JP3975261B2 - Photoelectron spectrometer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoelectron spectrometer.
[0002]
[Prior art]
In the conventional photoelectron spectrometer, the characteristic X-ray generated from the target material when the electron beam collides with the solid target material is used as the X-ray irradiated to the sample (use of an X-ray tube for electron beam excitation). ).
[0003]
For example, aluminum or magnesium is used as a target substance, and X-rays having a wavelength of 0.83 nm (photon energy 1487 eV) and a wavelength of 0.99 nm (photon energy 1254 eV), which are Kα characteristic X-rays thereof, have been used.
[0004]
[Problems to be solved by the invention]
  An object of the present invention is to provide a photoelectron spectrometer capable of realizing a reduction in measurement time.
[0005]
[Means for Solving the Problems]
  According to the first aspect of the present invention, a laser beam X-ray source that collects and irradiates a pulse laser beam onto a target member to form plasma, and extracts X-rays from the plasma, and X-rays emitted from the laser plasma X-ray source A filter for monochromatizing, and analyzing the energy of photoelectrons emitted from the sample surface when the sample is irradiated with X-rays, thereby identifying the type or chemical bonding state of atoms or molecules constituting the sample Applied to photoelectron spectrometerThe
[0006]
  The filter is formed by forming a thin film of a filter material on a support film, and the target member is a sheet-like member in which a plurality of different target substances are formed in a strip shape and arranged in parallel, and the sheet-like member is A switching mechanism that switches in a parallel direction and switches the target substance irradiated with the pulsed laser light is provided.
[0007]
  According to a second aspect of the present invention, in the photoelectron spectrometer according to the first aspect, a moving mechanism is provided for moving the sheet-like member in the extending direction of the target substance formed in a strip shape in a direction orthogonal to the parallel direction. It is a thing.
[0008]
  According to a third aspect of the present invention, in the photoelectron spectrometer according to the first or second aspect, each of the sheet-like members is formed by forming a thin film layer of a target substance on a sheet-like substrate in a band shape.
[0009]
  According to a fourth aspect of the present invention, in the photoelectron spectrometer according to the third aspect, the sheet-like substrate is exposed in a strip shape so as to be juxtaposed with the strip-shaped target substance formed on the sheet-like substrate.
[0010]
  Claim5The invention of claim 1 to claim 14In the photoelectron spectrometer according to any one of the above, an analysis mechanism relating to a time-of-flight method is provided as an analysis mechanism for performing photoelectron energy analysis.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In an embodiment of the present invention, a source of X-rays irradiated on a sample is a laser plasma X-ray source (LPX) that forms a plasma by condensing and irradiating a target material with pulsed laser light and extracts X-rays from the plasma. ).
[0012]
  LPX is an X-ray source that is small but has high luminance, has a luminance comparable to or higher than synchrotron radiation, and has a peak value of 10 compared to an X-ray tube excited by an electron beam. ⁸ About twice as bright.
[0013]
  And also in average brightness, by using a high repetition laser beam, it is 10% more than the X-ray tube. ² -10 ³ The value can be about twice as high.
[0014]
  For this reason, when LPX is used as an X-ray source of a photoelectron spectrometer, it becomes possible to irradiate a sample with high-intensity X-rays. The X-ray dose to the sample can be increased.
[0015]
  As a result, the number of photoelectrons emitted from the irradiated region (sample) increases and the measurement time can be shortened..
[0016]
  Furthermore, in the present embodiment, carbon, a carbon-containing material, nitrogen, a nitrogen-containing material, oxygen, an oxygen-containing material, fluorine, or a fluorine-containing material, which is a light element, is used as a target material for LPX.
[0017]
  When such a light element is used as a target material for LPX, the spectrum of X-rays emitted from plasma becomes several discrete line spectra, and the line width δλ satisfies λ / δλ> 1000.
[0018]
  For example, when carbon or a carbon-containing material is used as a target material (target substance) of LPX, C ⁴⁺ Ionic 1s ² -1s2p Wavelength due to transition 4.03nm X-ray and C ⁵⁺ Ionic 1s-2p Wavelength due to transition 3.37nm X-rays are strongly radiated.
[0019]
  If nitrogen is used, N ⁵⁺ Ionic 1s ² -1s2p Wavelength due to transition 2.88nm X-ray and N ⁶⁺ Ionic 1s-2p Wavelength due to transition 2.48nm X-rays are strongly radiated.
[0020]
  In the case of oxygen, O ⁶⁺ Ionic 1s ² -1s2p Wavelength due to transition 2.16nm X-ray and O ⁷⁺ Ionic 1s-2p Wavelength due to transition 1.90nm X-rays are strongly radiated.
[0021]
  In the case of fluorine, F ⁷⁺ Ionic 1s ² -1s2p Wavelength due to transition 1.68nm X-ray and F ⁸⁺ Ionic 1s-2p Wavelength due to transition 1.50nm X-rays are strongly radiated.
[0022]
  Since these X-rays are discrete line spectra, one line spectrum can be easily selected from the line spectrum group by utilizing the absorption edge of the substance.
[0023]
  Moreover, since the line width reaches about λ / δλ> 1000, a spectrum can be obtained with a resolution higher than the energy resolution of the conventional XPS apparatus without using a spectroscope.
[0024]
  For example, calcium (Ca), calcium-containing material (for example, calcium fluoride (CaF₂)), Rhodium (Rh), rhodium-containing material, palladium (Pd), palladium-containing material, silver (Ag) or silver-containing material is used as a filter material, and carbon or a carbon-containing material is used as a target material for LPX. Of the line spectra that are sometimes radiated, C⁴⁺Ion 1s²Monochromatic X-ray with a wavelength of 4.03nm can be extracted by -1s2p transitionThe
[0025]
Here, since calcium has an absorption edge due to the L shell at a wavelength of 3.55 nm, if calcium or a calcium-containing material is used as a filter material, 1 s shorter than the absorption edge.²-1s3p transition (C⁴⁺Ion, λ = 3.50nm), 1s-2p transition (C⁵⁺Ion, λ = 3.37nm), 1s-3p transition (C⁵⁺X-rays due to ions, λ = 2.85 nm) can be significantly attenuated, so C⁴⁺Ion 1s²Only X-rays with a wavelength of 4.03 nm due to the -1s2p transition can be extracted.
[0026]
Similarly, rhodium (Rh), palladium (Pd), and silver (Ag) have an absorption edge due to the M shell in the vicinity of a wavelength of 4 nm. Therefore, if these substances and contents of these substances are used as filter materials, C⁴⁺Ion 1s²Only X-rays with a wavelength of 4.03 nm due to the -1s2p transition can be extracted.
[0027]
  Also, when nitrogen (N), nitrogen-containing material, scandium (Sc), scandium-containing material, titanium (Ti) or titanium-containing material is used as a filter material, when carbon or a carbon-containing material is used as a target material for LPX C from the group of radiated line spectra⁵⁺Monochromatic X-rays with a wavelength of 3.37 nm can be extracted by 1s-2p transition of ionsThe
[0028]
Here, since nitrogen has an absorption edge due to the K shell at a wavelength of 3.10 nm, if nitrogen or a nitrogen-containing material is used as a filter material, the 1s-3p transition (C⁵⁺X-rays caused by ions, λ = 2.85 nm) can be significantly attenuated.
[0029]
In addition, for X-rays in a longer wavelength region than the absorption edge, the transmittance gradually decreases as the wavelength becomes longer.⁴⁺Ion 1s² X-rays with a wavelength of 4.03nm due to the -1s2p transition are also sufficiently attenuated,⁵⁺Only X-rays with a wavelength of 3.37 nm due to 1s-2p transition of ions can be extracted.
[0030]
Since nitrogen is a gas at normal temperature, when it is used as a filter material, the space between LPX and the sample may be filled with nitrogen gas.
[0031]
  Similarly, scandium (Sc) and titanium (Ti) also have absorption edges due to L shells at wavelengths of 3.09 nm and 2.74 nm, respectively, so these substances or substances containing these substances can be used as filter materials. C⁵⁺Only X-rays with a wavelength of 3.37 nm due to 1s-2p transition of ions can be extracted.The
[0032]
  Further, when titanium (Ti) or a titanium-containing material is used as a filter material, N is selected from the line spectrum group radiated when nitrogen or a nitrogen-containing material is used as the LPX target material.⁵⁺Ion 1s²Monochromatic X-ray with a wavelength of 2.88 nm can be extracted by -1s2p transitionThe
[0033]
As described above, since titanium has an absorption edge due to an L shell at a wavelength of 2.74 nm, if titanium or a titanium-containing material is used as a filter material, N⁵⁺Ion 1s²Only X-rays with a wavelength of 2.88 nm due to the -1s2p transition can be extracted.
[0034]
  Similarly, since indium (In) and tin (Sn) also have absorption edges due to M shells at wavelengths of 2.80 nm and 2.43 nm, if these substances or the contents of these substances are used as filter materials, N⁵⁺Ion 1s²X-rays with a wavelength of 2.88 nm can be extracted by -1s2p transitionThe
[0035]
  In addition, when vanadium (V) or a vanadium-containing material is used as a filter material, N is selected from the line spectrum group radiated when nitrogen or a nitrogen-containing material is used as the LPX target material.⁶⁺Monochromatic X-rays with a wavelength of 2.48 nm can be extracted by 1s-2p transition of ionsThe
[0036]
Here, since vanadium has an absorption edge due to the L shell at a wavelength of 2.43 nm, if vanadium or a vanadium-containing material is used as a filter material, N⁶⁺The 1s-3p transition of ions significantly attenuates the X-ray at a wavelength of 2.09nm, which is longer than the 2.48nm wavelength of the 1s-2p transition.²X-rays with a wavelength of 2.88 nm due to the -1s2p transition can also be sufficiently attenuated, so almost N⁶⁺Only X-rays with a wavelength of 2.48 nm due to 1s-2p transition of ions can be extracted.
[0037]
  Moreover, when chromium (Cr), chromium-containing material, magnesium (Mg) or magnesium-containing material is used as a filter material, it is selected from the line spectrum group radiated when oxygen or an oxygen-containing material is used as the LPX target material. O⁶⁺Ion 1s²Can extract monochromatic X-rays with a wavelength of 2.16 nm by -1s2p transitionThe
[0038]
Here, chromium and magnesium have absorption edges due to the L shell at wavelengths of 2.07 nm and 1.94 nm, respectively.⁶⁺Ion 1s²X-rays with a wavelength of 1.86 nm due to the -1s3p transition and O⁷⁺Since X-rays with a wavelength of 1.90 nm due to 1s-2p transition of ions can be significantly attenuated, O⁶⁺Ion 1s²Only X-rays with a wavelength of 2.16 nm due to the -1s2p transition can be extracted.
[0039]
  Further, fluorine (F), fluorine-containing material (for example, CF_Four Etc.), iron (Fe), iron-containing material, or xenon (Xe) is used as a filter material, it is O in the line spectrum group radiated when oxygen or an oxygen-containing material is used as the LPX target material.⁷⁺Monochromatic X-ray with a wavelength of 1.90 nm can be extracted by 1s-2p transition of ionsThe
[0040]
Here, fluorine has an absorption edge at a wavelength of 1.80 nm, iron has a wavelength of 1.75 nm, and xenon has an absorption edge at a wavelength of 1.85 nm, so when these substances or the contents of these substances are used as filter materials, O⁷⁺Only X-rays with a wavelength of 1.90 nm due to 1s-2p transition of ions can be extracted.
[0041]
  Further, when cobalt (Co), cobalt-containing material, barium (Ba), or barium-containing material is used as a filter material, it is selected from the line spectrum group radiated when fluorine or a fluorine-containing material is used as the LPX target material. F⁷⁺Ionic 1s²Can extract monochromatic X-rays with a wavelength of 1.68 nm by -1s2p transitionThe
[0042]
Here, cobalt and barium each have an absorption edge due to the L shell and the M shell at a wavelength of 1.59 nm.⁷⁺Ion 1s²X-ray with a wavelength of 1.45 nm due to the -1s3p transition and F⁸⁺X-rays with a wavelength of 1.50 nm due to 1s-2p transitions of ions can be significantly attenuated.⁷⁺Ion 1s²Only X-rays with a wavelength of 1.68 nm due to the -1s2p transition can be extracted.
[0043]
  Further, when neon (Ne), nickel (Ni), or a nickel-containing material is used as a filter material, F is selected from the line spectrum group radiated when fluorine or a fluorine-containing material is used as the LPX target material.⁸⁺Monochromatic X-ray with a wavelength of 1.50 nm can be extracted by 1s-2p transition of ionsThe
[0044]
Here, neon has an absorption edge at a wavelength of 1.43 nm and nickel has an absorption edge at a wavelength of 1.45 nm. Therefore, when these substances or the contents of these substances are used as filter materials, it is generally F.⁸⁺Only X-rays with a wavelength of 1.50 nm due to 1s-2p transition of ions can be extracted.
[0045]
  In this way, by selecting one line spectrum (X-ray) in the line spectrum group and irradiating the sample,The energy resolution of photoelectrons can be made higher than that of conventional photoelectron spectrometers (for example, 0.5 eV or less) (higher energy resolution).
[0046]
  Also,In this embodimentDoes not use a spectroscope, there is no decrease in the amount of X-rays associated with the use of the spectroscope, and as a result, the measurement time can be shortened compared with the case where the spectroscope is used by increasing the X-ray dose irradiated onto the sample. Yes (reduced measurement time).
[0047]
Further, when this line spectrum (X-ray) is used, the wavelength is in the soft X-ray region, which is longer than that of the X-ray generated from the above-mentioned X-ray tube. The X-ray optical element can be easily manufactured (making the X-ray optical element easy to manufacture).
[0048]
  for that reason,This embodimentIn this case, an X-ray optical element having a high reflectance and low aberration can be used, and the irradiated X-ray can be condensed with high accuracy on a minute region (for example, 10 μm or less) of the sample (high spatial resolution).
[0049]
  in this way,This embodimentAccording to 1. 1. Miniaturization and high brightness of X-ray source 2. Easy production of X-ray optical element to be used; 3. High energy resolution and high spatial resolution. 4. Reduction of measurement time Miniaturization of the entire apparatus can be realized.
[0050]
  Target substanceAnd / orfilterIt is preferred that the material is arbitrarily replaceableYes.
[0051]
With such a configuration, it becomes possible to select X-rays of several wavelengths and irradiate the sample, and an electron spectrum can be obtained using a plurality of wavelengths.
[0052]
Therefore, peak interference due to photoelectrons and Auger electrons on the electron spectrum can be solved.
[0053]
In addition, since the escape depth of photoelectrons from the sample surface depends on the kinetic energy of photoelectrons, analysis in the depth direction is also possible.
[0054]
In addition, since the irradiation target substance that can excite the inner shell electrons when irradiated with X-rays differs depending on the wavelength of X-rays to be irradiated, if a plurality of values are used as the wavelengths of irradiated X-rays, Different substances of interest corresponding to the wavelength can be observed.
[0055]
For example, when a boron (B, boron) compound (for example, BN) is used as a target material for LPX and X-rays (wavelength 4.86 nm, 255 eV) emitted by a 1s-2p transition of boron ions are used, carbon, Although inner shell electrons of elements contained in organic substances such as oxygen and nitrogen cannot be released (bonding energy of carbon 1s: ~ 284.2 eV, binding energy of oxygen 1s: ~ 543.1 eV, binding energy of nitrogen 1s: ~ 409.9 eV), inner-shell electrons such as aluminum and silicon can be emitted.
[0056]
Therefore, using X-rays of this wavelength, the photoelectron spectrum of aluminum in organic materials (2p binding energy: ~ 72.5 eV) can be observed without being disturbed by the electronic spectra from carbon, oxygen, and nitrogen in the background. The spectrum can be easily analyzed.
[0057]
In addition, carbon or a carbon-containing material is used as a target material for LPX, and carbon C⁴⁺Ion 1s²X-ray (wavelength 4.03nm, 308.5 eV) or -1s2p transition, or C⁵⁺If X-rays (wavelength: 3.37 nm, 368.3 eV) due to 1s-2p transition of ions are used, the inner electrons of carbon in organic materials can be excited, but the inner electrons of oxygen and nitrogen cannot be emitted. Only carbon in organic substances can be detected.
[0058]
Also, nitrogen or a nitrogen compound is used as a target material for LPX, and nitrogen N⁵⁺Ion 1s²X-ray (wavelength: 2.88 nm, 431.6 eV) due to -1s2p transition, or N⁶⁺If X-rays (wavelength: 2.48 nm, 501.4 eV) due to 1s-2p transition of ions are used, the inner electrons of carbon and nitrogen in organic materials can be excited, but the inner electrons of oxygen cannot be emitted. Carbon and nitrogen in organic materials can be observed.
[0059]
  filterAs a support film (self-supporting film)filterIt may be a thin film of materialYes.
[0060]
  For example,A self-supporting membrane made of filter material or gas of the filter material can be used, but if it is difficult to construct a self-supporting membrane with the filter material, another self-supporting membrane with a high transmittance for X-rays (for example, 0.1 μm thick) A thin film of a filter material may be formed on a silicon nitride film or a 1 μm-thick beryllium (Be) thin film by vapor deposition or sputtering.
[0061]
  Also,Between the X-ray source and the sample, an X-ray emitted from the X-ray source is passed through the filter, and then an optical element that focuses the light on a minute area on the sample, or an X-ray that passes through the filter It is preferable to arrange one or two or more optical elements for focusing on a micro area on the sample and to provide a mechanism for scanning the X-ray micro beam focused on the micro area or the sample.Yes.
[0062]
With such a configuration, a monochromatic (or substantially monochromatic) X-ray is condensed on a micro area on the sample, and a two-dimensional map for micro area observation is obtained by scanning the sample or the X-ray micro beam. Can do.
[0063]
  furtherIt is preferable to provide an analysis mechanism for the time-of-flight method as an analysis mechanism for performing photoelectron energy analysis.Yes.
[0064]
That is, in the photoelectron spectrometer of the present invention, LPX, which is a pulsed X-ray source, is used as the X-ray source. It is preferable to perform photoelectron analysis by the method.
[0065]
With this configuration, the photoelectrons emitted from the micro area of the sample can be detected efficiently, and the measurement time can be further shortened.
[0066]
Further, when LPX, which is a pulse X-ray source, is combined with a time-of-flight method, an instantaneous photoelectron spectrum can be obtained, so that a transient chemical state can be analyzed.
[0067]
EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to this example.
[0068]
【Example】
FIG. 1 is a schematic configuration diagram of the photoelectron spectrometer of the present embodiment.
[0069]
When the laser beam 103 emitted from the pulse laser device 100 is focused and irradiated on the target material on the tape-like target member 106 disposed in the vacuum vessel 101 by the lens 104, the target material is turned into plasma and X-rays are emitted. Is radiated.
[0070]
The inside of the vacuum vessel 101 is exhausted in advance by an exhaust device (not shown) to a pressure at which the generated X-rays are sufficiently transmitted.
[0071]
The tape-like target member 106 is obtained by forming thin film layers b and c of two types of target substances on a tape-like substrate a in a band shape. A state of the target member 106 viewed from the front is shown in FIG. 1, and a tape-like substrate is also a target substance.
[0072]
  As the tape-shaped substrate a, polyethylene (an example of a carbon-containing material and an oxygen-containing material) is used, and a thin film layer b of boron nitride (BN, an example of a nitrogen-containing material) and Teflon are formed thereon.(Registered trademark)A thin film layer c (an example of a fluorine-containing material) is formed in a band shape.
[0073]
The tape-like target member 106 is wound around a reel 117 and is movable in the B direction. Further, the target member 106 and the reel 117 can be integrally moved in the direction perpendicular to the paper surface so that an arbitrary target substance on the target member 106 can be irradiated with laser light.
[0074]
The X-ray 108 emitted from the plasma 107 passes through the X-ray transmission filter 115 and is then focused on a minute region on the sample 111 by a Walter mirror (an example of an X-ray focusing element) 110.
[0075]
A plurality (materials) of X-ray transmission filters are mounted on the filter holder 109.
[0076]
The filters are 0.5 μm thick scandium (Sc), 0.5 μm thick vanadium (V), 0.5 μm thick chromium (Cr), 0.5 μm thick nickel (Ni), and 1.3 μm thick carbon (C). Each thin film is attached. Further, these filters can be exchanged from the outside of the vacuum vessel by the linear introduction machine 116.
[0077]
In the measurement, for example, the target member 106 and the reel 117 are integrated vertically so that the laser beam is irradiated onto the tape-like substrate a (polyethylene, part a in the inset in FIG. 1) which is one of the target substances. The linear introducer 116 adjusts the position of the filter in the A direction so that the X-rays from the plasma pass through the scandium thin film filter.
[0078]
Since the material of the substrate a of the tape-like target member 106 is polyethylene (an example of a carbon-containing material), some discrete line spectra caused by carbon ions are radiated from the plasma. With filter, almost C⁵⁺Only X-rays with a wavelength of 3.37 nm due to 1s-2p transition of ions can be extracted.
[0079]
Further, the laser beam is irradiated to the thin film layer b (target material layer, part b in the inset in FIG. 1) of boron nitride (BN, an example of a nitrogen-containing material) formed in a strip shape on the substrate a. The position of the filter is adjusted by the straight line introducer 116 so that the target member 106 and the reel 117 move integrally in the direction perpendicular to the paper surface, and the X-rays from the plasma pass through the titanium thin film filter.
[0080]
The BN plasma radiates several discrete line spectra caused by nitrogen ions, but the titanium thin film filter allows N⁵⁺Ion 1s²Only X-rays with a wavelength of 2.88 nm due to the -1s2p transition can be extracted.
[0081]
  Also, Teflon in which the laser beam is formed in a strip shape on the substrate a(Registered trademark)The target member 106 and the reel 117 integrally move in the direction perpendicular to the paper surface so that the thin film layer c (an example of fluorine-containing material) c (target material layer, part c of the inset in FIG. 1) is irradiated. The position of the filter is adjusted by the straight line introducer 116 so that the X-rays from the filter pass through the nickel thin film filter.
[0082]
  Teflon(Registered trademark)Contains fluorine, the plasma emits some discrete line spectra caused by fluorine ions.⁸⁺Only X-rays with a wavelength of 1.50 nm due to 1s-2p transition of ions can be extracted.
[0083]
Further, the target member 106 and the reel 117 are integrally moved in the direction perpendicular to the paper surface so that the laser beam is irradiated onto the tape-like substrate a (an example of polyethylene or oxygen-containing material) which is one of the target substances, and plasma is also emitted. The position of the filter is adjusted by the straight line introducer 116 so that the X-rays from the filter pass through the filter of the chromium thin film.
[0084]
Since polyethylene contains oxygen, the plasma emits some discrete line spectra caused by oxygen ions.⁶⁺Ion 1s²Only X-rays with a wavelength of 2.16 nm due to the -1s2p transition can be extracted.
[0085]
Further, the target member 106 and the reel 117 move in the direction perpendicular to the paper surface so that the laser beam is irradiated onto the thin film layer b of boron nitride (an example of boron-containing material) formed in a strip shape on the substrate a. In addition, the position of the filter is adjusted by the linear introduction machine 116 so that X-rays from the plasma pass through the filter of the carbon thin film.
[0086]
Since BN contains boron (boron), several discrete line spectra caused by boron ions are radiated from the plasma.
[0087]
The carbon thin film used as a filter transmits X-rays (wavelength 4.8 nm) emitted by 1s-2p transitions of boron ions slightly longer in wavelength than the carbon K absorption edge (wavelength 4.4 nm). Since the transmittance is high and the transmittance of X-rays in the longer wavelength region and X-rays in the shorter wavelength region than the K absorption edge of carbon is low, the X-rays after passing through the carbon thin film filter are boron. X-rays (wavelength 4.86 nm) emitted by 1s-2p transition of ions are almost monochromatic.
[0088]
The X-rays monochromated by the filter as described above are irradiated onto the sample 111 by the Walter mirror 110, and photoelectrons 112 are emitted from the sample surface. The energy of the emitted photoelectrons is analyzed by the time-of-flight method.
[0089]
The photoelectrons 112 emitted from the sample surface pass through a flight tube covered with a magnetic shielding material 113 and then detected by a microchannel plate (MCP) 114 which is a photoelectron detector.
[0090]
The output signal is taken in as a digital signal by a high-speed digital oscilloscope (not shown), and the kinetic energy of photoelectrons is obtained by a calculator (not shown) from the detected value of the arrival time at the MCP.
[0091]
In addition, when one target substance contains multiple elements (for example, polyethylene (containing carbon and oxygen) or boron nitride (containing nitrogen and boron)), only the filter is used without replacing the target substance. The wavelength of the extracted X-ray may be changed by exchanging.
[0092]
The X-ray condensing element used in the present embodiment is a Walter type mirror that utilizes total reflection of X-rays, and the reflectance does not change much even if the wavelength of the X-rays changes. Even when the wavelength of the X-ray is changed, the X-ray optical element can be used without replacement.
[0093]
Similarly, an oblique incidence mirror (for example, a Kirkpatrick type) using total reflection may be used.
[0094]
If an optical element using a multilayer mirror (for example, a Schwarzschild mirror or an elliptical mirror) is used, the condensing element may be exchanged for each X-ray wavelength selected by the filter.
[0095]
In addition, a divergent magnetic field (P. Kruit and FHRead, J. Phys. E, 16, 1983, p313) as reported by P. Kruit and FHRead is added to the sample and flight tube section described above. As a result, most of the photoelectrons emitted from the sample can be captured, and the measurement time can be greatly shortened.
[0096]
Further, by arranging an electrode for reducing the speed of photoelectrons in the flight tube section, it is possible to lengthen the arrival time to the photoelectron detector and increase the energy resolution.
[0097]
Furthermore, when the time-of-flight method is used as the photoelectron detection method in this way, since the LPX is a pulse X-ray source, an instantaneous electron spectrum of the sample can be obtained.
[0098]
  In this embodiment, a solid thin film is used for the filter, but this may be a gas (for example, nitrogen gas, xenon gas, etc.).
[0099]
  In the case of using a gas, the wavelength of the X-ray to be selected (taken out) may be changed by changing the type of gas.
[0100]
【The invention's effect】
As described above, according to the photoelectron spectrometer of the present invention, the measurement time can be shortened.
[0101]
  In addition, X-rays having several wavelengths can be selected and irradiated on the sample, and an electronic spectrum can be obtained using a plurality of wavelengths.
[0102]
  Therefore, peak interference due to photoelectrons and Auger electrons on the electron spectrum can be solved. In addition, since the escape depth of photoelectrons from the sample surface depends on the kinetic energy of photoelectrons, analysis in the depth direction is also possible.
[0103]
  Furthermore, the irradiation target substance that can excite the inner shell electrons when irradiated with X-rays differs depending on the wavelength of X-rays to be irradiated. Therefore, when a plurality of values are used as the wavelengths of irradiated X-rays, Different substances of interest corresponding to the wavelength can be observed.
[0104]
In addition, the photoelectron spectrometer of the present invention can efficiently detect photoelectrons emitted from a minute region of a sample when an analysis mechanism related to the time-of-flight method is provided as an analysis mechanism for performing photoelectron energy analysis. Measurement time can be further shortened.
[0105]
Further, when LPX, which is a pulse X-ray source, is combined with a time-of-flight method, an instantaneous photoelectron spectrum can be obtained, so that a transient chemical state can be analyzed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a photoelectron spectrometer according to an embodiment.
[Explanation of main part codes]
100 ... pulse laser
101, 102 ... Vacuum container
103 ... Laser light
104 ... Lens
105 ... window
106 ... Tape-like target member
107 ... Plasma
108 ... X-ray
109 ... X-ray transmission filter holder
110 ... Walter mirror (an example of an X-ray optical element)
111 ... Sample
112 ... Photoelectron
113 ... Magnetic shielding material
114... Microchannel plate (an example of a photoelectron detector)
115 ... X-ray transmission filter
116 ... Straight line introduction machine
117 ... reel
A: Movement direction of X-ray transmission filter holder (109)
B: Movement direction of the tape-like target member (106)
a ... Tape-like substrate (polyethylene)
b: Boron nitride thin film layer
c ... Teflon(Registered trademark)Thin film layer

Claims (5)

A laser plasma X-ray source for condensing and irradiating the target member with pulsed laser light to form plasma, and extracting X-rays from the plasma;
A filter for monochromatic X-rays emitted from the laser plasma X-ray source,
In a photoelectron spectrometer for identifying the type or chemical bonding state of atoms or molecules constituting the sample by analyzing the energy of photoelectrons emitted from the sample surface when the sample is irradiated with X-rays,
The filter is formed by forming a thin film of filter material on a support film,
The target member is a sheet-like member in which a plurality of different target substances are each formed in a strip shape and arranged in parallel,
A photoelectron spectrometer comprising a switching mechanism for moving the sheet-like member in the parallel direction and switching a target substance irradiated with the pulsed laser light. The photoelectron spectrometer according to claim 1,
A photoelectron spectrometer comprising a moving mechanism for moving the sheet-like member in a direction perpendicular to the parallel direction and in an extending direction of the target substance formed in a band shape. The photoelectron spectrometer according to claim 1 or 2,
The sheet-like member is obtained by forming a thin film layer of the target substance in a band shape on a sheet-like substrate, respectively. The photoelectron spectrometer according to claim 3,
A photoelectron spectrometer characterized in that a sheet-like substrate is exposed in a strip shape so as to be juxtaposed with a strip-shaped target substance formed on the sheet-like substrate. In the photoelectron spectrometer according to any one of claims 1 to 4,
  A photoelectron spectrometer comprising an analysis mechanism relating to a time-of-flight method as an analysis mechanism for performing energy analysis of the photoelectrons.

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