JP2715406B2 - Electron energy analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to an ESCA (Electron Spectroscopy for Chemic).
al Analysis). (B) Conventional technology and its problems FIG. 3 is a configuration diagram of a conventional electron energy analyzer. This electron energy analyzer is of a non-dispersive type configured by combining energy filters. Electrons excited by the X-ray irradiation and emitted from the sample 20 are collected by the converging lens 21 and pass through the deceleration field 22, high-energy electrons are removed by the pre-filter 23, and enter the low-pass filter 24, where Electrons smaller than the kinetic energy are folded and pass through the aperture 25 to enter the high-pass filter 26, and only electrons larger than a predetermined kinetic energy pass through the high-pass filter 26 and are guided to the electron multiplier 27 as a detector. Will be crushed.
Reference numeral 28 denotes a quadrapole lens for determining the beam direction. In such a conventional energy analyzer, the sample
In order to change the trajectory of the electrons emitted from 20, a converging lens 21 and an electrode such as a pre-filter 23 are required, so that the structure is complicated, and the X-ray for exciting the sample 20 is also transmitted from a specific direction. Therefore, it was necessary to perform an operation such as rotating the sample 20 to change its direction during the analysis. The present invention has been made in view of the above points,
An object of the present invention is to provide an energy analyzer having a relatively simple structure and capable of performing an analysis without moving a sample. (C) Means for Solving the Problems In the present invention, in order to achieve the above object, X
A non-dispersive electron energy analyzer that irradiates a beam or an electron beam and analyzes the energy of electrons emitted from the sample is obtained by rotating an arc having the sample mounting position as a center of curvature around one axis. And a dome-shaped low-pass filter obtained by rotating an arc centered on a position at a predetermined distance from the center of curvature in a direction perpendicular to the axis around the axis. The filter is provided downstream of the high-pass filter with respect to the sample, and is configured such that electrons emitted from the sample are returned by the low-pass filter after passing through the high-pass filter and guided to the detector. . (D) Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of one embodiment of the present invention. In the figure, 1 is a sample, 11 is a filament, 2 is an X-ray source as an excitation source for the sample 1, and the X-ray source 2 is formed in a ring shape so as to surround the sample 1. Reference numeral 3 denotes an electron gun used for performing Auger analysis, and 4 denotes a shield surrounding the X-ray source 2. 5 is the first grid, 6 is the second grid 6a and the third grid
This is a high-pass filter including a grid 6b. Reference numeral 7 denotes a low-pass filter. The low-pass filter 7 includes a fourth grid 7a, a fifth grid 7b continuous with the fourth grid 7a, and a sixth grid 7c. Each grid 5
7c are each formed in a mesh shape. Reference numeral 9 denotes a detector such as an electron multiplier. The detector 9 is formed in a ring shape around an axis 8 passing through a point O on the sample 1. Therefore, the electrons emitted from sample 1
Because it can be captured sufficiently over 360 degrees,
The detection sensitivity is improved over the conventional example. Reference numeral 10 denotes an electrode for suppressing emission of secondary electrons due to electrons having high energy. This electrode 10 is formed along the low-pass filter 7, and its potential is the ground potential. . In the present invention, the high-pass filter 6 is formed in a hemispherical shape with the point O on the mounting position of the sample 1 as a center of curvature, while the fifth and sixth grids 7b, 7 of the low-pass filter 7 are formed.
c is formed in a dome shape obtained by rotating an arc having a center O ′ at a position separated from the center of curvature O by a predetermined distance around the axis 8. Further, the low-pass filter 7 is provided downstream of the high-pass filter 6 with respect to the sample 1. The reason why the high-pass filter 6 is formed in a hemispherical shape is that the trajectory of the electrons emitted from the sample 1 is always incident in the normal direction without being bent by the high-pass filter 6, and is guided to the low-pass filter 7 in the subsequent stage. It is. Further, the low-pass filter 7 is formed in a dome shape because the incident angle and the reflection angle of the electrons guided to the low-pass filter 7 are matched as shown by the phantom line, and the electrons turned back by the low-pass filter 7 are surely formed. This is for guiding to the detector 9. In this embodiment, the low-pass filter 6, the high-pass filter 7, and the first grid 5 are all formed with openings for inserting the electron gun 3 and the like. Further, the fourth grid 7a is formed continuously on the fifth grid 7b of the high-pass filter 7 as described above.
Is formed in a hemispherical shape with the point O as the center of curvature. The first grid 5 is also formed in a hemispherical shape. Next, the potential and action of each of the grids 5 to 7c will be described. The first grid 5 has a ground potential, and the second grid 6a has the same potential -v as the fourth and fifth grids 7a and 7b. Thereby, the first grid 5 and the second grid 5
Apply a deceleration field of -V to 6a. The third grid 6b is
The potential -E is lower than -V.
Electrons having higher energy than E pass through the grid 6b. The sixth grid 7c is the third grid 6b
The potential is slightly lower than that of-(E + ΔE). The electrons that have passed through the third grid 6b are accelerated to V between the third grid 6b and the fourth and fifth grids 7a and 7b.
4, between the fifth grid 7a, 7b and the sixth grid 7c,
Electrons having an energy lower than (E + ΔE) are bent and guided to the detector 9. FIG. 2 is a diagram showing the characteristics of the filter of this embodiment. The resolution of this energy analyzer is a half width ΔE. In this way, in the electron energy analyzer of the present invention, the electrons emitted from the surface of the sample 1 pass through the high-pass filter 6 and are bent by the low-pass filter 7 to draw a parabolic trajectory and are guided to the detector 9. The structure is relatively simple without the necessity of an electrode such as a converging lens or a pre-filter for changing the trajectory of electrons unlike the conventional example. In the above-described embodiment, the low-pass filter 6, the high-pass filter 7, and the like have the openings for inserting the electron gun 3, but as another embodiment of the present invention, the X-rays are not formed. You may comprise so that it may irradiate only a line. In the electron energy analyzer of the present invention, by using an ion gun instead of the electron gun 3,
The ion etching can be performed without moving the sample 1. (E) Effect As described above, according to the present invention, in the non-analytical type electron energy analyzer that irradiates a sample with X-rays or electron beams and analyzes the energy of electrons emitted from the sample, A hemispherical high-pass filter obtained by rotating an arc having a position as a center of curvature around one axis, and an arc having a center at a position away from the center of curvature by a predetermined distance in a direction perpendicular to the axis is formed around the axis. And a dome-shaped low-pass filter obtained by rotating the filter, the low-pass filter is provided at a stage subsequent to the sample than the high-pass filter, and electrons emitted from the sample are passed through the high-pass filter. Since it is configured to be bent by a low-pass filter and guided to the detector, a converging lens and a front-stage Since the detector can be placed at a position other than the axis without the need for electrodes such as filters, the structure is relatively simple, and the sample can be irradiated with X-rays from any direction. In addition, no operation such as rotating the sample is required at the time of analysis.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of one embodiment of the present invention, FIG. 2 is a characteristic diagram of a filter, and FIG. 3 is a configuration diagram of a conventional example. 1 ... sample, 2 ... X-ray source, 6 ... high-pass filter,
7: low-pass filter, 8: axis, O: center of curvature.

Claims (1)

(57) [Claims] In a non-dispersive electron energy analyzer that irradiates a sample with X-rays or an electron beam and analyzes the energy of electrons emitted from the sample, a circular arc having the sample mounting position as a center of curvature is rotated around one axis. And a dome-shaped low-pass filter obtained by rotating an arc centered on a position at a predetermined distance from the center of curvature in a direction perpendicular to the axis and around the axis. The low-pass filter is provided downstream of the high-pass filter with respect to the sample, and electrons emitted from the sample are returned by the low-pass filter after passing through the high-pass filter and guided to the detector. And an electron energy analyzer. 2. 2. The electron energy analyzer according to claim 1, wherein an opening for inserting an electron gun or the like is formed in a part of the high-pass filter and the low-pass filter.