JP2004301639A - Observation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an observation method for accurately observing a cross-sectional structure of a sample. <P>SOLUTION: After a film is peeled from a capacitor precursor 10 covered with a holding film 4 so as to observe the cross-sectional structure of the capacitor precursor 10 provided on the film, a cross section D is exposed by breaking the capacitor precursor 10, along with the holding film 4. Since the film is peeled, while a layer structure of the capacitor precursor 10 is held by the holding film 4, cracks and torsion due to a stress generated by peeling the film are less likely to be generated in the capacitor precursor 10, in comparison with conventional observation methods, in which the film is peeled without providing the holding film 4. The action can be obtained, when the film is peeled and the capacitor precursor 10 is broken. The layer structure of the capacitor precursor 10 can be maintained so as not to possibly change its state, before breaking it. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for observing a sample using an observation device such as an electron microscope, and more particularly to a method for observing a cross-sectional structure of the sample.
[0002]
[Prior art]
In recent years, electron microscopes have been widely used to observe the cross-sectional structure of a sample. The electron microscope uses a beam of electrons to magnify a microscopic observation area in a magnified image. For example, a transmission electron microscope (TEM) that forms an image based on an electron beam transmitted through a sample and a transmission electron microscope (TEM). A scanning electron microscope (SEM; Scanning Electron Microscope) that forms an image based on an electron beam reflected from a sample or an electron beam generated from the sample is known.
[0003]
Among these electron microscopes, many examples of observation of a sample using an SEM are already known. Specifically, for example, in the field of development of capacitors, in order to form a laminated capacitor in which dielectric films and electrode patterns are alternately laminated, using a capacitor precursor provided on a film is used. The cross-sectional structure of the capacitor precursor is observed with an SEM as needed. This capacitor precursor is formed by laminating a dielectric film and an electrode pattern one by one in this order. In forming a multilayer capacitor, for example, after a film is peeled from a capacitor precursor, a desired number of capacitor precursors are laminated (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-10-255549
[0005]
FIG. 17 illustrates the flow of a conventional observation method for observing the cross-sectional structure of a capacitor precursor using an SEM. When observing the cross-sectional structure of the capacitor precursor, first, the film is peeled from the capacitor precursor (Step 201). Subsequently, by breaking the capacitor precursor while freezing it using liquid nitrogen, the cross section of the capacitor precursor is exposed (step S202). Finally, after mounting the broken capacitor precursor on the sample stage, the cross-sectional structure of the capacitor precursor is observed using SEM (step S203). According to the observation result of the SEM, for example, information (for example, particle distribution and particle size) on the layer structure of the dielectric film and the electrode pattern can be obtained.
[0006]
[Problems to be solved by the invention]
By the way, in order to observe the cross-sectional structure of the capacitor precursor with high accuracy using the SEM, for example, it is necessary to break the capacitor precursor so that the layer structure does not change as much as possible from the state before the break. However, in the conventional observation method, for example, when the capacitor precursor is twisted or twisted due to the stress generated when the film is peeled or when the capacitor precursor is broken, the layer structure greatly changes from the state before the break. Therefore, there is a problem that it is difficult to observe the cross-sectional structure of the capacitor precursor with high accuracy.
[0007]
Further, in the conventional observation method, depending on the magnitude of the stress generated when the film is peeled off, the capacitor precursor may be unintentionally broken due to the stress. There is also a problem that it is difficult to expose the cross section by breaking the wire.
[0008]
The above-mentioned two problems become particularly remarkable when the dielectric film and the electrode pattern are extremely thin and their physical strength is reduced. Considering the market trend in which the dielectric film and the electrode pattern tend to become thinner and thinner with the miniaturization of the capacitor, the capacitor precursor is broken at the desired observation position and the cross-sectional structure of the capacitor precursor is increased. There is an urgent need to establish an observation method that can be observed with high accuracy.
[0009]
The present invention has been made in view of such a problem, and a first object of the present invention is to provide an observation method capable of observing a cross-sectional structure of a sample with high accuracy.
[0010]
It is a second object of the present invention to provide an observation method capable of exposing a cross section of a sample at a desired position.
[0011]
[Means for Solving the Problems]
The observation method according to the present invention is a method for observing a sample provided on a substrate, a first step of forming a holding film so as to cover the sample, a second step of peeling the substrate from the sample, The method includes a third step of exposing a cross section of the sample and a fourth step of observing the cross-sectional structure of the sample.
[0012]
In the observation method according to the present invention, in a state where the sample is held by the holding film, the substrate is peeled off from the sample and the cross section of the sample is exposed. As a result, the sample is less likely to be twisted or twisted due to the stress generated at the time of peeling the substrate or exposing the cross section of the sample, and the layer structure of the sample is maintained as little as possible from the state before the fracture. You.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
First, the configuration of a sample observed using the observation method according to one embodiment of the present invention will be briefly described with reference to FIGS. 1 and 2 show the configuration of a capacitor precursor 10 as a sample, FIG. 2 shows a plan configuration, and FIG. 1 shows a cross-sectional configuration along the line AA shown in FIG. In addition, the frame line C shown in FIG. 2 indicates a portion where the capacitor precursor 10 will be cut when forming the capacitor.
[0015]
The capacitor precursor 10 is used to form a multilayer capacitor, and is provided on a film 1 as a base. The capacitor precursor 10 has a configuration in which a dielectric film 2 and an electrode pattern 3 are laminated one by one in this order, and a plurality of electrode patterns 3 are arranged on the dielectric film 2 in a matrix. are doing.
[0016]
The dielectric film 2 is formed by, for example, kneading ceramic dielectric particles in a binder to form a coating, and has a thickness of about 1 μm to 10 μm. This binder contains, for example, polyvinyl butyral, polyvinyl acetal, acrylic resin, ethyl cellulose, or a combination of any two or more of these. The ceramic dielectric particles are made of, for example, barium titanium alloy oxide (BaTiO). ₃ ), Calcium titanium alloy oxide (CaTiO ₃ ) Or strontium titanium alloy oxide (SrTiO ₃ ).
[0017]
The electrode pattern 3 is formed by, for example, kneading metal particles in a binder to form a coating film pattern, and has a thickness of about 1 μm to 2 μm. This binder contains, for example, ethyl cellulose. The metal particles are, for example, nickel (Ni), palladium (Pd), silver-palladium alloy (AgPd), or the like.
[0018]
The film 1 is made of, for example, a polymer material such as PET, and has a thickness of about 20 μm to 30 μm.
[0019]
When a multilayer capacitor is formed using the capacitor precursor 10, for example, the film 1 is peeled off from the capacitor precursor 10, and a desired number of the capacitor precursors 10 are laminated. The capacitor precursor 10 is cut along the frame line C. Thereby, since the capacitor precursor 10 is divided for each region including the electrode pattern 3, a plurality of multilayer capacitors are formed.
[0020]
Next, a method for observing the capacitor precursor 10 shown in FIGS. 1 and 2 will be described with reference to FIGS. 3 to 6 are for explaining the observation step of the capacitor precursor 10, FIG. 3 shows the flow of the observation step, and FIGS. 4 to 6 show one of the observation steps (cross section in FIG. 1). (A cross-sectional configuration corresponding to the configuration).
[0021]
In this observation method, for example, the cross-sectional structure of the capacitor precursor 10 is observed as a pre-stage for obtaining information on the layer structure of the multilayer capacitor. When observing the capacitor precursor 10, after preparing the capacitor precursor 10 provided on the film 1 as shown in FIGS. 1 and 2, first, as shown in FIG. The holding film 4 is formed so as to cover 10 (FIG. 3; step S101). The holding film 4 is for physically holding the layer structure of the capacitor precursor 10. When the holding film 4 is formed, for example, a resin is applied so as to cover the capacitor precursor 10 to form a coating film, so that the thickness is about 50 μm to 500 μm. The resin used to form the holding film 4 includes, for example, (1) excellent handleability, (2) easy to break or cut, and (3) holding property of the layer structure in relation to the capacitor precursor 10. (4) excellent in adhesiveness and (5) low in reactivity, and specifically, a curable resin such as an epoxy resin is preferable. As this type of curable resin, for example, a room temperature curable resin is preferable in order to easily and quickly form the holding film 4.
[0022]
Subsequently, as shown in FIG. 5, the film 1 is peeled from the capacitor precursor 10 while holding the capacitor precursor 10 using the holding film 4 (FIG. 3; step S102).
[0023]
Subsequently, as shown in FIG. 6, the cross section D of the capacitor precursor 10 is exposed (FIG. 3; step S103). The details of this cross-section exposure step are, for example, as follows. That is, first, using a glass cutter or a cutter, a scratch (cut) is made in the holding film 4 at a position where the capacitor precursor 10 is to be broken (that is, a position where the cross-sectional structure of the capacitor precursor 10 is to be observed). Subsequently, the capacitor precursor 10 is put into liquid nitrogen while gripping both sides using radio pliers or the like, and the liquid crystal nitrogen is used to freeze the capacitor precursor 10 while bending the capacitor precursor 10 together with the holding film 4. Break. Thereby, the cross section D of the capacitor precursor 10 is exposed. It should be noted that the “break” described above, unlike “cut”, means that the cross section D is exposed by physically bending the capacitor precursor 10 without using a cutting tool such as a cutter.
[0024]
Subsequently, a method of observing the capacitor precursor 10 will be described. After exposing the cross section D of the capacitor precursor 10, the capacitor precursor 10 is left at room temperature. Finally, the fractured capacitor precursor 10 is placed on a sample table together with the holding film 4, and the cross-sectional structure of the capacitor precursor 10 is observed using an SEM (FIG. 3; step S104).
[0025]
In the observation method according to the present embodiment, after observing the cross-sectional structure of the capacitor precursor 10 provided on the film 1, the film 1 is peeled off from the capacitor precursor 10 covered by the holding film 4, Since the cross section D was exposed by breaking the capacitor precursor 10 together with the holding film 4, the layer structure of the capacitor precursor 10 was held by the holding film 4 having a sufficient thickness (about 50 μm to 500 μm). In the state, the film 1 is peeled from the capacitor precursor 10. In this case, compared to the conventional observation method in which the holding film 4 was not provided and the film 1 was peeled off in a state where the layer structure of the capacitor precursor 10 was not held by the holding film 4, The capacitor precursor 10 is less likely to be twisted or twisted due to the stress generated at the time of peeling. This effect is obtained not only when the film 1 is peeled but also when the capacitor precursor 10 is broken. Therefore, in the present embodiment, the layer structure of the capacitor precursor 10 can be maintained as little as possible from the state before the breakage, so that the dielectric film 2 and the electrode Even when the pattern 3 is thinned, the cross-sectional structure of the capacitor precursor 10 can be observed with high precision.
[0026]
Specifically, using the SEM observation results obtained by using this observation method, (1) grasping the layer structure of the dielectric film 2 and the electrode pattern 3 in a state almost close to the state before the fracture, (2) The number and distribution of particles (ceramic dielectric particles and metal particles) in the layer are measured, (3) the thickness of the layer is measured, and (4) the void (void) contained in the layer is measured. By measuring the number, distribution or cross-sectional area, (5) the distribution or cross-sectional area of the binder in the layer can be measured. Further, by utilizing the results of the SEM observation, an EPMA (Electron Probe Micro-Analyzer) analysis and a SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) can be easily performed.
[0027]
Further, in the present embodiment, as described above, since the film 1 is peeled in a state where the layer structure of the capacitor precursor 10 is held by the holding film 4, the film 1 is peeled without providing the holding film 4. Compared with the conventional observation method, the capacitor precursor 10 is less likely to break unintentionally due to the stress generated when the film 1 is peeled off. Therefore, in the present embodiment, since the capacitor precursor 10 can be broken at the original breaking step, the capacitor precursor 10 can be broken at a desired position, and the cross section D thereof can be exposed.
[0028]
Further, in the present embodiment, the provision of the thick holding film 4 on the thin capacitor precursor 10 increases the overall thickness by the thickness of the holding film 4, thereby improving the physical strength. Therefore, the handleability of the capacitor precursor 10 can be improved as compared with the case where the thin capacitor precursor 10 is handled as it is.
[0029]
Further, in the present embodiment, since the capacitor precursor 10 is broken while freezing using liquid nitrogen, for example, the capacitor precursor 10 is broken as compared with the case where the capacitor precursor 10 is broken at room temperature. In addition, it is extremely unlikely that Ret or twist will occur. Therefore, the cross-sectional structure of the capacitor precursor 10 can be observed with higher accuracy.
[0030]
In the present embodiment, as shown in FIG. 6, in order to expose the cross section D of the capacitor precursor 10, the capacitor precursor 10 is broken using a gripping tool such as pliers. However, the present invention is not limited to this. For example, the capacitor precursor 10 may be cut using a cutting tool such as a cutter or a microtome instead of the break. In this case, for example, the cutting of the capacitor precursor 10 may be performed in liquid nitrogen, or may be performed at room temperature. In this case, substantially the same effects as in the above embodiment can be obtained.
[0031]
Further, in this embodiment, as shown in FIG. 6, after exposing the cross section D of the capacitor precursor 10, the cross section D is cut using a cutting tool such as a microtome as necessary. May be used for flattening. This “flattening” means not only processing the cross section D so as to be in a precise flat state, but also processing the cross section D so as to be in a substantially flat state in which SEM observation can be appropriately performed in a later process. It is meant to include In this case, even if the cross section D has an uneven structure that can affect SEM observation due to the fracture state, the uneven structure is relaxed to the extent that SEM observation is possible. The cross-sectional structure of the body 10 can be observed with higher accuracy.
[0032]
Further, in the present embodiment, the holding film 4 is formed on the capacitor precursor 10 as shown in FIG. 4, but is not necessarily limited to this. For example, as shown in FIG. After the separation film 5 is formed on the capacitor precursor 10, the holding film 4 may be formed on the separation film 5. The separation film 5 is for physically separating the capacitor precursor 10 and the holding film 4 and can be formed by using an existing film forming method such as sputtering or CVD (Chemical Vapor Deposition). . As a material for forming the separation film 5, for example, a metal such as aluminum (Al), gold (Au) or platinum (Pt), an alloy such as a platinum-palladium alloy (PtPd), or an aluminum oxide (Al ₂ O ₃ ), A glass material, a carbon material such as DLC (Diamond Like Carbon), and the like. Further, the thickness of the separation film 5 may be about 50 nm. In this case, since the separation film 5 functions as a barrier and a boundary between the capacitor precursor 10 and the holding film 4, the holding film 4 is mixed with the dielectric film 2 and the binder in the electrode pattern 3, Alternatively, it is possible to prevent the holding film 4 from reacting with the binder, so that the capacitor precursor 10 and the holding film 4 can be visually and clearly distinguished in the SEM observation image.
[0033]
In the present embodiment, the cross section D of the capacitor precursor 10 is directly observed. However, the present invention is not limited to this. For example, another cross section other than the cross section may be observed. . Specifically, for example, after the cross section D of the capacitor precursor 10 is exposed, post-processing is further performed on the capacitor precursor 10 from the cross section D using Focused Ion Beam Etching (FIB). By utilizing the characteristic of the FIB in which the etching process proceeds in a direction orthogonal to the processing surface of the workpiece, two types of observation methods using the SEM can be selected. 8 to 11 are for explaining two types of SEM observation methods based on the post-processing mode. FIGS. 8 and 9 show a first observation method, and FIGS. 10 and 11 show a second observation method. The method is shown. 9 and 11 show plane configurations corresponding to the perspective configurations shown in FIGS. 8 and 10, respectively.
[0034]
As shown in FIG. 8, the capacitor precursor 10 and the holding film 4 are selectively etched from the cross section D to form a triangular prism-shaped depression K1, and another flat cross section P1 is exposed in the depression K1. In this case, in order to observe the cross section P1 using the SEM, as shown in FIG. 9, a portion (portion B) of the capacitor precursor 10 and the holding film 4 corresponding to the cross section P1 is obstructed. Therefore, it is necessary to observe from a direction (observation direction) V1 other than the direction orthogonal to the cross section P1. The angle θ1 between the cross section P1 and the observation direction V1 is, for example, 60 °. In this case, although the etching time required to form the depression K1 is relatively short, for example, due to the configuration of the SEM used for observation, the detector for electron beam detection is located on the opposite side to the cross section P1 with the part B interposed therebetween. If the portion 20 is arranged, the portion B becomes an obstacle, and it becomes difficult for the detector 20 to detect the electron beam, so that the quality (focus, contour, contrast, etc.) of the SEM observation image is reduced. Hereinafter, the observation method illustrated in FIGS. 8 and 9 is referred to as “tilt observation method” based on the observation direction V1.
[0035]
On the other hand, as shown in FIG. 10, the holding film 4 is selectively etched together with the capacitor precursor 10 from the cross section D to form a rectangular parallelepiped depression K2 whose one surface is exposed, and the depression K2 is formed in the depression K2. When another flat cross section P2 is exposed, as shown in FIG. 11, observation becomes possible from a direction (viewing direction) V2 orthogonal to the cross section P2. The angle θ2 between the cross section P2 and the observation direction V2 is approximately 90 °. In this case, although the etching time required to form the depression K2 becomes relatively long, for example, even if the detector 20 is arranged at the same position as that shown in FIG. Is larger than the case shown in FIG. 9 in which the portion B is in the way, so that the quality of the SEM observation image is ensured. Hereinafter, the observation method illustrated in FIGS. 10 and 11 is referred to as “orthogonal observation method” based on the observation direction V2.
[0036]
As described above, substantially the same effects as in the above embodiment can be obtained regardless of whether the oblique observation method or the orthogonal observation method is used. In particular, when the orthogonal observation method is used, the quality of the SEM observation image is ensured, so that the cross-sectional structure of the capacitor precursor 10 can be observed with higher accuracy.
[0037]
Further, in the present embodiment, the SEM is used to observe the cross-sectional structure of the capacitor precursor 10, but the present invention is not limited to this. For example, a TEM may be used instead of the SEM. . Of course, in the present embodiment, another observation method capable of observing the cross-sectional structure may be used similarly to the SEM or the TEM. In these cases, the same effects as in the above embodiment can be obtained.
[0038]
【Example】
Next, specific examples of the present invention will be described.
[0039]
First, the cross-sectional structure of the capacitor precursor was observed by SEM using the observation method of the present invention using the holding film, and the result shown in FIG. 12 was obtained. Further, when the cross-sectional structure of the capacitor precursor was observed by SEM using a conventional observation method not using a holding film, the result shown in FIG. 13 was obtained. 12 and 13 are SEM observation photographs of a wide field of view. FIGS. 12 (A), 13 (A) and 13 (B) show cross-sectional structures, and FIGS. 12 (B) and 13 (C) are for reference. Shows the surface structure.
[0040]
When the observation method of the present invention was used, as shown in FIG. 12 (A), the layer structure was not twisted, and there was very little Ret. Further, as shown in FIG. 12B, the surface was almost flat. On the other hand, when the conventional observation method was used, as shown in FIGS. 13A and 13B, the layer structure was greatly twisted, and there were many Re. Further, as shown in FIG. 13C, remarkable unevenness was observed on the surface. From these results, it was confirmed that the cross-sectional structure of the capacitor precursor can be observed with higher precision by using the observation method of the present invention than by using the conventional observation method.
[0041]
Next, regarding the observation method of the present invention, a comparison was made between two types of SEM observation methods (tilt observation method and orthogonal observation method) based on the post-processing form using FIB, and the results shown in FIGS. 14 and 15 were obtained. Was done. 14 and 15 are SEM observation photographs of a narrow visual field. FIG. 14 shows the tilt observation method, and FIG. 15 shows the orthogonal observation method.
[0042]
As shown in FIGS. 14 and 15, a laminated structure in which the dielectric film, the electrode pattern, and the holding film were laminated in this order was observed in either case of using the oblique observation method or the orthogonal observation method. . At this time, when the tilt observation method was used, as shown in FIG. 14, the focus was partially shifted, the outline was unclear, and the contrast was not sufficient. Further, it was not possible to specify whether the region seen between the particles was a void or a binder. On the other hand, when the orthogonal observation method was used, as shown in FIG. 15, the whole was in focus, the outline was clear, and the contrast was sufficient. Further, since the contrast was sufficient, it was possible to specify whether the region seen between the particles was a void or a binder. From these results, it was confirmed that the quality of the SEM observation image was higher when the orthogonal observation method was used than the tilt observation method.
[0043]
Next, with respect to the observation method of the present invention, when a separation film was provided between the capacitor precursor and the holding film and SEM observation was performed, the result shown in FIG. 16 was obtained. FIG. 16 is a narrow-field SEM observation photograph when a separation membrane (platinum-palladium alloy, 50 nm thick) is provided.
[0044]
When a separation film was provided between the capacitor precursor and the holding film, as shown in FIG. 16, the separation film was used as a boundary line for separating the capacitor precursor and the holding film in the SEM observation image. Was observed, and these capacitor precursors and the holding film were clearly distinguished visually. Further, based on the presence of the separation film, no appearance was observed in which the holding film was mixed with the binder in the dielectric film or the electrode pattern or the holding film reacted with the binder. From these results, it was confirmed that if a separation film was provided between the capacitor precursor and the holding film, it was possible to clearly distinguish the capacitor precursor and the holding film.
[0045]
As described above, the present invention has been described with reference to the embodiment and the example. However, the present invention is not limited to the embodiment and the example, and various modifications are possible.
[0046]
【The invention's effect】
As described above, according to the observation method of the present invention, in order to observe the cross-sectional structure of the sample provided on the substrate, the substrate is separated from the sample covered with the holding film, and then the cross-section of the sample is removed. Is exposed, the substrate is peeled off in a state where the sample is held by the holding film, and the cross section of the sample is exposed. Therefore, the cross-sectional structure of the sample can be observed with high accuracy, and the cross-section of the sample can be exposed at a desired position. In addition, the handling of the sample can be improved.
[0047]
In addition to the above, in the observation method according to the present invention, if the cross section of the sample is exposed while being frozen using liquid nitrogen, the sample is unlikely to be twisted or twisted. Therefore, the cross-sectional structure of the sample can be observed with higher accuracy.
[0048]
In the observation method according to the present invention, if the cross section of the sample is cut and flattened, the cross-sectional structure of the sample can be observed with higher accuracy.
[0049]
Further, in the observation method according to the present invention, if the sample is selectively etched from the cross section using focused ion beam etching to expose another cross section and the cross section is observed from an orthogonal direction, the observation can be performed. Image quality can be ensured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a cross-sectional configuration of a capacitor precursor observed using an observation method according to an embodiment of the present invention.
FIG. 2 is a plan view illustrating a planar configuration of the capacitor precursor illustrated in FIG.
FIG. 3 is a flowchart illustrating a flow of an observation method according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view for explaining one of the observation steps relating to the observation method according to one embodiment of the present invention.
FIG. 5 is a sectional view for explaining a step following FIG. 4;
FIG. 6 is a sectional view illustrating a step following FIG. 5;
FIG. 7 is a cross-sectional view illustrating a modified example of the observation method according to the embodiment of the present invention.
FIG. 8 is a perspective view for explaining an observation method (tilt observation method) based on a post-processing form using FIB relating to the observation method according to one embodiment of the present invention.
FIG. 9 is a plan view corresponding to FIG.
FIG. 10 is a perspective view for explaining an observation method (orthogonal observation method) based on a post-processing form using FIB related to the observation method according to one embodiment of the present invention.
FIG. 11 is a plan view corresponding to FIG. 10;
FIG. 12 is a wide-field SEM observation photograph using an observation method (without a separation membrane) according to one embodiment of the present invention.
FIG. 13 is a SEM observation photograph of a wide field using a conventional observation method.
FIG. 14 is a narrow-field SEM observation photograph using an observation method (tilt observation method) according to an embodiment of the present invention.
FIG. 15 is a SEM observation photograph of a narrow field using an observation method (orthogonal observation method) according to an embodiment of the present invention.
FIG. 16 is a narrow-field SEM observation photograph using an observation method (with a separation membrane) according to an embodiment of the present invention.
FIG. 17 is a flowchart for explaining the flow of a conventional observation method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Film, 2 ... Dielectric film, 3 ... Electrode pattern, 4 ... Retention film, 5 ... Separation film, 10 ... Capacitor precursor, 20 ... Detector, D, P1, P2 ... Cross section, K1, K2 ... Depression, V1, V2: Observation direction.

Claims (9)

A method for observing a sample provided on a base,
A first step of forming a holding film so as to cover the sample, a second step of peeling the substrate from the sample, a third step of exposing a cross section of the sample, and a cross-sectional structure of the sample. And a fourth step of observing. The observation method according to claim 1, wherein, in the third step, the cross section is exposed while the sample is frozen. 3. The observation method according to claim 1, wherein, in the third step, the cross section is exposed by breaking the sample together with the holding film. 4. 3. The observation method according to claim 1, wherein, in the third step, the cross section is exposed by cutting the sample together with the holding film. 4. 5. The observation method according to claim 1, wherein, in the third step, after exposing a cross section of the sample, the cross section is shaved and flattened. 6. 6. The method according to claim 1, wherein in the first step, after forming a separation film so as to cover the sample, the holding film is formed on the separation film. Observation method. The observation method according to claim 1, wherein in the fourth step, a cross-sectional structure of the sample is observed using an electron microscope. In the third step, after exposing a cross section of the sample, the sample is selectively etched from the cross section using focused ion beam etching to expose another cross section different from the cross section. ,
The observation method according to any one of claims 1 to 7, wherein in the fourth step, a cross-sectional structure of the other cross section is observed from a direction orthogonal to the cross section. 9. The capacitor precursor according to claim 1, wherein the capacitor precursor in which the dielectric film as the sample and the electrode pattern provided on the film as the base are laminated in this order is observed. The observation method described in the section.

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