Marker, alignment device, and alignment method

Abstract

The present invention provides an alignment device (100) for aligning first detection data with second detection data using a flat-shaped marker (25), the deivce involving a mesh member (M) having a plurality of randomly combined conductive wire members (11), the marker involving an adhesive attached to the mesh member (M). The alignment device comprises: an acquisition unit (101) that acquires, in the form of first detection data detected by a SEM (31) and second detection data detected by a Raman microspectrometer (32), detection data regarding the marker (25) and a sample (s1) placed to overlap part of the marker (25); an extraction unit (102) that extracts the marker (25) included in the first and second detection data; and a processing unit (103) that aligns the first detection data with the second detection data on the basis of the position of each marker (25).

Description

Marker, alignment device, and alignment method

[0001] The present disclosure relates to a marker, an alignment device, and an alignment method.

[0002] In order to measure the shape of a sample to be observed and to measure information about the chemical bonds that make up the molecules of the sample, shape measurement on the order of nanometers using a scanning electron microscope (SEM) and detection of molecular structure using a micro-Raman spectrometer are carried out simultaneously.

[0003] Since the measurement principles of SEM measurement and Raman microscope measurement are different, it is necessary to measure detection data separately using the SEM and Raman microscope, and then align the detection data measured by each device.

[0004] Japanese Patent Application Laid-Open No. 2003-144222 discloses that a sample placed on a sample stage is measured by a plurality of measuring devices in order to rapidly identify the unknown sample.

[0005] Japanese Patent Application Laid-Open No. 2000-258340

[0006] However, in the above-mentioned Patent Document 1, it is necessary to align the detection data obtained by a plurality of measuring devices, and there is a problem that alignment is difficult when the observed portion on the sample is minute.

[0007] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a marker, an alignment device, and an alignment method that enable easy alignment of detection data measured by multiple measurement devices.

[0008] A marker according to one aspect of the present disclosure is a marker used for aligning detection data, and comprises a mesh member formed by randomly combining a plurality of conductive linear members, with adhesive applied to the mesh member to form a flat plate shape.

[0009] An alignment device according to one aspect of the present disclosure includes a mesh member formed by randomly combining a plurality of conductive linear members, a marker formed into a flat plate shape by adhering an adhesive to the mesh member, and a sample arranged overlapping a portion of the marker. The alignment device also includes an acquisition unit that acquires first detection data detected by a first device and second detection data detected by a second device, an extraction unit that extracts the markers included in the first detection data and the second detection data, and a processing unit that aligns the first detection data and the second detection data based on the positions of the markers.

[0010] An alignment method according to one aspect of the present disclosure includes a mesh member formed by randomly combining a plurality of conductive linear members, a marker formed into a flat plate by adhering adhesive to the mesh member, and a sample arranged overlapping a portion of the marker, and the method acquires first detection data detected by a first device and second detection data detected by a second device, extracts the markers contained in the first detection data and the second detection data, and aligns the first detection data and the second detection data based on the positions of the markers.

[0011] According to the present disclosure, it is possible to easily align detection data measured by a plurality of measurement devices.

[0012] FIG. 1 is a block diagram showing the configuration of an alignment device according to an embodiment and its peripheral devices. FIG. 2 is a diagram showing the configuration of a marker according to an embodiment. FIG. 3 is a diagram showing the configuration of a mesh member included in the marker according to an embodiment. FIG. 4 is a perspective view of a stage on which a sample and a marker are placed. FIG. 5 is an explanatory diagram showing a state in which a sample and a marker are placed on the stage. FIG. 6A is an explanatory diagram showing a region D2 of the sample and marker placed on the stage. FIG. 6B is an explanatory diagram showing a microscope image of region D2 shown in FIG. 6A detected by SEM 31. FIG. 6C is an enlarged view of region D3 shown in FIG. 6B. FIG. 7 is a graph showing a Raman spectrum of region D4 shown in FIG. 6C. FIG. 8 is a flowchart showing a procedure for aligning a marker position using an alignment device according to an embodiment. FIG. 9 is a block diagram showing the hardware configuration of this embodiment.

[0013] An alignment apparatus according to an embodiment and a marker used in the alignment apparatus will be described below with reference to the drawings. Fig. 1 is a schematic diagram of an alignment apparatus 100 according to an embodiment and its peripheral devices.

[0014] As shown in FIG. 1 , the alignment device 100 is connected to a scanning electron microscope 31 (hereinafter referred to as SEM (Scanning Electron Microscope)) and a micro-Raman spectrometer 32. The alignment device 100 acquires detection data obtained by imaging a sample to be observed with the SEM 31 and detection data obtained by the micro-Raman spectrometer 32, and aligns the two sets of detection data. The SEM 31 (scanning electron microscope) is an example of a first device. The micro-Raman spectrometer 32 is an example of a second device. Note that a micro-infrared spectrometer may also be used as the second device.

[0015] The alignment device 100 according to this embodiment places a marker on a stage on which the sample to be observed is placed, and aligns the detection data captured by the SEM 31 and the detection data detected by the micro-Raman spectrometer 32 using the marker as an index.

[0016] First, the markers used for aligning the detection data will be described. Fig. 2 is an explanatory diagram showing the marker 25 according to the embodiment, and Fig. 3 is an explanatory diagram showing the configuration of the mesh member M included in the marker 25.

[0017] As shown in Fig. 3, the mesh member M has a mesh shape in which a plurality of linear members 11 are randomly combined. The linear members 11 are formed of a conductive material and have a diameter of, for example, 10 µm. The linear members 11 are preferably made of a material that does not emit fluorescence or phosphorescence. The linear members 11 are preferably made of aluminum, for example. Note that the linear members 11 are not limited to aluminum as long as they are conductive.

[0018] As shown in Figure 2, the marker 25 is formed by spraying an adhesive such as glue onto a mesh member M, which is made by randomly weaving a plurality of linear members 11, and then pressing the mesh member M into a sheet after the glue has been washed away. That is, the marker 25 is formed into a flat plate shape by applying adhesive to the mesh member M. The mesh member M is then cut into strips. Because the mesh member M is made up of a plurality of linear members 11 randomly combined, the marker 25 has a unique structure.

[0019] Since the marker 25 is in contact with a plurality of conductive linear members 11, all of the linear members 11 forming the mesh member M are electrically connected to one another. In other words, by grounding a portion of the mesh member M, all of the linear members 11 forming the mesh member M are grounded. Therefore, when measuring a non-conductive material using charged particles in the SEM 31 shown in FIG. 1 , the charge on the sample surface can be discharged to the ground.

[0020] Furthermore, by constructing the linear member 11 from a material that does not emit fluorescence or phosphorescence, a known spectroscopic spectrum that can be distinguished from the sample being observed can be detected in the Raman spectroscopic image detected by the micro-Raman spectroscopic device 32, making it possible to easily identify the position of the mesh member M.

[0021] The marker 25 according to this embodiment is used as an index for aligning the positions of the detection data detected by each device with high precision when a sample placed on a stage is detected by the SEM 31 (first device) and the micro-Raman spectrometer 32 (second device). This will be explained in detail below.

[0022] Fig. 4 is a perspective view of the stage 20 on which the sample to be measured is placed. As shown in Fig. 4, the stage 20 is disk-shaped, with the central portion serving as a placement surface 21 for placing the sample, and the peripheral portion 22 of the stage 20 is made of a metallic material. The peripheral portion 22 is grounded. In other words, the peripheral portion 22 serves as a ground electrode.

[0023] 5 is an explanatory diagram showing a state in which the sample s1 and the marker 25 are placed on the mounting surface 21 of the stage 20. The diameter D1 of the mounting surface 21 is, for example, 10 mm.

[0024] As shown in Fig. 5, the marker 25 is placed on the mounting surface 21 of the stage 20 so as to overlap a portion of the sample s1. While Fig. 5 shows an example in which the marker 25 is placed on the upper surface of the sample s1, the sample s1 may also be placed on the upper surface of the marker 25. A portion of the marker 25 is in contact with the peripheral portion 22. That is, the conductive mesh member M included in the marker 25 is grounded via the peripheral portion 22. Therefore, as described above, the charge on the sample s1 can be discharged to the ground.

[0025] Next, the SEM 31, micro-Raman spectrometer 32, and alignment device 100 shown in FIG. 1 will be described. The SEM 31 (scanning electron microscope) captures a microscopic image of the sample s1 to be observed. The SEM 31 has an EDS (energy dispersive X-ray spectroscopy) function. EDS is a function that performs elemental analysis by detecting characteristic X-rays emitted by atoms excited by an electron beam. Note that WDS (wavelength dispersive X-ray spectroscopy) may be used instead of EDS.

[0026] When the stage 20 shown in FIG. 5 is placed at a predetermined measurement position, the SEM 31 captures a microscope image (first detection data) of the sample s1 and the marker 25 placed on the stage 20. Furthermore, the SEM 31 acquires an EDS image (first detection data) of the sample s1. The EDS image is used to identify the position of the marker 25. That is, the EDS image can be used to extract the region of the components (e.g., aluminum atoms) of the linear member 11, thereby easily identifying the region of the marker 25. Furthermore, since the resolution of the EDS image is, in principle, comparable to the resolution of the SEM 31, detection data with a resolution of approximately 1 μm can be acquired with high accuracy. The SEM 31 outputs the detected microscope image and EDS image to the alignment device 100. The microscope image and EDS image are examples of first detection data.

[0027] When the stage 20 shown in FIG. 5 is placed at a predetermined measurement position, the micro-Raman spectroscopic device 32 detects a micro-Raman spectroscopic image (second detection data, hereinafter abbreviated as "Raman spectroscopic image") of the sample s1 and marker 25 placed on the stage 20. The micro-Raman spectroscopic device 32 outputs data of the detected Raman spectroscopic image to the alignment device 100. The Raman spectroscopic image is an example of second detection data. Note that a micro-infrared spectroscopic device may be used instead of the micro-Raman spectroscopic device 32. In this case, the second detection data is a micro-infrared spectroscopic image.

[0028] The stage 20 may be manually placed by an operator at a predetermined measurement position in the SEM 31 and the micro-Raman spectrometer 32. Alternatively, the stage 20 may be automatically moved to the predetermined measurement position in the SEM 31 and the micro-Raman spectrometer 32 using a transport mechanism (not shown).

[0029] As shown in FIG. 1, the alignment device 100 includes an acquisition unit 101, an extraction unit 102, and a processing unit 103.

[0030] The acquisition unit 101 acquires data on the microscopic image and EDS image captured by the SEM 31, and data on the Raman spectroscopic image detected by the micro-Raman spectrometer 32. That is, the acquisition unit 101 has a function of acquiring detection data of the marker 25 and the sample s1 arranged overlapping a part of the marker 25, such as the microscopic image and EDS image (first detection data) detected by the SEM 31 (first device), and the Raman spectroscopic image (second detection data) detected by the micro-Raman spectrometer 32 (second device). Note that, as described above, a WDS image may be used instead of the EDS image.

[0031] The extraction unit 102 extracts the markers 25 contained in the microscope image and EDS image, and the markers 25 contained in the Raman spectroscopic image. The method for extracting the markers 25 will be described below. As shown in FIG. 6A , a region D2 with a side length of 1000 μm (1 mm) is extracted as image data of 1024 × 1024 pixels for the sample s1 and marker 25 placed on the mounting surface 21 of the stage 20. As a result, as shown in FIG. 6B , the region D2 including the linear member 11 and the sample s1 is extracted. As described above, the diameter of the linear member 11 is approximately 10 μm, and therefore the linear member 11 appears as a linear image of approximately 10 pixels. By using the EDS described above, the region of the Al (aluminum) atoms can be extracted, thereby easily identifying the region of the linear member 11.

[0032] The resolution of the SEM 31 is about 1 nm. Therefore, for example, an enlarged image of a region D3 having sides of 10 μm each shown in FIG. 6B can be acquired with high resolution. FIG. 6C shows an enlarged image of the region D3, and the region D3 having sides of 10 μm each can be extracted as image data of 1024×1024 pixels.

[0033] In addition, a Raman spectroscopic image (not shown) is obtained by the micro-Raman spectroscopic device 32 in the region D2 shown in Fig. 6A. The theoretical spatial resolution of a typical micro-Raman spectroscopic device 32 is approximately the wavelength of the laser used as excitation light (several hundred nm to 1 µm). Therefore, the resolution of the Raman spectroscopic image is approximately 1 µm, which is comparable to the resolution of a microscope using the SEM 31 that generates image data of 1024 x 1024 pixels for an area 1000 µm on a side shown in Fig. 6B.

[0034] 7 is a graph showing the Raman spectrum of a region D4 having a side length of 1 μm and included in region D3 shown in FIG. 6C. As shown in FIG. 7, the Raman spectroscopic image has spectral data at each measurement point. The linear member 11 included in the marker 25 is formed of a known material (e.g., aluminum), so its Raman spectrum can be acquired in advance. By comparing the spectral data shown in FIG. 7 with the spectrum of the linear member 11, the region of the marker 25 in the Raman spectroscopic image can be identified.

[0035] For example, when a high-purity thin aluminum metal wire is used as the linear member 11, it is sufficient to extract from the Raman spectroscopic image a region where the Raman spectrum of aluminum hydroxide, an oxide that is easily generated on the surface, is detected. In this way, the extraction unit 102 can extract the marker 25 from the microscope image captured by the SEM 31 and the Raman spectroscopic image detected by the microscopic Raman spectrometer 32.

[0036] The processing unit 103 shown in Fig. 1 aligns the two pieces of detection data by superimposing the markers 25 included in the microscope image extracted by the extraction unit 102 on the markers 25 included in the Raman spectroscopic image. Since the two pieces of detection data can be acquired at a resolution of 1 pixel per 1 µm for a thin line region with a diameter of 10 µm, the two images can be aligned with an error accuracy of about 1 µm. The processing unit 103 performs a process of aligning the first detection data (microscope image, EDS image) and the second detection data (Raman spectroscopic image) based on the positions of the markers 25.

[0037] For example, by focusing on the marker 25 included in the two pieces of detection data and translating and rotating the marker 25 included in one piece of detection data, a position where the degree of overlap of the marker 25 in the two pieces of detection data is maximized is searched for. The area of ​​the marker 25 extracted from one piece of detection data is set to 100%, and an arbitrary threshold value (e.g., 80%) is set. By searching for the point where the degree of overlap of the marker 25 in the two pieces of detection data exceeds the threshold and is maximized, the two pieces of detection data can be aligned.

[0038] Next, a procedure for aligning the marker position using the above-described alignment device 100 will be described with reference to the flowchart shown in Fig. 8. First, in step S11 shown in Fig. 8, the user places the sample s1 to be observed on the placement surface 21 of the stage 20 shown in Fig. 4, and then places the marker 25 so that it overlaps with a part of the sample s1. As a result, the sample s1 and the marker 25 are placed on the placement surface 21, as shown in Fig. 5, for example.

[0039] In step S12, the user sets the stage 20 shown in Fig. 5 at a predetermined measurement position in the SEM 31 shown in Fig. 1 and acquires a microscope image and an EDS image. The data of the microscope image and the EDS image are output to the acquisition unit 101 of the alignment device 100.

[0040] In step S13, the extraction unit 102 of the alignment device 100 extracts the mesh member M of the marker 25 from the EDS image acquired by the acquisition unit 101. Specifically, as shown in FIG. 6B , the linear member 11 is extracted from the EDS image of the mesh member M included in the region D2 having a side length of 1000 μm.

[0041] In step S14, the user places the stage 20 shown in Fig. 5 at a predetermined measurement position in the microscopic Raman spectroscopic device 32 shown in Fig. 1 and acquires a Raman spectroscopic image. Data of the Raman spectroscopic image is output to the acquisition unit 101 of the alignment device 100.

[0042] In step S15, the extraction unit 102 extracts the mesh member M of the marker 25 from the Raman spectroscopic image acquired by the acquisition unit 101. Specifically, the mesh member M is extracted by comparing the spectrum shown in FIG. 7 with the spectrum of the material of the linear member 11.

[0043] In step S16, the processing unit 103 aligns the position of the mesh member M in the EDS image with the position of the mesh member M in the Raman spectroscopic image.

[0044] In step S17, the processing unit 103 superimposes the microscope image and the Raman spectroscopic image. That is, since the microscope image and the EDS image detected by the SEM 31 correspond to each other, the microscope image and the Raman spectroscopic image can be superimposed on each other based on the relative positional relationship between the EDS image and the Raman spectroscopic image.

[0045] Once the alignment of the two detection data, the microscope image and the Raman spectroscopic image, is completed for the region (region D2) of the marker 25 shown in Fig. 6A that is 1 mm (1000 µm) on a side, it becomes possible to align the region that does not include the marker 25 by using image processing techniques such as parallel translation. In other words, it becomes possible to align the entire sample s1 placed on the stage 20.

[0046] As such, the marker 25 of this embodiment is a marker 25 used to align detection data, and comprises a mesh member M made up of a random combination of multiple conductive linear members 11, and is formed into a flat plate shape by adhering adhesive (e.g., glue) to the mesh member M.

[0047] The marker 25 according to this embodiment is formed by randomly combining multiple linear members 11, so the probability that two areas with the same combination pattern exist is extremely low. Therefore, it is possible to match the mesh members M included in the markers 25 included in two different pieces of detection data. As a result, it is possible to align the two pieces of detection data with high accuracy.

[0048] Since the marker 25 has a rectangular shape, it can be easily placed on the placement surface 21 of the stage 20, and the boundary between the marker 25 and the sample s1 can be easily distinguished.

[0049] By using aluminum as the material for the linear member 11, it becomes possible to easily process the linear member 11 to form the marker 25. Furthermore, by using aluminum, it is possible to reduce the weight and cost of the marker 25.

[0050] In this embodiment, the first device is the SEM 31, and the second device is a micro-Raman spectrometer 32 or a micro-infrared spectrometer. Since the detection data detected by the SEM 31 and the micro-Raman spectrometer 32 or the micro-infrared spectrometer can be aligned, it is possible to measure the shape of the sample s1 and simultaneously obtain information on the chemical bonds that make up the molecules of the sample s1. Furthermore, it is possible to determine the characteristics of the sample s1 by superimposing the detection data detected by the SEM 31 and the micro-Raman spectrometer 32 or the micro-infrared spectrometer.

[0051] A mesh member M is formed by randomly combining a plurality of conductive linear members 11, and during measurement, the mesh member M is grounded by contacting it with the peripheral portion 22 of the stage 20 shown in Figure 4. Therefore, when measuring a non-conductive material using charged particles in the SEM 31, the charge on the surface of the material can be discharged to the ground.

[0052] In this embodiment, for example, at the research stage during material development, it becomes possible to evaluate the material properties of a sample by combining the analysis results from a plurality of analysis devices.

[0053] The alignment apparatus 100 of the present embodiment described above can be implemented as a general-purpose computer system including, for example, a CPU (Central Processing Unit, processor) 901, a memory 902, a storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), a communication device 904, an input device 905, and an output device 906, as shown in Fig. 9. The memory 902 and the storage 903 are storage devices. In this computer system, the CPU 901 executes a predetermined program loaded onto the memory 902, thereby realizing each function of the alignment apparatus 100.

[0054] The alignment apparatus 100 may be implemented by one computer or by multiple computers, or may be a virtual machine implemented on a computer.

[0055] The program for the alignment apparatus 100 can be stored in a computer-readable recording medium such as a HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), or DVD (Digital Versatile Disc), or can be distributed via a network. The computer-readable recording medium is, for example, a non-transitory recording medium.

[0056] It should be noted that the present disclosure is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof. For example, in the above-described embodiment, an example was described in which the first device is an SEM 31 (scanning electron microscope) and the second device is a Raman microspectrometer 32, but the present disclosure is not limited thereto, and other devices that acquire detection data may be used.

[0057] REFERENCE SIGNS LIST 11 Linear member 20 Stage 21 Mounting surface 22 Periphery 25 Marker 31 Scanning electron microscope (SEM) 32 Microscopic Raman spectroscopic device 100 Alignment device 101 Acquisition unit 102 Extraction unit 103 Processing unit M Mesh member s1 Sample

Claims

1. A marker used for aligning detection data, comprising a mesh member made of a random combination of multiple conductive linear members, and formed into a flat plate shape by applying an adhesive to the mesh member.

2. The marker according to claim 1, wherein the mesh member is in the shape of a strip.

3. The marker according to claim 1 or 2, wherein the linear member is made of aluminum.

4. An alignment device comprising: a mesh member comprising a randomly combined plurality of conductive linear members, an acquisition unit which acquires first detection data detected by a first device and second detection data detected by a second device of a marker formed into a flat plate shape by adhering an adhesive to the mesh member, and a sample overlapping a portion of the marker; an extraction unit which extracts the marker contained in the first detection data and the second detection data; and a processing unit which aligns the first detection data and the second detection data based on the position of each of the markers.

5. The alignment device according to claim 4, wherein the first device is an electron scanning microscope, and the second device is a micro-Raman spectrometer or a micro-infrared spectrometer.

6. The alignment device described in claim 5, wherein the electron scanning microscope acquires, as the first detection data, a microscopic image of the sample and a marker and an EDS image or a WDS image, the second device acquires, as the second detection data, a microscopic Raman spectroscopic image or a microscopic infrared spectroscopic image, and the processing unit aligns the microscopic image and the microscopic Raman spectroscopic image or the microscopic infrared spectroscopic image based on the marker contained in the EDS image or the WDS image, and the microscopic Raman spectroscopic image or the microscopic infrared spectroscopic image.

7. A method for aligning a sample comprising a mesh member formed by randomly combining a number of conductive linear members, a marker formed into a flat plate shape by adhering an adhesive to the mesh member, and a sample overlapping a part of the marker, the method comprising: acquiring first detection data detected by a first device and second detection data detected by a second device; extracting the marker contained in the first detection data and the second detection data; and aligning the first detection data and the second detection data based on the positions of the markers.

8. The alignment method according to claim 7, wherein a stage on which the marker is placed is provided with a ground electrode connected to ground, and a portion of the mesh member is in contact with the ground electrode.