JP2000011905A - Ion gun grid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily change the shape of a beam. SOLUTION: An ion beam emitting grid in an ion gun 14 is composed of two grids (a screen grid and an accelerating grid) 21, 22 for which grid holes 24 are formed throughout their surfaces, a doughnut plate-like ion beam molded- plate 23 incorporated in between the two grids 21, 22 and the ion gun 14. The shape of the beam is determined by the shape of a molded hole 25, so that the shape of the beam can be changed by replacing the ion beam molded-plate 23, while the grids 21, 22 are left as they are.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion gun for emitting an ion beam, and more particularly to a grid used for forming and emitting an ion beam in the ion gun.

[0002]

2. Description of the Related Art A conventional grid of this type comprises a set of grids 11 and 12, as shown in FIG.
Each of the disks 1 and 12 has a disk shape, and required grid holes 13 are arranged and formed in the center of the disk. The grids 11 and 12 are arranged at the ion beam emission position of the ion gun 14, and the grid 11 is used as a screen grid and the grid 12 is used as an acceleration grid.

When the ion gun 14 is operated, the grid 1
A high voltage is applied between 1 and 12, whereby an ion beam can be extracted from the plasma generated inside the ion gun 14. Note that the shape of the emitted ion beam 15 is determined by the shape of the grid holes 13 of the grids 11 and 12, that is, the contour shape of the group of grid holes.

[0004]

In the ion gun 14 using the grids 11 and 12 configured as described above, when changing the ion beam shape, the grids 11 and 12 are used.
The change has been made by replacing 12 with a grid having a grid hole arrangement that shaped the required beam shape, that is, the two grids 11 and 12 need to be replaced to change the beam shape. In order to obtain various types of beam shapes, it is necessary to prepare two grids each having a corresponding grid hole arrangement.

In order to reduce the beam shape, for example, an aperture is attached to the front surface of the grid 12, which is the exit side of the ion beam 15, but in this case, the aperture is sputtered by the ion beam 15. And the sputtered particles are ion gun 1
There is a problem that the ion gun 14 is adversely affected by flying and adhering in the direction 4.

[0006] In view of the above problems, an object of the present invention is to provide
It is an object of the present invention to provide a grid for an ion gun capable of obtaining a number of beam shapes with one kind of grid and preventing the ion gun from being adversely affected.

[0007]

According to the present invention, a grid used for ion beam emission in an ion gun has grid holes formed over the entire surface, and has two grids used as a screen grid and an acceleration grid. , And a donut plate-shaped ion beam forming plate incorporated between the two grids and the ion gun.

[0008]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention. In this example, the grid used for ion beam emission in the ion gun 14 is:
It is constituted by a set of grids 21 and 22 and an ion beam forming plate 23.

The grids 21 and 22 are used as a screen grid and an acceleration grid, respectively.
Both are disc-shaped, and grid holes 24
Are formed in an array. On the other hand, the ion beam forming plate 23 has a donut plate shape having a forming hole 25 at the center thereof, and is incorporated between the two grids 21 and 22 and the ion gun 14 as shown in the figure. I have.

The ions in the plasma generated inside the ion gun 14 are extracted by the high voltage applied between the grids 21 and 22. At this time, only the ions passing through the forming holes 25 of the ion beam forming plate 23 are removed. It is pulled out of the grids 21 and 22. Therefore, according to this example, the shape of the ion beam 15 is determined by the shape of the forming hole 25 of the ion beam forming plate 23, that is, by changing the ion beam forming plate 23 while keeping a set of grids 21 and 22 as they are, The beam shape can be changed.

Since the ion beam forming plate 23 is disposed between the ion gun 14 and the grids 21 and 22 as described above, the ion beam forming plate 23 is not sputtered by the ion beam 15 and thus has an adverse effect on the ion gun 14. Absent.

[0012]

As described above, according to the present invention, the shape of the ion beam can be changed by changing one ion beam shaping plate. Are simpler than those which are replaced one by one, and the number of parts to be prepared when obtaining various types of beam shapes is small.

Further, since the ion beam forming plate is not sputtered by the ion beam, there is no adverse effect on the ion gun.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

FIG. 2 is a view for explaining a conventional grid for an ion gun.

Claims (1)

[Claims] 1. A grid used in an ion gun for emitting an ion beam, wherein two grids are formed on the entire surface and are used as a screen grid and an acceleration grid, and the two grids and the ion gun. And a donut plate-shaped ion beam forming plate incorporated between the grids.