JPH0766873B2 - Fast atom beam source - Google Patents

Description

TECHNICAL FIELD The present invention relates to a radiation source for emitting constituent atoms or molecules of an insulator such as SiO ₂ or Al ₂ O ₃ as a fast atom beam or a fast molecular beam. It is a thing.

A fast atom is a general term for an atom having a much higher velocity than a gas molecule that is in thermal motion at room temperature. At room temperature, thermal kinetic atoms have kinetic energies around 0.05eV, so all atoms that fly with kinetic energies above 1eV fall into the category of fast atoms. When atoms with this energy fly in one direction, it is called a fast atom beam. Also, a molecular beam having this level of energy is put into the fast atom beam for convenience.

[Prior Art] Conventionally, for example, an RF sputtering apparatus has been used to emit constituent atoms and molecules of insulators such as SiO ₂ and Al ₂ O ₃ as fast atom beams.

FIG. 3 shows an outline of an example of such an RF sputtering apparatus. In FIG. 3, 21 and 22 are parallel plate electrodes, and 23 is an insulator plate, which is placed on the plate electrode 22. 24 is a high frequency power source, 25 is a positively charged ion beam, 26 is an electron, and 27 is a sputtered atom or molecule.

This device operates as follows.

A portion other than the high frequency power supply 24 is installed in a vacuum, and a gas such as argon is introduced until the pressure reaches 0.1 to 10 ^-3 Torr.
In this state, a high frequency electric field is applied between the electrodes 21 and 22 from the high frequency power supply 24. As a result, glow discharge is generated between the electrodes 21 and 22 and plasma is formed.

Consider now that the plate electrode 22 has a negative potential with respect to the electrode 21. At this time, the positively charged ions in the plasma become a beam 25 and are accelerated toward the flat plate electrode 22, and the electrons are flattened by the flat plate electrode 21.
Will be accelerated towards. Then, the positively charged ion beam 25 bombards the insulator flat plate 23 to sputter the constituent atoms and molecules of the insulator from the surface thereof. Atoms and molecules 27 sputtered from the surface are few eV regardless of the kinetic energy of the positively charged ion beam 25 incident on the surface of the insulating flat plate 23.
Has kinetic energy of. After all, a fast atom beam with kinetic energy of eV can be obtained.

The insulator flat plate 23, which has been bombarded with the positively charged ion beam 25, is charged and the potential of its surface rises instantaneously, so that the subsequent ion beam is blocked from entering and the emission of the fast atom beam 27 is stopped. However, in the next half cycle of the high frequency power supply 24, the electrode 22 has a positive potential with respect to the electrode 21, so that the electrons 26 in the plasma are accelerated toward the electrode 22 and enter the insulator flat plate 23, and The charge is neutralized, and in the next half cycle, the impact of the positively charged ion beam 25 on the insulating flat plate 23 is restarted again, and the fast atom beam 25 is emitted. Eventually, the fast atom beam 25 will be emitted intermittently in a fast cycle.

[Problems to be Solved by the Invention] As described above, in the conventional high-speed atomic beam generation method,
Since fast atom beams diverge and are emitted omnidirectionally from an insulating flat plate, it is difficult to obtain fast atom beams with a sufficient dose density.

Therefore, an object of the present invention is to provide a radiation source capable of generating a high-speed atomic beam having a high dose density by providing directivity for a high-speed atomic beam emitted from an insulator.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a metal cylinder, an insulator cylinder fitted in contact with the inside of the metal cylinder, a metal cylinder and an insulator cylinder. On the central axis of, and apart from these cylinders, in the middle between the cathode and the cylinder, in the middle between the cathode and the grid anode, and between the grid anode and the cylinder, the cylinder A shielding plate disposed close to the DC power source, a DC power source connected to apply a positive potential to the grid anode and a negative potential to the cathode, and a high frequency power source connected between the grid anode and the metal cylinder. It is characterized in that a high-speed atomic beam or a high-speed molecular beam is emitted.

[Operation] According to the present invention, the ion beam is obliquely incident on the surface of the insulator, the grid anode is arranged between the cathode and the cylinder, and the high frequency power source is provided between the grid anode and the metal cylinder. This high-frequency power source alternately changes the polarities of these electrodes at high speed, preventing charge-up on the surface of the insulator cylinder, and therefore the sputtered atoms or molecules have a directivity and dose density. High-speed atomic beam or molecular beam can be obtained.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

One embodiment of the present invention is shown in FIG.

In FIG. 1, 1 is a cathode, 2 is a grid anode, 3 is a metal cylinder, 4 is an insulating cylinder, and 5 is a shielding plate. 6 is an ion beam, 7 is a high-speed atom beam, 8 is a DC power supply, and 9 is a high-frequency power supply.

The cathode 1 is arranged apart from the metal cylinder 3 on the central axis of the metal cylinder 3, and the grid anode 2 is arranged close to the cathode 1. The shield plate 5 is arranged close to the metal cylinder 3 along the central axis of the metal cylinder 3. The insulator cylinder 4 is fitted in contact with the inside of the metal cylinder 3.

The parts other than the power supplies 8 and 9 are placed in a vacuum atmosphere, and a gas such as argon is introduced until the pressure reaches 0.1 to 10 ^-3 Torr. In this state, a DC power supply 8 is connected between the cathode 1 and the grid anode 2, and a high frequency power supply 9 is connected between the grid anode 2 and the metal cylinder 3.

As a result, glow discharge is generated between the cathode 1 and the grid anode 2 to form plasma. The electrons in the plasma are accelerated toward the grid anode 2 and collide with the argon gas to generate a large amount of positively charged ions of argon in the vicinity of the grid anode 2.

The positively charged ions of argon are accelerated toward the metal cylinder 3 when the output polarity of the high frequency power source 9 is negative and the grid anode 2 is positive, and the positively charged ion beam 6 is formed. Collides with the insulator cylinder 4. By this collision, the constituent atoms and molecules on the surface of the insulator cylinder 4 are sputtered, and the fast atom beam 7 having a kinetic energy of several eV is emitted.

Generally, the atoms or molecules 33 sputtered from the surface of the solid 32 which has been hit by the ion beam 31 have the directivity as shown in FIG.

Therefore, also in the case of the embodiment of the present invention shown in FIG. 1, the atoms or molecules sputtered from the surface of the insulator cylinder 4 by the oblique incidence of the ion beam 6 are emitted with directivity and have a convergent high-speed atomic beam. 7 will be obtained.

Now, the surface of the insulator cylinder 4 which has been impacted by the positively charged ion beam 6 is instantly charged and its potential rises to prevent the subsequent ion beam 6 from entering, so that the emission of the fast atom beam 7 is stopped. .

However, in the next half cycle of the high frequency power source 9, the metal cylinder 3 has a positive potential with respect to the grid anode 2, so that the electrons pass through the mesh of the grid electrode 2 and are accelerated toward the metal cylinder 3 to be insulated. It collides with the object cylinder 4 and neutralizes the charge on the front surface, and thus prevents the back surface of the insulator cylinder 4 from being charged up.

As a result, in the subsequent half-synchronization, the injection of the ion beam 6 into the insulator cylinder 4 is restarted, and the fast atom beam 7
Will be released.

It is to be noted that the ion beam 6 emitted from the grid anode 2 when the potential of the metal cylinder 3 is negative is prevented from advancing straight without entering the insulator cylinder 4 and being mixed into the high-speed atomic beam 7,
When the potential of the metal cylinder 3 is positive, in order to prevent electrons that have passed through the mesh of the grid anode 2 from traveling straight without colliding with the insulator cylinder 4 and mixing into the fast atom beam 7, A shield plate 5 is provided.

[Effects of the Invention] As described above, according to the present invention, the ion beam is obliquely incident on the surface of the insulator, and the grid anode is arranged between the grid anode and the metal cylinder. A high-frequency power supply is provided between the two electrodes, and the high-frequency power supply alternately changes the polarities of these electrodes at high speed, preventing charge-up on the cylindrical surface of the insulator, and thus directing the atoms or molecules to be sputtered. It is possible to obtain a high-speed atomic beam or molecular beam having high properties and high dose density.

By irradiating the substrate with such a high-speed atomic beam and depositing it on the substrate, a thin film having good adhesion can be formed, and it can also be effectively used for modifying the surface layer of the substrate.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram for explaining directivity of sputtered atoms or molecules when a solid surface is bombarded by an ion beam, and FIG. 3 is a conventional RF. It is a block diagram which shows an example which takes out a high-speed atomic beam using a sputtering device. 1 ... Cathode, 2 ... Grid anode, 3 ... Metal cylinder, 4 ... Insulator cylinder, 5 ... Shielding plate, 6 ... Ion beam, 7 ... Fast atom beam, 8 ... DC power supply, 9 …… High frequency power supply, 21, 22 …… Parallel plate electrode, 23 …… Insulator plate, 24 …… High frequency power supply, 25 …… Positively charged ion beam, 26 …… Electron, 27 …… Sputtered atom or molecule, 31 …… Ion beam, 32 …… Solid, 33 …… Sputtered atom or molecule.

Claims (1)

[Claims] 1. A metal cylinder, an insulator cylinder fitted in contact with the inside of the metal cylinder, and arranged on the central axes of the metal cylinder and the insulator cylinder and apart from these cylinders. A cathode, a grid anode disposed between the cathode and the cylinder, close to the cathode, and a shield plate disposed between the grid anode and the cylinder, and close to the cylinder. A direct current power source connected so as to apply a positive potential to the grid anode and a negative potential to the cathode, and a high frequency power source connected between the grid anode and the metal cylinder. A fast atom beam source characterized by emitting a fast molecular beam.