JPS60202645A - Ion beam irradiator - Google Patents

Abstract

PURPOSE:To minimize charging of a target made of an insulator by causing low energy electrons to float around the target when irradiating an ion beam upon the target. CONSTITUTION:When processing, implantation or analysis is performed on a target 5 made of an insulator by irradiating an ion beam 4 upon the target 5, an electron source 20 is installed in the concave area of a table holder 31. Then thermal electrons 21 from the electron source 20 are led into the space formed inside a mesh 23 to netralize the positive electrification caused by the irradiation of the ion beam 4. Therefore, a table 24 placed on an insulator 25, meshes 22 and 13 and the table holder 31 have a negative electric potential relative to the mesh 23, and the electrons 21 are floating and are sealed up inside the mesh 23. As a result, any charging of the target 5 is prevented by neutralizing the positive ionic charges, thereby enabling processing of the target 5 to be performed with high precision.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an apparatus for irradiating a target with an ion beam to perform processing, implantation analysis, etc. The purpose of this invention is to develop an ion beam irradiation apparatus suitable for minimizing charge-up due to beam irradiation in the case of a pattern with a pattern of irradiation.

[Background of the invention]

The first session shows the general structure of a sputter processing device, which is one application of ion beams.

The main part of the device is housed in a vacuum chamber 9, and a vacuum bomb 11 is installed.
2, exhaust the air to below 10-' Torr in all sections of X.

Ion source 1 (In this equipment, a high-performance liquid metal ion source is used because it is necessary to concentrate the ion beam 4 in a fine aK state.The ion beam 4 extracted from the ion source 1 is sent to the ion source 2. Focus.

Deflection 1. P on target 5 set on table 6)
Irradiate the r foot position and perform sputtering processing. Since the machining diameter of this device is 1 μm or less, the device is fixed to a foot plate 7 on an air servo mount 8 to eliminate vibrations of the device. When the target 5 is irradiated with the ion beam 4 using such a device, if the target 5 is a conductor, the charge of the ions 3 escapes from the table 6 to the ground. However, if the target 5 is an insulator or a pattern formed on an insulator substrate, the charges of the ions 5 will be detected by the ion beam irradiation unit.

It becomes impossible to control the focused irradiation of the beam, and prevention of this charge-up is a major part of ion beam processing.

Figure 2 shows one of the conventional methods of preventing charge amplifiers.
This paper describes one method, the single-child shower method. An electron shower 19 is irradiated from the side onto a target 5 on which the ion beam 4 is being irradiated to neutralize the charges of the ions 6. However, with this method, it is difficult to irradiate a single particle of electrons, and furthermore, parts other than the ion beam irradiation area are irradiated with t's, which becomes negative and disturbs the electric field near the target, causing the beam to irradiate. At the same time as it affects the trajectory, it also gives the target 5-eyed body an evil effect.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ion beam application device that minimizes charge-up of a target due to ion beam irradiation and also minimizes negative effects on the target and ion beam trajectory by means of neutralizing ion charges. be.

[Summary of the invention]

In methods such as electron shower, in which electrons are forcibly irradiated from the outside, negative charging of the target is unavoidable. but,
If the target is not directly irradiated with electrons and electrons with first-generation energy are left floating around the target, the electrons will be attracted to the positively charged portion due to ion irradiation, and the charge can be neutralized. Moreover, electrons are not attracted to areas other than the ion-irradiated area, and that area is not primarily charged.

[Embodiments of the invention]

Hereinafter, the present invention will be explained according to Examples.

Embodiment 1> Figure 3 is an explanation of the configuration of Kiyao's side. On the Kiyao side, the electron source 20 is housed in the table holder 51, and thermionic electrons 21 generated therefrom are drawn into the space within the mesh A25, and the positive charge caused by the ion beam irradiation is neutralized by the electrons 21. At this time.

The table 24 is installed on an insulator 25, and the table 24 is placed on an insulator 25.
Mesh B24 around the mesh A25 and mesh A25 Mesh 21 for electronic drawer. Since the table holder 61 maintains a negative potential with respect to the table 24 and the mesh A25, the electrons 21 are confined within the space between the table 24 and the mesh A25. At this time, electrons 21 are flowing into the table 24 and the mesh 3-A 25, but the electrons 21 are flowing into the surface of the target 5, which is an insulator, and if the surface area becomes even slightly negatively charged, more electrons will flow. does not flow in, and is insufficient to adversely affect the target 5 due to electrification. As a result of processing a C pattern formed on a glass substrate using the target hold method with the configuration of this example without a vapor layer at ℃, good processing results were obtained in which no influence of charge amplifier was observed. However, in the configuration of the embodiment, the electron 21 is 1
Shun, who left Metshu A23, was pushed back to 22 by Metsushi and entered Mech 5LA.
The rate at which electrons 21 were absorbed at 25 was even higher. Also, I1
Although four single-element sources 20 were arranged around the table 24 to make the electron density within the mesh A2S uniform, a place with a slightly lower density occurred in the center, and the beam trajectory changed.

Correction was necessary. Furthermore, in this configuration, since the electron 21 is always sent into the mesh A25, care must be taken to adjust the electron density. Filament i! by tlL flow value! It was necessary to apply feedback to the L source 26. in this way.

Although the configuration of this example left some gaps in operability,
The initial goal of processing insulators was now possible.

Example 2〉 In Figure 4, the electron 21 extracted from the electronic monument 2o is not used directly to neutralize the charge of the ion, but the electron 21 extracted from the electron monument 2o is accelerated to generate secondary ' such as AtL. - This figure shows a device for irradiating a metal plate 55 with high electron emission ability and using the secondary electrons 35 generated therefrom. metal plate 3
The secondary electron 55 generated by the electron impact from the metal plate 35 is attracted to the metal plate 35 (which is at an electric potential) Iy zA25, and the mesh A25 is 2a! Meet Metsu A25 and Qi 7-
It enters between 9 and 24. Target 5 is table 2
The electrons 63 that enter here and the charges of ions that enter from above are neutralized, and even if the target 5 is an insulator, processing can be performed without charging up. In addition, in this embodiment, mesh A25 and mesh A2
A resistor 39 is provided between M29 and the resistor 39. Therefore, as many electrons 33 enter the mesh A25 and the current flowing into the mesh A25 and the table 25 increases, this resistor 39 The voltage drops at mesh h
The dark potential difference between A 23 and the metal plate 35 decreases, and the number of electrons drawn into the mesh A 25 decreases. When the number of electrons 35 decreases, the drop in voltage decreases, so the potential difference between the two atoms increases and the number of electrons drawn increases. This feedback seedling is designed to keep the number of electrons 35 in the mesh A25 constant. electronic 35
The density of the resistor 59 can be adjusted by changing the resistance 59. In addition, in this embodiment, the secondary electrons 53 are blown out from five places around the table 25, but instead of blowing out the mesh A 25 once every 5 times as in the first embodiment and then pushing them back with the mesh & B 22, the secondary electrons 53 are directly blown out. Since the electrons 63 were drawn into the mesh A-A 25, the electron density within the mesh A 25 was more uniform in this example.

<Example 5> In Examples 1 and 2, a method was adopted in which electrons were emitted near the table and drawn into the mesh crystal. In this embodiment, plasma is generated, electrons are extracted from it, and these are used to neutralize the charge of ions. Plasma 48 is generated by placing a rare gas such as Ar in a chamber and applying high frequency to it using a coracoid coil 46 . From here, pull in'! ! It is guided into the mesh A2S by the l pole 45. Even with this method, young fruits similar to those of the previous example were obtained. Furthermore, real h'f91
J Y: ht jj Suhonbe 49 (-'Ct4#
The etching rate can be increased by switching to a reactive gas and performing ion beam assisted etching in a Cj atmosphere. The improvement in etching speed depends on the target, but it is an effective etching method that improves the etching speed by about one to two orders of magnitude, and is effective for targets that are not contaminated by CC. At the same time, since the plasma charge of the incident ion is neutralized by the negative charge of Cj-, etching can be performed without charge-up even if the target 5 is an insulator or a pattern formed on an insulator substrate, as in the case of introducing ions. This makes it possible to achieve high precision, high quality, and fast speed for any target 5.

〔Effect of the invention〕

As mentioned above, according to the present invention, x is relatively low:
4 df ((JxlogV)) of electrons can be stably supplied to the periphery of the target to be irradiated with the ion beam.

Therefore, if the target is an insulator or

Even in the case of patterns formed on insulating substrates.

Electrons around the target are attracted to the ion beam irradiation part and neutralize the positive charge of the ions, so there is no charge-up and the trajectory of the ion beam is not disturbed, just like when the target is a conductor. Processing is possible. moreover.

When neutralizing the glass charge with an electron shower, electrons are irradiated to areas other than the ion beam irradiation area, and that area has a negative impact on the charge-up 1 target, but in the present invention, the initial Since the inflow of electrons prevents further inflow of electrons, negative charge-up due to electrons can be reduced.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional ion beam microprocessing device, Figure 2 is an explanatory diagram of ion charge neutralization by electron shower, Figure 3 is a composition diagram of Example 10, and Figure A4 is a diagram of Example 2. The configuration diagram and Figure 5 are configuration diagrams of the sixth embodiment. 1...Ion section 2...Ion optical system 3...Ion 4...Ion beam 5...Target 6...
・Table 7...Surface plate 8...Air servo mount 9...Vacuum chamber 10...Secondary electron 11...
Secondary electron detector 12...Vacuum pump 16...Ion W controller 14...Optical system controller 15...Secondary electron nice play 16...Table controller 17...Exhaust system controller 18 ...Electron shower 19...Electron 20...Electron source 21...Electron 22...Mesh B 23...Mesh A24...
- Table 25... Insulating sheet 26... Filament power supply 27... Power supply for child extraction 28... Power supply for electronic pull-in 29... Power supply for electronic push-back 30... Power supply for electronic push-out 31. ...Table holder 62...Casing 53
...Secondary electron 64...Electron acceleration power supply 38...
Electronic drawer t&39...Resistor 40...Power source for electron drawing 41...Vacuum pump for differential pumping 42...Resistor 43 River case 44...Insulation ring 45...Electron drawing electrode 4
6... High frequency coil 47... Substrate 48... Plasma 49... Gas cylinder $ 1 Figure 1 θ- - Figure 2 Figure 3

Claims (1)

[Claims] t The ion source, the main system, the table that holds the irradiated object, and the main body that houses them (and the vacuum exhaust hole,
and an ion beam irradiation device taken from an electric W controller that drives them. An ion beam irradiation device characterized in that a magnetic pole is provided. 2. An ion beam irradiation device characterized in that two or more hemispherical mesh electrodes with different radii are arranged together as electrodes for suppressing the scattering of electrons. The ion beam irradiation device according to item 1 of the range of finding fM. An ion beam irradiation apparatus according to claim 1, characterized in that two electrons generated from a region are used. 4. The ion beam irradiation apparatus according to claim 1, wherein a plasma generation source is provided, and electrons extracted from the plasma generation source are used as the electron beam. 56. The ion beam irradiation apparatus according to claim 1, wherein the energy of the electrons existing around the workpiece is IKmV or less. 6. An ion beam irradiation device consisting of an ion source, a table for holding an irradiated object, a vacuum chamber for storing them, a vacuum evacuation string, and a power controller for driving them, which A plasma generation source for supplying reactive dregs ions to the surrounding area. and 1 for drawing out and transmitting reactive dregs ions, and suppressing the scattering of the above-mentioned reactive dregs ions.
An ion beam irradiation device that has an IL pole as its enemy.