Method for operating a laser system and for generating a target material plasma and for microstructure production therewith, and correspondingly configured laser system

Abstract

The invention relates to a method (18) for operating a laser system (1). In said method, electrodes (4) are supplied with a reduced HF-power in a soft start phase (15) in order to generate free electrons in a gaseous laser medium (3) and to facilitate plasma ignition (17). A switch is then made to continuous operation (16), in which the electrodes (4) are supplied with a greater HF-power. By means of subsequently generated laser radiation (9), a plasma of a target material (11) can be generated for generating secondary radiation (12). This secondary radiation (12) can be used to produce microchips (13) or semiconductor intermediate products (13). The invention also relates to a correspondingly configured laser system (1).

Description

[0001] METHOD FOR OPERATING A LASER SYSTEM AND FOR PRODUCEING A TARGET MATERIAL PLASMA AND FOR MANUFACTURING A MICROSTRUCTURE THEREBY AND A LASER SYSTEM SET UP CORRESPONDING TO THAT SYSTEM

[0002] The present invention lies in the field of high-frequency and laser technology and relates to a method for operating a laser system with a gaseous laser medium. The invention also relates to a correspondingly configured laser system. Furthermore, the invention relates to methods for generating a plasma of a target material for generating secondary radiation and for producing microchips or semiconductor intermediates using such a laser system.

[0003] Gas lasers have been known for a long time and can be used effectively in a variety of applications. A plasma is generated in a gaseous laser medium by positioning electrodes next to the laser medium and applying a voltage to the electrodes, thus permeating the laser medium with a high-frequency electric field. However, the plasma is not generated instantaneously when the voltage is applied. Until the plasma ignites in the laser medium, a significant portion of the electrical power applied to the electrodes is typically reflected by or from them. This reflected electrical power can potentially damage a high-frequency generator used for power generation, for example, by overheating.

[0004] To avoid this, a so-called ignition aid is often used. This allows an electric arc to be generated in the laser medium or a suitable gas mixture using appropriate hardware, thereby exciting it. This prevents excessive reflection of high-frequency power during the commissioning of such a laser system. However, this requires additional hardware to generate the arc, which can lead to manufacturing, cost, and maintenance expenses, and can increase the component diversity and complexity of the laser system. Therefore, a less complex solution for the safe, reliable, and damage-free commissioning of a laser system with a gaseous laser medium would be desirable. The object of the present invention is to enable the generation and use of laser radiation from a gas laser with particularly low effort.

[0005] The problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are specified in the dependent claims, the description, and the drawings. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims.

[0006] The first method according to the invention serves to operate a laser system comprising a gas volume, i.e., a gas container, in which a gaseous laser medium is located and on or next to which at least two electrodes are arranged. The gas container can therefore contain a gas serving as the laser medium or a gas mixture that itself contains a gas serving as the laser medium. According to the invention, the laser system is put into operation with an initial soft start phase. During this soft start phase, the electrodes are supplied with a reduced RF power (RF: high frequency), i.e., with a high-frequency voltage signal. This generates free electrons in the laser medium, at least in preparation for ignition, i.e., the generation of a plasma in the laser medium. During such a soft start, the laser medium can therefore be at least partially excited.The reduced RF power used during the soft start, i.e., during the soft start phase, can also be referred to as start-up power.

[0007] According to the invention, after the soft start-up phase, the system switches to continuous operation. In this continuous operation, the electrodes, particularly when plasma is ignited in the laser medium, are subjected to a higher average RF power compared to the reduced RF power used during the soft start-up phase. This higher RF power used in continuous operation, which can also be referred to as continuous operating power, can therefore be greater than the start-up power when considered on average over a period long compared to the period of the high frequency of the power or the power or voltage pulses. The start-up power, at least when considering the entire duration of the soft start-up phase, can be lower than the continuous operating power, either on average or at its maximum instantaneous value, compared to an equally long period during continuous operation.By means of the continuous operating power used during continuous operation, the plasma in the laser medium can be maintained permanently for laser generation during the corresponding operation of the laser system.

[0008] During the soft start phase, particularly before plasma ignition in the laser medium, a larger proportion of the supplied electrical power is reflected from the electrodes to the RF generator, which provides the power, than during continuous operation or when the plasma is ignited. The reduced RF power during the soft start phase, compared to subsequent continuous operation, thus protects the RF generator from damage. Even this reduced RF power can be sufficient to generate free electrons in the laser medium. With the presence of free electrons, the plasma can then be ignited more quickly, for example, compared to a cold start where full continuous operating power would be applied immediately.This can also contribute to the protection of the RF generator, as the plasma can potentially be ignited during the soft start phase, or the higher RF power only needs to be applied for a shorter period without ignited plasma before ignition. Furthermore, the RF generator can be controlled by software to generate and provide the different power levels during the soft start and continuous operation phases. Such software-based control of the RF generator, i.e., the power generation by the RF generator, can be implemented particularly easily and cost-effectively, as no additional hardware is required. The present invention thus eliminates the need for previously used ignition aid hardware or replaces it with software-based control. This ultimately saves on material and costs for the manufacture and maintenance of the laser system.

[0009] The present invention also relates to a laser system comprising a gas container for receiving a gaseous laser medium or a gas mixture comprising such a laser medium. Furthermore, the laser system according to the invention includes at least one RF generator and, in particular, electrodes arranged externally on or next to the gas container. The RF generator is connected to the electrodes in order to supply them with electrical power or voltage. The laser system also includes a control unit for controlling the electrical power generated, i.e., output, by the RF generator. The control unit can therefore be connected to the RF generator for appropriate control of the RF generator or be a component of the RF generator, i.e., integrated into it. According to the invention, the laser system is configured for the execution of the method according to the invention, in particular automatically or semi-automatically.The control unit can, for example, comprise a process unit, such as a microprocessor, microchip, microcontroller, or the like, and a computer-readable data storage device coupled to it. This data storage device can then contain a corresponding operating or computer program that encodes or implements the process steps, measures, or sequences, or corresponding control instructions, mentioned in connection with the methods according to the invention or also in connection with the laser system according to the invention. This operating or computer program can then be executed by means of the process unit to carry out the corresponding method or to effect its execution. The laser system according to the invention can therefore, in particular, be the laser system mentioned in connection with the method according to the invention, or correspond to it.The laser system may also include other components, such as optical elements and / or beam guidance elements and / or laser amplifiers and / or a beam trap and / or the like.

[0010] In one possible embodiment of the present invention, the laser system, and in particular its control unit, is configured to generate several RF pulses during the soft start phase for imparting reduced RF power to the electrodes. The time interval between these RF pulses is, in particular, many times greater than the duration of each individual RF pulse. For example, during the soft start phase, the duty cycle for power delivery to the electrodes can be lower, in particular much lower than 1% or less than 100%. The individual RF pulses can be so short, in particular, that the reflected power does not lead to damage or automatic shutdown of the RF generator. The time interval between the RF pulses prevents continuous load on the RF generator and allows for at least partial cooling of the RF generator between the RF pulses.In a possible further development of the present invention, the laser system is configured to supply the electrodes with continuous wave power during continuous operation. In other words, the laser system can be configured for continuous wave (CW) operation during the continuous operation phase. Thus, switching from the soft-start phase to continuous operation can entail or include switching from pulsed to continuous wave operation. Since the plasma in the laser medium is ignited during continuous operation, and the laser medium is therefore electrically conductive or becomes conductive relatively quickly, the reflected power in CW operation can be so low that it does not lead to damage or automatic shutdown of the RF generator.Continuous wave operation allows a particularly large amount of energy to be coupled into the laser medium, thus enabling effective generation of laser radiation or achieving a particularly high laser power.

[0011] In another possible embodiment of the present invention, the laser system is configured for pulse-width modulation of the power applied to the electrodes during operation of the laser system, i.e., a corresponding RF voltage signal. For example, an RF voltage signal with a fixed fundamental frequency – for example, 13.56 MHz – can be modulated. In this way, the RF pulses mentioned elsewhere can be generated during the soft start-up phase. The pulse frequency can then correspond to the modulation frequency or result from the superposition of the modulation frequency with the fundamental frequency. Likewise, other fundamental frequencies can be used depending on the application or requirements.In the embodiment of the present invention proposed here, the laser system is further configured to automatically set different modulations or modulation frequencies and / or different duty cycles of the pulse width modulation during the soft start-up phase on the one hand and during continuous operation on the other. The laser system can thus be configured for PWM control. This allows for simple, precise, and effective control of the excitation of the laser medium, the ignition of the plasma, the continuous operation of the laser system, and the load on the RF generator. This enables safe, robust, and reliable commissioning of the laser system as well as corresponding continuous operation. In another possible embodiment of the present invention, the laser system is configured to apply a voltage or...to increase the pulse or signal amplitude of the RF power applied to the electrodes. In other words, during the soft start phase, the reduced RF power can at least also be achieved by a reduced signal amplitude or a lower maximum voltage applied to the electrodes. This reduces or limits the load on the RF generator due to reflections. Depending on the laser medium or gas mixture used, the reduced signal amplitude or voltage can be set or preset so that at least a certain amount of free electrons can be generated in the laser medium or gas mixture. The reduced signal amplitude or voltage can be at least as large as or smaller than a threshold value necessary for complete plasma ignition in the laser medium or gas mixture. Likewise, an automatic or preset variation, in particular an increase, of the signal amplitude or voltage can be implemented.The voltage during the soft start phase makes this possible. This allows, for example, the initial generation of a certain amount of free electrons with a particularly low load on the RF generator, and the plasma can then be ignited later in or towards the end of the soft start phase. Due to the larger signal amplitude or voltage during continuous operation, the plasma can then be reliably maintained through reflected power, again with a relatively low load on the RF generator.

[0012] In a further possible embodiment of the present invention, the laser system is configured to maintain the soft start phase, particularly after each commissioning of the laser system, for a fixed, predetermined period. This period is referred to here as the soft start duration. The fixed duration of the soft start phase enables particularly simple control and design, as well as consistent operating behavior of the laser system. The precise soft start duration can be specified depending on the individual application. For example, depending on the desired behavior or requirements, and depending on the specific laser medium and / or geometry (e.g., the distance between the electrodes), a suitable soft start duration can be determined experimentally and / or using a model.The duration of the soft start phase can be determined using computer-aided simulation. In another possible embodiment of the present invention, the laser system is configured to maintain the soft start phase for more than 100 ms. The duration of the soft start phase, i.e., the soft start time mentioned elsewhere, can be, for example, at least 100 ms or at least 200 ms. To enable rapid commissioning of the laser system, i.e., timely generation of laser radiation after switching on the laser system, and to achieve high plasma stability as quickly as possible, the duration of the soft start phase can, for example, be at most 800 ms. For example, the soft start phase can be maintained for approximately 500 ms. This has proven to be an effective and practical value.

[0013] In another possible embodiment of the present invention, the laser system is configured to switch from the soft-start phase to continuous operation only after the plasma in the laser medium or the corresponding gas mixture has been ignited. In other words, the soft-start phase can last at least as long as, and thus the operating power can be used, until the plasma is ignited. Accordingly, the system only switches to continuous operation, i.e., the higher continuous operating power, once the plasma has already been ignited. For this purpose, the fixed duration of the soft-start phase mentioned elsewhere can be predefined or set accordingly. By igniting the plasma with the lower starting power, a relatively large pulse of reflected power during the switch to continuous operating power can be avoided.Even if, due to the preceding soft start phase, the plasma could be ignited more quickly at continuous operating power than without the soft start phase, the RF generator can be protected particularly effectively by the embodiment of the present invention proposed here, i.e., protected from damage or preconditions that would lead to an automatic shutdown.

[0014] In a possible further development of the present invention, the laser system is configured to monitor and / or measure the power reflected from the electrodes back to the RF generator and to detect plasma ignition based on its temporal profile. The applied or injected power to the electrodes can also be taken into account, as this is known or can be monitored. Until the plasma is generated or becomes sufficiently electrically conductive, the electrodes effectively represent open conductor ends at which at least a large portion of the injected power can be reflected. As soon as the system or the plasma ignites, for example, when the plasma ignites in CO2-containing gas mixtures, and becomes electrically conductive, only a smaller portion of the power is reflected, which may depend on the impedance matching of the plasma.Thus, ignition can be detected by a corresponding change in the reflected power. This ensures that the system only switches to continuous operation after the plasma has actually ignited. This allows, for example, consideration of the fact that the plasma ignition time, or the time between the initial power-up of the laser system and plasma ignition, can vary depending on different conditions or parameters. It also prevents the unnecessarily long use of start-up power. This can potentially lead to more reliable and / or efficient operation of the laser system.

[0015] In another possible embodiment of the present invention, the laser medium is or contains CO2, i.e., carbon dioxide. Accordingly, the laser system can be, or comprise, a CO2 laser. Such lasers can be used advantageously for various applications, and it has been shown that using CO2 as the laser medium makes the soft start phase practical for the safe and robust commissioning of the laser system.

[0016] In another possible embodiment of the present invention, the laser system is configured to generate EUV light, i.e., extreme ultraviolet radiation. To generate EUV light, a suitable target material, for example, a tin droplet, can be irradiated with a laser pulse, particularly repeatedly. This allows the target material to be at least partially converted into a plasma, which in turn emits EUV light. The laser system can therefore include, for example, a corresponding reaction chamber, a system for supplying the target material, optics for directing the laser radiation generated by the laser medium into the reaction chamber or onto the target material, and / or similar components. In this application, relatively high laser powers may be required, so the reduction in the load on the RF generator made possible by the present invention can be particularly beneficial.

[0017] The present invention also relates to a method for generating a target material plasma, i.e., a plasma from a predetermined target material for generating secondary radiation, in particular EUV light, for example for EUV lithography. In this second method according to the invention, the laser system according to the invention is provided. This laser system is then put into operation according to the first method according to the invention, and laser radiation is then generated continuously by means of the laser system. The generated laser radiation is then guided along a predetermined beam path and directed onto the target material. The target material is different from the laser medium used to generate the laser radiation.

[0018] The present invention also relates to a method for manufacturing microchips or semiconductor intermediates for manufacturing microchips. In this third method according to the invention, a semiconductor material is provided. The target material plasma is then generated according to the second method according to the invention. The secondary radiation generated by this target material plasma is then directed onto the semiconductor material. This forms a predetermined microstructure in the semiconductor material.

[0019] Further features of the invention may become apparent from the following description of the figures and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0020] The drawing shows in:

[0021] Fig. 1 is a schematic representation of a laser system;

[0022] Fig. 2 shows an exemplary diagram illustrating a power pulse for a soft start of the laser system;

[0023] Fig. 3 is an exemplary diagram illustrating a soft start phase and subsequent continuous operation of the laser system; and Fig. 4 is an exemplary schematic flow chart illustrating a method for operating the laser system.

[0024] Identical or functionally equivalent elements are marked with the same reference symbols in the figures.

[0025] Fig. 1 shows a partial schematic representation of a laser system 1. The laser system 1 comprises a gas container 2 containing a gaseous laser medium 3, for example CO2 or a CO2-containing gas mixture. At least two electrodes 4 are arranged on the outside of or next to this gas container 2. The laser system 1 also comprises at least one RF generator 5, which is connected to the electrodes 4 via appropriate electrical lines. When the laser system 1 is put into operation, a plasma is to be generated in the laser medium 3. This is created by the so-called ignition of the gas mixture contained in the gas container 2. For this purpose, a high-frequency voltage is applied to the electrodes 4 by means of the RF generator 5. In the unignited state, i.e., before a sufficiently electrically conductive plasma has been generated in the gas container 2 or the laser medium 3, at least approximately the full electrical power supplied by the RF generator 5 can be dissipated.The reflected power is reflected at the electrodes 4. The RF generator 5 can only withstand this reflected power for a certain period of time before it automatically shuts down, for example to prevent damage from overheating.

[0026] To address this problem, the power or voltage output by the RF generator 5 is controlled in a specific manner. For this purpose, the laser system 1 includes a corresponding control unit 6, which is schematically represented here by a processor 7 and a computer-readable data storage device 8 coupled to it. The control unit 6 can be connected to the RF generator 5 or be part of the RF generator 5, i.e., integrated into it.

[0027] The control unit 6 controls and executes the commissioning of the laser system 1, i.e., the ignition of the gas mixture or plasma to generate laser light, using a so-called soft start, which involves a gentle start followed by a switch to a continuous operating mode with increased power. The soft start ensures that during each ignition process, only relatively short high-frequency pulses are initially emitted by the RF generator 5. These relatively short pulses excite the gas mixture or the laser medium 3, generating a certain number of free electrons. After a certain period, the control unit 6 can switch to a continuous operating mode with full power output from the RF generator 5.

[0028] The soft start and the switch to continuous operation, as well as the different power levels, pulse frequencies, modulation patterns, or similar parameters used in these different operating phases, can be set or controlled via software settings or software-based control, for example, using MD values. The software, i.e., a corresponding operating program, can specify or predefine, for example, the duration of the soft start, the frequency and duty cycle of the high-frequency pulses, and / or other parameters. The hardware required to implement different power levels, pulse patterns, or modulations is typically already integrated into conventional laser systems 1 or conventional RF generators 5.

[0029] After the plasma of the laser medium 3 is ignited in the gas container 2, this plasma can generate light, which can be at least partially coupled out as laser radiation 9 in the laser system 1 and guided in a beam path 10. In the example shown here, the laser radiation 9 can then be directed onto a target material 11 to convert it into a target material plasma. This target material plasma can then in turn generate secondary radiation, namely, for example, EUV light 12. This EUV light 12 can then be directed by means of suitable optics onto a provided semiconductor material 13 to create a microstructure within it.

[0030] To further illustrate this, Fig. 2 shows an exemplary diagram in which the power P is plotted on the ordinate and the time t on the abscissa. The diagram illustrates the curves of an input power and a reflected power for two instances of a soft-start pulse 14. For the first instance, the initial input power P1 and the resulting initial reflection power R1 are shown. For the second instance, the second input power P2 and the resulting second reflection power P2 are shown. It can be seen that, despite certain variations in the curves, both the input power P1, P2 and the reflection power R1, R2 follow the same curve or pattern.The feed-in powers P1, P2 can initially increase, while the associated reflection powers R1, R2 can increase with a time delay until a certain conductivity of the gas mixture is reached, whereupon the reflection powers R1, R2 initially decrease again before the feed-in powers P1, P2 are switched off.

[0031] For further illustration, Fig. 3 shows another exemplary diagram, in which the power P and the time t are also plotted. However, a significantly longer period is shown here compared to Fig. 2. This includes a soft-start phase 15 and at least the beginning of a subsequent continuous operation 16. Within the soft-start phase 15, several soft-start pulses 14 are generated at time intervals. During the last soft-start pulse 14, the plasma is ignited in the laser medium 3, which is described here as point-source plasma ignition 17. The soft-start pulses 14 can, for example, have a width or length of 4 ps. This is long enough to generate some free electrons in the laser medium 3 or the corresponding gas mixture and ultimately ignite the plasma, and at the same time short enough that the RF generator 5 can tolerate the reflected power without damage.Overall, it is evident that several soft-start pulses 14 are initially generated, and subsequently, particularly after plasma ignition 17, a continuous power supply is fed in. This results in a higher average power supply during continuous operation 16 compared to the soft-start phase 15. Since the generated plasma is permanently electrically conductive after plasma ignition 17, the reflection powers R1 and R2 remain relatively low and pose no problem for the RF generator 5.

[0032] Fig. 4 shows an exemplary schematic flowchart 18 illustrating a method for operating the laser system 1, for example, for the production of microchips or semiconductor intermediates. In process step S1, the laser system 1, the target material 11, and the semiconductor material 13 are prepared. In process step S2, the laser system 1 is started up with the soft start phase 15. In process step S3, plasma ignition 17 then takes place. Subsequently, in process step S4, the system is automatically switched to continuous operation 16.

[0033] In process step S5, the laser radiation 9 generated is directed onto the target material 11, thereby generating the target material plasma. This target material plasma generates the EUV light 12, which is used to expose the semiconductor material 13 in process step S6.

[0034] The described use of soft start during the commissioning of laser system 1 can, for example, be implemented as the only commissioning mode or as a standard commissioning function, or it can be set manually, i.e., activated or deactivated, for example via a user interface of laser system 1.

[0035] Overall, the examples described show how a soft start for igniting a plasma, for example a CCh laser, can be implemented and applied.

[0036] REFERENCE MARK LIST

[0037] 1 laser system

[0038] 2 gas cylinders

[0039] 3 Laser medium

[0040] 4 electrodes

[0041] 5 RF generator

[0042] 6 Control unit

[0043] 7 processor

[0044] 8 Data storage

[0045] 9 Laser radiation

[0046] 10 Beam guidance

[0047] 11 Target material

[0048] 12 EUV light

[0049] 13 Semiconductor material

[0050] 14 Gentle start pulse

[0051] 15 Soft start phase

[0052] 16 Continuous operation

[0053] 17 Plasma ignition

[0054] 18 Schedule

[0055] P Performance

[0056] P1 first feed-in power

[0057] P2 second feed-in power

[0058] R1 first reflection power

[0059] R2 second reflection power t time

[0060] S1-S6 process steps

Claims

PATENT CLAIMS 1. Method (18) for operating a laser system (1) comprising a gas container (2) in which a gaseous laser medium (3) is located and on which electrodes (4) are arranged, wherein - the laser system (1) is put into operation with an initial soft start phase (15), during which the electrodes (4) are supplied with a reduced RF power in order to generate free electrons in the laser medium (3), and subsequently - is switched to continuous operation (16) in which the electrodes (4) are subjected to a higher RF power on average compared to the reduced RF power.

2. Laser system (1) comprising a gas container (2) for receiving a gaseous laser medium (3), electrodes (4) arranged thereon, an RF generator (5) for supplying the electrodes (4) with electrical power and a control unit (6) for controlling the electrical power (P, P1 , P2) generated by the RF generator (5), wherein the laser system (1) is configured to carry out the method (18) according to claim 1.

3. Laser system (1) according to claim 2, characterized in that the laser system (1) is configured to generate several RF pulses (14) during the soft start phase (15) for impinging the electrodes (4) with the reduced RF power, the time interval between which is, in particular by a multiple, greater than the duration of the RF pulses (14).

4. Laser system (1) according to claim 3, characterized in that the laser system (1) is configured to supply the electrodes (4) with continuous wave power in continuous operation (16).

5. Laser system (1) according to one of claims 2 to 4, characterized in that the laser system (1) is set up for pulse width modulation of the power (P, P1 , P2) with which the electrodes (4) are supplied during operation of the laser system (1), and the laser system (1) is set up to automatically adjust different modulation frequencies and / or different duty cycles of the pulse width modulation during the soft start phase (15) and during continuous operation (16).

6. Laser system (1) according to one of claims 2 to 5, characterized in that the laser system (1) is configured to increase a signal amplitude of the RF power (P, P1 , P2) when switching from the soft start phase (15) to continuous operation (16).

7. Laser system (1) according to one of claims 2 to 6, characterized in that the laser system (1) is configured to maintain the soft start phase (15) for a fixed soft start duration.

8. Laser system (1) according to one of claims 2 to 7, characterized in that the laser system (1) is configured to maintain the soft start phase (15) for more than 100 ms.

9. Laser system (1) according to one of claims 2 to 8, characterized in that the laser system (1) is designed to switch from the soft start phase (15) to continuous operation (16) only after the ignition (17) of a plasma in the laser medium (3).

10. Laser system (1) according to claim 9, characterized in that the laser system (1) is configured to monitor the power (R1 , R2) reflected from the electrodes (4) back to the RF generator (5) and to detect the ignition (17) of the plasma based on its temporal progression. 17 11. Laser system (1) according to one of claims 2 to 10, characterized in that the laser medium (3) is or contains CO2.

12. Laser system (1) according to one of claims 2 to 11 , characterized in that the laser system (1) is configured to generate EUV light (12).

13. Method (18) for generating a plasma of a target material (11) for generating secondary radiation (12), in particular EUV light (12), wherein - a laser system (1) according to one of claims 2 to 12 is provided, - the laser system (1) is put into operation according to the method (18) according to claim 1 and thus laser radiation (9) is generated in continuous operation (16), - the laser radiation (9) is guided along a predetermined beam path (10) and directed onto the target material (11) which is different from the laser medium (3).

14. Method (18) for manufacturing microchips (13) or of Semiconductor intermediates (13) for the manufacture of microchips, wherein - a semiconductor material (13) is provided, - the plasma of the target material (11) is generated by means of the method (18) according to claim 13, - the secondary radiation (12) generated by the plasma of the target material (11) is directed onto the semiconductor material (13) and thus a predetermined microstructure is formed in the semiconductor material (13).

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