JPH02100298A - 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 causing an ion beam generated at an ion source and an electron beam generated at an electron source to intersect with each other so as to neutralize the ion beam to form the high-speed atomic beam. CONSTITUTION:An ion beam 4 formed from positive ions available from an ion source 1 is caused to pass through an ion conversion lens 3 so that it converges and, since an elecrtron source 2 from which an electron beam 5 is available is installed such that the passage of the electron beam 5 intersects with that of the ion beam 4, the ion beam 4 intersects with and is therefore neutralized by the electron beam 5 to produce a high-speed atomic beam 6. The high-speed atomic beam can thus be obtained which does not substantially include positive ions and/or electrons, and 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 the scum of Ar or the like 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 includes an ion source that generates an ion beam made of positive ions, and an electron source that has an orbit that intersects the orbit of the ion beam and generates an electron beam. a high-speed atom source, an ion source that generates an ion beam consisting of positive ions, and a trajectory that intersects the trajectory of the ion beam,
an electron source that generates an electron beam, and a high-speed atom that is located on the trajectory of the ion beam and downstream of the intersection with the electron beam, and that removes the ion beam and the electron beam and extracts only the high-speed atomic beam. The present invention is a high-speed atom source characterized by comprising a line extraction means.

In the present invention, it is preferable that an ion focusing lens for focusing the ion beam generated by the ion source is provided between the ion source and the intersection of the ion beam and electron beam generated from the ion source, In this case, a focused high-speed atomic beam is obtained.

[Function] 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 crossed,
The ion beam is neutralized and becomes a high-speed atomic beam. Therefore, it is possible to obtain a high-speed atomic beam that does not substantially contain positive ions and electrons, and it is also possible to control the energy of the high-speed atomic beam to the energy of an ion beam.

In addition, if ion beams remain in the obtained fast atomic beam, it is possible to remove them by providing a means for extracting the fast atomic beams, such as a magnet or an electrode, on the trajectory of the fast atomic beam. It is possible to completely remove the ion beams that are present.

In general, by neutralizing a pre-focused ion beam with an electron beam, 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 4 consisting of positive ions obtained from the ion source 1 is focused through an ion focusing lens 3, and an electron beam 5 obtained from the electron source 2 is focused by the electron source 2 so that its trajectory intersects the trajectory of the ion beam 4. is installed, the ion beam 4 and the electron beam 5 intersect, and the ion beam 4 is neutralized by the electron beam 5.
A high-speed atomic beam 6 is obtained. In the fast atomic beam 6, some ions are mixed with the high speed atoms, but when the fast atomic beam 6 passes through a magnet (or electrode) 8 serving as a fast atomic beam extraction means, the ions are exposed to the magnetic field (or electric field). ), but since the high-speed atoms are not affected by the magnetic field (or electric field) and travel straight, a high-speed atomic beam 7 consisting only of high-speed atoms is obtained. The obtained high-speed atomic beam 7 passes through a shutter 9 and is irradiated onto a sample 10. A shutter 9 turns on and off the high-speed atomic beam.

Since the fast atoms 1I917 are obtained by neutralizing the ion beam focused by the ion focusing lens 2, they can be irradiated onto a minute area of the sample.

Furthermore, by controlling the energy of the ion beam 4, the energy of the fast atomic beam 7 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 11 extracted from the ion are accelerated by a secondary ion accelerating electrode 15, passed through an electrostatic analyzer 16, subjected to mass spectrometry by a sample analyzer 17, and detected by a 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 energy-controlled ion beam is substantially free of positive ions and electrons and is energy-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. .

Furthermore, if a high-speed atomic beam extraction means such as a magnet or electrode is provided, only high-speed atomic beams that do not contain positive ions can be obtained, making it possible to irradiate the sample only with high-speed atomic beams that are not affected by ions. It becomes possible.

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 2...Electron source 3...
Ion focusing lens 4... Ion beam 5... Electron beam 6, 7.13... High-speed atomic beam 8... Magnet (electrode)
9...Shutter 11...Secondary ion 15...Secondary ion accelerating electrode 17...Mass spectrometer agent

Claims (2)

[Claims] (1) A high-speed atom source characterized by comprising an ion source that generates an ion beam made of positive ions, and an electron source that has an orbit that intersects the orbit of the ion beam and generates an electron beam. (2) an ion source that generates an ion beam consisting of positive ions; an electron source that has an orbit that intersects the orbit of the ion beam and generates an electron beam; 1. A high-speed atomic beam extraction means, which is disposed on the downstream side of an intersection with a ray, and removes an ion beam and an electron beam and extracts only a high-speed atomic beam.