JPH02100299A - High-speed atomic source - Google Patents

Abstract

PURPOSE:To make it possible to obtain a high-speed atomic beam which does not substantially include positive ions and/or electrons and which is energy- controlled, by mixing together an ion beam generated by an ion source and an electron source generated by an electron source by means of a magnet so as to neutralize the ion source to form the high-speed atomic beam. CONSTITUTION:An ion beam 6 formed from positive ions available at an ion source 1 is caused to pass through an ion conversion lens 2 so that it converges and is then incident on a magnet 4. An electron beam 7 available at an electron source 3 is incident on the magnet 4 from the direction opposite to the ion beam 6. Since the ion beam 6 and the electron beam 7 have different polarities, they can be put on the same line by controlling the ion beam 6 incident on the magnet 4, the angle of incidence of the electron beam 7, and the magnetic field of the magnet 4. The ion beam 6 formed from the positive ions is neutralized by the electron beam 7 to obtain a high-speed atomic beam 8. The high- speed atomic beam can thus be obtained which does not substantially include positive ions and/or electrons, an which is energy-controlled.

Description

[Detailed description of the invention] [Industrial application field] FIELD OF THE INVENTION This invention relates to fast atomic sources.

[Prior Art] As a conventional high-speed atom source, for example, a high-speed atom source is known that utilizes gas atoms recoil by an ion beam when a gas such as Ar is irradiated with the ion beam.

[Problems to be solved by the invention] However, since conventional fast atom sources use gas atoms recoil by the ion beam, it is not possible to control the energy of the fast atom beam. There was a mixture of ion beams and ion beams. In addition, because a focused high-speed atomic beam cannot be obtained, it has not been possible to use a high-speed atomic source for local analysis methods.

For example, in beam analysis such as secondary ion mass spectrometry, when charged particles are used as the -order beam, there is a problem that the beam position shifts when the sample charges up. Using lines solves this problem. However, in the past, it could not be used for local analysis because a focused high-speed atomic beam could not be obtained.

The present invention has been made in response to the above-mentioned conventional circumstances, and aims to provide a high-speed atomic source that does not substantially contain positive ions or electrons and can obtain an energy-controlled high-speed atomic beam. purpose.

[Means for Solving the Problems] The present invention provides an ion source that generates an ion beam composed of positive ions, an electron beam source that generates an electron beam, and a magnet that mixes and neutralizes the ion beam and the electron beam. an ion source that generates an ion beam consisting of positive ions; and an electron beam source that generates an electron beam;
A magnet for mixing and neutralizing the ion beam and the electron beam, and a high-speed atomic beam extraction means disposed downstream of the magnet for removing the ion beam and the electron beam and extracting only the high-speed atomic beam. It is a high-speed atomic source characterized by

In the present invention, it is preferable that an ion focusing lens is provided between the ion source and the magnet to focus the ion beam generated by the ion source, and in this case, a focused high-speed atomic beam can be obtained. It will be done.

[Operation] In the fast atom source of the present invention, the ion beam generated from the ion source and the electron beam generated from the electron source are mixed by a magnet, and the ion beam is neutralized to become a fast atom beam. Therefore, it is possible to obtain a high-speed electron beam that does not substantially contain positive ions and electrons, and the energy of the high-speed atomic beam can be combined with the energy of the ion beam.

In addition, if ion beams and/or electron beams remain in the obtained fast atomic beam, on the trajectory of the fast atomic beam,
By providing a high-speed atomic beam extraction means such as a magnet or an electrode, these charged particles can be completely removed.

Furthermore, by neutralizing the pre-focused ion beam with an electron beam, the focused high-speed atomic beam can be increased by 1, and a focused high-speed atomic beam can be obtained. It becomes possible to apply this method to local analysis methods such as the method.

[Example] Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention. An ion beam 6 consisting of positive ions obtained from an ion source 1 is focused through an ion focusing lens 2 and is incident on a single stone 4.

Further, the electron beam 7 obtained from the electron source 3 is incident on the magnet 4 from the opposite direction to the ion beam 6. Since the ion beam 6 and the electron beam 7 have different polarities, the ion beam 6 and the electron beam 7 are directed toward the magnet 4.
By controlling the incident angle of the electron beam and the magnetic field of the magnet 4, it is possible to bring the electron beam and the ion beam onto the same straight line.

The ion beam 6 made of positive ions is neutralized by the electron beam 7, and a high-speed atomic beam 8 is obtained. In the fast atomic beam 8, there is a mixture of some ions and electrons in addition to the fast atoms.
When the high-speed atomic beam 8 passes through the magnet or electrode 5 serving as the high-speed atomic beam extraction means, the ions and electrons are bent by the magnetic or electric field, while the high-speed atoms travel straight because they are not affected by the magnetic or electric field. A high-speed atomic beam 9 consisting only of high-speed atoms is obtained. The obtained high-speed atomic beam 9 passes through a shutter 10 and is irradiated onto a sample 11.

A shutter 10 turns on and off the high-speed atomic beam.

Since the high-speed atomic beam 9 is obtained by neutralizing the ion beam focused by the ion focusing lens 2, it can irradiate a minute region of the sample.

In addition, by controlling the energy of the ion beam 6,
The energy of the high-speed atomic beam 9 can be controlled.

FIG. 2 is an example in which the fast atom source according to the above embodiment is used in a secondary ion mass spectrometer. A sample 14 is irradiated with a fast atomic beam 13 obtained from a fast atomic source 12 . Sample 14
The secondary ions 19 emitted from the ion are accelerated by the secondary ion accelerating electrode 15, passed through the electrostatic analyzer 16, subjected to mass spectrometry by the mass spectrometer 17, and detected by the detector 18.

[Effects of the Invention] As explained above, according to the present invention, since the energy-controlled ion beam is neutralized with the electron beam, the ion beam does not substantially contain positive ions and electrons, and the energy is controlled. It is possible to obtain high-speed atomic beams.

In addition, when an ion focusing lens is provided, it is possible to neutralize the focused ion beam and obtain a focused high-speed atomic beam, making it possible to analyze microscopic areas using the high-speed atomic beam. .

Generally speaking, if a high-speed atomic beam extraction means such as a magnet or an electrode is installed, only high-speed atomic beams that do not contain positive ions or electrons can be obtained, so only high-speed atomic beams that are not affected by charged particles can be applied to the sample. It becomes possible to irradiate.

Furthermore, when the fast atom source according to the present method is applied to a secondary ion mass spectrometer, analysis can be performed in which the primary beam is not affected by sample charge-up.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of an embodiment of the present invention, and FIG. 2 is a schematic block diagram of a secondary ion mass spectrometer that is an applied example of the present invention. 1... Ion source 3... Electron source 5... Magnet (electrode) 7... Electron beam 8, 9.13... High speed atomic beam 10... Shutter 12... High speed atomic source 15 ... Secondary ion accelerating electrode 16 ... Electrostatic analyzer 18 ... Detector 2 ... Ion focusing lens 4 ... Magnet 6 ... Ion beams 11, 14 ... Sample 17 ... Mass spectrometer 19...Secondary ion

Claims (2)

[Claims] (1) A high speed system comprising an ion source that generates an ion beam made of positive ions, an electron beam source that generates an electron beam, and a magnet that mixes and neutralizes the ion beam and the electron beam. Atomic source. (2) An ion source that generates an ion beam consisting of positive ions, an electron beam source that generates an electron beam, a magnet that mixes and neutralizes the ion beam and the electron beam, and a magnet that is disposed downstream of the magnet. , a high-speed atomic beam extraction means for removing ion beams and electron beams and extracting only high-speed atomic beams.