Detection system and detection method of EUV photomask and storage medium

Abstract

The invention provides a detection system and a detection method of an EUV photomask and a storage medium. The detection system comprises an EUV light source used for providing a first light beam of an EUV wave band; the detection platform comprises a reflection unit, a translation platform and a detection detector, and the reflection unit is used for enabling the first light beam to irradiate a sample to be detected according to a preset incident angle. The translation stage is used for bearing the to-be-detected sample and moving at least one to-be-detected area of the to-be-detected sample to an irradiation area of the first light beam so as to generate a reflected second light beam and / or a transmitted third light beam, and the detection detector is arranged on a transmission path of the second light beam and / or the third light beam. Collecting the second light beam and / or the third light beam; and the processor is configured to determine the reflectivity, the transmittance, the granularity and / or the surface defect of the sample to be detected according to the light intensity information, the image information and / or the spectral information of the second light beam and / or the third light beam.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor processing, and in particular to a detection system for EUV masks, a detection method for EUV masks, and a computer-readable storage medium. Background Art

[0002] As the semiconductor processing technology nodes are gradually reduced, the requirements for the image resolution and the like of the corresponding lithography equipment in the process processing are also gradually increased, so that the central wavelength of the light source used in the lithography equipment has reached the extreme ultraviolet (EUV) band of 10-14 nm. Since the EUV light source has the characteristics of easy loss and short wavelength, it needs to be equipped with an EUV mask and a reflective optical system for use. However, the reflective optical system has very high requirements for precision, which means that the EUV mask not only needs to have a high reflectivity, but also has very high requirements for its defects, surface contamination, etc. Considering the high processing cost of the EUV mask, most of the existing technologies add an EUV mask pellicle at a certain distance from the surface of the EUV mask, but this also puts very high requirements on the reflectivity, defect rate and cleanliness of the EUV light protection film.

[0003] At present, the main methods in this field for detecting EUV masks and / or EUV mask pellicles are electron beams, electron microscopes, and deep ultra-violet (DUV) light source devices. However, the detection speed using electron beams or electron microscopes is extremely low, and the conventional detection time for each sample needs to be calculated in days. In addition, since the central wavelength of the DUV light source (170-200 nm) is one order of magnitude longer than that of EUV, its resolution is much lower than the actual requirements for EUV mask detection. Therefore, when using a DUV light source device to detect an EUV mask, very complex imaging algorithms are usually required to improve the resolution, resulting in a reduction in detection efficiency. In addition, since the detection band of the DUV light source device does not match the actual use band of the sample to be measured in the EUV lithography machine, its detection result is also difficult to reflect the state of the sample to be measured under actual working conditions, so there are defects of low detection accuracy and reliability.

[0004] In order to overcome the above-mentioned defects existing in the prior art, there is an urgent need in this field for a detection system for EUV masks, which is used to improve the resolution and detection efficiency of the light intensity information, image information and / or spectral information of EUV masks and / or EUV mask pellicles, and more truly reflect the state of the sample to be measured under the actual working conditions in the EUV lithography machine. Summary of the Invention

[0005] A brief overview of one or more aspects is given below to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects and is neither intended to identify key or decisive elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that follows.

[0006] To overcome the above-mentioned defects existing in the prior art, the present invention provides a detection system for EUV masks, a detection method for EUV masks, and a computer-readable storage medium, which can improve the resolution and detection efficiency of the intensity information, image information, and / or spectral information of EUV masks and / or EUV mask protective films by configuring an EUV light source in the EUV band, a reflection unit for adjusting the incident angle of the first beam, and a detection detector for real-time collecting the intensity information, image information, and / or spectral information of the second beam reflected by the sample to be measured and / or the third beam transmitted, and more truly reflect the state of the sample to be measured under the actual working conditions in the EUV lithography machine.

[0007] Specifically, the detection system for EUV masks provided by the first aspect of the present invention includes an EUV light source, a detection platform, and a processor. The EUV light source is used to provide a first beam in the EUV band. The detection platform includes a reflection unit, a translation stage, and a detection detector. The reflection unit is used to irradiate the sample to be measured with the first beam at a preset incident angle. The translation stage is used to carry the sample to be measured and move at least one area to be measured of it to the irradiation area of the first beam to generate a reflected second beam and / or a transmitted third beam. The detection detector is arranged on the transmission path of the second beam and / or the third beam to collect the second beam and / or the third beam. The processor is configured to: determine the reflectivity, transmittance, granularity, and / or surface defects of the sample to be measured according to the intensity information, image information, and / or spectral information of the second beam and / or the third beam.

[0008] Further, in some embodiments of the present invention, the EUV light source includes a laser, a VIS cavity, a compression cavity, and a focusing cavity. The laser is used to provide an initial beam in the near-infrared band. The VIS cavity is arranged after the VIS cavity and is used to broaden and / or frequency-double the initial beam. The compression cavity is arranged after the VIS cavity and is used to compress the laser pulse of the initial beam to concentrate its energy, and then hit it on a gas and / or solid medium to generate an internal beam in the EUV band. The focusing cavity is arranged after the compression cavity and is used to shape and / or focus the internal beam in the EUV band to provide the first beam in the EUV band to the detection platform.

[0009] Further, in some embodiments of the present invention, the detection detector includes a first detector for collecting image information and / or spectral information. The first detector is disposed on the transmission path of the second light beam. During the process of performing particle size detection and / or surface defect detection on the sample to be measured, the translation stage sequentially moves multiple regions to be measured of the sample to be measured to the irradiation region of the first light beam, so that the first detector can collect the image information and / or spectral information in the second light beam. The processor is further configured to: determine the particle size and / or surface defects on the surface of the sample to be measured according to the image information and / or spectral information corresponding to each region to be measured.

[0010] Further, in some embodiments of the present invention, a first standard sample is further included. Before performing the particle size detection and / or the surface defect detection on the sample to be measured, the translation stage also carries the first standard sample and sequentially moves multiple first standard regions of the first standard sample to the irradiation region of the first light beam, so that the first detector can collect the image information and / or spectral information in the second light beam. The processor is further configured to: determine the correction coefficient of the output signal of the first detector according to the image information and / or spectral information corresponding to each first standard region.

[0011] Further, in some embodiments of the present invention, a reference light module is further included. The reference light module is disposed between the EUV light source and the detection platform and includes a beam splitting unit and a reference detector. The beam splitting unit is disposed at the rear end of the EUV light source and is used to separate a part of the fourth light beam from the first light beam output by the EUV light source, transmit the fourth light beam to the reference detector to generate reference light information, and monitor the quality of the first light beam output by the EUV light source according to the reference light information.

[0012] Further, in some embodiments of the present invention, the detection detector includes a second detector and a third detector for collecting light intensity information. The second detector is disposed on the transmission path of the second light beam. The third detector is disposed on the transmission path of the third light beam. During the process of detecting the reflectivity and / or transmittance of the sample to be measured, the translation stage sequentially moves multiple regions to be measured of the sample to be measured to the irradiation region of the first light beam, so that the second detector collects the first light intensity information of the second light beam, and the third detector collects the second light intensity information of the third light beam. The processor is further configured to: determine the reflectivity of each region to be measured of the sample to be measured according to the third light intensity information of the fourth light beam collected by the reference detector and the first light intensity information corresponding to each region to be measured; and determine the transmittance of each region to be measured of the sample to be measured according to the third light intensity information and the second light intensity information corresponding to each region to be measured.

[0013] Further, in some embodiments of the present invention, a second standard sample is further included. Before detecting the reflectivity and / or transmittance of the sample to be measured, the translation stage also carries the second standard sample, first moves the through-hole region on the second standard sample to the irradiation region of the first light beam, so that the third detector collects the fourth light intensity information of the third light beam, and then moves the second standard region on the second standard sample to the irradiation region of the first light beam, so that the second detector collects the fifth light intensity information of the second light beam. The processor is further configured to: determine the first proportional relationship between the fourth light beam and the third light beam according to the third light intensity information and the fourth light intensity information; determine the second proportional relationship between the fourth light beam and the second light beam according to the third light intensity information and the fifth light intensity information; and determine the third proportional relationship between the first light beam and the fourth light beam according to the mean value of the first proportional relationship and the second proportional relationship.

[0014] Further, in some embodiments of the present invention, the processor is further configured to: determine the sixth light intensity information of the first light beam according to the third light intensity information and the third proportional relationship; determine the reflectivity of each region to be measured of the sample to be measured according to the sixth light intensity information and the first light intensity information corresponding to each region to be measured; and determine the transmittance of each region to be measured of the sample to be measured according to the sixth light intensity information and the second light intensity information corresponding to each region to be measured.

[0015] Further, in some embodiments of the present invention, the translation stage includes at least two carrying positions. The first carrying position carries the sample to be measured, while the second carrying position carries the second standard sample. Each time the translation stage completes the detection of a preset number of measurement regions on the sample to be measured, it moves the through-hole region and the second standard region on the second standard sample to the irradiation region of the first light beam in sequence once, so that the processor can verify the third proportional relationship between the first light beam and the fourth light beam.

[0016] Further, in some embodiments of the present invention, the detection platform further includes a fixing unit and / or an alignment unit. The fixing unit is disposed on the translation stage to fix the sample to be measured carried thereon. The alignment unit is used to accurately identify the position of the sample to be measured before and / or during the detection of the sample to be measured.

[0017] Further, in some embodiments of the present invention, the detection platform further includes a gate valve, a sampling chamber, a first isolation valve, a buffer chamber, a second isolation valve, and a discharging chamber. The reflection unit, the translation stage, and the detection detector are disposed in the sampling chamber. The sampling chamber is connected to the EUV light source or the reference light module at the front end via the gate valve and maintains a vacuum state during the detection of the sample to be measured. The discharging chamber is located at the rear end of the sampling chamber and has a discharging port for interacting with the external environment and maintains an atmospheric pressure state during the placement of the sample to be measured. The buffer chamber is connected to the sampling chamber via the first isolation valve and connected to the discharging chamber via the second isolation valve, and is used to realize the transmission of the sample to be measured and the air pressure conversion between the sampling chamber and the discharging chamber.

[0018] Further, in some embodiments of the present invention, a microenvironment control module is further included. The microenvironment control module includes an air box, a vacuum control mechanism, and a filtering unit, and is used to pump the air pressure in the buffer chamber to the vacuum state of the sampling chamber after obtaining the sample to be measured from the discharging chamber, and to introduce filtered clean gas into the buffer chamber after obtaining the sample to be measured that has completed the detection from the sampling chamber, so as to fill the air pressure in the buffer chamber to the atmospheric pressure state of the discharging chamber.

[0019] Further, in some embodiments of the present invention, an outer protection module is further included. The outer protection module includes an outer protection panel, a system outer frame, and a plurality of safety interlocks. Among them, the plurality of safety interlocks are disposed inside the outer protection panel and are used to cut off the dangerous components in the detection system when the outer protection panel is opened.

[0020] Further, in some embodiments of the present invention, the outer protection module further includes a sensor assembly and / or a signal lamp and / or an emergency stop button. The sensor assembly includes a smoke sensor and / or a leak-proof liquid sensor. The signal lamp is used to provide a light signal indicating the operating state of the detection system. The emergency stop button is used to urgently cut off the power supply of the detection system or dangerous components therein.

[0021] Further, in some embodiments of the present invention, an operation interaction module is further included. The operation interaction module is nested in the outer protection panel of the outer protection module and is used to receive detection instructions provided by the user and control the operation of each module in the detection system according to the detection instructions.

[0022] Further, in some embodiments of the present invention, the detection platform further includes a vibration isolation base. The vibration isolation base includes a marble platform, a vibration isolation unit, and a bottom frame, and is used to carry the detection components in the detection platform and isolate external vibration interference.

[0023] Further, in some embodiments of the present invention, a communication control module is further included. The communication control module is installed between the marble platform and the bottom frame and includes a main control computer and a communication unit to achieve communication control between the detection system and external devices.

[0024] Further, in some embodiments of the present invention, a power supply and distribution module is further included. The power supply and distribution module is installed inside the bottom frame and includes a main power distribution box and multiple subsystem power distribution boxes. The main power distribution box is used to supply power to each of the subsystem power distribution boxes. The first subsystem power distribution box is used to supply power to the EUV light source. The second subsystem power distribution box is used to supply power to the detection platform. The third subsystem power distribution box is used to supply power to other modules in the detection system.

[0025] Further, in some embodiments of the present invention, the sample to be tested includes an EUV photomask blank, an EUV photomask bare board, an EUV photomask protective film for EUV lithography process, or an EUV photomask assembly composed of the EUV photomask bare board and the EUV photomask protective film.

[0026] In addition, the above-mentioned EUV mask detection method provided according to the second aspect of the present invention includes the following steps: placing a sample to be measured into the EUV mask detection system provided according to the first aspect of the present invention; providing a first beam in the EUV band to the sample to be measured via the EUV light source of the detection system; acquiring a second beam reflected and / or a third beam transmitted by at least one area to be measured of the sample to be measured via the detection platform of the detection system; and determining the reflectivity, transmittance, granularity, and / or surface defects of the sample to be measured according to the light intensity information, image information, and / or spectral information of the second beam and / or the third beam via the processor of the detection system.

[0027] In addition, the above-mentioned computer-readable storage medium provided according to the third aspect of the present invention stores computer instructions. When the computer instructions are executed by a processor, the EUV mask detection method provided according to the second aspect of the present invention is implemented. Description of the Drawings

[0028] After reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings, the above features and advantages of the present invention can be better understood. In the drawings, the components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0029] Figure 1 The schematic architecture diagram of the EUV mask detection system provided according to some embodiments of the present invention is shown.

[0030] Figure 2 The schematic structural diagram of the EUV mask detection system provided according to some embodiments of the present invention is shown.

[0031] Figure 3 And Figure 4 The schematic structural diagram of the sampling chamber provided according to some embodiments of the present invention is shown.

[0032] Figure 5 The three-dimensional structural diagram of the EUV mask detection system provided according to some embodiments of the present invention is shown.

[0033] Figure 6 The schematic structural diagram of the outer protection module provided according to some embodiments of the present invention is shown.

[0034] Figure 7 The schematic flow diagram of the EUV mask detection method provided according to the second aspect of the present invention is shown. Detailed Description of the Embodiments

[0035] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be introduced in combination with preferred embodiments, this does not mean that the features of this invention are limited to this implementation manner. On the contrary, the purpose of introducing the invention in combination with the implementation manner is to cover other alternatives or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without using these details. In addition, in order to avoid confusing or obscuring the key points of the present invention, some specific details will be omitted in the description.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] In addition, the "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the orientations shown in this paragraph and the related drawings. This relative term is only for convenience of description and does not mean that the device described needs to be manufactured or operated in a specific orientation. Therefore, it should not be understood as a limitation to the present invention.

[0038] It can be understood that although terms such as "first", "second", "third" etc. can be used here to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below can be referred to as the second component, region, layer and / or part without departing from some embodiments of the present invention.

[0039] As described above, currently in this field, electron beams, electron microscopes, and DUV light source devices are mainly used to detect EUV photomasks and / or EUV photomask protective films. However, the detection speed using electron beams or electron microscopes is extremely low, and the conventional detection time for each sample needs to be calculated in days. In addition, since the central wavelength of the DUV light source is one order of magnitude longer than that of EUV, its resolution is much lower than the actual requirements for EUV photomask detection. Therefore, when using a DUV light source device to detect an EUV photomask, very complex imaging algorithms are usually required to improve the resolution, resulting in a reduction in detection efficiency. In addition, since the detection wavelength band of the DUV light source device does not match the actual use wavelength band of the sample to be measured in the EUV lithography machine, its detection results are also difficult to reflect the state of the sample to be measured under actual working conditions, thus having the defects of low detection accuracy and reliability.

[0040] To overcome the above-mentioned defects existing in the prior art, the present invention provides a detection system for EUV photomasks, a detection method for EUV photomasks, and a computer-readable storage medium, which can improve the resolution and detection efficiency of the light intensity information, image information, and / or spectral information of EUV photomasks and / or EUV photomask protective films by configuring an EUV light source in the EUV wavelength band, a reflection unit for adjusting the incident angle of the first light beam, and a detection detector that can collect the light intensity information, image information, and / or spectral information of the second light beam reflected and / or the third light beam transmitted by the sample to be measured in real time, and more truly reflect the state of the sample to be measured under actual working conditions in the EUV lithography machine.

[0041] In some non-limiting embodiments, the above-mentioned detection method for EUV photomasks provided in the second aspect of the present invention can be implemented based on the above-mentioned detection system for EUV photomasks provided in the first aspect of the present invention. Specifically, the detection system for EUV photomasks can be configured with a memory and a processor. The memory includes but is not limited to the above-mentioned computer-readable storage medium provided in the third aspect of the present invention, on which computer instructions are stored. The processor is connected to the memory and is configured to execute the computer instructions stored on the memory to implement the above-mentioned detection method for EUV photomasks provided in the first aspect of the present invention.

[0042] First, please refer to Figures 1 to 4 . Figure 1 shows a schematic diagram of the architecture of a detection system for EUV photomasks provided in some embodiments of the present invention. Figure 2 shows a schematic diagram of the internal structure of a detection system for EUV photomasks provided in some embodiments of the present invention. Figure 3 and Figure 4 shows a schematic diagram of the structure of a sampling chamber provided in some embodiments of the present invention.

[0043] As Figure 1As shown, the detection system of the EUV photomask provided by the first aspect of the present invention includes an EUV light source 11, a detection platform 12, and a processor 13. Here, the EUV light source 11 can select light sources such as LPP (Laser Produced Plasma), DPP (Discharge Produced Plasma), HHG (High Harmonic Generation), etc., to provide an input beam I in the EUV band in . The detection platform 12 may include a gate valve 121, a sampling chamber 122, a first isolation valve 123, a buffer chamber 124, a second isolation valve 125, and a discharge chamber 126. Here, the sampling chamber 122 is connected to the front-end EUV light source 11 or the reference light module 14 via the gate valve 121, and maintains the pressure in the chamber below 10e -5 Torr in a vacuum state during the detection of the sample to be measured. The discharge chamber 126 is located at the rear end of the sampling chamber 122, has a discharge port for interacting with the external environment, and maintains the pressure in the chamber at about 1 atm in an atmospheric pressure state during the placement of the sample to be measured. The buffer chamber 124 is connected to the sampling chamber 122 via the first isolation valve 123 and is connected to the discharge chamber 126 via the second isolation valve 125, and is used to realize the transmission of the sample to be measured and the air pressure conversion between the sampling chamber 122 and the discharge chamber 126. The processor 13 is configured with software and algorithm units, and is configured to determine the reflectivity, transmittance, granularity, and / or surface defects of the sample to be measured according to the intensity information, image information, and / or spectral information of the reflected beam I R and / or the transmitted beam I T collected by the sampling chamber 122

[0044] Furthermore, as Figure 2 shown, the EUV light source 11 may include a laser 111, a visible light (VIS) chamber 112, a compression chamber 113, and a focusing chamber 114. Here, the laser 111 is used to provide an initial beam in the near-infrared band (for example: 800 nm, 1030 nm, 1060 nm). The VIS chamber 112 can be arranged after the laser 111 in the scenario where the initial beam energy is insufficient, and is used to broaden and / or double-frequency the initial beam. The compression chamber 113 is arranged after the laser 111 or the VIS chamber 112, and is used to compress the laser pulse of the initial beam to concentrate its energy, and then hit it on the gas and / or solid medium to generate an internal beam in the EUV band. The focusing chamber 114 is arranged after the gas or solid medium of the compression chamber 113, and is used to shape and / or focus the internal beam in the EUV band to provide an input beam I in the EUV band to the detection platform 12 in .

[0045] In addition, as Figure 3 andFigure 4 As shown, the sampling chamber 122 of the detection platform 12 may include a reflection unit 1221, a translation stage 1222, and detection detectors 1223 to 1225. Herein, the reflection unit 1221 is used to adjust the angle of the input beam I in irradiating the sample to be measured 31, for example, to make the input beam I in irradiate the sample to be measured 31 at the same incident angle as that of the EUV lithography machine, so as to simulate the actual working conditions of the sample to be measured 31 such as EUV mask blanks, EUV mask bare boards, EUV mask protective films, or EUV mask assemblies composed of a combination of EUV mask bare boards and EUV mask protective films in the EUV lithography machine. The translation stage 1222 may preferably be configured with fixing units 1226 such as vacuum chucks, electrostatic chucks, clamping parts, etc., for carrying and fixing standard samples and / or samples to be measured 31, and moving at least one area to be measured thereof to the irradiation area of the input beam I in to generate a reflected beam I R and / or a transmitted beam I T . The detection detectors 1223 to 1225 include a first detector 1223 for collecting image information and / or spectral information, and a second detector 1224 and a third detector 1225 for collecting light intensity information. Among them, the first detector 1223 and the second detector 1224 are arranged on the transmission path of the reflected beam I R to collect the light intensity information, image information and / or spectral information in the reflected beam I R , and the third detector 1225 is arranged on the transmission path of the transmitted beam I T to collect the light intensity information in the transmitted beam I T .

[0046] Furthermore, in some embodiments, the detection platform 12 may preferably further include an alignment unit for accurately identifying the position of the sample to be measured 31 before and / or during the detection of the sample to be measured 31.

[0047] In addition, in Figure 1 , Figure 2 and Figure 4 shown in the embodiments, the detection system of the EUV mask may further include a reference light module 14. The reference light module 14 is arranged between the EUV light source 11 and the detection platform 12, and includes a beam splitting unit 141 and a reference detector 142. Herein, the beam splitting unit 141 may be a beam splitting lens or a grating, which is arranged at the rear end of the EUV light source 11 for separating a part of the reference beam I in from the input beam I ref provided by the EUV light source 11, and transmitting the reference beam I refTransmitted to the reference detector 142 to generate reference optical information. In this way, the reference optical module 14 can monitor the input beam I provided by the EUV light source 11 according to signals such as the collected light intensity distribution, spot size, spot position stability, and light intensity stability. in Whether the quality of the input beam I meets the standard, and provide a reference for subsequent reflectivity detection and / or transmittance detection.

[0048] In addition, please refer to Figure 1 , Figure 2 , Figure 5 and Figure 6 . Figure 5 Fig. shows a schematic three-dimensional structure diagram of a detection system for EUV photomasks according to some embodiments of the present invention. Figure 6 Fig. shows a schematic structure diagram of an outer protection module according to some embodiments of the present invention.

[0049] In Figure 1 , Figure 2 , Figure 5 and Figure 6 In the embodiments shown, the detection system for EUV photomasks provided in the first aspect of the present invention may further include a microenvironment control module 15. The microenvironment control module 15 includes an air box 151, a vacuum control mechanism 152, and a fan filter unit (FFU) 153. After obtaining the sample to be tested 31 from the loading chamber 126, the air pressure in the buffer chamber 124 is pumped to the vacuum state of the sampling chamber 122 (e.g., 10e -5 Torr), and after obtaining the sample to be tested 31 that has completed the detection from the sampling chamber 122, filtered compressed dry air (CDA) is introduced into the buffer chamber 124 to fill the air pressure in the buffer chamber 124 to the normal pressure state of the loading chamber 126 (e.g., 1 atm).

[0050] In addition, as Figure 5 shown, the detection platform 12 may further include a vibration isolation base. The vibration isolation base includes a marble platform 51, a vibration isolation unit 52, a bottom frame 53, and leveling pads 54, and is used to carry various precision detection components in the detection platform 12 and isolate external vibration interference.

[0051] In addition, as Figure 1 and Figure 5 shown, the detection system for EUV photomasks provided in the first aspect of the present invention may further include a communication control module 16. The communication control module 16 is installed between the marble platform 51 and the bottom frame 53, and includes a main control computer and a communication unit to realize the communication control between the detection system and external devices.

[0052] In addition, asFigure 1 and Figure 5 As shown in Figure 5 , the detection system for the EUV photomask provided in the first aspect of the present invention may further include a power supply and distribution module 17. The power supply and distribution module 17 is installed inside the bottom frame 53 and includes a main distribution box 171 and a plurality of subsystem distribution boxes 172-174. Here, the main distribution box 171 is used to supply power to each of the subsystem distribution boxes 172-174. The first subsystem distribution box 172 is used to supply power to the EUV light source 11. The second subsystem distribution box 173 is used to supply power to the detection platform 12. The third subsystem distribution box 174 is used to supply power to other modules such as the processor 13, the reference light module 14, the microenvironment control module 15, the communication control module 16, and the outer protection module 18 in the detection system.

[0053] In addition, in Figure 1 and Figure 6 As shown in the embodiment of Figure 6 , the detection system for the EUV photomask provided in the first aspect of the present invention may further include an outer protection module 18. The outer protection module 18 includes an outer protection panel 181, a system outer frame 182, and a plurality of safety interconnection locks. Here, the plurality of safety interconnection locks may be provided inside the outer protection panel 181 and are used to cut off dangerous components such as the laser 111 and the detection platform 12 in the detection system when the outer protection panel 181 is opened, so as to protect the detection system and the personal safety of users.

[0054] Furthermore, in some embodiments, the outer protection module 18 may further include a sensor assembly, a signal lamp 183, and / or an emergency stop button 184. The sensor assembly includes a smoke sensor and / or a leak-proof liquid sensor. The signal lamp 183 is used to provide a light signal indicating the operating state of the detection system. The emergency stop button 184 is used to emergently cut off the power supply of the detection system or the dangerous components therein to ensure the safety of users and equipment.

[0055] In addition, in Figure 1 and Figure 6 As shown in the embodiment of Figure 6 , the detection system for the EUV photomask provided in the first aspect of the present invention may further include an operation interaction module 19. The operation interaction module 19 may be nested in the outer protection panel 181 of the outer protection module 18 and is used to receive detection instructions provided by users and control the operation of each module in the detection system according to the detection instructions.

[0056] The working principles of the above EUV mask detection system and the processor 13 will be described below in conjunction with some embodiments of the EUV mask detection methods. Those skilled in the art can understand that these embodiments of the detection methods are only some non-restrictive implementation manners provided by the present invention, aiming to clearly show the main concept of the present invention and provide some specific solutions convenient for the public to implement, rather than restricting all functions or all working manners of the EUV mask detection system and the processor 13. Similarly, the EUV mask detection system and the processor 13 are also a non-restrictive implementation manner provided by the present invention, and do not limit the execution subject and execution order of each step in these EUV mask detection methods.

[0057] Please refer to Figure 1 、 Figure 3 、 Figure 4 and Figure 7 . Figure 7 FIG. shows a schematic flow chart of an EUV mask detection method provided according to a second aspect of the present invention.

[0058] As Figure 1 、 Figure 3 、 Figure 4 and Figure 7 shown, during the detection of the EUV mask, the user can first place the sample to be tested 31 into the loading chamber 126 of the detection platform 12, and transfer and load the sample to be tested 31 onto the translation stage 1222 of the sampling chamber 122 via the first isolation valve 123, the buffer chamber 124, the second isolation valve 125 and the microenvironment control module 15, and then open the gate valve 121 to provide an input beam I in the EUV band from the EUV light source 11 of the detection system to the sample to be tested 31. in . After that, the processor 13 can obtain at least one reflected beam I generated from the area to be tested of the sample to be tested 31 via the detection detectors 1223-1225 in the detection platform 12 R and / or transmitted beam I T , and then determine the reflectivity, transmittance, granularity and / or surface defects of the sample to be tested 31 according to the light intensity information, image information and / or spectral information of the reflected beam I R and / or transmitted beam I T .

[0059] In some embodiments, the detection of the EUV mask can be divided into a first type of detection of granularity and / or surface defects, and a second type of detection of transmittance and / or reflectivity. Among them, the first type of detection of granularity and / or surface defects requires the use of the first detector 1223 for collecting image information and / or spectral information, while the second type of detection of transmittance and / or reflectivity requires the use of the second detector 1224, the third detector 1225 and the reference detector 142 for collecting light intensity information.

[0060] Specifically, as Figure 3 shown, before performing the first type of detection on the sample 31 to be measured for particle size and / or surface defects, the detection platform 12 can first place a first standard sample with a known size or pattern on its translation stage 1222, and then control the translation stage 1222 to sequentially move multiple first standard regions of the first standard sample to the irradiation region of the input beam I in for the first detector 1223 to collect image information and / or spectral information in the reflected beam I R . Here, the image information collected by the first detector 1223 can be optionally the size or pattern of the first standard sample in the detection pattern coordinate system. Then, the processor 13 can determine the correction coefficient of the image output signal of the first detector 1223 by comparing the collected measured image information and / or measured spectral information with the known standard image information and / or standard spectral information.

[0061] Furthermore, in some embodiments, the processor 13 can also control the detection platform 12 to replace the first standard samples with multiple sizes or patterns for measurement to obtain multiple sets of correction coefficients of pattern information and / or spectral information, and then take the average of the multiple sets of correction coefficients to correct the image information and / or spectral information collected by the first detector 1223, so as to further improve the detection accuracy of the detection system for the particle size and / or surface defects of the sample surface.

[0062] After that, during the process of performing the first type of detection on the sample 31 to be measured for particle size and / or surface defects, the processor 13 can first control the translation stage 1222 to sequentially move multiple regions to be measured of the sample 31 to the irradiation region of the input beam I in for the first detector 1223 to collect image information and / or spectral information in the reflected beam I R , and then the processor splices and aggregates the image information and / or spectral information corresponding to each region to be measured to determine the particle size and / or surface defects on the surface of the sample 31 to be measured. The specific scheme of splicing and aggregating the image information and / or spectral information corresponding to each region to be measured to determine the particle size and / or surface defects on the surface of the sample 31 to be measured does not involve the technical improvement of the present invention and will not be elaborated here.

[0063] In addition, as Figure 4 shown, before performing the second type of detection on the sample 31 to be measured for reflectance and / or transmittance, the processor 13 can first obtain the third light intensity information of the reference beam I collected by the reference detector 142, and then place the second standard sample with a through-hole region and a second standard region on the translation stage 1222, and control the translation stage 1222 to move the through-hole region on the second standard sample to the input beam I ref in ​The illumination area is provided for the third detector 1225 to collect the transmitted light beam I T Then, the second standard area on the second standard sample is moved to the input beam I in The illumination area is provided for the second detector 1224 to collect the reflected light beam I R Afterwards, the processor 13 can first determine the reference beam I according to the third light intensity information and the fourth light intensity information. ref With the transmitted beam I T and determine the reference beam I according to the third light intensity information and the fifth light intensity information. ref With reflected beam I R The second proportional relationship between the first proportional relationship and the second proportional relationship is then used to determine the input beam I in With reference beam I ref There is a third proportional relationship between them which is determined by the hardware characteristics of various optical components.

[0064] Afterwards, in the process of performing the second type of detection of the reflectivity and / or transmittance of the sample 31 to be tested, the processor 13 may first control the translation stage 1222 to sequentially move the multiple test areas of the sample 31 to the input beam I. in The illumination area is provided for the second detector 1224 to collect the reflected light beam I R The first light intensity information is provided to the third detector 1225 for collecting the transmitted light beam I T Afterwards, the processor 13 can obtain the second light intensity information based on the third proportional relationship obtained above and the reference beam I collected in real time by the reference detector 142. ref The third light intensity information is used to determine the input light beam I under the actual measurement state. in The sixth light intensity information of the sample 31 to be tested is used, and then the reflectivity of each area to be tested of the sample 31 to be tested is determined according to the sixth light intensity information and the first light intensity information corresponding to each area to be tested, and the transmittance of each area to be tested of the sample 31 to be tested is determined according to the sixth light intensity information and the second light intensity information corresponding to each area to be tested. The specific scheme of determining the reflectivity and / or transmittance of each area to be tested of the sample 31 to be tested according to the sixth light intensity information and the first light intensity information and / or the second light intensity information corresponding to each area to be tested does not involve the technical improvement of the present invention and is not elaborated here.

[0065] Further, in some embodiments, the translation stage 1222 may include at least two carrying positions. Among them, the first carrying position is used to carry the sample 31 to be measured, and the remaining at least one second carrying position can be used to carry the first standard sample and / or the second standard sample. Thus, during the second type of detection of the reflectivity and / or transmittance of the sample 31 to be measured, the processor 13 can control the translation stage 1222 to move the through-hole area and the second standard area on the second standard sample to the irradiation area of the input beam I in once for each preset number of measurement areas on the sample 31 to be measured, so as to re-verify the third proportional relationship between the input beam I in and the reference beam I ref to avoid the influence of the change of the input beam I provided by the EUV light source 11 over time on the detection result, and more accurately reflect the real-time state of the sample 31 to be measured under actual working conditions. in

[0066] Those skilled in the art can understand that the above embodiments of setting the through-hole area on the second standard sample are only some non-limiting implementation manners provided by the present invention, aiming to clearly show the main concept of the present invention and provide some specific solutions convenient for the public to implement, rather than limiting the protection scope of the present invention.

[0067] Optionally, in some other embodiments, the translation stage 1222 may also only include the first carrying position for carrying the sample 31 to be measured, and the through-hole area opened on the sample carrying part, so as to achieve the same effect of determining the first proportional relationship between the reference beam I ref and the transmitted beam I T

[0068] Furthermore, in some embodiments, the above detection system of the EUV photomask provided by the present invention may be configured with the first detector 1223 for collecting image information and / or spectral information, and the reference detector 142, the second detector 1224 and the third detector 1225 for collecting light intensity information at the same time. Thus, the detection system can respectively perform reflectivity detection, transmittance detection, particle size detection and surface defect detection on the EUV photomask blank, the EUV photomask protective film and the EUV photomask assembly, so as to integrally meet various detection requirements for the EUV photomask, realize the miniaturization of the lithography machine, and improve the accuracy and efficiency of the lithography process.

[0069] ​​In summary, the above-mentioned EUV mask detection system, EUV mask detection method, and computer-readable storage medium provided by the present invention can all improve the resolution of the detected light intensity information, image information, and / or spectral information and the detection efficiency of the EUV mask by configuring an EUV light source in the EUV band, a reflection unit for adjusting the incident angle of the first light beam, and a detection detector for real-time collecting the light intensity information, image information, and / or spectral information of the second light beam reflected by the sample to be detected and / or the third light beam transmitted, so as to more truly reflect the state of the sample to be detected under actual working conditions.

[0070] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions not illustrated and described herein but understood by those skilled in the art.

[0071] The previous description of the present disclosure is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A detection system for an EUV mask, characterized in that, it includes: an EUV light source for providing a first light beam in the EUV band; a detection platform including a reflection unit, a translation stage and a detection detector. Among them, the reflection unit is used to make the first light beam irradiate the sample to be measured at a preset incident angle, the translation stage is used to carry the sample to be measured and move at least one area to be measured of it to the irradiation area of the first light beam to generate a reflected second light beam and / or a transmitted third light beam, and the detection detector is arranged on the transmission path of the second light beam and / or the third light beam to collect the second light beam and / or the third light beam; and a processor configured to: determine the reflectivity, transmittance, granularity and / or surface defects of the sample to be measured according to the light intensity information, image information and / or spectral information of the second light beam and / or the third light beam.

2. The detection system according to claim 1, characterized in that, the EUV light source includes a laser, a VIS cavity, a compression cavity and a focusing cavity, where, the laser is used to provide an initial light beam in the near-infrared band, the VIS cavity is arranged after the laser and is used to broaden and / or frequency-double the initial light beam, the compression cavity is arranged after the VIS cavity and is used to compress the laser pulse of the initial light beam to concentrate its energy, and then hit it on a gas and / or solid medium to generate an internal light beam in the EUV band, the focusing cavity is arranged after the compression cavity and is used to shape and / or focus the internal light beam in the EUV band to provide the first light beam in the EUV band to the detection platform.

3. The detection system according to claim 1, characterized in that, the detection detector includes a first detector for collecting image information and / or spectral information, where the first detector is arranged on the transmission path of the second light beam, during the process of detecting the granularity and / or surface defects of the sample to be measured, the translation stage moves multiple areas to be measured of the sample to be measured to the irradiation area of the first light beam in sequence for the first detector to collect the image information and / or spectral information in the second light beam, the processor is further configured to: determine the granularity and / or surface defects on the surface of the sample to be measured according to the image information and / or spectral information corresponding to each area to be measured.

4. The detection system according to claim 3, characterized in that, it further includes: a first standard sample. Among them, before detecting the granularity and / or surface defects of the sample to be measured, the translation stage also carries the first standard sample and moves multiple first standard areas of the first standard sample to the irradiation area of the first light beam in sequence for the first detector to collect the image information and / or spectral information in the second light beam, the processor is also configured to: determine the correction coefficient of the output signal of the first detector according to the image information and / or spectral information corresponding to each first standard area.

5. The detection system according to claim 1 or 3, characterized in that, it further includes: A reference optical module is provided between the EUV light source and the detection platform, and includes a beam splitting unit and a reference detector. The beam splitting unit is disposed at the rear end of the EUV light source and is configured to separate a part of the fourth light beam from the first light beam output by the EUV light source, transmit the fourth light beam to the reference detector to generate reference light information, and monitor the quality of the first light beam output by the EUV light source according to the reference light information.

6. The detection system according to claim 5, wherein, the detection detector includes a second detector and a third detector for collecting light intensity information. The second detector is disposed on the transmission path of the second light beam, and the third detector is disposed on the transmission path of the third light beam. During the process of detecting the reflectivity and / or transmittance of the sample to be measured, the translation stage sequentially moves multiple regions to be measured of the sample to be measured to the irradiation region of the first light beam, so that the second detector collects the first light intensity information of the second light beam, and the third detector collects the second light intensity information of the third light beam. The processor is further configured to: determine the reflectivity of each region to be measured of the sample to be measured according to the third light intensity information of the fourth light beam collected by the reference detector and the first light intensity information corresponding to each region to be measured; and determine the transmittance of each region to be measured of the sample to be measured according to the third light intensity information and the second light intensity information corresponding to each region to be measured.

7. The detection system according to claim 6, wherein, it further includes: a second standard sample. Before detecting the reflectivity and / or transmittance of the sample to be measured, the translation stage also carries the second standard sample, first moves the through-hole region on the second standard sample to the irradiation region of the first light beam, so that the third detector collects the fourth light intensity information of the third light beam, and then moves the second standard region on the second standard sample to the irradiation region of the first light beam, so that the second detector collects the fifth light intensity information of the second light beam. The processor is further configured to: determine a first proportional relationship between the fourth light beam and the third light beam according to the third light intensity information and the fourth light intensity information; determine a second proportional relationship between the fourth light beam and the second light beam according to the third light intensity information and the fifth light intensity information; and determine a third proportional relationship between the first light beam and the fourth light beam according to the average value of the first proportional relationship and the second proportional relationship.

8. The detection system according to claim 7, wherein, the processor is further configured to: determine the sixth light intensity information of the first light beam according to the third light intensity information and the third proportional relationship; determine the reflectivity of each region to be measured of the sample to be measured according to the sixth light intensity information and the first light intensity information corresponding to each region to be measured; and Determine the transmittance of each of the regions to be measured of the sample to be measured according to the sixth light intensity information and the second light intensity information corresponding to each of the regions to be measured.

9. The detection system according to claim 7, wherein, the translation stage includes at least two carrying positions, wherein a first carrying position carries the sample to be measured, and a second carrying position carries the second standard sample, each time the translation stage completes the detection of a preset number of regions to be measured on the sample to be measured, the through-hole region and the second standard region on the second standard sample are sequentially moved to the irradiation region of the first light beam once, so that the processor can verify the third proportional relationship between the first light beam and the fourth light beam.

10. The detection system according to claim 1, wherein, the detection platform further includes: a fixing unit, arranged on the translation stage to fix the sample to be measured carried thereon; and / or an alignment unit, configured to accurately identify the position of the sample to be measured before and / or during the detection of the sample to be measured.

11. The detection system according to claim 1, wherein, the detection platform further includes a valve, a sampling chamber, a first isolation valve, a buffer chamber, a second isolation valve and a discharging chamber, wherein, the reflection unit, the translation stage and the detection detector are arranged in the sampling chamber, the sampling chamber is connected to the EUV light source or the reference light module at the front end via the valve, and maintains a vacuum state during the detection of the sample to be measured, the discharging chamber is located at the rear end of the sampling chamber, has a discharging port for interacting with the external environment, and maintains an atmospheric pressure state during the placement of the sample to be measured, the buffer chamber is connected to the sampling chamber via the first isolation valve and connected to the discharging chamber via the second isolation valve, and is used to realize the transmission of the sample to be measured and the air pressure conversion between the sampling chamber and the discharging chamber.

12. The detection system according to claim 11, wherein, it further includes: a microenvironment control module, including an air tank, a vacuum control mechanism and a filtering unit, configured to pump the air pressure in the buffer chamber to the vacuum state of the sampling chamber after obtaining the sample to be measured from the discharging chamber, and introduce filtered clean gas into the buffer chamber after obtaining the sample to be measured that has been detected from the sampling chamber, so as to fill the air pressure in the buffer chamber to the atmospheric pressure state of the discharging chamber.

13. The detection system according to claim 1, wherein, it further includes: an external protection module, including an external protection panel, a system outer frame and a plurality of safety interconnection locks, wherein the plurality of safety interconnection locks are arranged inside the external protection panel and are used to cut off the dangerous components in the detection system when the external protection panel is opened.

14. The detection system according to claim 13, wherein, the external protection module further includes: a sensor assembly, including a smoke sensor and / or a leak-proof liquid sensor; and / or a signal lamp, configured to provide a light signal indicating the operating state of the detection system; and / or an emergency stop button, configured to emergently cut off the power supply of the detection system or the dangerous components therein.

15. The detection system according to claim 13, characterized in that, it further comprises: an operation interaction module, nested in the outer protection panel of the outer protection module, for receiving detection instructions provided by a user and controlling the operation of each module in the detection system according to the detection instructions.

16. The detection system according to claim 13, characterized in that, the detection platform further comprises: a vibration isolation base, including a marble platform, vibration isolation units and a bottom frame, for carrying detection elements in the detection platform and isolating external vibration interference.

17. The detection system according to claim 16, characterized in that, it further comprises: a communication control module, installed between the marble platform and the bottom frame and including a main control computer and a communication unit to realize communication control between the detection system and external devices.

18. The detection system according to claim 16, characterized in that, it further comprises: a power supply and distribution module, installed inside the bottom frame and including a main power distribution box and a plurality of subsystem power distribution boxes. Among them, the main power distribution box is used to supply power to each of the subsystem power distribution boxes, the first subsystem power distribution box is used to supply power to the EUV light source, the second subsystem power distribution box is used to supply power to the detection platform, and the third subsystem power distribution box is used to supply power to other modules in the detection system.

19. The detection system according to claim 1, characterized in that, the sample to be measured includes an EUV mask blank, an EUV mask bare board, an EUV mask protective film for EUV lithography process, or an EUV mask assembly composed of the EUV mask bare board and the EUV mask protective film.

20. A method for detecting an EUV mask, characterized in that, it includes the following steps: placing the sample to be measured into the detection system for EUV mask according to any one of claims 1 to 19; providing a first beam in the EUV band to the sample to be measured via the EUV light source of the detection system; acquiring a second beam reflected and / or a third beam transmitted by at least one region to be measured of the sample to be measured via the detection platform of the detection system; and determining the reflectivity, transmittance, granularity and / or surface defects of the sample to be measured according to the light intensity information, image information and / or spectral information of the second beam and / or the third beam via the processor of the detection system.

21. A computer-readable storage medium, on which computer instructions are stored, characterized in that, when the computer instructions are executed by a processor, the method for detecting an EUV mask according to claim 20 is implemented.

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