DE102016104331B3 - Lighting device and method for spatially periodic patterning of a surface - Google Patents

Abstract

The invention relates to an illumination device for patterning a surface of a substrate (26) positioned in a sample plane (P) by irradiating the substrate surface with an illumination pattern corresponding to the pattern to be introduced having an energy density above a process threshold of the substrate surface, comprising a seed laser (12 ) for generating a seed beam (14), - a dynamic beam modulator (16) for spatially modulating the seed beam (14), - a first imaging optics (18) for imaging the dynamic beam modulator (16) in an intermediate image (20) in an intermediate image plane (Z), - in the beam path between the dynamic beam modulator (16) and the intermediate image plane (Z) arranged laser optical amplifier (22) and - a second imaging optics (24) for imaging the intermediate image (20) in the sample plane (P ). The invention is characterized in that a grating interferometer (32) is arranged in the beam path between the second imaging optics (24) and the sample plane (P).

Description

Field of the invention

• – einen Seed-Laser zur Erzeugung eines Seed-Strahls,
• – einen dynamischen Strahlmodulator zur räumlichen Modulation des Seed-Strahls,
• – eine erste Abbildungsoptik zur Abbildung des dynamischen Strahlmodulators in einem Zwischenbild in einer Zwischenbildebene,
• – einen im Strahlengang zwischen dem dynamischen Strahlmodulator und der Zwischenbildebene angeordneten laseroptischen Verstärker und
• – eine zweite Abbildungsoptik zur Abbildung des Zwischenbildes in die Probenebene.

The invention relates to a lighting apparatus for patterning a surface of a substrate positioned in a sample plane by irradiating the substrate surface with a lighting pattern corresponding to the pattern to be introduced having an energy density above a process threshold of the substrate surface

• A seed laser for generating a seed beam,
• A dynamic beam modulator for spatially modulating the seed beam,
• A first imaging optics for imaging the dynamic beam modulator in an intermediate image in an intermediate image plane,
• - In the beam path between the dynamic beam modulator and the intermediate image plane arranged laser optical amplifier and
• - A second imaging optics for mapping the intermediate image in the sample plane.

The invention further relates to a method for operating in particular such a lighting device.

State of the art

A generic lighting device is known from the DE 102 96 370 B4 ,

The cited document discloses an apparatus for exposing a photoresist-coated substrate to a lighting pattern. For this purpose, the beam of a laser light source is first spatially modulated by a dynamic beam modulator. In this case, a dynamic beam modulator is generally understood to mean an optical device with which the spatial intensity distribution of the cross section of a light beam can be variably modulated. The person skilled in both transmissive and reflective variants are known. Purely by way of example of the former type is a liquid crystal display (LCD) called, which can happen depending on the individual control of its pixels corresponding portions of the light beam or absorbed. Purely by way of example of the latter type is a micromirror array (MMA), which, depending on the individual tilt position of its micromirrors, reflects corresponding portions of the light beam either into the beam path or out of the beam path. For the sake of simplicity, the AN position of the corresponding light-guiding element of the dynamic beam modulator should be mentioned in all cases when the corresponding portion of the light beam is directed into the beam path, and from the OFF position of the light-guiding element, if the corresponding portion of the light beam from the beam path Will get removed.

In the known device, the thus modulated laser beam is fed as a seed beam into a laser-optical amplifier unit, which amplifies the light intensity of the beam while maintaining its spatial modulation. Reinforcements by a factor of about 100 are known to those skilled in the art.

By means of a first imaging optics, the dynamic beam modulator is imaged in an intermediate image in an intermediate image plane, wherein the laser optical amplifier unit is arranged between the dynamic beam modulator and the intermediate image plane. The intermediate image thus represents an amplified image of the dynamic beam modulator.

In the cited document is proposed to modulate the seed beam by means of the dynamic beam modulator column-like. The intermediate image is therefore constructed from an alternating sequence of light and dark image columns. By means of a second imaging optics, the intermediate image is imaged onto the sample surface, wherein the second imaging optics includes a cylinder optic which compresses the intermediate image parallel to the image columns when it is imaged into the sample plane. In other words, each bright image column of the intermediate image is compressed to a bright pixel in the sample plane; each dark image column of the intermediate image is compressed to a dark pixel in the sample plane. The image in the sample plane is therefore designed as a linear, alternating sequence of light and dark pixels.

In order to process the substrate surface flat, the substrate is perpendicular to the extension of the line-shaped image, d. H. move parallel to the compression direction of the cylinder optics. By changing the control of the dynamic beam modulator can thus be generated on the substrate surface a grid-like patterned surface modification. In the known device, the surface modification is carried out by exposure of a photosensitive photoresist coating of the substrate. It is conceivable, assuming sufficient Engeriedichte, also a surface modification by laser ablation o. Ä ..

Particularly in the context of counterfeit-proof markings, an extremely fine patterning of the substrate surface is required. Here, the previously described, known technology soon reaches its limits. To form a fine structure superimposed on the described raster pattern, it would be a finely structured beam modulator and / or require a more compact imaging optics. The former is technically not feasible at the moment. The latter would indeed be feasible at a high cost for a correspondingly precise optics, but would have the disadvantage of a significant reduction of the processing area on the substrate, which would lead to significantly longer process times.

For spatially periodic structuring of substrate surfaces interferometric methods are known. The pattern structure to be introduced into the substrate surface does not result from the (beam-optical) imaging of a mask but from the superimposition of selectively generated partial beams which generate an intensity modulation on the substrate surface by constructive and destructive interference. From the DE 10 2006 032 053 A1 Such a grating interferometer or a special method for its use is known. General comments on grating interferometers can be found, for example, in Hersher, RR; Leith, EN: "Grating Interferometers for Producing Large Holographic gratings", Applied Optics, Vol. 7 (1990). In the context of the present description, a grating interferometer is understood to mean a device having at least two optical gratings aligned parallel to one another and perpendicular to an optical axis. Such a grating interferometer is used particularly advantageously if the distance d between each two adjacent grids is equal to the distance between the last grating in the beam direction and a further sample plane P arranged further downstream. Grating periods of the gratings are preferably also in a particular relationship to one another, which determines the orders of the usable partial beams interfering with each other in P. For the embodiment of the grating interferometer, which is particularly relevant in practice, as a 2-grating interferometer with two grids G1 and G2 with respective grating periods p1 and p2, the following applies: Should the partial beams of order n1 produced by diffraction at G1 be diffracted again at G2 and the resulting sub-beams of order n2 in P are to be brought to the interfering superposition, the ratio of the grating periods p2 / p1 = n2 / (2 · n1) is to be selected. The generalization to lattice interferometer with more than two gratings is familiar to those skilled in the art.

From the US 2006/0109532 A1 For example, an interference lithography method and a corresponding apparatus for patterning surfaces are known in which light from a light source is provided with an interference pattern by means of a two-stage interferometric grating arrangement and imaged onto a substrate to be exposed via transfer optics.

Also the DE 10 2011 081 110 A1 discloses a comparable interference lithography method and apparatus.

task

It is the object of the present invention to further develop a generic lighting device such that a finer structured patterning of the substrate surface is made possible without significant additional costs.

Presentation of the invention

This object is achieved in conjunction with the features of the preamble of claim 1, characterized in that a grating interferometer is arranged in the beam path between the second imaging optics and the sample plane.

The core of the invention is to produce an interferometrically generated fine structure by interposing a known grid interferometer in the area behind the second imaging optics of the generic illumination device, which superimposes the raster image generated by the dynamic beam modulator in each of its bright pixels. The dark pixels, however, remain dark. This leads to extremely forgery-proof patterns on the substrate surface, since the fine structure very much depends on the properties of the grating interferometer. These can in turn be varied during the patterning process, so that there is an extremely wide range of possible variations both in terms of basic pattern screening and in terms of fine structuring. A specially selected pattern is thus difficult to identify on the one hand and almost impossible to reproduce on the other hand unless the same lighting device and the same operating method are used as for the production of the original sample.

Preferably, the lattice planes of the grating interferometer are aligned parallel to the sample plane and its output-side lattice is preferably arranged in a distance of its lattice from each other corresponding distance in front of the sample plane.

The grating interferometer is preferably arranged in a beam path of parallel beam guidance. Likewise, the laser optical amplifier is preferably arranged in a beam path section of parallel beam guidance. This can be realized by a preferred configuration of the first and the second imaging optics, which will be described below in the context of the embodiment.

Although the specific design of the dynamic beam modulator for the core idea of the present invention is of minor importance, a dynamic beam modulator is preferably used with row and column-wise arranged light-guiding elements, as it is already known in principle from the cited prior art. Particularly preferred is a programmable micromirror array with tiltable micromirrors arranged in rows and columns. In any case, the dynamic beam modulator should preferably be designed such that the intermediate image is made up of a multiplicity of pixels arranged in rows and columns which, in their ON position, are bright or, in the OFF position, corresponding to the respective position of the associated light-conducting element. Position, are dark. The person skilled in the art will understand that the terms "line" and "column" in the context of beam modulation - of whatever technical origin - only serve to distinguish different modulation or image dimensions and no statement about a specific orientation, for example relative to a base on the the device according to the invention could be constructed, imply.

As is also known in principle from the prior art, it is preferably provided that the second imaging optics comprise a cylinder optic which compresses the intermediate image when it is being imageed in the sample plane in the column direction. The effect of these measures has already been extensively discussed in the discussion of the prior art.

However, the concept of mapping is widely understood in this context. In particular, two advantageous variants of the invention should be included. In a first variant, it is provided that the compression of the intermediate image corresponds to its focusing in the sample plane. In other words, in this variant, the distance between the cylinder optics and the sample plane is selected such that the sample plane lies in the region of the beam waist in the column direction. The individual images of the individual micromirrors of the micromirror arrays preferably used as the beam modulator are therefore superimposed in columns in this variant. This constitutes the basis for the particularly advantageous operating method explained in more detail below.

Thus, in this embodiment of the invention, a linear, alternating sequence of light and dark pixels also results as an image in the sample plane, the bright pixels, however, showing an interferometrically produced fine structure due to the grating interferometer. Note that this fine structure is retained even in the cylinder-optical compression of the original, bright image columns. This seems like a surprising result.

In another variant of the invention, however, it is provided that the compression of the intermediate image corresponds to its disproportionately decreasing in the column direction image in the sample plane. In other words, the cylinder optics is not used in this variant for the column-wise superimposition of micromirror frames, but to their in one dimension (namely in the column direction) greater than in the other dimension (namely in the row direction) reduced, a separation of the individual images retaining image. This can be adjusted by an appropriate choice of the distance between cylinder optics and sample plane, the sample plane comes to rest outside the beam waist.

In order to pattern the surface of the substrate, it is of course possible to use the linear feed of the substrate known from the prior art parallel to the direction of compression of the cylindrical lens. However, a development of the present invention provides, as an alternative or in addition, to the second imaging optics comprising a beam-swiveling unit, by means of which the beam coming from the intermediate image when it is being imaged into the sample plane can be pivoted parallel to the compression direction of the cylinder optics. For example, a galvanic deflection mirror can be used for this purpose. This is preferably arranged in the beam path in front of the cylinder optics and thus also in front of the grating interferometer. The pivoting of a deflection mirror can be more precise and faster than the linear mechanical movement of the sample itself. In this way valuable process time is saved.

When selecting the laser light source, a wide range of possible variations is available to the person skilled in the art. In a specific embodiment, the seed laser is designed as an ultrashort pulse laser. This leads to particularly high energy densities, with which even high process thresholds of a substrate can be overcome. The disadvantage here, however, is the high load of the laser optical amplifier, which could take damage at such energy densities. In a further development of the invention, it is therefore provided that a laser-optical pulse expander and in the beam path between the laser-optical amplifier and the intermediate image plane, a laser-optical pulse compressor is arranged in the beam path in front of the dynamic beam modulator. In other words, an ultrashort pulse imitated by the seed laser is stretched by means of the laser-optical pulse-extensor, which reduces its energy density. After modulation in the dynamic beam modulator and amplification in the laser optical amplifier by means of the laser optical Pulse compressor a recompression of the now amplified pulse and thus an increase in its energy density.

In cases where a solid-state laser with typically quite long-wave output radiation is used as a seed laser, it is preferably provided to arrange an optical frequency multiplier in the beam path between the dynamic beam modulator and the laser-optical amplifier. Conveniently, the optical frequency multiplier is arranged in the region of a beam waist narrowing of the seed beam. The background to this measure is that processing light in the UV range is required for many processing applications. On the one hand, this applies to many optically transparent substrates. On the other hand, finer interference structures can be generated with shorter wavelengths than with longer wavelengths. However, solid-state lasers emit predominantly in the infrared range. The proposed frequency multiplication also low-cost solid-state lasers can be used with their high pulse rates. In cases without frequency multipliers, excimer lasers represent a favorable choice of light source.

• – einen Seed-Laser zur Erzeugung eines Seed-Strahls,
• – einen dynamischen Strahlmodulator zur räumlichen Modulation des Seed-Strahls,
• – eine erste Abbildungsoptik zur Abbildung des dynamischen Strahlmodulators in einer Zwischenbildebene,
• – eine zweite Abbildungsoptik zur Abbildung des Zwischenbildes in die Probenebene, wobei der dynamische Strahlmodulator eine Vielzahl von zeilen- und spaltenweise angeordneten Lichtleitelementen aufweist, mittels derer entsprechende Lichtanteile des Seed-Strahls entweder, in AN-Stellung, eines Lichtleitelements entlang des Strahlengangs leitbar oder, in seiner AUS-Stellung, aus dem Strahlengang entfernbar sind, sodass das Zwischenbild aus einer Vielzahl von zeilen- und spaltenweise angeordnete Bildpunkten aufgebaut ist, die entsprechend der jeweiligen Stellung des zugeordneten Lichtleitelementes entweder in dessen AN-Stellung hell oder in dessen AUS-Stellung dunkel sind, und wobei die zweite Abbildungsoptik eine das Zwischenbild bei seiner Abbildung in die Probenebene in Spaltenrichtung komprimierende Zylinderoptik aufweist, umfassend die Schritte:
• – zunächst Ansteuern des dynamischen Strahlmodulators, sodass das Zwischenbild eine alternierende Folge heller und dunkler Bildspalten enthält, und
• – sodann iterativ • Messen und Miteinander-Vergleichen der Beleuchtungsintensitäten jedes aus der Kompression einer hellen Bildspalte resultierenden, hellen Bildpunktes in der Probenebene, • falls die Intensität eines der hellen Bildpunkte größer ist als die Intensität eines anderen der hellen Bildpunkte: Umschalten eines Lichtleitelementes in der zugeordneten Spalte des dynamischen Strahlmodulators von seiner AN-Stellung in seine AUS-Stellung, bis eine innerhalb vorgegebener Grenzen homogene Intensitätsverteilung zwischen den hellen Bildpunkten in der Probenebene erreicht ist.

It has been found that, due to different causes, an undesirable inhomogeneity of the intensity distribution between the pixels of the image in the sample plane can occur. The reasons for this are, in particular, inhomogeneities in the seed beam, inhomogeneous laser amplification and imperfections of the optics used. This is all the more evident when using a laser optical amplifier, which in turn can contribute to further inhomogeneities. In order to achieve an improved homogeneity of the intensity distribution between the bright pixels of the image in the sample plane, the operating method according to the invention already mentioned above can be used. This is a method for patterning a surface of a substrate positioned in a sample plane by irradiating the substrate surface with an illumination pattern of an energy density corresponding to the pattern to be introduced above a process threshold of the substrate surface by means of a lighting device comprising:

• A seed laser for generating a seed beam,
• A dynamic beam modulator for spatially modulating the seed beam,
• A first imaging optics for imaging the dynamic beam modulator in an intermediate image plane,
• A second imaging optics for imaging the intermediate image in the sample plane, wherein the dynamic beam modulator has a plurality of line and column-wise arranged light-guiding elements, by means of which corresponding light components of the seed beam can be conducted either in the ON position of a light-conducting element along the beam path or in its OFF position, are removed from the beam path, so that the intermediate image is constructed of a plurality of row-and column-wise arranged pixels, the dark according to the respective position of the associated light-guiding element either in its ON position dark or in its OFF position and wherein the second imaging optics has a cylinder optic which compresses the intermediate image as it is being imageed in the sample plane in the column direction, comprising the steps:
• - Initially driving the dynamic beam modulator, so that the intermediate image contains an alternating sequence of light and dark image columns, and
• - then iteratively • measuring and comparing the illumination intensities of each resulting from the compression of a bright image column, bright pixel in the sample plane, • if the intensity of one of the bright pixels is greater than the intensity of another of the bright pixels: switching a light guide in the associated column of the dynamic beam modulator from its ON position to its OFF position until within a given limits homogeneous intensity distribution between the bright pixels in the sample plane is reached.

This method makes use of the circumstance that each bright pixel on the substrate surface can be understood as an integration of the light beam components of an entire column of connected light-conducting elements of the dynamic beam modulator. Switching off one or more light-guiding elements of such a column leads to a reduction of the overall intensity of the corresponding image point in the sample plane. The proposed operating method therefore provides first to check the bright pixels in the sample plane for their homogeneity. If it turns out that one of these pixels is brighter than at least one other pixel, it can be dimmed by switching off a light-guiding element of the associated column of light-guiding elements. A re-examination of the homogeneity of the intensity distribution between the bright pixels in the sample plane shows whether the measure had the desired result, ie. H. whether the intensities of the bright pixels are homogeneously distributed within a given tolerance. If this is the case, the homogenization process ends here. If this is not yet the case, the explained comparison and switch-off steps are repeated iteratively until the goal has been reached.

This homogenization process can be carried out before starting a surface treatment of a sample. Alternatively or additionally, it is also possible to carry out the homogenization process during the machining process in order to achieve a constant readjustment. The person skilled in the art will understand that it is not absolutely necessary to measure the intensities of the bright pixels in the sample plane itself. The measurement of decoupled, representative beam proportions is sufficient for this purpose.

Preferred embodiments are subject of the dependent claims.

Further features and advantages of the invention will become apparent from the following specific description and the drawings.

Brief description of the drawings

Show it:

1 : a schematic representation of an exemplary construction of a lighting device according to the invention and

2 : the lighting device of 1 with extensions

Detailed description of preferred embodiments

Like reference numerals in the figures indicate like or analogous elements.

1 shows a highly schematic representation of a basic version of a lighting device according to the invention 10 , this contains as a light source a seed laser 12 , which may be formed, for example, as an excimer laser. This sends a seed beam 14 which typically has a wavelength in the ultraviolet spectral range and is emitted pulsed. The seed beam 14 is in 1 already shown widened. A corresponding beam expansion optics is in 1 not shown separately. The seed beam 14 is applied to a dynamic beam modulator designed as a micromirror array 16 directed. Below the beam modulator 16 is in 1 schematically an exemplary pattern for controlling the beam modulator 16 shown. In particular, the micromirrors are switched on or off in columns, ie tilted so that they reflect corresponding portions of the seed beam either into the further beam path (ON, bright columns) or out of the further beam path (OFF, dark columns). Note that for better illustration, the pattern of the dynamic beam modulator 16 , the intermediate picture 20 or the image in the sample plane P are shown in negative representation.

By means of a first imaging optics 18 becomes an intermediate picture 20 imaged in an intermediate image plane Z. Preferably, a slightly magnified image is selected, as in 1 indicated.

In the illustrated embodiment, the first imaging optics 18 of two cooperating elements, namely a condenser optics 181 , which before the dynamic beam modulator 16 is arranged and the seed beam 14 behind the beam modulator 16 focused, as well as a main imaging optics 182 , which is positioned at the distance of its focal length behind the aforementioned focus, so that they are followed by a beam path section with parallel beam guidance. The person skilled in the art recognizes that the condenser optics 181 makes no contribution to the actual figure, but rather only the creation of a beam path section with parallel beam guidance in the region of the laser optical amplifier 22 allows. The actual picture is taken from the main imaging optics 182 accomplished, which could be used alone in dispensing with the parallel beam path section.

In this parallel beam path section is a laser optical amplifier 22 arranged, without affecting the spatial beam modulation, an intensity gain of the seed beam 14 performs. Reinforcements can easily be achieved by a factor of 100 or more. The intermediate image shown in the intermediate image plane Z 20 thus provides an enlarged and amplified image of the beam modulator 16 represents.

By means of a second imaging optics 24 Now a picture of the intermediate picture takes place 20 in the sample plane P, in which the surface of a substrate to be processed 26 is arranged. Here passes through the amplified beam 14 ' several elements to be described below. In the embodiment shown, the second imaging optics comprises 24 two separate elements, namely a condenser optics 241 which is arranged in the intermediate image plane Z, and a main imaging optics 242 at a distance behind the condenser optics 241 is arranged, which corresponds to the sum of the focal lengths of both optics. This results in a parallel beam guidance in which the second imaging optics 24 subsequent beam path section and a further modifiable image of the intermediate image 20 in the sample level P.

For further modification of the picture, the amplified beam 14 ' initially by means of a arranged as a pivotable deflection mirror Strahlverschwenkungsvorrichtung 28 diverted. He then happens a cylinder optics 30 whose cylinder axis is transverse to the image columns of the intermediate image 20 is arranged. This results in the sample plane P compression of the image columns of the intermediate image 20 to a linear sequence of pixels, as in 1 below the sample plane P is indicated. Strahlverschwenkungsvorrichtung 28 and cylinder optics 30 can as modifying components of the second imaging optics 24 be considered.

Behind the cylinder optics 30 happens the amplified beam 14 ' a grating interferometer 32 , resulting in a fine structuring of the bright pixels in the sample plane P, as in 1 is also indicated below the sample plane P. It should be remembered that for better illustration, the pattern of the dynamic beam modulator 16 , the intermediate picture 20 or the image in the sample plane P are shown in negative representation.

As mentioned above, the deflection mirror 28 pivotally arranged as by the pivoting arrow 34 indicated. This results in the sample plane P, a migration of the local image parallel to the compression direction of the cylinder optics 30 as by the shift arrow 34 ' indicated. In this way, successively a larger area of the substrate 26 be edited, the column pattern in the dynamic beam modulator 16 synchronous with the pivoting of the deflecting mirror 28 can be changed so that an almost arbitrarily complex grid pattern on the surface of the substrate 26 can be generated.

It will be understood by those skilled in the art that it is typically desirable for all pixels in the sample plane to have the same energy density so that similar processing of the substrate surface occurs at each pixel. By imperfections in the seed beam, in the amplifier 22 and / or the optics, however, inhomogeneities may occur. As explained above, the illumination intensity and thus the energy density in each individual pixel in the sample plane corresponds to the summed intensity of the total associated image column in the intermediate image 20 , This addition results from the compression of the image columns of the intermediate image 20 to the pixels in the sample plane P by means of the cylinder optics 30 , By turning off individual micromirrors in image columns that generate a "too bright" point, therefore, the intensity of a pixel in the sample plane P can be attenuated. A preferred homogenization method therefore provides for directly or indirectly measuring the intensities of the individual bright pixels in the sample plane and by correspondingly switching off individual micromirrors in the beam modulator 16 iteratively to achieve a homogenization at the intensity level of the weakest bright pixel in the sample plane P.

2 shows the basic structure of 1 with different, optional extensions. Thus, when using short wavelength lasers, a frequency multiplier may be used 36 Find employment. This is preferred at the location of the beam waist behind the dynamic image modulator 16 arranged. The background to this measure is that processing light in the ultraviolet spectral range is required, in particular when optically transparent materials are used. In addition, a finer structuring is possible by the use of short-wave light.

When using ultrashort pulse lasers as a seed laser 12 It can help protect the amplifier 22 be useful, the ultrashort pulses first by means of a pulse-extensor 38 time to stretch them after amplification by the amplifier 22 by means of a pulse compressor 40 compress again to restore the energy density that is favorable for surface treatment.

Of course, the embodiments discussed in the specific description and shown in the figures represent only illustrative embodiments of the present invention. A broad range of possible variations will be apparent to those skilled in the art in light of the disclosure herein.

LIST OF REFERENCE NUMBERS

10

lighting device

12

Seed laser

14

Seed-beam

14 '

reinforced beam

16

dynamic beam modulator, microarray-Spiegl

18

first imaging optics

181

Condenser optics of 18

182

Main picture optics of 18

20

intermediate image

22

laser optical amplifier

24

second imaging optics

241

Condenser optics of 24

242

Main picture optics of 24

26

substratum

28

Beam swiveling unit, swiveling deflecting mirror

30

cylindrical optics

32

Grid interferometer

34

Verschwenkungspfeil

34 '

shift arrow

36

frequency

38

Pulse-Strecker

40

Pulse compressor

P

sample plane

Z

Intermediate image plane

Claims (15)

Illumination device for patterning a surface of a substrate positioned in a sample plane (P) ( 26 by irradiating the substrate surface with an illumination pattern corresponding to the pattern to be introduced of an energy density above a process threshold of the substrate surface, comprising - a seed laser ( 12 ) for generating a seed beam ( 14 ), - a dynamic beam modulator ( 16 ) for the spatial modulation of the seed beam ( 14 ), - a first imaging optics ( 18 ) for imaging the dynamic beam modulator ( 16 ) in an intermediate image ( 20 ) in an intermediate image plane (Z), - one in the beam path between the dynamic beam modulator ( 16 ) and the intermediate image plane (Z) arranged laser optical amplifier ( 22 ) and - a second imaging optics ( 24 ) for imaging the intermediate image ( 20 ) in the sample plane (P), characterized in that in the beam path between the second imaging optics ( 24 ) and the sample plane (P) a grating interferometer ( 32 ) is arranged. Lighting device according to claim 1, characterized in that the lattice planes of the grating interferometer ( 32 ) are aligned parallel to the sample plane (P) and its output-side grid is arranged in a distance corresponding to its grid spacing in front of the sample plane (P). Lighting device according to one of the preceding claims, characterized in that the grating interferometer ( 32 ) is arranged in a beam path portion of parallel beam guide. Lighting device according to one of the preceding claims, characterized in that the laser optical amplifier ( 22 ) is arranged in a beam path portion of parallel beam guide. Lighting device according to one of the preceding claims, characterized in that the dynamic beam modulator ( 16 ) has a multiplicity of light guide elements arranged in rows and columns, by means of which corresponding light components of the seed beam ( 14 ), in the ON position of a light guide element, along the beam path conductive or, in its OFF position, are removable from the beam path, so that the intermediate image is constructed of a plurality of line-by-line and column-by-pixel arranged corresponding to the respective position of the associated light-guiding element either, in the ON position, light or, in its OFF position, are dark. Lighting device according to claim 5, characterized in that the dynamic beam modulator ( 16 ) is designed as a programmable micromirror array with row-wise and column-wise arranged, tiltable micromirrors. Lighting device according to one of claims 5 to 6, characterized in that the second imaging optics ( 24 ) one the intermediate image ( 20 ) in its imaging in the sample plane (P) in the column direction compressing cylinder optics ( 30 ). Lighting device according to claim 7, characterized in that the compression of the intermediate image of its focus in the sample plane (P) corresponds. Lighting device according to claim 7, characterized in that the compression of the intermediate image corresponds to its disproportionately decreasing in the column direction image in the sample plane (P). Lighting device according to one of claims 7 to 9, characterized in that the second imaging optics ( 24 ) a beam swiveling unit ( 28 ), by means of which the intermediate image ( 20 ) in its illustration in the sample plane (P) parallel to the compression direction of the cylinder optics ( 30 ) is pivotable. Lighting device according to claim 10, characterized in that the grating lines of the input-side grating of the grating interferometer ( 32 ) parallel to the compression direction of the cylinder optics ( 30 ) are aligned. Lighting device according to one of the preceding claims, characterized in that the seed laser ( 12 ) is designed as an ultra-short pulse laser and in the beam path in front of the dynamic beam modulator ( 16 ) a laser-optical pulse expander ( 38 ) and in the beam path between the laser optical amplifier ( 22 ) and the intermediate image plane (Z) a laser-optical pulse compressor ( 40 ) is arranged. Lighting device according to one of the preceding claims, characterized in that the seed laser ( 12 ) is formed as a solid-state laser and in the beam path between the dynamic beam modulator ( 16 ) and the laser optical amplifier ( 22 ) an optical frequency multiplier ( 36 ) is arranged. Lighting device according to one of the preceding claims, characterized in that the seed laser ( 12 ) is formed as an excimer laser. Method for patterning a surface of a substrate positioned in a sample plane (P) ( 26 by irradiation of the substrate surface with an illumination pattern of an energy density corresponding to the pattern to be introduced above a process threshold of the substrate surface by means of a lighting device ( 10 ), which comprises: - a seed laser ( 12 ) for generating a seed beam ( 14 ), - a dynamic beam modulator ( 16 ) for the spatial modulation of the seed beam ( 14 ), - a first imaging optics ( 18 ) for imaging the dynamic beam modulator ( 16 ) in an intermediate image ( 20 ) in an intermediate image plane (Z), - a second imaging optics ( 24 ) for imaging the intermediate image ( 20 ) in the sample plane (P), wherein the dynamic beam modulator ( 16 ) has a plurality of row and column-wise arranged light-guiding elements, by means of which corresponding light components of the seed beam either, in the ON position, a light guide along the beam path conductive or, in its OFF position, are removable from the beam path, so that the intermediate image ( 20 ) is constructed of a plurality of pixels arranged in rows and columns, which are bright either in its ON position or dark in its OFF position according to the respective position of the associated light guide element, and wherein the second imaging optics ( 24 ) one the intermediate image ( 20 ) in its imaging in the sample plane (P) in the column direction focusing cylinder optics ( 30 ), comprising the steps: - firstly driving the dynamic beam modulator ( 16 ), so that the intermediate image ( 20 ) contains an alternating sequence of light and dark image columns, and then - iteratively • measuring and comparing the illumination intensities of each bright pixel resulting from the compression of a bright image column in the sample plane (P), if the intensity of one of the bright pixels is larger as the intensity of another of the bright pixels: switching a light-guiding element in the associated column of the dynamic beam modulator ( 16 ) from its ON position to its OFF position until a homogeneous distribution of intensity between the bright pixels in the sample plane (P) is achieved within predetermined limits.

Images