JP5234946B2 - Spectroscopic method and spectroscopic apparatus for ion energy - Google Patents

Description

  The present invention relates to a material surface analysis means using an ion beam. Specifically, the present invention is an instrument that measures ion energy scattered on a material surface with high resolution, and measures material composition analysis and film thickness. The present invention relates to an ion scattering spectrometer capable of measuring a light element depth profile with high sensitivity.

  In the measurement of scattered ions by an ion beam, as is known by Rutherford backscattering spectroscopy ("RBS" method), the energy of the scattered ions can interact with the nuclei of the elements in the film on the sample surface. . In addition, the energy of scattered ions from the element inside the sample is attenuated by the interaction between the incident ion beam and the electron cloud before and after the collision of the element. By measuring and analyzing the scattered ion energy based on these incident uniform ion energies, the thickness of the sample surface and the concentration distribution of elements in the depth direction can be examined. Similarly, an ion scattering spectroscopic method that measures the concentration distribution of the recoiled element in the depth direction by recoiling the light element in the sample with the incident ion beam and spectroscopically analyzing the energy of the recoiled ion. Is known as the “ERDA (Elastic Recoil Detection Analysis)” method. This “ERDA” method is intended for analysis of light elements in a sample and can use the same apparatus configuration as the “RBS” method. However, the measurement principle is different from the “RBS” method, and scattered primary ions ( Rather than measuring the energy of the beam ions), the irradiated surface of the sample is placed at an angle with respect to the primary incident ions (incident ion beam) and is ejected by the primary incident ions (incident ion beam). This is a measurement technique in which energy is given to light element ions that are lighter than the primary ions in the sample and the energy of the light element ions that jump out of the sample is subjected to energy spectroscopy.

In the method of splitting the scattered energy and splitting the scattered energy using the RBS method, as shown schematically in FIG. 8, instead of the semiconductor detector 29 conventionally used as a spectral means, polarized light is used. By using the electromagnet 30 and the (ion) position detector 31, the target is smaller in the depth direction of the sample, that is, in units of nanometers or angstroms than in the case of performing spectroscopy with a single semiconductor detector. A high-resolution RBS method (HRBS method) that can measure the concentration distribution (profile) in the depth direction of the element has been used. For example, in Patent Document 1 (see FIG. 1 of the same document), an electrostatic deflector corresponding to a magnetic field analysis tube 32 and a polarizing electromagnet is arranged in front of an ion position detector, and scattered incident ion energy. The trajectory is bent to remove scattered low-energy ions, and the scattered ions are held movable in a direction perpendicular to the plane on which the ion beam irradiation means, magnetic field analysis tube, and electrostatic deflector are located. Disclosed is an ion beam analyzer capable of performing precise measurement based on the principle of the RBS method, which can be detected by an ion detector to greatly reduce the measurement background noise derived from low-energy ions. Has been.
JP 2006-153751 A

  As in the case of the high-resolution RBS method, in the ERDA method, the trajectory of ion energy bounced by placing a deflecting electromagnet is bent, and energy spectroscopy is performed using a position detector (ion detector). In the depth direction of the sample, in the depth direction of the sample, that is, in the nanometer unit or angstrom unit, the depth direction of the target element is smaller than that in the case of performing spectroscopy using the semiconductor detector in the conventional ERDA method. A high-resolution ERDA method capable of measuring a concentration distribution (profile) has been used. In the ERDA method, since not only recoil ions but also primary incident ions enter the position detector, some separation means for excluding element ions other than light elements to be measured is required. Conventionally, as a separation means, a polymer film such as Mylar (for example, a polyester film thin film) or an aluminum thin film is installed on the front surface of the position detector, and primary ions (incident ions) or elements other than the measurement target A technique is used to prevent entry into the position detector. In order to improve the resolution in the sample depth direction, even in the above-mentioned high resolution ERDA method in which a deflecting electromagnet is arranged, the passing energy band by the deflecting electromagnet is used to shield and separate unnecessary ions mixed in primary ions (incident ions). The separation function due to the difference between the two and the parallel electrode on the rear surface of the deflecting electromagnet is applied, positive and negative voltages are applied, the ions of different masses are deflected by the electric field, and the ions entering the position detector are selected. .

In the ERDA method, since the element to be recoiled is an element that is lighter than the incident primary ion, when the He ion that has been conventionally used in the RBS method is used as the incident primary ion, the He is removed from the sample. H (hydrogen) ions that are lighter than the ions are recoiled. In order to separate the He of the incident primary ions, conventionally, only H (hydrogen) ions are used by using a separation means such as a Mylar film or an aluminum thin film whose film thickness is appropriately selected according to the energy of the incident primary ions. Is measured with a position detector. In the high resolution ERDA method in which a deflecting electromagnet is arranged and the element distribution is measured with high resolution in the depth direction of the sample, a thin film is not used as the separating means, and orbital deflection of recoil ions by the deflecting electromagnet is performed. Only hydrogen ions (H ⁺ ) are taken into the position detector by the deflection electrode provided on the rear surface of the deflection electromagnet. In this case, the ions that are lighter than the He ions are only H (hydrogen) ions, and since there are two types of elements that are scattered and recoiled, it is easy to separate them until they reach the position detector. A wide ion beam area up to low energy is used for recoil ion energy detection by a position detector. However, the high resolution ERDA method using the He ions as incident primary ions is limited to the analysis of only H (hydrogen) ions that are lighter than the He ions.

On the other hand, the ERDA method is used for the purpose of measuring an element recoiled other than hydrogen by using an element heavier than He as incident primary ions. In this case, various ions are used as the types of incident primary ions (example). For example, in Non-Patent Document 1, a 16 MeV oxygen ion beam is used as incident primary ions (incident ion beam), and a 12.5 μm Mylar film is used as the above-described separation means, and iron containing light elements is used. The results of an experimental analysis of the boron layer on the substrate are shown. In the case of this analysis condition, the (energy) spectrum of the obtained light element (H) overlaps with the (energy) spectrum of the other element (B), and if such an overlap occurs, the depth of the light element spectrum The direction profile cannot be measured accurately. This overlap is caused by expanding the energy region of each ion that is recoiled by changing the analysis conditions, such as increasing the energy of the incident primary ions and using heavy incident ions. Has been shown to be resolved. Therefore, conventionally, the ERDA method for measuring elements other than hydrogen is limited to a light element measurement method in which the energy of incident primary ions is limited to a high energy ion scattering region in units of MeV. It was.
P. Goppelt-Langer, et.al: Nucl. Instr. Meth. Phys. Res, vol. B118 (1996), P. 251

  As described above, although measurement needs such as concentration distribution in the sample depth direction are high for light elements, the measurement sensitivity is small in the measurement of scattered ions by the RBS method, and the measurement sensitivity in ion recoil particle measurement by the ERDA method. However, a device for accelerating heavy incident ions in units of MeV is required, and the depth resolution obtained under such analysis conditions is at most about several hundred to several tens of nm. In addition, in order to improve the resolution in the depth direction of the sample from angstroms to smaller resolutions in units of nanometers, a high resolution ERDA method in which a magnetic field type deflection electromagnet is arranged is used to make nitrogen ions as incident ions and 500 keV. Even in hydrogen analysis using a low incident ion energy of 1 MeV or less, the mass of each recoiled light element is close, so even if the sample contains several light elements, it will recoil Currently, only recoil hydrogen atoms can be separated from the energy of light elements and ions.

  Therefore, an object of the present invention is to use an incident ion heavier than He and measure a light element having an atomic number of 1 to 9 within a range of incident ion energy as low as 1 MeV or less by a ERDA method. An ion energy spectroscopic method and a spectroscopic device capable of quantitatively measuring a concentration profile in the depth direction with high sensitivity and high accuracy in a short time.

  In order to solve the above problems, the present invention employs the following configuration.

The ion energy spectroscopic method according to claim 1 is directed to irradiating an object to be measured with an ion beam emitted from an ion generator, and to scatter the energy spectrum of ions scattered or recoiled by using a deflection electromagnet and an ion detector. In the ion energy spectroscopic method of measuring using an ion beam, the ion beam is an ion of an element having a mass larger than that of the element to be dispersed, and when measuring the energy spectrum of the ion, the exit side of the deflection electromagnet forming an electric field by the deflection electrodes provided on this electric field thus scattering or scattering and recoiling ions deflected separated, and the front of the ion detector, by providing a thin film for ion separation The ion incident on the ion detector is separated and selected.

The ion energy spectroscopic method according to claim 1 measures an energy spectrum of ions rebounded by irradiating a measurement object with an ion beam emitted from an ion generator, using a deflection electromagnet and an ion detector. In the ion energy spectroscopic method, the element to be subjected to the spectroscopic method is a light element of any of atomic numbers 1 to 9, and the ion beam is an ion of an element having a mass larger than that of the element to be spectroscopically targeted. When measuring the energy spectrum of the ions, the irradiation surface of the object to be measured is inclined with respect to the irradiation direction of the ion beam, and an electric field is formed by the deflection electrode provided on the exit side of the deflection electromagnet , separated by deflecting the recoil ions by the electric field, and the by a thin film for ion separation provided on the front of the ion detector Wherein the selecting by separating the ions incident on the on the detector.

  The ion energy spectroscopic method according to claim 3 is characterized in that the ion detector is a position detector using a multichannel plate or an array type semiconductor detector capable of position detection.

  The ion energy spectroscopic method according to claim 4 is characterized in that the ion energy of the ion beam is 1 MeV or less.

  In the ion energy spectroscopic method according to claim 5, the ions of the ion beam include helium (He), neon (Ne), argon (Ar), rare gas elements such as krypton (Kr), nitrogen (N), oxygen ( It is a gas element of O) or an ion of carbon (C).

The ion energy spectroscopic device according to claim 6 scatters by irradiating an object with an ion beam emitted from an ion source including an ion source and an acceleration tube for accelerating ions by a high voltage generator, or In an ion energy spectrometer that measures the energy spectrum of scattered and recoiled ions using a deflecting electromagnet and an ion detector, a deflecting electrode is provided on the exit side of the deflecting electromagnet, and ions are placed in front of the ion detector. When a separation thin film is provided and the energy spectrum of the ions is measured, an electric field is formed by the deflection electrode provided on the exit side of the deflection electromagnet, and the measurement is performed from scattered or scattered and recoiled ions. It is characterized in that ions are separated and selected.

The ion energy spectroscopic device according to claim 7 is recoiled by irradiating the object to be measured with an ion beam emitted from an ion source including an ion source and an acceleration tube for accelerating ions by a high voltage generator. In an ion energy spectroscopic device that measures the energy spectrum of ions to be measured using a deflecting electromagnet and an ion detector, a means for holding the irradiation surface of the object to be measured tilted with respect to the irradiation direction of the ion beam is provided. A deflection electrode is provided on the exit side of the deflection electromagnet, and a thin film for ion separation is provided in front of the ion detector to measure the energy spectrum of the ions, provided on the exit side of the deflection electromagnet. forming an electric field by the deflection electrodes, the scattered ions of recoil ions and the ion beam is selected to separate the recoil ions to be measured And said that there was Unishi.

  The ion energy spectrometer according to claim 8 is characterized in that the ion detector is a position detector using a multichannel plate or an array type semiconductor detector capable of position detection.

  The ion energy spectrometer according to claim 9 is characterized in that the high voltage generator has a power generation capacity in which the maximum energy of the ion beam emitted from the ion generator is 1 MeV.

  The ion energy spectroscopic device according to claim 10 is characterized in that the thin film for ion separation is an ultrathin film composed of light elements whose film constituent elements and compositions are known.

  In the ion energy spectroscopic device according to claim 11, the Mylar film is mounted on a mounting frame along an outer periphery thereof, and a vacuum vessel in which the position detector is disposed can be evacuated via a gate valve. The mylar membrane is moved to the membrane exchange space by the transfer rod while connected to the membrane exchange space provided with the transfer rod and kept in vacuum at the time of membrane exchange, and the vacuum vessel is evacuated by the vacuum gate valve. While holding, the membrane exchange space is opened to the atmosphere and the mylar membrane is taken out and exchanged in the atmosphere. After the exchanged mylar membrane is inserted into the membrane exchange space, the membrane exchange space is evacuated and the vacuum The gate valve is opened, and the exchanged Mylar film is placed in a vacuum container kept in a vacuum state by a transfer rod.

  In the present invention, since the deflecting electromagnet and the deflecting electrode are provided on the exit side of the scattered ions or recoil ions, and the thin film for ion separation is provided in front of the position detector, the incident ions of 1 MeV or less are low. In the energy range, scattered ions or recoil ions can be separated and their spectra can be selected, so that the element profile (concentration distribution) in the depth direction of the light elements of atomic numbers 1 to 9 to be measured is highly sensitive and high. It becomes possible to measure in a short time with accuracy.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. This embodiment is an example that embodies the present invention, and does not limit the technical scope of the present invention.

  FIG. 1 shows an entire ion energy spectrometer according to an embodiment of the present invention. In the accelerator tank 1, an ion source 2, a high voltage generator 3 capable of generating a voltage of 1 MV, an accelerator tube 4, and an accelerator terminal held at a high voltage that can be set continuously and variably from 1 MV to about 100 kV 5 and a container 6 filled with ion gas is connected to the ion source 2. The ion beam 7 emitted from the accelerator terminal 5 disposed at the exit side of the ion source 2 and maintained at a high voltage in the range of about 1 MV to 100 kV is accelerated by the acceleration tube 4 and is arranged on the downstream side of the beam line. After being separated from the impurity ions by the filter 8 and the beam size being shaped by the slit 9, the shaped beam size is further narrowed down by the electrostatic Q lens 10 as necessary. The sample (object to be measured) 12 is irradiated.

  On the exit side of the analysis chamber 11, there is disposed a detection port 13 set so that scattered ions of the irradiation beam colliding with the element nucleus of the sample 12 are detected at a detection angle θa (≈90 °). A deflection electromagnet 16 in which an electromagnetic magnet coil 15 is held by a yoke 14 is disposed on the exit side of the detection port 13. A position detector 17 is disposed on the exit side of the deflection electromagnet 16. A deflection electrode 18 is provided between the deflection electromagnet 16 and the position detector 17, and a thin film made of, for example, a polyester film is provided on the front surface of the position detector 17 in order to remove ions that are not subject to spectroscopy. Ion separation means 19 such as (for example, Mylar membrane) is provided. As the ion separation means 19 used in the present invention, an ultrathin film composed of a light element having a known film constituent element and composition can be applied. Examples of the light element include H, C, O, and N, as well as elements having an atomic number of up to about 14, such as Be, Al, and Si.

The ion beam 7 irradiated to the sample 12 in the analysis chamber 11 collides with the nucleus of the element of the sample 12, and the scattered ions due to this collision pass through the detection port 13 set at the detection angle θa and are deflected electromagnets 16. The orbit is bent by the magnetic field generated by the electromagnetic magnet coil 15. Among the scattered ions, the higher energy ions are less bent and the lower energy ions are bent more rapidly, so that the position reaching the position detector 17 reflects the energy level of the scattered ions. . In the deflection electrode 18, scattered ions that become noise are distributed, and the separating means 19 can pass only scattered ions having a predetermined mass and having energy of a predetermined level or higher. From the count of the number of scattered ions at the position reaching the detector 17, the spectral height of the ions to be dispersed can be obtained.
Note that, by reducing the detection angle θa, the position detector 17 can detect recoil ions as well as scattered ions.

  FIG. 2 shows an ion beam recoil spectrometer (ERDA method) according to another embodiment. In this spectroscopic device, the sample 12 is placed in the analysis chamber 11 with respect to the beam irradiation direction so that light elements in the sample 12 are likely to recoil by irradiation with an ion beam emitted from an ion source (not shown). The sample 12 is set with the detection angle θb smaller than the detection angle θa shown in FIG. 1, for example, θb tilted to about 30 ° from the irradiation direction. The detection port 13 is selected from the detection ports 13 provided on the outer periphery of the analysis chamber 11 so as to be detected at the detection angle θb (≈30 °), and an electrostatic Q lens is provided on the exit side of the detection port 13. 10, a deflection electromagnet 16 is disposed on the exit side of the electrostatic Q lens 10, and position detection is performed on the exit side of the deflection electromagnet 16, as in the case of the ion energy spectrometer shown in FIG. 1. A vessel 17 is arranged. A deflection electrode 18 is provided between the deflection electromagnet 16 and the position detector 17, and a thin film (for example, a polyester film) is formed on the front surface of the position detector 17 in order to remove ions that are not subject to spectroscopy. For example, ion separation means (not shown) such as a Mylar membrane) is provided.

A light element having atomic numbers 1 to 9 in the sample 12 is irradiated by an ion beam of an element having a mass larger than that of the light element ions, which is irradiated on the sample 12 in the analysis chamber 11 and is a measurement target in the sample 12. The recoil ions of this light element pass through the detection port 13, the divergence angle is narrowed by the electrostatic Q lens 10 and enters the deflecting electromagnet 16, and the high resolution RSB analysis by the spectroscopic device shown in FIG. As in the case, the trajectory of recoil ions is bent and dispersed. The deflecting electromagnet 16 receives not only the recoil ions but also scattered ions of the irradiated ion beam at the same time, so that the deflecting electromagnet 16 receives orbital deflection different from the recoil ions depending on its energy, ion charge and mass. Although some of the scattered ions are removed by this orbital deflection, the deflection electrode 18 is provided in order to completely separate from the recoil ions. FIG. 3 shows that a recoil ion of a light element (hydrogen (H)) and a scattered ion (carbon (C ⁺ , C ²⁺ )) having a mass larger than that of the light element are separated by the deflection electrode 18. It is shown schematically. Only the recoil ions (H ⁺ ) of the light element to be measured enter the position detector 17, and scattered ions (C ⁺ , C ²⁺ ) that become noise are distributed and do not enter the position detector 17. . In this way, as in the case of the above-described high resolution RSB, the spectral height of the element ions to be measured is obtained from the count of the number of recoil ions at the position reaching the position detector 17.

  Scattered ions or recoil ions measured by the above-described high resolution RBS method or high resolution ERDA method are scattered by the energy of the incident ions, the scattering angle or recoil angle, the type of the incident ions, the element configuration of the object to be measured, etc. It enters the deflection electromagnet 16 (see FIGS. 1 and 2) with energy or recoil energy. The incident ions receive an electromagnetic force generated by e (ion charge amount) / m (ion mass) under the action of the magnetic field of the deflecting electromagnet 16, and each energy of the incident scattered ions or recoil ions ( The incident trajectory is bent for each ion velocity). As a result of bending the trajectory, when a position detector 17 having a multi-channel plate (MCP) is used as an ion detector, the position detector 17 measures ions incident on different positions. Thus, the position corresponding to the energy entering the deflection electromagnet 18 is measured, and the ion energy is measured by measuring the position. However, as in the present invention, when the incident ion energy is as low as 1 MeV and the measurement target element is a light element having atomic numbers 1 to 9, scattered ions or recoil ions entering the deflection electromagnet 16 are not generated. In the energy possessed by the magnetic field, the difference in electromagnetic force corresponding to the energy of the ions that can be received by the magnetic field e (ion charge amount) / m (ion mass) is not so great that the position change due to the orbital curvature can be clearly detected. Therefore, the scattered ions or recoil ions to be measured cannot be separated and selected only by the deflection electromagnet 16 and the deflection electrode 18 provided on the exit side thereof.

  Table 1 shows the magnetic field strength of the deflecting electromagnet necessary for measuring He ions when the He ions in the measurement object are measured with the incident ions being nitrogen ions (monovalent) and the incident ion energy being 500 keV and 400 keV. The calculation example of the energy which each light element ion has when the other light element ion described in Table 1 other than He ion passes the same track | orbit of the said deflection electromagnet is shown. From Table 1, the energy difference between hydrogen ions and other light element ions including He ions is clear for any incident ion energy, but the energy difference between other light element ions including He ions is clear. Is smaller than for hydrogen ions. This can be applied to the separation of the lightest light element from other light elements only by arranging a deflecting electromagnet and a deflecting electrode. , Removal, or detection of elements between recoil ions.

In addition, as shown in FIG. 4, the divalent and trivalent incident nitrogen ions that recoil He ions can be separated and removed under the conditions optimized by the above calculation so that other light elements do not enter. It has also been found that the ions N ⁺² and N ⁺³ are mixed with scattered ions, and e (ion charge amount) among light ions whose orbits are determined by the above-mentioned ratio of e (ion charge amount) / m (ion mass). The increase in the value of) means that the same trajectory is taken even if the mass of the incident ions is large, and it was found that separation and removal of these scattered ions is necessary.

  In the present invention, as shown in FIGS. 1 and 2, a thin film, for example, a Mylar film, which is a polyester film film, is installed as the ion separation means 19 before the position detector 17. In order to select an appropriate film thickness of this mylar film, several types of mylar films having different film thicknesses are prepared in advance so that only ions having a predetermined energy or higher of a predetermined ion species can pass through. By selecting a Mylar film and placing it in front of the position detector 17, if the ions have low energy, they cannot pass through the film thickness and are stopped by the Mylar film and removed. Even if the ion has a large energy, if the ion has a large mass, the energy loss at the time of passing through the film is large, so that the ion cannot stop and pass through the Mylar film. In addition, there are various cases in which the type of scattered ions mixed into ions to be measured and ions to be removed or recoil ions, and their energy, charge and mass are different. Therefore, depending on the ions to be measured and the measurement conditions, the setting conditions of the object to be measured such as the type of incident ions, the energy of the incident ions, the detection angle, the magnetic field strength of the deflecting magnet, the electric field strength of the deflecting electrode, and the Mylar film Thickness selection is necessary.

  FIGS. 5A and 5B show recoil ion spectra when the measurement target ion is boron (B), which is a light element, in the high resolution ERDA apparatus shown in FIG. ) Is the spectrum when the Mylar membrane of the ion separation means 19 is not installed before the position detector 17, and (b) is the spectrum when the Mylar membrane is installed. Table 2 shows the spectrum measurement conditions for recoil ions. In Table 2, the beam incident angle is an angle from the normal line of the sample (measurement object) irradiation surface.

  From FIG. 5 (a), when the Mylar film is not installed, the atomic number is 1 in the spectrum of boron (B) to be measured, which remains on the surface of the object to be measured, rather than boron (B). The spectrum of carbon (C), which is a light element that is as large as possible, overlaps, but from FIG. 5 (b), when the Mylar film is installed, only the spectrum of boron (B) as the measurement target is detected. I understand.

  Since the Mylar film is a thin film having a thickness of μm, care must be taken in handling, and the Mylar film must have a uniform surface with respect to the incidence of scattered ions and recoil ions. In addition, the ions to be measured collide with the ions inside the Mylar film due to the incidence of the ions, and the target ions to be selectively passed also cause energy attenuation due to the collision and diffusion of the deflection trajectory due to scattering. It is desirable to install it just before the position detector. For this reason, a Mylar film mounting frame is prepared in advance, and can be attached or detached immediately before the position detector (how many types of position detectors are available). FIG. 6 shows a mechanism for attaching / detaching the Mylar film immediately before the position detector. The mylar film 19a is mounted on a frame 20 along the outer periphery thereof, and the frame 20 on which the mylar film 19a is mounted is detachably supported by a support base 21. The position detector 17 is disposed in a vacuum vessel 22 provided with a load lock mechanism (not shown). The vacuum vessel 22 communicates with a vacuum exhaust port 24 via a gate valve 23 and can be evacuated. It has become. The lower side of the gate valve 23 is connected to a membrane exchange space 25 where the Mylar membrane 19 a is attached to and detached from the frame 20, and a transfer rod 26 is disposed below the membrane exchange space 25. Due to the expansion and contraction of the transfer rod 26, the frame 20 attached with the mylar film 19a and supported by the support base 21 can move up and down between the vacuum vessel 22 and the membrane exchange space 25. An opening 25a for taking out the frame 20 to the atmosphere at the time of membrane exchange is provided on the side surface of the membrane exchange space 25. The opening 25a is hermetically sealed by a lid 28 having an opening / closing bolt 27. Open and close as possible. At the time of exchanging the Mylar membrane 19a, the gate valve 23 is opened, the vacuum vessel 22 and the membrane exchange space 25 are opened in a vacuum state, and the transfer rod 26 is pressed against the support 21 by the tip of the rod. Then, the rod 26 is contracted and the support base 21 is lowered to the membrane exchange space 25 with the mylar membrane 19a attached, and the gate valve 23 is closed, and the vacuum state of the vacuum vessel 22 is maintained. . Then, the lid 27 of the membrane exchange space 25 is opened, the frame 20 is taken out into the atmosphere, the mylar membrane 19a is exchanged, and then the frame 20 with the updated mylar membrane 19a attached is inserted into the membrane exchange space 25. The space 25 sealed with the lid 27 is evacuated. Thereafter, the gate valve 23 is opened, the vacuum vessel 22 and the membrane exchange space 25 are opened, the transfer rod 26 is extended, and the support base 21 together with the frame 20 with the mylar membrane 19a attached is attached to the predetermined inside of the vacuum vessel 22. The mylar film 19 a is disposed immediately before the position detector 17. In this way, the mylar film can be exchanged without opening the atmosphere while maintaining the vacuum degree of the vacuum vessel 22. When this film exchange mechanism is used to prepare mylar films with various film thicknesses on the mounting frame 20, similar to the change of the operating parameters, it is possible to change the film conditions easily, and in the object to be measured. It is possible to separate and remove various interfering elements and impurity elements present in the measurement condition of the measurement target element can be set efficiently, and the setting time can be shortened.

  As the ion detector, by using an array type semiconductor detector in which semiconductor detection elements are arranged in a one-dimensional direction on a substrate by a microfabrication technique, the positions of scattered ions and recoil ions entering the detector Ion energy and ion counting can be performed simultaneously. FIG. 7 is a spectrum of light element recoil ions when Ar ions are used as incident ions. Thus, even when the position is converted into energy and plotted on the horizontal axis and the count is plotted on the vertical axis and the spectrum is displayed, the ion energy of each can be measured independently, so that the ion species can be distinguished. If necessary, it is possible to remove the spectrum of any light element from the spectrum of each measured light element, so there is no need to provide a thin film for ion separation, such as the Mylar film, before the position detector. However, ions that are not to be measured can be separated and removed.

It is explanatory drawing which shows the structure of the spectrometer of ion energy of embodiment of this invention. It is explanatory drawing which shows the structure of the spectrometer of ion energy of other embodiment. It is explanatory drawing which shows typically the condition which isolate | separates the light element made into the measuring object from a scattered ion with a deflection | deviation electrode. It is explanatory drawing which shows an example in which the spectrum of a recoil ion and a scattering ion is mixed. It is explanatory drawing which shows distribution of the recoil ion spectrum by the presence or absence of the installation of a Mylar film. It is explanatory drawing which shows the structure of the attachment or detachment mechanism of a mylar film. It is explanatory drawing which shows the spectrum of the recoil ion of a light element at the time of using a semiconductor detector. It is explanatory drawing which shows typically the spectroscopy method of a prior art.

Explanation of symbols

1: Accelerator tank 2: Ion source 3: High voltage generator 4: Acceleration tube 5: Accelerator terminal 6: Ion gas container 7: Ion beam 8: Vienna filter 9 Slit 10: Electrostatic Q lens 11: Analysis chamber 12: Sample (object to be measured)
13: Detection port 14: Yoke 15: Electromagnetic magnet coil 16: Deflection magnet 17: Position detector 18: Deflection electrode 19: Ion separation means 19a: Mylar membrane 20: Frame 21: Support base 22: Vacuum vessel 23: Gate valve 24 : Vacuum exhaust port 25: Membrane exchange space 25a: Opening 26: Transfer rod 27: Opening / closing bolt 28: Cover

Claims (11)

In an ion energy spectroscopic method in which an ion beam emitted from an ion generator is irradiated on an object to be measured, and an energy spectrum of ions scattered or scattered and recoiled is measured using a deflecting electromagnet and an ion detector. The ion beam is an ion of an element having a mass larger than that of an element to be dispersed, and when measuring the energy spectrum of the ion, an electric field is formed by a deflection electrode provided on the exit side of the deflection electromagnet , the front of the electric field thus scattering or scatters and deflects the recoil ions separated, and the ion detector, by providing a thin film for ion separation, to separate the ions incident on the ion detector Ion energy spectroscopic method, characterized by screening. An ion energy spectroscopic method for measuring the energy spectrum of ions recoiled by irradiating an object with an ion beam emitted from an ion generator using a deflecting electromagnet and an ion detector. The element to be is a light element of any of atomic numbers 1-9, the ion beam is an ion of an element having a mass larger than the element to be dispersed, and when measuring the energy spectrum of the ion, The irradiation surface of the object to be measured is inclined with respect to the irradiation direction of the ion beam, an electric field is formed by a deflection electrode provided on the exit side of the deflection electromagnet, and ions recoiled by the electric field are deflected. separated, and be screened to separate the ions incident on the ion detector by a thin film for ion separation provided on the front of the ion detector Ion energy method spectroscopy, characterized in that.   3. The ion energy spectroscopic method according to claim 1, wherein the ion detector is a position detector using a multi-channel plate or an array type semiconductor detector capable of position detection.   The ion energy spectroscopic method according to claim 1, wherein the ion energy of the ion beam is 1 MeV or less.   The ions of the ion beam are helium (He), neon (Ne), argon (Ar), krypton (Kr) rare gas element, nitrogen (N), oxygen (O) gas element, or carbon (C). The ion energy spectroscopic method according to claim 1, wherein the ion energy spectroscopic method is any one of the ions. An energy spectrum of ions scattered or scattered and recoiled by irradiating an object with an ion beam emitted from an ion generator equipped with an ion source and an acceleration tube that accelerates ions by a high-voltage generator. In an ion energy spectrometer that measures using a deflection electromagnet and an ion detector, a deflection electrode is provided on the exit side of the deflection electromagnet, a thin film for ion separation is provided in front of the ion detector, and the energy of the ions When measuring a spectrum, an electric field is formed by a deflection electrode provided on the exit side of the deflection electromagnet, and ions to be measured are separated and selected from scattered or scattered and recoil ions. Characteristic ion energy scattering spectrometer. An ion source and an ion beam emitted from an ion generator equipped with an accelerating tube that accelerates ions by a high-voltage generator irradiates the object to be measured, and the energy spectrum of the rebounded ion is detected by a deflecting magnet and ion detection. In an ion energy spectroscopic device that measures using a measuring instrument, the ion energy spectroscopic device is provided with means for tilting and holding the irradiation surface of the object to be measured with respect to the irradiation direction of the ion beam, and a deflection electrode is provided on the exit side of the deflection electromagnet And, when a thin film for ion separation is provided in front of the ion detector and the energy spectrum of the ions is measured, an electric field is formed by the deflection electrode provided on the exit side of the deflection electromagnet, and recoil ions And recoil ions to be measured are separated and selected from the scattered ions of the ion beam. Light equipment.   8. The ion energy spectroscopic apparatus according to claim 6, wherein the ion detector is a position detector using a multi-channel plate or an array type semiconductor detector capable of position detection.   9. The ion energy spectroscopic device according to claim 6, wherein the high voltage generator includes a power generation capacity in which the maximum energy of an ion beam emitted from the ion generator is 1 MeV.   The ion energy spectroscopic apparatus according to claim 6, wherein the ion separation thin film is an ultrathin film having a film constituent element and a composition composed of known light elements.   The ultra-thin film is attached to a mounting frame along the outer periphery thereof, and the vacuum vessel in which the position detector is arranged is connected to a membrane exchange space portion having a transfer rod that can be evacuated through a gate valve. The membrane exchange space is opened to the atmosphere while the mylar membrane is moved to the membrane exchange space by the transfer rod while the vacuum is maintained at the time of membrane exchange, and the vacuum vessel is held in vacuum by the vacuum gate valve. The mylar membrane is taken out into the atmosphere and exchanged. After the exchanged mylar membrane is inserted into the membrane exchange space, the membrane exchange space is evacuated, the vacuum gate valve is opened, and the exchange is performed by the transfer rod. 11. The ion energy spectroscopic device according to claim 10, wherein the mylar film is disposed in a vacuum container maintained in a vacuum state.

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