EUV mask defect detection device

Abstract

The present invention discloses an EUV mask defect detection device, comprising a base plate, a first base, a mounting bracket, a displacement assembly and a main vacuum assembly, wherein the first base is fixed to the base plate, the mounting bracket is fixed to the top of the first base, the main vacuum assembly is fixed to the top of the mounting bracket, and the bottom of the main vacuum assembly is connected to the first base via a displacement assembly, and the displacement assembly is used to adjust the Z-direction position of the main vacuum assembly; the device also comprises a second base, a tripod bracket and a scanning vacuum assembly, wherein the second base is fixed to the base plate, the tripod bracket is fixed to the top of the second base, the scanning vacuum assembly is fixed to the tripod bracket, and the scanning vacuum assembly is connected to the main vacuum assembly via a bellows; the present invention separates the scanning vacuum cavity from the main vacuum cavity and uses a bellows to avoid a rigid connection, thereby solving the problem of vibration caused by scanning during the exposure process affecting the imaging quality.

Description

Technical Field

[0001] The present invention relates to the technical field of EUV mask defect detection, and in particular to an EUV mask defect detection device. Background Art

[0002] The mass production of UV lithography technology is a crucial step in advancing lithography towards smaller process nodes such as 7nm and 5nm. EUV mask defect inspection is a critical step in improving chip production yield and reducing production costs in the lithography process. EUV masks primarily consist of a Mo / Si multilayer reflective layer and an absorption layer. Therefore, EUV mask defects primarily include surface absorption defects and phase defects buried within the multilayer. Due to the limited penetration depth of non-actinic (DUV, SEM) mask inspection into EUV multilayers, phase defects buried within the multilayer are difficult to detect, leading to missed defects. Furthermore, mask particles or contaminants have varying absorption coefficients at different wavelengths, making non-actinic methods prone to false defects. Therefore, EUV light is the only reliable method for understanding the physical response of defects, repairs, pattern deviations, and optical proximity correction. However, EUV light has a high absorption coefficient for nearly all materials, so mask inspection using EUV light requires a vacuum operating environment for the imaging system. This places high demands on the cavity and motion control mechanisms involved in the engineering design. Furthermore, for high-magnification, nanometer-scale imaging, mechanical stability with exposure times in the order of seconds is paramount for the successful implementation of EUV mask microscopy. Specifically, EUV mask defect imaging systems require that the relative motion between the mask and imaging lens be maintained at the nanometer level during exposure. Therefore, to achieve stable EUV mask defect inspection in complex environments, the overall mechanical design should focus on vacuum vibration isolation between the mask and imaging lens.

[0003] Currently, several EUV mask defect inspection devices, such as AIMS, SHARP, and Lasertec, have been commercialized. Their engineering designs not only meet the necessary modulation requirements but also operate in complex and diverse factory environments. Because different inspection devices require different optical solutions, these optical designs also require different mechanical design parameters. In other words, each mechanical design is customized. To address this issue, we propose an EUV mask defect inspection device. Summary of the Invention

[0004] The object of the present invention is to provide an EUV mask defect detection device to solve the problems raised in the above background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solutions: an EUV mask defect inspection device, comprising a base plate, a first base, a mounting bracket, and a main vacuum assembly, wherein the first base is fixed to the base plate, the mounting bracket is fixed to the top of the first base, and the main vacuum assembly is fixed to the top of the mounting bracket;

[0006] It also includes a second base, a tripod bracket and a scanning vacuum component. The second base is fixed on the bottom plate, the tripod bracket is fixed on the top of the second base, the scanning vacuum component is fixed on the tripod bracket, and the scanning vacuum component is connected to the main vacuum component through a bellows.

[0007] Preferably, the main vacuum assembly includes a support plate, a main vacuum chamber, a displacement assembly, a first motion adjustment mechanism, a second motion adjustment mechanism, a third motion adjustment mechanism, an optical element, a substrate, a support frame and a pupil monitor. The support plate is fixed above the mounting bracket, the main vacuum chamber is fixed on the support plate, the bottom of the support plate is connected to the first base through the mounting bracket, the substrate is located inside the main vacuum chamber, and its bottom is fixed to the first base through the displacement assembly, the pupil monitor is fixed on the support frame, a through hole is provided in the middle of the substrate, and the through hole is used for the pupil monitor to effectively monitor the light beam line, and the first motion adjustment mechanism, the second motion adjustment mechanism, the third motion adjustment mechanism and the optical element are all fixed on the substrate.

[0008] Preferably, the displacement assembly includes a third base, a Z-axis displacement stage and a fixed pillar. The bottom of the third base is connected to the first base through the Z-axis displacement stage. The bottom of the fixed pillar is fixed on the third base. The top of the fixed pillar passes through the support plate, the main vacuum chamber and the substrate. The connection between the fixed pillar and the main vacuum chamber is sealed by a bellows.

[0009] Preferably, there are three fixed pillars, and the three fixed pillars are distributed in a "triangle" shape between the third base and the support plate.

[0010] Preferably, the scanning vacuum component includes: a scanning vacuum chamber, which is connected to the main vacuum chamber through a bellows, and the scanning vacuum chamber is fixed on a tripod; a fourth motion adjustment mechanism, which is fixed inside the scanning vacuum chamber; a detector, which is installed above the scanning vacuum chamber and located at the image plane of the imaging system, and is used to record the imaging situation; a beam position monitor, which is installed at the entrance of the beam station and is used to monitor the beam entry situation and the relative position of the light spot; a beam incident angle monitor, which is arranged on one side of the main vacuum chamber and is used to assist in system adjustment; a vacuum valve, which is installed at the entrance of the beam station and is used to isolate the chamber from the light source when necessary to prevent the repeated charging and discharging process of the chamber vacuum during the installation and debugging of the microscopic imaging system from affecting the working environment of the light source.

[0011] Preferably, it also includes a vacuum pump, which is fixed on the first base and is used to maintain the vacuum degree in the main vacuum chamber and the scanning vacuum chamber at 10 -7 Below torr level.

[0012] Preferably, the first motion adjustment mechanism, the second motion adjustment mechanism, the third motion adjustment mechanism and the fourth motion adjustment mechanism are all piezoelectric nano-displacement stages.

[0013] Preferably, the detector is an EUV sensitive camera, and is one of CCD, sCMOS and MCP.

[0014] Preferably, the beam incident angle monitor consists of a window, a YAG crystal and a camera.

[0015] Preferably, the first base, the second base and the third base are all marble bases.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Vibration isolation:

[0018] (1) The scanning vacuum chamber is separated from the main vacuum chamber (the air chamber is connected, but a bellows is used to avoid a rigid connection), which solves the problem of vibration caused by scanning during the exposure process, affecting the imaging quality;

[0019] (2) The main vacuum chamber is connected to the base inside the chamber through a bellows to avoid a rigid connection, thereby solving the problem that the surrounding environmental factors may produce a resonance effect on the chamber, and the vibration is transmitted from the rigid connection to the base, the first motion adjustment mechanism, the second motion adjustment mechanism, the third motion adjustment mechanism and the fourth motion adjustment mechanism, affecting the stability of EUV mask microscopy imaging;

[0020] (3) A laser interferometer and a capacitive sensor are used to monitor the relative motion between the objective lens system and the mask, and a closed-loop feedback is formed with the motion adjustment mechanism to maintain the relative motion between the objective lens and the mask at the nanometer level during exposure.

[0021] 2. Regarding pupil monitor design, the advantages of placing the pupil monitor outside the vacuum chamber include:

[0022] (1) The requirements for pupil monitoring microscopes are reduced (no need to work in a vacuum environment);

[0023] (2) Reserve sufficient control space for the microscope to achieve diversification of microscope selection;

[0024] (3) A motion adjustment mechanism that adapts to the vacuum chamber needs to be equipped inside the vacuum chamber and needs to move together with the mask platform; separating the pupil monitor reduces the requirements for the motion adjustment mechanism on the one hand, and reduces the load on the motion adjustment mechanism of the mask platform on the other hand.

[0025] 3. Incident angle monitor:

[0026] Since the EUV mask inspection system is a reflective imaging system, it is necessary to consider avoiding the overlap of the incident light cone angle and the reflected light cone angle during design. In addition, the reflectivity of the EUV mask multilayer reflective film is different under different incident angles, especially under large-angle incidence within a certain range of incident angles, the reflectivity will drop sharply. Therefore, there is a trade-off between the system's main ray incident angle and the numerical aperture. Under a specific numerical aperture, it is ensured that the incident light cone and the reflected light cone do not overlap, and a minimum main ray incident angle is set. Therefore, the control and monitoring of the main ray incident angle is particularly important. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the displacement assembly structure of the present invention;

[0029] Figure 3 This is a schematic diagram of the main vacuum chamber structure of the present invention;

[0030] Figure 4 Schematic diagram of the internal structure of the main vacuum chamber of the present invention;

[0031] Figure 5 This is a schematic diagram of the structure of the scanning vacuum component of the present invention.

[0032] 1. Base plate; 2. First base; 3. Mounting bracket; 4. Displacement assembly; 5. Main vacuum assembly; 6. Second base; 7. Triangle bracket; 8. Scanning vacuum assembly; 9. Support plate; 10. Main vacuum chamber; 11. First motion adjustment mechanism; 12. Second motion adjustment mechanism; 13. Third motion adjustment mechanism; 14. Optical element; 15. Substrate; 16. Support frame; 17. Pupil monitor; 18. Third base; 19. Z-axis displacement stage; 20. Fixed pillar; 21. Scanning vacuum chamber; 22. Fourth motion adjustment mechanism; 23. Detector; 24. Vacuum valve; 25. Beam incident angle monitor; 26. Beam position monitor; 27. Vacuum pump. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] The present invention provides a technical solution: an EUV mask defect inspection device, comprising a base plate 1, a first base 2, a mounting bracket 3 and a main vacuum assembly 5, wherein the first base 2 is fixed on the base plate 1, the base plate 1 provides a rigid platform for an EUV mask inspection microscopic imaging device, the mounting bracket 3 is fixed to the top of the first base 2, and the main vacuum assembly 5 is fixed to the top of the mounting bracket 3;

[0035] As a preferred embodiment, it also includes a second base 6, a tripod bracket 7 and a scanning vacuum component 8, the second base 6 is fixed on the base plate 1, the tripod bracket 7 is fixed on the top of the second base 6, the scanning vacuum component 8 is fixed on the tripod bracket 7, and the scanning vacuum component 8 is connected to the main vacuum component 5 through a bellows.

[0036] As a preferred embodiment, the main vacuum component 5 includes a support plate 9, a main vacuum chamber 10, a displacement component 4, a first motion adjustment mechanism 11, a second motion adjustment mechanism 12, a third motion adjustment mechanism 13, an optical element 14, a substrate 15, a support frame 16 and a pupil monitor 17. The support plate 9 is fixed above the mounting bracket 3, the main vacuum chamber 10 is fixed on the support plate 9, and the bottom of the support plate 9 is connected to the first base 2 through the mounting bracket 3. The substrate 15 is located inside the main vacuum chamber 10, and its bottom is fixed to the first base 2 through the displacement component 4. The pupil monitor 17 is fixed on the support frame 16, and the support frame 16 is connected to the first base 2. A through hole is provided in the middle of the substrate 15, and the through hole is used for the pupil monitor 17 to effectively monitor the light beam line. The first motion adjustment mechanism 11, the second motion adjustment mechanism 12, the third motion adjustment mechanism 13 and the optical element 14 are all fixed on the substrate 15.

[0037] The optical components include aperture, condenser, objective lens and mask, etc., with a size of about 10mm.

[0038] Main vacuum chamber 10 vacuum degree <10 -7 torr, the main vacuum chamber 10 provides a stable working environment for the EUV mask inspection microscopy imaging system.

[0039] The first motion adjustment mechanism 11 controls the position and posture of the objective lens system: adjusts the alignment and imaging of the objective lens system; forms a closed-loop feedback system with the laser interferometer and the capacitive sensor to control the relative movement between the objective lens system and the mask; the second motion adjustment mechanism 12 controls each optical element 14 in the illumination system, including but not limited to lenses, Fresnel zone plates, ellipsoidal reflectors, spherical reflectors, and apertures; the third motion adjustment mechanism 13 controls the position and posture of the mask.

[0040] The pupil monitor is installed outside the main vacuum chamber 10. On the one hand, it is used to monitor the condition of the illumination pupil with the help of the YAG crystal; on the other hand, it is used to monitor the position of the light spot during installation and adjustment.

[0041] As a preferred embodiment, the displacement assembly 4 includes a third base 18, a Z-axis displacement stage 19 and a fixed pillar 20. The bottom of the third base 18 is connected to the first base 2 through the Z-axis displacement stage 19. The bottom of the fixed pillar 20 is fixed on the third base 18. The top of the fixed pillar 20 passes through the support plate 9, the main vacuum chamber 10 and the substrate 15. The connection between the fixed pillar 20 and the main vacuum chamber 10 is sealed by a bellows.

[0042] As a preferred embodiment, three fixing pillars 20 are provided, and the three fixing pillars 20 are distributed in a “triangle” shape between the third base 18 and the support plate 9 .

[0043] As a preferred embodiment, the scanning vacuum component 8 includes: a scanning vacuum chamber 21, which is connected to the main vacuum chamber 10 through a bellows, and the scanning vacuum chamber 21 is fixed on the tripod 7; a fourth motion adjustment mechanism 22, which is fixed inside the scanning vacuum chamber 21; a detector 23, which is installed above the scanning vacuum chamber 21 and is located at the image plane of the imaging system, and is used to record the imaging situation; a beam position monitor 26, which is installed at the entrance of the beam station and is used to monitor the beam entry situation and the relative position of the light spot; a beam incident angle monitor 25, which is arranged on one side of the main vacuum chamber 10 and is used to assist in system adjustment; a vacuum valve 24, which is installed at the entrance of the beam station and is used to isolate the cavity from the light source when necessary to prevent the repeated filling and discharging process of the cavity vacuum during the installation and debugging of the microscopic imaging system from affecting the working environment of the light source.

[0044] The fourth motion adjustment mechanism 22 controls the position and posture of the scanning reflector. When the light source is restarted and the position of the light spot changes, the motion adjustment mechanism is controlled to allow the light spot to hit the center of the scanning reflector.

[0045] Scanning vacuum chamber 21 vacuum degree <10 -7 torr, is connected to the main vacuum chamber 10 through a bellows, and includes a motion adjustment mechanism inside to provide a stable working environment for the scanning galvanometer.

[0046] As a preferred embodiment, a vacuum pump 27 is further included, and the vacuum pump 27 is fixed on the first base 2, and is used to maintain the vacuum degree in the main vacuum chamber 10 and the scanning vacuum chamber 21 at 10 -7 Below the torr level, it provides a stable working environment for EUV mask detection equipment.

[0047] As a preferred embodiment, the first motion adjustment mechanism 11, the second motion adjustment mechanism 12, the third motion adjustment mechanism 13 and the fourth motion adjustment mechanism 22 are all piezoelectric nano-displacement stages, which are suitable for working in an ultra-high vacuum environment.

[0048] As a preferred embodiment, the detector 23 includes but is not limited to EUV-sensitive cameras such as CCD, sCMOS and MCP, which are installed above the scanning vacuum chamber 21 and located at the image plane of the imaging system. The detector 23 is used to record the imaging situation.

[0049] As a preferred embodiment, a beam position monitor 26 is installed at the entrance of the beam station. The purpose of the beam position monitor 26 is to monitor the beam entry situation and the relative position of the light spot. The monitor includes but is not limited to an EUV sensitive detector 23 and a YAG crystal.

[0050] As a preferred embodiment, a beam incident angle monitor 25 is installed on one side of the main vacuum chamber 10. It consists of a window, a YAG crystal, and a camera to assist in system alignment. Given the incident angle of the incoming beamline, as well as the positions of the reflector and mask field of view, if the beamline passes through the scanning mirror and the reticle and ultimately detects a light spot at the beam incident angle monitor 25, it indicates that the beamline's principal ray incident angle at the mask is the designed angle.

[0051] As a preferred embodiment, the first base 2, the second base 6 and the third base 18 are all marble bases, and marble can reduce the impact of vibration by increasing damping.

[0052] EUV mask defect inspection systems, while differing in control aspects corresponding to different optical designs, share similarities such as a vacuum environment and vibration isolation. Furthermore, these systems also feature pupil monitoring systems and auxiliary assembly and adjustment systems.

[0053] Vacuum extraction and maintenance:

[0054] First, use a mechanical pump to extract the air in the cavity to a certain degree, then use an ion pump to continue to reduce the vacuum degree inside the cavity, and maintain the vacuum degree in the scanning vacuum cavity 21 and the main vacuum cavity 10 less than 10 -7 torr.

[0055] Vibration isolation:

[0056] 1. We separate the scanning vacuum chamber 21 from the main vacuum chamber 10 and connect them with an air chamber. However, we use a bellows to avoid a rigid connection, thus solving the problem of vibration caused by scanning during the exposure process, which affects the imaging quality.

[0057] 2. The main vacuum chamber 10 is connected to the base inside the chamber through a bellows to avoid a rigid connection. This solves the problem of the ambient environment causing resonance effects on the chamber. The rigid connection transmits vibrations to the base, the first motion adjustment mechanism 11, the second motion adjustment mechanism 12, the third motion adjustment mechanism 13, and the fourth motion adjustment mechanism 22, affecting the stability of EUV mask microscopy imaging.

[0058] 3. Use a laser interferometer and a capacitive sensor to monitor the relative motion between the objective lens system and the mask, and form a closed-loop feedback with the motion adjustment mechanism 51 to maintain the relative motion between the objective lens and the mask at the nanometer level during exposure.

[0059] Regarding pupil monitor design, the advantages of placing the pupil monitor outside the vacuum chamber include:

[0060] 1. The requirements for pupil monitoring microscopes are reduced and they do not need to work in a vacuum environment;

[0061] 2. Reserve sufficient control space for the microscope to achieve diversification of microscope selection;

[0062] 3. A motion adjustment mechanism that adapts to the vacuum chamber needs to be equipped inside the vacuum chamber and needs to move along with the mask platform; separating the pupil monitor reduces the requirements for the motion adjustment mechanism on the one hand, and reduces the load on the motion adjustment mechanism of the mask platform on the other hand.

[0063] Incident Angle Monitor:

[0064] Because EUV mask inspection systems employ reflective imaging, design considerations must be taken to avoid overlap between the incident and reflected light cone angles. Furthermore, the reflectivity of the EUV mask's multilayer reflective coating varies at different angles of incidence, particularly at high angles within a certain range. Consequently, there is a trade-off between the system's principal ray angle of incidence and the numerical aperture. At a specific numerical aperture, a minimum principal ray angle of incidence is established to ensure that the incident and reflected light cones do not overlap. Therefore, controlling and monitoring the principal ray angle of incidence is crucial.

[0065] The monitoring of the incident angle of the main light line is implemented as follows:

[0066] By adjusting the relative position and posture of the scanning mirror with the center of the reticle as a reference, the principal ray incident angle of the beam line on the mask can be controlled. The corresponding beam line is reflected by the mask and emitted from the beam incident angle monitor 25. Multiple points are preset on the beam incident angle monitor 25, corresponding to specific principal ray incident angles of the beam line on the mask. Simply adjust the relative position and posture of the scanning mirror until the corresponding light spot is detected on the beam incident angle monitor 25.

[0067] Compared with traditional calibration methods, this method does not require the use of rangefinders for measurement. It also takes into account the offset between the locator origin and the screen coordinate system. By sampling multiple sets of positioning data synchronized with the camera and locator, the camera and locator extrinsics and the offset between the locator origin and the screen can be solved simultaneously.

[0068] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0069] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An EUV mask defect detection device, characterized in that: It comprises a bottom plate (1), a first base (2), a mounting bracket (3) and a main vacuum assembly (5), wherein the first base (2) is fixed on the bottom plate (1), the mounting bracket (3) is fixed on the top of the first base (2), and the main vacuum assembly (5) is fixed on the top of the mounting bracket (3); It also includes a second base (6), a tripod bracket (7) and a scanning vacuum assembly (8), wherein the second base (6) is fixed on the bottom plate (1), the tripod bracket (7) is fixed on the top of the second base (6), the scanning vacuum assembly (8) is fixed on the tripod bracket (7), and the scanning vacuum assembly (8) is connected to the main vacuum assembly (5) through a bellows; The main vacuum assembly (5) comprises a support plate (9), a main vacuum chamber (10), a displacement assembly (4), a first motion adjustment mechanism (11), a second motion adjustment mechanism (12), a third motion adjustment mechanism (13), an optical element (14), a substrate (15), a support frame (16) and a pupil monitor (17), wherein the support plate (9) is fixed above the mounting bracket (3), the main vacuum chamber (10) is fixed on the support plate (9), the bottom of the support plate (9) is connected to the first base (2) via the mounting bracket (3), and the substrate ( 15) is located inside the main vacuum chamber (10), and its bottom is fixed to the first base (2) through a displacement assembly (4), the pupil monitor (17) is fixed to the support frame (16), and the support frame (16) is connected to the first base (2), a through hole is provided in the middle of the base (15), and the through hole is used for the pupil monitor (17) to monitor the light beam line, and the first motion adjustment mechanism (11), the second motion adjustment mechanism (12), the third motion adjustment mechanism (13) and the optical element (14) are all fixed on the base (15); The displacement assembly (4) comprises a third base (18), a Z-axis displacement stage (19) and a fixed support (20), wherein the bottom of the third base (18) is connected to the first base (2) via the Z-axis displacement stage (19), the bottom of the fixed support (20) is fixed to the third base (18), the top of the fixed support (20) passes through the support plate (9), the main vacuum chamber (10) and the base plate (15), and the connection between the fixed support (20) and the main vacuum chamber (10) is sealed by a bellows; The scanning vacuum assembly (8) comprises: A scanning vacuum chamber (21), the scanning vacuum chamber (21) being connected to the main vacuum chamber (10) via a bellows, and the scanning vacuum chamber (21) being fixed on a tripod support (7); a fourth motion regulating mechanism (22), the fourth motion regulating mechanism (22) being fixed inside the scanning vacuum chamber (21); A detector (23), the detector (23) being mounted above the scanning vacuum chamber (21) and located at an image plane of the imaging system, and being used to record imaging conditions; A beam position monitor (26), the beam position monitor (26) being installed at the entrance of the beam station and used to monitor the beam entry situation and the relative position of the light spot; A beam incident angle monitor (25) is provided on one side of the main vacuum chamber (10) and is used to assist in system adjustment; A vacuum valve (24) is installed at the entrance of the light beam station and is used to isolate the cavity from the light source to prevent the repeated charging and discharging process of the cavity vacuum during the installation and commissioning of the microscopic imaging system from affecting the working environment of the light source.

2. The EUV mask defect detection device according to claim 1, wherein: There are three fixed pillars (20), and the three fixed pillars (20) are distributed in a triangular shape between the third base (18) and the support plate (9).

3. The EUV mask defect detection device according to claim 1, wherein: The system further comprises a vacuum pump (27), which is fixed on the first base (2) and is used to maintain the vacuum degree in the main vacuum chamber (10) and the scanning vacuum chamber (21) at 10 -7 Below torr level.

4. The EUV mask defect detection device according to claim 3, wherein: The first motion regulating mechanism (11), the second motion regulating mechanism (12), the third motion regulating mechanism (13) and the fourth motion regulating mechanism (22) are all piezoelectric nano displacement stages.

5. The EUV mask defect detection device according to claim 1, wherein: The detector (23) is an EUV-sensitive camera, and is one of CCD and sCMOS.

6. The EUV mask defect detection device according to claim 5, characterized in that: The beam incident angle monitor (25) includes a YAG crystal and a camera.

7. The EUV mask defect detection device according to claim 6, characterized in that: The first base (2), the second base (6) and the third base (18) are all marble bases.

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