JPH07209498A - Charged particle emitting device - Google Patents

Abstract

PURPOSE:To scan a charged particle beam at high speed with a simple device structure by providing a charged particle source, a quadrupole lens for converting the charged particle beam generated from the charged particle source, and a means for scanning a wide beam. CONSTITUTION:The charged particle beam of electron beam or ion beam emitted from a charged particle source 1 is passed through a quadrupole lens 5, whereby it is formed into a widely spread charged particle beam 3. In the sectional form 10 of the emitting surface, the central part of the wide charged particle beam is slightly swollen. This wide beam 3 is scanned in the orthogonal direction 11 by use of' the same scanning electrode as in the past, whereby a two-dimensional beam emission can be applied to a body to be emitted. Thus, a high-speed and uniform emission can be performed by the wide beam formed by use of the quadrupole lens 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle irradiation apparatus, and more particularly to an apparatus for irradiating charged particles such as an ion beam and an electron beam used in semiconductor processing, exhaust gas processing apparatus and the like.

[0002]

2. Description of the Related Art As a conventional method of two-dimensionally scanning a charged particle beam, such as an electron beam or ion beam irradiation device, a sawtooth magnetic field variation with time in a direction orthogonal to the charged particle beam. And the electric field fluctuation was applied to uniformly irradiate the irradiated object with the charged particle beam. Therefore, a magnet or an electrode for two scans is required. Therefore, the scanning device tends to be large.

Further, when irradiating a charged particle beam on a fluid irradiation target, it is necessary to make the scanning frequency faster than the flow velocity of the fluid for uniform irradiation. Further, when the charged particles are accelerated in the vacuum container and then taken out from the vacuum container, it is necessary to increase the scanning speed on the thin film in order to avoid deterioration of the thin film passing through due to heat or the like.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a charged particle irradiation apparatus capable of scanning a charged particle beam at high speed with a simple apparatus configuration.

[0005]

A charged particle irradiation apparatus according to the present invention is an apparatus for irradiating charged particles in a solid, liquid or gaseous state with a charged particle source and a charge generated from the charged particle source. A quadrupole lens for converting a particle beam into a wide beam and a means for scanning the wide beam are provided.

[0006]

According to the present invention, unlike the conventional charged particle irradiating apparatus which irradiates the beam by expanding it by scanning a two-dimensional charged particle beam, the beam shape is expanded by a quadrupole lens. The feature is that a wide beam is formed and the wide beam is scanned. Therefore, the scanning of the prior art usually required a scanning power source in two directions, but with the above configuration, scanning in one direction of the charged particle beam having a constant energy becomes unnecessary, and the apparatus can be downsized. High-speed scanning becomes easy.

Conventionally, in order to form a wide beam, a method of scanning the beam or enlarging the beam source has been adopted.
A wide beam can be easily obtained by using a quadrupole lens. Further, by moving the quadrupole lens itself, it is possible to easily perform two-dimensional irradiation on the irradiation target.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First to fourth embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 are
It is explanatory drawing corresponding to 1st thru | or 4th Example, respectively.
(A) shows the structure of an apparatus, (B) shows the cross-sectional shape of the irradiation surface of a charged particle beam. FIG. 5 is an explanatory diagram showing the operation of the quadrupole lens. In the drawings, the same reference numerals indicate the same or corresponding parts.

FIG. 1 shows a charged particle irradiation apparatus according to the first embodiment of the present invention. The charged particle beam 2 that is an electron beam or an ion beam emitted from the charged particle source 1 passes through the quadrupole lens 5 and becomes a charged particle beam 3 having a wide spread. The cross-sectional shape 10 of the irradiation surface is such that the central portion of the wide charged particle beam is slightly swollen as shown in the figure. By scanning the wide beam 3 in the orthogonal direction 11 using a scanning electrode similar to the conventional one, a two-dimensional beam irradiation can be performed on the irradiation target.

FIG. 5 shows a sectional structure of a plane of the quadrupole lens which is perpendicular to the charged particle beam. Four magnets 9 are arranged as shown in the drawing, and the charged particle beam 8 flows in the central portion of the magnet 9 perpendicularly to the paper surface and from the back to the front. The charged particles receive the Lorentz force 10 due to the magnetic field, and a wide beam shown in FIG. 1B is formed.

The electric potential and magnetic potential of the quadrupole lens for deflecting the charged particle beam are determined by the equation (1) in the case of the magnetic field lens shown in FIG. Here, X1 and X1 'are displacement and velocity before passing the quadrupole lens, and X2 and X2' are displacement and velocity after passing through the quadrupole lens. It is possible to appropriately design the quadrupole lens by such a mathematical formula.

[0012]

[Equation 1]

However, θ = βL β = (e / 2mφ) B e: Charge of charged particles (Coulomb) m: Mass of charged particles (Kg) B: Magnetic field strength (stella) L: Quadrupole lens Beam passing length (m) φ: Charged particle potential

FIG. 2 shows a charged particle irradiation apparatus according to the second embodiment of the present invention. In this embodiment, a correction electrode 6 for correcting a wide beam in which the central portion shown in FIG. 1B of the first embodiment is slightly swollen is provided. The correction electrode 6 is composed of parallel plate electrodes and the like, and the shape of the beam passing between the electrodes is corrected to a flat shape as shown by reference numeral 14 in FIG. 3 (B).
Alternatively, the flat shape shown by reference numeral 14 may be modified by using magnetic poles.

FIG. 3 shows a charged particle irradiation apparatus according to the third embodiment of the present invention. In the present embodiment, the diameter of the charged particle beam incident on the quadrupole lens is expanded and expanded so that the central portion of the wide beam formed by the quadrupole lens shown in FIG. The beam 4 is used as the beam 4 to improve the spread shape 13 of the wide beam 3 of the charged particles after passing through the quadrupole lens. Therefore, the magnifying lens 7 is provided for the charged particle beam incident on the quadrupole lens.

FIG. 4 shows a charged particle irradiation apparatus according to the fourth embodiment of the present invention. In the present embodiment, the disk 9 is irradiated with the irradiation object by mechanically rotating the magnet 9 constituting the quadrupole lens about the charged particle beam.

In this way, the charged particle beam is converted into X, Y
Compared with two-dimensional scanning in the direction, the irradiation target can be irradiated with the charged particle beam uniformly at high speed with a simple structure. Incidentally, instead of mechanically rotating the quadrupole lens in the fourth embodiment, the magnet 9 may be constituted by an electromagnet and a rotating magnetic field may be formed to perform scanning in a disc shape. As described above, various modifications can be made without departing from the spirit of the present embodiment.

[0018]

As described above, according to the present invention, the scanning means of the charged particle irradiation apparatus enables high-speed and uniform irradiation with a wide beam formed by using a quadrupole lens. Therefore, it is possible to facilitate the use of charged particles used in semiconductor manufacturing and electron beam irradiators, and a large industrial effect can be expected.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a charged particle irradiation apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a charged particle irradiation device according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a charged particle irradiation apparatus according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of a charged particle irradiation device according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the operation of the quadrupole lens.

[Explanation of symbols]

 1 Charged Particle Source 2, 3, 4, 8 Charged Particle Beam 5 Quadrupole Lens 6 Correction Electrode 7 Beam Diameter Increasing Lens 9 Magnets 10, 12, 13, 14 Beam Cross Section

Claims (4)

[Claims] 1. A device for irradiating a solid, liquid or gaseous object to be charged with charged particles, and a quadrupole lens for converting a charged particle beam generated from the charged particle source into a wide beam. And a means for scanning the wide beam, wherein the charged particle irradiation apparatus is provided. 2. The charged particle irradiation apparatus according to claim 1, further comprising an electrode or a magnetic pole for correcting the beam shape of the wide beam converted by the quadrupole lens. 3. The charged particle according to claim 1, further comprising a lens that expands a beam generated from the charged particle source, and the expanded beam is converted into a wide beam by the quadrupole lens. Irradiation device. 4. The charged particle irradiation apparatus according to claim 1, wherein the means for scanning the wide beam is means for moving the quadrupole lens itself.