Method of inspecting semiconductor device

Abstract

A method of inspecting a sample includes performing a focusing operation on a target pattern of the sample. The focusing operation includes scanning a target pattern at different focusing heights to obtain a plurality of focused images. The method further includes using at least one of the plurality of focused images as a target pattern image of the target pattern, and then measuring a size of the target pattern based on the target pattern image.

Description

[0001] This application is a divisional application of an invention patent application with an application date of March 3, 2017, application number 201710123069.7, and invention name “Inspection method and system and method for inspecting semiconductor devices using the same”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This patent application claims the priority benefit of Korean Patent Application No. 10-2016-0025805 filed on March 3, 2016 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0004] The inventive concept relates to an inspection method and system, and a method of inspecting a semiconductor device using the inspection method and system. Background Art

[0005] Semiconductor devices are important components in the electronics industry due to their small-sized, multifunctional and / or low-cost characteristics. Semiconductor devices can be manufactured using various processes such as photolithography, etching, deposition, ion implantation and cleaning processes.

[0006] The inspection process is performed to inspect whether there is any failure in the pattern of the manufactured semiconductor device. By performing the inspection process, it is possible to optimize the process conditions of the manufacturing process and determine whether there is any failure in the semiconductor device at an early stage.

[0007] As semiconductor devices decrease in size, there is an increasing need for methods and systems that can reliably measure the dimensions of fine features in semiconductor devices. Summary of the invention

[0008] Some embodiments of the present inventive concepts provide a method and system configured to examine a sample within a reduced processing time.

[0009] Some embodiments of the inventive concept provide a method of cost effectively inspecting a semiconductor device.

[0010] In one aspect, a method for inspecting a sample may include: performing a focusing operation on a target pattern of the sample. The focusing operation may include scanning the target pattern at different focus levels to obtain a plurality of focused images. The method may also include using at least one of the plurality of focused images as a target pattern image of the target pattern, and then measuring a size of the target pattern based on the target pattern image.

[0011] In another aspect, a system for inspecting a sample may include: an image scanning unit configured to obtain an image of a pattern formed on the sample; and a controller configured to control the image scanning unit. The controller may be configured to control the image scanning unit to perform a scanning operation on the pattern at different focus heights and obtain a plurality of focused images. The system may also include: a data processing unit configured to store at least one of the plurality of focused images as a pattern image of the pattern and measure a size of the pattern based on the pattern image.

[0012] In another aspect, a method for inspecting a semiconductor device may include: providing a semiconductor substrate having a target pattern; placing an image scanning unit on the semiconductor substrate; operating a controller connected to the image scanning unit to control the image scanning unit to perform a scanning operation on the target pattern at different focusing heights and obtain a plurality of focused images; operating a data processing unit connected to the image scanning unit to store at least one of the plurality of focused images as a target pattern image of the target pattern and measuring a size of the target pattern based on the target pattern image; and checking whether the size of the target pattern is within an allowable range.

[0013] In another aspect, a method for inspecting a sample may include performing a focusing operation on a pattern of the sample. The focusing operation may include scanning the pattern at different focus heights spaced apart from each other in a first direction to obtain a plurality of focused images. The method may also include using at least one of the plurality of focused images as a pattern image of the pattern and measuring a size of the pattern based on the pattern image.

[0014] In another aspect, a method for inspecting a semiconductor device includes: providing a semiconductor substrate having a target pattern and a reference pattern spaced apart from each other; placing an image scanning unit on the semiconductor substrate; operating a controller connected to the image scanning unit to control the image scanning unit to perform a first scanning operation on the reference pattern at different focus heights and obtain a plurality of first focus images; operating a data processing unit connected to the image scanning unit to store at least one of the plurality of first focus images as a reference pattern image of the reference pattern; using the reference pattern image to locate a target pattern spaced apart from the reference pattern; operating the controller connected to the image scanning unit to control the image scanning unit to perform a second scanning operation on the target pattern at different focus heights and obtain a plurality of second focus images; operating the data processing unit connected to the image scanning unit to store at least one of the plurality of second focus images as a target pattern image of the target pattern and measuring a size of the target pattern based on the target pattern image; and inspecting whether the size of the target pattern is within an allowable range. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] These and / or other aspects and advantages of the present general inventive concept will become clear and more easily understood from the following description of embodiments in conjunction with the accompanying drawings.

[0016] Figure 1 is a schematic diagram illustrating a sample inspection system according to some embodiments of the present inventive concept.

[0017] Figure 2 is a flowchart illustrating a sample inspection method according to some embodiments of the inventive concept.

[0018] Figure 3 It is shown Figure 2 Flow chart of the operation of step S200.

[0019] Figure 4 It is shown Figure 2 Flow chart of the operation of step S300.

[0020] Figure 5 It is shown Figure 2 Flow chart of the operation of step S500.

[0021] Figure 6 It is shown Figure 2 Flow chart of the operation of step S600.

[0022] Figure 7 It is indicated by Figure 1 Schematic diagram of a scanning operation with adjustable focus height performed by an image scanning unit.

[0023] Figure 8 yes Figure 7 An enlarged view of portion 'Q' is shown.

[0024] Fig. 9 It is shown by Figure 1 A graph showing image characteristics of a focused image obtained by an image scanning unit.

[0025] Fig.10 is a flowchart illustrating a method of inspecting a semiconductor device using a sample inspection method according to some embodiments of the inventive concept. DETAILED DESCRIPTION

[0026] Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the drawings.

[0027] Figure 1 is a schematic diagram illustrating a sample inspection system 500 according to some embodiments of the inventive concept.

[0028] refer to Figure 1 , the sample inspection system 500 may include an image scanning device 200 and a computer 300. The image scanning device 200 may include a chamber 100 in which a sample 10 may be placed and an image scanning unit 110. The image scanning unit 110 is connected to the chamber 100 and is configured to obtain an image from a pattern in the sample 10. A stage 102 on which the sample 10 may be loaded may be provided in the chamber 100. The image scanning device 200 may be configured to perform non-destructive testing. As an example, the image scanning unit 110 may be a scanning electron microscope (SEM), and the chamber 100 may be a vacuum chamber.

[0029] The computer 300 can control the image scanning device 200 to obtain image data from the sample 10, and can process the image data obtained by the image scanning device 200. For example, the computer 300 may include a controller 120 configured to control the image scanning device 200, a data processing unit 130 configured to process information of various data types, and a library 140 configured to store information of various data types. The library 140 may include, for example, a hard disk drive and / or a non-volatile semiconductor memory device, such as a flash (FLASH) memory device, a phase change memory device, and / or a magnetic memory device. The data processing unit 130 may communicate with the image scanning unit 110, the controller 120, and the library 140. The controller 120 may communicate with the data processing unit and the image scanning unit 110. The functions of each of the controller 120, the data processing unit 130, and the library 140 will be described in more detail below. Although not shown, the computer 300 may also include an input / output unit and an interface unit. The input / output unit may include a keyboard, a key area, and / or a display device, etc. The image data obtained by the image scanning device 200 can be transmitted to the computer 300 through the interface unit. In addition, the data processed by the computer 300 can be transmitted to the image scanning device 200 through the interface unit. The interface unit may include, for example, a wired element, a wireless element, a universal serial bus (USB) port, etc. The controller 120, the data processing unit 130, the library 140, the input / output unit, and the interface unit may be coupled to each other via at least one data bus.

[0030] The sample inspection system 500 can be used to perform an inspection process on a sample, for example, sample 10. Figures 2 to 9 A sample inspection method according to some embodiments of the present inventive concept is described.

[0031] Figure 2 is a flowchart illustrating a sample inspection method according to some embodiments of the inventive concept. Figure 3 It is shown Figure 2 The flowchart of the operation of step S200 is shown in FIG. Figure 4It is shown Figure 2 Flow chart of the operation of step S300. Figure 5 It is shown Figure 2 The flowchart of the operation of step S500 is shown in FIG. Figure 6 It is shown Figure 2 Flow chart of the operation of step S600. Figure 7 It is indicated by Figure 1 FIG. 1 is a schematic diagram of a scanning operation with adjustable focus height performed by the image scanning unit 110, and FIG. Figure 8 yes Figure 7 Magnified view of portion 'Q' of FIG. Fig. 9 It is shown by Figure 1 FIG. 1 is a graph showing image characteristics of a focused image obtained by the image scanning unit 110 .

[0032] refer to Figure 1 and Figure 2 , the sample 10 may be loaded on a stage 102 in a chamber 100 of an image scanning device 200. The sample 10 may be, for example, a wafer on which a fine pattern is provided. The fine pattern may include: a target pattern whose size is to be measured; and a reference pattern spaced from the target pattern to provide information about the position of the target pattern. As an example, the reference pattern may have a unique shape distinguishable from other patterns adjacent thereto, and the target pattern may be one of the regularly arranged fine patterns.

[0033] The image scanning unit 110 may be positioned on the sample 10 to perform a focusing operation on a reference pattern of the sample 10 ( S100 ).

[0034] First, refer to Figures 7 to 9 The focusing operation of the image scanning unit 110 is described. The focusing operation may include scanning the surface 10S of the sample 10 having the fine pattern 20 thereon. The focusing height of the image scanning unit 110 may be adjusted during scanning the surface 10S of the sample 10, such as Figure 7 and Figure 8As shown. The fine pattern 20 may include a reference pattern and / or a target pattern. The focus of the image scanning unit 110 may be formed on the surface 10S of the sample 10. In this embodiment, the surface 10S of the sample 10 may be defined as being positioned at a focus height, such as a third focus height FL3, relative to the image scanning unit 110. The adjustment of the focus height of the image scanning unit 110 may include changing the focus height of the image scanning unit 110 from the focus height of FL3 to other focus heights, such as the first focus height FL1, the second focus height FL2, or the fourth focus height FL4, in a direction perpendicular to the surface 10S of the sample 10, such as the z direction. The fourth focus height FL4 may be above and spaced from the third focus height FL3 in the z direction. The second focus height FL2 may be below and spaced from the third focus height FL3 in the z direction. The first focus height FL1 may be below and spaced from the second focus height FL2 in the z direction. A scanning operation may be performed at each focus height (i.e., the first to fourth focus heights FL1, FL2, FL3, or FL4) and on a plane substantially parallel to the surface 10S of the sample 10, for example, an xy plane. The xy plane may be substantially parallel to the surface 10A of the sample 10, and the z direction may be substantially perpendicular to the xy plane. A focusing operation may be performed to obtain a focused image at each of a plurality of focus heights, i.e., the first to fourth focus heights FL1, FL2, FL3, and FL4. The inventive concept is described as having the first to fourth focus heights FL1, FL2, FL3, and FL4; however, the inventive concept is not limited thereto. For example, the inventive concept may include more or less than four focus heights.

[0035] In some embodiments, the image scanning unit 110 may be a scanning electron microscope. For example, the image scanning unit 110 may be configured to scan the surface 10S of the sample 10 using an electron beam e. In such an embodiment, the focus of the electron beam e may be formed on the surface 10S of the sample 10, and in this embodiment, the surface 10S of the sample 10 may be defined as being placed at a focus height, such as a third focus height FL3, relative to the image scanning unit 110. The scanning operation of the image scanning unit 110 may be performed on the surface 10S of the sample 10 on the xy plane. Figure 1The focus height of the image scanning unit 110 is changed under the control of the controller 120. The change of the focus height of the image scanning unit 110 can be performed in a direction perpendicular to the surface 10S or the xy plane of the sample 10, that is, the z direction. In an embodiment where the image scanning unit 110 is a scanning electron microscope, the electric field generated in the image scanning unit 110 can be controlled to change the propagation direction of the electron beam e, and thereby change the focus height of the image scanning unit 110. At each changed focus height, such as the first focus height FL1, the second focus height FL2, and / or the fourth focus height FL4, the image scanning unit 110 can perform a scanning operation on the surface 10S of the sample 10 in a direction parallel to the xy plane.

[0036] That is, the focusing operation on the fine pattern 20 of the sample 10 may include performing a scanning operation at each of the first to fourth focusing heights FL1, FL2, FL3, and / or FL4 spaced from each other along the z direction in a direction parallel to the xy plane. Therefore, a plurality of focused images IMG1, IMG2, IMG3, and IMG4 may be obtained at the first to fourth focusing heights FL1, FL2, FL3, and FL4, respectively, as shown in FIG. Fig. 9 shown. Fig. 9 The x-axis of the graph represents the focus height FL, and Fig. 9 The y-axis of the graph represents resolution. The multiple focused images IMG1, IMG2, IMG3, and IMG4 may have different resolutions. The image with the highest resolution among the focused images IMG1, IMG2, IMG3, and IMG4 may be selected as the best focused image, such as the focused image IMG3; and the focus height of the best focused image, such as the third focus height FL3, may be defined as the best focus.

[0037] Reference back Figure 1 and Figure 2 The focusing operation on the reference pattern 20 may include scanning the surface 10S of the sample 10 having the reference pattern, and during such scanning operation, the focusing height of the image scanning unit 110 may be adjusted between a plurality of focusing heights, such as the reference pattern. Figures 7 to 9 As described. Therefore, a plurality of first focused images IMG1r, IMG2r, IMG3r, and IMG4r of the reference pattern may be obtained at each focus height. The image with the highest resolution among the first focused images IMG1r, IMG2r, IMG3r, and IMG4r may be selected as the first best focused image, such as focused image IMG3r, and the focus height of the first best focused image of the focused image IMG3r, such as the third focus height FL3, may be defined as the best focus.

[0038] refer to Figure 1 , Figure 2 and Figure 3 After the focusing operation on the reference pattern, a reference pattern image may be obtained from the reference pattern (S200). Obtaining the reference pattern image may include an operation Figure 1 The data processing unit 130 is configured to obtain first focused images IMG1r, IMG2r, IMG3r, and IMG4r from the image scanning unit 110 (S210), and select at least one of the first focused images IMG1r, IMG2r, IMG3r, and IMG4r as a reference pattern image of a reference pattern (S220). In some embodiments, a first best focused image, such as focused image IMG3r, or a composite image of a first best focused image such as focused image IMG3r and other first focused images, such as IMG1r, IMG2r, and IMG4r, may be selected as a reference pattern image. That is, the data processing unit 130 may be configured to store the first best focused image IMG3r or the composite image as a reference pattern image. As a result, a reference pattern image may be obtained from the first focused images IMG1r, IMG2r, IMG3r, and IMG4r obtained during a focusing operation on the reference pattern without an additional scanning operation on the reference pattern.

[0039] refer to Figure 1 , Figure 2 and Figure 4 , the reference pattern image can be used for the addressing operation (S300) of finding the target pattern. For example, Figure 1 The data processing unit 130 may be operated or configured to compare the reference pattern image with the first comparable object image and identify the reference pattern (S310). The first comparable object image may be stored in Figure 1 The data processing unit 130 can be configured to extract the first comparable object image from the library 140, and can be used as a reference image for identifying the reference pattern. The data processing unit 130 can be configured to extract the first comparable object image from the library 140, and identify the reference pattern based on whether the reference pattern image is consistent with the first comparable object image. Afterwards, the target pattern can be located based on the position or address information of the target pattern relative to the reference pattern (S320). The position information of the target pattern can be information stored in the library 140. If the reference pattern is identified, the data processing unit 130 can extract the position information of the target pattern from the library 140. The data processing unit 130 can provide the position information of the target pattern to the controller 120. Based on the position information of the target pattern provided from the data processing unit 130, the controller 120 can control the image scanning unit 110 to move the imaging area of ​​the image scanning unit 110 from the reference pattern to the target pattern.

[0040] Reference back Figure 1 and Figure 2, after the controller 120 moves the imaging area of ​​the image scanning unit 110 to the target pattern, the image scanning unit 110 may perform a focusing operation on the target pattern of the sample 10 (S400). The focusing operation on the target pattern may include scanning the surface of the sample 10 having the target pattern at different focusing heights, for example, first to fourth focusing heights FL1 to FL4 spaced apart from each other in the z direction, as shown in reference Figures 7 to 9 As described. Therefore, a plurality of second focused images IMG1t, IMG2t, IMG3t, and IMG4t of the target pattern may be obtained. The image with the highest resolution among the second focused images IMG1t, IMG2t, IMG3t, and IMG4t may be selected as the second best focused image, such as focused image IMG3t, and the focusing height of the second best focused image, such as focused image IMG3t, such as the third focusing height FL3, may be defined as the best focus.

[0041] refer to Figure 1 , Figure 2 and Figure 5 After the focusing operation on the target pattern, a target pattern image may be obtained from the target pattern (S500). Obtaining the target pattern image may include operating Figure 1 The data processing unit 130 uses the image scanning unit 110 to obtain the second focused images IMG1t, IMG2t, IMG3t and IMG4t (S510), and selects at least one of the second focused images IMG1t, IMG2t, IMG3t and IMG4t as the target pattern image of the target pattern (S520). In some embodiments, the second best focused image among the second focused images IMG1t, IMG2t, IMG3t and IMG4t, such as the focused image IMG3t, or a composite image of the second best focused image such as IMG3t and other second focused images, such as the focused images IMG1t, IMG2t and IMG4t, can be selected as the target pattern image. That is, the data processing unit 130 can be configured to store the second best focused image IMG3t or the composite image as the target pattern image. As a result, the target pattern image can be obtained from the second focused images IMG1t, IMG2t, IMG3t and IMG4t obtained during the focusing operation on the target pattern without an additional scanning operation on the target pattern.

[0042] Obtaining the target pattern image may also include adjusting image properties of the image, such as brightness and contrast, based on the target pattern image (S530). The data processing unit 130 may provide the target pattern image to the controller 120. The controller 120 may control the image scanning unit 110 to adjust the brightness and contrast of the image obtained from the sample 10 based on the target pattern image provided from the data processing unit 130. The image scanning unit 110 may be, for example, a scanning electron microscope, and in such an embodiment, in order to adjust the brightness and contrast of the image obtained from the sample 10, the controller 120 may control the image scanning unit 110 to adjust the incident angle of the electron beam e propagating from the image scanning unit 110 toward the surface 10S of the sample 10 and / or the accelerating voltage applied to the image scanning unit 110.

[0043] refer to Figure 1 , Figure 2 and Figure 6 , the target pattern image can be used to measure the size of the target pattern (S600). First, the target pattern image can be compared with the second comparable object image to identify the target pattern (S610). The second comparable object image can be stored in Figure 1 library 140, and can be used as a reference image for identifying a target pattern. The data processing unit 130 can be configured to extract a second comparable object image from the library 140 to check whether the target pattern image is consistent with the second comparable object image and identify the target pattern based on the result of the inspection. Next, the image scanning unit 110 can perform a scanning operation on the identified target pattern to obtain image data (S620). That is, the data processing unit 130 can provide identification information of the target pattern to the controller 120, and the image scanning unit 110 can perform a scanning operation on the identified target pattern under the control of the controller 120. Thereafter, the data processing unit 130 can measure the size of the target pattern based on the image data obtained from the image scanning unit 110 (S630). In some embodiments, the image scanning unit 110 can be, for example, a scanning electron microscope configured to emit an electron beam e onto a surface 10S of the sample 10, such as Figure 7 In such an embodiment, the image data obtained from the image scanning unit 110 may contain information about secondary electrons emitted from the surface 10S of the sample 10. In the data processing unit 130, the information about the secondary electrons may be used to measure the size of the target pattern formed on the surface 10S of the sample 10, such as the line width. The size of the target pattern measured based on the image data may be stored in the library 140 and may be displayed on the input / output unit of the computer 300.

[0044] Fig.10is a flowchart illustrating a method of inspecting a semiconductor device using a sample inspection method according to some embodiments of the inventive concept.

[0045] refer to Figure 1 and Fig.10 , a sample 10, such as a semiconductor substrate, having a reference pattern and a target pattern may be provided (S700). As an example, the reference pattern may have a unique shape distinguishable from other patterns adjacent thereto, and the target pattern may be one of fine patterns repeatedly formed on the semiconductor substrate 10. The reference pattern may be provided to be spaced from the target pattern and may be used as a position reference for finding the target pattern, and an inspection may be performed to measure the size of the target pattern. The semiconductor substrate 10 may be loaded on a stage 102 provided in a chamber 100 of an image scanning device 200, and an image scanning unit 110 of the image scanning device 200 may be placed on the semiconductor substrate 10 (S710).

[0046] The controller 120 connected to the image scanning unit 110 may be operated to obtain a plurality of first focused images IMG1r, IMG2r, IMG3r, and IMG4r from the reference pattern (S720). The first focused images IMG1r, IMG2r, IMG3r, and IMG4r may be obtained by performing a focusing operation on the reference pattern using the image scanning unit 110. That is, the controller 120 may be configured to control the image scanning unit 110 to obtain the first focused images IMG1r, IMG2r, IMG3r, and IMG4r. The focusing operation on the reference pattern may include scanning the surface of the semiconductor substrate 10 having the reference pattern at different focusing heights, for example, first to fourth focusing heights FL1 to FL4 spaced apart from each other in the z direction, such as the reference pattern. Figures 7 to 9 described.

[0047] The data processing unit 130 connected to the image scanning unit 110 may be operated to obtain a reference pattern image of the reference pattern, and may find a target pattern using the reference pattern image (S730).

[0048] Obtaining the reference pattern image may include obtaining first focused images IMG1r, IMG2r, IMG3r, and IMG4r from the image scanning unit 110, and selecting at least one of the plurality of first focused images IMG1r, IMG2r, IMG3r, and IMG4r as the reference pattern image. Figure 3That is, the data processing unit 130 may store a first best focused image selected from the first focused images IMG1r, IMG2r, IMG3r, and IMG4r, that is, a focused image IMG3r having the highest resolution, or a composite image of the first best focused image IMG3r and other first focused images IMG1r, IMG2r, and IMG4r as a reference pattern image.

[0049] The search for the target pattern may include: operating the data processing unit 130 to compare the reference pattern image with the first comparable object image and identify the reference pattern; and then, searching for the target pattern based on information about the position or address of the target pattern relative to the reference pattern, such as the reference pattern. Figure 4 The data processing unit 130 may extract the position information of the target pattern relative to the reference pattern from the library 140, and the controller 120 may control the image scanning unit 110 based on the position information of the target pattern provided from the data processing unit 130 so that the imaging area of ​​the image scanning unit 110 moves from the reference pattern to the target pattern.

[0050] The controller 120 connected to the image scanning unit 110 may be operated to obtain a plurality of second focused images IMG1t, IMG2t, IMG3t, and IMG4t from the target pattern (S740). The second focused images IMG1t, IMG2t, IMG3t, and IMG4t may be obtained by performing a focusing operation on the target pattern using the image scanning unit 110. That is, the controller 120 may control the image scanning unit 110 to perform a focusing operation on the target pattern. The focusing operation on the target pattern may include scanning the surface 10S of the semiconductor substrate 10 having the target pattern at different focusing heights, for example, first to fourth focusing heights FL1 to FL4 spaced apart from each other in the z direction, as shown in reference Figures 7 to 9 described.

[0051] The data processing unit 130 operably connected to the image scanning unit 110 may obtain a target pattern image of the target pattern from the image scanning unit 110 and measure a size of the target pattern based on the target pattern image ( S750 ).

[0052] Obtaining the target pattern image may include: obtaining a plurality of second focused images IMG1t, IMG2t, IMG3t, and IMG4t from the image scanning unit 110; and then selecting at least one of the plurality of second focused images IMG1t, IMG2t, IMG3t, and IMG4t as the target pattern image, as shown in FIG. Figure 5That is, the data processing unit 130 may store the second best focused image selected from the second focused images IMG1t, IMG2t, IMG3t, and IMG4t, that is, the focused image IMG3t having the highest resolution, or a composite image of the second best focused image IMG3t and other second focused images IMG1t, IMG2t, and IMG4t as the target pattern image. Obtaining the target pattern image may also include adjusting image properties of the image, such as brightness and contrast, based on the target pattern image. That is, the controller 120 may control the image scanning unit 110 to adjust the brightness and contrast of the image obtained from the semiconductor substrate 10 based on the target pattern image provided from the data processing unit 130 to the controller 120, such as in combination with Figure 5 described.

[0053] As reference Figure 6 The measuring the size of the target pattern may include: comparing the target pattern image with the second comparable object image to identify the target pattern; performing a scanning operation on the identified target pattern to obtain image data; and then, measuring the size of the target pattern based on the image data. The data processing unit 130 may be configured to extract the second comparable object image from the library 140 to check whether the target pattern image is consistent with the second comparable object image, and identify the target pattern based on the result of the inspection. The data processing unit 130 may provide the identification information of the target pattern to the controller 120, and the controller 120 may control the image scanning unit 110 to perform a scanning operation on the identified target pattern. As a result, image data about the target pattern may be obtained by the image scanning unit 110. Afterwards, the data processing unit 130 may measure the size of the target pattern based on the image data obtained from the image scanning unit 110.

[0054] After measuring the size of the target pattern, the semiconductor substrate 10 may be unloaded from the stage 102 and the chamber 100. Thereafter, a step for checking whether the size of the target pattern is within an allowable range may be performed (S760). If the size of the target pattern is within the allowable range, a subsequent manufacturing process for forming a semiconductor device on the semiconductor substrate 10 may be performed (S770). If the size of the target pattern is not within the allowable range, an alarm may be generated (S780).

[0055] According to some embodiments of the inventive concept, the image scanning unit 110 may be configured to obtain a plurality of focused images, for example, first focused images IMG1r, IMG2r, IMG3r, and IMG4r, and select and use at least one of the first focused images IMG1r, IMG2r, IMG3r, and IMG4r as a reference pattern image during a focusing operation on a reference pattern formed on the sample 10. In addition, the image scanning unit 110 may be configured to obtain a plurality of focused images, for example, second focused images IMG1t, IMG2t, IMG3t, and IMG4t, and select and use at least one of the second focused images IMG1t, IMG2t, IMG3t, and IMG4t as a target pattern image during a focusing operation on a target pattern formed on the sample 10. That is, a reference pattern image or a target pattern image can be easily obtained from a plurality of focused images, for example, first focused images IMG1r, IMG2r, IMG3r, and IMG4r and second focused images IMG1t, IMG2t, IMG3t, and IMG4t, respectively, without an additional scanning operation on the reference pattern or the target pattern, and the plurality of focused images are obtained during a focusing operation on the reference pattern or the target pattern. Therefore, it is possible to reduce the processing time spent on inspecting the sample 10 having the reference pattern and / or the target pattern.

[0056] In addition, when the method or system according to some embodiments of the inventive concept is used to inspect a semiconductor device, the processing time taken to inspect the semiconductor device can be reduced. As a result, the manufacturing cost of the semiconductor device can be reduced.

[0057] According to some embodiments of the present inventive concept, the image scanning unit may be configured to obtain a plurality of focused images during a focusing operation on a pattern formed on a sample, and to select and use at least one of the focused images as a pattern image. As a result, the pattern image can be easily obtained from the focused image obtained during the focusing operation on the pattern without an additional scanning operation on the pattern. Therefore, the processing time spent on inspecting a sample having a pattern can be reduced.

[0058] Furthermore, when methods or systems according to some embodiments of the inventive concept are used to inspect a semiconductor device, a processing time taken to inspect the semiconductor device may be reduced, and as a result, a manufacturing cost of the semiconductor device may be reduced.

[0059] Although several embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in the embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for inspecting a semiconductor device, include: providing a semiconductor substrate having a target pattern and a reference pattern spaced apart from each other; An image scanning unit is disposed on the semiconductor substrate; operating a controller connected to the image scanning unit to control the image scanning unit to perform a first scanning operation on the reference pattern at different focus heights and obtain a plurality of first focus images; operating a data processing unit connected to the image scanning unit to store at least one of the plurality of first focused images as a reference pattern image of a reference pattern; using the reference pattern image to locate a target pattern spaced apart from the reference pattern; operating a controller connected to the image scanning unit to control the image scanning unit to perform a second scanning operation at target patterns of different focus heights and obtain a plurality of second focused images; operating a data processing unit connected to the image scanning unit to store at least one of the plurality of second focused images as a target pattern image of the target pattern and to measure a size of the target pattern based on the target pattern image; as well as Check whether the size of the target pattern is within the allowable range.

2. The method according to claim 1, in, The data processing unit is configured to select an image with the highest resolution among the plurality of first focused images as a best focused image, and store the best focused image as a reference pattern image.

3. The method according to claim 1, in, The data processing unit is configured to select an image with the highest resolution among the plurality of first focused images as a best focused image, and store a composite image of the best focused image and other focused images among the plurality of first focused images as a reference pattern image.

4. The method according to claim 1, in, The data processing unit is configured to select an image with the highest resolution among the plurality of second focused images as a best focused image, and store the best focused image as a target pattern image.

5. The method according to claim 1, in, The data processing unit is configured to select an image with the highest resolution among the plurality of second focused images as a best focused image, and store a composite image of the best focused image and other focused images among the plurality of second focused images as a target pattern image.

6. The method according to claim 1, in, Positioning target patterns include: operating a data processing unit to identify a reference pattern based on whether the reference pattern image matches a comparable object image of the reference pattern; and The controller is operated to move an imaging area of ​​the image scanning unit from the reference pattern to the target pattern based on information about the position of the target pattern relative to the reference pattern.

7. The method according to claim 1, in, The image scanning unit is a scanning electron microscope.

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