JPH0445264A - Thin film forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film forming apparatus, and more particularly to a thin film forming apparatus that forms a thin film on a substrate using a cluster ion source.

[Prior Art] Fig. 3 shows, for example, the procedure of
nationalJon Engineering
Con) (ress)J (TSIAT'83&TP
1 is a configuration diagram showing a conventional R-ICB device shown in AT'83).

In the figure, symbol (1) is a vacuum chamber maintained at a predetermined degree of vacuum, (2) is a vacuum exhaust system connected to vacuum chamber (1), and (3) is a vacuum chamber that is connected to the lower part of vacuum chamber (1). A closed crucible is provided, the upper part of which is provided with at least one nozzle (4). (5) is the vapor deposition material filled in the crucible (3), and 6) is the crucible (3).
(7) is a heat shield plate that blocks radiant heat from the heating filament (6);
8) is a cluster (massive atomic group) ejected from the nozzle (4), (9) is a crucible (3), and a heating filament (6).
) and a heat shield plate (7).

(10) is an ionized filament that emits electrons, (1
1) is an electron extraction electrode that extracts electrons from the ionized filament (10) and accelerates them toward the cluster (8);
12) is a heat shield plate that shields the radiant heat from the ionized filament (1o), (13) is the ionized filament (10), the electron extraction electrode (11), and the heat shield plate (
12).

(14) is a cluster ion ionized to a positive charge by the ionization means (13), and (15) is an acceleration electrode that accelerates the cluster ion (14) with an electric field to impart kinetic energy.

(16) is a substrate provided in the vacuum chamber (1) facing the crucible (3), and (1) and are thin films deposited on the surface of the substrate (16).

(18) is a gas cylinder filled with a reactive gas such as oxygen or nitrogen, (19) is a valve provided on the gas cylinder (18), and (20) is a valve (19) at one end.
A pipe (21) is connected to a gas cylinder (18) and a valve (technique 9) with the other end opening into the vacuum chamber (1).
and a reactive gas introduction system consisting of a pipe (20).

(22) is a first AC power source for heating the heating filament (6); (23) is a first DC power source that positively biases the potential of the crucible (3) with respect to the heating filament (6); 24) is a second AC power source for heating the ionizing filament (10), (25) is a 27th AC power source for negatively biasing the ionizing filament (10) with respect to the electron extraction electrode (11), (26) is a third DC power source that biases the electron extraction electrode (11) and the crucible (3) to a positive potential with respect to the accelerating electrode (15) which is at ground potential.

(27) is a cluster ion source consisting of a steam generation source (9), an ionization means (13), an accelerating electrode (15), and a power supply device for these.

In the conventional ICB device configured as described above,
When forming a thin film on the substrate (16), first
) is evacuated by the vacuum evacuation system (2) until a degree of vacuum of about I x 10-' mzHg is reached.

Next, the electrons emitted from the heating filament (6) are accelerated by the electric field applied by the first DC power source (23), and the accelerated electrons are caused to collide with the crucible (3).
3) Heat to a temperature where the vapor pressure within is several HzHg.

Due to this heating, the vapor deposition substance (5) in the crucible (3) is evaporated and ejected from the nozzle (4). At this time, the ejected vapor deposition substance (5) becomes a supercooled state due to adiabatic expansion due to the pressure difference between the inside and outside of the crucible (3), and about 10 to 100 atoms combine to form a cluster (8).

This cluster (8) is an ionized filament (10)
A part of the cluster ions (14) are ionized by the electron beam emitted from the electron beam, and the cluster ions (14) are accelerated and controlled by the electric field formed by the accelerating electrode (15), and are not ionized. impinges on the surface of the substrate (16) together with neutral clusters (8).

On the other hand, a reactive gas introduction system (21) is located near the substrate (16).
There is a reactive gas introduced from
It is about 5 to 10-'zzHg. For this reason, the substrate (1
6), cluster (8) and cluster ion (1
4) with the reactive gas, and as a result, the substrate <1
A thin film of the compound (17) is formed in 6).

[Problems to be Solved by the Invention] In the conventional thin film forming apparatus configured as described above, when an insulating material is formed on the substrate (16), charges of ions incident on the substrate (16) accumulate. As a result, the formed thin film (17) is charged up, causing a local discharge with the surrounding ground potential area, and the thin film (17)
There was a problem in that it could cause damage such as discharge marks. Furthermore, there is a problem in that the incidence of the cluster ions (14) onto the substrate (16) may be obstructed by the generation of an electric field due to charge-up.

This invention was made with the aim of solving the above-mentioned problems, and it is possible to prevent ion charges from being accumulated in a thin film, thereby preventing charge-up of the thin film, and
The object of the present invention is to provide a thin film forming apparatus that can prevent damage to the thin film due to local discharge, allow cluster ions to be quickly incident on the substrate, and improve film quality.

"Means for Solving the Problems" A thin film forming apparatus according to the present invention is one in which a high frequency power source is connected to a substrate, and an electron supply means for supplying electrons to the thin film is provided in a vacuum chamber.

[Operation] In the present invention, by applying a high frequency voltage to the substrate, electrons are supplied from the electron supply means to the thin film on the surface of the substrate, thereby neutralizing the positive charges of ions accumulated in the thin film.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a thin film forming apparatus according to an embodiment of the present invention, and the same or corresponding parts as in FIG. 3 are given the same reference numerals, and the explanation thereof will be omitted.

In the figure, symbol (31) is a high frequency power supply connected to the substrate (16), and (32) is a substrate (
1B), the electron supply filament (33) is a third AC power supply connected to the electron supply filament (32), and the third AC power supply (33) powers the electron supply filament (32). is heated.
(34) is an electron supply means consisting of an electron supply filament (32) and a third AC power source (33).

In the thin film forming apparatus configured as described above, the thin film (17) is formed on the substrate (16) in the same manner as in the conventional example, but at this time, the third AC power source (33) is used to form the electron supply filament (32). ) is heated, and a high frequency voltage is applied to the substrate (16) by a high frequency power source (31).

While the substrate (16) is at negative potential, the electron supply filament) (3
Electrons do not move from 2), but when the substrate (16) has a certain positive potential, electrons are supplied from the electron supply filament (32) toward the substrate (16), that is, to the thin film (1). This neutralizes the positive charges of the cluster ions (14) and reactive gas ions accumulated in the thin film (1). That is, while the substrate (16) is at a negative potential, a thin I
I (17) The accumulated positive charges are transferred to the substrate (16)
When becomes a positive potential, it will be immediately neutralized. substrate(
Since a high frequency voltage is applied to the substrate (16),
The change in the potential of the thin film (17) is fast, so that the positive charges are quickly neutralized and the thin film (17) is prevented from being charged up.

On the other hand, since the substrate (16) is biased by the high frequency power source (31) and electrons move more easily than ions, the impedance of the substrate (16) and thin film (17) decreases, and the electron supply filament ) (32) to the substrate (16) can be relatively easily recovered by the high frequency power source (31).

Furthermore, when the amount of electrons supplied from the electron supply filament (32) increases, the substrate (16) is charged to a negative potential.
The amount of electron supply is controlled in the opposite manner, and there is no risk of damaging the substrate (16) due to excessive negative charge.

In addition, in the above embodiment, the electron supply means (34) is composed of an electron supply filament (32) and a third AC power source (33) and supplies thermoelectrons, but the present invention is not limited to this. For example, a device that supplies photoelectrons as shown in FIG. 2 may be used.

Here, FIG. 2 is a configuration diagram showing a thin film forming apparatus according to another embodiment of the present invention. This electron supply target (
41) is made of a material that easily emits photoelectrons, such as celsium, silver, calcium, or barium, or oxides or compounds thereof. (42) is an ultraviolet light source such as an excimer laser or a mercury lamp that irradiates the electron supply target (41) with ultraviolet light; (43) is a beam splitter;
(44) is a reflection mirror, (45) is an electron supply target (41), an ultraviolet light source (42), and a beam splitter (
43) and a reflecting mirror (44).

In such a thin film forming apparatus, an ultraviolet light source (42)
irradiate the electron supply target (41) with ultraviolet light,
This supplies photoelectrons to the thin film (17).

Further, in each of the above embodiments, the thin film (17) of the compound is formed by using the reactive gas introduction system (21), but the reactive gas introduction system (21) may not be provided.

Furthermore, in the above embodiment, the cluster ion source (27) is
Although the ICB device used in the combination is shown, multiple ICs using multiple combinations are shown.
It may be a B device.

[Effects of the Invention] As explained above, the thin film forming apparatus of the present invention supplies electrons from the electron supply means to the thin film on the substrate surface by applying a high frequency voltage to the substrate, and removes ions accumulated in the thin film. By neutralizing the positive charge of the thin film, it is possible to prevent ion charges from accumulating in the thin film and prevent the thin film from being charged up, thereby preventing damage to the thin film due to local discharge. In addition, the cluster ions can be made to enter the substrate quickly, and as a result, the film quality can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional example. In the figure, (1) is a vacuum chamber, (16) is a substrate, and (17) is a vacuum chamber.
) is a thin film, (27) is a cluster ion source, (31) is a high frequency power supply, and (45) is an electron supply means. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] a vacuum chamber for accommodating a substrate; a cluster ion source provided in the vacuum chamber to form a thin film on the substrate; a high frequency power source connected to the substrate;
A thin film forming apparatus comprising: electron supply means for supplying electrons to the thin film.