JPH0697601B2 - Cylindrical mirror energy analyzer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical mirror surface type energy analyzer used for Auger analysis and the like, and more particularly to an apparatus for improving energy resolution.

[0002]

2. Description of the Related Art Energy used for Auger analysis
As the analyzer, a cylindrical mirror surface energy analyzer (hereinafter abbreviated as CMA) is used because a solid angle of an opening for introducing electrons to be analyzed into the analyzer can be made large.
FIG. 5 is a schematic view showing a main part of a conventional all-cylindrical mirror surface type CMA. In FIG. 5, one side such as an inner cylindrical electrode and an outer cylindrical electrode, which will be described later, is omitted for simplification of description. In the figure, 1 is a sample, and this sample 1 is irradiated with an electron beam 2 from an electron beam source (not shown). As a result, Auger electrons 3 are generated from the surface of the sample 1. Reference numeral 4 denotes an inner cylindrical electrode that is grounded, and the outer cylindrical electrode 5 is coaxial with the inner cylindrical electrode 4.
Is provided, and a negative (−) potential is applied to the outer cylindrical electrode 5 from a variable power source (not shown). Where 4a
Is an entrance opening formed in the inner cylindrical electrode 4 for guiding the Auger electrons 3 generated from the sample 1 into an electric field formed between the inner cylindrical electrode 4 and the outer cylindrical electrode 5, and 4b is It is an emission opening for selectively passing only those of the Auger electrons 3 guided into the electric field, which have a specific orbit. 6 is, for example, a continuous diode type electron beam detector, and 7
Is a slit width variable slit arranged on the front surface of the electron beam detector 6, and the slit width 1 of the variable slit 7 is configured to be variable from the atmosphere side. The energy resolution and incident amount of the electron 3 to the electron beam detector 6 can be changed.

[0003]

By the way, in the conventional apparatus thus constructed, the Auger electrons 3 emitted from the sample 1 take an electron orbit as shown in FIG. Converged. FIG. 6 shows the vicinity of the variable slit 7 when the Auger electron 3 radiated from the sample 1 is dispersed at the half aperture angle Δα = 8 ° and is emitted from the emission opening 4b with energy of −500 ± 0.8 eV. Shows the electron orbit at, and the solid line (a) shows the energy of 500.
It is an electron orbit of eV, and within the dotted line (b) is 500 + 0.8
electron orbit of eV, 500-0.8e in the dashed line (C)
The electron orbit of V is shown. As is clear from FIG. 6, in such a device, the electron orbit in the vicinity of the variable slit 7 greatly spreads, and the aberration of the electron orbit becomes relatively large. FIG. 7 shows the energy value of the analyzer 50 when the slit width of the variable slit 7 is l = 0.45 mm.
This is a spectrum waveform when set to 0 eV, and the energy resolution in this case is 2.89 eV. Also, FIG.
Shows a spectrum waveform when the slit width 1 is 0.2 mm, and the energy resolution in this case is 2.0
It was 3 eV. Therefore, in such a conventional device, even if the slit width 1 of the variable slit 7 is changed, the energy resolution is not improved so much, and energy analysis with high resolution cannot be performed.

The present invention has been made in view of the above points,
An object of the present invention is to provide a cylindrical mirror surface type energy analyzer capable of selectively switching between high resolution energy analysis and high sensitivity analysis in Auger analysis and the like.

[0005]

Means for Solving the Problems The present invention for achieving the above object is to introduce electrons generated by irradiation of a sample with a charged particle beam between an inner cylindrical electrode and an outer cylindrical electrode arranged coaxially, In the device configured to detect the electrons energy-analyzed by the both electrodes by limiting them by a slit provided between the opening formed in the inner cylindrical electrode and the electron beam detector, the opening A second slit is arranged between the slit and the slit, and operating means for inserting and removing the second slit in the electron beam orbit is provided on the atmosphere side.

[0006]

In the energy analysis with high resolution, the second slit is inserted into the electron orbit by the slit moving rod to reduce the orbit aberration near the variable slit of the Auger electron emitted from the emission opening 4b. In this state, the slit width of the variable slit is set small, and the resolution is dramatically improved. During high-sensitivity energy analysis that does not require a high resolution, the second slit 10 is removed from the electron orbit.

[0007]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram showing a main part of a CMA according to an embodiment of the present invention. The same components as those of the conventional device shown in FIG. In FIG. 1, 10 is a second slit arranged between the output opening 4b of the inner cylindrical electrode 4 and the variable slit 7 and in the vicinity of the output opening 4b. It is attached to the rod 11. This slit moving rod 1
Reference numeral 1 denotes a second slit 10 which is pierced through a case 13 while holding a vacuum by a bellows 12 and by moving the slit moving rod 11 in the direction of arrow R or L.
Can be inserted into or removed from the electron orbit, that is, can be positioned on or off the electron orbit.

To what extent the aberration and energy resolution of electron trajectories are improved in the apparatus constructed as described above under the same conditions as in the conventional apparatus will be described.
First, the Auger electrons 3 emitted from the sample 1 have a half-opening angle Δα = 8 before passing through the path to the exit opening 4b.
The light is dispersed at an angle of 0 ° and becomes an Auger electron 3 having an energy value of 500 ± 0.8 eV and is emitted from the emission opening 4b.
Therefore, the second slit 10 is inserted on the electron orbit by the slit moving rod 11. By doing so, the electron trajectories near the variable slit 7 are as shown in FIG. In Fig. 2, the energy in the solid line (a) is 500e.
It is an electron orbit of V, and within the dotted line (b) is 500 + 0.8e
Electron orbit of V, 500-0.8 eV in the dashed line (C)
Is the electron orbit. As is clear from FIG. 2, the electron trajectory in the vicinity of the variable slit 7 is the second slit 10
Is inserted in the electron orbit, the half aperture angle Δα = 8
Even when the light is dispersed at .degree., .DELTA..alpha. '= 2.degree. Is substantially obtained on the side of the emission opening 4b, and the aberration of the electron orbit is smaller than that of the conventional device shown in FIG. FIG. 3 shows such a device, in which the slit width l of the variable slit 7 is l = 0.45 m.
This is a spectrum waveform when the energy value of the analyzer is set to 500 eV in m, and the energy in this case is
The resolution is 2.95 eV. Further, FIG. 4 shows a spectrum waveform when the slit width 1 of the variable slit 7 is 0.2 mm, and the energy resolution in this case was 1.34 eV. Therefore, if the second slit 10 is arranged between the exit opening 4b and the variable slit 7 and the slit width 1 of the variable slit 7 is set small, the resolution is remarkably improved.
Analysis can be performed. Of course, the second slit 10 can be positioned on the electron orbit by the slit moving rod 11 or can be removed from the electron orbit. Therefore, when the resolution is not required so much,
High-sensitivity energy analysis is also possible by removing the slit 10 from the electron orbit.

It should be noted that the above-described embodiment is merely an example and can be modified and implemented. In the above embodiment, the second slit 10 provided with one slit was used, but a slit having a plurality of slits having different slit widths may be used to select an appropriate slit width for analysis. good.

Further, although the present embodiment has been described by taking the all-cylindrical specular energy analyzer as an example, the present invention is not limited to this, and the present invention is applied to a semi-cylindrical specular energy analyzer. May be.

[0012]

As described above in detail, according to the device of the present invention, in the CMA, the second slit is arranged between the variable slit and the emission opening formed in the inner cylindrical electrode, and the second slit is provided. Since the slit can be inserted into and removed from the electron beam orbit by operating from the atmosphere side, a cylindrical mirror surface that can selectively switch energy analysis with high resolution and energy analysis with high sensitivity in Auger analysis etc. A type energy analyzer is provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a main part of a CMA according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining electron beam trajectories in the vicinity of the variable slit of the embodiment apparatus.

FIG. 3 is a diagram for explaining the energy resolution when the slit width 1 of the variable slit is changed in the apparatus of this embodiment.

FIG. 4 is a diagram for explaining energy resolution when the slit width 1 of a variable slit is changed in the apparatus of this embodiment.

FIG. 5 is a schematic diagram showing a main part of a CMA of a conventional device.

FIG. 6 is a diagram for explaining an electron beam trajectory in the vicinity of a variable slit of a conventional device.

FIG. 7 is a diagram for explaining energy resolution when the slit width 1 of the variable slit is changed in the conventional device.

FIG. 8 is a diagram for explaining the energy resolution when the slit width 1 of the variable slit is changed in the conventional device.

[Explanation of symbols]

 1 Sample 2 Electron Beam 3 Auger Electron 4 Inner Cylindrical Electrode 5 Outer Cylindrical Electrode 6 Electron Beam Detector 7 Variable Slit 10 Second Slit 11 Slit Moving Rod 12 Bellows 13 Cases

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01J 49/06 4230-5E // G01N 23/227 7172-2J

Claims (1)

[Claims] 1. Electrons generated by irradiation of a sample with a charged particle beam are guided between an inner cylindrical electrode and an outer cylindrical electrode arranged coaxially, and the electrons energy-analyzed by the both electrodes are introduced into the inner cylindrical electrode. In a device configured to limit and detect by a slit provided between the opening formed in and the electron beam detector, while arranging a second slit between the opening and the slit, A cylindrical specular energy analyzer characterized in that an operating means for inserting and removing the second slit into and from an electron beam orbit is provided on the atmosphere side.