Biosensor

Abstract

This invention provides a biosensor. The biosensor includes multiple sensor units. Each sensor unit includes one or more photodiodes, a first aperture component disposed on the photodiode, an intermediate layer disposed on the first aperture component, a second aperture component disposed on the intermediate layer, and a waveguide disposed on the second aperture component. The second aperture component includes an upper grating element, and the first aperture component includes one or more lower grating elements, wherein the grating period of the upper grating element is less than or equal to the grating period of the one or more lower grating elements. The absolute value difference between the first polarization angle between the upper and lower grating elements in one of the sensor units and the second polarization angle between the upper and lower grating elements in one of the adjacent sensor units is 90°.

Description

Technical Field

[0001] This invention relates to a biosensor, and more particularly to a biosensor having a grating array. Background Art

[0002] Recently, integrated sensing devices have been used in bioanalysis. In such applications, biometric objects or biological samples can be placed on a biosensor, and light reflected or emitted by the objects or samples can be guided to the photodiode of the biosensor. Therefore, the outline of the biometric object or the biological characteristics of the biological sample can be determined and identified for further analysis.

[0003] In the evolution of biosensors, in pursuit of lower costs and higher throughput, the array density of biosensors is generally increased by reducing the spacing width or well pitch. However, reducing the array size may lead to crosstalk between adjacent wells during operation and may prevent the accurate detection of individual fluorescence signals, resulting in inaccurate analytical results.

[0004] While existing biosensors generally meet the requirements, they are not satisfactory in all aspects. Therefore, there is still a need for a novel biosensor that can reduce crosstalk. In addition, there is a desire to create a biosensor that can accurately identify various biosignatures and biological responses. Summary of the Invention

[0005] According to some embodiments of the present invention, a biosensor is provided. The biosensor includes a plurality of sensor units. Each sensor unit includes one or more photodiodes, a first aperture element disposed on the photodiode, an intermediate layer disposed on the first aperture element, a second aperture element disposed on the intermediate layer, and a waveguide disposed on the second aperture element. The second aperture element includes an upper grating element, and the first aperture element includes one or more lower grating elements, wherein the grating period of the upper grating element is less than or equal to the grating period of the one or more lower grating elements. The absolute value difference between the first polarization angle between the upper and lower grating elements in one of the sensor units and the second polarization angle between the upper and lower grating elements in one of the adjacent sensor units is 90°.

[0006] According to other embodiments of the present invention, another biosensor is also provided. The biosensor includes a plurality of sensor units. Each sensor unit includes one or more photodiodes, a first aperture element disposed on the photodiode, an intermediate layer disposed on the first aperture element, a second aperture element disposed on the intermediate layer, and a waveguide disposed on the second aperture element. The intermediate layer includes an angle-sensitive filter layer. The second aperture element includes an upper grating element, and the first aperture element includes one or more lower grating elements, wherein the grating period of the upper grating element is less than or equal to the grating period of the one or more lower grating elements.

[0007] The following embodiments are described in detail with reference to the accompanying drawings. Attached Figure Description

[0008] A more comprehensive understanding of the embodiments of the present invention will be achieved by reading the following detailed description and examples in conjunction with the accompanying drawings, wherein:

[0009] Figure 1A and Figure 1B This is a cross-sectional view of a biosensor according to some embodiments of the present invention.

[0010] Figure 1C This is a top view of a biosensor according to some embodiments of the present invention.

[0011] Figure 2 This is a top view illustrating a sensor unit according to various embodiments of the present invention.

[0012] Figures 3A to 3D It is the transmission spectrum of light passing through the upper or lower grating element, which is formed of various materials and has various grating periods.

[0013] Figure 4A and Figure 4B Other embodiments of the present invention are shown, respectively, in cross-sectional and top views of the biosensor.

[0014] Figure 4C and Figure 4D Other embodiments of the present invention are shown, respectively, in cross-sectional and top views of a biosensor with biased nanopores.

[0015] Figure 4E Showing the use Figure 4C and Figure 4D The illustrated embodiment provides a biosensor for detecting biological samples.

[0016] Figures 4F to 4H This is a top view showing a sensor unit including lower grating elements in various configurations.

[0017] Figure 5A and Figure 5BOther embodiments of the present invention are shown, respectively, in cross-sectional and top views of the biosensor.

[0018] The attached figures are labeled as follows:

[0019] 10, 20, 30: Biosensors

[0020] 100A, 100B: Sensor Unit

[0021] 102:Substrate

[0022] 104: Photodiode

[0023] 106: Intermediate Layer

[0024] 108: First aperture component

[0025] 108A, 108A1, 108A2, 108A3, 108A4, 108A5, 108A6, 108B, 108B1, 108B2, 108B3, 108B4: Lower grating element

[0026] 110: Second aperture component

[0027] 110A, 110B: Upper grating element

[0028] 112: Waveguide

[0029] 114: Platform Layer

[0030] 116: Nanopores

[0031] 118: Biological Samples

[0032] A-A',B-B': line segment

[0033] L1: Part 1

[0034] L2: Part Two

[0035] θ1: First angle

[0036] θ2: Second angle Detailed Implementation

[0037] The following details a biosensor according to embodiments of the present invention. For illustrative purposes, numerous specific details and embodiments are set forth in the following detailed description to provide a complete understanding of the embodiments of the present invention. The specific elements and states described in the following detailed description are intended to clearly illustrate the embodiments of the present invention. However, the exemplary embodiments described herein are obviously used for illustrative purposes only, and the concept of the embodiments of the present invention can be presented in various forms and is not limited to these exemplary embodiments.

[0038] Furthermore, to clearly describe the embodiments of the present invention, similar and / or corresponding numbers may be used in the drawings of different embodiments to represent similar and / or corresponding elements. However, this does not imply any relationship between the different embodiments. It should be understood that the description of this exemplary embodiment should be understood in conjunction with the accompanying drawings, which are also considered part of the description of the embodiments of the present invention. The drawings are not shown to scale of actual devices and elements. In addition, structures and devices are shown schematically to simplify the drawings.

[0039] Furthermore, the phrase "a membrane layer is located above or on top of another membrane layer" can refer to a situation where the membrane layer is in direct contact with the other membrane layers. Alternatively, it could refer to a situation where the membrane layer is not in direct contact with the other membrane layers, in which case one or more intermediate layers are disposed between the membrane layer and the other membrane layers.

[0040] Furthermore, this specification uses relative terms. For example, "lower" or "upper" is used to describe the relative position of one element to another. It should be understood that if the device is flipped upside down, the element described as being on the "lower" side will become the element on the "upper" side.

[0041] It should be understood that although terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, films, and / or portions, these elements, components, regions, films, and / or portions should not be limited by these terms. These terms are only used to distinguish different elements, components, regions, films, and / or portions. Therefore, the first elements, components, regions, films, and / or portions discussed below may be referred to as second elements, components, regions, films, and / or portions without departing from the teachings of embodiments of the present invention.

[0042] The word “about” usually means within 10% of a given value or range, preferably within 5%, or within 3%, or within 2%, or within 1%, and more preferably within 0.5%. The quantity given here is an approximate quantity, meaning that the meaning of “about” can still be implied even without a specific mention of “about”.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should be understood that these terms, as defined in general dictionaries, should be interpreted as having a meaning consistent with the background or context of the relevant art and this invention, and should not be interpreted in an idealized or overly formal manner, unless specifically defined in the embodiments of this invention.

[0044] According to some embodiments of the present invention, a biosensor includes multiple sensor units, each sensor unit including one or more lower grating elements in a first aperture feature and an upper grating element in a second aperture feature. A first polarization angle between the lower and upper grating elements in one of the sensor units differs from a second polarization angle between the lower and upper grating elements in adjacent sensor units. Therefore, crosstalk between adjacent sensor units can be reduced. Furthermore, the grating period of the upper grating element is less than or equal to the grating period of the lower grating element, and the individual grating periods of the lower grating elements can be gradually increased. Light emitted or reflected from the biological sample, after passing through the lower grating element, can be split into several rays with different spectral distributions, thus allowing the biosensor to obtain more detailed information about the biological sample and easily distinguish differences between various biological samples. Moreover, when the biological sample is irradiated with excitation light (e.g., through a waveguide), the upper grating element with a specific grating period can partially block the excitation light to avoid interference with detection.

[0045] Figure 1A and Figure 1B This is a cross-sectional view of a biosensor 10 according to some embodiments of the present invention, and Figure 1C This is a top view of a biosensor 10 according to some embodiments of the present invention. (Refer to...) Figure 1A The biosensor 10 includes multiple sensor units 100A and 100B. Each sensor unit 100A and sensor unit 100B includes one or more photodiodes 104, a first aperture component 108, an intermediate layer 106, a second aperture component 110, and a waveguide 112. Although Figure 1A and Figure 1B Only one photodiode 104 is shown in each of sensor units 100A and 100B, but the number of photodiodes 104 in each sensor unit is not limited thereto. In other embodiments shown in the following figures, each sensor unit may include more than one photodiode 104.

[0046] A photodiode 104 is disposed in a substrate 102. In some embodiments, the substrate 102 may be a semiconductor substrate such as a silicon substrate. Furthermore, in some embodiments, the semiconductor substrate may also be an elemental semiconductor, a compound semiconductor, an alloy semiconductor, or a combination thereof. Elemental semiconductors include germanium. Compound semiconductors include gallium nitride (GaN), silicon carbide (SiC), gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), indium arsenide (InAs), and / or indium antimonide (InSb). Alloy semiconductors include silicon-germanium (SiGe) alloys, gallium arsenide phosphide (GaAsP) alloys, aluminum indium arsenide (AlInAs) alloys, aluminum gallium arsenide (AlGaAs) alloys, gallium arsenide indium (GaInAs) alloys, gallium phosphide indium (GaInP) alloys, and / or gallium arsenide indium phosphide (GaInAsP) alloys.

[0047] Photodiode 104 can be used to detect light reflected or emitted by an object or biological sample. Photodiode 104 converts the measured light into a current signal and can be connected to the source and drain of a metal-oxide-semiconductor transistor (not shown), which can then transmit the current to another component, such as another metal-oxide-semiconductor transistor. Other components may include, but are not limited to, a reset transistor, a current-source follower, or a row selector to convert the current into a digital signal.

[0048] In some embodiments, an intermediate layer 106 is disposed on the substrate 102 and the photodiode 104. The intermediate layer 106 may include a dielectric material, a semiconductor material, any other suitable material, or a combination thereof. For example, the dielectric material may include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), silicon oxycarbide (SiCO), silicon carbonitride (SiCN), silicon carbonitride (SiOCN), or a combination thereof. For example, the semiconductor material may include silicon, silicon carbide, any suitable semiconductor material, or a combination thereof. In other embodiments, the intermediate layer 106 may include an organic material or a polymer material. For example, the organic material or polymer material may include photoresist, benzocyclobutene (BCB), polyamide, polymethyl methacrylate (PMMA), or a combination thereof.

[0049] In some embodiments, the intermediate layer 106 may be transparent. More specifically, the material of the intermediate layer 106 may have a light transmittance of greater than 90% for light with wavelengths between 200 nm and 1100 nm, or preferably greater than 95%. The intermediate layer 106 may be formed using suitable deposition techniques such as spin-on coating, chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), other suitable deposition methods, or combinations thereof.

[0050] The first aperture component 108 is disposed above the photodiode 104 and also on the intermediate layer 106. The first aperture component 108 of each sensor unit 100A and sensor unit 100B respectively includes one or more lower grating elements 108A and 108B. For example... Figure 1A As shown, each of the lower grating elements 108A and 108B corresponds to a photodiode 104. In embodiments where the sensor unit 100A or the sensor unit 100B includes one or more lower grating elements 108A or 108B and one or more photodiodes 104, the lower grating elements 108A and 108B may also each correspond to a photodiode 104.

[0051] An intermediate layer 106 is also disposed on the first aperture component 108, and a second aperture component 110 is disposed on the intermediate layer 106, such that a portion of the intermediate layer 106 is sandwiched between the first aperture component 108 and the second aperture component 110. The second aperture component 110 of each sensor unit 100A and sensor unit 100B respectively includes an upper grating element 110A and an upper grating element 110B. Similarly, the upper grating element 110A of sensor unit 100A and the upper grating element 110B of sensor unit 100B each correspond to a photodiode 104. In embodiments where sensor unit 100A and sensor unit 100B include one or more photodiodes 104, such as two, four or more photodiodes 104, the upper grating element 110A of sensor unit 110A and the upper grating element 110B of sensor unit 100B may each correspond to two, four or more photodiodes 104 in sensor units 100A and 100B.

[0052] In some embodiments, the grating period of the lower grating element 108A is the same as that of the lower grating element 108B, and the grating period of the upper grating element 110A is the same as that of the upper grating element 110B. However, in other embodiments, the grating period of the lower grating element 108A is different from that of the lower grating element 108B, and the grating period of the upper grating element 110A is different from that of the upper grating element 110B.

[0053] Furthermore, the grating periods of the upper grating elements 110A and 110B are less than or equal to the grating periods of the lower grating elements 108A and 108B. In embodiments where sensor units 100A and 100B each have more than one lower grating element 108A and 108B, the grating periods of the upper grating elements 110A and 110B are less than or equal to the grating periods of all lower grating elements 108A and 108B. However, in each sensor unit 100A and 100B, the individual lower grating elements may have the same or different grating periods.

[0054] The upper grating elements 110A and 110B may have a specific grating period to allow light of a specific wavelength to pass through. When the sample is irradiated with excitation light, the upper grating elements 110A and 110B may partially block the excitation light from passing through them. Furthermore, the lower grating elements 108A and 108B may have a larger grating period than or the same as that of the upper grating elements 110A and 110B to further block the remaining excitation light and filter the specific spectrum of light emitted or reflected by the sample.

[0055] Generally, when the lower grating elements 108A and 108B are designed to have a larger grating period than the upper grating elements 110A and 110B, only incident light of longer wavelengths can pass through the lower grating elements 108A and 108B. Therefore, spectral selectivity can be achieved.

[0056] Furthermore, both the lower grating element 108A and the upper grating element 110A in sensor unit 100A have a first polarization angle, and both the lower grating element 108B and the upper grating element 110B in sensor unit 100B, which is adjacent to sensor unit 100A, have a second polarization angle. Figure 1A As shown, the first polarization angles of the lower grating element 108A and the upper grating element 110A are different from the second polarization angles of the lower grating element 108B and the upper grating element 110B. More specifically, any two adjacent sensor units (e.g., Figure 1C The lower grating element and the upper grating element in the sensor units 100A and 100B shown in the top view have different polarization angles.

[0057] As used herein, the term "polarization angle" refers to the inability of light rays polarized at an angle of 90° or 270° relative to this polarization angle to pass through the upper or lower grating element having this polarization angle. The absolute difference between the first and second polarization angles can be greater than 0° and less than 180°, for example, 0°, 45°, 90°, 135°, or 180°. In some specific embodiments, the absolute difference between the first and second polarization angles is 90°. In this case, the polarization direction of light rays passing through the lower grating element 108A and upper grating element 110A of sensor unit 100A is perpendicular to the polarization direction of light rays passing through the lower grating element 108B and upper grating element 110B of sensor unit 100B. Because the polarization angles of the lower and upper grating elements in any two adjacent sensor units are different, crosstalk between adjacent sensor units can be reduced, and therefore each sensor unit can detect light signals from objects or biological samples with high fidelity.

[0058] In some embodiments, the lower grating elements 108A and 108B may have a circular, rectangular, square, or hexagonal shape in the top view of the sensor units 100A and 100B. In some embodiments, the upper grating elements 110A and 110B may have a circular, rectangular, square, or hexagonal shape in the top view of the sensor units 100A and 100B. In embodiments where the sensor units 100A and 100B each have one or more lower grating elements 108A and one or more lower grating elements 108B, the lower grating elements 108A and 108B may together have a circular, rectangular, square, or hexagonal shape in the top view of the sensor units 100A and 100B. Furthermore, in some embodiments, in a top view of the biosensor 10, the lower grating elements 108A and 108B may form a nano-slit array, and the upper grating elements 110A and 110B may also form a nano-slit array (not shown).

[0059] The materials of the first aperture component 108 and the second aperture component 110 may include metallic materials, semiconductor materials, or combinations thereof. For example, metallic materials may include Al, Cu, Au, Ag, W, Ti, or alloys thereof, and semiconductor materials may include SiC. The materials of the first aperture component 108 and the second aperture component 110 may be the same or different from each other. In some embodiments, the thickness of the first aperture component 108 is in the range of about 25 nm to about 500 nm, preferably between about 50 nm and about 250 nm. In some embodiments, the thickness of the second aperture component 110 is in the range of about 25 nm to about 500 nm, preferably between about 50 nm and about 250 nm.

[0060] According to other embodiments of the present invention, the first aperture component 108 and the second aperture component 110 may each comprise a stack of metal layer-insulator layer-metal layer. The metal layer may include any of the aforementioned metals, and the insulating layer may include SiO2, Al2O3, or a combination thereof. Each metal layer of the metal layer-insulator layer-metal layer stack may have a thickness of about 20 nm to about 150 nm, for example, about 40 nm. The insulating layer of the metal layer-insulator layer-metal layer stack may have a thickness of about 60 nm to about 200 nm, for example, about 100 nm. The overall thickness of the metal layer-insulator layer-metal layer stack is in the range of about 100 nm to about 500 nm, preferably between about 100 nm and about 300 nm.

[0061] Patterning processes can be performed on the first aperture component 108 and the second aperture component 110 to form grating elements with desired grating periods and polarization angles. The patterning process may include photolithography and etching processes. In some embodiments, the photolithography process may include photoresist coating, soft baking, hard baking, mask alignment, exposure, post-exposure baking, developing the photoresist, rinsing, drying, or other suitable processes. In some embodiments, the etching process may include dry etching processes, such as plasma etching (PE), reactive ion etching (RIE), inductively coupled plasma reactive ion etching (ICP-RIE), or combinations thereof. As mentioned above, the lower grating elements 108A and 108B and the upper grating elements 110A and 110B can each have a specific grating period according to design requirements, but the grating period of the lower grating elements 108A and 108B is greater than or equal to the grating period of the upper grating elements 110A and 110B.

[0062] In some embodiments, the intermediate layer 106 disposed between the first aperture component 108 and the second aperture component 110 may include a color filter layer. For example, the color filter layer may be a rejection filter layer, which can further filter the excitation light to prevent the excitation light from entering the photodiode 104. In other embodiments, the color filter layer may also include an absorption filter layer, an interference filter layer, a plasmonic metasurface structure, a dielectric metasurface structure, or a combination thereof. The color filter layer may be a single-layer structure or a multi-layer structure.

[0063] In some specific embodiments, the color filter layer is an angle-sensitive filter. When incident light enters the angle-sensitive filter layer at a large incident angle, the wavelength equivalent component of the incident light in the direction perpendicular to the angle-sensitive filter layer will decrease, thus causing a blue-shift in the incident light spectrum. The angle-sensitive filter layer can be a dielectric interference filter layer, which is formed by alternately depositing high-refractive-index and low-refractive-index dielectric materials. If the refractive index in the visible light wavelength range is greater than about 1.7, this refractive index is considered high. Dielectric materials with high refractive index can include Nb2O5, Ta2O5, TiO2, Si3N4, Al2O3, SiH, or combinations thereof. If the refractive index in the visible light wavelength range is less than about 1.7, this refractive index is considered low. Dielectric materials with low refractive index can include SiO2, Al2O3, organic polymers, air, or combinations thereof. Alternatively, the angle-sensitive filter layer can be a plasmonic sub-filter layer or a dielectric metasurface structure.

[0064] Furthermore, in some embodiments, at least one lens may be disposed in the intermediate layer 106 located between the first aperture component 108 and the second aperture component 110. The lens focuses the emitted or reflected light from the sample, such that the emitted or reflected light, after passing through several film layers, can still maintain a light intensity sufficient for detection.

[0065] Reference Figure 1A The intermediate layer 106 may also be disposed on the second aperture component 110, and the waveguide 112 is disposed on the second aperture component 110 and the intermediate layer 106. Light emitted from the light source (not shown) can be transmitted to the position where the sample is placed or fixed through the waveguide 112. The waveguide 112 can be a linear waveguide or a planar waveguide.

[0066] like Figure 1A As shown, according to some embodiments of the present invention, the sensor unit 100A and sensor unit 100B of the biosensor 10 may each further include a platen layer 114 disposed on the waveguide 112. The platen layer 114 may provide a flat surface for biometric identification, such as identifying fingerprints or the outline of objects.

[0067] In some embodiments, the platform layer 114 may be transparent or translucent. More specifically, in embodiments where the platform layer 114 is transparent, the material of the platform layer 114 may have a light transmittance of greater than 85% for light with wavelengths between 400 nm and 750 nm, or preferably greater than 92%. In embodiments where the platform layer 114 is translucent, the material of the platform layer 114 may have a light transmittance of greater than 25% and less than 85% for light with wavelengths between 400 nm and 750 nm.

[0068] The material of the platform layer 114 may include silicon oxide (SiO2), amorphous silicon (a-Si), aluminum oxide (Al2O3), niobium oxide (Nb2O5), polymers, or combinations thereof. For example, polymers may include benzocyclobutene (BCB), polyimide (PI), polymethyl methacrylate (PMMA), cyclic olefin copolymer (COP), polycarbonate (PC), another suitable material, or combinations thereof, but are not limited thereto. The platform layer 114 may be formed using sputtering, evaporation, spin coating, chemical vapor deposition, molecular beam deposition, any other suitable process, or combinations thereof. For example, chemical vapor deposition processes may include low-pressure chemical vapor deposition (LPCVD), low-temperature chemical vapor deposition (LTCVD), rapid thermal chemical vapor deposition (RTCVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition, or combinations thereof.

[0069] In some embodiments, a portion of the surface of platform layer 114 may be modified such that only the modified portion can capture the desired biological sample. For example, some functional groups on the surface of platform layer 114 may be modified to capture the desired biological sample. Furthermore, the modified portions of the surface of platform layer 114 may be further modified to enhance the fixation effect on the biological sample. For example, in some embodiments, self-assembly monolayers (SAMs), functional polymers, or hydrogels may be used to coat or treat platform layer 114 to fix the biological sample in a specific location for easy detection. The biological sample may be fixed to platform layer 114 based on its weight, size, surface charge, or Van der Waals force, etc.

[0070] Reference Figure 1B The biosensor 10 comprises sensor units 100A and 100B, each having nanowells 116 formed within a platform layer 114. Biological samples to be detected can be contained within the nanowells 116. The nanowells 116 can be formed by creating openings in the platform layer 114 after deposition. Similarly, the surface of the nanowells 116 can be modified using a similar method as described above to enhance the immobilization of the biological sample.

[0071] Next, refer to Figure 1C , Figure 1C Show Figure 1B The diagram shows a top view of the biosensor 10. It should be noted that, for simplicity only, aside from the nanopores 116, Figure 1C The film or element above the first aperture component 108 is omitted in the top view of the following figures. In some embodiments, the nanopores 116 may be disposed at the center of symmetry of the respective sensor units 100A and 100B. However, in other embodiments, the nanopores may be offset from the center of symmetry of the respective sensor units 100A and 100B.

[0072] Figure 2 This is a top view of a sensor unit 100A having one or more lower grating elements 108A, according to another embodiment of the present invention. As described above, the first aperture component 108 of the sensor unit 100A may include one or more lower grating elements 108A, which define an m×n grating array, where m and n are positive integers and may be the same or different. For example, in Figure 2 On the left side, the first aperture component 108 of the sensor unit 100A includes nine lower grating elements 108A, which define a 3×3 grating array. Figure 2 On the right side, the first aperture component 108 of the sensor unit 100A includes 16 lower grating elements 108A, which define a 4×4 grating array. Furthermore, nanopores 116 may be located at the center of symmetry of the grating array defined by the lower grating elements 108A. Although all lower grating elements 108A are located at... Figure 2 The images shown are of the same grating period, but it should be understood that each sensor unit 100A may include several lower grating elements with different grating periods.

[0073] Although the lower grating element 108A is Figure 2 The images shown have the same grating period, but it should be noted that the lower grating elements 108A may have individual grating periods that are the same or different from each other, as will be described in more detail below.

[0074] Figures 3A to 3DIt is the transmission spectrum of light passing through the lower or upper grating element, which is formed of Al, Cu, Au, and Ag, respectively, and has various grating periods. For example... Figures 3A to 3D As shown, an upper or lower grating element with a larger grating period can allow longer wavelength incident light to pass through while blocking shorter wavelength incident light. For example, Figure 3A In this study, incident light with wavelengths greater than 500 nm can exhibit a transmittance greater than 80% and can pass through the lower or upper grating element with a grating period of 250 nm. When using a lower or upper grating element with a grating period of 400 nm, only incident light with wavelengths greater than 600 nm can pass through it. Furthermore, different materials may result in different spectral selectivity. Therefore, the desired spectral selectivity can be achieved by selecting appropriate materials and adjusting the grating periods of the lower and upper grating elements.

[0075] Figure 4A and Figure 4B Other embodiments of the present invention are shown, respectively, in cross-sectional and top views of the biosensor 20. Figure 4A and Figure 4B As shown, sensor units 100A and 100B each have two lower grating elements 108A1 and 108A2 and two lower grating elements 108B1 and 108B2, respectively. In one sensor unit, the two lower grating elements define a 1×2 grating array. For example, lower grating elements 108A1 and 108A2 define a 1×2 grating array in sensor unit 100A, and lower grating elements 108B1 and 108B2 define a 1×2 grating array in sensor unit 100B.

[0076] In these embodiments, the grating period of the lower grating element 108A1 is less than the grating period of the lower grating element 108A2, and the grating period of the lower grating element 108B1 is less than the grating period of the lower grating element 108B2. The grating period of the upper grating element 110A is less than or equal to the grating period of the lower grating element 108A1, and the grating period of the upper grating element 110B is less than or equal to the grating period of the lower grating element 108B1. Each lower grating element corresponds to a photodiode 104. Emitted or reflected light from the biological sample passing through the two lower grating elements 108A1, 108A2 or 108B1, 108B2 in each of the sensor units 100A and 100B can be divided into two parts with two spectral distribution types, and each part can be detected by a photodiode 104. Therefore, more information can be obtained from the emitted or reflected light passing through the individual sensor units.

[0077] Furthermore, the upper grating element 110A and lower grating elements 108A1 and 108A2 in sensor unit 100A have a first polarization angle, and the upper grating element 110B and lower grating elements 108B1 and 108B2 in sensor unit 100B have a second polarization angle, the first polarization angle being different from the second polarization angle. Therefore, crosstalk between adjacent sensor units 100A and 100B can be reduced. In some specific embodiments, the absolute difference between the first polarization angle and the second polarization angle is 90°.

[0078] Reference Figure 4C and Figure 4D , Figure 4C and Figure 4D Other embodiments of the present invention are shown, respectively, in cross-sectional and top views of a biosensor 20 having biased nanopores 116. Figure 4C and Figure 4D In the illustrated embodiment, the intermediate layer 106 between the first aperture component 108 and the second aperture component 110 includes an angle-sensitive filter layer. The nanopores 116 of each sensor unit 100A and 100B are biased at the center of symmetry of the individual grating arrays defined by the lower grating elements 108A1, 108A2 and 108B1, 108B2. Furthermore, the distance between the nanopores 116 and the lower grating element 108A2 or 108B2 with the smaller grating period is less than the distance between the nanopores 116 and the lower grating element 108A1 or 108B1.

[0079] Figure 4E Showing the use Figure 4C and Figure 4D The biosensor 20 shown is used to detect a biological sample 118. When the biological sample 118 is illuminated by light transmitted via waveguide 112, the biological sample 118 can generate emitted or reflected light. A first portion L1 of the emitted or reflected light enters the upper grating element 110A at a first angle θ1 (that is, enters the lower grating element 108A1 at a first angle θ1), and a second portion L2 of the emitted or reflected light enters the upper grating element 110A at a second angle θ2 (that is, enters the lower grating element 108A2 at a second angle θ2). The first angle θ1 is greater than the second angle θ2 because the nanopore 116 is biased at the center of symmetry of the sensor unit 100A and is closer to the lower grating element 108A2.

[0080] After the first portion L1 of the emitted or reflected light passes through the angle-sensitive filter layer in the intermediate layer 106 between the first aperture member 108 and the second aperture member 110, the first portion L1 of the emitted or reflected light will have a shorter wavelength due to the blue shift caused by the angle-sensitive filter layer. Therefore, a lower grating element with a smaller grating period is needed for spectral selection, such as the lower grating element 108A1 in sensor unit 100A and the lower grating element 108B1 in sensor unit 100B. On the other hand, after the second portion L2 of the emitted or reflected light passes through the angle-sensitive layer, the second portion L2 of the emitted or reflected light has a longer wavelength than the first portion L1. Therefore, a lower grating element with a larger grating period is needed, such as the lower grating element 108A2 in sensor unit 100A and the lower grating element 108B2 in sensor unit 100B.

[0081] Figures 4F to 4H A top view is shown of a sensor unit 100A that includes lower grating elements in various configurations. Figures 4F to 4H The sensor unit 100A in the middle and Figure 4D The sensor unit 100A in the illustrated embodiment is similar, but... Figure 4F The sensor unit 100A has four lower grating elements that define a 2×2 grating array, and Figure 4G and Figure 4H The sensor unit 100A has nine lower grating elements that define a 3×3 grating array.

[0082] In embodiments where the sensor unit 100A includes more than one lower grating element, the grating period of each lower grating element decreases as the lateral distance between the lower grating element and the nanopore 116 increases. The lateral distance used here can be the horizontal distance between the lower grating element and the nanopore 116 along the X or Y direction. Figure 4F In the sensor unit 100A, there is one lower grating element 108A1, two lower grating elements 108A2, and one lower grating element 108A3. The grating period of the lower grating element 108A3 is less than the grating period of the lower grating element 108A2, and the grating period of the lower grating element 108A2 is less than the grating period of the lower grating element 108A1.

[0083] Emitted or reflected light entering the lower grating element at a large incident angle may have weak light intensity. Therefore, as the lateral distance between the lower grating element and the nanopore 116 increases, more lower grating elements with smaller grating periods are needed to obtain sufficient light intensity for analysis. For example, Figure 4GIn the sensor unit 100A, there are three lower grating elements 108A4, three lower grating elements 108A3, two lower grating elements 108A2, and one lower grating element 108A1. Among all the lower grating elements, the lower grating element 108A4 is farthest from the nanopore 116, and therefore has the smallest grating period. In contrast, the lower grating element 108A1 is closest to the nanopore 116, and therefore has the largest grating period.

[0084] Figure 4H In the sensor unit 100A, there are three lower grating elements 108A6, two lower grating elements 108A5, one lower grating element 108A4, one lower grating element 108A3, one lower grating element 108A2, and one lower grating element 108A1. Figure 4H In the illustrated embodiment, the nanopore 116 is disposed at the center of the grating array defined by the lower grating elements 108A1, 108A2, 108A3, and 108A4. The lower grating elements 108A1-108A4 have individual grating periods that differ from each other. Similarly, the lower grating element 108A6, which is furthest from the nanopore 116, has the smallest grating period, and the lower grating element 108A5, which is closer to the nanopore 116 than the lower grating element 108A6, has a larger grating period than the lower grating element 108A6. The lower grating elements 108A1-108A4 can be configured with different grating periods to allow for more diverse spectral selection. Furthermore, the configuration of the lower grating elements 108A1-108A4 is not limited to... Figure 4H As shown in the figure, the lower grating elements 108A1-108A4 can be arranged arbitrarily, as long as the lower grating elements 108A1-108A4 are arranged in a 2×2 manner and located directly below the nanopore 116.

[0085] Reference Figure 5A and Figure 5B , Figure 5A and Figure 5B According to other embodiments of the present invention, a cross-sectional view and a top view of the biosensor 30 are shown respectively. Figure 5A and Figure 5B The biosensor 30 shown and Figure 4A and Figure 4B The biosensor 20 shown is similar, but sensor units 100A and 100B each have four lower grating elements arranged in a 2×2 configuration. Cross-sectional views of sensor units 100A and 100B of the biosensor 30 are extracted along line segments A-A' and B-B', respectively. Although Figure 5B The diagram shows how sensor units 100A and 100B are arranged alternately along the X direction, but it should be noted that sensor units 100A and 100B can also be arranged in the same way along the Y direction.

[0086] In some embodiments, the lower grating elements 108A1-A4 may have gradually increasing individual grating periods, and the individual grating periods of the lower grating elements 108A1-108A4 are smaller than the grating period of the upper grating element 110A. In other embodiments, one or more of the lower grating elements 108A1-108A4 may have the same grating period as the upper grating element 110A. As mentioned above, the first polarization angle between the lower grating elements 108A1-108A4 and the upper grating element 110A in the sensor unit 100A is different from the second polarization angle between the lower grating elements 108B1-108B4 and the upper grating element 110B in the sensor unit 100B. Furthermore, in Figure 5A and Figure 5B In the embodiment shown, the nanopore 116 is located at the center of symmetry of the 2×2 grating array defined by the lower grating elements 108A1-108A4 or 108B1-108B4.

[0087] Although one, two, and four lower grating elements are shown in the accompanying figures mentioned above, it should be understood that the number of lower grating elements in each sensor unit is not limited thereto. In other embodiments, each sensor unit may have a plurality of lower grating elements defining an m×n grating array, where m and n are positive integers and may be the same or different.

[0088] In summary, according to some embodiments of the present invention, each sensor unit of a biosensor may have an upper grating element and one or more lower grating elements. The first polarization angle of the upper and lower grating elements in one of the sensor units differs from the second polarization angle of the upper and lower grating elements in adjacent sensor units. Therefore, crosstalk between adjacent sensor units can be reduced. Furthermore, the lower grating elements may have gradually increasing individual grating periods, and the individual grating period of the lower grating element is greater than or equal to the grating period of the upper grating element. A biosensor with such a lower grating element can accurately detect objects or biological samples and easily distinguish differences between various objects or biological samples.

[0089] While some embodiments and advantages of the present invention have been described in detail, it should be understood that various modifications, substitutions, and refinements can be made without departing from the spirit and scope of the invention as defined by its protection scope. For example, those skilled in the art will readily understand that many components, functions, processes, and materials described herein can be altered without departing from the scope of the invention. Furthermore, the scope of the present invention is not limited to the specific embodiments of the processes, machines, manufacturing, material composition, methods, and steps described in the specification. Those skilled in the art will readily understand from the present invention that any existing or future developed processes, machines, manufacturing, material composition, methods, or steps that can achieve substantially the same function or substantially the same result as the corresponding embodiments described herein can be used according to the embodiments of the present invention. Therefore, the protection scope of the present invention includes the aforementioned processes, machines, manufacturing, material composition, methods, or steps.

Claims

1. A biosensor, comprising: Multiple sensor units, Each of the plurality of sensor units includes: One or more photodiodes; A first aperture component is disposed on one or more of the photodiodes; An intermediate layer is disposed on the first aperture component; A second aperture component is disposed on the intermediate layer; and A waveguide is disposed on the second aperture component; The second aperture component includes an upper grating element, and the first aperture component includes one or more lower grating elements, wherein the grating period of the upper grating element is less than or equal to the grating period of the one or more lower grating elements; Furthermore, the absolute difference between a first polarization angle between the upper and lower grating elements in one of the plurality of sensor units and a second polarization angle between the upper and lower grating elements in one of the plurality of adjacent sensor units is 90°.

2. The biosensor of claim 1, wherein each of the plurality of sensor units further comprises a platform layer disposed on the waveguide, and wherein the platform layer is modified to fix a biological sample to the platform layer.

3. The biosensor of claim 1, wherein two or more lower grating elements define a grating array, and the individual grating periods of the two or more lower grating elements in the grating array gradually increase.

4. The biosensor of claim 2, wherein a nanopore is formed in the platform layer for accommodating a biological sample.

5. The biosensor of claim 4, wherein two or more lower grating elements define a grating array, and the nanopore is located at a center of symmetry of the grating array.

6. The biosensor of claim 4, wherein two or more lower grating elements define a grating array, the nanopores being biased at a center of symmetry of the grating array, and wherein the intermediate layer includes an angle-sensitive filter layer.

7. The biosensor of claim 4, wherein the grating period of each of the plurality of lower grating elements decreases as a lateral distance between the plurality of lower grating elements and the nanopore increases.

8. The biosensor of claim 1, wherein: Each of the one or more lower grating elements corresponds to one of the one or more photodiodes; The first aperture component or the second aperture component comprises a stack of metal layers-insulating layers-metal layers; and At least one lens is provided in the intermediate layer.

9. The biosensor of claim 1, wherein the intermediate layer includes a color filter layer, and wherein the color filter layer has a single-layer structure or a multi-layer structure.

10. The biosensor of claim 1, wherein the upper grating element has a circular shape, a rectangular shape, a square shape, or a hexagonal shape in a top view, and the one or more lower grating elements together have a circular shape, a rectangular shape, a square shape, or a hexagonal shape in a top view.

11. A biosensor, comprising: Multiple sensor units, Each of the plurality of sensor units includes: One or more photodiodes; A first aperture component is disposed on one or more of the photodiodes; An intermediate layer is disposed on the first aperture component and includes an angle-sensitive filter layer; A second aperture component is disposed on the intermediate layer; and A waveguide is disposed on the second aperture component; Furthermore, the second aperture component includes an upper grating element, the first aperture component includes one or more lower grating elements, and the grating period of the upper grating element is less than or equal to the grating period of the one or more lower grating elements.

12. The biosensor of claim 11, wherein the absolute difference between a first polarization angle of the upper grating element and the lower grating element in one of the plurality of sensor units and a second polarization angle of the upper grating element and the lower grating element in one of the plurality of sensor units adjacent to each other is 90°, and wherein each of the plurality of sensor units further comprises a platform layer disposed on the waveguide, and a nanopore is formed in the platform layer for accommodating a biological sample.

13. The biosensor of claim 12, wherein: A first lower grating element and a second lower grating element define a grating array; The first lower grating element has a first grating period, and the second lower grating element has a second grating period, the second grating period being greater than the first grating period; The nanopore is offset at a symmetrical center of the grating array; and The distance between the nanopore and the second lower grating element is smaller than the distance between the nanopore and the first lower grating element.

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