JPS63269443A - Electron beam apparatus - Google Patents

Abstract

PURPOSE:To make it possible to remove contamination of an aperture, optical parts, etc., while maintaining vacuum-state thereof by housing a rare gas inlet, an ion beam generator, a magnetic coil for plasma and a coil for ion- neutralization in a tube. CONSTITUTION:Ar gas is put in a plasma-state by introducing rare gas (Ar) maintained in a vacuum-state into a tube 21 through a rare gas inlet 33 and applying voltages to a cathode 44, an anode 45 and a magnetic coil 35. Ar<+> ion beam is accelerated and pulled out into the tube by controlling a control grid 46 and a pulling out grid 47. The surface of an aperture 31, for example, is scanned and irradiated with Ar<+> ion beam by controlling an alignment coil 23 or a sub-deflector 25. By way of application of a voltage to a filament 37 for ion-neutralization provided just before the aperture 31, Ar<+> ion is neutralized just before it and Ar atoms are guided to collide with the surface of the aperture 31 for etching. Therefore, contamination can be removed.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to an insulating film that adheres over time to optical system components in the lens barrel of electron beam testers, electron microscopes, electron beam exposure devices, etc. In order to remove contamination, which is a substance generated when sulfur, carbon compounds, etc. It is characterized by comprising a generator, a plasma electromagnetic coil, and an ion neutralization coil.

Thereby, contamination attached to the electron beam path noaperture and electron lens can be etched away by scanning the main and sub deflectors, the 7-line coil, and the scan coil while maintaining a vacuum.

Therefore, it is possible to omit the conventional disassembly and assembly of the electron beam column, exhaust operations, and the like. It is also possible to substantially extend the life of the electronic optical system components.

[Industrial application field]

The present invention relates to an electron beam device, and more particularly to an electron beam detector having a function of removing contamination within an electron beam column.

[Conventional technology]

FIG. 2 is a diagram illustrating a conventional example.

First, to briefly explain the structure of the electron beam Stl, in the figure, 1 is an electron beam column, 2 is an electron gun, 3 is an alignment coil, and 4 is a main deflector.

5 is a sub-deflector, 6 and 8 are electron lenses, 7 is a scan coil, 9 is a 7-node, 10.11 and 12 are apertures (stops), 13 is a sample chamber, 14 is a stage, and 15 is an electron beam. There is.

Next, a vacuum pump is used to evacuate the inside of the lens barrel of the electron beam device. At this time, oil from the vacuum pump, grease from the O-ring, etc. become impurities and may enter the lens barrel in small amounts. However, according to the conventional configuration, an insulating film (contamination) adheres to the aperture, optical system components, etc. over time, and when the electron beam hits this, the insulating film is damaged. It induces a charge-up phenomenon in which electric charges are charged. This causes the electron beam to be abnormally deflected, causing instability such as the electron beam not passing through the optical axis.

For this reason, it is necessary to remove contamination, and it is not necessary to disassemble the electron beam column each time, take out the aperture and optical system parts one by one, and clean each part with a cloth soaked in A7Ton, etc. must not.

After cleaning each part, assemble the electron beam column.
Furthermore, there is a maintenance problem in that exhaust work must be performed.

The present invention was created in view of the problems of the conventional example, and provides an electron beam device having a function of removing contamination from the aperture, optical system components, etc. while maintaining a vacuum state within the lens barrel. The purpose is to provide.

[Means for solving problems]

In order to achieve the above object, the present invention provides an electron gun 22, an alignment coil 23. multiple apertures 30, 31, 32,
In an electron beam device having electronic components and optical system components such as deflectors 24 and 25, electron lenses 26 and 28, and scan coil 27, a rare gas inlet 33 for introducing rare gas into the electron beam column 21; , an ion beam generating section 34 provided below the electron gun 22, an electromagnetic coil 35 provided around the ion beam generating section 34 and used for plasma generation, and each electronic component and optical system component within the lens barrel 21. Ion neutralizing filaments 36 and 37 are provided on the surface to be cleaned.

38.39 An electron beam device is provided.

[Effect]

According to the present invention, for example, when cleaning the aperture for the main deflector, a rare gas is introduced into the lens barrel, and the rare gas ions (for example, Ar) that have been turned into plasma in the ion generator are accelerated to The rare gas ion beam is controlled by a sub-deflector, the rare gas ions are neutralized just before using the ion neutralization alignment provided on the aperture, and the accelerated rare gas (Ar) By impacting the surface, it can be etched, thereby removing contamination.

Therefore, while maintaining a vacuum state, it is possible to clean optical system components and the like without disassembling the electron beam column as in the past.

〔Example〕

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

FIG. 1 is a diagram for explaining an electron beam device according to an embodiment of the present invention. FIG. 1 (&) is a configuration diagram of the electron beam device, and FIG. FIG.

In the same figure (a), 21 is an electron beam column body, 22 is an electron gun, 23 is an alignment coil for aligning the beam, and 24 and 25 are main and sub electrostatic deflectors for deflecting the beam. , 26 and 28 are electron lenses that function as optical lenses, 27 is a scanning coil that scans the beam, 29 is 7 nodes, 30, 31, and 3.
2 is an aperture that functions as an optical diaphragm; 33 is a rare gas inlet; 34 is an ion beam generator for converting the gas into plasma, accelerating it, and extracting it; 35 is an electromagnetic coil for plasma generation; 36°, 37. 38 and 39 are filaments for ion neutralization, 40 is a sample chamber, 41 is a stage, 42
indicates an electron beam.

In addition, in the same figure (b), 43 is a rare gas ion beam;
44 is a cathode for emitting thermoelectrons, 45 is a cylindrical anode for converting rare gas into plasma, 46 is a mesh-like control grid for controlling the rare gas ion beam 43, and 47 is for controlling the rare gas ion beam. A mesh-like drawer grid 48 is used to draw the lens into the lens barrel, and numeral 48 indicates an insulating holder that supports the mesh-like drawer grid.

Next, we will explain the operation when cleaning contamination.

First, a rare gas, for example Ar in the present invention, is introduced into the lens barrel 21 through the rare gas inlet 33 while maintaining a vacuum state.

A voltage is applied to the cathode 44, the anode 45, and the electromagnetic coil 35 to turn the Ar gas into plasma. Then, the control grid 46 and the extraction grid 47 are adjusted to accelerate the Ar' ion beam and extract it into the lens barrel.

For example, when it is desired to remove contamination attached to the aperture 31, the alignment coil 23 or the sub-deflector 25 is controlled to
By applying a voltage to the ion neutralizing filament 37 provided just before the 0-order aperture 31 that scans and irradiates the surface of 1, the Ar'' ions are neutralized just before the aperture 31 and the Ar atoms collide with the surface of the aperture. This removes contamination.

Note that unless the rare gas ion beam is neutralized, the alignment coil 23, main and sub deflectors 24 and 25, electron lenses 26 and 28 . It can be deflected or reduced by the scan coil 27.

In this way, contamination that has adhered to the surfaces of other apertures and optical components can be sequentially removed by f:I without breaking the vacuum.
I can do M and I can do J. This eliminates the need for the conventional work of disassembling the electron beam column, assembling it, and evacuation.

[Effects of the Invention] As described above, according to the present invention, contamination attached to the aperture, optical components, etc. can be cleaned while maintaining a vacuum state.

This makes it possible to omit the conventional disassembly, assembly, exhaust work, etc., thereby making it possible to improve the operating efficiency of the electron beam device.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the configuration of an electron beam apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating details of the present invention. (Explanation of symbols) 1.21...Electron beam column, 2.22...Electron mirror, 3.23...Alignment coil. 4.24... Main deflector, 5.25... Sub-deflector, 6.8, 26.28... Electronic lens, 7.27...
Scan coil, 9.29...7 nodes. 10.11, 12, 29, 30, 31.32... Avert t, 13.40... Sample chamber, 14.41... Stage, 15.42... Electron beam. 33... Rare gas inlet, 34... Ion beam generation part. 35... Electromagnetic coil. 36.37, 38.39...Filament for ion neutralization, 43...Island gas ion beam, 44...Cathode. 45... Anode. 46... Control grid, 47... Drawer grid, 48... Insulating holder.

Claims (1)

[Claims] In the electron beam column (21), an electron gun (22), an alignment coil (23), a plurality of apertures (30, 31, 32), a deflector (24, 25), a plurality of electron Lenses (26, 28) and scan coils (2
In an electron beam device having electronic components and optical system components such as 7), a rare gas inlet (33) for introducing a rare gas provided in the electron beam column (21), and a rare gas inlet (33) for introducing a rare gas provided in the electron beam column (21);
2) an ion beam generation section (34) provided below, an electromagnetic coil (35) provided around the ion beam generation section (34) and used for plasma generation, and the lens barrel (21).
) ion neutralizing filaments (36, 37, 3) provided on the surface to be cleaned for each electronic component and optical system component.
8, 39).