JPS63290266A - Cluster ion beam device - Google Patents

Abstract

PURPOSE:To prevent deterioration in the quality of a film on a substrate by monoatomic and monomolecular ions of large energy by providing a means for deflecting an ion beam and slit for shutting off the ion beam between a cluster ion gun and the substrate in a cluster ion beam device. CONSTITUTION:A crucible 3 with a heater in a bell-jar 1 is heated to melt the material in the crucible. The melt is ejected from a small hole of the crucible 3 and is ionized by an ionizing unit 4. The ions are accelerated as the ion beam 2 contg. clusters by an accelerating electrode 5. The cluster ions in the ion beam 2 are deflected to the central part and the monoatomic ions and monomolecular ions of the large energy are deflected off the center of the ion beam 2 by the electromagnetic effect of the accelerating electrode 5 in this case and, therefore, the said monoatomic ions and monomolecular ions are shut off by a slit 6 and are thereby prevented from arriving at the substrate 7. The breakdown of the thin film of the cluster ions on the substrate by the monoatomic and monomolecular ions of the large energy is prevented and the good-quality film is formed on the substrate 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a film forming apparatus for cluster ion beam evaporation, which is one of thin film forming techniques.

[Prior Art] In recent years, a cluster ion beam evaporation method has been developed as one of the thin film forming methods, and has attracted attention because the G film produced by this method has good W1 quality such as density and crystallinity.

Cluster ion beam evaporation is a process in which a cluster of atoms (or molecules) (hereinafter referred to as
This is a thin film formation method in which clusters (referred to as clusters) are ionized and further accelerated by an electric field to give large interlocking energy to the clusters, causing them to adhere to a substrate.

[Problems to be Solved by the Present Invention] The number of atoms or molecules (hereinafter referred to as particles) in clusters formed by conventional cluster ion beam film deposition equipment varies widely from one to several thousand. Clusters consisting of single atoms or molecules that do not form clusters, and a small number of particles, are ionized and have the following negative effects.

(a) For clusters consisting of single atoms, single molecules, or several particles, increasing the acceleration voltage to about 5 kV increases the energy per unit particle, causing destruction of the formed film or substrate surface and generation of defects. This reduces film quality.

(b) High-energy clusters like those shown in (a) have a large sputtering effect on the film surface and therefore reduce the deposition rate.

(c) During film formation of insulators and semiconductor materials, charge accumulation due to ions occurs, which causes malfunctions in semiconductor devices such as ICs.

However, in the conventional cluster ion beam device, the energy per cluster cannot be controlled, so the above-mentioned problem cannot be solved.

Further, even when a plurality of ion guns are used, it is extremely difficult to make the flow rate of the deposition beam from each ion gun uniform in order to obtain a desired composition on the substrate.

[Means and effects for solving the problems] The present invention is a cluster ion beam device that solves the above-mentioned problems.

The device of the present invention includes a device between the cluster ion gun and the substrate.
A means for deflecting the traveling direction of the ion beam emitted from the cluster ion gun using a magnetic field and a slit capable of blocking the deflected ion beam are provided to selectively control the clusters to be deposited on the substrate.

When a magnetic force is applied to an ion beam, the degree of deflection is greater for clusters with fewer particles, and the ion beam deviates from the center of the beam.If the ion beam is blocked by a slit to prevent it from reaching the substrate, the particles will pass through the slit. A film is formed only in clusters with a certain number of particles or more. Since the slit is variable, the size of the slit can be changed depending on the degree of deflection of clusters with a desired number of particles to obtain a desired film.

[Example] Hereinafter, the present invention will be explained in detail with reference to the embodiment shown in FIG.

FIG. 1 shows the W component of a cluster ion beam film forming apparatus showing an embodiment of the present invention. EL is a Pel jar with a crucible and a heating device 3 inside, an ionization unit 4 for ionizing the evaporated material coming out of the crucible, Furthermore, an electromagnet that also serves as an accelerating electrode5. A slit 6 for selectively shielding the ion beam and a basic holder 8 for holding the substrate 7 are arranged. 2 is an ion beam. In this case, the distance from the slit 6 from which the ion beam comes out to the substrate 7 is 10 to 50 cm.
It is about a meal. The electromagnet 5 has a cylindrical shape with a diameter of 50 cm and a height of 10 cm, and the magnetic flux density at the center can be varied up to about 500 gauss. 9 is a DC power supply for accelerating the ion beam 2 connected to the crucible and the heating device 3. By grounding the substrate holder 8 and the electromagnet 5, a positive voltage can be applied to the crucible and the heating device 3 in a variable manner up to about 10 kV. 10 more
is a power supply for magnet generation connected to the electromagnet 5. still,
Although omitted in the figure, a vacuum evacuation device is connected to the outside of the Pelger 1.

The vapor deposition material generated from the crucible and the heat source 3 is ionized by the ionization unit 4 and flies through the electromagnet 5 with an energy of about 100 eV. The ionized cluster beam is deflected by an electromagnet 5 and further passed through a slit 6.
Only desired clusters pass through and fly toward the substrate 7.

Orthogonal coordinates are taken in which the direction connecting the ion beam 2' emitted from the ionization unit and the substrate 7 is the X axis, the direction of the magnetic field is the Y axis, and the direction perpendicular to the X axis and the Y axis is the X axis. According to approximate calculations, the kinetic energy of cluster ions is
, the magnetic flux density in the electromagnet 5 is B, and the length of the magnetic field in the X-axis direction is a. Be-e-a3/n]τV - (I), where e is the elementary charge.

Now V = 100eV, B = 100gaus
If s, a = 10 cm, then from formula (I), silver 1
The valence ion Ag- is bent in the magnetic field of this device in the direction of the Z-axis by about 33 cII, while the 1000-atom silver cutister ion Ag 1000- is bent by about 1 cm. In this case, in order to obtain a good film, the number of constituent atoms of the cluster is 1000 to 5000, so X
In the slit 6 perpendicular to the axis, about 0.5~ from the center of the beam
IC! A t-circular window is provided in I to allow only cluster ions of a desired number of atoms to pass through. When silver was deposited under these conditions using the apparatus shown in FIG. 1, a thin film with strong adhesion and good electrical properties was obtained.

The vapor deposition material is not limited to silver, and can be vapor-deposited in the form of one molecule of atoms, compounds, and clusters of complexes of all types.

[Effects of the Invention] As described above, since the cluster ion beam device of the present invention can control the number of particles in the cluster, it exhibits the following excellent effects.

(A) Destruction of the film or substrate surface and generation of defects due to single atom or single molecule ions having high energy per particle can be prevented, and high quality E[ can be obtained.

(B) The sputtering effect on the film surface caused by high-energy particles as in (A) can be prevented, and the deposition rate can be increased.

CC) Charge accumulation caused by ions during film formation of insulators and semiconductor materials is reduced, and malfunctions of semiconductor elements and devices such as ICs are reduced.

Furthermore, since the size of the slits can be changed, clusters can be controlled and thin films with uniform density and good crystallinity can be obtained with good reproducibility.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a cluster ion beam apparatus representing one embodiment of the present invention. l...Perger. 2.2'...Ion beam. 3... Crucible and heating device. 4... Ionization unit, 5... Electromagnet that also serves as an accelerating electrode. 6...Slit. 7... Board, 8... Board holder, 9.10... DC power supply.

Claims (1)

[Scope of Claims] 1) A cluster ion beam device characterized in that a traveling direction of an ion beam emitted from an ion gun is deflected by a magnetic field between a cluster ion gun and a substrate. 2) The cluster ion beam device according to claim 1, characterized in that a slit is provided in the course of the ion beam deflected by the magnetic field. 3) The cluster ion beam device according to claim 1, wherein in the slits according to claim 2, the slit interval can be changed.