Extracorporeal frequency-doubled continuous deep ultraviolet laser device, system and semiconductor inspection system

Abstract

The disclosure provides an extracorporeal frequency-doubling continuous deep ultraviolet laser device, a laser system and a semiconductor detection system. The device comprises an infrared laser module, a green laser module and a deep ultraviolet laser module. The infrared laser module is used to generate target continuous infrared laser; the green laser module comprises an infrared mirror assembly and a first conversion assembly, the infrared mirror assembly is used to convert the transmission light path of the target continuous infrared laser from a first red light path to a second red light path, and the first conversion assembly is used to perform multi-pass second harmonic conversion on the target continuous infrared laser to obtain target continuous green laser. The deep ultraviolet laser module comprises a green light mirror and a second conversion assembly, the green light mirror is used to convert the transmission light path of the target continuous green laser from a first green light path to a second green light path, and the second conversion assembly is used to perform multi-pass fourth harmonic conversion on the target continuous green laser to obtain target continuous deep ultraviolet laser. In this way, the technical implementation difficulty can be reduced, and the conversion efficiency can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of laser technology, and more specifically, to a continuous deep ultraviolet laser device, a laser system, and a semiconductor detection system. Background Technology

[0002] Currently, using continuous-wave deep ultraviolet lasers for defect detection in semiconductors (such as wafers) has become a mainstream technology. Specifically, resonant cavity technology can be used to improve harmonic conversion efficiency to achieve higher power output. However, this technology is complex, expensive, and the system is sensitive, requiring strict control over vibration, temperature, and humidity, resulting in demanding transportation and usage conditions and high maintenance costs. On the other hand, conventional continuous-wave external single-pass harmonic lasers, due to their lower conversion efficiency, cannot achieve the required higher power. Therefore, how to reduce technical difficulty while ensuring conversion efficiency is a pressing technical problem to be solved. Summary of the Invention

[0003] In view of this, the purpose of this disclosure is to provide a continuous deep ultraviolet laser device and laser system that can improve conversion efficiency while reducing the technical difficulty of implementation.

[0004] This disclosure provides an extracavity frequency-doubled continuous deep ultraviolet laser device, including an infrared laser module, a green laser module, and a deep ultraviolet laser module; wherein, the infrared laser module is used to generate a target continuous infrared laser, the green laser module is used to perform multi-pass second harmonic conversion on the target continuous infrared laser to convert it into a target continuous green laser, and the deep ultraviolet laser module is used to perform multi-pass fourth harmonic conversion on the target continuous green laser to convert it into a target continuous deep ultraviolet laser; the target continuous deep ultraviolet laser is used for semiconductor detection;

[0005] The green laser module includes an infrared reflector assembly and a first conversion assembly; the infrared reflector assembly is used to convert the transmission optical path of the target continuous infrared laser into a first red optical path and a second red optical path; the first conversion assembly is used to perform multi-pass second harmonic conversion on the target continuous infrared laser transmitted through the second red optical path to obtain the target continuous green laser.

[0006] The deep ultraviolet laser module includes a green light reflector and a second conversion component. The green light reflector is used to convert the transmission optical path of the target continuous green laser into a first green light optical path and a second green light optical path. The second conversion component is used to perform multi-pass fourth harmonic conversion on the target continuous green laser transmitted through the second green light optical path to obtain the target continuous deep ultraviolet laser.

[0007] In one possible implementation, when the second harmonic conversion is double-pass, the first conversion component includes a first frequency doubling element, a first reflector, a first dichroic mirror, and a first optical power absorber.

[0008] The first frequency doubling element is used to receive the target continuous infrared laser transmitted through the second red light optical path, and convert a portion of the target continuous infrared laser into a first continuous green laser, wherein the first continuous green laser and the first remaining continuous infrared laser form a first mixed light;

[0009] The first reflector is disposed on one side of the first frequency doubling element and is used to reflect the received first mixed light to the first frequency doubling element, so that the first frequency doubling element converts part of the reflected first remaining continuous infrared laser energy into the first continuous green laser to form the target continuous green laser; the transmission optical path of the target continuous green laser avoids the infrared reflector assembly;

[0010] The first dichroic mirror is disposed on the side of the first frequency doubling element away from the first reflector, and is used to transmit the second residual continuous infrared laser after dual-pass conversion by the first frequency doubling element to the first optical power absorber, and reflect the target continuous green laser to the first green light path; the transmission optical path of the second residual continuous infrared laser output from the first frequency doubling element avoids the infrared reflector assembly.

[0011] In one possible implementation, the first conversion component further includes a first phase compensation element disposed between the first frequency doubling element and the first reflector, for making the first residual continuous infrared laser phase-matched with the first continuous green light.

[0012] In one possible implementation, when the fourth harmonic conversion is double-pass, the second conversion component includes a second frequency doubling element, a second reflector, and a second dichroic mirror;

[0013] The second frequency doubling element is disposed on one side of the green light reflector and is used to receive the target continuous green laser transmitted through the second green light optical path, and convert part of the target continuous green laser into a first continuous deep ultraviolet laser. The first continuous deep ultraviolet laser and the first remaining continuous green laser form a second mixed light.

[0014] The second reflector is disposed on the side of the second frequency doubling element away from the green light reflector, and is used to reflect the received second mixed light to the second frequency doubling element, so that the second frequency doubling element converts part of the reflected first remaining continuous green laser energy into first continuous deep ultraviolet light to form the target continuous deep ultraviolet laser; the transmission optical path of the target continuous deep ultraviolet laser avoids the green light reflector;

[0015] The second dichroic mirror is disposed on the side of the second frequency doubling element away from the second reflector, and is used to transmit the second residual continuous green laser after the second frequency doubling element has undergone double-pass conversion, and to reflect the target continuous deep ultraviolet laser; the transmission optical path of the second residual continuous green laser output from the second frequency doubling element avoids the green light reflector.

[0016] In one possible implementation, the second conversion component further includes a second phase compensation element disposed between the second frequency doubling element and the second reflector, for making the first remaining continuous green laser phase-matched with the first continuous deep ultraviolet laser.

[0017] In one possible implementation, the first reflector is a bicolor concave reflector for reflecting infrared laser and green laser; and / or, the first frequency doubling element is a noncritical phase-matched second-harmonic nonlinear crystal.

[0018] In one possible implementation, the second reflector is a bicolor concave reflector for reflecting green laser and deep ultraviolet laser; and / or, the second frequency doubling element is a fourth harmonic nonlinear crystal, and the length of the second frequency doubling element is greater than a preset length.

[0019] In one possible implementation, the infrared reflector assembly includes a first infrared reflector and a second infrared reflector, wherein the first infrared reflector is disposed on the first red light path; and the second infrared reflector is disposed on the second red light path.

[0020] In one possible implementation, the second conversion component further includes a shaping element disposed on the first green light path, which is used to shape the target continuous green laser into an elliptical spot before outputting it. The major axis of the elliptical spot corresponds to the phase-matching direction of the second frequency doubling element, and the minor axis of the elliptical spot corresponds to the non-phase-matching direction of the second frequency doubling element.

[0021] In one possible implementation, the infrared laser module includes:

[0022] Infrared laser, used to generate initial continuous infrared laser light;

[0023] An infrared light adjustment component is disposed on the initial red light path of the initial continuous infrared laser, and is used to adjust the power and polarization state of the initial continuous infrared laser to obtain the target continuous infrared laser; the direction of the first red light path of the target continuous infrared laser is the same as the direction of the initial red light path.

[0024] In one possible implementation, the infrared light adjustment component includes:

[0025] The first light-collecting mirror is disposed on the initial red light path and is used to reflect part of the initial continuous infrared laser to the first power probe and output the remaining initial continuous infrared laser.

[0026] A first power probe is used to detect the power of the initial continuous infrared laser, and when the power of the initial continuous infrared laser exceeds a first preset range, a first adjustment command is generated; the first adjustment command is used to instruct the infrared laser to adjust the power of the initial continuous infrared laser so that the initial continuous infrared laser is within the first preset range;

[0027] A first half-wave plate is disposed on the initial red light path to change the polarization direction of the initial continuous infrared laser.

[0028] A polarization beam splitter is disposed on the initial red light path and located on the side of the first half-wave plate away from the first light-collecting mirror. It is used to split the remaining initial continuous infrared laser after changing the polarization direction into a first continuous infrared laser and a second continuous infrared laser with different polarization directions. The optical path direction of the first continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the second continuous infrared laser is perpendicular to that of the initial continuous infrared laser.

[0029] A first focusing lens is disposed on the initial red light path, located on the side of the polarization beam splitter away from the first half-wave plate, for focusing the first continuous infrared laser into the target continuous infrared laser, and the target continuous infrared laser is incident on the infrared reflector assembly along the first red light path.

[0030] The second light-collecting mirror is positioned in the optical path direction of the second continuous infrared laser and is used to reflect part of the second continuous infrared laser to the second power probe and output the remaining second continuous infrared laser to the third optical power absorber.

[0031] The second power probe is used to detect the power of the second continuous infrared laser, and the power of the second continuous infrared laser is used to determine whether the power of the first continuous infrared laser exceeds a second preset range.

[0032] If the power of the first continuous infrared laser exceeds the second preset range, a second adjustment command is generated. The second adjustment command is used to instruct the half-wave plate to adjust its rotation angle so that the power of the first continuous infrared laser is within the second preset range.

[0033] In one possible implementation, when the second harmonic conversion order is N and the N-pass paths are partially collinear, where N is an even number greater than 2, the first conversion component includes M sets of reflection components, a third frequency doubling element, and a third dichroic mirror, where M is half of N.

[0034] The third frequency doubling element is used to receive the target continuous infrared laser transmitted through the second red light optical path, and to convert the target continuous infrared laser through the M group of reflection components into N-pass conversion to form target mixed light; the target mixed light includes target continuous green laser and target remaining continuous infrared laser;

[0035] The infrared reflector assembly is also used to receive the target mixed light and convert the transmission optical path of the target mixed light into a first mixed optical path and a second mixed optical path, wherein the first mixed optical path is parallel to and opposite in direction to the second red light optical path, and the second mixed optical path is parallel to and opposite in direction to the first red light optical path;

[0036] The third dichroic mirror is disposed on the second mixing optical path and is used to reflect the target continuous green laser to the first green light optical path.

[0037] In one possible implementation, when the second harmonic conversion order is N and all N paths are non-collinear, the first conversion component includes M sets of reflection components, a third frequency doubling element, and a third dichroic mirror, wherein N is a positive integer greater than 2, and M is a positive integer less than N by 1.

[0038] The third frequency doubling element is used to receive the target continuous infrared laser transmitted through the second red light optical path, and to convert the target continuous infrared laser through the M group of reflection components into N-pass conversion to form target mixed light; the target mixed light includes target continuous green laser and target remaining continuous infrared laser;

[0039] The third dichroic mirror is used to transmit the remaining continuous infrared laser of the target and reflect the continuous green laser of the target back to the first green light path.

[0040] In one possible implementation, each set of reflective components includes a phase compensation element and a light reflection element; the M sets of reflective components are respectively located on opposite sides of the third frequency harmonic element, wherein the phase compensation element and the light reflection element in each set of reflective components are spaced apart, and the phase compensation element is close to the third frequency harmonic element.

[0041] In one possible implementation, the light reflecting element is a bicolor concave mirror used to reflect infrared laser and green laser; the phase compensation element is a quartz plate.

[0042] In one possible implementation, the third frequency-doubling element is a non-critical phase-matched second-harmonic nonlinear crystal.

[0043] In one possible implementation, the infrared laser module includes:

[0044] Infrared laser, used to generate initial continuous infrared laser light;

[0045] An infrared light adjustment component is disposed on the initial red light path of the initial continuous infrared laser, and is used to adjust the polarization state of the initial continuous infrared laser to obtain the target continuous infrared laser; the direction of the first red light path of the target continuous infrared laser is the same as the direction of the initial red light path.

[0046] In one possible implementation, the infrared light adjustment assembly includes a first polarizing beam splitter, a Faraday rotator, a second half-wave plate, a second polarizing beam splitter, and a second focusing lens arranged sequentially at intervals along the initial red light path; the third dichroic mirror is disposed between the second polarizing beam splitter and the second focusing lens.

[0047] The first polarization beam splitter is used to split the initial continuous infrared laser into a third continuous infrared laser and a fourth continuous infrared laser with different polarization directions; wherein, the optical path direction of the third continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the fourth continuous infrared laser is perpendicular to that of the initial continuous infrared laser.

[0048] The Faraday rotator is used to deflect the polarization state of the incident beam by 45 degrees.

[0049] The second half-wave plate is used to change the polarization direction of the third continuous infrared laser.

[0050] The second polarization beam splitter is used to split the third continuous infrared laser, after its polarization direction has been changed, into a fifth continuous infrared laser and a sixth continuous infrared laser with different polarization directions; wherein, the optical path direction of the fifth continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the sixth continuous infrared laser is perpendicular to that of the initial continuous infrared laser.

[0051] The second focusing lens is used to focus the fifth continuous infrared laser into the target continuous infrared laser, and the target continuous infrared laser is incident on the infrared reflector assembly along the first red light path.

[0052] In one possible implementation, the infrared light adjustment assembly includes a first polarization beam splitter and a second focusing lens arranged sequentially at intervals along the initial red light path;

[0053] The first polarization beam splitter is used to split the initial continuous infrared laser into a third continuous infrared laser and a fourth continuous infrared laser with different polarization directions, wherein the optical path direction of the third continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the fourth continuous infrared laser is perpendicular to that of the initial continuous infrared laser.

[0054] The second focusing lens is used to focus the third continuous infrared laser into the target continuous infrared laser, and the target continuous infrared laser is incident on the infrared reflector assembly along the first red light path.

[0055] In one possible implementation, the infrared light adjustment component further includes:

[0056] A fourth optical power absorber is disposed in the transmission optical path of the fourth continuous infrared laser and is used to absorb the fourth continuous infrared laser.

[0057] This disclosure provides a multi-channel continuous deep ultraviolet laser system, including the extracavity frequency-doubled continuous deep ultraviolet laser device described in any of the above possible embodiments and a plurality of deep ultraviolet laser modules described in any of the above possible embodiments;

[0058] The multiple deep ultraviolet laser modules are arranged in a hierarchical manner. Each level of deep ultraviolet laser module is used to receive the second residual continuous green laser output from the deep ultraviolet laser module of the previous level, and to perform fourth harmonic conversion on the second residual continuous green laser to convert the second residual continuous green laser into the target continuous deep ultraviolet laser output.

[0059] This disclosure provides a semiconductor inspection system, including at least one semiconductor to be inspected and a continuous deep ultraviolet laser device as described in any of the above possible embodiments, or a multi-channel continuous deep ultraviolet laser system as described in the above possible embodiments. The continuous deep ultraviolet laser device is used to generate target continuous deep ultraviolet lasers to perform defect detection on the at least one semiconductor to be inspected; the multi-channel continuous deep ultraviolet laser system is used to generate multiple target continuous deep ultraviolet lasers, each target continuous deep ultraviolet laser being used to perform defect detection on a different semiconductor.

[0060] The continuous deep ultraviolet laser device, multi-channel continuous deep ultraviolet laser system, and semiconductor detection system provided in this disclosure, due to the use of extracavity frequency doubling technology, can reduce costs and environmental requirements compared to intracavity resonant cavity technology. Furthermore, multi-pass conversion technology is used in both the second and fourth harmonic conversion processes, which improves conversion efficiency compared to single-pass conversion.

[0061] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0062] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0063] Figure 1 This diagram illustrates a principle block diagram of an extracavity frequency-doubled continuous deep ultraviolet laser device provided in an embodiment of the present disclosure;

[0064] Figure 2 A schematic block diagram of another extracavity frequency-doubled continuous deep ultraviolet laser device provided in an embodiment of this disclosure is shown;

[0065] Figure 3 A schematic diagram of the structure of a dual-pass extracavity frequency-doubled continuous deep ultraviolet laser device provided in an embodiment of this disclosure is shown;

[0066] Figure 4 A schematic diagram of the structure of an infrared laser module and a multi-channel green laser module provided in an embodiment of this disclosure is shown.

[0067] Figure 5 A schematic diagram of another infrared laser module and a multi-pass green laser module provided in this disclosure embodiment is shown.

[0068] Figure 6 A schematic diagram of the structure of another infrared laser module and a multi-channel green laser module provided in the embodiments of this disclosure is shown;

[0069] Figure 7 A schematic block diagram of a multi-channel continuous deep ultraviolet laser system provided in an embodiment of this disclosure is shown. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0071] In the field of semiconductor inspection (such as wafer inspection), low-noise, high-stability deep ultraviolet lasers are typically required as the inspection light source. Although high-repetition-rate picosecond deep ultraviolet lasers can be considered quasi-continuous light sources, their relatively high peak power makes them prone to damaging wafers and causing particles on the wafer to explode. Therefore, continuous deep ultraviolet light sources are more suitable for wafer defect inspection.

[0072] Currently, the main performance indicators for continuous-wave deep ultraviolet (SVUV) lasers used in defect detection are relative intensity noise, output power stability, and output power. A common 266nm SVUV laser can generate 532nm green light from a 1064nm infrared fundamental frequency light through second harmonic generation, and then generate 266nm from the green light through fourth harmonic generation. While the principle of generating SVUV lasers is simple, achieving low-noise, high-stability, and high-power (above 1W) SVUV lasers remains a significant challenge for the industry.

[0073] Research has shown that resonant cavity technology can be used to improve the conversion efficiency of the fourth harmonic to achieve higher power output. However, this technology is complex, expensive, and the system is sensitive to vibration and temperature / humidity, resulting in demanding transportation and usage conditions and high maintenance costs.

[0074] Since the conversion efficiency of nonlinear crystal frequency doubling is proportional to the peak power density of the incident light, the square of the crystal length, and the phase matching factor, and inversely proportional to the area of ​​the incident light, when using continuous light external harmonic generation to generate continuous deep ultraviolet laser, the peak power of continuous light is the same as the average power, which is much lower than that of pulsed light, resulting in a lower conversion efficiency and an inability to achieve the required higher power.

[0075] In addition, semiconductor inspection equipment generally limits the power of the light source to a preset range. For example, wafer inspection equipment generally limits the power of the light source to 700W. This limits the pump power of the diode, and thus it is necessary to improve the pump-to-infrared conversion efficiency as much as possible.

[0076] On the other hand, if the infrared power is too high, it is difficult to obtain a narrow linewidth output. That is, due to the limitation on infrared power, it is necessary to maximize the conversion efficiency of the second harmonic to obtain sufficiently high green laser power, while simultaneously maximizing the efficiency of the fourth harmonic to obtain high-power (watt-level) deep ultraviolet laser output. Therefore, how to reduce technical difficulty while ensuring conversion efficiency is a pressing technical problem that needs to be solved.

[0077] Based on the above research, this disclosure provides an extracavity frequency-doubled continuous deep ultraviolet laser device that can improve conversion efficiency while reducing cost and device complexity.

[0078] The extracavity frequency-doubled continuous deep ultraviolet laser device provided in the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0079] See Figure 1 As shown, the extracavity frequency-doubled continuous deep ultraviolet laser device 100 provided in this embodiment includes an infrared laser module 10, a green laser module 20, and a deep ultraviolet laser module 30. The infrared laser module 10 generates a target continuous infrared laser, the green laser module 20 performs multi-pass second harmonic conversion on the target continuous infrared laser to convert it into a target continuous green laser, and the deep ultraviolet laser module 30 performs multi-pass fourth harmonic conversion on the target continuous green laser to convert it into a target continuous deep ultraviolet laser. The target continuous deep ultraviolet laser is used to detect semiconductors. In this embodiment, the semiconductor includes a wafer and a photomask, etc.

[0080] Specifically, see Figure 2 As shown, the infrared laser module 10 includes an infrared laser 101 and an infrared light adjustment component 102. The infrared laser 101 is used to generate an initial continuous infrared laser. Exemplarily, the infrared laser 101 may include a polarization-maintaining fiber seed source plus a polarization-maintaining fiber amplifier.

[0081] When the second harmonic conversion is double-pass, the infrared light adjustment component 102 is disposed on the initial red light path of the initial continuous infrared laser, and is used to adjust the power and polarization state of the initial continuous infrared laser to obtain the target continuous infrared laser; the direction of the first red light path of the target continuous infrared laser is the same as the direction of the initial red light path.

[0082] The green laser module 20 includes an infrared reflector assembly 201 and a first conversion assembly 202. The infrared reflector assembly 201 is used to convert the transmission optical path of the target continuous infrared laser into a second red optical path. The first conversion assembly 202 is used to perform multi-pass second harmonic conversion on the target continuous infrared laser transmitted through the second red optical path to obtain the target continuous green laser.

[0083] The deep ultraviolet laser module includes a green light reflector 301 and a second conversion component 302. The green light reflector 301 is used to convert the transmission optical path of the target continuous green laser into a second green light optical path. The second conversion component 302 is used to perform multi-pass fourth harmonic conversion on the target continuous green laser transmitted through the second green light optical path to obtain the target continuous deep ultraviolet laser.

[0084] For example, the wavelength of the target continuous infrared laser is 1064 nm, the wavelength of the target continuous green laser is 532 nm, and the wavelength of the target continuous deep ultraviolet laser is 266 nm.

[0085] In this embodiment of the disclosure, "multi-pass" refers to a double-pass, triple-pass, or more-than-double-pass structure. Generally, a single-pass structure refers to the fundamental frequency light passing through a nonlinear crystal only once, meaning the fundamental frequency light undergoes only one conversion. A double-pass structure, on the other hand, involves the fundamental frequency light passing through the nonlinear crystal twice, achieving two conversions. Similarly, a multi-pass structure involves the fundamental frequency light passing through the nonlinear crystal multiple times, achieving multiple conversions.

[0086] In this embodiment, the continuous deep ultraviolet laser device 100 employs extracavity frequency doubling technology, which reduces costs and environmental requirements compared to intracavity resonant cavity technology. Furthermore, multi-pass conversion technology is used in both the second and fourth harmonic conversion processes, thus improving conversion efficiency compared to single-pass conversion.

[0087] Understandably, for the infrared laser 101, factors such as diode current fluctuations and amplifier spontaneous emission noise (ASE noise) can cause output power fluctuations. Furthermore, temperature fluctuations in the water chiller, environment, and optical fiber can lead to slow changes in the polarization-maintaining output polarization angle, which significantly impacts the subsequent frequency doubling process, resulting in large power fluctuations in the final deep ultraviolet laser output. Therefore, this disclosure proposes an infrared laser module 101 that can achieve stable infrared polarization output.

[0088] Specifically, please refer to Figure 3 ,in Figure 3This is a schematic diagram of a dual-pass extracavity frequency-doubled continuous deep ultraviolet laser device provided in an embodiment of this disclosure. When the second harmonic conversion is dual-pass, the infrared light adjustment component includes a first light-collecting mirror 11, a first power probe 12, a first half-wave plate 13, a polarization beam splitter 14, a second light-collecting mirror 15, a third optical power absorber 16, a first focusing lens 17, and a second power probe 18.

[0089] The first light-collecting mirror 11 is disposed on the initial red light path to reflect a portion of the initial continuous infrared laser to the first power probe 12 and output the remaining initial continuous infrared laser. The first power probe 12 is used to detect the power of the initial continuous infrared laser and generate a first adjustment command when the power of the initial continuous infrared laser exceeds a first preset range. The first adjustment command is used to instruct the infrared laser 101 to adjust the power of the initial continuous infrared laser so that the initial continuous infrared laser is within the first preset range.

[0090] A first half-wave plate 13 is disposed on the initial red light path to change the polarization direction of the initial continuous infrared laser. A polarization beam splitter 14 is disposed on the initial red light path, located on the side of the first half-wave plate 13 away from the first light-collecting mirror 11, to split the remaining initial continuous infrared laser after the polarization direction change into a first continuous infrared laser and a second continuous infrared laser with different polarization directions; wherein the optical path direction of the first continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the second continuous infrared laser is perpendicular to that of the initial continuous infrared laser.

[0091] The first focusing lens 17 is disposed on the initial red light path, located on the side of the polarization beam splitter 14 opposite to the first half-wave plate 13, and is used to focus the first continuous infrared laser into the target continuous infrared laser. The target continuous infrared laser is incident on the infrared reflector assembly 201 along the first red light path. Specifically, the focal point of the first focusing lens 17 coincides with the center of the first frequency doubling element 23, which can improve the conversion efficiency.

[0092] The second light-collecting mirror 15 is positioned along the optical path of the second continuous infrared laser, reflecting a portion of the second continuous infrared laser to the second power probe 18 and outputting the remaining second continuous infrared laser to the third optical power absorber 16. The second power probe 18 detects the power of the second continuous infrared laser, which determines whether the power of the first continuous infrared laser exceeds a second preset range. If the power of the first continuous infrared laser exceeds the second preset range, a second adjustment command is generated, instructing the first half-wave plate 13 to adjust its rotation angle so that the power of the first continuous infrared laser is within the second preset range.

[0093] The infrared laser module 10 provided in this embodiment outputs an initial infrared laser from an infrared laser 101 through an optical fiber collimator. After the initial infrared laser is output, a small portion of the light is reflected by a first light-collecting mirror 11 and enters a first power probe 12 for real-time monitoring. If the light exceeds a first preset range, the amplifier current of the infrared laser 101 is adjusted to control the power within the first preset range, thereby realizing the function of an amplifier power negative feedback control system.

[0094] Furthermore, the combination of the first half-wave plate 13 and the polarization beam splitter 14 can correct changes in the polarization angle of linearly polarized light, ensuring that the power of the transmitted light from the polarization beam splitter 14 remains constant. Specifically, a first half-wave plate 13 and a polarization beam splitter 14 are added behind the first light-collecting mirror 11. The S-polarized light (second continuous infrared laser) reflected from the polarization beam splitter 14 is partially reflected by the second light-collecting mirror 15 and enters the second power probe 16 for real-time monitoring. If it exceeds a second preset range, the rotation angle of the first half-wave plate 13 is adjusted so that the power of the transmitted light (first continuous infrared laser) from the polarization beam splitter 14 is controlled within the second preset range, thereby realizing the function of the automatic polarization state correction system.

[0095] Please continue reading. Figure 3 The infrared reflector assembly 201 includes a first infrared reflector 21 and a second infrared reflector 22. The first infrared reflector 21 is disposed on the first red light path; the second infrared reflector 22 is disposed on the second red light path.

[0096] For example, the first conversion component 202 includes a first frequency doubling element 23, a first reflector 24, a first dichroic mirror 25, and a first optical power absorber 26. Specifically, the first frequency doubling element 23 is used to receive the target continuous infrared laser transmitted through the second red light path and convert a portion of the target continuous infrared laser into a first continuous green laser. The first continuous green laser and the first remaining continuous infrared laser form a first mixed light.

[0097] The first reflector 24 is disposed on one side of the first frequency doubling element 23, and is used to reflect the received first mixed light to the first frequency doubling element 23, so that the first frequency doubling element 23 converts part of the reflected first remaining continuous infrared laser energy into a first continuous green laser, forming the target continuous green laser. The transmission optical path of the target continuous green laser avoids the second infrared reflector 22 in the infrared reflector assembly 201.

[0098] The first dichroic mirror 25 is disposed on the side of the first frequency doubling element 23 away from the first reflector 24, and is used to transmit the second residual continuous infrared laser after double-pass conversion by the first frequency doubling element 23 to the first optical power absorber 26, and reflect the target continuous green laser to the first green light path. The transmission optical path of the second residual continuous infrared laser output from the first frequency doubling element 23 avoids the second infrared reflector 22 in the infrared reflector assembly 201.

[0099] Optionally, the first conversion component 202 may further include a first phase compensation element. Figure 3 Not shown in the image, please refer to the following: Figure 4 The first phase compensation element is disposed between the first frequency doubling element 23 and the first reflector 24 to make the first remaining continuous infrared laser phase-matched with the first continuous green light.

[0100] Optionally, the first reflector 24 is a bicolor concave reflector used to reflect infrared laser and green laser. The first frequency doubling element 23 is a noncritical phase-matched second-harmonic nonlinear crystal.

[0101] It should be noted that when the second harmonic conversion is a double-pass circuit, the double-pass paths of the second harmonic can be collinear or non-collinear. Collinearity means that the path of the second pass returns along the exact same path as the first pass, while non-collinearity means that the paths of the second and first passes are misaligned.

[0102] The optical path process of the green laser module 20 is explained below.

[0103] After the target infrared continuous laser passes through the first frequency doubling element 23 (a second-harmonic nonlinear crystal, also known as an SHG crystal), it generates continuous green light (the first continuous green laser) and residual infrared laser (the first residual continuous infrared laser). These are then refocused onto the first frequency doubling element 23 via a concave reflector (the first reflector 24), where the second harmonic effect occurs again, further coupling infrared power to the green light, thus achieving higher green light power. The mixed beam of infrared and green light, reflected back to the first frequency doubling element 23, is slightly misaligned with the original incident infrared beam (the target infrared continuous laser). This allows the mixed beam to bypass the second infrared reflector 22 and strike the first dichroic mirror 25. The infrared beam (the second residual continuous infrared laser) is transmitted through the first dichroic mirror 25 and absorbed by the first optical power absorber 26, without returning to the original incident light path. The green light (the target continuous green laser) within the mixed beam is reflected by the first dichroic mirror 25 and enters the deep ultraviolet laser module 30.

[0104] Here, the first frequency doubling element 23 adopts a non-critical phase-matched (NCPM) type LBO crystal, and the receiving angle of the fundamental frequency incident light reaches 1718 mrad*cm. This means that the incident angle requirement of the infrared beam is not high. Therefore, for the beam that is reflected back to the first frequency doubling element 23, it is not necessary to re-incidentate the crystal along the original optical path. A deviation of a certain angle range will not affect the conversion efficiency of the second frequency doubling action. Thus, the second harmonic conversion of the dual-pass can be realized. In other words, a higher power target continuous green laser can be obtained by reusing the remaining infrared light for the second frequency doubling action.

[0105] Please continue reading. Figure 3 In some embodiments, when the fourth harmonic conversion is double-pass, the second conversion component 302 includes a second frequency doubling element 31, a second reflector 32, and a second dichroic mirror 33.

[0106] The second frequency doubling element 31 is disposed on one side of the green light reflector 301, and is used to receive the target continuous green laser transmitted through the second green light optical path, and convert part of the target continuous green laser into a first continuous deep ultraviolet laser. The first continuous deep ultraviolet laser and the first remaining continuous green laser form a second mixed light.

[0107] The second reflector 32 is disposed on the side of the second frequency doubling element away from the green light reflector 301, and is used to reflect the received second mixed light to the second frequency doubling element 31, so that the second frequency doubling element 31 converts part of the energy of the first remaining continuous green laser into the first continuous deep ultraviolet light, forming the target continuous deep ultraviolet laser; the transmission optical path of the target continuous deep ultraviolet laser avoids the green light reflector.

[0108] The second dichroic mirror 33 is disposed on the side of the second frequency doubling element 31 away from the second reflector 32, and is used to transmit the second residual continuous green laser after double-pass conversion by the second frequency doubling element 31, and reflect the target continuous deep ultraviolet laser. The transmission optical path of the second residual continuous green laser output from the second frequency doubling element 31 avoids the green light reflector.

[0109] Optionally, the second conversion component 302 further includes a second optical power absorber 34 for receiving a second residual continuous green laser emitted from the second dichroic mirror 33.

[0110] Alternatively, the second conversion component 302 further includes a second phase compensation element. Figure 3 Not shown in the image, please refer to the following: Figure 4 The second phase compensation element is disposed between the second frequency doubling element 31 and the second reflector 33, so as to make the first remaining continuous green laser phase matched with the first continuous deep ultraviolet laser.

[0111] Here, phase compensation elements (such as the first phase compensation element and the second phase compensation element) can make the fundamental frequency light and the frequency-doubled light phase-matched. In this way, the frequency-doubled light will not flow back to become the fundamental frequency light due to phase mismatch, and the energy of the fundamental frequency light will be further converted into the frequency-doubled light, so that the power of the frequency-doubled light will be further increased and the frequency doubling efficiency will be improved.

[0112] It should be understood that, similar to the second harmonic of the double-pass circuit, the double-pass paths of the fourth harmonic can be collinear or non-collinear.

[0113] Furthermore, regarding the multi-pass conversion process of the frequency doubling element, when the fundamental frequency light (such as the target continuous infrared laser) passes through the first frequency doubling element 23 for the first time, a portion of the infrared light is converted into green light. At this time, it is only a small part and serves as the seed light for the second frequency doubling. When the mixed light passes through the first frequency doubling element 23 for the second time, the initial phase difference between the frequency doubling seed light and the fundamental frequency light is adjusted to an integer multiple of 2π through phase compensation. The infrared light of the mixed light will be further converted into green light. In this way, as the number of times the light passes through the first frequency doubling element 23 increases, it is equivalent to increasing the length of the first frequency doubling element 23 by multiples, so as to achieve high-efficiency frequency doubling of low peak power laser.

[0114] Optionally, the second reflector 32 is a bicolor concave reflector used to reflect green laser and deep ultraviolet laser. The second frequency doubling element 31 is a fourth harmonic nonlinear crystal, and the length of the second frequency doubling element 31 is greater than a preset length. For example, the second frequency doubling element 31 can be a β-phase barium borate crystal (also known as a BBO crystal).

[0115] Alternatively, the second conversion component 202 further includes a shaping element 35, which is disposed on the first green light path and is used to shape the target continuous green laser into an elliptical spot before outputting it. The major axis of the elliptical spot corresponds to the phase matching direction of the second frequency doubling element 31, and the minor axis of the elliptical spot corresponds to the non-phase matching direction of the second frequency doubling element 31.

[0116] For example, the shaping element 35 may be a diffractive optical element or a cylindrical mirror, and the focal plane of the shaping element 35 may coincide with the focal plane of the second dichroic mirror 33, while the center of the second frequency doubling element 31 is located at the focal plane.

[0117] The elliptical focusing method in this embodiment can achieve the use of a longer crystal and a smaller spot area, which is beneficial to further improve the conversion efficiency.

[0118] It should be noted that, in order to further improve the conversion efficiency when generating the target continuous green laser, a shaping element can also be used to shape the target continuous infrared laser into an elliptical spot before inputting it into the first frequency doubling element 23.

[0119] The optical path process of the deep ultraviolet laser module 30 is explained below.

[0120] Following the above embodiment, the first dichroic mirror 25 reflects the target continuous green laser separately, which is then transformed into an elliptical spot after passing through the shaping element 35. This spot is then focused onto the center of the second frequency doubling element 31 (a fourth harmonic nonlinear crystal, also known as an FHG crystal), generating a deep ultraviolet laser (the first continuous deep ultraviolet laser). This laser, along with the remaining green light (the first remaining continuous green laser), is then refocused onto the second frequency doubling element 31 through the second reflecting mirror 32, where the fourth harmonic effect occurs again. This further couples the green laser power to the deep ultraviolet laser, thus obtaining a deeper ultraviolet laser with higher power. The second mixed beam, reflected back to the second frequency doubling element 31, is slightly misaligned with the original incident green light (target continuous green laser) beam, allowing the mixed beam to bypass the green light reflector 301 and strike the second dichroic mirror 33. The green light beam (second residual continuous green laser) is transmitted through the second dichroic mirror 33 and absorbed by the second optical power absorber 34, while the deep ultraviolet laser in the second mixed beam is reflected by the second dichroic mirror 33, resulting in the final output target continuous deep ultraviolet laser.

[0121] In some embodiments, to further improve conversion efficiency, an N-pass method can be used for second harmonic conversion, where N is a positive integer greater than 2. In this embodiment, with... Figure 3 Similarly, the infrared laser module 10 also includes an infrared laser and an infrared light adjustment component 102.

[0122] The difference lies in that the infrared light adjustment component 102 is disposed on the initial red light optical path that transmits the initial continuous infrared laser, and is used to adjust the polarization state of the initial continuous infrared laser to obtain the target continuous infrared laser. The direction of the first red light optical path that transmits the target continuous infrared laser is the same as the direction of the initial red light optical path.

[0123] Specifically, such as Figure 4 As shown, the infrared light adjustment component 102 includes a first polarization beam splitter 51, a Faraday rotator 52, a second half-wave plate 53, a second polarization beam splitter 54, and a second focusing lens 55, which are arranged sequentially and at intervals along the initial red light path.

[0124] The first polarization beam splitter 51 is used to split the initial continuous infrared laser into a third continuous infrared laser and a fourth continuous infrared laser with different polarization directions; wherein, the optical path direction of the third continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the fourth continuous infrared laser is perpendicular to that of the initial continuous infrared laser.

[0125] The Faraday rotator 52 is used to deflect the polarization state of the incident beam by 45 degrees. The second half-wave plate 53 is used to change the polarization direction of the third continuous infrared laser.

[0126] The second polarization beam splitter 54 is used to split the third continuous infrared laser with a changed polarization direction into a fifth continuous infrared laser and a sixth continuous infrared laser with different polarization directions; wherein, the optical path direction of the fifth continuous infrared laser is the same as the optical path direction of the initial continuous infrared laser, and the optical path direction of the sixth continuous infrared laser is perpendicular to the optical path direction of the initial continuous infrared laser.

[0127] The second focusing lens 55 is used to focus the fifth continuous infrared laser into the target continuous infrared laser, and the target continuous infrared laser is incident on the infrared reflector assembly 201 along the first red light path.

[0128] Optionally, the infrared light adjustment component 102 further includes a fourth optical power absorber 56, which is disposed in the transmission optical path of the fourth continuous infrared laser and is used to absorb the fourth continuous infrared laser.

[0129] In this embodiment, the second harmonic conversion has N passes, and the paths of the N passes are partially collinear, where N is an even number greater than 2. That is, when the number of passes is even, the first conversion component 202 may include M sets of reflective components 61, a third frequency doubling element 62, and a third dichroic mirror 63, where M is half of N. For example, in the case of a six-pass circuit, there are three sets of reflective components 61, and in the case of a four-pass circuit, there are two sets of reflective components 61.

[0130] The third frequency doubling element 62 is used to receive the target continuous infrared laser transmitted through the second red light optical path, and convert the target continuous infrared laser into target mixed light after M-pass conversion by the M-group reflection components 61; the target mixed light includes target continuous green laser and target remaining continuous infrared laser.

[0131] The infrared reflector assembly 201 is also used to receive the target mixed light and convert the transmission optical route of the target mixed light into a first mixed optical path and a second mixed optical path, wherein the first mixed optical path is parallel to and opposite in direction to the second red light optical path, and the second mixed optical path is parallel to and opposite in direction to the first red light optical path.

[0132] The third dichroic mirror 63 is disposed on the second mixing optical path and is used to reflect the target continuous green laser to the first green light optical path. Specifically, the third dichroic mirror 63 is disposed between the second polarizing beam splitter 54 and the second focusing lens 55, and is used to project infrared laser and reflect green laser.

[0133] For example, each set of reflective components 61 includes phase compensation elements 611 (specifically 611a, 611b, 611c) and light reflective elements 612 (specifically 612a, 612b, 612c). The M sets of reflective components 61 are respectively located on opposite sides of the third frequency harmonic element 62, wherein the phase compensation elements 611 and the light reflective elements 612 in each set of reflective components 61 are spaced apart, and the phase compensation elements 611 are close to the third frequency harmonic element 62.

[0134] Optionally, the light reflecting element 612 is a bicolor concave mirror used to reflect infrared laser and green laser. The phase compensation element 611 is a quartz plate, and the third frequency doubling element 62 is a noncritical phase-matched second harmonic nonlinear crystal, for example, a lithium triborate (LBO) crystal.

[0135] It should be noted that in multi-pass frequency doubling, the fundamental frequency light and the frequency-doubled light have different wavelengths during air propagation. The different refractive indices of the air introduce an additional phase difference, resulting in a certain phase difference between the fundamental frequency light and the frequency-doubled light during the return journey. Therefore, in this embodiment, a quartz sheet of a certain thickness is introduced to compensate for the phase difference between the fundamental frequency light and the frequency-doubled light, ensuring that the fundamental frequency light and the frequency-doubled light are in phase, thereby achieving the effect of multiple frequency doubling enhancement. The phase compensation element here is similar to the aforementioned first and second phase compensation elements, and the third frequency doubling element 62 is similar to the first frequency doubling element 23.

[0136] The following is about Figure 4 The optical path principle of the multi-channel infrared laser module 10 and the green laser module 20 is explained.

[0137] The initial continuous infrared laser emitted from the infrared laser 101 is transmitted through the first polarization beam splitter 51, then passes through the Faraday rotator 52 to rotate the light polarization by 45°. Next, the second half-wave plate 53 adjusts the polarization direction, and combined with the action of the second polarization beam splitter 54, the polarization direction is adjusted to the horizontal direction. Then, it passes through the third dichroic mirror 63 and the second focusing lens 55 to obtain the target continuous infrared laser. This target continuous infrared laser passes through the first infrared reflector 21 and the second infrared reflector 22, where it is converted from a first red light path to a second red light path. It then passes through the third frequency doubling element 62, and then through the phase compensation element 611a to strike the light reflecting element 612a. The light reflecting element 612a reflects and converges the laser back to the third frequency doubling element 62, and then through the phase compensation element 611b to strike the light reflecting element 612b. After passing through the light-emitting element 612b, the light passes through the third frequency-doubling element 62, then through the phase compensation element 611c and hits the light-reflecting element 612c. After being reflected by the light-reflecting element 612c, it passes through the third frequency-doubling element 62, then through the phase compensation element 611b and hits the light-reflecting element 612b. After passing through the light-reflecting element 612b, it passes through the third frequency-doubling element 62 again, then through the phase compensation element 611a and hits the light-reflecting element 612a. After passing through the light-reflecting element 612a, it passes through the third frequency-doubling element 62 again and is transmitted to the second infrared reflector 22. Then, it returns along the original optical path and passes through the third dichroic mirror 63 to extract the target continuous green laser. The remaining continuous infrared laser will continue to return, pass through the Faraday rotator 52, and the polarization of the light will be rotated by 45°. The light will be reflected along the first polarization beam splitter 51 to the fourth optical power absorber 56 and absorbed.

[0138] Specifically, the first optical path is: target continuous infrared laser → first infrared reflector 21 → second infrared reflector 22 → third frequency doubling element 62 → phase compensation element 611a → optical reflection element 612a; the second optical path is: optical reflection element 612a → phase compensation element 611a → third frequency doubling element 62 → phase compensation element 611b → optical reflection element 612b; the third optical path is: optical reflection element 612b → phase compensation element 611b → third frequency doubling element 62 → phase compensation element 611c → optical reflection element 612c; the fourth optical path is: The optical path is as follows: light reflecting element 612c → phase compensation element 611c → third frequency doubling element 62 → phase compensation element 611b → light reflecting element 612b; the fifth optical path is: light reflecting element 612b → phase compensation element 611b → third frequency doubling element 62 → phase compensation element 611a → light reflecting element 612a; the sixth optical path is: light reflecting element 612a → phase compensation element 611a → third frequency doubling element 62 → second infrared reflector 22 → first infrared reflector 21 → second focusing lens 55 → third dichroic mirror 63 → output target continuous green laser.

[0139] It should be noted that the above explanation only applies to the six-way configuration; the same applies to other configurations such as four-way, eight-way, and more. For example, in the case of a four-way configuration, one set of reflective components 61 can be removed to the right of the third frequency harmonic element 62. Optionally, the set of phase compensation elements 611a and light reflective elements 612a can be removed, or the set of phase compensation elements 611c and light reflective elements 612c can be removed. In the case of an eight-way configuration, another set of reflective components 61 can be added to the left of the third frequency harmonic element 62.

[0140] See Figure 5 and Figure 6 As shown, when the number of second harmonic conversions is N and all N paths are non-collinear, the first conversion component 202 may include M sets of reflection components 61, a third frequency doubling element 62, and a third dichroic mirror 63. In this embodiment, N can be a positive integer greater than 2, and M is a positive integer less than N by 1.

[0141] in, Figure 5 The embodiment described above is a three-way connection where all components are non-collinear. The specific optical path is as follows:

[0142] The first optical path is: target continuous infrared laser → first infrared reflector 21 → second infrared reflector 22 → third frequency doubling element 62 → phase compensation element 611a → light reflection element 612a; the second optical path is: light reflection element 612a → phase compensation element 611a → third frequency doubling element 62 → phase compensation element 611b → light reflection element 612b; the third optical path is: light reflection element 612b → phase compensation element 611b → third frequency doubling element 62 → third dichroic mirror 63 → output target continuous green laser.

[0143] Figure 6 The embodiment described above is a four-way configuration where all components are non-collinear. The specific optical path is as follows:

[0144] The first optical path is: target continuous infrared laser → first infrared reflector 21 → second infrared reflector 22 → third frequency doubling element 62 → phase compensation element 611a → light reflection element 612a; the second optical path is: light reflection element 612a → phase compensation element 611a → third frequency doubling element 62 → phase compensation element 611b → light reflection element 612b; the third optical path is: light reflection element 612b → phase compensation element 611b → third frequency doubling element 62 → phase compensation element 611c → light reflection element 612c; the fourth optical path is: light reflection element 612c → phase compensation element 611c → third frequency doubling element 62 → third dichroic mirror 63 → output target continuous green laser.

[0145] against Figure 5 and Figure 6 The embodiments in, and Figure 4 The difference in the Chinese embodiment is that the third dichroic mirror 63 is positioned differently, and the target mixed light does not pass through the infrared reflector assembly 201, but is emitted (reflected) directly through the third dichroic mirror 63.

[0146] Furthermore, in this embodiment, the infrared light adjustment component 102 and Figure 4 Unlike the previous embodiment, in this case, the infrared light adjustment assembly 102 includes a first polarization beam splitter 51 and a second focusing lens 55 arranged sequentially at intervals along the initial red light path. The first polarization beam splitter 51 splits the initial continuous infrared laser into a third and a fourth continuous infrared laser with different polarization directions. The optical path direction of the third continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the fourth continuous infrared laser is perpendicular to that of the initial continuous infrared laser. The second focusing lens 55 focuses the third continuous infrared laser into the target continuous infrared laser, which is incident on the infrared reflector assembly 201 along the first red light path.

[0147] In addition, Figure 5 and Figure 6 In the embodiment, the target residual continuous infrared laser in the target mixed light is emitted through the third dichroic mirror 63 and can then pass through the fifth optical power absorber 64 (see reference). Figure 5 (As shown) absorption.

[0148] In addition, it should be noted that, Figure 4 The infrared light adjustment component 102 in the embodiments may also include Figure 3 The second light-collecting mirror 15, the third optical power absorber 16, and the second power probe 18 are included in the structure. In this way, the power of the light split by the second polarization beam splitter 54 can be detected, and the rotation angle of the second half-wave plate 53 can be adjusted based on the detection result.

[0149] See Figure 7 The diagram shown is a schematic block diagram of a multi-channel continuous deep ultraviolet laser system provided in an embodiment of this disclosure. The multi-channel continuous deep ultraviolet laser system 1000 includes the extracavity frequency-doubled continuous deep ultraviolet laser device 100 described in any of the preceding embodiments and a plurality of deep ultraviolet laser modules 30 described in any of the preceding embodiments. The plurality of deep ultraviolet laser modules 30 are arranged in a hierarchical manner. Each level of deep ultraviolet laser module 30 receives the second residual continuous green laser output from the previous level's deep ultraviolet laser module 30 and performs fourth harmonic conversion on the second residual continuous green laser to convert it into a target continuous deep ultraviolet laser output.

[0150] Furthermore, in some embodiments of the semiconductor inspection system provided in this disclosure, the semiconductor inspection system includes at least one semiconductor to be inspected and a continuous deep ultraviolet laser device 100 as described in any of the foregoing embodiments. The continuous deep ultraviolet laser device 100 is used to generate target continuous deep ultraviolet laser light to perform defect detection on the at least one semiconductor to be inspected. In other embodiments, the semiconductor inspection system includes at least one semiconductor to be inspected and a multi-channel continuous deep ultraviolet laser system 1000 as described in any of the foregoing embodiments. The multi-channel continuous deep ultraviolet laser system 1000 is used to generate multiple target continuous deep ultraviolet lasers, each of which is used to perform defect detection on a different semiconductor.

[0151] Of course, the target continuous deep ultraviolet laser generated by the continuous deep ultraviolet laser device 100 can also be used for the packaging of electronic components, marking, drilling, welding, cutting and other fields of industrial parts, depending on actual needs.

[0152] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0153] The embodiments described above are some, but not all, of the embodiments disclosed herein. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0154] In the description of the embodiments of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the disclosed product is in use. They are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the referred electric laser system or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0155] In the description of this disclosure, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0156] Finally, it should be noted that the above-described embodiments are merely specific implementations of this disclosure, used to illustrate the technical solutions of this disclosure, and not to limit it. The protection scope of this disclosure is not limited thereto. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this disclosure; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure. All should be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the protection scope of the claims.

Claims

1. An extracavity frequency-doubled continuous deep ultraviolet laser device, characterized in that, It includes an infrared laser module, a green laser module, and a deep ultraviolet laser module; wherein, the infrared laser module is used to generate a target continuous infrared laser, the green laser module is used to perform multi-pass second harmonic conversion on the target continuous infrared laser to convert it into a target continuous green laser, and the deep ultraviolet laser module is used to perform multi-pass fourth harmonic conversion on the target continuous green laser to convert it into a target continuous deep ultraviolet laser; the target continuous deep ultraviolet laser is used for semiconductor detection; The green laser module includes an infrared reflector assembly and a first conversion assembly; the infrared reflector assembly is used to convert the transmission optical path of the target continuous infrared laser into a first red optical path and a second red optical path; the first conversion assembly is used to perform multi-pass second harmonic conversion on the target continuous infrared laser transmitted through the second red optical path to obtain the target continuous green laser. The deep ultraviolet laser module includes a green light reflector and a second conversion component. The green light reflector is used to convert the transmission optical path of the target continuous green laser into a first green light optical path and a second green light optical path. The second conversion component is used to perform multi-pass fourth harmonic conversion on the target continuous green laser transmitted through the second green light optical path to obtain the target continuous deep ultraviolet laser. The second harmonic conversion is a double-pass conversion, and the first conversion component includes a first frequency doubling element, a first reflector, a first dichroic mirror, a first optical power absorber, and a first phase compensation element. The first frequency doubling element is used to receive the target continuous infrared laser transmitted through the second red light optical path, and convert a portion of the target continuous infrared laser into a first continuous green laser, wherein the first continuous green laser and the first remaining continuous infrared laser form a first mixed light; The first reflector is disposed on one side of the first frequency doubling element and is used to reflect the received first mixed light to the first frequency doubling element, so that the first frequency doubling element converts part of the reflected first remaining continuous infrared laser energy into the first continuous green laser to form the target continuous green laser; the transmission optical path of the target continuous green laser avoids the infrared reflector assembly; The first dichroic mirror is disposed on the side of the first frequency doubling element away from the first reflector, and is used to transmit the second residual continuous infrared laser after dual-pass conversion by the first frequency doubling element to the first optical power absorber, and reflect the target continuous green laser to the first green light path; the transmission optical path of the second residual continuous infrared laser output from the first frequency doubling element avoids the infrared reflector assembly; The first phase compensation element is disposed between the first frequency doubling element and the first reflector, and is used to make the first remaining continuous infrared laser phase-matched with the first continuous green light.

2. The laser device according to claim 1, characterized in that, The fourth harmonic conversion is a double-pass conversion, and the second conversion component includes a second frequency doubling element, a second reflector, and a second dichroic mirror; The second frequency doubling element is disposed on one side of the green light reflector and is used to receive the target continuous green laser transmitted through the second green light optical path, and convert part of the target continuous green laser into a first continuous deep ultraviolet laser. The first continuous deep ultraviolet laser and the first remaining continuous green laser form a second mixed light. The second reflector is disposed on the side of the second frequency doubling element away from the green light reflector, and is used to reflect the received second mixed light to the second frequency doubling element, so that the second frequency doubling element converts part of the reflected first remaining continuous green laser energy into first continuous deep ultraviolet light to form the target continuous deep ultraviolet laser; the transmission optical path of the target continuous deep ultraviolet laser avoids the green light reflector; The second dichroic mirror is disposed on the side of the second frequency doubling element away from the second reflector, and is used to transmit the second residual continuous green laser after the second frequency doubling element has undergone double-pass conversion, and to reflect the target continuous deep ultraviolet laser; the transmission optical path of the second residual continuous green laser output from the second frequency doubling element avoids the green light reflector.

3. The laser device according to claim 2, characterized in that, The second conversion component further includes a second phase compensation element, which is disposed between the second frequency doubling element and the second reflector, for making the first remaining continuous green laser phase-matched with the first continuous deep ultraviolet laser.

4. The laser device according to claim 1, characterized in that, The first reflector is a bicolor concave reflector used to reflect infrared laser and green laser; and / or, the first frequency doubling element is a non-critical phase-matched second-harmonic nonlinear crystal.

5. An extracavity frequency-doubled continuous deep ultraviolet laser device, characterized in that, It includes an infrared laser module, a green laser module, and a deep ultraviolet laser module; wherein, the infrared laser module is used to generate a target continuous infrared laser, the green laser module is used to perform multi-pass second harmonic conversion on the target continuous infrared laser to convert it into a target continuous green laser, and the deep ultraviolet laser module is used to perform multi-pass fourth harmonic conversion on the target continuous green laser to convert it into a target continuous deep ultraviolet laser; the target continuous deep ultraviolet laser is used for semiconductor detection; The green laser module includes an infrared reflector assembly and a first conversion assembly; the infrared reflector assembly is used to convert the transmission optical path of the target continuous infrared laser into a first red optical path and a second red optical path; the first conversion assembly is used to perform multi-pass second harmonic conversion on the target continuous infrared laser transmitted through the second red optical path to obtain the target continuous green laser. The deep ultraviolet laser module includes a green light reflector and a second conversion component. The green light reflector is used to convert the transmission optical path of the target continuous green laser into a first green light optical path and a second green light optical path. The second conversion component is used to perform multi-pass fourth harmonic conversion on the target continuous green laser transmitted through the second green light optical path to obtain the target continuous deep ultraviolet laser. The fourth harmonic conversion is a double-pass conversion, and the second conversion component includes a second frequency doubling element, a second reflector, a second dichroic mirror, and a second phase compensation element. The second frequency doubling element is disposed on one side of the green light reflector and is used to receive the target continuous green laser transmitted through the second green light optical path, and convert part of the target continuous green laser into a first continuous deep ultraviolet laser. The first continuous deep ultraviolet laser and the first remaining continuous green laser form a second mixed light. The second reflector is disposed on the side of the second frequency doubling element away from the green light reflector, and is used to reflect the received second mixed light to the second frequency doubling element, so that the second frequency doubling element converts part of the reflected first remaining continuous green laser energy into first continuous deep ultraviolet light to form the target continuous deep ultraviolet laser; the transmission optical path of the target continuous deep ultraviolet laser avoids the green light reflector; The second dichroic mirror is disposed on the side of the second frequency doubling element away from the second reflector, and is used to transmit the second residual continuous green laser after the second frequency doubling element has undergone double-pass conversion, and to reflect the target continuous deep ultraviolet laser; the transmission optical path of the second residual continuous green laser output from the second frequency doubling element avoids the green light reflector; The second phase compensation element is disposed between the second frequency doubling element and the second reflector, and is used to make the first remaining continuous green laser phase-matched with the first continuous deep ultraviolet laser.

6. The laser device according to claim 2 or 5, characterized in that, The second reflector is a bicolor concave reflector used to reflect green laser and deep ultraviolet laser; and / or, the second frequency doubling element is a fourth harmonic nonlinear crystal, and the length of the second frequency doubling element is greater than a preset length.

7. The laser device according to claim 1 or 5, characterized in that, The infrared reflector assembly includes a first infrared reflector and a second infrared reflector, wherein the first infrared reflector is disposed on the first red light path; and the second infrared reflector is disposed on the second red light path.

8. The laser device according to claim 2 or 5, characterized in that, The second conversion component further includes a shaping element disposed on the first green light path, which is used to shape the target continuous green laser into an elliptical spot before outputting it. The major axis of the elliptical spot corresponds to the phase matching direction of the second frequency doubling element, and the minor axis of the elliptical spot corresponds to the non-phase matching direction of the second frequency doubling element.

9. The laser device according to claim 1 or 5, characterized in that, The infrared laser module includes: Infrared laser, used to generate initial continuous infrared laser light; An infrared light adjustment component is disposed on the initial red light path of the initial continuous infrared laser, and is used to adjust the power and polarization state of the initial continuous infrared laser to obtain the target continuous infrared laser; the direction of the first red light path of the target continuous infrared laser is the same as the direction of the initial red light path.

10. The laser device according to claim 9, characterized in that, The infrared light adjustment component includes: The first light-collecting mirror is disposed on the initial red light path and is used to reflect part of the initial continuous infrared laser to the first power probe and output the remaining initial continuous infrared laser. The first power probe is used to detect the power of the initial continuous infrared laser, and when the power of the initial continuous infrared laser exceeds a first preset range, it generates a first adjustment command; the first adjustment command is used to instruct the infrared laser to adjust the power of the initial continuous infrared laser so that the initial continuous infrared laser is within the first preset range; A first half-wave plate is disposed on the initial red light path to change the polarization direction of the initial continuous infrared laser. A polarization beam splitter is disposed on the initial red light path and located on the side of the first half-wave plate away from the first light-collecting mirror. It is used to split the remaining initial continuous infrared laser after changing the polarization direction into a first continuous infrared laser and a second continuous infrared laser with different polarization directions. The optical path direction of the first continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the second continuous infrared laser is perpendicular to that of the initial continuous infrared laser. A first focusing lens is disposed on the initial red light path, located on the side of the polarization beam splitter away from the first half-wave plate, for focusing the first continuous infrared laser into the target continuous infrared laser, and the target continuous infrared laser is incident on the infrared reflector assembly along the first red light path. The second light-collecting mirror is positioned in the optical path direction of the second continuous infrared laser and is used to reflect part of the second continuous infrared laser to the second power probe and output the remaining second continuous infrared laser to the third optical power absorber. The second power probe is used to detect the power of the second continuous infrared laser, and the power of the second continuous infrared laser is used to determine whether the power of the first continuous infrared laser exceeds a second preset range. If the power of the first continuous infrared laser exceeds the second preset range, a second adjustment command is generated. The second adjustment command is used to instruct the half-wave plate to adjust its rotation angle so that the power of the first continuous infrared laser is within the second preset range.

11. An extracavity frequency-doubled continuous deep ultraviolet laser device, characterized in that, It includes an infrared laser module, a green laser module, and a deep ultraviolet laser module; wherein, the infrared laser module is used to generate a target continuous infrared laser, the green laser module is used to perform multi-pass second harmonic conversion on the target continuous infrared laser to convert it into a target continuous green laser, and the deep ultraviolet laser module is used to perform multi-pass fourth harmonic conversion on the target continuous green laser to convert it into a target continuous deep ultraviolet laser; the target continuous deep ultraviolet laser is used for semiconductor detection; The green laser module includes an infrared reflector assembly and a first conversion assembly; the infrared reflector assembly is used to convert the transmission optical path of the target continuous infrared laser into a first red optical path and a second red optical path; the first conversion assembly is used to perform multi-pass second harmonic conversion on the target continuous infrared laser transmitted through the second red optical path to obtain the target continuous green laser. The deep ultraviolet laser module includes a green light reflector and a second conversion component. The green light reflector is used to convert the transmission optical path of the target continuous green laser into a first green light optical path and a second green light optical path. The second conversion component is used to perform multi-pass fourth harmonic conversion on the target continuous green laser transmitted through the second green light optical path to obtain the target continuous deep ultraviolet laser. The second harmonic conversion order is N, and the paths of the N paths are partially collinear, where N is an even number greater than 2. The first conversion component includes M sets of reflection components, a third frequency doubling element, and a third dichroic mirror, where M is half of N. The third frequency doubling element is used to receive the target continuous infrared laser transmitted through the second red light optical path, and to convert the target continuous infrared laser through the M group of reflection components into N-pass conversion to form target mixed light; the target mixed light includes target continuous green laser and target remaining continuous infrared laser; The infrared reflector assembly is also used to receive the target mixed light and convert the transmission optical path of the target mixed light into a first mixed optical path and a second mixed optical path, wherein the first mixed optical path is parallel to and opposite in direction to the second red light optical path, and the second mixed optical path is parallel to and opposite in direction to the first red light optical path; The third dichroic mirror is disposed on the second mixing optical path and is used to reflect the target continuous green laser to the first green light optical path.

12. An extracavity frequency-doubled continuous deep ultraviolet laser device, characterized in that, It includes an infrared laser module, a green laser module, and a deep ultraviolet laser module; wherein, the infrared laser module is used to generate a target continuous infrared laser, the green laser module is used to perform multi-pass second harmonic conversion on the target continuous infrared laser to convert it into a target continuous green laser, and the deep ultraviolet laser module is used to perform multi-pass fourth harmonic conversion on the target continuous green laser to convert it into a target continuous deep ultraviolet laser; the target continuous deep ultraviolet laser is used for semiconductor detection; The green laser module includes an infrared reflector assembly and a first conversion assembly; the infrared reflector assembly is used to convert the transmission optical path of the target continuous infrared laser into a first red optical path and a second red optical path; the first conversion assembly is used to perform multi-pass second harmonic conversion on the target continuous infrared laser transmitted through the second red optical path to obtain the target continuous green laser. The deep ultraviolet laser module includes a green light reflector and a second conversion component. The green light reflector is used to convert the transmission optical path of the target continuous green laser into a first green light optical path and a second green light optical path. The second conversion component is used to perform multi-pass fourth harmonic conversion on the target continuous green laser transmitted through the second green light optical path to obtain the target continuous deep ultraviolet laser. The second harmonic conversion has N channels and all N channels are non-collinear. The first conversion component includes M sets of reflection components, a third frequency doubling element, and a third dichroic mirror. N is a positive integer greater than 2, and M is a positive integer less than N by 1. The third frequency doubling element is used to receive the target continuous infrared laser transmitted through the second red light optical path, and to convert the target continuous infrared laser through the M group of reflection components into N-pass conversion to form target mixed light; the target mixed light includes target continuous green laser and target remaining continuous infrared laser; The third dichroic mirror is used to transmit the remaining continuous infrared laser of the target and reflect the continuous green laser of the target back to the first green light path.

13. The laser device according to claim 11 or 12, characterized in that, Each set of reflective components includes a phase compensation element and a light reflection element; the M sets of reflective components are respectively located on opposite sides of the third harmonic element, wherein the phase compensation element and the light reflection element in each set of reflective components are spaced apart, and the phase compensation element is close to the third harmonic element.

14. The laser device according to claim 13, characterized in that, The light reflecting element is a two-color concave mirror used to reflect infrared laser and green laser; the phase compensation element is a quartz plate.

15. The laser device according to claim 11 or 12, characterized in that, The third frequency doubling element is a non-critical phase-matched second-harmonic nonlinear crystal.

16. The laser device according to claim 11 or 12, characterized in that, The infrared laser module includes: Infrared laser, used to generate initial continuous infrared laser light; An infrared light adjustment component is disposed on the initial red light path of the initial continuous infrared laser, and is used to adjust the polarization state of the initial continuous infrared laser to obtain the target continuous infrared laser; the direction of the first red light path of the target continuous infrared laser is the same as the direction of the initial red light path.

17. The laser device according to claim 16, characterized in that, The infrared light adjustment assembly includes a first polarizing beam splitter, a Faraday rotator, a second half-wave plate, a second polarizing beam splitter, and a second focusing lens arranged sequentially and at intervals along the initial red light path; the third dichroic mirror is disposed between the second polarizing beam splitter and the second focusing lens; The first polarization beam splitter is used to split the initial continuous infrared laser into a third continuous infrared laser and a fourth continuous infrared laser with different polarization directions; wherein, the optical path direction of the third continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the fourth continuous infrared laser is perpendicular to that of the initial continuous infrared laser. The Faraday rotator is used to deflect the polarization state of the incident beam by 45 degrees. The second half-wave plate is used to change the polarization direction of the third continuous infrared laser. The second polarization beam splitter is used to split the third continuous infrared laser, after its polarization direction has been changed, into a fifth continuous infrared laser and a sixth continuous infrared laser with different polarization directions; wherein, the optical path direction of the fifth continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the sixth continuous infrared laser is perpendicular to that of the initial continuous infrared laser. The second focusing lens is used to focus the fifth continuous infrared laser into the target continuous infrared laser, and the target continuous infrared laser is incident on the infrared reflector assembly along the first red light path.

18. The laser device according to claim 16, characterized in that, The infrared light adjustment component includes a first polarization beam splitter and a second focusing lens arranged sequentially at intervals along the initial red light path; The first polarization beam splitter is used to split the initial continuous infrared laser into a third continuous infrared laser and a fourth continuous infrared laser with different polarization directions, wherein the optical path direction of the third continuous infrared laser is the same as that of the initial continuous infrared laser, and the optical path direction of the fourth continuous infrared laser is perpendicular to that of the initial continuous infrared laser. The second focusing lens is used to focus the third continuous infrared laser into the target continuous infrared laser, and the target continuous infrared laser is incident on the infrared reflector assembly along the first red light path.

19. The laser device according to claim 17 or 18, characterized in that, The infrared light adjustment component further includes: A fourth optical power absorber is disposed in the transmission optical path of the fourth continuous infrared laser and is used to absorb the fourth continuous infrared laser.

20. A multi-channel continuous deep ultraviolet laser system, characterized in that, Includes an extracavity frequency-doubled continuous deep ultraviolet laser device according to any one of claims 1-19 and a plurality of deep ultraviolet laser modules according to any one of claims 1-19; The multiple deep ultraviolet laser modules are arranged in a hierarchical manner. Each level of deep ultraviolet laser module is used to receive the second residual continuous green laser output from the deep ultraviolet laser module of the previous level, and to perform fourth harmonic conversion on the second residual continuous green laser to convert the second residual continuous green laser into the target continuous deep ultraviolet laser output.

21. A semiconductor detection system, characterized in that, The device includes at least one semiconductor to be tested and a continuous deep ultraviolet laser device according to any one of claims 1-19 or a multi-channel continuous deep ultraviolet laser system according to claim 20, wherein the continuous deep ultraviolet laser device is used to generate target continuous deep ultraviolet lasers to perform defect detection on the at least one semiconductor to be tested; and the multi-channel continuous deep ultraviolet laser system is used to generate multiple target continuous deep ultraviolet lasers, each of which is used to perform defect detection on a different semiconductor.

Images