Apparatus and method for measuring the phase of an euv mask and method of manufacturing a mask

Abstract

The present disclosure provides an apparatus and a method for measuring a phase of an extreme ultraviolet (EUV) mask and a method of manufacturing a mask. The apparatus for measuring a phase of an EUV mask includes an EUV light source configured to generate and output EUV light, at least one mirror configured to reflect the EUV light as reflected EUV light incident on an EUV mask to be measured, a mask stage on which the EUV mask is disposed, a detector configured to receive the EUV light reflected from the EUV mask to obtain a two-dimensional (2D) image and measure reflectivity and diffraction efficiency of the EUV mask, and a processor configured to determine the phase of the EUV mask by using the reflectivity and the diffraction efficiency of the EUV mask.

Description

Technical Field

[0001] The present invention relates to extreme ultraviolet (EUV) masks, and more specifically, to apparatus and methods for measuring the phase of an EUV mask and methods for manufacturing EUV masks. Background Technology

[0002] Photolithography is a technology that significantly impacts the miniaturization of semiconductor devices. To overcome the resolution limitations in photolithography, research is underway on light sources with shorter wavelengths. Recently, EUV lithography using EUV light has been developed. EUV light is dispersed in a medium (such as a material or air) and is well absorbed by most materials. Therefore, reflective masks are used instead of transmission masks during the exposure process. On the other hand, when inspection or metrology equipment used with transmission masks is applied to reflective masks, the resolution or defect detection sensitivity may not be satisfactory. In particular, when inspection or metrology equipment that actually uses EUV light is not used, it may be difficult to meet the specifications required during mask manufacturing. Summary of the Invention

[0003] The present invention relates to an apparatus and method for accurately measuring the phase of an extreme ultraviolet (EUV) mask, and a method for manufacturing an EUV mask including the method.

[0004] According to one aspect of the present invention, an apparatus for measuring the phase of an EUV mask is provided, the apparatus comprising: an EUV light source configured to generate and output EUV light; at least one reflector configured to reflect the EUV light as reflected EUV light incident on an EUV mask to be measured; a mask stage on which the EUV mask is disposed; a detector configured to receive EUV light reflected from the EUV mask to obtain a two-dimensional (2D) image and to measure the reflectivity and diffraction efficiency of the EUV mask; and a processor configured to calculate or determine the phase of the EUV mask using the reflectivity and diffraction efficiency of the EUV mask.

[0005] According to one aspect of the present invention, an apparatus for measuring the phase of an EUV mask is provided, the apparatus comprising: an EUV light source configured to generate and output EUV coherent light; at least one reflector configured to reflect the EUV coherent light as reflected EUV coherent light incident on an EUV mask to be measured; a mask stage on which the EUV mask is disposed; a detector configured to receive the EUV coherent light reflected from the EUV mask to obtain a two-dimensional (2D) image and to measure the reflectivity and diffraction efficiency of the EUV mask; and a processor configured to calculate or determine the phase of the EUV mask using the reflectivity and diffraction efficiency of the EUV mask. The EUV mask includes a first mask pattern region for measuring reflectivity and a second mask pattern region for measuring diffraction efficiency.

[0006] According to one aspect of the present invention, a method for measuring the phase of an EUV mask is provided, the method comprising: measuring the reflectance of multiple layers of a first mask pattern region of the EUV mask to be measured using a phase measuring device; measuring the reflectance of an absorbing layer of the first mask pattern region using the phase measuring device; measuring the diffraction efficiency of a pattern of an absorbing layer of a second mask pattern region of the EUV mask using the phase measuring device; and calculating or determining the phase of the EUV mask using the reflectance of each of the multiple layers and the absorbing layer of the first mask pattern region and the diffraction efficiency of the pattern of the absorbing layer of the second mask pattern region.

[0007] According to one aspect of the present invention, a method for manufacturing an EUV mask is provided, the method comprising: manufacturing a first EUV mask; measuring the reflectance of multiple layers of a first mask pattern region of a second EUV mask to be measured using a phase measuring device; measuring the reflectance of an absorption layer of the first mask pattern region using the phase measuring device; measuring the diffraction efficiency of a pattern of an absorption layer of a second mask pattern region of the second EUV mask using the phase measuring device; calculating the phase of the first EUV mask using the reflectance of each of the multiple layers and absorption layers of the first mask pattern region and the diffraction efficiency of the pattern of an absorption layer of the second mask pattern region; determining whether the calculated phase is within an acceptable range; and completing the manufacturing of the first EUV mask when the phase is within an acceptable range. Attached Figure Description

[0008] The embodiments of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0009] Figure 1 This is a block diagram schematically illustrating an apparatus for measuring the phase of an extreme ultraviolet (EUV) mask according to an embodiment of the present invention.

[0010] Figure 2A and Figure 2B It will be by Figure 1 A cross-sectional view of an EUV mask measured by a device used to measure the phase of an EUV mask;

[0011] Figure 3 To show in more detail Figure 2A A cross-sectional view of the structure of an EUV mask;

[0012] Figures 4A to 4C It is shown by using Figure 1 A conceptual diagram of the apparatus used to measure the phase of an EUV mask and the process of measuring the phase of an EUV mask;

[0013] Figure 5 It is shown by using Figure 1A conceptual diagram illustrating the principle of a device for measuring the phase of an EUV mask.

[0014] Figures 6 to 8 This is a block diagram schematically illustrating an apparatus for measuring the phase of an extreme ultraviolet (EUV) mask according to an embodiment of the present invention.

[0015] Figure 9 This is a flowchart illustrating a method for measuring the phase of an EUV mask according to an embodiment of the present invention; and

[0016] Figure 10 This is a flowchart illustrating a method for manufacturing an EUV mask according to an embodiment of the present invention. Detailed Implementation

[0017] In the following, embodiments of the inventive concept will be described in detail with reference to the accompanying drawings. The same reference numerals always denote the same elements, and their previous descriptions may be omitted.

[0018] Figure 1 This is a block diagram schematically illustrating an apparatus 1000 for measuring the phase of an extreme ultraviolet (EUV) mask according to an embodiment of the present invention.

[0019] Reference Figure 1 The apparatus 1000 for measuring the phase of an EUV mask according to the present embodiment (hereinafter referred to as the "phase measuring apparatus") may include an EUV light source 100, a coherence unit or coherence system 200, a mirror unit or mirror system 300, a mask stage 400, a detector 500, and a processor 600.

[0020] EUV source 100 can be a device for generating and outputting EUV light, and specifically can generate and output 13.5 nm EUV light. For example, EUV source 100 can generate EUV light through plasma discharge. Laser plasma, discharge plasma, or high-temperature plasma can be used for plasma discharge.

[0021] On the other hand, femtosecond laser devices can be used for laser plasma. More specifically, femtosecond laser devices can include, for example, femtosecond titanium (Ti):sapphire laser devices. Femtosecond Ti:sapphire laser devices can generate pulsed lasers with frequencies of tens of MHz and can have a correlator connected to them. The laser from the femtosecond laser device can be directed into or onto a discharge cavity using a focusing lens. In the discharge cavity, a plasma-generating gas, such as neon, can be stored. By directing the laser onto the neon gas stored in the discharge cavity, plasma is generated, and light of various wavelengths (including EUV light) can be emitted from the plasma.

[0022] The coherence unit 200 may include a pinhole plate 210 and a filter 220. The pinhole plate 210 may be disposed at the rear end of the EUV light source 100 and may reduce the EUV light according to the pinhole size. Furthermore, the pinhole plate 210 may improve the spatial coherence of the light, so that the EUV light from the EUV light source 100 may become coherent light or coherent light. On the other hand, in the phase measurement device 1000 according to the present embodiment, the pinhole plate 210 is disposed between the EUV light source 100 and the filter 220. However, the position of the pinhole plate 210 is not limited to this. For example, according to one embodiment, the pinhole plate 210 may be disposed at the rear end of the filter 220.

[0023] Filter 220 can selectively transmit only EUV light from the light composition emitted from EUV source 100 and can remove other light components. For example, the light initially emitted from EUV source 100 (i.e., light emitted from plasma) can include light of various wavelengths, such as EUV light or vacuum ultraviolet (VUV) light. Therefore, filter 220 can allow only EUV light to illuminate EUV mask 2000 by blocking other light components besides EUV light from the light composition emitted from EUV source 100. Filter 220 can be considered to improve the spectral coherence of light.

[0024] Filter 220 may include, for example, a zirconium filter. Alternatively, the EUV light output through filter 220 may be EUV light with a center wavelength of 13.5 nm. For example, filter 220 may include an X-ray mirror. The X-ray mirror can illuminate EUV light with a center wavelength of 13.5 nm onto EUV mask 2000. That is, the X-ray mirror can select EUV light with a center wavelength of 13.5 nm and the mirror unit 300 can be used to illuminate the selected EUV light onto EUV mask 2000.

[0025] On the other hand, according to one embodiment, the coherence unit 200 may further include a shutter disposed between the EUV light source 100 and the pinhole plate 210 or between the EUV light source 100 and the filter 220. The shutter can control the amount of EUV light irradiating the EUV mask 2000 by controlling the amount of EUV light output from the EUV light source 100.

[0026] The mirror unit 300 may include a first mirror 310 and a second mirror 320. The first mirror 310 can converge EUV light, and the second mirror 320 can guide EUV light to be incident on the EUV mask 2000 at a predetermined angle. In the phase measurement apparatus 1000 according to the present embodiment, the first mirror 310 may be a concave mirror or include a concave mirror, and the second mirror 320 may be a planar mirror or include a planar mirror. For example, the first mirror 310 may be or include a concave mirror such as a spherical mirror or an elliptical mirror.

[0027] The positions and functions of the first reflector 310 and the second reflector 320 will be described in more detail. The first reflector 310 can be arranged around the EUV mask 2000 on the side of the coherence unit 200 away from the EUV source 100. Furthermore, the first reflector 310, being a concave reflector, can have a concave surface that reflects EUV light and converges the reflected EUV light onto the second reflector 320. Therefore, EUV light can be incident on the first reflector 310 and then reflected towards the upper space where the second reflector 320 is arranged. Furthermore, EUV light can be converged through the first reflector 310 and can be incident on the second reflector 320. Specifically, for example, when the first reflector 310 is a spherical or elliptical reflector, the second reflector 320 can be arranged at the focal point of the spherical or elliptical reflector. Therefore, EUV light incident on the first reflector 310 can be reflected from the first reflector 310 and can be converged onto the second reflector 320 arranged at the focal point of the first reflector 310.

[0028] The second reflector 320 can be arranged in the upper space of the EUV mask 2000 (e.g., above the EUV mask 2000). For example, the second reflector 320 can be arranged at a position higher than the first reflector 310. However, according to one embodiment, the second reflector 320 can be arranged at a position lower than the first reflector 310. Furthermore, the second reflector 320, as a planar reflector, can have a plane that reflects EUV light onto the EUV mask 2000. Therefore, EUV light incident from the first reflector 310 can be reflected by the second reflector 320 and can travel towards the upper surface of the EUV mask 2000.

[0029] On the other hand, the tilt angle of the second reflector 320 can be controlled such that the incident angle θ of the EUV light onto the upper surface of the EUV mask 2000 is 2° to 10° (e.g., relative to the normal perpendicular to the upper surface of the EUV mask 2000). In the phase measurement apparatus 1000 according to the present embodiment, the tilt angle of the second reflector 320 can be controlled such that the incident angle θ of the EUV light is approximately 6°. Furthermore, the light incident on the EUV mask 2000 can be diffracted and reflected due to the pattern of the absorption layer formed on the upper surface of the EUV mask 2000. Figure 1 In the diagram, the portion of light reflected from the EUV mask 2000 marked with a solid line represents the 0th-order diffracted light, and the portion marked with a dashed line represents the first-order diffracted light. Based on the shape of each pattern in the absorption layer formed on the upper surface of the EUV mask 2000, diffracted light of the second order and above can be obtained.

[0030] Due to the arrangement of the first reflector 310 as a concave reflector and the second reflector 320 as a planar reflector, the phase measurement device 1000 according to the present embodiment can effectively irradiate EUV light onto the EUV mask 2000 even in a narrow space.

[0031] The EUV mask 2000 to be measured can be arranged on the mask stage 400. According to one embodiment, the mask stage 400 can move horizontally in the XY plane and vertically in the Z-axis. Depending on the two-dimensional or three-dimensional movement of the mask stage 400, the EUV mask 2000 can also move in two or three dimensions. According to one embodiment, the mask stage 400 may include a position sensor to control the position or measurement position of the EUV mask 2000.

[0032] Detector 500 detects EUV light reflected and diffracted from EUV mask 2000. As a device capable of performing spatial decomposition, detector 500 may include an imaging device capable of acquiring a far-field diffraction image as a two-dimensional (2D) image. This imaging device can collect the field spectrum of the reflected light, convert the reflected light into an electrical signal, and output the electrical signal. For example, in the phase measurement device 1000 according to the present embodiment, detector 500 may include a charge-coupled device (CCD) camera using X-rays. However, detector 500 is not limited to a CCD camera. For example, detector 500 may include a photodiode array (PDA) detector and a CMOS image sensor (CIS) camera.

[0033] Detector 500 can measure multiple layers of EUV mask 2000 (see reference). Figure 2A (2100) and the first absorption layer (refer to) Figure 2A The reflectance of each of the 2200 and the second absorption layer of the EUV mask 2000 (refer to...) Figure 2B The diffraction efficiency of the pattern at 2200a). (Refer to...) Figures 4A to 4C The reflectivity of each of the multilayer and the first absorption layer, as well as the diffraction efficiency of the pattern of the second absorption layer, are described in more detail.

[0034] Processor 600 can reconstruct the image through a program based on imaging information received from detector 500. Furthermore, processor 600 can calculate the phase of the EUV mask based on the imaging information. Here, the imaging information may include the reflectance of each of the multiple layers and the first absorption layer of the EUV mask 2000, as well as the diffraction efficiency of the pattern of the second absorption layer of the EUV mask 2000. Therefore, processor 600 can specifically calculate the absolute value of the phase of the EUV mask 2000 by using the reflectance and diffraction efficiency of the EUV mask 2000 to be measured. (See reference...) Figure 5 The phase calculation via processor 600 is described in more detail. On the other hand, processor 600 may include an interface such as a personal computer (PC) to allow large amounts of data from detector 500 to be processed in a short time.

[0035] The phase measurement apparatus 1000 according to the present embodiment can measure the reflectivity of each of the multilayers and absorption layers in the first mask pattern region of an EUV mask using EUV light and a detector (such as a CCD camera), receive diffracted light in the second mask pattern region of the EUV mask, and measure the diffraction efficiency of the diffracted light by using the reflectivity of the multilayers in the first mask pattern region or the intensity of the reflected light. Furthermore, the phase measurement apparatus 1000 according to the present embodiment can accurately measure the phase of the EUV mask by specifically calculating the absolute value of the phase of the EUV mask via a formula for diffraction efficiency or a phase measurement algorithm based on the reflectivity of each of the multilayers and absorption layers in the first mask pattern region and the diffraction efficiency of the diffracted light. Therefore, the phase measurement apparatus 1000 according to the present embodiment can significantly improve the quality of the EUV mask by providing accurate phase information about the EUV mask.

[0036] For reference, since current EUV masks with an absorption layer region having approximately 2% reflectivity are not perfect binary masks, it is necessary to manage the reflectivity and phase of the EUV mask. Here, a binary mask can refer to a mask having a multilayer region and an absorption layer region, where the multilayer region has almost 100% reflectivity and the absorption layer region has almost 0% reflectivity. Furthermore, in the EUV phase-shifting mask (PSM) to be developed, the phase of the EUV mask is one of the most important factors limiting the quality of the EUV mask. Conventional measuring devices cannot specifically measure the absolute value of the phase of the EUV mask. The phase measuring device 1000 according to the current embodiment can accurately measure the phase of the EUV mask using the aforementioned components and phase measurement algorithm, thus significantly improving the quality of the EUV mask.

[0037] Figure 2A and Figure 2B It will be by Figure 1 A cross-sectional view of an EUV mask 2000 measured by an apparatus used to measure the phase of an EUV mask.

[0038] Reference Figure 2A The EUV mask 2000 may include a first mask pattern region 2000A1. The first mask pattern region 2000A1 may include a multilayer 2100 and a first absorption layer 2200. The multilayer 2100 may have a structure in which two different material layers are alternately stacked. For example, the multilayer 2100 may have a structure in which silicon (Si) layers and molybdenum (Mo) layers are alternately stacked. More specifically, for example, the multilayer 2100 may be formed by stacking about 40 to 60 bilayers, each bilayer including a Si layer and a Mo layer. Furthermore, the Si layer and Mo layer forming the multilayer 2100 may have thicknesses of about 3 nm and 4 nm, respectively.

[0039] On the other hand, the multilayer 2100 can be formed on a mask substrate (such as a Si substrate or a quartz substrate). (See reference...) Figure 3 The EUV mask, including the mask substrate, is described in more detail.

[0040] The first absorption layer 2200 can be disposed on the multilayer 2100. Furthermore, as... Figure 2A As shown, a first absorption layer 2200 with a predetermined pattern can be disposed on a multilayer 2100. For example, the first absorption layer 2200 may have a line and space pattern that is spaced apart from each other in a first direction (x-direction) and extends in a second direction (y-direction). The pattern of the first absorption layer 2200 is not limited to a line and space pattern. The pattern of the first absorption layer 2200 can be repeatable, making phase calculation easier. However, the pattern of the first absorption layer 2200 does not necessarily have to be repeatable.

[0041] The first absorbing layer 2200, which absorbs EUV light, can be formed of tantalum nitride (TaN), Ta, titanium nitride (TiN), or Ti. However, the material of the first absorbing layer 2200 is not limited to the above-mentioned materials. On the other hand, although not shown, a capping layer can exist between the first absorbing layer 2200 and the multilayer 2100. (Refer to...) Figure 3 A more detailed description of the caprock.

[0042] In the apparatus 1000 for measuring the phase of an EUV mask according to the present embodiment, the first mask pattern region 2000A1 of the EUV mask 2000 may include a pattern of first absorption layers 2200 on the order of millimeters. That is, in the first mask pattern region 2000A1, when the first absorption layers 2200, which are line and spacing patterns, are regularly repeated and the distance or spacing between the first absorption layers 2200 has a first width W1 and a first pitch P1 in the first direction (x direction), each of the first width W1 and the first pitch P1 is about a few millimeters, and according to the definition of pitch, the first pitch P1 is greater than the first width W1.

[0043] In the following text, the portion of the first absorption layer 2200 that exposes the multilayer 2100 is referred to as the multilayer region MLA, and a portion of the first absorption layer 2200 is referred to as the absorption layer region ALA. Due to the characteristics that the multilayer region MLA is bright and the absorption layer region ALA is dark, the multilayer region MLA is referred to as the bright area and the absorption layer region ALA is referred to as the dark area.

[0044] The first mask pattern region 2000A1 can be used to measure the reflectance of the multilayer region MLA and the absorption layer region ALA. Generally, reflectance can be defined as the ratio of the intensity of reflected light to the intensity of incident light. When the size of the absorption layer pattern and the distance between the absorption layers are very small, it may be difficult to accurately measure the reflectance of each of the multilayer region MLA and the absorption layer region ALA. That is, when measuring the reflectance of the multilayer region MLA, light generated by reflection, diffraction, and scattering in the absorption layer region ALA may be included in the reflected light from the multilayer region MLA, making it impossible to measure the reflectance of the multilayer region MLA correctly. Furthermore, when calculating the reflectance of the absorption layer region ALA, the reflected light from the multilayer region MLA may affect the measurement, or reflections from the side surfaces of the absorption layer may affect the measurement, thus preventing an accurate measurement of the reflectance of the absorption layer region ALA.

[0045] Therefore, the aforementioned problem can be solved by forming the pattern of the first absorption layer 2200 of the first mask pattern region 2000A1 relatively large, at the millimeter level. Thus, the apparatus 1000 for measuring the phase of an EUV mask according to the present embodiment can accurately measure the reflectance of each of the multilayer region MLA and the absorption layer region ALA using the first mask pattern region 2000A1.

[0046] Reference Figure 2B The EUV mask 2000 may include a second mask pattern region 2000A2, which may include a multilayer 2100 and a second absorption layer 2200a. The second absorption layer 2200a may differ in size from the first absorption layer 2200 of the first mask pattern region 2000A1. More specifically, the multilayer 2100 of the second mask pattern region 2000A2 may be the same as that described for the multilayer 2100 of the first mask pattern region 2000A1. On the other hand, the material or properties of the second absorption layer 2200a may be the same as those described for the first absorption layer 2200 of the first mask pattern region 2000A1. However, the pattern of the second absorption layer 2200a may differ from the pattern of the first absorption layer 2200 of the first mask pattern region 2000A1 in that the pattern of the second absorption layer 2200a has a micrometer-scale size. For example, the second absorption layer 2200a, which is a line and spacing pattern, may have a second width W2 of about a few micrometers and a second pitch P2 of about a few micrometers in the first direction (x direction). Furthermore, according to the definition of pitch, the second pitch P2 is greater than the second width W2.

[0047] The second mask pattern region 2000A2 can be used to measure the diffraction efficiency of the absorption layer pattern. Diffraction efficiency can be defined as the ratio of the intensity of diffracted light in the absorption layer pattern to the intensity of reflected light in the multilayer region MLA. Furthermore, diffraction efficiency can be defined for each of the 0th-order diffracted light and higher-order diffracted light components. That is, the diffraction efficiency of the 0th-order diffracted light can be defined as the ratio of the intensity of the 0th-order diffracted light to the intensity of reflected light in the multilayer region MLA, and the diffraction efficiency of the first-order diffracted light can be defined as the ratio of the intensity of the first-order diffracted light to the intensity of reflected light in the multilayer region MLA.

[0048] The apparatus 1000 for measuring the phase of an EUV mask according to the current embodiment can actually measure the phase of an actual EUV mask and can correctly determine whether the phase of the actual EUV mask 2000 is defective by measuring the phase of the EUV mask 2000, which is measured by measuring the diffraction efficiency of a second mask pattern region 2000A2 of the EUV mask 2000, which includes a pattern of a second absorber layer 2200a at the micrometer scale.

[0049] For reference, the size of an actual EUV mask pattern can be on the nanometer scale. Calculating the optical diffraction efficiency of an actual EUV mask with a nanometer-scale absorption layer pattern, and the phase of the actual EUV mask based on the diffraction efficiency, can be very complex. However, considering the conceptual aspects of the phase of an EUV mask, when the thickness of the absorption layer is almost zero, the difference between the phase of an EUV mask with a micrometer-scale absorption layer pattern and that with a nanometer-scale absorption layer pattern may be small. Therefore, the apparatus 1000 for measuring the phase of an EUV mask according to the present embodiment can calculate the phase of the EUV mask 2000 after calculating the diffraction efficiency of the second mask pattern region 2000A2 with a micrometer-scale second absorption layer 2200a pattern, by making the thickness of the second absorption layer 2200a almost zero. The calculated phase of the EUV mask 2000 is similar to the phase of an actual EUV mask and can help determine whether the phase of the actual EUV mask is defective.

[0050] Figure 3 To show in more detail Figure 2A A cross-sectional view of the structure of the EUV mask 2000. (Previous references will be omitted.) Figure 2A The given description.

[0051] Reference Figure 3 The EUV mask 2000 may include a mask substrate 2010, a back surface coating 2020, a multilayer 2100, a capping layer 2030, and a first absorber layer 2200. The mask substrate 2010 may be formed of a low thermal expansion material (LTEM). For example, the mask substrate 2010 may be a silicon substrate or a quartz substrate, or may include a silicon substrate or a quartz substrate.

[0052] A back surface coating 2020 can be formed on the lower surface of the mask substrate 2010, and a multilayer 2100 can be formed on the upper surface of the mask substrate 2010. The back surface coating 2020 can be formed of a conductive material such as a metal. The multilayer 2100 can include multiple alternately stacked Si layers 2120 and Mo layers 2110. The multilayer 2100 can be used with respect to... Figure 2A The first mask pattern area 2000A1 is the same as the multilayer 2100 described.

[0053] A capping layer 2030 may be formed on the multilayer 2100. A first absorbing layer 2200 may be formed on the capping layer 2030. That is, the capping layer 2030 may be located between the first absorbing layer 2200 and the multilayer 2100. The capping layer 2030 may include one or more material layers and may protect the multilayer 2100. For example, the capping layer 2030 may be formed of ruthenium (Ru). However, the material of the capping layer 2030 is not limited to Ru.

[0054] The first absorption layer 2200 may include an absorber 2210 and an anti-reflective coating (ARC) layer 2220. The absorber 2210 may be a layer that absorbs EUV light and may be formed of TaN, Ta, TiN, or Ti as described above. However, the material of the absorber 2210 is not limited to the materials described above. According to one embodiment, the ARC layer 2220, which prevents incident EUV light from being reflected, may be omitted.

[0055] like Figure 3 As shown, EUV light can be incident on the EUV mask 2000 at an incident angle of 6° and reflected at a reflection angle of 6°. Here, the incident angle and reflection angle are defined relative to the normal NL perpendicular to the upper surface of the EUV mask 2000, and the normal NL is... Figure 3 The lines are marked with dashed lines. The normal NL can be a vertical line. Furthermore, EUV light incident on the EUV mask 2000 can be diffracted due to the pattern of the first absorption layer 2200. Figure 3 The diagram shows the 0th-order diffraction beam (0th-Ld) marked with a solid line and the first-order diffraction beam (1st-Ld) marked with a dashed line. Diffraction beams may include diffraction beams of the second order and above.

[0056] Figures 4A to 4C It is shown by using Figure 1 A conceptual diagram of the apparatus used to measure the phase of an EUV mask, illustrating the process of measuring the phase of an EUV mask. (Refer to...) Figures 1 to 3 To describe it, and for the sake of brevity, refer to the previous... Figures 1 to 3 The given description can be omitted.

[0057] Reference Figure 4A First, the reflectance Rml of the multilayer region MLA of the first mask pattern region 2000A1 of the EUV mask 2000 is measured using the phase measurement device 1000 according to the present embodiment. Figure 4A For simplicity, only the multilayer region MLA of the first mask pattern region 2000A1 is shown. As described above, reflectivity R can be defined as the ratio of the intensity of reflected light to the intensity of incident light. Therefore, the reflectivity Rml of the multilayer region MLA can be calculated by measuring the EUV light Lrm reflected from the multilayer region MLA via detector 500 and dividing the intensity of the measured EUV light by the intensity of the EUV light incident on the multilayer region MLA.

[0058] Reference Figure 4B The reflectance Rabs of the absorption layer region ALA of the first mask pattern region 2000A1 of the EUV mask 2000 is measured by using the phase measurement device 1000 according to the present embodiment. Figure 4BFor convenience, the absorption layer region ALA of the first mask pattern region 2000A1 and only the portion of the multilayer region MLA adjacent to the absorption layer region ALA of the first mask pattern region 2000A1 are shown. The reflectivity Rabs of the absorption layer region ALA can be obtained by the same method as obtaining the reflectivity Rml of the multilayer region MLA. That is, the reflectivity Rabs of the absorption layer region ALA can be obtained by measuring the EUV light Lra reflected from the absorption layer region ALA and dividing the intensity of the measured EUV light by the intensity of the EUV light incident on the absorption layer region ALA.

[0059] Reference Figure 4C After obtaining the reflectance Rml of the multilayer region MLA of the first mask pattern region 2000A1 and the reflectance Rabs of the absorption layer region ALA of the first mask pattern region 2000A1, the diffraction efficiency of the diffracted light from the pattern of the second absorption layer 2200a of the second mask pattern region 2000A2 of the EUV mask 2000 is measured using the phase measurement device 1000 according to the present embodiment. More specifically, the diffracted light reflected from the pattern of the second absorption layer 2200a of the second mask pattern region 2000A2 is measured by the detector 500, and the intensity of the measured diffracted light is calculated by composition. For example, the intensity of the 0th-Ld diffracted light and the intensity of the 1st-Ld diffracted light are calculated. The diffraction efficiency can be defined as the ratio of the intensity of the diffracted light of the pattern of the second absorption layer 2200a to the intensity of the reflected light of the multilayer region MLA. Furthermore, the diffraction efficiency can be obtained by composition. For example, the diffraction efficiency I0 of the 0th-order diffracted light 0th-Ld can be obtained by dividing the intensity of the 0th-order diffracted light 0th-Ld by the intensity of the reflected light from the multilayer region MLA. Similarly, the diffraction efficiency I1 of the 1st-Ld of the first-order diffracted light can be obtained by dividing the intensity of the 1st-Ld of the first-order diffracted light by the intensity of the reflected light from the multilayer region MLA.

[0060] Then, by using the reflectivity Rml of the multilayer region MLA, the reflectivity Rabs of the absorption layer region ALA, and the diffraction efficiency of each component of the diffracted light, the absolute value of the phase of the EUV mask 2000 can be specifically calculated. On the other hand, the calculated phase of the EUV mask 2000, as described above, is similar to the phase of an actual EUV mask. (Refer to...) Figure 5 The principle of obtaining the absolute value of the phase of the EUV mask is described in more detail.

[0061] Figure 5 It is shown by using Figure 1 A conceptual diagram illustrating the principle of an apparatus for measuring the phase of an EUV mask. For simplicity, the preceding references can be omitted. Figures 1 to 4C The given description.

[0062] Reference Figure 5 The EUV mask 2000 may include multiple layers 2100 and a second absorption layer 2200a. On the other hand, as... Figure 5 As shown, the second absorption layer 2200a has a repeating pattern of lines and spacing that are spaced apart from each other in a first direction (x-direction) and extend in a second direction (y-direction). Figure 5 In the middle, A 0,ML and A 1,ML These can be represented as the 0th-order diffraction light and the 1st-order diffraction light in a multilayer 2100, respectively. 0,abs and A 1,abs These can be represented as the 0th order diffraction light and the first order diffraction light in the second absorption layer 2200a, respectively.

[0063] According to diffraction theory, when the thickness t of the second absorption layer 2200a is almost 0, the diffraction efficiency I0 of the 0th order diffracted light and the diffraction efficiency I1 of the first order diffracted light in the repeating line and spacing pattern can be expressed by Equation 1 and Equation 2.

[0064]

[0065]

[0066] Where w can represent the distance between patterns in the second absorption layer 2200a in the first direction (x direction) or the width of the multilayer region MLA, and p can represent the pitch of each pattern in the second absorption layer 2200a in the first direction (x direction). Furthermore, Rr can represent the ratio Rabs / Rml of the reflectivity Rabs of the absorption layer region ALA or dark area to the reflectivity Rml of the multilayer region MLA or bright area. It can represent the phase of EUV mask 2000.

[0067] On the other hand, I0 and I1 can be calculated or determined by the phase measuring device 1000 according to the present embodiment, as described above. Therefore, by calculating or determining w that simultaneously satisfies I0 and I1 using Formula 1 and Formula 2... The phase of the EUV mask 2000 can be calculated or determined. Furthermore, when w is measured or obtained by a measuring instrument using other methods, or when w is previously known or possessed, it can be calculated by substituting w into Formulas 1 and 2. It can calculate the phase of EUV mask 2000.

[0068] On the other hand, when the distance between the patterns of the second absorption layer 2200a is half the pitch of each pattern of the second absorption layer 2200a, that is, when w = p / 2 is established, It can be represented by Formula 3.

[0069]

[0070] The phase measurement device 1000 according to the current embodiment can measure the reflectivity Rml of the multilayer region MLA and the reflectivity Rabs of the absorption layer region ALA using the first mask pattern region 2000A1 of the EUV mask 2000, can measure the diffraction efficiency values ​​I0 and I1 of the diffracted light components using the second mask pattern region 2000A2 of the EUV mask 2000, and can specifically calculate the phase of the EUV mask 2000 by applying the diffraction efficiency values ​​I0 and I1 to Formulas 1 and 2 according to diffraction theory.

[0071] For reference, when the second absorption layer 2200a has a repeating pattern in the form of lines and spacing, the diffracted light of the second order and above is negligible and therefore need not be considered. However, when the second absorption layer 2200a has a repeating pattern different from the repeating pattern in the form of lines and spacing, according to diffraction theory, a different formula for diffraction efficiency can be derived from Equations 1 and 2, and the diffracted light of the second order and above can be considered. Furthermore, when the second absorption layer 2200a does not have this repeating pattern, the formula for diffraction efficiency may become more complex.

[0072] Figures 6 to 8 This is a block diagram illustrating an apparatus for measuring the phase of an EUV mask according to an embodiment of the present invention. For brevity, previous references may be omitted. Figures 1 to 5 The given description.

[0073] Reference Figure 6 The phase measurement device 1000a according to the current embodiment can be configured in conjunction with the mirror unit or mirror system 300a. Figure 1 The phase measuring device 1000 differs from the one described above. Specifically, in the phase measuring device 1000a according to the present embodiment, the mirror unit 300a includes a first mirror 310a and a second mirror 320. The first mirror 310a may not be a concave mirror and may be a planar mirror like the second mirror 320. When the EUV light from the EUV source 100 does not spread widely, convergence may not be necessary. Therefore, in the phase measuring device 1000a according to the present embodiment, the first mirror 310a of the mirror unit 300a may be formed of a planar mirror.

[0074] Reference Figure 7 The phase measurement device 1000b according to the current embodiment can be configured with the EUV light source 100a and the coherence unit or coherence system 200a. Figure 1The phase measurement device 1000 differs from the phase measurement device 1000b according to the present embodiment. Specifically, in the phase measurement device 1000b, the coherence unit 200a may only include the filter 220 and may not include the pinhole plate. Furthermore, the EUV light source 100a may not be a conventional EUV light source and may be a coherent EUV light source that outputs coherent EUV light. For example, the EUV light source 100a may be a high harmonic generation (HHG) EUV light source that generates higher-order harmonics.

[0075] When the EUV light source 100a is a coherent EUV light source, considering that the pinhole plate is arranged to improve the spatial coherence of the light, the pinhole plate may not be necessary. Therefore, in the phase measurement apparatus 1000b according to the present embodiment, the coherence unit 200a may not include the pinhole plate and may only include the filter 220. Although the EUV light source 100a is a coherent EUV light source, when it is necessary to reduce the size of the EUV light, a pinhole plate in which pinholes with corresponding sizes are formed may be arranged or provided.

[0076] Reference Figure 8 The phase measurement device 1000c according to the current embodiment can be configured in conjunction with the mirror unit or mirror system 300b. Figure 1 The phase measurement device 1000 differs from the one described in the present embodiment. Specifically, in the phase measurement device 1000c according to the present embodiment, the mirror unit 300b may include only the second mirror 320 and may not include the first mirror. Therefore, EUV light from the coherence unit 200 can be incident on the second mirror 320 and can be reflected from the second mirror 320 and directly incident on the EUV mask 2000 to be measured.

[0077] The second reflector 320, serving as a plane reflector, can have the same... Figure 1 The second reflector 320 of the phase measuring device 1000 has essentially the same function. That is, the second reflector 320 can cause EUV light to be incident on the EUV mask 2000 at an incident angle θ of approximately 6°. According to one embodiment, the second reflector 320 can converge EUV light and cause the converged EUV light to be incident on the EUV mask 2000. In this case, the second reflector 320 can be in the form of a concave reflector.

[0078] In the phase measurement apparatus 1000c according to the present embodiment, in order to cause EUV light to be incident on the EUV mask 2000 at an incident angle θ of about 6°, the second reflector 320 can be arranged at a specific distance from the EUV mask 2000. However, in the phase measurement apparatus 1000c according to the present embodiment, only the second reflector 320 is arranged or provided, which can be advantageous in terms of optical loss.

[0079] Figure 9This is a flowchart illustrating a method for measuring the phase of an EUV mask according to an embodiment of the present invention. (Refer to...) Figures 1 to 2B Provide a description, and for the sake of brevity, previous references can be omitted. Figures 1 to 8 The given description.

[0080] Reference Figure 9 In the method for measuring an EUV mask according to the current embodiment (hereinafter referred to as the "phase measurement method"), firstly, in operation S110, the reflectance of the multilayer 2100 or multilayer region MLA of the first mask pattern region 2000A1 of the EUV mask 2000 is measured using a phase measurement device 1000. The reflectance of the multilayer 2100 can be calculated by measuring the EUV light reflected from the multilayer 2100 by a detector 500 and dividing the intensity of the measured EUV light by the intensity of the EUV light incident on the multilayer 2100 based on the definition of reflectance.

[0081] Next, in operation S120, the reflectance of the first absorption layer 2200 or absorption layer region ALA of the first mask pattern region 2000A1 of the EUV mask 2000 is measured using the phase measurement device 1000. The reflectance of the first absorption layer 2200 can be calculated in the same manner as calculating the reflectance of the multilayer 2100 by measuring the EUV light reflected from the first absorption layer 2200 by the detector 500 and dividing the intensity of the measured EUV light by the intensity of the EUV light incident on the first absorption layer 2200.

[0082] Then, in operation S130, the diffraction efficiency of each pattern of the second absorption layer 2200a of the second mask pattern region 2000A2 of the EUV mask 2000 is measured using the phase measurement device 1000. The diffraction efficiency can be calculated by dividing the intensity of the diffracted light from each pattern of the second absorption layer 2200a by the intensity of the EUV light reflected from the multilayer 2100. Furthermore, the diffraction efficiency can be calculated for each component of the diffracted light. For example, the diffraction efficiency I0 of the 0th-order diffracted light can be calculated by dividing the intensity of the 0th-order diffracted light by the intensity of the EUV light reflected from the multilayer 2100. Similarly, the diffraction efficiency I1 of the first-order diffracted light can be calculated by dividing the intensity of the first-order diffracted light by the intensity of the EUV light reflected from the multilayer 2100.

[0083] exist Figure 9 In this process, the operations are performed in the following order: operation S110 measuring the reflectance of the multilayer, operation S120 measuring the reflectance of the first absorption layer, and operation S130 measuring the diffraction efficiency of each pattern in the second absorption layer. However, the inventive concept is not limited thereto. For example, the operations can be performed independently, and the order in which the operations are performed can be arbitrary.

[0084] After measuring the reflectance of each of the multilayers 2100 and the first absorption layer 2200 of the EUV mask 2000, and measuring the diffraction efficiency of each pattern of the second absorption layer 2200a, the phase of the EUV mask 2000 is calculated in operation S140. The phase of the EUV mask 2000 can be calculated by applying the measured reflectance and diffraction efficiency to Equations 1 and 2 according to diffraction theory. For example, when the pattern of the second absorption layer 2200a of the EUV mask 2000 repeats in the form of lines and spacing, the distance between the patterns of the second absorption layer 2200a is w, and the pitch of each pattern of the second absorption layer 2200a is p, the diffraction efficiency I0 of the 0th order diffracted light and the diffraction efficiency I1 of the first order diffracted light are expressed by Equations 1 and 2, and by obtaining a result that simultaneously satisfies Equations 1 and 2... Alternatively, it can be obtained by applying the measured or previously known w to Equations 1 and 2. The phase of the EUV mask 2000 can be calculated. Furthermore, the calculated phase of the EUV mask 2000 is similar to the phase of the actual EUV mask and can, as mentioned above, help determine whether the phase of the actual EUV mask is defective.

[0085] Figure 10 This is a flowchart illustrating a method for manufacturing an EUV mask according to an embodiment of the concept of the present invention. (Refer to...) Figures 1 to 2B Provide a description, and for the sake of brevity, previous references can be omitted. Figure 9 The given description.

[0086] Reference Figure 10 In the method for manufacturing an EUV mask according to the current embodiment, firstly, an EUV mask is manufactured in operation S210. The EUV mask can be manufactured using methods typically used for manufacturing EUV masks. For example, an EUV mask can be manufactured by performing a pattern layout design on the mask, obtaining design data on the mask via an OPC method, transmitting mask tape output (MTO) design data, preparing mask data, exposing the mask substrate, and performing subsequent processes.

[0087] Then, the phase of the EUV mask is measured in operation S220. The phase of the EUV mask can be measured without measuring the phase of the previously manufactured actual EUV mask, and can be as follows: Figure 9 The phase measurement method described herein involves measuring the phase using a first mask pattern region 2000A1 and a second mask pattern region 2000A2 of an EUV mask 2000. Detailed methods for measuring the phase of an EUV mask are referenced. Figure 9 The description is the same.

[0088] Next, in operation S230, it is determined whether the measured phase of the EUV mask is within the allowable range. Normally, the EUV mask must have the required phase. However, when the material or pattern of each of the first absorption layer 2200 and the second absorption layer 2200a is defective, the EUV mask may not have the required phase. On the other hand, defects in the pattern of each of the first absorption layer 2200 and the second absorption layer 2200a may be caused by process errors when forming the pattern of each of the first absorption layer 2200 and the second absorption layer 2200a. Therefore, by... Figure 9 The phase measurement method measures the phase of the EUV mask 2000, which can indirectly measure the phase of the actual EUV mask. As mentioned above, the phase of the EUV mask 2000 can be similar to the phase of the actual EUV mask.

[0089] For reference, EUV mask 2000 may differ in scale from an actual EUV mask, and the materials of multilayer 2100, the first absorber layer 2200, and the second absorber layer 2200a may be the same as those of the multilayers and absorber layers of the actual EUV mask, and the manufacturing process of EUV mask 2000 may be the same as that of the actual EUV mask. Therefore, during the manufacturing of an actual EUV mask, if errors in the material or process conditions of each absorber layer cause the phase of the actual EUV mask to deviate from the allowable range, the same error may occur in EUV mask 2000, and the measured phase may also deviate from the allowable range.

[0090] When the calculated phase is within the allowable range (yes), the EUV mask fabrication is completed in operation S240. When the calculated phase deviates from the allowable range (no), the cause is analyzed and / or the process conditions are changed in operation S250. Here, the process conditions may include the materials of the multilayer 2100 and the first absorber layer 2200 and the second absorber layer 2200a. Then, the process returns to operation S210 for fabricating the EUV mask, and a new EUV mask is fabricated based on the changed process conditions.

[0091] The method for manufacturing an EUV mask according to the current embodiment can be achieved by referring to... Figure 9 The described phase measurement method accurately measures the phase of an EUV mask and determines whether the phase of the EUV mask is defective, thus significantly improving the quality of the EUV mask.

[0092] Although the inventive concept has been specifically shown and described with reference to embodiments thereof, it will be understood that various changes in form and detail may be made therein without departing from the scope of the appended claims.

[0093] This application claims the benefit of Korean Patent Application No. 10-2020-0034057, filed on March 19, 2020, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. An apparatus for measuring the phase of an extreme ultraviolet (EUV) mask, the apparatus comprising: EUV light source, configured to generate and output EUV light; At least one reflector is configured to reflect the EUV light as reflected EUV light incident on the EUV mask to be measured; A mask stage, on which the EUV mask is arranged; A detector is configured to receive EUV light reflected from the EUV mask to obtain a two-dimensional (2D) image and to measure the reflectivity and diffraction efficiency of the EUV mask. as well as A processor configured to determine the phase of the EUV mask using the reflectivity and diffraction efficiency of the EUV mask.

2. The apparatus for measuring the phase of an extreme ultraviolet (EUV) mask as claimed in claim 1, wherein the EUV mask comprises a first mask pattern region for measuring reflectivity and a second mask pattern region for measuring diffraction efficiency. Each of the first mask pattern region and the second mask pattern region includes a pattern of multiple layers and an absorption layer on the multiple layers. The detector is configured to receive reflected light from the multilayer of the first mask pattern region and reflected light from the absorption layer of the first mask pattern region, and to measure the reflectivity of the multilayer of the first mask pattern region and the reflectivity of the absorption layer of the first mask pattern region. The detector is configured to receive diffracted light from the pattern of the absorption layer in the second mask pattern region, and to measure the diffraction efficiency using the reflected light from the multilayer of the first mask pattern region. The diffraction efficiency is expressed as the ratio of the intensity of the diffracted light to the intensity of the reflected light from the multilayer of the first mask pattern region.

3. The apparatus for measuring the phase of an extreme ultraviolet mask as claimed in claim 2, wherein the pattern of the absorption layer in the second mask pattern region comprises a repeating line and spacing pattern. in, When the width of each spacing of the pattern in the absorption layer of the second mask pattern region is w and the pitch of each pattern in the absorption layer of the second mask pattern region is p, The diffraction efficiency I0 of the 0th-order diffracted light and the diffraction efficiency I1 of the 1st-order diffracted light are expressed by Equation 1 and Equation 2, respectively. Official 1 Formula 2, and Where Rr represents the ratio of the reflectivity of the absorption layer in the first mask pattern region to the reflectivity of the multiple layers in the first mask pattern region, and The phase of the EUV mask is indicated.

4. The apparatus for measuring the phase of an extreme ultraviolet mask as described in claim 3, wherein w and I1 simultaneously satisfy the measured I0 and I1 are calculated. , or the aforementioned The calculation is performed by measuring w and substituting the measured w into Formulas 1 and 2.

5. The apparatus for measuring the phase of an extreme ultraviolet mask as described in claim 3, wherein, When w is 1 / 2 of p Official 3, The It is represented by Formula 3.

6. The apparatus for measuring the phase of an extreme ultraviolet mask as claimed in claim 1, wherein the at least one reflector comprises a first reflector and a second reflector. The first reflector is configured to reflect the EUV light from the EUV light source and focus the reflected EUV light onto the second reflector. The second reflector is configured to reflect the EUV light from the first reflector as the reflected EUV light incident on the EUV mask to be measured.

7. The apparatus for measuring the phase of an extreme ultraviolet mask as claimed in claim 1, further comprising a pinhole plate and a filter at the rear end of the EUV light source. The EUV light is converted into coherent light using the pinhole plate.

8. An apparatus for measuring the phase of an extreme ultraviolet (EUV) mask, the apparatus comprising: EUV light source, configured to generate and output EUV coherent light; At least one mirror is configured to reflect the EUV coherent light as reflected EUV coherent light incident on the EUV mask to be measured. A mask stage on which the EUV mask is disposed; A detector is configured to receive EUV coherent light reflected from the EUV mask to obtain a two-dimensional (2D) image and to measure the reflectivity and diffraction efficiency of the EUV mask. as well as The processor is configured to calculate the phase of the EUV mask using the reflectivity and diffraction efficiency of the EUV mask. The EUV mask includes a first mask pattern region for measuring reflectivity and a second mask pattern region for measuring diffraction efficiency.

9. The apparatus for measuring the phase of an extreme ultraviolet mask as claimed in claim 8, wherein the first mask pattern region comprises multiple layers and a pattern of a first absorption layer on the multiple layers of the first mask pattern region, each of the patterns of the first absorption layer having a millimeter-level pitch. The second mask pattern region includes multiple layers and a pattern of a second absorption layer on the multiple layers of the second mask pattern region, each of the patterns of the second absorption layer having a pitch on the order of micrometers. The detector is configured to receive reflected light from the multilayer of the first mask pattern region and reflected light from the first absorption layer of the first mask pattern region, and to measure the reflectivity of the multilayer of the first mask pattern region and the reflectivity of the first absorption layer. The detector is configured to receive diffracted light from the pattern of the second absorption layer in the second mask pattern region, and to measure the diffraction efficiency using the reflected light from the multilayer of the first mask pattern region. The diffraction efficiency is represented by the ratio of the intensity of the diffracted light to the intensity of the reflected light from the multilayer of the first mask pattern region.

10. The apparatus for measuring the phase of an extreme ultraviolet mask as claimed in claim 9, wherein the pattern of the second absorption layer comprises a repeating line and spacing pattern. in, When the width of each spacing of the pattern in the second absorption layer is w and the pitch of each pattern in the second absorption layer is p, The diffraction efficiency I0 of the 0th-order diffracted light and the diffraction efficiency I1 of the 1st-order diffracted light are expressed by Equation 1 and Equation 2, respectively. Official 1 Formula 2, and Where Rr represents the ratio of the reflectivity of the first absorption layer to the reflectivity of the multiple layers in the first mask pattern region, and The phase of the EUV mask is indicated.

11. The apparatus for measuring the phase of an extreme ultraviolet mask as claimed in claim 10, wherein w and I1 simultaneously satisfy the measured I0 and I1 are calculated. , or the aforementioned The calculation is performed by measuring w and substituting the measured w into Formulas 1 and 2.

12. The apparatus for measuring the phase of an extreme ultraviolet mask as claimed in claim 8, wherein the at least one reflector comprises a first reflector and a second reflector. The first reflector is configured to reflect the EUV coherent light from the EUV light source and focus the reflected EUV coherent light onto the second reflector. The second reflector is configured to reflect the EUV coherent light from the first reflector as the reflected EUV coherent light incident on the EUV mask to be measured at an incident angle of 6°.

13. A method for measuring the phase of an extreme ultraviolet (EUV) mask, the method comprising: The reflectance of multiple layers of the first mask pattern region of the EUV mask to be measured is measured using a phase measurement device; The reflectivity of the absorption layer in the first mask pattern region is measured using the phase measurement device. The diffraction efficiency of the absorption layer pattern in the second mask pattern region of the EUV mask is measured using the phase measurement device. as well as The phase of the EUV mask is determined using the reflectivity of each of the multilayers and the absorption layers in the first mask pattern region and the diffraction efficiency of the pattern of the absorption layer in the second mask pattern region.

14. The method for measuring the phase of an extreme ultraviolet mask as claimed in claim 13, wherein the phase measuring device comprises: EUV light source, configured to generate and output EUV light; At least one reflector is configured to reflect the EUV light as reflected EUV light incident on the EUV mask; A mask stage on which the EUV mask is disposed; A detector is configured to receive EUV light reflected from the EUV mask to obtain a two-dimensional (2D) image and to measure the reflectivity and diffraction efficiency of the EUV mask. as well as A processor configured to calculate the phase of the EUV mask using the reflectivity and diffraction efficiency of the EUV mask.

15. The method for measuring the phase of an extreme ultraviolet mask as claimed in claim 14, wherein the order in which the reflectance measurement of the multilayer of the first mask pattern region, the reflectance measurement of the absorption layer of the first mask pattern region, and the diffraction efficiency measurement of the pattern of the absorption layer of the second mask pattern region are performed is arbitrary. in, In measuring the reflectivity of the multiple layers in the first mask pattern region, the detector receives reflected light from the multiple layers in the first mask pattern region and measures the reflectivity of the multiple layers in the first mask pattern region. In the measurement of the reflectivity of the absorption layer in the first mask pattern region, the detector receives the reflected light from the absorption layer in the first mask pattern region and measures the reflectivity of the absorption layer in the first mask pattern region. In the measurement of the diffraction efficiency of the pattern of the absorption layer in the second mask pattern region, the detector receives diffracted light from the pattern of the absorption layer in the second mask pattern region and measures the diffraction efficiency using the reflected light from the multilayer of the first mask pattern region. The diffraction efficiency is expressed as the ratio of the intensity of the diffracted light to the intensity of the reflected light from the multilayer of the first mask pattern region.

16. A method for manufacturing an extreme ultraviolet (EUV) mask, the method comprising: Manufacturing the first EUV mask; The reflectance of multiple layers of the first mask pattern region of the second EUV mask to be measured is measured using a phase measurement device; The reflectivity of the absorption layer in the first mask pattern region is measured using the phase measurement device. The diffraction efficiency of the absorption layer pattern in the second mask pattern region of the second EUV mask is measured using the phase measurement device. The phase of the first EUV mask is calculated using the reflectivity of each of the multilayers and the absorption layer in the first mask pattern region and the diffraction efficiency of the pattern of the absorption layer in the second mask pattern region. Determine whether the calculated phase is within the acceptable range; as well as When the phase is within the allowable range, the fabrication of the first EUV mask is completed.

17. The method of manufacturing an extreme ultraviolet mask as claimed in claim 16, wherein the phase measurement device comprises: EUV light source, configured to generate and output EUV light; At least one reflector is configured to reflect the EUV light as reflected EUV light incident on the second EUV mask; A mask stage on which the second EUV mask is disposed; A detector is configured to receive EUV light reflected from the second EUV mask to obtain a two-dimensional (2D) image and to measure the reflectivity and diffraction efficiency of the second EUV mask. as well as The processor is configured to calculate the phase of the first EUV mask using the reflectivity and diffraction efficiency of the second EUV mask.

18. The method of manufacturing an extreme ultraviolet mask as claimed in claim 17, wherein the order in which the reflectance measurement of the multilayer of the first mask pattern region, the reflectance measurement of the absorption layer of the first mask pattern region, and the diffraction efficiency measurement of the pattern of the absorption layer of the second mask pattern region are performed is arbitrary. in, In measuring the reflectivity of the multiple layers in the first mask pattern region, the detector receives reflected light from the multiple layers in the first mask pattern region and measures the reflectivity of the multiple layers in the first mask pattern region. In the measurement of the reflectivity of the absorption layer in the first mask pattern region, the detector receives the reflected light from the absorption layer in the first mask pattern region and measures the reflectivity of the absorption layer in the first mask pattern region. In the measurement of the diffraction efficiency of the pattern of the absorption layer in the second mask pattern region, the detector receives diffracted light from the pattern of the absorption layer in the second mask pattern region and measures the diffraction efficiency using the reflected light from the multilayer of the first mask pattern region. The diffraction efficiency is expressed as the ratio of the intensity of the diffracted light to the intensity of the reflected light from the multilayer of the first mask pattern region.

19. The method of manufacturing an extreme ultraviolet mask as claimed in claim 18, wherein the pattern of the absorption layer in the second mask pattern region comprises a repeating line and spacing pattern. in, When the width of each spacing of the pattern in the absorption layer of the second mask pattern region is w and the pitch of each pattern in the absorption layer of the second mask pattern region is p, The diffraction efficiency I0 of the 0th-order diffracted light and the diffraction efficiency I1 of the 1st-order diffracted light are expressed by Equation 1 and Equation 2, respectively. Official 1 Formula 2, and Where Rr represents the ratio of the reflectivity of the absorption layer in the first mask pattern region to the reflectivity of the multiple layers in the first mask pattern region. This indicates the phase of the first EUV mask.

20. The method of manufacturing an extreme ultraviolet mask as described in claim 17, wherein the at least one reflector comprises a first reflector and a second reflector. The first reflector is configured to reflect the EUV light from the EUV light source and focus the reflected EUV light onto the second reflector. The second reflector is configured to reflect the EUV light from the first reflector as the reflected EUV light incident on the second EUV mask to be measured at an incident angle of 6°.

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