Electrostatic deflection and focusing type energy analyzer, imaging type electron spectrometer, reflection imaging type electron spectrometer, and spin vector distribution imaging device

Abstract

Provided is an electrostatic deflection convergence-type energy analyzer that has a wide acceptance angle and high two-dimensional convergence performance, is capable of imaging a two-dimensional real-space image and an emission angle distribution, and enables two-dimensional convergence and imaging at 90°deflection with respect to an incident direction. One or a plurality of outer electrodes and a plurality of inner electrodes are disposed along the shapes of two rotating bodies formed on the inside and the outside of a common rotating axis. The inner-surface shape of the outer electrode has a tapered shape becoming smaller in diameter toward both ends. The outer-surface shape of the inner electrodes has a tapered shape becoming smaller in diameter toward both ends. An electron incident hole and exit hole are formed in each of the outer electrodes at both ends on the rotating axis. The outer electrode and the inner electrodes have applied thereto voltages for accelerating and decelerating electrons in proportion to the energy of incident electrons. One or a plurality of electrodes except for the inner electrodes at both ends have applied thereto a voltage that is at least twice a converted acceleration voltage obtained by converting the energy of electrons into an acceleration voltage with reference to the potential of the outer electrode having the incident hole formed therein.

Description

[Technical field]

[0001] The present invention relates to photoelectron spectroscopy devices such as UPS (Ultraviolet Photoelectron Spectroscopy), XPS (X-ray Photoelectron Spectroscopy), and ARPES (Angle Resolved Photoelectron Spectroscopy), Auger electron spectroscopy devices, photoelectron diffraction devices, photoelectron microscopes, and spin polarization analysis devices. [Background technology]

[0002] In electron spectroscopy, sensitivity is one of the most important performance characteristics along with energy resolution. When measuring photoelectrons or Auger electrons, if the signal is weak and almost completely buried in noise, it is necessary to significantly increase the accumulation time to obtain a sufficient signal-to-noise ratio. However, this not only makes the measurement inefficient, but it is often necessary to limit the continuous measurement time due to time constraints such as the usage time of the synchrotron radiation facility and the duration of the excitation light source. In addition, for samples that are easily damaged by radiation, such as organic materials, or samples that are easily changed over time, long-term measurements are prevented, and in many cases, the weak signals are not fully captured. In addition, advanced doping techniques are used in research into new semiconductor and superconducting materials, and it is known that even minute amounts of dopants can bring about large changes in the materials. Capturing such weak signals from dopants is extremely important in the development of new materials.

[0003] Electron spectroscopy can measure the energy distribution of electrons emitted from a sample, as well as the emission angle distribution. The energy distribution measurement provides information on the elemental composition, while the emission angle distribution measurement provides information on the composition and electronic state in the depth direction. In addition, since the momentum in the in-plane direction of the sample is conserved during the photoelectron emission process, information on the momentum of electrons in a material can be obtained by measuring the kinetic energy and emission angle of the photoelectrons. By irradiating a sample with ultraviolet or X-rays and adjusting the energy to the valence band to measure the kinetic energy and emission angle distribution of the photoelectrons, the energy band structure of the material can be evaluated and the properties of the material can be roughly determined.

[0004] Furthermore, when the kinetic energy of photoelectrons emitted from the inner shell exceeds several hundred eV, a strong peak called the forward convergence peak appears in the direction connecting the photoelectron-emitting atom and the scattering atoms around it. By measuring this peak over a wide angular range, it is possible to directly capture the atomic arrangement around a specific atom. It is also possible to calculate the interatomic distance from the diameter of the diffraction ring formed around the forward convergence peak. As described above, the measurement of the emission angle distribution using an electron spectrometer makes it possible to obtain detailed information at the atomic level that is difficult to obtain using other analytical methods, and is a very powerful method for developing new materials and researching the mechanisms behind unknown physical properties.

[0005] However, while the widely used electrostatic hemispherical energy analyzer (hereafter referred to as CHA) has high energy resolution, the input lens has a small acceptance angle, making it difficult to use it for two-dimensional photoelectron spectroscopy or atomic structure analysis, which acquires emission angle distributions over a wide solid angle. In addition, the coaxial cylindrical mirror energy analyzer (hereafter referred to as CMA), which is widely used mainly for Auger electron spectroscopy, is known as an analyzer with a large acceptance solid angle, but its acceptance angle is still insufficient for the above analysis.

[0006] Therefore, a two-dimensional spherical mirror analyzer with an acceptance angle of ±60° was developed (Non-Patent Document 1), and band dispersion structure measurements (Non-Patent Documents 2 and 3) and atomic arrangement structure measurements (Non-Patent Documents 4 and 5) were performed on various samples. Although the energy resolution of this analyzer was improved stepwise through improvements, it was not possible to achieve sufficient resolution for more detailed analysis, such as structural analysis with chemical shift resolution. Therefore, a spherical aberration correction lens with an acceptance angle of ±45° to ±50° was invented (Patent Documents 1 and 2, Non-Patent Documents 6 and 7), and an attempt was made to combine it with the input lens of a CHA (Non-Patent Document 8). Recently, the present inventors have proposed a spherical aberration correction lens with a full angle (±90°) acceptance (Patent Document 3). In the ultraviolet light region of several tens of eV or less, a full angle acceptance photoelectron analyzer has already been developed using PEEM (photoelectron microscope) technology (Non-Patent Documents 9 and 10).

[0007] The above-mentioned CHA is already widely used, and various designs of devices have been developed so far. However, one feature is that the acceptance angle in the energy dispersion direction of the electrostatic hemisphere is very small. As a result, to obtain high energy resolution, the incidence angle on the electrostatic hemisphere must be kept to about ±2° or less. To obtain high spatial resolution and high angular resolution in the measurement of two-dimensional real space images and emission angle distribution, the incidence angle on the electrostatic hemisphere must be kept to about ±2° or ±1° or less. Therefore, in the development of high-performance analytical devices using CHA, it is necessary to design the input lens system on the premise that the acceptance angle of the electrostatic hemisphere is very small. With conventional input lenses using normal electrostatic lenses, whose spherical aberration increases with the incidence angle, the acceptance angle at which a convergent beam can be formed is limited to about ±7°. In this case, the convergence angle can be made about ±2° at a relatively low magnification. Here, the magnification (M) is defined as M=b / a, where a is the size of the observed object on the object plane (sample plane) of the input lens, and b is the size of the image of the observed object on the image plane of the input lens. In the case of an Einzel-type lens, where the energy of the electrons does not change at the entrance and exit of the lens, this value is roughly the ratio of the angle of incidence to the angle of convergence. The magnification of the input lens is one of the important conditions that determine the sensitivity of the CHA, and if this magnification is set high, the sensitivity will decrease significantly depending on the size of the slit provided at the entrance of the electrostatic hemisphere. Therefore, in the conventional input lens mentioned above, the magnification is usually set low. For example, in the case of an Einzel-type lens, when electrons with an opening angle of ±7° are converged at an opening angle of ±2°, a low magnification of about 3.5 is sufficient.

[0008] On the other hand, in order to efficiently measure the emission angle distribution in a wide angle range, as described above, spherical aberration correction lenses with an acceptance angle widened to about ±50° have been developed (Patent Documents 1 and 2, Non-Patent Documents 6 and 7), and the inventors have also proposed a full-angle (±90°) acceptance converging lens. The full-angle acceptance converging lens makes it possible to realize an analyzer that completely determines the energy and momentum of electrons. However, when designing an input lens system that accepts electrons at a wide angle using such a wide-angle acceptance converging lens and converges them at an opening angle of about ±2° or less, there are problems in that the magnification becomes very high compared to conventional input lenses and the length of the lens system becomes quite long. For example, when electrons are accepted at an acceptance angle of ±50° or ±90° and converged at an opening angle of ±2°, the irradiation spot on the sample is enlarged to about 25 times or 45 times at the exit surface of the wide-angle acceptance converging lens even without deceleration. Furthermore, when decelerating electrons of energy E to energy E' in order to obtain high energy resolution, the magnification M can be expressed by the following formula according to the law of constancy of brightness: Here, M0 is the magnification determined by the angle of incidence and the angle of emergence.

[0009]

number

[0010] For example, when 1000 eV electrons are decelerated to 50 eV using the above lens, the magnification is about 100 to 200 times. When the magnification is increased in this way, the number of electrons blocked by the slit inserted at the entrance of the electrostatic hemisphere increases, and the slit width must be widened to obtain sufficient sensitivity. However, widening the slit width results in a decrease in energy resolution. In most conventional CHAs, the magnification of the input lens is about 5 times or less.

[0011] The best way to solve this problem is to widen the acceptance angle of the energy analyzer. One might consider using a CMA with a larger acceptance angle instead of the electrostatic hemisphere of the CHA. However, the CMA uses grids at the entrance and exit of the inner cylinder through which the electrons pass, and the electrons are scattered when passing through these entrances and exits, which causes their trajectories to become distorted. This makes it difficult to image the real space or angular distribution with high resolution using the CMA. As described above, to realize a high-performance electron spectrometer that can form a real spatial image or an angular distribution, an energy analyzer with an acceptance angle wider than the electrostatic hemisphere of the CHA without using a grid is required.

[0012] Next, in addition to measuring the energy and momentum of electrons, we will explain the measurement of electron spin, which can affect the properties of substances and materials. Spin polarization analysis devices include the Mott detector and SPLEED detector that utilize spin-orbit interaction, and the VLEED detector that utilizes spin exchange interaction (Non-Patent Document 11). In recent years, a two-dimensional spin analyzer using an Ir (001) single crystal substrate has also been developed (Non-Patent Document 10). In addition, by combining a conventionally known electrostatic 90° deflector with a magnetic field lens type spin rotator (hereinafter referred to as a spin rotator), it is possible to measure the spin polarization in three directions, including within the sample plane and perpendicular to the plane (Patent Document 5). However, the conventional electrostatic 90° deflector does not have the imaging performance to converge the beam two-dimensionally, and there is a problem that it cannot be applied to a two-dimensional spin analysis device that closely examines the real space image and the emission angle distribution.

[0013] The spin polarization in the direction perpendicular to the sample surface can be measured by bending the trajectory of the electrons emitted from the sample by 90° in an electric field before they enter the spin detector, and this method has already been realized by combining a quarter-cylindrical electrostatic 90° deflector (hereinafter referred to as a 90° deflector) (Non-Patent Document 11) with a VLEED detector. In addition, in the 90° deflector, the electrons are deflected by 90° in an arc under the condition that the central force and centrifugal force due to the cylindrical electric field are balanced, but it is also possible to deflect the electrons by 90° using a spherically symmetric electric field instead of a cylindrical electric field, and a spin polarization analysis device using this 90° deflector (hereinafter referred to as a 90° spherical deflector) has also become possible (Non-Patent Document 12).

[0014] However, in the cylindrically symmetric electric field used in the 90° deflector and the spherically symmetric electric field used in the 90° spherical deflector, the convergence in the deflection plane is at 127° deflection and 180° deflection, respectively, and does not converge at 90° deflection. Therefore, an improved 90° deflector that can deflect and converge an electron beam emitted from one point in the deflection plane direction by 90° (Non-Patent Document 13) and a 90° deflection analyzer that enables 90° deflection and convergence in the deflection plane direction by combining a 90° spherical deflector with a lens have also been proposed (Non-Patent Document 14). However, among the electrons incident at a certain opening angle, while it is possible to converge the electrons in the deflection plane direction, there is a problem that it is not possible to converge the electrons in other directions at the same time, and it is difficult to apply it to two-dimensional spin analysis that forms a two-dimensional real space image and an emission angle distribution.

[0015] It is important to have imaging capabilities for two-dimensional real space images and emission angle distributions in order to perform detailed analysis of spin polarization. Although the two-dimensional spin analyzer disclosed in Non-Patent Document 10 enables two-dimensional analysis of spin polarization in the in-plane direction of the sample, two-dimensional analysis of spin polarization perpendicular to the sample has not yet been realized. It is expected that detailed analysis of spin polarization perpendicular to the sample will be indispensable in the future in spintronics research on high-density magnetic memory devices and the like. As described above, in order to perform two-dimensional analysis of spin polarization perpendicular to the sample, it is effective to deflect the electrons emitted from the sample by 90° in an electric field before they are incident on the two-dimensional spin detector. However, when a conventional electrostatic 90° deflector is used, there is a problem that the convergence is only in the in-plane direction of the deflection, there is no two-dimensional imaging capability, and two-dimensional position and angle information is lost.

[0016] On the other hand, it is also possible to perform three-dimensional measurement of spin polarization using a Wien filter type spin rotation device instead of an electrostatic 90° deflector (see, for example, Patent Document 4 and Non-Patent Document 15). In particular, the spin rotation device shown in Patent Document 4 enables three-dimensional manipulation of spins by a multipole Wien filter. The Wien filter is an energy analyzer that utilizes the fact that when electrons are injected into orthogonal electric and magnetic fields, the force from the electric field and the force from the magnetic field (Lorentz force) are balanced and only electrons of a certain energy move in a straight line. In this analyzer, the electrons injected at a certain aperture angle can be focused by adjusting the voltage applied to the electric field forming electrodes and the voltage (or current) applied to the electromagnets. The Wien filter also has the effect of rotating the spin of electrons, and by appropriately adjusting the applied voltage (or current), the spin along the optical axis can be rotated to a direction perpendicular to the optical axis.

[0017] However, the conditions for converging an electron beam emitted from one point and for rotating the spin by 90° do not match, and if the Wien filter is set to the latter condition, the electron beam cannot be converged at the exit. Therefore, although Wien filter-type spin rotation devices are used in photoelectron microscopes and other devices to observe real space images of the 3D resolution of the spin polarization of a parallel electron beam, it is difficult to apply them to 2D analytical devices that can image both 2D real space images and emission angle distributions. Therefore, in order to obtain both a 3D spin-resolved 2D real space image and emission angle distribution, it is necessary to deflect the electron direction by 90° and at the same time provide a converging and imaging effect not only in the direction within the deflection plane but also in the direction perpendicular to it. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] Patent No. 4802340 [Patent Document 2] Patent No. 4900389 [Patent Document 3] Patent application 2019-227788 [Patent Document 4] International Publication Pamphlet WO2012 / 173007 [Patent Document 5] International Publication Pamphlet WO2012 / 066024 [Non-patent literature]

[0019] [Non-Patent Document 1] H. Daimon, “New display-type analyzer for the energy and the angular distribution of charged particles”, Rev. Sci. Instrum. 59, 545 (1988). [Non-Patent Document 2] F. Matsui, et al., “Three-dimensional band mapping of graphite”, Appl. Phys. Lett. 81, 2556 (2002). [Non-Patent Document 3] F. Matsui, et al., “Atomic-orbital analysis of the Cu Fermi surface by two-dimensional photoelectron spectroscopy”, Phys. Rev. B 72, 195417 (2005). [Non-Patent Document 4] F. Matsui, T. Matsushita and H. Daimon, “Stereo atomscope and diffraction spectroscopy-Atomic site specific property analysis”, J. Electron Spectrosc. Relat.Phenom. 178-179, 221 (2010). [Non-Patent Document 5] F. Matsui, et al., “Selective detection of angular-momentum-polarized Auger electrons by atomic stereography”, Phys. Rev. Lett. 114, 015501 (2015). [Non-Patent Document 6] H. Matsuda, H. Daimon, M. Kato and M. Kudo, “Approach for simultaneous measurement of two-dimensional angular distribution of charged particles: Spherical aberration correction using an ellipsoidal mesh”, Phys. Rev. E 71, 066503 (2005). [Non-Patent Document 7] H. Matsuda and H. Daimon, “Approach for simultaneous measurement of two-dimensional angular distribution of charged particles. II. Deceleration and focusing of wide-angle beams using a curved mesh lens”, Phys. Rev. E 74, 036501 (2006). [Non-Patent Document 8] H. Matsuda, et al., “Development of display-type ellipsoidal meshanalyzer: Computational evaluation and experimental validation”, J. Electron Spectrosc. Relat. Phenom. 195(2014) 382. [Non-Patent Document 9] M. Kotsugi et al., “Microspectroscopic two-dimensional Fermi surface mapping using a photoelectron emission microscope”, Rev. Sci. Instrum., 74, 2754 (2003). [Non-Patent Document 10] C. Tusche et al., “Spin resolved bandstructure imaging with a high resolution momentum microscope”, Ultramicroscopy 159, 520 (2015). [Non-Patent Document 11] T. Okuda, et al., J. Electron Spectrosc. Relat. Phenom. 201, 23 (2015). [Non-Patent Document 12] E. Kisker, et al., Rev. Sci. Instrum. 50, 1598 (1979). [Non-Patent Document 13] L.Vattuone, M.Rocca, “Electrostatic electron analyzer with 90° deflection angle”, Rev.Sci. Instrum.73 3861 (2002). [Non-Patent Document 14] AW Ross, et al., J. Electron Spectrosc.Relat. Phenom. 69, 189 (1994). [Non-Patent Document 15] T. Kohashi, et al., “A spin rotator used for detecting all three magnetization vector components in spin-polarized electron microscopy”, J. Mag. Soc. Jpn. 18, 7 (1994). Summary of the Invention [Problem to be solved by the invention]

[0020] In view of the above circumstances, a first object of the present invention is to provide an electrostatic deflection and focusing type energy analyzer that can perform analysis with high energy resolution even when the acceptance angle is wider than that of the electrostatic hemispherical portion of a CHA. A second object of the present invention is to provide an imaging electron spectrometer that enables imaging of a two-dimensional real space image and an emission angle distribution with high energy resolution. A third object of the present invention is to provide a spin polarization analysis instrument that can measure the spin polarization in the direction perpendicular to the sample surface by deflecting electrons emitted from the sample by 90° in an electric field before they are incident on the two-dimensional spin detector, in addition to two-dimensional analysis of the spin polarization in the in-plane direction of the sample, thereby enabling three-dimensional measurement of the spin polarization. If these challenges can be resolved, it will be possible to provide a groundbreaking analytical tool for detailed analysis of the three physical quantities of electrons (energy, momentum, and spin). [Means for solving the problem]

[0021] In order to solve the above problems, the electrostatic deflection and focusing type energy analyzer of the present invention has the following features 1) to 7). 1) One or more outer electrodes and multiple inner electrodes are arranged along the shapes of two rotating bodies formed on the inside and outside with a common rotating shaft. Here, the two rotating bodies formed on the inside and outside with a common rotating shaft have a configuration in which the outer rotating body encompasses the inner rotating body. 2) An electron entrance hole and an electron exit hole are formed on the rotation axis of the electrodes at both ends of the outer electrode. 3) A voltage application means is provided for applying voltages to the outer electrode and the inner electrode to accelerate and decelerate electrons. Here, a voltage for accelerating and decelerating electrons may be applied to the outer electrode and the inner electrode in proportion to the energy of the incident electrons. 4) The inner surface of the outer electrode has a shape that tapers toward the entrance hole and toward the exit hole. Here, the shape of the inner surface shape of the outer electrode that becomes smaller in diameter toward the entrance hole is preferably a tapered shape, a toroidal surface shape, or a ring shape, and the shape of the inner surface shape of the outer electrode that becomes smaller in diameter toward the exit hole is preferably a tapered shape, a toroidal surface shape, or a ring shape. 5) The outer surface shape of the inner electrode is a shape that becomes smaller in diameter toward the entrance hole, a rod shape extending toward the entrance hole, or a shape that widens in diameter at the end on the entrance hole side, and a shape that becomes smaller in diameter toward the exit hole, a rod shape extending toward the exit hole, or a shape that widens in diameter at the end on the exit hole side. Here, the shape of the outer surface of the inner electrode that becomes smaller in diameter toward the entrance hole is preferably a tapered shape or a toroidal surface shape, or a step shape that becomes smaller in diameter in stages toward the entrance hole, and the shape that becomes smaller in diameter toward the exit hole is preferably a tapered shape or a toroidal surface shape, or a step shape that becomes smaller in diameter in stages toward the exit hole. The inner surface shape of the outer electrode and the outer surface shape of the inner electrode are basically the same on the entrance hole side and the exit hole side, but they do not necessarily have to be the same and may be different shapes. For example, various combinations are possible, such as a tapered shape on the entrance hole side and a ring shape on the exit hole side. In addition, a step shape in which the diameter gradually decreases includes, for example, a case in which an electrode with a small diameter is placed in the center, but the diameter is reduced by just one step near the entrance hole.

[0022] 6) The voltage application means in 3) applies a voltage to one or more inner electrodes excluding the electrodes at both ends of the inner electrode that is at least twice, and preferably at least 2 to 5 times, the converted acceleration voltage obtained by converting the energy of electrons into an acceleration voltage, based on the potential of the outer electrode in which the entrance hole is formed. The converted acceleration voltage is defined as a voltage obtained by converting the energy of electrons into an acceleration voltage. For example, the converted acceleration voltage of 1 eV is 1V. The voltage 2 to 5 times or more of the converted acceleration voltage is a voltage of 2E to 5EV or more when the energy of electrons is EeV. Here, the voltage applied to one or more inner electrodes excluding the electrodes at both ends of the inner electrode is preferably set to a voltage 10 times or more of the converted acceleration voltage obtained by converting the energy of electrons into an acceleration voltage, based on the potential of the outer electrode in which the entrance hole is formed. For example, a high voltage of 10 kV or more is set for an electron energy of 1000 eV. This is because the angle of incidence to the energy analysis unit can be further widened, the magnification of the input lens for wide-angle capture can be further reduced, the sensitivity in wide-angle capture can be further increased, and the energy resolution can be further improved. 7) A voltage is applied to each electrode so that the electrons entering through the entrance hole are converged to the position of the exit hole at a predetermined exit angle with the rotation axis so that the central orbit forms a predetermined entrance angle with the rotation axis.

[0023] According to the electrostatic deflection and focusing type energy analyzer having the above features 1) to 7), by optimizing the shape, arrangement, and applied voltage of each electrode, it becomes possible to perform energy analysis by capturing electrons at a larger capture angle than the electrostatic hemispherical part of the CHA and deflecting and focusing them without using a grid. That is, by using the electrostatic deflection and focusing type energy analyzer of the present invention instead of the electrostatic hemispherical part of the CHA, it is possible to widen the incident angle to the energy analysis part by about three times, which makes it possible to reduce the magnification of the input lens for wide-angle capture to about 1 / 3 and increase the sensitivity in wide-angle capture to about 9 times, thereby improving the energy resolution.

[0024] In the electrostatic deflection and convergence type energy analyzer of the present invention, when the inner surface shape of the outer electrode and the outer surface shape of the inner electrode have a tapered shape that becomes smaller toward the entrance hole and the exit hole, the taper angle measured from the rotation axis may be the same on the entrance hole side and the exit hole side. Also, the inner surface shape of the outer electrode and the outer surface shape of the inner electrode may be symmetrical with respect to a plane that intersects the line connecting the entrance hole and the exit hole at the midpoint of the line perpendicularly to the line. For example, the outer electrodes and the inner electrodes may be arranged along the shapes of two rotating bodies obtained by rotating the lower bases of two isosceles trapezoids that have different heights and a common symmetry plane about a common rotation axis, and symmetrical with respect to the symmetry plane.

[0025] In the electrostatic deflection and focusing type energy analyzer of the present invention, the voltage applied to one or more inner electrodes excluding the electrodes at both ends of the inner electrode is 10 to 50 times the converted acceleration voltage obtained by converting the electron energy into an acceleration voltage. Furthermore, when the outer electrode is composed of three or more electrodes, the voltage applied to one or more of the outer electrodes excluding the electrodes at both ends is preferably 10 times or less the reduced acceleration voltage.

[0026] In the electrostatic deflection focusing energy analyzer of the present invention, the deflection angle is preferably 90°. The electrostatic deflection focusing energy analyzer of this embodiment may be referred to as a "90° electrostatic deflection focusing energy analyzer" below. The 90° electrostatic deflection focusing energy analyzer of this embodiment can achieve 90° deflection by an electrostatic field and two-dimensional focusing and imaging. As described later, particularly in spin analysis, it is possible to achieve two-dimensional focusing and imaging by bending the traveling direction by 90° without changing the direction of spin, and to obtain a spin-resolved two-dimensional real space image and emission angle distribution. The incidence angle is not particularly limited, but may be 45° incidence angle, 45° emission angle, and 90° deflection angle.

[0027] The electrostatic deflection and focusing type energy analyzer of the present invention may have any of the following deflection angles. By optimizing the shape, arrangement, and applied voltage of each electrode, it is possible to design an energy analyzer having any deflection angle in the range of 45° to 180°. Some examples are given below. The specified angle of incidence is 22.5° and the deflection angle is 45°. The specified angle of incidence is 30° and the deflection angle is 60°. The specified angle of incidence is 60° and the deflection angle is 120°. The specified incidence angle is 67.5° and the deflection angle is 135°. The specified incidence angle is 75° and the deflection angle is 150°. The incident angle is not particularly limited, and the incident angle and the exit angle may be adjusted so that the deflection angle is an angle between 45°, 60°, 120°, 135°, 150°, or any angle between 45° and 180°.

[0028] In the electrostatic deflection and focusing type energy analyzer of the present invention, the inner electrode may be divided into two parts so that the electrons on the central orbit can pass across the rotation axis, and by changing the voltage conditions applied to the electrodes, it may be possible to control whether the central orbit crosses the rotation axis, thereby making it possible to switch between deflection and non-deflection of the electrons emerging from the exit hole. A feature of this analyzer is that the inner electrode is separated into two parts (the entrance side and the exit side), and as a result, electrons can pass through the space between the left and right inner electrodes across the rotation axis. By changing the voltage conditions applied to the electrodes, it is possible to control whether electrons pass through the space between the left and right inner electrodes or not, and thereby to switch between deflection and non-deflection of the outgoing electrons. Such an electrostatic deflection focusing type energy analyzer may be referred to as a "deflection-switching electrostatic focusing type energy analyzer" hereinafter.

[0029] In the electrostatic deflection and focusing type energy analyzer of the present invention, the rotor may be a rotor having a rotation angle of 90° to 180°, and a compensation electrode for compensating the electric field at the cut surface may be provided. As described later, as long as a mirror or the like is not placed at the position of the emission hole to reflect electrons, the rotor may not be a 360° rotor, but may be a 180° rotor or a rotor having any rotation angle, and the electrostatic field may be used to realize deflection, two-dimensional focusing, and imaging.

[0030] Next, the imaging electron spectrometer of the present invention will be described. The imaging electron spectrometer of the present invention is an electron spectrometer that uses the electrostatic deflection-focusing energy analyzer of the present invention described above, and by providing an input lens in front of the analyzer and a projection lens and a detector in the rear of the analyzer, it is possible to measure not only a real space image of the sample, but also a two-dimensional emission angle distribution over a wide angle at once with high energy resolution. Here, the input lens has an entrance hole for the energy analyzer on its lens axis, and is arranged so that the lens axis and the rotation axis of the energy analyzer form a predetermined incident angle, and captures electrons emitted from the sample and emits them to the entrance hole. Note that it is preferable for the input lens to have a function of switching between an angular distribution and a real space image. The projection lens has an exit hole for the energy analyzer on the projection lens axis, and is arranged so that the projection lens axis and the rotation axis of the energy analyzer form a specified exit angle, and takes in electrons deflected and focused by the energy analyzer from the exit hole. The detector detects the electrons that have passed through the projection lens in two dimensions and measures a two-dimensional real space image or emission angle distribution. It is preferable to provide an aperture or a slit at the entrance hole (inlet) and the exit hole (outlet) of the energy analyzer.

[0031] Furthermore, the reflective imaging electron spectrometer of the present invention is an electron spectrometer that uses the electrostatic deflection focusing type energy analyzer of the present invention described above (excluding those with a 180° rotator), and is a reflective type energy analyzer that can measure not only a real space image of the sample but also a two-dimensional emission angle distribution over a wide angle at once with high energy resolution by providing an electron reflection mirror at the exit hole of the energy analyzer and providing a front-stage input lens, a rear-stage projection lens and a detector at the entrance hole of the energy analyzer. The input lens has the entrance hole of the energy analyzer on the lens axis, and is positioned so that the lens axis and the rotation axis of the energy analyzer form a specified angle of incidence, capturing electrons emitted from the sample and sending them out to the entrance hole. The mirror is positioned so that the direction of the perpendicular to the exit hole of the energy analyzer coincides with the direction of the rotation axis. A single crystal mirror can be used as the mirror, and in particular, a spin analysis function can be obtained by using an Ir(001) single crystal mirror. The projection lens has an entrance hole on the projection lens axis, and is positioned so that the projection lens axis and the rotation axis of the energy analyzer form a specified incident angle, and electrons that are deflected and focused by the energy analyzer, reflected by a mirror, and then deflected and focused again are taken in from the entrance hole. The detector detects the electrons that have passed through the projection lens in two dimensions, and measures a two-dimensional real space image or emission angle distribution. It is preferable to provide an aperture or a slit at the entrance hole (which serves as both the entrance and exit) of the energy analyzer.

[0032] Next, the spin vector distribution imaging device of the present invention will be described. A spin vector distribution imaging device according to a first aspect of the present invention comprises a 90° electrostatic deflection and focusing type energy analyzer of the present invention (a rotor having a rotation angle of 90° to 180°, including an energy analyzer provided with a compensation electrode that compensates for the electric field at the cut surface) having a deflection angle of 90°, and further comprises the following configurations 1a) to 1d). 1a) An input lens has an entrance hole for an energy analyzer on the lens axis, and is positioned so that the lens axis and the rotation axis of the energy analyzer form a specified angle of incidence. It captures electrons emitted from the sample and outputs them to the entrance hole. 1b) An electrostatic lens in which the exit hole of the energy analyzer is located on the axis of the electrostatic lens and is positioned so that the electrostatic lens axis and the rotation axis of the energy analyzer form a specified exit angle, and which captures electrons deflected and focused by the energy analyzer through the exit hole. 1c) A two-dimensional spin filter placed on the axis of the electrostatic lens at the exit side of the electrostatic lens. 1d) A projection lens that captures the electrons reflected by the spin filter and a detector that detects the electrons that have passed through the projection lens.

[0033] Here, it is preferable to further add the following configurations 1e) and 1f) to the above configuration. 1e) A driving means for retracting the spin filter from the electrostatic lens axis. 1f) A second projection lens that captures electrons emitted by the electrostatic lens while the spin filter is retracted by the driving means, and a second detector that detects electrons that have transmitted through the second projection lens.

[0034] A spin vector distribution imaging apparatus according to a second aspect of the present invention comprises the above-mentioned 90° electrostatic deflection and focusing type energy analyzer of the present invention, and further comprises the following configurations 2a) to 2d). 2a) An input lens in which the entrance hole of the energy analyzer is placed on the lens axis and is positioned so that the lens axis and the rotation axis of the energy analyzer form a specified angle of incidence. The input lens captures electrons emitted from the sample and emits them to the entrance hole. 2b) A two-dimensional spin filter placed at the exit hole of the energy analyzer, perpendicular to the axis of rotation. 2c) A projection lens in which the entrance hole of an energy analyzer is placed on the axis of the projection lens and is positioned so that the projection lens axis and the rotation axis form a specified angle of incidence, and which takes in, through the entrance hole, electrons that are deflected and focused by the energy analyzer, reflected by the two-dimensional spin filter, and then deflected and focused again. 2d) A detector that detects electrons that have passed through the projection lens.

[0035] A spin vector distribution imaging device according to a third aspect of the present invention is a 90° electrostatic deflection and focusing type energy analyzer according to the present invention described above, which comprises an energy analyzer capable of switching the deflection angle, and further comprises the following configurations 3a) to 3f). 3a) An input lens, which has an entrance hole for an energy analyzer on the lens axis and is positioned so that the lens axis and the rotation axis of the energy analyzer form a specified angle of incidence, collects electrons emitted from the sample and emits them to the entrance hole. 3b) An electrostatic lens in which the exit hole of the energy analyzer is located on the axis of the electrostatic lens and is positioned so that the electrostatic lens axis and the rotation axis of the energy analyzer form a specified exit angle, and which captures electrons deflected and focused by the energy analyzer through the exit hole. 3c) A two-dimensional spin filter placed on the axis of the electrostatic lens at the exit side of the electrostatic lens. 3d) A first projection lens that captures electrons reflected by the two-dimensional spin filter, and a first detector that detects electrons that have transmitted through the first projection lens. 3e) A second projection lens, the exit hole of which is located on the axis of the projection lens and arranged so that the axis of the projection lens and the axis of rotation of the energy analyzer form a specified exit angle, which captures electrons converged by the energy analyzer through the exit hole without being deflected. 3f) A second detector that detects the electrons that have been transmitted through the second projection lens.

[0036] A spin vector distribution imaging device of a fourth aspect of the present invention is a spin vector distribution imaging device of any of the first to third aspects described above, but instead of using the 90° electrostatic deflection and focusing type energy analyzer of the present invention described above, a combination of multiple energy analyzers having deflection angles in the range of 45 to 150° is used to achieve a deflection angle of 90°.

[0037] In the spin vector distribution imaging device of the first to fourth aspects of the present invention, a spin rotator may be provided which is arranged inside or outside at least one of the input lens and the electrostatic lens and rotates spins by 90° in a plane perpendicular to each lens axis. By providing spin rotators (which rotate the spins by 90° in a plane perpendicular to the lens axis) at the front and rear of the 90° electrostatic deflection and focusing type energy analyzer, it is possible to determine which of the three directions of spin polarization within the sample plane and perpendicular to the plane to analyze by combining the ON / OFF states of the two spin rotators. This makes it possible to create a two-dimensional analysis device that analyzes three-dimensional spin polarization using a two-dimensional real space image and emission angle distribution. Effect of the Invention

[0038] The electrostatic deflection and focusing type energy analyzer of the present invention has the advantage of being able to capture electrons at a larger capture angle than the electrostatic hemispherical portion of the CHA without using a grid, deflecting and focusing the electron trajectory, and improving the energy resolution. The imaging electron spectrometer of the present invention has the advantage that it can measure not only a real space image of a sample but also a two-dimensional emission angle distribution over a wide angle at once with high energy resolution. The spin vector distribution imaging device of the present invention has an advantage that it is possible to analyze three-dimensional spin polarization using a two-dimensional real space image and emission angle distribution. [Brief description of the drawings]

[0039] [Figure 1] Schematic diagram of the electrostatic deflection and focusing type energy analyzer of the first embodiment [Diagram 2] A graph showing the aperture aberration of the electrostatic deflection and focusing type energy analyzer of the first embodiment and a graph showing the relationship between the angle of incidence and the angle of emergence. [Diagram 3] FIG. 1 is an explanatory diagram of energy dispersion in the electrostatic deflection and focusing type energy analyzer of the first embodiment. [Figure 4] Two-dimensional real space image of the electrostatic deflection and focusing type energy analyzer of Example 1 [Diagram 5] Diagram of the shapes of the outer and inner electrodes of an electrostatic deflection and focusing type energy analyzer [Figure 6] FIG. 2 is an explanatory diagram of an imaging electron spectrometer according to a second embodiment of the present invention; [Figure 7] Cross-sectional view of 360° and 180° rotating electrostatic deflection and focusing type energy analyzer [Figure 8] Configuration diagram of a reflective imaging electron spectrometer according to the third embodiment [Figure 9] Configuration diagram of a spin vector distribution imaging device according to the fourth embodiment [Figure 10] FIG. 13 is a diagram showing the configuration of a spin vector distribution imaging device according to the fifth embodiment. [Figure 11] FIG. 6 is an explanatory diagram of a switching type electrostatic deflection and focusing type energy analyzer according to the sixth embodiment. [Figure 12] FIG. 14 is an explanatory diagram of electron trajectories under other voltage conditions of the switching type electrostatic deflection and focusing type energy analyzer of the sixth embodiment. [Figure 13] FIG. 13 is an explanatory diagram of a spin vector distribution imaging device according to the seventh embodiment. [Figure 14] An explanatory diagram of a 90° electrostatic deflection and focusing type energy analyzer that combines an energy analyzer with a deflection angle of β1 and an energy analyzer with a deflection angle of β2 (Example 8) [Figure 15] Diagram of the combination that realizes a 90° electrostatic deflection and focusing type energy analyzer (when β1=β2) [Figure 16] Schematic diagram of the combination conditions for realizing a 90° electrostatic deflection and focusing type energy analyzer. (a) When β1=β2, (b) When β1≠β2 [Figure 17] Schematic diagram of an electrostatic deflection and focusing type energy analyzer with deflection angles of 45° and 60° [Figure 18]Diagram of a two-stage combination electrostatic deflection and focusing type energy analyzer: (a) a combination of two 45° electrostatic deflection and focusing type energy analyzers; (b) a combination of two 60° electrostatic deflection and focusing type energy analyzers. [Figure 19] Illustrative diagram of electrostatic deflection and focusing type energy analyzer with deflection angles of 120°, 135°, and 150° [Figure 20] Schematic diagram of a conventional electrostatic hemispherical energy analyzer (CHA) [Figure 21] Graph showing aperture aberration of CHA [Figure 22] Point source image of the electrostatic hemisphere of the CHA [Diagram 23] Schematic diagram of a prior art Concentric Mirror Analyzer (CMA) [Figure 24] Graph showing aperture aberration of CMA [Diagram 25] Schematic diagram of a prior art VLEED detector [Figure 26] Schematic diagram of a conventional spin-resolved electron spectroscopy device [Figure 27] Schematic diagram of another prior art spin-resolved electron spectroscopy device. [Figure 28] Schematic diagram of the spin polarization analyzer using a 90° spherical deflector [Figure 29] Improved 90° deflector diagram [Diagram 30] Combination of 90° spherical deflector and lens [Diagram 31] Illustration of spin rotation by multipole Wien filter [Diagram 32] 9 is an explanatory diagram of an electrostatic deflection and focusing type energy analyzer according to the ninth embodiment. [Diagram 33] FIG. 10 is an explanatory diagram of an electrostatic deflection and focusing type energy analyzer according to a tenth embodiment of the present invention. [Diagram 34] FIG. 11 is an explanatory diagram of an electrostatic deflection and focusing type energy analyzer according to the eleventh embodiment. [Diagram 35] Graph showing aperture aberration of the electrostatic deflection and focusing type energy analyzer of Example 11 [Diagram 36] FIG. 12 is an explanatory diagram of an electrostatic deflection and focusing type energy analyzer according to the twelfth embodiment. BEST MODE FOR CARRYING OUT THEINVENTION

[0040] First, the basic structure and measurement principle of conventional CHA and CMA, which are standard energy analyzers for photoelectron spectroscopy and Auger electron spectroscopy, are explained, and then the electrostatic deflection and focusing type energy analyzer of the present invention is explained in comparison with these analyzers. In addition, the structure of the conventional spin polarization analysis device is also explained below, and the features of the present invention are clarified by comparing it with the spin vector distribution imaging device of the present invention.

[0041] (1) About the Electrostatic Hemispherical Energy Analyzer (CHA) As shown in Figure 20, the CHA is an analyzer that uses the focusing effect of a spherically symmetric electric field, consisting of an input lens that takes in and focuses electrons (or charged particles) emitted from the sample, an electrostatic hemispherical section consisting of an inner sphere and an outer sphere, a slit at the entrance of the electrostatic hemispherical section, and a detector at the exit of the electrostatic hemispherical section. As shown in Figure 20, if the distance from the center O of the electrostatic hemispherical section to the central axis (optical axis) of the input lens is R0, in the case of an ideal spherically symmetric electric field, the electric potential at any point between the inner and outer spheres (distance r from O) is given by the following equation (1). Here, E pass is the pass energy of the electrostatic hemisphere, V0 is the electric potential at r = R0, and e is the elementary charge. The coefficient of the first term in formula (1) is determined by the condition of balance between the centrifugal force and the central force at the central orbit. The central orbit is the energy E k =E pass When the centrifugal force is stronger than the central force (i.e., E k >E pass When the central force is stronger (i.e., E k <E pass In the case of , the trajectory deviates inward. k =E pass The electron beam of E is detected by the detector after making a 180° turn around the center orbit and converging at the exit position.k E pass The electrons slightly higher than the center move away from the center O, k E pass The electrons slightly lower than the center of the electron beam have their focal point shifted toward the center O. Thus, the detector at the exit of the electrostatic hemisphere provides energy dispersion in the direction shown in Figure 20. Also, a one-dimensional real space image or emission angle distribution is obtained in the direction perpendicular to the paper.

[0042] In the schematic diagram of FIG. 20, an image plane is formed at the entrance slit position. In this case, a one-dimensional real space image is obtained in the direction perpendicular to the paper surface of the detector. If a diffraction plane is formed at the entrance slit position by switching the voltage applied to the input lens, a one-dimensional emission angle distribution is obtained in the direction perpendicular to the paper surface of the detector. In this way, a one-dimensional real space image or angle distribution can be selected by the entrance slit of the electrostatic hemisphere, and a one-dimensional real space image or emission angle distribution accompanied by energy dispersion can be obtained by the detector installed at the exit of the electrostatic hemisphere. In addition, if the energy is adjusted to a sharp photoelectron peak from the core level, the electrons entering the electrostatic hemisphere will have approximately a single energy, so it is also possible to widen the entrance slit to enter a two-dimensional real space image or angle distribution and display the image on the screen of the detector.

[0043]

number

[0044] The characteristics of the electrostatic hemisphere will be concretely shown by numerical values ​​below. First, the voltage applied to the inner and outer spheres of the electrostatic hemisphere will be shown. The radius R of the inner and outer spheres is determined by the design of the analyzer. in , R out (See Figure 20) and the central orbit radius R0 are determined, so the path energy E pass and the central orbit potential V0 can be determined according to the measurement. pass Once V0 is determined, the voltages applied to the inner and outer spheres can be calculated using the above formula (1). V0 is set to the same potential as the exit electrode of the input lens, and the reduction ratio of the input lens is changed (i.e., Epass In Fig. 20, the radius of the inner and outer spheres R in =0.75R0, R out = 1.25R0. In this case, the voltage V applied to the inner and outer spheres in and V out are expressed as the following equations (2) and (3), respectively. For simplicity, E pass If we take V0 as the reference, the voltages applied to the inner and outer spheres are approximately 667V and -400V, respectively. The energy of the electron (here, the pass energy E pass If we call the reduced accelerating voltage the voltage obtained by dividing e by the elementary charge e (i.e., converted into an accelerating voltage), then the absolute values ​​of the voltages applied to the inner sphere and outer sphere will be approximately 0.67 and 0.4 times the reduced accelerating voltage, respectively.

[0045]

number

[0046]

number

[0047] The electron trajectory of the electrostatic hemisphere shown in Figure 20 is the trajectory when the incidence angle α on the electrostatic hemisphere is limited to ±3°. To obtain high convergence at the exit of the electrostatic hemisphere, it is necessary to keep the incidence angle α small. The left panel of Figure 21 shows the result of trajectory calculation with the incidence angle α expanded to ±8°. Here, the central trajectory radius R0 is set to 100 mm. The upper right graph of Figure 21 shows the aperture aberration, and the lower right graph shows the relationship between the incidence angle α and the exit angle α'. According to theoretical calculations, the aperture aberration of the electrostatic hemisphere is given by the following equation (4).

[0048]

number

[0049] Here, O(α 4) is a summary of the higher-order terms of α. Figure 21 shows the calculation results of the aperture aberration (including higher-order terms) as well as an aberration curve (dashed line) approximated by only the first term on the right-hand side of the above formula (4). It can be seen that the two are in good agreement up to an incidence angle of about ±7° (=0.12 rad). α in formula (4) 2 The coefficient (-2R0) of the aperture aberration coefficient (hereafter, C A In the case of Figure 21, C A =-2R0=-200. As shown in Figure 21, the aperture aberration of the electrostatic hemisphere increases as the square of α, and when α=4°, an aberration of approximately 1 mm occurs for R0=100 mm. In this way, if the angle of incidence is not sufficiently limited, large aperture aberration occurs, making it difficult to obtain a two-dimensional real space image. Furthermore, as will be shown below, in order to obtain high energy resolution, it is necessary to suppress the aperture aberration by limiting the angle of incidence to a small value. An estimate of the energy resolution of the electrostatic hemisphere at full width at half maximum (FWHM) is given by Eq. (5) below.

[0050]

number

[0051] Here, α max is the maximum angle of incidence on the electrostatic hemisphere, and w is the width of the entrance and exit slits. The energy resolution defined in the above equation (5) represents the FWHM energy width that can be separated when electrons incident from an area of ​​width w are cut off by an area of ​​width w. The energy E pass When the intensity of the electrons is high, the slit width can be reduced to suppress the contribution of the slit width to the energy resolution, but otherwise the reduction in intensity prevents the slit width from being reduced sufficiently. Therefore, in many analyzers, the energy resolution is improved by increasing the central orbit radius R0. How small the slit width can be is dependent on the spot size or flux of the X-ray or electron beam irradiated on the sample and the magnification of the input lens.

[0052] In current photoelectron spectroscopy and Auger electron spectroscopy, the spot size of X-rays or electron beams on the sample can be about 10 to 100 μm, but here we will use a slightly larger size of 50 μm. If the magnification of the input lens is 5, the magnification of the electrostatic hemisphere is 1, so it seems appropriate to set the slit width to 0.25 mm. In this case, the contribution of the second term on the right-hand side of equation (5) is 1 / (8·R0). This contribution is 0.125×10 when R0=100 mm. -2 When R0 = 200 mm, it is 0.0625 × 10 -2 The first term on the right side of equation (5) is the incidence angle α max However, in this case, a significant decrease in strength is unavoidable. For example, max = If you change from ±3° to ±1°, the strength will decrease to about 1 / 9.

[0053] Table 1 below shows α max = ±2° to ±8°, the energy resolution of the electrostatic hemisphere is calculated using the first term on the right side of formula (5). In order to obtain high energy resolution while avoiding a significant decrease in intensity, the incidence angle α max It can be seen that it is necessary to set it to about ±2 (or ±3°).

[0054] [Table 1]

[0055] FIG. 22 shows the case where a 5×5 (1 mm pitch) point source is assumed on the incident surface of the electrostatic hemisphere, and the incident angle α max Over a solid angle range of energy E pass This is a two-dimensional real space image obtained at the exit of the electrostatic hemisphere when electrons of α max The angle ranges from ±1° to ±6°. Here, the coordinate x' is in the direction shown in FIG. 21, and the coordinate y' is in the direction perpendicular to the paper. α max As the aberration increases, the spatial resolution in the x' direction decreases significantly. maxIf α is within ±2°, a relatively good real space image can be obtained. max It can be seen that when the angle is set to ±4° or more, two point sources 1 mm apart are connected in the real space image and cannot be resolved. In order to obtain a two-dimensional real space image with high spatial resolution at the exit of the electrostatic hemisphere, it seems necessary to limit the angle of incidence on the electrostatic hemisphere to ±1° or ±2° or less. However, limiting the angle of incidence to ±1° or less causes a problem in that the intensity of the photoelectrons drops significantly.

[0056] (2) About the Concentric Mirror Analyzer (CMA) As shown in Figure 23, the CMA is an analyzer that uses the focusing effect of a cylindrically symmetric electric field, consisting of a coaxial cylinder consisting of an inner cylinder and an outer cylinder, a slit provided at the rear of the coaxial cylinder, and a detector. Here, the entrance and exit of the inner cylinder where the electrons enter and leave are cylindrical grids, which allow the electrons to pass through without destroying the cylindrically symmetric electric field. In the case of an ideal cylindrically symmetric electric field, the electric potential at any point (distance r from the central axis z) between the inner and outer cylinders of the CMA is expressed by the following equation (6).

[0057]

number

[0058] Here, E pass is the path energy of the CMA, R in is the radius of the inner cylinder, and e is the elementary charge. K is a parameter that determines the strength of the electric field, and in Figure 23, it is set to K = 1.31. The inner cylinder is usually set to ground potential, so in equation (6), r=R in In this equation, V(r)=0, but if you want to set an arbitrary potential on the inner cylinder, you can add that potential to equation (6). In FIG. 23, the ratio of the radii of the outer and inner cylinders is 2.66. In this case, the voltage applied to the outer cylinder is, from equation (6), E pass = 1000 eV, it is about -746 V. The energy of the electron E passIf the converted acceleration voltage is calculated by dividing by the elementary charge e, the absolute value of the voltage applied to the outer cylinder is approximately 0.75 times the converted acceleration voltage. The voltage applied to the inner cylinder is 0 times the converted acceleration voltage. The central orbit is the energy E k =E pass is the electron orbital. The angle of incidence of an arbitrary orbit into a cylindrically symmetric electric field is expressed as θ = 42.3° + α measured from the central axis z, and α is hereafter referred to as the incidence angle. An electron that enters a cylindrically symmetric electric field is subjected to a force toward the central axis z and changes direction, E k =E pass The electron orbital bundle of E passes through the exit grid with its central orbit forming an angle of 42.3° with the central axis z and converges at the slit position. Although not shown in the figure, the convergence point is E k >E pass On the right side, E k <E pass When , it moves to the left and E k If the gap is misaligned, the electrons will not be able to pass through the slit.

[0059] Figure 24 shows the relationship between the incidence angle α and the aperture aberration when the distance L between the origin on the sample and the point where the central orbit intersects with the z-axis is 275 mm (when L is set to 275 mm, the length of the central orbit from the origin to the slit position is almost the same as the length of the central orbit of the electrostatic hemisphere shown in Figure 21). Figure 24 also shows the results for K=1.33 and K=1.35 in addition to K=1.31. However, when K=1.33, L=279 mm, and when K=1.35, L=283 mm. When K=1.31 is set, α=0° becomes the stationary point, and the aberration is almost zero in the vicinity. Therefore, if you want to minimize the aberration, you can select K to 1.31 and limit the incidence angle. Conversely, if you want to increase the acceptance angle even at the expense of convergence, you should set K to a value slightly larger than 1.31 (for example, about 1.33). The value of K can be easily changed by the voltage applied to the outer cylinder. However, it should be noted that, as mentioned above, when the value of K changes, the value of L also changes. In other words, when the value of L changes, the optimal positions of the slit and detector change.

[0060] As can be seen by comparing the aperture aberrations shown in Figures 21 and 24, the cylindrically symmetric electric field used in the CMA has a stronger focusing effect than the spherically symmetric electric field used in the CHA. This is because the CMA has third-order aperture aberration, while the CHA has second-order aperture aberration. As a result, a high energy resolution is expected from the CMA, but in reality, the high energy resolution obtained with the CHA has not been achieved with the CMA. The reason for this is that the CMA uses two grid electrodes, and the electrons are scattered by the grid at the entrance and exit of the cylindrically symmetric electric field, resulting in a decrease in convergence. Thus, it is difficult for the CMA to achieve a high energy resolution like that obtained with the CHA. In addition, it is difficult for the CMA to obtain a high-resolution real space image and emission angle distribution due to the scattering effect of the grid.

[0061] (3) Conventional spin polarization analysis equipment Representative spin polarization analyzers include the Mott detector and SPLEED detector, which utilize spin-orbit interaction, and the VLEED detector, which utilizes spin exchange interaction. Recently, a two-dimensional spin analyzer using an Ir(001) single crystal substrate has been developed (Non-Patent Document 10). Figure 25 is a schematic diagram of a VLEED detector (Non-Patent Document 11). This spin polarization analyzer is a detector that utilizes the fact that when low-energy electrons are incident on a target magnetized by a coil, the intensity of the reflected electrons changes depending on whether the electron spin is parallel or anti-parallel to the magnetization of the target. A thin iron film is used as the target.

[0062] Figure 26 is a schematic diagram of a spin polarization analyzer that combines CHA and VLEED. z and z' are the optical axes between the sample and electrostatic hemisphere and between the electrostatic hemisphere and the target, respectively. The axes y and y' are taken along the direction connecting the center of the electrostatic hemisphere to the entrance or exit, and x and x' are perpendicular to z and y and z' and y', respectively. Since the CHA consists only of an electric field, the spin direction of an electron does not change when it passes through the CHA.

[0063] In the spin polarization analysis device in Figure 26, a coil is installed in the y' direction, allowing the measurement of spin polarization in the y direction within the sample plane. If it is also desired to measure spin polarization in the x direction using the spin polarization analysis device in Figure 26, the sample can be rotated 90° in the in-plane direction, but rotating the sample will cause even a slight shift in the measurement area. This can be a fatal problem in microarea analysis. An effective way to avoid this problem is to install a spin rotator that rotates the spins 90° in a plane perpendicular to the lens axis in the input lens or in the front stage of the spin analyzer. This allows the spins in the in-plane direction of the sample to be rotated by 90° in-plane without rotating the sample. In addition, in the case of a spin polarization analysis device using VLEED, coils that magnetize the target in two directions instead of a spin rotator are provided, and by switching the direction of magnetization, it is possible to measure the spin polarization in the x and y directions in the sample plane. However, none of the above methods can measure the spin polarization in the z direction. To measure the spin polarization in the z direction, it is effective to use a method in which the electron trajectory is bent by 90° with an electric field before the electrons enter the target.

[0064] Figure 27 is a schematic diagram of a spin polarization analyzer that performs spin analysis using this method. Here, the electron trajectory is bent by 90° in the z'y' plane, which makes it possible to measure the spin polarization in the direction perpendicular to the sample surface (z direction). A quarter-cylindrical electrostatic 90° deflector (90° deflector) as shown in Figure 27 is used to bend the electron trajectory by 90°. To measure the spin polarization in the x and y directions without rotating the sample, spin rotators are installed between the input lens and the electrostatic hemisphere and between the 90° deflector and the spin analyzer, as shown in Figure 27. In Figure 27, both spin rotators (SR1, SR2) are set to OFF. However, by setting SR1 to OFF and SR2 to ON, the spin polarization in the x direction in the sample plane can be measured, and by setting both SR1 and SR2 to ON, the spin polarization in the y direction in the sample plane can be measured. In the case of a spin analyzer using VLEED, instead of providing the second spin rotator SR2, a coil can be added in the x' direction. The above method allows the measurement of three-dimensional spin polarization.

[0065] In the 90° deflector, the electrons are deflected by 90° in a circular arc under the condition that the central force and the centrifugal force due to the cylindrical electric field are balanced. A spherically symmetric electric field can be used instead of a cylindrical electric field to deflect the electrons by 90°. Figure 28 shows a schematic diagram of a spin polarization analyzer using a 90° spherical deflector. The 90° deflector and the 90° spherical deflector have a simple structure and are suitable for bending a parallel beam by 90°. However, these deflectors cannot converge a beam with an angular spread that originates from a single point. In the case of a cylindrical electric field, there is a converging effect within the deflection plane, but there is no converging effect in the perpendicular direction. Also, the converging effect within the deflection plane converges a beam that originates from a single point at a deflection angle of 127°, and a deflector with a deflection angle set to 90° does not provide sufficient converging effect. In a spherically symmetric electric field, there is a converging effect not only within the deflection plane but also in the direction perpendicular to it, but a beam emitted from a single point converges at a deflection angle of 180° and becomes a divergent beam at a deflection angle of 90°.

[0066] Figure 29 is a schematic cross-sectional view of an improved 90° deflector. With the improved 90° deflector, an electron beam emitted from one point can be deflected 90° within the deflection plane to converge. However, with this method, it is not possible to converge the beam simultaneously in two directions, the direction within the deflection plane and the direction perpendicular to it. With a 90° spherical deflector, it is possible to narrow the widened beam by combining a lens at the exit, as shown in Figure 30. However, even with this method, it is not possible to converge the beam simultaneously in two directions.

[0067] The 90° deflection analyzer shown in Figures 27 to 30 can be used for three-dimensional measurement of spin polarization, but instead of using such a deflection analyzer, it is possible to perform three-dimensional measurement of spin polarization using a Wien filter type spin rotation device. With a Wien filter type spin rotation device, spins perpendicular to the sample surface can be rotated by 90° to incline the sample surface in the in-plane direction without changing the beam direction, and as shown in Figure 31, three-dimensional manipulation of spins is possible using a multipole Wien filter. However, even with this method, it has not been possible to achieve two-dimensional focusing of a beam with an angular spread while simultaneously rotating the spins by 90°.

[0068] As described above, the conventional electrostatic hemispherical energy analyzer (CHA), the concentric cylindrical mirror analyzer (CMA), and the conventional spin-resolved electron spectroscopy device have been described, but in the following, some examples of the embodiments of the present invention will be described in detail with reference to the drawings. Note that the scope of the present invention is not limited to the following examples and illustrated examples, and many modifications and variations are possible. Example 1

[0069] (90° electrostatic deflection and focusing type energy analyzer) Fig. 1 (1) is a schematic diagram of one embodiment of the 90° electrostatic deflection and focusing type energy analyzer of the present invention. In the 90° electrostatic deflection and focusing type energy analyzer 1, five outer electrodes EL1, EL2, EL3, EL4, EL5 and three inner electrodes EL6, EL7, EL8 are arranged along the shape of two rotating bodies formed on the inside and outside with a common rotation axis 13, and an electron entrance hole 11 and an exit hole 12 are formed on the rotation axis 13 of the electrodes at both ends of the outer electrodes. The inner surface shape of the outer electrodes has a tapered shape that becomes smaller toward the entrance hole 11 and the exit hole 12, except for the central electrode (EL3), and the outer surface shape of the inner electrodes has a tapered shape that becomes smaller toward the entrance hole 11 and the exit hole 12, except for the central electrode (EL7). If the position in the direction of the rotation axis is represented as z0, and the entrance of the energy analyzer 1 is z0=0 and the exit is z0=L, then the outer electrode and the inner electrode are symmetrical with respect to the central plane 14 at z0=L / 2.

[0070] As shown in FIG. 1(2), the energy analyzer 1 has five outer electrodes EL1, EL2, EL3, EL4, EL5 and three inner electrodes L6, EL7, EL8 arranged along the three-dimensional surface shape of two rotating bodies obtained by rotating the lower bases of two isosceles trapezoids (20a, 20b) with different heights around the rotation axis 13. Voltages for accelerating and decelerating electrons are applied to the outer electrodes and the inner electrodes in proportion to the energy of the incident electrons. In particular, a voltage three times or more of the converted acceleration voltage obtained by converting the energy of electrons into an acceleration voltage is set to one or more electrodes except for the electrodes at both ends of the inner electrode, based on the potential of the outer electrode in which the entrance hole 11 is formed, and the voltage applied to each electrode is adjusted so that the central orbit of the electrons is converged at the position of the exit hole 12 with a predetermined exit angle (45°) with the rotation axis 13 so that the central orbit of the electrons is at a predetermined entrance angle (45°) with the rotation axis 13. This makes it possible to capture electrons with an angular spread, deflect them by 90°, and focus them in two dimensions. In addition to the schematic shape of the electrodes, Figure 1(1) shows the electron trajectory and equipotential lines. The electrons emitted from z0=0 are first accelerated by a gentle electric field, then accelerated by a strong electric field while changing direction, becoming parallel to the rotation axis z0 at around z0=L / 2, then decelerating while changing direction and converging at the exit position.

[0071] The electrons in the central orbit are incident at an incident angle of 45° and reach the convergence point at an exit angle of 45°. In this way, the direction of the central orbit is changed by 90° by the electric field. If the incident angle measured from the central orbit is α, in Figure 1(1), the electron orbits are shown at 1° intervals from α=-8° to +8°. The sample can be placed on the z0=0 plane as shown in Figure 1(1), or it can be placed on the sample plane by introducing an input lens as described later. When the sample is placed on the z0=0 plane, the electron beam or light is irradiated from a hole (not shown) opened in the inner or outer electrode. Here, it is also possible to place the electron gun inside the inner electrode. Although not shown in Fig. 1(1), a slit for energy selection is placed at the exit position, and a detector is placed behind it. When the sample is placed on the z0=0 plane, high energy resolution can be obtained only in the analysis of the low energy region, but a large solid angle of acceptance due to axial symmetry and hence high sensitivity are expected.

[0072] A graph showing the aperture aberration of the 90° electrostatic deflection and convergence type energy analyzer in FIG. 1(1) is shown in FIG. 2(a). Here, the length L of the analyzer is set to 275 mm. (In this case, the length of the central orbit is almost the same as the length of the central orbit of the electrostatic hemisphere of the CHA shown in FIG. 21.) A, B, C, and D shown in the graph in FIG. 2(a) are the results of adjusting the applied voltage of each electrode (EL1 to EL8) so that the image blur caused by the aperture aberration is reduced when the range of the incident angle α (acceptance angle) of the energy analyzer is set to ±2°, ±6°, ±8°, and ±10°, respectively. It can be seen that the image blur caused by the aperture aberration is significantly reduced compared to that in the case of the CHA shown in FIG. 21. In the CMA, it is also possible to minimize the image blur caused by the aperture aberration by adjusting the applied voltage according to the acceptance angle as shown in FIG. 24, but in this case, the difficulty is that the convergence position changes.

[0073] In the energy analyzer of the present invention, the applied voltage can be optimized without changing the focal position. Also, the image blur caused by aperture aberration can be reduced to the same level as that of the CMA or even less. What is important here is that, unlike the CMA, the energy analyzer of the present invention does not use a grid electrode. When electrons pass through a grid electrode, their trajectories are disturbed, so it is desirable not to use a grid electrode in an energy analyzer with an imaging function.

[0074] FIG. 2(b) shows the relationship between the incident angle and the exit angle when the acceptance angle is ±10°. In the CHA, as shown in FIG. 21, the deviation in the absolute values ​​of the incident angle and the exit angle becomes noticeable from about α = ±5°, but in the energy analyzer of the present invention, the absolute values ​​of the incident angle and the exit angle are almost the same over the entire acceptance angle, that is, the angle is preserved. In this way, the energy analyzer of the present invention is suitable for measuring the angular distribution. The adjusted voltages for A to D are shown in Table 2 below. Note that the values ​​shown here are based on the pass energy E pass The voltage value for E = 1000 eV. The values ​​for other pass energies are shown in Table 2. pass The voltages are obtained by varying the electrode EL1 in proportion to the potential V1 (≠0) of the electrode EL1. Although Table 2 shows the voltage values ​​when the electrode EL1 is set to the ground potential, EL1 may be set to a potential V1 (≠0) other than the ground potential. In this case, a voltage obtained by adding V1 to the voltages shown in Table 2 is applied to the electrodes other than EL1. In A to D, the electrodes EL1 and EL5 are set to the ground potential, EL2, EL4, EL6, and EL8 are set to the same potential, and the voltages of only EL3 and EL7 are adjusted. Electron Energy E pass If the converted acceleration voltage is calculated by dividing by the elementary charge e, a voltage of about 3 to 4 times the converted acceleration voltage is applied to EL3, and a voltage of about 23 to 25 times the converted acceleration voltage is applied to EL7. Compared with the voltages applied to CHA and CMA described above, it can be seen that the voltages applied to EL3 and EL7 are one or two orders of magnitude higher. The optimal voltages applied to each electrode vary depending on the shape and arrangement of the electrodes. As a result, a voltage of about 0 to 10 times the converted acceleration voltage is applied to EL3, and a voltage of about 10 to 50 times the converted acceleration voltage is applied to EL7. However, when high convergence performance is not required, the voltage applied to EL7 may be 3 to 5 times or more and 10 times or less of the converted acceleration voltage.

[0075] [Table 2]

[0076] 3(a) to (d) show the results of calculating the energy dispersion in the 90° electrostatic deflection and focusing type energy analyzer of FIG. 1(1). ΔE(=EE pass ) and path energy E pass The ratio to is taken in the range of -0.05 to +0.05. The energy resolution can be estimated from this variance. Table 3 below shows the calculated contribution corresponding to the first term on the right hand side of the above equation (5), which shows the energy resolution in the case of CHA. This is an estimate of the energy resolution that becomes possible when the spot size of the irradiation beam approaches zero.

[0077] It can be seen from a comparison of Tables 1 and 3 that this resolution is better than that of the CHA when the acceptance angle is set to ±6° or less. However, the contribution corresponding to the second term on the right side of the above equation (5) (which is affected by the spot size of the irradiation beam) is about five times larger than that of the CHA. Therefore, when the spot size of the irradiation beam is large, the 90° electrostatic deflection and focusing type energy analyzer of Figure 1 (1) is at a disadvantage in terms of energy resolution compared to the CHA. However, at present, high flux beams of about Φ10 to 100 μm are generally available. When such a small spot beam is used, the 90° electrostatic deflection and focusing type energy analyzer has a smaller contribution corresponding to the second term on the right side of the above equation (5), making it possible to achieve high energy resolution.

[0078] [Table 3]

[0079] Figures 4(a)-(f) show the results of calculating two-dimensional real space images in the 90° electrostatic deflection and focusing type energy analyzer of Figure 1(1), similarly to Figure 22. Here, the maximum value of the incident angle α (acceptance angle) is considered to be ±2° to ±8°. As shown in Figure 22, in the electrostatic hemisphere of the CHA, unless the acceptance angle is set to about ±2° or less, large aperture aberration occurs and a practical two-dimensional image cannot be obtained. However, as shown in Figure 4, in the 90° electrostatic deflection and focusing type energy analyzer, it is possible to obtain a practical two-dimensional image even if the acceptance angle is widened to about ±5° to ±6°. Moreover, from a comparison of Tables 1 and 3 above, it can be seen that at this acceptance angle, an energy resolution comparable to that of the CHA can be achieved.

[0080] Figures 5(a)-(h) are schematic diagrams of examples of 90° electrostatic deflection and focusing type energy analyzers of the present invention, which have different electrode shapes and arrangements from the energy analyzer shown in Figure 1(1) but have a similar function. In each example, electrons enter through an entrance hole provided at one end of the outer electrode and converge at the position of an exit hole provided at the other end. In Figure 5 and the following description, the shape of the electrode refers to the inner surface shape in the case of the outer electrode, and the outer surface shape in the case of the inner electrode.

[0081] 5(a) shows an energy analyzer of the present invention, characterized in that multiple outer electrodes and multiple inner electrodes are arranged along two rotational planes formed on the inside and outside of a common rotation axis, and the outer and inner electrodes have a toroidal surface shape. Here, the outer and inner electrodes having a toroidal surface shape are characterized in that the diameters of the outer and inner electrodes become smaller toward the entrance and exit holes, and the space formed between them becomes narrower toward both ends.

[0082] 5(b) is a schematic diagram of an energy analyzer of the present invention, characterized in that multiple outer electrodes and multiple inner electrodes are arranged along two rotational planes formed on the inside and outside with a common rotation axis, some of the outer electrodes are ring-shaped electrodes with round holes in the plate, and the inner electrodes have a tapered shape with a diameter that decreases toward the entrance hole and exit hole. Here, the ring-shaped electrodes are set to have a smaller hole diameter near the entrance hole and exit hole so that the space formed between the outer electrode and the inner electrode is narrow around the entrance hole and exit hole.

[0083] Fig. 5(c) is a schematic diagram of an energy analyzer of the present invention, characterized in that a plurality of outer electrodes and a plurality of inner electrodes are arranged along two rotational planes formed on the inside and outside with a common rotation axis, and some of the outer electrodes are ring-shaped electrodes having a tapered shape with a diameter that decreases toward the entrance hole and the exit hole. Here, as in the case of Fig. 5(b), the inner electrodes have a tapered shape with a diameter that decreases toward the entrance hole and the exit hole, and the ring-shaped electrodes close to the entrance hole and the exit hole are set to have a small hole diameter.

[0084] Fig. 5(d) is a schematic diagram of an energy analyzer of the present invention, in which multiple outer electrodes and multiple inner electrodes are arranged along two rotational planes formed on the inside and outside of a common rotation axis, and the inner electrodes have a step shape extending to the vicinity of the entrance hole and the exit hole. Here, the step shape is characterized by a diameter that becomes smaller near the entrance hole and the exit hole. The outer electrode has a tapered shape that becomes smaller toward the entrance hole and the exit hole, as in the embodiment of Fig. 1(1), and the space formed between the outer electrode and the inner electrode is narrow around the entrance hole and the exit hole.

[0085] 5(e) is a schematic diagram of an energy analyzer of the present invention, characterized in that a plurality of outer electrodes and a plurality of inner electrodes are arranged along two rotational planes formed on the inside and outside of a common rotation axis, and the inner electrodes have a rod shape extending to the vicinity of the entrance hole and the exit hole. Here, each of the plurality of rod-shaped electrodes may have a different outer diameter.

[0086] FIG. 5(f) is a schematic diagram of an energy analyzer of the present invention, characterized in that multiple outer electrodes and multiple inner electrodes are arranged along two rotational surfaces formed on the inside and outside of a common rotation axis, and the inner electrodes have an axially symmetric shape with a wider diameter at their ends.

[0087] Figures 5(g) and 5(h) are examples of the energy analyzer of the present invention in which the number of inner electrodes and outer electrodes is set to 2. Figure 5(g) shows a configuration in which multiple outer electrodes and multiple inner electrodes are arranged along two rotational planes formed on the inside and outside with a common rotation axis, the outer electrodes are the same as those in Figure 1(1), and the inner electrodes are rod-shaped or cylindrical electrodes that extend to the vicinity of the entrance and exit holes, and bead-shaped electrodes that pass through the rod-shaped or cylindrical electrodes. FIG. 5(h) is characterized in that the outer electrode is composed of an axisymmetric electrode extending to the entrance hole and the exit hole and an axisymmetric electrode arranged inside the entrance hole and the exit hole. The inner electrode has a tapered shape with a diameter decreasing toward the entrance hole and the exit hole. In the designs of FIG. 5(e), FIG. 5(f), FIG. 5(g), and FIG. 5(h), the convergence performance is decreased and the acceptance angle is set smaller than other designs. If an even smaller acceptance angle is acceptable, the energy analyzer of the present invention can be designed by combining the inner electrode of FIG. 5(g) with the outer electrode of FIG. 5(h) and consisting of a total of four electrodes, two inner electrodes and two outer electrodes. In the type of FIG. 5(g), in order to improve the convergence performance, it is effective to increase the degree of freedom of the shape of the inner electrode and optimize the shape, or to increase the number of bead-shaped electrodes in the design. In addition, in the type of FIG. 5(h), the convergence performance can be improved by increasing the number of outer electrodes in the design.

[0088] As in the case of Fig. 1(1), in Fig. 5(a) to (h), a voltage that accelerates and decelerates electrons is applied to the outer electrode and the inner electrode in proportion to the energy of the incident electrons. A voltage that is 3 to 5 times or more of a converted acceleration voltage obtained by converting the energy of electrons into an acceleration voltage is set to one or more inner electrodes excluding the electrodes at both ends of the inner electrode, with the potential of the outer electrode in which the entrance hole is formed as the reference. However, in order to obtain high focusing performance, it is desirable to set the voltage to about 10 to 50 times the converted acceleration voltage with the potential of the outer electrode in which the entrance hole is formed as the reference.

[0089] In the electrostatic deflection and focusing type energy analyzer of the present invention, the number of electrodes is not limited to those shown in FIG. 1(1) and FIG. 5. The number of the inner electrodes and the outer electrodes may be two or more, but considering both performance and cost, it is preferable to provide about three to five inner electrodes and about three to seven outer electrodes. In addition, it is preferable that the inner electrodes and the outer electrodes are shaped and arranged so that the space formed between them is narrowed around the entrance hole and the exit hole as shown in FIG. 1(1) and FIG. 5. This makes it possible to suppress the electric field applied to the entrance hole and the exit hole to a small value. In addition, it is preferable that the inner electrodes and the outer electrodes are plane-symmetrical with respect to a plane that perpendicularly intersects with the line connecting the entrance hole and the exit hole at the midpoint of the line. However, in an actual design, plane symmetry is not necessarily required, and a shape that is not plane symmetrical may be used depending on the overall design of the analysis device. 1 and 5, the electrons in the central orbit are incident at an incident angle of 45° and emitted at an exit angle of 45°, but the incident and exit angles of the central orbit are not limited to these, and it is also possible to design a 90° deflection electrostatic focusing type energy analyzer by setting the incident angle to 50° and the exit angle to 40°, for example. In this case, it is preferable that the inner and outer electrodes are asymmetrical with respect to the plane that intersects perpendicularly with the midpoint of the line connecting the entrance hole and the exit hole. Although various types of electrode shapes are shown in Fig. 5, these shape types can be freely combined to design various types of electrostatic deflection and focusing type energy analyzers, not limited to those shown in Fig. 5. The combination of shape types can be freely changed not only between the outer electrode and the inner electrode, but also between the entrance hole side and the exit hole side. Example 2

[0090] (Imaging electron spectrometer) FIG. 6(a) is a schematic diagram of one embodiment of the imaging electron spectrometer of the present invention, showing a configuration in which an input lens is placed in front of the 90° electrostatic deflection and focusing type energy analyzer in FIG. 1(1) and a projection lens is placed in the rear. By decelerating the electrons emitted from the sample by the input lens and making them enter the energy analyzer, it is possible to achieve high energy resolution over a wide energy range. The 90° electrostatic deflection and focusing type energy analyzer is expected to be highly effective when combined with a wide-angle input lens. As described above, in order to obtain a two-dimensional real space image or emission angle distribution with practical spatial or angular resolution using the CHA, it is necessary to keep the incidence angle on the electrostatic hemisphere at about ±2° or less.

[0091] However, if a spherical aberration correction lens with an acceptance angle of ±50° or a convergent lens with a full angle (±90°) is used to accept electrons from a sample at an opening angle of ±50° or ±90° and converge them at an opening angle of about ±2° or less, the magnification becomes very high. Even if the electrons are converged at the same energy as when they were incident (without deceleration) using an input lens, the magnification becomes about 25 times or 45 times when electrons with an opening angle of ±50° or ±90° are converged at an opening angle of ±2°. If they are decelerated, the magnification becomes even higher. For example, if 1000 eV electrons are decelerated to 50 eV, the magnification becomes about 100 to 200 times according to the law of brightness constancy. If the magnification becomes so high that small apertures or slits are inserted on the entrance and exit sides of the energy analyzer as shown in Figure 6(a), most of the electrons cannot pass through the apertures or slits, and the sensitivity is significantly reduced. Therefore, by using the 90° electrostatic deflection and focusing type energy analyzer of the present invention instead of the CHA, the angle of incidence to the energy analysis section can be widened by about three times, making it possible to increase the sensitivity by about nine times compared to when a CHA is used.

[0092] The basic configuration of the device in FIG. 6(b) is the same as that of the device in FIG. 6(a), but the structure of the energy analyzer is slightly different. In FIG. 6(b), the energy analyzer is a 180° rotator instead of a 360° rotator in order to save space. FIG. 7 shows cross-sectional views of the energy analyzers in FIG. 6(a) and (b) cut in a direction perpendicular to the paper. In the 360° rotator type shown in FIG. 7(a), the inner electrode is fixed by a fixed leg. The fixed leg is installed in a place where the influence on the electric field is as small as possible, and the electrodes EL6 and EL8 are fixed to the electrodes EL2 and EL4 by the fixed leg, respectively. In the 180° rotator type, a compensation electrode as shown in FIG. 7(b) is provided to compensate the electric field at the cut surface. Instead of using a 180° rotation type energy analyzer, it is also possible to achieve further space saving by using an energy analyzer with a rotation angle of 180° or less. In this case, it is preferable to set the rotation angle to 90° to 180°. In the case of an energy analyzer with a rotation angle of 180° or less, a compensation electrode is provided to compensate the electric field at the cutting surface, as in FIG. 7(b). Example 3

[0093] (Reflection Imaging Electron Spectrometer) FIG. 8 shows an embodiment of the reflective imaging electron spectrometer of the present invention. The reflective imaging electron spectrometer of this embodiment is characterized in that the electrons deflected and focused by 90° by the 90° electrostatic deflection and focusing type energy analyzer of embodiment 1 are reflected by a single crystal mirror and deflected and focused by 90° again. Electrons emitted from the sample are focused by an input lens and enter the energy analyzer through an aperture tilted by 45°. The incident electrons are deflected and focused by 90°, reflected by a single crystal mirror, and returned to the position of the entrance aperture by the 90° deflection and focusing, from which they are emitted in a direction perpendicular to the incident direction. The emitted electrons are imaged by a projection lens as a two-dimensional real space image or emission angle distribution and are applied to a detector. The entrance aperture also serves as the exit aperture that selects the energy, and the energy resolution and sensitivity depend heavily on the size of this aperture. Therefore, in order to adjust the energy resolution and sensitivity according to the measurement, it is desirable for the aperture section to have multiple apertures of different sizes and a mechanism for switching between them, or to have a mechanism such as an iris that can freely change the size.

[0094] The energy analyzer in the reflection imaging electron spectrometer shown in Figure 8 has twice the energy dispersion compared to the energy analyzer shown in Figure 6, so higher energy resolution can be expected. However, noise may increase due to inelastic scattering at the single crystal mirror placed at the exit hole of the energy analyzer, decreasing the signal-to-noise ratio (SN). Therefore, in order to reduce noise, it is effective to perform energy selection in two stages (two focusing positions). Selection by the aperture described above is the second stage, and the first stage uses a single crystal mirror for energy selection as shown in Figure 8. The portion of the single crystal mirror for energy selection that corresponds to the aperture is single crystal, and the other parts are covered with electron absorbing material. Example 4

[0095] (Spin Vector Distribution Imaging Device) FIG. 9 shows an embodiment of the spin vector distribution imaging device of the present invention using the 90° electrostatic deflection and focusing type energy analyzer of FIG. 1(1). In the spin vector distribution imaging device shown in FIG. 9, a two-dimensional spin filter 8 is provided as shown in the figure in order to measure a two-dimensional real space image or emission angle distribution by spin resolution. An electrostatic lens 19 is provided in front of the two-dimensional spin filter 8 and adjusted so that electrons are incident on the two-dimensional spin filter 8 with appropriate energy and angle. After that, the electrons reflected by the two-dimensional spin filter 8 are projected onto the first detector 4a by the first projection lens 3a. The two-dimensional spin filter 8 can be retracted from the optical axis, and when in the retracted state, the second projection lens 3b and the second detector 4b are used to obtain a normal (spin integral) two-dimensional real space image or two-dimensional emission angle distribution.

[0096] Spin rotators 7a (SR1) and 7b (SR2), installed on the optical axis in front of and behind the 90° deflection energy analyzer 1, are used for three-dimensional spin resolution in the sample plane and perpendicular to the plane. SR1 and SR2 are set to rotate the spins by 90° in a plane perpendicular to the optical axis (hereinafter referred to as "ON") or not to rotate them (hereinafter referred to as "OFF"). When both SR1 and SR2 are OFF, the spin polarization in the y direction in the sample plane (perpendicular to the paper) can be measured. To measure the spin polarization in the x direction in the sample plane, only SR1 should be ON, and to measure the spin polarization in the direction perpendicular to the sample plane (z direction), only SR2 should be ON.

[0097] In the spin vector distribution imaging device in FIG. 9, the first projection lens 3a and the first detector 4a are arranged on the same plane as the deflection plane. However, the two-dimensional spin filter 8, the first projection lens 3a, and the first detector 4a may be arranged rotated 90° in the direction perpendicular to the paper surface around the intersection of the z' and z" axes. In this case, the spin polarization in the direction perpendicular to the sample surface (z direction) can be measured when both SR1 and SR2 are OFF. To measure the spin polarization in the x direction in the sample surface, both SR1 and SR2 should be turned ON, and to measure the spin polarization in the y direction in the sample surface, only SR2 should be turned ON.

[0098] Although a spin vector distribution imaging device equipped with a spin rotator is shown in Fig. 9 and in the following examples, the spin rotator is not necessarily required. Instead of providing a spin rotator, it is also possible to determine the direction of spins to be detected by rotating the sample and / or the spin analyzer consisting of a two-dimensional spin filter, a projection lens, and a detector. In addition, although FIG. 9 shows a spin vector distribution imaging device using a 360° rotator type energy analyzer, it is also possible to configure a spin vector distribution imaging device using an energy analyzer with a rotation angle of 180° or less. Example 5

[0099] (Spin Vector Distribution Imaging Device) FIG. 10 is a schematic diagram of a simplified spin vector distribution imaging device using the reflection imaging electron spectrometer shown in FIG. 8. Instead of a single crystal mirror, a two-dimensional spin filter 8 such as Au / Ir(001) is used. This allows a two-dimensional real space image or emission angle distribution that has been spin-analyzed to be obtained by the detector. The input lens 2 may or may not include a spin rotator 7, as in the spin vector distribution imaging device shown in FIG. 9. If a spin rotator is included, it becomes possible to measure the spin polarization in two directions in the sample plane. When the spin rotator 7 is OFF, the spin polarization in the y direction (perpendicular to the paper) of the sample 10 can be measured, and when the spin rotator 7 is ON, the spin polarization in the x direction of the sample plane can be measured. Also, as described above, instead of including a spin rotator, the spin polarization in two directions in the sample plane 10 can be measured by rotating the sample 10. Example 6

[0100] (Switchable electrostatic deflection and focusing type energy analyzer) FIG. 11 is a schematic diagram of an embodiment of the switching electrostatic deflection and focusing type energy analyzer of the present invention. The switching electrostatic deflection and focusing type energy analyzer shown in FIG. 11 has seven outer electrodes EL1, EL2, . . . EL7 and six inner electrodes EL8, EL9, . . . EL13, the inner surface shape of the outer electrodes is axially symmetric, the outer surface shape of the inner electrodes is axially symmetric, and they are arranged coaxially. If the entrance of the analyzer is z0=0 and the exit is z0=L, the outer electrodes and the inner electrodes are symmetric with respect to the plane of z0=L / 2. In addition, the outer electrodes and the inner electrodes have a tapered shape in which the entrance side electrodes (EL1, EL2, EL8) have a diameter narrowing toward the entrance, and the exit side electrodes (EL6, EL7, EL13) have a tapered shape in which the diameter narrowing toward the exit, similar to the 90° electrostatic deflection and focusing type energy analyzer of FIG. 1(1).

[0101] The greatest feature of the switchable electrostatic deflection and focusing type energy analyzer in Figure 11 is that the inner electrode is separated into two regions, and as a result, electrons can pass through the space created between the left and right inner electrodes. The electron trajectories and equipotential lines shown in Figure 11 are the results for a 90° deflection. The trajectory that is incident at an angle of 45° from the central axis z is the central trajectory, and trajectories with an incidence angle range of ±8° from that are shown. These trajectories have somewhat lower convergence at z0=L than the trajectory shown in Figure 1(1). Table 4 below shows the voltages applied to each electrode of the switchable electrostatic deflection and focusing type energy analyzer in Figure 11, determined by simulation (pass energy E pass = 1000 eV). For 1 keV electrons, EL10 and EL11 are given a high voltage of 13 kV.

[0102] [Table 4]

[0103] Figures 12(a) and (b) show the results of switching the deflection by changing the voltage conditions in the switching type electrostatic deflection and focusing type energy analyzer of Figure 11. pass= 1000 eV) are shown in Tables 5 and 6 below. In Figures 12(a) and 12(b), unlike the case of Figure 11, the electrons pass through an electric field formed between the left and right inner electrodes. In the case of Figure 12(a), the trajectory converges once near z0 = L / 2, and then converges again at z0 = L. In contrast, in the case of Figure 12(b), the trajectory converges at z0 = L without any crossover. Here, in both cases, the trajectory draws an S-shape and returns to the original direction at z0 = L. In other words, the final deflection angle is 0°. On the other hand, the energy dispersion in the case of Fig. 12(a) is about the same as that in Fig. 11, but in the case of Fig. 12(b) it is significantly reduced compared to the case of Fig. 12(a) due to the cancellation effect. As a result, the setting in Fig. 12(a) can be suitably used for energy analysis, and the setting in Fig. 12(b) can be suitably used for PEEM (photoelectron electron microscope) measurements with reduced chromatic aberration.

[0104] [Table 5]

[0105] [Table 6] Example 7

[0106] (Spin Vector Distribution Imaging Device) Figure 13 is a schematic diagram of a spin vector distribution imaging apparatus using the switchable electrostatic deflection and focusing type energy analyzer shown in Figures 11 and 12. Three measurement modes are shown: Figure 13(a) is the spin resolved mode, Figure 13(b) is the spin integral mode, and Figure 13(c) is the photoelectron electron microscopy (PEEM) mode.

[0107] In the spin-resolved mode, the deflection-switching energy analyzer is set to a 90° deflection condition. For electrons deflected by 90°, an electrostatic lens 19, a second spin rotator 7b (SR2), a two-dimensional spin filter 8, a first projection lens 3a (installed in the direction perpendicular to the paper surface), and a first detector 4a are installed, and three-dimensional spin polarization can be measured using the same principle as the three-dimensional spin polarization analysis device in Figure 9. When both the second spin rotator 7b (SR2) and the first spin rotator 7a (SR1) (installed in the input lens) are set to OFF, the spin polarization in the direction perpendicular to the surface of the sample 10 can be measured.

[0108] In spin integral mode, the second projection lens 3b and second detector 4b installed for the electrons on the S-shaped orbit can measure a normal two-dimensional real space image or two-dimensional emission angle distribution without spin resolution. Here, the two-dimensional real space image is measured using the sharp photoelectron spectrum peak of inner shell excitation. On the other hand, most of the photoelectrons emitted by irradiation with vacuum ultraviolet rays or X-rays are secondary electrons. Secondary electrons are electrons that have lost energy in various processes before being emitted, and have a wide range of energies.

[0109] In PEEM, these secondary electrons are usually used to form an image, obtaining a bright contrast due to the difference in the work function of the surface. The PEEM mode in Figure 13(c) is a mode for measuring such PEEM images. In PEEM mode, the settings in Figure 12(b) are used, which cancel the energy dispersion. This makes it possible to obtain clear PEEM images with reduced chromatic aberration. The device in Figure 13 is unique in that it is equipped with the PEEM measurement function (compared to the device in Figure 9) and that the measurement mode can now be switched simply by the voltage applied to each element. Example 8

[0110] (Other 90° electrostatic deflection focusing type energy analyzers) Another embodiment of an electrostatic energy analyzer performing 90° deflection focusing will be described with reference to Fig. 14. As shown in Fig. 14, the electrostatic energy analyzer of this embodiment is configured by combining two or more electron optical systems. Here, each of the combined electron optical systems may be any of an electrostatic focusing mirror, an electrostatic deflector, and an electrostatic lens. In Figure 14, the two electron optical systems used in the combination are represented diagrammatically as A and B. A has a deflection angle β1, and B has a deflection angle β2. However, when an electrostatic lens is used for A or B, the central orbit is not the central axis of the lens, but an orbit that enters at a certain angle from the central axis and exits at a certain angle, and the deflection angle at this time is represented as β1 or β2. Assume that electrons on the central orbit enter or exit perpendicularly to both end faces of A and B. Both end faces of A and B are placed perpendicular to the xy plane, and the right end face of A and the left end face of B are placed opposite each other. If the vector perpendicular to the left end face of A is vector a, and the vector perpendicular to the right end face of B is vector b, they are given by the following equation (7) using β1 and β2.

[0111]

number

[0112] When B is rotated by angle γ around the x-axis, the vector perpendicular to the right end face of B is given by the following equation (8). Here, the condition for vector a and vector b' to be perpendicular is given by the following equation (9), so the condition for the rotation angle γ for a 90° deflection is given by the following equation (10).

[0113]

number

[0114]

number

[0115]

number

[0116] Based on the above, several combinations that achieve 90° deflection using two electron optical systems with equal deflection angles (β1=β2) are shown in Figure 15. For example, when β1=β2=60°, combining with γ=70.5° results in 90° deflection. Figure 16(a) shows the conditions for 90° deflection when β1=β2. This condition is only valid when the deflection angle is 45-135°. In this case, 90° deflection can be achieved by selecting γ shown in the figure. Figure 16(b) shows the conditions for 90° deflection for several β1s when β2≠β1. The dotted lines for γ=90° and β2=90° represent the relationship between β2 and γ when β1=90° and β1=0°, respectively.

[0117] Figures 17(a) and (b) show examples of a 45° electrostatic deflection and focusing type energy analyzer and a 60° electrostatic deflection and focusing type energy analyzer, respectively. In the case of the 45° electrostatic deflection and focusing type energy analyzer, the central trajectory is an trajectory that is incident at an angle of 22.5° from the central axis, and in the case of the 60° electrostatic deflection and focusing type energy analyzer, the central trajectory is an trajectory that is incident at an angle of 30° from the central axis. Figures 17(a) and (b) show trajectories with an incidence angle range of ±8° measured from the central trajectory. The convergence of these trajectories is lower than that of the 90° electrostatic deflection and focusing type energy analyzer in Figure 1(1), but high convergence can be obtained by limiting the incidence angle to about ±5°.

[0118] In the case of the 45° electrostatic deflection and focusing type energy analyzer in FIG. 17(a), a 90° deflection can be achieved by combining two identical ones at a rotation angle γ=0°, as in the case shown in FIG. 15(a). FIG. 18(a) shows a 90° electrostatic deflection and focusing type energy analyzer using this combination. On the other hand, in the case of the 60° electrostatic deflection and focusing type energy analyzer, a 90° deflection can be achieved by combining two identical ones at a rotation angle γ=70.5°, as in FIG. 15(b). FIG. 18(b) shows a 90° electrostatic deflection and focusing type energy analyzer using this combination. Also, when the 45° electrostatic deflection and focusing type energy analyzer in FIG. 17 and the 60° electrostatic deflection and focusing type energy analyzer are combined, a 90° deflection can be achieved by setting the rotation angle γ=54.7°, according to the above formula (10).

[0119] 19(a), (b), and (c) show schematic diagrams of examples of a 120° electrostatic deflection and focusing type energy analyzer, a 135° electrostatic deflection and focusing type energy analyzer, and a 150° electrostatic deflection and focusing type energy analyzer, respectively. The central trajectory is an trajectory incident at angles of 60°, 67.5°, and 75° from the central axis, respectively. In FIG. 19(a), (b), and (c), trajectories with an incident angle range of ±8° measured from the central trajectory are shown. These trajectories have improved convergence compared to the trajectories in FIG. 17(a) and (b). It is also possible to design an energy analyzer with a deflection angle of 150° or more and 180° or less with the same electrode configuration as FIG. 19. However, the convergence performance is significantly reduced when the deflection angle is about 160° or more. Also, according to FIG. 16(b) or the above formula (10), it is also possible to achieve a 90° deflection using an analyzer with a large deflection angle as in FIG. 19(a) and (b). However, when the deflection angle is large, due to geometric constraints, an energy analyzer having a rotation angle of 180° or less is used, rather than the 360° rotation type shown in FIG. 17 (see FIG. 7).

[0120] Energy analyzers with small deflection angles and those with large deflection angles each have their own advantages and disadvantages. First, when using an energy analyzer with a small deflection angle, as shown in Figures 17(a) and (b), there is the advantage that it is easier to design the combination with the input lens. However, as the deflection angle becomes smaller, there is a problem that the energy dispersion becomes smaller and the energy resolution decreases. On the other hand, in the case of an energy analyzer with a large deflection angle as shown in Figures 19(a) and (b), the energy resolution is improved, but when combined with an input lens or another energy analyzer, a complex design such as a 180° rotator type is required.

[0121] Table 7 below summarizes the applied voltages for the electrostatic deflection and focusing type energy analyzers shown in Figures 1, 17, and 19. These are the pass energies E pass =1000 eV. In these energy analyzers, a high voltage of about 13 to 24 kV is applied to the inner electrode EL7 for 1000 eV. Not limited to the electrostatic deflection focusing type energy analyzers shown in Figs. 1, 17, and 19, in the electrostatic deflection focusing type energy analyzer of the present invention, it is desirable to set the voltage applied to at least one electrode of the inner electrodes in the range of about 10 to 50 kV for 1000 eV. However, when high focusing performance is not required, the voltage applied to at least one electrode of the inner electrodes may be about 2 to 5 kV or more and about 10 kV or less for 1000 eV.

[0122] [Table 7]

[0123] Although an electrostatic deflection and focusing type energy analyzer having a specific deflection angle has been shown as an embodiment, the electrostatic deflection and focusing type energy analyzer of the present invention can also be provided as an energy analyzer having any deflection angle between 45° and 180° by using a similar design. Example 9

[0124] The electrostatic deflection and focusing type energy analyzer shown in FIG. 32(a) has the same configuration as that shown in FIG. 1, but the voltage applied to EL7 is 10 times the converted accelerating voltage (E pass The aperture aberration was minimized by adjusting the outer diameter of the inner electrode, the inner diameter of the outer electrode, and the voltage applied to EL3 (10 kV for EL7 = 1 keV). In FIG. 1, the ratio of the outer diameter to the length L of the inner electrode is about 0.12, and the ratio of the inner diameter to the length L of the outer electrode is about 0.64, whereas in FIG. 32(a), the ratio of the outer diameter to the length L of the inner electrode is about 0.27, and the ratio of the inner diameter to the length L of the outer electrode is about 0.76. In the electrostatic deflection and focusing type energy analyzer in FIG. 32(a), the blurring of the image due to the aperture aberration increases by about 13 times as shown in FIG. 32(b) compared to the configuration of the electrostatic deflection and focusing type energy analyzer in FIG. 1. Thus, when the voltage applied to EL7 is reduced to about 10 times the converted accelerating voltage, the decrease in the focusing performance becomes noticeable. However, this decrease in the focusing performance can be significantly reduced by forming the inner electrode in an appropriate shape. Example 10

[0125] Here, to explain what shape is appropriate for the inner electrode in the electrostatic deflection and convergence type energy analyzer of the present invention, an example is shown in Fig. 33(a). For EL7, as in the case of Fig. 32(a), a voltage 10 times the converted acceleration voltage is set. EL6 and EL8, different from the electrostatic deflection and convergence type energy analyzers shown in Fig. 1 and Fig. 32(a), have a stepped shape characterized by two outer diameters D1 and D2 (D1 < D2). In Fig. 33(a), the ratio of D1 to the length L is 0.11, and the ratio of D2 to the length L is 0.24. Also, the ratio of the inner diameter of the outer electrode to the length L is about 0.76. As shown in Fig. 33(b), the convergence performance is inferior compared to the case of the electrostatic deflection and convergence type energy analyzer shown in Fig. 1, but it can be seen that it is significantly improved compared to the case of the electrostatic deflection and convergence type energy analyzer shown in Fig. 32(a). In Fig. 33(a), EL6 and EL8, similar to the case of the electrostatic deflection and convergence type energy analyzers shown in Fig. 1 and Fig. 32(a), have a tapered portion whose diameter decreases toward the inlet or outlet, but a design without this tapered portion is also effective, and the simplest shape may be a coaxial two-stage cylindrical shape characterized only by two outer diameters D1 and D2 and two lengths in the z-axis direction.

Example 11

[0126] Fig. 34 shows an embodiment of the electrostatic deflection and convergence type energy analyzer of the present invention when a lower voltage is applied to the inner electrode EL7. Figs. 34(a), (b), and (c) show the cases where voltages 5 times, 2 times, and 1.5 times the converted acceleration voltage (E pass= 1 keV, respectively) are applied. In either case, the inner electrodes EL6 and EL8 have a step shape with a tapered portion on the inlet or outlet side. However, as in the case of FIG. 33, a design without the tapered portion is also effective, and a coaxial two-stage cylindrical shape characterized only by two outer diameters D1 and D2 and two lengths in the z-axis direction may be used. The outer surface of EL7 has a cylindrical shape with an outer diameter larger than D1 and D2. In this way, the inner electrode has a coaxial three-stage cylindrical shape as a whole, excluding the tapered portion. Figures 34(a), (b), and (c) show the results of adjusting the three outer diameters, the lengths of each portion, and the applied voltage so that the aperture aberration is minimized. The ratios of D1, D2, and D3 to the length L are D1 / L=0.11, D2 / L=0.26, and D3 / L=0.38 for the electrostatic deflection and focusing energy analyzer shown in Fig. 34(a), D1 / L=0.13, D2 / L=0.28, and D3 / L=0.52 for the electrostatic deflection and focusing energy analyzer shown in Fig. 34(b), and D1 / L=0.13, D2 / L=0.28, and D3 / L=0.51 for the electrostatic deflection and focusing energy analyzer shown in Fig. 34(c). The ratio of the inner diameter of the outer electrode to the length L is about 0.76 for the electrostatic deflection and focusing energy analyzer shown in Fig. 34(a), and 0.87 for the electrostatic deflection and focusing energy analyzers shown in Fig. 34(b) and Fig. 34(c).

[0127] The aperture aberration in the case of the electrostatic deflection and focusing type energy analyzer shown in Fig. 34(a), (b), and (c) is shown in Fig. 35 together with the aperture aberration in the case of the electrostatic deflection and focusing type energy analyzer shown in Fig. 1 and Fig. 33(a). It should be noted here that the aperture aberration increases as the voltage applied to EL7 is lowered. Therefore, in order to reduce the aperture aberration, it is desirable to set the voltage applied to EL7 as high as possible. Another point to note is that the aperture aberration increases rapidly when the voltage applied to EL7 is lowered from 2 times to 1.5 times the reduced acceleration voltage. Therefore, it is desirable to set the voltage applied to EL7 to about 2 times or more the reduced acceleration voltage. It is possible to further reduce the aperture aberration by setting the voltage applied to EL7 higher than that of the electrostatic deflection and focusing type energy analyzer shown in Fig. 1. However, the voltage applied to EL7 cannot be set to an unlimited high value, but is subject to constraints in the design and manufacture of the inner diameter electrode. Example 12

[0128] Figure 36 shows an example of an electrostatic deflection and focusing type energy analyzer of the present invention when the voltage applied to EL7 is set to 50 times the reduced accelerating voltage. As a result of optimization, the outer diameter of EL7 is smaller than that of EL6 and EL8. As this figure suggests, the voltage applied to EL7 is limited to about 50 times, and if it is attempted to be increased beyond this, the outer diameter of EL7 becomes too small, causing problems such as difficulty in wiring and insulation.

[0129] When the electrostatic deflection and focusing type energy analyzer of the present invention is used in an imaging device, it is necessary to sufficiently reduce the aperture aberration, and in this case, it is desirable to set the voltage applied to EL7 to about 10 to 50 times the reduced acceleration voltage, based on Fig. 35 and the above considerations. Furthermore, when both high focusing performance and ease of design and manufacture are required, it is desirable to set the voltage applied to EL7 to about 20 to 30 times the reduced acceleration voltage.

[0130] Table 8 below summarizes the applied voltages in the electrostatic deflection and focusing type energy analyzers shown in Figures 32(a), 33(a), 34(a), 34(b), 34(c), and 36. From Table 8, it can be seen that the way voltages are applied to EL1 to EL8 changes with the electrostatic deflection and focusing type energy analyzer shown in Figure 34(b). When the voltage applied to EL7 is about twice the converted acceleration voltage or more, 0 or a positive voltage is applied to the other electrodes, and when the voltage applied to EL7 is about twice the converted acceleration voltage or less, 0 or a negative voltage is applied to the other electrodes. In the case of the electrostatic deflection and focusing type energy analyzer shown in Figure 34(b), the outer electrodes EL1 to EL5 are all set to the same potential (0V), so they can also be designed together as one electrode. In addition, in the case of the electrostatic deflection and focusing type energy analyzer shown in FIG. 34(a), the outer electrodes can be designed as three electrodes in total, since (adjacent) EL1, EL2, EL4, and EL5 are at the same potential (0V). Thus, the number of outer electrodes is not limited to five, EL1 to EL5, as shown in the embodiment, but may be three or one, or may be two, four, or six or more. Furthermore, the number of inner electrodes is not limited to three, EL6 to EL8, as shown in the embodiment, but may be four or more. Increasing the number of electrodes allows for more fine adjustment of the electric field.

[0131] [Table 8]

[0132] The shape and arrangement of the electrodes may be changed in various ways as long as they are capable of forming an electric field similar to that shown in the examples. Here, the characteristics of the electric field of the electrostatic deflection and focusing type energy analyzer of the present invention will be described. 1) When electrons enter an electrostatic deflection and focusing type energy analyzer, they are accelerated by the electric field and gradually change direction. 2) The axis (z-axis) of the electrostatic deflection and focusing type energy analyzer is parallel to the midpoint (z=L / 2) between the entrance point and the exit point or at a position close to it. 3) After that, the electrons decelerate and change direction little by little until they reach the ejection position. At this point, the electrons in the central orbit are ejected at a specified deflection angle.

[0133] On the other hand, in the case of a CMA (coaxial cylindrical mirror analyzer), electrons entering a cylindrical electric field change direction by deceleration, become parallel to the z-axis at the midpoint between the entrance point and the exit point, and then change direction while being accelerated to reach the exit position. In addition, in a CHA, electrons in a central orbit are neither accelerated nor decelerated because they describe a circular orbit due to the balance between the central force and centrifugal force caused by a spherically symmetric electric field. In this way, the electrostatic deflection and focusing type energy analyzer of the present invention is fundamentally different from the electric fields used in CMA and CHA. [Industrial Applicability]

[0134] The present invention is useful for energy analyzers, photoelectron spectrometers, and spin polarization analyzers. [Explanation of symbols]

[0135] 1 90° electrostatic deflection and focusing type energy analyzer 2 Input Lens 3,3a,3b Projection lens 4,4a,4b Detector 5 Single crystal mirror 6 Aperture 7,7a,7b Spin Rotator 8. Two-dimensional spin filter 9 Light or electron beam 10 Samples 11 Entrance hole 12 Exit hole 13 Rotation axis 14 Central plane 17 Inner electrode fixing leg 18 Compensation electrode 19 Electrostatic Lens 20a, 20b isosceles trapezoid

Claims

1. the device comprises one or more outer electrodes and a plurality of inner electrodes arranged along the shapes of two rotors formed on the inside and outside of a common rotation axis, electron entrance holes and exit holes formed on the rotation axis of electrodes at both ends of the outer electrode, and a voltage application means for applying a voltage to the outer electrode and the inner electrode for accelerating and decelerating electrons, the inner surface shape of the outer electrode is a shape that decreases in diameter toward the entrance hole and a shape that decreases in diameter toward the exit hole, an outer surface shape of the inner electrode is a shape that becomes smaller in diameter toward the entrance hole, a rod shape extending toward the entrance hole, or a shape that expands in diameter at an end portion on the entrance hole side, and a shape that becomes smaller in diameter toward the exit hole, a rod shape extending toward the exit hole, or a shape that expands in diameter at an end portion on the exit hole side, the voltage applying means applies a voltage to the inner electrode excluding the electrodes at both ends of the inner electrode, the voltage being at least twice the converted acceleration voltage obtained by converting the energy of electrons into an acceleration voltage with reference to the potential of the outer electrode in which the entrance hole is formed, an electrostatic deflection and focusing type energy analyzer, characterized in that a voltage is applied to each electrode such that electrons incident from said entrance hole are converged to the position of said exit hole at a predetermined exit angle with respect to said rotation axis such that the central orbit forms a predetermined entrance angle with said rotation axis.

2. 2. The electrostatic deflection and focusing type energy analyzer according to claim 1, wherein the inner surface shape of the outer electrode and the outer surface shape of the inner electrode are symmetrical with respect to a plane that intersects the line connecting the entrance hole and the exit hole perpendicularly at the midpoint of the line.

3. the shape of the inner surface of the outer electrode, the diameter of which decreases toward the entrance hole, is a tapered shape, a toroidal surface shape, or a ring shape, and the shape of the inner surface of the outer electrode, the diameter of which decreases toward the exit hole, is a tapered shape, a toroidal surface shape, or a ring shape; 3. The electrostatic deflection and focusing type energy analyzer according to claim 1, wherein the shape of the outer surface of the inner electrode that becomes smaller in diameter toward the entrance hole is a tapered shape or a toroidal surface shape, or a step shape that becomes smaller in diameter in stages toward the entrance hole, and the shape of the outer surface of the inner electrode that becomes smaller in diameter toward the exit hole is a tapered shape or a toroidal surface shape, or a step shape that becomes smaller in diameter in stages toward the exit hole.

4. 4. An electrostatic deflection and focusing type energy analyzer according to any one of claims 1 to 3, characterized in that a voltage applied to one or more inner electrodes excluding the electrodes at both ends of the inner electrode is 10 to 50 times a converted acceleration voltage obtained by converting electron energy into an acceleration voltage.

5. 5. The electrostatic deflection and focusing type energy analyzer according to claim 4, wherein a voltage applied to one or more outer electrodes excluding the electrodes at both ends of the outer electrode is 10 times or less the reduced acceleration voltage.

6. 6. The electrostatic deflection and focusing type energy analyzer according to claim 1, wherein the deflection angle is 90 degrees.

7. 6. The electrostatic deflection and focusing type energy analyzer according to claim 1, wherein the deflection angle is any one of 45°, 60°, 120°, 135°, and 150°.

8. 6. The electrostatic deflection and focusing type energy analyzer according to claim 1, wherein the deflection angle is equal to or greater than 45° and less than 90°, or greater than 90° and less than 180°.

9. the inner electrode is divided into two parts so that electrons in a central orbit can pass across the axis of rotation; 9. An electrostatic deflection and focusing type energy analyzer according to claim 1, characterized in that by changing the voltage conditions applied to the electrodes, it is possible to control whether or not the central orbit crosses the rotation axis, thereby switching between deflection and non-deflection of electrons emitted from the exit hole.

10. The electrostatic deflection and focusing type energy analyzer according to any one of claims 1 to 8, characterized in that the rotating body has a rotation angle of 90° to 180°, and a compensation electrode is provided to compensate for the electric field at the cut surface.

11. An electron spectrometer using the electrostatic deflection focusing type energy analyzer according to any one of claims 1 to 10, an input lens that is disposed such that the entrance hole is located on a lens axis and the lens axis and the rotation axis form the predetermined incident angle, and that captures electrons emitted from the sample and outputs them to the entrance hole; a projection lens that is disposed so that the exit hole is located on a projection lens axis and the projection lens axis and the rotation axis form the predetermined exit angle, and that takes in, through the exit hole, electrons deflected and focused by the electrostatic deflection and focus type energy analyzer; a detector for detecting electrons transmitted through the projection lens; An imaging type electron spectrometer comprising:

12. An electron spectrometer using the electrostatic deflection and focusing type energy analyzer according to any one of claims 1 to 9, an input lens that is disposed such that the entrance hole is located on a lens axis and the lens axis and the rotation axis form the predetermined incident angle, and that captures electrons emitted from the sample and outputs them to the entrance hole; a mirror disposed at the exit hole of the energy analyzer and perpendicular to the axis of rotation; a projection lens that is disposed so that the entrance hole is located on a projection lens axis and the projection lens axis and the rotation axis form the predetermined incident angle, and that takes in, through the entrance hole, electrons that are deflected and focused by the electrostatic deflection and focus type energy analyzer and are reflected by the mirror and then deflected and focused again; a detector for detecting electrons transmitted through the projection lens; A reflective imaging electron spectrometer comprising:

13. The electrostatic deflection and focusing type energy analyzer according to claim 6 or the electrostatic deflection and focusing type energy analyzer according to claim 9, wherein the deflection angle is 90°; an input lens that is disposed such that the entrance hole is located on a lens axis and the lens axis and the rotation axis form the predetermined incident angle, and that captures electrons emitted from the sample and outputs them to the entrance hole; an electrostatic lens that is disposed such that the exit hole is located on an electrostatic lens axis and the electrostatic lens axis and the rotation axis form the predetermined exit angle, and that takes in, through the exit hole, electrons that are deflected and focused by the electrostatic deflection and focus type energy analyzer; a two-dimensional spin filter disposed on the axis of the electrostatic lens at the exit side of the electrostatic lens; a projection lens that captures electrons reflected by the spin filter and a detector that detects electrons that have passed through the projection lens; A spin vector distribution imaging device comprising:

14. The electrostatic deflection and focusing type energy analyzer of claim 6; an input lens that is disposed such that the entrance hole is located on a lens axis and the lens axis and the rotation axis form the predetermined incident angle, and that captures electrons emitted from a sample and emits the electrons to the entrance hole; a two-dimensional spin filter disposed at the exit hole of the electrostatic deflection and focusing type energy analyzer and perpendicular to the rotation axis; a projection lens that is disposed so that the entrance hole is located on a projection lens axis and the projection lens axis and the rotation axis form the predetermined incident angle, and that takes in, through the entrance hole, electrons that are deflected and focused by the electrostatic deflection and focus type energy analyzer and are reflected by the two-dimensional spin filter and then deflected and focused again; a detector for detecting electrons transmitted through the projection lens; A spin vector distribution imaging device comprising:

15. 10. The electrostatic deflection and focusing type energy analyzer according to claim 9, wherein the deflection angle is 90 degrees; an input lens that is disposed such that the entrance hole is located on a lens axis and the lens axis and the rotation axis form the predetermined incident angle, and that captures electrons emitted from a sample and emits the electrons to the entrance hole; an electrostatic lens that is disposed such that the exit hole is located on an electrostatic lens axis and the electrostatic lens axis and the rotation axis form the predetermined exit angle, and that takes in, through the exit hole, electrons that are deflected and focused by the electrostatic deflection and focus type energy analyzer; a two-dimensional spin filter disposed on the axis of the electrostatic lens at the exit side of the electrostatic lens; a first projection lens that captures electrons reflected by the spin filter and a first detector that detects electrons that have passed through the first projection lens; a second projection lens that is disposed so that the exit hole is located on a projection lens axis and the projection lens axis and the rotation axis form the predetermined exit angle, and that takes in, from the exit hole, electrons that are converged without being deflected by the electrostatic deflection and convergence type energy analyzer; a second detector for detecting electrons transmitted through the second projection lens; A spin vector distribution imaging device comprising:

16. A spin vector distribution imaging device according to any one of claims 13 to 15, characterized in that the electrostatic deflection and focusing type energy analyzer having a deflection angle of 90° is replaced with a combination of multiple electrostatic deflection and focusing type energy analyzers according to claim 7, or with a combination of multiple electrostatic deflection and focusing type energy analyzers according to any one of claims 1 to 5 having a deflection angle set to 45° to 150°.

17. A spin vector distribution imaging device as described in any one of claims 13 to 16, characterized in that it is provided with a spin rotator arranged inside or outside at least one of the input lens and the electrostatic lens, rotating spins by 90° in a plane perpendicular to each lens axis.

Images