JPS6355745B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multipole electrode structure for use in a device for electrostatic deflection of charged particle beams. Multipole electrodes are used in electron beam exposure devices, electron microscopes, cathode ray tubes, image pickup tubes, etc. to accurately deflect beams or to shape the cross-section of beams.

A multipolar electrode has a structure in which a large number of electrode pieces are arranged in a ring shape symmetrically with respect to the central axis of the electrode, the electrode pieces are surrounded by a support made of an insulating material, and the electrode pieces are fixed to this support. There is. However, in such a structure, during operation, the support of the insulating material becomes electrically charged, and the undesirable electric field due to this charging permeates into the deflection electric field, disturbs the deflection electric field, and reduces the deflection accuracy of the charged particle beam. This will reduce the operational accuracy of electron beam exposure devices, electron microscopes, etc. equipped with multipole electrodes.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multielectrode structure configured to prevent the electric field from seeping into the deflection electric field due to charging of the electrode support, thereby ensuring a normal distribution of the deflection electric field.

This object is achieved according to the invention by connecting together electrode pieces to which the same potential is applied among electrode pieces arranged symmetrically about one axis by a plurality of metal peripheral connection pieces at different levels of said axis, and This is achieved by a multipole electrode structure in which the outer circumferential connecting pieces are connected by an insulating support placed on the outer circumferential connecting pieces so as not to be exposed to the deflection space behind the electrode body.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Please refer to FIG. Among the electrode pieces arranged symmetrically about one axis, the electrode pieces to which the same potential is applied, for example, 1 ₅ , 1 ₇ , 1 ₉ are connected together by a metal outer peripheral connecting piece 2A ₂ , and another electrode piece with the same potential is applied. The electrode pieces 1 ₃ , 1 ₁ , 1 ₁₁ to be applied are integrally connected by the outer peripheral connecting piece 2A ₁ , and the same potential is applied to the electrode pieces 1 ₆ , 1 at a lower level along the axis. ₄ and 1 ₂ are integrally connected by an outer peripheral connecting piece 2B ₁ , and other electrode pieces 1 ₈ , 1 ₁₀ and 1 ₁₂ to which the same potential is applied are integrally connected by an outer peripheral connecting piece 2B ₂ . At the higher level, both ends of the outer peripheral connecting pieces 2A ₁ and 2A ₂ face each other at a distance behind the electrode pieces 1 ₄ and 1 ₁₀ ,
Similarly, at the lower level, the outer peripheral connection piece 2B ₁
and 2B ₂ are opposed to each other at a distance behind the electrode pieces 1 ₇ and 1 ₁ . The insulating support 3 is arranged on these outer peripheral connection pieces and fixes the electrode pieces together as a whole. There is no part of the insulating support 3 that is exposed to the deflection space surrounded by the electrode pieces, so it is difficult to be charged, and even if it is charged, it is extremely unlikely that the electric field will seep into the deflection space.

outer peripheral connecting piece 2A′ ₁ at a level near the bottom,
2A′ ₂ ; The relationship between 2B′ ₁ , _2B ′ ₂ and the electrode pieces has already been described.
2A ₂ ; The relationship is the same as that between 2B ₁ , 2B ₂ and the electrode piece. The insulating supports to be fixed to the outer peripheral connecting pieces 2A' ₁ , 2A'₂;2B' ₁ , 2B' ₂ are not shown for the sake of simplicity. Note that 4 indicates an outer housing.

See Figure 2. The only difference from the first embodiment shown in FIG. 1 is the shape of the insulating support 3. A flat insulating support 3 is fixed behind the electrode to the outer circumferential connecting pieces at different levels in such a way as to bridge the spaced apart opposing ends of the outer circumferential connecting pieces, thereby integrally forming an electrode piece assembly. are doing.

See Figure 3. The only difference between this embodiment and the embodiment shown in FIG. 2 is the shape of the insulating support 3. A block-shaped insulating support 3 is arranged behind the electrode between the peripheral connecting pieces at different levels in such a way as to bridge the spaced apart opposite ends of the peripheral connecting pieces;
It is fixed to the outer peripheral connecting piece to integrally constitute an electrode piece assembly.

Please refer to FIG. The difference from the first embodiment shown in FIG. 1 is that the electrode pieces are tilted at the same angle at the same level with respect to the central axis of the deflection space so as to give spin to the motion of charged particles. The configuration is the same as that of the first embodiment.

In either embodiment, the electrode pieces to which the same potential is applied are connected by a metal outer connection piece, and these outer connection pieces to which different potentials are applied are connected to each other to form an integral electrode piece. The support body is placed behind the electrode pieces by removing the gap between adjacent electrode pieces to avoid exposing the insulating material to the deflection space and preventing the electric field caused by the charging of the insulating material from seeping into the deflection space. are doing.

[Brief explanation of the drawing]

FIG. 1 is a partially exploded perspective view of a first embodiment of the present invention. FIG. 2 is a perspective view similar to FIG. 1 showing a second embodiment of the invention. Third
The figure shows the third part of the multi-electrode assembly with the housing removed.
It is a perspective view showing an example of this. FIG. 4 is a perspective view showing a portion of a multi-electrode assembly according to a fourth embodiment of the present invention. In the figure: 1... Electrode piece, 2... Metal peripheral connection piece,
3...Insulating support body, 4...Housing.

Claims (1)

[Scope of Claims] 1. Electrode pieces arranged symmetrically about one axis; a metal peripheral connecting piece integrally connected to selected ones of said electrode pieces at different levels of said axis; and A multipole electrode structure characterized by comprising an insulating support that fixes the outer peripheral connection pieces to each other without being exposed in the gap between adjacent electrode pieces. 2. A multipole electrode structure according to claim 1, wherein each of said electrode pieces is inclined parallel to said axis or at the same level and at the same angle to said axis.