Dielectric mirror-based multispectral filter array

Abstract

To provide a multispectral image device to capture multispectral image data.SOLUTION: An optical sensor device includes a set of optical sensors and a substrate. The optical sensor device also includes a multispectral filter array 105 placed on the substrate. The multispectral filter array includes: a first dielectric mirror 110-1 placed on the substrate; a spacer 120 placed on the first dielectric mirror; and a second dielectric mirror 110-2 placed on the spacer. The second dielectric mirror is aligned with two or more sensor elements in a set of sensor elements.SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001] A multispectral imaging device may be utilized to capture multispectral image data. For example, a multispectral imaging device may capture image data for a set of electromagnetic frequencies. A multispectral imaging device may include a set of sensor elements (e.g., optical sensors, spectral sensors, and / or image sensors) that capture the image data. For example, an array of sensor elements may be utilized to capture information regarding multiple frequencies. A particular sensor element of the sensor element array may be associated with a filter that limits the range of frequencies directed to the particular sensor element. Summary of the Invention

[0002] According to some possible embodiments, the optical sensor device may include a set of optical sensors. The optical sensor device may include a substrate. The optical sensor device may include a multi-spectral filter array disposed on the substrate. The multi-spectral filter array may include a first dielectric mirror disposed on the substrate. The spacer may include a set of layers. The multi-spectral filter array may include a second dielectric mirror disposed on the spacer. The second dielectric mirror may be aligned with two or more sensor elements of the set of sensor elements.

[0003] According to some possible embodiments, the optical filter may include a first layer. The first layer may be a first dielectric mirror that reflects a portion of the light directed to the first layer. The first layer may be deposited on a substrate associated with the set of optical sensors. The optical filter may include a second set of layers. The second set of layers may be deposited only on the first layer. The second set of layers may be associated with a channel set corresponding to the set of sensor elements. The channels of the channel set may be associated with a particular thickness corresponding to a particular wavelength of light directed to a particular optical sensor of the set of optical sensors. The optical filter may include a third layer. The third layer may be a second dielectric mirror that reflects a portion of the light directed to the third layer. The third layer may be deposited on a set of a plurality of sensor elements associated with the set of second layers.

[0004] According to some possible embodiments, the system may include a set of optical sensors integrated into the substrate. The system may include a multispectral filter array deposited on the substrate. The multispectral filter may include a first dielectric mirror for partially reflecting light from the light source. The first dielectric mirror may include a first quarter-wave stack of high and low refractive index layers. The multispectral filter may include a second dielectric mirror for partially reflecting light from the light source. The second dielectric mirror may include a second quarter-wave stack of high and low refractive index layers. The multispectral filter array may include a plurality of high refractive index spacer layers disposed between the first and second dielectric mirrors. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a schematic diagram of an embodiment described herein. [Diagram 2] 1A-1C are diagrams of an example manufacturing process for a sensor device having a multispectral filter array. [Figure 3A] FIG. 3 is an example diagram of the example process shown in FIG. 2. [Figure 3B] FIG. 3 is an example diagram of the example process shown in FIG. 2. [Figure 3C] FIG. 3 is an example diagram of the example process shown in FIG. 2. [Figure 4A] FIG. 3 is a diagram of another embodiment of the example process shown in FIG. 2. [Figure 4B] FIG. 3 is a diagram of another embodiment of the example process shown in FIG. 2. [Figure 4C] FIG. 3 is a diagram of another embodiment of the example process shown in FIG. 2. [Figure 5A] FIG. 3 is a diagram of another embodiment of the example process shown in FIG. 2. [Figure 5B] FIG. 3 is a diagram of another embodiment of the example process shown in FIG. 2. [Figure 6A] FIG. 3 is a diagram of another embodiment of the example process shown in FIG. 2. [Figure 6B] FIG. 3 is a diagram of another embodiment of the example process shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] In the following detailed description of the embodiments, reference will be made to the accompanying drawings, in which the same reference numbers in different drawings may identify the same or similar elements, and in which:

[0007] A sensor element (e.g., a light sensor) may be incorporated into the light sensor device to obtain information (e.g., spectral data) about a set of electromagnetic frequencies. For example, the light sensor may include a particular sensor element, such as an image sensor, a multispectral sensor, etc., capable of performing a sensor measurement of light directed to the particular sensor element. In this case, the light sensor device may utilize one or more image sensor technologies, such as an image sensor using complementary metal oxide semiconductor (CMOS) technology, an image sensor using charge-coupled device (CCD) technology, etc. The light sensor device may include multiple sensor elements (e.g., an array of sensor elements, a super array of sensor elements, a distributed array of sensor elements, etc.), each configured to obtain image data. Additionally or alternatively, the light sensor device may include a set of sensor elements, each associated with a different wavelength of light and configured to obtain a set of images.

[0008] The sensor elements may be associated with filters that filter the light directed toward the sensor elements. For example, the sensor elements may be lined with a linear variable filter (LVF), a circular variable filter (CVF), a Fabry-Perot filter, etc., that filter a portion of the light directed toward the light sensor. However, it may be difficult to integrate a filter array using an LVF or CVF, or to pattern filters in conjunction with a semiconductor. Furthermore, some sets of filters utilized for multispectral sensing may be associated with relatively large angular shift values, relatively small spectral ranges, etc., that may reduce the spectral range of information that can be captured or the accuracy of the information captured. Furthermore, environmental conditions, such as temperature, may affect the operation of the sensor elements by causing the filters to change the wavelength of light directed toward the sensor elements.

[0009] The embodiments described herein may utilize environmentally durable multispectral filter arrays using dielectric mirrors, such as quarter-wave stack type mirrors or distributed Bragg reflector type mirrors, for multispectral detection. In this manner, optical filters for optical sensor devices may be provided that have improved durability, improved spectral range, improved temperature shift, improved transmission, and reduced angular shift compared to one or more other types of filters. Additionally, the difficulty of incorporating the filters onto semiconductor-based sensor elements or sensor element arrays may be reduced compared to one or more other types of filters.

[0010] 1 is a schematic diagram of an embodiment 100 described herein. As shown in FIG. 1, the multi-spectral filter 105 may include a first dielectric mirror 110-1, a second dielectric mirror 110-2, and a spacer 120.

[0011] As further shown in FIG. 1, the first dielectric mirror 110-1 and the second dielectric mirror 110-2 may sandwich a spacer 120. In other words, the spacer 120 may separate the first dielectric mirror 110-1 and the second dielectric mirror 110-2 by a threshold distance, and / or a surface of the spacer 120 may be at least partially surrounded by the first dielectric mirror 110-1 and the second dielectric mirror 110-2. In some embodiments, the dielectric mirror 110 may be associated with a particular material. For example, the dielectric mirror 110 may be a deposited layer of dielectric material (e.g., a set of deposited silicon hydrogen layers or silicon oxide layers) that form a quarter-wave stack. The dielectric mirror 110-2 may align with each sensor element of the sensor element array associated with each channel of the multispectral filter array.

[0012] In some embodiments, the spacer 120 may include one or more spacer layers 130. For example, the spacer 120 may include a set of spacer layers 130-1 through 130-5 (e.g., dielectric layers). In some embodiments, the thickness of one or more layers 130 may be related to ensuring a minimum spacer thickness for a particular wavelength.

[0013] In some examples, such as for a wavelength of 842 nanometers (nm) directed to one or more sensors, layer 130-1 may be associated with a thickness of 108.5 nm. In this manner, spacer 120 ensures a minimum separation between dielectric mirrors 110 for the wavelength of light to be directed to one or more sensor elements. In some embodiments, the thicknesses of one or more spacer layers 130 may be associated based on a binary number. For example, spacer layer 130-2 may be associated with a thickness of about 26.9 nanometers, spacer layer 130-3 may be associated with a thickness of about 13.5 nanometers, spacer layer 130-4 may be associated with a thickness of about 6.7 nanometers, and spacer layer 130-5 may be associated with a thickness of about 3.4 nanometers.

[0014] In some embodiments, the multi-spectral filter 105 may be deposited on a substrate associated with an optical sensor device of the sensor system. For example, the dielectric mirror 110-1 may be deposited (e.g., by a deposition process and / or a photolithographic lift-off process) on a substrate including an array of sensor elements for capturing information (e.g., spectral data). In some embodiments, the spacer 120 enables the capture of information associated with multiple wavelengths. For example, a first portion of the spacer 120 aligned with a first sensor element (e.g., a back-illuminated optical sensor or a front-illuminated optical sensor) may be associated with a first thickness, and a second portion of the spacer 120 aligned with a second optical sensor may be associated with a second thickness. In this case, light directed to the first sensor element and the second sensor element may correspond to a first wavelength of the first sensor element based on the first thickness and a second wavelength of the second sensor element based on the second thickness. In some embodiments, the dielectric mirrors 110-1 and / or 110-2 may be aligned with the sensor elements of the sensor system, such as a majority of the sensor elements, all of the sensor elements, etc. In this manner, the multi-spectral filter 105 enables multi-spectral detection by an optical sensor device using spacers (e.g., spacer 120) associated with multiple thicknesses and associated with multiple portions aligned with multiple sensor elements of the optical sensor device.

[0015] As noted above, Figure 1 is merely one example. Other examples are possible and may differ from the example described with respect to Figure 1.

[0016] Figure 2 is a flow chart illustrating an example process 200 for fabricating an optical sensor device having a multispectral filter array, such as the multispectral filter 105 shown in Figure 1. The process 200 may be applied to the design of an optical sensor device having a multispectral filter array used to capture information related to a spectral measurement. Figures 3A-3C are diagrams of an example implementation 300 of the example process 200 shown in Figure 2.

[0017] As shown in FIG. 2, the process 200 may include starting fabrication on an optical sensor device (block 210). For example, as shown in FIG. 3A by reference number 304, a substrate 306 may include a set of sensor elements 308 integrated into the substrate 306. In some embodiments, the substrate 306 may be associated with a particular configuration. For example, the substrate 306 may include a silicon-based substrate. In another example, the substrate 306 may include a glass-based substrate, and the sensor elements 308 are disposed on a silicon-based wafer that is bonded to the glass-based substrate, as described herein with respect to FIGS. 8A and 8B. Additionally or alternatively, the substrate 306 may be associated with a multi-spectral filter array associated with a relatively low angular shift under relatively high temperature conditions.

[0018] In some embodiments, the substrate 306 may include one or more conductive paths (not shown) for providing information obtained by the set of sensor elements 308. For example, the substrate 306 may include a set of conductive paths that enable the substrate 306 to be attached to another device and provide data from the set of sensor elements 308 to the other device, such as a camera device, a scanning device, a measurement device, a processing device, a microcontroller device, etc. In some embodiments, the substrate 306 may be associated with multiple layers of substrate material. For example, the substrate 306 may include a multi-layer substrate with layers associated with receiving the set of sensor elements 308.

[0019] In some embodiments, the substrate 306 may be associated with a particular type of sensor element 308. For example, the substrate 306 may be associated with one or more sensor elements of a sensor array, one or more photodiodes overlying or adjacent to CMOS technology, CCD technology, etc. In some embodiments, the sensor elements 308 may include a set of back-illuminated photosensors. In this case, the substrate 306 may be thinner than in other configurations, allowing light to be directed through the silicon surface to the photosensors.

[0020] As further shown in FIG. 2, the process 200 may include depositing a plurality of layers of a multispectral filter array on a substrate associated with a light sensor device (block 220). For example, as further shown by reference number 310 in FIG. 3A, a first mirror structure 312 may be deposited on the substrate 306. In some embodiments, the first mirror structure 312 may be a dielectric mirror aligned with a set of sensor elements of the light sensor device. In some embodiments, the first mirror structure 312 may be associated with a uniform thickness. In some embodiments, the first mirror structure 312 may be disposed within a threshold proximity of the substrate 306, such as on an intermediate layer between the substrate 306 and the first mirror structure 312. In other words, the first mirror structure 312 may not necessarily be disposed on the substrate 306, but may be disposed on an intermediate layer between the substrate 306 and the first mirror structure 312.

[0021] In some embodiments, the mirror structure 312 may be associated with a particular composition, such as a dielectric component. For example, the mirror structure 312 may utilize an oxide-based material (e.g., high-index oxides such as Nb2O5, Ta2O5, TiO2, HfO2, or low-index oxides such as SiO2, Al2O3, etc.), a nitride-based material (e.g., Si3N4), a germanium-based material, or a silicon-based material (e.g., a silicon hydrogen-based material or a silicon carbide-based material, etc.), etc.

[0022] In some embodiments, the mirror structure 312 and / or one or more other layers may be deposited on the substrate 306 or on another layer using a pulsed magnetron sputtering deposition process. For example, a coating platform may be associated with depositing the mirror structure 312 at a thickness based on the refractive index of the selected material and the wavelength of the desired mirror. Similarly, a coating platform may be associated with a particular semiconductor wafer size (e.g., a 200 millimeter (mm) wafer or a 300 mm wafer) and may utilize a pulsed magnetron to deposit layers of a particular thickness described herein (e.g., less than 5 nanometers (nm) thick, less than 2 nm thick, or less than 1 nm thick for some spacer layers, and other thicknesses such as greater than 5 nm or greater than 100 nm for other spacer layers).

[0023] In some embodiments, a set of spacer layers of spacers may be deposited to separate the mirror structure 312 from another mirror structure. For example, as further shown in FIG. 3A by reference number 314, a cavity first spacer layer 316 may be deposited on the mirror structure 312 (e.g., using a pulsed magnetron sputtering deposition process). In some embodiments, the first spacer layer 316 may be deposited on the mirror structure 312 based on a patterning technique. For example, a lift-off process may be utilized to form the first spacer layer 316 of a specific thickness. The first spacer layer 316 and / or another spacer layer may be disposed blanket on the mirror structure 312. For example, the first spacer layer 316 may include one or more separate portions forming a continuous spacer layer on a continuous dielectric mirror. In this case, the first spacer layer 316 and / or one or more other spacer layers may be a set of blanket layers having the first mirror structure 312 and another mirror structure as described herein to form a plurality of channels aligned with the set of sensor elements 308 that direct light towards a corresponding plurality of sensor elements 308.

[0024] In some embodiments, the first spacer layer 316 associated with the first mirror structure 312 and another mirror structure described herein may be associated with performing a particular filtering function. In some embodiments, based on the desired spectral range from the light source (e.g., between about 380 nm and about 1110 nm sent to the light sensor) or the desire for reduced angular shift, the first spacer layer 316 and / or one or more other spacer layers may utilize an oxide-based material (e.g., for the visible spectral range, niobium titanium oxide (NbTiOx), niobium oxide, titanium oxide, tantalum oxide, or combinations thereof, etc.), a nitride-based material (e.g., silicon nitride), a silicon-based material (e.g., for the spectral range greater than 650 nm, silicon hydride (SiH), silicon carbide (SiC), or silicon (Si)), or a germanium (Ge)-based material (e.g., for the infrared spectral range), etc. In some embodiments, the first spacer layer 316 may utilize a particular material to achieve reduced angular shift compared to another material. For example, utilizing a Si-H based material can reduce the angle shift as compared to using a silicon dioxide (SiO2) based material. In another example, the first spacer layer 316 may utilize another type of oxide material, nitride material, or fluoride material, etc. In some embodiments, the light source may generate light in a particular spectral range (e.g., between about 700 nanometers and about 1100 nanometers).

[0025] In some embodiments, the mirror structure 312 and / or one or more other mirror structures and the first spacer layer 316 and / or one or more other spacer layers may be selected to maximize the refractive index ratio between the set of spacer layers and the set of mirrors. For example, the optical sensor device may utilize a silicon dioxide (SiO2) based material for the low refractive index layer material of the dielectric mirror (refractive index of about 1.47 at 890 nm) and a silicon hydride (Si:H) for the high refractive index layer material of the dielectric mirror (refractive index of about 3.66 at 890 nm). Similarly, the optical sensor device may utilize a niobium titanium oxide (NbTiOx) based material (refractive index of about 2.33 at 890 nm). For example, the mirror structure 312 and / or one or more other mirror structures may utilize a silicon dioxide based material and / or a hydrogenated silicon based material to provide a relatively large spectral range, and the first spacer layer 316 and / or one or more other spacer layers may utilize a hydrogenated silicon based material, or a material such as niobium titanium oxide, tantalum oxide, niobium oxide, titanium oxide, or mixtures thereof to provide a relatively reduced thermal shift.

[0026] A second spacer layer 320 may be deposited on the first spacer layer 316, as indicated by reference numeral 318 in Figure 3B. For example, the second spacer layer 320 may be deposited using a reactive sputtering process, a pulsed magnetron sputtering process, an ion beam assisted deposition process, an ion beam sputtering process, a dual ion beam sputtering process, a reactive direct current sputtering process, an alternating current sputtering process, a radio frequency sputtering process, an atomic layer deposition process, or the like. Although described herein with respect to a particular order of deposition of layers, other orders of deposition of layers may be utilized.

[0027] In some embodiments, the second spacer 120 may be associated with a thickness relative to the first spacer layer 316. For example, if the first spacer layer 316 is associated with a first thickness t0, the second spacer layer 320 may be deposited with a second thickness t1. In some embodiments, the second spacer layer 320 may be deposited on a portion of the first spacer layer 316. For example, based on a desired spacer thickness arrangement for a channel set, the second spacer layer may be deposited on a subset of the surface of the first spacer layer to cause the first sensor element 308 to be associated with the first spacer thickness and the second sensor element 308 to be associated with the second spacer thickness, such that the first sensor element 308 can capture information regarding a first wavelength and the second sensor element 308 can capture information regarding a second wavelength. Additionally or alternatively, a first layer may be deposited to cover a set of sensor elements, a second layer may be deposited to cover half of the set of sensor elements, a third layer may be deposited to cover a portion of the sensor elements, etc. Further details regarding patterning of the set of spacer layers are described with respect to Figures 4A-4C and 5A-5B.

[0028] As further shown in FIG. 3B by reference number 322, the third spacer layer 324 may be deposited on the second spacer layer 320 and / or the first spacer layer 316. For example, the third spacer layer 324 and / or one or more subsequent spacer layers (not shown) may be deposited. In some embodiments, the third spacer layer 324 (and / or one or more other spacer layers n, where n is 2 or more) may be associated with half the thickness of the previous layer (e.g., the second spacer layer 320 relative to the third spacer layer 324). In other words, the third spacer layer 324 may have a thickness that is 1 / 2 the thickness of the second spacer layer 320. In some embodiments, the third spacer layer 324 may be selectively deposited on a portion of the first spacer layer 316 and / or the second spacer layer 320. For example, a first portion of the third spacer layer 324 may be deposited on a portion of the first spacer layer 316 and a second portion of the third spacer layer 324 may be deposited on a portion of the second spacer layer 320, such that multiple sensor elements 308 can be associated with multiple spacer thicknesses and can capture information regarding multiple wavelengths.

[0029] As shown by reference number 326 in FIG. 3B, a mirror structure 328 may be deposited. For example, the mirror structure 328 may be deposited on one or more portions of one or more layers (e.g., the first spacer layer 316, the second spacer layer 320, the third spacer layer 324, or another subsequent layer). In some embodiments, the mirror structure 328 may be a dielectric mirror aligned with a light sensor (e.g., the sensor element 308) of a light sensor device. Deposited based on the spacer layers 316, 320, and 324, the mirror structure 328 is separated from the mirror structure 312 by a cavity. In this way, light may be directed toward one or more sensor elements 308 at one or more wavelengths. In some embodiments, another layer may be deposited between the mirror structure 328 and the spacer layer 324. For example, a thin film layer or the like may be deposited to perform one or more functions.

[0030] As shown in FIG. 3C, a set of out-of-band shield layers 332 (e.g., a set of layers forming a patterned shield) may be deposited prior to depositing the lens 330. Alternatively, a set of anti-reflective coating layers 334 may be deposited. In this case, the mirror structure 328 may be deposited on the anti-reflective coating layers 334, as shown in FIG. 3C. In some embodiments, multiple separate filter coatings may be deposited. Additionally or alternatively, a single shield may be deposited to suppress out-of-band light of multiple wavelengths, multiple channels, etc.

[0031] As further shown in FIG. 2, in some embodiments, the process 200 may include depositing one or more other layers associated with the multi-spectral filter array (block 230). For example, as described in detail herein, filters such as anti-reflective coating filters (e.g., anti-reflective coating layers), out-of-band blocking filters (e.g., out-of-band blocking layers), higher-order suppression filters, etc., may be deposited on the mirror structure 328, etc. As further shown in FIG. 2, the process 200 may include finalizing the light sensor device with the multi-spectral filter array (block 240). For example, as further shown in FIG. 3B by reference numeral 326, a set of lenses 330 may be attached to the mirror structure 328. For example, a particular lens 330, such as a glass lens, a plastic lens, etc., may be attached to the mirror structure 328 to change the characteristics of the light directed to the corresponding sensor element 308, such as to focus light, distort light, direct light, increase the angular tolerance that light can enter the light sensor device, or increase the amount of light directed to the sensor element 308 of the light sensor device.

[0032] In this manner, the multispectral Fabry-Perot filter array may be constructed using dielectric mirrors and / or quarter-wave stacks. Additionally or alternatively, based on the use of dielectric mirrors, a relatively large spectral bandwidth may be achieved compared to the use of a different type of mirror. Additionally or alternatively, based on the use of niobium titanium oxide spacer layers, a relatively low temperature shift may be achieved without significantly reducing the shielding range of the multispectral filter array compared to the use of a different type of spacer. Additionally or alternatively, based on the use of pulsed magnetron sputtering and / or lift-off processes, the multispectral filter array may be incorporated into an optical sensor device having a semiconductor substrate that is not overly difficult to fabricate.

[0033] Although Figure 2 illustrates example blocks of process 200, in some embodiments, process 200 may include additional blocks, fewer blocks, different blocks, or blocks arranged differently than those illustrated in Figure 2. Additionally, or alternatively, two or more blocks of process 200 may be performed in parallel. As noted above, Figures 3A-3C are provided by way of example only. Other examples are possible and may differ from those described with respect to Figures 3A-3C.

[0034] Figures 4A-4C are diagrams of an embodiment 400 related to the example process 200 shown in Figure 2. Figures 4A-4C show an example of a layout of a filter array of a multi-spectral filter.

[0035] As shown in FIG. 4A, a filter array 401 may be associated with a set of layers. The filter array 401 may be a 4×4 filter array including 16 channels (e.g., optical channels) corresponding to 16 sensor elements. In some embodiments, the filter array 401 corresponds to the example multispectral filter 105 shown in the cross-sectional view of FIG. 1. In some embodiments, each channel may be associated with a sensor array. For example, a channel may include a sensor array having a set of sensor elements associated with capturing information about light directed at it with the channel. In some embodiments, each channel may be associated with a particular thickness for each spacer layer. The thickness of the set of spacer layers for a channel may be selected based on the desired wavelength of information to be captured by the optical sensor corresponding to the channel. In some embodiments, the 4×4 filter array (e.g., or another dimensional filter array) may be associated with a particular patterning, such as a mosaic pattern (e.g., a snapshot Bayer mosaic pattern), a tile pattern (e.g., a snapshot tile pattern), or a line pattern (e.g., a continuous line scan pattern, or a non-continuous line scan pattern).

[0036] Based on the spectral range captured by the photosensor, the thickness of the spacer layer sandwiched between the mirrors of the 4×4 filter array is: t max =2*(λ max / (4*n ref )); t min =2*(λ min / (4*n ref )); where t max represents the total thickness of the spacer layer separating the set of mirror structures for the highest central wavelength at which information is captured, and λ max represents the highest central wavelength at which image data is captured, and n ref represents the refractive index of the spacer layer, and t minrepresents the total thickness of the spacer layer separating the set of mirror structures for the lowest central wavelength at which image data is captured, and λ min represents the highest central wavelength at which image data is captured.

[0037] The number of layers of the spacer layer to be deposited to form a channel set (e.g., 16 channels of a 4×4 filter array) is c=2 x ; It may be determined that c = 1 / 2, where c represents the maximum number of channels that can be generated for a given number x of deposited spacer layers. In some embodiments, a maximum number of channels can be selected for a particular number of spacer layers. For example, a maximum of 16 channels may be generated for the deposition of four spacer layers, but another number of channels, such as 9 channels, 10 channels, etc., may be selected for four spacer layers. In this case, one or more channels may be omitted or duplicated. For example, if a particular optical sensor is associated with a lack of performance for capturing image data for a particular wavelength, information about the particular wavelength may be captured by multiple optical sensors associated with multiple channels to improve the accuracy of the information.

[0038] The thickness of each layer of the spacer layer for a particular channel (e.g., for a set of equidistant channels) is t0=t min ; t1=(c / 2) / ((c-1)*2*n ref )*(λ max -λ min ); t n =t n-1 / 2; n = log2(c); where t nwhere t0 represents the thickness of the nth layer (e.g., t0 is the first layer and t1 is the second layer) and c represents the number of channels in the channel set. In some embodiments, non-equidistant channel sets may be utilized. For example, a discontinuous patterning of channels may be selected to obtain information about a first set of wavelengths and a second set of wavelengths that are discontinuous with the first set of wavelengths. In this case, t min and t max is still determined, but a different set of intermediate layers may be selected. In some embodiments, a different number of channels may be utilized. Additionally or alternatively, channel patterning may be utilized with multiple channels having a common thickness, thereby allowing multiple light sensors to capture information about a common wavelength of light.

[0039] As indicated by reference number 402, the filter array 401 includes layers 402,N (e.g., of a spacer layer between a first mirror structure and a second mirror structure), with each channel associated with a particular thickness to direct light of a particular wavelength to a corresponding photosensor. For example, a first group of channels of layer 402 is associated with a thickness of 8*t4, indicating that a layer with a thickness of 8*t4 (where t4 represents the thickness of the fourth layer) has been deposited (e.g., on top of the first mirror structure or on top of another layer, such as a protective layer, deposited on top of the first mirror structure). Similarly, a second group of channels of layer 402 is associated with a thickness of 0*t4, indicating that deposition has been performed for these channels, but lift-off has been used to remove the deposited material.

[0040] As further shown in FIG. 4A by reference number 404, layer 404, N+1 is deposited on layer 402. Layer 404 includes a first group of channels associated with a thickness of 4*t4 and a second group of channels associated with a thickness of 0*t4. In some embodiments, the thickness of layer 404 is selected based on the thickness of layer 402. For example, when fabricating a multispectral filter (e.g., a filter associated with a binary sequence of filter layers), the thickness of layer 404 may be selected as half the thickness of layer 402. In another example, another relationship between layer 402 and layer 404 may be utilized. For example, layer 404 may be 75% of the thickness of layer 402, and a subsequent layer may be 33%, 25%, etc., of the thickness of layer 404. In another example, layer 404 may be 50% of layer 402, and a subsequent layer may be 33% of the thickness of layer 404, or 10% of the thickness of layer 404, etc.

[0041] As further shown by reference numeral 406 in FIG. 4A, layer 406, N+2 is deposited on layer 404. Layer 406 includes a first group of channels associated with a thickness of 2*t4 and a second group of channels associated with a thickness of 0*t4. As shown by reference numeral 408, layer 408, N+3 is deposited on layer 406. Layer 408 includes a first group of channels associated with a thickness of 1*t4 and a second group of channels associated with a thickness of 0*t4. As shown by reference numeral 410, the thicknesses of layers N to N+3 of filter array 401 are determined based on summing the thicknesses of each layer of each channel. For example, based on the binary sequence and the arrangement of the filter layers, each channel may be associated with a different thickness, thereby enabling each corresponding optical sensor to capture information about a different wavelength. Thereon, t1 to t n The thickness t0 of the layer in which the min ) may relate to the wavelength of light at which information (e.g., spectral data) is to be captured.

[0042] As shown in FIG. 4B, a similar filter array 421 may be associated with a set of layers, each associated with one or more thicknesses. As indicated by reference numeral 422, layer 422, M includes a first group of channels associated with a thickness of 8*t4 and a second group of channels associated with a thickness of 0*t4. As indicated by reference numeral 424, layer 424, M+1 includes a first group of channels associated with a thickness of 4*t4 and a second group of channels associated with a thickness of 0*t4. As indicated by reference numeral 426, layer 426, M+2 includes a first group of channels associated with a thickness of 2*t4 and a second group of channels associated with a thickness of 0*t4. As indicated by reference numeral 428, layer 428, M+3 includes a first group of channels associated with a thickness of 1*t4 and a second group of channels associated with a thickness of 0*t4. As indicated by reference numeral 430, the result of the deposition of layers 422, 424, 426, and 428 is a set of thicknesses for a set of channels of filter array 421 that enables the optical sensors of filter array 421 to capture image data for a set of wavelengths.

[0043] As shown in FIG. 4C, alternative filter array 441 may utilize a linear arrangement of 16 channels rather than the 4×4 arrangement of filter array 401 and filter array 421. As indicated by reference numeral 442, layer 442, L includes a first group of channels having a thickness of 8*t4 and a second group of channels having a thickness of 0*t4. As indicated by reference numeral 444, layer 444, L+1 includes a first group of channels having a thickness of 4*t4 and a second group of channels having a thickness of 0*t4. As indicated by reference numeral 446, layer 446, L+2 includes a first group of channels having a thickness of 2*t4 and a second group of channels having a thickness of 0*t4. As indicated by reference numeral 448, layer 448, L+3 includes a first group of channels having a thickness of 1*t4 and a second group of channels having a thickness of 0*t4. As indicated by reference numeral 450, the result of the deposition of layers 442, 444, 446, and 448 is a set of thicknesses for a set of channels of filter array 441 that causes the optical sensor to capture image data for a set of wavelengths.

[0044] As mentioned above, Figures 4A-4C are provided as examples only, and other examples are possible and may differ from those described with respect to Figures 4A-4C.

[0045] Figures 5A and 5B are diagrams of an embodiment 500 of the example process 200 shown in Figure 2. Figures 5A and 5B show an example of a filter array layout for a multi-spectral filter having non-uniform channel spacing.

[0046] As shown in FIG. 5A, a filter array 501 (e.g., a multispectral filter) may utilize a non-equidistant channel layout. For example, as indicated by reference numerals 502-508, layer 502 may include a group of channels having a thickness of 10*t4, layer 504 may include a group of channels having a thickness of 5*t4, layer 506 may include a group of channels having a thickness of 3*t4, and layer 508 may include a group of channels having a thickness of 1*t4. As indicated by reference numeral 510, the result of the deposition of layers 502, 504, 506, and 508 is a set of non-equidistant thicknesses for each channel. For example, channel 511 is associated with a thickness of 0*t4, channel 512 is associated with a thickness of 1*t4, channel 513 is associated with a thickness of 4*t4, and channel 514 is associated with a thickness of 3*t4 (e.g., the channel associated with a thickness of 2*t4 is excluded). In this manner, filter array 501 enables a set of optical sensors associated with filter array 501 to capture information about a non-contiguous set of wavelengths (e.g., a set of wavelengths in which the wavelengths are not equally spaced apart).

[0047] As shown in FIG. 5B, a similar filter array 521 may utilize non-equidistant channel spacing. For example, as indicated by reference numerals 522-528, layer 522 may include a group of channels having a thickness of 15*t4, layer 524 may include a group of channels having a thickness of 4*t4, layer 526 may include a group of channels having a thickness of 2*t4, and layer 528 may include a group of channels having a thickness of 1*t4. As indicated by reference numeral 530, the result of the deposition of layers 522, 524, 526, and 528 is a set of thicknesses for a non-equidistant set of channels. For example, channel 531 is associated with a thickness of 2*t4, channel 532 is associated with a thickness of 6*t4, channel 533 is associated with a thickness of 21*t4, and channel 534 is associated with a thickness of 17*t4 (e.g., channels with thicknesses 8*t4-14*t4 are excluded). The discontinuity between channel 532 and channel 533 allows a set of optical sensors associated with filter array 521 to capture information about two wavelength ranges separated by a spectral amount that is not equal to the separation between the other channels of filter array 521.

[0048] As mentioned above, Figures 5A and 5B are provided as examples only, and other examples are possible and may differ from those described with respect to Figures 5A and 5B.

[0049] 6A and 6B are diagrams of an embodiment 600 of the exemplary process 200 shown in FIG.

[0050] 6A, the sensor elements 308 may be disposed on a substrate 306 during the manufacture of a light sensor device as described herein. A glass wafer 602 may be provided onto which a set of filter and spacer layers may be deposited as described herein.

[0051] As shown in FIG. 6B, after depositing the set of layers 604 on the glass wafer 602 , the glass wafer 602 and the layers 604 are bonded to the substrate 306 , as indicated by reference numeral 606 .

[0052] As mentioned above, Figures 6A and 6B are provided as examples only, other examples are possible and may differ from those described with respect to Figures 6A and 6B.

[0053] In this manner, a multi-spectral filter array for a light sensor device may be fabricated that is integrated onto a semiconductor substrate of the light sensor device, provides a relatively low angular shift and a relatively high spectral range, as well as is environmentally durable compared to other filter structures such as LVF type filters, CVF type filters, etc.

[0054] The above disclosure provides illustrations and descriptions, but is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the embodiments.

[0055] Some embodiments are described herein in relation to a threshold value. As used herein, meeting a threshold may refer to a value greater than the threshold, more than the threshold, higher than the threshold, equal to or greater than the threshold, less than the threshold, lower than the threshold, less than or equal to the threshold, the same as the threshold, etc.

[0056] Although particular combinations of features are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of possible embodiments. Indeed, many of these features can be combined in ways not specifically recited in the claims and / or disclosed in the specification. Although each dependent claim listed below may depend directly on only one claim, the disclosure of possible embodiments includes each dependent claim in combination with every other claim in the claim set.

[0057] No element, act, or instruction used herein should be construed as critical or essential unless expressly stated. Also, as used herein, the articles "a" and "an" are intended to include one or more things, and may be used interchangeably with "one or more." Furthermore, as used herein, the term "set" is intended to include one or more things (e.g., related, unrelated, a combination of related and unrelated, etc.), and may be used interchangeably with "one or more." When only one thing is intended, the term "one" or similar words are used. Also, as used herein, the terms "has, have, having, etc." are intended to be open-ended terms. Furthermore, the phrase "based on" is intended to mean "based at least in part on" unless expressly stated otherwise.

Claims

1. A method for manufacturing an optical sensor device having a multispectral filter having a plurality of channels, comprising: depositing a first mirror over a substrate; depositing first to fourth spacer layers on the first mirror using a lift-off process to form a spacer; depositing a second mirror over the spacer; Including, the spacer comprises niobium titanium oxide; a thickness of the spacer in one of the plurality of channels is different from a thickness of the spacer in any other channel of the plurality of channels; The thicknesses of the spacers of the plurality of channels are not arranged at equal intervals and are discontinuous when counted from the thinnest. method.

2. the second spacer layer is deposited on the first spacer layer; The method of claim 1.

3. 1. A multi-spectral filter having a plurality of channels, comprising: A substrate; a first mirror deposited on the substrate; a spacer disposed on at least a portion of the first mirror; a second mirror disposed on the spacer; the spacer comprises niobium titanium oxide; a thickness of the spacer in one of the plurality of channels is different from a thickness of the spacer in any other channel of the plurality of channels; The thicknesses of the spacers of the plurality of channels are not arranged at equal intervals and are discontinuous when counted from the thinnest. Multispectral filters.

Images