decoder, and output circuitry.

[0039] An electronic device may include the image sensor. The electronic device may be one of the following: a mobile phone, smartphone, tablet computer, smart tablet computer, digital camera, video recorder, laptop computer, television, smart television, smart refrigerator, security camera, robot, or medical camera. Attached Figure Description

[0040] The above and other aspects, features, and advantages of exemplary embodiments of the present disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0041] Figure 1 This is a block diagram of an image sensor according to an example embodiment;

[0042] Figure 2 It is along Figure 1 A cross-sectional view of the spectral filter intercepted by line II-II′;

[0043] Figures 3A to 3E This is a diagram illustrating a method for manufacturing a spectral filter according to an example embodiment;

[0044] Figures 4A to 4E This is a diagram illustrating a method for manufacturing a spectral filter according to another example embodiment;

[0045] Figure 5 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0046] Figure 6 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0047] Figure 7This is a cross-sectional view of a spectral filter according to another example embodiment;

[0048] Figure 8 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0049] Figure 9 yes Figure 8 The transmission spectrum curve of the spectral filter, but the spectral filter has a first filter array with unit filters corresponding to seven center wavelengths and a second filter array with unit filters corresponding to nine center wavelengths.

[0050] Figure 10 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0051] Figure 11 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0052] Figure 12 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0053] Figure 13 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0054] Figure 14 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0055] Figure 15 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0056] Figure 16 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0057] Figure 17 This is a cross-sectional view of a spectral filter according to another example embodiment;

[0058] Figure 18 It is applicable Figure 1 A planar diagram of an example spectral filter for an image sensor;

[0059] Figure 19 It is applicable Figure 1 A planar view of another example of a spectral filter for an image sensor;

[0060] Figure 20 It is applicable Figure 1 A planar view of another example of a spectral filter for an image sensor;

[0061] Figure 21 This is a schematic block diagram of an electronic device including an image sensor according to an example embodiment;

[0062] Figure 22 yes Figure 21 A schematic block diagram of the camera module; and

[0063] Figures 23 to 32 This is a view of various examples of electronic devices that utilize image sensors according to exemplary embodiments. Detailed Implementation

[0064] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein the same reference numerals denote the same elements throughout the drawings. In this respect, exemplary embodiments may take different forms and should not be construed as being limited to the description set forth herein. Therefore, exemplary embodiments are described below only with reference to the accompanying drawings to explain various aspects. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list.

[0065] For ease of explanation and clarity, the dimensions of each constituent element shown in the accompanying drawings may be enlarged. Although exemplary embodiments have been described, these embodiments are merely illustrative, and those skilled in the art to which this disclosure pertains can make various modifications and changes based on these descriptions.

[0066] When a component is disposed "above" or "on top of" another component, the component may include not only elements that directly contact the upper / lower / left / right side of the other component, but also elements disposed in a non-contact manner above / below / left / right of the other component. As used herein, the singular forms "a," "an," and "the" are intended to also include the plural forms, unless the context clearly indicates otherwise. It will be understood that the terms "comprising" and / or "including" as used herein indicate the presence of the stated feature or component, but do not exclude the presence or addition of one or more other features or components.

[0067] In the context of describing this disclosure, the terms “a,” “an,” and “the,” and similar pronouns, should be interpreted to cover both singular and plural cases. Furthermore, the steps of all the methods described herein may be performed in any suitable order, unless otherwise indicated herein or explicitly stated otherwise by the context. This disclosure is not limited to the order of the described steps.

[0068] Furthermore, terms such as “section,” “unit,” “module,” etc., used in the specification may refer to a unit for performing at least one function or operation, and the unit may be implemented by hardware, software, or a combination of hardware and software.

[0069] Furthermore, the connecting lines or connectors shown in the accompanying figures are intended to illustrate functional relationships and / or physical or logical couplings between various components. It should be noted that in actual equipment, many alternative or additional functional relationships, physical connections, or logical connections may exist.

[0070] Any and all examples or language (such as "such as") provided herein are intended only to better illustrate this disclosure and do not limit the scope of this disclosure unless otherwise required.

[0071] Figure 1 This is a schematic block diagram of an image sensor 1000 according to an example embodiment.

[0072] refer to Figure 1 The image sensor 1000 may include a spectral filter 1100, a pixel array 4100, a timing controller 4010, a line decoder 4020, and an output circuit 4030. The image sensor 1000 may include a charge-coupled device (CCD) image sensor or a complementary metal-oxide-semiconductor (CMOS) image sensor, but this disclosure is not limited thereto.

[0073] The spectral filter 1100 may include multiple unit filters that transmit light of different wavelength ranges and are arranged in a two-dimensional manner. The pixel array 4100 may include multiple pixels that detect light of different wavelengths transmitted through the unit filters. Specifically, the pixel array 4100 may include pixels arranged in a two-dimensional manner along multiple rows and columns. The row decoder 4020 may select one of the rows of the pixel array 4100 in response to a row address signal output from the timing controller 4010. The output circuit 4030 may output a light detection signal from the pixels arranged in the selected row, column by column. For this purpose, the output circuit 4030 may include a column decoder and an analog-to-digital converter (ADC). For example, the output circuit 4030 may include multiple ADCs arranged between the column decoder and the pixel array 4100 for each column, or a single ADC arranged at the output of the column decoder. The timing controller 4010, the row decoder 4020, and the output circuit 4030 may be implemented by a single chip or separate chips. The processor for processing the image signal output through the output circuit 4030 can be implemented by a single chip having a timing controller 4010, a line decoder 4020, and the output circuit 4030. The pixel array 4100 may include multiple pixels that detect light of different wavelengths, and the pixels may be arranged in various ways.

[0074] The spectral filter 1100 of the image sensor 1000 is described in detail below. Figure 2 It is along Figure 1 A schematic cross-sectional view of the spectral filter intercepted by line II-II′.

[0075] refer to Figure 1 and Figure 2 The spectral filter 1100 may include multiple unit filters 111, 112, 113 and 114 arranged in a two-dimensional manner on a plane. Figure 2 An example of four unit filters (e.g., first unit filter 111, second unit filter 112, third unit filter 113, and fourth unit filter 114) is shown.

[0076] Each of the first to fourth unit filters 111, 112, 113 and 114 can transmit light with a specific center wavelength and has a Fabry-Perot structure in which the first cavity 141, the second cavity 142, the third cavity 143 and the fourth cavity 144 are disposed between two spaced-apart metal reflective layers 131 and 132. Figure 2 Vertically spaced reflective layers 131 and 132 are shown.

[0077] When light passes through one of the metal reflective layers 131 and 132 and is incident on the first cavity 141, the second cavity 142, the third cavity 143, and the fourth cavity 144, the light can reciprocate between the metal reflective layers 131 and 132 within the first cavity 141, the second cavity 142, the third cavity 143, and the fourth cavity 144, resulting in constructive and destructive interference. Light with a specific center wavelength and satisfying the constructive interference condition can exit to the outside of the first unit filter 111, the second unit filter 112, the third unit filter 113, and the fourth unit filter 114. The wavelength band and center wavelength of the light passing through the unit filters 111, 112, 113, and 114 can be determined based on the reflection bands of the metal reflective layers 131 and 132 and the characteristics of the first cavity 141, the second cavity 142, the third cavity 143, and the fourth cavity 144. As an example, the cavity length, the effective refractive index, and the skin depth of the metal reflective layer are parameters for determining the center wavelength.

[0078] For the metal reflective layers 131 and 132, the first metal may include, for example, Al, Cu, Ag, Au, TiN, etc. However, this disclosure is not limited thereto. Although the metal reflective layers 131 and 132 may have a thickness of tens of nanometers, this disclosure is not limited thereto.

[0079] The first unit filter 111, the second unit filter 112, the third unit filter 113, and the fourth unit filter 114 can be configured to have different center wavelengths. For this purpose, the first unit filter 111, the second unit filter 112, the third unit filter 113, and the fourth unit filter 114 can include a first cavity 141, a second cavity 142, a third cavity 143, and a fourth cavity 144 with different thicknesses according to the center wavelength.

[0080] Specifically, each of the first cavity 141, the second cavity 142, the third cavity 143, and the fourth cavity 144 may include a plurality of vertically stacked etch stop layers. Here, the plurality of etch stop layers 151 and 152 may be configured to have a constant total thickness according to the center wavelength. Figure 2 The illustration shows the case where each of the first cavity 141, the second cavity 142, the third cavity 143, and the fourth cavity 144 includes a first etch stop layer 151 and a second etch stop layer 152.

[0081] In addition to the first etch stop layer 151 and the second etch stop layer 152, each of the second cavity 142, the third cavity 143, and the fourth cavity 144 may further include at least one of the first dielectric layer 161 and the second dielectric layer 162. Here, at least one of the first dielectric layer 161 and the second dielectric layer 162 may be configured to have a total thickness that varies according to the center wavelength of the respective unit filters 111, 112, 113, and 114. Figure 2 This illustrates the case where the thickness of the first dielectric layer 161 is greater than the thickness of the second dielectric layer 162.

[0082] refer to Figure 2 The second cavity 142 may further include a second dielectric layer 162, the third cavity 143 may further include a first dielectric layer 161, and the fourth cavity 144 may further include both the first dielectric layer 161 and the second dielectric layer 162. Because multiple etch stop layers and dielectric layers of different thicknesses are included in the first cavity 141 to the fourth cavity 144, the first cavity 141 can have the thinnest thickness, while the fourth cavity 144 can have the largest thickness. In this case, among the first unit filter 111 to the fourth unit filter 114, the first unit filter 111 can have the shortest center wavelength, and the fourth unit filter 114 can have the longest center wavelength.

[0083] Each of the first etch stop layer 151 and the second etch stop layer 152 may be a layer introduced to facilitate the formation of first cavities 141 to fourth cavities 144 with different thicknesses, and may include a material having an etch selectivity different from that of the first dielectric layer 161 and the second dielectric layer 162, as described below.

[0084] The first etch stop layer 151 and the second etch stop layer 152 may comprise materials having optical properties similar to those of the first dielectric layer 161 and the second dielectric layer 162. For example, the difference between the refractive index of the material comprised in the first dielectric layer 161 and the second dielectric layer 162 and the refractive index of the material comprised in the first etch stop layer 151 and the second etch stop layer 152 may be less than or equal to 2.5. However, this disclosure is not limited thereto. More specifically, the difference between the refractive index of the material comprised in the first dielectric layer 161 and the second dielectric layer 162 and the refractive index of the material comprised in the first etch stop layer 151 and the second etch stop layer 152 may be less than or equal to 1. Properties such as differences in refractive index and differences in etch selectivity may be considered to minimize optical loss between layers.

[0085] For example, the first dielectric layer 161 and the second dielectric layer 162 may comprise silicon, silicon oxide, or silicon nitride, and the first etch stop layer 151 and the second etch stop layer 152 may comprise silicon oxide, titanium oxide, or hafnium oxide. However, this disclosure is not limited thereto.

[0086] Specifically, the first dielectric layer 161 and the second dielectric layer 162 may comprise silicon nitride, and the first etch stop layer 151 and the second etch stop layer 152 may comprise hafnium oxide. Alternatively, the first dielectric layer 161 and the second dielectric layer 162 may comprise silicon nitride, and the first etch stop layer 151 and the second etch stop layer 152 may comprise titanium oxide. Alternatively, the first dielectric layer 161 and the second dielectric layer 162 may comprise silicon nitride, and the first etch stop layer 151 and the second etch stop layer 152 may comprise titanium oxide. Finally, the first dielectric layer 161 and the second dielectric layer 162 may comprise silicon, and the first etch stop layer 151 and the second etch stop layer 152 may comprise silicon nitride.

[0087] Figures 3A to 3E It is used to explain the manufacturing process. Figure 2 A diagram illustrating an example of the method for using the spectral filter 1100.

[0088] refer to Figure 3A A first etch stop layer 151 with a thickness of L was deposited on the lower metal reflective layer 131, and then a first dielectric layer 161′ with a thickness of d was deposited on the first etch stop layer 151. Figure 3A The first region 111′ to the fourth region 114′ represent the regions where the first unit filter 111 to the fourth unit filter 114 are to be formed.

[0089] As described above, the first etch stop layer 151 may comprise a material having an etch selectivity different from that of the first dielectric layer 161′. For example, the difference between the refractive index of the material comprised in the first dielectric layer 161′ and the refractive index of the material comprised in the first etch stop layer 151 may be less than or equal to 2.5. For example, the first dielectric layer 161′ may comprise silicon, silicon oxide, or silicon nitride, and the first etch stop layer 151 may comprise silicon oxide, titanium oxide, or hafnium oxide. The etch selectivity between the first dielectric layer and the etch stop layer may differ by a factor of 5 or greater. As an example, HfO2 may be used as the etch stop layer and SiN may be used as the dielectric layer. The difference in refractive index between these two materials is relatively small, while the difference in etch selectivity is relatively large. The etch selectivity may differ by a factor of 10 or greater. The difference in etch selectivity may vary depending on the type of etching technique used (such as wet etching or dry etching). This characteristic of the difference in etch selectivity between the etch stop layer material and the dielectric layer material can also be applied to other example embodiments described herein.

[0090] refer to Figure 3B A patterning process, including photolithography and etching, can be performed on the first dielectric layer 161'. Therefore, a patterned first dielectric layer 161 can be formed by removing a portion of the first dielectric layer 161' via etching. Etching of the first dielectric layer 161' can be performed, for example, by a dry etching process, but this disclosure is not limited thereto. Figure 3B This illustrates a case where a patterned first dielectric layer 161 is formed in a third region 113' and a fourth region 114' by removing the first dielectric layer 161' from the first region 111' and the second region 112'. The first etch stop layer 151 in the first region 111' and the second region 112' can be exposed to the outside due to the etching of the first dielectric layer 161'.

[0091] refer to Figure 3C A second etch stop layer 152 with a thickness of L can be deposited on the first etch stop layer 151 in the first region 111′ and the second region 112′, and on the first dielectric layer 161 in the third region 113′ and the fourth region 114′, respectively. Then, a second dielectric layer 162′ with a thickness of d / 2 can be deposited on the second etch stop layer 152.

[0092] As described above, the second etch stop layer 152 may include a material having an etch selectivity different from that of the second dielectric layer 162'. For example, the difference between the refractive index of the material included in the second dielectric layer 162' and the refractive index of the material included in the second etch stop layer 152 may be less than or equal to 2.5. The second etch stop layer 152 may include the same material as the first etch stop layer 151, but this disclosure is not limited thereto. The second dielectric layer 162' may include the same material as the first dielectric layer 161', but this disclosure is not limited thereto.

[0093] refer to Figure 3D A patterning process, including photolithography and etching, can be performed on the second dielectric layer 162'. Therefore, a patterned second dielectric layer 162 can be formed by removing a portion of the second dielectric layer 162' via etching. Figure 3D This illustrates a case where a patterned second dielectric layer 162 is formed in the second region 112' and the fourth region 114' by removing the second dielectric layer 162' from the first region 111' and the third region 113'. The second etch stop layer 152 in the first region 111' and the third region 113' can be exposed to the outside due to the etching of the second dielectric layer 162'.

[0094] Therefore, a first cavity 141, a second cavity 142, a third cavity 143, and a fourth cavity 144 with different thicknesses can be formed in the first region 111′, the second region 112′, the third region 113′, and the fourth region 114′. In particular, the thickness t1 of the first cavity 141 can be 2L, the thickness t2 of the second cavity 142 can be 2L+d / 2, the thickness t3 of the third cavity 143 can be 2L+d, and the thickness t4 of the fourth cavity 144 can be 2L+3d / 2.

[0095] refer to Figure 3E The first unit filter 111 to the fourth unit filter 114 can be completed by forming an upper metal reflective layer 132 on the first cavity 141 to the fourth cavity 144 with different thicknesses.

[0096] Figures 4A to 4E It is used to explain the manufacturing process. Figure 2 A figure showing another example of the method of the spectral filter 1100.

[0097] refer to Figure 4A A first etch stop layer 251 with a thickness of L1 is deposited on the lower metal reflective layer 131, and then a first dielectric layer 261′ with a thickness of d1 is deposited on the first etch stop layer 251.

[0098] refer to Figure 4BA patterning process, including photolithography and etching, can be performed on the first dielectric layer 261'. Therefore, a patterned first dielectric layer 261 can be formed by removing a portion of the first dielectric layer 261' via etching. Figure 4B The diagram illustrates the case where a patterned first dielectric layer 261 is formed in the third region 113' and the fourth region 114' by removing the first dielectric layer 261' in the first region 111' and the second region 112'.

[0099] refer to Figure 4C A second etch stop layer 252 of thickness L2 can be deposited on the first etch stop layer 251 in the first region 111′ and the second region 112′, and on the first dielectric layer 261 in the third region 113′ and the fourth region 114′, respectively. Then, a second dielectric layer 262′ of thickness d2 (<d1) can be deposited on the second etch stop layer 252. The second etch stop layer 252 may include a material having an etch selectivity different from that of the second dielectric layer 262′.

[0100] refer to Figure 4D A patterning process, including photolithography and etching, can be performed on the second dielectric layer 262'. Therefore, a patterned second dielectric layer 262 can be formed by removing a portion of the second dielectric layer 262' via etching. Figure 4D This illustrates the case where a patterned second dielectric layer 262 is formed in the second region 112' and the fourth region 114' by removing the second dielectric layer 262' from the first region 111' and the third region 113'.

[0101] Therefore, a first cavity 141, a second cavity 142, a third cavity 143, and a fourth cavity 144 with different thicknesses can be formed in the first region 111′, the second region 112′, the third region 113′, and the fourth region 114′. In particular, the thickness t1 of the first cavity 141 can be L1+L2, the thickness t2 of the second cavity 142 can be L1+L2+d2, the thickness t3 of the third cavity 143 can be L1+L2+d1, and the thickness t4 of the fourth cavity 144 can be L1+L2+d1+d2.

[0102] refer to Figure 4E The first unit filter 111 to the fourth unit filter 114 can be completed by forming an upper metal reflective layer 132 on the first cavity 141 to the fourth cavity 144 with different thicknesses. Functionally, the spectral filter can operate in any orientation, and in order to facilitate the manufacture of additional optical components that operate together with the spectral filter, the formed filter can be inverted to present a flat-top surface.

[0103] According to the above example embodiment, cavities 141 to 144 are formed by using etch stop layers 151, 152, 251, and 252, which have etch selectivity different from that of dielectric layers 161, 162, 261, and 262. Cavities 141 to 144 can be precisely shaped to their respective desired thicknesses. The total thickness of the etch stop layers can be from 10 nm to 100 nm, and the total thickness of the dielectric layers can be from 10 nm to 500 nm.

[0104] In the above description, a method for forming four cavities 141 to 144 with different thicknesses is described. Those skilled in the art will understand that additional cavity structures with additional thicknesses can be added vertically before forming the top reflective layer 132. The additional cavity structures can be formed by sequentially forming a third etch stop layer and a third dielectric layer on the second etch stop layers 152 and 252 and the second dielectric layers 162 and 262, respectively. Eight cavities with different thicknesses can be formed by selectively removing a portion of the third dielectric layer via a patterning process. Furthermore, a transmission dielectric layer for improving transmittance can be additionally formed below the lower metal reflective layer 131 and above the upper metal reflective layer 132. The formation of the transmission dielectric layer will be described below.

[0105] In the above description, the case of forming cavities 141 to 144 with different thicknesses on a single metal reflective layer 131 is described. However, the first filter array and the second filter array can also be manufactured by forming cavities with different thicknesses on a first metal reflective layer and a second metal reflective layer arranged adjacently on a plane, as described below. In such a case, at least one spacer can also be formed in at least one of the first filter array and the second filter array to adjust the thickness of the cavity. Furthermore, the aforementioned cavities with different thicknesses can be formed on the Bragg reflective layer described below, and can be formed on the metal reflective layer and the Bragg reflective layer arranged on a plane.

[0106] Figure 5 This is a cross-sectional view of a spectral filter 1200 according to another example embodiment. Figure 5 A spectral filter 1200 comprising eight cavities 341 to 348 with varying thicknesses is shown.

[0107] refer to Figure 5 Eight cavities 341 to 348, each with a different thickness according to the center wavelength, can be disposed between two vertically spaced metal reflective layers 131 and 132. Here, each of the first to eighth cavities 348 may include a plurality of etch stop layers 351, 352, and 353 having a constant total thickness. Specifically, each of the first to eighth cavities 348 may include a first etch stop layer 351, a second etch stop layer 352, and a third etch stop layer 353.

[0108] In addition to the first etch stop layer 351, the second etch stop layer 352, and the third etch stop layer 353, each of the second cavity 342 to the eighth cavity 348 may further include at least one of the first dielectric layer 361, the second dielectric layer 362, and the third dielectric layer 363, the total thickness of which varies according to the center wavelength. Here, the first etch stop layer 351, the second etch stop layer 352, and the third etch stop layer 353 may include a material having an etch selectivity different from that of the first dielectric layer 361, the second dielectric layer 362, and the third dielectric layer 363. For example, the difference between the refractive index of the material included in the first dielectric layer 361, the second dielectric layer 362, and the third dielectric layer 363 and the refractive index of the material included in the first etch stop layer 351, the second etch stop layer 352, and the third etch stop layer 353 may be less than or equal to 2.5. As discussed above, the difference in etch selectivity between the etch stop layer and the corresponding dielectric layer may be a factor of 5 or greater, or a factor of 10 or greater.

[0109] Figure 5 This illustrates a scenario where the thickness of the first dielectric layer 361 is greater than the sum of the thicknesses of the second dielectric layer 362 and the third dielectric layer 363, and the thickness of the second dielectric layer 362 is greater than the thickness of the third dielectric layer 363. The second cavity 342 may also include the third dielectric layer 363, the third cavity 343 may also include the second dielectric layer 362, the fourth cavity 344 may also include the second dielectric layer 362 and the third dielectric layer 363, the fifth cavity 345 may also include the first dielectric layer 361, the sixth cavity 346 may also include the first dielectric layer 361 and the third dielectric layer 363, the seventh cavity 347 may also include the first dielectric layer 361 and the second dielectric layer 362, and the eighth cavity 348 may also include the first dielectric layer 361, the second dielectric layer 362, and the third dielectric layer 363. Therefore, among the first cavities 341 to the eighth cavities 348, the first cavity 341 may have the thinnest thickness, and the eighth cavity 348 may have the largest thickness.

[0110] Figure 6 This is a cross-sectional view of a spectral filter 1300 according to another example embodiment.

[0111] refer to Figure 6 The spectral filter 1300 may include a first filter array 410 and a second filter array 420 arranged on a plane. Although the first filter array 410 and the second filter array 420 may be arranged on substantially the same plane, this disclosure is not limited thereto.

[0112] The first filter array 410 may include at least one of a first unit filter 411, a second unit filter 412, a third unit filter 413, and a fourth unit filter 414 having a center wavelength in a first wavelength range. The first wavelength range may be, for example, a range from about 250 nm to about 600 nm. However, this is merely exemplary, and the first wavelength range may also be various wavelength ranges depending on design conditions. Figure 6 The illustration shows a first filter array 410 comprising four unit filters (e.g., first unit filter 411, second unit filter 412, third unit filter 413, and fourth unit filter 414).

[0113] The second filter array 420 may include at least one of a fifth unit filter 421, a sixth unit filter 422, a seventh unit filter 423, and an eighth unit filter 424 having a center wavelength in the second wavelength range. The second wavelength range may be longer than the first wavelength range. For example, the second wavelength range may be from about 600 nm to about 1100 nm. However, this is only exemplary, and the second wavelength range may also be various wavelength ranges depending on design conditions. Figure 6 The second filter array 420 is shown to include four unit filters (e.g., fifth unit filter 421, sixth unit filter 422, seventh unit filter 423 and eighth unit filter 424).

[0114] Each of the first unit filter 411, the second unit filter 412, the third unit filter 413, and the fourth unit filter 414 constituting the first filter array 410 may include: two first metal reflective layers 431 and 432 arranged vertically spaced apart from each other; and cavities 441, 442, 443, and 444 disposed between the first metal reflective layers 431 and 432.

[0115] The first metal reflective layers 431 and 432 may comprise a first metal capable of reflecting light in a first wavelength range. For example, the first metal may comprise Al, Ag, Au, TiN, etc. However, this disclosure is not limited thereto. While the first metal reflective layers 431 and 432 may have a thickness of tens of nanometers, this is merely exemplary.

[0116] The first unit filter 411, the second unit filter 412, the third unit filter 413, and the fourth unit filter 414 may have different center wavelengths within a first wavelength range. Therefore, the first unit filter 411, the second unit filter 412, the third unit filter 413, and the fourth unit filter 414 may include a first cavity 441, a second cavity 442, a third cavity 443, and a fourth cavity 444 with different thicknesses.

[0117] The first cavity 441 to the fourth cavity 444 can have the same Figure 2 The first cavity 141 to the fourth cavity 144 have the same configuration. Each of the first cavity 441, the second cavity 442, the third cavity 443, and the fourth cavity 444 may include a plurality of etch stop layers 451 and 452 having a constant total thickness. In particular, each of the first cavity 441, the second cavity 442, the third cavity 443, and the fourth cavity 444 may include a first etch stop layer 451 and a second etch stop layer 452. In addition to the first etch stop layer 451 and the second etch stop layer 452, the second cavity 442, the third cavity 443, and the fourth cavity 444 may also include at least one of a first dielectric layer 461 and a second dielectric layer 462, the total thickness of which varies according to the center wavelength. Figure 6 This illustrates the case where the thickness of the first dielectric layer 461 is greater than the thickness of the second dielectric layer 462.

[0118] The second cavity 442 may further include a second dielectric layer 462, the third cavity 443 may further include a first dielectric layer 461, and the fourth cavity 444 may further include a first dielectric layer 461 and a second dielectric layer 462. Therefore, among the first cavities 441 to the fourth cavities 444, the first cavity 441 may have the thinnest thickness, and the fourth cavity 444 may have the largest thickness. The first etch stop layer 451 and the second etch stop layer 452 may include materials having an etch selectivity different from that of the first dielectric layer 461 and the second dielectric layer 462. For example, the difference between the refractive index of the material included in the first dielectric layer 461 and the second dielectric layer 462 and the refractive index of the material included in the first etch stop layer 451 and the second etch stop layer 452 may be less than or equal to 2.5.

[0119] Each of the fifth unit filter 421, the sixth unit filter 422, the seventh unit filter 423, and the eighth unit filter 424 constituting the second filter array 420 may include: two second metal reflective layers 471 and 472 arranged vertically spaced apart from each other; and a fifth cavity 481, a sixth cavity 482, a seventh cavity 483, and an eighth cavity 484 disposed between the second metal reflective layers 471 and 472.

[0120] The second metal reflective layers 471 and 472 may comprise a second metal capable of reflecting light in a second wavelength range. For example, the second metal may comprise Cu, Ag, Au, TiN, etc. However, this disclosure is not limited thereto. While the second metal reflective layers 471 and 472 may have a thickness of tens of nanometers, this is merely exemplary.

[0121] The second metal constituting the second metal reflective layers 471 and 472 can be a different metal than the first metal constituting the first metal reflective layers 431 and 432. For example, when the first metal reflective layers 431 and 432 comprise Al, the second metal reflective layers 471 and 472 can comprise Cu. Furthermore, for example, when the first metal reflective layers 431 and 432 comprise Al, the second metal reflective layers 471 and 472 can comprise Ag. Furthermore, for example, when the first metal reflective layers 431 and 432 comprise Ag, the second metal reflective layers 471 and 472 can comprise Cu.

[0122] The fifth unit filter 421, the sixth unit filter 422, the seventh unit filter 423, and the eighth unit filter 424 may have different center wavelengths within the second wavelength range. Therefore, the fifth unit filter 421, the sixth unit filter 422, the seventh unit filter 423, and the eighth unit filter 424 may include fifth cavities 481, sixth cavities 482, seventh cavities 483, and eighth cavities 484 with different thicknesses. Here, fifth cavities 481, sixth cavities 482, seventh cavities 483, and eighth cavities 484 may have the same configuration as the first cavity 441, second cavity 442, third cavity 443, and fourth cavity 444 described above.

[0123] As described above, since a first filter array 410 with cavities 441, 442, 443, and 444 of different thicknesses is disposed between the first metal reflective layers 431 and 432, and a second filter array 420 with cavities 481, 482, 483, and 484 of different thicknesses is disposed between the second metal reflective layers 471 and 472, and these are arranged on a plane, a spectral filter with broadband characteristics including a first wavelength range and a second wavelength range (e.g., a wavelength range from ultraviolet to near-infrared) can be realized.

[0124] Figure 7 This is a cross-sectional view of a spectral filter 1400 according to another example embodiment. Figure 7 Spectral filter 1400 and Figure 6 The spectral filter 1300 is the same, except that the second filter array 520 also includes a first spacer 491 and a second spacer 492 for adjusting the thickness of cavities 581, 582, 583 and 584.

[0125] refer to Figure 7The spectral filter 1400 may include a first filter array 510 and a second filter array 520 arranged on a plane. The first filter array 510 may include a first unit filter 511, a second unit filter 512, a third unit filter 513 and a fourth unit filter 514, and the second filter array 520 may include a fifth unit filter 521, a sixth unit filter 522, a seventh unit filter 523 and an eighth unit filter 524.

[0126] The first unit filter 511, the second unit filter 512, the third unit filter 513, and the fourth unit filter 514 may include a first cavity 541, a second cavity 542, a third cavity 543, and a fourth cavity 544 with different thicknesses and disposed between two first metal reflective layers 431 and 432 that are vertically spaced apart from each other. The first unit filters to the fourth unit filters 511, 512, 513, and 514 are... Figure 6 The first unit filters to the fourth unit filters 411, 412, 413 and 414 are the same.

[0127] The fifth unit filter 521, the sixth unit filter 522, the seventh unit filter 523 and the eighth unit filter 524 may include a fifth cavity 581, a sixth cavity 582, a seventh cavity 583 and an eighth cavity 584 with different thicknesses and disposed between two second metal reflective layers 471 and 472 that are vertically spaced apart from each other.

[0128] Each of the fifth cavity 581, the sixth cavity 582, the seventh cavity 583, and the eighth cavity 584 may include a plurality of etch stop layers 451 and 452 having a constant total thickness. In addition to the first etch stop layer 451 and the second etch stop layer 452, the sixth cavity 582, the seventh cavity 583, and the eighth cavity 584 may also include at least one of a first dielectric layer 461 and a second dielectric layer 462 whose total thickness varies according to the center wavelength.

[0129] Each of the fifth cavity 581, the sixth cavity 582, the seventh cavity 583, and the eighth cavity 584 may further include at least one of the first spacer 491 and the second spacer 492. Here, at least one of the first spacer 491 and the second spacer 492 can adjust the thickness of the fifth cavity 581, the sixth cavity 582, the seventh cavity 583, and the eighth cavity 584 to allow the fifth unit filter 521, the sixth unit filter 522, the seventh unit filter 523, and the eighth unit filter 524 to have the desired center wavelength. The first spacer 491 and the second spacer 492 may include a specific dielectric material. For example, the first spacer 491 and the second spacer 492 may include the same material as in the first dielectric layer 461 and the second dielectric layer 462, but this disclosure is not limited thereto.

[0130] Figure 7 The illustration shows the first spacer 491 and the second spacer 492 disposed below and above the fifth cavity 581, sixth cavity 582, seventh cavity 583, and eighth cavity 584, respectively. However, this disclosure is not limited thereto, and the spacers may be disposed only below or only above the fifth cavity 581, sixth cavity 582, seventh cavity 583, and eighth cavity 584. The spacers may also be disposed inside the fifth cavity 581, sixth cavity 582, seventh cavity 583, and eighth cavity 584.

[0131] Figure 8 This is a cross-sectional view of a spectral filter 1500 according to another example embodiment. Hereinafter, aspects that differ from the example embodiment described above will be described in detail.

[0132] refer to Figure 8 The spectral filter 1500 may include a first filter array 610 and a second filter array 620 arranged on a plane. The first filter array 610 may include a first unit filter 611, a second unit filter 612, a third unit filter 613 and a fourth unit filter 614, and the second filter array 620 may include a fifth unit filter 621, a sixth unit filter 622, a seventh unit filter 623 and an eighth unit filter 624.

[0133] Each of the first unit filter 611, the second unit filter 612, the third unit filter 613, and the fourth unit filter 614 may include: two first metal reflective layers 431 and 432 vertically spaced apart from each other; a first cavity 641, a second cavity 642, a third cavity 643, and a fourth cavity 644 disposed between the first metal reflective layers; and a first transmission dielectric layer 671 and a second transmission dielectric layer 672 respectively disposed below and above the first cavity 641, the second cavity 642, the third cavity 643, and the fourth cavity 644. Cavities 641 to 644 may be identical to cavity structures 441 to 444. Since the first metal reflective layers 431 and 432 and the first to fourth cavities 641, 642, 643, and 644 are described above, their description is omitted.

[0134] The first transmission dielectric layer 671 and the second transmission dielectric layer 672 can improve the transmittance of the first unit filter to the fourth unit filter 611, 612, 613 and 614. Each of the first transmission dielectric layer 671 and the second transmission dielectric layer 672 may include titanium oxide, silicon nitride, hafnium oxide, silicon oxide, high refractive index polymer, etc., but this disclosure is not limited thereto.

[0135] Both the first transmission dielectric layer 671 and the second transmission dielectric layer 672 may include a single-layer structure or a multi-layer structure. Figure 8 The illustration shows a case where the first transmission dielectric layer 671 has a single-layer structure and the second transmission dielectric layer 672 has a three-layer structure. Here, the second transmission dielectric layer 672 may have a structure in which first material layers 672a and second material layers 672b, which are different from each other, are stacked alternately.

[0136] The thicknesses of the first transmission dielectric layer 671 and the second transmission dielectric layer 672 can be varied according to the center wavelength. Figure 8 The thickness of the first transmission dielectric layer 671 and the second transmission dielectric layer 672 is shown to increase as the center wavelength of the first unit filter 611, the second unit filter 612, the third unit filter 613 and the fourth unit filter 614 increases.

[0137] Each of the fifth unit filter 621, the sixth unit filter 622, the seventh unit filter 623, and the eighth unit filter 624 may include: two second metal reflective layers 471 and 472 vertically spaced apart from each other; a fifth cavity 681, a sixth cavity 682, a seventh cavity 683, and an eighth cavity 684 disposed between the second metal reflective layers 471 and 472; and a third dielectric layer 681 and a fourth dielectric layer 682 disposed below and above the fifth cavity 681, the sixth cavity 682, the seventh cavity 683, and the eighth cavity 684. Cavities 681 to 684 are identical to the cavity structures 481 to 484 described above. Since the second metal reflective layers 471 and 472 and the fifth to eighth cavities 681, 682, 683, and 684 are as described above, their description is omitted.

[0138] Similar to the first and second transmission dielectric layers 671 and 672, the third and fourth dielectric layers 681 and 682 can improve the transmittance of the fifth to eighth unit filters 621, 622, 623, and 624. Each of the third and fourth dielectric layers 681 and 682 may include titanium oxide, silicon nitride, hafnium oxide, silicon oxide, high refractive index polymers, etc., but this disclosure is not limited thereto.

[0139] Each of the third dielectric layer 681 and the fourth dielectric layer 682 may include a single-layer structure or a multi-layer structure. Figure 8 The diagram illustrates a case where the third dielectric layer 681 has a single-layer structure and the fourth dielectric layer 682 has a two-layer structure. Here, the fourth dielectric layer 682 may have a structure in which a first material layer 682a and a second material layer 682b, which are different from each other, are stacked alternately.

[0140] The thicknesses of the third dielectric layer 681 and the fourth dielectric layer 682 can be varied according to the center wavelength. Figure 8The thickness of the third dielectric layer 681 and the fourth dielectric layer 682 is shown to increase as the center wavelength of the fifth unit filter 621, the sixth unit filter 622, the seventh unit filter 623 and the eighth unit filter 624 increases.

[0141] Figure 9 Is with Figure 8 The transmission spectrum curve of a filter similar to the 1500 spectral filter. Although Figure 8 Filter arrays 610 and 620, each comprising four filter units, are shown, but... Figure 9 It shows in Figure 8 The spectral filter 1500 is configured such that the first filter array 610 includes seven unit filters with different center wavelengths and the second filter array 620 includes nine unit filters with different center wavelengths in the case of the transmission spectrum.

[0142] The first metal reflective layers 431 and 432 comprise Al, the second metal reflective layers 471 and 472 comprise Cu, and cavities 641 to 644 and 681 to 684 comprise TiO2 (etch stop layer) and SiN (dielectric layer). Each of the first dielectric layer 671 and the third dielectric layer 681 comprises SiN, and each of the second dielectric layer 672 and the fourth dielectric layer 682 may comprise a multilayer film of TiO2 and SiN. Figure 9 In this diagram, "D1" represents the transmission spectrum of the first filter array 610, and "D2" represents the transmission spectrum of the second filter array 620. (Reference) Figure 9 As can be seen, the spectral filter 1500 achieves broadband characteristics and high transmittance.

[0143] Figure 10 This is a cross-sectional view of a spectral filter 1600 according to another example embodiment. Figure 10 In the spectral filter 1600, each of the first to eighth unit filters 711 to 714 and 721 to 724 can have a multi-cavity structure.

[0144] refer to Figure 10 The first filter array 710 may include a first unit filter 711, a second unit filter 712, a third unit filter 713 and a fourth unit filter 714, and the second filter array 720 may include a fifth unit filter 721, a sixth unit filter 722, a seventh unit filter 723 and an eighth unit filter 724.

[0145] Each of the first unit filter 711, the second unit filter 712, the third unit filter 713, and the fourth unit filter 714 may include: three first metal reflective layers 531, 532, and 533 spaced apart from each other; and two cavities 741, 742, 743, and 744 disposed between the first metal reflective layers 531, 532, and 533. Here, since the first metal reflective layers 531, 532, and 533 and the cavities 741, 742, 743, and 744 with different thicknesses may include the structures described previously in the example embodiments, their description is omitted. The central reflective layer 532 is shared by the cavities above and below the layer 532. The central reflective layer 532 forms a resonator pair with the lower reflective layer 531 and another resonator pair with the upper reflective layer 533. The central metal reflective layer 532 may be thicker than the lower reflective layer 531 and the upper reflective layer 533.

[0146] Each of the fifth unit filter 721, the sixth unit filter 722, the seventh unit filter 723, and the eighth unit filter 724 may include: three second metal reflective layers 571, 572, and 573 spaced apart from each other; and two cavities 781, 782, 783, and 784 disposed between the second metal reflective layers 571, 572, and 573. Here, because the second metal reflective layers 571, 572, and 573 and the cavities 781, 782, 783, and 784 with different thicknesses may include structures as described in the previous example embodiments, their description is omitted.

[0147] Although each of the unit filters 711 to 714 and 721 to 724 is described above as including two stacked cavities 741, 742, 743, 744 and 781, 782, 783, 784, this is merely an example, and each of the unit filters 711 to 714 and 721 to 724 may include three or more stacked cavities.

[0148] Figure 11 This is a cross-sectional view of a spectral filter 1700 according to another example embodiment.

[0149] refer to Figure 11 The spectral filter 1700 may include multiple unit filters 811, 812, 813 and 814 arranged in a two-dimensional manner on a plane. Figure 11 An example of four unit filters (e.g., first unit filter 811, second unit filter 812, third unit filter 813, and fourth unit filter 814) is shown.

[0150] Each of the first unit filter 811, the second unit filter 812, the third unit filter 813, and the fourth unit filter 814 can transmit light with a specific center wavelength and has a Fabry-Perot structure in which cavities 841, 842, 843, and 844 are disposed between two Bragg reflector layers 851 and 852 that are vertically spaced apart from each other.

[0151] When light passes through at least one of Bragg reflectors 851 and 852 and is incident on cavities 841, 842, 843, and 844, the light can reciprocate between Bragg reflectors 851 and 852 within cavities 841, 842, 843, and 844, resulting in constructive and destructive interference. Light with a specific center wavelength and satisfying the constructive interference condition can exit to the outside of each of the first unit filter 811, the second unit filter 812, the third unit filter 813, and the fourth unit filter 814. The wavelength band and center wavelength of the light passing through unit filters 811, 812, 813, and 814 can be determined based on the reflection bands of Bragg reflectors 851 and 852 and the characteristics of cavities 841, 842, 843, and 844.

[0152] Because the specific configurations of the first cavity 841, the second cavity 842, the third cavity 843, and the fourth cavity 844, which have different thicknesses, are as described in the example embodiments above, their descriptions are omitted.

[0153] Each of the Bragg reflector layers 851 and 852 may have the following structure: first material layers 851a and 852a and second material layers 851b and 852b with different refractive indices are alternately stacked. For example, the first material layers 851a and 852a and the second material layers 851b and 852b may respectively comprise silicon oxide and titanium oxide. As another example, the first material layers 851a and 852a and the second material layers 851b and 852b may respectively comprise silicon oxide and silicon. However, this is merely an example, and the first material layers 851a and 852a and the second material layers 851b and 852b may comprise a variety of other materials.

[0154] Figure 12 This is a cross-sectional view of a spectral filter 1800 according to another example embodiment.

[0155] refer to Figure 12 The spectral filter 1800 may include a first filter array 910 and a second filter array 920 arranged on a plane. The first filter array 910 may include at least one of a first unit filter 911 and a second unit filter 912 having a center wavelength in a first wavelength range. Figure 12The diagram illustrates a first filter array 910 comprising two unit filters (e.g., first unit filter 911 and second unit filter 912).

[0156] Each of the first unit filter 911 and the second unit filter 912 may include: two first Bragg reflector layers 951 and 952 vertically spaced apart from each other; and cavities 941 and 942 disposed between the first Bragg reflector layers 951 and 952. Here, the first Bragg reflector layers 951 and 952 may have a structure in which material layers with different refractive indices are stacked alternately. The first cavity 941 and the second cavity 942 may have different thicknesses, and since the specific configuration of these cavities has been described above, their description is omitted.

[0157] The second filter array 920 may include at least one of a third unit filter 921 and a fourth unit filter 922 having a center wavelength in the second wavelength range. Figure 12 The second filter array 920 is shown to include two unit filters (e.g., a third unit filter 921 and a fourth unit filter 922).

[0158] Each of the third unit filter 921 and the fourth unit filter 922 may include: two second Bragg reflector layers 953 and 954 vertically spaced apart from each other; and cavities 961 and 962 disposed between the second Bragg reflector layers 953 and 954. Here, the second Bragg reflector layers 953 and 954 may have a structure in which material layers with different refractive indices are alternately stacked. The material layers constituting the second Bragg reflector layers 953 and 954 may differ from the material layers constituting the first Bragg reflector layers 951 and 952 in at least one aspect of material thickness and mass. The third cavity 961 and the fourth cavity 962 may have different thicknesses, and their description is omitted because the specific configuration of these cavities has been described above.

[0159] Meanwhile, although each of the unit filters 911, 912, 921 and 922 is described above as including a single-cavity structure, this disclosure is not limited thereto, and each of the unit filters 911, 912, 921 and 922 may have a multi-cavity structure.

[0160] Figure 13 This is a cross-sectional view of a spectral filter 1900 according to another example embodiment.

[0161] refer to Figure 13The spectral filter 1900 may include a first filter array 1010 and a second filter array 1020 arranged on a plane. The first filter array 1010 may include at least one of a first unit filter 1011 and a second unit filter 1012 having a center wavelength in a first wavelength range. Figure 13 The illustration shows a first filter array 1010 comprising two unit filters (e.g., first unit filter 1011 and second unit filter 1012).

[0162] Each of the first unit filter 1011 and the second unit filter 1012 may include: two metal reflective layers 1031 and 1032 that are vertically spaced apart from each other; and cavities 1041 and 1042 disposed between the metal reflective layers 1031 and 1032. Since the metal reflective layers 1031 and 1032 and the first and second cavities 1041 and 1042, which have different thicknesses, are described as above, their description is omitted.

[0163] The second filter array 1020 may include at least one of a third unit filter 1021 and a fourth unit filter 1022 having a center wavelength in the second wavelength range. Figure 13 The second filter array 1020 is shown to include two unit filters (e.g., a third unit filter 1021 and a fourth unit filter 1022).

[0164] Each of the third unit filter 1021 and the fourth unit filter 1022 may include: two Bragg reflector layers 1051 and 1052 that are vertically spaced apart from each other; and cavities 1061 and 1062 disposed between the Bragg reflector layers 1051 and 1052. Since the Bragg reflector layers 1051 and 1052 and the third and fourth cavities 1061 and 1062, which have different thicknesses, are described as above, their description is omitted.

[0165] Figure 14 This is a cross-sectional view of a spectral filter 2100 according to another example embodiment.

[0166] refer to Figure 14 The spectral filter 2100 may include: a first filter array 1110 and a second filter array 1120; and a microlens array 1150 disposed above the first filter array 1110 and the second filter array 1120. For convenience, Figure 14 The diagram illustrates a scenario where the first filter array 1110 includes a first unit filter 1111, a second unit filter 1112, and a third unit filter 1113, and the second filter array 1120 may include a fourth unit filter 1121, a fifth unit filter 1122, and a sixth unit filter 1123.

[0167] The first filter array 1110 can be any one of the first filter arrays 410, 510, 610, 710, 910, and 1010 described above, and the second filter array 1120 can be any one of the second filter arrays 420, 520, 620, 720, 920, and 1020 described above. Descriptions of the first filter array 1110 and the second filter array 1120 are omitted.

[0168] A microlens array 1150 having multiple microlenses 1150a can be disposed above a first filter array 1110 and a second filter array 1120. The microlenses 1150a can be used to focus external light so that it is incident on appropriate first unit filters to sixth unit filters 1111, 1112, 1113, 1121, 1122 and 1123.

[0169] Figure 14 The illustration shows a configuration where microlens 1150a is arranged in a one-to-one correspondence with the first to sixth unit filters 1111, 1112, 1113, 1121, 1122, and 1123. However, this is merely exemplary, and at least two of the first to sixth unit filters 1111, 1112, 1113, 1121, 1122, and 1123 may be configured to correspond to one microlens 1150a.

[0170] Figure 15 This is a schematic cross-sectional view of a spectral filter 2200 according to another example embodiment.

[0171] refer to Figure 15 The spectral filter 2200 may include: a first filter array 1210 and a second filter array 1220; and a color filter array 1230. The first filter array 1210, the second filter array 1220, and the color filter array 1230 may be arranged on substantially the same plane.

[0172] For convenience, Figure 15 The illustration shows a configuration where the first filter array 1210 includes a first unit filter 1211, a second unit filter 1212, and a third unit filter 1213, and the second filter array 1220 may include a fourth unit filter 1221, a fifth unit filter 1222, and a sixth unit filter 1223. The first filter array 1210 can be any one of the aforementioned first filter arrays 410, 510, 610, 710, 910, and 1010, and the second filter array 1220 can be any one of the aforementioned second filter arrays 420, 520, 620, 720, 920, and 1020. Descriptions of the first filter array 1210 and the second filter array 1220 are omitted.

[0173] The color filter array 1230 may include, for example, a red color filter 1231, a green color filter 1232, and a blue color filter 1233. The red color filter 1231 can transmit red light with a wavelength of about 600 nm to about 700 nm, the green color filter 1232 can transmit green light with a wavelength of about 500 nm to about 600 nm, and the blue color filter 1233 can transmit blue light with a wavelength of about 400 nm to about 500 nm. For example, typical color filters used in color display devices such as liquid crystal display devices and organic light-emitting display devices can be used as red color filter 1231, green color filter 1232, and blue color filter 1233. A microlens array 1250 including a plurality of microlenses 1250a may be further disposed above the first filter array 1210, the second filter array 1220, and the color filter array 1230.

[0174] According to the example embodiment, information related to the center wavelengths of unit filters 1211, 1212, 1213, 1221, 1222 and 1223 can be obtained not only by using the first filter array 1210 and the second filter array 1220, but also by using the color filter array 1230 to obtain information related to the wavelengths of red, green and blue light.

[0175] Figure 16 This is a schematic cross-sectional view of a spectral filter 2300 according to another example embodiment.

[0176] refer to Figure 16 The spectral filter 2300 may include: a first filter array 1310 and a second filter array 1320; and an additional filter array 2500 disposed on the first filter array 1310 and the second filter array 1320.

[0177] For convenience, Figure 16 The illustration shows a configuration where the first filter array 1310 includes a first unit filter 1311, a second unit filter 1312, and a third unit filter 1313, and the second filter array 1320 may include a fourth unit filter 1321, a fifth unit filter 1322, and a sixth unit filter 1323. The first filter array 1310 can be any one of the aforementioned first filter arrays 410, 510, 610, 710, 910, and 1010, and the second filter array 1320 can be any one of the aforementioned second filter arrays 420, 520, 620, 720, 920, and 1020. Descriptions of the first filter array 1310 and the second filter array 1320 are omitted.

[0178] The additional filter array 2500 may include multiple first to third additional filters 2501, 2502 and 2503. Figure 16 The following configuration is illustrated: a first additional filter 2501 is configured to correspond to a first unit filter 1311 and a second unit filter 1312; a second additional filter 2502 is configured to correspond to a third unit filter 1313 and a fourth unit filter 1321; and a third additional filter 2503 is configured to correspond to a fifth unit filter 1322 and a sixth unit filter 1323. However, this is merely exemplary, and each of the first additional filter 2501, the second additional filter 2502, and the third additional filter 2503 may be configured to correspond to one unit filter (1311, 1312, 1313, 1321, 1322, or 1323) or three or more unit filters (1311, 1312, 1313, 1321, 1322, and 1323).

[0179] Each of the first supplementary filter 2501, the second supplementary filter 2502, and the third supplementary filter 2503 can block light in an undesirable wavelength band for the corresponding unit filter (1311, 1312, 1313, 1321, 1322, and 1323). For example, when the first unit filter 1311 and the second unit filter 1312 have a center wavelength in the band of about 400 nm to about 500 nm, the first supplementary filter 2501 may include a blue filter that transmits blue light. Furthermore, when the third unit filter 1313 and the fourth unit filter 1321 have a center wavelength in the band of about 500 nm to about 600 nm, the second supplementary filter 2502 may include a green filter that transmits green light. When the fifth unit filter 1322 and the sixth unit filter 1323 have a center wavelength in the band of about 600 nm to about 700 nm, the third supplementary filter 2503 may include a red filter that transmits red light.

[0180] The additional filter array 2500 may include a color filter array. In this case, the first additional filter 2501, the second additional filter 2502, and the third additional filter 2503 may each include a blue color filter, a green color filter, and a red color filter, respectively. For example, typical color filters used in color display devices such as liquid crystal display devices and organic light-emitting display devices can be used as blue, green, and red color filters.

[0181] The additional filter array 2500 may include a broadband filter array. In this case, the first additional filter 2501, the second additional filter 2502, and the third additional filter 2503 may each include a first broadband filter, a second broadband filter, and a third broadband filter, respectively. Each of the first broadband filter, the second broadband filter, and the third broadband filter may have, for example, a multi-cavity structure or a metal mirror structure.

[0182] Figure 17 This is a schematic cross-sectional view of a spectral filter 3000 according to another example embodiment.

[0183] refer to Figure 17 The spectral filter 3000 may include: a first filter array 1410 and a second filter array 1420; and a short-wavelength absorption filter 1610 and a long-wavelength cutoff filter 1620 disposed on the first filter array 1410 and the second filter array 1420.

[0184] For convenience, Figure 17 The illustration shows a first filter array 1410 comprising a first unit filter 1411, a second unit filter 1412, and a third unit filter 1413, and a second filter array 1420 comprising a fourth unit filter 1421, a fifth unit filter 1422, and a sixth unit filter 1423. The first filter array 1410 can be any one of the aforementioned first filter arrays 410, 510, 610, 710, 910, and 1010, and the second filter array 1420 can be any one of the aforementioned second filter arrays 420, 520, 620, 720, 920, and 1020. Further description of the first filter array 1410 and the second filter array 1420 is omitted.

[0185] The short-wavelength absorption filter 1610 can be disposed in some of the unit filters (1411, 1413, and 1422) among unit filters 1411, 1412, 1413, 1421, 1422, and 1423, and the long-wavelength cutoff filter 1620 can be disposed in other unit filters (1412, 1421, and 1423) among unit filters 1411, 1412, 1413, 1421, 1422, and 1423. Although Figure 17The illustration shows each of the short-wavelength absorption filter 1610 and the long-wavelength cutoff filter 1620 configured to correspond to one unit filter (1411, 1412, 1413, 1421, 1422 or 1423), but the disclosure is not limited thereto, and each of the short-wavelength absorption filter 1610 and the long-wavelength cutoff filter 1620 may be configured to correspond to two or more unit filters (1411, 1412, 1413, 1421, 1422 and 1423).

[0186] The short-wavelength absorption filter 1610 can, for example, block short-wavelength light such as visible light. The short-wavelength absorption filter 1610 can be fabricated by depositing silicon, for example, as a material for absorbing visible light, onto some of the unit filters (1411, 1413, and 1422) from the first to the sixth unit filters 1411, 1412, 1413, 1421, 1422, and 1423. The unit filters (1411, 1413, and 1422) with the short-wavelength absorption filter 1610 can transmit near-infrared (NIR) light with wavelengths longer than visible light.

[0187] The long-wavelength cutoff filter 1620 can, for example, cut off light with a long wavelength such as NIR light. The long-wavelength cutoff filter 1620 may include an NIR light cutoff filter. Unit filters (1412, 1421, and 1423) provided with the long-wavelength cutoff filter 1620 can transmit visible light with a wavelength shorter than that of NIR light.

[0188] According to the example embodiment, since the short-wavelength absorption filter 1610 and the long-wavelength cutoff filter 1620 are disposed on the first filter array 1410 and the second filter array 1420, a spectral filter 3000 with broadband characteristics capable of achieving the range from the visible light band to the NIR band can be manufactured.

[0189] Figure 18 It is applicable Figure 1 A plan view of an example of the spectral filter 9100 of the image sensor 1000.

[0190] refer to Figure 18 The spectral filter 9100 may include multiple filter banks 9110 arranged in a two-dimensional manner. Each of the filter banks 9110 may include sixteen unit filters F1 to F16 arranged in a 4×4 array.

[0191] The first unit filter F1 and the second unit filter F2 can have center wavelengths UV1 and UV2 in the ultraviolet range, and the third unit filters F3 to the fifth unit filters F5 can have center wavelengths B1 to B3 in the blue light range. The sixth unit filters F6 to the eleventh unit filters F11 can have center wavelengths G1 to G6 in the green light range, and the twelfth unit filters F12 to the fourteenth unit filters F14 can have center wavelengths R1 to R3 in the red light range. The fifteenth unit filter F15 and the sixteenth unit filter F16 can have center wavelengths NIR1 and NIR2 in the near-infrared range.

[0192] Figure 19 It is applicable Figure 1 A plan view of another example of the spectral filter 9100 of the image sensor 1000. For ease of illustration, Figure 19 This is a planar diagram of a 9120 filter bank.

[0193] refer to Figure 19 Each filter bank 9120 may include nine unit filters F1 to F9 arranged in a 3×3 array. The first unit filter F1 and the second unit filter F2 may have center wavelengths UV1 and UV2 in the ultraviolet range, and the fourth unit filter F4, the fifth unit filter F5, and the seventh unit filter F7 may have center wavelengths B1 to B3 in the blue light range. The third unit filter F3 and the sixth unit filter F6 may have center wavelengths G1 and G2 in the green light range, and the eighth unit filter F8 and the ninth unit filter F9 may have center wavelengths R1 and R2 in the red light range.

[0194] Figure 20 It is applicable Figure 1 A plan view of another example of the spectral filter 9100 of the image sensor 1000. For ease of illustration, Figure 20 This is a planar diagram of a 9130 filter bank.

[0195] refer to Figure 20Each filter bank 9130 may include twenty-five unit filters F1 to F25 arranged in a 5×5 array. The first unit filters F1 to the third unit filters F3 may have center wavelengths UV1 to UV3 in the ultraviolet range, and the sixth unit filter F6, the seventh unit filter F7, the eighth unit filter F8, the eleventh unit filter F11, and the twelfth unit filter F12 may have center wavelengths B1 to B5 in the blue light range. The fourth unit filter F4, the fifth unit filter F5, the ninth unit filter F9, the sixteenth unit filter F16, the seventeenth unit filter F17, the twenty-first unit filter F21, and the twenty-second unit filter F22 may have center wavelengths G1 to G7 in the green light range, and the tenth unit filter F10, the thirteenth unit filter F13, the fourteenth unit filter F14, the fifteenth unit filter F15, the eighteenth unit filter F18, and the nineteenth unit filter F19 may have center wavelengths R1 to R6 in the red light range. The twentieth unit filter F20, the twenty-third unit filter F23, the twenty-fourth unit filter F24, and the twenty-fifth unit filter F25 can have center wavelengths NIR1 to NIR4 in the near-infrared range.

[0196] The image sensor 1000 with the aforementioned spectral filter can be used in various high-performance optical devices or high-performance electronic devices. Electronic devices may include, for example, smartphones, mobile phones, cellular phones, personal digital assistants (PDAs), laptops, personal computers (PCs), various portable devices, home appliances, security cameras, medical cameras, automobiles, Internet of Things (IoT) devices, and other mobile or non-mobile computing devices, but this disclosure is not limited thereto.

[0197] In addition to the image sensor 1000, the electronic device may also include a processor (e.g., an application processor (AP)) for controlling the image sensor, controlling multiple hardware or software components by driving an operating system or application via the processor, and performing various data processing and calculations. The processor may also include a graphics processing unit (GPU) and / or an image signal processor. When the processor includes an image signal processor, images (or videos) acquired by the image sensor can be stored and / or output using the processor.

[0198] Figure 21 This is a schematic block diagram of an electronic device ED01 including an image sensor 1000 according to an example embodiment. (See reference) Figure 21In the network environment ED00, electronic device ED01 can communicate with another electronic device ED02 via a first network ED98 (short-range wireless communication network, etc.) or with another electronic device ED04 and / or server ED08 via a second network ED99 (long-range wireless communication network, etc.). Electronic device ED01 can communicate with electronic device ED04 via server ED08. Electronic device ED01 may include a processor ED20, a memory ED30, an input device ED50, an audio output device ED55, a display device ED60, an audio module ED70, a sensor module ED76, an interface ED77, a haptic module ED79, a camera module ED80, a power management module ED88, a battery ED89, a communication module ED90, a user identification module ED96, and / or an antenna module ED97. In electronic device ED01, some components (such as the display device ED60) may be omitted or other components may be added. Some components may be implemented by an integrated circuit. For example, the sensor module ED76 (fingerprint sensor, iris sensor, illuminance sensor, etc.) can be implemented by embedding it in the display device ED60 (display, etc.). Furthermore, when the image sensor 1000 includes spectral functionality, some functions of the sensor module ED76 (color sensor and illuminance sensor) can be implemented by the image sensor 1000 instead of a separate sensor module.

[0199] Processor ED20 can control one or more other components (hardware and software components, etc.) of electronic device ED01 connected to processor ED20 by executing software (program ED40, etc.) and perform various data processing or calculations. As part of the data processing or calculation, processor ED20 can load commands and / or data received from other components (sensor module ED76, communication module ED90, etc.) into volatile memory ED32, process the commands and / or data stored in volatile memory ED32, and store the result data in non-volatile memory ED34. Processor ED20 may include a main processor ED21 (central processing unit, application processor, etc.) and an auxiliary processor ED23 (graphics processing unit, image signal processor, sensor hub processor, communication processor, etc.) that can operate independently of or with the main processor ED21. Auxiliary processor ED23 can use less power than main processor ED21 and can perform specialized functions.

[0200] The auxiliary processor ED23 can replace the main processor ED21 when the main processor ED21 is inactive (sleep state) or, when the main processor ED21 is active (application execution state), work with the main processor ED21 to control the functions and / or states related to some components of the electronic device ED01 (display device ED60, sensor module ED76, communication module ED90, etc.). The auxiliary processor ED23 (image signal processor, communication processor, etc.) can be implemented as part of other functionally related components (camera module ED80, communication module ED90, etc.).

[0201] The memory ED30 can store various data required by the constituent elements of the electronic device ED01 (processor ED20, sensor module ED76, etc.). The data may include, for example, software (program ED40, etc.) and input and / or output data related to commands associated with it. The memory ED30 may include volatile memory ED32 and / or non-volatile memory ED34. The non-volatile memory ED34 may include internal memory ED36 fixedly installed in the electronic device ED01 and removable external memory ED38.

[0202] The program ED40 can be stored as software in the memory ED30 and may include the operating system ED24, middleware ED44 and / or application ED46.

[0203] Input device ED50 can receive commands and / or data from outside the electronic device ED01 (such as from a user) for use by the constituent elements (such as processor ED20) of the electronic device ED01. Input device ED50 may include a microphone, mouse, keyboard, and / or digital pen (such as a stylus pen).

[0204] Audio output device ED55 can output audio signals to the external device ED01. Audio output device ED55 may include a speaker and / or a handset. The speaker can be used for general purposes such as multimedia playback or recording playback, and the handset can be used to receive incoming calls. The handset can be implemented by being coupled as part of the speaker or by using a separate, independent device.

[0205] Display device ED60 can visually provide information to the outside of electronic device ED01. Display device ED60 may include a display, holographic device or projector, and control circuitry for controlling the corresponding device. Display device ED60 may include touch circuitry configured to detect touch and / or sensor circuitry configured to measure the intensity of the force generated by the touch (pressure sensor, etc.).

[0206] The audio module ED70 can convert sound into electrical signals or vice versa. The audio module ED70 can obtain sound through the input device ED50, or output sound through the speakers and / or headphones of another electronic device (such as electronic device ED02) connected to the audio output device ED55 and / or electronic device ED01 via wired or wireless means.

[0207] The sensor module ED76 can detect the operating status (power, temperature, etc.) or external environmental status (user status, etc.) of the electronic device ED01, and generate electrical signals and / or data values ​​corresponding to the detected status. The sensor module ED76 may include gesture sensors, gyroscope sensors, barometric pressure sensors, magnetic sensors, accelerometers, grip sensors, proximity sensors, color sensors, IR sensors, biometric sensors, temperature sensors, humidity sensors, and / or illuminance sensors.

[0208] Interface ED77 can support one or more specified protocols used by electronic device ED01 to connect to another electronic device (electronic device ED02, etc.) via wired or wireless means. Interface ED77 may include High Definition Multimedia Interface (HDMI), Universal Serial Bus (USB) interface, SD card interface and / or audio interface.

[0209] The connection terminal ED78 may include a connector that facilitates the physical connection of electronic device ED01 to another electronic device (electronic device ED02, etc.). The connection terminal ED78 may include an HDMI connector, a USB connector, an SD card connector, and / or an audio connector (headphone connector, etc.).

[0210] The ED79 haptic module can convert electrical signals into mechanical stimuli (vibration, movement, etc.) or electrical stimuli that can be perceived by the user through touch or motion. The ED79 haptic module may include a motor, piezoelectric devices, and / or electrical stimulation devices.

[0211] The ED80 camera module can capture still images and video. The ED80 camera module may include: a lens assembly comprising one or more lenses; Figure 1 The camera module ED80 includes an image sensor 1000, an image signal processor, and / or a flash. The lens assembly within the camera module can capture light emitted from the subject for image capture.

[0212] The power management module ED88 manages the power supplied to the electronic device ED01. The power management module ED88 can be implemented as part of a power management integrated circuit (PMIC).

[0213] Battery ED89 can supply power to the constituent components of electronic device ED01. Battery ED89 may include non-rechargeable primary batteries, rechargeable secondary batteries, and / or fuel cells.

[0214] Communication module ED90 can establish a wired and / or wireless communication channel between electronic device ED01 and another electronic device (electronic device ED02, electronic device ED04, or server ED08, etc.), and support communication through the established communication channel. Communication module ED90 can operate independently of processor ED20 (application processor, etc.) and may include one or more communication processors supporting wired and / or wireless communication. Communication module ED90 may include wireless communication module ED92 (cellular communication module, short-range wireless communication module, Global Navigation Satellite System (GNSS) communication module, etc.) and / or wired communication module ED94 (local area network (LAN) communication module, power line communication module, etc.). In the above communication modules, the corresponding communication module can communicate with another electronic device through a first network ED98 (a short-range communication network such as Bluetooth, Wi-Fi Direct, or Infrared Data Association (IrDA)) or a second network ED99 (a long-range communication network such as a cellular network, the Internet, or computer network (LAN, WAN, etc.). These various types of communication modules can be integrated into a single component (a single chip, etc.) or implemented as multiple separate components (multiple chips). The wireless communication module ED92 can verify and authenticate the electronic device ED01 in a communication network (e.g., the first network ED98 and / or the second network ED99) by using user information (International Mobile Subscriber Identity (IMSI), etc.) stored in the user identification module ED96.

[0215] Antenna module ED97 can transmit signals and / or power to or from an external device (such as another electronic device). The antenna may include a transmitter formed in a conductive pattern on a substrate (such as a printed circuit board (PCB)). Antenna module ED97 may include one or more antennas. When antenna module ED97 includes multiple antennas, communication module ED90 can select from the multiple antennas an appropriate antenna for a communication method used in a communication network such as first network ED98 and / or second network ED99. Signals and / or power can be transmitted or received between communication module ED90 and another electronic device via the selected antenna. Other components besides the antenna (such as an RFIC) may be included as part of antenna module ED97.

[0216] Some of these components can be connected to each other through communication methods between peripheral devices (bus, general purpose input and output (GPIO), serial peripheral interface (SPI), mobile industry processor interface (MIPI), etc.) and can exchange signals (commands, data, etc.).

[0217] Commands or data can be sent or received between electronic device ED01 and external electronic device ED04 via server ED08 connected to the second network ED99. Electronic devices ED02 and ED04 can be of the same or different type as electronic device ED01. All or part of the operations performed in electronic device ED01 can be performed in one or more electronic devices (ED02, ED04, and ED08). For example, when electronic device ED01 needs to perform a function or service, it can request one or more electronic devices to perform a part of the entire function or service, rather than performing the function or service itself. The one or more electronic devices receiving the request can perform additional functions or services related to the request and send the results of the execution back to electronic device ED01. Cloud computing, distributed computing, and / or client-server computing technologies can be used for this purpose.

[0218] Figure 22 yes Figure 21 A schematic block diagram of the ED80 camera module. (Reference) Figure 22 The camera module ED80 may include a lens assembly CM10, a flash CM20, and an image sensor 1000. Figure 1 The camera module ED80 may include an image sensor 1000, an image stabilizer CM40, a memory CM50 (buffer memory, etc.), and / or an image signal processor CM60. The lens assembly CM10 can collect light emitted from the subject for image capture. The camera module ED80 may include multiple lens assemblies CM10, and in this case, the camera module ED80 may include a dual-camera system, a 360-degree camera, or a spherical camera. Some of the lens assemblies CM10 may have the same lens properties (angle of view, focal length, autofocus, f-number, optical zoom, etc.) or different lens properties. The lens assembly CM10 may include a wide-angle lens or a telephoto lens.

[0219] The flash CM20 can emit light to enhance light emitted or reflected from the subject. The flash CM20 may include one or more light-emitting diodes (red-green-blue (RGB) LEDs, white LEDs, infrared LEDs, ultraviolet LEDs, etc.) and / or a xenon lamp. The image sensor 1000 may include... Figure 1The image sensor 1000 converts light emitted or reflected from the subject and transmitted through the lens assembly CM10 into electrical signals, thereby obtaining an image corresponding to the subject. The image sensor 1000 may include one or more sensors selected from image sensors with different properties (e.g., RGB sensor, black-and-white (BW) sensor, IR sensor, or UV sensor). Each sensor included in the image sensor 1000 may be implemented as a charge-coupled device (CCD) sensor and / or a complementary metal-oxide-semiconductor (CMOS) sensor.

[0220] Image stabilizer CM40 can move one or more lenses or image sensors 1000 included in lens assembly CM10 in a specific direction in response to movement of camera module ED80 or electronic device ED01 including camera module EDS0, or can compensate for the negative effects caused by movement by controlling the movement characteristics of image sensor 1000 (adjusting readout timing, etc.). Image stabilizer CM40 can detect movement of camera module ED80 or electronic device ED01 by using a gyroscope sensor (not shown) or accelerometer sensor (not shown) arranged inside or outside camera module ED80. Image stabilizer CM40 can be implemented in an optical form.

[0221] The memory CM50 can store part or all of the image data acquired by the image sensor 1000 for subsequent image processing operations. For example, when multiple images are acquired at high speed, only the low-resolution image is displayed, while the acquired raw data (Bayer pattern data, high-resolution data, etc.) is stored in the memory CM50. The memory CM50 can then be used to send the raw data of the selected (user-selected, etc.) image to the image signal processor CM60. The memory CM50 can be incorporated into the memory ED30 of the electronic device ED01 or configured as a separate memory for independent operation.

[0222] The image signal processor CM60 can perform image processing on images acquired by the image sensor 1000 or image data stored in the memory CM50. Image processing may include depth map generation, 3D modeling, panorama generation, feature point extraction, image compositing, and / or image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, etc.). The image signal processor CM60 can perform control (exposure time control or readout timing control, etc.) on components included in the camera module ED80 (image sensor 1000, etc.). Images processed by the image signal processor CM60 can be stored again in the memory CM50 for additional processing or provided to external components of the camera module ED80 (memory ED30, display device ED60, electronic device ED02, electronic device ED04, server ED08, etc.). The image signal processor CM60 can be incorporated into the processor ED20 or configured as a separate processor operating independently of the processor ED20. When the image signal processor CM60 is configured as a separate processor from the processor ED20, the image processed by the image signal processor CM60 can undergo additional image processing by the processor ED20 and then be displayed by the display device ED60.

[0223] Electronic device ED01 may include multiple camera modules ED80 with different attributes or functions. In this case, one of the camera modules ED80 may be a wide-angle camera and another may be a telephoto camera. Similarly, one of the camera modules ED80 may be a front-facing camera and another may be a rear-facing camera.

[0224] The image sensor 1000 according to the example embodiment can be applied to Figure 23 The mobile phone or smartphone shown is 5100m. Figure 24 The tablet computer or smart tablet computer 5200 shown is... Figure 25 The digital camera or video recorder 5300 shown Figure 26 The laptop computer shown is 5400. Figure 27 The television or smart TV 5500 shown is an example. For instance, a smartphone 5100m or a smart tablet computer 5200 may include multiple high-resolution cameras, each equipped with a high-resolution image sensor. By using the high-resolution cameras, depth information of the subject in the image can be extracted, the image can be adjusted for focus, or the subject in the image can be automatically identified.

[0225] Furthermore, the image sensor 1000 can be applied to Figure 28 The smart refrigerator 5600 shown Figure 29 The security camera 5700 shown Figure 30 The robot 5800 shown Figure 31Examples include the medical camera 5900. For instance, the smart refrigerator 5600 can automatically identify food in the refrigerator using an image sensor and notify the user of the presence of specific food items, the types of food placed or removed, etc., via a smartphone. The security camera 5700 can provide ultra-high-resolution images and can identify objects or people in images even in dark environments using high sensitivity. The robot 5800 can be deployed in disaster sites or industrial sites where people cannot directly access them, and the robot 5800 can provide high-resolution images. The medical camera 5900 can provide high-resolution images for diagnosis or surgery, and therefore the field of view can be dynamically adjusted.

[0226] Furthermore, the image sensor 1000 can be applied to Figure 32 The vehicle 6000 is shown. The vehicle 6000 may include a plurality of vehicle cameras 6010, 6020, 6030, and 6040 arranged in various locations. Each of the vehicle cameras 6010, 6020, 6030, and 6040 may include an image sensor according to an example embodiment. The vehicle 6000 can provide the driver with various information relating to the interior or surroundings of the vehicle 6000 by using the vehicle cameras 6010, 6020, 6030, and 6040, thus enabling automatic identification of objects or people in the images and providing the information required for autonomous driving.

[0227] It should be understood that the exemplary embodiments described herein should be considered descriptive only and not for limiting purposes. The description of features or aspects in each exemplary embodiment should typically be regarded as applicable to other similar features or aspects in other exemplary embodiments. Although one or more exemplary embodiments have been described with reference to the accompanying drawings, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the appended claims and their equivalents.

Claims

1. A spectral filter, comprising: Two primary reflective layers, spaced apart from each other and facing each other; as well as At least a first cavity and a second cavity are disposed between the two first reflective layers, wherein the first cavity has a different thickness than the second cavity, the thickness of the first cavity being determined according to a first center wavelength, and the thickness of the second cavity being determined according to a second center wavelength. Each of the first cavity and the second cavity includes multiple etch stop layers with a constant total thickness. The first cavity includes a second dielectric layer among one or more dielectric layers, and the second cavity includes a first dielectric layer among the one or more dielectric layers, wherein the thickness of the second dielectric layer and the thickness of the first dielectric layer are different from each other according to the first center wavelength of the first cavity and the second center wavelength of the second cavity. The plurality of etch stop layers include a first etch stop layer and a second etch stop layer. The first cavity includes: a first etch stop layer disposed on the lower of the two first reflective layers; a second etch stop layer disposed on the first etch stop layer and in direct contact with the first etch stop layer; and a second dielectric layer disposed on the second etch stop layer. The second cavity includes: a first etch stop layer disposed on the lower first reflective layer of the two first reflective layers; a first dielectric layer disposed on the first etch stop layer; and a second etch stop layer disposed on the first dielectric layer.

2. The spectral filter according to claim 1, It also includes a third cavity, and in which, The first cavity, the second cavity, and the third cavity are arranged in a two-dimensional manner between the two first reflective layers. The third cavity includes: a first etch stop layer disposed on the lower first reflective layer of the two first reflective layers; a first dielectric layer disposed on the first etch stop layer; a second etch stop layer disposed on the first dielectric layer; and a second dielectric layer disposed on the second etch stop layer.

3. The spectral filter according to claim 1, in, The difference between the refractive index of the material included in the one or more dielectric layers and the refractive index of the material included in the etch stop layer is less than or equal to 2.

5.

4. The spectral filter according to claim 3, in, The difference between the refractive index of the material included in the one or more dielectric layers and the refractive index of the material included in the etch stop layer is less than or equal to 1.

5. The spectral filter according to claim 1, in, The one or more dielectric layers include silicon, silicon oxide, or silicon nitride.

6. The spectral filter according to claim 5, in, The etch stop layer comprises silicon oxide, titanium oxide, or hafnium oxide, and wherein the etch selectivity of the material comprising the etch stop layer differs from the etch selectivity of the one or more dielectric layers by a factor of 5 or greater.

7. The spectral filter according to claim 6, in, The one or more dielectric layers comprise silicon nitride, and the etch stop layer comprises hafnium oxide; or the one or more dielectric layers comprise silicon nitride, and the etch stop layer comprises titanium oxide; or the one or more dielectric layers comprise silicon oxide, and the etch stop layer comprises hafnium oxide; or the one or more dielectric layers comprise silicon oxide, and the etch stop layer comprises titanium oxide; or the one or more dielectric layers comprise silicon, and the etch stop layer comprises silicon oxide.

8. The spectral filter according to claim 1, in, The first reflective layer includes a metallic reflective layer.

9. The spectral filter according to claim 8, in, The metal reflective layer includes Al, Cu, Ag, Au, or TiN.

10. The spectral filter according to claim 1, in, The first reflective layer includes a Bragg reflective layer.

11. The spectral filter according to claim 1, in, A first transmission dielectric layer for improving transmittance is disposed below the lower first reflective layer of the two first reflective layers, and a second transmission dielectric layer for improving transmittance is disposed above the upper first reflective layer of the two first reflective layers.

12. The spectral filter according to claim 11, in, The first and second transmission dielectric layers each have a thickness that varies according to the center wavelength of the first and second cavities, respectively.

13. The spectral filter according to claim 1, further comprising: Two second reflective layers are disposed on one side of the two first reflective layers in the lateral direction; as well as At least a third cavity and a fourth cavity are disposed between the two second reflective layers, wherein the third cavity has a different thickness than the fourth cavity. Each of the third cavity and the fourth cavity includes the plurality of etch stop layers, and the third cavity and the fourth cavity include the one or more dielectric layers.

14. The spectral filter according to claim 13, in, At least one of the third cavity and the fourth cavity also includes at least one spacer for adjusting the thickness.

15. The spectral filter according to claim 13, in, The second reflective layer includes a metallic reflective layer or a Bragg reflective layer.

16. The spectral filter according to claim 13, in, A first transmission dielectric layer for improving transmittance is disposed below the lower second reflective layer of the two second reflective layers, and a second transmission dielectric layer for improving transmittance is disposed above the upper second reflective layer of the two second reflective layers.

17. A method for manufacturing a spectral filter, the method comprising: A first etch stop layer is formed on the lower reflective layer, and a first dielectric layer is formed on the first etch stop layer; A portion of the first dielectric layer is etched to expose a portion of the first etch stop layer; A second etch stop layer is formed on the exposed portion of the first etch stop layer and on the first dielectric layer, and a second dielectric layer is formed on the second etch stop layer; A portion of the second dielectric layer is etched to expose a portion of the second etch stop layer, wherein at least the top of the second dielectric layer and the top of the exposed portion of the second etch stop layer form respective boundaries of a first cavity and a second cavity having different thicknesses; and An upper reflective layer is formed on the first cavity and the second cavity. The first cavity includes: a first etch stop layer disposed on the lower reflective layer; a second etch stop layer disposed on the first etch stop layer and in direct contact with the first etch stop layer; and a second dielectric layer disposed on the second etch stop layer. The second cavity includes: a first etch stop layer disposed on the lower reflective layer; a first dielectric layer disposed on the first etch stop layer; and a second etch stop layer disposed on the first dielectric layer.

18. The method of claim 17, further comprising: After etching the portion of the second dielectric layer to expose the portion of the second etch stop layer, a third etch stop layer is formed on the exposed portion of the second etch stop layer and on the second dielectric layer, and a third dielectric layer is formed on the third etch stop layer. as well as A portion of the third dielectric layer is etched to expose a portion of the third etch stop layer.

19. The method according to claim 17, in, The difference between the refractive index of the materials included in the first dielectric layer and the second dielectric layer and the refractive index of the materials included in the first etch stop layer and the second etch stop layer is less than or equal to 2.

5.

20. The method according to claim 19, in, The difference between the refractive index of the materials included in the first dielectric layer and the second dielectric layer and the refractive index of the materials included in the first etch stop layer and the second etch stop layer is less than or equal to 1.

21. The method according to claim 19, in, The first dielectric layer and the second dielectric layer comprise silicon, silicon oxide, or silicon nitride, and wherein the first etch stop layer and the second etch stop layer comprise materials whose etch selectivity differs from that of the first dielectric layer and the second dielectric layer by a factor of 5 or greater.

22. The method according to claim 20, in, The first etch stop layer and the second etch stop layer comprise silicon oxide, titanium oxide, or hafnium oxide.

23. The method of claim 17, further comprising: At least one spacer for adjusting the thickness is formed in at least one of the first cavity and the second cavity.

24. The method according to claim 17, in, Each of the lower reflective layer and the upper reflective layer includes a metallic reflective layer or a Bragg reflective layer.

25. The method according to claim 17, in, Each of the lower reflective layer and the upper reflective layer includes: a first metal reflective layer and a second metal reflective layer arranged on a plane.

26. The method according to claim 17, in, Each of the lower reflective layer and the upper reflective layer includes: a metallic reflective layer and a Bragg reflective layer arranged on a plane.

27. The method of claim 17, further comprising: A first transmission dielectric layer for improving transmittance is formed below the lower reflective layer and a second transmission dielectric layer for improving transmittance is formed above the upper reflective layer.

28. The method according to claim 27, in, The first transmission dielectric layer, used to improve transmittance, is formed to have a different thickness depending on the center wavelength.

29. An image sensor, comprising: Spectral filter according to any one of claims 1 to 16; as well as A pixel array that receives light transmitted through the spectral filter.

30. The image sensor of claim 29, further comprising: One or more processors are configured to operate as a timing controller, a line decoder, and output circuitry.

31. An electronic device comprising the image sensor according to claim 29.

32. The electronic device according to claim 31, comprising one of the following: a mobile phone, a smartphone, a tablet computer, a smart tablet computer, a digital camera, a video recorder, a laptop computer, a television set, a smart television set, a smart refrigerator, a security camera, a robot, or a medical camera.

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