JP7452854B2 - Sample for hydrogen permeation detection and its manufacturing method - Google Patents

Description

The present invention uses scanning electrons from a scanning electron microscope to excite hydrogen atoms that have passed through the back side of a plate-shaped sample or hydrogen atoms that have bubbled up from inside the material of the sample, and then desorb hydrogen ions using an electron transition-induced desorption method. The present invention relates to a sample for hydrogen permeation detection, in which an ESD image of the desorbed hydrogen ions is obtained in synchronization with the scanning of an electron beam of a scanning electron microscope.

Conventionally, for such hydrogen permeation detection, a hydrogen permeation diffusion path observation device disclosed in Patent Document 1, for example, has been used. The hydrogen permeation diffusion path observation device consists of a scanning electron microscope, an analysis chamber, a diaphragm-type vacuum container into which the sample is mounted, and hydrogen piping that is connected to the diaphragm-type vacuum container and supplies hydrogen to the back side of the sample. We are prepared. The sample becomes a diaphragm that partitions the analysis chamber from a hollow part of the diaphragm-type vacuum container that accommodates hydrogen (hereinafter referred to as hydrogen chamber). Hydrogen gushing out from the sample surface is excited by the electron beam used to obtain a scanning electron microscope image (hereinafter referred to as SEM image), becomes hydrogen ions, and desorbs from the surface (ESD (Electron (referred to as a "stimulated desorption" mechanism), an ESD image due to this hydrogen ion is acquired together with an SEM image.

Japanese Patent Application Publication No. 2017-187457

By the way, in such a hydrogen permeation diffusion path observation device, as mentioned above, the sample itself also functions as a diaphragm separating the analysis chamber and the hydrogen chamber, so it has a certain degree of rigidity and functions as a vacuum seal. is necessary.
On the other hand, if the sample is formed into a thin film that is too thin to stand on its own, it will have low rigidity, making it difficult to maintain its shape, and it will no longer function as the aforementioned diaphragm. Put it away. For this reason, with respect to such samples, it has been virtually impossible to detect hydrogen permeation using a single sample.

Furthermore, if a local insulating region exists on the surface of a thin film sample that is too thin to stand on its own, the insulating region will be locally negatively charged, resulting in so-called charge-up. As a result, it becomes difficult for electrons to approach the charge-up occurrence area of the insulating region during electron irradiation, resulting in non-uniform electron irradiation density over the entire surface of the sample.

On the other hand, with general electron microscopes, there are methods that neutralize the surfaces of insulators and plastics that are prone to charge-up by irradiating them with positive ions, and methods that neutralize the surfaces of insulators and plastics when measuring the insulators and plastics themselves. A known method is to coat the battery with a thin film of carbon or metal to suppress the occurrence of charge-up.

However, when measuring secondary electrons, placing a thin film of carbon or metal on the sample surface is effective in suppressing charge-up, but when measuring hydrogen ions, Since there is a possibility that hydrogen ion permeation may be hindered, the use of such a thin film of carbon or metal is not necessarily effective for hydrogen ion permeation.

In view of the above points, the present invention provides a sample for hydrogen permeation detection in which a support member imparts desired rigidity and a function as a vacuum seal to a thin film-like sample body that is so low in rigidity that it cannot stand on its own. The first purpose is to provide the same, and the second purpose is to provide a method for manufacturing the same.

The first purpose is to use the scanning electrons of a scanning electron microscope to excite the hydrogen atoms that have passed through the back side of the sample or the hydrogen atoms that have bubbled up from inside the material of the sample, and to desorb the hydrogen ions using the electron transition-induced desorption method. A sample for hydrogen permeation detection, in which an electron impact desorption image of the desorbed hydrogen ions is obtained in synchronization with the scanning of an electron beam of a scanning electron microscope, and the sample has a predetermined stiffness and hydrogen permeability. a plate-shaped support member, and a thin film-like sample body disposed on the surface of the support member, and the support member functions as a diaphragm that partitions the analysis chamber of the scanning electron microscope and the hydrogen chamber of the sample holder. Functional rigidity is achieved by a sample for hydrogen permeation detection that has a thickness of 100 μm to 1000 μm, and the sample body is a thin film that cannot stand on its own.
Preferably, the sample body has an insulating portion locally or is entirely made of an insulating material, and a conductive thin film having hydrogen permeability is disposed with a uniform thickness over the entire surface of the sample body. It is set up.

In the above configuration , the support member is preferably made of palladium, vanadium, niobium, tantalum, titanium, zirconium, silver, or an alloy thereof. Preferably, the front and/or back surfaces of the support member are mirror polished. This support member is preferably formed homogeneously with respect to hydrogen permeability and is composed of grains or single crystals that are large, for example an order of magnitude or more larger, than the structural distribution of the sample body; In contrast, it may be composed of microcrystals that are smaller, for example, one order of magnitude or more smaller. The sample body is preferably locally provided with insulating portions or entirely composed of an insulating material, and a conductive thin film with hydrogen permeability is disposed on the surface of the sample body.

The second object is achieved by a method for manufacturing a sample for hydrogen permeation detection, which comprises forming a sample body on the surface of a support member by a chemical deposition method or a physical deposition method.

In the above configuration, the sample body is preferably formed by any one of a vacuum evaporation method, an electron beam evaporation method, or a sputtering method.
A conductive thin film is formed on the surface of the sample body, preferably by vapor deposition. This conductive thin film is preferably formed by vacuum evaporation, electron beam evaporation, or sputtering, or may be formed by sputtering to the extent that it does not damage the surface of the sample.

According to the present invention, it is possible to provide a sample for hydrogen permeation detection in which desired rigidity is imparted by a support member to a thin film-like sample body that is so low in rigidity that it cannot stand on its own, and a method for manufacturing the same. can.

FIG. 1 is an enlarged cross-sectional view showing the configuration of a first embodiment of a sample for hydrogen permeation detection according to the present invention. 2 is a diagram schematically showing a configuration example of a hydrogen permeation diffusion path observation device for performing hydrogen permeation detection on the sample of FIG. 1. FIG. FIG. 3 is a partially enlarged view showing the mounting structure of a hydrogen ion detection unit and a sample holder in the analysis chamber of the hydrogen permeation diffusion path observation device of FIG. 2; FIG. 3 is a block diagram showing the configuration of a control section of the hydrogen permeation diffusion path observation device of FIG. 2. FIG. FIG. 3 is a block diagram showing the configuration of the entire electron impact desorption control section of the hydrogen permeation diffusion path observation device of FIG. 2. FIG. FIG. 3 is a schematic diagram showing the relationship between electron beam scanning and two-dimensional measurement of an ESD image. FIG. 2 is a flow diagram for measuring a two-dimensional ESD image by scanning an electron beam. FIG. 2 is a diagram showing an example of a crystal structure having large crystal grains as a support member that supports the sample of FIG. 1. FIG. 9 is a diagram showing a further enlarged view of the crystal structure of FIG. 8. FIG. FIG. 2 is an enlarged cross-sectional view showing the configuration of a second embodiment of a sample for hydrogen permeation detection according to the present invention.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
FIG. 1 shows the configuration of a first embodiment of a sample for hydrogen permeation detection (hereinafter referred to as sample) according to the present invention.

In FIG. 1, the sample 45 includes a support member 46 and a sample main body 47 disposed on the surface of the support member 46. The sample body 47 is a thin film layer made of a conductive material or an insulating material. In the illustrated case, insulating regions 48a and 48b are provided in a part of the sample body 47. The insulating regions 48a, 48b are not limited to one location, but a plurality of insulating regions 48a, 48b are provided. The support member 46 is made of a material with predetermined rigidity and hydrogen permeability, and is formed into a flat plate shape.
The predetermined rigidity means that the shape of the sample body 47 can be maintained in the hydrogen permeation diffusion path observation device 10 described later, and the hollow part 12a (called a hydrogen chamber) of the analysis chamber 11 and sample holder 12 of the scanning electron microscope 15 ) is rigid enough to function as a diaphragm between the two. As the material having such rigidity and hydrogen permeability, metal materials such as palladium, vanadium, niobium, tantalum, titanium, zirconium, silver, and alloys thereof are suitable. Examples of the alloy include an alloy of palladium and silver.

Further, the support member 46 is appropriately selected to have a predetermined rigidity depending on the type of the sample body 47 disposed on the surface of the support member 46, with a thickness ranging from about 100 μm to 1000 μm, for example. Although the dimensions of the support member 46 are arbitrary, the diameter may be, for example, about 5 mm to 20 mm.

Furthermore, the support member 46 is preferably mirror-polished on its front and/or back surfaces. By mirror-polishing the surface of the support member 46, when hydrogen atoms are desorbed from the surface of the support member 46, it is not affected by the surface shape of the support member 46, and accurate hydrogen permeation detection can be performed. In addition, the back surface of the support member 46 is mirror-polished to improve adhesion and ensure vacuum sealability as a partitioning membrane.

The above-mentioned material of the support member 46 has a predetermined rigidity, can function as the diaphragm, and has high hydrogen permeability, and has been put to practical use as a so-called hydrogen filter, and has hydrogen permeability, so it is suitable for the support member. 46, and does not interfere with the permeation of hydrogen ions during hydrogen permeation detection.

Furthermore, the support member 46 is uniformly formed with respect to hydrogen permeability. According to this configuration, by disposing the sample body 47 on the surface of the support member 46 which is formed uniformly in terms of hydrogen permeability, hydrogen permeation detection by inducing electron transition in the sample body 47 can be performed using hydrogen permeability of the support member 46. It can be performed uniformly and accurately over the entire surface of the sample body 47 without being affected by the transmittance.

Specifically, the support member 46 is made of crystal grains or single crystals that are sufficiently large relative to the region of the sample body 47 where hydrogen permeation detection is to be performed, that is, the structural distribution or the field of view of the scanning electron microscope 15. It consists of The crystal grains or single crystals of the support member 46 may be composed of crystal grains or single crystals that are one order of magnitude or more larger than the structural distribution of the sample body 47. For example, if the structural distribution of the sample body 47 is smaller than 30 μm, the support member 46 may be made of crystal grains or single crystals with a size of 300 μm or more. As a result, the region of the sample body 47 in which hydrogen permeation detection is to be performed, that is, the structural distribution, is contained within only one crystal of the support member 46, and the hydrogen permeation detection by electron transition induction in the sample body 47 is carried out in the support member 46. This can be performed uniformly and accurately over the entire surface of the sample body 47 without being affected by the crystal boundaries of the sample body 47.

On the other hand, the support member 46 has a large number of microscopic particles that are sufficiently small, for example, one or more orders of magnitude smaller than the region of the sample body 47 where hydrogen permeation detection is to be performed, that is, the structural distribution, or the field of view of the scanning electron microscope 15. It may be composed of crystals. For example, if the structural distribution of the sample body 47 is 30 μm, the grain size of the microcrystals may be 3 μm or less. As a result, the region of the sample body 47 where hydrogen permeation detection is to be performed is covered by a large number of microcrystals of the support member 46, and the hydrogen permeability becomes almost uniform as a whole. Transition-induced hydrogen permeation detection can be performed uniformly and accurately over the entire surface of the sample body 47 without being affected by the crystal boundaries of the support member 46.

The sample body 47 is made of a material such as metal or Si. Here, the sample body 47 is deposited on the surface of the support member 46 by a chemical deposition method (CVD method) or a physical deposition method (PVD method) according to an embodiment of the method for manufacturing a sample for hydrogen permeation detection according to the present invention. It is possible to form a film. As the physical deposition method, it is formed as a coating film on the surface of the support member 46 by any vapor deposition method such as a vacuum vapor deposition method, an electron beam vapor deposition method, a sputtering method, or the like. Thereby, the sample body 47 can be reliably and uniformly formed on the surface of the support member 46 by, for example, vapor deposition, particularly vacuum vapor deposition, electron beam vapor deposition, or sputtering.

The sample body 47 is a thin film with such low rigidity that it cannot stand on its own. For this reason, when the sample body 47 is disposed on the surface of the support member 46, it is necessary to reinforce it with the support member 46 so that it can maintain its shape independently. It can function as a diaphragm that partitions the hydrogen chamber 12a. Note that the sample body 47 may or may not have a hydrogen diffusion preventing effect or a hydrogen diffusion suppressing effect. Furthermore, the sample body 47 also includes a thin film that partially has a hydrogen diffusion prevention effect or hydrogen diffusion suppression effect.

The sample 45 for hydrogen permeation detection according to the embodiment of the present invention is configured as described above, and the case where hydrogen permeation detection is performed on this sample 45 will be described. FIG. 2 schematically shows a configuration example of the hydrogen permeation diffusion path observation device 10 for detecting hydrogen permeation on the sample 45, and FIG. 3 shows hydrogen ion detection in the analysis chamber 11 of the hydrogen permeation diffusion path observation device 10. FIG. 3 is a partially enlarged view showing the structure of the section 20, the mounting structure of the sample holder 12, and the like.

As shown in FIG. 2, the hydrogen permeation diffusion path observation device 10 is equipped with a scanning electron microscope 15, and in the analysis chamber 11 of the scanning electron microscope 15, an electron An electron source 16 for emitting radiation is provided. Furthermore, the analysis chamber 11 includes a secondary electron detector 18 that detects secondary electrons generated by the electron beam 16a irradiated onto the sample 45 in the analysis chamber 11, and a secondary electron detector 18 that detects secondary electrons generated by the electron beam 16a irradiated from the electron source 16. It includes a hydrogen ion detection section 20 that detects ions, a control section 50 that controls the hydrogen ion detection section 20, and a gas supply section 19 that supplies hydrogen to the hydrogen pipe 14 connected to the back side of the sample 45. There is.

The sample 45 may be heated within the analysis chamber 11 by a sample heating section (not shown). Further, the sample 45 is fixed to a sample mounting portion (not shown) of the sample holder 12 or bonded by welding or the like. As shown in FIG. 3, the sample 45 is placed in the analysis chamber 11 of the scanning electron microscope 15 together with the sample holder 12. Thereby, the sample 45 partitions off the hydrogen chamber 12a of the sample holder 12 and the analysis chamber 11, so the sample 45 functions as a diaphragm that partitions the analysis chamber 11 and the hydrogen chamber 12a.

The hydrogen ion detection unit 20 includes a collection mechanism 21 that collects hydrogen ions generated from the surface of the sample 45, an ion energy decomposition unit 22 that removes other than hydrogen ions, and an ion energy decomposition unit 22 that detects hydrogen ions that have passed through the ion energy decomposition unit 22. It consists of a detection section 23.

In the sample holder 12, hydrogen supplied from the hydrogen gas supply unit 19 and existing inside the hydrogen chamber 12a of the sample holder 12 is in contact with the back side of the sample 45, and from the back side of the support member 46 of the sample 45. be introduced internally. This hydrogen diffuses inside the support member 46 and the sample body 47 of the sample 45, reaches the front side of the sample 45, that is, the surface of the sample body 47, and is released from the surface of the sample body 47. That is, hydrogen and deuterium permeate from the back side of the sample 45 to the front side. By irradiating the hydrogen that has reached the surface of the sample body 47 with the electron beam 16a, hydrogen ions are desorbed from the sample body 47 by electron impact desorption (ESD), and the hydrogen ions are focused by the collection mechanism 21. The hydrogen ions are detected by the hydrogen ion detection section 20.

The hydrogen ion detection section 20 detects hydrogen ions generated on the surface of the sample body 47 using the ESD method. A two-dimensional image of hydrogen ions detected by scanning with the electron beam 16a is also called an ESD image or an ESD map.

A collection mechanism 21 is provided near the surface of the sample 45 to efficiently collect desorbed ions. The illustrated collection mechanism 21 is made of a mesh of metal wires, for example, and is a lens with a grid structure. Ions of the target gas, such as hydrogen ions, collected by the collection mechanism 21 enter the hydrogen ion detection section 20 . The ion energy decomposition unit 22 selects hydrogen ions, for example, and makes them enter the ion detector 23 .

The ion energy decomposition unit 22 is composed of a metal electrode having a lid shape so that the ion detector 23 does not directly face the sample 45. The ion energy decomposition unit 22 can use an electrode having a shape including a cylinder or a cone. A suitable positive voltage is applied to the cylindrical electrode of the ion energy decomposition section 22, and only ions of the target gas, such as hydrogen ions, are guided to the ion detector 23 by an electric field, and the sample 45 is irradiated with the electron beam 16a. light and electrons can be removed. As the ion detector 23, for example, a Ceratron or a secondary electron multiplier can be used.

The control unit 50 acquires an SEM image of secondary electrons generated from the sample 45 by scanning the electron beam 16a irradiated from the electron source 16, and detects hydrogen atoms flowing out from point defects inside or on the surface of the sample 45. Hydrogen is ionized by electron impact desorption (ESD) of an electron beam, and an ESD image of the hydrogen ions is acquired in synchronization with the scanning of the electron beam. Here, in ESD, when irradiated electrons come out of a material and stay on the surface, the electrons in the hydrogen atoms become excited or are stripped off, ionizing the hydrogen atoms. As a result, hydrogen ions change from a bonded state to an anti-bond state and are released, and an ESD image is obtained by imaging the released hydrogen ions. Then, the position information of the detected hydrogen ions is obtained by synchronizing the SEM image and the ESD image of the sample 45 by the control unit 50, and the position of the point defect on the sample 45 can be detected.

Next, the configuration and operation of the control section 50 of the hydrogen ion detection device 10 will be described in more detail. The block diagrams in FIGS. 4 and 5 respectively show the configurations of the control section 50 and the overall electron impact desorption control section 52, and FIG. 6 is a schematic diagram showing the relationship between scanning of the electron source 16 and two-dimensional measurement of the ESD image. It is.

As shown in FIG. 4, the control unit 50 includes an electron microscope overall control unit 51 that controls the scanning electron microscope 15, and an electron impact desorption overall control unit 52 that acquires an ESD image. . In addition to the electron microscope overall control section 51, the control section 50 includes a secondary electron detection section 53 for acquiring a scanning electron microscope image (SEM image) of the sample 45, an electron optical system control section 54, and an SEM It is comprised of an image calculation unit 55, a high-voltage stabilized power supply 56, an input device 57, a display 58, a storage device 59, and the like. The electron microscope overall control section 51 controls a secondary electron detection section 53 , an electron optical system control section 54 , an image calculation section 55 for SEM, a high voltage stabilized power supply 56 , and a storage device 59 . The output of the secondary electron detector 18 disposed in the analysis chamber 11 of the scanning electron microscope 15 is input to the secondary electron detection section 53.

Next, the electron impact desorption overall control section 52 will be explained. As shown in FIG. 5, the electron impact desorption overall control section 52 that controls the acquisition of the ESD image includes a two-dimensional multi-channel scaler 60, a pulse coefficient section 61, a synchronization control section 62, and a two-dimensional It is composed of a plane sorting section 63, a microprocessor 72, and the like.
The output 67a of the hydrogen ion detection section 20 disposed in the analysis chamber 11 is input to the pulse counting section 61 via the electron impact desorption ion detection section 67. A scanning signal is inputted to the electron impact desorption overall control section 52 from the electron optical system control section 54, and is controlled in synchronization with the SEM image. Further, a display 65 and a storage device 66 are connected to the electron impact desorption overall control section 52 .

The microprocessor 72 may be a microcomputer such as a microcontroller, a personal computer, or an FPGA (Field-Programmable Gate Array), which is a field-programmable gate array.

As shown in FIG. 4, the scanning signal outputted from the electron optical system control section 54 to the electron impact desorption overall control section 52 is transmitted to the electron source as a vertical scanning signal 62a via the synchronization control section 62, as shown in FIG. 16 first deflection coils 16b. The horizontal scanning signal 62b from the synchronization control section 62 is output to the second deflection coil 16c of the electron source 16. Information 62c regarding the scanning position from the synchronization control section 62 is output to the microprocessor 72.

The hydrogen ion count signal 61a output from the pulse counting section 61 is output to the microprocessor 72 as a hydrogen ion count signal at each scanning position.

The ESD image generated by the microprocessor 72 is output to the display 65 via an input/output interface (I/O) 72a, and to the storage device 66 via an input/output interface (I/O) 72b.

Next, the operation of the electron impact desorption overall control section 52 will be explained.
As shown in FIG. 6, the electron beam 16a generated from the electron source 16 passes through the first deflection coil 16b and the second deflection coil 16c, and is scanned in the horizontal direction and vertical direction, and is then applied to the sample 45. Irradiated in dimension.

The clock signal of the vertical scanning signal 62a, which is a digital signal generated by the synchronization control unit 62 shown in FIG. is applied to Similarly, the clock signal of the horizontal scanning signal 62b, which is a digital signal, is converted into a sawtooth wave by a digital-to-analog converter (DAC) 62e and applied to the second deflection coil 16c of the electron source 16.

Control is started so that a total of 2048 pulses of a vertical scanning signal (vertical clock) are generated by a one-pulse shooting timing signal (Shoot timing, hereinafter referred to as an ST signal). A total of 2048 pulses of horizontal pixel signals (horizontal clock) are output during the pulse width period of one pulse of the vertical scanning signal. This generates a two-dimensional scan of approximately 4.19 million pixels of 2048 rows x 2048 columns (=4194304). In other words, the signals counted by the pulse counting section 61 are calculated from the ion detector 23 at each scanning position by synchronizing a plurality of counters consisting of an ST signal, a clock signal for vertical scanning, and a clock signal for horizontal scanning. It can be obtained as a count of hydrogen ions.

Next, a method for acquiring an ESD image will be explained.
FIG. 7 is a flow diagram for measuring a two-dimensional ESD image by scanning. As shown in FIG. 7, acquisition of a two-dimensional ESD image can be performed through the following steps.
Step 1: Hydrogen ions desorbed from the surface of the sample 45 are detected by the ion detector 23.
Step 2: Quantitative measurement of hydrogen ions detected by the ion detector 23 is performed by the pulse counting section 61.
Step 3: The synchronization control unit 62 that generates the clock signal for vertical scanning and the clock signal for horizontal scanning shown in FIG. 6 counts hydrogen ions at each two-dimensional measurement point of the sample 45.
Step 4: The count number of hydrogen ions at each two-dimensional measurement point of the sample 45 measured in Step 3 is stored in the memory of the storage device 66.
Step 5: The ion signals stored in the memory of the storage device 66 are rearranged as a two-dimensional image (ESD image) based on the clock signal for vertical scanning and the clock signal for horizontal scanning.
Step 6: Display the ESD image obtained in Step 5 on the display 65, and save the image and numerical data in the storage device 66.
As a result, an ESD image of the same area as the SEM image is obtained.

The acquisition of ESD images in steps 1 to 6 above can be executed using software created in a program creation environment specialized for controlling measuring equipment. As such software, LabVIEW (registered trademark) manufactured by National Instruments (http://www.ni.com/labview/ja/) can be used. The ESD images in steps 1 to 6 above can be acquired by the two-dimensional multichannel scaler 60 executed by a program created in LabVIEW in the microprocessor 72.

In the hydrogen permeation diffusion path observation device 10, an SEM image can be obtained in the same manner as conventional methods. The signal from the secondary electron detector 18 is detected by the secondary electron detection section 53 of the control section 50 and displayed on the display 58 by the electron microscope overall control section 51.

In this way, according to the hydrogen permeation diffusion path observation device 10, by comparing the SEM image of the sample 45 using secondary electrons and the ESD image obtained in step 6 above, it is possible to determine the structure of the sample body 47 made of metal, for example. It becomes possible to investigate the relationship between local structure and hydrogen permeation. For example, as for the local structure, it is possible to compare the crystal grain size and crystal structure of a metal with hydrogen permeation, that is, hydrogen release ability.

Here, since the spatial resolution of the hydrogen release position essentially depends on the magnification of the scanning electron microscope 15, it can be improved to the same level as the magnification of the scanning electron microscope 15. A resolution of 10 nm or less can be obtained. The limit of the magnification of the scanning electron microscope 15 is determined by the vibration removal of the scanning electron microscope 15 and its surroundings, and the diameter of the electron beam.

Furthermore, in order to match hydrogen ion detection with the secondary electron detection limit of the scanning electron microscope 15, the difference in flight time between electrons and hydrogen ions becomes a problem, but the electron scanning time during measurement is slowed down. This can be dealt with by shortening the distance between the ion detector 23 and the sample 45.

In this way, in the sample 45, the sample main body 47, which is made of a thin film with such low rigidity that it cannot stand on its own, is placed on the support member 46, so that it is reinforced by the support member 46. Since it has a predetermined rigidity, it reliably functions as a diaphragm that partitions the analysis chamber 11 and the hydrogen chamber 12a of the scanning electron microscope 15. Therefore, even if the sample body 47 is made of a thin film that cannot stand on its own, hydrogen permeation detection can be performed.

Here, as shown by arrow A in FIG. 1, the hydrogen that has diffused through the support member 46, which is uniform and has high hydrogen permeability, has a hydrogen diffusion prevention effect or a hydrogen diffusion suppression effect with respect to the sample body 47 of the sample 45. In some cases, it does not pass through the sample body 47, or only a small amount passes through it.
On the other hand, as shown by arrow B, the hydrogen that has diffused through the support member 46, which is uniform and has high hydrogen permeability, has no hydrogen diffusion prevention effect or hydrogen diffusion suppression effect with respect to the sample body 47 of the sample 45. In some cases, the sample body 47 is transmitted with high transmittance. Therefore, since the support member 46 is uniform and has high hydrogen permeability, the surface hydrogen distribution that permeates through the sample body 47 reflects the hydrogen permeation characteristics of the sample body 47.

As explained above, in the sample 45 for detecting hydrogen permeation of the present invention, even if the sample body 47 is a thin film with such low rigidity that it cannot stand on its own, a plate with predetermined rigidity and hydrogen permeability can be used. Since the sample body 47 is supported and reinforced by the shaped support member 46, the shape of the sample body 47 can be reliably maintained, and for hydrogen permeation detection, analysis using the scanning electron microscope 15 in the hydrogen permeation diffusion path observation device 10 is possible. It can function satisfactorily as a diaphragm that partitions the chamber 11 and the hydrogen chamber 12a. Therefore, even if the sample body 47 is a thin film with such low rigidity that it cannot stand on its own, hydrogen permeation through the sample body 47 can be reliably detected.

A prototype example of the support member 46 constituting the sample 45 will be described.
In this prototype example, the support member 46 was constructed from a polycrystalline thin plate of palladium, and the front and back surfaces of the palladium thin plate were polished and heat treated. The polishing and heat treatment of the front and back surfaces of the palladium thin plate may be performed not only once but repeatedly.
For the structural analysis of such a prototype example of the support member 46, the surface was imaged using the scanning electron microscope 15. The SEM image is shown in FIG. 8, and the EBSD image obtained by electron back scattering diffraction (hereinafter referred to as EBSD) is shown in FIG. 9.
8 and 9, the crystal structure of the support member 46 is expressed, and each crystal grain is 300 μm or more, and a uniform hydrogen supply substrate could be obtained within the field of view of the scanning electron microscope 15. Note that the three markers near the center of the image in FIG. 8 are marked with an ion beam or laser to identify the location.

FIG. 10 shows a second embodiment of a sample for hydrogen permeation detection according to the present invention. In the sample 45A of FIG. 10, the support member 46 is the same as that of the sample 45 shown in FIG. However, in the second embodiment, a conductive thin film 49 is further provided over the entire surface of the sample body 47 including the insulating regions 48a and 48b.

The insulating regions 48a and 48b may be made of the same insulating material, for example, an insulating film such as an oxide film or a nitride film formed on the surface of the sample body 47, depending on the manufacturing method. do not. The insulating regions 48a and 48b may be not only an insulating film formed on the surface of the sample body 47, but also an insulating film formed so as to be embedded in the surface from the inside.

The conductive thin film 49 is made of a conductive material having hydrogen permeability, preferably a material that does not cause interdiffusion with the surface of the sample body 47. Since mutual diffusion does not occur, even if the conductive thin film 49 is provided, the surface condition of the sample body 47 will not be affected and changed.

Here, metal materials such as palladium, vanadium, niobium, tantalum, titanium, zirconium, silver, and alloys thereof are suitable as the conductive material having hydrogen permeability. Examples of the alloy include an alloy of palladium and silver. These materials have high hydrogen permeability and have been put to practical use as so-called hydrogen filters, and do not impede the permeation of hydrogen ions during hydrogen permeation detection.

Here, the conductive thin film 49 is formed on the surface of the sample body 47 by a chemical deposition method (CVD method) or a physical deposition method (PVD method) according to the method for manufacturing the sample 45A for hydrogen permeation detection according to the present invention. It can be membraned. As the physical deposition method, it is formed as a coating film on the surface of the sample body 47 by a vapor deposition method such as a vacuum vapor deposition method, an electron beam vapor deposition method, or a sputtering method. As a result, the conductive thin film 49 is uniformly formed with an accurate film thickness on the surface of the sample body 47 by evaporation, particularly by vacuum evaporation, electron beam evaporation, or sputtering.
In the case of the sputtering method, the surface condition of the sample body 47 can be changed by forming the conductive thin film 49 to such an extent that the surface of the sample body 47 will not be damaged by particles etc. that collide with the surface of the sample body 47 by sputtering. There is no change, and accurate hydrogen permeation detection can be performed.

Furthermore, the conductive thin film 49 has a uniform film thickness as a whole, and the film thickness is, for example, equal to or less than the spatial resolution of the scanning electron microscope 15 used for hydrogen permeation detection, for example, 50 nm or less, preferably The thickness is selected to be about 10 nm to 20 nm, or from several nm to about 10 nm. Note that the conductive thin film 49 is preferably formed to have a thickness of several nm to 10 nm, for example, about 2 nm to 10 nm. If the conductive thin film 49 is too thick, hydrogen permeability will decrease, and hydrogen ions will move horizontally within the conductive thin film 49, resulting in a decrease in resolution. On the other hand, if the film thickness is too thin, it is difficult to form a uniform film thickness.

According to the sample 45A of the second embodiment, as in the case of the sample 45, the sample body 47 is reinforced by the support member 46, thereby partitioning the analysis chamber 11 of the scanning electron microscope 15 and the hydrogen chamber 12a. May function as a diaphragm. Furthermore, when hydrogen permeation detection is performed, charge-up does not occur in the insulating regions 48a, 48b due to the presence of the conductive thin film 49, so that the electron density does not decrease in these insulating regions 48a, 48b. , hydrogen permeation detection can be reliably performed over the entire sample body 47.

According to the sample 45A of the second embodiment, since the conductive thin film 49 having hydrogen permeability is disposed on the surface of the sample body 47, the sample 45A is exposed to the scanning electron beam of the scanning electron microscope 15. When detecting hydrogen permeation by excitation by electron transition induction, even if electrons try to accumulate in the insulating regions 48a, 48b of the sample main body 47, they move along the conductive thin film 49, causing the electrons to accumulate in the insulating regions 48a, 48b of the sample body 47. 48b is charged and the so-called charge-up is prevented from occurring. Therefore, the hydrogen ions excited by the above-mentioned electronic transition induction are desorbed without being affected by charge-up.

Here, since the conductive thin film 49 has hydrogen permeability, hydrogen ions are desorbed without being hindered by the presence of the conductive thin film 49. Thereby, by synchronizing the ESD image of the desorbed hydrogen ions with the scanning of the electron beam of the scanning electron microscope 15, the ESD image can be accurately acquired, and hydrogen ion transmission detection can be performed with high precision.

Note that since the hydrogen atoms detected by hydrogen permeation detection store the history of the permeation path up to that point as information, the hydrogen atoms are This history information is not erased when passing through the conductive thin film 49, and only the influence of charge-up can be eliminated.

The present invention can be implemented in various forms without departing from the spirit thereof. In the embodiment described above, the sample body 47 of the sample 45 is made of a conductive material such as steel or stainless steel, but is not limited to this and may be made of an insulating material. it is obvious.

Further, in the embodiment described above, the sample 45A includes the insulating regions 48a and 48b made of oxide or the like locally disposed on the surface area of the sample body 47, but the sample 45A is not limited to this. The entire surface of the sample body 47 may be provided with an insulating region, and the sample body 47 itself may be composed of an insulating material.

10: Hydrogen permeation diffusion path measuring device, 11: Analysis chamber, 12: Sample holder, 12a: Hollow part (hydrogen chamber), 14: Hydrogen piping, 15: Scanning electron microscope, 16: Electron source,
18: Secondary electron detector, 19: Gas supply section, 20: Hydrogen ion detection section, 21: Collection mechanism, 22: Ion energy decomposition section, 23: Ion detector, 45, 45A: Sample for hydrogen permeation detection , 46: Support member, 47: Sample body, 48a, 48b: Insulating region, 49: Conductive thin film with hydrogen permeability,
50: Control unit, 51: Electron microscope overall control unit, 52: Electron impact desorption overall control unit,
53: Secondary electron detection unit, 54: Electron optical system control unit, 55: Image calculation unit for SEM,
56: High voltage stabilized power supply, 57: Input device, 58, 65: Display,
59, 66: Storage device, 60: Two-dimensional multi-channel scaler,
61: Pulse counting unit, 61a: Hydrogen ion count signal, 62: Synchronous control unit,
62a: Vertical scanning signal, 62b: Horizontal scanning signal, 62c: Information regarding scanning position,
62d, 62e: Digital-to-analog converter, 63: Measurement signal rearrangement unit into a two-dimensional plane, 64: Image calculation unit for ESD, 67: Electron impact desorption ion detection unit, 72: Microprocessor, 72a, 72b :I/O interface

Claims (13)

Hydrogen atoms that have passed through the back side of the sample or that have bubbled up from inside the material of the sample are excited by the scanning electrons of a scanning electron microscope, and the hydrogen ions are desorbed using the electron transition-induced desorption method. A plate-shaped support member having predetermined rigidity and hydrogen permeability, which is a sample for detecting hydrogen permeation, which acquires an electron impact desorption image of the desorbed hydrogen ions in synchronization with electron beam scanning. and a thin film-like sample body disposed on the surface of the supporting member, the supporting member having a size that can function as a diaphragm that partitions the analysis chamber of the scanning electron microscope and the hydrogen chamber of the sample holder. A sample for hydrogen permeation detection, wherein the sample body is a thin film that cannot stand on its own by itself, and has a thickness of 100 μm to 1000 μm so as to have a rigidity of . The sample for hydrogen permeation detection according to claim 1 , wherein the support member is made of palladium, vanadium, niobium, tantalum, titanium, zirconium, silver, or an alloy thereof. The sample for hydrogen permeation detection according to claim 1 or 2 , wherein the support member has a mirror-polished front and/or back surface. The sample for hydrogen permeation detection according to any one of claims 1 to 3 , wherein the support member is formed uniformly in terms of hydrogen permeability. 5. The sample for detecting hydrogen permeation according to claim 4 , wherein the support member is composed of crystal grains or single crystals that are larger than the structural distribution of the sample body. 5. The sample for hydrogen permeation detection according to claim 4 , wherein the support member is composed of microcrystals that are smaller than the structural distribution of the sample body. Claim 1: The sample body has an insulating portion locally or is entirely made of an insulating material, and a conductive thin film with hydrogen permeability is disposed on the surface of the sample body. 6. The sample for hydrogen permeation detection according to any one of 6 to 6 . 8. The method for manufacturing a sample for hydrogen permeation detection according to claim 1, wherein the sample body is formed on the surface of the support member by a chemical deposition method or a physical deposition method. 9. The method for manufacturing a sample for hydrogen permeation detection according to claim 8 , wherein the sample body is formed by any one of a vacuum evaporation method, an electron beam evaporation method, or a sputtering method. 9. The method for manufacturing a sample for hydrogen permeation detection according to claim 8 , wherein the conductive thin film is formed on the surface of the sample body by vapor deposition. The method for manufacturing a sample for hydrogen permeation detection according to claim 10 , wherein the conductive thin film is formed by a vacuum evaporation method or an electron beam evaporation method. 11. The method for manufacturing a sample for hydrogen permeation detection according to claim 10 , wherein the conductive thin film is formed by sputtering to an extent that does not damage the surface of the sample body. Hydrogen atoms that have passed through the back side of the sample or that have bubbled up from inside the material of the sample are excited by the scanning electrons of a scanning electron microscope, and the hydrogen ions are desorbed using the electron transition-induced desorption method. A plate-shaped support member having predetermined rigidity and hydrogen permeability, which is a sample for detecting hydrogen permeation, which acquires an electron impact desorption image of the desorbed hydrogen ions in synchronization with electron beam scanning. and a thin film-like sample body disposed on the surface of the supporting member, the supporting member having a size that can function as a diaphragm that partitions the analysis chamber of the scanning electron microscope and the hydrogen chamber of the sample holder. The thickness is from 100 μm to 1000 μm so that it has a stiffness of
The sample body is a thin film that cannot stand on its own,
The sample body has an insulating portion locally or is entirely made of an insulating material, and a conductive thin film with hydrogen permeability is disposed on the entire surface of the sample body with a uniform thickness. Sample for hydrogen permeation detection.

Images