JPH08104980A - Cluster ion beam sputtering device - Google Patents

Abstract

PURPOSE: To selectively irradiate a work piece with only the cluster ions meeting sputtering by passing a cluster ion beam through a cluster size selector combined with an electrostatic lens and an aperture. CONSTITUTION: Gases which are gaseous at ordinary temp. are ejected as gaseous clusters from a nozzle 1. These gases are made into the beam by a skimmer 2. The beam is passed through an ionizing electrode system 3 to form the gaseous cluster ion beam. The work piece 7 is irradiated with the beam and is thereby subjected to sputtering. The cluster ion beam is passed through the cluster size selector consisting of an electrostatic lens electrode 4 and aperture 5 of the sputtering device. The beam is converged and diverged by the electric field of the electrostatic lens electrode 4. Only the beam of the necessary cluster size is converged to the hole of an aperture 5. As a result, the cluster ion beam of the large size is selected exclusive of the cluster ions and atom-form cluster ions of the small size and the work piece 7 is irradiated with the beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cluster ion beam sputtering apparatus. More specifically, the present invention relates to a simple sputtering device equipped with a device for selecting large-sized cluster ions required for sputtering processing.

[0002]

2. Description of the Related Art Conventionally, various gas phase reaction methods have been developed for the purpose of forming a thin film, and one of the methods is a cluster ion which is ionized by irradiating a cluster consisting of a cluster of massive atoms or a group of molecules with an electron. Sputtering by the beam irradiation method has been put to practical use.

In the case of this method, it is considered that it is necessary to irradiate the workpiece with large-sized cluster ions. Therefore, the method of selecting larger-sized cluster ions is this cluster. It has been an important issue for the sputtering processing by the ion beam irradiation method. That is, for example, it is known that large-sized cluster ions have lower energy than small-sized cluster ions even when accelerated by the same voltage, and the lateral sputter effect at the time of substrate collision is remarkable. Therefore, it is considered important in sputter processing to remove small-sized cluster ions and atomic ions and select large-sized cluster ion beams. Therefore, as a method for selecting the cluster size, a magnetic field method, an ExB method, a method combining flight time and pulse chop, a deceleration electric field method, and the like have been proposed so far.

However, in the case of these conventional methods, in the magnetic field method and the ExB method, a heavy magnet must be incorporated in the sputtering apparatus, which is not suitable because the apparatus becomes complicated, and the time-of-flight method is used. However, since the required equipment is complicated, it is difficult to handle, and there is a problem as a method for selecting the cluster size. Furthermore, the deceleration electric field method has a simple structure and is easy to select cluster sizes, but it is difficult to select cluster ions of a specific size.

Therefore, in a sputter processing apparatus using the cluster ion beam irradiation method, single atoms and small-sized cluster ions are removed, and large-sized cluster ions required for sputter processing are simply and easily obtained.
It was strongly desired to realize an improved method capable of effectively selecting. The present invention has been made in view of the above circumstances, eliminates the drawbacks of conventional cluster selection methods, selects only cluster ions of a size suitable for sputter processing, and selectively processes the cluster ions. It is intended to provide a sputtering device for irradiating an object.

[0006]

In order to solve the above-mentioned problems, the present invention is characterized in that a cluster ion beam irradiation device is provided with a cluster size selection device including an electrostatic lens and an aperture. Provide a sputter device. Further, the present invention, as such a sputtering device, is required for the sputtering process by using a cluster size selection device including a cluster of atoms or a group of molecules of a gaseous substance at room temperature, which is a cluster of atoms, and a cluster size selection device including an aperture. Provide a device for taking out only large-sized clusters and irradiating a workpiece to perform sputter processing.

[0007]

That is, according to the present invention, by using the cluster size selection device in which the electrostatic lens and the aperture are combined as described above, only the clusters of larger size are taken out, and the workpiece is irradiated and sputtered. It is possible.

More specifically, chromatic aberration occurs when the energy of the beam entering the electrostatic lens is different. On the other hand, the cluster ion beam includes clusters of different sizes, and therefore has a beam having energy dependent on the cluster size. Therefore, the use of the electric field lens causes chromatic aberration depending on the size of the cluster. Therefore, clusters with different energies also have different focal positions, so if you set an aperture at the focal point and adjust the lens voltage to focus on the aperture, you can obtain a beam of that energy, that is, a beam with a specific cluster size. Can be sorted.

The selection of cluster size is particularly effective when the gas cluster made of a substance that is gaseous at room temperature, which is proposed by the inventor of the present invention, is ionized and used. This is because the energy is controlled by the cluster size and the characteristics of the gas cluster ion beam are further exerted. This for gas cluster, effective sputtering film forming _{CO 2, N 2, O 2} , their compound, a hydrocarbon, may be a reactive gas of a silicon compound or the like.

These gas clusters can be made into a beam by ejecting a compressed gas from a nozzle and then passing it through a skimmer. Of course, the device of the present invention can be applied not only to gas clusters but also to clusters of vaporized atoms or molecules such as metals. Hereinafter, the cluster ion beam sputtering apparatus of the present invention will be described in more detail with reference to examples.

[0011]

1 and 2 of the accompanying drawings are schematic views of a cluster ion beam sputtering apparatus of the present invention. Then, FIGS. 1 and 2 describe a sputtering apparatus using a gas cluster ion beam, and FIG. 2 shows a more specific apparatus configuration.

For example, referring to FIG. 1, a simple type sputtering device having a cluster size selection device that combines an electrostatic lens and an aperture provided in the gas cluster ion beam irradiation device will be described. The cluster ion generated from the nozzle (1) will be described. The beam passes through the skimmer (2) and enters the ionization electrode system (3). The ionized ion beam is extracted and accelerated by the electric field formed by the extraction electrode of the ionization electrode system (3), and enters the electrostatic lens electrode (4).

In this case, it is not always necessary to use the extraction electrode for extraction and acceleration. If a sufficient current is drawn, it is better not to apply a voltage to the extraction electrode.
Since the cluster ion beam already has an energy of several eV to several hundreds eV at the time of forming the ion beam, it is possible to extract relatively efficiently. Electrostatic lens electrode (4)
The cluster ion beam passing through is subjected to convergent divergence by the electric field created by the electrostatic lens electrode (4). The convergent divergence depends on the initial velocity energy of the cluster. An aperture (5) is placed at the position where it exits the electrostatic lens electrode (4), and only the beam having the required cluster size is focused on the aperture (5). Other sizes of cluster ion beams are not focused, so the current density is small. The beam emitted from the aperture (5) is appropriately converged and deflected by the subsequent converging electrode (6), and is irradiated on the workpiece (7) to be sputter processed.

Referring to FIG. 2 more specifically, the nozzle (1) as described above is positionally adjustable in the gas cluster generation chamber (10) and the skimmer (2) is arranged in the ionization chamber. An ionization electrode system (3), an electrostatic lens electrode (4), an aperture (5), and an ionization vacuum gauge (8) which can move up and down are arranged in (11). This ionization vacuum gauge (8) measures the cluster beam intensity, and the ionization electrode system (3) is not operated when measuring. The ionization vacuum gauge (8) may be installed between the ionization electrode system (3) and the skimmer (2) for the same purpose.
After the acceleration electrode (21) in the irradiation chamber (12), the left and right deflection electrodes (22), the upper and lower deflection electrodes (23), and the shutter (24) are placed in the high-voltage chamber (13) to be processed. The object (7) is sputtered.

The high voltage chamber (13) has a support (2
Supported by 5). With such a device, actually, on the surface of the silicon substrate as the workpiece,
It is possible to control the cluster size of CO ₂ gas cluster ions to be within a predetermined range and form a SiO ₂ cured film by sputtering.

[0016]

As described in detail above, according to the present invention, a sputtering apparatus having a cluster size selection device combining an electrostatic lens and an aperture provided in the cluster ion beam irradiation device can be used simply, efficiently and with high performance. Will be possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a gas cluster ion beam sputtering apparatus.

FIG. 2 is a cross-sectional view of the configuration of a more specific gas cluster ion beam sputtering apparatus.

[Explanation of symbols]

 1 Nozzle 2 Skimmer 3 Ionization Electrode System 4 Electrostatic Lens Electrode 5 Aperture 6 Focusing Electrode 7 Workpiece 8 Ionization Vacuum Gauge 10 Gas Cluster Generation Chamber 11 Ionization Chamber 12 Irradiation Chamber 13 High Voltage Chamber 21 Acceleration Electrode 22 Left and Right Deflection Electrode 23 Up and Down Deflection electrode 24 Shutter 25 Support material

Claims (2)

[Claims] 1. A sputtering apparatus, comprising: a cluster ion beam irradiation apparatus, comprising a cluster size selection device in which an electrostatic lens and an aperture are combined. 2. A cluster ion beam device is provided with a gas supply part made of a gaseous substance at room temperature, a nozzle for ejecting the gas, and a skimmer for forming the gas cluster ejected from the nozzle into a beam. The sputtering apparatus according to claim 1, which is a gas cluster ion beam apparatus.