Laser lithography apparatus for preparing three-

Abstract

The invention relates to a laser lithography device (10) for producing a three-dimensional structure in a lithographic material (12), comprising a lithographic material carrier (14) for receiving the lithographic material (12), a laser beam source (15) for generating a plurality of laser write beams (26), a lens (70) for focusing the laser write beams (26) in each case into a focal point assigned to the respective laser write beam (26), and a scanning device (78) for moving the focus. A waveguide assembly (54) is provided which comprises a plurality of waveguides (56) for guiding the laser write beams (26), each laser write beam (26) being assigned to a respective waveguide (56), and the waveguides (56) being arranged in the optical path between the laser beam source (15) and the lens (70).

Description

Technical Field

[0001] This invention relates to a laser lithography apparatus for fabricating three-dimensional structures and a method for operating the laser lithography apparatus. Background Technology

[0002] The laser lithography technique mentioned in this context is also known as, for example, stereolithography or direct laser writing. Using this technique, a structure is written onto a photosensitive material, typically initially in a liquid state, using a laser writing beam. This photosensitive material is referred to as a photolithographic material in this context. During this process, the laser writing beam locally triggers a curing effect within the photolithographic material. For example, curing occurs due to localized polymerization of the photolithographic material caused by photon absorption. In optical lithography, such a photolithographic material is also called a photoresist. In stereolithography, such a photolithographic material is also called a resin.

[0003] Laser lithography, or direct laser writing, is advantageous for fabricating microstructures or nanostructures where high precision is desired while maintaining design freedom and molding flexibility. Unlike methods such as mask lithography, this technique allows for the writing of different structures without the need for tools like masks to define the structure.

[0004] Several techniques are known that, to varying degrees, can lead to direct contact between focusing optics or their optical terminal elements and photolithographic materials. First, it is known in principle that the desired overall structure is generated by sequentially writing a series of partial structures (e.g., layer-by-layer or wafer-by-wafer), which then complement each other to form the desired structure.

[0005] In one class of known techniques, a write beam irradiates the surface of a photolithographic material mass, causing localized curing on the surface. Typically, these methods are based on linear processes, such as single-photon absorption and the resulting localized changes in the photolithographic material. To write three-dimensional extended structures, in such methods, after writing one layer, another layer of photolithographic material is applied in an application step. This can be achieved by gradually immersing a substrate with the structure to be written onto it into a bath of photolithographic material, and structuring the surface separately using the write beam. In such techniques, the terminal elements of focusing optics may come into contact with the photolithographic material.

[0006] Another approach utilizes the physical principles of two-photon polymerization, or more broadly, multiphoton polymerization, to achieve curing of the lithography material even within the material itself (i.e., below the surface). This is achieved by coordinating the write beam and the lithography material so that the curing effect occurs with the participation of nonlinear effects. For example, the write beam can be selected within a spectral range where curing is typically ineffective in triggering curing effects in the lithography material. For instance, the lithography material and the write beam can be coordinated such that curing is only initiated when two or more photons from the write beam are absorbed (i.e., two-photon polymerization or multiphoton polymerization). In this context, the term "multiphoton polymerization" refers to polymerization initiated by the absorption of two or more photons. In this respect, the term "multiphoton absorption" in this specification also includes both "two-photon absorption" and "two-step absorption" processes. The conditions required for multiphoton polymerization are typically only achievable in regions of enhanced intensity. Such regions of enhanced intensity are typically provided in the focal region of the laser write beam. In this respect, the focal point is the beam waist of the laser write beam, which is generated by suitable optical elements (e.g., beam guiding optics, beam shaping optics, and / or objectives). In order to prepare extended 3D structures by photolithography, the focus can be moved through the volume of the photolithographic material based on geometric description data, and the curing process can be triggered locally.

[0007] Three-dimensional structure fabrication using two-photon polymerization is typically performed at working distances ranging from 100 µm (micrometers) to 20 mm (millimeters). The working distance is the distance between the focal point and the optical terminal element of the objective lens used to generate the focal point. At such small working distances, contact between the lens and the photolithography material is usually unavoidable. In particular, the objective lens is immersed in the photolithography material. Fabrication methods where the objective lens is at least partially immersed in the photolithography material can also be called immersion multiphoton polymerization. In this case, during the fabrication of the three-dimensional structure, the photolithography material frequently comes into contact with the objective lens, especially with the optical terminal element.

[0008] Regardless of the specific technology used, one challenge is that writing to complex structures can be time-consuming, and accelerating the writing process should generally not come at the expense of accuracy.

[0009] EP4163083A1 discloses an apparatus for fabricating three-dimensional parts based on photolithography. The apparatus includes a beam splitter for dividing an input light beam into multiple beams, which are then focused onto a focal point within the material. Furthermore, the apparatus includes multiple acousto-optic modulators corresponding to the number of beams. An acousto-optic modulator is arranged in each optical path to move the focal point of a specific beam. Summary of the Invention

[0010] The objective of this invention is, in particular, to achieve the precise fabrication of three-dimensional structures using laser lithography.

[0011] This objective is achieved by a laser lithography apparatus having the features of claim 1 and a method having the features of claim 16. Advantageous and preferred embodiments of the invention are included in the appended claims.

[0012] The laser lithography apparatus according to the present invention is configured to fabricate a three-dimensional structure in a lithographic material. The laser lithography apparatus includes a lithographic material carrier, a laser beam source, a lens, a scanning device, and a waveguide assembly. The lithographic material carrier is designed to carry the lithographic material. The laser beam source is designed to generate multiple laser writing beams. The lens is designed to focus each laser writing beam to a focal point assigned to each laser writing beam. The scanning device is designed to move the position of the focal point. The waveguide assembly has multiple waveguides for guiding the laser writing beams. Each waveguide corresponds to one laser writing beam. The waveguides are arranged in the optical path between the laser beam source and the objective lens. Each waveguide has a first end and a second end opposite to the first end. Each first end is configured to couple into the laser writing beam, and each second end is configured to decouple the laser writing beam coupled into the first end. The second ends of the multiple waveguides are held by a holding matrix of the waveguide assembly.

[0013] Waveguide components can generate a defined spatial arrangement of laser writing beams relative to each other and can stably maintain this arrangement to resist interference.

[0014] Waveguide components also enable compact designs, allowing laser lithography apparatuses to be implemented in a space-saving manner. This enables laser lithography apparatuses to fabricate particularly precise and interference-resistant three-dimensional structures in a space-saving way.

[0015] Multiple laser writing beams and associated waveguide components allow for the parallel fabrication of structures. By using multiple laser writing beams, the fabrication time of three-dimensional structures is reduced, enabling the fabrication or creation of three-dimensional structures particularly quickly.

[0016] A laser writing beam is applied to or focused onto a photolithographic material. The laser writing beam and the photolithographic material can be coordinated to allow the material to be locally converted into an exposure state, particularly a polymerization or curing state, in or around multiple regions at or around the focal point of each laser writing beam, thereby creating three-dimensional structures through multiphoton polymerization.

[0017] The laser writing beam can pass through a frequency doubling device to double its frequency. The frequency doubling device can be positioned between the waveguide assembly and the objective lens. The frequency doubling device can include a nonlinear crystal, such as a lithium niobate crystal. The nonlinear crystal can be arranged to be phase-matched to the laser writing beam, 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 a holding matrix.

[0018] The photolithography material carrier can be designed to hold photolithography material to create a three-dimensional structure. Specifically, the photolithography material carrier is configured to hold a certain volume of photolithography material, allowing the laser writing beam to be focused onto the photolithography material. The photolithography material carrier can hold the photolithography material, allowing an objective lens to be immersed in the photolithography material to create a three-dimensional structure.

[0019] Preferably, the photolithography material support is designed to hold the photolithography material in place to create a three-dimensional structure. The photolithography material support can also be referred to as a photolithography material carrier.

[0020] The photolithography material can be supported by a photolithography material carrier. The photolithography apparatus may also include the photolithography material.

[0021] For the lithography material carrier, various geometric designs can be considered, each offering different advantages. For example, the carrier can be designed as a tank, container, or vessel to hold the lithography material. Alternatively, it can be designed as a stage, carrier, or substrate, on which the lithography material is placed in droplet or layer form. To create three-dimensional structures on a substrate, the substrate, particularly a wafer-like substrate, can be placed on a stage, with the lithography material placed on it in droplet or layer form. This stage can be the machine tool stage of a lithography apparatus.

[0022] The photolithography material carrier can be designed to be transparent to the laser writing beam in at least a portion of its area. For example, the walls, bottom, or cover plate of the photolithography material carrier (if present in a particular design) can be designed to be transparent to the laser writing beam. Therefore, the laser writing beam can pass through the photolithography material carrier and be focused onto the photolithography material. For example, it allows for irradiation or exposure of the photolithography material from below.

[0023] Each laser writing beam can propagate along an associated beam axis. The beam axes of the laser writing beams can be different from each other. The beam axes of the laser writing beams can be oriented to be parallel to each other and offset from each other. A beam axis can be understood as the longitudinal axis extending along the propagation direction of a particular laser beam. 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. An effective Poynting vector can be, for example, an intensity-weighted average Poynting vector.

[0024] Each input laser beam can be a continuous-wave laser beam or a pulsed laser beam. In particular, the pulse duration of the laser pulses in the laser writing beam can be from 50 femtoseconds to 500 nanoseconds. Each laser writing beam can be designed to convert the photolithographic material to an exposed state, and in particular to cure it, by means of two-photon or multi-photon polymerization.

[0025] Focusing multiple laser writing beams can include forming multiple focal points. Specifically, all laser writing beams can be focused using the same objective lens, particularly ensuring that each laser writing beam has its own assigned focal point. Preferably, this arrangement places the focal point within the volume of the photolithographic material, more preferably below the surface of the photolithographic material.

[0026] Objective lenses can, for example, have numerical apertures ranging from 0.01 to 1.6 (inclusive). In particular, high numerical apertures can help achieve high precision.

[0027] To fabricate three-dimensional structures, lenses can be immersed in photolithography materials. In other words, the creation of three-dimensional structures can be achieved through immersion multiphoton polymerization.

[0028] The scanning device can be designed to move the focal point relative to the photolithographic material reservoir. Movement can be understood as performing a motion. Each movement can be achieved by a driver for the scanning device, particularly a linear driver and / or a rotary driver. In other words, the scanning device can have actuators for repositioning, particularly stepper motors or linear actuators.

[0029] The focal point can be moved relative to the photolithography material holder by moving the photolithography material holder. During the movement of the focal point relative to the photolithography material holder by moving the photolithography material holder, the holding matrix and / or objective lens can remain stationary.

[0030] Alternatively, the scanning device can be designed to move the focal point relative to the photolithography material reservoir by moving a lens.

[0031] As an alternative or supplement to the above options, the laser writing beam can be deflected by means of an optical deflection device of a scanning device, so that the focal point is moved relative to the photolithography material receiving portion.

[0032] An optical deflection device can be positioned between the waveguide assembly and the objective lens. The optical deflection device may include a scanning mirror, a galvanometer, an acousto-optic deflector, an acousto-optic modulator, and / or a thin-film beam splitter for deflecting the laser writing beam.

[0033] Each waveguide can be designed to guide or direct a specific laser writing beam. Each waveguide can be designed as a hollow fiber or a solid fiber, or contain both hollow and solid fibers.

[0034] The second ends can be spaced apart from each other in the propagation direction of the laser writing beam coupled from them. In other words, each second end of the plurality of waveguides can have an end face configured to decouple the laser writing beam coupled from the first end, wherein the end faces of the second ends are arranged in different planes. In other words, the second ends extend to different distances. Advantageously, this allows for the simultaneous exposure of photolithography material in different planes. This can improve the stability of the 3D structure during the creation or printing process. In addition, 3D structures can be created faster. In particular, this allows for higher focal fill density.

[0035] The holding matrix can be formed of plastic, resin, glass, or silicon, and the second end of the waveguide is at least partially, and particularly segmentally, embedded in the holding matrix. Within the holding matrix, the waveguides can extend parallel to each other and be offset from each other.

[0036] The retaining matrix may have a substrate with precision-machined V-grooves for inserting waveguides. Alternatively, the retaining matrix may have a microstructured perforated plate, into which waveguides can be inserted. Alternatively, the retaining matrix may have multiple sleeves, into which waveguides can be inserted. Alternatively, the retaining matrix may be a welded connection between the second ends of waveguides in a waveguide assembly.

[0037] In another improved version of the laser lithography apparatus, the second ends of multiple waveguides are held in a linear or two-dimensional arrangement by a holding matrix. The linear and / or two-dimensional arrangement can be a regular arrangement.

[0038] If the second ends are kept in a linear arrangement, they can be equidistant from each other. If the second ends are kept in a two-dimensional arrangement, they can be arranged in a crystalline structure. A crystalline structure can be understood as the second ends being arranged like a lattice, with a periodic repeating pattern.

[0039] In another improved version of the laser lithography apparatus, the distance between two adjacent second ends in multiple waveguides ranges from 25 µm to 1000 µm, particularly from 115 µm to 600 µm. This allows for particularly compact waveguide assemblies.

[0040] In another improved version of the laser lithography apparatus, each of the multiple waveguides has a second end face configured to decouple the laser writing beam coupled to the first end. The end faces of the second ends are arranged in a plane. This plane can be aligned perpendicular to the propagation direction of the coupled laser writing beam.

[0041] In another improvement to the laser lithography apparatus, the scanning device is configured to move the focal point relative to the lithography material carrier by moving the holding matrix. For this purpose, the scanning device may include an actuator that moves the holding matrix, particularly a servo motor or a linear actuator, preferably a vibratory piezoelectric actuator.

[0042] The waveguide, particularly its second end, can move following the motion of the holding matrix, for example, through corresponding (elastic) deformation, bending, etc. The movement of the holding matrix can be achieved by the movement of the holding matrix transverse to the laser writing beam and / or the longitudinal movement of the holding matrix relative to the laser writing beam.

[0043] During the movement of the focal point relative to the photolithography material support by moving the holding matrix, the objective lens can remain stationary or move together with the holding matrix. Moving the holding matrix and lens together means that the holding matrix and lens are moved simultaneously by the scanning device along the same direction by the same distance. For example, the joint movement of the holding matrix and lens can be achieved using the same driver in the scanning device.

[0044] In another improvement to the laser lithography apparatus, each waveguide is designed as a hollow optical fiber. This ensures a significant reduction in unwanted absorption and a substantial increase in the waveguide's damage threshold. Furthermore, each hollow optical fiber can be matched to its associated laser writing beam, preventing pulse broadening of the laser pulse as it passes through the hollow fiber. The hollow optical fiber can be an optical fiber with a hollow core.

[0045] In another improved version of the laser lithography apparatus, each waveguide is selected from the group consisting of: HC-PCF fiber, especially HC-Kagome fiber; HC-PBGF fiber; HC-ARF fiber; HC-IC fiber; RH fiber; LMA fiber; PCF fiber.

[0046] HC-PCF fiber can be understood as hollow photonic crystal fiber, HC-Kagome fiber as hollow kagome fiber, HC-PBGF fiber as hollow photonic bandgap fiber, HC-ARF fiber as hollow anti-resonant fiber, HC-IC fiber as hollow suppression coupling fiber, RH fiber as radiation-resistant fiber, LMA fiber as large mode area fiber, and PCF fiber as photonic crystal fiber.

[0047] In another improvement to the laser lithography apparatus, the laser beam source has a demultiplexing unit designed to divide the laser beam into at least a number of laser writing beams in time, specifically two, three, or four laser writing beams, through demultiplexing. The demultiplexing unit can be configured to divide the laser beam into multiple laser writing beams in time through demultiplexing.

[0048] For laser lithography employing two-photon or multi-photon polymerization, temporal demultiplexing can be particularly advantageous. The lithographic material is converted to an exposure state due to a nonlinear process, particularly during polymerization or curing. Therefore, when using a pulsed laser beam, the peak power of each individual laser pulse is a relevant variable in the two-photon or multi-photon polymerization process. By temporally demultiplexing the laser beam, the peak power of the resulting laser writing beam is higher than that generated by continuous beam splitting (e.g., 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 passive optical elements. Therefore, temporal demultiplexing improves the process efficiency of two-photon or multi-photon polymerization.

[0049] The laser beam source may include 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, the pulse duration of the laser pulse in a pulsed laser beam may be from 50 femtoseconds to 500 nanoseconds.

[0050] The demultiplexing unit can be arranged between the laser module and the lens, especially in the direction of laser beam propagation.

[0051] Laser beams can be demultiplexed temporally and / or spatially. Specifically, laser beams can be demultiplexed temporally and spatially simultaneously. Preferably, demultiplexing the laser beam allows it to be segmented temporally and / or spatially. Segmentation can be understood as deflection, guidance, decoupling, or extraction. Segmentation can be achieved using optical switches. These optical switches can be fiber-integrated optical switches.

[0052] Demultiplexing, particularly the inverse process of multiplexing, can include directing or guiding at least a portion of the power of a laser beam to one of a plurality of outputs of a demultiplexing unit. At least a portion of the power of the laser beam directed or guided toward the output can form a laser write beam after passing through that output. Demultiplexing can also involve alternately directing or guiding at least a portion of the power of a laser beam to different outputs of the demultiplexing unit.

[0053] Demultiplexing can be achieved by decoupling a portion of the laser beam sufficient to convert the photolithographic material into an exposed state to form a laser writing beam. Specifically, decoupling can be implemented such that the specific laser writing beam at its focal point has an exposure dose, energy dose, and / or intensity sufficient to induce two-photon or multi-photon polymerization of the photolithographic material. Exposure can be achieved through two-photon or multi-photon polymerization.

[0054] For example, a photolithographic material can be liquid in its unexposed state and solid in its exposed state. In other words, by locally converting the photolithographic material to an exposed state, it can be locally solidified. Subsequently, the unexposed and liquid photolithographic material can be separated from the photolithographic material that has solidified due to exposure, for example, in the context of a development step.

[0055] In alternative examples, the photolithographic material can be solid in its unexposed state, while in its exposed state, its structure, such as chemical structure, molecular structure, crosslinking, and degree of polymerization, can be altered compared to its unexposed state. In other words, the crosslinking of the photolithographic material can be changed to locally expose it. Subsequently, the unexposed photolithographic material can be separated from the exposed photolithographic material, for example, during the development step.

[0056] If the laser beam is a pulsed laser beam, demultiplexing can be a process of selecting individual laser pulses or groups of laser pulses from the pulsed input laser beam. If the laser beam is a continuous-wave laser beam, demultiplexing can be a process of forming a pulsed laser written beam, wherein the pulse width and / or pulse length are specifically equal to the switching duration of the demultiplexing unit. For example, duty cycle pulses can be generated by the demultiplexing unit. In other words, a continuous-wave laser beam can be modulated into pulses using the demultiplexing unit.

[0057] The demultiplexing of laser beams can be constant over time, periodic, or signal-based. For example, demultiplexing can be performed such that each laser write beam formed by the demultiplexing unit is formed by the laser beam within a specified time period. This specified time period can be, for example, 100 femtoseconds to 500 nanoseconds.

[0058] The beam axis of the laser writing beam formed by the demultiplexing unit can be different from the beam axis of the laser beam. In particular, the beam axis of the laser beam can be oriented orthogonal to the beam axis of the laser writing beam. In other words, each beam axis of the laser writing beam can extend non-collinearly with the beam axis of the laser beam.

[0059] Demultiplexing separates the focal points both spatially and temporally. In other words, the laser writing beams formed by the demultiplexing units can be focused so that the individual laser writing beams formed by the demultiplexing units continuously form focal points adjacent to each other in space.

[0060] In an improved laser lithography apparatus, the laser beam is a pulsed laser beam comprising multiple laser pulses. The demultiplexing unit is designed to perform demultiplexing by decoupling a first set of laser pulses and at least a second set of laser pulses from the pulsed laser beam. The first set of laser pulses forms a first laser writing beam, and the second set of laser pulses forms a second laser writing beam. The first and second sets of laser pulses can be separated from each other in time and space. This decoupling can be referred to as pulse selection.

[0061] In an improved version of a laser lithography apparatus, the demultiplexing unit has multiple optical switches, particularly three, four, or five, arranged in series in the optical path of the laser beam. Each optical switch, in its switched position, is configured to form a laser writing beam by decoupling a portion of the laser beam sufficient to convert the lithographic material into an exposed state. In its unswitched position, the laser writing beam is not decoupled. Each optical switch can be designed as a fiber-integrated optical switch.

[0062] Optical switches can be arranged in series along the propagation direction of the laser beam. The number of optical switches can be equal to the number of laser writing beams. In each case, a separate optical switch can be used to form the laser writing beam.

[0063] Each optical switch may have an acousto-optic modulator or acousto-optic deflector for decoupling a portion of the laser beam sufficient to transition the photolithographic material to an exposed state. Each optical switch may have a digital input for switching the optical switch to a switched position. A signal may be applied to the digital input to cause the optical switch to switch between a switched position and a non-switched position. For example, when a signal is applied to the digital input, the optical switch may be in the switched position, and when no signal is applied to the digital input, the optical switch may be in the non-switched position.

[0064] When the optical switch is in the non-switching position, it is specially configured so that the laser beam can pass through the optical switch without forming a laser writing beam.

[0065] It is conceivable that the degree of decoupling of each optical switch is adjustable, particularly continuously adjustable. The degree of decoupling of the optical switch can be a ratio between the power (particularly peak or average power) of the laser writing beam formed by the optical switch and the power (particularly peak or average power) of the laser beam upstream of the optical switch. In the non-switching position, the degree of decoupling can be 0%. In other words, when the degree of decoupling is 0%, the laser beam can pass through the optical switch without forming a laser writing beam. In the switched position, the degree of decoupling can be, for example, 10%, 20%, 30%, 40%, 50%, 60%, 80%, 90%, or 95%. In other words, when the optical switch is continuously in the switched position, the power of the laser writing beam formed by the optical switch is equal to 10%, 20%, 30%, 40%, 50%, 60%, 80%, 90%, or 95% of the power of the laser beam upstream of the optical switch.

[0066] Optical switches can have analog input terminals, and signals can be applied to these terminals to adjust the degree of decoupling. By adjusting the degree of decoupling, different exposure levels of the photolithography material can be achieved.

[0067] In one improved embodiment of a laser lithography apparatus, the demultiplexing unit includes an optical switch. The demultiplexing unit has an optical component configured to guide the input laser beam multiple times through the optical switch. In a switching position, the optical switch is configured to form a laser writing beam by decoupling a portion of the laser beam sufficient to convert the lithographic material into an exposed state.

[0068] Specifically, the demultiplexing unit can have a single optical switch. The optical components can then be configured to guide the input laser beam through the optical switch two, three, or four times. The optical components can be configured to guide the laser beam through the optical switch multiple times at different incident angles. The above description of the optical switch also applies to optical switches through which the laser beam is repeatedly guided.

[0069] In one improved embodiment of a laser lithography apparatus, the apparatus includes a power detection unit for detecting the power of the laser beam following a demultiplexing unit. The apparatus also includes a control unit configured to control the demultiplexing unit based on the detected laser beam power, thereby forming a plurality of laser writing beams by demultiplexing the laser beam. The control unit may be a computer or a computing unit.

[0070] The power detection unit, which can be a photodiode or a power detector, is used to detect the power of the laser beam. The power detection unit can be arranged such that it detects the power of the residual beam of the laser beam. The residual beam is not the laser-written beam. The residual beam is the beam remaining after the laser beam has passed through the demultiplexing unit. The power can be the power of the residual beam.

[0071] In one improved embodiment of a laser lithography apparatus, the laser beam source has several laser modules, particularly one, two, or three laser modules, which are used to generate multiple laser writing beams. The laser modules can generate laser writing beams that differ from each other, for example, in their wavelength, power, and / or pulse characteristics.

[0072] Each laser module can be designed as a laser diode.

[0073] Several laser modules can be electronically modulated. In particular, by electronically modulating the laser modules, laser writing beams that are separated from each other in time and space can be generated. Several laser modules can be modulated by direct modulation, for example, by electrically switching the supply current.

[0074] Each laser module can be configured to generate a continuous-wave laser beam or a pulsed laser beam. Alternatively, one laser module may be configured to generate a continuous-wave laser beam while the other is configured to generate a pulsed laser beam.

[0075] The laser module can directly and / or indirectly generate a laser write beam. If the laser module directly generates a laser write beam, the number of laser modules can be equal to the number of laser beams, wherein each laser module generates a laser write beam that is coupled into a waveguide assembly. If the laser module indirectly generates a laser write beam, the laser beam generated by the laser module can be split into at least two laser write beams, for example, by demultiplexing the laser beam. If the laser module generates both direct and indirect laser write beams, at least two laser modules can be provided, wherein one laser module directly generates a laser write beam coupled into a waveguide assembly, and the other laser module indirectly generates a laser beam that is split into at least two laser write beams, for example, by demultiplexing the laser beam.

[0076] In one improved embodiment of a laser lithography apparatus, at least one laser module is coupled to a waveguide assembly to couple laser radiation generated by the laser module into the waveguide assembly. The laser module may have an optical fiber output. To couple the laser radiation generated by the laser module, the optical fiber output can be fused to a first end of the waveguide of the waveguide assembly. Alternatively, the optical fiber output and the first end of the waveguide can be fixed together by a coupler to couple the generated laser radiation to the first end.

[0077] At least one laser module may have a waveguide coupling unit for coupling the laser module to the waveguide of the waveguide assembly. Specifically, the waveguide coupling unit may be, or is referred to as, an optical fiber coupling unit. The waveguide coupling unit may be permanently mounted to the laser module or designed to be detachable. Advantageously, a permanently mounted waveguide coupling unit can improve the stability and reliability of the lithography apparatus.

[0078] In one improvement of the laser lithography apparatus, the laser lithography apparatus has a demultiplexing unit designed to divide at least one laser beam from the laser module into several laser writing beams, specifically into one, two, or three laser writing beams, by temporally demultiplexing at least one laser beam from the laser module.

[0079] The method according to the invention is designed for operating a laser lithography apparatus according to any one of the preceding claims.

[0080] For example, this method can be a method for fabricating three-dimensional structures using a photolithography apparatus. The method may include the following steps: receiving photolithographic material using a photolithographic material receptacle; generating a laser writing beam using a laser beam source; coupling multiple laser writing beams into a waveguide assembly; decoupling the laser writing beams from the waveguide assembly; focusing each laser writing beam onto a focal point assigned to each beam using a lens, wherein the focal point is located within the volume of the photolithographic material; and fabricating a three-dimensional structure in the photolithographic material using the focused laser writing beams.

[0081] Regarding the step of focusing the laser writing beam, particularly prior to focusing the laser writing beam, the method may include the step of immersing a lens into the photolithographic material. In other words, the method can be an immersion multiphoton polymerization method.

[0082] Regarding the steps of generating a laser writing beam using a laser beam source, the method may include the following steps: demultiplexing the laser beam of the laser module of the laser beam source to form at least one laser writing beam by dividing the laser beam in time. Attached Figure Description

[0083] Other advantages and aspects of the invention will become apparent from the claims and the following description of preferred exemplary embodiments of the invention, which are described below in conjunction with the accompanying drawings. Elements that are identical or functionally corresponding are given the same reference numerals. In the drawings: Figure 1 A schematic diagram of a laser lithography apparatus is shown; Figure 2 A schematic representation of the operation of the demultiplexing unit of a laser lithography apparatus is shown; Figure 3 A schematic diagram of the front view of the waveguide assembly of the laser lithography device is shown; Figure 4 It shows Figure 3 A schematic diagram of a variation of the waveguide component; Figure 5 A schematic representation of the focal point of the laser writing beam in the focal plane is shown; Figure 6 It shows Figure 5 A schematic representation of the focal point in a plane perpendicular to the focal plane; Figure 7 for Figure 1 A schematic diagram of a modified laser lithography apparatus; Figure 8 for Figure 1 A schematic diagram of another variant of the laser lithography apparatus. Detailed Implementation

[0084] Figure 1 A laser lithography apparatus 10 is shown, which is used to prepare three-dimensional structures in a lithographic material 12 by multiphoton polymerization.

[0085] The laser lithography apparatus 10 has a lithography material carrier 14. The lithography material carrier 14 is designed as a worktable in the form of a machine tool table. A wafer-shaped substrate 16 is placed on the lithography material carrier 14, on which a three-dimensional structure will be created.

[0086] The photolithography material 12 is placed on the photolithography material carrier 14 and the substrate 16 in the form of droplets. Figure 1 The photolithography material 12 is shown in contact with the photolithography material carrier 14 and the substrate 16. In an alternative embodiment (not shown), the photolithography material is only in contact with the substrate. In both cases, the photolithography material carrier 14 is designed to support the photolithography material 12 for the purpose of creating a three-dimensional structure.

[0087] The laser lithography apparatus 10 has a laser beam source 15 for generating multiple laser writing beams 26. Figure 1 In the exemplary embodiment shown, the laser beam source 15 has a laser module 18. The laser module 18 is designed to generate a laser beam 20. The laser beam 20 propagates along a propagation direction 22.

[0088] Laser beam 20 is a pulsed laser beam with multiple laser pulses. The pulse duration of the laser pulses in pulsed laser beam 20 is 250 femtoseconds. The repetition rate of the laser pulses in pulsed laser beam 20 is 80 MHz.

[0089] The laser lithography apparatus 10 includes a demultiplexing unit 24. The demultiplexing unit 24 is arranged after the laser module 18 in the propagation direction 22 of the laser beam 20. The demultiplexing unit 24 is configured to divide the laser beam 20 into multiple laser writing beams 26 in time and space through demultiplexing.

[0090] Each laser writing beam 26 propagates along a beam axis. The beam axis is the longitudinal axis extending along the propagation direction of a specific laser writing beam 26. The beam axes of the laser writing beams 26 are different from each other. The beam axes of the laser writing beams 26 are oriented to be parallel to each other and offset from each other. The beam axes of the laser writing beams 26 are oriented orthogonally to each other with the beam axis of the laser beam 20. In other words, the beam axes of the laser writing beams 26 do not extend collinearly with the beam axis of the laser beam 20.

[0091] exist Figure 1 In the example shown, the demultiplexing unit 24 splits the laser beam 20 into a total of four laser writing beams 26. For this purpose, the demultiplexing unit 24 has a total of four optical switches 28, which are arranged in series along the propagation direction 22. In other words, when the optical switches 28 are in the non-switching position, the laser beam 20 can pass through the optical switches 28 successively without being affected.

[0092] In each case, an optical switch 28 is provided for forming the laser writing beam 26. Each optical switch 28 is configured in a switched position to form the laser writing beam 26 by the laser beam 20. Each optical switch 28 is designed as an acousto-optic modulator. The laser writing beam 26 is formed by decoupling a portion of the laser beam from the laser beam 20 sufficient to cure the photolithographic material 12. In other words, demultiplexing is guiding or directing this sufficient portion of the laser beam to one of the several outputs 29 of the demultiplexing unit 24. In the exemplary embodiment shown, this is achieved by the optical switch 28 and a deflector (not shown for simplicity).

[0093] The demultiplexing unit 24 has a total of four output terminals 29. The number of output terminals 29 is equal to the number of laser writing beams 26 formed by the demultiplexing unit 24. A portion of the laser beam guided or directed to the output terminal 29 forms the laser writing beam 26 after passing through the output terminal 29.

[0094] In order to form four laser writing beams 26 by demultiplexing unit 24, optical switch 28 is switched to the switching position in sequence, and then a sufficient amount of laser beam is decoupled from laser beam 20 and guided to the associated output terminal 29.

[0095] Each optical switch 28 has a digital input terminal for switching the optical switch between a non-switching position and a switched position. Switching between the switched and non-switching positions is achieved by applying a signal to the digital input terminal. In the example shown, when a signal is applied to the digital input terminal, the optical switch 28 is in the switched position, and when no signal is applied to the digital input terminal, the optical switch 28 is in the non-switching position.

[0096] The laser lithography apparatus 10 has a control unit 30 configured to control a demultiplexing unit 24 to form a laser writing beam 26 by demultiplexing the laser beam 20. The control unit 30 sequentially switches the optical switches 28 to switching positions. To do this, the control unit 30 sequentially applies signals to the digital input terminals of each optical switch 28.

[0097] The laser lithography apparatus 10 includes a power detection unit 32 in the form of a power detector, used to detect the power of the laser beam 20 after the demultiplexing unit 24. Therefore, the power detection unit 32 detects the power of the laser beam 20 remaining after it passes through the demultiplexing unit 24. Figure 1 In the example shown, the power detection unit 32 is arranged such that when the optical switch 28 is in the non-switching position and the laser beam 20 passes sequentially through the optical switch 28 without being affected by it, the laser beam 20 is incident on the power detection unit 32. The power detection unit 32 detects the power of the laser beam 20, which is equal to the power of the laser beam 20 upstream of the demultiplexing unit 24.

[0098] If one of the optical switches 28 is in the switching position, and for example, 80% of the peak power of the laser beam 20 is decoupled to form the laser writing beam 26, then the power detection unit 32 will then detect the power of the laser beam 20, wherein the peak power of the laser beam 20 incident on the power detection unit 32 is equal to 20% of the peak power of the laser beam 20 upstream of the demultiplexing unit 24.

[0099] The control unit 30 is configured to control the demultiplexing unit 24 based on the power detected by the power detection unit 32.

[0100] Figure 2 An operational example of understanding the multiplexing unit 24 is shown.

[0101] Figure 2 In a), the individual laser pulses 34 of the pulsed laser beam 20 upstream of the demultiplexing unit 24 are shown in arrow form on the time axis 36. Figure 2In sections b) through e), the timing changes of the signals applied by the control unit 30 to the digital input terminals of each optical switch 28 are shown on time axis 36. When the signal value is 1, the corresponding optical switch 28 is in the switched position. When the signal value is 0, the corresponding optical switch 28 is in the unswitched position.

[0102] The control unit 30 is configured to sequentially apply signals to the digital inputs of the optical switches 28 for a specified duration. This specified duration is the same for all optical switches 28. Figure 2 In an exemplary embodiment, a specified duration is selected such that each optical switch 28 decouples ten laser pulses 34 from the laser beam 20. In other words, the control unit 30 is configured to apply a signal to the digital input of the optical switch 28 for a duration of ten laser pulses 34. However, different specified durations may also be selected, resulting in the decoupling of more or fewer laser pulses 34. The decoupled laser pulses 34 at least partially form the laser writing beam 26.

[0103] Between two signals sequentially applied to optical switch 28, no signal is applied to optical switch 28 for a specified time period. Figure 2 In an exemplary embodiment, a specified time period is selected such that between the decoupled laser pulses 34, there are two laser pulses 34 that are not decoupled by the optical switch 28. These undecoupled laser pulses 34 reach the power detection unit 32. However, different specified time periods can also be selected, such that more or fewer laser pulses reach the power detection unit 32.

[0104] In detail, Figure 2 The diagram shows two laser pulses 34 arriving at the power detection unit 32 within time period 38. The control unit 30 applies power to the first optical switch 28. Figure 2 The signal shown in b) reaches time period 40, which includes ten laser pulses 34. The ten laser pulses 34, decoupled by the first optical switch 28, at least partially form the first laser writing beam 26. Subsequently, two laser pulses 34 within time period 42 reach the power detection unit 32. The control unit 30 applies power to the second optical switch 28. Figure 2 The signal shown in c) reaches time period 44, which includes ten laser pulses 34. The ten laser pulses 34, decoupled by the second optical switch 28, at least partially form the second laser writing beam 26. Then, two laser pulses 34 within time period 46 reach the power detection unit 32. The control unit 30 applies power to the third optical switch 28. Figure 2The signal shown in d) reaches time period 48, which includes ten laser pulses 34. The ten laser pulses 34, decoupled by the third optical switch 28, at least partially form the third laser writing beam 26. Then, two laser pulses 34 within time period 50 reach the power detection unit 32. The control unit 30 applies power to the fourth optical switch 28. Figure 2 The signal shown in e) reaches time period 52, which contains ten laser pulses 34. The ten laser pulses 34 decoupled by the fourth optical switch 28 at least partially form the fourth laser writing beam 26. The sequence of signals applied to the optical switch 28 restarts with the next two laser pulses 34.

[0105] The calibration of the optical switches 28, particularly the calibration of the time offset for the operation of the optical switches 28, is performed as follows: In each case, a periodic signal is applied to each of the two optical switches 28, while no signal is applied to the remaining optical switches 28. Then, the time offset between the two periodic signals is changed, while the average power is detected by the power detection unit 32. In this case, when both optical switches 28 are simultaneously in the switching position, the power detection unit 32 detects the maximum average power. The time offset of this state can be used to determine the occurrence of [something] for the two optical switches 28. Figure 2 The time offset of the operating state is shown. The remaining optical switches 28 are calibrated accordingly.

[0106] Demultiplexing unit 24 is designed to perform demultiplexing by decoupling groups of laser pulses from pulsed laser beam 20. These groups of laser pulses form laser writing beam 26. In other words, demultiplexing unit 24 forms laser writing beam 26 through pulse selection. Laser writing beam 26 is formed by temporally and spatially dividing the laser pulses 34 of laser beam 20.

[0107] Each optical switch 28 has an analog input terminal, to which a signal can be applied to set the degree of decoupling. The degree of decoupling of each optical switch 28 can be continuously and steplessly adjusted. The degree of decoupling is the ratio between the peak power of the laser writing beam 26 formed by the optical switch 28 and the peak power of the laser beam 20 upstream of the optical switch 28.

[0108] Control unit 30 is configured to apply a signal to the corresponding optical switch 28 to adjust the degree of decoupling. In the example shown, control unit 30 applies a signal to the analog input such that the degree of decoupling is 80%. In other words, the peak power of the laser pulse decoupled by optical switch 28 is reduced by 20% compared to the peak power of the laser pulse from laser beam 20.

[0109] The laser lithography apparatus 10 has a waveguide assembly 54, see [link / reference] Figure 1The waveguide assembly 54 has multiple waveguides 56 for guiding multiple laser writing beams 26. One waveguide 56 is assigned to one laser writing beam 26.

[0110] Waveguides 56 are arranged in the optical path after demultiplexing unit 24. Each waveguide 56 is a hollow optical fiber, i.e., a hollow photonic crystal fiber. Each waveguide 56 is designed to guide or direct the laser writing beam 26 associated with each waveguide 56.

[0111] Each waveguide 56 has a first end 58 and a second end 60 opposite to the first end. Each first end 58 is configured to couple a laser writing beam 26 associated with the waveguide 56. The laser writing beam 26 is coupled into the waveguide 56 via free-space beam coupling. Each second end 60 has an end face configured to decouple the laser writing beam 26 coupled to the first end 58. Therefore, each second end 60 is configured to decouple the laser writing beam 26 coupled to the first end 58.

[0112] The second end 60 is held by a holding matrix 62 of the waveguide assembly 54, within which the waveguides 56 extend parallel to each other and are offset from one another. In the example shown, the holding matrix 62 includes a substrate with precision-machined parallel V-grooves. The substrate may be made of, for example, plastic, resin, glass, or silicon. The waveguides 56 are inserted into the V-grooves. The free space between the waveguides 56 and the substrate is filled with an adhesive suitable for optical devices, such as in the form of UV adhesive. The cover of the holding matrix 62 is glued in place, pressing the waveguides 56 into the V-grooves.

[0113] The end face of the second end 60 is arranged in a plane. This plane and end face 64 are aligned perpendicular to the propagation direction of the coupled laser writing beam 26.

[0114] Figure 3 A schematic representation of the end face 64 of waveguide assembly 54 is shown. The second ends 60 of waveguide 56 are held by a holding matrix 62 in a regular linear arrangement. In other words, the second ends 60 are equidistant from each other by a distance 66. The distance 66 between any two adjacent second ends 60 is 250 µm.

[0115] Figure 4 It shows Figure 3 Another exemplary embodiment of the waveguide assembly 54 is suitable for up to eight laser writing beams. The same reference numerals are used for the same and functionally equivalent elements, as can be seen above regarding… Figure 3 The description of exemplary embodiments will therefore essentially only describe the differences that exist.

[0116] Figure 4The second end 60 of the waveguide component 54 is held by a holding matrix 62 in a regular two-dimensional arrangement. The second end 60 is arranged in a crystal structure. In other words, the second end 60 is arranged in a periodic repeating pattern.

[0117] Figure 1 The photolithography apparatus 10 is shown with an optical deflection device 68 in the form of a galvanometer and an objective lens 70 in the optical path of the laser writing beam 26 following the waveguide assembly 54. The optical deflection device 68 is designed to deflect the laser writing beam 26, and the objective lens 70 is designed to focus the laser writing beam 26.

[0118] Objective lens 70 is immersed in photolithography material 12. Objective lens 70 focuses laser writing beam 26 to create a three-dimensional structure in photolithography material 12. The focal points of laser writing beam 26 are all located in a single focal plane.

[0119] Figure 5 A schematic representation of the focal plane and individual focal points 72. The focal points 72 are formed within the photolithographic material 12 by demultiplexing the laser beam 20, thus separating them temporally and spatially. This... Figure 5 It is shown in the middle through the dashed and solid lines at focus 72.

[0120] Figure 6 for Figure 5 A schematic representation of the focal point 72 in a plane perpendicular to the focal plane 74. A region 76 surrounding the focal point of the laser writing beam is shown, in which the photolithographic material 12 is cured by multiphoton polymerization. Therefore, the laser writing beam 26 formed by demultiplexing has a portion of the laser beam 20 sufficient to cure the photolithographic material 12.

[0121] Figure 1 The lithography apparatus 10 is shown to include a scanning device 78 for moving a focal point 72 relative to a lithography material carrier 14. The scanning device 78 includes an optical deflection device 68. Additionally, the scanning device 78 includes an actuator 80 disposed on the lithography material carrier 14, an actuator 82 disposed on the objective lens 70, and an actuator 84 disposed on a holding matrix 62. Each actuator 80, 82, and 84 is a linear actuator in the form of a piezoelectric actuator. Other types of actuators may be considered in alternative embodiments (not shown).

[0122] In an alternative exemplary embodiment (not shown), the lithography apparatus 10 may have at least one of actuators 80, 82, 84.

[0123] By using the actuator 80 arranged on the photolithography material carrier 14, the scanning device 78 can move the focal point 72 relative to the photolithography material carrier 14 by moving the photolithography material carrier 14. By using the actuator 82 arranged on the objective lens 70, the scanning device 78 can move the focal point 72 relative to the photolithography material carrier 14 by moving the objective lens 70. By using the actuator 84 arranged on the holding matrix 62, the scanning device 78 can move the focal point 72 relative to the photolithography material carrier 14 by moving the holding matrix 62. By using the optical deflection device 68, the scanning device 78 can move the focal point 72 relative to the photolithography material carrier 14 by moving the laser writing beam 26.

[0124] The laser lithography apparatus 10 is designed to perform a method for fabricating a three-dimensional structure in a lithographic material 12. The method involves the following steps: receiving the lithographic material 12 through a lithographic material receiving portion 14; generating a laser writing beam 26 through a laser beam source 15; coupling the laser writing beam 26 to a waveguide assembly 54; decoupling the laser writing beam 26 from the waveguide assembly 54; immersing a lens 70 into the lithographic material 12; focusing the laser writing beam 26 using the lens 70 at a focal point assigned to each laser writing beam 26, wherein the focal point is located within the volume of the lithographic material 12; and fabricating a three-dimensional structure in the lithographic material 12 using the focused laser writing beam 26.

[0125] Figure 7 It shows Figure 1 Another exemplary embodiment of the laser lithography apparatus 10, wherein the same reference numerals are used for the same and functionally equivalent elements, and in this regard, see the above description of... Figure 1 The description of exemplary embodiments will therefore primarily focus on the differences that exist.

[0126] The laser beam source 15 has an additional laser module 86. This additional laser module 86 is designed to generate a continuous-wave laser beam. In an alternative exemplary embodiment (not shown), the additional laser module may be designed to generate a pulsed laser beam.

[0127] exist Figure 7 In an exemplary embodiment, the additional laser module 86 is coupled to the waveguide 56 of the waveguide assembly 54. In other words, the additional laser module 86 provides its generated laser beam at the fiber optic output end, which is coupled to the first end of the waveguide 56 of the waveguide assembly 54. To couple the generated laser radiation, the fiber optic output end can be fused to the first end of the waveguide 56. Alternatively, the fiber optic output end and the first end of the waveguide 56 can be fixed by a coupler to couple the generated laser radiation to the first end.

[0128] In an alternative embodiment (not shown), the laser module can also be modulated by direct modulation, for example by electrically switching the power supply current.

[0129] Figure 7 The demultiplexing unit 24 of the laser lithography apparatus 10 has three optical switches 28. Each optical switch 28 generates a laser writing beam 26 by demultiplexing the laser beam 20. These three laser writing beams 26 are coupled into the other three waveguides 56 of the waveguide assembly 54 via free-space beam coupling.

[0130] Figure 8 It shows Figure 1 The laser lithography device 10 and Figure 7 Another exemplary embodiment of the laser lithography apparatus 10, wherein the same reference numerals are used for the same and functionally equivalent elements, and in this regard, see above regarding Figure 1 and Figure 7 The description of the exemplary embodiments will therefore focus primarily on the differences present.

[0131] The laser beam source 15 has four laser modules 86. Each laser module 86 is designed to generate a pulsed laser beam. Each pulsed laser beam generated is a laser writing beam.

[0132] exist Figure 8 In an exemplary embodiment, each laser module 86 is coupled to a waveguide 56 of the waveguide assembly 54. In other words, each laser module 86 provides its generated laser beam at an optical fiber output end, which is coupled into a first end of the waveguide 56 of the waveguide assembly 54.

[0133] The control unit 30 is designed to control the laser module 86, causing the laser module 86 to generate laser writing beams sequentially or simultaneously. The sequential generation of laser writing beams can be achieved by directly modulating the laser module 86, for example, by electrically switching the power supply current.

[0134] In an alternative embodiment (not shown), the laser module may have an integrated power modulator, such as an acousto-optic modulator, which is controlled by a control unit.

[0135] For example, the control unit 30 can control the laser modules 86 so that each laser module 86 sequentially generates a laser writing beam for a specified duration. Thus, the focal point 72 is formed within the photolithography material 12, thereby separating them temporally and spatially.

[0136] Alternatively, the control unit 30 can control the laser modules 86 so that each laser module 86 simultaneously generates a laser writing beam for a specified duration. This causes the focal points 72 to be formed simultaneously and arranged side by side within the photolithography material 12.

Claims

1. A laser lithography apparatus (10) for creating three-dimensional structures in a lithographic material (12), comprising: Photolithography material carrier (14), the photolithography material carrier (14) is used to carry the photolithography material (12); A laser beam source (15) is used to generate multiple laser writing beams (26). Lens (70), the lens (70) being used to focus the laser writing beams (26) respectively at the focal points assigned to the respective laser writing beams (26); and A scanning device (78) for moving the focal point, Its features are: A waveguide assembly (54) having a plurality of waveguides (56) for guiding the laser writing beam (26), wherein each laser writing beam (26) is assigned to one waveguide (56), and wherein the waveguides (56) are arranged in the optical path between the laser beam source (15) and the lens (70). Each waveguide (56) has a first end (58) and a second end (60) opposite to the first end (58). Each first end (58) is configured to couple a laser writing beam (26), and each second end (60) is configured to decouple the laser writing beam (26) coupled to the first end (58). The second end (60) of the plurality of waveguides (56) is held by the holding matrix (62) of the waveguide assembly (54).

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

3. The laser lithography apparatus (10) according to claim 2, wherein, The distance between two adjacent second ends (60) of the plurality of waveguides (56) is 25 µm to 1000 µm, particularly 115 µm to 600 µm.

4. The laser lithography apparatus (10) according to any one of the preceding claims, wherein, Each of the plurality of waveguides (56) has a second end (60) having an end face configured to decouple the laser writing beam (26) coupled into the first end (58). The end face of the second end (60) is arranged in a plane.

5. The laser lithography apparatus (10) according to any one of the preceding claims, wherein, The scanning device (78) is configured to move the focal point relative to the photolithography material carrier (14) by moving the holding matrix (62).

6. The laser lithography apparatus (10) according to any one of the preceding claims, wherein, Each waveguide (56) is configured as an optical hollow fiber.

7. The laser lithography apparatus (10) according to claim 6, wherein, Each waveguide (56) is selected from the group consisting of: HC-PCF fiber, especially HC-Kagome fiber; HC-PBGF fiber; HC-ARF fiber; HC-IC fiber; RH fiber; LMA fiber; PCF fiber.

8. The laser lithography apparatus (10) according to any one of the preceding claims, wherein, The laser beam source (15) has a demultiplexing unit (24) configured to divide the laser beam (20) into at least a number of laser writing beams (26) in time by demultiplexing.

9. The laser lithography apparatus (10) according to claim 8. in, The laser beam (20) is a pulsed laser beam containing multiple laser pulses; The demultiplexing unit (24) is designed to perform the demultiplexing by decoupling a first set of laser pulses (34) and at least a second set of laser pulses (34) from the pulsed laser beam (20); The first set of laser pulses (34) forms a first laser writing beam (26), and the second set of laser pulses (34) forms a second laser writing beam (26).

10. The laser lithography apparatus (10) according to claim 8 or 9. in, The demultiplexing unit (24) has a plurality of optical switches (28), which are arranged in series in the optical path of the laser beam (20); Each optical switch (28) is configured in the switching position to form a corresponding laser writing beam (26) by decoupling a portion of the laser beam sufficient to convert the photolithography material (12) into an exposed state.

11. The laser lithography apparatus (10) according to claim 8 or 9. in, The demultiplexing unit (24) has an optical switch (28); The demultiplexing unit (24) has an optical component configured to guide the laser beam (20) through the optical switch (28) multiple times. The optical switch (28) is configured in the switching position to form a laser writing beam (26) by decoupling a portion of the laser beam required to convert the photolithography material (12) into an exposure state.

12. The laser lithography apparatus (10) according to any one of claims 8 to 11. in, The laser lithography apparatus (10) has a power detection unit (32) for detecting the power of the laser beam (20) after the demultiplexing unit (24); The laser lithography apparatus (10) has a control unit (30) configured to control the demultiplexing unit (24) based on the detected power of the laser beam (20) to form the plurality of laser writing beams (26) by demultiplexing the laser beam (20).

13. The laser lithography apparatus (10) according to any one of the preceding claims. in, To generate the plurality of laser writing beams (26), the laser beam source (15) has a plurality of laser modules (86).

14. The laser lithography apparatus (10) according to claim 13. in, At least one laser module (86) is coupled to the waveguide assembly (54).

15. The laser lithography apparatus (10) according to claim 13 or 14. in, The laser lithography apparatus (10) has a demultiplexing unit (24) configured to divide at least one laser beam (20) of the laser module (18) into several laser writing beams (26) in time by demultiplexing.

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

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