JPS6227563A - Apparatus for forming film with cluster ion beam - Google Patents

Abstract

PURPOSE:To stably form a film with reproducibility by placing a means of deflecting an ion beam emitted from a cluster ion gun from the forward direction by a magnetic field between the ion gun and a substrate. CONSTITUTION:An ion beam 2 emitted from a cluster ion gun 3 has <=about 100eV energy and reaches a substrate 5 held by a substrate holder 6 by the action of an acceleration electrode 4. At this time, the ion beam 2 is deflected from the forward direction by the magnetic field of an electromagnet 8 placed between the ion gun 3 and the substrate 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cluster ion beam film forming apparatus, which is one of film forming techniques.

(Prior Art) In recent years, a cluster ion beam evaporation method has been developed as one of the film forming methods, and is attracting attention because the thin films produced by this method have good film quality such as density and crystallinity. In other words, in the cluster ion beam deposition method, the vapor of the vapor deposited material is ejected into a vacuum from a nozzle, ionizes the massed atomic groups (clusters) to be expelled, and then accelerates them with an electric field, thereby imparting large kinetic energy to the clusters. This is a film formation method in which the film is attached to a substrate.

However, in conventional cluster ion beam deposition equipment, the number of atoms forming clusters is distributed over a wide range from 1 to several thousand, and single atoms or single molecules that do not form clusters are also Includes many. These monoatomic or monomolecular ionized particles had the following adverse effects on film formation.

(,) For monoatomic or monomolecular ions, when the acceleration voltage is increased to about 10 kilohertz, the energy per particle increases, resulting in destruction of the formed film or substrate surface and generation of defects, resulting in a decrease in film quality. let

(b) High-energy particles such as those described above have a large effect of causing smoke and ivy on the film surface, thereby reducing the deposition rate.

(c) When the number of ionized particles in the deposition beam increases, the beam diameter increases due to repulsion between space charges, reducing the deposition rate.

(d) During the film formation of M-bound materials and semiconductor materials, charge accumulation due to ions occurs, and this charge accumulation causes malfunctions in semiconductor elements such as ICs.

Furthermore, with conventional cluster ion beam evaporation equipment, it is not possible to control the number of particles constituting a cluster or the energy per particle, so it takes time to find the optimal values for film formation conditions such as substrate temperature and acceleration voltage. Furthermore, it has been extremely difficult to form a stable film with reproducibility.

(Problems to be Solved by the Invention) The present invention has been made for the purpose of solving all of the above-mentioned conventional problems. The object of the present invention is to provide a cluster ion beam film forming apparatus in which the number of particles constituting the cluster ion beam or the energy per particle can be controlled.

(Means for Solving the Problems) As a means for solving the above problems, the present invention provides a method in which the traveling direction of the ion beam emitted from the cluster ion gun is controlled by a magnetic field between the cluster ion gun and the base. The gist of the present invention is to provide a means for deflecting the magnetic field, to make the position of the base body movable, and to change the strength of the magnetic field.

(Function) With the above configuration, unclustered monoatomic or monomolecular ions are greatly deflected by the magnetic field, so they can be prevented from reaching the substrate, and the configuration of cluster ions to be deposited on the substrate can be prevented. The number of particles can be selected and controlled.

(Example) Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a configuration diagram of a cluster ion beam film forming apparatus showing an embodiment of the present invention. In this figure, numeral 1 is a Pelger, and inside it there is a cluster ion gun 3 that emits an ion beam 2, an acceleration electrode 4 that accelerates the ion beam 2 facing the cluster ion gun 3, and a base 5. A substrate holder 6 for holding the substrate, and a shield and a turf for shielding the ion beam 2 are arranged. At this time, the distance between the cluster ion gun 3 and the substrate holder 6 is approximately 40 mm. 8 is an electromagnet provided between the cluster ion gun 3 and the shutter 7, and the magnetic pole face of this electromagnet 8 is 20c! They have a size of 11 x 20 crR, are parallel to each other, have a gap of 5 cIn, and can vary the magnetic velocity density at the center up to about 3000 Gauss. 9 is
This is a DC power supply for accelerating the ion beam 2 connected to the accelerating electrode 4. The cluster ion gun 3 is grounded and a negative voltage can be applied to the accelerating electrode 4 in a variable range up to about 10 kg. l.

is a crystal oscillator film thickness sensor. Although not shown in the figure, a vacuum evacuation device is connected to the outside of the Pelger I.

The cluster ion beam film forming apparatus according to the present invention is configured as described above, and the ion beam 2 emitted from the cluster ion gun 3 has an energy of about 100 electrons, and is transferred to the substrate holder 6 by the accelerating electrode 4. The robot flies toward the base 5 held by the robot. And electromagnet 8
Therefore, when a magnetic field is applied in a direction substantially perpendicular to the traveling direction of the ion beam 2, the traveling direction of the ion beam 2 is deflected. Now, orthogonal three-dimensional coordinates are taken in which the direction connecting the cluster ion gun 3 and the accelerating electrode 4 is the X axis, the direction of the magnetic field is the Y axis, and the two axes are the directions perpendicular to the X axis and the Y axis.

According to an approximate calculation, the kinetic energy of the cluster ion is V electron volts, and the magnetic flux density in the electromagnet 8 is B1, and the spread of the magnetic field in the X-axis direction is the continuation of the IM cluster ion being bent in the magnetic field. , at the upper end of the electromagnet 8,
The distance R of deflection in the Z-axis direction is given by RΣg4&/2B (1). Here, e is the charge production amount.

- For example, when ■ = 100 electron Gault and B = 2500 Gauss, from the above formula (1), the monovalent silver ion Ag+ is
In the magnetic field of this device, it is bent in the Z-axis direction by about 5 degrees, and even after leaving the magnetic field in the electromagnet 8, it flies with a relatively large velocity component in the Z-axis direction.

In addition, under the same conditions, when the number of constituent particles is 1000 silver cluster ions Ag1000, the monovalent ion Ag
It receives only about 1/30 of the + deflection, and the velocity component in the Z-axis direction is small.

Further, in the above embodiment, the magnetic pole face of the electromagnet 8 is square, but the shape of the magnetic pole face is not limited to this.Other shapes include two rectangles, one trapezoid, one circle, an oval, a sector, and a triangle. It is. In addition, a cluster ion gun 3 and an electromagnet 8
Although the number of cluster ion guns 3 and electromagnets 8 is one, it is also possible to have a plurality of cluster ion guns 3 and electromagnets 8.

Furthermore, in the above embodiment, the cluster ion gun 3 was grounded and a negative voltage was applied to the accelerating electrode 4; however, the accelerating electrode 4
It is also possible to ground the cluster ion gun 3 and apply a positive voltage to the cluster ion gun 3. In addition, six motion calculations were performed on silver cluster ions in a cluster ion magnetic field, but the film forming material is not limited to silver, but all atomic molecules and compounds.

Possible for clusters of complexes.

(Effects of the Invention) As explained above, the cluster ion beam deposition apparatus according to the present invention uses an electromagnet to direct the traveling direction of an unclustered monoatomic or monomolecular ion beam emitted from a cluster ion. Since it can be deflected by a magnetic field, it has the following excellent effects.

(,) By using monoatomic or monomolecular ions with high energy per particle, destruction of the formed film or substrate surface and generation of defects are eliminated, and a high-quality thin film with excellent crystallinity can be obtained.

(b) The sputtering effect on the film surface caused by the high-energy particles as described above disappears, and the deposition rate increases.

(c) the amount of space charge in the deposit beam is relatively reduced;
Enlargement of the beam diameter due to repulsion between charges is reduced, increasing the deposition rate.

(d) During film formation of insulators and semiconductor materials, charge accumulation due to ions is reduced, and malfunctions of semiconductor devices such as ICs are reduced.

In addition, by making the substrate holder holding the substrate movable and changing the strength of the magnetic field, it is possible to select and control the number of constituent particles of the cluster ions to be deposited on the substrate. It becomes easy to find the optimum values for film formation conditions such as acceleration voltage, and stable film formation with further reproducibility can be performed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a cluster ion beam film forming apparatus according to the present invention. 1...Pelger, 2,21...Ion beam, 3
...Cluster ion gun, 4...Acceleration electrode, 5...
・Base, 6...Base holder, 8...Electromagnet, 9.
...DC power supply.

Claims (3)

[Claims] (1) A cluster ion beam film forming apparatus characterized in that means is provided between the cluster ion gun and the substrate for deflecting the traveling direction of the ion beam emitted from the cluster ion gun using a magnetic field. (2) The cluster ion beam film forming apparatus according to claim 1, wherein the position of the base is movable. (3) The cluster ion beam film forming apparatus according to claim 1, wherein the strength of the magnetic field is variable.