KR100725261B1 - The manufacturing method of nano material - Google Patents

Abstract

A method of manufacturing a nano material is provided to increase reliability of specimen analysis through a transmission electronic microscope and precisely defining a three-dimensional structure of the nano material. A method of manufacturing a nano material includes the steps of mixing a specimen material(205) with a coupling agent(206) such as adhesive, curing, and other materials, inserting the specimen mixture(210), in which the specimen material mixed with the coupling agent, into a tune(211), heating the tube, in which the specimen material is contained, to cure the specimen mixture, cutting the cured specimen material in the tube by appropriate sizes, and flattening the specimen mixture in the cut tube. The tube is heated to 120 to 150 degrees of centigrade for ten minutes.

Description

The Manufacturing Method of Nano Material

1A is a flowchart illustrating a method for fabricating a nanomaterial sample existing in a conventional semiconductor device or thin film.

FIG. 1B is a process-specific schematic diagram illustrating the sample manufacturing method of FIG. 1A.

2A to 2D are schematic diagrams for each process illustrating a method for preparing a nanomaterial sample according to the present invention.

3 is a cross-sectional view illustrating ion milling and diffraction methods for analyzing nanomaterial samples according to the present invention.

4A and 4B are photographs taken by analyzing a nanomaterial sample according to the present invention.

Description of the main parts of the drawing

101: sample 102: dummy wafer

103: adhesive layer 104: grid

201: container 205: sample

206: binder 210: sample mixture

211: tube 212: plate

220, 225: ion beam 230: X-ray source

235: detector

The present invention relates to a sample preparation method, and more particularly, to a nanomaterial sample preparation method for analyzing nanomaterials using a diffraction method.

Nano represents one billionth of a nanometer, which can be seen as a billionth of a 1m electron microscope, and is extremely small, with 3-4 atoms arranged. Therefore, in order to synthesize and utilize nanomaterials, precise analysis and verification techniques are required, which is called nanotechnology.

Hereinafter, a conventional sample manufacturing process will be described with reference to the drawings.

FIG. 1A is a flowchart illustrating a method for preparing a nanomaterial sample used in a conventional semiconductor device or a thin film, and FIG. 1B is a schematic diagram illustrating the sample manufacturing method of FIG. 1.

Referring to FIGS. 1A and 1B, in order to fabricate a fine nanomaterial, first, a sample 101 and a dummy wafer 102 are prepared (S11). The sample 101 is a sample for cross-sectional observation for thin film characterization, and is prepared in a size of about 5 mm × 10 mm, and the dummy wafer 102 is for supporting the sample 101, and is approximately the same size as the sample 101. In preparation, two samples 101 and four dummy wafers 102 are prepared in FIG. 1B.

Then, the surface of the sample 101 to be observed in cross section is cleaned with alcohol or the like and pasted so that the cleaned surface faces. Then, the dummy wafer 102 is attached to the sample 101 (S12). At this time, in order to adhere the sample 101 and the dummy wafer 102, an adhesive 103 such as M-610 or G1 epoxy is used. The adhesive 103 is applied to the surface of the dummy wafer 102, and then the temperature is raised to harden the adhesive 103.

Next, in order to grind the bonded sample 101 and the dummy paper 102, the sample 101 is attached to a jig (not shown) and polished using sandpaper. In order to attach to the jig, the crystal wax can be fixed to the jig by placing the crystal wax on a heating plate at about 150 ° C., attaching the sample 101 and the jig, and then cooling the sample. On the other hand, when heat is applied to the sample 101 attached to the jig, the sample 101 can be detached from the jig again. In order to reduce the thickness of the attached dummy paper 102 and the sample 101, a thin cutting is performed using various cutting devices (for example, diamond saw blades). The cut sample 101 is polished again using sandpaper (S13). In general, when the sample 101 is polished, the polishing is started at roughness 400 and uniformly polished to about 2000. The thickness of the sample 101 is about 100 µm or less, and 1000 or more fine abrasive is used.

The next step is to dimple the grinding of the sample 101 polished in step (S13) to a few μm using a dimple (a device that grinds thinner to 10 μm or less using a cog wheel having a diameter of about 1 cm). It is a step to continue to grind (S14). At this time, after the grid 104 is mounted, it is checked whether the interface 105 formed by the sample 101 and the sample 101 and the interface 106 formed by the sample 101 and the dummy wafer 102 are well bonded. do. Then, using a diamond slurry with a different diameter of the brass wheel and the particle size is polished until the surface state of the sample 101 becomes a mirror surface. The next step is to perform the ion milling process to make the periphery thin so that it is easy to observe the final fine holes before analyzing the specimen (S15). This process is sputtered using an argon beam until the hole 107 is formed on the surface of the dimpled sample 101.

The most important method of analyzing a sample produced through the above-described process steps is a method using a transmission electron microscope. In general, X-ray diffraction analysis is used to determine the crystallinity of the prepared sample, and transmission electron microscope is used to observe the microstructure of the sample.

However, when analyzing a sample using a transmission electron microscope, the direction of the electron beam incident on the sample must be exactly perpendicular to the sample. In addition, when the transmission electron microscope is used during the preparation of the sample, there is a problem that the sample is heated by the electron beam applied to the sample from the electron microscope, so that a fine structural change may occur in the sample. In the case of an unknown material whose properties are not known at all, it is not easy to analyze the material with a transmission electron microscope. Moreover, in order to examine the three-dimensional arrangement or stacked form of the manufactured sample, the transmission of the sample material to be observed The disadvantage is that the process is cumbersome because prior knowledge of the crystal orientation must be known before viewing under a microscope.

In particular, in the case of producing a sample using the above-described conventional sample fabrication process, it is not easier to analyze the crystallization direction of the produced sample, or the lamination form of the nano rings or plates. Of course, when using the above-described process, there is a problem that it is difficult to control the thickness when preparing the sample, it is not easy to obtain the analysis conditions for observing the arrangement form when analyzing the produced sample.

The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to mix nanomaterials with a binder capable of bonding, curing, adhering and curing when preparing a sample, and performing an X-ray diffraction process on the mixed sample. In addition, to provide a sample preparation method for producing a sample.

In addition, another object of the present invention is to provide a sample preparation method that can improve the reliability of the sample analysis through the transmission electron microscope and accurately identify the three-dimensional structural analysis of the nanomaterial by using the sample preparation method described above.

According to an aspect of the present invention for achieving the above object, the sample preparation method comprises the steps of mixing a sample material and a binder for bonding the sample material; Filling a tube of a predetermined size with a sample mixture mixed with the sample material and a binder; Heating the sample mixture filled in the tube; Heating the sample mixture, and then cutting the sample mixture filled into a tube to an appropriate size; And adjusting the thickness of the cut sample mixture.

Preferably, in the thickness adjusting step, an ion milling process is used to adjust the thickness of the sample mixture. During the ion milling process, the method further comprises an X-ray diffraction analysis step for milling the sample mixture according to the desired crystal direction and the desired angle. In the thickness adjusting step, the ion milling process is performed at a predetermined angle by confirming the stacked form and arrangement of the sample compound in the X-ray diffraction analysis step using the diffraction image difference. The binder uses a material capable of undergoing at least one of bonding and curing. The binder is an epoxy based material. The sample material is a nanomaterial and the tube consists of a material containing copper.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail.

FIG. 2A is a flowchart illustrating a method for preparing a nanomaterial sample according to the present invention, and FIG. 2B is a process-specific schematic diagram illustrating a method for preparing a nanomaterial sample according to the present invention.

2A and 2B, in order to prepare the sample 215, first, the sample material 205 and the binder 206 capable of bonding, curing, bonding and curing are mixed in a suitable container 201 (S21, FIG. (A) of 2b). In the present embodiment, the sample material 205 is a nano material having extremely fine particles, and a general powder sample is used. The sample material 205 includes a nano powder sample such as Gd, Au, TiO ₂ , and carbon nano tube. The binder 210 used in the present embodiment is a material capable of bonding the powder sample and then curing or bonding and curing the powder sample, G1 epoxy manufactured by Gatan, 2-ton epoxy manufactured by Devcon, Epoxy materials such as 5-min epoxy produced by Devcon, and M-610 bond manufactured by Measurement Group are used.

In this embodiment, Gatan's G1 epoxy is used, and Gatan's G1 epoxy is known to have the least damage to the beam during ion polishing to be used in the post process. Since the epoxy material can be classified into bonding and curing, when the nanosample 205 and the binder 206 are mixed, a separate adhesive resin (not shown) is added first and the binder 206 is further added to the sample material 205. The sample material 205 may be mixed by mixing only the sample material 205 and the binder 206 without additionally mixing or adding a separate adhesive resin. Herein, the resin means an epoxy adhesive material before putting the stacking agent 206. Of course, the mixing order and ratio of the resin and the binder 206 may be adjusted according to external factors such as the temperature applied to the sample material 205. The sample material 205 and the binder 206 may adjust the mixing ratio according to whether to observe an image of the manufactured sample or to observe a high resolution. In the case of the purpose of image observation, the addition rate of the sample is lowered than the case of preparing the sample for the purpose of high resolution observation. The binder 206 is adjusted depending on the weight ratio of the sample material or the weight ratio of the sample material and the resin.

 Next, referring to step S22 and FIG. 2B (b), the sample mixture 210 in which the sample material 205 and the binder 206 are mixed is put into the tube 211. The tube 211 may use a tube made of various materials, but generally uses a copper-containing material having good resistance to electron beams, and in this embodiment, a tube made of brass is used. In addition, the tube 211 is a size that can be mounted on the sample mounting holder of the electron microscope used to analyze the sample, and uses a tube of about 3 mm in diameter. In the next step, the tube 211 containing the sample mixture 210 is heated (S23). In order to heat the tube 211, after mounting the tube 211 containing the sample mixture 210 in the heating plate 212, a predetermined temperature at a predetermined temperature so that the molding (molding) is well achieved Heat for hours. In this embodiment, the sample mixture 210 is heated for about 10 minutes in the temperature range of 120 ~ 150 ℃.

Referring to step (S24) and (c) of FIG. 2B, the sample mixture 210 contained in the tube 211 is cured, and then cut into an appropriate size using a cutter (for example, a diamond cutter). . After the sample preparation is completed, the cured sample mixture 215 may be cut by varying the size according to the type of analytical device used to analyze the sample. Cut about 3mm enough to fit. In the next step, the sample mixture 210 filled in the cut tube is made thin (S25, FIG. 2B (d)). At this time, the thinning of the sample mixture 210 uses an ion milling process of thinning the periphery so as to easily form and observe fine holes before the sample 210 is analyzed.

At this time, in step (S25), X-ray diffraction method can be further applied during the ion milling process, unlike the sample preparation method for producing a nano-material floating on the mesh grid and the sample preparation method for the conventional cross-sectional analysis. In the case of further using the X-ray diffraction process, the sample can be prepared according to the crystal form and the desired angle of the sample.

3 is a cross-sectional view illustrating an ion milling process and an X-ray diffraction method for preparing a sample according to the present invention. In this embodiment, sputtering is performed while rotating the sample mixture 210 in order to ion mill the sample mixture 210. Sputtering is performed while irradiating the argon beams 220 and 225 above and below the sample mixture 210. This process continues until a hole having a slightly smooth surface is formed in the sample mixture 210. During the ion milling of the sample mixture 210, the crystal state of the mixed sample 210 may be analyzed using X-ray diffraction. In order to analyze the sample mixture 210 using the X-ray diffraction method, the X-ray diffraction analysis apparatus (not shown) provided in the lower portion of the stage (not shown) on which the sample mixture 210 is mounted is provided. Line 230 is applied to sample mixture 210.

When the X-rays are applied to the sample mixture 210, the crystal arrangement state of the sample mixture 210 made of nanomaterials is also used during the ion milling process (that is, the sample polishing process) using the detector 235 provided in one region of the stage. You can check. Specifically, in order to analyze the sample mixture 210 by applying the X-ray diffraction method during the ion milling process, the sample mixture 210 is stopped in the state in which the sputtering process (ie, the rotating process) of the sample 210 is stopped. After the X-rays are applied, the ion milling process continues. However, if the X-ray diffraction cannot proceed immediately during the sample preparation process, the sample mixture 210 may be suspended and then transferred to an X-ray diffraction analyzer equipped separately for analysis.

4a and 4b are photographs taken by analyzing the sample mixture according to the present invention. Figure 4a is a photograph showing the plate shape of the prepared sample mixture, Figure 4b is a photograph showing the arrangement of the nano ring.

As shown in FIG. 4A, in order to selectively observe the nanoplate shape 401, the X-ray diffraction analysis disclosed in FIG. 3 is performed, followed by ion milling at the angle to find the beam direction in which the stripes appear in the diffraction results. do. In addition, when the X-ray diffraction method is applied to the region 402 in which the nanoplate and the nanoring are mixed in FIG. 4A, the shapes of the nanoplate and the nanoring may be observed.

Referring to FIG. 4B, a regular arrangement of single nanorings 403 and stacked nanorings 404 are observed. In order to observe the regular arrangement of the single nano ring 403, check the diffraction pattern of the single nano ring 403 portion, then find and fix the angle at which the pattern appears during ion milling, and then selectively observe by ion milling. do. The shape of the stacked nanoring 404 is slightly changed in the position of the diffraction point or the diffraction angle, unlike the regular arrangement of the single nanoring 403 on the diffraction pattern. Therefore, using this to find a fixed angle that can be seen in the stacked form well. In order to find a three-dimensional stacking form, the stacking nano-rings 404 can be observed by performing ion milling by constantly fixing the tilting angle during the ion milling, after finding the angle at which the lamination is regularly arranged.

Since the diffraction pattern of the nanomaterial sample can be obtained first through the sample preparation method and the X-ray diffraction method, if the diffraction pattern is applied by applying the X-ray diffraction method in the ion milling process proposed in the present invention, the shape of the nanomaterial According to the observation and the three-dimensional stacked form can be observed.

The present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims.

As described above, the present invention provides a precise analysis result according to each shape of the nanocrystals by adjusting the shape of a specific nanomaterial by applying a diffraction method during ion milling in the sample analysis method of the nanomaterial. You get the effect.

In addition, the ion milling after the molding of the nanomaterials can be used to suppress the loss of the prototype of the nanomaterials due to heat, and when the three-dimensional lamination forms exist in the nanomaterials, the direction to be observed can be set using the X-ray diffraction method. It is effective in analyzing the shape and structure of nanomaterials such as particles, particles, rings, rings and plates.

Claims (8)

Mixing a nanomaterial as a sample material and an epoxy-based material as a binder to bond the nanomaterial; Filling the tube with a sample mixture in which the nanomaterial and the epoxy material are mixed; Heating the sample mixture filled in the tube; Heating the sample mixture and cutting the tube filled with the sample mixture; And Milling the cut tube Sample preparation method comprising a. The method of claim 1, Sample milling method using the ion milling (milling) process in the milling step. The method of claim 2, During the ion milling process, further comprising an X-ray diffraction analysis step for milling the sample mixture filled in the cut tube according to the desired crystallographic direction and the desired angle. The method of claim 3, In the milling step A method for preparing a sample in which the ion milling process is performed at a predetermined angle by checking the stacked form and arrangement of the sample compound in the X-ray diffraction analysis step using the diffraction image difference. The method of claim 1, The epoxy-based material is a sample manufacturing method using a material that can proceed at least one of bonding and curing. The method of claim 5, The epoxy material is a sample manufacturing method of one of G1 epoxy, 2-ton epoxy, 5-min epoxy and M-610 bond. The method of claim 1, Sample preparation method is a nano powder sample or a carbon nano tube that is the nanomaterial. The method of claim 1, The tube is made of a material containing copper.

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