JPS6121789Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ion gun, and particularly to a small ion gun.

In a conventional ion beam generator, gas stored in a gas cylinder is introduced into an evacuated ion gun barrel, and the gas molecules are ionized to generate an ion beam.

Therefore, the device requires a gas cylinder accommodating portion, resulting in a large size.

The present invention has been made to overcome these conventional drawbacks, and one embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment of the present invention. In the figure, reference numeral 1 denotes an ion gun upper cylinder, and the upper part of the ion gun upper cylinder 1 is formed of an insulator 2. As shown in FIG. The insulator 2 has metal terminals 3a and 3b for conducting heating current.
is penetrated. A metal terminal 5 for applying a positive high voltage to an emitter 4, which will be described later, passes through the center of the insulator 2. Reference numeral 6 denotes a support plate made of an insulator, and an emitter 4 and plugs 8a and 8b are attached to the support plate 6 so as to pass through the support plate 6. Plugs 8a and 8b are filament 7
It is connected to the. At the tips of the terminals 3a, 3b, 5, sockets are formed to mechanically fix the plugs 8a, 8b and emitter 4 and to connect them electrically when they are inserted. The support plate 6 has an adsorbent material 9 that has numerous pores of the same size as molecules and adsorbs gases that become ionic species.
A donut-shaped storage tube 10 for storing the is integrally attached. At the tip of the storage tube, there is a second
As shown enlarged in the figure, the openings 11a, 11b, 1
1c and 11d are perforated. A valve body 12 is provided inside the tip to open the openings 11a, 11b, 11c, and 11d only during gas adsorption and gas release.
is provided. The valve body 12 is arranged at 4 equal angles.
It is a rotatable plate with several holes. An arm 13 is integrally attached to the valve body 12, and the arm 13 is connected to the rod 1 inserted from outside the ion gun barrel.
4, openings 11a, 11b, 11c, 11d
The housing cylinder 10 is opened and closed depending on the position of the hole in the valve body 12. Reference numeral 15 denotes a lower cylinder of the ion gun, and the lower cylinder 15 and the upper cylinder 1 are detachably attached to each other through a flange portion 16. The lower cylinder 15 has a cathode 17
is installed.

In the configuration as described above, first, the upper cylinder 1 is removed from the lower cylinder 15, and the support plate 6 and the support plate 6 are removed.
After removing the plugs 8a, 8b, emitter 4, and storage cylinder 10 that were integrally attached to the upper cylinder 1 from the metal terminals 3a, 3b, and 5 of the upper cylinder 1, the storage cylinder 10 was baked out and was absorbed by the absorbent material 9. The gas is completely desorbed from the adsorbent 9, and the storage cylinder 10 is kept at a low temperature and left in a gas atmosphere of ionic species.
The adsorbent is allowed to sufficiently adsorb the gas. Next, valve body 1
After closing the holes 11a, 11b, 11c, and 11d with 2, insert the plugs 8a, 8b integrally attached to the support plate 6, and the ends of the emitter 4 into the sockets of the metal terminals 3a, 3b, and 5, respectively. The support plate 6 is attached to the upper cylinder 1.

After the space surrounded by the upper tube 1 and the lower tube 15 is evacuated, the valve body 12 connected to the arm 13 by the rod 14 is rotated to open the storage tube 10. In this state, a high positive voltage is applied to the emitter 5 through the metal terminal 5 with respect to the cathode 17, and the filament 7 is connected to the terminal 3.
A heating current of a predetermined current commensurate with an appropriate gas release rate is supplied via a and 3b. As a result, the gas adsorbed by the adsorbent 9 is released from the adsorbent, and the openings 11a, 11b, 11c, 1 of the storage cylinder 10 are
It jumps out from 1d. The gas ejected from the storage cylinder 10 is polarized by the high electric field formed near the tip of the emitter 4, and is further polarized by the emitter 4.
is attracted very close to the tip of the particle, and is positively ionized at the tip by a strong electric field. The positive ions thus generated are accelerated toward the cathode 17 and taken out as an ion beam through an aperture provided in the cathode 17.

FIG. 3 shows still another embodiment, and the same components as in FIG. 2 are given the same numbers and their explanations are omitted. In FIG. 3, reference numeral 18 denotes a liquid nitrogen dewar, and the liquid nitrogen dewar 18 is thermally connected to the metal terminal 5. Since the terminal 5 is given high voltage via the insulated cable 19,
The dual 18 is surrounded by a case 20 made of an insulator. 21 is liquid nitrogen; 2
2 is the lid of the Duer. Also, metal terminals 3a, 3
b is also connected to a heating power source (not shown) via cables 23a, 23b. Furthermore, in this embodiment, the storage tube 10 is made of metal with good thermal conductivity, and is attached in contact with the emitter 4.

In this configuration, the storage cylinder 10 is cooled with liquid nitrogen via the emitter 4 and the terminal 5. Therefore, when the adsorbent 9 adsorbs a large amount of gas at an extremely low temperature, the plugs 8a, 8b and the emitter 4 are inserted into the sockets of the terminals 3a, 3b, 5, respectively, before the temperature rises. A storage cylinder 10 containing the adsorbent 9 can be attached to the upper cylinder 1 by inserting it into the upper cylinder 1.

In this way, by supplying a heating current to the filament 7 and heating the storage cylinder 10, a large amount of the adsorbed gas can be sequentially released from the adsorbent 9 and ionized.

As mentioned above, the ion gun based on the present invention does not require a gas cylinder or the like as a gas supply source, so the ion gun housing space can be reduced, and the ion gun can be used as an attachment such as an electron microscope sample sputtering means. Its usefulness is great when used as a

Furthermore, since the gas cylinder is not required, there is no need to consider insulation between the gas cylinder placed on the ground potential side and the ion gun section, which facilitates the production of the ion gun.

In the above-described embodiments, an example was described in which the present invention was applied to a field emission type ion gun, but the present invention can also be applied to other types of ion guns such as an electron impact type.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is an enlarged view of the tip of the storage cylinder, and FIG. 3 is a diagram showing another embodiment of the present invention. 1: Ion gun upper cylinder, 2: Insulator, 3a, 3
b, 5: metal terminal, 4: emitter, 6: support plate, 7: filament, 8a, 8b: plug,
9: Adsorbent, 10: Storage tube, 11a, 11b, 1
1c, 11d: Opening hole, 12: Valve body, 13: Arm, 14: Rod body, 15: Ion gun lower cylinder, 16:
Flange portion, 17: cathode, 18: liquid nitrogen duer, 19, 23a, 23b: cable, 20: case, 21: liquid nitrogen, 22: lid body.

Claims (1)

[Scope of utility model registration request] Comprising a gas discharge means for discharging a gas serving as an ion species into an ion gun barrel, a means for ionizing the discharged gas, and an extraction electrode for extracting ions generated by the ionization. In the device, the gas release means includes an adsorbent for adsorbing the gas, a means for removably attaching the adsorbent near the ionization means in the ion gun barrel, and a means for detachably attaching the adsorbent to the ion gun barrel. and means for heating the adsorbent disposed therein.