EUV mask defect detection device

Abstract

The invention discloses an EUV mask defect detection device, which comprises a bottom plate, a first base, a mounting bracket, a displacement assembly and a main vacuum assembly, the first base is fixed on the bottom plate, the mounting bracket is fixed on the top of the first base, the main vacuum assembly is fixed on the top of the mounting bracket, and the displacement assembly is fixed on the bottom plate. The bottom of the main vacuum assembly is connected with the first base through a displacement assembly, and the displacement assembly is used for adjusting the Z-direction position of the main vacuum assembly. The device further comprises a second base, a triangular support and a scanning vacuum assembly, the second base is fixed to the bottom plate, the triangular support is fixed to the top of the second base, the scanning vacuum assembly is fixed to the triangular support, and the scanning vacuum assembly is connected with the main vacuum assembly through a corrugated pipe. According to the invention, the scanning vacuum cavity is separated from the main vacuum cavity, rigid connection is avoided by using the corrugated pipe, and the problem that the imaging quality is influenced by vibration caused by scanning in the exposure process is solved.

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 an important step for lithography technology to move towards smaller process nodes such as 7nm and 5nm. EUV mask defect detection is a key step in the lithography process to improve chip production yield and reduce production costs. The EUV mask is mainly composed of a Mo / Si multilayer reflective layer and an absorption layer, so the types of EUV mask defects mainly include absorption defects on the surface of the multilayer and phase defects buried inside the multilayer. Since the penetration depth of non-actinic (DUV, SEM) mask detection on EUV multilayers is limited, the phase defects buried inside the multilayer are difficult to detect, which easily leads to missed defects. In addition, the absorption coefficients of mask particles or contaminants for different wavelengths are also different, and the use of non-actinic is prone to pseudo-defects. Therefore, the use of EUV light is the only reliable way to understand the physical response of defects, repairs, pattern deviations and optical proximity correction. However, EUV has the property of high absorption coefficients for almost all substances, so the use of EUV light for mask detection must provide a vacuum working environment for the imaging system. This puts forward higher requirements for the cavity and motion adjustment mechanism in engineering design. In addition, for high-magnification, nanometer-scale imaging, mechanical stability at exposure times in the order of seconds is the most important factor for the successful implementation of EUV mask microscopy. Specifically, the EUV mask defect imaging system requires that the relative motion of the mask and imaging lens be maintained at the nanometer level during exposure. Therefore, to achieve stable EUV mask defect detection in a complex environment, the overall mechanical design should focus on the vacuum vibration isolation of the mask and imaging lens.

[0003] At present, although AIMS, SHARP and lasertec and other EUV mask defect detection devices have been commercialized. Their engineering design can not only meet the necessary modulation requirements, but also can be used in factories with complex and diverse environments. Since different detection devices have different corresponding optical solutions, different optical design solutions have different specific parameter requirements for mechanical design, that is, each mechanical design has its customized nature. To this end, we propose an EUV mask defect detection 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 object, the present invention provides the following technical solution: an EUV mask defect detection device, comprising a bottom plate, a first base, a mounting bracket and a main vacuum assembly, wherein the first base is fixed to the bottom 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, wherein 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, 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 table and a fixed pillar, the bottom of the third base is connected to the first base through the Z-axis displacement table, the bottom of the fixed pillar is fixed to the third base, the top of the fixed pillar passes through the support plate, the main vacuum chamber and the substrate, and the connection between the fixed pillar and the main vacuum chamber is sealed by a bellows.

[0009] Preferably, three fixed pillars are provided, 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 the system installation and adjustment; a vacuum valve, which is installed at the entrance of the beam station and is used to isolate the cavity from the light source when necessary, so as to prevent the repeated charging 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.

[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 preventing the surrounding environmental factors from causing a resonance effect on the chamber. The rigid connection transmits vibration to the base, the first motion adjustment mechanism, the second motion adjustment mechanism, the third motion adjustment mechanism, and the fourth motion adjustment mechanism, thereby affecting the stability of EUV mask microscopic imaging.

[0020] (3) Use laser interferometer and 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 to maintain the relative motion between the objective lens and the mask at the nanometer level during exposure.

[0021] 2. Regarding the design of pupil monitor, the advantages of placing 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 and achieve diversification in the selection of microscopes;

[0024] (3) A motion adjustment mechanism that adapts to the vacuum chamber needs to be installed inside the vacuum chamber and needs to move together with the mask platform. Separating the pupil monitor reduces the requirements on 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 principal 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 principal ray incident angle is set. Therefore, the control and monitoring of the principal 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 It is a schematic diagram of the structure of the displacement assembly 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 This is a 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. Bottom 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 support; 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 be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0034] The present invention provides a technical solution: an EUV mask defect detection device, comprising a bottom plate 1, a first base 2, a mounting bracket 3 and a main vacuum component 5, wherein the first base 2 is fixed on the bottom plate 1, the bottom plate 1 provides a rigid platform for an EUV mask detection microscopic imaging device, the mounting bracket 3 is fixed on the top of the first base 2, and the main vacuum component 5 is fixed on 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, 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 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, 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, 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, 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 substrate 15.

[0037] The optical components include aperture, condenser, objective lens and mask, etc., and the size is 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 microscopic 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 adjustment.

[0041] As a preferred embodiment, the displacement assembly 4 includes a third base 18, a Z-axis displacement table 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 table 19, the bottom of the fixed pillar 20 is fixed to 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, and 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 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 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 station 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 the system installation and 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 charging 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 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 inspection equipment.

[0047] As a preferred implementation, 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, the beam incident angle monitor 25 is arranged on one side of the main vacuum chamber 10, and is composed of a window, a YAG crystal and a camera, and is used to assist the system in adjustment. The incident angle of the incoming beam line, as well as the positions of the reflector and the mask field of view are known. If the beam line passes through the scanning mirror and the mask, and finally a light spot is detected at the beam incident angle monitor 25, it means that the incident angle of the main ray of the beam line at the mask is incident at the angle designed by us.

[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] For EUV mask defect inspection devices, in addition to the differences in control aspects corresponding to different optical designs, similarities include: vacuum environment, vibration isolation, etc. In addition, pupil monitoring systems and auxiliary adjustment systems are additionally designed for the device.

[0053] Vacuum extraction and maintenance:

[0054] First, use a mechanical pump to evacuate the air in the cavity to a certain extent, and 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 by air chamber, but use bellows to avoid rigid connection, which solves the problem of vibration caused by scanning during exposure, affecting the imaging quality;

[0057] 2. The main vacuum chamber 10 is connected to the base inside the chamber through a bellows to avoid rigid connection, which solves the problem that the surrounding environmental factors may produce resonance effects on the chamber. The rigid connection transmits vibration 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, etc., which affects the stability of EUV mask microscopic imaging;

[0058] 3. Use laser interferometer and 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 enough control space for the microscope to diversify the selection of microscopes;

[0062] 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 on 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] 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 at different incident angles, especially at large angles 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, the incident light cone and the reflected light cone are guaranteed not to overlap, and a minimum main ray incident angle is set. Therefore, the control and monitoring of the main ray incident angle is particularly important.

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

[0066] Taking the center of the mask as the reference, the relative position and posture of the scanning mirror are adjusted to control the incident angle of the main ray of the light beam on the mask. The corresponding light beam is reflected by the mask and emitted from the light beam incident angle monitor 25. Multiple points are preset at the light beam incident angle monitor 25, corresponding to the specific main ray incident angle of the light beam at the mask. It is only necessary to adjust the relative position and posture of the scanning mirror until the corresponding light spot is detected at the light beam incident angle monitor 25.

[0067] Compared with the traditional calibration method, this method does not require the use of a rangefinder for measurement, and 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 the locator, the camera and locator extrinsic parameters, and the locator origin and screen offset can be solved simultaneously.

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

[0069] Although 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 the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An EUV mask defect detection device, characterized in that: The vacuum pump comprises a bottom plate (1), a first base (2), a mounting bracket (3) and a main vacuum component (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 component (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 component (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 component (8) is fixed on the tripod bracket (7), and the scanning vacuum component (8) is connected to the main vacuum component (5) via a bellows.

2. The EUV mask defect detection device according to claim 1, characterized in that: 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 fixed to the first base (2) via the mounting bracket (3). 5) 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 a 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, 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 substrate (15).

3. The EUV mask defect detection device according to claim 2, characterized in that: The displacement assembly (4) comprises a third base (18), a Z-axis displacement stage (19) and a fixed support (20); 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 is connected to the substrate (15); the connection between the fixed support (20) and the main vacuum chamber (10) is sealed by a bellows.

4. The EUV mask defect detection device according to claim 3, characterized in that: The fixed pillars (20) are provided in three numbers, and the three fixed pillars (20) are distributed in a "triangle" shape between the third base (18) and the support plate (9).

5. The EUV mask defect detection device according to claim 4, characterized in that: The scanning vacuum assembly (8) comprises: A scanning vacuum chamber (21), wherein the scanning vacuum chamber (21) is connected to the main vacuum chamber (10) via a bellows, and the scanning vacuum chamber (21) is fixed on a tripod bracket (7); A fourth motion adjustment mechanism (22), wherein the fourth motion adjustment mechanism (22) is fixed inside the scanning vacuum chamber (21); A detector (23), the detector (23) being installed 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), which is installed at the entrance of the beam station and is used to monitor the beam station entry situation and the relative position of the light spot; A light beam incident angle monitor (25) is arranged on one side of the main vacuum chamber (10) and is used to assist in system adjustment; The vacuum valve (24) is installed at the entrance of the light 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 commissioning of the microscopic imaging system from affecting the working environment of the light source.

6. The EUV mask defect detection device according to claim 5, characterized in that: The invention also comprises a vacuum pump (27), wherein 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 torr level.

7. The EUV mask defect detection device according to claim 6, characterized in that: 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.

8. The EUV mask defect detection device according to claim 5, characterized in that: The detector (23) is an EUV sensitive camera, and is one of CCD, sCMOS and MCP.

9. The EUV mask defect detection device according to claim 8, characterized in that: The light beam incident angle monitor (25) is composed of an open window, a YAG crystal and a camera.

10. The EUV mask defect detection device according to claim 9, characterized in that: The first base (2), the second base (6) and the third base (18) are all marble bases.

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