JP3360115B2 - Angle-resolved electron spectrometer with diffraction plane aperture transmission energy control system and analysis method using this spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle-resolved electron spectrometer of a diffraction plane aperture transmission energy control type and an analysis method using the spectrometer, and more particularly to an X-ray photoelectron spectrometer, an Auger electron spectrometer, and the like. The present invention relates to an angle-resolved electron spectrometer of a diffraction surface aperture transmission energy control system such as a photoelectron diffraction device and an analysis method using the spectrometer.

[0002]

2. Description of the Related Art Electron spectrometers such as an X-ray photoelectron spectrometer, an Auger electron spectrometer, and a photoelectron diffractometer are known as analyzers for solid surfaces. Used in the material industry.

[0003] In these electron spectrometers, an apparatus using angle-resolved electron spectroscopy realizes angle-resolved measurement by photoelectron / Auger electron spectroscopy (XPS, AES) measurement or similar measurement using ions. . This electron spectroscopy device utilizes the technology of the field of electro-optics from the viewpoint of using not only the surface analysis technology but also the technology of the spectroscopic analysis technology, and from the viewpoint of limiting the angle of electrons to an electro-optical or geometric angle. It is known as a device that can be realized by using it.

[0004] Angle-resolved electron spectroscopy applied to conventional electron spectroscopy includes the following two main measurement methods. In each of these two measurement methods, a combination of a hemispherical analyzer and an incident lens is used. In an electron spectrometer using a combination of a hemispherical analyzer and an incident lens, high energy resolution in measurement is realized. More specifically, by slowing down the electrons in the entrance lens, the kinetic energy is made constant in the analyzer, and as a result, the energy resolution can be made constant regardless of the magnitude of the energy of the measured electrons, In addition, electrons are condensed at the entrance of the analyzer by the lens function of the incident lens, and high sensitivity measurement can be realized. Here, the incident lens system has two functions, namely, a deceleration function for decelerating the electrons and a converging function for converging the electrons to the entrance of the analyzer.

In the first method, as shown in FIG. 1, when an electron emitted from one point on the sample surface 1 enters the analyzer, the electron at a solid angle that takes in the electron from the incident lens 3 is taken into consideration. The angle is limited. In the first method, the incident lens 3 has a function of converging electrons emitted from the sample 1 to the entrance of the analyzer, and has an angular resolution of a capturing area Sa on the sample 1 and a lens converging surface (capturing area Sa). Is equivalent to the image plane of the object point plane), and is geometrically determined by the size of the aperture 4 provided at the entrance of the analyzer and the position of the virtual lens 3.

That is, in the electrostatic lens optical system shown in FIG. 1, the capture area Sa of the sample 1 corresponds to an object point, and the aperture of the aperture 4 is located at an image point position where an image of the object point is formed. ing. Therefore, the electrons from the region Sa are guided to the analyzer.

In the second method, as shown in FIG. 2, the angle of the electrons is limited by a slit or an aperture 6. That is, the slit or the aperture 6 defines a parallel passage of electrons, and only the electrons passing through this passage are introduced into the analyzer. In this method, the angular resolution is determined geometrically by the shape of the aperture. Further, in the second method, unlike the first method, it is possible to measure with a high angular resolution even in a wide measurement area.

In each of the above-described photoelectron spectroscopy measurements, angle-resolved measurement is performed. In summary, the first method is to limit the angle by reducing the solid angle taken by the incident lens with respect to the measurement area, and the second method is
In this method, an aperture for regulating the angle is attached to the entrance of the incident lens. Both of them have a common feature that the angular resolution is geometrically determined because the incident electrons are mechanically limited in angle.

[0009]

The above-described first method is widely applied to an electron spectrometer using a hemispherical analyzer. However, there is a problem that the angular resolution depends on the size of the capturing area Sa, and when a large area is measured instead of a minute area, it is impossible to detect with a high angular resolution. There is.

In the above-mentioned second method, there is a problem that as the angle restriction on electrons becomes stricter, the loss increases, the detection sensitivity deteriorates, and the detection intensity decreases. These problems result in a problem that the measurement requires a long time and the reliability of the measurement result is reduced. Further, in the second method, when changing the angular resolution, there is a problem in that the aperture has to be exchanged, and the like is troublesome.

In the field of semiconductor technology in recent years, surface analysis technology by electron spectroscopy is indispensable for development, evaluation and analysis of various materials. Among them, angle-resolved measurement is of great importance, such as depth analysis and structural analysis using photoelectron diffraction measurement. However, due to the above-mentioned problems, the current analysis request has not been sufficiently satisfied. In recent years, there has been a demand for the development of an electron spectrometer capable of analyzing electrons with higher angular resolution that solves the above-mentioned problem.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to realize high energy resolution, high angular resolution, and high sensitivity electron spectrometry. It is an object of the present invention to provide an angle-resolved electron spectrometer capable of controlling the transmission energy of a diffraction plane aperture and an analysis method using the spectrometer.

Further, the present invention provides an angle-resolved electron spectrometer of a diffraction surface aperture transmission energy control system capable of realizing angle-resolved electron spectrometry having a lens whose position of the diffraction surface is small for different energies, and An object of the present invention is to provide an analysis method using a spectroscope.

According to the present invention, there is provided an inlet for allowing the incorporation of electrons emitted from the sample surface in various directions according to the composition and structure thereof, and the inlet defines a measurement region on the sample. An electron capturing means for converging electrons incident from the captured electrons in parallel along the optical axis toward the diffraction surface and forming an angle pattern of emitted electrons on the diffraction surface; A first electron lens forming means for forming an electrostatic electron lens, and an aperture disposed on the diffraction surface of the condenser lens, the passage having a passage for allowing collected electrons to pass therethrough, and an electron to be measured. And a first aperture for limiting the angle of the incident electrons to select electrons having a certain polar angle and azimuth from the sample, and passing through the first aperture. Hand leading electron When, angle-resolved electron spectrometer for angle-resolved measurement, characterized by comprising an electronic analyzer for analyzing guided electrons are provided.

According to the present invention, the step of taking in the electrons emitted from the sample surface in various directions in accordance with the composition and structure thereof in advance by defining a measurement area on the sample, Condensing electrons incident parallel to the optical axis toward a diffraction surface thereof with a first electrostatic electron lens, and forming an angle pattern of emitted electrons on the diffraction surface; The condensing electron is directed to an electron passage of the first aperture to which a potential corresponding to the electron to be measured is applied, and is allowed to pass through the passage through the passage. Angle limiting step of selecting electrons having a certain polar angle and azimuthal angle from the sample, guiding the electrons passing through the first aperture, and analyzing the energy of the guided electrons. And Angle-resolved electron spectrometer electronic analytical method used for angle-resolved measurement, characterized in, is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an angle-resolved electron spectrometer employing a diffraction surface aperture transmission energy control system according to the present invention will be described below with reference to the drawings.

FIG. 3 schematically shows an angle-resolved electron spectrometer employing a diffraction surface aperture transmission energy control system according to one embodiment of the present invention. In FIG. 3, 1
0 is a solid sample whose surface is to be measured by this system. The sample 10 is irradiated with X-rays from an X-ray source (not shown), and photoelectrons are emitted from the sample surface by the external photoelectric effect by the X-ray irradiation. In the measurement using photoelectron spectroscopy, photoelectrons are emitted from a sample by X-rays of a constant energy, and the electron spectrometer, ie,
By accurately measuring the kinetic energy of photoelectrons with an electron analyzer, the binding energy (binding energy) of the electrons in the sample is determined.

The apparatus shown in FIG. 3 comprises an energy analyzer 14 as an analyzer for analyzing the energy of photoelectrons, and an angle-resolving incident lens system 12 attached to the entrance side of the energy analyzer 14.

The angle-resolving incident lens system 12 forms an electron intake 16 for taking in the emitted photoelectrons and a preceding (first) electrostatic lens 18 for converging the acquired electrons to the analyzer entrance. Electrode section 20, a diffractive surface aperture 22 for limiting the incident angle of the photoelectrons guided to the energy analyzer 14, and an intermediate portion for converging the divergent electrons passing through the diffractive surface aperture 22 to the intermediate aperture 32. A retarding electrode portion 30 for forming the (second) electrostatic lens 28, an intermediate aperture 32 having an electron passage, and divergent electrons passing through the intermediate aperture 32 are again input to the input portion of the energy analyzer 14. A retarding electrode for forming a subsequent (third) electrostatic lens 38 having a retarding function for converging It is provided with a subsequent aperture 42 having an electron passage port for guiding 40 and converged electron energy analyzer 14.

The energy analyzer 14 has an electron analyzer 24 formed in a hemispherical shape and applied with a high voltage to generate an electric field therein, and a detector 26 for detecting photoelectrons. The detector 26 is connected to a position computer for calculating the incident position, and employs a so-called position-sensitive detector that detects the incident position and energy of photoelectrons and outputs data as a detection signal.

The angle-resolving incident lens system 12 and the energy analyzer 14 are arranged in a magnetic shield (not shown), and these, including the sample 10, are arranged in a evacuated housing. Further, the electron spectrometer controls a rotation mechanism 30 including a stepping motor for rotating the sample 10 to be measured, an X-ray source to generate X-rays having a desired wavelength, and supplies a voltage to be applied to the analyzer 24. A measurement control unit (not shown but usually used by a personal computer, which controls according to the sample and processes the data related to the high voltage applied to the analyzer 24 and the detection data from the detector 26 to analyze the sample. ).

The electrodes of the inner and outer spheres of the analyzer 24 are supplied with a potential for energy analysis.
6 and the intermediate aperture 32 are given a ground potential, and the electrodes 20, 30, and 40 are given a potential that satisfies the convergence conditions of the electrostatic lenses 18, 28 and 38 formed by these electrodes. A retarding potential is applied to each of the apertures 42 at the subsequent stage, and a potential for adjusting kinetic energy for reducing a change in the diffraction surface is applied to the diffraction surface aperture 22.

These potentials are applied from a potential applying circuit 50. Here, when the X-ray intensity to be applied to the sample 10, in other words, the power to be input to the X-ray source is determined, the value of the power is input to the potential setting circuit 52,
When the expected composition name of the sample 10 is similarly input from the outside to the potential setting circuit 52, the energy of electrons expected to be emitted from the sample 10 is estimated. The estimated energy corresponds to the predicted binding energy of the element to be measured, and the potential setting circuit 52 uses the diffraction surface aperture 2 based on the predicted energy.
2 is determined, and based on this potential, the potential to be applied to the electrode 20 forming the preceding electrostatic lens 18 is determined. Based on the output from the potential setting circuit 52, each of the electrodes 20, 30, 40 and the apertures 32, 4
The potential set to 2 is applied from the potential applying circuit 50. In a state where the adjusted potential is applied to the electrode 20 after the fine adjustment in the potential setting circuit 52, the diffraction surface of the electrostatic lens 18 formed by this electrode 20 is positioned on the surface of the diffraction surface aperture 22. The actual measurement is started after this adjustment.

FIG. 4 schematically shows details of the optical system of the angle resolving incident lens system 12 shown in FIG. The optical system of the lens system 12 shown in FIG. 4 is divided into two optical system parts with an intermediate aperture 32 as a boundary, and the front lens system part is an angle limiting unit 12 that limits the angle of an incident electron beam. The lens system part at the subsequent stage is a retarding unit 12-2 for decelerating the electrons so that the kinetic energy of the electrons becomes equal to the set analyzer transmission energy and introducing the electrons to the electron analyzer 24. In the lens system 12 shown in FIG. 4, electrons emitted from the sample 10 pass through the inlet 16 and are introduced into the lens electrode unit 20. At this time, the measurement area on the sample 10 is determined by the size of the inlet 16. The electrostatic lens 18 formed on the lens electrode unit 20 in the angle limiting unit 12-1 converts electrons entering in parallel into the diffraction surface of the electrostatic lens 18, that is, the diffraction surface aperture 22 arranged on the back focal plane. It has a function to converge to. More specifically, when the sample 10 is irradiated with X-rays, electrons are emitted from the sample 10 in various directions according to the composition and structure of the sample 10,
Although directed to the electrostatic lens 18, the diffractive surface aperture 22
Is located on the diffraction plane, that is, the back focal plane,
Only electrons incident on the electrostatic lens 18 in parallel with the optical axis of the electrostatic lens 18 are converged on the aperture of the diffraction surface aperture 22 that allows the passage of electrons, and pass through the diffraction surface aperture 22 into the analyzer 24. Be guided. In other words, an angle pattern of emitted electrons is formed on the diffraction surface, and by arranging the aperture 22 on the diffraction surface, electrons emitted from the sample 10 and having a certain polar angle and azimuth are collected. Thus, only electrons directed in a predetermined direction can be selectively captured. Here, the size of the diffraction surface aperture determines the range of the capture angle.
Further, a potential corresponding to the electrons to be measured is applied to the diffraction surface aperture 22, and the kinetic energy of the electrons passing through the diffraction surface aperture 22 is maintained substantially constant.

The electrons that have passed through the diffraction surface aperture 22 are
It is directed into the intermediate lens electrode section 30. The intermediate lens 28 formed in the intermediate lens electrode part 30 has a function of converging electrons whose kinetic energy is maintained substantially constant by being limited in angle by the intermediate aperture 32 by its lens action. The electrons that have passed through the intermediate aperture 32 are directed to the inside of a lens electrode unit 40 that forms the subsequent electrostatic lens 38. The latter electrostatic lens 38 has a function of decelerating the electrons so that the kinetic energy of the electrons becomes equal to the set analyzer transmission energy and converging the electrons to the latter aperture 42 so that the electrons can efficiently enter the analyzer entrance. have. The electrons passing through the rear-stage aperture 42 are subjected to energy analysis by the energy analyzer 14. That is, only specific electrons of the electrons introduced into the analyzer 24 are incident on the detector 26 through the analyzer path on the arc due to the electric field formed in the analyzer 24. The position and intensity of the light incident on the detector 26 are input to the measurement control unit as data and analyzed, and the measurement control unit analyzes the structure, composition, and the like of the sample surface.

As described above, the first electrostatic lens 18, the diffraction surface aperture 22, the intermediate converging lens electrode 30, the first electrostatic lens 18 formed by the intake port 16, the pre-converging lens electrode 20, and so on.
, An intermediate aperture lens 32, and a second convergent lens electrode 40 formed by
An angle-resolved electron spectrometer is constituted by the electrostatic lens 38, the rear aperture 42, and the electron analyzer 24. At this time, the angular resolution is determined by the size of the angular dispersion of the diffraction pattern formed by the lens function of the first electrostatic lens 18 and the size of the diffraction plane aperture 22.

The angle resolving incidence lens system 12 according to one embodiment of the present invention will be described by focusing on the following effects while comparing with the prior art.

(1) According to the decomposition type electron spectrometer of the present invention, it is possible to realize electron spectrometry having a high angular resolution in which the angular resolution does not depend on the capturing area and a wide area can be measured.

The obtained angular resolution of the conventional lens system using the image plane aperture shown in FIG. 1 will be compared with that of the lens system shown in FIG.
In the conventional lens system using the image plane aperture of FIG. 1, the angular resolution is determined by the size of the measurement area, the lens length (position), and the size of the image plane aperture. As shown in FIG. 5, when the size of the measurement area is a circle of radius r, the size of the image plane aperture is a circle of radius R, and the lens length is D,
The angular resolution is

[0030]

(Equation 1)

Is defined as Therefore, in order to restrict the angle strictly, the lens length D may be increased, or the size R of the image plane aperture may be reduced. However, as the measurement area r increases, the angular resolution decreases accordingly. In contrast, in a lens system using a diffraction surface aperture as shown in FIG. 4,
The angular resolution is determined only by the size of the diffraction plane aperture. That is, the angular resolution does not depend on the size of the measurement area, and can be improved by reducing the diameter of the diffraction surface aperture.

(2) According to the decomposition type electron spectrometer of the present invention, electron spectrometry with high angular resolution and high sensitivity without using an angle limiting aperture can be realized.

In the conventional lens system using the angle limiting aperture shown in FIG. 2, the angular resolution is determined only by the shape of the aperture. That is, as shown in FIG. 6, when the size of the measurement area is a circle with a radius r, the work distance is D, the length of the aperture is d, and the length of the aperture opening is a, the angular resolution is:

[0034]

(Equation 2)

Is defined as Therefore, in order to tighten the angle limit, the length d of the aperture may be increased and the length a of the aperture opening may be reduced. The size of the measurement area does not affect the angular resolution. However, as the length a of the aperture opening decreases, the aperture (transmittance) decreases accordingly, and the detection intensity decreases. On the other hand, in a lens system using a diffraction surface aperture as shown in FIG. 4, on the other hand, the angular resolution is determined only by the size of the diffraction surface aperture, and therefore does not depend on the size of the intake. The opening (transmission) rate is 100%.

(3) According to the resolved electron spectrometer of the present invention, it is possible to realize angle-resolved electron spectrometry having a lens whose position on the diffraction surface has a small change with respect to different energies. That is, a potential corresponding to the electrons to be measured is applied to the diffraction surface aperture 22, and the diffraction surface aperture 2
The kinetic energy of the electrons passing through 2 is maintained substantially constant. Therefore, the diffractive surface of the electrostatic lens 18 is always formed at the position of the diffractive surface aperture 22. As a result, the electrostatic lens 18 is formed as a lens whose positional change of the diffractive surface is small for different energies. Generally, when the energy of electrons changes, the position of the diffraction surface formed also changes. In general, the aperture for limiting the angle is almost always grounded and at the ground potential, and the change in the position of the diffraction surface due to the change in energy becomes remarkable in a low energy region. In electron spectroscopy, electrons with an energy width of several tens of eV are often measured simultaneously, and the position of the diffraction surface may change significantly. However, as described above, the potential corresponding to the electrons to be measured is applied to the diffraction surface aperture 22, and the diffraction surface of the electrostatic lens 18 is always formed at the position of the diffraction surface aperture 22. Large changes are prevented.

Hereinafter, the result of a simulation of the decomposition type electron spectrometer according to one embodiment of the present invention will be described with attention paid to the angular resolution.

The following simulation results will be described assuming that angle-resolved photoelectron spectroscopy is performed using the resolution type electron spectrometer shown in FIG. 4 as a model.

FIG. 7 shows the result of simulating the electron trajectory in the angle-resolved / retarding lens system. The reference numerals shown in FIG. 7 indicate the regions where the parts or portions indicated by the corresponding reference numerals shown in FIG. 3 are formed. In this simulation, it is assumed that an electron having an energy of 10 keV (Ek) is measured at an analyzer transmission energy of 12 eV (Epass), and the energy of the electron passing through the diffraction surface aperture 22 is 5 eV.
keV (Ea) (the diffraction plane aperture potential is-
The measurement area is set to a diameter of 4 mm. Here, before the determination of the angular resolution, that is, the first lens 18 forms a diffraction surface at the position of the aperture 22 by the lens function as described above. In the embodiment of the present invention, the diffraction surface aperture 22 which is not the ground potential is provided, and a potential for adjusting the kinetic energy is applied to the diffraction surface aperture 22 to suppress the change of the diffraction surface. In order to clarify this point, simulation results when the potential of the diffraction surface aperture 22 is -5000 V (differential surface aperture passing energy 5 keV) (type A) and when the potential of the diffraction surface aperture 22 is ground 0 V (type B) Are described below in comparison with each other.

FIGS. 8 and 9 show the change in the position of the diffraction surface with respect to different energies. FIG. 8 shows the simulation result of type A, and FIG. 9 shows the simulation result of type B. 8 and 9, the abscissa indicates the change width of the energy, and the ordinate indicates the distance from the sample to the position of the diffraction surface. ± 10 eV is assumed as the energy width of the electrons simultaneously detected by the electron spectrometry. When the energy of electrons changes in both types A and B, the position of the diffraction surface changes in the optical axis direction. It is also apparent from FIGS. 8 and 9 that the degree of the change increases as the energy decreases. FIG. 10 shows the rate of change, ie,
The slope of each plot is shown. In FIG. 10, the horizontal axis represents the energy of the measured electrons, the vertical axis represents the rate of change (slope) of the position of the diffraction plane, the straight line connected by □ represents the slope of type A, and the straight line connected by black circles. Indicates a type B inclination. As is apparent from FIG. 10, the change rate of the diffraction plane position is smaller in the type A than in the type B, and the energy indicating the intersection of the type A and the type B is equal to the aperture transmission energy 5000 eV. As described above, the rate of change in the position of the diffraction surface can be controlled by adjusting the energy passing through the diffraction surface aperture. In other words, when the transmitted energy is increased, ±
Since the energy change width of 10 eV becomes smaller as a ratio to the transmitted energy, the change ratio of the diffraction plane position also becomes smaller. As described above, in the embodiment of the present invention, the potential of the diffractive surface aperture 22 is adjusted, so that a lens system with less energy dependence can be realized, and high-angle resolution and high-energy resolution, and high-sensitivity photoelectron spectroscopy can be realized. be able to.

In the resolution type electron spectrometer according to one embodiment of the present invention, the energy resolution is determined by the rear lens. Here, the potential of the intermediate aperture 32 is
Because it is the ground, the front lens 18 and the rear lens 3
8 can be controlled and operated independently without interfering with each other. In addition, it is presumed that the rear lens 38 generally exhibits the same performance as the incident lens system used in the photoelectron spectroscopy device. That is, according to the electron spectroscope provided with the angle-resolving / retarding independent operation type incident lens system of the present invention, high-angle resolution, high-energy resolution, and high-sensitivity photoelectron spectroscopy can be realized.

As described above, the angle-resolved electron spectrometer of the diffraction plane aperture transmission energy control system according to the present invention has the following features.

Electrons (or ions) entering the entrance lens system from the inlet are condensed by the diffraction surface forming lens at the preceding stage, and the angle of the electrons is limited by an aperture arranged at the position of the diffraction surface. The electrons that have passed through the diffraction surface aperture and whose angle has been limited are converged on the intermediate aperture by the condensing lens in the preceding stage. The electrons that have passed through the intermediate aperture are retarded and converged by the subsequent lens electrode. The electrons that have passed through the latter aperture are energy analyzed by a hemispherical analyzer, and angle-resolved electron spectroscopy is performed.

The system of the present invention comprises an angle-resolved and complex retarding lens system and an electronic analyzer. The incident lens system includes a lens for limiting the angle and a diffractive surface aperture in front of the intermediate aperture, and a rear aperture. It is composed of a lens for retarding and a rear aperture.

By applying a potential for adjusting the transmission energy to the diffraction plane aperture, it is possible to control the rate of change of the diffraction plane position with respect to electrons having different energies. That is, by increasing the transmission energy on the diffraction surface, the rate of position change on the diffraction surface can be reduced.

[0046]

As described above, according to the angle-resolved electron spectroscope of the diffraction plane aperture transmission energy control type and the analysis method using this spectrometer of the present invention, high energy resolution, high angular resolution and high sensitivity are obtained. Electron spectrometry can be realized.

According to the angle-resolved electron spectroscopy of the diffraction plane aperture transmission energy control system of the present invention and the analysis method using the spectroscope, the angle-resolved type in which the change in the position of the diffraction plane is reduced for different energies Electron spectrometry can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the structure of an electron lens optical system arranged on the electron incident side of a hemispherical analyzer in a conventional electron spectrometer using angle-resolved electron spectrometry.

FIG. 2 is a schematic diagram showing the structure of an electron lens optical system arranged on the electron incident side of a hemispherical analyzer in a conventional electron spectrometer using angle-resolved electron spectrometry.

FIG. 3 is an explanatory view schematically showing an angle-resolved electron spectrometer of a diffraction surface aperture transmission energy control type according to an embodiment of the present invention.

FIG. 4 is a schematic diagram showing details of an optical system of an angle-resolved electron spectrometer of a diffraction plane aperture transmission energy control type shown in FIG. 3;

FIG. 5 is a schematic diagram for explaining an angular resolution derived from a measurement area and a size of an image plane aperture in the optical system of the incident lens system shown in FIG. 1;

6 is a schematic diagram for explaining an angular resolution derived from a measurement area and an aperture dimension in the optical system of the incident lens system shown in FIG. 2;

FIG. 7 is an explanatory diagram showing a result of simulating an electron trajectory in the incident lens system shown in FIG. 4;

8 is a graph simulating a change in the position of the diffraction surface with respect to different energies when the potential of the diffraction surface aperture is 4900 V (type A) in the simulation shown in FIG.

9 shows a case where the potential of the diffraction surface aperture in the simulation shown in FIG. 7 is ground 0V (type B)
7 is a graph simulating a change in the position of the diffraction surface with respect to different energies in FIG.

FIG. 10 is a graph showing a ratio (slope) of a change in the position of the diffraction surface with respect to the energy of the measured electrons in the simulation shown in FIG. 7;

[Explanation of symbols]

 Reference Signs List 1,10 ... Sample 3 ... Incident lens 4,6 ... Aperture 12 ... Angle-resolving incident lens system 14 ... Energy analyzer 16 ... Electron take-in port 18 ... Electrostatic lens 20: front electrode section 22: diffraction plane aperture 24: electron analyzer 26: detector 28: middle electrostatic lens 30: middle electrode section 38 ...・ Electrostatic lens at the later stage 40 ・ ・ ・ Electrode part at the later stage

Continuing on the front page (72) Inventor Shinji Omori 1-5-2 Monzennakacho, Koto-ku, Tokyo Yamaguchi Building 302 (72) Inventor Masaru Shiraki 1-27-26 Higashiyama, Meguro-ku, Tokyo 102 Chalet Higashiyama 102 (56) Reference Reference JP-A-62-290056 (JP, A) JP-A-9-106780 (JP, A) JP-A-3-165448 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 49/44 H01J 49/06 G01N 23/227

Claims (6)

(57) [Claims] An inlet for allowing the incorporation of electrons emitted from a sample surface in various directions depending on its composition and structure.
This inlet defines the measurement area on the sample.
Electron capturing means, and the incident electrons are incident parallel from the captured electrons along the optical axis.
Focused electrons are directed toward the diffraction surface, and
First electron lens forming means for forming a first electrostatic electron lens for forming an angular pattern of emitted electrons ; passage of the collected electrons, which is an aperture disposed on the diffraction surface of the condenser lens; A potential corresponding to the electrons to be measured is applied, and an angle limit is given to the incident electrons to set a certain polar angle and azimuth angle from the sample.
Angle-resolved measurement , comprising: a first aperture for selecting an electron having: a means for guiding electrons passing through the first aperture; and an electron analyzer for analyzing the guided electrons. angle-resolved electron spectrometer for. A second electron lens forming means for forming a second electron lens for converging electrons passing through the first aperture; and an electron converged by the second electron lens. A second aperture having a passage opening that allows the passage of the first and second electronic lenses for controlling the energy of electrons passing through the second aperture. An electron lens forming means, and a third aperture having a passage opening for allowing passage of the electrons converged by the third electron lens and introducing the electrons to the electron analyzer. Item 1. An angle-resolved electron spectrometer according to Item 1. 3. The electron lens forming means includes electrode means comprising a plurality of electrodes forming the first electron lens, and applies a potential to the first aperture according to electrons to be measured. And potential applying means for applying an electric potential to the electrode of the electrode means to form an electron lens in the electrode,
The image forming apparatus further includes a potential applying unit that adjusts a potential applied to the electrode according to a potential applied to the first aperture to adjust a diffraction surface of the electron lens to a position of the first aperture. The angle-resolved electron spectrometer according to claim 1, wherein 4. A measurement area on a sample is determined in advance for electrons emitted from a sample surface in various directions according to its composition and structure.
The capture process, and the parallel injection of the captured electrons along the optical axis.
The electrons to be focused are focused on the diffraction surface by the first electrostatic electron lens, and the angle pattern of the emitted electrons is formed on this diffraction surface.
Condensing step to be performed, disposed on the diffraction surface of the condensing lens, directing the condensed electrons to an electron passage of the first aperture to which a potential corresponding to the electrons to be measured is applied, and passing the passage through the passage. Allow and limit the angle of the incident electrons so that certain polar angles from the sample
An angle limiting step of selecting an electron having an azimuth and an azimuth angle; a step of guiding electrons passing through the first aperture; and an analyzing step of analyzing the energy of the guided electrons. An electron analysis method using an angle-resolved electron spectrometer for angle-resolved measurement . 5. The electron guiding step of converging electrons passing through the first aperture toward an electron passage of the second aperture with a second electron lens to permit passage of the electrons through the passage. And e. Passing the electrons passing through the second aperture to the first and the second
Led to a third electron lens which electrically independent with respect to the second electron lens, the energy control step of controlling the energy, the electrons are converged by the third electron lens toward the third aperture 5. A method of analyzing electrons using an angle-resolved electron spectrometer according to claim 4 , further comprising the steps of: allowing passage and selecting controlled electrons to be analyzed in said analysis step. 6. The first electron lens in the angle limiting step is formed of a plurality of electrodes to which a potential is applied, and a potential is applied to the first aperture in accordance with electrons to be measured. The method further includes a potential applying step of adjusting the potential applied to the electrode according to the potential applied to the first aperture to adjust the diffraction surface of the electron lens to the position of the first aperture. Claim 4
Method for analyzing electrons using an angle-resolved electron spectrometer.