阅读说明：本技术 基于氩氦的涂覆 (Argon helium based coating ) 是由 安德鲁·克拉克 乔治·J·欧肯法斯 于 2019-08-13 设计创作，主要内容包括：公开了基于氩氦的涂覆。溅射系统可以包括基底。溅射系统可以包括至少一个靶。至少一个靶可以包括至少一种涂覆材料,以将至少一层涂覆到基底上。至少一种涂覆材料可以在惰性气体存在下溅射到基底上。惰性气体可以包括氩气和氦气。(Argon helium based coatings are disclosed. The sputtering system can include a substrate. The sputtering system can include at least one target. The at least one target may include at least one coating material to coat at least one layer onto the substrate. The at least one coating material may be sputtered onto the substrate in the presence of an inert gas. The inert gas may include argon and helium.)

1. A sputtering system, comprising:

a substrate; and

at least one of the targets is provided with a target,

wherein the at least one target comprises at least one coating material to coat at least one layer onto the substrate,

wherein the at least one coating material is sputtered onto the substrate in the presence of an inert gas,

wherein the inert gas comprises argon and helium.

2. The sputtering system of claim 1, wherein said inert gas is associated with a ratio of argon to helium between about 1: 1 and about 1: 3.

3. The sputtering system of claim 1, wherein said inert gas is associated with 15% to 55% helium.

4. The sputtering system of claim 1, wherein said at least one coating material is sputtered onto said substrate in the presence of hydrogen gas for hydrogenating said at least one coating material.

5. The sputtering system of claim 4, wherein said hydrogen gas is associated with a concentration of about 8% to about 20%.

6. The sputtering system of claim 1, wherein said at least one layer comprises a first set of layers of a first type of material and a second set of layers of a second type of material.

7. The sputtering system of claim 1, wherein said sputtering system is a pulsed direct current magnetron sputtering system.

8. The sputtering system of claim 1, wherein a post-anneal internal stress level of said at least one layer is less than a threshold.

9. A coating system, comprising:

a vacuum chamber; and

an inert gas source for placing an inert gas in the vacuum chamber,

wherein the inert gas comprises a mixture of argon and helium,

wherein the coating system is configured to sputter coating material onto a substrate using the inert gas source.

10. The coating system of claim 9, wherein the inert gas source is at least one of a plasma activation source or an anode.

11. The coating system of claim 9, further comprising:

a coating material source of the coating material is provided.

12. The coating system of claim 11, wherein the coating material source is a target disposed on a cathode.

13. The coating system of claim 9, further comprising at least one power source to cause the inert gas to be placed in the vacuum chamber to sputter the coating material onto the substrate.

14. The coating system of claim 9, wherein the coating material comprises at least one of:

a silicon material is provided on the substrate,

a silicon dioxide material, wherein the silicon dioxide material,

a silicon germanium material, or

A germanium material.

15. The coating system of claim 9, wherein the coating system is configured to sputter the coating material onto the substrate to form an optical filter.

16. The coating system of claim 15, wherein the optical filter is associated with a pass band between approximately 700 nanometers (nm) and 2500nm or between approximately 2500nm and 8000 nm.

17. A method, comprising:

injecting a sputtering gas into a chamber of a sputtering system through the sputtering system, wherein the sputtering gas is a mixture of argon and helium; and

at least one coating material is sputtered by the sputtering system onto a substrate disposed in a chamber of the sputtering system based on injecting the sputtering gas into the chamber of the sputtering system.

18. The method of claim 17, wherein sputtering the at least one coating material onto the substrate comprises:

the at least one coating material is sputtered onto the substrate using an anode and a cathode disposed in a chamber of the sputtering system.

19. The method of claim 17, wherein injecting the sputtering gas comprises:

the sputtering gas is injected with an argon flow rate between about 200 and 500SCCM and a helium fraction between about 9% and about 60%.

20. The method of claim 17, wherein the at least one coating material is sputtered onto the first side of the substrate; and

the method further comprises the following steps:

another coating material is sputtered onto the other side of the substrate using another sputtering gas,

wherein the other sputtering gas comprises argon and does not comprise helium.

Technical Field

The present application relates to, but is not limited to, argon helium based coatings.

Background

The coating system can be used to coat a substrate with a particular material. For example, a pulsed Direct Current (DC) magnetron sputtering system may be used for deposition of thin film layers, thick film layers, and the like. Based on the deposition of a set of layers, an optical element may be formed. For example, the thin film may be used to form a filter, such as an optical interference filter. In some cases, the optical element may be associated with providing a particular function at a particular wavelength of light. For example, the optical interference filter may be used for light in the Near Infrared (NIR) range, light in the Mid Infrared (MIR) range, and the like.

In an example, the optical emitter may emit NIR light directed at the object. In this case, for a gesture recognition system, the optical transmitter may transmit NIR light to the user, and the NIR light may be reflected from the user to the optical receiver. The optical receiver may capture information about the NIR light, and this information may be used to identify gestures performed by the user. For example, the device may use the information to generate a three-dimensional representation of the user and recognize a gesture performed by the user based on the three-dimensional representation.

In another example, information about the NIR light may be used to identify the identity of the user, a characteristic of the user (e.g., height or weight), a characteristic of another type of target (e.g., distance to an object, size of an object, or shape of an object), and so forth. However, ambient light may interfere with NIR light during its transmission to the user and/or during its reflection from the user to the optical receiver. Thus, the optical receiver may be optically coupled to an optical filter, such as an optical interference filter, a bandpass filter, or the like, to allow the NIR light to pass toward the optical receiver.

Disclosure of Invention

According to some embodiments, a sputtering system can include a substrate. The sputtering system can include at least one target. The at least one target may include at least one coating material to coat the at least one layer onto the substrate. The at least one coating material may be sputtered onto the substrate in the presence of an inert gas. The inert gas may include argon and helium.

According to some embodiments, the coating system may comprise a vacuum chamber. The coating system may include a source of inert gas to place the inert gas in the vacuum chamber. The inert gas may comprise a mixture of argon and helium. The coating system may be configured to sputter the coating material onto the substrate using an inert gas source.

According to some embodiments, a method may include injecting a sputtering gas into a chamber of a sputtering system through the sputtering system. The sputtering gas may be a mixture of argon and helium. The method may include sputtering, by a sputtering system, at least one coating material onto a substrate disposed in a chamber of the sputtering system based on injecting a sputtering gas into the chamber of the sputtering system.

Aspects of the disclosure may be implemented in one or more of the following embodiments:

1) a sputtering system, comprising:

a substrate; and

at least one of the targets is provided with a target,

wherein the at least one target comprises at least one coating material to coat at least one layer onto the substrate,

wherein the at least one coating material is sputtered onto the substrate in the presence of an inert gas,

wherein the inert gas comprises argon and helium.

2) The sputtering system of 1), wherein the inert gas is associated with a ratio of argon to helium between about 1: 1 and about 1: 3.

3) The sputtering system of 1), wherein the inert gas is associated with 15% to 55% helium.

4) The sputtering system of 1), wherein the at least one coating material is sputtered onto the substrate in the presence of hydrogen gas for hydrogenating the at least one coating material.

5) The sputtering system of 4), wherein the hydrogen gas is associated with a concentration of about 8% to about 20%.

6) The sputtering system of 1), wherein the at least one layer comprises a first set of layers of a first type of material and a second set of layers of a second type of material.

7) The sputtering system of 1), wherein the sputtering system is a pulsed direct current magnetron sputtering system.

8) The sputtering system of 1), wherein the post-anneal internal stress level of the at least one layer is less than a threshold.

9) A coating system, comprising:

a vacuum chamber; and

an inert gas source for placing an inert gas in the vacuum chamber,

wherein the inert gas comprises a mixture of argon and helium,

wherein the coating system is configured to sputter coating material onto a substrate using the inert gas source.

10) The coating system of 9), wherein the inert gas source is at least one of a plasma activation source or an anode.

11) The coating system of 9), further comprising:

a coating material source of the coating material is provided.

12) The coating system of 11), wherein the coating material source is a target disposed on a cathode.

13) The coating system of 9), further comprising at least one power source to cause the inert gas to be placed in the vacuum chamber to sputter the coating material onto the substrate.

14) The coating system of 9), wherein the coating material comprises at least one of:

a silicon material is provided on the substrate,

a silicon dioxide material, wherein the silicon dioxide material,

a silicon germanium material, or

A germanium material.

15) The coating system of 9), wherein the coating system is configured to sputter the coating material onto the substrate to form an optical filter.

16) The coating system of 15), wherein the optical filter is associated with a passband between approximately 700 nanometers (nm) and 2500nm or between approximately 2500nm and 8000 nm.

17) A method, comprising:

injecting a sputtering gas into a chamber of a sputtering system through the sputtering system, wherein the sputtering gas is a mixture of argon and helium; and

at least one coating material is sputtered by the sputtering system onto a substrate disposed in a chamber of the sputtering system based on injecting the sputtering gas into the chamber of the sputtering system.

18) The method of 17), wherein sputtering the at least one coating material onto the substrate comprises:

the at least one coating material is sputtered onto the substrate using an anode and a cathode disposed in a chamber of the sputtering system.

19) The method of claim 17), wherein injecting the sputtering gas comprises:

the sputtering gas is injected with an argon flow rate between about 200 and 500SCCM and a helium fraction between about 9% and about 60%.

20) The method of 17), wherein the at least one coating material is sputtered onto the first side of the substrate; and

the method further comprises the following steps:

another coating material is sputtered onto the other side of the substrate using another sputtering gas,

wherein the other sputtering gas comprises argon and does not comprise helium.

Drawings

1A-1D are overview diagrams of example embodiments described herein.

Fig. 2 is a diagram of an example of features of an optical element associated with example embodiments described herein.

Fig. 3 is a diagram of an example of an optical element associated with example embodiments described herein.

Fig. 4 is a diagram of an optical system including optical elements associated with example embodiments described herein.

Detailed Description

The following detailed description of example embodiments refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements.

The optical receiver may receive light from a light source, such as an optical transmitter. For example, the optical receiver may receive Near Infrared (NIR) light or Mid Infrared (MIR) light from the optical transmitter and reflected from a target (e.g., a user or another object). In this case, the optical receiver may receive NIR light as well as ambient light, for example, light in the visible spectrum. The ambient light may include light from one or more light sources separate from the optical emitter, such as sunlight, light from a light bulb, and the like. Ambient light may degrade the accuracy of the measurements related to NIR light. For example, in gesture recognition systems, ambient light may reduce the accuracy of generating a three-dimensional image of a target based on NIR light. Thus, the optical receiver may be optically coupled to an optical element (e.g., an optical filter), such as an optical interference filter, a bandpass filter, or the like, to filter ambient light and pass NIR light toward the optical receiver. Similarly, the optical emitter may be optically coupled to the optical element to ensure that certain types of light (e.g., NIR light) are directed toward the target, for example, in sensing systems, measurement systems, communication systems, and the like.

The optical element may be manufactured using thin film technology, thick film technology, or the like. For example, a pulsed direct current magnetron sputtering system can be used to sputter particles onto a substrate to form one or more thin film layers (sometimes referred to as thin films). In this case, the sputtering system can sputter particles (e.g., silicon particles, silicon dioxide particles, germanium particles, silicon germanium particles, etc.) in a sputtering chamber filled with an inert gas such as argon.

However, sputtering particles in an argon environment, for example, may cause argon ions to be implanted into the film with momentum above a threshold. As a result, a threshold amount of intrinsic stress (e.g., compressive intrinsic stress) may be formed in the thin film and optical elements including the thin film. An optical element associated with a threshold amount of internal stress may be affected by a threshold amount of warpage or bending, which may result in a reduction in the optical performance of an optical system including the optical element. Furthermore, a threshold amount of internal stress may cause difficulties in wafer post-processing (e.g., dicing), which may reduce manufacturability of the optical element. To reduce internal stress induced warping, bending, etc., the optical element may be manufactured to have a threshold thickness, which may be achieved by depositing additional and/or thicker layers. Additional layers and/or thicker layers may result in excessive package size, cost, manufacturing complexity, time to complete manufacturing, etc.

Some embodiments described herein may utilize argon helium based coatings to reduce internal stresses in optical elements. For example, a sputter deposition system may use an environment that includes a mixture of argon and helium gases to reduce the amount of argon ions implanted into the film. In this way, the amount of internal stress in the optical element, e.g., the optical interference filter coating for NIR wavelengths or MIR wavelengths, may be reduced, thereby reducing warpage and/or bending of the optical element. Further, based on the reduction of the internal stress, the thickness of the optical element can be reduced without causing a poor durability of the optical element. In this manner, the use of argon and helium as the inert gas environment for sputter deposition reduces package size, reduces cost, reduces complexity, improves manufacturability, etc., relative to the use of an argon environment (without helium).

Fig. 1A-1D are diagrams of an example 100 of a sputter deposition system described herein.

As shown in fig. 1A, example 100 includes vacuum chamber 110, substrate 120, cathode 130, target 131, cathode power supply 140, anode 150, Plasma Activation Source (PAS)160, and PAS power supply 170. Target 131 may include a coating material source such as a silicon material source, a silicon dioxide material source, a germanium material source, a silicon germanium (SiGe) material source, a germanium hydride material source, or the like. The PAS power supply 170 may be used to power the PAS160 and may include a Radio Frequency (RF) power supply. A cathode power supply 140 may be used to power the cathode 130 and may include a pulsed Direct Current (DC) power supply.

Referring to FIG. 1A, target 131 is in hydrogen (H)₂) (e.g., a coating material for the hydrogenation target 131) and an inert gas (e.g., a mixture of argon and helium) to deposit the coating material (e.g., a hydrogenated silicon germanium material) as a layer on the substrate 120. In this manner, optical filters, such as optical interference filters associated with pass bands in the NIR range (e.g., between approximately 700 nanometers (nm) and 2500 nm), MIR range (e.g., between approximately 2500nm and 8000 nm), etc., and associated with less than a threshold angular offset (e.g., for three-dimensional sensing and/or other filtering functions) may be fabricated.

Although some embodiments described herein are described in terms of a sputtering gas being a mixture of argon and helium, another mixture is possible, such as a mixture of argon and another gas, a mixture of helium and another gas, or a mixture of a set of other gases. Further, although some embodiments described herein are described in terms of a mixture of two gases, some embodiments described herein may use three or more gases as the inert gas environment for sputter deposition. Based on the use of a mixture of argon and helium, the amount of argon ions implanted into the substrate 120 during sputter deposition may be reduced relative to using argon as an inert gas (without helium). Additional details regarding the inert gas are described herein with reference to fig. 2.

In some embodiments, vacuum chamber 110 can be filled with a first inert gas for a first sputter deposition process and a second inert gas for a second sputter deposition process. For example, to deposit a first coating associated with a thickness less than the threshold thickness of the optical element (e.g., to deposit one or more layers onto the first side of the substrate 120), the vacuum chamber 110 can be filled with a mixture of argon and helium, and to deposit a second coating associated with a thickness greater than or equal to the threshold thickness of the optical element (e.g., to deposit one or more layers onto the second side of the substrate 120), the vacuum chamber 110 can be filled with argon (without helium). In this manner, the sputter deposition system may balance wafer stresses including coating materials deposited onto both sides of the wafer, thereby improving wafer processing, increasing yield of post-coating processes (e.g., wafer dicing), reducing transmission wavefront errors, etc., relative to wafers having a greater amount of compressive internal stress.

Inert gases (e.g., argon and helium) may be injected into the chamber from an inert gas source, such as the anode 150 and/or the PAS 160. Hydrogen is introduced into the vacuum chamber 110 through the PAS160 for activating hydrogen. Additionally or alternatively, cathode 130 can cause hydrogen activation (e.g., in which case hydrogen can be introduced from another portion of vacuum chamber 110). Additionally or alternatively, anode 150 can cause hydrogen activation (e.g., in which case hydrogen can be introduced into vacuum chamber 110 through anode 150). In some embodiments, the hydrogen may take the form of hydrogen gas, a mixture of hydrogen gas and a noble gas (e.g., argon and/or helium), and the like. The PAS160 may be located within a threshold proximity of the cathode 130, allowing the plasma from the PAS160 and the plasma from the cathode 130 to overlap. The use of PAS160 allows thin film layers (e.g., hydrogenated silicon layers) to be deposited at relatively high deposition rates. In some embodiments, the thin film layer is deposited at a deposition rate of about 0.05nm/s to about 2.0nm/s, a deposition rate of about 0.5nm/s to about 1.2nm/s, a deposition rate of about 0.8nm/s, and the like.

Although the sputtering process is described herein in terms of hydrogenating layers (e.g., implanting hydrogen gas to deposit a hydrogenated silicon layer, a hydrogenated germanium layer, etc.), the sputtering process may use argon and helium as inert gases without implanting hydrogen gas for hydrogenating the layers. Additionally or alternatively, although the sputtering process is described herein with respect to a particular geometry and a particular implementation, other geometries and other implementations are possible. For example, hydrogen may be injected from another direction, from a gas manifold within a threshold proximity of the cathode 130, and so forth.

As shown in fig. 1B-1C, a similar sputter deposition system includes vacuum chamber 110, substrate 120, first cathode 180, second cathode 190, silicon target 181, germanium target 191, cathode power supply 140, anode 150, Plasma Activation Source (PAS)160, and PAS power supply 170. In this case, the silicon target 181 is a silicon target and the germanium target 191 is a germanium target.

As shown in fig. 1B, the silicon target 181 is oriented at about 0 degrees relative to the substrate 120 (e.g., substantially parallel to the substrate 120) and the germanium target 191 is oriented at about 120 degrees relative to the substrate 120. In this case, silicon and germanium are sputtered onto the substrate 120 from the cathode 180 and the cathode 190, respectively, from the silicon target 181 and the germanium target 191, respectively.

As shown in FIG. 1C, in a similar sputter deposition system, the silicon target 181 and the germanium target 191 are each oriented at about 60 degrees relative to the substrate 120, and silicon and germanium are sputtered from the silicon target 181 and the germanium target 191, respectively, onto the substrate 120 by the cathode 180 and the cathode 190, respectively.

As shown in FIG. 1D, in a similar sputter deposition system, the silicon target 181 is oriented at about 120 degrees relative to the substrate 120 and the germanium target 191 is oriented at about 0 degrees relative to the substrate 120. In this case, silicon and germanium are sputtered from a silicon target 181 and a germanium target 191, respectively, onto the substrate 120 from a cathode 180 and a cathode 190, respectively.

With respect to fig. 1A-1D, each configuration of components in a sputter deposition system using argon and helium as inert gases may result in different relative concentrations of silicon and germanium, while reducing the implantation of argon ions, as compared to a similar sputter deposition system in which helium is not used as part of the inert gas.

1A-1D are provided as examples only. Other examples are possible and may differ from the example described with reference to fig. 1A-1D.

Fig. 2 is a diagram 200 of an example of features of an optical element associated with example embodiments described herein.

As shown in FIG. 2, features of an optical element fabricated using a set of configurations 202 and 212 of a sputter deposition system are provided. Configuration 202 represents a baseline case using flow rates of 0 standard cubic centimeters per minute (SCCM) helium, 440SCCM argon, and 70SCCM hydrogen. In other words, configuration 202 represents an optical element manufactured using a sputter deposition system that does not include helium in the environment used for sputter deposition. As shown, the configuration 202 results in an optical element having a coating rate of 0.5179 nanometers per minute (nm/min), -a pre-bake (i.e., pre-annealed) internal stress of 1067 megapascals (MPa) (e.g., the amount of mechanical internal stress before heating the optical element to 280 degrees celsius (° c)), and-a post-bake (i.e., post-annealed) internal stress of 708MPa (e.g., the amount of mechanical internal stress after heating the optical element to 280 degrees celsius). In this case, the heating of the optical element results in a 34% reduction in the mechanical internal stresses.

In some embodiments, the sputter deposition system can be associated with an argon gas flow rate of between about 200 and 500SCCM, between about 240 and 440SCCM, and the like, and with a helium fraction (contribution) of between about 9% and about 60%, between about 8% and 20%, and the like. In some embodiments, the sputter deposition system can be associated with a helium gas flow rate of between about 50 and 300SCCM, between about 100 and 250SCCM, and the like. In some embodiments, the sputter deposition system can be associated with a hydrogen flow rate of between about 0 and 100SCCM, about 70SCCM, etc., and a hydrogen concentration of between about 8% and about 60%. In some embodiments, the sputter deposition system can be associated with a ratio of argon to helium between about 1: 1 and about 1: 3.

As further shown in FIG. 2, for configuration 204 and 212, different concentrations of helium and argon are used as inert gas environments for fabricating the respective optical elements. Using helium concentrations ranging from 100SCCM (e.g., in configuration 206) to 250SCCM (e.g., in configuration 212) and argon concentrations ranging from 240SCCM (e.g., in configuration 204) to 440SCCM (e.g., in configuration 206-212) results in a reduction of internal stresses between 10% (e.g., in configuration 206) and 30% (e.g., in configuration 204) relative to the baseline case, as compared to the baseline case of configuration 202. In other words, the use of a mixture of helium and argon as the inert gas environment for sputter deposition results in a silicon hydride optical element having reduced internal stress before baking and reduced internal stress after baking, as compared to the use of argon alone as the inert gas environment.

Although some embodiments described herein are described with respect to particular concentrations of argon and helium, and with respect to silicon hydride sputtering, other configurations are possible, such as other concentrations, other sputtering materials, and so forth.

As noted above, fig. 2 is provided as an example only. Other examples are possible and may differ from the example described with respect to fig. 2.

Fig. 3 is a diagram of an example optical filter 300. FIG. 3 illustrates an example stack of optical filters fabricated using the sputter deposition system described herein. As further shown in fig. 3, optical filter 300 includes an optical filter coating portion 310 and a substrate 320.

The optical filter coating portion 310 includes a set of optical filter layers. For example, optical filter coating portion 310 includes a first set of layers 330-1 through 330- (N +1) (N ≧ 1) and a second set of layers 340-1 through 340-N. In another example, optical filter coating portion 310 can be a single type of layer (e.g., one or more layers 330), three or more types of layers (e.g., one or more layers 330, one or more layers 340, and one or more other types of layers)One or more of) and the like. In some embodiments, layer 330 may include a set of layers of high index of refraction materials (H-layers), such as silicon germanium (SiGe) layers, silicon germanium hydride layers, and the like. Although some layers may be described as a particular material, such as SiGe, some layers may include (small amounts of) phosphor(s), boron, nitride, etc. In some embodiments, layer 340 may include a set of layers of low index material (Llayers), such as layers of silicon dioxide, or the like. Additionally or alternatively, the L layer may comprise a silicon nitride layer, Ta₂O₅Layer, Nb₂O₅Layer, TiO₂Layer of Al₂O₃Layer, ZrO₂Layer, Y₂O₃Layer, Si₃N₄Layers, combinations thereof, and the like.

In some implementations, optical filter coating portion 310 can be associated with a particular number m of layers. For example, a hydrogenated silicon germanium based optical filter may include a number of alternating layers, for example in the range of 2 to 200 layers. Based on using an inert gas environment with a mixture of argon and helium, the internal stress may be reduced relative to an argon environment (without helium) such that the particular number of layers may be less than a threshold amount, e.g., less than 200, less than 100, less than 50, less than 20, less than 10, less than 5, etc. In this manner, some embodiments described herein enable optical filters that are less than a threshold thickness and do not adversely affect durability, warpage, bending, etc. by being less than the threshold thickness.

In some implementations, each layer of optical filter coating portion 310 can be associated with a particular thickness. For example, layers 330 and 340 may each be associated with a thickness between 1nm and 1500nm, a thickness between 10nm and 500nm, and so forth. Additionally or alternatively, optical filter coating portion 310 can be associated with a thickness between 0.1 μm to 100 μm, 0.25 μm to 10 μm, and/or the like. In some examples, at least one of layers 330 and 340 may each be associated with a thickness of less than 1000nm, less than 100nm, or less than 5nm, etc. Additionally or alternatively, optical filter coating portion 310 can be associated with a thickness of less than 100 μm, less than 50 μm, less than 10 μm, and/or the like.

In some embodiments, a particular silicon germanium based material may be selected for layer 330. For example, layer 330 may be selected and/or fabricated (e.g., by a sputtering process using a mixture of argon and helium) to include a particular type of silicon germanium, such as SiGe-50, SiGe-40, SiGe-60, etc. In some embodiments, layer 330 may comprise a trace (trace amount) of another material, such as argon and/or helium, due to a sputter deposition process in an argon/helium inert gas environment as described herein.

In some embodiments, another material may be selected for layer 340. For example, layer 340 may include a set of silicon layers, a set of germanium layers, a set of silicon dioxide (SiO)₂) Layer, set of aluminium oxides (Al)₂O₃) Layer, set of titanium dioxide (TiO)₂) Layer, group of niobium pentoxide (Nb)₂O₅) Layer, set of tantalum pentoxide (Ta)₂O₅) Layer, a set of magnesium fluoride (MgF)₂) Layer, set of silicon nitride (Si)₃N₄) Layer, zirconium oxide (ZrO)₂) Layer, yttrium oxide (Y)₂O₃) And/or the like. For example, optical filter coating portion 310 can be a silicon/silica coating, a germanium/silica coating, a silicon-germanium/silica coating, or the like.

In some implementations, the optical filter coating portion 310 can be manufactured using a sputtering process. For example, as described herein, optical filter coating portion 310 can be fabricated using a pulsed magnetron based sputtering process to sputter alternating layers 330 and 340 on a glass substrate or another type of substrate. In some embodiments, the sputtering process may use multiple cathodes, for example, a first cathode sputtering silicon and a second cathode sputtering germanium as described herein.

In some implementations, the optical filter coating portion 310 can be annealed using one or more annealing processes (e.g., a first annealing process at about 280 degrees celsius or a temperature between about 200 degrees celsius and about 400 degrees celsius, a second annealing process at about 320 degrees celsius or a temperature between about 250 degrees celsius and about 350 degrees celsius, etc.).

As noted above, fig. 3 is provided as an example only. Other examples are possible and may differ from the example described with respect to fig. 3.

Fig. 4 is a diagram of an example implementation 400 described herein. As shown in fig. 4, the example embodiment 400 includes a sensor system 410. The sensor system 410 may be part of an optical system and may provide an electrical output corresponding to the sensor measurements. The sensor system 410 includes an optical filter structure 420 and an optical sensor 440, the optical filter structure 420 including an optical filter 430. For example, the optical filter structure 420 may include an optical filter 430 that performs an optical interference function or another type of optical filtering, such as a polarization beam splitting function, an inverse polarization beam splitting function, and so forth. The sensor system 410 includes an optical emitter 450 that emits an optical signal toward a target 460 (e.g., a person, an object, etc.).

Although the embodiments described herein may be described in terms of optical filters in a sensor system, the embodiments described herein may be used in another type of system, may be used external to a sensor system, and the like.

As further illustrated in fig. 4 by reference numeral 470, the input optical signal is directed to an optical filter structure 420. The input optical signals may include NIR light, MIR light, etc. emitted by optical emitter 450 as well as ambient light from the environment in which sensor system 410 is used. For example, when optical filter 430 is a band pass filter, optical emitter 450 may direct NIR light to a user of a gesture recognition system (e.g., a gesture performed by target 460), and the NIR light may be reflected from target 460 (e.g., a user) toward optical sensor 440 to allow optical sensor 440 to perform measurements of the NIR light. In this case, ambient light may be directed to the optical sensor 440 from one or more ambient light sources (e.g., light bulbs or the sun).

In another example, the plurality of light beams may be directed to the target 460 and a subset of the plurality of light beams may be reflected to the optical filter structure 420, as shown, the optical filter structure 420 may be arranged at an oblique angle with respect to the optical sensor 440. In some implementations, another tilt angle (e.g., a 0 degree tilt angle for a band pass filter) may be used. In some embodiments, the optical filter structure 420 may be disposed and/or formed directly on the optical sensor 440, rather than being disposed at a distance from the optical sensor 440. For example, optical filter structure 420 may be coated and patterned onto optical sensor 440 using, for example, photolithography, sputter deposition techniques (e.g., using argon and helium as a sputter deposited inert gas mixture), and the like. In another example, the optical emitter 450 may direct NIR light to another type of target 460, such as for detecting objects near a vehicle, detecting objects near a blind person, detecting proximity to an object (e.g., using LIDAR technology), etc., as a result of which NIR light and ambient light may be directed to the optical sensor 440.

As further illustrated by reference numeral 480 in fig. 4, a portion of the optical signal passes through optical filter 430 and optical filter structure 420. For example, alternating layers of silicon germanium (e.g., high index of refraction material) and another type of material (e.g., low index of refraction material, such as silicon dioxide (SiO) for optical filter 430₂) May cause a first polarization of light to be reflected in a first direction. In this case, based on a sputtering deposition technique using an inert gas atmosphere using a mixture of argon gas and helium gas as sputtering, the amount of internal stress in the optical filter 430 can be reduced relative to other techniques, thereby enabling reduction in the thickness of the optical filter 430, reduction in the size of the sensor system 410, and the like.

As further shown by reference numeral 490 in fig. 4, based on the portion of the optical signal that is passed to the optical sensor 440, the optical sensor 440 may provide an output electrical signal to the sensor system 410, for example, for recognizing a gesture of a user or detecting the presence of an object. In some implementations, another arrangement of optical filters 430 and optical sensors 440 may be utilized. For example, rather than passing the second portion of the optical signal collinear with the input optical signal, the optical filter 430 may direct the second portion of the optical signal to the optical sensor 440 at a different location in another direction. In another example, the optical sensor 440 may be an avalanche photodiode, a silicon-based detector, an indium gallium arsenide (InGaAs) detector, an infrared detector, or the like.

As noted above, fig. 4 is provided as an example only. Other examples are possible and may differ from the example described with respect to fig. 4.

In this way, optical elements, optical filters, optical systems, sensor systems, etc. can be manufactured using a sputter deposition process. Based on using a mixture of argon and helium as the inert gas environment for sputtering, the amount of argon ions embedded in the sputtered layer of the optical filter can be reduced, thereby reducing the amount of internal stress in the sputtered layer relative to using an argon environment (without helium). In this case, based on reducing the amount of internal stress in the sputtering layer, the thicknesses of the sputtering layer, the optical system, the sensor system, and the like can be reduced (relative to the sputtering layer having an increased amount of internal stress) without excessive bending, warping, and the like.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the embodiments.

Some embodiments are described herein in connection with a threshold. As used herein, meeting a threshold may refer to a value that is greater than the threshold, greater than or equal to the threshold, less than or equal to the threshold, and the like.

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

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more items, and may be used interchangeably with "one or more". Further, as used herein, the term "collection" is intended to include one or more items (e.g., related items, unrelated items, combinations of related items and unrelated items, etc.) and may be used interchangeably with "one or more". Where only one item is intended, the term "one" or similar language is used. Additionally, as used herein, the terms "having," "has," "having," and/or similar terms are intended to be open-ended terms. Further, the phrase "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.