JPS5931546A - Multipole electrode - Google Patents

Abstract

PURPOSE:To prevent charged electric field of an insulation substance from oozing to a deflection space as well as to make the captioned electrode compact, by bending the space between the neighboring electrode pieces projecting from inside of a hollow insulator, in case of a multipole electrode structure to be used as a static deflection device of a charged particle beam. CONSTITUTION:Electrode pieces D1-D20 are arranged. While being allowed to project from inside of a hollow insulator 1, which is continuous in the periphery. And the gap spaces 3 between the neighboring electrode pieces have the structure bent in the surface vertical to the vertical axis (namely, in the surface of paper). Due to said constitution, even if the insulator 1 is charged, a line of electric force is screened by said bent gaps thus scarcely influencing the electric field distribution of the deflection space.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multipole FIi pole structure for use in an electrostatic single deflection device for m-ton particle beams.

In general, multipole electrodes are used in electron beam exposure devices, multiton microscopes, high JJ plows, image pickup tubes, etc. in order to obtain a cosine-distributed digging field that can completely reduce beam deflection aberration.

It is advantageous to keep the beam trajectory as short as possible in order to reduce aberrations due to Kameko optical aberrations and interactions between Kameko. Therefore, the shape of the multipole electrode used must be made as small as possible and placed inside the focusing lens. Further, each polarization is supported by an insulator, and during operation, this insulator is charged and an electric field is generated thereby. If this awakening city world seeps into the deflection area, is the accurate deflection i1? Since lJ control becomes impossible, it is necessary to take measures to prevent such an undesirable band pa field from seeping into the deflection electric field.

FIG. 1 shows the structure of a conventional multi-polarized deflection device for obtaining a cosine distribution of electric potential that can reduce beam deflection aberrations.

In this tasteful conventional electrode structure, polarization pieces D1 to DI2
It has been a difficult problem to maintain high accuracy and prevent undesirable leakage.

When the electrodes D1 to D12 are held using the insulator 1, the insulator 1 is inevitably charged during operation (normally the insulator is charged to a voltage of 10 to 100 kV), and the resulting eye field is 1
It leaks into the flattened space 2 and disturbs the deflection eye field, and when the charged state of the insulator 1 changes, the stability of the deflection electric field deteriorates. In order to prevent this undesirable band IT field from being emitted into the desired field, the insulating material 1 supporting the polarizing pieces D1 to D12 should not be exposed in the deflection space 2 even in the slightest. It is necessary. Also, as a matter of course, the positional accuracy of the polarizing piece directly affects the aberrations of the deflection eye field, so it is important to support the polarizing piece as accurately as possible.

In order to prevent the insulating band art field from entering the deflection space, it is conceivable to increase the depth of the polarization gap in the radial direction or radial direction until the eye field no longer leaks. It's a big inconvenience because it's getting bigger. It is also possible to create a structure in which the insulator is placed on the back of the electrode piece so that the insulator is not visible from the electrode, as shown in Figure 2, but if you do this, you can fabricate a large number of electrodes (umbrella piece and insulator piece). It must be assembled with high precision, which poses many technical difficulties.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multilayer electrostatic deflection arrangement that is compact, precise, easy to manufacture, and in which the weighted electric field of the insulator does not leak into the deflection space.

The present invention will be described in detail below with reference to FIGS. 3 to 5.

Figure 3 shows a hollow insulator 1 whose periphery is continuous and a plurality of electrode pieces D1 to D20 protruding from the inner surface of this hollow insulator.
are arranged, and the gap space 3 between adjacent polarized pieces is
It has a structure that is bent in a plane perpendicular to the vertical axis (that is, in the plane of the paper). 5 is an annular housing. With this configuration, even if the insulator 1 is charged in one direction, the lines of electric force are blocked by the bent IGL gap, and there is almost no influence on the electric field distribution in the deflection space.

The method for manufacturing a multipole electrode according to the present invention shown in FIG.
This will be explained with reference to the figures. An annular conductor 4, which serves as polarization for a 1Jil direction device, is fixed integrally with an annular insulator 1. A large number of magnetic pole pieces 01 and D2 are separated from each other by making cuts in the annular conductor 4 to reach the inner surface of the annular insulator 1 along a bending path in a plane perpendicular to the longitudinal axis of the annular composite.・・・・・・
form. It is advantageous to make curved cuts in the annular conductor 4 by wire-cut electrical discharge machining. Alternatively, instead of the annular conductor 4, a solid cylindrical conductor may be fixed to the annular insulator 1 and wire-cut electric discharge machining may be used to carve it into the configuration shown in FIG. By such processing, it is possible to avoid the disadvantages of forming a large number of polarizing pieces of complicated shapes, and precisely arranging and fixing them to the entire annular insulator.

Fig. 15-a shows a semi-finished product of another actual measurement example, and Fig. 5-b shows a finished product. A multipole electrode as shown in Fig. 5-b is manufactured by making a bending cut in the semi-finished hollow rectangular conductor 4 shown in Fig. m5-a to reach the insulator 1. Usually, as the insulator, glass macor (part name), ceramics, etc., which are capable of cutting, are used.

[Brief explanation of the drawing]

FIG. 1.2 is a diagram for explaining a conventional electrode structure, and FIG. 6 shows the structure of a first example of a multipole electrostatic 1s direction electrode according to the present invention. FIG. 4 shows a semi-finished product of an actual example of J31. Figure 5-a shows a semi-finished product of the embodiment of FA2,
Figure 5-b shows a second embodiment. In the figure, D1 to D20...Polarizing piece, ■...Annular insulator, 3...Bending gap path, 4...Annular conductor

Claims (1)

[Claims] (]) Comprising a hollow insulator with a continuous periphery and a plurality of electrode pieces protruding from the inner surface of the hollow insulator, the space between adjacent electrode pieces is in a plane perpendicular to the vertical axis. A multipolar electrode characterized by being bent inside. (2) The metal body is fixed integrally inside the hollow, recessed body, @
Machining all of the above-mentioned metal members so that the space between the electrode pieces that fit together constitutes a plurality of electrode pieces separated by a bending path that is bent in a plane perpendicular to the longitudinal side 1'ff: Features A method for manufacturing a multipolar electrode. (3) The previous d's own gold arc; claim 2, in which the power of the book is wire cut and processed. The method for manufacturing the multipolar electrode described in Section 1.