JPS6331480Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic lens structure, and more particularly to an electrostatic lens structure with a compact structure.

For example, in an Augier spectrometer, a limited region of the surface of a sample is irradiated with ions from an ion gun, etching is performed, and the sample is analyzed in the depth direction. At this time, the ion beam is focused on the sample to a diameter of, for example, 1 mm to 0.1 mm, but for this reason,
Approximately two stages of electrostatic lenses are prepared. Figure 1 shows such a two-stage electrostatic lens, 1A,
1B, 1C, 1D, and 1E are cylindrical electrodes. The respective electrodes are insulating members 2A, 2B, 2C, 2D.
The electrodes 1A,
1C and 1E are grounded, and a high voltage on the order of several KV is applied to electrodes 1B and 1D, resulting in a two-stage electrostatic lens effect brought about by these electrodes. Here, since there is a potential difference of several KV between each adjacent electrode, each insulating member must be sufficiently long and made of an insulating material with excellent voltage resistance, making the lens as a whole large. , it becomes expensive.

This invention was made in view of the above points,
The purpose is to provide a compact electrostatic lens structure.

The electrostatic lens structure based on the present invention includes a support,
At least three electrodes fixed to the support and to which a ground potential or a low voltage is applied, and an insulator sandwiched between the two outer and inner electrodes, to which a high voltage is applied. The structure includes at least two high voltage electrodes and an insulator sandwiched between the high voltage electrodes, and the electrodes to which the ground potential or low voltage is applied and the high voltage electrodes are arranged alternately. It is characterized by

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 2, 11 is an insulating base, and an ion source 12 and a conductive support 13 are fixed to the base 11, and both ends of the support 13 are formed in a cylindrical shape. . Cylindrical electrodes 14, 15, and 16 are screwed and fixed to the support 13, and an electrode 17 is provided between the electrodes 14 and 15, and an electrode is provided between the electrodes 15 and 16. 18 are arranged. A cylindrical insulator 19 is interposed between the electrodes 17 and 14, a cylindrical insulator 20 is interposed between the electrodes 17 and 18, and a cylindrical insulator 20 is interposed between the electrodes 18 and 16. A shaped insulator 21 is interposed respectively. The insulators 20 and 21 are partially cut out at two places, and are in contact with each other except for the cutout parts, and the support part 18a of the electrode 18 is interposed in one of the cutout parts, and the support part 18a of the electrode 18 is inserted through the other cutout part. The support rod 15a of the electrode 15 is arranged accordingly. Furthermore, the electrode 1
Although not shown, an insulator 22 is screwed to the insulator 6, and a pair of X-direction deflection electrodes 23 and 24 are screwed to the insulator 22. still,
Although not shown, a pair of deflection electrodes in the Y direction are also screwed to the insulator 22.

In the configuration as described above, when assembling each electrode, first, the support 13 is fixed to the base 11,
Thereafter, the electrodes 14, 15, 16 are fixed to the support 13, but when screwing these electrodes, the insulators 19, 20, 21 and the electrodes 17, 18 are placed in predetermined positions, and these insulators are and electrodes are sandwiched and fixed by electrodes 14 and 16, and the whole is integrated. The conductive support 13
The electrodes 14, 15, 16 fixed to are at ground potential, and the electrodes 17, 1 adjacent to the ground electrodes
A high voltage of several KV is applied to 8 from a high voltage power supply (not shown), and as a result, a two-stage electrostatic lens is constructed. Here, the electrodes at ground potential are connected to each other by a support 13, and the electrodes 17 and 18 to which a high voltage is applied are connected via an insulator 20. As a result, the insulators that require sufficient consideration for withstand voltage are the insulator 1 that connects the high voltage electrode and the ground electrode.
9 and 21, and the insulators 19 and 21 need only be formed large (long) using a material with excellent insulating properties, and the other insulators 20 should be formed small (short) using a material with low withstand voltage. becomes possible. Therefore, it is possible to reduce the number of insulators that must be considered for voltage resistance, which would otherwise make the lens structure long and large. Since it becomes possible to use small materials or conductors, the design of the lens structure becomes easier. In this embodiment, the deflection electrodes 23 and 24 to which a relatively low voltage is applied are made of a thin insulator 22.
It is fixed to the ground electrode 16 via.

As detailed above, the present invention provides a compact electrostatic lens structure. Note that the present invention is not limited to the embodiments described above, and can be modified in many ways. For example, a plurality of ground electrodes are fixed to a conductive support, and this support is made of an insulating material.Although the explanation was given using a two-stage lens structure as an example, the present invention can also be applied to a lens structure with three or more stages. Can be applied. Furthermore, although the electrodes 14, 15, and 16 are grounded, the present invention can also be applied to cases where a relatively low voltage is applied to these electrodes.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing the structure of a conventional electrostatic lens.
FIG. 2 is a sectional view showing an embodiment of the present invention. 11: base, 12: ion source, 13: support,
14, 15, 16: Ground electrode, 17, 18: High voltage electrode, 19, 20, 21, 22: Insulator, 2
3, 24: Deflection electrode.

Claims (1)

[Scope of utility model registration request] Insulation is provided between the support 13, at least three electrodes 14, 15, 16 fixed to the support 13 and to which ground potential or low voltage is applied, and the two outer electrodes 14, 16. At least two high voltage electrodes 17 and 18 are sandwiched between objects 19 and 21 to which a high voltage is applied, and an insulator 20 is sandwiched between the high voltage electrodes, and the ground potential or the low An electrostatic lens structure configured to alternately arrange electrodes to which voltage is applied and high voltage electrodes.