JPH1192945A - Method for measuring average crystallite diameter, manufacture of thin film and manufacturing device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring an average crystallite diameter of a thin film of a material having a crystal structure formed in a minute region of <=1 μm square and a device for manufacturing the thin film. SOLUTION: In the method for measuring the average crystallite diameter, a sample of the material having absorption in UV region and the crystal structure is irradiated with electron beams, energy-loss spectrum of reflected electrons is measured and the crystallite diameter is obtained by using correlation between spectrum data and average crystallite diameter of the sample. Used data appeared in the electron energy-loss spectrum are, for instance, (1) energy value of a plasmon peak and relative intensity of the plasmon peak to an elastic scattering peak or its shape, (2) energy value of a peak resulted from π→π*transition and relative intensity of the π→π* peak to the elastic scattering peak or its shape or (3) a shape of a background of a continuous spectrum formed by inelastic scattering electrons or relative intensity of a point to the elastic scattering peak.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the average crystallite diameter of a thin film of a material having an absorption in the ultraviolet region and having a crystal structure, particularly a method of measuring the average crystallite diameter of a carbon thin film containing graphite as a main component. Regarding the manufacturing method,
The present invention relates to an apparatus for producing a carbon thin film having means for analyzing a state of a carbon thin film to be incorporated in a micro area of μm square or less, and a method for feeding back the result of the state analyzing means to production conditions.

[0002]

2. Description of the Related Art Graphite (also called graphite), which is an allotrope of carbon, is based on a hexagonal mesh plane structure composed of sp ² hybrid orbitals and has the following unique physical properties. In other words, in the plane of the carbon mesh, it exhibits properties such as semimetallic conductivity, thermal conductivity three times that of copper, very high elastic modulus and mechanical strength, while electrical conductivity along the laminating direction. Properties and thermal conductivity are remarkably low, exhibiting a large anisotropy with the physical properties in the plane direction.

[0003] Various models have been proposed for the stacking structure of carbon net planes.
Is defined as a turbostratic structure in which mesh planes are randomly stacked and a graphite crystal structure in which the planes are regularly coordinated. The mesh plane spacing is 0.344 nm for the turbostratic structure, and 0.1 mm for the graphite crystal structure. 335 nm (R.
E. Franklin, Proc. Roy. Soc., A209, 196 (1951)).

[0004] In a graphite material, its structure is sometimes defined by the size (crystallite diameter) of a crystallite, and the crystallite diameter Lc in the direction perpendicular to the hexagonal mesh plane and the crystallite in the direction parallel to the hexagonal mesh plane are determined. Two diameters La are usually used. In addition,
The “crystallite” in the present invention means an individual unit crystal (microcrystal) constituting a polycrystal or a unit crystal (microcrystal) observed in an amorphous state. In this specification,
When simply referred to as the crystallite diameter of graphite, it refers to the crystallite diameter (Lc) perpendicular to the hexagonal mesh plane.

[0005] Due to such structural properties, as well as high heat resistance and chemical resistance, graphite is widely used as an important industrial material, for example, refractory materials, nuclear reactor materials, heating elements, and the like. In addition, graphite having high crystallinity is used for a monochromator and a filter because it exhibits excellent spectral and reflection characteristics with respect to X-rays and neutron rays.

[0006] Recently, graphite intercalation compounds utilizing a laminated space of graphite have received particular attention, and lithium ion batteries, which are applications of the compounds, have already been put into practical use as small, high-performance secondary batteries. Furthermore, electronic circuit materials such as resistor coatings, adsorbents using pore structures,
It is also used as an electron-emitting material, and these materials tend to be improved in quality, miniaturized, and thinned year by year. At the same time, there has been a demand for a method of analyzing the structure of a graphite material incorporated in a surface and a minute portion, particularly an analysis method of an average crystallite diameter.

[0007] It is known that when the average crystallite diameter changes in a graphite material, the specific resistance, the thermal conductivity, the bending strength, and the like greatly differ. For example, regarding the above three physical property values, in the case of glassy carbon having Lc of 10 nm, about 50 × 10 ⁻⁴ Ωcm and about 3 kcal
/ Mhr ° C, about 900 kgf / cm ² , Lc is 20 nm
About 40 × 10 ⁻⁴ Ωcm for glassy carbon,
About 7 kcal / mhr ° C, about 1100 kgf / cm ² ,
In the case of artificial graphite, about 10 × 10 ^-4 Ωcm, about 1
It is 20 kcal / mhr ° C and about 200 kgf / cm ² . That is, the graphite material has a large difference in physical properties even if the average crystallite diameter is slightly changed. Therefore, in the case of a graphite material, it is required to analyze the average crystallite diameter in order to analyze the material properties.

Conventionally, as a method of forming the above-mentioned graphite, particularly a thin film containing a graphite component, a hydrocarbon-based gas is introduced onto a substrate heated to a high temperature, and the gas is thermally decomposed to deposit carbon in a gas phase. A thermal CVD method, a plasma CVD method of activating a hydrocarbon-based gas by introducing plasma into the reaction space and depositing carbon at a lower temperature, and a method of forming a film-like polymer compound by heat treatment are used. Have been.

For example, hydrocarbons such as methane are thermally decomposed by thermal plasma to form a turbostratic crystal structure (crystallite thickness (Lc)).
(Japanese Patent Publication No. 6-102531) to obtain a scaly film showing the intermediate position between graphite single crystal and amorphous carbon, and applying the catalytic function of nickel oxide to thermal CVD method (supporting nickel oxide on the substrate surface) ), 350-45
Method of forming carbon coating at low temperature of 0 ° C.
No. 0638), a method of obtaining a graphite film by oxidizing a plurality of polymer films in advance, laminating, pressurizing, and heat-treating (JP-A-5-17115), a method of forming a polyimide compound film having a fluorene skeleton by graphite. Disclosed are a method in which a graphite film is obtained by sandwiching and heating and baking a plate (Japanese Patent Laid-Open No. 5-43213), a method in which carbon melted in a metal column is precipitated on a graphite seed crystal (Japanese Patent Laid-Open No. 5-78194), and the like. Have been.

As a method for producing ultrafine graphite powder, a method is disclosed in which a carbon raw material is subjected to arc discharge under reduced pressure, and vaporized carbon vapor is cooled and solidified (Japanese Patent Laid-Open No. 7-20641).
No. 6) is disclosed.

Conventionally, the structure (crystal structure) of these graphite materials has been analyzed by X-ray diffraction, Raman spectroscopy, observation with a transmission electron microscope, X-ray photoelectron spectroscopy, vacuum ultraviolet photoelectron spectroscopy, high-resolution energy loss Spectroscopy, transmission electron energy loss spectroscopy, slow electron diffraction, etc. have been used (eg, Shun Aizawa, Surface Science, Vol. 11, No. 7).
No. 398 (1990)).

In the X-ray diffraction method, a structure is obtained from a diffraction pattern obtained by irradiating a sample to be analyzed with X-rays and a model calculation. The distance between a diffraction peak and a hexagonal mesh plane and the half width of the diffraction peak are determined. From (B), the average crystallite diameter (Lc) in the direction perpendicular to the hexagonal mesh plane is estimated. It is known that the following relationship exists between the half width B and the crystallite diameter Lc.

LcBcos θ = 0.9λ where θ is the Bragg angle and λ is the wavelength of the X-ray.

In the Raman spectroscopy, a laser beam is usually used as an excitation source, and a structure is obtained from a spectrum obtained by dispersing Raman scattered light from a sample to be analyzed. Average in the direction parallel to the hexagonal mesh plane from the center wave number, half width and intensity ratio of the peak (1580 cm ^-1 , E _2g mode) derived from the graphite structure and the peak (around 1360 cm ^-1 , edge mode) reflecting the disorder of the structure The crystallite size (Lc) is estimated (see, for example, F. Tuinstra and JL Koenig, J. Chem.
Phys., 53, 1126 (1970)).

The observation method using a transmission electron microscope is a method of directly observing graphite crystals or particles using a transmission electron microscope after thinning a sample to be analyzed to about 100 nm (including photographing on a silver halide film). .

X-ray photoelectron spectroscopy irradiates a sample to be analyzed in ultra-high vacuum with soft X-rays and analyzes the kinetic energy of photoelectrons emitted from the surface. The photoelectron peak and the X-ray excited Auger electron peak are analyzed. The information on the chemical bond state of carbon can be obtained from the energy value, shape, presence or absence of an energy loss peak, and the like. In particular, from the energy loss (inelastic scattering) peak due to the π → π ^* transition and plasmon, s
p ² presence of carbon, more knowledge is obtained about the chemical state.

In the vacuum ultraviolet photoelectron spectroscopy, a sample to be analyzed is irradiated with vacuum ultraviolet light of about several tens of eV in an ultra-high vacuum, and the kinetic energy of photoelectrons emitted from the surface is analyzed. Information mainly on phonons such as relationships is obtained.

The high-resolution energy loss spectroscopy generally irradiates a sample to be analyzed with a monochromatic electron beam of about several tens of eV, and analyzes the energy of inelastically scattered electrons. Basically, vacuum ultraviolet photoelectron spectroscopy is used. Information such as phonon dispersion of graphite is obtained in the same manner as the information obtained by the method.

In transmission electron energy loss spectroscopy, the energy loss of electrons transmitted through a thin film sample is measured using a transmission electron microscope, and local state analysis of a solid is performed. By this method, π →
It has been reported that the values of energy loss due to π ^* transition and plasmon greatly differ depending on the crystallinity, that is, the higher the crystallinity of graphite, the larger the above π → π ^* transition and the plasmon loss energy (LB
Leder and JA Suddeth, J. Appl. Phys., 31, 1422
(1960)). In the same report, calculations show that the difference in density causes the energy shift.

The slow electron diffraction method irradiates an analyte with an electron beam having a wavelength (usually several hundreds eV) substantially equal to the atomic spacing of the solid, and obtains information on the atomic arrangement on the solid surface from the direction and intensity of the scattered electrons. When the sample to be analyzed is graphite, the lattice constant and the like can be estimated from the ring-shaped pattern.

[0021]

However, in the above-mentioned method of forming graphite or a thin film containing a graphite component, the method of controlling the structure of graphite, especially the diameter of graphite crystallites, incorporates it into a part of an electronic device or the like. For example, there is a problem that it cannot be formed in a minute area of 1 μm square or less.

The structure of a graphite thin film incorporated in the above-mentioned minute region, for example, a minute region of 1 μm square or less, particularly the method of analyzing graphite crystallite diameter itself has the following problems.

First, in X-ray diffraction, X-ray photoelectron spectroscopy, and vacuum ultraviolet photoelectron spectroscopy using X-rays or vacuum ultraviolet light, which is difficult to collect in principle, as incident light (excitation source), 1
There is a problem that it is impossible to analyze a minute area of less than μm square. At the present stage, it is difficult to reduce the laser beam generally used for Raman spectroscopy to 1 μm or less. That is, in order to analyze a minute region of 1 μm square or less, the primary excitation source (probe) is substantially limited to electrons or ions that can be easily focused.

The Raman spectroscopy using a photon (usually visible light) as a detection signal also has a problem that only a surface having a depth of 10 nm or less cannot be selectively analyzed.

Hereinafter, problems of other techniques in the analysis of the graphite material in the minute portion will be described in order.

In the observation method using a transmission electron microscope, a specific minute region can be analyzed in detail, but on the other hand, it takes a long time to prepare a sample (because the sample to be analyzed needs to be thinned to about 10 nm). In order to measure the diameter, when the particle diameters are not uniform, there is a problem that many particles must be observed, that is, it takes a long time.

Also, in the transmitted electron energy loss analysis method, there is a problem that it takes a long time to prepare a sample.

Although high-resolution energy loss spectroscopy allows detailed investigation of the phonon dispersion of graphite on the outermost surface, information on the crystallite diameter of graphite cannot be obtained with an electron beam at an energy level usually used as a primary excitation source. There is a problem. In addition, since a mechanism for making the primary electron beam monochromatic is required, there is also a problem that the size of the analyzing apparatus is slightly increased.

Although the low-speed electron diffraction method can obtain information such as the lattice constant of graphite on a minute portion and on the surface, it has a problem that it cannot obtain direct information on the crystallite diameter of graphite. Further, when the sample to be analyzed is a graphite thin film, there is also a problem that the diffraction pattern becomes complicated due to the influence of the underlayer (multiple diffraction) and analysis becomes difficult.

Further, when an observation method using a transmission electron microscope which requires pretreatment of the sample to be analyzed or when an independent analyzer is used, the sample to be analyzed must be once released to the atmosphere. There is also a problem that the analysis sample is contaminated.

As described above, in a conventionally known method of forming graphite or a thin film containing a graphite component,
It is difficult to control the structure of the graphite, particularly the graphite crystallite diameter, to incorporate it into a certain part of an electronic device or the like, for example, to form it in a minute area of 1 μm square or less. In addition, it is also difficult to analyze the structure of the graphite thin film formed in the minute region itself, and particularly it is extremely difficult to measure the average crystallite diameter of the graphite material in the surface region having a depth of 10 nm or less and a minute region of 1 μm square or less. There is a problem. If the structure analysis of the graphite thin film in such a small area cannot be accurately performed, it is difficult to effectively control the conditions for forming the thin film with a small area.

An object of the present invention is to form a thin film in a minute area of 1 μm square or less while controlling the structure of a material having a crystal structure such as graphite, and analyze the structure of the thin film formed in the minute area, in particular, It is an object of the present invention to provide a method for measuring the average crystallite diameter, and to provide an apparatus for producing such a thin film.

[0033]

According to the present invention, an analyte sample of a material having an absorption in the ultraviolet region and having a crystal structure is irradiated with an electron beam, and an energy loss spectrum of reflected electrons is measured. There is provided a method for measuring an average crystallite diameter, characterized by utilizing a spectrum.

According to the present invention, an apparatus for producing a thin film of a material having an absorption in the ultraviolet region and having a crystal structure by a chemical vapor reaction is provided with a reflected electron energy loss spectroscopy mechanism. An apparatus for producing the thin film is provided.

A feature of the apparatus of the present invention is that a mechanism for controlling conditions for forming a thin film based on a signal from the reflected electron energy loss spectroscopic analysis mechanism is added.

Further, according to the present invention, in a method of producing a thin film of a material having an absorption in the ultraviolet region and having a crystal structure by a chemical vapor reaction, the chemical state of the thin film is changed to a reflected electron without being released to the atmosphere. There is provided a method for producing a thin film, characterized in that the thin film is produced while analyzing the result by energy loss spectroscopy and feeding back the obtained result to the conditions for producing the thin film.

In the analysis by reflected electron energy loss spectroscopy, the sample to be analyzed is irradiated with an electron beam, the energy loss spectrum of the reflected electrons is measured, and the information obtained from the analysis result of the spectrum is used to prepare a thin film. Feedback to conditions is also a feature of the method of the present invention.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION In the average crystallite diameter measurement method of the present invention for analyzing the structure of a thin film of a material having an absorption in the ultraviolet region and having a crystal structure, an electron beam is applied to the thin film to be analyzed. The energy loss spectrum of the irradiated and reflected electrons is measured. The use of the spectrum means that the next 3 appearing in the electron energy loss spectrum
(1) the energy value of the plasmon peak (loss energy is in the range of 20 to 30 eV) and the elastic scattering peak, that is, the peak at the electron loss energy of 0 eV reflected on the sample surface without losing energy; At least one of the relative intensity of the plasmon peak and the shape of the background (background of a continuous spectrum formed by inelastic scattered electrons), and (2) π → π
^* The energy value of the peak resulting from the transition (the loss energy is in the range of 4-8 eV), the relative intensity of the π → π ^* peak with respect to the elastic scattering peak, and the background (the continuous energy formed by the inelastic scattered electrons). At least one of the following shapes: (3)
The shape of the background of a continuous spectrum formed by inelastic scattered electrons, or a point relative to the elastic scattering peak (1/4 to 9/1 of the elastic scattering peak energy)
0 is desirable), and the crystallite diameter is determined by utilizing a correlation between at least one of the relative intensities of the sample material and the average crystallite diameter obtained by a known method of the sample material. It means to ask. In particular, in order to measure a peak derived from the π → π ^* transition with high sensitivity, it is preferable in the present invention to use an electron beam in a range of 200 eV to 3 keV as the electron beam.

The term "ultraviolet light" used in the present invention means an electromagnetic wave in a wavelength range from 360 nm, which is a short wavelength end of visible light, to 1 nm.

When an electron beam is used as a primary excitation source (probe) for irradiating a sample to be analyzed, it is easy to focus the beam diameter to 1 μm or less, and as described later, a field emission type electron gun is used. When the acceleration voltage is set to 1 keV and the emission current is set to 1 nA, an electron beam diameter of about 200 nm can be obtained. When combined with secondary electron image observation, determination of the analysis position is extremely easy, and it is also possible to scan a specific region with the electron beam.

On the other hand, as is well known, the analysis depth depends on the kinetic energy of the detected electron. Although it is difficult to accurately determine the analysis depth, the following briefly describes the mean free path of electrons and the analysis depth estimated therefrom.

For the mean free path of electrons, for example,
According to Tanuma et al., When the energy of the electron is 200 eV, it is 0.6 to 1.0 nm, and the energy of the electron is 1 keV.
0.9 to 3.0 nm and electron energy of 2 ke
V in the range of 1.8 to 5.0 nm (S. Tanuma, C.
J. Pawell and DR Penn, Surf.Sci., 192, L849 (19
89) However, it does not relate to graphite samples. ).

The above mean free path (calculated value) of the electron,
95% of the electrons escaping from the surface (i.e. the electrons to be analyzed) are contained in a depth three times the mean free path;
The analysis depth when the backscattered electrons are to be analyzed is further reduced, and the analysis depth when using an electron beam in the range of 200 eV to 3 keV is substantially 10 nm.
It can be considered as follows. When the energy of the electron beam is reduced, the analysis depth becomes shallower.

The electron beam in the present invention means an electron beam emitted from an electron gun or an electron beam with an electron beam deflector added thereto. The electron gun is preferably a field emission type electron gun. In this case, a mechanism for making the electron beam monochromatic is not particularly required. A thermionic electron gun can also be used, but in this case, the energy half width ΔE of the electron beam from the electron gun is desirably 0.4 eV or less. However, when this half width of energy cannot be realized, a monochromatic mechanism may be combined. Whichever electron gun is used, one having a stable emission current is preferable. As the electron gun, a commercially available electron gun can be used. Usually, an electrostatic lens or an electromagnetic lens for focusing emitted electrons is incorporated.

The emission current from the electron gun is usually 100
It is set between pA and several tens nA. The diameter of the electron beam from the electron gun largely depends on the electron gun used and the accelerating voltage. For example, a field emission type electron gun was used, the acceleration voltage was set to a typical 1 keV, and the emission current was set to 1 nA. In this case, it is about 200 nm.

For measuring the energy loss spectrum of the electrons reflected on the surface of the sample to be analyzed, it is preferable to use a deflection dispersion type energy analyzer which can obtain a high energy resolution. The energy analyzer includes a magnetic field deflection method, an electrostatic deflection method, and a Wie combining a magnetic field and an electric field.
There are an n-filter type and the like, and among them, a small and economical electrostatic deflection type energy analyzer is preferable.
Note that any energy analyzer such as a concentric hemisphere type, a cylindrical mirror type, and a coaxial cylindrical mirror type may be used as long as it is an energy analyzer of an electrostatic deflection system. When a concentric hemispherical analyzer is used as the energy analyzer, an electrostatic lens for focusing, accelerating, and decelerating the reflected electrons may be added to the incident side of the analyzer.

For detection of reflected electrons, a channeltron,
A multichannel plate, an electron multiplier, or the like can be used, and an amplifier may be added as necessary. As the detection method, either a method of using the analog mode to amplify with a lock-in amplifier or a method of using the pulse count mode and performing pulse count after pulse height discrimination may be used.

As described above, the method for measuring the average crystallite diameter of a material having an absorption in the ultraviolet region and having a crystal structure according to the present invention can be rapidly performed at least with an electron gun and an electron energy analyzer. Therefore, it can be easily combined with other various vacuum vessels, for example, various processing apparatuses such as a film forming apparatus.

In the present invention, the sample to be analyzed, which is a material having an absorption in the ultraviolet region and having a crystal structure, is particularly preferable when the material is mainly composed of carbon, particularly graphite. (Ie, has a peak similar to the π → π ^* transition), and
Any substance having a crystal structure similar to that of graphite can be applied.

In the present invention, a thin film of a material having a crystal structure that absorbs in the ultraviolet region and has a crystal structure, in particular, a carbon thin film containing graphite as a main component, is formed by a conventional chemical vapor reaction such as the above-mentioned thermal CVD method or plasma CVD method. The thin film is irradiated with an electron beam by the above-described method, analyzed by reflected electron energy loss spectroscopy, and the analysis result is fed back to the thin film manufacturing mechanism to control the manufacturing conditions. . The mechanism for controlling the manufacturing conditions is, for example, a mechanism for providing feedback to the flow rate of the source gas, the substrate temperature, and the like by adding a control unit.

In the present invention, the mechanism for performing the backscattered electron energy loss spectroscopy is preferably installed directly in the thin film production container in order to feed back the result obtained in the analysis to the thin film production conditions. It may be installed in another container separated from the thin film production container.
Further, the reflected electron energy loss spectroscopy mechanism includes at least an electron gun and an electron energy analyzer,
The primary electron beam energy from the electron gun is preferably set in the range from 200 eV to 3 keV as described above.

As the thin film made of a material having an absorption in the ultraviolet region and having a crystal structure according to the present invention, a carbon thin film containing graphite as a main component is employed as described above. Especially,
It is preferable that the average crystallite diameter of graphite is in the range of 2 nm to several tens nm, and the thickness of the carbon thin film is 100 nm or less, and / or the region where the thin film is incorporated is 1 μm square or less. Here, "mainly as a main component" means that at least 50% or more of graphite is contained in a formed thin film, and particularly includes a film composed of only graphite. Examples of other contained elements or constituents include halogen elements such as nitrogen, oxygen, hydrogen, and fluorine, metals such as Pd and Pt, metal oxides such as PdO and SnO ₂ , TiC, and SiC.
And semiconductors such as Si and Ge.

[0053]

EXAMPLES The method for measuring the average crystallite diameter of graphite of the present invention will be described below with reference to examples.

Example 1 FIG. 1 is a schematic diagram showing a measuring system used in the present invention.

In FIG. 1, reference numeral 1 denotes a vacuum vessel, 2 denotes an electron gun, 3 denotes an electron energy analyzer including a detection system, 4 denotes a sample stage, 5 denotes a sample to be analyzed, and 6 denotes a primary emitted from the electron gun 2. An electron beam 7 is an electron reflected on the surface of the sample 5 to be analyzed. In this system, the sample 5 is analyzed by irradiating the sample 5 with an electron beam 6 from the electron gun 2 in the vacuum vessel 1 and detecting the reflected electrons 7 by the analyzer 3. In addition,
The measurement in this example was performed using a commercially available Auger electron spectrometer equipped with a field emission electron gun and a concentric hemispherical energy analyzer.

As the sample to be analyzed, four types of graphite whose average crystallite diameter Lc was previously determined by an X-ray diffraction method (crystallite diameters Lc were 1 nm, 2 nm, 8 nm, and 2 nm, respectively)
At 0 nm, the error was about ± 0.2 nm). In addition,
About the average crystallite diameter Lc of the four types of graphite, almost the same value was obtained from Raman spectroscopy. That is, the average crystallite diameter Lc of the four types of graphite shows the same tendency both in the vertical direction (determined by X-ray diffraction method) and in the parallel direction (determined by Raman spectroscopy) with respect to the hexagonal mesh plane. there were.

The main measurement conditions were: acceleration energy of primary electrons: about 1 keV, primary electron current: about 2 nA, analyzer operation mode: constant reduction ratio mode (4 to 40), pressure in the apparatus: 5 × 10 ^-8 Pa or less. The primary electron beam diameter under these conditions is about 15
It was 0 nm.

FIG. 2 shows the energy loss spectrum of the backscattered electrons measured under such conditions by the intensity normalized by the elastic scattering peak, that is, the peak of the electron loss energy of 0 eV.

In FIG. 2, the loss energy is 4 to 8e.
The peak observed in the range of V is a double bond carbon (π →
π ^* ), and the loss energy is 20-30.
The peak observed in the eV range is due to plasmons.

As is clear from FIG. 2, when the crystallite diameter of graphite changes, the energy value of the plasmon peak appears in the energy loss spectrum of the reflected electrons (loss energy is in the range of 20 to 30 eV).
The relative intensity of the plasmon peak with respect to the elastic scattering peak or its shape, (2) the energy value of the peak derived from the π → π ^* transition (loss energy is in the range of 4 to 8 eV), and the π with respect to the elastic scattering peak. → It can be seen that the relative intensity of the π ^* peak or its shape changes.

FIGS. 3 and 4 show the energy values and the relative intensities of the plasmon peak and the π → π ^* peak for four types of graphites having different average crystallite diameters. This shows that there is a good correlation between the strength of (1), the strength of (2), and the crystallite diameter of graphite.

Further, when the crystallite diameter of graphite changes, the shape of the background of a continuous spectrum formed by inelastic scattered electrons slightly changes.

For example, if the electron loss energy is 500 eV
The relative intensity of the background with respect to the elastic scattering peak at point (1) increases as the crystallite diameter decreases (not shown). This is because the probability of inelastic scattering increases as the crystallite diameter of graphite decreases.

That is, it is considered that the shape and intensity of the background of a continuous spectrum formed by inelastic scattering also reflect the crystallite diameter of graphite, which is also applied to the analysis of the crystallite diameter of graphite. May be possible.

As described above, in the electron energy loss spectrum, the relative intensity of the above-mentioned plasmon peak (1) or its shape, (2) the relative intensity of the π → π ^* peak or its shape, and ( The shape of the background in the spectrum of 3) or the relative intensity at a certain point with respect to the elastic scattering peak well reflects the crystallite diameter of graphite, and if these correlations are used, the surface having a depth of 10 nm or less can be used. The average crystallite diameter of graphite existing in a minute region of 1 μm square or less can be easily obtained.

Example 2 Next, graphite carbon was deposited on metal Co by thermal CVD, and the average crystallite diameter of the graphite was determined using the energy loss spectrum of reflected electrons according to the present invention.
The results obtained by Raman spectroscopy and X-ray diffraction will be described.

First, a method of preparing a sample to be analyzed will be described with reference to FIG. FIG. 5 shows a substrate for forming and analyzing thermal CVD carbon, 8 is a quartz glass substrate, and 9 is a metal Co thin film. As shown in FIG. 5, three types of the metal Co thin film 9 having different widths I, II and III were patterned on the same substrate. The thickness of the metal Co thin film is about 100 nm
And

Next, the substrate was heated to 800 ° C., and thermal CVD carbon using acetone as a source was deposited on the metal Co thin film. The introduction pressure of acetone was 1 Torr, and the amount of carbon deposited (film thickness described later) was controlled by the acetone introduction time.

When the carbon on the metal Co thin film obtained by the above method was observed with a scanning electron microscope, it was found that the carbon was deposited in the form of islands having a size of several μm. It was found that there was a portion where little was deposited. Therefore, the portion where the carbon was deposited in an island shape was measured by an atomic force microscope (AFM), and the step was taken as the film thickness of the deposited carbon.

In this embodiment, the introduction time of acetone was changed in four ways, and the film thickness of the deposited carbon was 1 nm, 6 nm, 33 nm,
The average crystallite diameter of graphite was determined by the above method using the material having a diameter of 105 nm. The sample to be analyzed was cooled to room temperature and released to the atmosphere, and then analyzed by the above method. Table 1 shows the results.

In Table 1, the mark x indicates that the measurement could not be performed. In the method of using the energy loss spectrum of reflected electrons according to the present invention, the measurement conditions for the spectrum were the same as in Example 1.

[0072]

[Table 1]

As is clear from Table 1, a depth of 10 mm, which was difficult with conventional methods such as Raman spectroscopy and X-ray diffraction, was used.
It has been found that the average crystallite diameter of graphite existing on the surface of not more than nm and in the minute region of not more than 1 μm square can be accurately and easily obtained by using the method of the present invention.

As described above, according to the method for measuring the average crystallite diameter of the present invention, the surface having a depth of 10 nm or less and the thickness of 1 μm can be obtained only by using an electron gun and an electron energy analyzer.
The average crystallite diameter of graphite existing in a small area of four or less sides can be easily obtained.

Next, a description will be given of an apparatus and method for manufacturing a thin film having a mechanism for analyzing a carbon thin film containing graphite as a main component as described above.

Embodiment 3 In this embodiment, an example will be described in which a thermal CVD method and reflection electron energy loss spectroscopy are combined to form a carbon thin film having a controlled crystallite diameter of graphite in a minute region having a width of 1 μm or less. .

FIG. 6 shows the structure of an apparatus for producing a carbon thin film used in this example. In FIG. 6, 11 is a vacuum container,
12 is an electron gun, 13 is an electron energy analyzer including a detection system, 14 is a sample stage, 15 is a sample to be analyzed, 16 is a primary electron beam emitted from the electron gun 12, and 17 is a surface of the sample 15 to be analyzed. The reflected electrons, 18 is a power supply for heating the sample, 1
9 is a source gas cylinder, 20 is a valve, 21 is a flow control device, and 22 is control means. The vacuum vessel 11, the electron gun 12, the analyzer 13, and the sample stage 14 constitute a thin-film analysis system similar to that shown in FIG. 1. For reflected electron energy loss spectroscopy, a field emission electron gun is used as an electron gun. And a concentric hemispherical energy analyzer was used as an analyzer.

In the present embodiment, the carbon thin film was formed by using the same carbon thin film forming and analyzing substrate as shown in FIG. 5 and the carbon thin film forming apparatus shown in FIG. . In this embodiment, the portion I (width 0.5) in FIG.
μm), a graphite thin film having an average crystallite diameter of 2 nm was formed as follows.

First, the conditions of the thermal CVD were as follows: the source gas was acetone, the introduction pressure was 1 Torr (fixed), and the initial substrate temperature was 800 ° C.

The measurement conditions for the backscattered electron energy loss spectroscopy were the same as in Example 1. However, in this example, the analysis was performed in the same vacuum vessel 11 without exposing the sample to the atmosphere. That is, after acetone was introduced for a certain period of time, the system was evacuated once and the reflected electron energy loss spectrum was measured. During the spectrum measurement, the substrate temperature was not changed. As will be described later, after the spectrum measurement was completed, the spectrum was analyzed, and if necessary, control was performed so that the substrate temperature was changed at that time. This series of operations was performed every 10 minutes after the introduction of acetone gas.

The signal obtained by the above-described reflected electron energy loss spectroscopy was fed back to the sample heating power supply 18 through the control means 22. That is, in the present embodiment, the correlation between the substrate temperature and the crystallite diameter of graphite, which has been determined in advance, and the correlation between the reflected electron energy loss spectrum and the crystallite diameter of graphite described above were used. When a graphite thin film was formed in this manner, the substrate temperature was 780 ° C. 30 minutes after the introduction of the acetone gas was started.

As a result, in this example, a thin film having an average crystallite diameter of graphite (2 nm) uniform in the depth direction was able to be formed in a minute region having a width of 1 μm or less.

Example 4 In this example, a thin film having an average crystallite diameter of graphite of 10 nm was produced in a minute region having a width of 1 μm or less by using the same apparatus and the same method as in Example 3.

The difference from the third embodiment is that the initial substrate temperature is
Only at 0 ° C. Also in this example, a thin film in which the average crystallite diameter of graphite was uniform in the depth direction could be formed in a minute region.

Example 5 In this example, a thin film having an average crystallite diameter of graphite of 3 nm was formed in a minute region having a width of 1 μm or less by using the same apparatus and the same method as in Example 3.

The difference from the third embodiment is that the metal C shown in FIG.
o using a metal Ni thin film instead of the thin film 9, using benzene instead of acetone as a source gas,
The point is that the initial substrate temperature was set to 850 ° C. Also in this example, a thin film in which the average crystallite diameter of graphite was uniform in the depth direction could be formed in a minute region.

Example 6 In this example, the conditions of thermal CVD and reflection were different except that the apparatus for producing a carbon thin film shown in FIG. 7 was used instead of the apparatus for producing a carbon thin film shown in FIG. A carbon thin film was formed under the same conditions for electron energy loss spectroscopy.
7, the same reference numerals as those in FIG. 6 indicate the same members as those in FIG.

In the apparatus shown in FIG. 7, the reflected electron energy loss spectroscopic analysis mechanism has a measuring vessel 3 different from the carbon thin film producing vessel 31.
2, the carbon thin film production container 31 and the measurement container 32 are separated by a gate valve 33. After the carbon thin film is manufactured in the carbon thin film manufacturing container 31 for 10 minutes, the sample 15 to be analyzed is transported together with the sample stage 14 to the measurement container 32 by the sample transport mechanism 34, and the reflected electron energy loss spectrum is measured in the container 32. After the measurement, the substrate was returned to the carbon thin film production container 31, and the result obtained by backscattered electron energy loss spectroscopy was used to form a carbon thin film by adjusting the substrate temperature through control means (not shown).

Also in this example, a thin film in which the average crystallite diameter of graphite was uniform in the depth direction could be formed in a minute region.

As described above, by using the apparatus and method for manufacturing a thin film of the present invention, a material having a crystal structure of 1 μm square or less is controlled while controlling the crystallite diameter of a material having a crystal structure, such as graphite, having absorption in the ultraviolet region. A thin film of the material can be formed in a minute region.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a reflected electron energy loss spectrometer according to the present invention.

FIG. 2 is a backscattered electron energy loss spectrum of graphite having an average crystallite diameter of 1, 2, 8, and 20 nm.

FIG. 3 is a graph showing the relationship between π → π ^* loss energy of graphite and the relative intensity of the same peak (normalized by elastic scattering peak intensity).

FIG. 4 is a graph showing a relationship between plasmon loss energy of graphite and relative intensity of the same peak (normalized by elastic scattering peak intensity).

FIG. 5 is a plan view of a substrate for forming and analyzing a carbon thin film by a thermal CVD method used in Examples.

FIG. 6 is a schematic view showing one embodiment of a carbon thin film producing apparatus used in the present invention.

FIG. 7 is a schematic view showing another embodiment of the thin film production apparatus of the present invention.

[Explanation of symbols]

 1, 11 Vacuum container 2, 12 Electron gun 3, 13 Electron energy analyzer including detection system 4, 14 Sample stage 5, 15 Sample to be analyzed (substrate) 6, 16 Primary electron beam emitted from electron gun 2 7 , 17 Electrons reflected on the surface of the sample 5 to be analyzed 8 Quartz glass substrate 9 Metal Co thin film 18 Sample heating power supply 19 Source gas cylinder 20 Valve 21 Flow control device 22 Control means 31 Carbon thin film forming container 32 Measurement container 33 Gate valve 34 Sample Transport mechanism

Claims (30)

[Claims] In a method for measuring the average crystallite diameter of a material having an absorption in the ultraviolet region and having a crystal structure, an analyte is irradiated with an electron beam, and an energy loss spectrum of reflected electrons is measured. A measurement method characterized by using a spectrum. 2. The measuring method according to claim 1, wherein the energy of the electron beam is in a range from 200 eV to 3 keV. 3. The method according to claim 1, wherein the sample is made of a material containing carbon as a main component. 4. The measuring method according to claim 3, wherein the material containing carbon as a main component is made of graphite. 5. The material has a crystallite diameter of 2 nm to several tens of nanometers.
The measuring method according to claim 1, 3 or 4, wherein the measuring method is within a range of m. 6. The sample according to claim 1, wherein the sample is a thin film, and the average crystallite diameter of the material in a region within 10 nm from the surface of the thin film and within 1 μm square is measured. 4. The measuring method according to 4. 7. An energy value of a plasmon peak appearing in an electron energy loss spectrum, at least one of a relative intensity of the plasmon peak with respect to an elastic scattering peak, and a background shape, and an average crystallite diameter of a sample material. The method according to claim 1, wherein the crystallite diameter is determined using a correlation between the two. 8. The method according to claim 1, wherein an energy value of a peak derived from a π → π ^* transition appearing in an electron energy loss spectrum, at least one of a relative intensity of the π → π ^* peak with respect to an elastic scattering peak, and a shape of a background, The method according to claim 1, wherein the crystallite diameter is determined using a correlation between the material and the average crystallite diameter of the material. 9. The shape of the background of a continuous spectrum formed by inelastic scattered electrons appearing in an electron energy loss spectrum, or the relative intensity of a certain point with respect to an elastic scattering peak, and the average crystallite of a sample material The method according to claim 1, wherein the crystallite diameter is determined using a correlation with the diameter. 10. An apparatus for producing a thin film of a material having an absorption in the ultraviolet region and having a crystal structure by a chemical vapor reaction, comprising a thin film production container and a reflected electron energy loss spectroscopic analysis mechanism. Thin film manufacturing apparatus. 11. The thin film producing apparatus according to claim 10, wherein the reflected electron energy loss spectroscopic analysis mechanism is provided in a thin film producing container. 12. The apparatus for producing a thin film according to claim 10, wherein said reflected electron energy loss spectroscopy mechanism is provided in another container separated from a thin film production container by a gate valve. 13. The apparatus for producing a thin film according to claim 10, wherein the reflected electron energy loss spectroscopy mechanism has at least an electron gun and an electron energy analyzer. 14. The thin film is a carbon thin film.
An apparatus for producing a thin film according to any one of 0 to 13. 15. The apparatus according to claim 14, wherein the carbon thin film is a carbon thin film containing graphite as a main component. 16. The thin film according to claim 14, wherein the carbon thin film is a carbon thin film made of graphite, and the average crystallite diameter of the graphite is in a range of 2 nm to several tens nm. Production equipment. 17. The apparatus according to claim 14, wherein the thickness of the carbon thin film is 100 nm or less, and / or the area where the thin film is incorporated is 1 μm square or less. 18. The apparatus for producing a thin film according to claim 10, further comprising a mechanism for controlling conditions for producing the thin film based on a signal from the reflected electron energy loss spectroscopy analysis mechanism. 19. The apparatus for producing a thin film according to claim 10, wherein the reflected electron energy loss spectroscopy mechanism has means for irradiating a primary electron beam having an energy in the range of 200 eV to 3 keV. 20. A method for producing a thin film of a material having an absorption in the ultraviolet region and a crystal structure by a chemical vapor reaction, wherein the chemical state of the thin film is analyzed by reflected electron energy loss spectroscopy without opening to the atmosphere. And producing the thin film while feeding back the obtained results to the thin film production conditions. 21. The method according to claim 19, wherein the analysis by reflected electron energy loss spectroscopy is performed by irradiating a sample to be analyzed with an electron beam, measuring an energy loss spectrum of reflected electrons, and using the spectrum. Claim 20
3. The method for producing a thin film according to 1. 22. The method according to claim 20, wherein at least an electron gun and an electron energy analyzer are used for the analysis by the reflected electron energy loss spectroscopy. 23. The energy of a primary electron beam used for analysis by the reflected electron energy loss spectroscopy is 20.
21. The method according to claim 20, wherein the thickness is in a range of 0 eV to 3 keV. 24. The thin film is a carbon thin film.
24. The method for producing a thin film according to any one of items 23 to 23. 25. The method according to claim 24, wherein the carbon thin film is a carbon thin film containing graphite as a main component. 26. The thin film according to claim 24, wherein the carbon thin film is a carbon thin film made of graphite, and the average crystallite diameter of the graphite is in a range of 2 nm to several tens nm. Production method. 27. The method for producing a thin film according to claim 24, wherein the thickness of the carbon thin film is 100 nm or less, and / or the area where the thin film is incorporated is 1 μm square or less. 28. The analysis by reflected electron energy loss spectroscopy, wherein at least one of an energy value of a plasmon peak appearing in an electron energy loss spectrum, a relative intensity of the plasmon peak with respect to an elastic scattering peak, and a shape of a background, 26. The method for producing a thin film according to claim 20, wherein the crystallite diameter of the thin film is obtained using a correlation between the average crystallite diameter of the thin film material. 29. The analysis by reflected electron energy loss spectroscopy shows that the energy value of the peak derived from the π → π ^* transition appearing in the electron energy loss spectrum, the relative intensity of the π → π ^* peak with respect to the elastic scattering peak, 26. The method for producing a thin film according to claim 20, wherein the crystallite diameter is obtained by using a correlation between at least one of the shapes of the background and the average crystallite diameter of the thin film material. . 30. The analysis by the reflected electron energy loss spectroscopy is performed by determining the shape of the background of a continuous spectrum formed by inelastic scattered electrons appearing in the electron energy loss spectrum, or the relative position of a point to an elastic scattering peak. 26. The method for producing a thin film according to claim 20, wherein the crystallite diameter is determined using a correlation between the strength and the average crystallite diameter of the thin film material.