METHOD FOR STRUCTURING A STRUCTURAL LAYER USING LASER RADIATION

Description

[0001] The invention relates to a method for structuring a structural layer by means of laser radiation.

[0002] It is known to process a structural layer using laser radiation to remove parts of the structural layer and thus achieve a predetermined structure, which can be the subject of a component itself or serve as a mask for further processing. For example, in the manufacture and processing of semiconductor components, it is known to structure a structural layer using laser radiation, particularly in the manufacture of large-area semiconductor components such as photovoltaic solar cells or OLEDs.

[0003] In this process, a layered structure is provided with at least one carrier layer and at least one structural layer arranged on the carrier layer. By exposing the layered structure to laser radiation, the structural layer is removed in partial areas to form a desired structure. Such a method, which additionally involves a lift-off of a material layer, is known from DE 10 2007 006 640 A1.

[0004] In a variety of manufacturing processes, particularly in semiconductor devices and especially in photovoltaic solar cells, it is desirable to pattern the structural layer with lines that are as thin as possible, especially straight lines. While such patterning is generally possible by means of additional masking steps using photolithography, such processes require a high level of equipment complexity and are therefore very costly. Further methods for patterning a structural layer are known from JP 2017 060991 A (disclosing the preamble of claim 1), US 2018 / 257174 A1, or JP 5 103054 B2.

[0005] There is therefore a need to improve known methods in which a structural layer is structured by means of laser radiation so that thinner lines and / or lines with less damage to the carrier layer can be produced in the structural layer.

[0006] This object is achieved by a method according to claim 1. Advantageous embodiments of the method can be found in the dependent claims.

[0007] The method according to the invention for structuring a structural layer using laser radiation comprises the following method steps: In method step A, a layer structure is provided with at least one carrier layer and at least one structural layer arranged on the carrier layer. In method step B, the layer structure is exposed to laser radiation in order to remove the structural layer in partial areas.

[0008] What is essential is that in a sub-step B1 the layer structure is exposed to laser radiation in a first processing area B1 with a first fluence Φ L1 of the laser radiation, so that in the first processing area B1 exposed to laser radiation a threshold fluence Φ S of the layer system for ablating the structural layer is reduced to a reduced threshold fluence Φ B1 < Φ S, wherein the first fluence Φ L1 is below the threshold fluence Φ S of the layer system. In a sub-step B2 the layer structure is exposed to laser radiation in a second processing area B2 with a second fluence Φ L2, wherein the second fluence Φ L2 is greater than the reduced threshold fluence Φ B1 of the first processing area and smaller than the threshold fluence Φ S. The second processing area B2 covers only a partial area of the first processing area B1.The initial threshold fluence Φ S of the layer system is thus reduced in step B1 by means of laser radiation to the threshold fluence Φ B1 .

[0009] The present invention is based on the realization that, in the prior art methods, the formation of thin lines requires precise and high focusing of a laser beam. This places high demands on the precision and repeatability of the optics used for the laser beam, which ultimately increases processing costs. On the other hand, in the prior art methods, a laser fluence greater than the threshold fluence of the layer system is always used to ablate the structural layer, so that at least partial ablation of the structural layer occurs directly through exposure to laser radiation. However, this entails a considerable risk of damaging the layer structure in the processing area, in particular damaging the carrier layer.This is particularly relevant when the method is used to process semiconductor structures and in particular when the carrier layer is a semiconductor layer, in particular a silicon layer.

[0010] In previous methods, openings were created in the structural layer using laser pulses and the openings were arranged in a row to create a desired shape for the opening, in particular a line. For this purpose, the layer structure has a specific threshold fluence, depending on material parameters, in particular the materials used and the layer thicknesses of the layers in the layer structure, above which exposure to laser radiation leads to ablation of the structural layer. The threshold fluence Φ S of the layer system for ablating the structural layer can thus be easily determined for each layer system by increasing the fluence of the laser radiation starting from a low fluence until ablation of the structural layer occurs. In addition, studies on threshold fluence are also known, for example in J. Bonse, et al. "Femtosecond laser ablation of silicon-modification thresholds and morphology", Appl. Phys.A, Vol. 74, No. 1, pp. 19 - 25, JAM.2002.

[0011] The present invention now utilizes the finding that even when the layer structure is exposed to a pressure below the threshold fluence Φ S of the layer system for ablating the structural layer, although no ablation of the structural layer occurs, the layer structure is altered, in particular a reduction in the threshold fluence Φ B1 in the processing area B1 exposed to laser radiation of fluence Φ L1 in sub-step B1. Sub-step B1 thus generates a lower threshold fluence Φ B1 in the layer structure in the processing area B1, compared to the threshold fluence Φ S in the non-processed areas of the layer structure.

[0012] In sub-step B2, the layer structure is exposed to laser radiation in a second processing area B2 with a second fluence Φ L2 , wherein the second fluence Φ L2 is also smaller than the threshold fluence Φ S. As a result, no ablation takes place in the areas that were not exposed to laser radiation of fluence Φ L1 in sub-step B1, since the second fluence Φ L2 of the laser radiation in sub-step B2 is smaller than the threshold fluence Φ S. However, in the areas in which the processing area B2 overlaps with the processing area B1, ablation of the structural layer takes place because the second fluence Φ L2 of the laser radiation in sub-step B2 is greater than the threshold fluence Φ B1 in the first processing area B1.

[0013] Since the second processing area covers only a partial area of the first processing area B1, the ablation of the structural layer in sub-step B2 takes place in an area which is smaller than the processing area B1 and also smaller than the processing area B2 and roughly corresponds to the intersection between the processing areas B1 and B2, i.e. the area in which the processing area B2 overlaps with the processing area B1.

[0014] A further advantage is that, for a given numerical aperture of an optical imaging system for the laser radiation, smaller structure sizes can be achieved than with previously known methods, or a smaller numerical aperture can be selected for a given structure size, typically enabling a shorter processing time.

[0015] Advantageously, in sub-step B1, the layer structure is exposed to laser radiation of the first fluence Φ L1 , which is greater than an incubation fluence Φ I of the layer structure. The incubation fluence Φ I represents a lower limit for the laser fluence, above which a significant change in the threshold fluence of the layer structure occurs in the first processing area B1 exposed to laser radiation. The incubation fluence Φ I also depends on material parameters of the layer structure, in particular the layer materials and the thickness of the individual layers, and can be determined in a simple series of tests by increasing the laser fluence starting from a low laser fluence and constantly checking whether a change in the threshold fluence has been achieved. A change in the threshold fluence can typically already be detected optically. In addition, techniques for determining such limit fluences are known and, for example, described in JMLiu "Simple technique for measurements of pulsed Gaussian-beam spot sizes", Optics Letters, Vol. 7, No. 5, May 1982 beschrieben:.

[0016] Liu describes the method for determining two threshold fluences that correspond to two modifications, in this case the formation of a pre-damaged zone (Φ I ) and the ablation of an overlying layer (Φ S ), where Φ I <Φ S . It is hereby proposed how this method can be extended to determine the threshold fluence Φ B1: first, the threshold fluences Φ I and Φ S are determined for the substrate in question using the Liu method. Next, a fluence Φ 0 is selected such that Φ I < Φ 0 < Φ B1 . Spatially separated locations are each subjected to a pulse with this fluence. In a second step, the same locations are subjected to increasing fluence. Analogous to Liu's method, the threshold fluence Φ B1 for ablation on a pre-damaged substrate can then be determined by extrapolating the opened area to 0.

[0017] The method according to the invention has the advantage that ablation of the structural layer occurs only in the overlapping area of the processing areas B1 and B2. This allows structures with precise dimensions, in particular thin lines with a line width smaller than the diameter of the laser beam, to be formed in the processing area. Thus, compared to the methods known from the prior art, less focusing is required, and the structure size can be reduced while maintaining the same focusing.

[0018] Furthermore, laser radiation with a fluence lower than the threshold fluence Φ S is used in process steps B1 and B2. This results in a lower maximum energy input into the layer structure compared to the processes known from the prior art, and thus there is a lower risk of damage, particularly to the carrier layer.

[0019] Advantageously, the second processing area B2 covers less than 50%, in particular less than 20%, of the area of the first processing area B1. This achieves the previously described reduction in the layer structure without requiring an increase in the focus of the laser beam. In particular, it is advantageous for the second processing area B2 to cover in the range of 1% to 50%, in particular 5% to 20%, of the area of the first processing area B1.

[0020] In an advantageous embodiment, the structural layer has a lower absorption than the carrier layer by a factor of 2, preferably by a factor of 10, particularly preferably by a factor of 100 compared to the laser radiation used in process step B1 and preferably compared to the laser radiation used in process step B2. This results in the advantage of reduced energy input into the structural layer by the laser radiation, thus promoting ablation at the interface between the carrier layer and the structural layer.

[0021] In order to additionally reduce influences due to possible damage to the layer structure, in particular to the carrier layer, caused by the laser radiation, it is advantageous that a healing step is carried out after process step B1, with an energy input, preferably a heating, at least in the processing area B1, preferably at least in the processing areas B1 and B2.

[0022] By introducing energy into the processing area(s), in particular heating at least the processing area(s), preferably the entire layer structure, annealing can take place in a manner known per se, which in the case of semiconductor structures is known to the person skilled in the art as annealing.

[0023] The annealing step is preferably performed by locally exposing the layer structure to laser radiation. This has the advantage that the annealing step does not affect areas of the layer structure outside the processing areas. It has also been observed that the subsequent annealing step can contribute to the complete opening of previously incompletely ablated areas.

[0024] Advantageously, in process step B1, a local modification of the carrier layer takes place, in particular a local change in the crystal structure of the carrier layer, preferably an amorphization of the carrier layer in the processing area B1. This reliably reduces the threshold fluence in the processing area B1.

[0025] The local modification of the carrier layer in the processing area B1 is preferably carried out at a depth of at least 10 nm, in particular at least 20 nm, and preferably at least 50 nm, starting from the interface between the carrier layer and the structural layer. This ensures that ablation occurs in sub-step B2 due to the reduced threshold fluence in sub-step B1.

[0026] In process step B1 and preferably also in process step B2, an advantageous embodiment uses pulsed laser radiation. The use of pulsed laser radiation has the advantage of inducing the necessary temperature gradients required for the local modification.

[0027] In an advantageous further development, the pulsed laser radiation has a pulse duration that is less than 1 ns, preferably less than 1 ps, at least in method step B1.

[0028] The further development described above is based on the finding that a laser pulse with the stated pulse duration can lead to irreversible amorphization of the structural layer in the first processing area B1 in a simple and reliable manner. This is because the comparatively short pulse duration also means that a small amount of heat is introduced into the structural layer when it is exposed to laser radiation in the first processing area B1. This allows the structural layer to be amorphized in the first processing area, as mentioned above. In addition, the structural layer releases the previously introduced heat to its surroundings in a very short cooling time, so that the amorphized area cannot recrystallize. By achieving irreversible amorphization, the threshold fluence in the first processing area B1 can be permanently reduced.

[0029] In a further advantageous embodiment of the method according to the invention, the use of pulsed laser radiation enables the use of pulsed laser radiation from a common laser source in process steps B1 and B2. Thus, laser pulses from one laser source are used to irradiate both the first processing area B1 and the second processing area B2. Advantageously, the fluences Φ L1 and Φ L2 are identical.

[0030] Advantageously, a laser pulse of the laser source is split into at least a first and a second laser pulse by means of a beam splitter, and the first laser pulse is used for method step B1 and the second laser pulse is used for method step B2.

[0031] In an advantageous development of the method described above, a time offset between the impact of the first laser pulse on the first processing area B1 and the impact of the second laser pulse on the second processing area B2 is achieved by the second laser pulse traveling through a longer optical path than the first laser pulse.

[0032] This has the advantage that the process can be carried out using a cost-effective setup with only one laser source.

[0033] The device for structuring a structural layer by means of laser radiation comprises a laser beam source for generating a pulsed output beam, a beam splitter arranged in the beam path of the output laser beam for splitting the output laser beam into at least a first and a second processing laser beam.

[0034] The device is designed to apply the first processing laser beam to a first processing region B1 of a structural layer and the second processing laser beam to a second processing region B2 of the structural layer, wherein the second processing region B2 covers only a partial region of the first processing region B1 and the optical path length of the first processing laser beam is shorter than the optical path length of the second processing laser beam. In an advantageous development, the device has an optical element, in particular a beam splitter, which is designed to divide the fluences of the two optical beam paths in a predetermined ratio. In a further advantageous development, an attenuator of the device is additionally arranged as an optical element in one of the beam paths of the first or second processing laser beam in order to reduce the intensity.

[0035] It is therefore advantageous that the laser power differs in both beam paths.

[0036] The time offset of the impact of the two laser pulses is thus achieved by the optical path length difference of the first and second processing laser beams. The path length difference is preferably in the range of 1 cm to 10 m, particularly preferably in the range of 1 m to 10 m. For example, a path length difference of approximately 300 cm results in a time difference between the impact of the first and second laser pulses of approximately 10 ns. Such a time difference is sufficient for typical laser pulses, which typically have a pulse length in the picosecond or femtosecond range.

[0037] Advantageously, a laser source is used which emits laser pulses with a time interval between two laser pulses which is greater than the aforementioned time difference between the impact of the first and the second laser pulse.

[0038] Advantageously, laser radiation in the wavelength range of 200 nm to 1100 nm, in particular 300 nm to 600 nm, is used in method step B1 and preferably also in method step B2. This allows the use of conventional apparatus and lasers. The aforementioned preferred wavelength ranges for the laser radiation are particularly advantageous when using the method for processing a semiconductor component, in particular a carrier layer, which is a semiconductor layer, particularly preferably a silicon layer.

[0039] Preferably, in process step B1 and more preferably also in process step B2, laser radiation with a fluence in the range 0.01 J / cm 2< to 0.8 J / cm 2<, in particular in the range 0.05 to 0.2 J / cm 2< is used.

[0040] Laser radiation in such a fluence range is particularly advantageous for processing a layer structure with a silicon layer as the carrier layer.

[0041] A pulse duration of less than 1 ns, especially less than 1 ps, is advantageous.

[0042] There is also a need to be able to vary the line width during the process, e.g., to create wedge-shaped lines that offer a better trade-off between conductivity and shading. In an advantageous embodiment, the degree of coverage of the first processing area B1 and the second processing area B2 is therefore varied to vary the line width of the resulting pattern.

[0043] In particular, it is advantageous to continuously reduce or increase the degree of coverage in order to achieve structuring with decreasing or increasing width.

[0044] As described above, the method according to the invention is particularly suitable for processing a structural layer in the production of a semiconductor component, preferably a large-area semiconductor component, in particular a photovoltaic solar cell.

[0045] The carrier layer is therefore preferably a semiconductor layer, particularly preferably a silicon layer and / or a semiconductor wafer.

[0046] The structural layer can be formed as a known structural layer and / or masking layer. For typical applications, particularly in the field of photovoltaics, it is advantageous for the structural layer to be a dielectric layer.

[0047] It is within the scope of the invention for the structural layer to be arranged indirectly on the carrier layer with the interposition of additional layers. To achieve precise ablation of the structural layer, it is advantageous for the structural layer to be arranged directly on the carrier layer.

[0048] The layer system is preferably used for producing a semiconductor component, in particular a photovoltaic solar cell. In particular, it is advantageous for the structural layer to be used as a masking layer for forming a selective doping and / or a metallic contact structure of the semiconductor component.

[0049] Further advantageous embodiments and advantageous features are explained below using exemplary embodiments and the figures. Herein: Figure 1 shows schematic representations of partial steps of a method according to the invention; Figure 2 shows plan views of overlapping processing areas; and Figure 3 shows a device, not part of the invention.

[0050] In Figure 1 Substeps of an exemplary embodiment of a method according to the invention are shown schematically. In method step A, a layer structure is provided with a carrier layer 1, which is designed as a silicon wafer for producing a photovoltaic solar cell. A structural layer 2, designed as a dielectric layer, in this case as a silicon oxide layer with a thickness of 100 nm, is arranged directly on the carrier layer 1. The silicon wafer has a thickness of 150 µm.

[0051] The carrier layer 1 has dopings known per se for forming a photovoltaic solar cell, in particular an emitter arranged on the upper front side with a p-doping and a base doping of the opposite doping type, an n-doping.

[0052] In a process step B, the layer structure is exposed to laser radiation in order to remove the structural layer 2 in partial areas.

[0053] In a sub-step B1, the layer structure is exposed to a first fluence Φ L1 of the laser radiation by means of laser radiation 3 in a first processing area B1.

[0054] This reduces the threshold fluence for ablating the structural layer 2 in a modification area 4: In the present case, in sub-step B1, laser radiation with a wavelength of 515 nm, a pulse duration of 180 fs, a beam quality of M 2< <1.1, a 1 / e 2< beam diameter of 100 µm at the focus, and a first fluence Φ L1 = 0.1 J / cm 2< is used. This results in a modification area approximately the width of the first processing area B1 and, in this case, with a depth of <1 µm.

[0055] In the modification region, the threshold fluence Φ S of the layer structure for ablating the carrier layer 1 is reduced from the original Φ S = 0.130 J / cm 2 to a reduced threshold fluence Φ B1 of 0.086 J / cm 2 . The first fluence Φ L1 used in sub-step B1 is thus below the threshold fluence Φ S , so that although a modification of the modification region 4 occurs with a reduction of the threshold fluence Φ S in the modification region 4, there is no ablation of the structural layer 2.

[0056] In a sub-step B2, the layer structure is exposed to laser radiation 5 in a second processing area B2. The laser radiation 5 has a second fluence Φ L2, which is greater than the reduced threshold fluence Φ B1 in the modification area 4 and smaller than the threshold fluence Φ S.

[0057] In the present case, the laser radiation 5 has the following parameters: a wavelength of 515 nm, a pulse duration of 180 fs, a beam quality of M 2< <1.1, a 1 / e 2< beam diameter of 100 µm at the focus, and a first fluence Φ L1 = 0.1 J / cm 2< .

[0058] Since the second fluence Φ L2 is greater than the reduced threshold fluence Φ B1, an ablation of the structural layer 2 takes place in the ablation area 6 in sub-step B2. The ablation area 6 roughly corresponds to the area in which the processing area B2 covers the processing area B1. In this case, the second processing area B2 covers a partial area of the first processing area B1, which corresponds to approximately 40% of the area of the processing area B1. The exposure to laser radiation in sub-step B2 also leads to a modification of the structural layer in a second modification area 7. In particular, in the overlap area of the first modification area 4 and the second modification area 7, and thus in the overlap area between the first processing area B1 and the second processing area B2, a more pronounced modification of the structural layer 2 takes place.

[0059] For this reason, annealing takes place in process step C, in which the layer structure is heated to a temperature in the range of 500 °C to 1000 °C, in this case 900 °C, for a period of time in the range of 1 hour to 5 minutes, in this case 10 minutes, in order to anneal the modification in the modification regions 4 and 7.

[0060] In Figure 2 Various designs of processing areas B1 and B2 are shown in a top view.

[0061] First, in the upper area of the Figure 2the use of laser radiation for ablating a structural layer according to the prior art is shown: Accordingly, the layer structure is exposed to laser radiation, which typically has a circular diameter. The laser radiation 8 according to the prior art has a fluence that is greater than the threshold fluence of the layer structure, so that ablation of the structural layer occurs in the circular region 8. The intensity of the laser radiation typically has a Gaussian shape. Accordingly, in a circular edge region shown in dashed lines, no ablation of the structural layer occurs, since here the intensity and fluence of the laser radiation are below the threshold fluence, but at least an at least slight modification of the carrier layer does occur. This modification region 9 thus lies in a region in which the structural layer is not removed.

[0062] Sub-images a to c depict various shapes of processing areas B1 and B2. Embodiments a and b utilize laser radiation with a circular cross-section, while the embodiment in sub-image c utilizes laser radiation with a square cross-section. The non-hatched overlapping areas, in which ablation of the carrier layer 1 occurs, are formed accordingly. Sub-images a and b differ in that sub-image b exhibits a larger overlap U between processing areas B1 and B2, and thus ablation of the carrier layer occurs over a larger area.

[0063] If several machining operations are now carried out with offset machining areas B1 and B2, especially along the direction A in Figure 2a or 2b, adjacent or overlapping ablation areas can be created, and thus, for example, linear, in particular at least approximately rectilinear openings can be created by ablating the structural layer. In a further development, the degree of coverage between processing areas B1 and B2 is varied, in this case continuously reduced, so that a linear opening of the structural layer with decreasing width is created. Likewise, a linear opening of the structural layer with increasing width can be created by continuously increasing the degree of coverage.

[0064] In Figure 3 A device for structuring a structural layer using laser radiation is shown. The device has a laser beam source 10, which in this case is designed as a solid-state laser, to generate an output laser beam 11 consisting of laser pulses with a wavelength of 515 nm and a pulse length of 180 fs.

[0065] By means of a beam splitter 12 of the device, the output beam 11 is split into a first processing laser beam 13 and a second processing laser beam 14. The splitting occurs with identical intensities, so that the laser pulses of the first processing laser beam and the second processing laser beam have approximately the same laser parameters.

[0066] The first processing beam 13 is imaged via an optical lens 15 onto a processing area B1 of a substrate 16, which has carrier layer 1 and structural layer 2. The second processing laser beam 14 is deflected via three optical mirrors 17 and also imaged via the optical lens 15 onto a processing area B2 of the substrate 16.

[0067] In the representation according to Figure 3For clarity, the laser beams 11, 13 and 14 are shown as thin lines. In fact, the first processing laser beam 13 and the second processing laser beam 14 overlap on the surface of the substrate 16, so that in plan view a partial overlap according to Figure 2a ) consists.

[0068] Due to the deflection via the three mirrors 17, the optical path length between beam splitter 12 and substrate 16 of the second processing laser beam 14 is greater than that of the first processing laser beam 13 between beam splitter 12 and substrate 16. The difference in the optical path length is approximately 300 cm, so that the laser pulse in the processing area B2 strikes the substrate 16 approximately 10 ns later than the laser pulse in the processing area B1.

[0069] The laser beam source 10 is designed to emit laser pulses at a time interval greater than the time difference between the laser pulses' impact. In this case, laser pulses are emitted by the laser beam source 10 at a time interval of 5 ns. List of reference symbols

[0070] 1Carrier layer 2Structural layer 3Laser radiation of fluence Φ L1 4First modification region 5Laser radiation of fluence Φ L2 6Ablation region 7Second modification region 8Laser radiation state of the art 9Modification region state of the art 10Laser beam source 11Output laser beam 12Beam splitter 13First processing laser beam 14Second processing laser beam 15Optical lens 16Substrate 17Optical mirrors B1first processing area B2second processing area UOverlap

Claims

1. Method for structuring a structural layer (2) by means of laser radiation, with the method steps of A. Providing a layer structure with at least one substrate layer and at least one structural layer (2) arranged on the substrate layer and B. Applying laser radiation to the layer structure, in order to remove the structural layer (2) in sections, wherein in method step B in one sub-step B1, laser radiation is applied to the layer structure in a first processing region B1 with a first fluence ΦL1 of the laser radiation, such that, in the first processing region B1 to which laser radiation is applied, a threshold fluence ΦS of the layer system is lowered to a reduced threshold fluence ΦB1 < ΦS for ablation of the structural layer (2), wherein the first fluence ΦL1 is below the threshold fluence ΦS of the layer system and in one sub-step B2, laser radiation is applied to the layer structure in a second processing region B2 with a second fluence ΦL2, characterized in that the second fluence ΦL2 is greater than the reduced threshold fluence ΦB1 of the first processing region B1 and lower than the threshold fluence ΦS, and in that the second processing region B2 only covers a section of the first processing region B1.

2. Method according to claim 1, characterized in that the second processing region B2 covers less than 50%, in particular less than 20% of the area of the first processing region B1, in particular, in that the second processing region B2 covers in the range of 1% to 50%, in particular 5% to 20%, of the area of the first processing region B1.

3. Method according to any one of the preceding claims, characterized in that the structural layer (2) has a lower absorption by a factor of 2, preferably by a factor of 10, particularly preferably by a factor of 100, relative to the substrate layer compared to the laser radiation used in method step B1 and preferably compared to the laser radiation used in method step B2.

4. Method according to any one of the preceding claims, characterized in that an annealing step takes place after method step B1, with an energy input, preferably heating, at least in the processing region B1, preferably at least in the processing regions B1 and B2, and in particular, in that the annealing step takes place between the method steps B1 and B2, preferably, in that the annealing step is performed by means of local application of laser radiation to the layer structure.

5. Method according to any one of the preceding claims, characterized in that in method step B1, a local modification of the substrate layer, in particular a local change to a crystal structure of the substrate layer, preferably an amorphisation of the substrate layer, takes place in the processing region B1, in particular, in that the local modification of the substrate layer in the processing region B1 has a depth of at least 5nm, in particular at least 10nm, preferably at least 100nm.

6. Method according to any one of the preceding claims, characterized in that pulsed laser radiation is used in method step B1 and preferably in method step B2, wherein, in particular, the pulsed laser output has a pulse duration, at least in method step B1, which is less than 1ns, preferably less than 1ps.

7. Method according to claim 6, characterized in that in method step B1 and B2, pulsed laser radiation from a common laser source is used, wherein a laser pulse of the laser source is divided into at least a first and a second laser pulse by means of a beam splitter and the first laser pulse is used for method step B1 and the second laser pulse is used for method step B2, in particular in that a time delay between the impact of the first laser pulse on the first processing region B1 and the impact of the second laser pulse on the second processing region B2 is achieved by the second laser pulse passing through a longer optical path than the first laser pulse and preferably, in that the laser output differs in both beam paths.

8. Method according to any one of the preceding claims, characterized in that in method step B1 and preferably in method step B2, laser radiation in the wavelength range of 200 nm to 1100nm, in particular 300 nm to 600 nm, is used.

9. Method according to any one of the preceding claims, characterized in that in method step B1 and preferably in method step B2, laser radiation with a fluence in the range of 0.01 to 0.8 J / cm2, in particular in the range of 0.05 to 0.2 J / cm2, is used.

10. Method according to any one of the preceding claims, characterized in that the substrate layer is a semiconductor layer, in particular a silicon layer and / or a semiconductor wafer and / or in that the structural layer (2) is a dielectric layer.

11. Method according to any one of the preceding claims, characterized in that the structural layer (2) is arranged directly on the substrate layer.

12. Method according to any one of the preceding claims, characterized in that the layer system is used to produce a semiconductor component, in particular a photovoltaic solar cell, preferably, in that the structural layer (2) is used as a masking layer for creating a selective doping and / or a metallic contacting structure of the semiconductor component.

13. Method according to any one of the preceding claims, characterized in that the degree of coverage of the first processing region B1 and the second region B2 is varied, in order to vary a line width of the structuring produced.

14. Method according to any one of the preceding claims, characterized in that the first processing region B2 only covers a section of the second processing region B1.