JPS61245453A - Linear electron beam thermal processor - Google Patents

Abstract

PURPOSE:To increase the beam current density of linear electron beam by forming the electron pass hole in an electrode for taking out an electron beam from a rectangular cathode in rectangular at the cathode side while in circular at the anode side. CONSTITUTION:A linear electron beam processor is constructed with a rectangular cathode 1, a control electrode 2 having a rectangular hole 12, a take-out electrode 3, an anode 5 and an electron lens 6. Here, the electron pass hole in the take-out electrode 3 is formed in rectangular 13 at the cathode 1 side while in circular 14 at the anode 5 side. Then a linear electron beam 4 is produced from an anisotropic three electrodes comprising the cathode 1, the control electrode 2 and the rectangular hole 13 of the take-out electrode 3 and projected analogously onto a sample 7 through a rotary symmetrical electron lens system comprising the circular hole 14 of the take-out electrode 3, the anode 5 and the electron lens 6. Consequently, the beam current density is increased and distributed uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a linear electron beam heat treatment apparatus for heat treating samples such as conductors, semiconductors, dielectrics, etc. by irradiating electron beams.

(Prior art and its problems) When heat-treating a material, processing capacity is greater when the shape of the electron beam irradiation surface on the material surface is linear compared to the usual spot-like shape. There are cases where it is effective. To generate such a linear electron beam, 1. For example, an anisotropic method combining a rectangular cathode, a control electrode with a matching rectangular hole, and an anode with a rectangular hole similar to these rectangles is used. It is conceivable to use a magnetic electron gun. In such an electron gun, near the anode,
That is, when the working distance is small, a linear electron beam is formed. However, when the sample is placed at a distance of about 6 cm from the anode, the long sides become long, resulting in a disadvantage that the energy density of the beam becomes small and the density distribution becomes uniform and strong.

(Objective of the present invention) The present invention eliminates such conventional drawbacks, and enables the beam current density of a linear electron beam to be large and have a small distribution even for a sample placed relatively far from the electron source. The aim is to provide a uniform device.

(Structure of the Invention) According to the present invention, a rectangular cathode, a control electrode having a rectangular hole and surrounding the cathode, an anode which is at a high potential with respect to the cathode and has a circular hole through which electrons can pass; Located between the anodes.

A linear electron beam heat treatment apparatus having an extraction electrode with a high potential on both the anode and the anode, wherein the shape of the electron passage hole of the extraction electrode is rectangular on the side opposite to the cathode and circular on the side opposite to the anode. A shaped electron beam heat treatment apparatus is obtained.

(Detailed explanation of the structure) 1. The present invention solves the problems of the prior art 1 rather than the above-mentioned member which adopts the 0 structure. First, a rectangular cathode '2', a control electrode each having a rectangular hole, and a height j
・1 Potential extraction A linear electron beam with a high potential and a large beam current density is extracted from the 11 poles. A circular hole is provided at the rear stage of the extraction electrode, and an anode having a circular hole opposing the extraction electrode constitutes an axially rotationally symmetrical electrode system, and thereafter it is easy to configure an axially rotationally symmetrical electron lens system. The linear electron beam, which has passed through the extraction electrode and has been accelerated to a high potential, is decelerated to a predetermined low potential by the anode, and is moved to a position far away from the anode.

It has a large current density and allows projection with uniform density.

(Example) Hereinafter, the explanation will be made in detail based on the example of the present invention with reference to the drawings. FIG. 1 is a sectional view of the main part of an embodiment of the present invention and shows the hole shapes of each electrode, etc.

In FIG. 1, a cathode 1 having a rectangular electron emitting part, a control electrode 2 having a rectangular hole that fits the electron emitting part, and an extraction electrode having a rectangular hole for passing electrons on the cathode side. A linear electron beam 4 is generated by an anisotropic three-electrode type electron beam 4 consisting of 3 and 3. A sufficiently high potential, eg, 60 kV, is applied to the extraction electrode 3 relative to the cathode 1, and a large beam current, eg, 100 mA, is extracted. A linear electron beam with a high beam current density formed near the extraction electrode 3 is decelerated by setting the potential between the cathode 1 and the anode 5 to, for example, 15 kV, and then projected onto the surface of the sample 70 by the electron lens 6. irradiate. By scanning the linear electron beam in the short side direction of the linear electron beam using a beam deflection system (not shown), a large area of the surface of the sample 70 can be heat-treated at once. Also, after shifting the linear electron beam a little in the long side direction, scanning is performed in the short side direction as described above.

By sequentially repeating the above operations), the entire surface of the sample 7 can be heated in a shorter time than when using a spot beam. In this case, instead of tj electron beam deflection scanning, the sample 7 may be mechanically moved and heated.

The shape of the electron passage hole of the extraction electrode 3 is rectangular on the cathode side, but it is changed in the middle and is a circular hole on the side facing the anode 5.
Together with this, an axially rotationally symmetrical electromagnetic field lens is formed.
A linear electron beam with a high current density formed in the vicinity of the extraction electrode 3 can be projected onto the sample 7 in a similar manner with a high energy density; for example, under the above conditions, approximately 40 kW/ctl
A high energy density of 1 has been achieved. In addition, the current density distribution in the long side direction is within 3% and the distribution is even. The hole shape on the side facing the anode (circular) 14. The hole shape at the 7th node (circular) 15. This is the shape (circular) 16 of the magnetic pole of the electron lens or the inner diameter of the electrode.

(Effects of the Invention) According to the linear electron beam heat treatment apparatus of the present invention, a sharp linear beam (e.g. , short side Q, 3 mm, long side 5 mm) from the anode, for example 6
It is possible to irradiate the sample surface 0cn+ away with a uniform current density distribution in the long side direction.

Therefore, the efficiency of heat treatment and the handling of samples can be facilitated.

Further, the anode facing hole 14° of the extraction electrode in FIG. 1 and the anode 15. If each diameter dimension of the electron lens inner diameter 16 is made sufficiently large (for example, 5 times or more) compared to the passing electron beam dimension, the projection aberration of the electron beam due to this axially rotationally symmetric electromagnetic pole system can be reduced, and the beam in the long side direction can be reduced. FIG. 3 is a schematic diagram showing how the uniformity of current density distribution is impaired.

In the figure, 1... Cathode 2... Control electrode 3... Extraction electrode 4... Linear electron beam 5... Anode 6... ...Electron lens 7... Each sample is shown.

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Claims (1)

[Claims] a rectangular cathode, a control electrode having a rectangular hole and surrounding the cathode, an anode having a high potential with respect to the cathode and having a circular hole for passing electrons, and an anode located between the cathode and the anode. In a linear electron beam heat treatment apparatus equipped with an extraction electrode having a higher potential than Beam heat treatment equipment.