JPH0310708B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor deposition apparatus configured to perform vapor deposition by introducing a reaction gas into a vapor deposition tank, and particularly to an apparatus called a reactive vapor deposition apparatus.

This type of reactive vapor deposition equipment is used, for example, in ITO (Indium).
When forming a transparent conductive film made of Tin Oxide,
In the presence of ionized or activated oxygen gas
The In--Sn alloy and/or its oxides can be evaporated from the ITO tablets and deposited onto the substrate.

DC ion plating equipment and RF ion plating equipment are known as reactive vapor deposition equipment. Among these, RF ion plating using high-frequency discharge was published in Japanese Patent Application Laid-open No. 1983-
No. 84474, JP-A-49-113733, JP-A-49-
No. 120877 and each publication. For example, as shown in FIG. 1, in a vacuum chamber 30,
The substrate 2 is heated with a heater 34, and a predetermined voltage (-10V to -10kV) is applied to the back electrode of the substrate 2 as necessary.
35 is applied, while an alternating current voltage 71 is applied to the coil electrode 70 (high frequency discharge electrode) placed on the evaporation source 25 (the frequency of the alternating current is arbitrary, but if a high frequency (for example, 13.56 MHz) is used, The glow discharge generated between the substrate 2 and the electrode 70 activates or ionizes each atom of the unactivated reaction gas from the inlet tube 36 together with the vapor of the evaporated substance. For example, an ITO film is deposited on the substrate 2.

However, it has been found that the above-mentioned known devices mainly have fatal defects as shown in (1) and (2) below.

(1) High-frequency discharge is performed stably in a low vacuum on the order of 10 ^{-3 to} 10 ^-4 Torr, so
At a high degree of vacuum on the order of 10 ^-4 Torr, the discharge becomes unstable, making it difficult to perform reactive deposition. Therefore, in order to increase the adhesion strength of the deposited film and make the deposited film dense, it is necessary to apply a high voltage to the substrate to be deposited to accelerate the evaporated substance with an electric field.
However, when depositing on an insulating substrate, such as a glass or plastic substrate, it is difficult to provide a voltage applying means.

(2) Due to the large amount of evaporated substances adhering to the high-frequency discharge electrode, during long-term film formation, the adhering evaporated substances are bombarded and peeled off by the discharge, making the discharge unstable. Otherwise, the vapor may mix into the evaporation source, making the deposited film non-uniform.
Further, evaporated substances adhere to the high frequency introduction terminal, causing high frequency leakage.

The inventors of the present invention have discovered a device that can solve all of the above-mentioned problems by uniquely configuring the gas discharge section, and have arrived at the present invention.

That is, the vapor deposition apparatus according to the present invention is a vapor deposition apparatus configured to perform vapor deposition by introducing a reaction gas into a vapor deposition tank, in which the reaction gas is introduced into a predetermined location within the vapor deposition tank from a gas inlet. The present invention is characterized in that a gas discharge section consisting of a guiding gas introduction pipe and a discharge electrode arranged around the gas introduction pipe is provided within the vapor deposition premises.

The vapor deposition apparatus according to the present invention has the following superior features (1) to (3) as compared to the known apparatus described above.

(1) The discharge section is equipped with an introduction tube that guides the reaction gas from the gas introduction port, and a discharge can be generated within the introduction tube using the discharge electrode around the introduction tube, so the gas pressure in the discharge region can be reduced. It can be maintained higher than the gas pressure in the space inside the deposition tank. Therefore, high-frequency discharge can be performed stably, and the gas pressure in the space inside the vapor deposition tank can be lowered, so that electric field acceleration of the evaporated substance is not required, and it is possible to form a high-quality vapor deposited film.

(2) Since the discharge electrode is installed around the gas introduction tube, the gas pressure inside the deposition tank does not increase.
It is possible to efficiently ionize or activate the gas in the introduction tube, which maintains the gas pressure at a high level, and send it into the deposition space. For this reason, ionized or activated gas components can be efficiently incorporated into the deposited film.

(3) Since gas discharge occurs within the gas introduction tube and the discharge electrode and high frequency introduction terminal are isolated from the discharge electric field, bombardment by gas ions does not occur, and heating of the electrode material and evaporation due to bombardment,
Contamination of the film forming space can be prevented.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a reactive vapor deposition apparatus according to this example. That is, a vacuum pump (not shown) is connected to the bell gear 30 forming a vacuum chamber via an exhaust path 38 having a butterfly valve 32, and thereby the inside of the bell gear 30 is preliminarily heated to a temperature of, for example, 10 ^-5 to ^{10 -7} Torr. Keep it in a high vacuum state. The substrate 2 is placed inside the bell jar 30 and heated to a temperature of 600 by the heater 34.
℃ or less, preferably 300℃ or less, and
While introducing activated or ionized reaction gas into the bell jar 30 through a gas discharge tube 37 (described in detail later) connected to the gas inlet 36 (gas pressure is 1×10 ^-6 to 8 ×10 ^-4 Torr), the deposition material is heated and evaporated from the evaporation source 25 disposed within the bell gear 30 so as to face the substrate 2.
This heating means may be an electron beam 27 using an electron gun heating device 26 or a resistance heating method. Also, the substrate 2 (actually the back electrode (not shown))
A negative bias voltage 35 can be applied as necessary.

What should be noted here is that the gas discharge tube 37 is constructed as shown in FIGS. 3 to 5.

That is, the discharge section 37 is detachably attached to the outwardly projecting tube section 30a provided on the bell jar 30 via the attachment plate 39. Mounting plate 39
A through hole (inlet) 40 connected to the gas inlet 36 is formed in the center of the inlet 40, and around the inlet 40, a ring-shaped protrusion 41 with a small diameter and a ring-shaped protrusion 42 with a large diameter are arranged concentrically. It is set in. and,
A gas introduction pipe 43 is removably fitted and fixed to the inner protrusion 41 so as to wrap around it, and a cylindrical anti-stick member 44 is attached to the outer protrusion 42.
are similarly fitted and fixed. For example, a coil-shaped discharge electrode 45 is wound between the outer periphery of the introduction tube 43 and the inner periphery of the adhesion prevention member 44 . Introductory pipe 43
A common ring plate 46 constituting a part of the anti-adhesive member is fixed to the inner end surfaces of the anti-adhesive member 44 with screws 47, whereby the introduction pipe 43 and the anti-adhesive member 44 are connected to the discharge electrode. 45 is attached to the mounting plate 39. However, various mounting methods or orders may be considered, and the ring plate 46 may be fixed in advance as described above and then fitted into the projections 41 and 42 at the same time.

A high frequency introduction terminal 48 connected to one end of an electrode 45 is fitted and fixed in advance on the mounting plate 39, and a gas introduction pipe 50 from the outside is screwed and fixed in the center via a threaded portion 49. . The mounting plate 39 is fixed to the protruding tube portion 30a of the bell gear 30 so as to close the opening 53 by screwing the screws 52 into the screw holes 51 in the peripheral portion. At this time, an O-ring 55 made of rubber for sealing, for example, is fitted into the ring-shaped groove 54 formed on the inner surface of the mounting plate 39, and the protruding pipe portion 30a and the mounting plate 39 are airtightly connected via this O-ring. Bonded and fixed.

As described above, the gas discharge section 37 according to this example is removably mounted inside the bell jar 30 via the mounting plate 39. In addition, L due to the coil electrode 45
Constructed as a coupling type (inductively coupled type),
Ions or activation components of the reaction gas generated in the gas introduction pipe 43 by the application of a high frequency voltage are released from the discharge opening 56 into the inner space of the bellgear 30 (i.e.,
The evaporated substance 25 is led out into a flight space (a flight space) in which the evaporated substance 25 flies toward the substrate 2.

To explain a specific example of the structure of this reactive vapor deposition apparatus, first, in the discharge section 37, the gas introduction tube 43 is made of an insulating material, for example, a quartz or pyrex glass tube with an inner diameter of 2 to 10 cm. The discharge electrode 45 is formed as a metal antenna wound around the introduction tube 43, for example, a stainless steel pipe wound up into a spiral circle with an inner diameter of 5 cmφ to 20 cmφ (in this case, the electrode is connected by passing cooling water through the pipe). It can be water cooled from the inside).
Further, the high frequency wave is introduced into the bell gear from the introduction terminal 48 after passing through a matching circuit (not shown) outside the bell gear. Electrode 45
The other end is a free end. Anti-fouling member 44
(Furthermore, 46) represents the introduction tube 43 and the electrode 45.
It is provided in order to prevent evaporated substances from adhering to these and the high-frequency introduction terminal 48, and to stabilize the discharge by preventing leakage of high-frequency power. It is made up of

Further, the introduction pipe 50 is made of stainless steel or Teflon pipe, and the reaction gas introduced through this pipe is oxygen, nitrogen,
hydrogen, methane, propane, silane, phosphine,
A mixed gas of at least one of diborane, arsine, etc. and an inert gas such as argon can be used. The evaporated substance (25 in Figure 2) is at least one selected from the group consisting of tungsten, molybdenum, chromium, iridium, tantalum, titanium, nickel, indium-tin, aluminum, silicon oxides, nitrides, etc. It will be done.
For example, indium-tin and/or
or its oxide (introduced gas is oxygen + Ar), silicon or aluminum and/or its nitride (introduced gas is N ₂ ), amorphous silicon hydride (a-Si:H) to form a nitride film. Silicon (introduced gas is hydrogen) can be applied to the membrane as vaporized substance. For example, when using a mixed gas of oxygen and argon as the introduced gas, oxygen (flow rate 30c.c./
min), when introducing argon gas (flow rate 50c.c./min), the degree of vacuum in the evaporation space in the bell gear 30 is maintained on the order of 10 ^-5 to ^{10 -4} Torr, and the inlet tube 4
Stable high-frequency discharge within 3 (introduced high-frequency power is 0W)
~3KW). The relationship between the degree of vacuum in the deposition space and the degree of vacuum in the introduction tube 43 can be arbitrarily adjusted by changing the flow rate of the introduced gas, the flow rate of the exhaust gas, the area of the gas discharge opening 56, and the like.
It is desirable that the area of the gas discharge opening 56 is, for example, 5 to 30 cm ² .

The reactive vapor deposition apparatus provided with the gas discharge section 37 as described above has the following features (1) to (5) compared to conventional apparatuses.

(1) By arranging the gas introduction pipe 43 in a position close to the introduction port 36 (or 40), the discharge area 5
Since the gas pressure in step 7 can be maintained higher than the gas pressure in the deposition space, stable high-frequency discharge is possible. Moreover, since the ions generated in the introduction tube 43 can be introduced into the bell jar immediately through the discharge opening 56, the amount and efficiency of introduction can be increased. In addition, the gas pressure in the evaporation space can be lowered, eliminating the need for electric field acceleration of the evaporated substance.
The material of the substrate to be vapor-deposited can be selected from a wide range, and a high-quality vapor-deposited film can be formed.

(2) By arranging the discharge electrode 45 around the outer circumference of the introduction tube 43, the gas inside the introduction tube 43 can be efficiently ionized or activated while keeping the gas pressure high without increasing the gas pressure in the vapor deposition space. can. In addition, since the gas discharge region is limited within the discharge tube 43 and isolated from the electrode 45, the electrode 45 can be prevented from being bombarded by gas ions generated during discharge. In other words, it is possible to prevent the electrode material from being heated or evaporated by bombardment, thereby preventing contamination of the deposition space.

(3) Since the adhesion prevention members 44 and 46 are provided so as to enclose the introduction tube 43 and the electrode 45, the introduction tube 43,
It is possible to prevent evaporated substances from adhering to the electrode 45 and the high-frequency introduction terminal 48, and also to effectively prevent leakage of high-frequency waves through the mounting plate 39, the electrode 45, and the introduction pipe 43, so that discharge can be performed stably. can.

(4) Unlike the structure of the conventional discharge section, the seal member 55 is isolated from the gas discharge region 57 by the introduction pipe 43 etc. (it is not in contact with the discharge region 57); It is possible to prevent deterioration of sealing performance such as damage to the sealing member, gas leakage due to fatigue, etc. due to discharge.

(5) Since the gas discharge section 37 can be attached to the wall of the bell jar 30 with a simple mechanism, the attachment or detachment work is facilitated. Furthermore, since it is set within the protruding tube portion 30a that protrudes outward from the vapor deposition space, it does not interfere with vapor deposition.

Although it is conceivable to configure the gas discharge section 37 as shown in FIG. 6, the intended purpose cannot be achieved with this. The discharge section 37 in FIG.
One cylindrical electrode member 6 having a gas inlet 61'
2', a discharge space member 64' made of, for example, cylindrical glass, surrounding a discharge space 63' with one electrode member 62' provided at one end, and an outlet provided at the other end of this discharge space member 64'. The gas inlet 61 For example, hydrogen gas supplied through the outlet 65' generates a glow discharge in the discharge space 63', whereby active hydrogen consisting of hydrogen atoms or molecules activated by electronic energy and ionized hydrogen ions are discharged from the outlet 65'. be done. The discharge space member 64' in this illustrated example has a double pipe structure and is configured to allow cooling water to flow therethrough.
8' indicates the cooling water inlet and outlet. 69' is a cooling fin for one electrode member 62'. The distance between the electrodes in the above hydrogen gas discharge tube 37 is 10 to 15 cm.
The applied voltage is 6000 V, and the pressure in the discharge space 63' is approximately 10 ^-2 Torr. However, in this gas discharge section 37, the electrodes 62', 6
6' and the seal member (not shown) at the electrode mounting position communicate with the discharge region 63', so they are bombarded by gas ions generated during discharge, resulting in the generation of contaminants and a reduction in sealing performance. As a result, the discharge section cannot be used in practical use.

Unlike FIG. 4, FIG. 7 shows an example in which the discharge electrode is composed of a plurality of rings 45a and 45b arranged so as to enclose the circumferential surface of the introduction tube 43. Among these, one ring-shaped electrode 45a is connected to the high frequency introduction terminal 48 by a lead wire 67, and the other ring-shaped electrode 45b is connected to the metal anti-corrosion member 44 by a lead wire 58, and is attached to the metal attachment. It is grounded via a plate 39. The electrodes 45a and 45b have an inner diameter of 2 to 10 cmφ and a width of 0.5 cm, for example.
It consists of a band ring made of copper or stainless steel with a length of ~10 cm, and generates a C-coupling type (capacitive coupling type) discharge in the introduction tube 43 (the band ring can be cooled by wrapping a water-cooled tube around it. ).

Next, an actual reactive vapor deposition apparatus using the above gas discharge section 37 will be explained with reference to FIGS. 8 and 9. However, parts common to the above-described example are given common reference numerals, and their explanations may be omitted.

A gas discharge section 37 is attached to the bell jar 30 as a vacuum chamber in the same manner as described above, while a sheet 2 as a substrate to be evaporated placed facing the evaporation material 25 is transferred from a supply roll 59 to a take-up roll 60.
sent to. These two rolls have adhesion prevention plates 61,
62 are arranged respectively. The substrate 2 is a wire mesh 63
It is heated uniformly by a heater (for example, a halogen lamp heater) 34 equipped with a reflecting plate 65 arranged behind the lamp. Further, a film thickness meter (for example, a known crystal monitor) 64 for controlling the thickness of the vapor deposited film formed on the substrate 2 is arranged.

Such a deposition apparatus can be operated under the following conditions.

Evaporation material 25: ITO tablets (Sn5% by weight) Evaporation method: Electron gun heating Deposition substrate 2: Metal sheet or resin (e.g. polyethylene terephthalate) sheet Temperature of deposition substrate 2: 70 to 300°C Introduced gas: Oxygen gas (30℃) .c./min) and argon gas (50c.c./min: to keep the amount of oxygen constant and adjust the degree of oxidation by oxygen). The flow rate can be controlled individually.

High-frequency discharge device 37: The one shown in FIG. 3 or FIG. 7 (high-frequency power 50W to 1KW) In other words, a mixed gas of oxygen and argon is discharged in or activated by the discharge device 37, and the bell jar 30
The ITO 25 was evaporated by heating with an electron gun while being introduced into the evaporation space 66 inside the evaporation space 66, and reacted with introduced gas ions or active gas components to be evaporated onto the substrate 2. As a result, the evaporation rate of the evaporation material can be increased from 100 to 2000Å/
min, and when the board conveyance speed is 50 to 200 cm/min, the sheet resistance on the board is 500Ω/cm ² to 1M.
It was possible to form an ITO film with a resistance of Ω/cm ² and a light transmittance of 80 to 90%.

Although the present invention has been illustrated above, the above-mentioned example can be further modified based on the technical idea of the present invention.

For example, a plurality of the gas introduction pipes 43 described above can be provided, and as shown in FIG. It can be installed by wrapping it around. This is advantageous because the ionized or activated gas components can be more uniformly distributed on the deposition surface of the substrate 2. Moreover, the gas distribution can be arbitrarily adjusted depending on the arrangement of the gas introduction pipe. The number of discharge electrodes may be two or more, and the shape including the gas introduction tube may be rectangular or the like other than circular. Further, the mounting position and the structure of the mounting location of the gas discharge part with respect to the bell gear can be variously modified. Furthermore, the gas discharge portion may protrude into the deposition space of the bell gear. Desirable results can also be obtained by arranging the gas discharge opening of the discharge section so as to face the substrate to be evaporated, or by arranging it so that the gas can be supplied near the substrate to be evaporated or the evaporation source.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a conventional RF ion plating apparatus. 2 to 10 show examples of the present invention, in which FIG. 2 is a schematic sectional view of a reactive vapor deposition apparatus, FIG. 3 is an enlarged sectional view of a gas discharge section, and FIG. 4 is a gas discharge part. 5 is an exploded perspective view of the gas discharge section (however, the high frequency discharge electrode is omitted), FIG. 6 is a sectional view of the gas discharge section having a configuration different from that of the present invention, and FIG. 7 is a different perspective view of the gas discharge section. FIG. 8 is a schematic cross-sectional view of an actual reactive vapor deposition apparatus.
FIG. 9 is a sectional view taken along the line X--X in FIG. 7, and FIG. 10 is a perspective view of still another gas discharge section. In addition, in the symbols shown in the drawings, 2... substrate to be evaporated, 25... evaporation material, 26... electron gun, 3
0... Belgear, 30a... Projecting pipe portion, 34...
...Heater, 36, 40...Gas inlet, 37...
...Gas discharge part, 39...Mounting plate, 41, 42...
...Protrusion, 43...Gas introduction pipe, 44, 46, 6
1, 62... adhesion prevention member or adhesion prevention plate, 45, 45
a, 45b...Electrode for discharge, 48...High frequency introduction terminal, 55...Seal member, 56...Gas discharge opening, 57...Discharge area, 59...Supply roll, 60
. . . Take-up roll, 64 . . . Film thickness gauge, 65 . . . Reflective plate, 66 .

Claims (1)

[Scope of Claims] 1. In a vapor deposition apparatus configured to perform vapor deposition by introducing a reaction gas into a vapor deposition tank, the reaction gas is guided to a predetermined location within the vapor deposition tank from a gas inlet. A vapor deposition apparatus characterized in that a gas discharge section consisting of a gas introduction tube and a discharge electrode arranged around the gas introduction tube is provided in the vapor deposition tank. 2. The device according to claim 1, wherein the seal portion for airtightly attaching the gas discharge portion to the vapor deposition tank is provided at a position isolated from the discharge area of the gas discharge portion. 3 In the gas introduction tube and discharge electrode of the gas discharge section,
The device according to claim 1 or 2, wherein an adhesion prevention member is provided to prevent evaporated substances from adhering thereto. 4. The device according to any one of claims 1 to 3, wherein the gas introduction pipe is made of an insulating member. 5. The apparatus according to any one of claims 1 to 4, in which a plurality of gas introduction pipes are provided, and a reaction gas is introduced into each of these pipes. 6 At least one discharge electrode is arranged;
An apparatus according to any one of claims 1 to 5. 7. The device according to any one of claims 1 to 6, wherein the discharge electrode is a metal antenna wound around a gas introduction tube. 8. The discharge electrode consists of a plurality of ring-shaped metal electrodes arranged so as to surround the gas introduction tube.
An apparatus according to any one of claims 1 to 6. 9. The device according to any one of claims 1 to 8, wherein the gas discharge section is detachably attached to the wall of the vapor deposition tank. 10. The apparatus according to claim 9, wherein the gas discharge section is removably attached to the vapor deposition tank via an attachment plate. 11. The device according to claim 10, wherein the mounting plate is provided with a gas introduction port, and the gas introduction pipe is fixed so as to surround the gas introduction port. 12. The device according to claim 11, wherein the gas introduction pipe is removably fitted and fixed to a projection provided on the mounting plate. 13. Claims 10 to 13, wherein an anti-adhesion member for preventing evaporated substances from adhering to the gas introduction tube and the discharge electrode is removably fitted and fixed to a protrusion provided on the mounting plate. 12. The device according to any one of item 12. 14. The device according to any one of claims 10 to 13, wherein the peripheral portion of the mounting plate and the wall of the vapor deposition tank are bonded and fixed to each other via a sealing member. 15 The wall of the vapor deposition tank is provided with an outwardly protruding tube section that communicates with the inside and outside of the tank, and a gas discharge section is disposed within this protruding tube section, and the opening of the protruding tube section is connected to the mounting plate of the gas discharge section. 15. A device as claimed in claim 14, wherein the device is closed.