Plasma light source and semiconductor equipment

Abstract

The invention relates to the field of semiconductors, in particular to a plasma light source and semiconductor equipment. The plasma light source comprises a laser module used for emitting one or more laser beams; the optical shaping module is used for shaping the one or more laser beams, so that the laser beams form a plurality of laser spots in the plasma container, and each laser spot is used for forming and maintaining a plasma core; the light source collection module is used for acquiring and outputting radiation light emitted by the plurality of plasma cores; the control module is used for acquiring an oscillation signal of a plasma flow field in the plasma container and adjusting the laser module and / or the optical shaping module when the oscillation signal reflects that the plasma flow field is not in a steady state so as to adjust the distance between the at least two plasma cores and / or the size of at least one plasma core; therefore, the plasma flow field is in a steady state. The stability of the output power of the plasma light source can be improved.

Description

Technical Field

[0001] This application relates to the semiconductor field, and in particular to a plasma light source and semiconductor device. Background Technology

[0002] Laser-Sustaining Plasma (LSP) sources (hereinafter referred to as plasma sources) are widely used in the semiconductor field for semiconductor processing and measurement. Plasma sources have advantages such as small size, high energy deposition efficiency, high luminous intensity at the same power, and longer lifespan.

[0003] The plasma source is continuously powered by a high-energy laser: the laser beam is focused within a sealed cavity, continuously heating and ionizing the working gas to form a steady-state plasma; the high-temperature plasma radiates intense light outward through mechanisms such as electron transitions and bremsstrahlung. The non-uniform heating of the laser causes significant temperature and density (pressure) gradients in the plasma and its surroundings. Driven by buoyancy, the high-temperature plasma and the surrounding cold gas generate natural convection. When the Rayleigh number (or the corresponding dimensionless parameter) exceeds a critical value, the flow becomes unstable, inducing periodic eddy shedding, and even developing into turbulence. This periodic flow field oscillation modulates the morphology and temperature distribution of the plasma in real time, causing the radiated power to fluctuate at the same frequency, manifesting as "jitter" in the output power of the light source, thereby reducing the short-term stability and application accuracy of the LSP light source. Summary of the Invention

[0004] This application discloses a plasma light source and a semiconductor device to solve the problem of poor stability of plasma light source output power in related technologies.

[0005] In a first aspect, this application provides a plasma source, comprising: a laser module for emitting one or more laser beams; an optical shaping module for shaping the one or more laser beams such that the one or more laser beams form multiple laser spots within a plasma container, each laser spot being used to form and maintain a plasma core; a light source collection module for acquiring and outputting radiation emitted by the multiple plasma cores; and a control module for acquiring an oscillation signal of the plasma flow field within the plasma container, and, if the oscillation signal indicates that the plasma flow field is not in a steady state, adjusting one or more of the laser module and the optical shaping module to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core, so that the plasma flow field is in a steady state.

[0006] Because the laser spot has a high energy density, and plasma nuclei form and remain in areas of high laser energy density, plasma nuclei form and remain in the location of the laser spot; that is, one laser spot can be considered as corresponding to one plasma nucleus. The above embodiment uses an optical shaping module to form multiple laser spots within the plasma container, thus enabling the formation and maintenance of multiple plasma nuclei within the container. By adjusting one or more of the laser module and optical shaping module, the distance between laser spots (which affects the spacing between plasma nuclei) can be easily adjusted. The power density of the laser spot can also be easily adjusted by adjusting its size or power (which affects the amount of heat absorbed by the plasma nuclei, and consequently, their size). By adjusting the spacing between multiple plasma nuclei and their size, the degree of heating of the surrounding flow field by the plasma nuclei can be adjusted, thereby regulating the interaction between the plasma nuclei. When the interaction between the plasma nuclei meets certain conditions, the flow field reaches a steady state. Suppressing convection within the plasma flow field helps maintain its stability and improves the stability of the plasma source's output power.

[0007] Related technologies involve adding additional equipment such as built-in electrodes (to drive the flow field electronically), pneumatic pumps, and inlet air channels to stabilize the flow field. These methods are often structurally and controllably complex. Compared to related technologies, this application involves minimal structural modifications to the plasma source (the structural modification is, for example, adjusting the structure of the optical shaping module to enable the formation of multiple laser spots within the plasma container), offering advantages in terms of simple structure and low cost. The control logic of this application is also relatively simple and easy to implement.

[0008] Furthermore, compared to schemes containing only a single plasma core within the plasma container, the size of each plasma core in a multi-plasma core scheme is smaller than that in a single-plasma core scheme, assuming the same total power of the laser module. On one hand, a larger plasma size can lead to a negative lensing effect—the laser refracts and defocuses within the plasma core, reducing the energy conversion efficiency when the plasma core interacts with the laser. The relatively smaller plasma in this application helps to mitigate the negative lensing effect and improve the efficiency of the plasma source. On the other hand, the ability of the light source collection module to collect plasma radiation is limited by the size of the output port used to collect the plasma radiation. Large-sized cores have large radiation divergence angles, making it difficult to capture edge rays. Small-sized cores approximate point sources, with concentrated radiation, allowing for collection with a smaller solid angle, reducing energy waste, and further improving the overall system efficiency. Simultaneously, as the laser power increases, the plasma in a single core grows towards the laser, reducing the laser power density in the plasma core, leading to a decrease in plasma temperature, and eventually saturating the effective power coupled to the output port or light bar. Multi-core plasma, because the laser energy is distributed to multiple cores, can maintain a smaller plasma size and higher core temperature and core light intensity, achieving a multi-core "synergistic effect" (that is, compared to a single core, the overall system efficiency is improved through multiple cores).

[0009] In some embodiments, the oscillation signal includes an oscillation frequency and an oscillation phase; wherein, the plasma flow field not being in a steady state includes: the plasma flow field being in a first state and the plasma flow field being in a second state; in the first state, the oscillation frequency and the oscillation phase of the plurality of plasma cores are the same; in the second state, the oscillation frequency of the plurality of plasma cores is the same, and the oscillation phase of one of the plurality of plasma cores is different from the oscillation phase of the other plasma cores; wherein, when the oscillation signal indicates that the plasma flow field is not in a steady state, adjusting one or more of the laser module and the optical shaping module to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core includes: when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase one or more of the spacing between at least two plasma cores and decrease the size of at least one plasma core; and / or when the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to decrease one or more of the spacing between at least two plasma cores and increase the size of at least one plasma core.

[0010] The inventors discovered that the states of a plasma flow field can include a steady state (understandably, in a steady state, the flow field does not oscillate and therefore has no frequency or phase), a first state with the same frequency and phase, and a second state with the same frequency but out of phase. The first state may arise because the distance between the two plasma cores is relatively short, or the plasma size is large, leading to greater interaction between the two plasma cores. Therefore, in the first state, increasing the distance and / or decreasing the size of the plasma cores is beneficial for achieving a steady flow field. The second state may arise because the distance between the two plasma cores is relatively long, or the plasma size is small, leading to less interaction between the two plasma cores. The core mechanism is the change in the flow field shear layer (i.e., the change in the velocity field gradient) around the different plasma cores: in the first state, the flow fields of different cores merge, and the internal shear layer between different cores disappears; in the second state, the flow fields of different cores are relatively independent, and there is a relatively complete shear layer between different cores; when the flow fields of different cores are moderately correlated, the flow field shear layer between different cores is beneficial for maintaining a steady flow field. Therefore, in the second state, reducing the spacing and / or increasing the size of the plasma core, and in the first state, increasing the spacing and / or decreasing the size of the plasma core, are beneficial to making the flow field steady.

[0011] In some embodiments, the optical shaping module includes a reflector bowl having multiple focal points, such that the one or more laser beams are reflected by the reflector bowl to form the multiple laser spots at the multiple focal points.

[0012] The above embodiments provide a structure capable of forming multiple plasma cores, which is simple in structure and easy to implement.

[0013] In some embodiments, the optical shaping module further includes: a ring module located in the optical path between the laser module and the reflector bowl, for shaping the shape of the one or more laser beams into a ring; wherein, when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: adjusting the optical shaping module to increase the size of the ring to increase the spacing between the at least two plasma cores; wherein, when the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes: adjusting the optical shaping module to decrease the size of the ring to decrease the spacing between the at least two plasma cores.

[0014] The above embodiments provide a method for adjusting the spacing between plasma cores. By adjusting the annular module to adjust the annular size of the annular beam incident on the reflector bowl, the spacing between plasma cores can be adjusted. The adjustment method is simple and convenient.

[0015] In some embodiments, the laser module is used to emit a laser beam; the optical shaping module includes: a beam splitter for splitting the laser beam into at least two sub-laser beams, each sub-laser beam being used to form a laser spot.

[0016] In some embodiments, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core when the oscillation signal indicates that the plasma flow field is in the first state includes: adjusting the beam splitter to increase the spacing between the at least two sub-laser beams to increase the spacing between the at least two plasma cores; adjusting one or more of the laser module and the optical shaping module to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core when the oscillation signal indicates that the plasma flow field is in the second state includes: adjusting the beam splitter to decrease the spacing between the at least two sub-laser beams to decrease the spacing between the at least two plasma cores.

[0017] In the above embodiments, by adjusting the beam splitter to adjust the spacing between the sub-laser beams, a method is provided that can conveniently adjust the spacing between plasma cores.

[0018] In some embodiments, the beam splitter includes at least a first output head and a second output head, and the at least two sub-laser beams include a first sub-laser beam and a second sub-laser beam. The first output head is used to output the first sub-laser beam, and the second output head is used to output the second sub-laser beam. The optical shaping module further includes an optical fiber connected to the second output head, so that the second sub-laser beam output by the second output head is emitted at the output end of the optical fiber.

[0019] The above embodiments provide a simple and easy-to-implement multi-core plasma light source structure. By setting optical fibers, the emission position of the second sub-laser beam can be changed, making the structural design of the plasma light source more flexible.

[0020] In some embodiments, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core when the oscillation signal indicates that the plasma flow field is in the first state includes: adjusting the position of the emitting end of the optical fiber to increase the spacing between the at least two plasma cores; adjusting one or more of the laser module and the optical shaping module to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core when the oscillation signal indicates that the plasma flow field is in the second state includes: adjusting the position of the emitting end of the optical fiber to decrease the spacing between the at least two plasma cores.

[0021] In the above embodiments, by adjusting the position of the emitting end of the optical fiber, the spacing between plasma cores can be easily adjusted, so that the plasma flow field is in a steady state.

[0022] In some embodiments, the optical shaping module further includes: a first reflector located on the optical path between the first light-emitting head and the plasma container, for reflecting the first sub-laser beam into the plasma container; and a second reflector located on the optical path between the optical fiber and the plasma container, for reflecting the second sub-laser beam into the plasma container.

[0023] In the above embodiments, on the one hand, the direction of the optical path can be adjusted by setting the first and second reflectors, making the structural design of the plasma source more flexible. On the other hand, by adjusting the first and second reflectors, the optical paths of the first and second sub-laser beams can be easily adjusted, thereby conveniently adjusting the distance between the laser spots.

[0024] In some embodiments, when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: adjusting at least one of the distance between the first reflector and the second reflector, the tilt angle of the first reflector, and the tilt angle of the second reflector to increase the spacing between the at least two plasma cores; When the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes: adjusting at least one of the distance between the first reflector and the second reflector, the tilt angle of the first reflector, and the tilt angle of the second reflector to decrease the spacing between the at least two plasma cores.

[0025] In the above embodiments, the spacing between plasma cores can be conveniently adjusted by adjusting one or more of the distance between the first and second reflectors, the tilt angle of the first and second reflectors.

[0026] In some embodiments, the beam splitter is a beam splitter, and the at least two sub-laser beams include a third sub-laser beam and a fourth sub-laser beam. The beam splitter is used to reflect the first laser beam to form the third sub-laser beam and to allow the third sub-laser beam to be incident into the plasma container, and to transmit the first laser beam to form the fourth sub-laser beam. The optical shaping module further includes a third reflector located on the optical path between the fourth sub-laser beam and the plasma container, used to reflect the fourth sub-laser beam into the plasma container.

[0027] The above embodiment utilizes a beam splitter and a third reflector to allow the third and fourth sub-laser beams to be incident into the plasma container respectively, thereby forming two laser spots respectively, providing a simple and easy-to-implement structure for a plasma source that can provide multiple plasma cores.

[0028] In some embodiments, when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: increasing the distance between the beam splitter and the reflector, adjusting the tilt angle of the beam splitter, and adjusting the tilt angle of the reflector to increase the spacing between the at least two plasma cores; When the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes: decreasing the distance between the beam splitter and the reflector, adjusting the tilt angle of the beam splitter, and adjusting the tilt angle of the reflector to decrease the spacing between the at least two plasma cores.

[0029] In the above embodiments, the spacing between plasma cores can be conveniently adjusted by adjusting the distance between the beam splitter and the reflector.

[0030] In some embodiments, the laser module is used to emit multiple laser beams, and the optical shaping module is used to form a plasma core for each laser beam; wherein, when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: adjusting the laser module to adjust one or more of the positions where at least one of the multiple laser beams is incident on the plasma container to increase the spacing between the at least two plasma cores; wherein, when the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes: adjusting the laser module to adjust the position where at least one of the multiple laser beams is incident on the plasma container to decrease the spacing between the at least two plasma cores.

[0031] In the above embodiments, multiple plasma cores are generated using a laser module capable of emitting multiple laser beams, which is simple to implement, and the spacing between the plasma cores can be easily adjusted by adjusting the laser module and the optical shaping module.

[0032] In some embodiments, when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: adjusting the laser module to reduce the power of the one or more laser beams to decrease the size of at least one plasma core, and adjusting the laser module and the optical shaping module to increase the solid angle of the laser beam to decrease the size of at least one plasma core; when the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes: adjusting the laser module to increase the power of the one or more laser beams to increase the size of at least one plasma core, and adjusting the laser module and the optical shaping module to decrease the solid angle of the laser beam to increase the size of at least one plasma core.

[0033] In the above embodiments, the size of the plasma core can be adjusted by adjusting the power and solid angle of the laser beam, which allows users to more flexibly adjust the laser module or optical shaping module, thereby adjusting the heat absorbed by the plasma core and changing the magnitude of the interaction between the plasma cores, so that the plasma flow field is in a steady state.

[0034] In some embodiments, the plasma flow field not being in a steady state further includes: the plasma flow field being in a third state, in which the oscillation frequency of one of the plurality of plasma cores is different from the oscillation frequencies of the other plasma cores; wherein, the step of adjusting one or more of the laser module and the optical shaping module to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core when the oscillation signal indicates that the plasma flow field is not in a steady state further includes: adjusting one or more of the laser module and the optical shaping module to make the size of the plurality of plasma cores the same and adjusting the spacing between at least two of the plurality of plasma cores when the oscillation signal indicates that the plasma flow field is in the third state, so that the size of the plurality of plasma cores is the same and adjusting the spacing between at least two of the plurality of plasma cores.

[0035] The above embodiments provide a method for achieving a steady state when the oscillation frequencies of the plasma cores are different. First, the sizes of the multiple plasma cores are adjusted to be identical, which helps to ensure that the oscillation frequencies of the multiple plasma cores are the same. Then, the spacing between the multiple plasma cores is adjusted to facilitate a steady-state plasma flow field.

[0036] Secondly, this application provides a semiconductor device including a plasma light source as described in any of the above embodiments. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a plasma light source according to some embodiments of this application.

[0039] Figure 2 This is a side view of a bifocal reflector bowl according to some embodiments of this application.

[0040] Figure 3 This is a top view of a bifocal reflector bowl according to some embodiments of this application.

[0041] Figure 4 This is a top view of a trifocal reflector bowl according to some embodiments of this application.

[0042] Figure 5 This is a schematic diagram of the structure of a plasma light source according to other embodiments of this application.

[0043] Figure 6 This is a schematic diagram of the structure of a plasma light source according to some embodiments of this application.

[0044] Figure 7 This is a schematic diagram of the structure of a plasma light source according to some embodiments of this application.

[0045] Figure 8 This is a schematic diagram of the structure of a plasma light source control method according to some embodiments of the present disclosure.

[0046] Explanation of reference numerals in the attached figures: 100-Plasma source; 110-Laser Module; 120 - Optical Shaping Module; 121-Reflector bowl; 1211-Receiving hole; 122-Ring Module; 123-Beam splitter; 1231-First output beam head; 1232-Second output beam head; 1234-Beam splitter; 124-fiber optic cable; 125 - First Reflector; 126 - Second reflector; 127 - Third Reflector; 130 - Light source collection module; 140 - Laser beam; 141 - First sub-laser beam; 142 - Second sub-laser beam; 143 - Third sub-laser beam; 144 - Fourth sub-laser beam; 150 - Plasma container; 160-Reflector; 170- Semi-transparent lens. Detailed Implementation

[0047] Plasma light sources are key equipment supporting the semiconductor industry and cutting-edge scientific research, and are widely used in semiconductor equipment. For example, plasma light sources can be used in precision fields such as chip processing, chip mask defect detection, and nanoscale microscopic imaging.

[0048] Example 1 Figure 1 This is a schematic diagram of the structure of a plasma light source according to some embodiments of this application.

[0049] like Figure 1 As shown, this application provides a plasma light source 100, including a laser module 110, an optical shaping module 120, a light source collection module 130, and a control module. The working process of the plasma light source 100 can be referred to below. Figure 8 The example shown.

[0050] Laser module 110 is used to emit one or more laser beams 140. The laser beams 140 can ignite plasma, that is, convert a working gas into plasma. The working gas includes, but is not limited to, single gases or mixtures of gases such as Xe, Ar, Ne, Kr, He, N2, H2O, O2, H2, D2, F2, CH4, and Hg. The laser beams 140 can be pulsed lasers or continuous lasers. In some embodiments, the laser beams 140 can be collimated lasers.

[0051] The optical shaping module 120 is used to shape one or more laser beams 140, such that the one or more laser beams 140 form multiple laser spots within the plasma container 150, each laser spot being used to form and maintain a plasma core. The optical shaping module 120 will be described later with reference to some embodiments. The multiple laser spots can be distributed horizontally or vertically; they can be symmetrically or asymmetrically distributed. The plasma container 150 can contain and maintain a multi-core plasma. In some embodiments, the plasma container 150 can be used to contain a working gas.

[0052] The light source collection module 130 is used to acquire and output the radiation emitted by multiple plasma cores. The light source collection module 130 can collect and aggregate the radiation emitted by multiple plasma cores before outputting it. It should be understood that the light output by the light source collection module 130 is the same light output by the plasma light source 100.

[0053] A control module (not shown) is used to acquire the oscillation signal of the plasma flow field within the plasma container 150, and, when the oscillation signal indicates that the plasma flow field is not in a steady state, to adjust one or more of the laser module 110 and the optical shaping module 120 to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core, so as to bring the plasma flow field into a steady state. The oscillation signal includes, for example, the oscillation frequency and oscillation phase, and the oscillation signal of the plasma flow field includes, for example, the oscillation signal of each plasma core. In some embodiments, the oscillation signal of the plasma flow field can be acquired by one or more of the following methods: diagnosing the power jitter signal of the light source, identifying the optical schlieren system, diagnosing the flow field jitter signal of the plasma light source 100 (e.g., jitter signals of one or more physical quantities such as temperature, pressure, density, and velocity), and diagnosing the jitter signal of the wall temperature of the plasma container 150. Taking the power jitter signal of the light source as an example, the power jitter time-domain signal output by the light source can be acquired first, filtered, and the power jitter signal caused by the oscillation of the flow field around the plasma core can be retained, and this can be used as the oscillation signal of the plasma flow field. The oscillation signal of the plasma flow field can be directly acquired by the control module, or it can be acquired by other modules (such as the light source collection module 130) and then transmitted to the control module; this application does not limit this. As one implementation, the control module can control the plasma flow field based on feedback control principles. For example, if the oscillation signal indicates that the plasma flow field is not in a steady state, the control module generates a feedback adjustment signal to adjust one or more of the laser module 110 and the optical shaping module 120. It then again judges the state of the plasma flow field based on the oscillation signal. If it is still not in a steady state, it generates another feedback adjustment signal. Through continuous feedback control, the plasma flow field is brought to a steady state.

[0054] Because the laser spot has a high energy density, and plasma nuclei form and remain in areas of high laser energy density, plasma nuclei form and remain in the location of the laser spot; that is, one laser spot can be considered as corresponding to one plasma nucleus. The above embodiment uses an optical shaping module to form and maintain multiple laser spots within the plasma container, thus enabling the formation of multiple plasma nuclei within the container. By adjusting one or more of the laser module and the optical shaping module, the distance between laser spots can be easily adjusted (this affects the spacing between plasma nuclei). The power density of the laser spot can also be easily adjusted by adjusting its size or power (this affects the amount of heat absorbed by the plasma nuclei, and consequently, their size). By adjusting the spacing between multiple plasma nuclei and their size, the degree of heating of the surrounding flow field by the plasma nuclei can be adjusted, thereby regulating the interaction between the plasma nuclei. When the interaction between the plasma nuclei meets certain conditions, the flow field reaches a steady state. Suppressing convection within the plasma flow field helps maintain its stability and improves the stability of the plasma source's output power.

[0055] Related technologies involve adding additional equipment such as built-in electrodes (to drive the flow field electronically), pneumatic pumps, and inlet air channels to stabilize the flow field. These methods are often structurally and controllably complex. Compared to related technologies, this application involves minimal structural modifications to the plasma source (the structural modification is, for example, adjusting the structure of the optical shaping module to enable the formation of multiple laser spots within the plasma container), offering advantages in terms of simple structure and low cost. The control logic of this application is also relatively simple and easy to implement.

[0056] Furthermore, compared to schemes containing only a single plasma core within the plasma container, the size of each plasma core in a multi-plasma core scheme is smaller than that in a single-plasma core scheme, assuming the same total power of the laser module. On one hand, a larger plasma size can lead to a negative lensing effect—the laser refracts and defocuses within the plasma core, reducing the energy conversion efficiency when the plasma core interacts with the laser. The relatively smaller plasma in this application helps to mitigate the negative lensing effect and improve the efficiency of the plasma source. On the other hand, the ability of the light source collection module to collect plasma radiation is limited by the size of the output port used to collect the plasma radiation. Large-sized cores have large radiation divergence angles, making it difficult to capture edge rays. Small-sized cores approximate point sources, with concentrated radiation, allowing for collection with a smaller solid angle, reducing energy waste, and further improving the overall system efficiency. Simultaneously, as the laser power increases, the plasma in a single core grows towards the laser, reducing the laser power density in the plasma core, leading to a decrease in plasma temperature, and eventually saturating the effective power coupled to the output port or light bar. Multi-core plasma, because the laser energy is distributed to multiple cores, can maintain a smaller plasma size and higher core temperature and core light intensity, achieving a multi-core "synergistic effect" (that is, compared to a single core, the overall system efficiency is improved through multiple cores).

[0057] Through research, the inventors discovered that, taking a dual-plasma core as an example, when the distance between the two plasma cores is close, buoyancy convection leads to single-frequency flow field oscillations, with both cores exhibiting the same oscillation frequency and phase (simply put, in-phase). Increasing the distance between the plasma cores gradually stabilizes the flow field oscillations, bringing them to a steady state where the characteristic frequency disappears. Further increasing the distance causes the flow field to oscillate again, with the two cores exhibiting the same oscillation frequency but different phases (e.g., opposite phases), a situation that can be simply described as in-phase but out-of-phase.

[0058] In some embodiments, the plasma flow field not being in a steady state includes the plasma flow field being in a first state and the plasma flow field being in a second state. In the first state, the oscillation frequency and oscillation phase of the multiple plasma cores are all the same. In the second state, the oscillation frequency of the multiple plasma cores is all the same, and one of the multiple plasma cores has an oscillation phase different from the oscillation phases of the other plasma cores.

[0059] It should be understood that "same frequency" here can include oscillation frequencies that are strictly the same, and oscillation frequencies that are not strictly the same but whose difference is less than a threshold. "In phase" can also include oscillation phases that are strictly the same and oscillation phases that are not strictly the same but whose difference is less than a threshold; "different phase" can include oscillation phase differences that are greater than a threshold.

[0060] When the oscillation signal-responding plasma flow field is not in a steady state, adjusting one or more of the laser module 110 and the optical shaping module 120 to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core includes: when the oscillation signal-responding plasma flow field is in a first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase one or more of the spacing between at least two plasma cores and decrease the size of at least one plasma core; and when the oscillation signal-responding plasma flow field is in a second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to decrease one or more of the spacing between at least two plasma cores and increase the size of at least one plasma core.

[0061] The inventors discovered that the states of a plasma flow field can include a steady state (understandably, in a steady state, the flow field does not oscillate and therefore has no frequency or phase), a first state with the same frequency and phase, and a second state with the same frequency but out of phase. The first state may arise because the distance between the two plasma cores is relatively short, or the plasma size is large, leading to a greater interaction between the two plasma cores. Therefore, in the first state, increasing the distance and / or decreasing the size of the plasma cores is beneficial for making the flow field steady. The second state may arise because the distance between the two plasma cores is relatively long, or the plasma size is small, leading to a lesser interaction between the two plasma cores. Therefore, in the second state, decreasing the distance and / or increasing the size of the plasma cores is beneficial for making the flow field steady. The core mechanism is the change in the flow field shear layer (i.e., the change in the velocity field gradient) around the different plasma cores: in the first state, the flow fields of different cores merge, and the internal shear layer between different cores disappears; in the second state, the flow fields of different cores are relatively independent, and there is a relatively complete shear layer between different cores; when the flow fields of different cores are moderately balanced, the flow field shear layer between different cores is beneficial for maintaining a steady flow field. Therefore, in the second state, reducing the spacing and / or increasing the size of the plasma core, and in the first state, increasing the spacing and / or decreasing the size of the plasma core, are beneficial to making the flow field steady.

[0062] The optical shaping module 120 is described below with reference to some embodiments.

[0063] In some embodiments, such as Figure 1 As shown, the optical shaping module 120 includes a reflector bowl 121. Here, the reflector bowl 121 has multiple focal points, so that one or more laser beams 140 are reflected by the reflector bowl 121 to form multiple laser spots at the multiple focal points.

[0064] The above embodiments provide a structure capable of forming multiple plasma cores, which is simple in structure and easy to implement.

[0065] As one implementation, the reflector bowl 121 is also used to reflect light emitted by the plasma, so that the light source collection module 130 can collect the light emitted by the plasma. For example... Figure 2 As shown, a portion of the light emitted by the plasma is reflected by the reflector bowl 121 to the semi-transparent mirror 170 (described later), and then reflected by the semi-transparent mirror 170 to the light source collection module 130. The lasers incident on and exiting the plasma container 150 can share the reflector bowl 121. This allows the reflector bowl 121 to form multiple plasma cores and also helps the light source collection module 130 collect the light emitted by the plasma. On the one hand, by fully utilizing the reflector bowl 121, additional optical elements to help the light source collection module 130 collect the light emitted by the plasma are no longer needed, reducing system complexity. On the other hand, the reflector bowl 121 allows some light that would not normally be collected by the light source collection module 130 to be collected, thus improving the efficiency of the plasma light source 100.

[0066] Figure 2 This is a side view of a bifocal reflector bowl according to some embodiments of this application. Figure 3 This is a top view of a bifocal reflector bowl according to some embodiments of this application. Figure 4 This is a top view of a trifocal reflector bowl according to some embodiments of this application.

[0067] As some implementation methods, such Figure 2 and Figure 3 As shown, the reflector bowl 121 has two focal points, thereby enabling the formation and maintenance of two plasma cores. By adjusting the spacing between the two plasma cores or the size of each plasma core, the flow field can be easily brought into a steady state.

[0068] As for other implementation methods, such as Figure 4 As shown, the reflector bowl 121 has three focal points.

[0069] As another implementation, the reflector bowl 121 can have four or more focal points.

[0070] As some implementation methods Figure 2 and Figure 3 The reflector bowl 121 shown is an irregularly shaped curved composite reflector bowl.

[0071] In other implementations, the reflector bowl 121 is composed of multiple arrayed ordinary reflector bowls, which are typically of a regular shape, such as a hemispherical reflector bowl. For example, Figure 2 and Figure 3 The reflector bowl 121 shown can be formed by splicing together two ordinary reflector bowls.

[0072] In some embodiments, multiple foci are symmetrically distributed so that the spacing between multiple plasma cores is the same, which is beneficial for the flow field state to be close to or in a steady state.

[0073] In some embodiments, such as Figure 2 As shown, the reflector bowl 121 has a receiving hole 1211 for accommodating or at least partially accommodating the plasma container 150. As some implementations, such as Figure 2 and Figure 3 As shown, the receiving hole 1211 can be located in the center of the reflector bowl 121. This allows for easy disassembly and maintenance of the plasma container 150 and related accessories (such as the cathode connection circuit) via the receiving hole 1211.

[0074] In some other embodiments, the reflector bowl 121 may not have a receiving hole 1211, and the plasma container 150 may be disposed above the reflector bowl 121.

[0075] In some embodiments, the optical shaping module 120 includes a ring module 122. The ring module 122 is located in the optical path between the laser module 110 and the reflector bowl 121, and is used to shape one or more laser beams 140 into a ring shape, that is, to make the beam incident on the reflector bowl 121 a ring beam. Figure 1 As shown, the shape of the annular beam is schematically illustrated in the optical path between the annular module 122 and the reflector bowl 121 (more specifically, in the optical path between the annular module 122 and the reflector 160). The annular module 122 can also adjust the size of the annular beam in response to a control module. The size of the annular beam includes, for example, one or more of the inner diameter, outer diameter, and the difference between the inner and outer diameters of the annular beam. When the oscillation signal responds to the plasma flow field in a first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: adjusting the optical shaping module 120 to increase the size of the annulus to increase the spacing between at least two plasma cores. When the oscillation signal responds to the plasma flow field in a second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes: adjusting the optical shaping module 120 to decrease the size of the annulus to decrease the spacing between at least two plasma cores.

[0076] The above embodiment provides a method for adjusting the spacing between plasma cores. By adjusting the annular module 122 to adjust the annular size of the annular beam incident on the reflector bowl 121, the spacing between plasma cores can be adjusted. The adjustment method is simple and convenient.

[0077] As one implementation, adjusting the ring module 122 includes adjusting the position of the ring module 122. For example... Figure 1 As shown, the ring size of the ring beam can be adjusted by adjusting the distance between the optical module and the laser module 110. This adjustment method is simple and convenient.

[0078] The following examples illustrate how to adjust the size of the plasma core.

[0079] The inventors noted that different laser powers result in different amounts of heat absorbed by the plasma core, leading to different heating capabilities of the plasma core to the surrounding flow field. Therefore, the heating capability of the plasma core to the surrounding flow field can be adjusted by regulating the laser power. Furthermore, different solid angles (e.g., converging solid angles) of the laser result in different laser power densities at the convergence point, leading to different amounts of heat absorbed by the plasma core and different heating capabilities of the plasma core to the surrounding flow field. Therefore, the heating capability of the plasma core to the surrounding flow field can also be adjusted by regulating the converging solid angle of the laser beam. In some embodiments, when the oscillation signal indicates that the plasma flow field is in a first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: adjusting the laser module 110 to decrease the power of one or more laser beams 140 to decrease the size of at least one plasma core, and adjusting the laser module 110 and the optical shaping module 120 to increase the solid angle (e.g., converging solid angle) of the laser beam to decrease the size of at least one plasma core. When the oscillation signal response plasma flow field is in the second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: adjusting the laser module 110 to increase the power of one or more laser beams to increase the size of at least one plasma core, and adjusting the laser module 110 and the optical shaping module 120 to reduce the solid angle of the laser beam to increase the size of at least one plasma core.

[0080] In the above embodiments, the size of the plasma core can be adjusted by adjusting the power and solid angle of the laser beam, which allows users to more flexibly adjust the laser module 110 or the optical shaping module 120, thereby adjusting the heat absorbed by the plasma core to change the magnitude of the interaction between the plasma cores and keep the plasma flow field in a steady state.

[0081] As one implementation, the solid angle of the laser beam can be adjusted by regulating the numerical aperture (NA) of at least one of the optical elements (such as a light-conveying bowl 121 or a lens) contained in the laser module 110 and the optical shaping module 120.

[0082] In some embodiments, the plasma flow field not being in a steady state also includes the plasma flow field being in a third state. In the third state, one of the plurality of plasma cores has an oscillation frequency different from the oscillation frequencies of the other plasma cores (i.e., different frequencies). As some implementations, when the oscillation signal indicates that the plasma flow field is not in a steady state, adjusting one or more of the laser module 110 and the optical shaping module 120 to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core further includes: when the oscillation signal indicates that the plasma flow field is in a third state, adjusting one or more of the laser module 110 and the optical shaping module 120 to make the plurality of plasma cores the same size and adjusting the spacing between at least two of the plurality of plasma cores.

[0083] The above embodiments provide a method for achieving a steady state when the oscillation frequencies of the plasma cores are different. First, the sizes of the multiple plasma cores are adjusted to be identical, which helps to ensure that the oscillation frequencies of the multiple plasma cores are the same. Then, the spacing between the multiple plasma cores is adjusted to facilitate a steady-state plasma flow field.

[0084] In some embodiments, such as Figure 1 As shown, the plasma source 100 may also include a reflector 160. The reflector 160 is used to adjust the direction of the optical path so that the laser emitted from the optical shaping module can be incident on the reflector bowl 121. It should be understood that the reflector 160 is not necessary; the positional relationship between the optical shaping module and the reflector bowl 121 can be configured so that the laser emitted from the optical shaping module can be incident on the reflector bowl 121 without passing through the reflector 160.

[0085] In some embodiments, such as Figure 1As shown, the plasma light source 100 may also include a semi-transparent mirror 170. The semi-transparent mirror 170 is used to allow the laser emitted from the optical shaping module to pass through the semi-transparent mirror 170 and enter the reflector bowl 121, and to allow the light emitted from the plasma to be reflected by the semi-transparent mirror 170 to reach the light source collection module 130.

[0086] As one implementation, the optical shaping module 120 also includes one or more focusing elements (not shown) for focusing the laser beam to form a laser spot. The focusing element is, for example, a lens.

[0087] In some embodiments, the plasma container 150 is, for example, a quartz container (e.g., a quartz light bulb) or a metal container with an optical window. The plasma container 150 can be an open container or a closed container. The plasma ignition method can include electrode ignition and electrodeless ignition, and electrodeless ignition can include pulsed laser ignition and radio frequency wave ignition.

[0088] In some embodiments, this application can be used in short-arc lamps, where multiple electrodes form multiple plasma discharge channels, and the stability of the flow field inside the short-arc lamp can be controlled by adjusting the electrode spacing.

[0089] In some embodiments, the multiple laser beams can be parallel laser beams. This helps to make the plasma symmetrical and avoids the formation of plasma at the intersection of non-parallel lasers.

[0090] In some embodiments, the optical shaping module may further include a collimating laser shaping module for collimating the laser before it converges.

[0091] In some embodiments, one or more laser beams may be incident perpendicularly on the plasma container 150.

[0092] In some embodiments, when there are three or more plasma cores in the container, the flow field oscillation may have more than three oscillation modes. The relationship between the oscillation mode and the distance between the plasma cores can be determined by experiments or simulations, and corresponding feedback adjustment schemes can be formulated.

[0093] In some embodiments, the control module can acquire the oscillation signal of the plasma flow field in real time. The control module can detect the state of the plasma flow field in real time and generate feedback adjustment signals.

[0094] Example 2 Figure 5 This is a schematic diagram of the structure of a plasma light source according to other embodiments of this application.

[0095] In some embodiments, such as Figure 5As shown, laser module 110 is used to emit a laser beam. Optical shaping module 120 includes beam splitter 123. Beam splitter 123 is used to split a laser beam into at least two sub-laser beams, each sub-laser beam being used to form a laser spot.

[0096] The above embodiment utilizes a beam splitter 123 to divide the laser beam into at least two sub-laser beams, each sub-laser beam forming a laser spot, thereby enabling the formation of multiple laser spots, and thus multiple plasma nuclei. This provides a structure capable of generating multiple plasma nuclei, with a simple structure. Furthermore, the beam splitter 123 can easily adjust the spacing between the sub-laser beams to regulate the spacing between the plasma nuclei, and it can also easily adjust the energy distribution of the sub-laser beams, thereby adjusting the size of the plasma nuclei.

[0097] As one implementation, the optical shaping module 120 also includes one or more focusing elements (not shown) for focusing each sub-laser beam to form a laser spot. The focusing element is, for example, a lens. The focusing element can be positioned in the optical path between the beam splitter 123 and the plasma container 150.

[0098] As one implementation, the optical shaping module 120 also includes one or more mirrors 160 for adjusting the direction of the optical path so that the laser emitted from the beam splitter 123 can be incident into the plasma container 150.

[0099] In some embodiments, when the oscillation signal responds to the plasma flow field in a first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes adjusting the beam splitter 123 to increase the spacing between at least two sub-laser beams, thereby increasing the spacing between at least two plasma cores. When the oscillation signal responds to the plasma flow field in a second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes adjusting the beam splitter 123 to decrease the spacing between at least two sub-laser beams, thereby decreasing the spacing between at least two plasma cores.

[0100] In the above embodiments, by adjusting the beam splitter 123 to adjust the spacing between sub-laser beams, a method is provided that can conveniently adjust the spacing between plasma cores.

[0101] Example 3 Example 3 can refer to the relevant descriptions of Example 1 and Example 2, and the same parts will not be repeated.

[0102] Figure 6 This is a schematic diagram of the structure of a plasma light source according to some embodiments of this application.

[0103] In some embodiments, such as Figure 6 As shown, the beam splitter 123 includes at least a first output head 1231 and a second output head 1232. At least two sub-laser beams include a first sub-laser beam 141 and a second sub-laser beam 142. The first output head 1231 outputs the first sub-laser beam 141, and the second output head 1232 outputs the second sub-laser beam 142. The optical shaping module 120 also includes an optical fiber 124. The optical fiber 124 is connected to the second output head 1232, so that the second sub-laser beam 142 output by the second output head 1232 exits at the output end of the optical fiber 124.

[0104] The above embodiments provide a simple and easy-to-implement multi-core plasma light source 100 structure. By setting the optical fiber 124, the emission position of the second sub-laser beam 142 can be changed, making the structural design of the plasma light source 100 more flexible.

[0105] In some embodiments, when the oscillation signal-responding plasma flow field is in a first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes adjusting the position of the emitting end of the optical fiber 124 to increase the spacing between at least two plasma cores. When the oscillation signal-responding plasma flow field is in a second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes adjusting the position of the emitting end of the optical fiber 124 to decrease the spacing between at least two plasma cores.

[0106] In the above embodiments, by adjusting the position of the emitting end of the optical fiber 124, the spacing between plasma cores can be conveniently adjusted, so that the plasma flow field is in a steady state.

[0107] In some embodiments, the optical shaping module 120 further includes one or more focusing elements (not shown) for focusing each sub-laser beam to form a laser spot. The focusing element is, for example, a lens. The focusing element may be positioned in the optical path between the beam splitter 123 and the plasma container 150.

[0108] In some embodiments, such as Figure 6As shown, the optical shaping module 120 may further include a first reflector 125 and a second reflector 126. The first reflector 125 is located in the optical path between the first output head 1231 and the plasma container 150, and is used to reflect the first sub-laser beam 141 into the plasma container 150. The second reflector 126 is located in the optical path between the optical fiber 124 and the plasma container 150, and is used to reflect the second sub-laser beam 142 into the plasma container 150.

[0109] In the above embodiments, on the one hand, by setting the first reflector 125 and the second reflector 126, the direction of the optical path can be adjusted, making the structural design of the plasma light source 100 more flexible. On the other hand, by adjusting the first reflector 125 and the second reflector 126, the optical paths of the first sub-laser beam 141 and the second sub-laser beam 142 can be conveniently adjusted, thereby conveniently adjusting the distance between the laser spots.

[0110] In some embodiments, when the oscillation signal-responding plasma flow field is in a first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes adjusting (e.g., increasing) one or more of the distance between the first reflector 125 and the second reflector 126, the tilt angle of the first reflector 125 and the tilt angle of the second reflector 126 to increase the spacing between at least two plasma cores. When the oscillation signal-responding plasma flow field is in a second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes adjusting (e.g., decreasing) one or more of the distance between the first reflector 125 and the second reflector 126, the tilt angle of the first reflector 125 and the tilt angle of the second reflector 126 to decrease the spacing between at least two plasma cores.

[0111] In the above embodiments, the spacing between plasma cores can be conveniently adjusted by adjusting one or more of the distance between the first reflector 125 and the second reflector 126, the tilt angle of the first reflector 125 and the tilt angle of the second reflector 126.

[0112] In some embodiments, the position of the emitting end of the optical fiber 124 can be adjusted so that the second sub-laser beam 142 emitted from the emitting end of the optical fiber 124 can enter the plasma container 150 without passing through a reflector. In this case, it is not necessary to set a reflector between the optical fiber 124 and the plasma core, which helps to simplify the structure.

[0113] In some embodiments, the first optical head 1231 and the second optical head 1232 can be connected to two optical fibers 124 respectively. By changing the position of the emitting ends of the two optical fibers 124, the spacing between the laser spots can be conveniently adjusted.

[0114] Example 4 Example 4 can refer to the relevant descriptions of Example 1, Example 2 and Example 3, and the same parts will not be repeated.

[0115] Figure 7 This is a schematic diagram of the structure of a plasma light source according to some embodiments of this application.

[0116] In some embodiments, such as Figure 7 As shown, the laser module 110 is used to emit a laser beam, and the optical shaping module 120 includes a beam splitter 123, such as a beam splitter 1234, for splitting the laser beam into at least two sub-laser beams, each sub-laser beam being used to form a laser spot. The at least two sub-laser beams include a third sub-laser beam 143 and a fourth sub-laser beam 144. The beam splitter 1234 is used to reflect one laser beam to form the third sub-laser beam 143 and to allow the third sub-laser beam 143 to enter the plasma container 150, and to transmit one laser beam to form the fourth sub-laser beam 144. The optical shaping module 120 also includes a third reflector 127. The third reflector 127 is located in the optical path between the fourth sub-laser beam 144 and the plasma container 150, and is used to reflect the fourth sub-laser beam 144 into the plasma container 150. It should be understood that here, the third sub-laser beam 143 and the fourth sub-laser beam 144 are respectively used to form and maintain a laser spot.

[0117] The above embodiment utilizes beam splitter 1234 and third reflector 127 to allow the third sub-laser beam 143 and the fourth sub-laser beam 144 to be incident into plasma container 150 respectively, thereby forming two laser spots respectively, providing a simple and easy-to-implement structure for a plasma source that can provide multiple plasma cores.

[0118] In some embodiments, when the oscillation signal-responding plasma flow field is in a first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes increasing the distance between the beam splitter 1234 and the reflector to increase the spacing between at least two plasma cores. When the oscillation signal-responding plasma flow field is in a second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to decrease the spacing between at least two plasma cores and increase the size of at least one plasma core includes decreasing the distance between the beam splitter 1234 and the reflector to decrease the spacing between at least two plasma cores.

[0119] In the above embodiments, the spacing between plasma cores can be conveniently adjusted by adjusting the distance between the beam splitter 1234 and the reflector.

[0120] Example 5 Example 5 can refer to the relevant descriptions of Example 1, Example 2, Example 3 and Example 4, and the same parts will not be repeated.

[0121] In some embodiments, the laser module 110 is used to emit multiple laser beams, and the optical shaping module 120 is used to make each laser beam form a plasma core.

[0122] When the oscillation signal response plasma flow field is in the first state, adjusting one or more of the laser module 110 and the optical shaping module 120 to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: adjusting the laser module 110 to adjust the position of at least one of the plurality of laser beams incident on the plasma container 150 to increase the spacing between at least two plasma cores. When the oscillation signal response plasma flow field is in the second state, adjusting one or more of the laser module 110 and the optical shaping module 120 to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: adjusting the laser module 110 to adjust the position of at least one of the plurality of laser beams incident on the plasma container 150 to reduce the spacing between at least two plasma cores.

[0123] In the above embodiments, multiple plasma cores are generated using a laser module 110 capable of emitting multiple laser beams, which is simple to implement, and the spacing between the plasma cores can be easily adjusted by adjusting the laser module 110 and the optical shaping module 120.

[0124] Example 6 Based on the above embodiments, this embodiment provides a semiconductor device, including the plasma light source 100 described in any of the above embodiments. The semiconductor device is, for example, a device for defect detection using the plasma light source 100.

[0125] Example 7 Based on the above embodiments, this embodiment provides a method for controlling a plasma light source.

[0126] Figure 8 This is a schematic flowchart illustrating a plasma source control method according to some embodiments of the present disclosure. Figure 8 As shown, the control method for a semiconductor light source may include the following steps.

[0127] Step S1: Form and maintain multiple plasma cores. For example, multiple laser spots can be formed, and plasma can be ignited at the laser spots.

[0128] Step S2: Acquire the oscillation signal of the plasma flow field. For example, it can be acquired through one or more acquisition methods such as power acquisition, schlieren acquisition, and plasma container wall temperature.

[0129] Step S3: Identify the state of the plasma flow field.

[0130] Step S4: Determine whether the plasma flow field is in a steady state.

[0131] If the flow field is in a steady state, no further action is needed. Alternatively, in some implementations, step S2 can be continuously executed if the flow field is in a steady state.

[0132] If the flow field oscillates, proceed to step S5 to generate a feedback adjustment signal, adjust one or more of the laser module and optical shaping module, change the plasma core spacing or the size of the plasma core, and repeat steps S2 to S4 until the flow field reaches a steady state.

[0133] The foregoing preferred embodiments have further illustrated the objectives, technical solutions, and advantages of the present invention. It should be understood that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A plasma light source, characterized in that, include: A laser module is used to emit one or more laser beams; An optical shaping module is used to shape the one or more laser beams so that the one or more laser beams form multiple laser spots within a plasma container, each laser spot being used to form and maintain a plasma core; A light source collection module is used to acquire and output the radiation emitted by multiple plasma cores; as well as A control module is configured to acquire an oscillation signal of the plasma flow field within the plasma container, and, if the oscillation signal indicates that the plasma flow field is not in a steady state, adjust one or more of the laser module and the optical shaping module to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core to bring the plasma flow field to a steady state.

2. The plasma light source according to claim 1, characterized in that, The oscillation signal includes an oscillation frequency and an oscillation phase; Wherein, the plasma flow field not being in a steady state includes: the plasma flow field being in a first state and the plasma flow field being in a second state; In the first state, the oscillation frequency and oscillation phase of the plurality of plasma cores are the same; In the second state, the oscillation frequencies of the plurality of plasma cores are all the same, and the oscillation phase of one of the plurality of plasma cores is different from the oscillation phases of the other plasma cores. Wherein, adjusting one or more of the laser module and the optical shaping module to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core when the oscillation signal indicates that the plasma flow field is not in a steady state includes: When the oscillation signal indicates that the plasma flow field is in the first state, one or more of the laser module and the optical shaping module are adjusted to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core; and / or When the oscillation signal indicates that the plasma flow field is in the second state, one or more of the laser module and the optical shaping module are adjusted to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core.

3. The plasma light source according to claim 1 or 2, characterized in that, The optical shaping module includes: A reflector bowl having multiple focal points, such that the one or more laser beams, after being reflected by the reflector bowl, form the multiple laser spots at the multiple focal points.

4. The plasma light source according to claim 3, characterized in that, The optical shaping module also includes: A ring module, located in the optical path between the laser module and the reflector bowl, is used to shape the shape of one or more laser beams into a ring; Wherein, when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: Adjust the optical shaping module to increase the size of the ring, thereby increasing the spacing between the at least two plasma cores; Wherein, when the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: The optical shaping module is adjusted to reduce the size of the ring, thereby reducing the distance between the at least two plasma cores.

5. The plasma light source according to claim 1 or 2, characterized in that, The laser module is used to emit a laser beam; the optical shaping module includes: A beam splitter is used to split a laser beam into at least two sub-laser beams, each sub-laser beam being used to form a laser spot.

6. The plasma light source according to claim 5, characterized in that, When the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: Adjust the beam splitter to increase the spacing between the at least two sub-laser beams, thereby increasing the spacing between the at least two plasma cores; When the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: The beam splitter is adjusted to reduce the spacing between the at least two sub-laser beams, thereby reducing the spacing between the at least two plasma cores.

7. The plasma light source according to claim 5 or 6, characterized in that, The beam splitter includes at least a first output head and a second output head, and the at least two sub-laser beams include a first sub-laser beam and a second sub-laser beam. The first output head is used to output the first sub-laser beam, and the second output head is used to output the second sub-laser beam. The optical shaping module also includes: An optical fiber is connected to the second output head so that the second sub-laser beam output from the second output head is emitted from the output end of the optical fiber.

8. The plasma light source according to claim 7, characterized in that, When the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: Adjust the position of the exit end of the optical fiber to increase the spacing between the at least two plasma cores; When the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: Adjust the position of the exit end of the optical fiber to reduce the spacing between the at least two plasma cores.

9. The plasma light source according to claim 7 or 8, characterized in that, The optical shaping module also includes: The first reflector is located in the optical path between the first light-emitting head and the plasma container, and is used to reflect the first sub-laser beam into the plasma container; The second reflector, located in the optical path between the optical fiber and the plasma container, is used to reflect the second sub-laser beam into the plasma container.

10. The plasma light source according to claim 9, characterized in that, When the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: Adjust at least one of the distance between the first and second reflectors, the tilt angle of the first reflector, and the tilt angle of the second reflector to increase the spacing between the at least two plasma cores; When the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: Adjust at least one of the distance between the first and second reflectors, the tilt angle of the first reflector, and the tilt angle of the second reflector to reduce the spacing between the at least two plasma cores.

11. The plasma light source according to claim 5, characterized in that, The beam splitter is a beam splitter mirror, and the at least two sub-laser beams include a third sub-laser beam and a fourth sub-laser beam. The beam splitter mirror is used to reflect one of the laser beams to form the third sub-laser beam and to allow the third sub-laser beam to enter the plasma container, and to transmit the one laser beam to form the fourth sub-laser beam; the optical shaping module further includes: The third reflector is located in the optical path between the fourth sub-laser beam and the plasma container, and is used to reflect the fourth sub-laser beam into the plasma container.

12. The plasma light source according to claim 11, characterized in that, When the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: Increasing the distance between the beam splitter and the reflector, adjusting the tilt angle of the beam splitter, and adjusting the tilt angle of the reflector are at least one of the following methods to increase the spacing between the at least two plasma cores; When the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: At least one of the following methods can be used to reduce the distance between the at least two plasma cores: reducing the distance between the beam splitter and the reflector, adjusting the tilt angle of the beam splitter, and adjusting the tilt angle of the reflector.

13. The plasma light source according to claim 1 or 2, characterized in that, The laser module is used to emit multiple laser beams, and the optical shaping module is used to make each laser beam form a plasma core. Wherein, when the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: Adjust the laser module to adjust one or more of the positions of at least one laser beam incident on the plasma container, thereby increasing the spacing between the at least two plasma cores; Wherein, when the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: The laser module is adjusted to adjust the position of at least one of the plurality of laser beams incident on the plasma container, thereby reducing the distance between the at least two plasma cores.

14. The plasma light source according to any one of claims 1-13, characterized in that, When the oscillation signal indicates that the plasma flow field is in the first state, adjusting one or more of the laser module and the optical shaping module to increase the spacing between at least two plasma cores and decrease the size of at least one plasma core includes: Adjusting the laser module to reduce the power of one or more laser beams to reduce the size of at least one plasma core, and adjusting the laser module and the optical shaping module to increase the solid angle of the laser beam to reduce the size of at least one plasma core; When the oscillation signal indicates that the plasma flow field is in the second state, adjusting one or more of the laser module and the optical shaping module to reduce the spacing between at least two plasma cores and increase the size of at least one plasma core includes: Adjusting the laser module to increase the power of the one or more laser beams to increase the size of the at least one plasma core, and adjusting the laser module and the optical shaping module to decrease the solid angle of the laser beams to increase the size of the at least one plasma core are one or more of the following:

15. The plasma light source according to any one of claims 2-14, characterized in that, The plasma flow field not being in a steady state also includes: the plasma flow field being in a third state, in which the oscillation frequency of one of the plurality of plasma cores is different from the oscillation frequency of the other plasma cores; The step of adjusting one or more of the laser module and the optical shaping module to adjust one or more of the spacing between at least two plasma cores and the size of at least one plasma core when the oscillation signal indicates that the plasma flow field is not in a steady state, further includes: When the oscillation signal indicates that the plasma flow field is in the third state, one or more of the laser module and the optical shaping module are adjusted so that the multiple plasma cores have the same size, and the spacing between at least two of the multiple plasma cores is adjusted.

16. A semiconductor device, characterized in that, include: The plasma light source as described in any one of claims 1-15.

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