EUV flare measuring device, measuring method, measurement system, and filter structure used therein

Abstract

An EUV measurement system is provided. The EUV measurement system may comprise: a light source generating EUV light; a splitter that receives the EUV light generated by the light source and separates the EUV light into first EUV light and second EUV light; an optical system that controls a path of the second EUV light separated by the splitter and irradiates the second EUV light to a target; a detector that detects the intensity and the shape of third EUV light by collecting the third EUV light, which is the second EUV light that has been transmitted through the target or reflected from the target; and a filter that is disposed between the target and the detector and blocks a portion of the third EUV light collected by the detector, wherein an EUV flare generated by the target is measured using the intensity and the shape detected from the third EUV light that is partially blocked by the filter.

Description

EUV flare measuring device, measuring method, and measuring system, and filter structure used therein

[0001] The present invention relates to an apparatus, method, and system for measuring EUV flare generated from materials used in an EUV process, and a filter structure used therein.

[0002] EUV lithography, which utilizes shorter wavelength light sources, has been introduced to realize integrated semiconductor devices and overcome the resolution limitations of conventional photolithography processes. Due to the high photon energy of EUV light, it is easily absorbed by all materials; therefore, multilayer thin-film-based reflective optical systems are used to control the light path, resulting in oblique incidence conditions. Furthermore, particles generated during the EUV lithography process can adhere to the inside of the lithography chamber or optical components with a significant probability. This leads to localized loss of light constituting the circuit patterns engraved on the EUV mask, causing defects in the final wafer image. Consequently, EUV pellicles are being actively developed as a means to mitigate the EUV mask particle issue by introducing them at specific locations on the EUV mask.

[0003] Since light scattering occurs inversely proportional to the square of the wavelength, 13.5 nm EUV, which is much shorter than the wavelength of light sources used in conventional lithography processes, exhibits a significant degree of scattering depending on the materials or structures of reflective and transmissive optical components. The scattered light induces EUV flare during the lithography process and exposes EUV to unintended areas on the wafer, which can lead to reduced patterning accuracy—such as decreased image contrast, changes in critical dimension (CD), and circuit pattern displacement—and increase linewidth roughness due to exposure non-uniformity, ultimately limiting the process window. Such EUV flare can manifest differently depending on the materials and structures constituting the optical components. In particular, imperfections in the optical components, including surface roughness, act as a primary factor.

[0004] Roughness resulting from the multilayer thin film structure of 80 or more layers constituting the EUV reflector can exist not only on the surface but also between the thin films, and there are limitations in measuring the degree of light scattering caused by the roughness existing between the thin films. In addition, EUV light can be strongly scattered by the materials and structure of EUV pellicles being developed for the purpose of high transmittance for EUV, and there are also limitations in measuring the surface roughness that causes scattering for pellicles fabricated in the form of thin films at the level of tens of nanometers.

[0005] Accordingly, in the field of next-generation EUV masks, which are being actively developed to improve mask pattern image transfer characteristics and pattern image resolution in the EUV lithography process, and in the field of EUV pellicles, which are being researched and developed as a means to protect them, it is essential to measure the EUV flare generated by each material and structure.

[0006] The technical problem that the present invention aims to solve is to provide an EUV flare measuring device.

[0007] Another technical problem that the present invention aims to solve is to provide an EUV flare measurement system.

[0008] Another technical problem that the present invention aims to solve is to provide a method for measuring EUV.

[0009] Another technical problem that the present invention aims to solve is to provide a filter structure used for measuring EUV flare.

[0010] Another technical problem that the present invention aims to solve is to provide an EUV flare measuring device, a measuring method, and a measuring system having high accuracy and reliability, and a filter structure used therein.

[0011] The technical problems that the present invention aims to solve are not limited to those described above.

[0012] To solve the technical problems described above, the present invention provides an EUV flare measurement system.

[0013] According to one embodiment, the EUV flare measurement system may include a light source that generates EUV light, a splitter that receives the EUV light generated from the light source and separates it into a first EUV light and a second EUV light, an optical system that controls the path of the second EUV light separated from the splitter and irradiates the second EUV light onto a target, a detector that collects the second EUV light that passes through the target or is reflected from the target and detects the intensity and shape of the third EUV light, and a filter disposed between the target and the detector that blocks a portion of the third EUV light collected by the detector, wherein the system may measure an EUV flare generated by the target using the intensity and shape detected from the third EUV light that is partially blocked by the filter.

[0014] According to one embodiment, an image of the third EUV light is obtained using the intensity and shape detected from the third EUV light, which is partially blocked by the filter, and the EUV flare generated by the target is measured by calculating the flare value of the third EUV light using the intensity of the green region and the intensity of the blue region within the image.

[0015] According to one embodiment, the flare value of the third EUV light may be calculated according to the following <Equation 1>.

[0016] <Mathematical Formula 1>

[0017]

[0018] (EUV flare: 3rd EUV light flare value, ∑ Green Intensity counts: The sum of intensities detected from all pixels included in the green area within the image above, ∑ BlueIntensity counts: The sum of intensities detected in all pixels included in the blue area of ​​the image above)

[0019] According to one embodiment, the apparatus further includes a first detector that collects the first EUV light separated from the splitter and detects the intensity and shape of the first EUV light, and a detector that collects the third EUV light and detects the intensity and shape of the third EUV light is defined as a second detector, wherein the shape and size of the filter that blocks the third EUV light are determined using the intensity of the first EUV light detected by the first detector and the intensity of the third EUV light detected by the second detector.

[0020] According to one embodiment, the intensity of the third EUV light used to determine the shape and size of the filter may include that detected from the third EUV light that is not partially blocked by the filter.

[0021] According to one embodiment, the intensity of the third EUV light is corrected using the ratio of the intensity of the third EUV light to the intensity of the first EUV light, and the shape and size of the filter are determined from an image obtained using the corrected intensity of the third EUV light.

[0022] According to one embodiment, the third EUV light, which is partially blocked by the filter, may be collected by the detector while positioned so that the center of the filter and the center of the third EUV light overlap.

[0023]

[0024] To solve the technical problems described above, the present invention provides a method for measuring EUV flare.

[0025] According to one embodiment, the EUV flare measurement method may include the steps of: separating EUV light generated from a light source into a first EUV light and a second EUV light; controlling the path of the second EUV light to irradiate the second EUV light onto a target; filtering the third EUV light that passes through the target or is reflected from the target to block a portion of the third EUV light; collecting the third EUV light that is partially blocked and obtaining an image of the third EUV light using the intensity and shape of the collected third EUV light; and calculating a flare value of the third EUV light from the image of the third EUV light.

[0026] According to one embodiment, the step of calculating the flare value of the third EUV light may include the step of measuring the intensity of a green region in the image, the step of measuring the intensity of a blue region in the image, and the step of calculating the flare value of the third EUV light using the following <Equation 1>.

[0027] <Mathematical Formula 1>

[0028]

[0029] (EUV flare: 3rd EUV light flare value, ∑ Green Intensity counts: The sum of intensities detected from all pixels included in the green area within the image above, ∑ Blue Intensity counts: The sum of intensities detected in all pixels included in the blue area of ​​the image above)

[0030] According to one embodiment, the method further includes a step of determining the size and shape of a filter for filtering the third EUV light after the step of irradiating the second light as a target and before the step of blocking a portion of the third EUV light, wherein the step of determining the size and shape of the filter may include: a step of collecting the first EUV light and detecting the intensity and shape of the first EUV light; a step of collecting the third EUV light and detecting the intensity and shape of the third EUV light; a step of correcting the intensity of the third EUV light using the ratio of the intensity of the third EUV light to the intensity of the first EUV light; and a step of obtaining an image of the corrected third EUV light using the corrected intensity of the third EUV light.

[0031]

[0032] To solve the technical problems described above, the present invention provides a filter structure for measuring EUV flare.

[0033] According to one embodiment, the filter structure for measuring EUV flare may include a filter jig, a first filter disposed on the filter jig and transmitting EUV light, and a second filter disposed on the filter jig spaced apart from the first filter and including a transmitting area that transmits EUV light and a blocking area that blocks EUV light.

[0034] According to one embodiment, the transmission region may include zirconium (Zr), and the blocking region may include any one of a material having a high absorption rate for EUV light wavelengths, such as gold (Au) and platinum (Pt).

[0035]

[0036] To solve the technical problems described above, the present invention provides an EUV flare measuring device.

[0037] According to one embodiment, the EUV flare measuring device comprises a light source that generates EUV light, a splitter that receives the EUV light generated from the light source and separates it into a first EUV light and a second EUV light, a mirror that controls the path of the second EUV light separated from the splitter and irradiates the second EUV light onto a target, a first detector that collects the first EUV light and detects the intensity and shape of the first EUV light, and a second detector that collects the third EUV light that passes through the target or is reflected from the target and detects the intensity and shape of the third EUV light, wherein the second detector may be capable of changing its position to collect the third-1 EUV light that passes through the target at a first location and collect the third-2 EUV light that is reflected from the target at a second location different from the first location.

[0038] According to one embodiment, the EUV flare measuring device may further include a filter disposed between the target and the second detector to block a portion of the third EUV light collected by the detector.

[0039] According to one embodiment, the filter may include a transmitting region that transmits EUV light and a blocking region that blocks EUV light, wherein the center of the blocking region and the center of the third EUV light may overlap.

[0040] The present invention can measure EUV flares generated from materials and structures used in the EUV process and can provide high accuracy and reliability for the measurement. In addition, accessibility to EUV flare measurement can be improved because EUV flares can be measured without complex equipment and high-difficulty alignment.

[0041] Accordingly, the present invention can be easily applied to research on material selection and structural design optimization of reflective and transmissive optical components for EUV lithography processes. In addition, it can be applied to research on improving pattern transfer characteristics and image resolution of next-generation EUV masks, and can also be easily applied to the development of high-transmittance EUV pellicle materials and structures as means to protect them. Furthermore, it can be utilized in technology to improve semiconductor device yield by enhancing mask pattern image transfer characteristics and pattern image resolution, and since quantitative measurement of EUV flare is possible, the effects on the resolution, linewidth roughness, and sensitivity of EUV resist can be quantitatively evaluated, thereby enabling resist performance optimization, and it can also be applied to the field of developing new resist materials.

[0042] FIG. 1 is a drawing for explaining an EUV flare measurement system according to an embodiment of the present invention.

[0043] FIG. 2 is a diagram illustrating the process of measuring EUV flare generated from a transmissive target using an EUV flare measurement system according to an embodiment of the present invention.

[0044] FIG. 3 is a diagram illustrating the process of measuring EUV flare generated from a reflective target using an EUV flare measurement system according to an embodiment of the present invention.

[0045] FIGS. 4 and 5 are drawings for explaining a filter structure included in an EUV flare measurement system according to an embodiment of the present invention.

[0046] FIG. 6 is a drawing showing an image obtained without a beam stop applied, which is included in an EUV flare measurement system according to an embodiment of the present invention.

[0047] FIG. 7 is a drawing showing an image obtained with a beam stop applied, which is included in an EUV flare measurement system according to an embodiment of the present invention.

[0048] FIG. 8 is a flowchart illustrating an EUV flare measurement method according to an embodiment of the present invention.

[0049] FIG. 9 is a flowchart for specifically explaining step S300 of the EUV flare measurement method according to an embodiment of the present invention.

[0050] FIG. 10 is a flowchart for specifically explaining step S600 of the EUV flare measurement method according to an embodiment of the present invention.

[0051] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the concept of the present invention is sufficiently conveyed to those skilled in the art.

[0052] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of the films and regions are exaggerated for the effective description of the technical content.

[0053] Additionally, although terms such as first, second, third, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. Accordingly, what is referred to as the first component in one embodiment may be referred to as the second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiment. Furthermore, in this specification, "and / or" is used to mean including at least one of the components listed before and after it.

[0054] In the specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, components, or combinations thereof described in the specification, and should not be understood as excluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. Additionally, in this specification, "connection" is used to include both indirectly connecting multiple components and directly connecting them.

[0055] Furthermore, in describing the present invention below, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted.

[0056] FIG. 1 is a drawing for explaining an EUV flare measurement system according to an embodiment of the present invention, FIG. 2 is a drawing for explaining the process of measuring EUV flare generated from a transmissive target using an EUV flare measurement system according to an embodiment of the present invention, FIG. 3 is a drawing for explaining the process of measuring EUV flare generated from a reflective target using an EUV flare measurement system according to an embodiment of the present invention, FIG. 4 and FIG. 5 are drawings for explaining a filter structure included in an EUV flare measurement system according to an embodiment of the present invention, FIG. 6 is a drawing showing an image obtained in a state where a beam stop included in an EUV flare measurement system according to an embodiment of the present invention is not applied, and FIG. 7 is a drawing showing an image obtained in a state where a beam stop included in an EUV flare measurement system according to an embodiment of the present invention is applied.

[0057] Referring to FIGS. 1 to 3, the EUV flare measurement system according to the above embodiment may include a light source (100), a splitter (200), an optical system (300), a first detector (410), a second detector (420), and a filter structure (500). Additionally, the device comprising the light source (100), the splitter (200), the optical system (300), the first detector (410), the second detector (420), and the filter structure (500) may also be defined as an EUV flare measurement device. Each component is described below.

[0058] The light source (100) can generate and emit EUV light (L0). According to one embodiment, the light source (100) can emit 13.56 nm coherent EUV light generated in a higher harmonic manner.

[0059] The EUV light (L0) generated from the light source (100) may be supplied to the splitter (200). The splitter (200) may separate the EUV light (L0) into a first EUV light (L1) and a second EUV light (L2). According to one embodiment, the splitter (200) may reflect some of the EUV light (L0) and transmit other parts. According to one embodiment, the EUV light (L0) reflected from the splitter (200) may be defined as the first EUV light (L1). Alternatively, the EUV light (L0) transmitted through the splitter (200) may be defined as the second EUV light (L2).

[0060] According to one embodiment, a pre-filter (SF) may be disposed between the light source (100) and the splitter (200). For example, the pre-filter (SF) may include a spectral filter. Accordingly, the EUV light (L0) generated from the light source (100) may be provided to the splitter (200) after being filtered through the pre-filter (SF).

[0061] The first EUV light (L1) separated from the splitter (200) can be provided to the first detector (410). The first detector (410) can collect the first EUV light (L1) and detect the intensity and shape of the first EUV light (L1).

[0062] Alternatively, the second EUV light (L2) separated from the splitter (200) may be provided to the optical system (300). According to one embodiment, the optical system (300) may include a reflective mirror. The optical system (300) may control the path of the second EUV light (L2) to irradiate the second EUV light (L2) onto a target (TG). According to one embodiment, the second EUV light (L2), whose path is controlled through the optical system (300), may be irradiated onto the target (TG) such that it forms an angle of 6° with respect to the normal direction of the upper surface of the target (TG). That is, the second EUV light (L2), whose path is controlled through the optical system (300), may be irradiated onto the target (TG) to satisfy the condition of oblique incidence of 6°.

[0063] According to one embodiment, the target (TG) transmits or reflects EUV light and may include materials and structures used in the EUV process. For example, the target (TG) may include either an EUV mask or an EUV pellicle.

[0064] According to one embodiment, the second EUV light (L2) transmitted through the target (TG) and the second EUV light (L2) reflected from the target (TG) can be defined as the third EUV light (L3). More specifically, the second EUV light (L2) transmitted through the target (TG) is the third-1 EUV light (L3). 3-1 It can be defined as ). In contrast, the second EUV light (L2) reflected from the target (TG) is the third-second EUV light (L 3-2 It can be defined as ).

[0065] The third EUV light (L3) can be provided to the second detector (420) via the filter structure (500). To this end, the filter structure (500) can be placed between the target (TG) and the second detector (420).

[0066] Referring to FIGS. 4 and 5, the filter structure (500) may include a first filter (510), a second filter (520), a filter jig (530), and a filter stage (540).

[0067] The filter jig (530) is intended to support the first filter (510) and the second filter (520), and the first filter (510) and the second filter (520) may be placed on the filter jig (530). The first filter (510) and the second filter (520) may be placed on the filter jig (530) and may be placed side by side so as to be spaced apart from each other.

[0068] While the first filter (510) consists only of a region that transmits EUV light, the second filter (520) may consist of a transmission region (520a) that transmits EUV light and a blocking region (520b) that blocks EUV light. According to one embodiment, a beam stop containing a material that blocks EUV light may be disposed in the blocking region (520b). For example, the beam stop may include any one of a material having a high absorption rate for EUV light wavelengths, such as gold (Au) and platinum (Pt). Alternatively, the transmission region (520a) may include zirconium (Zr). According to one embodiment, both the first filter (510) and the second filter (520) may include a spectral filter.

[0069] The filter stage (540) can move the position of the filter jig (530). According to one embodiment, the filter stage (540) can move the position of the filter jig (530) so that the third EUV light (L3) passes through the first filter (510) and is collected by the second detector, or move the position of the filter jig (530) so that the third EUV light (L3) passes through the second filter (520) and is collected by the second detector.

[0070] In particular, when the position of the filter jig (530) is moved so that the third EUV light (L3) passes through the second filter (520) and is collected by the second detector, the position of the filter jig (530) may be moved so that the center of the blocking area (520b) of the second filter (520), that is, the center of the beam stop and the center of the third EUV light (L3) overlap. Accordingly, when the third EUV light (L3) passes through the second filter (520) and is collected by the second detector (420), it may be collected by the second detector (420) with a portion (center area) of the third EUV light (L3) blocked by the beam stop.

[0071] The second detector (420) can collect the third EUV light (L3) and detect the intensity and shape of the third EUV light (L3). According to one embodiment, the second detector (420) may be configured to be movable. For example, the second detector (420) may detect the third-1 EUV light (L3) through which the second EUV light (L2) has passed through the target (TG). 3-1 ) is collected at the first position (P1), and the second EUV light (L2) is the third-second EUV light (L) reflected from the target (TG). 3-2 The location may be changed so that the ) is collected at a second location (P2) different from the first location (P1).

[0072] The above EUV flare measurement system and device can acquire an image of the first EUV light (L1) using the intensity and shape of the first EUV light (L1) detected through the first detector (410), and acquire an image of the third EUV light (L3) using the intensity and shape of the third EUV light (L3) detected through the second detector (420). According to one embodiment, the image of the first EUV light (L1) can be acquired from the first detector (410), and the image of the third EUV light (L3) can be acquired from the third detector (430).

[0073] The above EUV flare measurement system and device can measure EUV flare generated by the target (TG) using an image of the third EUV light (L3), and can measure EUV flare generated by the target (TG) using an image of the third EUV light (L3) in which a portion (central region) is blocked by the second filter (520).

[0074] As illustrated in FIG. 6, when using an image of the third EUV light (L3) in which a portion (central area) is not blocked by the second filter (520) (an image obtained without beam stop applied), the image includes not only the EUV light scattered by the target (TG) (area appearing as green and blue) but also the EUV light not scattered (area appearing as red), so the measurement of the EUV light scattered by the target (TG) may not be relatively accurate.

[0075] However, as illustrated in FIG. 7, when using an image of the third EUV light (L3) in which a portion (central area) is blocked by the second filter (520) (an image obtained with a beam stop applied), EUV light not scattered by the target (TG) (regions appearing in red) can be excluded, so the measurement of EUV light scattered by the target (TG) can be performed relatively accurately. That is, by using an image of the third EUV light (L3) in which a portion (central area) is blocked by the second filter (520), the EUV flare generated by the target (TG) can be measured with high reliability.

[0076] The EUV flare generated by the target (TG) can be measured by quantitatively calculating the flare value of the third EUV light (L3), and the flare value of the third EUV light (L3) can be quantitatively calculated according to the following <Equation 1>. For example, if the flare value of the third EUV light (L3) is calculated to be high, the EUV flare generated by the target (TG) can be measured as being relatively high, and conversely, if the flare value of the third EUV light (L3) is calculated to be low, the EUV flare generated by the target (TG) can be measured as being relatively low.

[0077] <Mathematical Formula 1>

[0078]

[0079] (EUV flare: 3rd EUV light flare value, ∑ Green Intensity counts: The sum of intensities detected from all pixels included in the green area within the image above, ∑ Blue Intensity counts: The sum of intensities detected in all pixels included in the blue area of ​​the image above)

[0080] In order to improve the measurement reliability and accuracy of the EUV flare generated from the target (TG), the above EUV flare measurement system and device can determine the shape and size of the beam stop using the intensity of the first EUV light (L1) detected by the first detector (410) and the intensity of the third EUV light (L3) detected by the second detector (420). That is, the shape and size of the area where the third EUV light (L3) is blocked can be determined.

[0081] More specifically, the intensity of the third EUV light (L3) used to determine the shape and size of the beam stop can be detected from the third EUV light (L3) that has passed through the first filter (510), that is, the third EUV light (L3) in which a portion is not blocked.

[0082] Additionally, the shape and size of the beam stop can be determined from an image obtained using the corrected intensity of the third EUV light (L3) by correcting the intensity of the third EUV light (L3) using the ratio of the intensity of the third EUV light (L3) to the intensity of the first EUV light (L1). The beam stop, whose shape and size are determined through the process described above, can be defined as a corrected beam stop.

[0083] When the flare value of the third EUV light (L3) is calculated with the corrected beam stop applied, the EUV light that is not scattered by the target (TG) within the image of the third EUV light (L3) (the area appearing in red) can be excluded as much as possible, so the accuracy and reliability of the flare value of the third EUV light (L3) calculated by <Equation 1> can be improved.

[0084]

[0085] The EUV flare measurement system and apparatus according to an embodiment of the present invention have been described above. Hereinafter, an EUV flare measurement method according to an embodiment of the present invention will be described. The EUV flare measurement method according to the above embodiment can be performed through the EUV flare measurement system and apparatus described with reference to FIGS. 1 to 7.

[0086] FIG. 8 is a flowchart for explaining an EUV flare measurement method according to an embodiment of the present invention, FIG. 9 is a flowchart for specifically explaining step S300 of an EUV flare measurement method according to an embodiment of the present invention, and FIG. 10 is a flowchart for specifically explaining step S600 of an EUV flare measurement method according to an embodiment of the present invention.

[0087] Referring to FIGS. 8 to 10, EUV light (L0) generated from a light source (100) can be separated into a first EUV light (L1) and a second EUV light (L2) (S100). According to one embodiment, the light source (100) can emit 13.56 nm coherent EUV light generated in a higher harmonic manner. According to one embodiment, the EUV light (L0) can be separated through a splitter (200). More specifically, the splitter (200) can reflect a portion of the EUV light (L0) and transmit another portion. In this case, the EUV light (L0) reflected from the splitter (200) can be defined as the first EUV light (L1). In contrast, the EUV light (L0) that has passed through the splitter (200) can be defined as the second EUV light (L2).

[0088] By controlling the path of the second EUV light (L2) separated from the splitter (200), the second EUV light (L2) can be irradiated onto a target (TG) (S200). According to one embodiment, the second EUV light (L2) can be irradiated onto the target (TG) at an angle of 6° with respect to the normal direction of the upper surface of the target (TG). That is, the second EUV light (L2) can be irradiated onto the target (TG) to satisfy the condition of oblique incidence of 6°. According to one embodiment, the target (TG) transmits or reflects EUV light and may include materials and structures used in the EUV process. For example, the target (TG) may include either an EUV mask or an EUV pellicle.

[0089] According to one embodiment, the second EUV light (L2) transmitted through the target (TG) and the second EUV light (L2) reflected from the target (TG) can be defined as the third EUV light (L3). More specifically, the second EUV light (L2) transmitted through the target (TG) is the third-1 EUV light (L3). 3-1 It can be defined as ). In contrast, the second EUV light (L2) reflected from the target (TG) is the third-second EUV light (L 3-2 It can be defined as ).

[0090] The size and shape of a filter for filtering the third EUV light (L3) may be determined (S300). According to one embodiment, the step of determining the size and shape of the filter (S300) may include: collecting the first EUV light (L1) and detecting the intensity and shape of the first EUV light (L1) (S310); collecting the third EUV light (L3) and detecting the intensity and shape of the third EUV light (L3) (S320); correcting the intensity of the third EUV light (L3) using the ratio of the intensity of the third EUV light (L3) to the intensity of the first EUV light (L1) (S330); and obtaining an image of the corrected third EUV light (L3) using the corrected intensity of the third EUV light (L3) (S340).

[0091] That is, the intensity of the third EUV light (L3) is corrected using the ratio of the intensity of the third EUV light (L3) to the intensity of the first EUV light (L1), and the size and shape of the filter can be determined from the image obtained using the corrected intensity of the third EUV light (L3).

[0092] By filtering the third EUV light (L3) using the filter whose size and shape are determined in step S300, a portion of the third EUV light (L3) can be blocked (S400). Subsequently, the third EUV light (L3) with a portion blocked is collected, and an image of the third EUV light (L3) can be obtained using the intensity and shape of the collected third EUV light (L3) (S500).

[0093] Finally, the flare value of the third EUV light (L3) can be calculated from the image of the third EUV light (L3) (S600). Accordingly, the EUV flare generated by the target (TG) can be measured. More specifically, the step of calculating the flare value of the third EUV light (L3) (S600) may include the step of measuring the intensity of the green region within the image of the third EUV light (L3) (S610), the step of measuring the intensity of the blue region within the image of the third EUV light (L3) (S620), and the step of calculating the flare value of the third EUV light (L3) using <Equation 1> (S630).

[0094] <Mathematical Formula 1>

[0095]

[0096] (EUV flare: 3rd EUV light flare value, ∑ Green Intensity counts: The sum of intensities detected from all pixels included in the green area within the image above, ∑ Blue Intensity counts: The sum of intensities detected in all pixels included in the blue area of ​​the image above)

[0097]

[0098] Although the present invention has been described in detail using preferred embodiments, the scope of the invention is not limited to specific embodiments and should be interpreted by the appended claims. Furthermore, those skilled in the art will understand that many modifications and variations are possible without departing from the scope of the invention.

[0099] The present invention can be used in the semiconductor industry.

Claims

1. A light source that generates EUV light; A splitter that receives the EUV light generated from the above light source and separates it into a first EUV light and a second EUV light; An optical system that controls the path of the second EUV light separated from the splitter and irradiates the second EUV light onto a target; A detector that detects the intensity and shape of the third EUV light by collecting the second EUV light that passes through the target or is reflected from the target; and It includes a filter disposed between the target and the detector to block a portion of the third EUV light collected by the detector, An EUV flare measurement system comprising measuring an EUV flare generated by a target using the intensity and shape detected from the third EUV light, which is partially blocked by the filter.

2. In Paragraph 1, An image of the third EUV light is obtained using the intensity and shape detected from the third EUV light, which is partially blocked by the filter above, and An EUV flare measurement system comprising measuring EUV flare generated by the target by calculating the flare value of the third EUV light using the intensity of the green region and the intensity of the blue region in the image above.

3. In Paragraph 2, An EUV flare measurement system comprising the above third EUV light flare value being calculated according to <Equation 1> below. <Mathematical Formula 1> (EUV flare: 3rd EUV light flare value, ∑ Green Intensity counts: The sum of intensities detected from all pixels included in the green area within the image above, ∑ Blue Intensity counts: The sum of intensities detected in all pixels included in the blue area of ​​the image above) 4. In Paragraph 1, It further includes a first detector that collects the first EUV light separated from the splitter and detects the intensity and shape of the first EUV light. A detector that collects the third EUV light and detects the intensity and shape of the third EUV light is defined as a second detector, An EUV flare measurement system comprising determining the shape and size of a filter that blocks the third EUV light using the intensity of the first EUV light detected by the first detector and the intensity of the third EUV light detected by the second detector.

5. In Paragraph 4, An EUV flare measurement system, wherein the intensity of the third EUV light used to determine the shape and size of the filter comprises that detected from the third EUV light that is not partially blocked by the filter.

6. In Paragraph 4, The intensity of the third EUV light is corrected using the ratio of the intensity of the third EUV light to the intensity of the first EUV light, and An EUV flare measurement system comprising determining the shape and size of the filter from an image obtained using the corrected intensity of the third EUV light.

7. In Paragraph 1, An EUV flare measurement system comprising collecting the third EUV light, which is partially blocked by the filter, at the detector while positioned so that the center of the filter and the center of the third EUV light overlap.

8. A step of separating EUV light generated from a light source into first EUV light and second EUV light; A step of controlling the path of the second EUV light to irradiate the second EUV light onto a target; A step of blocking a portion of the third EUV light by filtering the second EUV light that passes through the target or the third EUV light reflected from the target; A step of collecting the third EUV light with a portion blocked, and acquiring an image of the third EUV light using the intensity and shape of the collected third EUV light; and EUV flare measurement method comprising the step of calculating a flare value of the third EUV light from an image of the third EUV light.

9. In Paragraph 8, The step of calculating the flare value of the third EUV light above is, A step of measuring the intensity of the green area within the above image; A step of measuring the intensity of the blue region within the above image; and EUV flare measurement method comprising the step of calculating the flare value of the third EUV light using the following <Mathematical Formula 1>. <Mathematical Formula 1> (EUV flare: 3rd EUV light flare value, ∑ Green Intensity counts: The sum of intensities detected from all pixels included in the green area within the image above, ∑ Blue Intensity counts: The sum of intensities detected in all pixels included in the blue area of ​​the image above) 10. In Paragraph 8, The method further includes a step of determining the size and shape of a filter for filtering the third EUV light after the step of irradiating the second light target and before the step of blocking a portion of the third EUV light, wherein The step of determining the size and shape of the above filter is, A step of collecting the first EUV light and detecting the intensity and shape of the first EUV light; A step of collecting the third EUV light and detecting the intensity and shape of the third EUV light; A step of correcting the intensity of the third EUV light using the ratio of the intensity of the third EUV light to the intensity of the first EUV light; and EUV flare measurement method comprising the step of acquiring an image of the corrected third EUV light using the corrected intensity of the third EUV light.

11. Filter Jig; A first filter disposed on the filter jig and transmitting EUV light; and A filter structure for measuring EUV flare, comprising a second filter disposed on the filter jig spaced apart from the first filter and including a transmitting region that transmits EUV light and a blocking region that blocks EUV light.

12. In Paragraph 11, The above-mentioned transmission region contains zirconium (Zr), and The above-mentioned blocking region comprises either gold (Au) or platinum (Pt), forming a filter structure for measuring EUV flare.

13. Light source that generates EUV light; A splitter that receives the EUV light generated from the above light source and separates it into a first EUV light and a second EUV light; A mirror that controls the path of the second EUV light separated from the splitter and irradiates the second EUV light toward a target; A first detector that collects the first EUV light and detects the intensity and shape of the first EUV light; and The second detector includes a second detector that detects the intensity and shape of the third EUV light by collecting the second EUV light that passes through the target or is reflected from the target. An EUV flare measuring device comprising a second detector capable of changing its position to collect a third-1 EUV light that has passed through the target at a first location, and to collect a third-2 EUV light that has been reflected from the target at a second location different from the first location.

14. In Paragraph 13, An EUV flare measuring device further comprising a filter disposed between the target and the second detector to block a portion of the third EUV light collected by the detector.

15. In Paragraph 14, The above filter includes a transmitting region that transmits EUV light and a blocking region that blocks EUV light, An EUV flare measuring device comprising a configuration in which the center of the blocking region and the center of the third EUV light are positioned to overlap.

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