DE102019121106A1 - Method and device for generating a three-dimensional structure with at least one flat partial area - Google Patents

Abstract

The invention is based on a method for generating a three-dimensional structure with at least one flat, uneven partial area (30) in a lithography material (16) that can be polymerized in a spatially resolved manner by irradiating a laser (18) in a focus (18a) of the laser. The position of the focus (18a) within the lithography material (16) is determined by a first mechanism (20) for adjusting the focus (18a) along a Z direction running parallel to a beam axis of the laser (18) and by a second mechanism (22 ) adjustable for adjusting the focus (18a) in an XY plane running transversely to the beam axis of the laser (18). The method comprises determining a series of adjacent trajectories (24) for moving the focus (18a) depending on data on the three-dimensional structure (28) and generating the three-dimensional structure (28) by moving the focus (18a) Laser along the trajectories (24). It is proposed that at least those sections of the trajectories (24) which are intended to generate the flat, uneven partial area (30) run at least essentially parallel in a projection onto the XY plane.

Description

The invention relates to a method for generating a three-dimensional structure by irradiating a laser into a spatially resolved polymerizable lithography material according to the preamble of claim 1 and a corresponding device.

It is known to generate three-dimensional structures by spatially resolved polymerizing of lithography materials in the focus of a laser beam through its repetitive lateral movement on planes perpendicular to the optical axis. In this case, a polymerized structure is often first created within a lithography material, the lithography material surrounding the structure, for example liquid or thin-film, is removed in a development process and the structure is possibly visible thermally and / or by exposure to a light source of a suitable wavelength, such as UV light Light and NIR light, post-hardened.

The invention relates particularly, but not exclusively, to processes based on two- or multi-photon polymerization. Lasers are used with wavelengths that cannot trigger polymerization processes in the lithographic material with a single photon, but with multiphoton processes. Due to the quadratic intensity dependency of the induction of multi-photon processes compared to single-photon processes, the spatial resolution can be improved and the probability of undesired or uncontrolled polymerisation processes outside the focal volume of the laser beam can be reduced, whereby in particular focusing optics can also be immersed in the lithography material ("Dip-In “) Without the lithography material solidifying and adhering to the light exit surface of the focusing optics.

In the document Hong-Bo Sun and Satoshi Kawata, "Two-Photon Laser Precision Microfabrication and Its Applications to Micro-Nano Devices and Systems," J. Lightwave Technol. 21, 624- (2003) a process known as “envelope writing” is disclosed, in which first a shell of the structure is written by spatially resolved polymerisation, this is developed by treatment with a solvent and the liquid core made of lithographic material within the envelope is then post-hardened by extensive UV radiation. Compared to processes in which the entire volume of the three-dimensional structure is scanned with the laser focus, the process times can be significantly accelerated by writing the envelope. The corresponding envelope is successively formed as a layer by layer by a lateral movement of the laser focus.

From the Paper Serbin et al "Three-dimensional nanostructuring of hybrid materials by two-photon polymerization" (Proceedings of SPIE Vol. 5222 Nanocrystals, and Organic and Hybrid Nanomaterials, edited by David L. Andrews, Zeno Gaburro, Alexander N. Cartwright, Charles YC Lee, (SPIE, Bellingham, WA, 2003) 0277-786X / 03 / $ 15.00) it is known to write by envelope and subsequent post-crosslinking analogous to Kawata et al. to write any structures in a layer-by-layer manner in order to form the three-dimensional structure as a shell and the unexposed outer material to be washed away with a suitable solvent and the inner core to be crosslinked with a UV light source.

From the Paper "Femtosecond laser polymerization of hybrid microoptical elements and their integration on the fiber tip", Mangirdas Malinauskas et. al. Proceedings of SPIE, vol. 7716 It is known to produce lens structures on the end faces of fiber optics by envelope writing and subsequent post-hardening.

To move the focus within the lithography material, the lithography material is provided on a carrier or substrate or in a bath container. To adjust the focus along a Z direction running parallel to a beam axis of the laser, e.g. the focusing optics are moved or adjusted.

Adjustment of the focus in an XY plane running transversely to the beam axis of the laser is generally used using a second mechanism which, in particular, operates independently of the first mechanism. This includes, in particular, a sample table or chuck that can be adjusted in the XY plane with mechanical, magnetic or electrical actuators, so that in order to generate the only relevant relative movement between the body / volume of the lithography material and the laser focus, the latter remains immobile in the surrounding space and the lithography material through the Laser focus is moved through or by a lateral / transverse adjustment of the laser focus, by z. B. Galvo scanner, the lithography material remains stationary and the laser focus is moved through the material. The movement of the lithography material in particular, but also of the entire optics in the XY plane, is much slower and more difficult to control than the movement of the focus in the Z direction due to the inertia of the mechanical actuators or the piezoelectric creep behavior. However, the lateral movement of the lithography material is not as efficient as the lateral movement of the laser focus due to the inertia of the axes used.

For example, it is from the EP-3287262 A1 It is also known to introduce the non-focused beam from a laser source into the focusing optics via a galvo scanner system and to hold the material to be processed on the surface of a chuck or a hexapod. This is in turn arranged on a second, displaceable carrier which can be rotated in the XY plane and around the Z axis. The inertia of the galvo scanner system is less than that of actuators that have to move larger masses, but the writing area is limited to the field of view of the focusing optics and only allows relatively small movements of the focus, so that larger structures can be stitched. must be composed of smaller structures. This stitching usually leads to seams which are disadvantageous for their function, especially in the case of optical elements, since they generate aberrations and scattering and can thus significantly worsen the functioning of the optical elements produced by means of the method.

When writing or generating envelopes or other two-dimensional manifolds in three-dimensional space, the laser focus is moved along predetermined trajectories that are calculated depending on data that describe the structure to be generated, with shrinkage of the structure during development, drying and / or Post-hardening can be taken into account and pre-compensated.

Algorithms for calculating these trajectories are mainly known from classic, additive 3D printing, in which the structure is built up in layers, i.e. For cuts parallel to the XY plane in different Z positions, layers or contours of the structure are created one after the other and the structure is built up progressively in the Z direction. The three-dimensional topography of a body is mapped using two-dimensional mathematical functions and then implemented in the manufacturing process. In classic, additive 3D printing, this layer-by-layer structure makes sense for static reasons. However, these static reasons do not exist in laser lithographic processes.

Little attention has been paid to algorithms for calculating the trajectories that take into account the special requirements of laser lithography.

The invention is based on the task of accelerating laser lithographic processes of the type described above.

The object is achieved by a method for generating a three-dimensional structure having the features of claim 1, by a corresponding computer program product and a device for carrying out such a method. Advantageous embodiments of the invention emerge from the subclaims.

The invention relates to a method for generating a three-dimensional structure with at least one flat, uneven sub-area in a lithography material of any type which can be polymerized in a spatially resolved manner by irradiating a laser in a focus of the laser. In this context, a sub-area is to be described as "flat", which in the frame The accuracy given by the finite focal diameter is a two-dimensional manifold, the thickness of which is therefore essentially constant and of the order of magnitude of a focal diameter, whereby multi-layer surfaces should also be described as a flat sub-area, provided the thickness is at least essentially constant. "Essentially constant" means that the thickness is in a predominant part, e.g. can make up at least 80%, in particular at least 90% of the area, is constant and constant and in the remaining parts e.g. Support structures can be provided to support the surface, e.g. to avoid an unwanted collapse of a shell prior to resolidification.

“Uneven” is a flat area that differs significantly from a plane in three-dimensional space, especially if the curvature tensor differs from zero everywhere except in isolated points or lines, in particular has two eigenvalues different from zero, for example two linearly independent ones Directions is convex or concave.

According to the invention, the position of the focus within the lithography material is defined by a first mechanism for adjusting the focus along a Z direction running parallel to a beam axis of the laser and a second mechanism for adjusting the focus in a direction transverse to the beam axis of the laser XY plane adjustable.

The method comprises the determination of a series of adjacent trajectories for a movement of the focus as a function of data from the three-dimensional structure. In this context, "adjacent to each other" means that the distances between the trajectories of the family of trajectories and the next trajectories are in the order of magnitude of the focal diameter or slightly smaller, so that by moving the laser focus along the trajectories of the family of trajectories, a steady or quasi-continuous surface arises. The individual trajectories do not have to be in sections from one another be separated, but can be combined into a single overall trajectory, which is then traversed, for example, in a meandering manner, in which case adjacent sections of the overall trajectory running at a constant distance from one another are referred to as trajectories in the sense of the invention. For objectives with a high numerical aperture (NA), distances in the range from 0.1 µm to 5 µm are preferred. If structures with an optical function are written, trajectories are preferably generated at intervals of 0.1 µm to 1 µm.

Moving the focus creates the three-dimensional structure by moving the focus of the laser along the trajectories. The “movement of the focus” includes either the continuous irradiation and operation of the laser or the generation of regular pulses, whereby in the latter case the focus is not moved continuously but in small steps, the length of which is of the order of magnitude of the focal diameter, so that the completely or partially overlap polymerized areas generated by the individual pulses and thus form a quasi-continuous, linear polymerized structure in the lithography material.

According to the invention, it is proposed that at least those sections of the trajectories which are determined to generate the flat, uneven section run at least essentially parallel in a projection onto the XY plane. As a result, it can be achieved that when traversing the trajectories, the slower second mechanism for adjusting the focus in the XY plane running transversely to the beam axis of the laser only has to be moved at a constant speed and no accelerations need to be controlled due to which the trajectory speed to avoid of precision losses would have to be reduced. The processing times can be reduced compared to conventional solutions in which the trajectories are calculated in such a way that their Z component remains essentially constant, while the direction of the path speed changes rapidly in the XY plane.

In particular, it is proposed that a path speed of the sections of the path curves for generating the flat, uneven section is at least essentially constant in a projection onto the XY plane.

In this context, the feature “essentially parallel” of the trajectories or “essentially constant” in relation to the path speed is to be understood in such a way that the advantageous effects of the invention are achieved even with slight deviations, the strength of which depends on the ratio of the inertia of the axes depends, ie the slower XY-axes do not become a limiting factor for the writing speed. This can be achieved, for example, if the trajectories are determined in such a way that a maximum amount of an XY component of the transverse trajectory acceleration is by at least one factor 10 is smaller than the maximum amount of a Z component of the transverse path acceleration. The maximum values of the Z component of the acceleration values are preferably between 50 and 1,000,000 mm / s ² .

As an alternative to the control with constant path speed, a control with a constant amount of path speed in space or a control with a constant degree of networking can also be selected in the projection onto the XY plane, whereby in the latter, in addition to the path speed, the laser intensity and, if necessary, an immersion depth can flow in.

The invention is particularly, but not exclusively, advantageously applicable to those methods in which the flat, uneven sub-area is a sub-area of an outer shell of the three-dimensional structure, the method then in particular the creation of the outer shell of the three-dimensional structure by moving the focus of the Laser along the trajectories, the removal of the unpolymerized lithography material in a space outside the outer shell and optionally the post-curing of the unpolymerized lithography material inside the outer shell by exposure and / or heating. However, it is not absolutely necessary that the material located inside has to be post-hardened, but it can also be in the liquid state. The method is also suitable for producing self-supporting surfaces, e.g. Dome-like structures that are not filled with lithography material in the final state.

The first mechanism for adjusting the focus can in particular comprise an adjustable lens which is preferably, but not necessarily, designed to be immersed in the lithography material.

It is also proposed that the first mechanism have a particularly short settling time (step-and-settle time or setting time) of less than 50 ms, in particular less than 10 ms.

It is also proposed that a settling time of the first mechanism by at least one factor 5 is smaller than a settling time of the second mechanism. As a result, a particularly noticeable gain in time can be achieved by determining the trajectories according to the invention.

This can be achieved in particular in that the first mechanism is designed as a combined mechanism, consisting of an air-bearing axis and a piezo-axis, the piezo-axis executing the fast components of the overall movement and the more sluggish air-bearing axis performing the slower components of the overall movement generated.

The second mechanism, which can in particular be an XY stage, is designed in various configurations of the invention to move a carrier with or without a rim or a bath container for holding the lithography material with a fixed XY position of the beam axis in the XY plane. In further refinements of the invention, the lithography material can be held by capillary forces, so that even with very liquid material there is no need for any limitation by containers.

Another possibility to hold the lithographic material is the combination of e.g. hydrophobic material with hydrophilic surfaces (and vice versa). The lithographic material remains in position. If the materials are shifted against each other, the lithography material to be structured moves with them.

It is further proposed that the trajectories are determined in such a way that a distance between the trajectory and a surface of the three-dimensional structure changes locally along a trajectory and a longitudinal diameter of the focus is changed as a function of the distance. In particular, the longitudinal diameter of the focus can be changed by changing an intensity of the laser. The Z component of the surface of the three-dimensional structure to be traced can then be generated in a portion corresponding to the Z component of the trajectory and a portion realized by the distance or half the longitudinal diameter of the laser focus. The dynamic properties of the power control of the laser on the one hand and the first mechanism on the other hand can be taken into account in the division.

Another aspect of the invention relates to a computer program product for determining trajectories for use in a method of the aforementioned type.

Another aspect of the invention relates to a device with a computer program product of the aforementioned type installed thereon, a carrier with or without a rim or bath container for a lithography material, a laser for spatially resolved polymerisation of the lithography material, a first mechanism for adjusting the focus along a beam axis parallel to a beam axis of the laser running Z-direction, a second mechanism in an XY plane running transversely to the beam axis of the laser, and a control unit which is designed to determine the trajectories for generating a three-dimensional structure with the aid of the computer program product and the focus of the laser with moving the first mechanism and the second mechanism in the lithographic material along the trajectories.

Further features and advantages emerge from the following description of the figures. The entire description, the claims and the figures disclose features of the invention in specific exemplary embodiments and combinations. The person skilled in the art will also consider the features individually and combine them into further combinations or sub-combinations in order to adapt the invention as defined in the claims to his needs or to special areas of application.

• 1 eine Vorrichtung zum Erzeugen einer dreidimensionalen Struktur nach einem ersten Ausführungsbeispiel der Erfindung;
• 2 eine Schematische Darstellung von nach dem Stand der Technik berechneten Bahnkurven;
• 3 eine Schematische Darstellung von nach dem erfindungsgemäßen Verfahren berechneten Bahnkurven;
• 4 eine Vorrichtung zum Erzeugen einer dreidimensionalen Struktur nach einem zweiten Ausführungsbeispiel der Erfindung;
• 5 eine Vorrichtung zum Erzeugen einer dreidimensionalen Struktur nach einem dritten Ausführungsbeispiel der Erfindung;
• 6 eine Vorrichtung zum Erzeugen einer dreidimensionalen Struktur nach einem vierten Ausführungsbeispiel der Erfindung;
• 7a - 7c verschiedene Schritte eines erfindungsgemäßen Verfahrens;
• 8a - 8c ein weiteres Anwendungsbeispiel des erfindungsgemäßen Verfahrens zur Erzeugung eines diffraktiven optischen Elements (DOE);
• 9 ein weiteres Anwendungsbeispiel des erfindungsgemäßen Verfahrens zur Erzeugung einer frei tragenden Fläche;
• 10 ein weiteres Anwendungsbeispiel des erfindungsgemäßen Verfahrens zur Erzeugung der frei tragenden Fläche aus 9; und
• 11 ein weiteres Ausführungsbeispiel des erfindungsgemäßen Verfahrens mit einer entlang einer Bahnkurve variierenden Strahlungsintensität.

Show:

• 1 a device for generating a three-dimensional structure according to a first embodiment of the invention;
• 2 a schematic representation of trajectories calculated according to the prior art;
• 3 a schematic representation of trajectories calculated according to the method according to the invention;
• 4th a device for generating a three-dimensional structure according to a second embodiment of the invention;
• 5 a device for generating a three-dimensional structure according to a third embodiment of the invention;
• 6th a device for generating a three-dimensional structure according to a fourth embodiment of the invention;
• 7a - 7c various steps of a method according to the invention;
• 8a - 8c a further application example of the method according to the invention for producing a diffractive optical element (DOE);
• 9 a further application example of the method according to the invention for producing a self-supporting surface;
• 10 Another application example of the method according to the invention for producing the self-supporting surface 9 ; and
• 11 a further embodiment of the method according to the invention with a radiation intensity that varies along a trajectory.

1 shows a first embodiment of the invention. A device according to the invention comprises a control unit 10 with a computer program product according to the invention installed thereon which, when executed, carries out a method according to the invention. The device comprises a laser source (not shown), an objective 12 with adjustable focus and a bath tank 14th for a lithographic material 16 , which is an organic, inorganic or organic-inorganic mixed material with polymerization initiators. The laser wavelength and intensity of a laser 18th from the laser source is tuned so that in the laser focus 18a Polymerization processes are initiated by two- or multi-photon reactions, leading to crosslinking of the lithographic material 16 lead and the lithographic material 16 Polymerize in a spatially resolved manner. As already mentioned, in other configurations of the invention the lithography material can also be held without a bath container, for example on flat supports, by capillary forces or by wetting effects.

The objective 12 or the laser focus 18a can from the control unit 10 through a first mechanism 20th to adjust the focus along a Z-direction running parallel to a beam axis of the laser, with a fixed XY position of the beam axis in the XY plane.

The bath tank 14th with the lithographic material 16 stands on an XY stage 22nd in a transverse direction to the beam axis of the laser 18th extending XY-plane can be moved so that the lithography material 16 moved along. By moving the XY stage 22nd therefore the laser focus moves 18a within the lithographic material 16 or relative to the lithographic material 16 .

The control unit 10 moves the laser focus to create a three-dimensional structure 18a along specified trajectories 24 in three-dimensional space within the lithographic material 16 . The control unit calculates in advance 10 these trajectories with the aid of the computer program product 24 from 3D data of the three-dimensional structure and then moves the focus 18a of the laser 18th with the first mechanism 20th and the second mechanism 22nd along the calculated trajectories in the lithographic material 16 .

The advantages of the invention come into play in particular when at least one flat, uneven sub-area has to be generated when generating a three-dimensional structure, because the structure or a precursor structure (such as a shell) comprises such a sub-area or is a flat, uneven structure overall. This occurs in particular with "envelope writing", but could also occur in other contexts.

In this case, the flat, uneven sub-area is made up of a sequence of adjacent trajectories 24 generated with essentially the same distance, which correspond to a regular hatching in three-dimensional space. According to the invention, the sections of the trajectories run 24 , which are intended to generate the flat, uneven sub-area, in a projection 24 ' ( 3 ) at least substantially parallel to the XY plane.

In the in 2 and 3 shown example is the outer shell 30th a convex lens structure while the volume is within the envelope 30th should remain untreated. The case 30th is a flat, uneven partial area within the meaning of the invention.

After the in 2 Prior art shown, the three-dimensional surface or the three-dimensional body is cut in cutting planes running parallel to the XY plane and the laser is cut in trajectories 24a is performed, which also run in these cutting planes, so that a projection of the trajectories 24a on the XY plane of the curvilinear contour or height line of the three-dimensional body (in the case of the 2 circular) follows. The movement of the laser focus along this contour is controlled solely by the second mechanism 22nd controlled.

According to the invention, as in 3 shown, the three-dimensional surface or the three-dimensional body is cut in cutting planes running parallel to the Z-axis and the laser focus 18th is along trajectories 24 guided or controlled, which run in these cutting planes, so that the projection 24 ' there is a straight line on the XY plane of each trajectory. Because of the straightness of this projection 24 ' corresponds to that of the second mechanism 22nd controlled component of the movement of a linear movement at constant speed that does not require fast reaction times. If the second mechanism 22nd comprises two independent actuators for controlling the two degrees of freedom XY, in a particularly advantageous exemplary embodiment the direction of the straight line along a degree of freedom can be selected so that only one of the actuators has to be actuated.

The path speed of the sections of the path curves 24 for generating the flat, uneven sub-area 30th is at least substantially constant in one embodiment of the invention in a projection onto the XY plane. However, embodiments of the invention are conceivable in which the XY component of the path speed is variable, for example from the rate of change of the Z position or the Z component of the path speed, the immersion depth of the focal length of the lens depends. Even then, the acceleration components in the XY plane are usually much lower than those in the Z direction, so that the reaction times of the second mechanism are slower 22nd hardly matter.

4th shows a second embodiment of the invention with a bath tank 14th , which has a transparent bath floor through which the laser 18th can be radiated through. A substrate 26th is on a first mechanism that can be moved in the Z direction 20th immersed in the bath.

5 shows an apparatus for generating a three-dimensional structure according to a third embodiment of the invention. In addition to the features of the first embodiment, the lens 12 tiltable by a polar angle θ. The first mechanism 20th accordingly has two degrees of freedom.

6th shows an apparatus for generating a three-dimensional structure according to a fourth embodiment of the invention. The lithographic material 16 hangs as droplets under a substrate 26th and the lens 12 is from below into the lithographic material 16 immersed. As a result, small structures can also be created without separate, expensive containers.

7a - 7c schematically show various steps of a method according to the invention, here for producing a lens 28 on a substrate 26th . First, as in 7a shown on the basis of 3D data of the three-dimensional structure of the desired lens 28 from the control unit 10 the trajectories 24 calculated as they are in 3 are shown in such a way that the trajectories 24 in the projection 24 ' the trajectories run parallel to the XY plane, specifically in the X direction.

By moving the laser focus 18a the convex outer shell of the lens is generated along these trajectories, each of the trajectories 24 on the substrate 26th begins and ends so that the polymerized, thread-like areas corresponding to the trajectories are anchored to the substrate. The convex outer shell is a flat, uneven sub-area made of polymerized material, which is composed of the thread-like areas. The trajectories 24 are so close to one another that adjacent polymerized, thread-like areas merge and stick together as a result of the polymerization and form a structure that even after the development step ( 7b) is sufficiently stable to keep the liquid core dimensionally stable. If necessary, support structures (ribs or the like) can be incorporated.

Then, as in 7b shown, the unpolymerized lithography material outside the outer shell is removed by washing with suitable solvents. The polymerized shell remains 30th with a liquid core 32 .

Finally, as in 7c shown, the liquid core 32 as a lens 28 designed three-dimensional structure by illuminating with UV light or visible light 34 post-hardened and / or dried. A shrinkage of the material in this step is taken into account when calculating the trajectories 24 taken into account and pre-compensated.

8a - 8c show a further application example of the method according to the invention for producing a three-dimensional structure configured as a diffractive optical element (DOE) 28 . Here too the trajectories are 24 chosen so that their projection onto the XY plane is straight.

9 shows a further application example of the method according to the invention for producing a self-supporting surface. The method according to the invention can be applied to virtually any structure. Here too the trajectories are 24 chosen so that each their projection 24 ' runs in a straight line on the XY plane. The projections form a host of parallels.

10 shows a further application example of the method according to the invention for producing the self-supporting surface from 9 . In the in 10 The application example shown here are the trajectories 24 chosen so that their projection on the XY plane runs in parallel curves, ie curves running at a constant distance from one another, but whose curvature is much less than a Z component of a curvature vector or curvature tensor of the trajectories 24 .

11 shows a further embodiment of the method according to the invention with a radiation intensity varying along a trajectory. The embodiment in 11 differs from that in the 7a - 7c illustrated embodiment in particular in that the trajectories 24 the target surface 38 the target structure does not follow the target structure at a constant distance but the trajectories 24 so be calculated the distance between the trajectory curve 24 and the target surface 38 the target structure along the trajectory 24 changes.

To still one of the target surface 38 To generate a corresponding target structure, the difference is determined by a depending on the distance between the trajectory 24 and the target surface 38 the radiation power of the laser set for the target structure 18th compensated. The longitudinal diameter of the elliptical focal volume 18a , within which the intensity threshold for the polymerization is exceeded, depends on the intensity or radiation power of the laser 18th . The controller controls the radiant power in such a way that half the longitudinal diameter corresponds to the distance between the trajectory 24 and the target surface 38 corresponds. A focal point 18b of focus 18a is then along the trajectory 24 moves, and the intensity is varied so that the upper edges of the focal volumes 18a the target surface 38 trace.

The one for tracing the target surface 38 Movement to be controlled Z coordinate is therefore broken down into a first part, which is made with the aid of a first mechanism 20th the center point 18b of focus along the trajectory 24 moves, and a second part, which is realized by a time-dependent change in the laser power. This division can take place in particular by a spatial frequency breakdown in Fourier space, the components with lower frequencies being the slower first mechanism 20th be assigned.

In addition to varying the laser power, the variation of the intensity can also be achieved by means of a diaphragm, a variation of the path speed or multiple exposure of certain voxels.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 3287262 A1 [0009]

Non-patent literature cited

• Hong-Bo Sun and Satoshi Kawata, "Two-Photon Laser Precision Microfabrication and Its Applications to Micro-Nano Devices and Systems," J. Lightwave Technol. 21, 624- (2003) [0004]
• Paper Serbin et al "Three-dimensional nanostructuring of hybrid materials by two-photon polymerization" (Proceedings of SPIE Vol. 5222 Nanocrystals, and Organic and Hybrid Nanomaterials, edited by David L. Andrews, Zeno Gaburro, Alexander N. Cartwright, Charles YC Lee, (SPIE, Bellingham, WA, 2003) 0277-786X / 03 / $ 15.00) [0005]
• Paper "Femtosecond laser polymerization of hybrid microoptical elements and their integration on the fiber tip", Mangirdas Malinauskas et. al. Proceedings of SPIE, vol. 7716 [0006]

Claims (13)

A method for generating a three-dimensional structure (28) with at least one flat, uneven partial area (30) in a lithography material (16) that can be polymerized in a spatially resolved manner by irradiating a laser (18) in a focus (18a) of the laser (18), the position of the Focus (18a) within the lithography material (16) by: • a first mechanism (20) for adjusting the focus (18a) along a Z direction running parallel to a beam axis of the laser and • a second mechanism (22) for adjusting the focus (18a) is adjustable in an XY plane running transversely to the beam axis of the laser, the method comprising: determining a series of adjacent trajectories (24) for a movement of the focus (18a) as a function of data on the three-dimensional structure (32); and • generating the three-dimensional structure (32) by moving the focus (18a) of the laser along the trajectories (24), characterized in that at least the sections of the trajectories (24) which are used to produce the flat, uneven partial area (30) are determined, run at least substantially parallel in a projection onto the XY plane. Procedure according to Claim 1 , characterized in that a path speed of the sections of the path curves (24) for generating the flat, uneven section (30) in a projection onto the XY plane is at least substantially constant. Method according to one of the preceding claims, characterized in that the trajectories (24) are determined such that a maximum amount of an XY component of the transverse trajectory acceleration is at least a factor of 10 smaller than the maximum amount of a Z component of the transverse trajectory acceleration. Method according to one of the preceding claims, characterized in that the flat, uneven partial area is a partial area of an outer shell (30) of the three-dimensional structure (28). Procedure according to Claim 4 , characterized in that the generation of the three-dimensional structure (28) comprises: • the generation of the outer shell (30) of the three-dimensional structure (28) by moving the focus (18a) of the laser along the trajectories (24); • removing the unpolymerized lithographic material (16) in a space outside the outer shell (30); and • post-hardening of the unpolymerized lithography material (32) within the outer shell (30) by exposure and / or heating. Method according to one of the preceding claims, characterized in that the first mechanism (20) for adjusting the focus (18a) comprises an adjustable lens (12). Method according to one of the preceding claims, characterized in that a settling time of the first mechanism is at least a factor 5 smaller than a settling time of the second mechanism. Method according to one of the preceding claims, characterized in that the first mechanism (20) is designed as a combined mechanism, consisting of an air-bearing axis and a piezo-axis, the piezo-axis executing the fast components of the overall movement and the more sluggish air-bearing axis generates slower components of the overall movement. Method according to one of the preceding claims, characterized in that the second mechanism (22) is designed to hold a carrier with or without a rim (26) or a bath container (14) for holding the lithographic material (16) in relation to the surrounding space To move the XY position of the beam axis of the laser (18) in the XY plane. Method according to one of the preceding claims, characterized in that the trajectories (24) are determined such that a distance between the trajectory (24) and a surface (38) of the three-dimensional structure (32) changes locally along a trajectory (24) and a longitudinal diameter of the focus (18a) is changed depending on the distance. Procedure according to Claim 10 , characterized in that the longitudinal diameter of the focus (18a) is changed by changing an intensity of the laser (18). Computer program product for determining trajectories (24) for use in a method according to one of the preceding claims. Device with a computer program product installed thereon Claim 10 , a carrier with or without a rim or bath container (14) for a lithography material (16), a laser (18) for the spatially resolved polymerisation of the lithography material (18), a first mechanism (20) for adjusting the focus (18a) along a parallel to a beam axis of the laser (18) extending Z- Direction, a second mechanism (22) in for moving the focus (18a) relative to the lithography material (16) in an XY plane running transversely to the beam axis of the laser, and a control unit (10) which is designed to control the trajectories (24 ) to create a three-dimensional structure (28) with the computer program product and to move the focus (18a) of the laser with the first mechanism (20) and the second mechanism (22) along the trajectories in the lithography material (16).

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