JPH06108237A - Ion plating device - Google Patents

Abstract

PURPOSE:To form an insulating film of a good quality on a substrate extending over many hours by covering the electrode surface of a counter electrode with an inert gas, repulsing an evaporation flow, etc., so that it scarcely reaches the surface of the counter electrode, and maintaining conductivity of the counter electrode for many hours. CONSTITUTION:Reaction gas 21 is led into a vacuum chamber 1 in which a film material 6 is melted and evaporated and an evaporation flow 7 is formed. Also, plasma 15 from a plasma gun 14 is radiated to the evaporation flow 7, and an electron in the plasma 15 is attracted by a counter electrode 16. Subsequently, the evaporation flow 7 and the reaction gas 21 are ionized to positive, these ionized evaporation flow 7 and the reaction gas 21 come into collision with a substrate 8 applied to negative and are solidified, and an insulating film is formed on the substrate 8. In this case, a gas film device 30 for covering the electrode surface of the counter electrode 16 with an inert gas (argon) 22 is provided, and pressure in the electrode surface of the inert gas 22 is set to >=10<3> torr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion plating device, and more particularly to a counter electrode for a plasma gun used in an ion plating device for forming an insulating film.

[0002]

[Prior Art] Ion plating
Is a film forming method in which vaporized atoms and / or reactive atoms that have been vaporized by heating are ionized and collide with a negatively applied substrate to solidify. A conventional ion plating apparatus for performing such ion plating generates a vacuum chamber 1 having a crucible 5 therein, an electron gun 3 for irradiating the crucible with an electron beam 4, and a plasma 15, as shown in FIG. 3, for example. A plasma gun 14, a counter electrode 16 for attracting electrons in the plasma, a reaction gas introduction nozzle 13 for introducing a reaction gas 21, and the like are provided, and the substrate 8 is negatively applied to the electron gun 3.
By irradiating the crucible 5 with the electron beam 4 to melt and evaporate the film material 6 in the crucible to form an evaporation flow 7 of the film material 6, generate a plasma 15 by the plasma gun 14 and attract electrons by the counter electrode 16. Thus, the vaporization flow 7 and the reaction gas 21 are positively ionized, and the ionized vaporization flow 7 and the reaction gas 21 are collided with the negatively applied substrate 8 to be solidified to form an insulating film on the substrate.

[0003]

However, in such a conventional ion plating apparatus, the insulating film formed on the substrate is formed not only on the substrate but also on the surface of the counter electrode 16, so that the counter electrode 16 is formed. There is a problem that the conductivity decreases as the film formation progresses. Therefore, the plasma 15 becomes unstable or cannot be maintained, and there is a problem that the evaporation flow by the plasma and the ionization of the reaction gas are extremely reduced. As a result, ion plating is not substantially performed and vapor deposition is merely performed, and the film quality of the insulating film formed on the substrate is deteriorated (poor and not dense, insufficient crystallization, hardness is reduced, Etc.) and the adhesion between the insulating film and the substrate is reduced. Further, since such a phenomenon occurs in an extremely short time, for example, a few minutes to a dozen minutes, there is a problem that the stable operation of the plasma gun for a long time is practically impossible.

The present invention was devised to solve the above-mentioned various problems. That is, the present invention is
It is difficult to form an insulating film on the surface of the counter electrode, the electrons in the plasma can be attracted stably for a long time, and an ion plating device that can stably form a high-quality insulating film on the substrate for a long time The purpose is to provide.

[0005]

According to the present invention, a film material is dissolved and evaporated in a vacuum chamber to form an evaporation flow toward a substrate, and a reaction gas is introduced into the vacuum chamber,
A plasma gun is used to generate a plasma intersecting with the vaporization flow, electrons in the plasma are attracted by a counter electrode to positively ionize the vaporization flow and the reaction gas, and the ionized vaporization flow and the reaction gas are negatively applied. In an ion plating apparatus for forming an insulating film on a substrate by colliding and solidifying on the substrate, 10 ⁻³ to
There is provided an ion plating device comprising a gas film device for covering the electrode surface with an inert gas so as to have a pressure of rr or more.

According to an embodiment of the present invention, the gas film device includes a gas blowout hole provided on an electrode surface of a counter electrode and a gas for supplying an inert gas to the gas blowout hole through the inside of the counter electrode. It is preferable that it is composed of a supply device, and thereby the inert gas is blown from the inside of the counter electrode to the electrode surface of the counter electrode through the gas blowing holes. Further, the gas film device includes a gas nozzle provided so as to flow an inert gas along the electrode surface of the counter electrode, and a gas supply device for supplying the inert gas to the gas nozzle. Is preferably sprayed along the electrode surface of the counter electrode. Further, it is preferable that the inert gas is argon gas.

[0007]

According to the present invention, the average moving distance (average free path) of atoms or molecules until the atoms or molecules of the evaporative flow or the reaction gas collide with each other in the vacuum chamber is the pressure (pressure) in a normal ion plating apparatus. For example, 5 × 10 ^-4 to
rr) is long (for example, 500 mm), and a pressure of 10 ⁻³ torr or more is short (for example, 50 mm or less).

That is, according to the constitution of the present invention, the gas film
Depending on the device, 10 ^-3pressure over torr
Since the electrode surface is covered with an inert gas so that
Pressure close to vacuum (eg 5 × 10^-Fourtorr)
Atoms of the evaporative flow or reaction gas approaching the counter electrode or
Molecules are gas atoms of the inert gas immediately in the inert gas.
It collides with (molecule) and is bounced back. Therefore, the insulating film is formed.
The evaporative flow that forms a film and the atoms or molecules of the reaction gas are opposite electrodes.
It is difficult to reach the surface of the counter electrode.
No film is formed. This increases the conductivity of the counter electrode.
It can be maintained over time,
Plasma is stable for a long time, and the evaporation flow by plasma
Also, the ionization of the reaction gas is performed stably, and it is dense and crystalline.
Is sufficient, the hardness is high, and the adhesion with the substrate is high,
Forming a good quality insulating film on a substrate for a long time
You can

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an ion plating apparatus according to the present invention, and FIG. 2 is another overall configuration diagram of an ion plating apparatus according to the present invention. 1 to 3, common parts are designated by the same reference numerals and used.

1 and 2, the ion plating apparatus according to the present invention dissolves and evaporates the film material 6 in the vacuum chamber 1 to form an evaporation flow 7 toward the substrate 8 and reacts in the vacuum chamber 1. A gas 15 is introduced, and a plasma 15 crosses the vaporized stream 7 by a plasma gun 14.
Are generated, the electrons in the plasma 15 are attracted by the counter electrode 16 to positively ionize the evaporation flow 7 and the reaction gas 21, and the ionized evaporation flow 7 and reaction gas 2 are generated.
The insulating film is formed on the substrate 8 by colliding with and solidifying the substrate 8 to which 1 is negatively applied.

That is, in FIGS. 1 and 2, the vacuum chamber 1 is evacuated by a vacuum pump (not shown).
The chamber is maintained at a pressure suitable for ion plating, for example, 5 × 10 ⁻⁴ torr. The ion plating apparatus according to the present invention includes an electron gun 3, which generates an electron beam 4, which is irradiated on a crucible 5 to melt and evaporate an evaporation material 6, and the evaporation material 6 evaporates. It is adapted to form an evaporation stream 7.

Further, in the ion plating apparatus according to the present invention, the plasma gun 14, the focusing coil 17 and the counter electrode 1 are provided as means for ionizing the vaporization flow 7 and the reaction gas 21.
6, a converging coil 18, an insulating portion 19, and a counter electrode power source 20. The plasma gun 14 generates a plasma 15 in which positive ions and electrons coexist. Counter electrode 16
Are installed at positions substantially opposite to the plasma gun 14 and are insulated from the vacuum chamber 1 via an insulating portion 19. The counter electrode 16 is applied with a relatively positive (plus) voltage from the vacuum chamber 1 by the counter electrode power supply 20, attracting electrons in the plasma 15 to the counter electrode 16, and evaporating flow 7 passing through the plasma. Also, the reaction gas 21 is ionized into positive ions.

The focusing coils 17 and 18 generate a magnetic field for focusing the plasma so that the plasma does not spread. The focusing coils 17 and 18 are preferably provided on both the plasma gun side and the counter electrode side as shown. The converging coil 18 on the counter electrode side may be provided inside the counter electrode (not shown). When the plasma 15 emitted from the plasma gun 14 is irradiated to the vaporization flow 7 with the above-described configuration, when the electrons in the plasma 15 mainly collide with the vaporization flow 7 and the reaction gas 21, the vaporization flow 7 and the reaction gas 21 are positive ions. Ionize to.

The substrate 8 is supplied with a high frequency (for example, 13.56 MH) from a high frequency power source 11 via a high frequency matching device 10.
z) is being applied. The substrate 8 itself may be an insulator or a conductor, but since the insulator is deposited on the substrate 8, a high frequency is applied so that a negative voltage can be applied to the surface of the insulator. The high frequency matching device 10 is a matching device that matches the impedance on the load side so that a negative voltage can be effectively applied to the surface of the insulator. In addition, in order to maintain the substrate 8 at a constant temperature and stabilize the film forming conditions, the heater 12
Should be provided.

A reaction gas 21 is introduced into the vacuum chamber 1 through a reaction gas introduction nozzle 13. The reaction gas 21 is oxygen (O ₂ ) when, for example, alumina Al ₂ O ₃ is deposited on the substrate 8. The evaporation material 6 is aluminum (Al) or alumina (Al ₂ O ₃ ), and oxygen O ₂ is introduced as the reaction gas 21 to form alumina (Al ₂ O ₃ ) on the substrate. The ratio of aluminum to oxygen of alumina formed on the substrate is not always 2: 3,
Strictly speaking, it should be expressed as Al _x O _y , but here it is simply expressed as Al ₂ O ₃ .

The ion plating device of the present invention further comprises a gas film device 30 for covering the electrode surface of the counter electrode 16 with an inert gas 22 of 10 ⁻³ torr or more. In FIG. 1, the gas film device 30 includes a plurality of gas outlets 23 provided on the electrode surface of the counter electrode 16 and a gas supply device that supplies an inert gas to the gas outlets 23 through the inside of the counter electrode 16, that is, a gas supply device. And an active gas introduction nozzle 24.
As a result, the inert gas 22 can be blown from the inside of the counter electrode through the gas blowing holes 23 from the front surface of the counter electrode 16 to the electrode surface in a shower shape.

In FIG. 2, the gas film device 30 includes a gas nozzle 25 provided so as to flow an inert gas along the electrode surface of the counter electrode 16, and a gas supply for supplying the inert gas 22 to the gas nozzle 25. The apparatus, that is, the inert gas introducing nozzle 24. This allows the inert gas 22
Can be sprayed along the electrode surface of the counter electrode 16.

The pressure of the inert gas 22 is preferably 10 ^-3 torr or more, and particularly preferably 10 ^-2 torr or more. The moving distance of gas molecules until the gas molecules collide with each other in the vacuum chamber is 5 at a pressure in a normal ion plating apparatus, that is, at about 5 × 10 ⁻⁴ torr.
It is around 00 mm, about 10 mm at 10 ^-3 torr, 10
^It is about 5 mm at ^-2 torr and about 0.5 mm at 10 ^-1 torr. Therefore, by setting the pressure of the inert gas 22 in the gas film device 30 to at least 10 ⁻³ torr or more, the gas molecules that have come close to the counter electrode are made to collide with the gas molecules of the high-pressure inert gas and rebound. You can

The inert gas 22 is a gas such as helium (He), neon (Ne), or argon (Ar), and is preferably argon gas having a large molecular weight and inexpensive. This makes it possible to reliably repel gas molecules that have come close to the counter electrode by collision with gas molecules of an inert gas having a large molecular weight. The reaction gas 2 is used instead of the inert gas 22.
Although 1 may be used directly, it is less effective than an inert gas.

Using the apparatus shown in FIG. 1, an ion plating test was performed using Al ₂ O ₃ (aluminum oxide) as the evaporation material 6 and oxygen (O ₂ ) as the reaction gas 21. When only the first vacuum evacuation is performed, evacuation is performed to the 10 ⁻⁶ torr level, then the evaporation material 6 is evaporated by the electron gun 3, oxygen (O ₂ ) is introduced from the reaction gas introduction nozzle 13, and 5 ×
The film was formed under a pressure of 10 ⁻⁴ torr. The output of the plasma gun 14 was 60 V × 150 A, and the counter electrode power supply 20 was several V (volts). Electron gun 3 is about 6 kW, substrate 8
The voltage applied to was -100 to -200V.
Further, the substrate 8 was heated to 500 ° C. by the heater 12.

As a result of the above test, the plasma from the plasma gun can be stably maintained for a long time (2 hours or more),
It was possible to maintain the ionization of the evaporation flow 7 and the reaction gas 21 for a long time, and it was possible to form an insulating film of alumina having good film quality and good adhesion to the substrate 8. In addition, the counter electrode is likely to reach a high temperature because it is exposed to plasma, but as a result of the above test,
The blowing / spraying of the inert gas had the attendant effect of combined cooling. Further, even if the ion plating apparatus according to the present invention is used without applying a negative voltage to the substrate, ionized evaporation flow and reaction gas are deposited on the substrate, so that there is no means for ionizing, that is, simply “deposition”. A very good film quality was obtained as compared with.

[0022]

As described above, according to the present invention, when the moving distance of the gas molecules until the gas molecules collide with each other in the vacuum chamber is a pressure (for example, 5 × 10 ⁻⁴ torr) in a normal ion plating apparatus. Long (eg 500 mm), 10
It is based on a new viewpoint that it is short (for example, 50 mm) at a pressure of ^-3 torr or more.

That is, according to the present invention, since the electrode surface of the counter electrode is covered with the inert gas of 10 ⁻³ torr or more by the gas film device, a pressure close to vacuum (for example, 5 × 10 ⁻⁴ ton).
The vapor or reaction gas atoms or molecules that have passed through rr) and have come close to the counter electrode immediately collide with the gas atoms (molecules) of the inert gas in the inert gas and are repelled. Therefore, the vaporization flow for forming the insulating film and the atoms or molecules of the reaction gas hardly reach the surface of the counter electrode, and the insulating film is hardly formed on the surface of the counter electrode. As a result, the conductivity of the counter electrode can be maintained for a long time, the plasma by the plasma gun is stable for a long time, the evaporative flow by the plasma and the ionization of the reaction gas are also stably performed, and dense and crystallization is possible. It is possible to form a high-quality insulating film having sufficient hardness, high hardness, and high adhesion with the substrate on the substrate for a long time.

In summary, according to the present invention, therefore, it is difficult to form an insulating film on the surface of the counter electrode, the electrons in the plasma can be attracted stably for a long time, and a stable and high-quality insulation can be obtained for a long time. The film can be deposited on a substrate.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an ion plating apparatus according to the present invention.

FIG. 2 is another partial configuration diagram of the ion plating apparatus according to the present invention.

FIG. 3 is an overall configuration diagram of a conventional ion plating apparatus.

[Explanation of symbols]

 1 Vacuum Chamber 2 Vacuum Evacuation 3 Electron Gun 4 Electron Beam 5 Crucible 6 Evaporating Material 7 Evaporating Flow 8 Substrate 9 Insulating Section 10 High Frequency Matching Device 11 High Frequency Power Supply 12 Substrate Heater 13 Reactive Gas Introducing Nozzle 14 Plasma Gun 15 Plasma 16 Counter Electrode 17 Focusing coil 18 Focusing coil 19 Insulating part 20 Counter electrode power source 21 Reactive gas 22 Inert gas 23 Outlet hole 24 Inert gas introduction nozzle 25 Gas nozzle

Claims (4)

[Claims] 1. A film material is melted and evaporated in a vacuum chamber to form an evaporation flow toward a substrate, a reaction gas is introduced into the vacuum chamber, and a plasma gun is used to generate plasma intersecting the evaporation flow. Electrons in the plasma are attracted by the counter electrode to positively ionize the vaporization flow and the reaction gas, and the ionized vaporization flow and the reaction gas are collided and solidified on the substrate to which the negative is applied to form an insulating film on the substrate. An ion plating apparatus for forming a film, comprising: a gas film apparatus for covering the electrode surface of the counter electrode with an inert gas so that a pressure of 10 ^-3 torr or more is provided on the electrode surface of the counter electrode. . 2. The gas film device comprises a gas blowout hole provided on an electrode surface of a counter electrode, and a gas supply device for supplying an inert gas to the gas blowout hole through the inside of the counter electrode. To blow an inert gas from the inside of the counter electrode to the electrode surface of the counter electrode through the gas outlet holes.
The ion plating device according to claim 1, wherein: 3. The gas film device comprises a gas nozzle provided so as to flow an inert gas along the electrode surface of the counter electrode, and a gas supply device for supplying the inert gas to the gas nozzle. The ion plating device according to claim 1, wherein an inert gas is blown along the electrode surface of the counter electrode. 4. The inert gas is argon gas.
The ion plating device according to claim 2 or 3, characterized in that.