Optical Interference Filter

Abstract

In some embodiments, the optical interference filter includes a substrate; and a set of layers disposed on the substrate. The set of layers includes a first subset of layers comprising an aluminum nitride (AlN) material, wherein the stress of the first subset of layers is between -1000 MPa and 800 MPa; and a second subset of layers comprising at least one other material.

Description

Background Technology

[0001] Optical devices can be used to capture information about light. For example, an optical device can capture a set of information about wavelengths associated with light. An optical device may include a collection of sensor elements (e.g., optical sensors, spectral sensors, and / or image sensors) that capture information. For example, an array of sensor elements can be used to capture information about multiple wavelengths. The array of sensor elements can be associated with an optical filter. The optical filter may include a passband associated with light in a first wavelength range that passes through the sensor element array. The optical filter may also be associated with blocking light in a second wavelength range from passing through the sensor element array. Summary of the Invention

[0002] In some embodiments, the optical interference filter includes a substrate; and a set of layers disposed on the substrate. The set of layers includes a first subset of layers, wherein the first subset of layers includes an aluminum nitride (AlN) material; and a second subset of layers, wherein the second subset of layers includes a silicon hydride (Si:H) material.

[0003] In some embodiments, the optical interference filter includes a set of layers, the set of layers including a first subset of layers comprising AlN material; and a second subset of layers comprising Si:H material.

[0004] In some embodiments, a method includes supplying an inert gas to a chamber, wherein the inert gas includes at least one of argon (Ar) or helium (He); supplying nitrogen (N2) to the chamber; and sputtering an aluminum (Al) target based on the supply of the inert gas and N2 gas to form an assembly of a first layer comprising AlN on a substrate, wherein the assembly of the first layer is alternately formed on the substrate with an assembly of a second layer comprising Si:H. Attached Figure Description

[0005] Figure 1 This is an overview diagram of the example implementation described in this article.

[0006] Figure 2 This is a diagram of an example optical filter described in this article.

[0007] Figure 3 This is an example illustration of a sputtering deposition system used to manufacture the optical filters described herein.

[0008] Figures 4A-4B This is a diagram illustrating an example stress curve of an AlN layer formed using the sputtering process described herein.

[0009] Figure 5This is a diagram illustrating example curves of the extinction coefficient and refractive index of an assembly of AlN layers formed using the sputtering process described herein.

[0010] Figure 6 This is a graph illustrating example curves showing the transmission performance of the optical filter described herein. Detailed Implementation

[0011] The following detailed description of exemplary embodiments is given with reference to the accompanying drawings. The same reference numerals in different drawings may identify the same or similar elements. The following description uses a spectrometer as an example. However, the techniques, principles, processes, and methods described herein can be used with any sensor, including but not limited to other optical and spectral sensors.

[0012] Optical filters can be fabricated by forming one or more layers on a substrate. For example, a conventional optical filter may comprise alternating layers of at least a first, second, and third material (e.g., alternating layers of silicon hydride (Si:H), silicon dioxide (SiO2), and tantalum pentoxide (Ta2O5)) to allow the conventional optical filter to pass through a threshold percentage of light (e.g., at least 65%) associated with a specific spectral range (e.g., a spectral range between 800 and 1000 nanometers (nm)). However, forming alternating layers of at least three materials is complex and may result in the formation of low-quality layers that introduce defects or allow defects to propagate through the conventional optical filter. This can degrade the performance, manufacturability, and / or reliability of the conventional optical filter.

[0013] Furthermore, in many cases, the stress in each of one or more layers of a conventional optical filter is compressive (e.g., the stress in a layer is less than 0 MPa), resulting in compressive stress (e.g., net stress) in one or more layers. This causes the conventional optical filter to bend (e.g., flex). This results in one or more layers suffering from coating runoff, which affects the performance of the conventional optical filter. It also makes conventional optical filters more fragile (e.g., compared to planar optical filters) and / or makes their transportation, handling, and / or use more difficult.

[0014] Some embodiments described herein provide an optical filter comprising a set of layers disposed on a substrate. The set of layers may include a first subset of layers comprising an aluminum nitride (AlN) material and a second subset of layers comprising a silicon hydride (Si:H) material arranged in an alternating layer sequence. In some embodiments, the optical filter allows a threshold percentage of light (e.g., at least 85%) associated with a specific spectral range (e.g., a spectral range between 800 and 1000 nm) to pass through. In this manner, the optical filter provides improved transmission performance compared to conventional optical filters. Furthermore, the optical filter comprises only two alternating layers, which reduces the complexity associated with forming the set of layers. This reduces the likelihood of forming low-quality layers and thus reduces the likelihood of defects being introduced or allowed to propagate through the optical filter. Therefore, the performance, manufacturability, and / or reliability of the optical filter are improved compared to conventional optical filters.

[0015] In some embodiments, the stress of the first subset of layers comprising AlN material can be between -1000 and 800 MPa. Therefore, in some embodiments, when the stress of the second subset of layers is compressive, the stress of the AlN material can be configured to be tensile (e.g., greater than or equal to 0 MPa), or vice versa. In this way, the amount of bending caused by the assembly of layers disposed on the substrate can be minimized (e.g., by balancing the stress of the compressive layers and the tensile layers of the optical filter). For example, one subset of the first subset and the second subset of layers may include tensile material, while the other subset may include compressive material, which can result in the stress of the assembly of layers being approximately zero MPa (e.g., within tolerance). This minimizes the amount of bending in the optical filter, which reduces coating runoff and thereby improves the performance of the optical filter (e.g., compared to conventional optical filters subjected to bending). This also improves the durability of the optical filter and / or makes the transport, handling, and / or use of the optical filter easier compared to conventional optical filters subjected to bending.

[0016] Figure 1 This is an overview diagram of the example implementation 100 described herein. (As shown...) Figure 1 As shown, example embodiment 100 includes a sensor system 110. Sensor system 110 may be part of an optical system and may provide an electrical output corresponding to a sensor-defined value. Sensor system 110 includes an optical filter structure 120 (including an optical filter 130) and an optical sensor 140. For example, optical filter structure 120 may include optical filter 130 performing passband filtering. In another example, optical filter 130 may be aligned with the sensor element array of optical sensor 140.

[0017] While some of the implementations described herein can be described based on optical filters in a sensor system, the implementations described herein can be used in another type of system, outside of a sensor system, or in other configurations.

[0018] like Figure 1 As further shown, and indicated by reference numeral 150, the input optical signal is directed to the optical filter structure 120. The input optical signal may include, but is not limited to, light associated with a specific spectral range (e.g., a spectral range centered at approximately 900 nm, such as a spectral range of 800 nm to 1000 nm; a spectral range of 500 nm to 5500 nm; or another spectral range). For example, the optical emitter may direct light to the optical sensor 140 to allow the optical sensor 140 to perform light measurements. In another example, the optical emitter may direct light of another spectral range for another function, such as a testing function, a sensing function, or a communication function.

[0019] like Figure 1 As further shown, and indicated by reference numeral 160, a first portion of the optical signal having a first spectral range is not passed through the optical filter 130 and the optical filter structure 120. For example, a dielectric filter stack that may include a high-refractive-index material layer and a low-refractive-index material layer of the optical filter 130 may cause the first portion of light to be reflected, absorbed, etc., in a first direction. In this case, the first portion of light may be the threshold portion of light incident on the optical filter 130, which is not included in the bandpass of the optical filter 130, such as light that is not greater than 95% in a specific spectral range centered at about 900 nm. As shown by reference numeral 170, a second portion of the optical signal is passed through the optical filter 130 and the optical filter structure 120. For example, the optical filter 130 may allow light having a second spectral range to pass through in a second direction toward the optical sensor 140. In this case, the second portion of light may be the threshold portion of light incident on the optical filter 130 within the bandpass of the optical filter 130, such as incident light that is greater than 50% in a spectral range centered at about 900 nm.

[0020] like Figure 1As further illustrated, based on the second portion of the optical signal transmitted to the optical sensor 140, the optical sensor 140 can provide an output electrical signal 180 to the sensor system 110, such as for imaging, ambient light sensing, detecting the presence of an object, performing measurements, or facilitating communication. In some embodiments, an alternative arrangement of the optical filter 130 and the optical sensor 140 can be utilized. For example, instead of having the second portion of the optical signal pass collinearly with the input optical signal, the optical filter 130 can direct the second portion of the optical signal in a different direction to the optical sensor 140, which is positioned differently.

[0021] As mentioned above, providing Figure 1 As an example. Other examples can be related to... Figure 1 The descriptions are different.

[0022] Figure 2 This is a diagram of an example optical filter 200. In some embodiments, the optical filter 200 may be an optical interference filter and / or may include a spectral filter, a multispectral filter, a bandpass filter, a blocking filter, a long-pass filter, a short-pass filter, a dichroic filter, a linear variable filter, a circular variable filter, a Fabry-Perot filter, a Bayer filter, a plasma filter, a photonic crystal filter, a nanostructure or metamaterial filter, an absorptive filter, a beam splitter, a polarization beam splitter, a notch filter, an anti-reflection filter, a reflector or mirror, etc. Figure 2 An exemplary stack of optical filters 200 is shown. Figure 2 As further shown, the optical filter 200 includes a substrate 210 and a collection of layers 220.

[0023] Substrate 210 may include a glass substrate, a polymer substrate, a polycarbonate substrate, a metal substrate, a silicon (Si) substrate, a germanium (Ge) substrate, or an active device wafer (e.g., examples including photodiodes (PDs), PD arrays, avalanche photodiodes (APDs), APD arrays, charge-coupled device (CCD) sensors, and / or complementary metal-oxide-semiconductor (CMOS) sensors). In some embodiments, the thickness of substrate 210 may be greater than or equal to 20 nanometers (nm), 50 micrometers (μm), and / or 500 μm. Alternatively or additionally, the thickness of the substrate may be less than or equal to a specific thickness threshold. For example, a specific thickness threshold may be less than or equal to 5000 micrometers.

[0024] A set of layers 220 (e.g., a set of optical filter layers) may be disposed on a substrate 210 (e.g., directly disposed on a substrate 210) and may include one or more subsets of layers. For example, the set of layers 220 may include a first subset 230 of layers (e.g., first subsets 230-1 to 230-(N+1) (N≥1)) (also referred to herein as layer A) and a second subset 240 of layers (e.g., second subsets 240-1 to 240-N) (also referred to herein as layer B). In some embodiments, the first subset 230 and the second subset 240 of layers may be arranged in a specific order (e.g., an alternating layer order), such as (AB). m (m≥1) sequence, (AB) m -A sequence, (BA) m Sequence, B-(BA) m One order or another. For example, such as Figure 2 As shown, the first subset 230 of the layer and the second subset 240 of the layer are (AB). N The sequence of -A is positioned, wherein layer A (e.g., layer 230-1) is disposed on the surface (e.g., top surface) of optical filter 200, and layer A (e.g., layer 230-(N+1)) is disposed on the surface (e.g., top surface) of substrate 210.

[0025] In some embodiments, the layer set 220 may be disposed on a single surface (e.g., the top surface) of the substrate 210 (e.g., as shown in the figure). Figure 2 (As shown). Alternatively, a first portion of the set of layers 220 may be disposed on a first surface (e.g., the top surface) of the substrate 210, and a second portion of the set of layers 220 may be disposed on a second surface (e.g., the bottom surface) of the substrate 210. For example, a first portion of a first subset 230 of layers and a first portion of a second subset 230 of layers may be arranged on the first surface of the substrate 210 in a first specific order, and a second portion of a first subset 230 of layers and a second portion of a second subset 230 of layers may be arranged on the second surface of the substrate 210 in a second specific order.

[0026] In some embodiments, one or more additional layers may be included in the optical filter 200, such as one or more protective layers, one or more capping layers (e.g., to provide environmental protection to the assembly of layers 220), and / or one or more layers to provide one or more other filtering functions (e.g., a barrier or anti-reflective coating, etc.). For example, in a single-surface configuration, additional layers (e.g., capping layers), such as dielectric layers (e.g., comprising oxide materials such as silicon dioxide (SiO2), zirconium dioxide (ZrO2), and / or yttrium oxide (Y2O3); nitride materials such as silicon nitride (Si3N4), titanium nitride (TiN), and / or zirconium nitride (ZrN); and / or another material providing environmental protection) may be disposed on the surface (e.g., the top surface) of the assembly of layers 220. As another example, in a dual-surface construction, a first additional layer may be disposed on the surface of a first portion of the layer set 220 (e.g., the top surface), and a second additional layer may be disposed on the surface of a second portion of the layer set 220 (e.g., the bottom surface).

[0027] The first subset 230 of the layers may include aluminum nitride (AlN) material. For example, each layer 230 of the first subset 230 of the layers may include AlN material. The second subset 240 of the layers may include at least one other material (e.g., at least one material other than AlN material), such as at least one of the following materials: silicon (Si) material, silicon and hydrogen (SiH) material, silicon hydride (Si:H) material, helium-containing silicon hydride (Si:H-He) material, amorphous silicon (a-Si) material, silicon nitride (SiN) material, germanium (Ge) material, germanium hydride (Ge:H) material, silicon germanium (SiGe) material, silicon germanium hydride (SiGe:H) material, silicon carbide (SiC) material, silicon carbide hydride (SiC:H) material, silicon dioxide (SiO2) material, tantalum pentoxide (Ta2O5) material, niobium pentoxide (Nb2O5) material, niobium titanium oxide (NbTiO) material. x Examples include materials such as niobium tantalum pentoxide (Nb₂TaO₅), titanium dioxide (TiO₂), alumina (Al₂O₃), zirconium oxide (ZrO₂), yttrium oxide (Y₂O₃), or hafnium oxide (HfO₂). For example, each layer 240 of the second subset 240 of the layers may include at least one other material.

[0028] In some embodiments, the stress (e.g., net stress) of the first subset 230 of layers can be between -1000 and 800 MPa (e.g., greater than or equal to -1000 MPa and less than or equal to 800 MPa). Alternatively or additionally, the stress of each layer 230 of the first subset 230 of layers can be between -1000 and 800 MPa. That is, the stress of a particular layer 230 of the first subset 230 of layers can be between -1000 and 800 MPa, and the stress of another particular layer 230 of the first subset 230 of layers can be between -1000 and 800 MPa. The stress of a particular layer 230 can be the same as or different from the stress of other particular layers 230. For example, the stress of a particular layer 230 can be tensile (e.g., greater than or equal to 0 MPa), while the stress of another particular layer 230 can be compressive (e.g., less than 0 MPa), or vice versa.

[0029] In some embodiments, the stress (e.g., net stress) of the set 230 of layers may be approximately zero (0) MPa (e.g., within a tolerance of less than or equal to 5 MPa). Therefore, at least one subset of the first subset 230 and the second subset 240 of layers may include a tensile material, while another subset of the first subset 230 and the second subset 240 of layers may include a compressive material (e.g., to make the stress of the set 230 of layers approximately 0 MPa). For example, the first subset 230 of layers may include a tensile material, while the second subset 240 of layers may include a compressive material, or vice versa. As another example, the first subset 230 of layers may include a tensile AlN material, and the second subset 240 of layers may include at least one other compressive material (e.g., compressed Si material, compressed Si:H material, compressed Si:H-He material, or compressed a-Si material, etc.).

[0030] In some embodiments, each layer in the set 230 of layers may be associated with a specific thickness. For example, layers in the first subset 230 or the second subset 240 of layers may have a thickness between 5 nm and 2000 nm. In some embodiments, the first subset 230 or the second subset 240 of layers may be associated with multiple thicknesses, such as a first thickness of the first subset 230 and a second thickness of the second subset 240 of layers, a first thickness of a first portion of the first subset 230 and a second thickness of a second portion of the first subset 230 of layers, or a first thickness of a first portion of the second subset 240 of layers and a second thickness of a second portion of the second subset 240 of layers, etc. Therefore, the layer thickness and / or the number of layers may be selected based on a set of desired optical characteristics of the optical filter 200, such as desired passband, desired transmittance, and / or another optical characteristic. For example, the thickness and / or number of layers can be selected to allow the optical filter 200 to be used in a spectral range between 800 nm and 1000 nm (e.g., with a center wavelength of about 900 nm), a spectral range between 500 and 5500 nm, or another spectral range.

[0031] In some embodiments, the set of layers 230 may be configured to allow a threshold percentage of light associated with a specific spectral range to pass through. For example, the set of layers 230 may be configured to allow a threshold percentage of light associated with a spectral range between 800 and 1000 nm (e.g., having a center wavelength of about 900 nm) to pass through. The threshold range may, for example, be greater than or equal to 85%. In some embodiments, for light having wavelengths between 500 nm and 5500 nm, the refractive index of the first subset 230 of layers may be between 1.9 and 2.2, and / or for light having wavelengths between 500 nm and 5500 nm, the refractive index of the second subset 240 of layers may be between 3.5 and 3.9. In some embodiments, the extinction coefficient of the first subset 230 of layers for light having wavelengths between 500 nm and 5500 nm may be less than 0.001.

[0032] In some embodiments, a sputtering process can be used to form the set of layers 230. For example, a magnetron sputtering process (e.g., pulsed magnetron sputtering) can be used to sputter a first subset 230 of layers and / or a second subset 240 of layers (e.g., in an alternating layer sequence) onto the substrate 210 to form the set of layers 230. In this way, an optical filter 200 can be fabricated. This document relates to... Figure 3 Further details regarding the manufacture of the optical filter 200 are described below.

[0033] As mentioned above, providing Figure 2 As an example. Other examples can be related to... Figure 2 The descriptions are different.

[0034] Figure 3 This is a diagram of an example 300 of a sputtering deposition system used to manufacture an optical filter (e.g., optical filter 200) as described herein. The sputtering deposition system can be used to implement sputtering processes (such as magnetron sputtering).

[0035] like Figure 3 As shown, Example 300 includes a vacuum chamber 310 and a substrate 320 (e.g., corresponding to the description herein). Figure 2 The described components include a substrate 210, a cathode 330, a target 331, a cathode power supply 340, an anode 350, a plasma activation source (PAS) 360, and a PAS power supply 370. The target 331 may be made of aluminum (Al). The PAS power supply 370 can be used to power the PAS 360 and may include a radio frequency (RF) power supply. The cathode power supply 340 can be used to power the cathode 330 and may include a pulsed direct current (DC) power supply.

[0036] about Figure 3 The target 331 can be sputtered in the presence of nitrogen (N2) and / or an inert gas (e.g., including argon (Ar), helium (He), and / or neon (Ne)) to deposit aluminum nitride (AlN) as at least one layer on the substrate 320. For example, N2 gas and an inert gas can each be supplied to the vacuum chamber 310, which can cause sputtering of the target 331 to form an assembly of first layers including AlN on the substrate 320 (e.g., as further described herein). In some embodiments, the assembly of first layers can be alternately formed on the substrate with an assembly of second layers including at least one other material, such as an assembly of second layers including Si, Si:H, Si:H-He, a-Si, and / or any other material described herein (e.g., regarding the materials described herein). Figure 2 The second subset 240 of the described layers. An assembly of second layers can be formed on a substrate (e.g., in a similar manner to that described further herein) by supplying a second gas (e.g., hydrogen (H2)) and an inert gas (e.g., comprising Ar, He, and / or Ne) to a vacuum chamber 310 to induce sputtering of another target (e.g., a silicon target) to form an assembly of second layers (e.g., comprising Si:H in this example).

[0037] To form the AlN layer, an inert gas can be supplied to the vacuum chamber 310 via the anode 350 and / or PAS 360. N2 gas can be introduced into the vacuum chamber 310 via PAS 360, which is used to activate the N2 gas. Alternatively or additionally, the cathode 330 can induce N2 gas activation (e.g., in this case, N2 gas can be introduced from another part of the vacuum chamber 310) or the anode 350 can induce N2 gas activation (e.g., in this case, N2 gas can be introduced into the vacuum chamber 310 via the anode 350). PAS 360 can be located near the threshold of the cathode 330, allowing plasma from PAS 360 and plasma from the cathode 330 to overlap. The use of PAS 360 allows for AlN deposition at a relatively high deposition rate. In some implementations, AlN can be deposited at a deposition rate of about 0.05 nm / s to about 2.0 nm / s, at a deposition rate of about 0.5 nm / s to about 1.2 nm / s, at a deposition rate of about 0.8 nm / s, or similar rates.

[0038] In some embodiments, the stress of the AlN layer can be adjusted (e.g., after formation) based on controlling the composition and / or amount of the inert gas supplied to the vacuum chamber 310. For example, when the inert gas includes Ar, the amount of Ar and / or the amount of inert gas supplied to the vacuum chamber 310 can be controlled to keep the stress of the aluminum nitride layer between -230 and 800 MPa. Alternatively or additionally, when the inert gas includes Ar, the amount of Ar and / or the amount of inert gas supplied to the vacuum chamber 310 can be controlled to keep the stress (e.g., net stress) of the assembly comprising the first layer of AlN between -230 and 800 MPa. As another example, when the inert gas includes He and / or Ne, the amount of He and / or Ne and / or the amount of inert gas supplied to the vacuum chamber 310 can be controlled to keep the stress of the AlN layer between -1000 and 150 MPa. Alternatively or concurrently, when the inert gas includes He and / or Ne, the amount of He and / or Ne and / or the amount of inert gas supplied to the vacuum chamber 310 can be controlled to ensure that the stress of the assembly comprising the first layer of AlN is between -1000 and 150 MPa.

[0039] Although this document describes the sputtering process according to a specific geometry and implementation, other geometries and implementations are possible. For example, N2 gas can be injected from another direction and / or from a gas manifold adjacent to the threshold of cathode 330. Although this document describes different component configurations, different materials, different manufacturing processes, etc., can also be used to achieve different relative concentrations of AlN.

[0040] As mentioned above, providing Figure 3 As an example. Other examples can be related to... Figure 3 The descriptions are different.

[0041] Figures 4A-4B This is a diagram illustrating an example curve 400 of the stress in an AlN layer formed using the sputtering process described herein (e.g., magnetron sputtering). Figure 4A As shown, when supplied at a flow rate of 120 to 370 standard cubic centimeters per minute (sccm) (e.g., supplied to the site described herein). Figure 3 When the vacuum chamber 310 of the described sputtering deposition system contains an inert gas of Ar, the stress in the AlN layer can be configured from -230 to 650 MPa. For example... Figure 4B As shown, when supplied at a flow rate between 0 and 500 sccm (e.g., supplied to the site described herein). Figure 3 When the vacuum chamber 310 of the described sputtering deposition system contains an inert gas of He, the stress of the AlN layer can be configured between -950 and 175 MPa.

[0042] As mentioned above, providing Figures 4A-4B As an example. Other examples can be related to... Figures 4A-4B The descriptions are different.

[0043] Figure 5 This is a plot of example curves 500 showing the extinction coefficient (k) and refractive index (r) of an assembly of AlN layers formed using the sputtering process described herein (e.g., magnetron sputtering). Figure 5 As shown, for light with wavelengths between 500 and 2000 nm, the extinction coefficient can be less than 0.001. Figure 5 Furthermore, for light with wavelengths between 500 and 2000 nm, the refractive index can be less than 2.2.

[0044] As mentioned above, providing Figure 5 As an example. Other examples can be related to... Figure 5 The descriptions are different.

[0045] Figure 6 This is a diagram illustrating example curve 600 of the transmission performance of the optical filter described herein (e.g., optical filter 200). The optical filter comprises a set of layers (e.g., set of layers 220), which includes a first subset of layers containing AlN material (e.g., first subset of layers 230) and a second subset of layers containing Si:H material (e.g., second subset of layers 240). Figure 6As shown, the optical filter can transmit more than about 85% (with a peak of about 92%) of light with wavelengths between 920 and 960 nm. Conversely, an alternative optical filter comprises an assembly of layers, including a first subset of layers containing Ta₂O₅ material and a second subset of layers containing Si:H material. This Si:H material can transmit more than 60% (with a peak of about 67%) of light with wavelengths between 920 and 960 nm. Therefore, for the spectral range between 920 and 960 nm, the optical filter described herein exhibits improved transmission performance compared to the alternative optical filter.

[0046] As mentioned above, providing Figure 6 As an example. Other examples can be related to... Figure 6 The descriptions are different.

[0047] The foregoing 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 can be made based on the foregoing disclosure, or modifications and variations can be derived from the practice of the embodiments.

[0048] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, or a combination of hardware and software. It will be apparent that the systems and / or methods described herein can be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not a limitation on the implementation. Therefore, while this document describes the operation and behavior of systems and / or methods without reference to specific software code, it should be understood that software and hardware can be used to implement systems and / or methods based on those described herein.

[0049] As used herein, when a solution or material is represented by a specific chemical name or formula, the solution or material may include non-stoichiometric variations of the stoichiometric formula identified by the chemical name. For example, the aluminum nitride (AlN) material described herein may include AlN x , where x is between 0.8 and 1.2.

[0050] As used in this article, depending on the context, a threshold can refer to a value that is greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, or not equal to the threshold.

[0051] Even if a particular combination of features is recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various embodiments. In fact, 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 directly depend on only one claim, the disclosure of various embodiments includes each dependent claim in combination with every other claim in the claim set. As used herein, the phrase “at least one” in the list of items refers to any combination of these items, including a single member. As an example, “at least one of the following: a, b, or c” is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination of multiple identical items.

[0052] The elements, actions, or instructions used herein should not be construed as critical or necessary unless explicitly stated otherwise. Furthermore, as used herein, the articles “a” and “one” are intended to include one or more items and are used interchangeably with “one or more.” Furthermore, as used herein, the article “the” is intended to include one or more referenced items in relation to the article “the” and is used interchangeably with “the one or more.” Furthermore, as used herein, the term “set” is intended to include one or more items (e.g., related items, unrelated items, or a combination of related and unrelated items) and is used interchangeably with “one or more.” Where only one item is referred to, the phrase “only one” or similar language is used. Furthermore, 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 “at least partially based on” unless explicitly stated otherwise. Furthermore, as used herein, the term "or" is intended to be inclusive when used in series and may be used interchangeably with "and / or" unless otherwise expressly stated (e.g., if used in combination with "either one" or "only one"). Additionally, spatially relative terms such as "below," "lower," "bottom," "above," "upper," "top," etc., may be used herein for ease of description to describe the relationship between one (or more) element(s) or feature as shown in the accompanying drawings and another (or more) element(s). Spatially relative terms are intended to cover different orientations of devices, apparatuses, and / or elements in use or operation other than those depicted in the accompanying drawings. The device may be oriented in other ways (rotated 90 degrees or otherwise) and the spatially relative descriptors used herein may be interpreted accordingly.

Claims

1. An optical interference filter, comprising: substrate; as well as An assembly of layers is disposed on the substrate, wherein the assembly of layers includes: The first subset of the layer, The first subset of the layers comprises tensile aluminum nitride (AlN) material having a stress greater than or equal to 0 MPa. as well as The second subset of the layer, The second subset of the layer comprises compressed hydrogenated silicon Si:H material with a stress of less than 0 MPa.

2. The optical interference filter according to claim 1, wherein the thickness of the substrate is greater than or equal to 50 micrometers.

3. The optical interference filter of claim 1, wherein the assembly of layers is configured to allow light to pass through at a threshold percentage associated with a spectral range between 800 nm and 1000 nm, and The threshold percentage of the light is greater than or equal to 85%.

4. The optical interference filter of claim 1, wherein for light with wavelengths between 500 nm and 5500 nm, the refractive index of the first subset of the layer is between 1.9 and 2.

2.

5. The optical interference filter of claim 1, wherein for light with wavelengths between 500 nm and 5500 nm, the refractive index of the second subset of the layer is between 3.5 and 3.

9.

6. The optical interference filter of claim 1, wherein for light with wavelengths between 500 nm and 5500 nm, the extinction coefficient of the first subset of the layer is less than 0.

001.

7. The optical interference filter of claim 1, wherein the assembly of the layers is deposited on the substrate using a magnetron sputtering process.

8. The optical interference filter of claim 1, wherein the first subset of the layer and the second subset of the layer are disposed on the substrate in an alternating layer order.

9. The optical interference filter of claim 1, wherein an additional layer is disposed on the assembly of said layers, and The additional layer comprises silicon dioxide (SiO2) material.

10. An optical interference filter, comprising: The set of layers, the set of layers includes: The first subset of the layer, The first subset of the layers comprises tensile aluminum nitride (AlN) material having a stress greater than or equal to 0 MPa; and The second subset of the layer, The second subset of the layer comprises a silicon hydride (Si:H) material, and The Si:H material mentioned therein includes a compressible material with a stress of less than 0 MPa.

11. The optical interference filter of claim 10, wherein the net stress of the assembly of said layers is approximately zero MPa.

12. The optical interference filter according to claim 10, wherein the stress of the stretched aluminum nitride (AlN) material is between 0 MPa and 800 MPa.

13. A method comprising: Supply gas to the chamber, An assembly of layers forming an optical interference filter based on the supply of said gas. The set of layers mentioned above includes: The first subset of the layers comprises tensile aluminum nitride (AlN) having a stress greater than or equal to 0 MPa, and The second subset of the layer comprises compressed hydrogenated silicon Si:H material with a stress of less than 0 MPa.

14. The method according to claim 13, The inert gas mentioned above includes helium (He). The method further includes: Hydrogen (H2) gas is supplied to the chamber; as well as The set forming the layers includes: Based on the supply of the inert gas and the supply of the H2 gas, a silicon target is sputtered to form a second subset of the layer.

15. The method of claim 13, wherein: The inert gas includes argon (Ar); and The stress in the first subset of the layer is between 0 MPa and 800 MPa.

16. The method of claim 13, wherein: The inert gas includes helium (He); and The stress in the first subset of the layer is between 0 MPa and 150 MPa.

17. The method according to claim 13, The gas mentioned is an inert gas including at least one of argon (Ar) or helium (He). The method further includes: Nitrogen (N2) gas is supplied to the chamber, and The set forming the layers includes: Based on the supply of inert gas and the N2 gas, an aluminum Al target is sputtered to form a first subset of the layer.

18. The method of claim 13, wherein forming the set of layers comprises: A magnetron sputtering process is used to sputter one or more of a first subset or a second subset of the layers onto the substrate of the optical interference filter.

19. The method of claim 13, wherein forming the set of layers comprises: The first subset of the layer is formed alternately with the second subset of the layer on the substrate.

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