Pattern generator and pattern generator driving method

Abstract

The pattern generator (1) comprises a pulsed laser light source, a spatial light modulator, a control module, an optical end system (50), and a stage positioning device. The optical end system is positioned to position a laser irradiation pattern (13) from the spatial light modulator on the writing surface (43). The optical end system further comprises a stripe switch (70) configured to optically move the position of the laser irradiation pattern on the writing surface in a sweep direction (61) parallel to the writing surface and perpendicular to the scanning direction (62). The control module is further positioned to generate individual samples of the laser irradiation pattern (13) at at least two predetermined positions in the sweep direction. The distance between the positions in the sweep direction is less than or equal to the width of the laser irradiation pattern on the writing surface in the sweep direction.

Description

Technical Field

[0001] This technology generally relates to pattern generators, particularly pulse pattern generators and methods for driving pulse pattern generators.

Background Art

[0002] Pattern generators are used today for many types of purposes. Pattern generators used in lithography systems or photomask lithography systems need to exhibit very accurate printing characteristics. One way to obtain high-quality pattern printing is, for example, to use a spatial light modulator (SLM) such as a digital micromirror device (DMD), a liquid crystal display (LCD), a grating light valve (GLV), a planar light valve (PLV), a microshutter array (MSA), an analog spatial light modulator (ASLM), and / or a liquid crystal on silicon (LCS). The SLM has an array of individually controllable elements arranged to generate an array of projection elements within an image area on a target surface. The illumination of each individual projection element is controlled by each such element and can be changed between each optical pulse of a pulsed laser.

[0003] 2 In particular, in direct writing devices, the writing speed is an important parameter with respect to both mm / min and throughput. Therefore, a very high pixel rate from the writing engine is required. In applications having resolution requirements lower than those generally required in this technical field, the combination of a high pixel rate and a large pixel size can cause a very high movement speed of the movable parts of the writing device. In many types of conventional XY writers, the speed and / or acceleration of the stage or carriage in the X direction becomes so high as to be immediately impractical.

[0004] In general, the movement speed of the writing stage in the X direction is given by multiplying the modulator's pixel rate by the pixel size and dividing by the number of pixels in the Y direction. For example, a 2D SLM with a refresh rate of 1000 Hz and a 2048 × 4096 micromirror (X / Y) and a pixel size of 1200 nm requires an X speed of approximately 2.4 m / s. This required X speed can be reduced by using a larger SLM with a wider Y direction. However, such large SLMs may be more difficult or expensive to manufacture. Also, some parts of the illumination and projection optics need to be enlarged, which increases cost and complexity.

[0005] Therefore, improvements to high-speed writing applications are needed. [Overview of the Initiative]

[0006] The general objective of this technology is to enable high-speed writing while maintaining a manageable level of physical movement speed.

[0007] The above objectives are achieved by methods and apparatus according to the independent claims. Preferred embodiments are defined in the dependent claims.

[0008] Generally speaking, in the first embodiment, the pattern generator includes a pulsed laser light source, a spatial light modulator (SLM), a control module, an optical end system, and a stage positioning device. The SLM is optically connected to the pulsed laser light source and is positioned to generate a laser irradiation pattern. The control module is positioned to control the SLM to generate a laser irradiation pattern based on print data. A target stage is positioned to hold a target having a photosensitive target surface. The optical end system is optically connected to the SLM and is positioned to position the laser irradiation pattern on a writing surface intended to coincide with the photosensitive target surface. The stage positioning device is configured to mechanically change the relative position between the SLM and the writing surface in a scanning direction parallel to the writing surface. The optical end system further includes a stripe switch. The stripe switch is configured to optically move the position of the laser irradiation pattern on the writing surface in a sweep direction parallel to the writing surface and perpendicular to the scanning direction. The control module is further positioned to control the SLM and the pulsed laser light source depending on the position provided by the stripe switch to generate individual samples of the laser irradiation pattern at at least two predetermined positions in the sweep direction. The distance between at least two default positions relative to the nearest other default position in the sweep direction is less than or equal to the width of the laser irradiation pattern on the writing surface in the sweep direction.

[0009] In a second embodiment, the operation method of the pattern generator includes providing print data representing the pattern to be generated. Pulsed laser light is supplied to the SLM. A spatial light modulator is controlled to generate a laser irradiation pattern according to the print data. The relative position between the SLM and the writing surface is mechanically changed in a scanning direction parallel to the writing surface. An optical end system is positioned to position the laser irradiation pattern on the writing surface. Stripe switches in the optical end system are controlled to optically move the position of the laser irradiation pattern on the writing surface in the sweep direction. The sweep direction is parallel to the writing surface but perpendicular to the scanning direction. The control of the spatial light modulator and the supply of pulsed laser light are further dependent on the control of the stripe switches, which control the SLM to generate separate samples of the laser irradiation pattern at at least two predetermined positions in the sweep direction, where the distance to the nearest other predetermined position in the sweep direction is less than or equal to the width of the laser irradiation pattern on the writing surface in the sweep direction.

[0010] One advantage of the proposed technology is that all pixel rates from high-speed SLMs are available in more writer designs. These solutions contribute to reducing the speed of the writing stage in the X direction, decreasing the reaction force, and shortening the acceleration distance, thereby reducing the heat generated by the motor. It can also improve the precision of the stage movement. This solution is also scalable to accommodate even higher pixel rates from SLM equipment. [Brief explanation of the drawing]

[0011] The present invention, along with its further objectives and advantages, is best understood by referring to the following description in conjunction with the accompanying drawings. [Figure 1] This is a schematic diagram of a pattern generator. [Figure 2] This is a schematic diagram of the cross-sectional side view of the pattern generator. [Figure 3] This is a schematic diagram of the conventional writing process. [Figure 4]This is a schematic diagram of an embodiment of a writing process in which one or more stripes are written simultaneously. [Figure 5] This is a schematic diagram of an embodiment of a process for writing two stripes simultaneously using a quasi-static MEMS mirror. [Figure 6] This is a schematic diagram of an embodiment of a three-strip simultaneous writing process using a quasi-static MEMS mirror. [Figure 7] This is a schematic diagram of an embodiment of a process for writing two stripes simultaneously using a resonant MEMS mirror. [Figure 8] This is a schematic diagram of an embodiment of a three-strip simultaneous writing process using a resonant MEMS mirror. [Figure 9] This is a schematic diagram of an embodiment of a four-strip simultaneous writing process using a resonant MEMS mirror. [Figure 10] This is a flow diagram of the steps in an embodiment of how the pattern generator operates. [Modes for carrying out the invention]

[0012] Throughout the drawings, the same reference number is used for the same or corresponding elements.

[0013] To better understand the proposed technology, it is helpful to begin with a brief overview of pattern generators.

[0014] Figure 1 schematically shows a pattern generator 1 based on an SLM 20. Note that this figure only illustrates the operating principle of the pattern generator 1 and the cooperation principle between its different parts, meaning that the geometric position and design details of the figure are not important. The SLM 20 is shown here as an array 3 of individually controllable elements 4, which in this embodiment are radiant reflection elements. A pulsed laser light source 10 generates pulsed light 5 that collides with the array 3 and is reflected, becoming a set of exposure beams 6 directed toward the target surface 44 of the target 42. The target surface 44 is typically supported by a target support 40. The SLM 20 and the pulsed laser light source 10 are controlled by a control module 30, which synchronizes the light pulses with the settings of the SLM 20. Each individual element 4 of the SLM 20 can be controlled to individually allow or suppress reflection for each light pulse. The control of the SLM 20 is based on print data stored in a memory 32 connected to the control module 30.

[0015] Light emanating from the active portion of the SLM 20 is directed towards the target surface 44 via the optical end system 50. On the target surface 44, the light forms an array 21 of projection elements 22. Together, the projection elements 22 form a laser irradiation pattern 13 on the projection region 14. The irradiation of each individual projection element 22 is controlled by the respective elements 4 of the SLM 20. Typically, there is a nominal optical scaling of the projection region 14 with respect to the SLM array 20. This nominal scaling is a uniform scaling determined by different design parameters such as different distances and normal optics. Arrangements for achieving such nominal scaling are well known to those skilled in the art and will not be further discussed.

[0016] The SLM 20 can be configured in many different ways. The details of the operation of the SLM 20 are not important to the present idea, as long as individual control of element 4 is provided and the SLM 20 produces an array 21 of projection elements 22 in the projection region 14 on the target surface 44.

[0017] After exposure of the projection area 14 according to the individual settings of element 4 of the SLM 20, the projection area 14 can be moved. This is usually done by moving the target support 40, the SLM 20, or both, by mechanically moving the SLM 20 relative to the target support 40. The movement is performed using the stage positioning device 60.

[0018] In other words, in one embodiment, the pattern generator 1 includes a pulsed laser light source 10 and an SLM 20 optically connected to the pulsed laser light source 10. The SLM 20 is arranged to generate a laser irradiation pattern 13. The control module 30 is arranged to control the SLM 20 to generate the laser irradiation pattern 13 based on the print data. The target stage 40 is arranged to hold a target 42 having a photosensitive target surface 44. The optical end system 50 is optically connected to the SLM 20 and arranged to position the laser irradiation pattern 13 on a writing surface 43 intended to coincide with the photosensitive target surface 44.

[0019] FIG. 2 is a schematic cross-sectional view of the pattern generator 1. Referring to FIG. 2, the stage positioning device 60 is configured to mechanically change the relative position between the SLM 20 and the writing surface 43 in a scanning direction 62 parallel to the writing surface 43.

[0020] Figure 3 schematically shows the operation of a prior art pattern generator 1. The SLM 20 directs a set of exposure beams 6 towards a target surface 44 of a writing surface 43, and forms a laser irradiation pattern 13 in a projection area 14 by an array 21 of projection elements 22. The SLM 22 is movable relative to the target surface 44 in a scanning direction 62, also referred to as the X direction. The projection area 14 has a width 48 in the scanning direction 62. Between each laser pulse, the SLM 22 moves by an X pulse distance 65 relative to the target surface 44. In some applications, this X pulse distance 65 may be equal to the width 48 of the projection area 14, which means that a new laser irradiation pattern 13 is created adjacent to the previous one. In other applications, an overlap 66 may be used, for example, to reduce edge effects. This overlap 66 is equal to the difference between the width 48 of the projection area 14 and the X pulse distance 65.

[0021] When the entire intended width in the scanning direction 62 is irradiated, the SLM 22 returns to the start position of the scan again, and a movement 63 of the target surface 44 relative to the SLM 20 is performed in a sweep direction 61 perpendicular to the scanning direction 62. The sweep direction 61 is also referred to as the Y direction. Thereafter, a new scan can be started. The height 47 of the projection area 14 in the sweep direction may be equal to the movement 63, in which case the scans are positioned adjacent to each other. However, similar to the X pulse distance 65, the movement 63 can be made smaller than the height 47 of the projection area 14, resulting in an overlap 64 of the scans.

[0022] As briefly explained in the background, when the acquisition speed of the print data and the speed at which the SLM 20 can be switched are high, the speed required to cause an appropriate relative movement between the SLM 20 and the target surface 44 can be very high.

[0023] According to the idea of ​​this technology, the speed in the X direction can be reduced by distributing the pixel rate across multiple stripes written in parallel in the Y direction. To achieve such parallel writing using a 2D SLM, the projection area resulting from the SLM needs to be shifted in the Y direction over a timeframe equal to the SLM's refresh rate. As will be further explained below, the Y shift can be achieved in several ways.

[0024] To achieve this objective, in one embodiment, the optical end system further includes a stripe switch. The stripe switch is configured to optically move the position of the laser irradiation pattern on the writing surface in a sweep direction parallel to the writing surface and perpendicular to the scanning direction. A control module is further arranged to control the SLM and pulsed laser light source depending on the position brought about by the stripe switch. This control is performed to generate individual samples of the laser irradiation pattern at at least two predetermined positions in the sweep direction. The distance to the nearest other predetermined position in the sweep direction is less than or equal to the width of the laser irradiation pattern on the writing surface in the sweep direction.

[0025] One embodiment of this is schematically shown in Figure 4. A set of exposure beams 6 is supplied to the optical end system 50. The stripe switch 70, in this particular embodiment, is a micro-electromechanical system (MEMS) mirror 72, which is positioned to switch the direction of the set of exposure beams 6 toward the target surface 44. Thus, the stripe switch 70 is configured to optically move the position of the laser irradiation pattern 13 on the writing surface 43 in a sweep direction 61 parallel to the writing surface 43 and perpendicular to the scanning direction 62. In this way, the switched set of exposure beams 6' can be directed toward each of two different stripes 45 in the scanning direction 62 (the dotted line 6'' indicates the previous direction of the switched exposure beam directed toward the other stripe 45 currently being printed). As will be further described below, the basic idea is not limited to two stripes 45 but can be applied to more than two stripes 45. The two stripes 45 are moved relative to each other in the sweep direction 61, as will be described in more detail below.

[0026] As described above, the control module is further arranged to control the SLM and pulsed laser light source depending on the position provided by the stripe switch 70, so as to generate individual samples of the laser irradiation pattern 13 at at least two predetermined positions in the sweep direction 61.

[0027] Because the two stripes 45 are written in parallel, the need to move the relative position between the SLM and the writing surface in the scanning direction 62 is reduced by approximately twofold while maintaining the same speed of the provided print data. In other words, the optical switching between the stripes 45 in the sweeping direction 61 reduces the physical movement speed of the SLM relative to the writing surface in the scanning direction 62.

[0028] The distance 74 to the nearest other predetermined position in the sweep direction 61 is less than or equal to the width of the laser irradiation pattern 13 on the writing surface 43 in the sweep direction 61. This ensures that the entire intended area to be written on the target surface 44 is irradiated at least once in the sweep direction 61.

[0029] If more than two stripes are used and written in parallel, the reduction in relative physical speed that can occur will be even greater.

[0030] Figure 5 schematically illustrates one embodiment of the printing process. A stripe switch moves the position of the laser irradiation pattern 13 on the writing surface in a periodic motion pattern. A complete cycle of the periodic motion pattern is performed within a certain period. This period is less than or equal to the quotient obtained by dividing the width 48 of the laser irradiation pattern 13 on the writing surface in the scanning direction 62 by a constant scanning speed of the relative position between the SLM and the writing surface. This ensures that the entire intended area to be written on the target surface is irradiated at least once in the scanning direction 62. The SLM and pulsed laser light are controlled in synchronization with the periodic motion pattern to generate individual samples of the laser irradiation pattern 13 at at least two predetermined positions in the sweep direction 61.

[0031] In other words, the laser irradiation pattern 13 is written to the first stripe 45A, but pulsed laser light from the switched exposure beam set reaches the target surface. In most applications, the laser pulses are short enough to allow the change in relative position between the SLM and the writing surface to continue during exposure. Once this exposure is complete, the change in relative position continues to move the position of the exposed area in the scanning direction 62. Simultaneously, the stripe switch changes the exposure position to the second stripe 45B in the sweep direction 61. The next laser pulse is allowed, and the laser irradiation pattern 13 is written to the second stripe 45B. The stripe switch then returns the exposure beam to the first stripe 45A, allowing the pattern of periodic movement to start again from the beginning.

[0032] After the writing of two or more stripes is complete, the relative position between the SLM and the writing surface is returned to the starting point in the scanning direction. Simultaneously, the relative position between the SLM and the writing surface in the sweep direction is also changed to prepare for the writing of new stripes. In other words, it is preferable that the stage positioning device be further configured to mechanically change the relative position between the SLM and the writing surface in the sweep direction 61. To reach all intended exposure positions, the amplitude 74 of the periodic motion pattern in the sweep direction 61 is generally greater than or equal to (m-1) / m times the step 75 in the sweep direction, where m is the number of predetermined positions in the sweep direction 61. In this embodiment having two stripes, the amplitude 74 of the periodic motion pattern in the sweep direction 61 is at least half the step 75 in the sweep direction 61.

[0033] In Figure 5, the actual patterns that were written are omitted compared to Figure 3 in order to improve the readability of the figure.

[0034] Figure 6 schematically illustrates the writing process for more than two simultaneous stripes 45A–45C. The control module is configured to control the SLM to generate a laser irradiation pattern at more than two predetermined positions equally spaced in the sweep direction. In this particular embodiment, there are three equally spaced stripes 45A–45C. The relative speed between the SLM and the writing surface here is approximately one-third compared to the situation where the stripes are written continuously. The required amplitude 74 of the switch in the sweep direction is at least two-thirds of the step 75 between consecutive scans.

[0035] In this particular embodiment, the distances in the scanning direction between the individual laser irradiation patterns 13 of each stripe 45A to 45C are also equal. In other words, the laser irradiation pattern 13 of stripe 45B moves in the scanning direction by the same amount as the laser irradiation pattern 13 of stripe 45C moves in the scanning direction relative to the laser irradiation pattern 13 of stripe 45B. However, as will be further explained below, this is not absolutely necessary and depends on the operability of the stripe switch. In this embodiment, the speed at which the stripe switch changes between stripe 45C and 45A is twice as fast as the speed between stripe 45A and 45B.

[0036] One possibility for implementing a stripe switch is to use a micro-electromechanical system (MEMS) mirror. MEMS mirrors are available in different versions. In different embodiments, quasi-static or resonant MEMS mirrors can be used.

[0037] Figures 5 and 6 may illustrate an implementation using a quasi-static MEMS mirror. Here, the position in the sweep direction 61 can be stopped at a precisely defined position. This allows for the selection of equally spaced stripes at selected timings. In these figures, the timings are selected at regular intervals, which can be advantageous in controlling the timing of laser pulses. However, in other embodiments, different timings may be selected for each different strip change.

[0038] In other words, the quasi-static MEMS mirror shifts the 2D-SLM image, i.e., the laser irradiation pattern 13, to discrete positions in the sweep direction 61. The velocity in the scanning direction 62 decreases by a coefficient equal to the number of different positions in the sweep direction 61. Thus, the mirror cycle consists of several small movements, typically 2 to 5, in the sweep direction, followed by a large negative return movement in the sweep direction.

[0039] Another option for MEMS mirrors is the resonant MEMS mirror. Such mirrors oscillate continuously between different states according to the system's resonant frequency. This allows for a relatively cost-effective and simple configuration, but has the disadvantage of not being able to independently control the timing of reaching different positions. In other words, the stripe switch moves the position of the laser irradiation pattern on the writing surface in a pattern of periodic motion with a frequency equal to the resonant frequency of the MEMS mirror.

[0040] Figure 7 schematically shows an embodiment of dual-stripe writing that can be realized using a resonant MEMS mirror. Curve 76 shows the movement of the center position of the laser irradiation pattern 13 when the laser is always on. This curve 76 consists of a constant-velocity mechanical movement in the scanning direction 62 provided by the stage positioning device and an oscillatory movement in the sweeping direction 61 provided by the resonant MEMS mirror. In this embodiment, a laser pulse is turned on at each endpoint of the oscillatory movement, and the laser irradiation pattern 13 is written onto the target surface 44.

[0041] The resonant MEMS mirror moves the 2D-SLM image, i.e., the laser irradiation pattern 13, to different possible positions in the sweep direction 61. The speed in the scanning direction 62 is reduced by the number of positions used in the sweep direction 61. The mirror moves the image in the sweep direction 61 at vibration frequencies, typically 2 to 4, corresponding to a portion of the SLM update frequency. The positions in the sweep direction are the result of a combination of the exposure light pulse rate, mirror deflection amplitude and frequency, and laser synchronization with respect to the resonant phase. For 2 to 4 positions in the sweep direction, the stripes can be precisely spaced equally.

[0042] Figure 8 schematically shows another embodiment of three-stripe writing that can be realized using a resonant MEMS mirror. Here, three equally spaced positions in the sweep direction 61 are selected. As the resonant mirror moves through these positions, laser pulses are emitted, and a laser irradiation pattern 13 is written onto the target surface 44. In order to arrange the laser irradiation pattern 13 at equal intervals in the sweep direction and at the same time difference Δt between exposures, the amplitude 74 of the resonant mirror's movement must be larger than that of a quasi-static MEMS mirror, and may be larger than the step 75 in the sweep direction 61.

[0043] Alternatively, if two exposure instances occur at the turning point of the MEMS mirror, the laser pulses must be controlled to occur at different time intervals.

[0044] Figure 9 schematically shows another embodiment of four-stripe writing that can be realized using a resonant MEMS mirror. In this embodiment, the amplitude 74 of the resonant mirror's movement is approximately the same as the step 75 in the sweep direction 61. The four equally spaced stripes 45A to 45D can be realized by parallel writing. This allows the required mechanical speed in the scanning direction to be reduced to 1 / 4. In this embodiment, it can also be seen that the time difference Δt between writing opportunities of different stripes is the same, i.e., the shifts between different stripes are equally spaced in the scanning direction 62 as well. This is achievable along with the equally spaced arrangement of the four stripes in the sweep direction 61. Therefore, the laser pulses must be controlled to occur in these regular time instances, having a constant phase shift between the resonant motion and the laser pulse opportunity. Since the SLM is usually always moving relative to the target surface, the temporally equally spaced exposure opportunities also result in equally spaced spatial offsets of the laser irradiation pattern 13 as described above.

[0045] This technical solution is particularly suitable when the pattern generator is a direct programmer. In that case, programming speed is of paramount importance.

[0046] However, this technical solution is also applicable in cases where the current scanning speed is not typically very high for such writing engines, such as in mask writers. Such writers are usually based on acousto-optic modulator (AOM) and / or acousto-optic deflector (AOD) writer operation. However, the current back-and-forth between stripes can be used to reduce the number of strokes required for X-speed or multi-pass writing by back-and-forth sweeping between multiple stripes. However, it has now been concluded that such implementations would require a major redesign to adapt the mirror behind the deflector.

[0047] Figure 10 is a flow diagram of the steps of an embodiment of how to operate a pattern generator. In step S10, print data representing the pattern to be generated is provided. In step S20, pulsed laser light is supplied to the SLM. In step S30, the SLM is controlled to generate a laser irradiation pattern according to the print data. In step S40, the relative position between the SLM and the writing surface is mechanically changed in a scanning direction parallel to the writing surface. In step S50, the optical end system is positioned to position the laser irradiation pattern on the writing surface. In step S55, the stripe switch of the optical end system is controlled to optically move the position of the laser irradiation pattern on the writing surface in a sweeping direction parallel to the writing surface and perpendicular to the scanning direction.

[0048] The control of the spatial light modulator and the supply of pulsed laser light are further performed by controlling the stripe switch to control the SLM so that it generates individual samples of the laser irradiation pattern at at least two predetermined positions in the sweep direction, where the distance to the other nearest predetermined position in the sweep direction is less than or equal to the width of the laser irradiation pattern on the writing surface in the sweep direction.

[0049] The steps are shown as consecutive steps in Figure 10. However, in reality, steps S20 to S55, and optionally step S10, are performed in cooperation with each other and usually overlap at least partially in time. This is shown by the dotted box S15.

[0050] In one embodiment, step S55, which controls the stripe switch, moves the position of the laser irradiation pattern on the writing surface in a periodic motion pattern. The complete cycle of the periodic motion pattern is performed in a period of time less than or equal to the quotient obtained by dividing the width of the laser irradiation pattern in the scanning direction on the writing surface by a constant scanning speed of the relative position between the SLM and the writing surface. The control of the spatial light modulator and the supply of pulsed laser light are synchronized with the periodic motion pattern to generate individual samples of the laser irradiation pattern at at least two predetermined positions in the sweep direction.

[0051] In a preferred embodiment, the method further includes step S60, in which the relative position between the SLM and the writing surface is mechanically changed in steps in the sweep direction. The amplitude of the pattern of periodic motion in the sweep direction is greater than or equal to the steps in the sweep direction.

[0052] In one embodiment, step S30, which controls the SLM, controls the SLM to generate a laser irradiation pattern at more than two predetermined positions in the sweep direction. The more than two predetermined positions are equally spaced in the sweep direction.

[0053] In one embodiment, step S55, which controls the stripe switch, includes controlling a micro-electromechanical system mirror.

[0054] In a further embodiment, step S55, which controls the stripe switch, includes controlling the resonant micro-electromechanical system mirror. Step S55, which controls the stripe switch, includes moving the position of the laser irradiation pattern on the writing surface in a pattern of periodic motion with a frequency equal to the resonant frequency of the micro-electromechanical system mirror.

[0055] In another further embodiment, step S55, which controls the stripe switch, includes controlling a quasi-static micro-electromechanical system mirror.

[0056] The embodiments described above should be understood as some exemplary examples of the present invention. Those skilled in the art will understand that various modifications, combinations, and changes can be made to the embodiments without departing from the scope of the invention. In particular, solutions of different parts in different embodiments can be combined in other configurations where technically possible. However, the scope of the invention is defined by the appended claims.

Claims

1. A pulsed laser light source (10), A spatial light modulator (20) is optically connected to the pulsed laser light source (10) and arranged to generate a laser irradiation pattern (13), A control module (30) is arranged to control the spatial light modulator (20) to generate a laser irradiation pattern (13) according to print data, A target stage (40) is positioned to hold a target (42) having a photosensitive target surface (44), Optical end system (50) is optically connected to the spatial light modulator (20) and positioned to position the laser irradiation pattern (13) on a writing surface (43) intended to coincide with the photosensitive target surface (44), The system includes a stage positioning device (60) configured to mechanically change the relative position between the spatial light modulator (20) and the writing surface (43) in a scanning direction (62) parallel to the writing surface (43), The optical end system (50) further includes a stripe switch (70) configured to optically move the position of the laser irradiation pattern (13) on the writing surface (43) in a sweeping direction (61) parallel to the writing surface (43) and perpendicular to the scanning direction (62), The control module (30) is further arranged to control the spatial light modulator (20) and the pulsed laser light source (10) in a manner dependent on a position provided by the stripe switch (70) such that it generates individual samples of the laser irradiation pattern (13) at at least two predetermined positions in the sweep direction (61) where the distance to the other nearest predetermined position in the sweep direction (61) is less than or equal to the width (47) of the laser irradiation pattern (13) in the sweep direction (61) on the writing surface (43). A pattern generator (1) characterized by the following:

2. The stripe switch (70) moves the position of the laser irradiation pattern (13) on the writing surface (43) in a periodic motion pattern such that its complete cycle is performed in a period of time less than or equal to the quotient obtained by dividing the width (48) of the scanning direction (62) of the laser irradiation pattern (13) on the writing surface (43) by a constant scanning speed of the relative position between the spatial light modulator (20) and the writing surface (43). The spatial light modulator (20) and the pulsed laser light source (10) are controlled in synchronization with the pattern of periodic motion to generate individual samples of the laser irradiation pattern (13) at the at least two predetermined positions in the sweep direction (61). The pattern generator according to claim 1, characterized in that

3. The stage positioning device (60) is further configured to mechanically change the relative position between the spatial light modulator (20) and the writing surface (43) in steps (75) in the sweep direction (61), The amplitude (74) of the periodic motion pattern in the sweep direction (61) is greater than or equal to (m-1) / m times the step (75) in the sweep direction (61), where m is the number of predetermined positions in the sweep direction (61). The pattern generator according to claim 2, characterized in that

4. The control module (30) is configured to control the spatial light modulator (20) to generate a laser irradiation pattern (13) at more than two predetermined positions in the sweep direction (61). The more than two predetermined positions are equally spaced in the sweeping direction (61). A pattern generator according to any one of claims 1 to 3, characterized in that

5. The stripe switch (70) includes a micro-electromechanical system mirror (72), A pattern generator according to any one of claims 1 to 4, characterized in that

6. The aforementioned micro-electromechanical system mirror (72) is a resonant micro-electromechanical system mirror, The stripe switch (70) moves the position of the laser irradiation pattern (13) on the writing surface (43) in a pattern of periodic movement with a frequency equal to the resonant frequency of the micro-electromechanical system mirror. The pattern generator according to claim 5, characterized in that

7. The aforementioned micro-electromechanical system mirror (72) is a quasi-static micro-electromechanical system mirror. The pattern generator according to claim 5, characterized in that

8. The pattern generator (1) is a direct writing device. A pattern generator according to any one of claims 1 to 7, characterized in that

9. The steps include providing print data representing the generated pattern (S10), The steps include supplying pulsed laser light to a spatial light modulator (20) (S20), The steps include controlling the spatial light modulator (20) to generate a laser irradiation pattern (13) according to the print data (S30), The steps include: (S40) mechanically changing the relative position between the spatial light modulator (20) and the writing surface (43) in a scanning direction (62) parallel to the writing surface (43), The steps include (S50) positioning the optical end system (50) on the writing surface (43) to position the laser irradiation pattern (13), The step of controlling the stripe switch (70) of the optical end system (50) so as to optically move the position of the laser irradiation pattern (13) on the writing surface (43) in a sweeping direction (61) parallel to the writing surface (43) and perpendicular to the scanning direction (62) (S55), The control (S30) of the spatial light modulator (20) and the supply of pulsed laser light (S20) are further performed depending on the control (S55) of the stripe switch (70) to control the spatial light modulator (20) to generate separate samples of the laser irradiation pattern (13) at at least two predetermined positions in the sweep direction (61) where the distance (63) to the nearest other predetermined position in the sweep direction (61) is less than or equal to the width (47) of the laser irradiation pattern (13) in the sweep direction (61) on the writing surface (43). A method for operating a pattern generator, characterized by the features described above.

10. The step of controlling the stripe switch involves moving the position of the laser irradiation pattern on the writing surface in a periodic operating pattern in which the complete cycle is performed within a period of time smaller than or equal to the quotient obtained by dividing the width of the laser irradiation pattern on the writing surface in the scanning direction by a constant scanning speed between the spatial light modulator and the writing surface. The control of the spatial light modulator and the supply of the pulsed laser light are synchronized with the periodic operation pattern to generate the individual samples of the laser irradiation pattern at the at least two predetermined positions in the sweep direction. The method according to claim 9, characterized in that

11. The step further includes mechanically changing the relative position between the spatial light modulator (20) and the writing surface (43) in steps (75) in the sweeping direction (61), The amplitude (74) of the periodic operation pattern in the sweep direction (61) is greater than or equal to the step (75) in the sweep direction (61). The method according to claim 10, characterized in that

12. The control of the spatial light modulator (20) (S30) controls the spatial light modulator (20) to generate the laser irradiation pattern (13) at more than two predetermined positions in the sweep direction (13), The more than two predetermined positions are equally spaced in the sweeping direction (61). The method according to any one of claims 9 to 11, characterized in that

13. The method according to any one of claims 9 to 12, characterized in that the control of the stripe switch (70) (S55) includes the control of a micro-electromechanical system mirror (72).

14. The control of the stripe switch (70) (S55) includes the control of the resonant micro-electromechanical system mirror, The control of the stripe switch (70) (S55) moves the position of the laser irradiation pattern (13) on the writing surface (43) in a periodic operating pattern with a frequency equal to the resonant frequency of the micro-electromechanical system mirror. The method according to claim 13, characterized in that it includes the following.

15. The control of the stripe switch (70) (S55) includes the control of a quasi-static micro-electromechanical system mirror. The method according to claim 13, characterized in that

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