JPH09195036A - Vapor deposition device and production of thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technology for forming a thin film (compound thin film in particular) on the inside face of a hollow object to be film-formed represented by a slender tube. SOLUTION: At the time of forming a thin film on the inside face of an object to be film-formed having a hollow inside face, the opening parts 161 and 162 are airtightly clogged by clogging members 51 and 52 having a conductive heating element 3 in which a vapor depositing material is arranged, and vapor deposition is executed while the same is evacuated. After the vapor deposition, reactive gases are introduced from gas introducing ports 41 and 42 provided on the clogging members 51 and 52 , and voltage is applied to the space between the conductive heating element 3 and the object 9 to be film- formed to generate plasma of the reactive gases, by which the thin film formed in the object to be film-formed and the reactive gases can be brought into reaction. The compound thin film having a compsn. close to the stoichiometric compsn. can be obtd.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vapor deposition technique,
In particular, the present invention relates to a technique for forming a thin film on the inner surface of a hollow object to be film-formed.

[0002]

2. Description of the Related Art A general vapor deposition apparatus of the prior art will be described with reference to numeral 102 in FIG. 7. The vapor deposition apparatus 102 has a vacuum chamber 110, and a crucible 117 is provided on the bottom surface thereof.
Is arranged. In the crucible 117, a vapor deposition material 116 made of a substance to be deposited is arranged. The vacuum chamber 110 is evacuated by a vacuum pump (not shown), and the electron beam 115 generated by the filament 113 is bent by a magnetic pole to vapor deposit. When the material 116 is irradiated, a vapor flow 118 is generated, and the flat plate-shaped substrate 1 is placed above the crucible 117.
A thin film of a substance forming the vapor deposition material 116 can be formed on the surface of 14.

However, such a flat substrate 11
There is a demand for forming a thin film on the inner surface of the object to be film-formed, which is hollow instead of 4. In such a case, the opening provided in the film formation target is directed toward the vapor deposition material 116,
Even if an attempt is made to form a thin film on the inner surface, the vapor flow 118
Is preferentially attached to the inner peripheral surface closer to the evaporation source,
A uniform film cannot be formed.

Particularly, when it is desired to form a compound thin film,
It is necessary to introduce a reactive gas into the vacuum chamber to react with the vapor deposition material, but in the conventional vapor deposition equipment, plasma cannot be generated inside the hollow film-forming target, and a compound thin film of good film quality is obtained. There was an inconvenience that I could not get. These inconveniences when forming a thin film on a hollow object to be film-formed occur even by using the ion plating method or the CVD method.

In such a case, it is conceivable that the target is placed inside the object to be film-formed and a thin film is formed on the inner surface by the sputtering method. However, when the object to be film-formed is an elongated tubular body, etc. The inner surface of the film-forming target and the target come close to each other, and stable discharge cannot be maintained unless the sputtering gas pressure is higher than usual (normal sputtering pressure is 10 ⁻³ to 10 ⁻² Pa). ). If sputtering is performed at high pressure, not only the quality of the resulting thin film deteriorates, but also the target surface is covered with the compound generated by the reaction, and only an extremely low sputtering rate can be obtained. It didn't even become practical.

[0006]

The present invention was created in order to solve the above-mentioned disadvantages of the prior art, and its purpose is to form a thin film on the inner surface of a hollow film-forming target represented by an elongated tube. Another object of the present invention is to provide a technique of forming a compound thin film, and further to provide a technique of forming a compound thin film on the inner surface of such a hollow film-forming target.

[0007]

In order to solve the above problems, an invention apparatus according to claim 1 has a thin film formed on the inner surface of a film-forming target object having at least one opening and having a hollow inside. In the vapor deposition apparatus, a closing member that airtightly closes the opening, a vapor deposition material is provided, and a conductive heating element provided in the closing member is provided, and the interior of the film formation target is It is characterized in that it can be evacuated.
In this case, a gas introduction hole for introducing a reactive gas may be provided in the closing member as in the invention device according to claim 2, and the film formation target may be formed as in the invention device according to claim 3. The target and the conductive heating element are electrically insulated from each other, and a voltage is applied between the conductive heating element and the target object to be film-formed to convert the reactive gas introduced from the gas introduction hole into plasma. It may be configured to be possible.

The invention method according to claim 4 is a thin film manufacturing method for forming a thin film on an inner surface of a film-forming target object having at least one opening and having a hollow interior, wherein a vapor deposition material is disposed. The conductive heating element is positioned inside the film formation target, the opening is hermetically closed to evacuate the inside of the film formation target, and the conductive heat generation element is energized to The vapor deposition material is vaporized.

The invention method according to claim 5 is a thin film manufacturing method for forming a thin film on the inner surface of a film-forming target having at least one opening and having a hollow interior, wherein a vapor deposition material is arranged. Positioning a conductive heating element in the film formation target,
The inside of the film formation target is evacuated, the conductive heating element is energized to evaporate the vapor deposition material, and a thin film of the vapor deposition material is formed on the inner surface of the film formation target. A reactive gas is introduced into an object, and a voltage is applied between the object to be film-formed and the conductive heating element to turn the reactive gas into plasma, and the reactive gas and the object to be film-formed. It is characterized in that a compound thin film is formed by reacting with the thin film formed on the inner surface of the object. In this case, when the vapor deposition material is evaporated, the reactive gas may be introduced into the film formation target as in the method of the sixth aspect of the invention.

According to such a configuration of the device of the present invention, when forming a thin film on the inner surface of a film-forming target having at least one opening and having a hollow inside, the opening is hermetically closed. Since the inside of the object to be film-formed is evacuated by a vacuum, and the conductive heating element in which the vapor deposition material is disposed is provided in the closing member, this conductive material can be used without a vacuum chamber. It becomes possible to form a uniform thin film of the vapor deposition material on the inner surface of the film formation target by energizing the heat generating element.

In this case, if a gas introduction hole for introducing the reactive gas is provided in the closing member of the vapor deposition apparatus, the vapor deposition material can be vaporized while introducing the reactive gas, and thus the vapor deposition material reacts with the vapor deposition material. It is also possible to react with a characteristic gas.

Further, the electrically conductive heating element and the object to be film-formed are electrically insulated from each other, the inside of the object to be film-formed is evacuated, and the reactive gas is introduced while introducing a reactive gas. Since plasma of the reactive gas is generated when a voltage is applied between the film formation target and the stoichiometric composition, the thin film formed on the inner surface of the film formation target is reacted with the reactive gas. It is possible to obtain a compound thin film close to

[0013]

Embodiments of the present invention will be described with reference to the drawings.

<Evaporation Apparatus> Reference numeral 2 in FIG. 1 shows an example of the evaporation apparatus of the present invention, which forms a thin film on the inner surface of a film-forming target 9 having a hollow inside. The film-forming target 9 is a member used in an accelerator for accelerating and storing positrons. By forming a TiN thin film on the inner surface, secondary electron emission is reduced and the positron life is extended. It is a thing.

The object 9 to be film-formed has a tubular portion 19 ₁ (inner diameter 50 mm × length 2000 mm) in which a metallic material is formed in a tubular shape and openings 16 ₁ and 16 ₂ are formed at both ends, and the tubular portion. The portion 19 ₁ has a protruding portion 19 ₂ which is projected near the center thereof, and the tubular portion 19 ₁ and the protruding portion 19 ₂ are configured so that the overall shape is a T-shape. The vapor deposition device 2 has closing members 5 ₁ , 5 ₂ , and the closing members 5 ₁ , 5 ₂ have openings 16 ₁ , 1 through insulating bushes 21 ₁ , 21 ₂ , respectively.
6 ₂ and is configured to hermetically close the inside of the film formation target 9.

The closing members 5 ₁ , 5 ₂ are made of an insulating material 2 respectively.
Electrodes 15 ₁ and 15 ₂ are provided via 2 ₁ and 22 ₂ , and a tungsten filament is provided between the electrodes 15 ₁ and 15 ₂ so as to be located on the central axis of the tubular portion 19 _1. A conductive heating element 3 composed of is provided. Electrode 1
A heating power source 18 is connected to 5 ₁ and 15 _2, and the heating power source 18 applies an AC voltage to both ends of the conductive heating element 3 to energize it, or applies a DC voltage to the conductive heating element 3. Thus, the DC voltage can be applied between the conductive heating element 3 and the film formation target 9. In addition, each of the closing members 5 ₁ and 5 ₂ is provided with gas introduction holes 4 ₁ and 4 ₂ , respectively, and nitrogen gas is introduced into the film formation target 9 through the mass flow controllers 14 ₁ and 14 _2. And various gases such as oxygen gas can be directly introduced.

An opening 16 ₃ is formed at an end of the convex portion 19 ₂ and the insulating bush 2 is formed in the opening 16 _3.
One end of the exhaust pipe 20 is connected via 1 ₃ .
A vacuum pump 13 is provided at the other end of the exhaust pipe 20, and when the vacuum pump 13 is activated, the inside of the film formation target 9 can be evacuated. A bias power source 17 is connected to the film-forming target 9,
A voltage can be applied between the film-forming target 9 and the conductive heating element 3.

<First Embodiment of Thin Film Manufacturing Method> An embodiment of a thin film manufacturing method for forming a thin film on the inner surface of the film-forming target 9 by using the vapor deposition apparatus 2 will be described. First, the inside of the film formation target 9 is 1.0 × 1 by using the vacuum pump 13.
It was evacuated to a pressure of 0 ^-6 Torr or less. afterwards,
Nitrogen gas was introduced by the mass flow controllers 14 ₁ and 14 ₂ until the inside of the film formation target 9 reached a pressure of 0.1 Torr, and the bias power supply 17 was applied to the conductive heating element 9 to form the film formation target 9 Was set to a potential of −0.5 kV to generate a nitrogen gas plasma, and the inner surface of the film formation target 9 was bombarded cleaned.

After the bombard cleaning, the bias power supply 17 is stopped, the introduction of nitrogen gas into the film-forming target 9 is stopped, and the chamber is evacuated again to a pressure of 1.0 × 10 ^-6 Torr or less. Then, the heating power source 18 was activated to generate an AC voltage, and the conductive heating element 3 was heated.

As shown in FIG. 2, which is a partially enlarged view of the conductive heating element 3, a titanium wire 10 is spirally wound. When the conductive heating element 3 generates heat, the titanium wire 10 is heated.
Are melted, and the molten titanium uniformly wets the surface of the conductive heating element 3.

The titanium wire 1 is activated when the heating power source 18 is activated.
0 melted to generate a titanium vapor flow, which uniformly reached the inner surface of the tubular portion 19 ₁ of the object 9 to be film-formed, and a Ti thin film having a thickness of 1000 Å was formed.

Immediately after the formation of the Ti thin film, nitrogen gas was introduced from the gas introduction holes 4 ₁ and 4 ₂ and the conductive heating element 3 was maintained while maintaining the nitrogen gas pressure of 0.1 Torr by the mass flow controllers 14 ₁ and 14 ₂ . Is set to the ground potential, the bias power supply 17 is activated, and the film formation target 9 is -1.0 kV.
Was applied to generate uniform plasma inside the film formation target 9. The Ti thin film was nitrided by this plasma for 5 minutes to form a TiN thin film.

The thickness of the TiN thin film formed in the tubular portion 19 ₁ having a total length of 2000 mm was measured at positions A to E shown in FIG. The results are shown in Table 1 below.

[0024]

[Table 1]

From the thickness distribution of Table 1, the TiN thin film is
It can be seen that the tubular portion 19 ₁ is formed to have a substantially uniform film thickness in the longitudinal direction.

The composition in the depth direction of this TiN thin film was determined by Auger analysis. The analysis result is shown in the graph of FIG. The composition of the thin film surface is approximately the same as the composition of the TiN thin film formed by reactive sputtering.

<Second Embodiment of Thin Film Manufacturing Method> An undeposited film-forming target 9 is used, and after vacuum evacuation, bombard cleaning, and formation of a Ti thin film on its inner surface under the same conditions as in the first embodiment, Nitrogen gas was immediately introduced from the gas introduction holes 4 ₁ and 4 ₂ to maintain the pressure inside the film formation target 9 at 0.1 Torr, and this time, the film formation target 9 was placed at the ground potential to make it conductive. A DC voltage of +1.0 kV was applied to the heating element 3. Also in this case, plasma was generated inside the film-forming target 9, and a TiN thin film having the same film thickness distribution and composition as in Example 1 could be obtained.

As described above, the voltage to be applied between the film-forming target 9 and the conductive heating element 3 after the Ti thin film is formed is not the DC voltage, and the film-forming target is also a high frequency voltage. 9
Plasma can be generated inside, and in this case as well, a TiN thin film having the same film thickness distribution and composition as in Example 1 could be obtained.

<Third Embodiment of Thin Film Manufacturing Method> The film-forming target 9 that has not been formed is subjected to vacuum evacuation and bombard cleaning under the same conditions as in the first embodiment, and then once 1.0 × 10 ⁻⁶ To
After vacuum evacuation to a pressure of rr or less, while controlling the flow rate by the mass flow controllers 14 ₁ and 14 ₂ , a mixed gas of carrier gas and nitrogen gas (nitrogen gas partial pressure is 1.0
X 10 ⁻⁴ Torr) is introduced, and the heating power supply 18 connected between the electrodes 15 ₁ and 15 ₂ is activated to generate an AC voltage so that the temperature of the film formation target 9 becomes 100 ° C. While the conductive heating element 3 is energized, TiN is deposited on the inner surface of the film-forming target 9.
_{An x} thin film was formed (x ≦ 1.0). The film formation rate of the TiN _x thin film at this time was 2.0 Å / sec.

Next, when plasma was generated under the same conditions as in Example 1, the TiN _x thin film was nitrided, and a TiN thin film having a stoichiometric composition could be obtained. The Auger analysis result of the TiN thin film obtained at this time is shown in the graph of FIG.

Although the case where the TiN thin film is formed by using the titanium wire 10 as the vapor deposition material and nitrogen gas as the reactive gas has been described above, the vapor deposition material of the present invention is not limited to titanium. Also, the reactive gas is not limited to nitrogen gas, and various gases such as ammonia gas, oxygen gas, and hydrocarbon gas (for example, CH ₄ gas) are used to form a nitride film, an oxide film, and a carbon film. Can be formed.

Further, as shown in FIG. 6, with respect to the film-forming target 9'which is entirely formed in a tubular shape, the closing member 5 ₂
Instead, the closing member 5 ′ ₂ is provided in the opening 16 ₂ so as to be airtightly closed, and one end of the exhaust pipe 20 ′ is connected to the opening 16 ′ ₃ of the closing member 5 ′ ₂ through the insulating bush 21 ′ _3. By connecting and connecting the vacuum pump 13 to the other end of the exhaust pipe 20 ′ to configure the vapor deposition device 52, the inside of the film formation target 9 ′ can be evacuated and the closing members 15 ₁ , 15 ′. _By the conductive heating element 3 and the gas introduction holes 41, 42 provided between the _two , a Ti thin film or a TiN thin film can be formed as in the _first and _second embodiments. This closing member 5 _{2 is connected} to both openings 16 ₁ , 1
The inside of the object to be film 9 provided on the 6 ₂ may be evacuated.

When forming a compound thin film, the present invention also includes a method for producing a compound thin film in which vapor deposition and plasma reaction are alternately repeated. Further, when forming the compound thin film, the method is not limited to the method of closing the opening and evacuating the inside of the film formation target. The present invention is included in the present invention as long as a conductive heating element on which a vapor deposition material is placed is positioned inside a hollow object to be film-formed and the conductive heating element is used as both a vapor deposition source and a plasma generating electrode.

[0034]

According to the present invention, a thin film can be formed on the inner surface of a film-forming target without providing a vacuum chamber by closing the opening of the film-forming target and evacuating the chamber. In this case, the thickness distribution of the formed thin film can be made uniform. Further, since the conductive heating element can be used as an electrode for converting the reactive gas introduced into the film formation target into plasma, it is possible to form a compound thin film having a uniform film quality.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a vapor deposition device of the present invention.

FIG. 2 is a partially enlarged view of a conductive heating element.

FIG. 3 is a diagram for explaining a film thickness measurement position.

FIG. 4 is a result of Auger analysis of a TiN thin film formed by an example of the method of the present invention.

FIG. 5: Auger analysis result of TiN thin film formed by another example of the method of the present invention

FIG. 6 is a diagram showing another example of the vapor deposition device of the present invention.

FIG. 7 shows an example of a conventional vapor deposition device.

[Explanation of symbols]

2, 52 ...... deposition apparatus 3 ...... conductive heating element 4 _1, 4 ₂ ...... gas introducing hole 5 _1, 5 _2, 5 _'2 ...... closure member 9 ...... deposition target object 10 ...... deposition material 16 _{1 to} 16 ₃ , 16 ' ₃ ...... Aperture

Claims (6)

[Claims] 1. A vapor deposition apparatus for forming a thin film on an inner surface of an object to be film-formed, which has at least one opening and has a hollow inside, and a closing member which hermetically closes the opening, and a vapor deposition material. And a conductive heating element provided in the closing member, and configured so that the inside of the film formation target can be evacuated. 2. The vapor deposition apparatus according to claim 1, wherein the closing member is provided with a gas introduction hole for introducing a reactive gas. 3. The film forming target and the conductive heating element are electrically insulated from each other, and a voltage is applied between the conductive heating element and the film forming target to introduce the gas introduction hole. 3. The vapor deposition apparatus according to claim 2, wherein the reactive gas introduced from the above is configured to be turned into plasma. 4. A thin-film manufacturing method for forming a thin film on an inner surface of a film-forming target having at least one opening and having a hollow inside, wherein the conductive heating element on which a vapor deposition material is disposed is coated with the conductive heating element. It is positioned inside the film-forming target, the opening is hermetically closed, the interior of the film-forming target is evacuated, and the conductive heating element is energized to vaporize the vapor deposition material. Thin film manufacturing method. 5. A thin-film manufacturing method for forming a thin film on an inner surface of a film-forming target having at least one opening and having a hollow inside, wherein the conductive heating element on which a vapor deposition material is disposed is applied to the target. Located inside the film formation target, the inside of the film formation target is evacuated, the conductive heating element is energized to vaporize the vapor deposition material, and the vapor deposition material is deposited on the inner surface of the film formation target. A thin film is formed, a reactive gas is introduced into the film formation target, and a voltage is applied between the film formation target and the conductive heating element to convert the reactive gas into plasma, A method of manufacturing a thin film, comprising reacting a reactive gas with a thin film formed on the inner surface of the film formation target. 6. The thin film manufacturing method according to claim 5, wherein the reactive gas is introduced into the film formation target when the vapor deposition material is evaporated.