JPS5937541B2 - electronic microscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses an electron microscope to observe the vapor deposition process and crystal growth process by depositing evaporated particles evaporated in a sample chamber onto a sample mesh.

As a conventional device of this kind, one having a structure as shown in FIG. 1 has been put into practical use.

That is, a plurality of filaments 4 and 4' serving as a vacuum evaporation source are provided in a space 3 in a sample chamber 2 placed above an objective lens 1.

The filaments ) 4 and 4' are connected to filament control power supplies 5 and 5' provided outside the sample chamber 2, and evaporated samples 6 and 6' are installed inside the filaments ) 4 and 4'.
has been inserted.

A magnetic pole piece 7 is provided at the center of the objective lens 1, and a sample mesh 8 (on which a carbon thin film or microgrid is stretched) 8 for observing electron microscope images is provided inside the magnetic pole piece. It is located.

When current is supplied to the filament 4 from the filament control power source 5, the filament 4 is heated, the evaporation material 6 begins to evaporate, and evaporation particles 9 are deposited on the sample mesh 8.

Similarly, the filament 4 is connected from the filament control power source 5'.
It is also possible to deposit vaporized particles 9' of the vaporized material 6' onto the sample mesh 8 by supplying current to the sample mesh 8.

Furthermore, by simultaneously heating the filaments 1-4 and 4', the vaporized materials 6 and 6' can be simultaneously deposited on the sample mesh.

At this time, by irradiating the sample mesh 8 with the electron beam 10, the vapor deposition process and crystal growth process can be observed.

However, in an apparatus using such a vacuum deposition method, a large amount of electric power is required to deposit a high melting point metal such as tungsten.

Furthermore, when a large current is supplied to the filament, an asymmetric leakage magnetic field is generated on the electron beam path, causing the electron beam to be improperly deflected, resulting in inconvenience in observation.

In view of these points, the present invention provides an apparatus for bombarding an evaporation material with a low-acceleration electron beam to evaporate it, and will be described in detail below with reference to FIG. 2.

In this figure, the same numbers as in FIG. 1 indicate the same components.

FIG. 2 is a longitudinal cross-sectional view showing an embodiment of the present invention. Reference numeral 11 denotes an annular evaporation electron beam source placed in the space 3 in the sample chamber 2, and the electron beam source includes an annular filament 12 and an annular filament 12. and a control electrode 13 placed so as to surround the filament.

The center of the annular filament 12 is aligned with the optical axis of the electron beam, and the filament is connected to a power source 14 provided outside the sample chamber 2, to which a negative high voltage of, for example, several KV is applied. At the same time, a heating current is supplied.

Note that a negative high voltage is applied to the control electrode 13 from a power source 14 .

Reference numerals 15a and 15b are evaporation materials placed above the electron beam generation source 11 and at symmetrical positions with respect to the electron beam optical axis, and are kept at ground potential. They are fixed to racks 16a and 16b, respectively.

The racks 16aj and 16b are movably held in a holder 18 fixed to the bottom of the focusing lens 17, and the moving direction of both ranks is parallel to the electron beam optical axis.

Pinions 19a and 19b are used to move the racks 16a and 16b, and both pinions are connected via shafts to motors 20a and 20b provided outside the sample chamber 2, respectively.

Reference numeral 21 denotes a cylindrical body for integrating the electron beam generation source 11 and the holding body 18.

Reference numeral 22 denotes an irradiation electron beam 10 provided at the center of the holder 18.
It is a hole for passing through.

However, now, as shown in the figure, the evaporation material 15
Take out only the annular filament 1 from the holder 18.
2, if a negative high voltage and heating current are supplied to the filament from the power source 14, the electrons E generated from the annular filament will impact the evaporation material 15a.

The evaporation material 15a is evaporated by the electron bombardment, and the evaporation particles V pass through the inside of the annular filament and are deposited on the sample mesh 8.

The evaporative material 15a is transferred to the holder 1 by the pinion 19a.
8 and the other evaporation material 1 by the pinion 19b.
When 5b is brought close to the annular filament 12, this evaporation material 15b is bombarded with electrons and evaporated.

Furthermore, if the evaporation materials 15a and 15b are brought close to the annular filament at the same time, the electron beam generated from the annular filament bombards both evaporation materials at the same time.

That is, the electron beam generated from the left side of the annular filament with the electron beam optical axis as the center irradiates the evaporation material 15a, and the electron beam generated from the right side of the annular filament with the electron beam optical axis as the center irradiates the evaporation material 15b. irradiate.

Therefore, the evaporation material 15a is placed on the sample mesh 8.

15b is deposited at the same time.

By irradiating the sample mesh 8 with the electron beam 10 during the vapor deposition or after the vapor deposition is completed, the vapor deposition process or crystal growth process can be observed.

As described above, in the present invention, since the evaporation material is evaporated by electron beam bombardment, the high melting point metal can be evaporated without requiring a large amount of power unlike the conventional vacuum evaporation method.

Furthermore, since the evaporation electron gun is annular and arranged symmetrically with respect to the electron beam optical axis, the leakage magnetic field generated from the evaporation electron gun becomes axially symmetrical, which prevents the irradiated electron beam from being improperly deflected. It has a great practical effect, such as eliminating the problem.

In the above description, the case where two evaporation materials are provided is shown, but one or three or more evaporation materials may be provided.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view for explaining a conventional device, and FIG. 2 is a vertical cross-sectional view for showing an embodiment of the present invention. In FIG. 2, 1 is an objective lens, 2 is a sample chamber, 7 is a magnetic pole piece, 8 is a sample mesh, 10 is an irradiation electron beam, 11 is an electron gun for deposition, 12 is an annular filament, 13 is a control electrode, and 14 is a 15a and 15b are evaporation materials, 16a and 16b are racks, 17 is a focusing lens, 18 is a holder,
19a and 19b are pinions, and 20a and 20b are motors.

Claims (1)

[Claims] 1. An annular vacuum evaporation electron gun is installed in the sample chamber, and the center of the electron gun is aligned with the electron beam optical axis, and the electron gun is held above the electron gun so that it can move forward and backward with respect to the electron gun. An electron microscope comprising: at least one evaporation material; the evaporation material is evaporated by bombarding the evaporation material with an electron beam from the electron gun;