Laser lithography apparatus for producing a three-dimensional structure and method for operating a laser lithography apparatus

Abstract

The invention relates to a laser lithography apparatus (10) for producing a three-dimensional structure in a lithography material (12), having a lithography material receptacle (14) for receiving the lithography material (12), a laser beam source (15) for creating a plurality of laser writing beams (26), a lens (70) for focusing each laser writing beam (26) in a focus assigned to the respective laser writing beam (26), and a scanning device (78) for displacing the foci. A waveguide arrangement (54) is provided, the latter comprising a plurality of waveguides (56) for guiding the laser writing beams (26), with each laser writing beam (26) being assigned a respective waveguide (56) and with the waveguides (56) being arranged in the beam path between the laser beam source (15) and the lens (70).

Description

[0001] Title: Laser lithography device for producing a three-dimensional structure and method for operating a laser lithography device

[0002] Description

[0003] The invention relates to a laser lithography device for producing a three-dimensional structure and a method for operating a laser lithography device.

[0004] The technique referred to in this context as laser lithography is also known as stereolithography or direct laser writing. In this technique, structures are written using a laser writing beam into a usually initially liquid, photosensitive substance, which in this context is referred to as lithography material. The laser writing beam triggers a local solidification effect in the lithography material. The solidification occurs, for example, due to local polymerization of the lithography material induced by photon absorption. In the field of optical lithography, such a lithography material is also called photoresist. In the field of stereolithography, it is also referred to as resin.

[0005] Laser lithography, or direct laser writing, is advantageously used in the creation of micro- or nanostructures when high precision is desired while maintaining design freedom and flexibility in shaping. Unlike mask lithography, for example, various structures can be written without the structure being predefined by a mask or similar device.

[0006] Various techniques are known for this, which can lead to varying degrees of direct contact between the focusing optics or its optical termination element and the lithography material. Basically, it is known that the desired overall structure is created by sequentially writing a series of substructures (e.g., layer by layer or slice by slice), which then combine to form the desired structure.

[0007] In one type of known technique, the writing beam strikes the surface of a volume of lithographic material and leads to local solidification at the surface. These processes are generally based on linear processes such as single-photon absorption and the resulting local change in the lithographic material. In order to write three-dimensional structures, in such processes, after writing a layer, an additional layer of lithographic material is applied in an application step. This can be achieved, for example, by gradually lowering a substrate with the structure to be written onto it into a bath of lithographic material and structuring the surface using the writing beam. With such techniques, it can happen that the end element of the focusing optics comes into contact with lithographic material.Another approach exploits the physical principle of two-photon polymerization, or more generally multi-photon polymerization, to achieve solidification of lithographic material even within a volume of lithographic material, i.e., even below the surface. This is made possible by matching the writing beam and lithographic material in such a way that a solidification effect occurs with the assistance of nonlinear effects. For example, the writing beam is selected in a spectral range that would normally not trigger a solidification effect in the lithographic material. For example, the lithographic material and writing beam can be matched in such a way that induced solidification occurs only upon absorption of two or more photons of the writing beam (two-photon polymerization or multi-photon polymerization).In this context, the term multi-photon polymerization refers to the induced polymerization by the absorption of two or more photons. For the purposes of this description, the term "multi-photon absorption" also includes the process of "two-photon absorption" and "two-stage absorption." The conditions required for multi-photon polymerization are generally only achieved in a zone of increased intensity. This zone of increased intensity is typically provided in an area around a focus of the laser writing beam. The focus is therefore a beam waist of the laser writing beam, which is generated by suitable optics, for example, beam guiding optics, beam shaping optics, and / or an objective lens.For the lithographic production of extended 3D structures, the focus can then be moved through a volume of lithographic material according to geometry description data and locally trigger a solidification process.

[0008] The production of three-dimensional structures using two-photon polymerization often takes place with a working distance of 100 pm (micrometers) to 20 mm (millimeters). The working distance is the distance between the focus and an optical closure element of a lens used to create the focus. At such short working distances, contact between the lens and the lithography material can often not be prevented. In particular, the lens is immersed in the lithography material. A manufacturing process in which the lens is at least partially immersed in the lithography material can also be referred to as dip-in multi-photon polymerization. During the production of three-dimensional structures, the lithography material often comes into contact with the lens and, in particular, with the optical closure element.

[0009] Regardless of the specific technique, one challenge is that the writing process for complex structures can be time-consuming, and acceleration should generally not be achieved at the expense of precision.

[0010] EP 4 163 083 A1 discloses a device for the lithography-based production of a three-dimensional component. The device has a beam splitter for splitting an input beam into several beams, which are focused on focal points within a material. Furthermore, the device has a number of acousto-optical modulators corresponding to the number of beams. An acousto-optical modulator is arranged in each beam path to shift the focal point of the respective beam.

[0011] The invention is based on the object of enabling the precise production of three-dimensional structures using laser lithography technology.

[0012] This object is achieved by a laser lithography device having the features of claim 1 and by a method having the features of claim 16. Advantageous and preferred embodiments of the invention are contained in the further claims.

[0013] A laser lithography device according to the invention is designed to produce a three-dimensional structure in a lithography material. The laser lithography device has a lithography material holder, a laser beam source, an objective lens, a scanning device, and a waveguide arrangement. The lithography material holder is designed to hold the lithography material. The laser beam source is designed to generate a plurality of laser writing beams. The objective lens is designed to focus the laser writing beams into a focus assigned to the respective laser writing beam. The scanning device is designed to shift the focuses. The waveguide arrangement has a plurality of waveguides for guiding the laser writing beams. One waveguide is assigned to each laser writing beam. The waveguides are arranged in the beam path between the laser beam source and the objective lens.Each waveguide has a first end and a second end opposite the first end. Each first end is configured to couple in a laser writing beam, and each second end is configured to couple out the laser writing beam coupled into the first end. The second ends of the plurality of waveguides are held by a holding matrix of the waveguide arrangement.

[0014] The waveguide arrangement can establish a defined, spatial arrangement of the laser writing beams relative to each other and maintain this robustness against interference. The waveguide arrangement also enables a compact design, allowing the laser lithography device to be implemented in a space-saving manner. This allows the laser lithography device to produce particularly precise and interference-resistant three-dimensional structures in a space-saving manner.

[0015] The multiple laser writing beams and the associated waveguide arrangement enable parallelized fabrication of structures. Using multiple laser writing beams reduces the fabrication time of the three-dimensional structure, thus enabling particularly rapid fabrication or production of the three-dimensional structure.

[0016] The laser writing beams impinge on the lithographic material or are focused into the lithographic material. The laser writing beams and the lithographic material can be coordinated in such a way that the lithographic material can be converted, in particular polymerized or solidified, into an exposed state locally within a plurality of regions in or around the respective foci of the laser writing beams to produce the three-dimensional structure by means of multi-photon polymerization.

[0017] The laser writing beams can pass through a frequency doubling device for doubling a frequency of the laser writing beams. The frequency doubling device can be arranged between the waveguide arrangement and the lens. The frequency doubling device can comprise a nonlinear crystal, for example, a lithium niobate crystal. The nonlinear crystal can be arranged in phase with the laser writing beams such that at least a portion of each laser writing beam is frequency-doubled after passing through the nonlinear crystal. The frequency doubling device can be held by the holding matrix.

[0018] The lithographic material holder can be configured to hold the lithographic material for the purpose of producing the three-dimensional structure. In particular, it is provided that the lithographic material holder can hold a volume of lithographic material such that the laser writing beams can be focused into the lithographic material. The lithographic material holder can hold the lithographic material such that the lens can be immersed in the lithographic material for the purpose of producing the three-dimensional structure.

[0019] Preferably, the lithographic material holder is designed to hold the lithographic material in position for creating the three-dimensional structure. The lithographic material holder can be referred to as a lithographic material carrier.

[0020] The lithography material holder can hold lithography material. The lithography device can also contain the lithography material.

[0021] Various geometric designs are conceivable for the lithographic material holder, each of which can offer different advantages. The lithographic material holder can be designed, for example, as a tub, container, or pot for holding the lithographic material. It is also conceivable for the lithographic material holder to be designed as a table, carrier, or substrate on which the lithographic material rests in droplet form or in layer form. It is also conceivable for a substrate, in particular in the form of a wafer, to be placed on the table for generating the three-dimensional structure, and for the lithographic material to rest on the substrate in droplet form or in layer form. The table can be a machine table of a lithography device.

[0022] The lithographic material holder can be designed to be transparent to the laser writing beams, at least in part. For example, walls, floors, or cover plates of the lithographic material holder, if present in the specific design, can be designed to be transparent to the laser writing beams. This allows the laser writing beams to be focused into the lithographic material through the lithographic material holder. For example, irradiation or exposure of the lithographic material from below can be enabled.

[0023] Each laser writing beam can propagate along an associated beam axis. The beam axes of the laser writing beams can be different from one another. The beam axes of the laser writing beams can be oriented parallel or offset from one another. A beam axis can be understood as a longitudinal axis of the respective laser beam that extends in the direction of its propagation. In this respect, the beam axis can be defined by the Poynting vector of the radiation. The Poynting vector can be an effective Poynting vector. The effective Poynting vector can, for example, be an intensity-weighted, averaged pointing vector.

[0024] Each laser writing beam can be a continuous-wave laser beam or a pulsed laser beam. In particular, a laser pulse of the laser writing beam can have a pulse duration of 50 femtoseconds to 500 nanoseconds. Each laser writing beam can be configured to convert the lithography material into an exposed state, in particular to solidify it, by means of two- or multiphoton polymerization.

[0025] Focusing the plurality of laser writing beams can comprise forming a plurality of foci. In particular, all laser writing beams are focused using the same lens, in particular such that each laser writing beam has its own, assigned focus. The arrangement is preferably such that the foci lie within a volume of lithographic material, preferably below the surface of the lithographic material.

[0026] For example, the lens can have a numerical aperture in the range from 0.01 to 1.6. High numerical apertures, in particular, can contribute to high precision.

[0027] The lens can be immersed in the lithography material during the creation of the three-dimensional structure. In other words, the three-dimensional structure can be created by dip-in multi-photon polymerization.

[0028] The scanning device can be configured to shift the focus relative to the lithography material holder. Shifting can be understood as performing a movement. Each shift can be performed by means of a drive, in particular a linear drive and / or a rotary drive, of the scanning device. In other words, the scanning device can have actuators, in particular servomotors or linear actuators, for the shifting.

[0029] The focus can be shifted relative to the lithographic material holder by shifting the lithographic material holder. During the shift of the focus relative to the lithographic material holder by shifting the lithographic material holder, the holding matrix and / or the lens can be stationary. Additionally or alternatively, the scanning device can be configured to shift the focus relative to the lithographic material holder by shifting the lens.

[0030] Alternatively or in addition to the aforementioned options, the focus can be shifted relative to the lithographic material holder by shifting the focus relative to the lithographic material holder by means of an optical deflection device of the scanning device by deflecting the laser writing beams.

[0031] The optical deflection device can be arranged between the waveguide arrangement and the lens. The optical deflection device can comprise a scanner mirror, a mirror galvanometer, an acousto-optical deflector, an acousto-optical modulator, and / or a membrane mirror for deflecting the laser writing beams.

[0032] Each waveguide can be configured to guide or direct the respective laser writing beam. Each waveguide can be configured as or comprise a hollow-core fiber or a solid-core fiber.

[0033] The second ends can be spaced apart from one another in the propagation direction of the laser writing beams coupled out from the second ends. In other words, each second end of the plurality of waveguides can have an end face configured to couple out the laser writing beam coupled into the first end, wherein the end faces of the second ends are arranged in different planes. In other words, the second ends protrude by different distances. This advantageously enables simultaneous exposure of the lithography material in different planes. This can increase the stability of the three-dimensional structure during the creation or printing process. In addition, the three-dimensional structure can be created more quickly. In particular, this can enable the realization of a higher packing density of the focuses.The holding matrix can be made of plastic, resin, glass, or silicon, in which the second ends of the waveguides are at least partially embedded, particularly in sections. Within the holding matrix, the waveguides can run parallel and offset from one another.

[0034] The holding matrix can comprise a substrate with precision-machined V-shaped notches for inserting the waveguides. Alternatively, the holding matrix can comprise a microstructured perforated plate, wherein the waveguides can be inserted into holes in the perforated plate. Alternatively, the holding matrix can comprise a plurality of ferrules, wherein the waveguides can be inserted into the ferrules. Alternatively, the holding matrix can be a welded connection between the second ends of the waveguides of the waveguide array.

[0035] In a further development of the laser lithography device, the second ends of the plurality of waveguides are held by the holding matrix in a linear arrangement or in a two-dimensional arrangement. The linear arrangement and / or the two-dimensional arrangement can be a regular arrangement.

[0036] If the second ends are arranged in a linear configuration, the second ends can be equally spaced from one another. If the second ends are arranged in a two-dimensional configuration, the second ends can be arranged in a crystal-like structure. Crystal-like structure can be understood to mean that the second ends are arranged like a dot lattice with a periodic, repeating pattern.

[0037] In a further development of the laser lithography device, the distance between two adjacent second ends of the plurality of waveguides is 25 pm to 1000 pm, in particular 115 pm to 600 pm. This results in a particularly compact waveguide arrangement.

[0038] In a further development of the laser lithography device, each second end of the plurality of waveguides has an end face configured to decouple the laser writing beam coupled into the first end. The end faces of the second ends are arranged in a plane. The plane can be oriented perpendicular to a propagation direction of the decoupled laser writing beams.

[0039] In a further development of the laser lithography device, the scanning device is configured to shift the foci relative to the lithography material holder by shifting the holding matrix. For this purpose, the scanning device can comprise actuators, in particular servo motors or linear actuators, preferably vibrating piezo actuators, which shift the holding matrix.

[0040] The waveguides, in particular their second ends, can follow the movement of the holding matrix, for example, through corresponding (elastic) deformation, bending, or the like. The displacement of the holding matrix can be achieved by means of a movement of the holding matrix transverse to the laser writing beams and / or a movement of the holding matrix longitudinal to the laser writing beams.

[0041] During the shifting of the focus relative to the lithography material holder by shifting the holding matrix, the lens can be stationary or shifted together with the holding matrix. Shifting the holding matrix together with the lens can mean that the holding matrix and the lens are shifted simultaneously in the same direction and by the same distance by the scanning device. The joint shifting of the holding matrix and the lens can be achieved, for example, using the same drive of the scanning device.

[0042] In a further development of the laser lithography device, each waveguide is formed as a hollow-core optical fiber. This significantly reduces unwanted absorption and significantly increases the destruction threshold of the waveguides. Furthermore, each hollow-core fiber can be tuned to its associated laser writing beam such that no pulse broadening of a laser pulse of the laser writing beam occurs after passing through the hollow-core fiber. The hollow-core optical fiber can be an optical fiber having a hollow fiber core. In a further development of the laser lithography device, each waveguide is selected from the group comprising: HC-PCF fibers, in particular HC-Kagome fibers, HC-PBGF fibers, HC-ARF fibers, HC-IC fibers, RH fibers, LMA fibers, and PCF fibers.

[0043] HC-PCF fibers can be called Hollow Core Photonic Crystal Fibers, HC-Kagome fibers can be called Hollow Core Kagome Fibers, HC-PBGF fibers can be called Hollow Core Photonic Bandgap Fibers, HC-ARF fibers can be called Hollow Core Anti-Resonant Fibers, HC-IC fibers can be called Hollow Core Inhibited Coupling Fibers, RH fibers can be called Radiation Hardened Fibers, LMA fibers can be called Large Mode Area Fibers, PCF fibers can be called Photonic Crystal Fibers. Photonic crystal fibers).

[0044] In a further development of the laser lithography device, the laser beam source has a demultiplexer unit configured to temporally divide a laser beam into at least a number of laser writing beams, in particular two, three, or four, by demultiplexing. The demultiplexer unit can be configured to temporally divide the laser beam into the plurality of laser writing beams by demultiplexing.

[0045] Temporal demultiplexing can be particularly advantageous for laser lithography when using two-photon or multi-photon polymerization. The lithographic material is converted into an exposed state, particularly polymerized or solidified, due to a nonlinear process. Therefore, when using a pulsed laser beam, the peak power of the individual laser pulses of the laser beam represents a relevant parameter for the two-photon or multi-photon polymerization process. Temporal demultiplexing of the laser beam results in the generation of laser writing beams with a higher peak power than laser writing beams generated by continuous beam splitting, for example, using a beam splitter. Continuous beam splitting can be understood as temporally continuous beam splitting or passive continuous beam splitting.Continuous beam splitting can be achieved using a passive optical element. Thus, temporal demultiplexing improves process efficiency in two-photon or multi-photon polymerization.

[0046] The laser beam source may comprise a laser module for generating the laser beam. The laser beam may be a continuous wave laser beam or a pulsed laser beam. In particular, a laser pulse of the pulsed laser beam may have a pulse duration of 50 femtoseconds to 500 nanoseconds.

[0047] The demultiplexer unit can be arranged between the laser module and the lens, in particular in the propagation direction of the laser beam.

[0048] Demultiplexing the laser beam can be a temporal and / or spatial demultiplexing of the laser beam. In particular, the temporal and spatial demultiplexing of the laser beam can occur simultaneously. Preferably, demultiplexing the laser beam can result in a temporal and spatial splitting of the laser beam. Splitting can mean deflecting, directing, decoupling, or extracting. Splitting can be performed using an optical switch. The optical switch can be a fiber-integrated optical switch.

[0049] Demultiplexing refers, in particular, to the opposite of multiplexer. Demultiplexing can involve directing or steering at least a power component of the laser beam to one of several outputs of the demultiplexer unit. The at least one power component of the laser beam directed or directed to the output can form a laser writing beam after passing through the output. Demultiplexing can involve alternately directing or steering at least power components of the laser beam to different outputs of the demultiplexer unit.

[0050] Demultiplexing can involve forming a laser writing beam by extracting a portion of the laser beam sufficient to transfer the lithographic material into an exposed state. In particular, the extraction can be performed such that the respective laser writing beam has at least the exposure dose, energy dose, and / or intensity sufficient for two- or multiphoton polymerization of the lithographic material at its focus. Exposure can be performed by means of two- or multiphoton polymerization.

[0051] For example, the lithographic material can be liquid in an unexposed state and solid in an exposed state. In other words, by locally converting the lithographic material into an exposed state, the lithographic material can be locally solidified. Subsequently, the unexposed and liquid lithographic material can be separated from the lithographic material that has solidified as a result of exposure, e.g., during a development step.

[0052] In an alternative example, the lithographic material may be solid in an unexposed state, and in an exposed state, its structure, e.g., chemical structure, molecular structure, cross-linking of the lithographic material, degree of polymerization, or similar, may be altered compared to the unexposed state. In other words, the local conversion of the lithographic material in an exposed state may be achieved by changing the cross-linking of the lithographic material. Subsequently, the unexposed lithographic material may be separated from the exposed lithographic material, e.g., in a development step.

[0053] If the laser beam is a pulsed laser beam, demultiplexing can be a pulse picking of individual laser pulses or laser pulse groups of the pulsed laser beam. If the laser beam is a continuous-wave laser beam, demultiplexing can be a formation of pulsed laser writing beams, wherein, in particular, a pulse width and / or a pulse length is equal to a switching duration of the demultiplexer unit. For example, duty cycle pulses can be generated by the demultiplexer unit. In other words, a continuous-wave laser beam can be overpulsed by the demultiplexer unit.

[0054] The demultiplexing of the laser beam can occur at a fixed time, periodically, or depending on a signal. For example, demultiplexing can occur in such a way that each laser writing beam formed by the demultiplexer unit is formed from the laser beam for a predetermined time period. The predetermined time period can be, for example, 100 femtoseconds to 500 nanoseconds.

[0055] The beam axes of the laser writing beams formed by the demultiplexer unit and a beam axis of the laser beam may differ from one another. In particular, the beam axis of the laser beam may be oriented orthogonally to the beam axes of the laser writing beams. In other words, the beam axes of the laser writing beams may not be collinear with the beam axis of the laser beam.

[0056] Demultiplexing allows the foci to be spatially and temporally separated from each other. In other words, the laser writing beams formed by the demultiplexer unit can be focused in such a way that the laser writing beams formed by the demultiplexer unit each form a focus, one after the other in time and one next to the other in space.

[0057] In one development of the laser lithography device, the laser beam is a pulsed laser beam comprising a plurality of laser pulses. The demultiplexer unit is designed such that demultiplexing occurs by coupling out a first group of laser pulses and at least one second group of laser pulses from the pulsed laser beam. The first group of laser pulses forms a first laser writing beam, and the second group of laser pulses forms a second laser writing beam. The first group of laser pulses and the second group of laser pulses can be separated from one another in time and space. The coupling out can be referred to as pulse picking. In one development of the laser lithography device, the demultiplexer unit has a plurality, in particular three, four, or five, of optical switches arranged one after the other in series in the beam path of the laser beam.In a switched position, each optical switch is configured to form a respective laser writing beam by coupling out a portion of the laser beam sufficient to transfer the lithographic material in an exposed state. In a non-switched position, no laser writing beam is coupled out. Each optical switch can be configured as a fiber-integrated optical switch.

[0058] The optical switches can be arranged in series in the propagation direction of the laser beam. The plurality of optical switches can be identical to the plurality of laser writing beams. One optical switch can be provided for each laser writing beam.

[0059] Each optical switch can have an acousto-optical modulator or an acousto-optical deflector for extracting a laser beam portion sufficient to transfer the lithography material into an exposed state from the laser beam. Each optical switch can have a digital input for transferring the optical switch to the switched position. A signal can be applied to the digital input to transfer the optical switch between the switched position and a non-switched position. For example, the optical switch can have the switched position when the signal is applied to the digital input and the non-switched position when no signal is applied to the digital input.

[0060] When the optical switch is in the non-switched position, it is provided in particular that the laser beam can pass through the optical switch without a laser writing beam being formed. It is conceivable that an output coupling level of each optical switch is adjustable, in particular continuously. The output coupling level of an optical switch can be a ratio of the power, in particular a peak power or an average power, of the laser writing beam formed by the optical switch relative to a power, in particular a peak power or an average power, of the laser beam upstream of the optical switch. In the non-switched position, the output coupling level can be 0%. In other words, with an output coupling level of 0%, the laser beam can pass through the optical switch without a laser writing beam being formed.In the switched position, the output coupling level can be, for example, 10%, 20%, 30%, 40%, 50%, 60%, 80%, 90%, or 95%. In other words, the power of the laser writing beam formed by the optical switch is 10%, 20%, 30%, 40%, 50%, 60%, 80%, 90%, or 95% of the power of the laser beam in front of the optical switch when the switch is continuously in the switched position.

[0061] The optical switch can have an analog input to which a signal can be applied to adjust the output coupling level. By adjusting the output coupling level, different exposure levels of the lithography material can be achieved.

[0062] In a further development of the laser lithography device, the demultiplexer unit comprises an optical switch. The demultiplexer unit comprises an optical arrangement configured to guide the laser beam multiple times over the optical switch. In a switched position, the optical switch is configured to form a laser writing beam by coupling out a laser beam portion required for transferring the lithography material in an exposed state from the laser beam.

[0063] The demultiplexer unit can, in particular, comprise a single optical switch. The optical arrangement can then be configured to guide the laser beam over the optical switch twice, three times, or four times. The optical arrangement can be configured to guide the laser beam over the optical switch multiple times at different angles of incidence. The above description of an optical switch can also apply to the optical switch over which the laser beam is guided multiple times.

[0064] In a further development of the laser lithography device, the laser lithography device has a power detection unit for detecting the power of the laser beam downstream of the demultiplexer unit. The laser lithography device has a control unit configured to control the demultiplexer unit for the purpose of forming the number of laser writing beams by demultiplexing the laser beam depending on the detected power of the laser beam. The control unit can be a computer or a processing unit.

[0065] The power detection unit can be a photodiode or a power detector for detecting the power of the laser beam. The power detection unit can be arranged such that the power detection unit detects the power of a residual beam of the laser beam. The residual beam may not be a laser write beam. The residual beam may be a beam remaining from the laser beam after passing through the demultiplexer unit. The power may be the power of the residual beam.

[0066] In a further development of the laser lithography device, the laser beam source for generating the plurality of laser writing beams comprises a number, in particular one, two, or three, laser modules. The laser modules can generate laser writing beams that differ from one another, for example, in wavelength, power, and / or pulse characteristics.

[0067] Each laser module can be designed as a laser diode.

[0068] The number of laser modules can be electronically modulated. In particular, electronic modulation of the laser modules can ensure that they generate laser writing beams that are separated from each other in time and space. The number of laser modules can be modulated by direct modulation, for example, by electrically switching the supply current.

[0069] Each laser module can be configured to generate a continuous-wave laser beam or a pulsed laser beam. Alternatively, one laser module can be configured to generate a continuous-wave laser beam, and another laser module can be configured to generate a pulsed laser beam.

[0070] The laser modules can generate the laser writing beams directly and / or indirectly. If the laser modules generate the laser writing beams directly, the number of laser modules can, for example, be equal to the plurality of laser beams, with each laser module generating a laser writing beam that is coupled into the waveguide arrangement. If the laser modules generate the laser writing beams indirectly, a laser beam generated by one laser module can be split into at least two laser writing beams, for example, by demultiplexing the laser beam.If the laser modules generate the laser writing beams directly and indirectly, at least two laser modules can be provided, wherein one laser module directly generates a laser writing beam that is coupled into the waveguide arrangement, and wherein another laser module indirectly generates a laser beam that is split into at least two laser writing beams, for example by demultiplexing the laser beam.

[0071] In a further development of the laser lithography device, at least one laser module and the waveguide arrangement are coupled to one another for coupling laser radiation generated by the laser module into the waveguide arrangement. The laser module can have a fiber output. For coupling the laser radiation generated by the laser module, the fiber output can be spliced ​​to a first end of a waveguide of the waveguide arrangement. Alternatively, the fiber output and the first end of the waveguide can be held by a coupler for the purpose of coupling the generated laser radiation into the first end. At least one laser module can have a waveguide coupling unit for coupling the laser module to a waveguide of the waveguide arrangement. In particular, the waveguide coupling unit can be referred to as a fiber coupling unit or can be such a unit.The waveguide coupling unit can be permanently installed with the laser module or can be detachable. Advantageously, a permanently installed waveguide coupling unit can increase the stability and reliability of the lithography device.

[0072] In a further development of the laser lithography device, the laser lithography device has a demultiplexer unit which is designed to divide at least one laser beam of a laser module into a number, in particular one, two or three, of laser writing beams by demultiplexing.

[0073] A method according to the invention is designed for operating a laser lithography device according to one of the preceding claims.

[0074] For example, the method can be a method for producing a three-dimensional structure using the lithography device. The method can comprise the steps of: receiving lithography material using the lithography material holder; generating laser writing beams using the laser beam source; coupling the plurality of laser writing beams into the waveguide arrangement; coupling the laser writing beams out of the waveguide arrangement; focusing the laser writing beams using the objective lens into a focus assigned to the respective laser writing beam, wherein the foci lie within a volume of lithography material; and generating the three-dimensional structure in the lithography material using the focused laser writing beams.

[0075] In connection with the step of focusing the laser writing beams, in particular before focusing, the method may comprise the step of immersing the lens into the lithography material. In other words, the method may be a dip-in multi-photon polymerization process. In connection with the step of generating laser writing beams using the laser beam source, the method may comprise the step of demultiplexing a laser beam of a laser module of the laser beam source for the purpose of forming at least one laser writing beam by temporally splitting the laser beam.

[0076] Further advantages and aspects of the invention will become apparent from the claims and the following description of preferred embodiments of the invention, which are explained below with reference to the figures. Identical and functionally corresponding elements are provided with identical reference numerals. Here:

[0077] Fig. 1 is a schematic view of a laser lithography device,

[0078] Fig. 2 is a schematic diagram of an operation of a demultiplexer unit of the laser lithography apparatus,

[0079] Fig. 3 is a schematic view of an end face of a waveguide arrangement of the laser lithography device,

[0080] Fig. 4 is a schematic view of Fig. 3 of a variant of the waveguide arrangement,

[0081] Fig. 5 is a schematic representation of the focus of the laser writing beams in a focal plane,

[0082] Fig. 6 is a schematic representation of the foci of Fig. 5 in a plane orthogonal to the focal plane,

[0083] Fig. 7 is a schematic view of Fig. 1 of a variant of the laser lithography device, and Fig. 8 is a schematic view of Fig. 1 of a further variant of the laser lithography device.

[0084] Fig. 1 shows a laser lithography device 10 for creating a three-dimensional structure in a lithography material 12 by means of multi-photon polymerization.

[0085] The laser lithography device 10 has a lithography material holder 14. The lithography material holder 14 is designed as a table in the form of a machine table. A substrate 16 in the form of a wafer, on which the three-dimensional structure is to be created, is placed on the lithography material holder 14.

[0086] The lithographic material 12 rests in a droplet-like manner on the lithographic material holder 14 and on the substrate 16. Fig. 1 shows that the lithographic material 12 contacts the lithographic material holder 14 and the substrate 16. In an alternative embodiment not shown, the lithographic material only contacts the substrate. In both cases, the lithographic material holder 14 is designed to receive the lithographic material 12 for the purpose of producing the three-dimensional structure.

[0087] The laser lithography device 10 has a laser beam source 15 for generating a plurality of laser writing beams 26. In the embodiment of Fig. 1, the laser beam source 15 has a laser module 18. The laser module 18 is configured to generate a laser beam 20. The laser beam 20 propagates in a propagation direction 22.

[0088] The laser beam 20 is a pulsed laser beam comprising a plurality of laser pulses. Each laser pulse of the pulsed laser beam 20 has a pulse duration of 250 femtoseconds. The laser pulses of the pulsed laser beam 20 have a repetition rate of 80 MHz.

[0089] The laser lithography device 10 has a demultiplexer unit 24. The demultiplexer unit 24 is arranged downstream of the laser module 18 in the propagation direction 22 of the laser beam 20. The demultiplexer unit 24 is configured to temporally and spatially divide the laser beam 20 into the plurality of laser writing beams 26 by demultiplexing.

[0090] Each laser writing beam 26 propagates along a beam axis. The beam axis is a longitudinal axis of the respective laser writing beam 26, which extends in the direction of its propagation. The beam axes of the laser writing beams 26 differ from one another. The beam axes of the laser writing beams 26 are oriented parallel to one another and offset. The beam axes of the laser writing beams 26 and a beam axis of the laser beam 20 are oriented orthogonally to one another. In other words, the beam axes of the laser writing beams 26 are not collinear with the beam axis of the laser beam 20.

[0091] In the example shown in Fig. 1, the laser beam 20 is split into a total of four laser writing beams 26 by the demultiplexer unit 24. For this purpose, the demultiplexer unit 24 has a total of four optical switches 28 arranged in series one after the other in the propagation direction 22. In other words, when the optical switches 28 are not switched, the laser beam 20 can pass through them one after the other without being influenced by the optical switches 28.

[0092] One optical switch 28 is provided for forming a laser writing beam 26. Each optical switch 28, in a switched position, is configured to form a respective laser writing beam 26 from the laser beam 20. Each optical switch 28 is designed as an acousto-optical modulator. The laser writing beams 26 are formed by coupling out a portion of the laser beam sufficient to solidify the lithography material 12 from the laser beam 20. In other words, demultiplexing is directing or steering the sufficient portion of the laser beam to one of several outputs 29 of the demultiplexer unit 24. In the illustrated embodiment, this is done by means of the optical switches 28 and deflecting mirrors (not shown for the sake of simplicity). In total, the demultiplexer unit 24 has four outputs 29.The number of outputs 29 is equal to the number of laser writing beams 26 formed by the demultiplexer unit 24. A laser beam portion directed or steered toward an output 29 forms a laser writing beam 26 after passing through the output 26.

[0093] In order to form the four laser writing beams 26 by means of the demultiplexer unit 24, an optical switch 28 is successively moved into the switched position, which then decouples a sufficient laser beam portion from the laser beam 20 and directs it to the associated output 29.

[0094] Each optical switch 28 has a digital input for switching the optical switch between the non-switched position and the switched position. Switching to the switched position or the non-switched position is accomplished by means of a signal applied to the digital input. In the example shown, the optical switch 28 is in the switched position when a signal is present at the digital input and in the non-switched position when no signal is present at the digital input.

[0095] The laser lithography device 10 has a control unit 30 configured to control the demultiplexer unit 24 for the purpose of forming the laser writing beams 26 by demultiplexing the laser beam 20. The optical switches 28 are successively switched to the switched position by the control unit 30. To this end, the control unit 30 applies a signal to the digital inputs of the individual optical switches 28 in succession.

[0096] The laser lithography device 10 has a power detection unit 32 in the form of a power detector for detecting a power of the laser beam 20 after the demultiplexer unit 24. The power detection unit 32 thus detects the power of the laser beam 20 that remains after the laser beam 20 has passed through the demultiplexer unit 24. In the example shown in Fig. 1, the power detection unit 32 is arranged such that when the optical switches 28 are in the unswitched position and the laser beam 20 passes through the optical switches 28 one after the other without being influenced by them, the laser beam 20 strikes the power detection unit 32. The power detection unit 32 detects a power of the laser beam 20 that is equal to a power of the laser beam 20 before the demultiplexer unit 24.

[0097] If one of the optical switches 28 is in the switched position and, for example, 80% of the peak power of the laser beam 20 is coupled out to form a laser writing beam 26, then the power detection unit 32 detects a power of the laser beam 20, wherein the peak power of the laser beam 20 impinging on the power detection unit 32 is 20% of the peak power of the laser beam 20 before the demultiplexer unit 24.

[0098] The control unit 30 is configured to control the demultiplexer unit 24 depending on the power detected by the power detection unit 32.

[0099] An example of operation of the demultiplexer unit 24 is shown in Fig. 2.

[0100] In Fig. 2 a), individual laser pulses 34 of the pulsed laser beam 20 are shown in the form of arrows along a time axis 36 before the demultiplexer unit 24. In Fig. 2 b) to e), a temporal profile of a signal, which the control unit 30 applies to the digital input of the respective optical switch 28, is shown along the time axis 36. If the signal has the value 1, the respective optical switch 28 assumes the switched position, and if the signal has the value 0, the respective optical switch 28 assumes the non-switched position.

[0101] The control unit 30 is configured to apply signals for a predetermined duration to the digital inputs of the optical switches 28 one after the other. The predetermined duration is the same for all optical switches 28. In the exemplary embodiment of Fig. 2, the predetermined duration is selected such that each optical switch 28 extracts ten laser pulses 34 from the laser beam 20. In other words, the control unit 30 is configured to apply signals for a duration of ten laser pulses 34 to the digital inputs of the optical switches 28. However, the predetermined duration can also be selected differently, so that more or fewer laser pulses 34 are extracted. The extracted laser pulses 34 at least partially form the laser writing beams 26.

[0102] Between two signals successively applied to the optical switches 28, no signal is applied to the optical switch 28 for a predetermined time period. In the exemplary embodiment of Fig. 2, the predetermined time period is selected such that between the decoupled laser pulses 34, two laser pulses 34 are not decoupled by the optical switches 28. The uncoupled laser pulses 34 reach the power detection unit 32. However, the predetermined time period can also be selected differently, so that more or fewer laser pulses reach the power detection unit 32.

[0103] In detail, Fig. 2 shows that two laser pulses 34 of a time period 38 reach the power detection unit 32. The control unit 30 applies the signal shown in Fig. 2 b) to a first optical switch 28 for a time period 40, which contains ten laser pulses 34. The ten laser pulses 34 coupled out by means of the first optical switch 28 at least partially form a first laser writing beam 26. Subsequently, two laser pulses 34 of a time period 42 reach the power detection unit 32. The control unit 30 applies the signal shown in Fig. 2 c) to a second optical switch 28 for a time period 44, which contains ten laser pulses 34. The ten laser pulses 34 coupled out by means of the second optical switch 28 form at least partially a second laser writing beam 26. Subsequently, the two laser pulses 34 of a time period 46 reach the power detection unit 32. The control unit 30 applies the signal shown in Fig.2 d) to a third optical switch 28 for a time period 48 which contains ten laser pulses 34. The ten laser pulses 34 coupled out by means of the third optical switch 28 at least partially form a third laser writing beam 26. The two laser pulses 34 of the time period 50 then reach the power detection unit 32. The control unit 30 applies the signal shown in Fig. 2 e) to a fourth optical switch 28 for a time period 52 which contains ten laser pulses 34. The ten laser pulses 34 coupled out by means of the fourth optical switch 28 at least partially form a fourth laser writing beam 26. With the subsequent two laser pulses 34, the sequence of applying the signal to the optical switches 28 starts again from the beginning.

[0104] Calibration of the optical switches 28, in particular calibration of the time offsets for operation of the optical switches 28, is carried out by applying a periodic signal to two optical switches 28 each, whereas no signal is applied to the remaining optical switches 28. Then, a time offset between the two periodic signals is changed and, at the same time, the average power is recorded using the power recording unit 32. In this case, a maximum average power is recorded at the power recording unit 32 when the two optical switches 28 are simultaneously in the switched position. Based on the time offset of this state, it can be determined at which time offset the operating state shown in Fig. 2 occurs for these two optical switches 28. Calibration of the remaining optical switches 28 is carried out accordingly.

[0105] The demultiplexer unit 24 is configured such that demultiplexing occurs by extracting groups of laser pulses from the pulsed laser beam 20. The groups of laser pulses form the laser writing beams 26. In other words, the demultiplexer unit 24 forms the laser writing beams 26 by pulse picking. The laser writing beams 26 are formed by temporally and spatially splitting the laser pulses 34 of the laser beam 20.

[0106] The optical switches 28 each have an analog input to which a signal for adjusting a coupling degree can be applied. The coupling degree of each optical switch 28 is continuously adjustable. The coupling degree is a ratio of the peak power of a laser writing beam 26 formed with an optical switch 28 relative to a peak power of the laser beam 20 upstream of the optical switch 28. The control unit 30 is configured to apply a signal for adjusting the coupling degree to the respective optical switch 28. In the example shown, the control unit 30 applies a signal to the analog input such that the coupling degree is 80%. In other words, a peak power of the laser pulses coupled out by the optical switches 28 is reduced by 20% compared to the peak power of the laser pulses of the laser beam 20.

[0107] The laser lithography device 10 has a waveguide arrangement 54, see Fig. 1. The waveguide arrangement 54 has a plurality of waveguides 56 for guiding the plurality of laser writing beams 26. Each waveguide 56 is assigned to a laser writing beam 26.

[0108] The waveguides 56 are arranged in the beam path downstream of the demultiplexer unit 24. Each waveguide 56 is a hollow-core optical fiber, specifically a hollow-core photonic crystal fiber. Each waveguide 56 is configured to guide or direct the laser writing beam 26 associated with the waveguide 56.

[0109] Each waveguide 56 has a first end 58 and a second end 60 opposite the first end. Each first end 58 is configured to couple the laser writing beam 26 associated with the waveguide 56. The laser writing beams 26 are coupled into the waveguide 56 via a free-beam coupling. Each second end 60 has an end face configured to couple out the laser writing beam 26 coupled into the first end 58. Thus, each second end 60 is configured to couple out the laser writing beam 26 coupled into the first end 58.

[0110] The second ends 60 are held by a holding matrix 62 of the waveguide arrangement 54. Within the holding matrix 62, the waveguides 56 run parallel and offset from one another. In the example shown, the holding matrix 62 has a substrate with precision-machined, parallel V-shaped notches. The substrate can be formed from plastic, resin, glass, or silicon, for example. The waveguides 56 are inserted into the notches. Free spaces between the waveguides 56 and the substrate are filled with an adhesive suitable for optics, for example in the form of UV adhesive. A cover of the holding matrix 62 is glued on, which presses the waveguides 56 into the V-shaped notches.

[0111] The end faces of the second ends 60 are arranged in a plane. The plane and the end faces 64 are aligned perpendicular to a propagation direction of the coupled-out laser writing beams 26.

[0112] Fig. 3 shows a schematic representation of the end face 64 of the waveguide arrangement 54. The second ends 60 of the waveguides 56 are held in a regular linear arrangement by the holding matrix 62. In other words, the second ends 60 are spaced equally apart by 66. The distance 66 between two adjacent second ends 60 is 250 pm.

[0113] Fig. 4 shows another embodiment of the waveguide arrangement 54 of Fig. 3, which is suitable for use with up to eight laser writing beams. Identical and functionally equivalent elements are denoted by the same reference numerals, and in this respect, reference can be made to the above explanations regarding the embodiment of Fig. 3, so that essentially only the existing differences will be discussed.

[0114] The second ends 60 of the waveguide array 54 of Fig. 4 are held in a regular two-dimensional array by the holding matrix 62. The second ends 60 are arranged in a crystal-structure-like manner. In other words, the second ends 60 are arranged in a periodic, repeating pattern.

[0115] Fig. 1 shows that the lithography device 10 has an optical deflection device 68 in the form of a mirror galvanometer and an objective 70 in the beam path of the laser writing beams 26 downstream of the waveguide arrangement 54. The optical deflection device 68 is designed to deflect the laser writing beams 26, and the objective 70 is designed to focus the laser writing beams 26.

[0116] The lens 70 is immersed in the lithographic material 12. The lens 70 focuses the laser writing beams 26 into the lithographic material 12 for the purpose of creating the three-dimensional structure. The foci of the laser writing beams 26 all lie in one focal plane.

[0117] Fig. 5 is a schematic representation of a view of the focal plane and the individual foci 72. By demultiplexing the laser beam 20, the foci 72 form within the lithographic material 12, separated from one another in time and space. This is illustrated in Fig. 5 by the dashed and solid representation of the foci 72.

[0118] Fig. 6 is a schematic representation of the foci 72 of Fig. 5 in a plane orthogonal to the focal plane 74. Shown are regions 76 around the foci of the laser writing beams, in which the lithographic material 12 solidifies by multiphoton polymerization. Thus, the laser writing beams 26 formed by demultiplexing comprise a laser beam portion from the laser beam 20 sufficient to solidify the lithographic material 12.

[0119] Fig. 1 shows that the lithography apparatus 10 has a scanning device 78 for displacing the focuses 72 relative to the lithography material holder 14. The scanning device 78 includes the optical deflection device 68. Furthermore, the scanning device 78 has an actuator 80 arranged on the lithography material holder 14, an actuator 82 arranged on the objective lens 70, and an actuator 84 arranged on the holding matrix 62. Each actuator 80, 82, 84 is a linear actuator in the form of a piezo actuator. In an alternative embodiment not shown, other actuator types are also conceivable.

[0120] In an alternative embodiment not shown, the lithography device 10 can have at least one actuator from the actuators 80, 82, 84. By means of the actuator 80 arranged on the lithography material holder 14, the scanning device 78 can displace the focuses 72 relative to the lithography material holder 14 by displacing the lithography material holder 14. By means of the actuator 82 arranged on the objective 70, the scanning device 78 can displace the focuses 72 relative to the lithography material holder 14 by displacing the objective 70. By means of the actuator 84 arranged on the holding matrix 62, the scanning device 78 can displace the focuses 72 relative to the lithography material holder 14 by displacing the holding matrix 62. By means of the optical deflection device 68, the scanning device 78 can shift the focuses 72 relative to the lithographic material holder 14 by deflecting the laser writing beams 26.

[0121] The laser lithography device 10 is configured to perform a method for generating a three-dimensional structure in the lithography material 12. The method comprises the steps of: receiving the lithography material 12 using the lithography material holder 14; generating laser writing beams 26 using the laser beam source 15; coupling the laser writing beams 26 into the waveguide arrangement 54; coupling the laser writing beams 26 out of the waveguide arrangement 54; immersing the objective lens 70 into the lithography material 12; focusing the laser writing beams 26 using the objective lens 70, each at a focus associated with the respective laser writing beam 26, wherein the foci lie within a volume of lithography material 12; and generating the three-dimensional structure in the lithography material 12 using the focused laser writing beams 26.

[0122] Fig. 7 shows a further embodiment of the laser lithography device 10 of Fig. 1. The same reference numerals are used for identical and functionally equivalent elements. Reference can be made to the above explanations regarding the embodiment of Fig. 1, so that essentially only the existing differences will be discussed. The laser beam source 15 has an additional laser module 86. The additional laser module 86 is designed to generate a continuous-wave laser beam. In an alternative embodiment not shown, the additional laser module can be designed to generate a pulsed laser beam.

[0123] In the embodiment of Fig. 7, the additional laser module 86 is coupled to a waveguide 56 of the waveguide arrangement 54. In other words, the additional laser module 86 provides its generated laser beam at a fiber output, which is coupled to the first end of a waveguide 56 of the waveguide arrangement 54. To couple the generated laser radiation, the fiber output can be spliced ​​to the first end of the waveguide 56. Alternatively, the fiber output and the first end of the waveguide 56 can be held by a coupler for the purpose of coupling the generated laser radiation into the first end.

[0124] In an alternative embodiment not shown, the laser module can additionally be modulated by direct modulation, for example by electrically switching the supply current.

[0125] The demultiplexer unit 24 of the laser lithography device 10 of Fig. 7 has three optical switches 28, each of which generates a laser writing beam 26 by demultiplexing the laser beam 20. The three laser writing beams 26 are coupled into the remaining three waveguides 56 of the waveguide arrangement 54 via a free-beam coupling.

[0126] Fig. 8 shows a further embodiment of the laser lithography device 10 of Fig. 1 and the laser lithography device 10 of Fig. 7. The same reference numerals are used for identical and functionally equivalent elements, and reference can be made to the above explanations regarding the embodiments of Figs. 1 and 7, so that essentially only the existing differences will be discussed. The laser beam source 15 has four laser modules 86. Each laser module 86 is designed to generate a pulsed laser beam. Each generated pulsed laser beam is a laser writing beam.

[0127] In the embodiment of Fig. 8, the laser modules 86 are each coupled to a waveguide 56 of the waveguide arrangement 54. In other words, each laser module 86 provides its generated laser writing beam at a fiber output, which is coupled to the first end of a waveguide 56 of the waveguide arrangement 54.

[0128] The control unit 30 is configured to control the laser modules 86 such that they generate the laser writing beams sequentially or simultaneously. The sequential generation of the laser writing beams can be achieved by direct modulation, for example, by electrically switching the supply current, of the laser modules 86.

[0129] In an alternative embodiment not shown, the laser modules can have an integrated power modulation, for example in the form of an acousto-optical modulator, which is controlled by the control unit.

[0130] For example, the control unit 30 can control the laser modules 86 such that the laser modules 86 each generate a laser writing beam sequentially for a predetermined period of time. As a result, the foci 72 are formed within the lithography material 12, separated from one another in time and space.

[0131] Alternatively, the control unit 30 can control the laser modules 86 such that the laser modules 86 each generate a laser writing beam simultaneously for a predetermined period of time. As a result, the foci 72 are formed simultaneously and arranged next to one another within the lithography material 12.

Claims

Patent claims 1. Laser lithography device (10) for producing a three-dimensional structure in a lithography material (12), comprising: a lithography material holder (14) for holding the lithography material (12), a laser beam source (15) for generating a plurality of laser writing beams (26), an objective (70) for focusing the laser writing beams (26) in a focus assigned to the respective laser writing beam (26), and a scanning device (78) for shifting the focuses, characterized by a waveguide arrangement (54) which has a plurality of waveguides (56) for guiding the laser writing beams (26), wherein each waveguide (56) is assigned to a laser writing beam (26), and wherein the waveguides (56) are arranged in the beam path between the laser beam source (15) and the objective (70), wherein each waveguide (56) has a first end (58) and a first end (58) opposite second end (60),wherein each first end (58) is configured to couple in a laser writing beam (26) and each second end (60) is configured to couple out the laser writing beam (26) coupled into the first end (58), wherein the second ends (60) of the plurality of waveguides (56) are held by a holding matrix (62) of the waveguide arrangement (54).

2. Laser lithography apparatus (10) according to claim 1, wherein the second ends (60) of the plurality of waveguides (56) are held by the holding matrix (62) in a linear array or in a two-dimensional array.

3. Laser lithography device (10) according to claim 2, wherein the distance between two adjacent second ends (60) of the plurality of waveguides (56) is 25 pm to 1000 pm, in particular 115 pm to 600 pm.

4. Laser lithography device (10) according to one of the preceding claims, wherein each second end (60) of the plurality of waveguides (56) has an end face which is configured to couple out the laser writing beam (26) coupled into the first end (58), wherein the end faces of the second ends (60) are arranged in a plane.

5. Laser lithography device (10) according to one of the preceding claims, wherein the scanning device (78) is configured to displace the foci relative to the lithography material holder (14) by means of a displacement of the holding matrix (62).

6. Laser lithography device (10) according to one of the preceding claims, wherein each waveguide (56) is formed as a hollow-core optical fiber.

7. Laser lithography device (10) according to claim 6, wherein each waveguide (56) is selected from the group comprising: HC-PCF fibers, in particular HC-Kagome fibers, HC-PBGF fibers, HC-ARF fibers, HC-IC fibers, RH fibers, LMA fibers, PCF fibers.

8. Laser lithography device (10) according to one of the preceding claims, wherein the laser beam source (15) has a demultiplexer unit (24) which is designed to divide a laser beam (20) by demultiplexing into at least a number of laser writing beams (26) in time.

9. Laser lithography apparatus (10) according to claim 8, wherein the laser beam (20) is a pulsed laser beam comprising a plurality of laser pulses, wherein the demultiplexer unit (24) is designed such that the demultiplexing is carried out by coupling out a first group of laser pulses (34) and at least one second group of laser pulses (34) from the pulsed laser beam (20), wherein the first group of laser pulses (34) forms a first laser writing beam (26) and the second group of laser pulses (34) forms a second laser writing beam (26).

10. Laser lithography device (10) according to claim 8 or 9, wherein the demultiplexer unit (24) has a plurality of optical switches (28) which are arranged in series one after the other in the beam path of the laser beam (20), wherein each optical switch (28) in a switched position is configured to form a respective laser writing beam (26) by coupling out a laser beam portion sufficient to convert the lithography material (12) into an exposed state.

11. Laser lithography device (10) according to one of the preceding claims 8 or 9, wherein the demultiplexer unit (24) has an optical switch (28), wherein the demultiplexer unit (24) has an optical arrangement which is designed to guide the laser beam (20) several times over the optical switch (28), wherein the optical switch (28) in a switched position is designed to form a laser writing beam (26) by coupling out a laser beam portion required to transfer the lithography material (12) into an exposed state.

12. Laser lithography device (10) according to one of the preceding claims 8 to 11, wherein the laser lithography device (10) has a power detection unit (32) for detecting a power of the laser beam (20) after the demultiplexer unit (24), wherein the laser lithography device (10) has a control unit (30) which is designed to control the demultiplexer unit (24) for the purpose of forming the plurality of laser writing beams (26) by demultiplexing the laser beam (20) as a function of the detected power of the laser beam (20).

13. Laser lithography device (10) according to one of the preceding claims, wherein the laser beam source (15) for generating the plurality of laser writing beams (26) has a number of laser modules (86).

14. Laser lithography apparatus (10) according to claim 13, wherein at least one laser module (86) and waveguide arrangement (54) are coupled together.

15. Laser lithography device (10) according to claim 13 or 14, wherein the laser lithography device (10) has a demultiplexer unit (24) which is configured to divide at least one laser beam (20) of a laser module (18) into a number of laser writing beams (26) by demultiplexing.

16. A method for operating a laser lithography device (10) according to one of the preceding claims.

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