Process for quantizing nanolayers by magnetron sputtering deposition

Abstract

A process for depositing a nanolaminate on a surface of a flat substrate, the process comprising the steps of:-mounting the substrate on a substrate support in a peripheral region (R) of a holder rotatable about its central axis B in a vacuum process system, the receiver comprises at least one magnetron sputtering station, the sputtering target of which is mounted to and spaced apart from a sputtering source, and at least one plasma processing station having a plasma source, both the sputtering target and the plasma source being directed towards different portions of the peripheral area (R), the method comprises the steps of:-providing a holder,-evacuating a receiver,-rotating the holder around a central axis at a constant speed,-introducing a sputtering gas into the receiver, and-introducing a reaction gas directly into at least one of a sputtering station or a plasma station,-discharging and igniting a magnetron in the sputtering station and setting a magnetron power level (Pm), and-igniting the plasma and setting a plasma power level (Pp) of the plasma source in the plasma processing station,-successively exposing the substrate to a magnetron discharge by rotating the holder to deposit a high refractive index material layer LH, and to a processing plasma to produce a low refractive index material layer L1, wherein the rotational speed of the holder and the magnetron power level (Pm) are set such that the layer thickness dh of the well layer Lh of the high refractive index material is 0.1 < = dh < = 5 nm.

Description

Technical Field

[0001] The present invention relates to a sputtering process for depositing a quantum-confined nanolaminate (QNL) on a substrate surface according to claim 1, an optical device according to claim 23, and a process system for depositing such a nanolaminate according to claim 30. Background Art

[0002] Optical interference coatings such as antireflection coatings, mirror coatings, or filter film coatings are based on a stack of materials having at least two different refractive indices n. The greater the refractive index difference between the materials, the stronger the interference effect. Therefore, a stack of layers using materials with a high refractive index difference requires a smaller number of individual layers, and thus the total thickness is less than that of a stack with a low refractive index difference. In addition to the refractive index, these materials must also meet another requirement, namely that they are transparent in the wavelength range of interest and the losses are negligible.

[0003] However, it is well known that in dielectric materials, the refractive index and the absorption edge are related. The absorption edge of materials with a high refractive index is at long wavelengths, while that of low refractive index materials is at shorter wavelengths.

[0004] A method to decouple the refractive index and the absorption edge is grazing incidence deposition, in which a columnar film structure is formed, thus reducing the effective refractive index. Therefore, an interference effect occurs between consecutive layers of the same material and the layers of the columnar structure. This produces interesting effects, such as higher laser damage resistance due to the absence of interfaces between different materials, but the disadvantage is an increased sensitivity to environmental conditions.

[0005] The latest concept for balancing these two properties is the quantum-confined nanolaminate (QNL), first proposed by Jupe et al. in 2019. In this concept, high refractive index thin layers and low refractive index thin layers with thicknesses in the nanometer range or below are stacked. The high refractive index material layers are called quantum well layers, and the low refractive index material layers are called barrier layers. The finite structural size results in a change in the bandgap, which can be adjusted by the physical thickness of the material, where the ratio of the materials determines the effective refractive index of the QNL.

[0006] In optical interference coatings, the decoupling of the bandgap and the refractive index potentially offers the advantage of using material combinations to design materials with any specific refractive index rather than searching for a limited number of known materials. For example, in the UV range, the bandgap of Ta2O5 can be shifted to shorter wavelengths, and thus it can replace the use of HfO2. This is desirable because hafnium targets are expensive and also because HfO2 has a tendency to grow polycrystalline with grain boundaries, which can cause losses due to stray light.

[0007] Another example has been detailed by Henning et al. in "Manufacturing of Si-based hybrid metamaterials for increasing the refractive index in interference coatings", Md.1, OIC 2022XX, which explains that the combination of amorphous silicon and SiO2 has the potential to be transparent even in the visible wavelength range, with an effective refractive index higher than 2.7. This material offers a greater advantage than the well-known TiO2, which is the material with the highest refractive index that is transparent in the visible wavelength range. However, so far, there is no experimental evidence of this effect.

[0008] So far, Steinecke et al. in "Quantizing nanolaminates as versatile materials for optical interference coating", J. optical Society of America, Vol. 59, No. 5 / 10, February 2020, have only experimentally demonstrated the QNL effect for atomic layer deposition (ALD) and ion beam sputtering (IBS) coatings. Although both of these alternative methods have produced good results, they have disadvantages in terms of mass production. The ALD growth rate is low because only one atomic layer is deposited in each coating cycle, while in IBS, the area target needs to be mechanically translated from one material of the nanolaminate to another, which also greatly limits the deposition rate. It was also explicitly mentioned in the same paper that several attempts to deposit such layers by RF sputtering were only reliably deposited when the layer thickness exceeded 5 nm, which was too thick to exhibit the quantization effect. Summary of the Invention

[0009] The object of the present invention is to solve the problems of the prior art and provide an alternative but industrially applicable process for depositing QNL films, as well as a corresponding vacuum process tool for producing such layers. In addition, the object of the present invention is to provide a new optical device that uses QNL films produced by the corresponding process.

[0010] These objects are achieved by a process having the features of claim 1, a vacuum process system for depositing such nanolaminates according to claim 30, and an optical device according to claim 23. Further embodiments of the process, process system, and device of the present invention are defined by the features of the corresponding dependent claims.

[0011] According to the present invention, a process for depositing a so-called quantum nanostructured laminate (QNL) on the surface of a flat substrate comprises the following steps: - In a vacuum process system, the substrate is mounted on a substrate support in the peripheral region (R) of a holder, the holder being rotatably mounted about its central axis B, the receiver comprising at least one magnetron sputtering station and at least one plasma treatment station, the sputtering target of the at least one magnetron sputtering station being mounted to a sputtering source and spaced from the magnetron sputtering station, the at least one plasma treatment station having another plasma source, the sputtering target and the plasma source each being directed according to their function to different parts of the peripheral region (R), - Evacuating the receiver, - Rotating the holder at a constant speed about the central axis, - Introducing a sputtering gas into the receiver, for example introducing the sputtering gas near the sputtering station or directly into the sputtering station, which can be achieved by means of a gas ring or another type of circumferential gas supply unit such as a trough-shaped gas supply unit, both of which can be mounted around the opening of the sputtering station or within the sputtering station, - Directly introducing a reactive gas into at least one of the sputtering station or the plasma station, where gas conduits of a similar or identical type can be selected, - Igniting a magnetron discharge in the sputtering station and setting the magnetron power level (P m ), and - Igniting a treatment discharge in the plasma treatment station and setting the plasma power level of the plasma source (P p ), - Exposing the substrate successively and preferably repeatedly to ° magnetron discharge to deposit a high refractive index material layer L h , and ° treatment discharge to produce a low refractive index material layer L1, where the rotational speed of the holder and the magnetron power level (P m ) are set such that the layer thickness d h of the potential well layer L of the high refractive index material with a refractive index higher than 1.65 h (sometimes also d 势阱 or t h ) is: 0.1 ≤ d h ≤ 5 nm (see Steinecke), for example 0.1 ≤ d h ≤ 4.0 nm, in particular for example 0.1 ≤ d h ≤ 3 nm.

[0012] In an embodiment of the present invention, the plasma power level (P p) such that the layer thickness d1 (sometimes also d 势垒 or t l ) of the low refractive index material barrier layer L1 with a refractive index that can be equal to or lower than 1.65 is: 0.1 ≤ d l ≤ 30 nm, for example, 0.1 ≤ d l ≤ 20 nm, particularly 0.5 ≤ d l ≤ 10 nm.

[0013] In an embodiment of the present invention, the target can be one of Al, Si, Ti, Zr, Hf, Nb, Ta, Ge, corresponding oxides, nitrides or mixtures thereof (such as AlTi, TiZr, NbTa, etc.), and corresponding oxides or nitrides. The high refractive index material deposited with such a target can be amorphous silicon (a-Si), oxides of transition metals such as TiO2, ZrO2, HfO2, Nb2O5, Ta2O5, etc. or corresponding mixtures, but as long as SiO2 is generated as the low refractive index material in the plasma station, Al2O3 or Si3N4 can also be deposited as the high refractive index material in the sputtering station.

[0014] In an embodiment of the present invention, the plasma station can include a plasma source, which is not a magnetron sputtering source here, and the reaction gas is directly introduced into the plasma station.

[0015] In an embodiment where a non-magnetron sputtering source plasma station is used to generate the second refractive index layer (such as the low refractive index layer), the target of the sputtering station only uses inert gas as an example, and the sputtering station can be set to a certain power level and maintained constant without further control measures. At the same time, the power of the plasma source can also be set to a constant level, and the plasma gas parameters in the plasma station can be controlled by a plasma emission monitor (PEM) through the intensity of at least one determined line of the gas-plasma emission. The plasma gas parameters can be, for example, the total pressure, the reaction gas pressure, but preferably the reaction gas flow rate.

[0016] When using such a plasma source, for example, for generating a low refractive index material layer, the target can be silicon, and a sputtering gas that can be an inert gas can be introduced near the sputtering station or directly into the sputtering station to deposit a high refractive index a-Si layer on the substrate surface through the sputtering station opening. Then, the reaction gas of the plasma source can be oxygen and is directly introduced into the plasma station to oxidize the surface area of the just-deposited a-Si layer when the substrate passes through the plasma discharge port of the plasma station. Therefore, directly introducing the reaction gas to the plasma source helps to avoid interfering with the sputtering process of the plasma station.

[0017] More specifically, when high refractive index layers and low refractive index layers (e.g., a-Si / SiO2) should be deposited alternately, the following parameters can be selected for a combination of a sputtering station and a plasma station for a target material having a Si-containing material (e.g., substantially pure silicon): Sputtering source power (P Sput ): 0.5 - 10 kW, e.g., 1 - 7 kW; Sputtering source gas flow rate (f Sput ): 10 - 300 sccm, e.g., 30 - 250 sccm; Plasma source power (P PSC ): 0.1 - 5 kW, e.g., 0.25 - 3 kW; Plasma source gas flow rate (f PSC ): 1 - 50 sccm, e.g., 2 - 30 sccm; Total pressure generated by the two gas flow rates: 1e -3 –2e -2 mbar.

[0018] In this case, the total pressure can be set relatively high with reference to known sputtering processes, so the ratio of sputtering gas to reaction gas (f sput / f PSC ) should be about 5 to 30 or 6 to 15 to avoid target poisoning of the Si-target.

[0019] As a specific example, after depositing a 0.5 nm thick a-Si layer at a rotation speed of 3 seconds per cycle, a target power of 2.5 kW, and an Ar flow rate of 200 sccm, the near-surface region of the 0.25 nm of the a-Si layer can be oxidized to SiO2 by applying the following parameters to the plasma source: P PSC = 250 W and f PSC = 2 sccm O2, resulting in a total pressure of 6e -3 mbar. Thus, a 0.25 nm thick a-Si layer can be produced on an Evatec Clusterline BPM magnetron sputtering deposition system, followed by a 0.25 nm thick SiO2 layer. Additional examples will be given in the detailed description of the present invention below.

[0020] In another embodiment of the present invention, the plasma processing station is another magnetron sputtering station including another target. The other target can be one of Si, SiO2, Si3N4, Al, Al2O3, or AlN for depositing a low refractive index material. In this embodiment, the sputtering gas can be directed to the sputtering station and the other sputtering station via separate gas conduits.

[0021] The power of the target and / or another target can be set. Simultaneously or later, a reactive gas can be introduced, for example, through a gas inlet that is the same as or different from the sputtering gas, and the reactive gas parameters in the sputtering station and / or another sputtering station can be controlled by a plasma emission monitor (PEM) based on the intensity of at least one defined line of the target-plasma emission in the transition region or transition mode of the reactive sputtering process, where the target surface is neither purely metallic nor completely poisoned by the reactive gas, such as oxidized, which makes it difficult to perform any other process control except with the PEM. Thus, a fully reacted layer can be deposited on the substrate without completely poisoning the target surface, enabling a high deposition rate to be maintained and process instabilities to be avoided.

[0022] Thus, as an example, when high refractive index layers and low refractive index layers should be deposited alternately, the following process parameters can be selected for the combination of two separate sputtering stations (including the sputtering station and another sputtering station): Sputtering source 1 for depositing the high refractive index layer L h : Power P Sput1 : 0.5 - 10 kW, for example 1 - 8 kW; Target material: Al, Si, Ti, Zr, Hf, Nb, Ta, Ge, corresponding oxides, nitrides or mixtures thereof. Deposition atmosphere: Usually a mixture of sputtering gas (any inert gas) and reactive gas (such as oxygen or nitrogen). The reactive gas is supplied at least near the sputtering station or at least directly to the sputtering station. The applied gas flow rate can be: 10 ≤ f 惰性 ≤ 200 sccm; 1 ≤ f 反应 ≤ 100 sccm. However, for the deposition of a-Si layers, a (pure) inert gas atmosphere should be used: 10 ≤ f 惰性 ≤ 300 sccm, see above.

[0023] Sputtering source 2 (another sputtering source) for depositing the low refractive index layer L1: Power P Sput2 : 0.5 - 10 kW, for example 1 - 8 kW; Target material: Al, Si, corresponding oxides, nitrides or mixtures thereof. Deposition atmosphere: Usually a mixture of sputtering gas (any inert gas) and reactive gas (such as nitrogen, however preferably oxygen). The reactive gas is supplied at least near the sputtering station or at least directly to the sputtering station. The applied gas flow rate can be: 10 ≤ f 惰性 ≤ 200 sccm; 1 ≤ f 反应 ≤ 100 sccm.

[0024] In any embodiment of the present invention, the sputtering gas may be any inert gas, such as at least one of argon, krypton, neon, xenon, or any mixture thereof.

[0025] In any embodiment of the present invention using a reactive gas, different or the same reactive gas and / or another reactive gas can be directly introduced into the sputtering station and directly into the plasma station, or alternatively or additionally into another sputtering station, for example, led to the corresponding two, three, four, or more stations through separate gas conduits. The reactive gas and / or another reactive gas may be oxygen or nitrogen.

[0026] In any embodiment of the present invention, a process baffle can be provided for the sputtering station and / or another sputtering station, where the process baffle can be closed during the ignition phase of the corresponding sputtering station until the sputtering process has stabilized and layer deposition can begin, and the baffle is opened during the deposition phase of the corresponding layer.

[0027] In an embodiment of the present invention, where n high refractive index material layers L h and n or n±1 low refractive index material layers L1 are alternately deposited on at least one surface of a flat substrate as a stack, and in the stack, the corresponding layer numbers n of layers L h and L1 can be at least 1, and: 1≤n≤10000, where a number of 2≤n≤2000 is most feasible.

[0028] An example of the thinnest deposited layer combination is the following combination: 0.1 nm of Ta2O5 / 0.2 nm of SiO2. A 500 nm thick nanolaminate can have 1666 layers of high refractive index and low refractive index layers alternating with each other. The typical thickness of an interference filter can be 1 to 300 nm. Additional examples will be given in the detailed description of the present invention below.

[0029] In another embodiment of the present invention, which can be combined with any other embodiment, at least one other layer or coating composed of several layers can be provided or deposited between the stack and the glass substrate and / or between the stack and the atmosphere. Exemplarily, such a coating can be an adhesion layer / coating facing the substrate, a scratch-resistant layer / coating facing the atmosphere, an AR or IR reflective coating.

[0030] For a stack composed of alternating high refractive index material layers and low refractive index material layers, the total refractive index reflects the percentages n of the corresponding high refractive index material and low refractive index material for the potential well layer and potential barrier layer of the stack SUM 2 =x*n h 2 +y*n l 2, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, and x + y = 1. In embodiments of the invention that can be applied to any embodiment of the present invention, unless there is a contradiction, the transmission edge T of the stack and the corresponding absorption edge (T - R) shift towards shorter wavelengths as the well thickness decreases. This means that for a stack of layers with the same high - refractive - index material and low - refractive - index material and the same percentage of high - refractive - index material to low - refractive - index material, it can be represented, for example, by the percentage of the total (optical) thickness (d h_tot = n * d h ) of the high - refractive - index material layers to the total (optical) thickness (d l_tot =(n ± 1) * d l ) of the low - refractive - index material layers. However, the well thicknesses are different. For example, as described above, for a combination of high - refractive - index oxide and / or nitride materials and low - refractive - index oxide and / or nitride materials, the corresponding shift of the transmission edge T can be expressed as follows: ΔT 50 = T 50_THICK – T 50_THINN , and 2 ≤ ΔT 50 ≤ 60 nm, for example 5 ≤ ΔT 50 ≤ 40 nm.

[0031] Due to the high refractive index of a - Si, the material combination a - Si / SiO2 exhibits a large shift of the transmission edge T: 20 ≤ ΔT 50 ≤ 600 nm, for example 50 ≤ ΔT 50 ≤ 400 nm.

[0032] Therefore, ΔT 50 is the difference in the transmittance T 50_THICK – T 50_THINN at 50%, where the transmittance of a stack of layers with a well - layer thickness d h_THICK ≥ 5 nm, for example 5 to 50 nm, is compared with the transmittance T h_THIN of a stack of layers with a thin well - layer d 50_THINN ≤ 3 nm, for example 3 to 0.1 nm, produced by the process of the present invention. For at least the coatings deposited by the process of the present invention, the thicknesses of all the well layers are preferably equal to the same value d h , and the thicknesses of all the barrier layers are preferably equal to the same value d l . These values can generally be different, where d h ≤ d l or d h < d l .

[0033] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, for a combination of, for example, high refractive index oxide and / or nitride materials and low refractive index oxide and / or nitride materials as described above, the energy gap E between the free radical state and the higher conduction band state gap as the thickness of the potential well layer L h decreases, the amount of increase is: ΔE gap = E gap_THINN - E gap_THICK , where: 0.01 ≤ ΔE gap ≤ 0.8 eV, for example 0.02 ≤ ΔE gap ≤ 0.4 eV.

[0034] For the material combination a-Si / SiO2, the following ranges have been determined: 0.01 ≤ ΔE gap ≤ 2 eV, for example 0.02 ≤ ΔE gap ≤ 1.5 eV, where ΔE gap is the E h_THIN of a layer with a thin potential well layer d gap_THINN ≤ 3 nm, for example 3 to 0.1 nm, produced by the process of the present invention h_THICK and the E gap_THICK of a stack of layers with a potential well layer thickness d h ≥ 5 nm, for example 5 to 50 nm. Here, the corresponding lower energy gap represents a potential well layer thickness d h of about 2 to 1.5 nm, and the higher energy gap represents a potential well layer thickness d

[0035] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the retainer is a turntable retainer, and the peripheral region (R) is defined by an outer ring. Wherein, on at least one main surface of the disc-shaped retainer, that is, on the upper surface or the lower surface of the turntable retainer, the substrate retainer is arranged along the ring. For example, the corresponding geometric center of the substrate retainer is arranged along the middle diameter of the ring. The flat substrate is mounted above or within a substrate support in a plane parallel to the turntable plane. The substrate support can be perpendicular to the turntable retainer with a horizontal rotation axis B. However, a horizontal turntable retainer, a corresponding turntable retainer plane P with a vertical rotation axis B, and a horizontally positioned substrate are preferred. Details of the corresponding turntable retainer can be found in the examples and drawings below.

[0036] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the retainer is a cylindrical or cylindrical polyhedral retainer, the peripheral region (R) is defined by the cylindrical or polyhedral surface of the retainer, and the substrate support is arranged such that its center is disposed on the cylindrical or polyhedral surface of the retainer along at least one constant-height diameter. In a plane substantially parallel to the cylindrical or polyhedral surface, a flat substrate can be mounted within or on the cylindrical or polyhedral surface. Here, "substantially parallel" means tangent to the cylindrical surface, typically with the center of the substrate as the contact point or the point closest to the cylindrical diameter of the retainer, depending on the type of support. Regarding the polyhedral surface, it means parallel to one face of the polyhedral surface. In both cases, due to the geometry of the support, as will be immediately understood by those skilled in the art, the substrate position includes positions a few millimeters above or below the corresponding retainer surface or retainer diameter. The axis B of the retainer can be horizontal. However, in this case, the vertical substrate position on a cylindrical retainer with a vertical axis B is preferred.

[0037] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the substrate can be a wafer, such as a silicon wafer or a glass wafer.

[0038] In another embodiment of the present invention, the substrate can be a wafer, the radial distance of the peripheral region (R) from the central axis B is 535 ± 60 mm, and the constant speed is set to 30 to 0.5 seconds per cycle, for example, 2 to 20 seconds per cycle, which is equal to seconds per cycle. With such a configuration, as an example, 16 wafers with a diameter of up to 200 mm (or 15 wafers and 1 blank wafer) can be coated simultaneously.

[0039] For any disc-shaped substrate such as a wafer, a disc-shaped circular target with a corresponding substantially cylindrical magnetron source or a corresponding linear sputtering source with a linear target can be used, where the diameter or circumference of the effective region, also known as the runway region, should protrude laterally beyond the substrate to achieve a uniform coating quality and thickness over the entire substrate surface. To utilize the circular target to provide the best target utilization rate, the target or the magnetic system can rotate. However, in the case of a turntable retainer, as described above and in the detailed description below, a static asymmetric magnet system can be beneficial for compensating for different deposition rates due to different radial velocities in the outer and inner regions of the substrate surface, as detailed in WO 2017042123 A1 of the same applicant in combination with Figures 4 and 2 and the corresponding description. To combine the best coating distribution with cost efficiency, the target diameter D T should be substantially larger than the diameter D of the wafer to be coated W , for example, 1.4*D W ≤D T ≤1.7*DW , where the magnet system is ultimately combined with the rotation of the magnet or the target, allowing for uniform erosion of the material over the entire surface of the target. For example, for a 200 mm wafer, the following ranges can be applied and good results obtained: 280 ≤ D T ≤ 340, especially 300 ≤ D T ≤ 320.

[0040] The present invention also includes an optical device that includes a substrate and an optical coating deposited on at least one side of the substrate, the optical coating being composed of at least one high refractive index material film and at least one low refractive index material film, wherein at least one of the high refractive index material film and / or the low refractive index material film is designed to have a defined high or low total QNL refractive index (n QNL ) of a quantized nanolaminated material (QNL), where the QNL film, i.e., a stack of quantized layers of high refractive index material and low refractive index material, includes at least one high refractive index material potential well layer L h and at least one low refractive index material barrier layer L1 that alternate with each other, where the layer thickness d h of the potential well layer L h is: 0.1 ≤ d h ≤ 6 nm, where preferably 0.1 ≤ d h ≤ 4.0 nm, for example 0.1 ≤ d h ≤ 3 nm.

[0041] In another embodiment of the device that can be combined with any other embodiment of the present invention, unless there is a contradiction, the layer thickness d1 of the low refractive index material barrier layer L1 is: 0.1 ≤ d l ≤ 30 nm, where preferably 0.1 ≤ d l ≤ 20 nm, for example 0.5 ≤ d l ≤ 10 nm.

[0042] In another embodiment of the present invention, the QNL film defines the high refractive index film of the optical coating.

[0043] In another embodiment of the present invention, the low refractive index material of the low refractive index film can be the same material as the low refractive index material of the barrier layer L1 in the QNL film.

[0044] The number n of the corresponding layers L h and L1 in the stacked QNL film is at least 1; 1 ≤ n ≤ 10000, for example 2 ≤ n ≤ 2000.

[0045] In any embodiment of the present invention, the device can be produced according to the process described above.

[0046] In an embodiment of the present invention, the optical coating can be an interference coating, such as an anti-reflection (AR) coating (for visible or IR light). The device can be a mirror, a semi-selective mirror, a filter, or a lens with a corresponding coating. When the device is a filter, it can be a notch, short-pass, or long-pass edge filter, a beam splitter, or a polarizer.

[0047] The present invention also includes a vacuum process system for depositing a so-called quantized nanolaminate material (QNL) on the surface of a flat substrate, the quantized nanolaminate material including at least one high refractive index material potential well layer L h and at least one low refractive index material barrier layer L1, the receiver including: - a holder rotatable about its central axis B and having a substrate support in its peripheral region (R), - at least one magnetron sputtering station, the sputtering target of which is mounted to a sputtering source and spaced apart from the magnetron sputtering station, - at least one plasma processing station having a plasma source, - the sputtering target and the plasma source are each directed to different parts of the peripheral region (R) according to their functions, for example via corresponding openings of the target station and the plasma station, - a sputtering gas inlet for introducing sputtering gas into the receiver, which can preferably be arranged near or in the sputtering station, for example around the target; thus, the sputtering gas inlet can include a gas ring or another type of circumferential gas supply unit, such as an opening around the sputtering station or a groove in the sputtering station, and - a reaction gas inlet and / or another reaction gas inlet for introducing reaction gas into the receiver, which can provide a reaction gas inlet at least near or in the sputtering station, and can provide another reaction gas inlet at least near or in the plasma station. In each case, the reaction gas inlet can also be a gas ring or another type of circumferential gas supply unit, such as an opening around the plasma / sputtering station or a groove in the plasma / sputtering station, such as a groove around the target.

[0048] Thereby, the rotational speed of the holder can be set to 30 to 0.5 seconds per revolution, for example 2 to 20 seconds per revolution (s / pass), and the magnetron power level (P m ) can be set to 0.5 - 10 kW, such that the layer thickness d h of the potential well layer L of a high refractive index material, such as a material with a refractive index greater than or equal to 1.65, h can be set to: 0.1 ≤ d h ≤ 6 nm, where preferably 0.1 ≤ d h ≤ 4.0 nm, for example 0.1 ≤ d h≤ 3 nm. Such a rotational speed and magnetron power level can be set for an industrial coating apparatus having a retainer diameter between 800 mm and 2000 mm and a target diameter between 280 and 450 mm to coat wafers having a diameter of 200 or 300 mm.

[0049] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the rotational speed of the retainer and the magnetron power level (P m ) can be set such that the layer thickness t1 of the barrier layer L1 of the low refractive index material can be: 0.1 ≤ d l ≤ 30 nm, where preferably 0.1 ≤ d l ≤ 20 nm, for example 0.5 ≤ d l ≤ 10 nm.

[0050] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the plasma station includes an inductively or capacitively coupled plasma source and a reactive plasma gas inlet that directly enters the plasma station, for example, where another gas inlet is arranged within the station. This another gas inlet can be connected to a nitrogen supply unit, but preferably to an oxygen supply unit.

[0051] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the plasma station is a capacitively coupled HF plasma source. The plasma source can be an inductive plasma source, such as IS300, but preferably a capacitively coupled RF plasma source, such as PSC303, and both types of plasma sources can be obtained from the Swiss manufacturer of vacuum and plasma equipment, Evatec AG. Details regarding the capacitively coupled RF plasma source that can be advantageously used in the present invention are disclosed in FIGS. 2, 6 - 8 and the corresponding description of WO 2020 / 161139 of the same applicant. The plasma source specifically includes a first capacitively coupled plasma generating electrode and a second capacitively coupled plasma generating electrode, where the first electrode has a larger electrode surface and the second electrode has a smaller electrode surface, and they are located in the vacuum receiver of the process system or the corresponding plasma station, or at the plasma outlet of the process system, as well as at the reactive gas inlet or feed port of the reactive gas supply unit here. The plasma outlet typically passes through the second electrode, which can include at least one grid with a transparency greater than 50%. The reference potential of the second electrode can be set, and this reference potential can be the ground potential. At least one of the larger and smaller electrode surfaces can be variable.

[0052] In addition, at least one coil device can be provided in the space between the first electrode and the second electrode to generate a magnetic field. In another embodiment of the plasma source, the first electrode can be cup-shaped, with its inner surface facing the second electrode, and a coil device can be provided along the outer surface of the cup-shaped first electrode to generate a magnetic field having a main direction component towards or away from the second electrode. The coil device can include at least two coils, which are independently powered by respective current sources.

[0053] In another embodiment of the present invention, the target can be a silicon target, and the sputtering gas inlet is only connected to an inert gas supply unit, for example, for depositing a silicon layer.

[0054] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, a plasma emission monitor (PEM) can be connected to the plasma region of the plasma source via an optical path of light to control the power of the plasma source or the flow rate of the reaction gas. Generally, all types of sputtering and plasma stations using reaction gases for processes can be equipped with plasma emission monitors (PEMs) to utilize the hysteresis effect in the transition mode and ensure complete oxidation at a high deposition rate. These monitors can be designed as broadband and / or monochromatic optical monitors.

[0055] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the plasma processing station is another magnetron sputtering station including another target. The other target can be one of Si, SiO2, Si3N4, Al, Al2O3, AlN, or a mixture thereof. In this case, another reaction gas inlet can be provided to the other target station.

[0056] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, the target of the target station is one of Al, Si, Ti, Zr, Hf, Nb, Ta, Ge, the corresponding oxides, nitrides, or a mixture thereof.

[0057] In another embodiment of the present invention that can be combined with any other embodiment of the present invention, unless there is a contradiction, separate reaction gas inlets can be provided for two sputtering stations, namely the sputtering station and another sputtering station. The corresponding reaction gas inlets can be connected to the same or different gas supply units through respective separate reaction gas flow controllers. In the same way, separate sputtering gas inlets can be provided for two sputtering stations with separately controllable sputtering gas flow controllers. The sputtering gas inlet and the reaction gas inlet can coincide within the corresponding chamber.

[0058] In another embodiment of the present invention capable of being combined with any other embodiment of the present invention, unless there is a contradiction, the retainer is a turntable retainer having a turntable retainer plane (P), the peripheral region (R) is defined by an outer ring, and on at least one main surface of the turntable retainer, for example, on the upper surface or the lower surface of the turntable retainer, the substrate retainer is arranged along the ring, for example, the corresponding geometric center of the substrate retainer is arranged along the middle diameter of the ring, wherein the flat substrate is mounted above or within a substrate support in a plane parallel to the turntable plane, the turntable plane can be perpendicular to the turntable retainer having a horizontal rotation axis B, however, a horizontal turntable retainer having a vertical rotation axis B and a horizontally positioned substrate is preferred.

[0059] For any embodiment of the turntable retainer, the magnetron sputtering station may include a circular target and a static magnet device, the magnet device: + is arranged in a plane (M) parallel to the plane (P); and + is non-rotationally symmetric about a target axis (C) that passes through the center of the magnet device and is perpendicular to the plane (M) parallel to the axis B.

[0060] In another embodiment of the present invention capable of being combined with any other embodiment of the present invention, unless there is a contradiction, the distance between the target and the turntable retainer can be varied in the Z direction, that is, in a direction perpendicular to the surfaces of the turntable and the substrate, according to process requirements.

[0061] In another embodiment, the magnet system can be divided along a line (K) in a plane (M) that perpendicularly intersects the target axis (C) into: an outer region away from the center of the turntable, and an inner region towards the center of the turntable, wherein it is effective that the outer region is larger than the inner region. Here, outer and inner refer to being farther or closer to the axis B.

[0062] The magnet device (11) can be symmetric or asymmetric about a symmetry axis (A) in the plane (M), wherein the axis (A) intersects the central axis (Z) of the turntable.

[0063] For any embodiment of the turntable retainer, the target can be a rotating target, which is arranged to be rotatable about its central target axis (C) parallel to, for example, the central axis B.

[0064] In another embodiment of the present invention, which can be combined with any other embodiment of the present invention, unless there is a contradiction, the retainer is a cylindrical or cylindrical polyhedral retainer, the peripheral region (R) is defined by the cylindrical or polyhedral surface of the retainer, and the substrate support is arranged such that the center of the substrate support is along at least one height diameter of the cylindrical or polyhedral retainer. Thus, in a plane substantially parallel to the cylindrical or polyhedral surface, the flat substrate is mounted within or on the cylindrical or polyhedral surface. Here, "substantially parallel" means tangent to the cylindrical surface, usually with the center of the substrate as the contact point with the cylinder, or parallel to one face of the polyhedral surface. In both cases, due to the geometry of the support, as will be immediately understood by those skilled in the art, the substrate position includes positions a few millimeters above or below the corresponding surface or geometric diameter. The axis B of the retainer can be horizontal, however, in this case, the vertical substrate position on the cylindrical retainer with a vertical axis B is preferred.

[0065] For the above-mentioned cylindrical or polyhedral retainer, a longitudinal plane or a cylindrical rotating magnetron is usually used. However, if a disc-shaped target is used, the substrate support in the peripheral region (R) of the retainer will preferably be positioned such that during the rotation of the retainer, the center of the substrate support together with the center of the circular substrate can be aligned with the target axis (C) at one position. In this case, a magnetron can be provided for the rotating magnet or the rotating target to support uniform target erosion.

[0066] The features of the above embodiments of the process, device, and / or receiver can be used in any combination, unless they are mutually contradictory. Description of the Drawings

[0067] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. These drawings are for illustrative purposes only and should not be construed as limiting. Among them:

[0068] Figure 1 Shows the energy / coating thickness scheme of QNL;

[0069] Figure 2A and Figure 2B Are a top view and a cross-sectional view of a process system with a cylindrical substrate retainer;

[0070] Figure 3A and Figure 3B Are a top view and a cross-sectional view of a process system with a turntable substrate retainer;

[0071] Figure 4A and Figure 4B Are a top view and a cross-sectional view of a process system with another turntable substrate retainer;

[0072] Figure 5It is a graph showing the relationship between transmittance and wavelength;

[0073] Figure 6 It is a Tauc-plot αhν 1 / 2 [eV / m] 1 / 2 and a graph showing the relationship with photon energy;

[0074] Figure 7 It is a graph showing the relationship between the energy gap and the potential well thickness / number of times;

[0075] Figure 8 It is a graph showing the relationship between the energy gap and the potential well thickness;

[0076] Figure 9 It is a graph showing the relationship between the refractive index and the potential well thickness;

[0077] Figure 10 It is a graph showing the relationship between the energy gap and the refractive index;

[0078] Figure 11 It is a graph showing the relationship between transmittance and wavelength;

[0079] Figure 12 It is a graph showing the relationship between reflectance and wavelength;

[0080] Figure 13 shows the optical device of the present invention;

[0081] Figure 14 It shows the transmission spectrum diagram of the mirror;

[0082] Figure 15 It shows the reflection spectrum diagram of the mirror;

[0083] Figure 16 It is a graph showing the relationship between transmittance and wavelength;

[0084] Figure 17 It is a graph showing the relationship between the total thickness and the rotation of the turntable;

[0085] Figure 18 It is d SiO2 / number of times and d a-Si / number of times;

[0086] Figure 19a and Figure 19b It shows the transmission spectrum diagram;

[0087] Figure 20 It is a Tauc-plot αhν 1 / 2 [eV / m] 1 / 2 and the graph of the relationship with photon energy;

[0088] Figure 21 It is E gap and the relationship with d a-Si / number of times;

[0089] Figure 22 is E gap is a graph of the relationship with the oxygen flow rate; and

[0090] Figure 23 is a graph of the transmittance of the LP filter versus wavelength. Detailed implementation mode

[0091] Figure 1 shows a schematic diagram of the relationship between energy and layer thickness, in which a material combination of using SiO2 as the barrier layer and Ta2O5 as the quantum well layer is used, similar to the general schematic diagram proposed by Steinecke cited above. Although optical coatings are usually amorphous and lack a well-defined energy band structure, there is an energy gap between the quasi-free radical state and the higher conduction band state. By restricting the structural dimensions, such as limiting the layer thickness in the optical coating system to extremely small values, this energy gap can be changed. Then, the low refractive index material will act as the barrier, while the high refractive index material will act as the quantum well. The periodic structure composed of high and low bandgap regions will limit the electron mobility. The new concept of the so-called quantized nanolaminates (QNL) with the thickness of the quantum well layer can independently adjust the optical bandgap and refractive index. The layer thickness of the quantum well (i.e., the Ta2O5 layer) needs to be below about 2 nm to show an obvious change in the energy gap. The barrier thickness also needs to be in the same range and is preferably thinner than the quantum well to obtain a higher effective refractive index.

[0092] Figure 2A shows a top view, while Figure 2B shows a cross-sectional view of a simplified process system 30', which includes a cylindrical holder 1' that can rotate around axis B. The process system 30' also includes a sputtering station 14, another sputtering station 14' and an optional plasma station 20 (dashed line) containing a plasma source 21. The sputtering station 14 and the sputtering station 14' respectively include sputtering sources 16 and 16', and the sputtering sources 16 and 16' respectively contain corresponding planar elongated sputtering targets 15 and 15' (also called linear targets), and the sputtering station 14 and the sputtering station 14' are respectively connected to separate gas supply units 28 and 28' to introduce sputtering and / or reactive gases near the target. The wafer 10 is mounted on the substrate supports 2, 3, 4,... along the height diameter of the cylindrical holder 1'. The target points to the cylindrical surface on which the substrate holder is mounted, and the cylindrical surface is the peripheral region R of such a process system.

[0093] Combined with Figure 3A and Figure 3B describe another vacuum process system, Figure 3A shows a top view, while Figure 3BA cross-sectional view of a simplified turntable process system is described. The turntable process system includes a turntable holder. The housing or vacuum processing receiver 12 has at least two (preferably three or more) sealable openings 13 and sealable opening 13'. The sealable openings 13 and sealable opening 13' are for receiving process stations, namely two sputtering stations including sputtering sources 16 and 16' having sputtering targets 15 and 15' and an optional plasma station 20 including a plasma source 21. The targets can be moved along axis C, which is axis Z with respect to the substrate and the turntable plane (see Figure 3B the double arrow in). Inside the receiver 12, there is a substantially circular turntable holder 1, and the positions of substrate supports 2 - 9 for accommodating the substrate 10 (shown only together with holders 2 and 8) are shown on the turntable holder. The overall surface of the turntable also defines plane P. The substrate supports 2 - 9 can be grooves, simple rims, pins, chucks, holders, fixtures or mounts that match the external shape of the substrate to be processed. If the substrate is fixed by a carrier, the mount can be a support for such a carrier.

[0094] The supports 2 - 9 are shown as circular, but this should not be a limiting factor for the shape of the substrate.

[0095] The turntable has a rotation axis B. The drive for rotating the turntable is omitted in Figure 3. A person skilled in the art will select a suitable solution.

[0096] The number and shape of the substrate supports will be defined by geometric constraints and the specifications of the vacuum process system.

[0097] It is shown that the sputtering sources 14 and 14' are respectively mounted on the openings 13 and 13', and are connected to the corresponding target supply units 27 and 27'. The target supply units can be radio frequency, direct current or pulsed direct current. According to the process requirements, each source can use the same type or different types of supply units. The PVD source 14 basically includes a circular material target 15 and a static magnet device 11. The magnet device defines a plane M, which is parallel to the plane P and thus perpendicular to the axis B. Another axis C is the central axis passing through the circular target and is perpendicular to the plane M and thus parallel to the axis B. The axis C also marks the centers of the openings 13 and 13' respectively. The radial distance between the selected axis B and the axis C is the same as the radial distance between the axis B and each substrate support 2...9. In other words, during each rotation of the turntable, the areas of each of the substrate supports and the openings 13 and 13' are at least completely aligned and completely opposite at the moment when the conditions are met. The number of openings can match the number of substrate positions, but is usually smaller. To avoid sputtering onto the turntable and the substrate when the target is preheated, an optional baffle 31 (dashed line) can be provided. When the baffle is missing or in the open position, the target is directed to the upper surface of the turntable holder on which the substrate holder is mounted, and the upper surface is the peripheral area R in such a process system.

[0098] The PVD sources 16 and 16' show the static magnet systems 11 and 11', which are designed in a way to compensate for the deposition non-uniformity caused by the different track lengths passed by the substrate during the rotational movement from below. It is also designed in a way that no barriers, shapers or masks are used.

[0099] The magnet system has a basic form described in the Figure 3A top view and includes two magnetic rings that surround each other and have opposite polarities. During operation, the plasma channel is basically restricted between the magnetic arches formed by the two magnetic rings. The two magnetic rings are basically trapezoidal or rounded triangular, but do not need to be symmetric as shown.

[0100] It is shown that the magnet systems 11 and 11' include a line K and an axis A, which intersects and is perpendicular to axis B, but the magnet systems 11 and 11' do not need to be symmetric as shown. The line K intersects an axis C and lies in a plane M, essentially dividing the region defined by the outer boundary of the magnet system (i.e., the outer periphery of the outer coil in the plane defined by A / K) into two halves of different sizes, namely an inner magnet region 17 with a smaller size that is radially closer to axis B and an outer magnet region 18 with a larger size that extends outward from the center (indicated by the arrow at axis A) (reference numerals are only shown together with magnet system 11'). Such a system can achieve a uniform coating of the substrate and compensate for system non-uniformities caused by the substrate passing along its curved arc path during the rotation of the turntable, as indicated by the three arrows below the sputtering sources 16 and 16'.

[0101] It has been proven that when using a turntable process system including such a magnet system, a coating uniformity of less than 1% for a SiO2 target can be achieved on the equivalent substrate area of a 6-inch wafer. For further details regarding such a magnet system, see WO 2017 / 042123 A1 by the same applicant.

[0102] Combined Figure 4A top view of and Figure 4B cross-sectional view of to describe a turntable process system similar to the turntable process system shown in Figure 3A and Figure 3B This is a basic system 30 that uses a sputtering station 14 to deposit an a-Si layer and subsequently uses a plasma source 21 of a plasma station 20 to oxidize the layer. A simplified system is shown here. Any target features shown in Figure 3 above can be the same, but these features are omitted for clarity. An oxygen supply unit is connected to the plasma station, and a cup-shaped first electrode 22 with a larger electrode surface is connected to a plasma power supply (i.e., a radio frequency power supply 24) to ignite and maintain the processing plasma. A grid 36 is installed in the plasma outlet as part of a second grounded electrode with a smaller electrode surface (not shown in detail). A vacuum pumping device 24 for evacuating the process system 30 and a turntable drive are clearly shown here. Separate vacuum pumping for the plasma station 20 and / or the target station 14 is optional (not shown). In addition, Figure 4B a separate substrate drive 25 integrated into the turntable is also shown. These drives rotate the substrate around axis C to optimize the layer distribution and processing in different processing steps within stations 14 and 20. Figure 4A and Figure 4B The features mentioned in Figure 3A and Figure 3BThe turntable system shown. The enclosure 23, operating at ground potential as part of a smaller (grounded) electrode, reaches close to the surface of the substrate and / or the turntable and confines the plasma from the grid 36 of the smaller electrode. Thus, the plasma stations can be well and sufficiently separated to prevent process disturbances within the sputtering station.

[0103] exist Figure 4A In the figure, an optional additional dual magnetron sputtering source 14" is shown in dashed lines, which includes two rotating targets 15". In such a sputtering source, the targets are operated alternately as cathodes and anodes, thereby effectively avoiding any target poisoning. As previously described Figure 3B As shown, such a sputtering source can be used with or instead of the target station 14 and target station 14' comprising a disk-shaped target 15 and a disk-shaped target 15'. Similarly, a sputtering station comprising two linear targets and driven in a dual magnetron configuration can be used, or more simply a sputtering station comprising a linear planar or rotating sputtering cathode (i.e., target), depending on the respective process requirements.

[0104] Experimental setup

[0105] For the QNL deposition and layer deposition of the optical devices described below, an Evatec Clusterline BPM magnetron sputtering deposition system was used. This is a commercially available process system consisting of a turntable, a plasma station and a vacuum receiver with up to four magnetron sputtering sources in a sputtering-down configuration, as described above. Figure 3A and Figure 3B as well as Figure 4A and Figure 4B The plasma source can be used for standard deposition to influence layer properties such as stress or surface roughness. For the deposition of Ta2O5-SiO2 QNL, the two sputtering sources can be operated within a very wide parameter range by using the plasma source. However, in the deposition of a-Si and SiO2, the plasma source has been used to oxidize the top of the a-Si layer deposited under the silicon sputtering source. Therefore, a process system comprising two sputtering stations and (another) plasma station is an extremely versatile process system, which specifically refers to a receiver comprising a turntable holder, but can also refer to a receiver comprising a cylindrical or quasi-cylindrical multi-faceted holder. All stations can be equipped with a POM system.

[0106] The deposition system can accommodate 15 substrates with a diameter of 200 mm. Substrate loading is performed automatically via a load lock. The oxide is deposited by reactive sputtering in pulsed DC mode and operates in transition mode close to or even into the hysteresis loop using a plasma emission monitor (PEM), thus ensuring complete oxidation at high deposition rates. The deposition system is also equipped with broadband and monochromatic optical monitors.

[0107] The turntable configuration is well-suited for the deposition of QNL. In the case of using a baffle, when the baffle is open, as the turntable continuously rotates, the substrate repeatedly passes under the active sputtering source. Thus, the substrate is exposed to both sources during each rotation. By setting the sputtering powers of the two sources to corresponding different values, the thickness ratio of the two materials can be defined and changed, and thus the refractive index of the stacked QNL film - i.e., the nanolayer stack (the sum of L h and L l and the sum of) - can be changed. The stacked QNL film is a so-called metamaterial that combines the characteristics of the two materials in a new way. See also below. The thickness of each layer pair in the QNL film can be further determined by the rotation speed of the turntable, but not by the material ratio. Other deposition parameters that affect the growth rate and material properties are the gas flows of argon and oxygen and the PEM setpoint, such as the intensity and spectral lines selected from the gas-plasma emission of the target plasma, respectively.

[0108] In the case of using a material combination of amorphous silicon and SiO2, the QNL structure is obtained in a slightly different way. In this case, a silicon source is used to deposit amorphous silicon in pure argon-plasma and is oxidized when passing under the plasma source. In this case, the plasma source always operates with oxygen. Similarly, the turntable speed and the process settings of the sputtering and plasma sources define the thicknesses of the two nanolaminated materials.

[0109] The sample is deposited on a double-sided polished Herasil glass sample. The sample is characterized by spectrophotometry for transmission and reflection at an angle of 8° at the same position on the sample using a PhotonRT spectrometer from EssentOptics.

[0110] The effective refractive index n and extinction coefficient k in the transparent range of the coating were determined using OptiChar from Optilayer. The models used were the normal dispersion model for n and the ultraviolet-visible light model for k. This evaluation can also determine the physical thickness d or d tot .

[0111] The effective refractive index of the resulting metamaterial is defined by the ratio of the high-refractive-index material and the low-refractive-index material and can be calculated by applying the effective medium theory, where f is the volume ratio between the high-refractive-index material and the low-refractive-index material, according to A. Feldman, “Modeling refractive index in mixed component systems”, Modeling of Optical Thin Films (1988), Volume 0821:

[0112] As described above, the effective refractive index N eff is derived from the spectral measurements of T and R. The refractive index n high and n low are derived from Ta2O5 and SiO2 monolayers. The values used are: Ta2O5 n high = 2.168 and SiO2 n low = 1.474, both refractive indices being related to a wavelength of 500 nm. Then, the volume ratio f of the two materials can be calculated according to formula (1).

[0113] The thickness per turntable pass can be calculated by dividing the physical thickness d of the metamaterial by the turntable speed (in seconds per pass). The thicknesses of the Ta2O5 and SiO2 layers can be calculated separately by multiplying the total thickness per pass by the coefficient f (i.e., 1 - f).

[0114] The optical bandgap is determined using the Tauc plot method, as explained in B.D. Viezbicke, S. Patel, B.E. Davis, and D.P. Birnie, “Evaluation of the tauc method for optical absorption edge determination: ZnO thin films as a model system,” Phys. Status Solidi B 252, 1700–1710 (2015).

[0115] Results of Ta2O5 / SiO2 - QNL

[0116] In the first experiment, the Si source and Ta source were operated at powers of 6 kW and 5 kW, respectively. The turntable speed varied from 3 seconds per pass to 15 seconds per pass, which means that the ratio of the high - refractive - index layer to the low - refractive - index layer remained constant, but the thickness of the single layer increased as the turntable rotation speed decreased (i.e., the time taken per rotation pass was longer). According to this theory, it was expected that the absorption edge would shift to shorter wavelengths as the thickness of the single potential well layer decreased, while the effective refractive index of all four samples would remain constant. As Figure 5 shown, the transmittance curves in the following experiments are below the reference curve of the fused silica (Herasil): #1: 3 seconds per pass #4: 12 seconds per pass #2: 6 seconds per pass #5: 15 seconds per pass #3: 9 seconds per pass.

[0117] As Figure 5As shown, the predicted trend can indeed be observed, and the absorption edge wavelength of sample #1 is the shortest, while that of sample #5 is the longest, with a difference of approximately 19 nm at T50%. In the longer wavelength range far from the absorption edge, all the curves overlap because they have the same effective refractive index. From these measurement values, the following conclusion can be drawn: the magnetron sputtered nanolayers do exhibit a quantization effect.

[0118] Figure 6 A Tauc plot of the same experiment is shown, in which αhν 1 / 2 [eV / m] 1 / 2 is plotted against the photon energy. The bandgap energy can be obtained by linearly extrapolating the transition region to αhν = 0, where the intersection with the photon energy axis is equal to the bandgap energy, and the difference between this bandgap energy and the energy gap, i.e., ΔE gap = E gap_thinn - E gap_thick = E gap_high - E gap_low is proportional, as Figure 1 shown. It can be seen that experiment #1 with the thinnest potential well layer L h shifts to the highest photon energy, while experiment #5 with the thickest potential well layer has the smallest shift.

[0119] Then, for the same set of samples, according to the description of the experimental setup, the effective refractive index and the bandgap energy are measured and calculated. Figure 7 The curves shown (refractive index: right scale, oblique squares; bandgap energy: left scale, triangles) indicate that the bandgap energy increases as the potential well thickness decreases, and the potential well thickness is the thickness d of Ta2O5. However, the refractive index remains constant at a value of approximately 1.56, corresponding to a thickness ratio of Ta2O5 and SiO2 of 1:9. These two findings are completely consistent with the conclusions drawn from the transmission measurement values. The shift of the absorption edge proves that the stack is composed of nanolaminated materials, rather than just a mixture of two materials.

[0120] Figures 5 to 7 The total physical thickness range of each layer stack in

[0121] is 700 - 704 nm, which corresponds to 600 pairs of nanolaminated material layers at a turntable speed of 3 seconds per revolution.

[0121] Subsequently, a series of experiments were carried out, and the thickness ratio of Ta2O5 and SiO2 was changed. As the main parameter, there are differences in the target power of each target. Since both sputtering processes are controlled by PEM, the PEM settings must also be adjusted to values suitable for the sputtering power. For each ratio of high refractive index layer to low refractive index layer, a set of deposition experimental operations were carried out at different turntable speeds to change the thickness of individual nanolayers. Generally, the selected turntable speeds are 1.5 / 3 / 4.5 / 6 / 9 / 12 / 15 seconds per revolution. InFigure 8 On the right side of (similar to Figure 9 and Figure 10 , referring to the same test series), it shows the ratio of the high refractive index material (d h_tot = n * d h ) to the low refractive index material (here d l_tot = n * d l ) in each test series (d h_tot / d l_tot ). Therefore, it can also be known from Figure 8 that the bandgap increases as the well thickness decreases. However, for Ta2O5 with a well thickness exceeding 2 - 3 nm, the bandgap becomes nearly constant because the thicker layer does not show quantization effects.

[0122] On the other hand, Figure 9 the relationship between the refractive index and the well thickness shown in Figure 10 and the relationship between the refractive index and the energy gap shown in Figure 9 and Figure 10 only show that the refractive index increases slightly but steadily as the well thickness increases, and this effect becomes more obvious when the refractive index is higher. It can be known from Figure 9 and Figure 10 that the refractive index can be adjusted within a very wide range and can basically cover the entire refractive index range from SiO2 to Ta2O5.

[0123] QNL, namely the use of Ta2O5 / SiO2 - QNL in optical devices

[0124] The above results prove that magnetron sputtering deposition can fabricate nanolaminates with quantum effects. It will be demonstrated below that by using a QNL stack with an appropriate total thickness to replace the high refractive index material, optical interference coatings such as antireflection (AR) coatings, mirrors, or filters can be designed and fabricated.

[0125] To demonstrate the feasibility of the QNL concept in optical interference coatings, an antireflection coating for a UV LED centered at a wavelength of 280 nm was selected as an example. This is a bilayer structure design. In this experiment, a QNL film with an effective refractive index of n = 1.7 and E gap = 4.48 eV at a wavelength of 550 nm was designed. Such a nanolaminate stack is composed of Ta2O5 layers and SiO2 layers with thicknesses of 0.31 nm and 0.76 nm respectively. This design uses a physical thickness of 120 nm as the total thickness of the QNL (i.e., there are approximately 120 individual nanolayers for each material (120 / 1.07 = 112.14 layers)), and uses a physical thickness of 136 nm as the thickness of SiO2. The total thickness corresponds to an optical thickness of approximately 3 times λ / 4 at λ = 280 nm.

[0126] Figure 11And Figure 12 show the transmittance and reflectance curves of a double-sided coated quartz substrate, which can be used as an antireflection device. The minimum reflectance and maximum transmittance both occur at the design wavelength of 280 nm, and when the coating is in the as-deposited state (#D) and the annealed state (#A) in a further processing step, the device curves match the design curve (#X) very well. The transmittance of the double-sided coated sample reaches 98.3% in the as-deposited state and 99.2% after annealing in air at 300 °C for 1 hour. The corresponding absorption losses are 1% and 0.3% respectively. For comparison, the transmittance of a double-layer antireflection coating composed of Ta2O5 (d = 100 nm) and SiO2 was optimized at a wavelength of 266 nm. The results show that the refractive index is the minimum at the design wavelength, but the absorption rates at wavelengths of 266 nm and 280 nm are 66% and 25% respectively. It is thus clearly shown that a "bulk" Ta2O5 layer cannot be used at the above ultraviolet wavelengths, while excellent performance can be obtained by using a QNL composed of Ta2O5 / SiO2-QNL, thus opening up a broad new application field. In summary, the QNL film can be regarded as a regular "bulk" layer with a corresponding effective refractive index in design and optical monitoring. Since two sputtering sources work simultaneously, the deposition rate of the antireflection QNL is usually 0.71 nm / s, which is higher than that of the corresponding single-layer SiO2 or Ta2O5.

[0127] Figure 13A Shows a schematic view of one side of the optical device 35 of the present invention, which is an antireflection device and can be coated on only one side (as shown) or both sides (as described above) of the substrate 10 of the optical device in a simple embodiment as a double-film 33, 34 system. Here, the QNL film 33 represents a high refractive index material coated with argon and can be designed for a specific required refractive index as shown above, while the low refractive index film 34 is selected from known low refractive index "bulk" materials (such as SiO2). For ease of production, the low refractive index "bulk" material and the low refractive index material in the QNL film can be the same material.

[0128] Figure 13B Shows the same device and magnifies the QNL film 33, where the QNL film 33 contains a high refractive index material layer L with a thickness of d h and a low refractive index material layer L with a thickness of d h and a thickness of d l The materials that can be used for the high refractive index layer L l are amorphous silicon (a-Si), silicon nitride (such as Si3N4), and Me h O x O y, where Me = Al, Ti, Zr, Hf, Nb, Ta, or Ge. Materials that can be used for the low refractive index layer L l are silicon oxide (e.g., SiO2), silicon nitride (e.g., Si3N4), and aluminum oxide (e.g., Al2O3). Professionals in the technical field know that whenever silicon nitride or aluminum oxide is used as the high refractive index layer material, the low refractive index layer material will be silicon oxide because of its lower refractive index. The QNL film 33 of the metamaterial can be directly deposited or deposited onto the substrate through an optional adhesion layer 36. Alternatively, the first low refractive index material layer of the QNL stack can be used as the adhesion layer 36, and the adhesion layer 36 will have the same layer thickness d l as layer L l . In Figure 13A and Figure 13B , due to the extremely large size difference between the substrate and the film, the curve represents an incomplete display of the substrate 10. In Figure 13B , due to the size difference between the nanolayer L h , L l and the low refractive index film 34, the curve represents an incomplete display of the low refractive index film 34.

[0129] Reflective in-situ broadband optical monitoring in the wavelength range of 380 - 980 nm was studied. Due to the large thickness of the layer, the signal can be observed for a longer time, and the change of the signal can also be reflected by the reflection maximum. The results show that the change of the reflection signal of the QNL is very regular, exactly the same as the change of a single layer with the corresponding effective refractive index, so it is extremely suitable for controlling the thickness of the film stack containing the QNL.

[0130] As the second example of applying the QNL concept in optical interference coatings, a mirror composed of 30 SiO2 and QNL Ta2O5 - SiO2 layers with an optical thickness of one - quarter wavelength for each layer was deposited for a wavelength of 355 nm. For comparison, an equivalent mirror with a standard design composed of a total of 26 SiO2 and Ta2O5 layers with an optical thickness of one - quarter wavelength for each layer was deposited.

[0131] Both of the two designs used broadband optical monitoring for deposition. The measurement results are highly consistent with the design, indicating that the QNL layer can be applied like a conventional layer, as detailed in Figure 14 and Figure 15Transmission and refractive index spectra of the corresponding coatings. The curves of the devices with deposited or calculated QNL coatings are called #D and #X, respectively. The curves of the comparison coatings are called #D' and #X', respectively. Both mirrors are centered very well at the design wavelength. As expected, the reflection band of the mirror containing QNL is narrower due to the lower effective refractive index of QNL. When comparing the transmission regions below 300 nm wavelength, it is obvious that the standard design exhibits poorer transmission, while the QNL mirror only experiences losses within a range of 2 - 5% above the absorption edge.

[0132] Results of a-Si / SiO2 QNL

[0133] The samples were again deposited on double-sided polished Herasil glass samples, which is a fused silica glass (also known as quartz glass or silica glass) melted from grown quartz crystals. Such glass is high-quality optical glass without voids and inclusions and exhibits optical homogeneity at least in the functional direction. All a-Si / SiO2 samples were annealed in air at 280 °C or 500 °C for 1 hour.

[0134] In the first experiment, the silicon sputtering source and the plasma source were operated at powers of 5 kW and 1 kW, respectively. When the sample passed through the sputtering source, a layer of amorphous silicon film was deposited. Then, as the turntable rotated, the sample was translated under the plasma source, where a part of the previously deposited a-Si layer was oxidized. This sequence was repeated continuously within the specified coating time.

[0135] In the first experiment, the turntable speed varied from 1.5 seconds to 12 seconds per rotation, increasing the thickness of a single nanolaminate layer. The coating time for the series of four samples was kept constant, and the resulting nanolaminate stack thickness was approximately 180 nm. In Figure 16 it can be seen from the transmission curves of 4 experimental operations measured by spectrophotometry that there are three characteristics of the layer: the wavelength of the absorption edge, the loss within the transparent wavelength range, and the refractive index of the layer. The transmission curves in the following experiments are shown below the reference curve of quartz glass (Herasil): #6: 1.5 s / rotation #8: 6 s / rotation #7: 3 s / rotation #9: 12 s / rotation.

[0136] First, the absorption edge of this series of deposition experiments shifts to shorter wavelengths as the turntable speed increases. The absorption edge of the sample with a speed of 1.5 seconds per revolution is at the shortest wavelength, while that of the sample with a speed of 12 seconds per revolution is at the longest wavelength. With a fixed transmittance of 80%, the difference between the samples is approximately 280 nm. For easy comparison, the black dashed line represents the starting point of transmittance of a conventional amorphous silicon layer.

[0137] Second, the maximum transmittance at the half-wave optical thickness (λ / 2) is in close contact with the solid line representing uncoated quartz, indicating that the QNL has a low absorption rate in the longer wavelength range.

[0138] Third, the transmittance at 1500 nm increases as the turntable speed increases. This indicates that the effective refractive index of the nanolaminated material decreases. Below, we will first explain the change in refractive index and then the shift of the absorption edge.

[0139] As described in the experimental section, the effective refractive index n can be determined from the measured transmittance and reflectance values. eff and the total layer thickness d tot . Then, by dividing d tot by the number of turntable rotations, the deposition thickness per turntable rotation can be obtained. As expected, the deposition thickness per rotation is linearly related to the turntable speed, as Figure 17 shown. However, the individual thicknesses of a-Si to SiO2 calculated by the method described in the experimental section do not show a linear increase, as Figure 18 shown. In the experiment with the fastest turntable speed, an a-Si layer with a thickness of 0.7 nm was deposited, and then a SiO2 layer with a thickness of 0.6 nm was oxidized by the oxygen plasma of PSC. However, when the turntable speed reached the lowest value of 12 seconds per revolution, only 1.8 nm of SiO2 was oxidized from 4.2 nm of a-Si. However, the decrease in the oxidation rate is expected because the penetration depth of the high-energy oxygen species generated in the plasma source is limited even with an extended exposure time. Therefore, the proportion of SiO2 in the thicker layer is lower, resulting in an increase in refractive index. In fact, the increase in refractive index is confirmed, as shown by the right axis in Figure 18 .

[0140] Next, the shift of the absorption edge will be studied in more detail. As Figure 16 shown, the significant shift of the absorption edge is mainly attributed to the change in the average stoichiometry within the total thickness range of the nanolaminated material stack. To determine whether there is a quantum effect, it is necessary to compare nanolaminated material films when the thicknesses of a-Si and SiO2 increase but the thickness ratio remains constant. For this purpose, process settings such as the silicon source power and oxygen flow rate must be adjusted.

[0141] An example of such an experiment is as Figure 19a shown: In the 10th - 12th experimental operations, the ratio of SiO2:a - Si is constant, so the average composition is the same, but the total thickness passed through each time increases, i.e., #10 = 0.5, #11 = 1.1, and #12 = 2.3 nm. The measured transmittance values in these three experimental operations all show a shift in the absorption edge. At this time, it can be found that the deposited thin film exhibits a quantization effect. In the first step, the refractive index and extinction coefficient of experimental operation #12 (solid line) were measured. Figure 19a and Figure 19b The dashed lines representing #10’, #11’, and #12’ in show the transmittance curve simulation based on this dispersion data considering the slightly different layer thicknesses in the 10th to 12th experimental operations. As expected, for the mixture, the three simulated curves overlap in the absorption region below 600 nm. This is inconsistent with the measured curves of the deposited coatings #10, #11, and #12, which show that the thinner the potential well material a - Si, the more the absorption edge shifts towards shorter wavelengths. The final confirmation of quantization is observed from Figure 20 the bandgap energy shift in, which is determined by the above - mentioned Tauc plot. Figure 21 shows that the bandgap energy increases with the decrease in the thickness of the a - Si potential well, while the refractive index remains unchanged within the measurement accuracy. A 0.15 eV shift can be observed, corresponding to a wavelength shift of 60 nm. This observation confirms that the quantization effect can also be observed in the magnetron - sputtered material system a - Si / SiO2.

[0142] Subsequently, experiments were carried out using different deposition parameters. Figure 22 shows the relationship between the bandgap energy and refractive index and the oxygen flow rate in the plasma source in a series of experimental operations carried out at a turntable speed of 1.5 s / rotation. As the supply of oxygen in the plasma increases, the thickness of the SiO2 nanolayer increases, so the refractive index decreases, while the bandgap energy increases.

[0143] QNL, i.e., the use of a - Si / SiO2 QNL in optical devices

[0144] Long - pass filter

[0145] As shown in the previous section, in the a-Si / SiO2 system, QNLs can be fabricated over a wide range of refractive indices and bandgaps. In the previous section, the nanolaminates of experimental operation #10 were chosen as the high refractive index material, while SiO2 was chosen as the low refractive index material to deposit long-pass filters. As described in the experimental section, the QNLs were deposited using a combination of a silicon sputtering source and a plasma source, while the SiO2 layer was deposited from an additional sputtering source. A 16-layer design with a quarter-wave optical thickness was selected, and some of the outer layers were adjusted to form a curve for edge shaping. The refractive indices of Material #10 at 550 nm and 1000 nm were 3.18 and 2.79, respectively, and E gap was 1.72 eV. In this case, the physical thickness of the high refractive index layer with a quarter-wave optical thickness was 49 nm, and it consisted of a total of 180 alternating a-Si and SiO2 layers. Due to the turntable configuration of the BPM magnetron sputtering deposition system, the deposition rate of the nanolaminates was as high as that of a standard a-Si layer.

[0146] The coating thickness was monitored using reflectance in-situ broadband optical monitoring in the wavelength range of 380 - 980 nm. The results showed that the reflection signal of the QNL changed very regularly, exactly the same as that of a single layer with the corresponding effective refractive index. Therefore, it can be concluded that optical monitoring is extremely suitable for controlling the thickness of film stacks containing QNLs.

[0147] For comparison, the same type of filter was deposited based on the standard material combination of SiO2-TiO2, also using a 16-layer structure, with the same design principle as the nanolaminate filter. In Figure 23 this case, the device curves of the QNL coating in the deposited state and the calculated state were designated as #D SiO2 / QNL and #X SiO2 / QNL , where QNL refers to the corresponding a-Si / SiO2 stack. The curves of the comparison coatings in the deposited state and the calculated state were designated as #D’ SiO2 / TiO2 and #X’ SiO2 / TiO2 .

[0148] Obviously, the standard design only blocked half of the visible light range, while the QNL design blocked the entire visible light range. Of course, the SiO2-TiO2 design could achieve complete blocking, but at the cost of doubling the number of layers.

[0149] The total thickness of the standard SiO2-TiO2 coating is 1.4 μm, while the total thickness of the QNL-SiO2 design is 1 μm. In addition, the deposition rate of QNL is approximately twice that of TiO2. The reduction in thickness and the increase in deposition rate both shorten the deposition time by a factor of 2. Therefore, through comparison, it is found that the novel nanolayer material has great potential in significantly improving productivity and reducing manufacturing costs.

[0150] As shown above, magnetron sputtering using a deposition tool with a turntable configuration is very suitable for depositing quantum nanolaminated material layers and coatings. Each layer of the nanolaminated material stack is deposited in sequence. When the substrate passes under the silicon source, amorphous silicon is deposited; when the substrate passes through the plasma source, the top of the a-Si layer is oxidized to produce SiO2. This sequence is continuously repeated with each rotation of the turntable. The setting of the turntable rotation speed allows the selection of the total thickness of a-Si and SiO2 for each rotation, while the power settings of the sputtering source and the plasma source allow the setting of the thickness ratio of a-Si and SiO2. We demonstrated monolayers with a thickness of a few tenths of a nanometer and a wide a-Si volume ratio f = V a-Si / V SiO2 (i.e., 0.1 - 0.75).

[0151] The monolayers show a large shift in the absorption edge. Data analysis shows that there are two mechanisms causing this shift. First, the change in composition results in a higher proportion of SiO2 in the thin film, and the absorption edge shifts towards shorter wavelengths. This is a well-known effect. However, the second effect is caused by quantization, and to the inventors' knowledge, this second effect is demonstrated in the Si / SiO2 layer for the first time. When the thickness of the a-Si barrier layer decreases, the QNL with the same average composition shows a shift in the absorption edge. This is consistent with the theory, as described in Section 2 of the theory part.

[0152] Next, the QNL layer is used as the high refractive index material in an optical interference filter. It has been proven that the turntable configuration of the sputtering system can form a viable manufacturing process to make a long-pass filter block the visible part of the spectrum while transmitting NIR. From a technical perspective, the deposition of the filter is similar to the standard process, except that in the QNL layer, the two sources are powered simultaneously. In addition, optical monitoring can be used without any adjustment.

[0153] The long-pass filter coating highly matches the design and shows good transmittance in the wavelength range above 700 nm, thus confirming precise and reproducible deposition in the sub-nanometer range. For comparison, a standard SiO2 / TiO2 long-pass filter was also deposited. It is thus shown that, with the same number of layers, the blocking range of the standard SiO2 / TiO2 long-pass filter is significantly narrower than that of the QNL design. For a standard filter with the same characteristics as the QNL filter, the required number of layers is twice that of the QNL filter. This clearly shows that the QNL concept indeed opens up broad new application areas and can significantly improve productivity. List of reference numerals 1, 1’ Rotatable holders (turntable and cylinder) 2 - 9 Substrate supports 10 Substrate 11, 11’ (Another) magnet system 12 Receiver 13, 13’ Openings 14, 14’, 14” (Another) sputtering station 15, 15’, 15” (Another) target 16, 16’ (Another) sputtering source 17 Internal magnet region 18 External magnet region 19 Turntable drive 20 Plasma station 21 Plasma source 22 Plasma generation electrode 23 Enclosure 24 Vacuum pumping device 25 Substrate drive 26 Plasma power supply 27 Target supply unit 28, 28’ Gas supply from sputtering source 29 Gas supply from plasma source 30, 30’ Process system 31 Target baffle 32 AR - coating 33 QNL - film 34 Low refractive index material film 35 Optical device 36 Grating (ground electrode) 37 Dual magnetron 38 Rotating cathode A Axis Axis of rotation B Axis (optical rotation) C Line K L h and L l Nanolayers of high refractive index material and nanolayers of low refractive index material d h and d l L h and L l thicknesses of

Claims

1. A process for depositing a nanolaminate material on the surface of a flat substrate, the process comprising the following steps: - In a vacuum process system, a substrate is mounted on a substrate support in a peripheral region (R) of a retainer that is rotatable about its central axis B. The receiver includes at least one magnetron sputtering station and at least one plasma processing station. A sputtering target of the at least one magnetron sputtering station is mounted to a sputtering source and spaced apart from the magnetron sputtering station. The at least one plasma processing station has a plasma source. The sputtering target and the plasma source each point to different parts of the peripheral region (R). - Evacuate the receiver. - Rotate the retainer about the central axis at a constant speed. - Introduce a sputtering gas into the receiver, and - Introduce a reactive gas directly into at least one of the sputtering station or the plasma station. - Ignite the magnetron discharge and set the magnetron power level (P m ) in the sputtering station, and - Ignite the plasma in the plasma processing station and set the plasma power level (P p ) of the plasma source. - By rotating the retainer, expose the substrate successively to °Magnetron discharge to deposit a high refractive index material layer L h , and ° a processing plasma to produce a low refractive index material layer L1. wherein the rotational speed of the retainer and the magnetron power level (P m ) are set such that the potential well layer L of the high refractive index material h has a layer thickness d h of: 0.1 ≤ d h ≤ 5 nm.

2. The process according to claim 1, wherein the plasma power level (P p ) is set such that the barrier layer L of the low refractive index material l has a layer thickness d l of: 0.1 ≤ d h ≤ 30 nm.

3. The process according to any one of the preceding claims, wherein the target is one of Al, Si, Ti, Zr, Hf, Nb, Ta, Ge, the corresponding oxides, nitrides or mixtures thereof.

4. The process according to any one of the preceding claims, wherein the plasma station comprises a plasma source and the reaction gas is introduced directly into the plasma station.

5. The process according to claim 4, wherein the target is silicon, the sputtering gas is an inert gas and is introduced near the sputtering station or directly into the sputtering station.

6. The process according to any one of claims 4 and 5, wherein the power of the target is set, the power of the plasma source is set to a constant level, and a plasma emission monitor (PEM) is used to control the plasma gas parameters in the plasma station by the intensity of at least one determined line of the gas - plasma emission.

7. The process according to any one of claims 1 to 3, wherein the plasma processing station is another magnetron sputtering station comprising another target.

8. The process according to claim 7, wherein the other target is one of Si, SiO2, Si3N4, Al, Al2O3 or AlN.

9. The process according to any one of claims 7 or 8, wherein the sputtering gas is introduced into the sputtering station and / or the other sputtering station via a separate gas conduit.

10. The process according to one of the preceding claims, wherein the power of the target and / or the other target is set, and the reaction gas parameters in the sputtering station and / or the other sputtering station are controlled by the intensity of at least one determination line of the target plasma emission in the transition region or transition mode of the reactive sputtering process using a plasma emission monitor (PEM).

11. The process according to one of the preceding claims, wherein a process baffle is provided for the sputtering station and / or the other sputtering station, and the process baffle is closed during the ignition phase of the corresponding sputtering station and opened during the deposition phase of the corresponding layer.

12. The process according to one of the preceding claims, wherein the sputtering gas is at least one of argon, krypton, neon, xenon or any mixture thereof.

13. The process according to one of the preceding claims, wherein the reaction gas and / or another reaction gas is directly introduced into the sputtering station and directly introduced into the plasma station or the other sputtering station.

14. The process according to one of the preceding claims, wherein the reaction gas and / or the other reaction gas is oxygen and / or nitrogen.

15. The process according to one of the preceding claims, wherein n high refractive index material layers L h and n or n ± 1 low refractive index material layers L l are alternately deposited on at least one surface of the flat substrate as a stack, wherein the respective corresponding layers L h and L l in the stack have a quantity n of at least 1, and: 1 ≤ n ≤ 10000.

16. The process according to claim 15, wherein at least another layer or coating is deposited between the stack and the glass substrate and / or between the stack and the atmosphere.

17. The process according to claim 15 or 16, wherein the plasma processing station is another magnetron sputtering station, the reaction gas and the other reaction gas are oxygen and / or nitrogen, and the transmission edge T of the stack shifts towards shorter wavelengths as the potential well thickness decreases, such that: It is applicable to ΔT 50 = T 50_THICK – T 50_THINN where 2 ≤ ΔT 50 ≤ 60 nm, where T 50_THICK is the transmittance at 50% of the layer stack with a potential well thickness d h_THICK ≥ 5 nm, and T 50_THINN is the potential well thickness d h _THIN Transmittance at 50% of the layer stack ≤ 3 nm.

18. The process according to claim 17, wherein the energy gap E between the free radical state and the higher conduction band state gap As the potential well layer L h The amount of increase as the thickness decreases is: ΔE gap = E gap_THINN - E gap_THICK , where: 0.01 ≤ ΔE gap ≤ 0.8 eV, and E gap _ THINN is the energy gap of a layer stack in which a thin potential well layer d h_THIN ≤ 3 nm is deposited, E gap_THICK is the energy gap of a layer stack in which a thick potential well layer d h_THICK ≥ 5 nm is deposited.

19. The process according to claim 15 or 16, wherein the plasma processing station includes a plasma source, and the reaction gas is directly introduced into the plasma station, the target is silicon, the sputtering gas is an inert gas, and the transmission edge T of the stack shifts to a shorter wavelength as the potential well thickness decreases, such that: It is applicable to ΔT 50 = T 50_THICK – T 50_THINN , where 50 ≤ ΔT 50 ≤ 400 nm, where T 50_THICK is the transmittance at 50% of the layer stack with a potential well thickness d h_THICK ≥ 5 nm, and T 50_THINN is the transmittance at 50% of the layer stack with a potential well thickness d h _ THIN ≤ 3 nm.

20. The process according to claim 19, wherein the energy gap E between the free radical state and the higher conduction band state gap As the potential well layer L h The amount of increase as the thickness decreases is: ΔE gap = E gap_THINN - E gap_THICK , where: 0.01 ≤ ΔE gap ≤ 2 eV, and E gap_THINN is the energy gap of a layer stack in which a thin potential well layer d h_THIN ≤ 3 nm is deposited, E gap_THICK is the energy gap of a layer stack in which a thick potential well layer d h_THICK ≥ 5 nm is deposited.

21. The process according to any one of the preceding claims, wherein the retainer is a turntable retainer, the peripheral region (R) is defined by an outer ring, wherein the substrate retainer is arranged along the ring on at least one main surface of the disc-shaped retainer, and the flat substrate is mounted on or in a substrate support in a plane parallel to the turntable plane.

22. The process according to any one of claims 1 to 18, wherein the holder is a cylindrical or cylindrical polyhedral holder, the peripheral region (R) is defined by the cylindrical or polyhedral surface of the holder, and the substrate support is arranged such that its center is along at least one height diameter of the cylindrical or polyhedral holder, and wherein, in a plane substantially parallel to the cylindrical or polyhedral surface, the flat substrate is mounted among or on the cylindrical or polyhedral surfaces.

23. The process according to any one of the preceding claims, wherein the substrate is a wafer.

24. The process according to any one of the preceding claims, wherein the substrate is a wafer, and the peripheral region (R) has a radial distance from the central axis B of 535 ± 60 mm, and the constant speed is set to 30 - 0.5 seconds per revolution.

25. An optical device comprising a substrate and an optical coating deposited on at least one side of the substrate, the optical coating consisting of at least one high refractive index material film and at least one low refractive index material film, wherein at least one of the films is designed as a quantum well nanolaminate (QNL) film having a defined high or low total QNL refractive index (n QNL ), wherein the QNL film comprises at least one high refractive index material well layer L h alternating with at least one low refractive index material barrier layer L1, wherein the layer thickness d h of the well layer L h is such that: 0.1 ≤ d h ≤ 6 nm.

26. The device according to claim 25, wherein the layer thickness d l of the low refractive index material barrier layer L1 is such that: 0.1 ≤ d l ≤ 30 nm.

27. The device according to claim 25 or 26, wherein the QNL film defines the high refractive index film of the optical coating.

28. The device according to any one of claims 25 to 27, wherein the low refractive index material of the low refractive index film is the same material as the low refractive index material of the barrier layer L l in the QNL film.

29. The device according to any one of claims 25 to 28, wherein the number n of each respective layer L h and L l in the QNL film is at least 1, and: 1 ≤ n ≤ 10000.

30. The device according to any one of claims 25 to 29, wherein the QNL is produced at least according to any one of claims 1 to 22.

31. The device according to one of claims 25 to 29, wherein the optical coating is an interference coating, and the device is a mirror, a semi-selective mirror, a filter, or a lens with a corresponding coating.

32. The device according to claim 31, wherein the device is an edge filter, a beam splitter, a notch filter, or a polarizer.

33. A vacuum process system for depositing a quantum nanostructured laminate (QNL) consisting of at least one potential well layer L of a high refractive index material and at least one potential barrier layer L of a low refractive index material on the surface of a flat substrate, the receiver comprising: h and at least one potential barrier layer L of a low refractive index material l composed of a quantum nanostructured laminate (QNL), the receiver comprising: - A retainer that is rotatable about its central axis B and has a substrate support in a peripheral region (R) of the retainer. - At least one magnetron sputtering station, with a sputtering target mounted to a sputtering source and spaced apart from the magnetron sputtering station. - At least one plasma processing station having a plasma source. - The sputtering target and the plasma source each point to different parts of the peripheral region (R). - A sputtering gas inlet for introducing a sputtering gas into the receiver, and - A reactive gas inlet and / or another reactive gas inlet for introducing a reactive gas into the receiver. The rotational speed of the retainer can be set to 30 to 0.5 seconds per revolution, and the magnetron power level (P m ) can be set to 0.5 - 10 kW, such that the layer thickness d h of the high refractive index material potential well layer L h can be set to: 0.1 ≤ d h ≤ 6 nm.

34. The process system according to claim 33, wherein the rotational speed of the holder and the magnetron power level (P m ) can be set such that the layer thickness d of the potential barrier layer L1 of the low refractive index material l is: 0.1 ≤ d l ≤ 30 nm.

35. The process system according to claim 33 or 34, wherein the plasma station includes an inductively or capacitively coupled plasma source and a reaction gas inlet directly leading into the plasma station.

36. The process system according to one of claims 33 to 35, wherein the plasma station is a capacitively coupled HF plasma source.

37. The process system according to one of claims 33 to 36, wherein the target is a silicon target, and the sputtering gas inlet is connected to an inert gas supply unit.

38. The process system according to one of claims 33 to 37, wherein a plasma emission monitor (PEM) is connected to the plasma region of the plasma source via an optical path of light.

39. The process system according to claim 33 or 38, wherein the plasma processing station is another magnetron sputtering station including another target.

40. The process system according to claim 39, wherein the other target is one of Si, SiO2, Si3N4, Al, Al2O3, AlN, or a mixture thereof.

41. The process system according to one of claims 39 to 40, wherein the target is one of Al, Si, Ti, Zr, Hf, Nb, Ta, Ge, the corresponding oxides, nitrides, or a mixture thereof.

42. The process system according to one of claims 39 to 41, wherein both sputtering stations are provided with separate reaction gas inlets.

43. The process system according to one of claims 33 to 42, wherein the retainer is a turntable retainer having a turntable retainer plane (P), the peripheral region (R) being defined by an outer ring, wherein the substrate retainer is arranged along the ring on at least one main surface of the turntable retainer, and wherein the flat substrate is mounted on or in a substrate support in a plane parallel to the turntable plane.

44. The process system according to claim 43, wherein the magnetron sputtering station comprises a circular target and a static magnet arrangement, the magnet arrangement - being arranged in a plane (M) parallel to the plane (P); and - being non-rotationally symmetric about a target axis (C) which passes through the center of the magnet arrangement and is perpendicular to the plane (M).

45. The process system according to claim 44, wherein the region defined by the magnet system can be divided along a line (K) in the plane (M) which intersects the target axis (C) perpendicularly into: an outer region (16) remote from the center of the turntable, and an inner region (17) facing the center of the turntable, wherein it is effective that the outer region (16) is larger than the inner region (17).

46. The process system according to claim 45, wherein the magnet arrangement (11) is symmetric or asymmetric in the plane (M) about a symmetry axis (A), the axis (A) intersecting the central axis (Z) of the turntable.

47. The process system according to one of claims 44 to 46, wherein the target is a rotating target which is rotatably arranged about its target center axis (C).

48. The process system according to one of claims 33 to 42, wherein the retainer is a cylindrical or cylindrical polyhedral retainer, the peripheral region (R) being defined by the cylindrical or polyhedral surface of the retainer, and the substrate support is arranged such that its center is along at least one height diameter of the cylindrical or polyhedral retainer, and wherein, in a plane substantially parallel to the cylindrical or polyhedral surface, the flat substrate is mounted in or on the cylindrical or polyhedral surface in a manner matching the height with the height diameter.

49. A process system according to one of claims 33 to 48, comprising at least two magnetron sputtering stations and at least one non-magnetron plasma station, wherein each station includes a plasma emission monitor for controlling the reaction process in the corresponding station.

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