Method and device for determining at least one property of at least one layer using terahertz radiation

Abstract

A method for determining at least one property of at least one first layer that can be applied to a substrate using terahertz, THz, radiation, the method including determining at least one property of the substrate, applying a first layer to the substrate, and determining at least one property of the first layer.

Description

[Technical Field]

[0001] This disclosure relates to a method for determining at least one property of at least one layer using terahertz radiation.

[0002] This disclosure further relates to a device for determining at least one property of at least one layer using terahertz radiation. [Overview of the project] [Means for solving the problem]

[0003] An exemplary embodiment relates to a method for determining at least one property of at least one first layer that can be applied to a substrate using terahertz, THz, or radiation, the method comprising determining at least one property of the substrate, applying the first layer to the substrate, determining at least one property of the first layer, and determining at least one property of the layer applied to the substrate.

[0004] In further exemplary embodiments, the substrate has a metallic substrate or a non-metallic substrate having a metallic (e.g., metallized) surface. In further exemplary embodiments, the substrate has a non-metallic substrate, for example, the substrate has a plastic material.

[0005] In further exemplary embodiments, the method further includes applying at least one further layer, for example, an nth layer, to, for example, the first layer or a layer previously applied to the substrate, where n is a positive integer of 2 or more, and optionally determining at least one property of the at least one further layer.

[0006] In further exemplary embodiments, applying the first layer and / or at least one further layer can include, for example, applying a liquid and / or gaseous medium to at least one (e.g., uncoated or already coated) surface of a substrate that forms the layer to be targeted after application.

[0007] In further exemplary embodiments, some layers can be applied to a substrate or on top of each other by application, thereby, for example, resulting in a layer structure having a substrate and some layers.

[0008] In further exemplary embodiments, application includes coating a substrate by painting.

[0009] In further exemplary embodiments, the method includes repeating a) applying at least one further layer and optionally b) determining at least one property of at least one further layer. Thus, one or several properties of each layer can be determined continuously in an exemplary manner, and in further exemplary embodiments, interactions can also be considered, for example, also in the region of the interface between adjacent layers to each other.

[0010] In further exemplary embodiments, the repetition of applying at least one further layer is performed, for example, until a predefined end condition is met. For example, the presence of a number of layers that can be determined in advance on the substrate can characterize the end condition.

[0011] In further exemplary embodiments, for example, the number of layers equal to n can be applied. For example, at least one characteristic of the target layer is not determined for each of the number of layers equal to n, but instead, for example, is determined only for the number of layers equal to k < n. In other words, in further exemplary embodiments, at least one layer or some layers can also be applied even without at least one characteristic of the applied layers to be determined after those layers are applied. For example, at least one characteristic of at least one applied layer (or some layers) can be known a priori. For example, in further exemplary embodiments, it can be provided that the (i + 1)-th layer is applied after the i-th layer, and then, for example, at least one characteristic of two previously applied layers i and i + 1 can be determined.

[0012] In further exemplary embodiments, the THz radiation has at least one spectral component in the range of 0.1 THz to 30 THz, for example 0.3 THz to 10 THz.

[0013] In further exemplary embodiments, at least one characteristic of the substrate and / or the first layer and / or at least one further layer has at least one of the following elements, namely, a) optical properties, b) thickness, c) magnetic permeability, d) electrical conductivity, e) roughness.

[0014] In further exemplary embodiments, for example, the optical properties are dispersive with respect to the THz radiation. In further exemplary embodiments, the dispersion can be characterized by the refractive index n and the attenuation coefficient e. For example, in further exemplary embodiments, the refractive index n and / or the attenuation coefficient e can be determined by the frequency of the THz radiation, and as a result, the dispersion can be characterized by, for example, the values of the refractive index or the attenuation coefficient at different respective frequencies.

[0015] In further exemplary embodiments, the optical properties are, for example, a specific frequency and / or the structure of the layer or substrate and / or around the particles, for example, the refractive index or layer thickness and / or porosity and / or transmission and / or reflection, for example, the gradation.

[0016] In further exemplary embodiments, determining the properties of a substrate further includes determining at least one surface property of the surface of the substrate, for example, the at least one surface property having at least one of the following elements: a) roughness, b) shape, e.g., curvature, c) spatial location (e.g., can be characterized by the direction of the surface normal vector with respect to the optical axis of a THz device providing THz radiation), d) structure, e.g., arrangement of foreign matter on the substrate (e.g., metal deposits on a plastic substrate) and / or surface molding, e.g., structuring or microstructuring.

[0017] In further exemplary embodiments, at least one surface property is determined using, for example, at least one of the following elements: a) confocal microscopy, b) interference spectroscopy, c) optical coherence tomography, and d) three-dimensional imaging.

[0018] In further exemplary embodiments, the method further includes using at least one measurement method based on the reflection of THz radiation and / or at least one measurement method based on the transmission of THz radiation, e.g., THz spectroscopy and / or THz ellipsometry, and / or at least one further measurement method not based on THz radiation, e.g., tactile measurement, the method is performed for at least one of the following elements: a) determining at least one property of a substrate, b) determining at least one property of a first layer, c) determining at least one property of at least one further layer, and d) determining at least one surface property of the surface of the substrate.

[0019] In further exemplary embodiments, the method further includes changing the orientation of the substrate or the orientation of an object having the substrate. For example, in further exemplary embodiments, several THz-based and / or non-THz-based measurement methods can be used for some measurements of an object, and some measurements differ, for example, with respect to the orientation of the object or substrate, or, for example, with respect to the optical axis of a THz device. Thus, information useful or usable to determine at least one property can be determined for an anisotropic object, substrate, or layer.

[0020] In further exemplary embodiments, the method further includes, for example, changing the angle of incidence of THz radiation with respect to the normal vector of the surface of the substrate or a layer disposed on the substrate.

[0021] In further exemplary embodiments, the method further includes at least one of the following elements: a) changing the polarization (POL-TS) of the THz radiation; b) changing the direction of the path of the THz radiation; and c) reflecting the THz radiation at least periodically using at least one mirror that can be introduced into the beampath of the THz radiation for at least some THz-based measurements.

[0022] In further exemplary embodiments, the method further comprises performing at least one measurement method, or at least one measurement method on several measurement points, for example, a number of measurement points equal to M (M>1), where the several measurement points are, for example, assigned to different locations on the surface of the substrate or to corresponding layers.

[0023] In further exemplary embodiments, several measurement points may be used for a substrate ("substrate measurement") and at least one layer ("layer measurement"), or for several layers, and the same measurement point may preferably be used for the substrate and / or each layer(s), thereby improving accuracy. In further exemplary embodiments, each of the same measurement points may be used, for example, for all measurements.

[0024] In further exemplary embodiments, the method further includes combining the measurement results from several measurement points of a measurement method, for example, a number of measurement points equal to M. In further exemplary embodiments, for example, the measurement results from several measurement points of at least one measurement method (e.g., a measurement method for a substrate and / or at least one layer) can be used as input data for a model to determine at least one property.

[0025] In further exemplary embodiments, the method further includes determining at least one reference layer thickness, for example, determining a number of reference layer thicknesses equal to M for a first layer at a number of measurement points equal to M.

[0026] In further exemplary embodiments, for example, the same measurement points, or at least a portion of the same measurement points, are used to determine a number of reference layer thicknesses equal to M of the first layer, which are also used for measuring the substrate and / or at least one layer.

[0027] In further exemplary embodiments, the method further includes determining at least one reference layer thickness, for example, determining the reference layer thickness of at least one additional layer at a number of measurement points equal to M, for example, the nth layer, for a number of reference layer thicknesses equal to M.

[0028] In further exemplary embodiments, for example, the same measurement points, or at least a portion of the same measurement points, are used to determine a number of reference layer thicknesses equal to M of at least one further layer, which are also used for substrate measurement and / or measurement of at least one layer.

[0029] In further exemplary embodiments, the determination of the reference layer thickness of the first layer and / or at least one further layer is performed based on, for example, a tactile measurement method, based on one measurement method or one further measurement method that is not based on THz radiation.

[0030] In further exemplary embodiments, the determination of at least one reference layer thickness of the first layer is performed after the application of the first layer. In further exemplary embodiments, the determination of at least one reference layer thickness of at least one further layer is performed after the application of at least one further layer, for example, after all provided layers have been applied.

[0031] In further exemplary embodiments, a) performing at least one measurement method on a number of measurement points equal to, for example, M (M>1), and / or b) determining at least one reference layer thickness, for example, a number of reference layer thicknesses equal to M of a first layer, and / or c) determining at least one reference layer thickness, for example, a number of reference layer thicknesses equal to M of at least one further layer, each of these is performed on the same number of measurement points equal to, for example, M.

[0032] In further exemplary embodiments, the method further includes specifying and / or considering deviations of at least one reference layer thickness. Thus, possible deviations of at least one reference layer thickness from the actual layer thickness of the layer in question (e.g., due to the finite measurement precision of the measurement method used) can be considered, for example, to determine at least one property of the first layer.

[0033] In further exemplary embodiments, defining and / or considering a deviation of at least one reference layer thickness includes providing a layer thickness region that can be characterized by, for example, two layer thickness values, for example, the layer thickness region can be selected to exist at intervals where a reference layer thickness determined, for example, by a measurement technique, can be characterized in the layer thickness region.

[0034] In further exemplary embodiments, specifying and / or considering deviations of at least one reference layer thickness can be done, for example, for several measurement points, each.

[0035] For example, if the value RD11 is obtained as a reference layer thickness for a first layer at a first measurement point, the layer thickness region described above in an exemplary manner can be characterized by, for example, two layer thickness values ​​RD11-ΔRD1, RD11+ΔRD1, where, for example, the parameter ΔRD1 can be selected based on, for example, a known measurement accuracy for measuring the reference layer thickness RD11. In a further exemplary embodiment, the same procedure can be initiated in a manner comparable to further measurement points and their respective assigned reference layer thicknesses RD12, RD13, ... by defining, for example, corresponding layer thickness regions RD12-ΔRD1, RD12+ΔRD1, RD13-ΔRD1, RD13+ΔRD1, ...

[0036] In further exemplary embodiments, the method further includes, optionally, determining at least one optical property of the first layer based on a) at least one measurement result of at least one measurement method based on THz radiation applied to the first layer applied to the substrate, and b) also based on at least one layer thickness or at least one reference layer thickness. In further exemplary embodiments, at least one optical property of the first layer is determined using both at least one measurement result of at least one measurement method based on terahertz radiation applied to the first layer applied to the substrate, and at least one reference layer thickness.

[0037] In further exemplary embodiments, the method further includes, optionally, determining at least one optical property of the at least one further layer based on a) at least one measurement result of at least one measurement method based on THz radiation for the at least one further layer, and b) also based on at least one layer thickness or at least one reference layer thickness of the at least one further layer. In further exemplary embodiments, at least one optical property of the at least one further layer is determined using both at least one measurement result of at least one measurement method based on terahertz radiation and at least one reference layer thickness of the at least one further layer.

[0038] In further exemplary embodiments, determining at least one optical property of at least one further layer is, in addition, performed based on at least one reference layer thickness and / or at least one optical property of at least one layer applied to the substrate prior to at least one further layer, and / or based on at least one property of the substrate. Thus, in further exemplary embodiments, at least one optical property of at least one further layer can also be advantageously determined using information about at least one layer currently applied to the substrate.

[0039] In further exemplary embodiments, the method may include, for example, determining some variation of the optical properties of a first layer and / or at least one further layer, or at least one of the at least one further layer, and optionally determining a specific variation of some variation, for example, by variational calculation.

[0040] In further exemplary embodiments, some variations are determined or generated, for example, by using different values ​​of the reference layer thickness(s), meaning the layer thickness regions RD12-ΔRD1, RD12+ΔRD1, RD13-ΔRD1, RD13+ΔRD1, ... as described above in an exemplary manner.

[0041] In further exemplary embodiments, variations of several properties, e.g., optical properties, e.g., dispersion, can be determined for one, some, or all layers of an object. In further exemplary embodiments, for example, variational calculations can determine or select specific variations of (e.g., optical) properties for all layers based on these variations. In further exemplary embodiments, for example, selection can be performed according to at least one of the following criteria: precision (e.g., precision that can be characterized by agreement with measurement data from further / other methods, e.g., tactile reference measurements and / or micrographs, or measurement data from other THz-based methods), stability, and fit (e.g., agreement with values ​​that can be modeled based on the selected specific variations using measurements determined by, for example, THz-based methods).

[0042] In further exemplary embodiments, determining at least one optical property, such as dispersion, brings to light the following: modeling an object having a substrate and at least a first layer using a first model; optionally adjusting the first model to a determined reference layer thickness and / or at least one measurement result of at least one measurement method based on THz radiation applied to the first layer on the substrate, thereby obtaining an adjusted first model; and determining at least one optical property based on the first model and / or the adjusted first model.

[0043] In further exemplary embodiments, for example, the modeling of an object using the first model may involve the use of a predeterminable variance function of the type, such as Drude-Lorentz, Cauchy, Sellmeier, or Tauc-Lorentz. In further exemplary embodiments, a goodness-of-fit of variance, such as point-by-point goodness-of-fit, can be performed.

[0044] In further exemplary embodiments, a number of starting parameters can be predetermined, for example, for the dispersion function, based on prior knowledge of the object and / or based on at least one measurement result from the aforementioned measurements, such as the reference layer thickness, for example, THz-based and / or non-THz-based measurements.

[0045] In further exemplary embodiments, the appropriate distribution can be selected manually, for example, at least periodically. In further exemplary embodiments, the distribution can be selected automatically, for example, by inspection, for example, from a database, at least periodically (without human interaction).

[0046] In further exemplary embodiments, known variances, for example, for layers of objects not to be calibrated, can optionally be used for the first model. In further exemplary embodiments, several possible variances may also exist for each layer, and such variances may be determined based on the aforementioned measurements.

[0047] In further exemplary embodiments, arbitrarily adjusting the first model may include, for example, at least one of the following elements: a) adjusting or fitting at least one measurement point, for example several measurement points, for example all of several measurement points, for example simultaneously, for example by dispersion; b) adjusting or fitting at least one measurement point, for example several measurement points, for example all of several measurement points individually.

[0048] In further exemplary embodiments, the modifications described in the exemplary form of the present invention result in, for example, a) for the number of layers applied to a substrate equal to N, and for the number of measurement points equal to M (for example, per layer), a dispersion occurs for each of the K possible combinations of dispersions of known layers (for example, layers determined in advance according to the exemplary embodiments).

[0049] In further exemplary embodiments, the modifications described above in exemplary form result in b) for each of the number of possible combinations equal to K of the variances of known layers (e.g., layers determined in advance according to the exemplary embodiments), there are a number of variances equal to M.

[0050] In further exemplary embodiments, the method further includes, for example, selecting the best variance for each layer, and consequently, selecting the variance of, for example, a pre-determined one that best fits the data determined by the measurement technique. In further exemplary embodiments, the selection can be made for, for example, at least one layer, for, for, some layers, or for, for, all layers. For example, in some exemplary embodiments, a number of variances equal to (M+1)*K occur, for example, for each layer, where K characterizes the number of possible combinations and "*" represents a scalar multiplication operator.

[0051] In further exemplary embodiments, the selection of variances includes reducing a number of variances equal to (M+1)*K by using variational calculus and by selecting according to one of the following criteria, namely precision, stability, and goodness of fit.

[0052] In further exemplary embodiments, the method brings to light performing at least one measurement on an object having a substrate and a first layer using a measurement method based on the reflection of THz radiation and / or at least one measurement method based on the transmission of THz radiation and / or at least one further measurement method, for example, not based on THz radiation, at a number of points on the object equal to M (M>1), and determining at least one optical property of the first layer based on at least one measurement.

[0053] In further exemplary embodiments, the method further comprises at least one of the following elements: a) applying at least one additional layer to, for example, the first layer (or a pre-applied layer); b) performing at least one additional measurement on the substrate and the first layer and the object having the at least one additional layer, for example, not based on THz radiation, using at least one additional measurement method, for example, not based on THz radiation, at a number of points on the object equal to M (M>1) (e.g., the same points or measurement points used for at least one measurement method on the substrate and / or at least one other layer of the object); and c) determining at least one optical property of the at least one additional layer based on the at least one additional measurement.

[0054] Further exemplary embodiments relate to devices for performing methods according to multiple embodiments.

[0055] In further exemplary embodiments, the device is provided to have at least one THz device for emitting and / or receiving THz radiation. In further exemplary embodiments, the at least one THz device can be designed, for example, to perform at least periodically a) a THz-based measurement on an object in at least one transmission device, in which the THz radiation passes at least periodically over at least a portion of the object, and / or b) a THz-based measurement on an object in at least one reflection device, in which the THz radiation is reflected at least periodically over at least a portion of the object.

[0056] In further exemplary embodiments, the device further comprises at least one reflector for THz radiation, for example, the device being designed to position the reflector at least at a constant distance from a) at least partially in the beam path of THz radiation, and / or b) in a region of an object having a substrate or at least one surface of the substrate having space from at least one surface that can be determined in advance. Thus, in further exemplary embodiments, different measurement configurations for THz-based measurements on an object can be provided, the measurement configurations can determine information for determining at least one property of at least one first layer applied to the substrate, in further exemplary embodiments.

[0057] Further exemplary embodiments relate to a computer-readable storage medium that, when executed by a computer, includes a command that causes the computer to perform a method according to one of the embodiments.

[0058] Further exemplary embodiments relate to a computer program that, when executed by a computer, includes commands that require the computer to perform a method according to one of the embodiments.

[0059] Further exemplary embodiments relate to data transmission signals that transmit and / or characterize computer programs according to multiple embodiments.

[0060] Further exemplary embodiments relate to methods according to multiple embodiments, and / or devices according to multiple embodiments, and / or computer-readable storage media according to multiple embodiments, and / or computer programs according to multiple embodiments, and / or methods of using data transmission signals according to multiple embodiments, the methods of use relating to at least one of the following elements: a) determining at least one characteristic of a first layer; b) determining at least one characteristic of at least one further layer; c) calibrating a model and / or device for THz measurement, e.g., a model and / or device for THz measurement of a measured object having several layers applied to a substrate, in order to determine the layer thickness of several layers applied to a substrate, e.g.; d) expanding or revising calibration data for THz measurement.

[0061] Further features, applicability, and advantages of the present invention arise from the following description of exemplary embodiments of the invention shown in the drawings. All features described or shown, independently of the methods summarized in the claims or their backreferences, and independently of their formulas or depictions in the description or drawings, form the subject matter of the present invention, either alone or in any combination. [Brief explanation of the drawing]

[0062] [Figure 1] A schematic flowchart illustrating an exemplary embodiment is shown below. [Figure 2] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 3A] A schematic side view of the substrate according to a further exemplary embodiment is shown. [Figure 3B] A schematic aerial view of the substrate is shown according to a further exemplary embodiment. [Figure 4] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 5] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 6]A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 7] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 8] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 9] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 10] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 11] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 12] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 13A] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 13B] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 14] A schematic block diagram illustrating a further exemplary embodiment is shown below. [Figure 15] A schematic block diagram illustrating a further exemplary embodiment is shown below. [Figure 16] A schematic block diagram illustrating a further exemplary embodiment is shown below. [Figure 17A] A schematic representation of a substrate is shown according to a further exemplary embodiment. [Figure 17B] A schematic representation of a substrate is shown according to a further exemplary embodiment. [Figure 17C] A schematic representation of a substrate is shown according to a further exemplary embodiment. [Figure 17D] A schematic representation of a substrate is shown according to a further exemplary embodiment. [Figure 18] A schematic block diagram illustrating a further exemplary embodiment is shown below. [Figure 19] A schematic flowchart illustrating a further exemplary embodiment is shown below. [Figure 20] Further exemplary embodiments are schematically shown below. [Figure 21] Further exemplary embodiments are schematically shown below. [Figure 22] Further exemplary embodiments are schematically shown below. [Figure 23] Further exemplary embodiments are schematically shown below. [Figure 24] Further exemplary embodiments are schematically shown below. [Figure 25] Further exemplary embodiments are schematically shown below. [Figure 26] Further exemplary embodiments are schematically shown below. [Figure 27] Further exemplary embodiments are schematically shown below. [Figure 28] Further exemplary embodiments are schematically shown below. [Figure 29] Further exemplary embodiments are schematically shown below. [Figure 30] Further exemplary embodiments are schematically shown below. [Figure 31] Further exemplary embodiments are schematically shown below. [Figure 32] Further exemplary embodiments are schematically shown below. [Figure 33] Further exemplary embodiments are schematically shown below. [Figure 34] The following schematic diagram illustrates the modes of use by further exemplary embodiments. [Figure 35] A simplified block diagram illustrating a further exemplary embodiment is schematically shown. [Modes for carrying out the invention]

[0063] Referring to Figures 1 and 3, an exemplary embodiment relates to a method for determining at least one property of at least one first layer 12-1 that can be applied to a substrate 10 using terahertz, THz, or radiation, the method comprising determining at least one property E-10 of the substrate 10 (Figure 1), applying the first layer 12-1 to the substrate 10 (102), and determining at least one property E-12-1 of the first layer 12-1, and by extension, the property of the layer applied to the substrate 10 (104).

[0064] In further exemplary embodiments, the substrate 10 has a metallic substrate or a non-metallic substrate having a metallic (e.g., metallized) surface 10-a. In further exemplary embodiments, the substrate 10 has a non-metallic substrate, for example, the substrate has a plastic material.

[0065] In a further exemplary embodiment, as shown in Figure 2, the method further comprises applying at least one further layer, for example, an nth layer 12-n, to, for example, the first layer 12-1, or to a layer previously applied to the substrate 10, for example, n being a positive integer of 2 or more, applying 106-n, and optionally determining at least one characteristic E-12-n of the at least one further layer 12-n.

[0066] In further exemplary embodiments, applying the first layer 12-1 and / or at least one further layer 12-n may include, for example, applying a liquid and / or gaseous medium to at least one (e.g., uncoated or already coated) surface 10a of the substrate 10 that will form the layer in question after application.

[0067] In further exemplary embodiments, several layers can be applied to the substrate 10 or on top of each other, for example by applications 102, 106-n, thereby resulting in a layered structure OBJ having, for example, the substrate 10 and several layers 12-1, 12-2, 12-n.

[0068] In further embodiments, the substrate 10 may be, for example, a metallic substrate, in which embodiment a plurality of coating layers 12-1, 12-2, 12-n are applied. For example, the first coating layer 12-1 is applied to the surface of the substrate 10, and the second coating layer 12-2 is applied to the surface 12-1-a of the first coating layer 12-1, and so on. Optionally, in further exemplary embodiments, at least one further coating layer (not shown) can be applied to the surface 12-2-a of the second coating layer 12-2.

[0069] In a further exemplary embodiment, as shown in Figure 2, the method includes repeating a) applying 106-n at least one further layer 12-n, and optionally b) determining 108-n at least one characteristic E-12-n of at least one further layer. Thus, one or more characteristics of each layer 12-1, 12-2, 12-n can be determined sequentially in an exemplary manner, and in a further exemplary embodiment, interactions can also be considered, for example, in the region of the interface between adjacent layers 12-1, 12-2.

[0070] In further exemplary embodiments, the application of at least one additional layer is repeated 109 until, for example, a predetermined termination condition is satisfied. For example, the existence of a predetermined number of layers on the substrate 10 can characterize the termination condition.

[0071] In further exemplary embodiments, the THz radiation TS has at least one spectral component, for example, several spectral components, in the range of 0.1 THz to 30 THz, for example, 0.3 THz to 10 THz.

[0072] In further exemplary embodiments, at least one property E-10 of the substrate 10 and / or the first layer 12-1 and / or at least one further layer 12-n has at least one of the following elements: a) optical properties, b) thickness D-10 (Figure 3A), c) magnetic permeability, d) electrical conductivity, and e) roughness.

[0073] In further exemplary embodiments, for example, the optical properties are dispersed with respect to THz radiation TS. In further exemplary embodiments, the dispersion can be characterized by the refractive index n and the attenuation coefficient e.

[0074] In further exemplary embodiments, determining characteristic E-10 of the substrate 10 further includes determining at least one surface characteristic OE of the surface 10a of the substrate 10, for example, the at least one surface characteristic OE having at least one of the following elements: a) roughness, b) shape, e.g., curvature, c) spatial position (e.g., can be characterized by the direction of the normal vector of the surface 10a with respect to the optical axis of a THz device providing THz radiation TS) (see, for example, block 210 in Figure 14), d) structure, e.g., arrangement of foreign matter on the substrate 10 (e.g., metal deposits on a plastic substrate) and / or molding of the surface 10a, e.g., structuring or microstructuring.

[0075] In further exemplary embodiments, at least one surface characteristic OE is determined using, for example, at least one of the following elements: a) confocal microscopy, b) interference spectroscopy, c) optical coherence tomography, and d) three-dimensional imaging.

[0076] In a further exemplary embodiment, as shown in Figure 4, the method further includes using at least one measurement method 110a based on the reflection of THz radiation TS-1 (Figure 3A), and / or at least one measurement method 110b based on the transmission of THz radiation TS-2 (Figure 3A), and / or at least one further measurement method not based on THz radiation TS, e.g., a tactile measurement method 110c, and the method is performed for at least one of the following elements: a) determining at least one characteristic E-10 of the substrate 100, b) determining at least one characteristic E-12-1 of the first layer 104, c) determining at least one characteristic E-12-n of at least one further layer 12-n 108-n, and d) determining at least one surface characteristic OE of the surface 10a of the substrate 10.

[0077] In further exemplary embodiments, one or more measurement methods based on terahertz radiation, such as a) THz spectroscopy and b) THz ellipsometry, can be used, for example, at least periodically.

[0078] In a further exemplary embodiment, as shown in Figure 5, the method further includes changing the orientation OR-10 of the substrate 10, or the orientation OR-10 of the object OBJ having the substrate 10. For example, in a further exemplary embodiment, several THz-based and / or non-THz-based measurement methods can be used for some measurements of the object OBJ, and some measurements differ, for example, with respect to the orientation of the object OBJ (Figure 3A) or the substrate 10, or with respect to the optical axis of the THz device 210 (Figure 14). Thus, information useful or usable to determine at least one property can be determined for an anisotropic object OBJ or the substrate 10 or layers 12-1, 12-2,...

[0079] In further exemplary embodiments, the method further includes, for example, changing the angle of incidence EW-TS of THz radiation with respect to the normal vector of the surface 10a of the substrate 10 or the layers 12-1, 12-2, ... disposed thereon.

[0080] In further exemplary embodiments, the method further includes at least one of the following elements: a) changing the polarization POL-TS of the THz radiation 124; b) changing the direction DR-TS of the path of the THz radiation 126; c) reflecting the THz radiation at least periodically using at least one mirror or reflector that can be introduced into the beam path of the THz radiation for at least some THz-based measurements 128.

[0081] In a further exemplary embodiment, as shown in Figure 6, the method further includes performing at least one measurement method, or at least one measurement method on several measurement points, for example, a number of measurement points MP equal to M (M>1), where several measurement points MP are assigned to different locations on the surface 10a of the substrate 10 (Figure 3A) or to corresponding layers.

[0082] Figure 3B shows an aerial view of an object OBJ having a substrate 10 in exemplary form, with measurement points MP1, MP2, ..., MP8 in exemplary form, where M=8. In other embodiments, arrangements of measurement points MP1, MP2, ..., MP8 that differ substantially from the arrangement of the present invention shown in exemplary form of Figure 3B of the matrix are also conceivable.

[0083] In further exemplary embodiments, several measurement points MP (e.g., eight measurement points MP1, MP2, ..., MP8 shown in the exemplary configuration of Figure 3B) are each used for the substrate 10 ("substrate measurement") and at least one layer 12-1 ("layer measurement"), or for several layers 12-1, 12-2, ..., and the same measurement point MP is preferably used for the substrate 10 and / or each of the layers 12-1, 12-2, ..., thereby improving accuracy. In further exemplary embodiments, each of the same measurement points can be used, for example, for all measurements.

[0084] In further exemplary embodiments, several measurements, such as different types of THz-based (optional, and non-THz-based) measurements, can also be performed on each measurement point.

[0085] In a further exemplary embodiment, the method further includes combining the measurement results of several measurement points MP of the measurement method, for example, a number of measurement points equal to M.132 In a further exemplary embodiment, for example, the measurement results of several measurement points MP of at least one measurement method (e.g., a measurement method for substrate 10 and / or at least one layer 12-1) can be used as input data for model MOD to determine at least one characteristic E-12-1.

[0086] Combination 132 can be understood as an evaluation of combinations, for example, which includes combining, for example, measurement results, for example, using model MOD, for example, simultaneously, for example the evaluation of a combination, for example, for example, for example, for example, for example, for example, for

[0087] In further exemplary embodiments, the method may include evaluation of the results, e.g., evaluation of the measurement results, based on, for example, a model MOD and / or comparison with further measurements, e.g., reference measurements.

[0088] In a further exemplary embodiment, as shown in Figure 7, the method further determines at least one reference layer thickness RD-1, RD-1-1, ..., for example, a number of reference layer thicknesses RD11, RD12, ..., RD11 at a number of measurement points MP equal to M (M>=1) for, for example, the first layer RD12-1. M This includes determining 140.

[0089] In further exemplary embodiments, for example, the same measurement points, or at least a portion of the same measurement points, are used for substrate measurement (specifically, for example, for THz base substrate measurement) and / or for measurement of at least one layer (specifically, for example, for THz base layer measurement in at least one further layer 12-2), with a number of reference layer thicknesses RD11, RD12, ..., RD1 equal to M of the first layer 12-1. M Determine 140.

[0090] In further exemplary embodiments, the method further determines at least one reference layer thickness RD-n, for example, at least one further layer at a number of measurement points equal to M, for example, the nth layer with reference layer thicknesses RDn1, RDn2, ..., RDn M This includes determining 142.

[0091] In further exemplary embodiments, for example, the same measurement points, or at least a portion of the same measurement points, are used to determine a number of reference layer thicknesses equal to M of at least one additional layer, so as to be used in substrate measurements (specifically, for example, THz base substrate measurements) and / or at least one layer measurements (specifically, for example, THz base layer measurements, or some other layer measurements or all layer measurements).

[0092] In further exemplary embodiments, the determination 140 of the thickness of at least one reference layer of the first layer and / or at least one further layer, and / or the determination 142 of the thickness of at least one further layer, is performed based on, for example, a measurement method not based on THz radiation or one further measurement method, for example, a tactile measurement method. For example, a measurement method not based on THz radiation may have at least one of the following elements: a) visual analysis of a micrograph, b) tactile measurement, c) optical measurement, for example, confocal microscopy and / or interference spectroscopy and / or optical coherence tomography and / or three-dimensional imaging.

[0093] In further exemplary embodiments, the determination 140 of at least one reference layer thickness of the first layer 12-1 (Figure 7) is performed after the application of the first layer 12-1 to the substrate 10. In further exemplary embodiments, the determination 142 of at least one reference layer thickness of at least one further layer 12-2 is performed after the application of at least one further layer 12-2 (e.g., to the first layer 12.1), for example, after all the provided layers have been applied.

[0094] In further exemplary embodiments, a) performing at least one measurement method 110a, 110b, 110c (Figure 4) on several measurement points, for example a number of measurement points equal to M (M>1), and / or b) determining at least one reference layer thickness, for example a number of reference layer thicknesses equal to M for a first layer, and / or c) determining at least one reference layer thickness, for example a number of reference layer thicknesses equal to M for at least one further layer, each of these is performed on, for example, the same number of measurement points equal to M, MP-1, MP-2, ..., MP-M (e.g., MP-8).

[0095] In further exemplary embodiments, the method further includes defining and / or considering deviations of at least one reference layer thickness 144. Thus, possible deviations of at least one reference layer thickness RD-1 from the actual layer thickness of the layer 12-1 in question (e.g., due to the finite measurement precision of the measurement method used) can be considered, for example, in order to determine at least one characteristic E-12-1 of the first layer 12-1 104 (Figure 1).

[0096] In further exemplary embodiments, defining a deviation of at least one reference layer thickness 144 and / or considering 145 includes providing a layer thickness region that can be characterized by, for example, two layer thickness values, for example, the layer thickness region can be selected to be located at intervals in which a reference layer thickness determined, for example, by a measurement technique, can be characterized in the layer thickness region.

[0097] In further exemplary embodiments, defining and / or considering deviations of at least one reference layer thickness can be done, for example, for several measurement points, e.g., all measurement points MP1, MP2, ..., MP8.

[0098] For example, if the value RD11 is obtained as a reference layer thickness for the first layer 12-1 (Figure 3A) at the first measurement point MP1 (Figure 3B), the layer thickness region described above in an exemplary manner can be characterized by, for example, two layer thickness values ​​RD11-ΔRD1, RD11+ΔRD1, where, for example, the parameter ΔRD1 can be selected based on, for example, a known measurement accuracy for measuring the reference layer thickness RD11. In a further exemplary embodiment, the same procedure can be initiated in a comparable manner for further measurement points MP2, MP3, ..., and their respective assigned reference layer thicknesses RD12, RD13, ..., by defining, for example, the corresponding layer thickness regions RD12-ΔRD1, RD12+ΔRD1, RD13-ΔRD1, RD13+ΔRD1, ...

[0099] In further exemplary embodiments, some of the variational values ​​that can be used for variational calculations can be determined or generated based on the corresponding layer thickness regions RD12-ΔRD1, RD12+ΔRD1, RD13-ΔRD1, RD13+ΔRD1,...

[0100] In further exemplary embodiments, for example, some variation of the optical properties of a layer, such as dispersion, can be determined or formed, for example, by variation of the thickness specification of the layer within the layer thickness region defined above in an exemplary manner.

[0101] In a further exemplary embodiment, as shown in Figure 8, the method further includes determining at least one optical property OE-12-1 of the first layer 12-1, e.g., dispersion, based on a) at least one measurement result ME-TS-12-1 of at least one measurement method based on THz radiation TS,TS-1,TS-2 applied to the first layer 12-1 applied to the substrate 10, and optionally, b) also based on at least one layer thickness or at least one reference layer thickness RD-1.150 In a further exemplary embodiment, the method determines at least one optical property OE-12-1 of the first layer 12-1 using both the at least one measurement result ME-TS-12-1 of at least one measurement method based on terahertz radiation applied to the first layer 12-1 applied to the substrate 10, and at least one reference layer thickness RD1.150

[0102] In further exemplary embodiments, for example, the measurement result ME-TS-12-1 has several values ​​corresponding to, for example, several measurement points MP1, ..., MP8. The same applies to a more favorable embodiment of the reference layer thickness RD-1. In other words, in further exemplary embodiments, determination 150 can be performed based on several measurement points MP1, MP2, ..., MP8 for the measurement result ME-TS-12-1, and also based on several reference layer thicknesses RD-11, RD-12, ..., RD18 for several measurement points MP1, MP2, ..., MP8.

[0103] In further exemplary embodiments, the method further includes, optionally, a) determining at least one optical property OE-12-2,OE-12-n of at least one further layer 12-2,12-n based on at least one measurement result ME-TS-12-2,ME-TS-12-n of at least one further layer 12-2,12-n (for example, even for several result MPs) based on at least one measurement method ME-TS-12-2,ME-TS-12-n (for example, even for several result MPs), and b) also based on at least one layer thickness of at least one further layer or at least one reference layer thickness RD-2,RD-n,...152. In a further exemplary embodiment, at least one optical property OE-12-2,OE-12-n of at least one additional layer 12-2,12-n is determined using both at least one measurement result ME-TS-12-2,ME-TS-12-n and at least one reference layer thickness RD-2,RD-n,... of at least one additional layer 12-2,12-n.

[0104] In further exemplary embodiments, determining at least one optical property of at least one further layer 12-2 is further performed based on at least one reference layer thickness and / or at least one optical property of at least one layer 12-1 applied to the substrate 10 prior to at least one further layer 12-2, and / or based on at least one property E-10 of the substrate 10. Thus, in further exemplary embodiments, at least one optical property of at least one further layer 12-2 can also be advantageously determined using information about at least one layer 12-1 currently applied to the substrate 10.

[0105] In a further exemplary embodiment, as shown in Figure 9, determining at least one optical property includes: modeling an object OBJ having a substrate 10 and at least one first layer 12-1 using a first model MOD-1 1500; optionally adjusting the first model MOD-1 to match a determined reference layer thickness RD-1, RD-2 and / or at least one measurement result ME-TS-12-1 of at least one measurement method based on THz radiation applied to the first layer 12-1 applied to the substrate 10 1502, thereby obtaining the adjusted first model MOD-1'; and determining at least one optical property OE-12-1, OE-12-2, OE-12-n based on the first model MOD-1 and / or the adjusted first model MOD-1' 1504.

[0106] In further exemplary embodiments, for example, the modeling of an object OBJ using the first model MOD-1 may include the use of a predeterminable variance function DF of the type, such as Drude-Lorentz, Cauchy, Sellmeier, or Tauc-Lorentz. In further exemplary embodiments, a goodness-of-fit of variance, such as point-by-point goodness-of-fit, can be performed.

[0107] In further exemplary embodiments, several starting parameters can be predetermined for, for example, the dispersion function DF, based on prior knowledge of the object OBJ and / or based on at least one measurement result ME-TS-12-1 from the aforementioned measurements, such as the reference layer thickness, for example, THz-based and / or non-THz-based measurements.

[0108] In further exemplary embodiments, the appropriate distribution can be selected manually, for example, at least periodically. In further exemplary embodiments, the distribution can be selected automatically, for example, by inspection, for example, from a database, at least periodically (without human interaction).

[0109] In further exemplary embodiments, known variances, for example, for layers of objects OBJ that are not intended to be calibrated, can optionally be used for the first model MOD-1. In further exemplary embodiments, also, for example, several possible variances may exist for each layer, and such variances are determined, for example, based on the aforementioned measurements.

[0110] In further exemplary embodiments, the optional adjustment of the first model MOD-1 1502 may include, for example, at least one of the following elements: a) adjusting or fitting at least one measurement point, for example several measurement points, for example all of several measurement points, for example simultaneously, for example by dispersion ("Aspect 1"), b) adjusting or fitting at least one measurement point, for example several measurement points, for example all of several measurement points, for example individually ("Aspect 2").

[0111] In further exemplary embodiments, the modifications described above in exemplary form result in, for example, a) for the number of layers applied to the substrate 10 (Figure 3A) equal to N, and for the number of measurement points equal to M (for example, per layer), a dispersion occurs for each of the number of possible combinations equal to K of the dispersions of known layers (for example, layers determined in advance according to multiple embodiments).

[0112] In further exemplary embodiments, the modifications described above in exemplary form result in b) for each number of possible combinations of known layers (e.g., layers determined in advance according to multiple embodiments), there is a number of variances equal to M.

[0113] In further exemplary embodiments, the method further includes selecting the best variance, for example, per layer, for example, for some layers, or for example, for all layers, and consequently, selecting a pre-determined variance that best fits the data determined by the measurement technique. For example, in some exemplary embodiments, a number of variances equal to (M+1)*K occur, for example, per layer, for example, for some layers, or for example, for all layers, where K characterizes the number of possible combinations and "*" represents a scalar multiplication operator.

[0114] In further exemplary embodiments, the selection of variances includes reducing a number of variances equal to (M+1)*K by using variational calculations and by selecting according to one of the following criteria, namely precision, stability, and goodness of fit. In further exemplary embodiments, for example, the first model MOD-1 can be adjusted based on the selected variances (e.g., per layer).

[0115] In a further exemplary embodiment, Figure 10 brings to light the method optionally comprises providing a sample 160, for example, the sample having an object OBJ, providing 160, and performing at least one measurement M-1 on the object OBJ having a substrate 10 and a first layer 12-1 using at least one measurement method based on the reflection of THz radiation TS and / or the transmission of THz radiation TS and / or at least one further measurement method not based on THz radiation TS, for example, at a number of points equal to M (M>1) of the object OBJ (see, for example, measurement points MP1, MP2,... from Figure 3B), and determining at least one optical property OE-12-1 of the first layer 12-1 based on at least one measurement M-1.

[0116] In further exemplary embodiments, the method further comprises at least one of the following elements: a) applying at least one additional layer 12-2,12-n to, for example, the first layer (or pre-applied layer) 12-1 166; b) performing at least one measurement M-2,Mn on the substrate 10 and the object OBJ having the first layer 12-1 and at least one additional layer 12-2,12-n using, for example, at least one additional measurement not based on THz radiation at, for example, at least one additional measurement at points on the object equal to M (M>1) (see, for example, measurement points MP1, MP2,... from Figure 3B 168); c) determining at least one optical property OE-12-2,OE-12-n of the at least one additional layer based on at least one additional measurement M-2 169.

[0117] In further exemplary embodiments, optional sample measures 160 (Figure 10) and 1600 (Figure 11) include at least one of the following elements: a) providing a sample having a single layer, and thus providing it in the form of a substrate 10 to which, for example, a first layer 12-1 is applied; and b) providing a sample having several coatings, and thus providing it in the form of a substrate 10 to which, for example, several layers 12-1, 12-2, ... are applied.

[0118] In a further exemplary embodiment, in Figure 12, performing at least one measurement 162 (Figure 10) includes, for example, at least one of the following elements: a) performing a THz-based measurement, i.e., using a THz radiation TS, for example, a THz radiation TS-1 at least partially reflected by an object OBJ and / or a THz radiation TS-2 at least partially transmitted by an object OBJ 1662; and / or b) performing a measurement method not based on THz radiation, e.g., a) visual analysis of a micrograph, b) tactile measurement, c) performing an optical measurement, e.g., confocal microscopy and / or interference spectroscopy and / or optical coherence tomography and / or three-dimensional imaging 1624.

[0119] In a further exemplary embodiment, as shown in Figure 13A, determining at least one optical property OE-12-1 (e.g., dispersion of THz radiation TS,TS-1,TS-2) of at least one layer 12-1 1640 includes modeling a sample or object OBJ using a model 1642, optionally adjusting the model 1644, and selecting the best dispersion 1646.

[0120] In further exemplary embodiments, modeling 1642 includes at least one of the following elements: a) using known variances of, for example, uncalibrated layers (and there may also be several variances for each layer); b) using a reference layer thickness from a reference measurement; c) optionally determining a layer thickness region; d) employing a variance function (e.g., of the Drude-Lorentz, Cauchy, Sellmeier, or Tauc-Lorentz type) that has a starting parameter or uses point-specific goodness-of-fit of variances; and e) optionally manually selecting an appropriate variance, for example, by inspection, or automatically selecting one from a database.

[0121] Figure 13B schematically shows a flow chart according to a further exemplary embodiment. The method includes, for example, determining several variational VAR-OEs of, for example, a first layer and / or at least one further layer, or at least one optical property E-12-1 of at least one further layer, based on measurement results for different measurement points and / or corresponding layer thickness regions RD12-ΔRD1, RD12+ΔRD1, RD13-ΔRD1, RD13+ΔRD1,... 1040 and optionally determining a specific variational VAR-OE' of several variational VAR-OEs by, for example, variational calculation, in the sense of algorithmic optimization for selecting the variation (for example, best according to criteria that can be determined in advance), 1042 which refers to the layer thickness regions described above in exemplary form. In further exemplary embodiments, some of the variational values ​​that can be used for variational calculations can be determined or generated based on, for example, the corresponding layer thickness regions RD12-ΔRD1, RD12+ΔRD1, RD13-ΔRD1, RD13+ΔRD1,... In further exemplary embodiments, the above-described variation results in a) with respect to "Aspect 1", for example, for the number of layers applied to the substrate 10 (Figure 3A) equal to N, and for a number of measurement points equal to M (for example, per layer), a variance occurs for each number of possible combinations of the variances of known layers (for example, layers determined in advance according to multiple embodiments). In further exemplary embodiments, the above-described variation results in b) with respect to "Aspect 2", a variance equal to M occurs for each number of possible combinations of known layers (for example, layers determined in advance according to multiple embodiments).

[0122] In further exemplary embodiments, variational values ​​(VAR-OE) of several properties (Figure 13B), e.g., variational values ​​of optical properties, e.g., variational values ​​of dispersion, can be determined for one, some, or all layers of an object (OBJ) (Figure 3A). In further exemplary embodiments, specific variational values ​​of (e.g., optical) properties can be determined or selected for each layer based on these variational values, e.g., by variational calculation. In further exemplary embodiments, selections can be made according to at least one of the following criteria: precision (e.g., precision that can be characterized by agreement with measurement data from further / other measurement methods, e.g., tactile reference measurements and / or micrographs, or measurement data from other THz-based methods), stability, and fit (e.g., agreement with values ​​that can be modeled based on the selected specific variation(s) using measurements determined by, for example, THz-based measurement methods).

[0123] Further exemplary embodiments are shown in Figure 14 relating to a device 200 for performing a method according to multiple embodiments. The device 200 has a computer device ("computer") 202, a storage device 204 assigned to the computer device 202, the storage device 204 for periodically storing the following elements, namely a) data DAT, and b) at least one computer program PRG for performing a method according to multiple embodiments.

[0124] In further exemplary embodiments, the storage device 204 includes volatile memory (e.g., working memory (RAM)) 204a and / or non-volatile memory (e.g., flash EEPROM) 204b.

[0125] In further exemplary embodiments, the computer device 202 has at least one of the following elements, or any combination thereof: a microprocessor (μP), a microcontroller (μC), an application-specific integrated circuit (ASIC), a system-on-a-chip (SoC), a programmable logic component (e.g., FPGA, field-programmable gate array), and hardware connectivity.

[0126] Further exemplary embodiments relate to a computer-readable storage medium SM that, when executed by a computer 202, includes a command PRG that requests the computer to perform a method according to one of the embodiments.

[0127] Further exemplary embodiments relate to a computer program PRG that, when executed by computer 202, includes commands that require the computer to perform a method according to one of the embodiments.

[0128] Further exemplary embodiments relate to a data transmission signal DCS that transmits and / or characterizes a computer program PRG according to several embodiments. The data transmission signal DCS can be received, for example, via an optional data interface 206 of device 202.

[0129] In a further exemplary embodiment, the device 200 is provided to have at least one THz device 210 for emitting and / or receiving THz radiation TS. In a further exemplary embodiment, the at least one THz device 210 can be designed, for example, to at least periodically, a) perform a THz-based measurement on an object or substrate 10 with at least one transmission device, in which the THz radiation passes at least periodically over at least a portion of the object, and / or b) perform a THz-based measurement on the object with at least one reflection device, in which the THz radiation is reflected at least periodically over at least a portion of the object.

[0130] Figure 15 illustrates a schematic block diagram of the configuration 210a of a THz device 210 according to an exemplary embodiment, the THz device 210 being designed for THz base measurement by at least one reflected TSR of THz radiation TS on a substrate or object 10, for example. Block 211 is symbolically represented by a THz transmitter for transmitting THz radiation TS, and block 212 is symbolically represented by a THz detector for receiving reflected THz radiation TSR. A reflector or mirror 215 can optionally be provided, and the reflector 215 can be introduced at least periodically into the beampath of the THz radiation TS, or, for example, into space D, near at least one surface 10-b of the test subject or object, in a further exemplary embodiment, space D can be predetermined to be zero, and as a result, for example, an technical zero gap is created between the reflector 215 and surface 10-b.

[0131] Figure 16 illustrates a schematic block diagram of configuration 210b of the THz device 210 according to an exemplary embodiment, the THz device 210 being designed for THz base measurements by at least one transfer TS' of THz radiation TS through a substrate or object 10, for example. Components 211',212' in Figure 16 correspond, for example, to components 211,212 in Figure 15.

[0132] Figures 17A to 17D schematically show side views of the substrate according to further exemplary embodiments in different states. Figure 17A shows, for example, the substrate 10 in an initial state before coating. Figure 17B shows the substrate 10 with a first layer 12-1 applied to the surface 10a of the substrate 10. Figure 17C shows the substrate 10 with a second layer 12-2 applied to the substrate 10 or the first layer 12-1. Figure 17D shows the substrate 10 with a third layer 12-3 applied to the substrate 10 or the second layer 12-2.

[0133] FIG. 18 schematically shows a block diagram according to a further exemplary embodiment, with block arrows S for the substrate 10 according to FIG. 17 (“substrate measurement”), or for the layer(s) 12-1, 12-2, 12-3 applied on or over the substrate 10 (“layer measurement”), or for an object formed by the substrate 10 and the layer(s) 12-1, 12-2, 12-3 applied on the substrate 10 1-M , T1L 1-M , T2L 1-M , T3L 1-M are used to indicate different measurements.

[0134] In a further exemplary embodiment, a number of measurement points equal to, for example, M, are each used for both the substrate measurement S 1-M and the layer measurements T1L 1-M , T2L 1-M , T3L 1-M and are selected to be the same for all of a number of measurements, for example measurements S 1-M , T1L 1-M , T2L 1-M , T3L 1-M . This also applies to the measurement of the reference layer thickness in the case of further exemplary embodiments. In a further exemplary embodiment, the layer measurement T3L 1-M can be explained, for example, as an entirety of stack measurements according to the configuration of FIG. 17D. This is because the layer measurement relates, by way of example, to a complete stack having the substrate 10 and currently three layers 12-1, 12-2, 12-3.

[0135] In a further exemplary embodiment, the substrate measurement S of the substrate 10 (FIG. 17A) starting from the number of measurement points MP (FIG. 3B) (example: M = 8) 1-M can have, for example, the following measurement results, namely, S11, S12, S13, S14, S15, S16, S17, S18. In a further exemplary embodiment, as soon as the substrate measurement S 1-M is performed, the first layer 12-1 can be applied to the surface 10a of the substrate 10. In a further exemplary embodiment, the layer measurement T1L 1-MNext, this can be performed on the configuration of the substrate 10 having the first layer 12-1 (Figure 17B), and optionally, the reference layer thickness RD1 1-M Perform the following measurements (multiple measurements are possible).

[0136] In a further exemplary embodiment, layer measurement T1L is performed on the structure of a substrate 10 having a first layer 12-1 (Figure 17B) starting from the number of measurement points MP (Figure 3B) (in this example, M=8). 1-M For example, it may have the following measurement results, namely T1L1, T1L2, T1L3, T1L4, T1L5, T1L6, T1L7, T1L8.

[0137] In further exemplary embodiments, layer measurement T1L 1-M As soon as this is performed on the substrate 10 having the first layer 12-1 (Figure 17B), the second layer 12-2 can be applied to the substrate 10 or the first layer 12-1. In further exemplary embodiments, layer measurement T2L is then performed. 1-M This can be applied to the substrate 10 having the first layer 12-1 and the second layer 12-2 (Figure 17C) after the application of the second layer 12-2, and optionally, the reference layer thickness RD1 1-M and / or RD2 1-M Perform the following measurements (multiple measurements are possible).

[0138] In a further exemplary embodiment, layer measurement T2L is performed on the structure of a substrate 10 having a first layer 12-1 and a second layer 12-2 (Figure 17C), starting with the number of measurement points MP (Figure 3B) (in this example, M=8). 1-M For example, it may have the following measurement results, namely T2L1, T2L2, T2L3, T2L4, T2L5, T2L6, T2L7, T2L8.

[0139] In further exemplary embodiments, layer measurement T2L 1-M As soon as this is performed on the substrate 10 having the first layer 12-1 and the second layer 12-2 (Figure 17C), the third layer 12-3 can be applied to the substrate 10 or the second layer 12-2. In further exemplary embodiments, layer measurement T3L is then performed. 1-MThis can be applied to the substrate 10 having the first layer 12-1, the second layer 12-2, and the third layer 12-3 (Figure 17D) after the application of the third layer 12-3, and optionally, the reference layer thickness RD1 1-M and / or RD2 1-M and / or RD3 1-M Perform the following measurements (multiple measurements are possible).

[0140] In a further exemplary embodiment, layer measurement T3L is performed on a substrate 10 having a first layer 12-1, a second layer 12-2, and a third layer 12-3 (Figure 17D), starting with a number of measurement points MP (Figure 3B) (in this example, M=8). 1-M For example, it may have the following measurement results, namely T3L1, T3L2, T3L3, T3L4, T3L5, T3L6, T3L7, T3L8.

[0141] In further exemplary embodiments, each of the measurement results defined above in the exemplary manner is T1L1, T1L2, T1L3, T1L4, T1L5, T1L6, T1L7, T1L8, T2L1, T2L2, T2L3, T2L4, T2L5, T2L6, T2L7, T2L8, T3L1, T3L2, T3L3, T3L4, T3L5, T3L6, T3L7, T3L8, S11, S12, S13, S14, S15, S16, S17, and S18 can be obtained, for example, by the following methods, namely, at least one of a) a measurement method 110a based on the reflection of THz radiation TS, TS-1, b) a measurement method 110b based on the transmission of THz radiation TS, TS-2, and c) a further measurement method 110c not based on THz radiation TS, such as a tactile measurement method or an optical measurement method.

[0142] In a further exemplary embodiment, the reference layer thickness is, for example, the reference layer thickness RD1 for each of the three layers 12-1, 12-2, and 12-3. 1-M RD2 1-M RD3 1-MThe number equal to M is optionally determined for at least one of the three layers 12-1, 12-2, and 12-3, or for all three layers, using, for example, tactile and / or optical measurement methods, as already mentioned above. In further exemplary embodiments, the determination of the reference layer thickness for each corresponding layer can be performed, for example, after the application of the layer in question and / or after the application of at least one further layer.

[0143] In a further exemplary embodiment, the reference layer thickness RD1 for the first layer 12-1 (Figure 17B) starts from the number of measurement points MP (in this example, M=8). 1-M The measurement may have, for example, the following measurement results, namely RD11, RD12, RD13, RD14, RD15, RD16, RD17, RD18. In a further exemplary embodiment, the reference layer thickness RD2 for the second layer 12-2 (Figure 17C) starts from the number of measurement points MP (in this example, M=8). 1-M The measurement may have, for example, the following measurement results, namely RD21, RD22, RD23, RD24, RD25, RD26, RD27, RD28. In a further exemplary embodiment, the reference layer thickness RD3 for the third layer 12-3 (Figure 17D) starting from the number of measurement points MP (in this example, M=8) 1-M The measurement may have, for example, the following measurement results, namely RD31, RD32, RD33, RD34, RD35, RD36, RD37, RD38.

[0144] In further exemplary embodiments, possible deviations in the reference layer thickness can be taken into account, for example, by pre-determining the layer thickness region to reflect the final measurement accuracy of the reference layer thickness.

[0145] For example, with respect to the reference layer thickness RD1 of the first layer 12-1 at the first measurement point MP1 (Figure 3B), the layer thickness region can be characterized by two layer thickness values ​​RD11-ΔRD1 and RD11+ΔRD1, where, for example, the parameter ΔRD1 can be selected based on known measurement accuracy for measuring the reference layer thickness RD11. Similarly, in a further exemplary embodiment, the layer thickness region of the reference layer thickness RD12 of the first layer 12-1 can be determined in advance at the second measurement point MP2, as shown in the following equation, i.e., RD12-ΔRD1, RD12+ΔRD1, etc.

[0146] In a further exemplary embodiment, the layer thickness region is comparable to the reference layer thickness RD2 of the further layers 12-2, 12-3. 1-M RD3 1-M This can be determined in advance.

[0147] In further exemplary embodiments, one or more values ​​characterizing the dispersion of terahertz radiation TS in the first layer 12-1 are substrate measurement S 1-M and layer measurement T1L 1-M Selected based on, and the reference layer thickness RD1 is optional. 1-M Alternatively, based on a corresponding reference thickness region, a selection is made based on a first model that characterizes the configuration according to Figure 17B, for example, with respect to the refractive index and / or damping coefficient, the selection of which can be made, in a further exemplary embodiment, for example, after applying the first layer and performing the corresponding layer measurement(s) and / or at a later point (for example, after applying at least one further layer). In a further exemplary embodiment, a vector or matrix is ​​determined for each of a number of measurement points equal to, for example, M, which characterizes the variance with respect to, for example, the refractive index and / or damping coefficient using multiple values.

[0148] For example, in a further exemplary embodiment, the first vector v1 may have a numerical value of the refractive index, each of which is associated with a different frequency of THz radiation.

[0149] For example, in a further exemplary embodiment, the second vector v2 may have a numerical value of the attenuation coefficient, each of which is associated with a different frequency of THz radiation.

[0150] In further exemplary embodiments, the value relating to the dispersion for a predetermined THz radiation frequency can be characterized, for example, by a two-part tuple (n,e) having a refractive index n and an attenuation coefficient e for a predetermined frequency.

[0151] For example, the variance that can be determined for the first measurement point MP1 of the first layer 12-1 can be explained by a vector v3 of two tuples (n11, e11), and the variance that can be determined for the second measurement point MP2 of the first layer 12-1 can be explained by a vector of two tuples (n12, e12). For example, each of the vectors k has many pairs of tuples (e, n), and k characterizes the frequency exponent.

[0152] In further exemplary embodiments, substrate measurement S 1-M and layer measurement T1L 1-M ,T2L 1-M Based on this, the reference layer thickness RD1 can be set as desired. 1-M RD2 1-M Alternatively, based on the corresponding reference layer thickness region, and also based on a model characterizing the configuration according to, for example, Figure 17C, apply, for example, a second layer 12-2 and measure at least one layer T2L 1-M After performing this operation, one or more values ​​are determined for the dispersion of terahertz radiation TS in the second layer 12-2.

[0153] In further exemplary embodiments, the “value” for the variance of the second layer 12-2 is determined for each of the number of measurement points equal to M, for example, and the “value” for the variance of each measurement point can be characterized, for example, by the first vector v1 and / or the second vector v2 or vector v3 described above in an exemplary manner. For example, the variance that can be determined for the first measurement point MP1 of the second layer 12-2 can be described by two tuples (n21, e21), and the variance that can be determined for the second measurement point MP2 of the second layer 12-2 can be described by two tuples (n22, e22).

[0154] In further exemplary embodiments, as mentioned above, and also for several variances (or "values" relating to variance) at each measurement point, for example, several different layer thicknesses (e.g., each with a constant layer thickness) may be considered. In further exemplary embodiments, substrate measurement S 1-M and layer measurement T1L 1-M ,T2L 1-M T3L 1-M Based on this, the reference layer thickness RD1 can be set as desired. 1-M RD2 1-M RD3 1-M Alternatively, based on the corresponding reference layer thickness region, and also based on a third model that characterizes the configuration according to, for example, Figure 17D, a third layer 12-3 is applied, and at least one layer measurement T3L is performed. 1-M After this is done, one or more values ​​(for example, values ​​that can be characterized by the first vector v1 and / or the second vector v2, or vector v3 described above in an exemplary manner, respectively) are determined for the dispersion of the terahertz radiation TS in the third layer 12-3.

[0155] In further exemplary embodiments, a “value” relating to the variance of the third layer 12-3 (for example, a value that can be characterized in exemplary manner by the first vector v1 and / or the second vector v2 or vector v3 described above) is determined for each of the number of measurement points equal to M. For example, the variance that can be determined for the first measurement point MP1 of the third layer 12-3 can be described by two tuples (n31, e31), and the variance that can be determined for the second measurement point MP2 of the third layer 12-3 can be described by two tuples (n32, e32).

[0156] In further exemplary embodiments, further variances (for example, variances that can each be characterized in exemplary manner by the first vector v1 and / or the second vector v2, or vector v3 described above) can also be determined, for example, by simultaneously adjusting some or all of the measurement points.

[0157] In further exemplary embodiments, for example, the variance of layers 12-1, 12-2, 12-3, for example, for each layer, the variance of at least one of those layers, and the variance of each of those layers are determined as the measurement results S11, S12, S13, S14, S15, S16, S17, S18, T1L1, T1L2, T1L3, T1L4, T1L5, T1L6, T1L7, T1L8, T2L1, T2L2, T2L3, T2L4, T2 The determination can be made based on L5, T2L6, T2L7, T2L8, T3L1, T3L2, T3L3, T3L4, T3L5, T3L6, T3L7, T3L8, RD11, RD12, RD13, RD14, RD15, RD16, RD17, RD18, RD21, RD22, RD23, RD24, RD25, RD26, RD27, RD28, RD31, RD32, RD33, RD34, RD35, RD36, SRD37, RD38. In further exemplary embodiments, optimization or variational calculations can be performed for this purpose, for example, using the measurement results specified above and / or measurement results based on other measurements, for example, from the production or continuous production of components, or measurement results based on other stacks or objects, for example, THz-based (and / or non-THz-based) measurements.

[0158] In further exemplary embodiments, possible distributions can be automatically and / or manually pre-selected for each, for example, at least one layer, or for example, for all observed layers.

[0159] In further exemplary embodiments, the measurement results or determined variance of the first layer or at least one previous layer are advantageously used to determine the variance of the second layer or further layers, thereby improving accuracy.

[0160] Figure 19 shows a simplified flowchart according to a further exemplary embodiment. In an optional block 170, a substrate 10 is provided, and in block 171, the substrate 10 is evaluated by performing, for example, at least one measurement at a number of measurement points MP equal to M, for example, based on THz radiation TS (e.g., using reflection and / or transmission or ellipsometry). In a further exemplary embodiment, in block 171, at least one dispersion is determined for the substrate 10 and can be characterized, for example, by a refractive index n_S and a damping coefficient e_S, or by corresponding first vector v1 and / or second vector v2, or third vector v3.

[0161] In a further exemplary embodiment, in block 172, the first layer 12-1 (see Figure 17B) is applied to the surface 10a of the substrate 10, and then the first layer 12-1 is evaluated. In a further exemplary embodiment, the evaluation of the first layer 12-1 includes at least one of the following elements: a) performing at least one THz-based measurement (e.g., based on reflection and / or transfer, e.g., using ellipsometry); b) optionally performing at least one reference layer thickness measurement (which may also be performed later, e.g., after application of at least one further layer to the substrate 10); c) determining a plurality of dispersions of the first layer 12-1, e.g., the reference layer thickness can move freely within a range of measurement uncertainty, or can be fixed, e.g., in a layer thickness region that can be determined in advance, or to several reference thickness values ​​that can be determined in advance; and d) optionally performing a pre-selection of the dispersions determined in the first layer 12-1, e.g., automatically and / or via the user.

[0162] In a further exemplary embodiment, in block 173, the second layer 12-2 (see Figure 17C) is applied to the surface 10a of the substrate 10, or to the first layer 12-1 already applied to the substrate 10, and the second layer 12-2 is then evaluated, which can be performed in a further exemplary embodiment similar to the evaluation of the first layer 12-1 according to block 172, for example, and is performed using a difference that allows the second layer 12-2 to be evaluated in addition to, for example, the dispersion of the first layer 12-1 determined according to block 172 or optionally pre-selected. In further exemplary embodiments, the evaluation of the second layer 12-2 includes at least one of the following elements: a) performing at least one THz-based measurement (e.g., based on reflection and / or transfer, e.g., using ellipsometry); b) optionally performing at least one reference layer thickness measurement (which may also be performed later, e.g., after application of at least one further layer to the substrate 10); c) determining a plurality of dispersions of the second layer 12-2, where, for example, the reference layer thickness can move freely within a range of measurement uncertainty, or can be fixed, e.g., in a pre-determinable layer thickness region, or to several pre-determinable reference thickness values; and d) optionally performing a pre-selection of the dispersions determined in the second layer 12-2, e.g., automatically and / or via the user.

[0163] In a further exemplary embodiment, in block 174, the third layer 12-3 is applied to the surface 10a of the substrate 10, or to the second layer 12-2 already applied to the substrate 10, and then the third layer 12-3 is evaluated, which can be performed, for example, in a further exemplary embodiment, similar to the evaluation of the second layer 12-2 according to block 173, and the evaluation is performed using a difference that allows the third layer 12-3 to be evaluated in addition to, for example, the dispersion of the second layer 12-2 determined according to block 173, or optionally pre-selected.

[0164] Furthermore, in the optional block 175, the application and evaluation of at least one further layer, similar to blocks 172, 173, and 174 described above, is represented by symbols, for example, in an exemplary manner with reference to Figure 19.

[0165] In a further block 176 according to Figure 19, for example, using all the information or data obtained by blocks 170-175, the optimization and / or variational calculations are represented by symbols, for example, the variance of each evaluated layer can be determined, for example, based on the minimum deviation from the pre-determined thickness of each layer, and / or based on the stability of the evaluation, and / or based on the goodness of fit, when fitting the variance using at least one pre-determinable variance function.

[0166] Further exemplary embodiments are described below with reference to Figures 20 to 33, which relate in particular to possible THz-based measurement configurations 110a, 110b for performing methods according to exemplary embodiments.

[0167] Figure 20 schematically shows an object having a substrate 10 to which layer 12-1 is applied. In Figure 20, THz radiation TS can be irradiated from above onto the first layer 12-1 of the object ("irradiated from the front") using, for example, a THz device 210 according to Figure 14, and the THz radiation TSR reflected on the object can be detected by, for example, the THz device 210 (Figure 14). Also, as can be seen from Figure 20, the irradiated THz radiation TS is transmitted at least partially through layer 12-1.

[0168] Figure 21 shows a configuration comparable to Figure 20, and in addition to Figure 20, Figure 21 shows that the so-called back reflection of the THz radiation TS strikes the lower boundary surface 10-b (Figure 21) of the substrate 10.

[0169] Figure 22 shows a configuration comparable to Figure 20, where, unlike in Figure 20, the THz radiation TS is irradiated onto the substrate (and then onto layer 12-1) ("irradiated from the rear").

[0170] Figure 23 shows a configuration comparable to Figure 22, in which, in addition to Figure 22, the reflector 215 is positioned in space d from layer 12-1. In further exemplary embodiments, space d can be freely predetermined and selected, for example, as <1 mm at least periodically, for example, as <0.1 mm at least periodically, for example, so that at least periodically, a technical zero gap occurs between the reflector 215 and layer 12-1.

[0171] Figure 24 shows the transmission of terahertz radiation TS through an object, and the transmission portion TS' can be received by, for example, detector 212' (Figure 16).

[0172] Figure 25 shows the configuration of object 10,12-1 similar to that in Figure 24, using the transmission of terahertz radiation TS, including back-reflected TS''.

[0173] Currently, in Figures 20 to 25, layers 12-1 are imaged on the substrate 10, however, it should be noted that the respective measurement principles can be used together, and are not limited to objects having several layers. For more information on this, please refer to Figure 17D, for example.

[0174] Figure 26 illustrates a configuration for THz-based measurement according to a further exemplary embodiment. A reflector 215 is assigned to a THz device 300, which is a THz measurement head, and is positioned, for example, between an object and the THz device 300, so that THz radiation TS emitted at least partially directly by the THz device 300 strikes the object OBJ (in further exemplary embodiments, the object may have a configuration according to, for example, Figures 17A, 17B, 17C, and 17D), and at least a portion of the THz radiation TS TS1 that strikes the object OBJ and is reflected by the object OBJ is directed onto the reflector 215, reflected by the reflector 215, and irradiates the object OBJ again, see reference numeral TS2. Then, TS2 is reflected again by the object OBJ and detected, for example, by a detector (not shown) of the THz device 300, see reference numeral TS3. In further exemplary embodiments, the exemplary configuration according to Figure 26 can therefore also be described as a reflector having multiple paths for THz radiation TS through an object OBJ.

[0175] In a further exemplary configuration according to Figure 27, for example, a single path for THz radiation TS through object OBJ is created as a result, while in a further exemplary configuration according to Figure 28, for example, multiple paths for THz radiation TS through object OBJ are created as a result, and unlike the configuration according to Figure 26, in the configuration according to Figure 28, object OBJ is positioned between the THz device 300 and the reflector 215.

[0176] Figure 29 illustrates an exemplary configuration for THz-based measurement on an object OBJ according to a further exemplary embodiment, in which the transmission measurement can be performed using a THz parallel beam PS. The THz device 211" is also designed, for example, as a transceiver, and for this purpose emits THz radiation TS to a first reflector, for example, a mirror, for example, a parabolic mirror 216a, and the parabolic mirror 216a is designed so that the irradiated THz radiation TS is converted into a THz parallel beam PS that strikes the object OBJ. After the transmission of the THz parallel beam PS through the object OBJ, the THz parallel beam PS is redirected towards, for example, a planar reflector 215 using a further reflector, for example, a mirror, for example, a parabolic mirror 216b. The THz radiation reflected by the reflector 215 passes through the beam path described above, then travels in the opposite direction and, at the same time, is transmitted again through the object OBJ in the form of a THz parallel beam PS that can be detected by the transceiver 211". Alternatively, the THz radiation reflected by the reflector 215 can also be redirected towards another THz detector (not shown) by, for example, a mirror system (not shown), and unit 211" can also be formed as, for example, a THz transmitter (not a transceiver).

[0177] Figures 30 and 31 show, as an example, measurement configurations according to further exemplary embodiments with respect to the angle of incidence of THz radiation TS onto an object. In further exemplary embodiments, a comparable variation of the angle of incidence of THz radiation TS onto an object can also be used for measurements relating to the transmission of THz radiation through the object.

[0178] Figure 32 shows further reflectors, such as parabolic mirrors 216c and 216d, which can be used in further exemplary embodiments to form a beam of, for example, a THz radiation beam TS. For example, in a further exemplary embodiment, the parabolic mirror 216c can be used to direct a focused THz beam TS-F onto an object OBJ. For example, in a further exemplary embodiment, the parabolic mirror 216d can be used to direct a THz parallel beam PS onto an object OBJ.

[0179] In a further exemplary embodiment, as shown in Figure 33, the object OBJ can be rotated at least periodically relative to, for example, the THz device 210, and several THz-based measurements can be performed, each at a different angle of rotation A, so that the THz device 210 can deliver further information about the material of the object in question, in the case of an anisotropic object.

[0180] Referring to Figures 20 to 33, the configuration described above can, in further exemplary embodiments, be used at least periodically for measurements on the substrate 10, or for measurements on at least one layer 12-1, 12-2, 12n (Figure 3A) applied to the substrate 10, and in further exemplary embodiments, the measurement results thus obtained can be used to determine, for example, at least one optical property, such as the dispersion of at least one of the multiple layers.

[0181] Further exemplary embodiments, shown in Figure 34, relate to a method 400 of use of a method according to a plurality of embodiments, and / or a device according to a plurality of embodiments, and / or a computer-readable storage medium according to a plurality of embodiments, and / or a computer program according to a plurality of embodiments, and / or a data transmission signal according to a plurality of embodiments, wherein the method 400 relates to at least one of the following elements, namely, a) determining at least one characteristic E-12-1 of a first layer 12-1 402, b) determining at least one characteristic E-12-n of at least one further layer 12-n 404, c) calibrating the model and / or device 200 for THz measurement of a measured object OBJ having several layers 12-1, 12-2, 12-n applied to a substrate 10, for example, to determine the layer thickness of several layers applied to a substrate 406, and d) expanding or amending calibration data for THz measurement 408.

[0182] Further aspects and advantages of the principle according to multiple embodiments are described below, and according to the multiple embodiments, at least one of the embodiments described above can be combined essentially individually or in any combination with each other, according to further exemplary embodiments.

[0183] In further exemplary embodiments, the dispersion of a laminated OBJ (Figure 3A) can be calibrated using methods according to multiple embodiments, for example, by performing a series of coatings, and subsequently the application of individual layers 12-1, 12-2, 12-n (see, for example, block 102 (Figures 1, 2) and block 106-n (Figure 2)). In further exemplary embodiments, one or more measurements, for example, THz-based measurements and / or non-THz-based measurements, are performed after the application of the layer in question, for example, see blocks 104, 108-n according to Figures 1 and 2.

[0184] In further exemplary embodiments, a THz device 210 for, for example, THz time-domain spectroscopy (TDS) can be calibrated using principles according to multiple embodiments, and the layer thickness of a stacked object-joint (OBJ) can be determined, for example. The THz time-domain spectroscopy is based on reflectance measurements in the THz spectral range, for example, in the region of 0.1 THz to 30 THz, for example, 0.3 THz to 10 THz, as defined above. In further exemplary embodiments, the reflectance spectrum of the stacked object-joint (OBJ) to be measured (Figure 3A) is compared with, for example, a reference measurement of a metal substrate 10. From this comparison, in further exemplary embodiments, the spectral reflectance and phase difference can be calculated, for example. In further exemplary embodiments, the reflectance and the resulting phase difference of the stacked object-joint (OBJ) arise from, for example, the layer thickness and optical properties (e.g., refractive index n, and attenuation coefficient which can be characterized by, for example, an attenuation index e) of the individual layers 12-1, 12-2, 12-n, ... and the substrate 10, for example, based on Fresnel's formula and, for example, based on corrections between the sample measurement and the reference measurement. In further exemplary embodiments, the refractive index and the damping coefficient can be determined by frequency.

[0185] Further exemplary embodiments relate to the measurement of reflectance and phase difference of a stacked object-oriented OBJ and the comparison of this data with an optical model of the stacked OBJ, wherein the stacked OBJ specifically includes layer thicknesses of layers 12-1, 12-2, and 12-n, and their optical properties, such as dispersion, and the stacked OBJ describes, for example, the spreading of terahertz radiation TS of the object OBJ. In further exemplary embodiments, the theoretical reflectance spectrum can be adjusted by changing the optical model.

[0186] Specifically, in the case of an object OBJ having several layers 12-1, 12-2, 12-n, in further exemplary embodiments, the layer thickness and dispersion of the stacked layers cannot all be clearly determined simultaneously from measurements (e.g., THz-based). In further exemplary embodiments, the dispersion of the layer material may not be known in the THz spectral range, for example, and may not be available in certain literature. Therefore, the optical properties of the layer material of several layers 12-1, 12-2, 12-n can be advantageously and efficiently determined using principles according to multiple embodiments.

[0187] In further exemplary embodiments, some layer materials of a multilayer system formed by an object OBJ may interact with other layer materials in adjacent layers (e.g., by diffusion, different interconnections, etc.), and therefore their optical properties may change (e.g., compared to the optical properties of these materials in individual layers). In further exemplary embodiments, the dispersion of the layer materials of an actual layer system can therefore be calibrated using the principles according to the embodiment, which can be advantageously characterized, for example, by the object OBJ.

[0188] For example, using a process according to the exemplary embodiment described above with reference to Figures 1 to 34, the optical properties of the layer materials of layers 12-1, 12-2, and 12-n of a multilayer system OBJ in the THz spectral range can be determined or calibrated.

[0189] In further exemplary embodiments, after, for example, coating step 102 (Figure 1), 106-n (Figure 2), for example, after all of coating steps 102, 106-n, one or more measurements are performed in different ways (e.g., THz-based and / or non-THz-based ways). In further exemplary embodiments, this advantageously allows one or more layers, for example all subsequent layers applied later, to be calibrated with corresponding prior knowledge of the underlying layers. In further exemplary embodiments, this allows both to consider inter-layer interactions and to calibrate the layers as completely as possible with prior knowledge of the underlying stack or lamination.

[0190] As described several times above, the exemplary embodiment enables the coating of a series of coatings, for example, all layers 12-1, 12-2, 12-n of a multilayer structure (Figure 3A), and also enables the characterization or evaluation of each newly applied layer / stack OBJ (for example, determining the dispersion(s) and / or layer thickness(s)) after each processing step (e.g., coating), using information already obtained from the aforementioned processing steps.

[0191] In further exemplary embodiments, the substrate 10 may be, for example, a metal body, such as a part of a vehicle body, or a model of a part of a vehicle body. In further exemplary embodiments, the first layer 12-1 may be a primer, which functions, for example, as a binder between the surface 10a of the substrate 10 and the second layer 12-2. In further exemplary embodiments, the second layer 12-2 may be, for example, a base coat. In further exemplary embodiments, the third layer 12-3 may be, for example, a clear coat.

[0192] The principle, according to multiple embodiments, is not limited to the exemplary use of painted body parts as predefined examples and / or the number of layers given as an example, but the principle can also be applied, for example, specifically, to other multilayer systems that have access to THz measurement methods.

[0193] In further exemplary embodiments, several variances or variance values ​​for each layer and measurement point, or alternatively or in addition, a shared variance for each layer of all measurement points (e.g., simultaneous fitting of all measurement points), can be determined, for example, depending on the number of layers and the number of measurement points MP M.

[0194] In further exemplary embodiments, variational calculations can determine the optimal combination of all variances, which can be determined, for example, by the best fit or best match with the reference layer thickness, or by the highest sensitivity or highest stability. In further exemplary embodiments, additional criteria can be used to determine the best variance for each of the layers under consideration for the defined variational calculations.

[0195] In further exemplary embodiments, the "best" dispersion of individual layers may not necessarily be the "best" dispersion for a stacked object-oriented jug (e.g., one resulting from diffusion). Optionally, a particular combination of layer dispersions may best fit the stacked object-oriented jug, while the individual layer dispersions may be relatively poorly suited. Principles according to multiple embodiments can determine the dispersion that best fits the jug overall, taking into account possible interactions, such as between adjacent layers.

[0196] In further exemplary embodiments, methods according to multiple embodiments can be used in a robotic system having a robot for positioning the THz device 210, for example, and / or in another system, such as a laboratory system.

[0197] In further exemplary embodiments, methods according to multiple embodiments can be used in a target system (for example, a system for automated product measurement in a production device, for example) and / or another measurement system (for example, a system designed to perform THz-based measurements according to principles such as reflectivity and / or transfer and / or ellipsometry).

[0198] In further exemplary embodiments, the target system is, for example, a THz measuring system for continuous production that can be calibrated based on or using data acquired according to exemplary embodiments (e.g., optical properties of at least one layer) and measured values, for example, layer thickness for a painted body portion.

[0199] The principles according to multiple embodiments are not limited to the exemplary spectral range of THz radiation TS described above, but can also be used in spectral ranges of THz radiation that deviate from such exemplary spectral range.

[0200] In further exemplary embodiments, additional characterization of the layer thickness of layers 12-1, 12-2, and 12-n may be performed as optional by other methods, such as tactile methods and / or optical measurements (e.g., confocal microscopy, white light interferometry, OCT, ...), or by micrographs, for example, the reference layer thickness RD1 1-M RD2 1-M This can be done to determine this.

[0201] In further exemplary embodiments, the optical constants / dispersions of individual layers in a multilayer system can be determined using methods according to multiple embodiments.

[0202] In further exemplary embodiments, methods according to multiple embodiments are not specifically limited to the THz spectral range, but are similarly applicable to ellipsometry and / or reflectance measurements and transfer measurements in all current spectral ranges (e.g., the visible spectral range or the near-infrared spectral range).

[0203] In a further exemplary embodiment, as shown in Figure 35, the device 200 includes a positioning device 220 designed to move the THz device 210 and / or the object OBJ or substrate 10 relative to each other (e.g., rotatably and / or translatably). If an optional reflector 215 (Figure 15) is provided, the positioning device 220 can also be designed to move the optional reflector 215 relative to the THz device 210 and / or the object or substrate 10.

[0204] In a further exemplary embodiment, the positioning device 220 has a robot 221 on which a THz device 210, designed as, for example, a THz measuring head, is positioned to perform THz-based measurements.

[0205] In further exemplary embodiments, the positioning device 220 has at least one additional mounting element 222 in addition to, or as a replacement for, the robot 221, the mounting accuracy of which is better than that of the robot 221 with respect to determining and / or calibrating material data, for example, thereby improving measurement accuracy. For example, this is because, as a result, different measurement points MP can each be precisely moved to the focal point of the THz radiation TS.

[0206] In further exemplary embodiments, the positioning device 220 may include, for example, a 2D goniometer as a further installation element 222, an actuator for the z-axis, and optionally, a spatial and / or angle measuring unit 223, which determine, for example, the relative position between the sample OBJ and the measuring head 210.

[0207] In a further exemplary embodiment, the process arranged in the following exemplary manner is performed on a number of measurement points MP1, MP2, ..., MP8 equal to M of the sample OBJ (Figure 3B). 1. Rough positioning of the robot 221 in space x1, y1, z1 using the THz measurement head 210, for example, approaching the first measurement point MP1 and thereby aligning the THz measurement head 210 so that the focus of the THz radiation TS is at the first measurement point MP1. 2. Spatial / angle measurement, 3. Optionally, position correction using, for example, at least one additional installation element 222, 4. Control and measurement of space / angle, 5. If the space / angle is within the desired tolerance range, proceed to step 6; otherwise, return to step 3. 6. THz measurement (multiple measurements possible), 7. Potential alternative comparative measurements, e.g., comparative measurement of reference layer thickness using optical and / or tactile methods. 8. Approach the next measurement point MP2, and thereby align, for example, the THz measurement head 210, so that the focus of the THz radiation TS is at the second measurement point MP2, etc., and repeat the process as desired, until all measurement points equal to, for example, M are aligned.

[0208] In a further exemplary embodiment, unit 230 is provided to pressurize at least a portion of the beam path of THz radiation TS,TSR using a protective gas TRL, such as dry air, which can further improve accuracy when the absorption of THz radiation TS is unintentionally reduced by, for example, humid ambient air.

[0209] In further exemplary embodiments, device 200 can be used, for example, in a production device or paint factory to calibrate a THz measurement system based on the determined optical properties, for example, the dispersion of layers 12-1, 12-2, 12-n of an object OBJ.

[0210] In further exemplary embodiments, a series of calibrations of layers 12-1, 12-2, 12-n covers a specific layer thickness region (or a limited number of measurement points), and the thickness deviation that actually occurs on the coated substrate by the target system (e.g., a THz measurement system for continuous production that can be calibrated with data received according to multiple embodiments, e.g., a THz measurement system for continuous production that measures the layer thickness of painted body portions) can be considerably large. Specifically, in the case of metallic paints, the material data is determined by thickness, and this material data can be accurately measured in further embodiments, for example, within or around the thickness region of already existing / calibrated material data. In further exemplary embodiments, it is therefore suggested that the calibration data, which is determined using, for example, the method according to multiple embodiments, is continuously expanded and / or modified, for example, in an ongoing production process or other processing by the target system.

[0211] In further exemplary embodiments, for example, in the case of a coated object, such as a painted portion having considerably different thicknesses, the following process can be performed: a) THz base measurement of the lamination (e.g., an already existing layer), b) comparative measurement of the thickness, and c) post-calibration (and thus improvement of calibration) of the corresponding layer (usually the base coat 12-1) of the entire system OBJ, which allows for, for example, a continuous increase in the measurable thickness range.

Claims

1. A method for determining at least one property (E-12-1) of at least one first layer (12-1) applied to a substrate (10), using at least one measurement method (110a) based on the reflection of THz radiation (TS, TS-1) and / or at least one measurement method (110b) based on the transmission of THz radiation (TS, TS-2), Determining at least one characteristic (E-10) of the substrate (10) having at least one of the following: a) optical properties, b) thickness (D-10), c) magnetic permeability, d) electrical conductivity, and e) roughness (100), Applying the first layer (12-1) to the substrate (10) (102), (104) Determining at least one characteristic (E-12-1) of the first layer (12-1), having at least one of the following: a) optical properties, b) thickness (D-10), c) magnetic permeability, d) electrical conductivity, and e) roughness. Based on at least one measurement result (ME-TS-12-1) of at least one measurement method (110a, 110b) based on THz radiation (TS) applied to the first layer (12-1) applied to the substrate (10), at least one optical property (OE-12-1) of the first layer (12-1) is determined (150), Applying at least one further layer (12-n) (106-n), and determining at least one property (E-12-n) of the at least one further layer (12-n) having at least one of a) optical properties, b) thickness (D-10), c) permeability, d) electrical conductivity, and e) roughness (108-n), Based on at least one measurement result (ME-TS-12-2, ME-TS-12-n) of at least one additional layer (12-2, 12-n) based on THz radiation (TS) for the at least one additional layer (12-2, 12-n), at least one optical property (OE-12-2, OE-12-n) is determined (152), A method comprising determining (152) the at least one optical property (OE-12-2, OE-12-n) of the at least one further layer (12-2, 12-n), in addition to being performed based on at least one reference layer thickness and / or at least one optical property of at least one layer (12-1) applied to the substrate (10) prior to the at least one further layer (12-2, 12-n), and / or based on at least one property (E-10) of the substrate (10).

2. The method according to claim 1, wherein determining the properties (E-10) of the substrate (10) (100) further includes determining (100a) at least one surface property (OE) of the surface (10-a) of the substrate (10), the at least one surface property (OE) having at least one of a) roughness, b) shape, c) angle of the normal of the surface of the substrate with respect to the direction in which the THz radiation is emitted, and d) structure.

3. The method according to claim 2, wherein the at least one surface characteristic (OE) is determined using at least one of a) confocal microscopy, b) interference spectroscopy, c) optical coherence tomography, and d) three-dimensional imaging (100a).

4. The method according to claim 1, further comprising using (110) at least one further measurement method (110c) that is not based on THz spectroscopy and / or THz ellipsometry and / or THz radiation (TS), wherein the use (110) is performed for at least one of the following: a) determining at least one property (E-10) of the substrate (10) (100); b) determining at least one property (E-12-1) of the first layer (12-1) (104); c) determining at least one property (E-12-n) of the at least one further layer (12-2, 12-n) (108-n); d) determining at least one surface property (OE) of the surface (10-a) of the substrate (10) (100a).

5. The method according to claim 1, further comprising changing (120) the orientation (OR-10) of the substrate (10) with respect to the angle of incidence of the THz radiation (TS), or the orientation (OR-10) of an object (OBJ) having the substrate (10) with respect to the angle of incidence of the THz radiation (TS).

6. The method according to claim 1, further comprising changing the angle of incidence (EW-TS) of the THz radiation (TS) with respect to the normal (122) of the surface (10a) of the substrate (10) or of the layers (12-1, 12-n) provided on the surface (10a).

7. The method according to claim 1, further comprising at least one of the following: a) changing the polarization (POL-TS) of the THz radiation (TS) (124); b) changing the path direction (DR-TS) of the THz radiation (TS) (126); and c) reflecting the THz radiation (TS) at least periodically (128).

8. The method according to claim 1, further comprising performing at least one measurement method (110a, 110b) and / or at least one measurement method (110c) that is not based on THz radiation (TS) (130), or performing the at least one measurement method (110a, 110b, 110c) (130) on at least one measurement point (MP-1, MP-2, ..., MP-M).

9. The method further includes (132) combining the measurement results of multiple measurement points (MP-1, MP-2, ..., MP-M) of the measurement method (110a, 110b, 110c), wherein the measurement results of multiple measurement points (MP-1, MP-2, ..., MP-M) of the at least one measurement method (110a, 110b, 110c) for the substrate (10) and / or the at least one layer (12-1, 12-2, ..., ..., 12-n) determine the at least one characteristic (E-12-1), and less The method according to claim 8, wherein the data is used as input data for a model (MOD) for evaluation by combining measurement results to determine at least one characteristic (E-12-1, E-12-n), and is used as input data for a model (MOD) for evaluation by linking measurement results to determine the variation of the characteristics of layers (12-1, 12-2, ... 12-n) that explain a plurality of measurement results using the model (MOD).

10. The method according to claim 9, further comprising evaluating the measurement result using the model (MOD) and / or based on comparison with further reference measurements.

11. Determining at least one reference layer thickness (RD-1-1, RD-1-2, ..., RD-1-M) of the first layer (12-1) at at least one measurement point (MP-1, MP-2, ..., MP-M) (140), and / or determining at least one reference layer thickness (RD-1-1, RD-1-2, ..., RD-1-M) of the at least one further nth layer (12-2, 12-n) on the at least one measurement point (MP-1, MP-2, ..., MP-M) The method of claim 8, further comprising determining (142) the thickness of the illuminated layer (RD-n-1, RD-n-2, ..., RD-n-M), wherein the determination (140, 142) of the thickness of at least one reference layer (RD-1-1, RD-1-2, ..., RD-1-M), (RD-n-1, RD-n-2, ..., RD-n-M) is performed based on the measurement method (110c) which is not based on THz radiation (TS).

12. The method according to claim 8, wherein a) performing the at least one measurement method (110a, 110b, 110c) for at least one measurement point (MP-1, MP-2, ..., MP-M) (130), and / or b) determining the thickness of at least one reference layer (RD-1-1, RD-1-2, ..., RD-1-M) of the first layer (12-1) located on at least one measurement point (MP-1, MP-2, ..., MP-M) (140), and / or c) determining the thickness of at least one reference layer (RD-n-1, RD-n-2, ..., RD-n-M) of the at least one further layer (12-2, 12-n) (142), each of which is performed for the same at least one measurement point (MP-1, MP-2, ..., MP-M) of the first layer.

13. The method according to claim 11 or 12, further comprising defining (144) and / or considering (145) the deviation of the at least one reference layer thickness (RD-1, RD-n).

14. The method according to claim 1, further comprising determining at least one optical property (OE-12-1) of the first layer (12-1) based on at least one layer thickness or at least one reference layer thickness (RD-1) (150).

15. The method according to claim 1, further comprising determining at least one optical property (OE-12-2, OE-12-n) of the at least one further layer (12-2, 12-n) based on at least one reference layer thickness of the at least one further layer (12-2, 12-n) or the at least one reference layer thickness (RD-2, RD-n) (152).

16. Determining the at least one optical property (OE-12-1, OE-12-2, OE-12-n) (150, 152) involves modeling an object (OBJ) having the substrate (10) and at least the first layer (12-1) using a first model (MOD-1) (1500), and determining the determined reference layer thickness (RD-1) based on THz radiation (TS) applied to the first layer (12-1) on the substrate (10). The method according to claim 14, comprising: adjusting the first model (MOD-1) to match the at least one measurement result of the and / or the at least one measurement method (110a, 110b) (1502) to obtain an adjusted first model (MOD-1'); and determining the at least one optical property based on the first model (MOD-1) and / or the adjusted first model (MOD-1') (1404).

17. The method according to claim 1, comprising: performing at least one measurement (M-1) on an object (OBJ) having the substrate (10) and the first layer (12-1) using a measurement method (110a) based on the reflection of the THz radiation (TS, TS-1), and / or at least one measurement method (110b) based on the transmission of the THz radiation (TS, TS-2), and / or at least one further measurement method (110c) not based on THz radiation (TS) at some point on the object (OBJ) (162); and determining at least one optical property (OE-12-1) of the first layer (12-1) based on the at least one measurement (M-1) (164).

18. a) Applying at least one further layer (12-2, 12-n) to the first layer (12-1) (166), b) Using a measurement method based on the reflection of the THz radiation (TS, TS-1) (110a), and / or at least one measurement method based on the transmission of the THz radiation (TS, TS-2) (110b), and / or at least one further measurement method (110c) not based on THz radiation (TS) at some point of the object (OBJ), the substrate (10) and the The method according to claim 17, further comprising: a) performing at least one measurement (M-2, M-N) on an object (OBJ) having a first layer (12-1) and the at least one further layer (12-2, 12-n) (168); c) determining at least one optical property (OE-12-2, OE-12-n) of the at least one further layer (12-2, 12-n) based on the at least one further measurement (M-1) (169).

19. The method according to claim 8, comprising: determining several variations (VAR-OE) of the first layer (12-1) and / or at least one further layer (12-2), or of the at least one further layer (12-2), based on measurement results relating to different measurement points and / or layer thickness regions (1040); and determining a specific variation (VAR-OE') of the several variations (VAR-OE) (1042).

20. A device (200) for performing the method according to claim 1, having at least one THz device (210) for emitting and / or receiving THz radiation (TS, TSR, TS').

21. The device (200) according to claim 20, further comprising at least one reflector (215) for the THz radiation, wherein the device (200) is designed to position the reflector (215) at least at a certain distance from a) at least partially in the beam path of the THz radiation (TS) and / or b) in a region of at least one surface (10b) of the substrate (10) having space (D) from at least one predetermined surface (10b), or in a region of an object (OBJ) having the substrate (10).

22. A method (400) of using the device (200) according to claim 20, relating to at least one of the following: a) determining the at least one characteristic (E-12-1) of the first layer (12-1) (402); b) determining the at least one characteristic (E-12-n) of the at least one further layer (12-2, 12-n) (404); c) calibrating the model and / or device (200) for THz measurement to measure a measured object having the several layers (12-1, 12-2, ...) applied to the substrate (10) in order to determine the layer thickness of the several layers (12-1, 12-2, ...) applied to the substrate (10) (406); d) expanding (408) or amending, or calibrating or recalibrating the calibration data for THz measurement based on further THz measurements.

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