JP2968663B2 - Electron gun - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun, and more particularly to an electron gun provided in an ion implantation apparatus for eliminating charge of a semiconductor substrate when the semiconductor substrate is ion-implanted.

[0002]

2. Description of the Related Art A conventional electron gun is shown in FIGS.
As shown in FIG. 9B and FIGS. 9A and 9B, a filament 2 for emitting electrons and a fixing rod 3 for inserting and fixing the filament 2 and a filament fastening portion 4 for fastening the filament 2 are provided. Becomes a filament body 5
And a pair of split insulators 1 for fixing the filament main body 5 in two.

Next, the operation will be described. The filament main body 5 is sandwiched and fixed between the pair of split insulators 1 and attached to the electron gun main body via the pair of split insulators 1. Two long rods at both ends of the fixing rod 3 are connected to a power source as electrodes, and the filament 2 generates heat to emit electrons, which cancels the charge on the semiconductor substrate.

[0004]

This conventional electron gun is,
Since the welding of the fixing rod and the filament at the filament fastening portion applies a load to the filament and easily breaks, the filament fastening portion is fastened with a ring and only the ring is welded. Therefore, when the electron gun is used continuously for a long time, the filament fastening portion is heated, and the filament fastening portion is detached or the periphery of the filament fastening portion is easily contaminated, and the insulation failure is likely to occur. Therefore, there is a problem that the life of the filament main body is short because the insulation failure occurs earlier than the life due to the consumption of the filament.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electron gun having a long life without causing insulation failure due to detachment of a filament fastening portion and contamination of the surroundings.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a filament for emitting electrons, a fixing rod for fixing the filament, and the fixing rod is attached to an end of the filament on the side of the heat generating portion to fasten the filament. An electron gun comprising: a filament main body having a ring-shaped filament fastening portion; and a pair of split insulators sandwiching the fixing rod and attaching the filament main body to the electron gun main body. a stepped bore for embedding the filament fastening portion including the tip of the fixing rod to the heat generating portion side of the filament of the insulator is provided, the step
Filament clamping including the tip of the fixing rod in the hole
The joint is entirely surrounded by the pair of split insulators.
It has a buried structure to be rare .

[0007]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view in which the filament main body of the first embodiment of the present invention is incorporated in one of two split insulators, and FIGS. 2 (a) and 2 (b) show the two split insulators of FIG. FIGS. 3A and 3B are a plan view and a side view of the filament main body of FIG. A first embodiment of the present invention is:
As shown in FIGS. 1, 2 (a) and 2 (b) and FIGS. 3 (a) and 3 (b), the fixing rod 3 sandwiching the filament 2 is formed to have a shorter heating portion side of the filament 2. On the other hand, a stepped hole having a hole diameter and a depth large enough to embed the filament fastening portion 4 including the tip of the fixing rod 3 is formed on the heat generating portion side of the filament 2 of the pair of split insulators 1.

A filament 2 and a pair of split insulators 1
Is formed in this way, when the fixing rod 3 is incorporated into the pair of split insulators 1, the filament fastening portion 4 is embedded in the pair of split insulators 1. Become. The joining between the fixing rod 3 and the filament 2 is performed by welding at one end at the end of the filament 2 opposite to the heat generating portion. When the filament 2 and the fixing rod 3 are welded to each other on the heating part side of the filament 2, the filament becomes brittle and causes disconnection. I do.

When the filament main body 5 and a pair of split insulators 5 are assembled in such a structure and assembled into the electron gun main body and used continuously for a long time, the filament fastening portion 4 is used.
Is buried in the stepped hole of the pair of split insulators 1, it is possible to prevent occurrence of insulation failure due to detachment of the filament fastening portion 4, dirt, and the like.

FIG. 4 is a side view in which the filament main body of the second embodiment of the present invention is incorporated into one of the two insulators, and FIGS. 5 (a) and 5 (b) are views of the two insulators of FIG. FIGS. 6A and 6B are a plan view and a side view of the filament main body of FIG. A second embodiment of the present invention
As shown in FIGS. 4, 5 (a) and 5 (b) and FIGS. 6 (a) and 6 (b), the shape of the filament main body 5 is as shown in FIGS.
(B) The heating element side of the pair of split insulators 1 is expanded to a position where the filament fastening part 4 can be embedded, and the hole diameter and depth of the expanded part are fixed. This is an example in which a stepped hole large enough to embed the filament fastening portion 4 including the tip of the rod 3 is formed. The other structure of the electron gun is the same as that of the first embodiment. Same as the example.

[0012]

As described above, the present invention has a structure in which the filament fastening portion is buried in a pair of split insulators, so that the heat generated for a long time use of the electron gun is obtained. Although the insulation failure due to the detachment of the filament fastening portion or the contamination due to dirt is the life of the filament, the life of the filament is purely consumed, so that the life of the filament can be extended.
Conventionally, in the use state where the life of the filament is about 14 days, the present invention has an effect that the life can be extended to about 28 days, which is twice as long.

[Brief description of the drawings]

FIG. 1 shows a filament body according to a first embodiment of the present invention,
It is a side view incorporated in one of the crack insulators.

2 (a) and 2 (b) are a plan view and a side view of the split insulator of FIG. 1. FIG.

3A and 3B are a plan view and a side view of the filament main body of FIG.

FIG. 4 shows a second embodiment of the filament main body according to the present invention.
It is a side view incorporated in one of the crack insulators.

FIGS. 5A and 5B are a plan view and a side view of the split insulator of FIG. 4;

FIGS. 6A and 6B are a plan view and a side view of the filament main body of FIG.

FIG. 7 is a side view of an example in which a filament main body of a conventional electron gun is incorporated into one of two split insulators.

8 (a) and (b) are a plan view and a side view of the split insulator of FIG. 7;

FIGS. 9A and 9B are a plan view and a side view of the filament main body of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Split insulator 2 Filament 3 Fixing rod 4 Filament fastening part 5 Filament main body

Claims (1)

(57) [Claims] 1. A filament for emitting electrons, a fixing rod for fixing the filament, and a ring-shaped filament fastening portion attached to an end of the fixing rod on the heating portion side of the filament for fastening the filament. An electron gun comprising: a filament main body having a filament; and a pair of split insulators sandwiching the fixing rod and attaching the filament main body to the electron gun main body. A stepped hole for embedding a filament fastening portion including the tip of the fixing rod is provided on the side, and the fixing rod is
The filament fastening portion including the tip of
An electron gun, wherein the electron gun is embedded so that the entire outer periphery is surrounded by an insulator .