Optical measurement apparatus, measuring method using the same, and method for fabricating semiconductor device using the same

Abstract

An optical measurement facility with improved measurement sensitivity and measurement reliability, an optical measurement method using the same, and a method for manufacturing a semiconductor device using the same are provided. The method for manufacturing a semiconductor device includes generating polarized light, generating a pupil image of a measurement target using the polarized light, generating a self-interference image using the pupil image, analyzing the self-interference image to measure the measurement target, and performing a semiconductor process on the measurement target, wherein generating the self-interference image includes generating a plurality of beams split from the pupil image using one or more beam displacers and interfering the plurality of beams.

Description

Technology Field

[0001] The present invention relates to an optical measurement facility, an optical measurement method using the same, and a method for manufacturing a semiconductor device using the same. More specifically, the present invention relates to an optical measurement facility using ellipsometry, an optical measurement method using the same, and a method for manufacturing a semiconductor device using the same. Background Technology

[0002] Ellipsometry is an optical technique used to study the dielectric properties of wafers. Also known simply as the ellipsometry, it can generate information about a sample by analyzing changes in the polarization of reflected light from a sample (e.g., a wafer surface). For example, the polarization state of reflected light from a sample varies depending on the optical properties of the sample material and the thickness of the sample layer. By measuring these changes in polarization, ellipsometry can determine fundamental physical quantities of the material, such as the complex refractive index or dielectric function tensor, and derive information about the sample, such as its shape, crystal state, chemical structure, and electrical conductivity.

[0003] Meanwhile, Imaging Ellipsometry (IE) or Spectroscopic Imaging Ellipsometry (SIE) is a type of ellipsometry that utilizes a broadband light source. The problem to be solved

[0004] The technical problem that the present invention aims to solve is to provide a method for manufacturing a semiconductor device using optical measurement equipment and an optical measurement method.

[0005] Another technical problem that the present invention aims to solve is to provide an optical measurement system with improved measurement sensitivity and measurement reliability.

[0006] Another technical problem that the present invention aims to solve is to provide an optical measurement method with improved measurement sensitivity and measurement consistency.

[0007] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0008] A method for manufacturing a semiconductor device according to some embodiments for achieving the above technical problem comprises generating polarized light, generating a pupil image of a measurement target using the polarized light, generating a self-interference image using the pupil image, analyzing the self-interference image to measure the measurement target, and performing a semiconductor process on the measurement target, wherein generating the self-interference image includes generating a plurality of beams split from the pupil image using one or more beam displacers and interfering the plurality of beams.

[0009] An optical measurement facility according to some embodiments for achieving the above other technical objectives includes a light source unit that generates and outputs light, a polarization generation unit that generates polarized light from light, an optical system that generates a pupil image of a measurement target using polarization, a self-interference generation unit that generates a plurality of beams split from the pupil image by including one or more beam displacers, and a detection unit that detects a self-interference image generated by the plurality of beams interfering with each other.

[0010] An optical measurement facility according to some embodiments for achieving the above other technical objectives comprises a light source unit that generates and outputs light, a polarization generating unit that generates polarized light from the light, a first beam splitter that incidents the polarized light on a measurement target and emits reflected light reflected from the measurement target, an objective lens that collects the polarized light on a measurement target and provides a pupil image of the measurement target from the reflected light, a self-interference generating unit that generates a plurality of beams split from the pupil image, and a first detection unit that detects a self-interference image generated by the plurality of beams interfering with each other, wherein the self-interference generating unit comprises a first beam shifter and a second beam shifter that generate a plurality of beams, a first wave plate interposed between the first beam shifter and the second beam shifter, and an analyzer that filters the polarization state of the plurality of beams.

[0011] An optical measurement method according to some embodiments for achieving the above-mentioned additional technical task comprises generating polarized light incident on a measurement target, generating a pupil image of the measurement target using an objective lens, generating a plurality of beams split from the pupil image using one or more beam displacers, generating a self-interference image by interfering the plurality of beams using an analyzer, and measuring the measurement target by analyzing the self-interference image.

[0012] Specific details of other embodiments are included in the detailed description and drawings. Brief explanation of the drawing

[0013] FIG. 1 is a schematic conceptual diagram for explaining an optical measuring facility according to some embodiments. Figure 2 is a diagram illustrating the optical system of Figure 1. Figure 3 is a graph to explain the data obtained using the optical system of Figure 2. Figures 4 and 5 are drawings for explaining the magnetic interference generating unit of Figure 1. FIG. 6 is an exemplary graph for explaining a plurality of split beams formed by the magnetic interference generating unit of FIG. 5. FIG. 7 is an exemplary magnetic interference image obtained using an optical measurement facility according to some embodiments. FIG. 8 is a schematic conceptual diagram for explaining optical measurement equipment according to some embodiments. Figure 9 is a diagram illustrating the magnetic interference generating unit of Figure 8. FIG. 10 is an exemplary graph for explaining a plurality of split beams formed by the magnetic interference generating unit of FIG. 9. FIG. 11 is an exemplary magnetic interference image obtained using an optical measurement facility according to some embodiments. FIG. 12 is a schematic conceptual diagram for explaining optical measurement equipment according to some embodiments. FIG. 13 is a schematic conceptual diagram for explaining optical measurement equipment according to some embodiments. FIG. 14 is a schematic conceptual diagram for explaining optical measurement equipment according to some embodiments. FIG. 15 is an exemplary flowchart for explaining an optical measurement method according to some embodiments. FIG. 16 is an exemplary flowchart illustrating the step of analyzing a magnetic interference image in an optical measurement method according to some embodiments. FIG. 17 is an exemplary flowchart for explaining a method of manufacturing a semiconductor device according to some embodiments. Specific details for implementing the invention

[0014] Hereinafter, an optical measuring apparatus according to exemplary embodiments will be described with reference to FIGS. 1 to 14.

[0015] FIG. 1 is a schematic conceptual diagram for explaining an optical measurement facility according to some embodiments. FIG. 2 is a diagram for explaining the optical system of FIG. 1. FIG. 3 is a graph for explaining data obtained using the optical system of FIG. 2. FIG. 4 and FIG. 5 are diagrams for explaining the magnetic interference generator of FIG. 1. FIG. 6 is an exemplary graph for explaining a plurality of split beams formed by the magnetic interference generator of FIG. 5. FIG. 7 is an exemplary magnetic interference image obtained using an optical measurement facility according to some embodiments.

[0016] Referring to FIGS. 1 to 7, an optical measurement facility according to some embodiments includes a light source unit (120), a polarization generating unit (130), an optical system (140), a first beam splitter (150), a magnetic interference generating unit (160), a first detection unit (170), and an image analysis unit (175).

[0017] The light source unit (120) can generate and output light. For example, the light source unit (120) can generate and output broadband (or multi-wavelength) light. The broadband light may be polychromatic light containing light of multiple wavelength bands. The broadband light may have a wide wavelength range, for example, from the ultraviolet wavelength region (e.g., about 100 nm to about 400 nm) to the infrared wavelength region (e.g., about 750 nm to about 1,000 μm). For example, the light source unit (120) can generate and output light with a wavelength range of about 150 nm to about 2,100 nm.

[0018] The light source (120) may be, for example, a halogen lamp light source or an LED light source that generates continuous spectrum light, but is not limited thereto.

[0019] In some embodiments, the light source unit (120) may include a monochromator. The monochromator can convert the broadband light into monochromatic light and output it. Here, monochromatic light may refer to light with a very short wavelength (e.g., light having a wavelength of several nanometers). The monochromator can output a plurality of monochromatic lights while sweeping with a predetermined wavelength width within a predetermined wavelength range. For example, the monochromator can sweep the broadband light in units of a predetermined wavelength width. The monochromator may include a grating or prism capable of spectrally separating the incident light by wavelength, but is not limited thereto.

[0020] The polarization generating unit (130) can polarize and output light emitted from the light source unit (120). The polarization may include, for example, at least one of linear polarization, circular polarization, and elliptical polarization. Through this, the polarization generating unit (130) can generate and output polarized light from the light source unit (120). The polarization generating unit (130) may include, for example, a first lens array (132a, 132b, 132c), a first polarizer (134; first polarizer), and an aperture (136; aperture).

[0021] The first polarizer (134) can polarize light emitted from the light source unit (120). The first polarizer (134) may include, for example, a polarizing plate or a polarizing prism, but is not limited thereto.

[0022] The first lens array (132a, 132b, 132c) can transmit light emitted from the light source unit (120) to a measurement target (110) placed on the stage (100). For example, the first lens (132a) can convert the light emitted from the light source unit (120) into parallel light and emit it to the first polarizer (134). The polarized light generated by the first polarizer (134) can pass through the second lens (132b) and the third lens (132c) and be incident on the measurement target (110).

[0023] The aperture (136) can control the size of the polarized light generated by the first polarizer (134). For example, the aperture (136) may be interposed between the second lens (132b) and the third lens (132c). The aperture (136) may limit the diameter of the light beam of the polarized light emitted from the second lens (132b) and provide it to the third lens (132c).

[0024] The first beam splitter (150) can direct polarized light emitted from the polarization generating unit (130) toward the measurement target (110) and direct reflected light from the measurement target (110) toward the first detection unit (170). For example, the first beam splitter (150) can reflect polarized light emitted from the polarization generating unit (130) and direct it toward the optical system (140). Additionally, the first beam splitter (150) can transmit reflected light from the measurement target (110) and direct it toward the magnetic interference generating unit (160).

[0025] The optical system (140) can concentrate polarized light emitted from the first beam splitter (150) toward the measurement target (110). For example, the optical system (140) may include an objective lens (142). The objective lens (142) can concentrate polarized light emitted from the first beam splitter (150) and direct it toward the measurement target (110). The objective lens (142) may be positioned so that a focus is formed on the surface of the measurement target (110). Additionally, the optical system (140) can convert reflected light reflected from the measurement target (110) into parallel light. The optical system (140) can emit the reflected light converted into parallel light toward the first beam splitter (150).

[0026] The optical system (140) can provide a pupil image of the measurement target (110). The pupil image of the measurement target (110) refers to an image of the measurement target (110) formed on the pupil plane (PP) of the objective lens (142). Here, the pupil plane (PP) may refer to the back focal plane of the objective lens (142). That is, the objective lens (142) can form a pupil image on the pupil plane (PP) from reflected light reflected from the measurement target (110).

[0027] For example, as illustrated in FIG. 2, the measurement target (110) may include a micro pattern (112). When the measurement target (110) is a wafer, the micro pattern (112) may include various integrated circuits and wirings required for a semiconductor device. In this case, the objective lens (142) can concentrate polarized light and direct it onto the micro pattern (112), and can form a pupil image on the pupil plane (PP) from the reflected light reflected from the micro pattern (112).

[0028] In some embodiments, the objective lens (142) may have a high numerical aperture (NA). For example, the numerical aperture (NA) of the objective lens (142) may be about 0.9 or higher. For example, the numerical aperture (NA) of the objective lens (142) may be about 0.92 to about 0.98.

[0029] In some embodiments, the optical system (140) may be moved relative to the measurement target (110). For example, the stage (100) on which the measurement target (110) is placed may be operated so that the optical system (140) may be moved relative to the measurement target (110). Through this, pupil images of various points on the measurement target (110) may be provided.

[0030] An optical measurement facility according to some embodiments can obtain polarization information for multiple angles simultaneously by using pupil images provided from an optical system (140). Here, polarization information may include the amplitude ratio (Ψ) of reflected light reflected from a measurement target (110), phase difference (Δ), degree of polarization (DOP), Mueller matrix, etc.

[0031] Specifically, as illustrated in FIG. 2, the pupil image of the measurement target (110) formed on the pupil plane (PP) may include polarization information for various angles of incidence (θ) and azimuth angles (φ). Here, the angle of incidence (θ) may be defined as the angle formed by polarized light incident on the measurement target (110) passing through a specific point on the pupil plane (PP) (e.g., a first point (P1)) and a normal (VA) perpendicular to the incident boundary surface. The angle of incidence (θ) may be, for example, 0° to about 75°, but is not limited thereto. Additionally, the azimuth angle (φ) may be defined as the angle formed by a reference point on the pupil plane (PP) (e.g., a first point (P1)) and another point on the pupil plane (PP) (e.g., a second point (P2)) with respect to the normal (VA). Through this, the pupil image of the measurement target (110) can have polarization information for various angles at different points on the pupil plane (PP) (e.g., first to fourth points (P1 to P4)). The azimuth angle (φ) may be, for example, 0° to 360°, but is not limited thereto.

[0032] Additionally, as described above, the light source unit (120) can output a plurality of monochromatic lights while sweeping with a predetermined wavelength width within a predetermined wavelength range. Through this, as shown in FIG. 3, the pupil image of the measurement target (110) can provide at least three-dimensional polarization information (angle of incidence (θ), azimuth (φ), and wavelength (λ)) in one shot. In FIG. 3, λ1, λ2, ?, λ n-1 , λ n represents the average wavelength of each monochromatic light.

[0033] The pupil image provided from the optical system (140) can pass through the first beam splitter (150) and be emitted to the self-interference generating unit (160). The self-interference generating unit (160) can generate a self-interference image from the pupil image of the measurement target (110). The self-interference generating unit (160) may include, for example, a second lens array (162a, 162b), one or more beam displacers (164; beam displacer) and an analyzer (168; analyzer).

[0034] The beam shifter (164) may include a material having birefringence (e.g., calcite, etc.). Accordingly, the beam shifter (164) can form a plurality of beams that are split from the pupil image of the measurement target (110). The split plurality of beams can interfere with each other to generate a magnetic interference image of the pupil image. For example, the beam shifter (164) can [represent] an incident beam (W) incident on the magnetic interference generating unit (160). i It may include a first beam displacement device (164a) and a second beam displacement device (164b) arranged sequentially along the direction of travel (Z) of the beam. The first beam displacement device (164a) and the second beam displacement device (164b) may each have birefringence.

[0035] As shown in FIG. 4, the first beam displacement device (164a) is an incident beam (W) incident from the pupil image. i ) can be divided. Incident beam (W i ) is the first horizontal component beam (W 11 ) and the first vertical component beam (W 12 It may include ). The first horizontal component beam (W 11 ) is the incident beam (W i An incident beam (W) vibrating in a direction parallel to the plane of incidence (e.g., p-polarization direction (η)) i It is the polarization component (i.e., the p-polarization component) of ), and the first vertical component beam (W 12 ) is the incident beam (W i An incident beam (W) vibrating in a direction perpendicular to the plane of incidence (e.g., the s-polarization direction (ξ)). i It is the polarization component of ) (i.e., the s-polarization component).

[0036] Since the first beam displacement device (164a) has birefringence, the first horizontal component beam (W 11 ) and the first vertical component beam (W 12 ) may have different refractive indices for the first beam shifter (164a). For example, the first optical axis (OA1) of the first beam shifter (164a) is the incident beam (W i It can be placed within a first plane (η-Z plane) including the direction of propagation (Z) and the p-polarization direction (η).

[0037] In this case, the first horizontal component beam (W 11 ) can be an extraordinary wave for the first beam displacement device (164a), and the first vertical component beam (W 12 ) can be an ordinary wave for the first beam displacement device (164a). For example, an incident beam (W i ) can be incident perpendicularly toward the first beam displacement device (164a). At this time, the first horizontal component beam (W 11 ) can be refracted by the first optical axis (OA1), and the first vertical component beam (W12 ) may not be refracted. That is, the first horizontal component beam (W 11 ) can be shifted in the p-polarization direction (η), and the first vertical component beam (W 12 ) may not be shifted. Through this, the first beam displacement device (164a) is the incident beam (W i ) is the first horizontal component beam (W 11 ) and the first vertical component beam (W 12 It can be divided into ).

[0038] The second beam displacement device (164b) is the first horizontal component beam (W) that passed through the first beam displacement device (164a). 11 ) and the first vertical component beam (W 12 At least one of ) can be shifted. In some embodiments, the first optical axis (OA1) of the first beam shifter (164a) may be different from the second optical axis (OA2) of the second beam shifter (164b). For example, the first optical axis (OA1) and the second optical axis (OA2) may not be parallel to each other.

[0039] In some embodiments, the incident beam (W i The plane including the direction of propagation (Z) and the first optical axis (OA1) of the incident beam (W i It may be perpendicular to a plane including the direction of propagation (Z) of ) and the second optical axis (OA2). For example, as shown in FIG. 5, the first optical axis (OA1) is an incident beam (W i It can be positioned within a first plane (η-Z plane) including the propagation direction (Z) and the p-polarization direction (η) of the ), and the second optical axis (OA2) is the incident beam (W i It can be placed within a second plane (ξ-Z plane) including the direction of propagation (Z) and the s-polarization direction (ξ).

[0040] In this case, the first horizontal component beam (W 11 ) can be a normal ray for the second beam displacement device (164b), and the first vertical component beam (W 12) can be an ideal ray for the second beam displacement device (164b). For example, the first horizontal component beam (W 11 ) and the first vertical component beam (W 12 Each ) can be incident perpendicularly toward the second beam displacement device (164b). At this time, the first horizontal component beam (W 11 ) may not be refracted, and the first vertical component beam (W 12 ) can be refracted by the second optical axis (OA2). That is, the first horizontal component beam (W 11 ) may not be shifted, and the first vertical component beam (W 12 ) can be shifted in the s-polarization direction (ξ).

[0041] Through this, one or more beam displacement devices (164) are incident beams (W i It is divided from ) and the incident beam (W i The first horizontal component beam (W) shifted from ) 11 ) and the first vertical component beam (W 12 ) can be generated. For example, as shown in FIG. 6, a first horizontal component beam (W 11 ) is the incident beam (W i It can be shifted by S1 in the p-polarization direction (η) from ), and the first vertical component beam (W 12 ) is the incident beam (W i It can be shifted by S2 in the s-polarization direction (ξ) from ).

[0042] The second lens array (162a, 162b) can transmit a pupil image of a measurement target (110) provided from the optical system (140) to a beam shifter (164) and transmit a plurality of beams split by the beam shifter (164) to a first detector (170). For example, the fourth lens (162a) can convert light emitted from the first beam splitter (150) into parallel light and emit it to the beam shifter (164). A plurality of beams split by the beam shifter (164) (e.g., a first horizontal component beam (W 11 ) and the first vertical component beam (W12 )) can be incident on the first detector (170) through the fifth lens (162b). The fifth lens (162b) can concentrate a plurality of beams emitted from the beam displacement device (164) to the first detector (170).

[0043] The analyzer (168) may be interposed between the beam shifter (164) and the first detector (170). For example, the analyzer (168) may be interposed between the second beam shifter (164b) and the fifth lens (162b). The analyzer (168) may filter the polarization state of a plurality of beams split by the beam shifter (164). For example, the analyzer (168) may filter the polarization state of a plurality of beams split by the beam shifter (164) (e.g., the first horizontal component beam (W 11 ) and the first vertical component beam (W 12 It may include a second polarizer that polarizes )). The second polarizer may include, for example, a polarizing plate or a polarizing prism, but is not limited thereto.

[0044] Through this, the analyzer (168) can cause multiple beams divided by the beam displacement device (164) to interfere with each other. For example, the first horizontal component beam (W 11 ) and the first vertical component beam (W 12 ) can be polarized by the analyzer (168) to have the same polarization direction. Accordingly, the polarized first horizontal component beam (W 11 ) and the first vertical component beam (W 12 ) can interfere with each other to generate a self-interference image.

[0045] The first detection unit (170) can generate a two-dimensional (2D) image of the magnetic interference image generated by the magnetic interference generating unit (160). For example, the magnetic interference image generated by the magnetic interference generating unit (160) can be formed on the first detection unit (170) through the fifth lens (162b). The first detection unit (170) may be, for example, a CCD (Charge Coupled Device) camera, but is not limited thereto.

[0046] For example, a magnetic interference image such as that of FIG. 7 can be obtained through the first detection unit (170). Beams divided from the magnetic interference generating unit (160) (e.g., a first horizontal component beam (W 11 ) and the first vertical component beam (W 12 In the case where the number of )) is 2, as shown in FIG. 7, the acquired magnetic interference image may include a line-shaped interference pattern. However, this is merely an example, and it goes without saying that the acquired magnetic interference image may vary depending on the configuration of the magnetic interference generation unit (160).

[0047] The image analysis unit (175) can analyze the magnetic interference image obtained through the first detection unit (170). For example, the magnetic interference image in the form of a two-dimensional (2D) image generated from the first detection unit (170) can be analyzed by the image analysis unit (175). As the magnetic interference image is analyzed by the image analysis unit (175), polarization information (e.g., amplitude ratio (Ψ), phase difference (Δ), degree of polarization (DOP), Mueller matrix, etc.) regarding the pupil image of the measurement target (110) can be provided. Through this, the image analysis unit (175) can derive information regarding the measurement target (110), such as the shape, crystal state, chemical structure, and electrical conductivity of the material.

[0048] The image analysis unit (175) may be, for example, a PC (Personal Computer), workstation, supercomputer, etc. equipped with an analysis process, but is not limited thereto. In some embodiments, the image analysis unit (175) may be formed integrally with the first detection unit (170) to form part of a detector or detection device.

[0049] In some embodiments, the image analysis unit (175) can analyze the magnetic interference image using domain transform analysis. This will be described in more detail later in the description of FIG. 16.

[0050] As semiconductor devices become increasingly highly integrated, more precise measurement is required, and as the correlation between measurement parameters (e.g., width and depth of fine patterns) increases, high measurement sensitivity and measurement consistency are required.

[0051] An optical measurement facility according to some embodiments can significantly improve measurement sensitivity and measurement compatibility by using a pupil image and a magnetic interference image generated from the pupil image.

[0052] Specifically, as described above, the pupil image of the measurement target (110) provided by the optical system (140) may include polarization information for multiple angles (e.g., various angles of incidence (θ) and azimuth (φ)) simultaneously. This can provide significantly improved measurement sensitivity and measurement accuracy compared to optical measurement equipment that provides information for only one angle at a time (e.g., one angle of incidence or one azimuth at a time).

[0053] In addition, such pupil images can be precisely analyzed as magnetic interference images generated through the magnetic interference generation unit (160). For example, as described above, magnetic interference images generated from pupil images can be precisely analyzed through the image analysis unit (175). Through this, an optical measurement facility with significantly improved measurement sensitivity and measurement alignment and an optical measurement method using the same can be provided.

[0054] FIG. 8 is a schematic conceptual diagram for explaining an optical measurement facility according to some embodiments. FIG. 9 is a diagram for explaining the magnetic interference generation unit of FIG. 8. FIG. 10 is an exemplary graph for explaining a plurality of split beams formed by the magnetic interference generation unit of FIG. 9. FIG. 11 is an exemplary magnetic interference image obtained using an optical measurement facility according to some embodiments. For convenience of explanation, parts that overlap with those described above using FIG. 1 to 7 are briefly explained or omitted.

[0055] Referring to FIGS. 8 to 11, in an optical measurement apparatus according to some embodiments, the magnetic interference generating unit (160) includes a plurality of beam displacement devices (164) and wave plates (166).

[0056] A plurality of beam displacement devices (164) are incident beams (W) incident on the magnetic interference generating unit (160). i It may include a first beam displacement device (164a), a second beam displacement device (164b), a third beam displacement device (164c), and a fourth beam displacement device (164d) arranged sequentially along the direction of travel (Z) of the beam. The first beam displacement device (164a), the second beam displacement device (164b), the third beam displacement device (164c), and the fourth beam displacement device (164d) may each have birefringence.

[0057] The wave plate (166) can change the polarization state of the incident beam. For example, the wave plate (166) can change the polarization direction of the incident beam. The wave plate (166) can be interposed between the second beam shifter (164b) and the third beam shifter (164c). Through this, the wave plate (166) can change the first horizontal component beam (W) that has passed through the second beam shifter (164b). 11 By changing the polarization direction of ) the first changing beam (W r1 ) can be generated. In addition, the wave plate (166) can generate the first vertical component beam (W) that has passed through the second beam displacement device (164b). 12 By changing the polarization direction of ) the second modified beam (W r2 Can generate ).

[0058] For example, the optical axis of the wave plate (166) is the first horizontal component beam (W) that has passed through the second beam displacement device (164b). 11 It may include a half-wave plate that forms 22.5° with the polarization direction of ) (e.g., p-polarization direction (η)). In this case, the wave plate (166) is a first horizontal component beam (W) that has passed through the second beam displacement device (164b). 11 By changing the polarization direction of ) by 45°, the first modified beam (W r1 ) can be generated. This first changing beam (W r1 ) is the second horizontal component beam (W 21 ) and the second vertical component beam (W 22 It may include ). A second horizontal component beam (W 21 ) is the incident beam (W i A first changing beam (W) vibrating in a direction parallel to the plane of incidence of ) (e.g., p-polarization direction (η)). r1 ) is the polarization component (i.e., the p-polarization component), and the second vertical component beam (W 22 ) is the first changing beam (W r1 A first changing beam (W) vibrating in a direction perpendicular to the plane of incidence of ) (e.g., s-polarization direction (ξ)). r1 It is the polarization component of ) (i.e., the s-polarization component).

[0059] Additionally, the optical axis of the wave plate (166) is the first vertical component beam (W) that passed through the second beam displacement device (164b). 12 It may include a half-wave plate (HWP) that forms 22.5° with the polarization direction of ) (e.g., s-polarization direction (ξ)). In this case, the wave plate (166) is a first vertical component beam (W) that has passed through the second beam displacement device (164b). 12 By changing the polarization direction of ) by 45°, the second modified beam (W r2 ) can be generated. This second change beam (W r2 ) is the third horizontal component beam (W 23 ) and the third vertical component beam (W 24 It may include ). A third horizontal component beam (W 23 ) is the incident beam (W i A second changing beam (W) vibrating in a direction parallel to the plane of incidence of ) (e.g., p-polarization direction (η)) r2 It is the polarization component (i.e., the p-polarization component) of ), and the third vertical component beam (W 24 ) is the second changing beam (W r2 A second changing beam (W) vibrating in a direction perpendicular to the plane of incidence of ) (e.g., s-polarization direction (ξ)). r2 It is the polarization component of ) (i.e., the s-polarization component).

[0060] Since the third beam displacement device (164c) has birefringence, the second horizontal component beam (W 21 ) and the second vertical component beam (W 22 ) can have different refractive indices for the third beam displacement device (164c), and the third horizontal component beam (W 23 ) and the third vertical component beam (W 24 ) may have different refractive indices for the third beam shifter (164c). For example, the third optical axis (OA3) of the third beam shifter (164c) is the incident beam (W i It can be placed within a first plane (η-Z plane) including the direction of propagation (Z) and the p-polarization direction (η).

[0061] In this case, the second horizontal component beam (W 21 ) and third horizontal component beam (W 23 ) can be an ideal ray for the third beam displacement device (164c), and the second vertical component beam (W 22 ) and the third vertical component beam (W 24 ) can be the normal beam for the third beam displacement device (164c). For example, the first changing beam (W r1 ) and second change beam (W r2 ) can be incident perpendicularly toward the third beam displacement device (164c). At this time, the second horizontal component beam (W 21 ) and third horizontal component beam (W 23 ) can be refracted by the third optical axis (OA3), and the second vertical component beam (W 22 ) and the third vertical component beam (W 24 ) may not be refracted. That is, the second horizontal component beam (W 21 ) and third horizontal component beam (W 23 ) can be shifted in the p-polarization direction (η), and the second vertical component beam (W 22 ) and the third vertical component beam (W 24 ) may not be shifted. Through this, the third beam displacementr (164c) is the first changing beam (W r1 ) the second horizontal component beam (W 21 ) and the second vertical component beam (W 22 It can be divided into ), and the second changing beam (W r2 ) the third horizontal component beam (W 23 ) and the third vertical component beam (W 24 It can be divided into ).

[0062] The fourth beam displacement device (164d) is the second horizontal component beam (W) that passed through the third beam displacement device (164c). 21 ) and the second vertical component beam (W 22At least one of ) can be shifted, and the third horizontal component beam (W) that passes through the third beam displacement device (164c) can be shifted. 23 ) and the third vertical component beam (W 24 At least one of ) can be shifted. In some embodiments, the third optical axis (OA3) of the third beam shifter (164c) may be different from the fourth optical axis (OA4) of the fourth beam shifter (164d). For example, the third optical axis (OA3) and the fourth optical axis (OA4) may not be parallel to each other.

[0063] In some embodiments, the incident beam (W i The plane including the direction of propagation (Z) and the third optical axis (OA3) is the incident beam (W i It may be perpendicular to a plane including the direction of propagation (Z) of ) and the fourth optical axis (OA4). For example, as shown in FIG. 9, the third optical axis (OA3) is an incident beam (W i It can be positioned within a first plane (η-Z plane) including the propagation direction (Z) and p-polarization direction (η) of ), and the fourth optical axis (OA4) is the incident beam (W i It can be placed within a second plane (ξ-Z plane) including the direction of propagation (Z) and the s-polarization direction (ξ).

[0064] In this case, the second horizontal component beam (W 21 ) and third horizontal component beam (W 23 ) can be a normal ray for the fourth beam displacement device (164d), and the second vertical component beam (W 22 ) and the third vertical component beam (W 24 ) can be an ideal ray for the fourth beam displacement device (164d). For example, the second horizontal component beam (W 21 ), second vertical component beam (W 22 ), third horizontal component beam (W 23 ) and the fourth vertical component beam (W 24 Each ) can be incident perpendicularly toward the fourth beam displacement device (164d). At this time, the second horizontal component beam (W 21) and third horizontal component beam (W 23 ) may not be refracted, and the second vertical component beam (W 22 ) and the third vertical component beam (W 24 ) can be refracted by the fourth optical axis (OA4). That is, the second horizontal component beam (W 21 ) and third horizontal component beam (W 23 ) may not be shifted, and the second vertical component beam (W 22 ) and the third vertical component beam (W 24 ) can be shifted in the s-polarization direction (ξ).

[0065] Through this, one or more beam displacement devices (164) are incident beams (W i It is divided from ) and the incident beam (W i The second horizontal component beam (W) shifted from ) 21 ), second vertical component beam (W 22 ), third horizontal component beam (W 23 ) and the fourth vertical component beam (W 24 ) can be generated. For example, as shown in FIG. 10, a second horizontal component beam (W 21 ) is the first changing beam (W r1 It can be shifted by S3 in the p-polarization direction (η) from ), and the third horizontal component beam (W 23 ) is the second changing beam (W r2 It can be shifted by S3 in the p-polarization direction (η) from ). Also, the second vertical component beam (W 22 ) is the first changing beam (W r1 It can be shifted by S4 in the s-polarization direction (ξ) from ), and the third vertical component beam (W 24 ) is the second changing beam (W r2 It can be shifted by S4 in the s-polarization direction (ξ) from ).

[0066] 2nd horizontal component beam (W 21 ), second vertical component beam (W 22 ), third horizontal component beam (W 23) and the fourth vertical component beam (W 24 ) can be polarized by the analyzer (168) to have the same polarization direction. Accordingly, the polarized second horizontal component beam (W 21 ), second vertical component beam (W 22 ), third horizontal component beam (W 23 ) and the fourth vertical component beam (W 24 ) can interfere with each other to generate a self-interference image.

[0067] Beams divided from the magnetic interference generating unit (160) (e.g., a second horizontal component beam (W21), a second vertical component beam (W 22 ), third horizontal component beam (W 23 ) and the fourth vertical component beam (W 24 In the case where the number of )) is 4, as shown in FIG. 11, the acquired magnetic interference image may include a lattice-shaped interference pattern. However, this is merely an example, and the acquired magnetic interference image may vary depending on the configuration of the magnetic interference generation unit (160).

[0068] FIG. 12 is a schematic conceptual diagram for explaining optical measurement equipment according to some embodiments. For convenience of explanation, parts that overlap with those described above using FIG. 1 to 11 are briefly explained or omitted.

[0069] Referring to FIG. 12, in an optical measurement facility according to some embodiments, the magnetic interference generating unit (160) includes a plurality of beam displacement devices (164) and a plurality of wave plates (166).

[0070] A plurality of beam displacement devices (164) are, for example, incident beams (W) incident on the magnetic interference generating unit (160). iIt may include a first beam displacement device (164a), a second beam displacement device (164b), a third beam displacement device (164c), a fourth beam displacement device (164d), a fifth beam displacement device (164e), and a sixth beam displacement device (164f) arranged in order along the direction of travel (Z) of the beam displacement device. The first beam displacement device (164a), the second beam displacement device (164b), the third beam displacement device (164c), the fourth beam displacement device (164d), the fifth beam displacement device (164e), and the sixth beam displacement device (164f) may each have birefringence.

[0071] A plurality of wave plates (166) may include, for example, a first wave plate (166a) and a second wave plate (166b). The first wave plate (166a) may be interposed between the second beam shifter (164b) and the third beam shifter (164c). The first wave plate (166a) and the second wave plate (166b) may each change the polarization state of an incident beam. For example, the first wave plate (166a) may change the polarization direction of beams passing through the second beam shifter (164b), and the second wave plate (166b) may change the polarization direction of beams passing through the fourth beam shifter (164d).

[0072] The fifth beam shifter (164e) and the sixth beam shifter (164f) are similar to the third beam shifter (164c) and the sixth beam shifter (164f) described above using FIG. 8, respectively, and the first wave plate (166a) and the second wave plate (166b) are similar to the wave plate (166) described above using FIG. 8, respectively, so a detailed description below is omitted. Accordingly, exemplarily, eight beams can be split from the magnetic interference generating unit (160).

[0073] FIG. 13 is a schematic conceptual diagram for explaining optical measurement equipment according to some embodiments. For convenience of explanation, parts that overlap with those described above using FIG. 1 to 11 are briefly explained or omitted.

[0074] Referring to FIG. 13, in an optical measuring apparatus according to some embodiments, the magnetic interference generating unit (160) and the polarization generating unit (130) further include a third wave plate (138).

[0075] The third wave plate (138) can change the polarization state of the polarized light emitted from the first polarizer (134). For example, the third wave plate (138) may be interposed between the first polarizer (134) and the second lens (132b). The third wave plate (138) can change the polarization direction of the incident polarized light and provide it to the second lens (132b). The third wave plate (138) may include, for example, a quarter-wave plate (QWP), but is not limited thereto.

[0076] FIG. 14 is a schematic conceptual diagram for explaining optical measurement equipment according to some embodiments. For convenience of explanation, parts that overlap with those described above using FIG. 1 to 11 are briefly explained or omitted.

[0077] Referring to FIG. 14, an optical measuring apparatus according to some embodiments further includes a second beam splitter (155) and a second detector (180).

[0078] The second beam splitter (155) can direct a portion of the reflected light reflected from the measurement target (110) toward the second detector (180) and emit another portion of the reflected light reflected from the measurement target (110) toward the first detector (170). For example, the second beam splitter (155) can reflect a portion of the reflected light reflected from the measurement target (110) and direct it toward the second detector (180). Additionally, the second beam splitter (155) can transmit the reflected light reflected from the measurement target (110) and emit it toward the magnetic interference generating unit (160).

[0079] The second detector (180) can generate a two-dimensional (2D) image of reflected light reflected from the measurement target (110). For example, reflected light reflected from the measurement target (110) can be formed on the second detector (180) through the sixth lens (182). The second detector (180) may be, for example, a CCD camera, but is not limited thereto. The two-dimensional image generated from the second detector (180) can be provided as a sample image of the measurement target (110). Such a sample image can be used for alignment of optical measurement equipment, etc., to further improve measurement accuracy.

[0080] Hereinafter, an optical measurement method according to exemplary embodiments will be described with reference to FIGS. 1 to 16.

[0081] FIG. 15 is an exemplary flowchart for explaining an optical measurement method according to some embodiments. For convenience of explanation, parts that overlap with those described above using FIG. 1 to 14 are briefly explained or omitted.

[0082] Referring to FIG. 15, first, polarized light is generated (S10).

[0083] Polarization may include, for example, at least one of linear polarized light, circular polarized light, and elliptical polarized light. The generation of polarization may be performed, for example, by the light source unit (120) and polarization generation unit (130) described above using FIGS. 1 to 14.

[0084] Next, a pupil image of the measurement target is generated using polarization (S20).

[0085] For example, an objective lens (e.g., the objective lens (142) of FIGS. 1 to 14) that collects the generated polarization and directs it onto a measurement target (e.g., the measurement target (110) of FIGS. 1 to 14) may be provided. A pupil image may be formed on the pupil plane of such an objective lens. Generating the pupil image may be performed, for example, by the optical system (140) described above using FIGS. 1 to 14.

[0086] Next, a magnetic interference image is generated using the pupil image (S30).

[0087] For example, a plurality of beams can be formed that are divided from the generated pupil image. Subsequently, the plurality of beams can be interfered with each other to generate a self-interference image for the pupil image. Generating the self-interference image can be performed, for example, by the self-interference generation unit (160) described above using FIGS. 1 to 14.

[0088] Next, the magnetic interference image is analyzed (S40).

[0089] For example, by analyzing the generated magnetic interference image, polarization information for the pupil image (e.g., amplitude ratio (Ψ), phase difference (Δ), degree of polarization (DOP), Mueller matrix, etc.) can be provided. Through this, information regarding the measurement target (110), such as the shape, crystal state, chemical structure, and electrical conductivity of the material, can be derived. Analyzing the magnetic interference image can be performed, for example, by the image analysis unit (175) described above using FIGS. 1 to 14.

[0090] FIG. 16 is an exemplary flowchart illustrating the step of analyzing a magnetic interference image in an optical measurement method according to some embodiments. For convenience of explanation, parts that overlap with those described above using FIG. 1 to 15 are briefly explained or omitted.

[0091] Referring to FIG. 16, in an optical measurement method according to some embodiments, analyzing a magnetic interference image (e.g., S40 of FIG. 15) may include using domain transformation analysis.

[0092] First, the generated magnetic interference image is transformed to create a transformed image (S41). For example, a 2D Fourier transform can be performed on the magnetic interference image. Through this, a transformed image can be created in which the magnetic interference image of the pupil image is transformed.

[0093] Next, the generated transformed image is separated by interference to generate multiple separated signals (S42). Separating the transformed image by interference can be performed, for example, by peak detection, filtering, centering, etc. Through this, multiple separated signals can be generated in which the transformed image is separated by interference.

[0094] Next, polarization components are generated by inverse transforming the separated multiple separation signals (S43). For example, a 2D Fourier inverse transform may be performed on each of the separated separation signals. Through this, separation pupil images corresponding to each separation signal may be generated. Additionally, polarization components may be extracted from the generated separation pupil images. In some embodiments, the polarization components may include Stokes vectors (or Stokes parameters).

[0095] Next, the measurement target is analyzed using polarization components (S44). For example, polarization information (e.g., amplitude ratio (Ψ), phase difference (Δ), degree of polarization (DOP), Mueller matrix, etc.) regarding the pupil image of the measurement target (e.g., wafer) can be obtained from the extracted polarization components (e.g., Stokes vector). The obtained polarization information can be compared with a theoretical formula or a library. Through this, information regarding the measurement target (e.g., wafer), such as the shape, crystal state, chemical structure, and electrical conductivity of the material, can be derived.

[0096] Hereinafter, a method for manufacturing a semiconductor device according to exemplary embodiments will be described with reference to FIGS. 1 to 17.

[0097] FIG. 17 is an exemplary flowchart for explaining a method of manufacturing a semiconductor device according to some embodiments. For convenience of explanation, parts that overlap with those described above using FIG. 1 to 16 are briefly explained or omitted.

[0098] Referring to FIG. 17, first, polarization is generated (S10), a pupil image of a measurement target is generated using the polarization (S20), a magnetic interference image is generated using the pupil image (S30), and the magnetic interference image is analyzed (S40). Since steps S10 to S40 are substantially the same as those described above using FIG. 15 and 16, a detailed description below is omitted.

[0099] Next, it is determined whether there is a defect in the measurement target (S50). Whether there is a defect in the measurement target (e.g., a wafer) can be determined by measuring the measurement target. For example, based on the results of measuring the measurement target using the optical measurement method described above with reference to FIGS. 15 and 16, it can be determined whether there are fine particles or scratches on the measurement target.

[0100] As a result of determining whether a defect exists in the measurement target (S50), if it is determined that a defect exists in the measurement target (Y), the type of defect and its cause are analyzed (S60). In some embodiments, a step of removing the defect through a cleaning process, etc., may be performed depending on the type of defect. Alternatively, in some embodiments, a step of discarding the corresponding measurement target may be performed depending on the type of defect.

[0101] As a result of determining whether a defect exists in the measurement target (S50), if it is determined that no defect exists in the measurement target (N), a semiconductor process is performed on the measurement target (S70). For example, if the measurement target is a wafer, a semiconductor process may be performed on the wafer. The semiconductor process on the wafer may include, for example, a deposition process, an etching process, an ion process, and a cleaning process, but is not limited thereto. As the semiconductor process on the wafer is performed, integrated circuits and wiring required for a semiconductor device may be formed. The semiconductor process on the wafer may also include a test process for a semiconductor device at the wafer level.

[0102] Once semiconductor chips are completed within the wafer through a semiconductor process on the wafer, the wafer can be individualized into individual semiconductor chips. Individualization into individual semiconductor chips can be achieved through a sawing process using a blade or a laser. Subsequently, a packaging process can be performed for each semiconductor chip. The packaging process may refer to a process of mounting each semiconductor chip onto a circuit board (e.g., a printed circuit board (PCB)) and sealing it with a sealant. Additionally, the packaging process may include forming a stack package by stacking multiple semiconductor chips in multiple layers on a circuit board, or forming a Package On Package (POP) structure by stacking stack packages on top of each other. A semiconductor package can be formed through the packaging process for each semiconductor chip. The semiconductor process on the wafer may also include a test process for the semiconductor device at the package level.

[0103] Although embodiments of the present invention have been described above with reference to the attached drawings, the present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0104] 100: Stage 110: Measurement Target 120: Light source unit 130: Polarization generation unit 132a, 132b, 132c: First lens array 134: First polarizer 136: Aperture 138: Third wave plate 140: Optical system 142: Objective lens 150: 1st Beam Splitter 155: 2nd Beam Splitter 160: Magnetic interference generator 162a, 162b: Second lens array 164: Beam Displacer 166: Wave Plate 166a: 1st wave plate 166b: 2nd wave plate 168: Analyzer 170: First detection unit 175: Image analysis unit 180: Second detection unit

Claims

Claim 1 A method for manufacturing a semiconductor device comprising generating polarized light, generating a pupil image of a measurement target using the polarized light, generating a self-interference image using the pupil image, analyzing the self-interference image to measure the measurement target, and performing a semiconductor process on the measurement target, wherein the pupil image includes polarization information for a plurality of incident angles and a plurality of azimuth angles in a single shot, and generating the self-interference image includes generating a plurality of beams split from the pupil image using one or more beam displacers and interfering the plurality of beams. Claim 2 In claim 1, the measurement target is a method for manufacturing a semiconductor device including a wafer. Claim 3 A method for manufacturing a semiconductor device according to claim 1, wherein the semiconductor process comprises at least one of a deposition process, an etching process, an ion process, a cleaning process, and a test process. Claim 4 A method for manufacturing a semiconductor device according to claim 1, wherein interfering the plurality of beams comprises polarizing the plurality of beams using a polarizer. Claim 5 A method for manufacturing a semiconductor device according to claim 1, wherein analyzing the magnetic interference image includes using domain transformation analysis. Claim 6 A method for manufacturing a semiconductor device according to claim 5, wherein the domain transformation analysis comprises generating a transformed image by transforming the magnetic interference image using a 2D Fourier transform, generating a plurality of interference signals by separating the transformed image by interference components, generating polarization components by inverse transforming the plurality of interference signals using a 2D Fourier inverse transform, and analyzing the measurement target using the polarization components. Claim 7 In claim 6, the method for manufacturing a semiconductor device wherein the polarization components include Stokes vectors. Claim 8 An optical measurement device comprising: a light source unit that generates and outputs light; a polarization generating unit that generates polarized light from the light; an optical system that generates a pupil image of a measurement target using the polarization; a self-interference generating unit that includes one or more beam displacers to generate a plurality of beams divided from the pupil image; and a detection unit that detects a self-interference image generated by the plurality of beams interfering with each other, wherein the pupil image includes polarization information for a plurality of incident angles and a plurality of azimuth angles in a single shot. Claim 9 In claim 8, the light comprises broadband light, and the light source comprises an optical measuring device including a monochromator that outputs monochromatic light having a predetermined wavelength width from the broadband light. Claim 10 In claim 8, the incident beam incident on the beam displacement device comprises a vertical component beam perpendicular to the optical axis of the beam displacement device and a horizontal component beam perpendicular to the vertical component beam, and the beam displacement device is an optical measuring device that separates the vertical component beam and the horizontal component beam. Claim 11 In claim 8, the magnetic interference generating unit comprises an optical measuring device including a first beam shifter having a first optical axis and a second beam shifter having a second optical axis different from the first optical axis. Claim 12 In claim 11, the plane including the propagation direction of the incident beam incident on the magnetic interference generating unit and the first optical axis is an optical measuring facility perpendicular to the plane including the propagation direction of the incident beam and the second optical axis. Claim 13 In claim 11, the magnetic interference generating unit further comprises an optical measuring device including a wave plate interposed between the first beam shifter and the second beam shifter. Claim 14 In claim 8, the magnetic interference generating unit further comprises a polarizer interposed between the beam displacement unit and the detection unit, an optical measurement facility. Claim 15 An optical measurement device comprising: a light source unit that generates and outputs light; a polarization generating unit that generates polarized light from the light; a first beam splitter that incidents the polarized light on a measurement target and emits reflected light reflected from the measurement target; an objective lens that collects the polarized light on the measurement target and provides a pupil image of the measurement target from the reflected light; a self-interference generating unit that generates a plurality of beams split from the pupil image; and a first detector unit that detects a self-interference image generated by the plurality of beams interfering with each other, wherein the pupil image includes polarization information for a plurality of incident angles and a plurality of azimuth angles in a single shot, and the self-interference generating unit comprises a first beam shifter and a second beam shifter that generate the plurality of beams, a first wave plate interposed between the first beam shifter and the second beam shifter, and an analyzer that filters the polarization state of the plurality of beams. Claim 16 In claim 15, the first beam shifter divides an incident beam incident on the magnetic interference generating unit into a first horizontal component beam and a first vertical component beam, the first wave plate changes the polarization state of the first horizontal component beam to generate a first modified beam and changes the polarization state of the first vertical component beam to generate a second modified beam, and the second beam shifter divides the first modified beam into a second horizontal component beam and a second vertical component beam, and divides the second modified beam into a third horizontal component beam and a third vertical component beam, an optical measuring device. Claim 17 In claim 16, the magnetic interference generating unit further comprises a third beam shifter between the first beam shifter and the first wave plate, and a fourth beam shifter between the first wave plate and the second beam shifter, wherein the first optical axis of the first beam shifter is different from the second optical axis of the third beam shifter, and the third optical axis of the second beam shifter is different from the fourth optical axis of the fourth beam shifter, an optical measuring device. Claim 18 An optical measurement facility according to claim 15, further comprising an image analysis unit that analyzes the magnetic interference image using domain transformation analysis. Claim 19 An optical measuring apparatus according to claim 15, further comprising: a second detector for detecting the reflected light; and a second beam splitter between the first beam splitter and the magnetic interference generating unit, which causes the reflected light to be incident on the second detector. Claim 20 An optical measurement method comprising generating polarized light incident on a measurement target, generating a pupil image of the measurement target using an objective lens, generating a plurality of beams split from the pupil image using one or more beam displacers, generating a self-interference image by interfering the plurality of beams using an analyzer, and analyzing the self-interference image to measure the measurement target, wherein the pupil image includes polarization information for a plurality of incident angles and a plurality of azimuth angles in a single shot.

Images