JP4133353B2 - Method for producing silicon oxide thin film or titanium oxide thin film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a useful method for producing a silicon oxide thin film or a titanium oxide thin film on a substrate using glow discharge plasma generated under a pressure near atmospheric pressure. The silicon oxide thin film and titanium oxide thin film obtained by the present invention can be applied in various fields such as coating on flat panel displays (FPD), building glass, automotive glass, and food packaging films.
[0002]
[Prior art]
In recent years, various functional thin films (functional deposition films) have been developed and put into practical use for the purpose of improving surface hardness, absorbing a specific wavelength, improving gas permeability, and exhibiting a photocatalytic function. Typical examples of such functional thin films are silicon oxide thin films and titanium oxide thin films.
[0003]
As a method for producing the silicon oxide thin film, a low pressure plasma CVD method (low pressure plasma vapor deposition method) in which a thin film is formed on a substrate by generating plasma by glow discharge under a reduced pressure condition of about 10 to 1000 Pa is common. Has been adopted. In forming a silicon oxide thin film by this low pressure plasma CVD method, N as a raw material (silicon source) is used. ₂ O-SiH _Four Series and O ₂ -Si (OC ₂ H _Five ) _Four A system or the like is used. In producing a titanium oxide thin film, a low-pressure sputtering method is generally employed, and as a raw material (titanium source), O ₂ -TiCl _Four Series and O ₂ -Ti (i-OC _Three H ₇ ) _Four A system or the like is used.
[0004]
However, under the low pressure conditions as in each of the above methods, a vacuum vessel or a vacuum exhaust facility such as a pump for evacuating the vacuum vessel is required, and the substrate is transported into the vacuum vessel to be formed. There are problems that the tact time until the film and the carry-out increase, and the cost of the apparatus itself increases. In addition, as the base material is increased in size, the apparatus is also increased in size, resulting in a very high apparatus cost. In addition, such a conventional technique has a drawback that the film forming speed cannot be increased so much and the productivity is poor.
[0005]
[Problems to be solved by the invention]
The present invention has been made under such circumstances, and its purpose is to manufacture a high-quality silicon oxide thin film or titanium oxide thin film with high productivity and low cost in the formation of a silicon oxide thin film or a titanium oxide thin film by plasma generation. It is to provide a method that can do this.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present inventors have studied from various angles. From the viewpoint of cost reduction, attention was paid to a method of forming glow discharge plasma under a pressure near atmospheric pressure. Such a method is proposed in, for example, Japanese Patent Application Laid-Open No. 6-2149. By adopting such a method basically by the present inventor, it is considered that inconveniences in equipment and cost due to the provision of a decompression device can be avoided. It was.
[0007]
On the other hand, as a method of forming a thin film with high productivity, attention has been paid to a technique of forming a film using a rotating electrode as disclosed in, for example, Japanese Patent Laid-Open No. 9-104985. Such a technique uses a discharge electrode as a rotating electrode and a substrate placed on the counter electrode, and generates plasma by glow discharge between the rotating electrode and the substrate (hereinafter referred to as “narrow gap”). By forming a line-shaped plasma in a narrow gap and scanning the substrate so as to cross the plasma space, film formation and surface treatment of a large area can be performed without increasing the size of the apparatus.
[0008]
The present inventors thought that if these techniques were applied, a technique suitable for the above-described purpose could be realized, but simply combining them would still cause problems to be solved, and further contrivance was required. It was done. That is, when a silicon oxide film is formed, a silicon alkoxide is used as a reaction gas, and when atmospheric pressure plasma CVD is applied, carbon containing silicon alkoxide (Si—O—R, R: alkyl group), Or the alkyl organic component was taken in the silicon oxide thin film as it was in the process of the plasma gas phase reaction, and there was a problem that a good quality film could not be formed. Moreover, if the molecular weight of the precursor of the silicon oxide thin film is increased by advancing the oxidation / crosslinking reaction, organic components may not remain in the plasma gas phase reaction. As a result, there arises a new problem that the adhesion of the film to the base material is lowered and the film forming speed is lowered.
[0009]
On the other hand, even when a titanium oxide film is formed, carbon containing titanium alkoxide (Ti-O-R, R: alkyl group) is used when titanium-based alkoxide is used as a reaction gas and atmospheric pressure plasma CVD is applied. Alternatively, the alkyl organic component is directly taken into the titanium oxide thin film during the plasma gas phase reaction process, resulting in a problem that a high-quality film cannot be formed. Also, in order to remove organic components by gas phase reaction, O ₂ If the / titanium-based alkoxide ratio is increased, a particle-like titanium oxide thin film is generated in the same manner as in the case of a silicon oxide film, which causes a decrease in adhesion to the substrate and a decrease in the film formation rate. It will be.
[0010]
Therefore, the present inventors use a rotating electrode and use a CVD apparatus that decomposes a silicon-based reactive gas or a titanium-based reactive gas under a pressure near atmospheric pressure to form a thin film on a substrate. Further studies have been made to realize a technology that is premised and that can also avoid the above-mentioned disadvantages.
[0011]
As a result, if a reactive gas containing at least an inert gas, oxygen and a silicon-based alkoxide is used as the silicon-based reactive gas, and the partial pressure ratio of the silicon-based alkoxide in the reactive gas is controlled within an appropriate range, the above object is achieved. It has been found that a suitable silicon oxide film can be formed. Further, as the titanium-based reaction gas, at least an inert gas and a titanium-based alkoxide are used, and if necessary, a reaction gas further containing oxygen is used, and the partial pressure ratio of the titanium alkoxide in the reaction gas is appropriately controlled within a range. The present inventors have found that an optimum titanium oxide film suitable for the above purpose can be formed, and the present invention has been completed.
[0012]
By the way, the inventors of the present invention have been researching a device configuration for forming a more appropriate functional thin film. As part of the research, for example, a device such as Japanese Patent Application No. 2001-394140 has also been proposed. is doing. This device basically uses an endless belt electrode in place of the rotating electrode, and its detailed configuration will be described later (see FIG. 2 below). It has also been found that the object of the present invention can be achieved using gas.
[0013]
That is, the method of the present invention that can achieve the above object is that a pressure near the atmospheric pressure is provided in a narrow gap between a cylindrical rotating electrode or an endless belt electrode and a counter electrode provided facing a part of the electrode. Using a CVD apparatus for generating a silicon discharge thin film on a base material placed on the counter electrode by decomposing a silicon-based reaction gas by generating plasma by glow discharge below, as the silicon-based reaction gas, The present invention has a gist in that a reactive gas containing an inert gas, oxygen, and a silicon-based alkoxide is used, and that the partial pressure ratio of the silicon-based alkoxide in the reactive gas is 0.1 to 3.0%.
[0014]
As the silicon source used in the above method, the silicon-based alkoxide is used from the viewpoint of safety when applying plasma CVD under a pressure close to atmospheric pressure. As such silicon-based alkoxide, tetraethoxysilane, One or more selected from the group consisting of tetramethoxysilane and methyltriethoxysilane can be mentioned. Moreover, in this method, it is preferable that the volume ratio of oxygen in the reaction gas to the silicon-based alkoxide (oxygen / silicon-based alkoxide) is 0.5 to 5.0.
[0015]
On the other hand, when forming a titanium oxide thin film, a titanium oxide thin film CVD apparatus having the above-described configuration is used, and a reactive gas containing an inert gas and a titanium alkoxide is used as the titanium reactive gas. If the operation is carried out with the partial pressure ratio of the titanium alkoxide in the reaction gas being 0.02 to 5.0% and the heating temperature of the substrate being 250 ° C. or higher, a titanium oxide thin film suitable for the above purpose can be obtained.
[0016]
As a titanium source used in this method, a titanium-based alkoxide is used from the viewpoint of safety when applying plasma CVD under a pressure near atmospheric pressure. As such a titanium-based alkoxide, Ti (i-OC) is used. _Three H ₇ ) _Four , Ti (t-OC _Four H ₉ ) _Four , Ti (OC ₂ H _Five ) _Four And Ti (n-OC _Four H ₉ ) _Four 1 type or more chosen from the group which consists of. In this method, a good quality titanium oxide thin film can be formed even if the reaction gas does not contain oxygen. However, if necessary, the reaction gas may contain oxygen. The volume ratio of oxygen to titanium alkoxide in the reaction gas (oxygen / titanium alkoxide) is preferably 2.0 or less.
[0017]
In any method, it is preferable to operate the cylindrical rotating electrode or the endless belt electrode at a peripheral speed of 3000 cm / min or more.
[0018]
In the present invention, a silicon oxide thin film or a titanium oxide thin film is formed on the surface of the substrate placed on the counter electrode surface by generating plasma in a narrow gap between the rotating electrode or endless belt electrode and the counter electrode as described above. The basic operation by using the rotating electrode or the endless belt electrode as described above is as follows. That is, if a rotating electrode or an endless belt electrode is used, a laminar flow is generated by these rotational movements, and it becomes possible to introduce a source gas between the electrode and the base material (narrow gap) by the action of this laminar flow, Further, the reaction product generated by the narrow gap plasma can be discharged from the narrow gap. By such an action, it is possible to forcibly supply the raw material to the narrow gap, so that high-speed film formation can be realized by increasing the rotation speed (that is, by increasing the peripheral speed).
[0019]
In the present invention, plasma CVD is applied at a pressure near atmospheric pressure as described above, and “pressure near atmospheric pressure” means a pressure of about 0.01 to 0.1 MPa. Among the ranges, a preferable pressure range is about 0.08 to 0.1 MPa from the viewpoint that pressure adjustment is easy and the device configuration mechanism is simplified.
[0020]
In glow discharge at a pressure close to atmospheric pressure, the life until recombination after ionization of gas molecules is short, and the mean free path of electrons is also short, so that glow discharge is stably generated between opposing narrow gap electrodes. For this purpose, it is necessary to capture charged particles of electrons and ions in a narrow gap. For this reason, when applying high frequency electric power to a rotating electrode or an endless belt electrode, it is preferable that it is a high frequency of 10 MHz or more.
[0021]
The silicon-based alkoxide used for forming the silicon oxide thin film is not particularly limited. For example, the tetraethoxysilane [TEOS; Si (OC ₂ H _Five ) _Four ], Tetramethoxysilane [TMOS; Si (OCH _Three ) _Four ] And methyltriethoxysilane [MTEOS; SiH _Three (OC ₂ H _Five ) _Three Among these, one kind can be used alone, or two or more kinds can be mixed and used. In addition, when applying plasma CVD under a pressure close to atmospheric pressure, these are O.O. ₂ It is a safe substance because of its low reactivity.
[0022]
The titanium-based alkoxide used for forming the titanium oxide thin film is not particularly limited. For example, the above-described Ti (i-OC) _Three H ₇ ) _Four , Ti (t-OC _Three H ₇ ) _Four Ti (OC ₂ H _Five ) _Four And Ti (OC ₂ H _Five ) _Three Among these, one kind can be used alone, or two or more kinds can be mixed and used. In addition, when applying plasma CVD under a pressure close to atmospheric pressure, these are O.O. ₂ This is a safe substance because of its low reactivity with, and a substance with a relatively high vapor pressure, which is easy to introduce under film-forming conditions under a pressure near atmospheric pressure.
[0023]
In forming the silicon oxide thin film, the ratio of the partial pressure of silicon alkoxide in the reaction gas (ratio of the partial pressure with respect to the total pressure of the reaction gas) needs to be 0.1 to 3.0%. When this partial pressure ratio is less than 0.1%, the film formation speed of the silicon oxide thin film is less than 0.05 nm · m / sec (the speed at which the scanning direction length is 1 m). For this reason, when forming a film by the scanning method, in order to form a certain film thickness on the surface of the substrate, the scanning speed of the substrate must be lowered, and the tact time is substantially reduced. It will increase.
[0024]
When the partial pressure ratio of the silicon-based alkoxide exceeds 3.0%, the silicon-based alkoxide raw material is excessively supplied to the plasma generated in the narrow gap, and the inert gas ratio in the processing gas becomes relatively low, and the atmospheric pressure The plasma generated in the narrow gap under the atmosphere becomes unstable, and a high-quality film cannot be formed.
[0025]
In forming the titanium oxide film, the ratio of the partial pressure of the titanium alkoxide in the reaction gas (ratio of the partial pressure with respect to the total pressure of the reaction gas) needs to be 0.02 to 5.0%. When this partial pressure ratio is less than 0.02%, the deposition rate of the titanium oxide film is less than 3 nm · m / min. Generally, in the case of film formation by sputtering, which is a conventional titanium oxide film formation technique, O ₂ Since reactive sputtering to which a gas is added is used, the film forming speed is very slow, about 3 nm / min. Similarly, the CVD apparatus has a low deposition rate because there is no titanium source having a high vapor pressure. When the partial pressure ratio of the titanium-based alkoxide exceeds 5.0%, as in the case of forming the silicon oxide film, the titanium-based alkoxide raw material is excessively supplied to the plasma generated in the narrow gap, and the inertness in the processing gas The gas ratio becomes relatively low, and the plasma generated in the narrow gap under an atmospheric pressure atmosphere becomes unstable, so that a high-quality film cannot be formed.
[0026]
In practicing the present invention, in order to generate a stable glow discharge, it is necessary to perform in an atmosphere that does not generate reactive radicals. Therefore, it is preferable to use a source gas mainly composed of an inert gas. Such inert gases include rare gases such as He, Ar, Xe, Kr, and N ₂ These gases can be used, and one or more of these can be used. Of the various inert gases, it is preferable to use He having a long life in a metastable excited state. From the above viewpoint, the ratio of the inert gas in the reaction gas is preferably about 75 to 99% by volume.
[0027]
In the case of forming a silicon oxide thin film, the silicon-based alkoxide as a silicon source in the silicon oxide thin film and the oxidation reaction of the silicon-based alkoxide with respect to the inert gas as described above, or quantification Then, oxygen as a crosslinking agent is mixed, a stable glow discharge is similarly generated in the narrow gap, and the silicon oxide thin film is formed on the substrate by scanning and moving in a direction perpendicular to the narrow gap.
[0028]
In the case of forming a titanium oxide thin film, a narrow gap is formed against the inert gas as described above for the crosslinking and oxidation reaction of the titanium alkoxide as a titanium source in the titanium oxide film and the titanium alkoxide. A stable glow discharge is generated at, and the titanium oxide thin film is formed on the substrate by scanning and moving in a direction perpendicular to the narrow gap.
[0029]
In order to form a silicon oxide thin film exhibiting the desired properties in the present invention, the oxygen blending amount in the reaction gas is about 0.5 to 5.0 in volume ratio (oxygen / silicon alkoxide) to silicon alkoxide. It is preferable. When this ratio is less than 0.5, the oxidation / crosslinking reaction of the silicon-based alkoxide becomes insufficient, and an alkoxide group (OR; which is a component of the silicon-based alkoxide) is formed in the silicon oxide thin film formed on the substrate. R is an alkyl group), and the hygroscopicity becomes high or becomes weak.
[0030]
In addition, when the volume ratio of oxygen to silicon alkoxide exceeds 5.0, the oxidation / crosslinking reaction to silicon alkoxide proceeds excessively, and the silicon oxide thin film in the gas phase before reaching the substrate surface. The molecular weight of the polymer precursor is too large, resulting in a particle-like silicon oxide thin film that is exhausted from the plasma space and contaminates the chamber or adheres to the substrate surface during film formation. Occurs. When such a situation occurs, there are inconveniences such as a decrease in the film formation rate and the generation of pinholes due to particles adhering to the film formation surface.
[0031]
In order to form a titanium oxide film exhibiting the desired properties in the present invention, the substrate heating temperature during the reaction is set to 250 ° C. or higher, and the oxygen blending amount in the reaction gas is set to a volume ratio (oxygen / silicon) with the titanium alkoxide. The alkoxide is preferably about 0 to 2.0. In the case of titanium alkoxide, unlike the case of silicon alkoxide, the heating temperature of the base material is 250 ° C. or higher (even if the volume ratio (oxygen / silicon alkoxide) is 0) even when oxygen is not present. The point will be described later), the alkyl group which is a component of the titanium-based alkoxide does not remain as it is due to the crosslinking reaction in the gas phase and the adhesion of the base material to the surface and the surface reaction, thereby obtaining a high-quality film. Will be.
[0032]
However, even in the case of forming a titanium oxide thin film, oxygen may be contained in the reaction gas if necessary. In this case, the volume ratio of oxygen to titanium alkoxide in the reaction gas (oxygen / titanium alkoxide) is It is preferable that it is 2.0 or less. When this volume ratio exceeds 2.0, the crosslinking and oxidation reaction to the titanium-based alkoxide proceeds excessively, and the molecular weight of the monomer that is the precursor of the titanium oxide thin film is in the gas phase before reaching the substrate surface. It becomes too large and becomes a particle-like titanium oxide thin film, which causes inconveniences such as a decrease in film formation rate and generation of pinholes due to particle adhesion, as in the case of a silicon oxide thin film.
[0033]
In practicing the present invention, it is preferable to operate the cylindrical rotating electrode or the endless belt electrode at a peripheral speed of 3000 cm / min or more. If the peripheral speed is less than 3000 cm / min, the film forming speed is reduced. The peripheral speed is preferably 10,000 cm / min or more, but is preferably 15000 cm / min or less in consideration of improvement in yield.
[0034]
In order to form a silicon oxide thin film of better quality by the method of the present invention, it is also an effective means to heat the base material, and in particular, the precursor reacts with the surface after the base material is adhered, It works effectively to reduce hydroxyl groups and organic components. From such a viewpoint, it is preferable that the heating temperature of the base material during the formation of the silicon oxide thin film is about 150 to 400 ° C.
[0035]
On the other hand, when forming a titanium oxide thin film by the method of the present invention, in order to form anatase type polycrystalline titanium oxide thin film that has a high film formation rate, no alkyl group remains, and expresses a photocatalytic effect, Heating the substrate is an indispensable requirement. In particular, heating the substrate is effective in that the surface reaction of the precursor on the substrate surface is activated, the organic component is vaporized, and the titanium oxide thin film is polycrystallized. The amorphous titanium oxide thin film in which the organic component remains has a refractive index as low as about 1.8. For example, in the case of a low reflection film coating by laminating a silicon oxide thin film and a titanium oxide thin film, the optimum design becomes difficult if the refractive index of the high refractive index titanium oxide film is about 1.8. In addition, since the deposition rate of the amorphous titanium oxide thin film is very low, the tact time increases, which causes a problem in terms of productivity. From the viewpoint of productivity, high refractive index, and functional characteristics of the photocatalyst, the heating temperature of the base material during film formation needs to be 250 ° C., preferably 300 ° C. or higher.
[0036]
In carrying out the present invention, the distance between the rotating electrode or the endless belt electrode and the substrate placed on the counter electrode (the distance of the narrow gap) is the power applied to the rotating electrode or the endless belt electrode, processing Although it is determined by the type of gas, composition ratio, etc., it is preferably about 1 to 3 mm. When this distance is less than 1 mm, the reactive gas cannot be stably supplied to the narrow gap, and the narrow gap variation in the width direction of the rotating electrode or the endless belt electrode becomes remarkable, and uniform film formation becomes difficult. In addition, with the narrowing of the narrow gap, in order to realize stable plasma generation, it is necessary to capture plasma charged particles of electrons and ions, and a high frequency of 100 MHz or more is required. Such a high-frequency power source of 100 MHz or more becomes industrially expensive and disadvantageous in terms of cost.
[0037]
On the other hand, if the narrow gap exceeds 3 mm, the deposition rate may decrease due to the decrease in the electric field and the plasma density, or the deposition precursor may be caused by the laminar flow generated by the rotation of the rotating electrode and the endless belt electrode. Problems such as a decrease in film formation speed and contamination in the chamber due to discharge from the substrate occur.
[0038]
In the present invention, the material of the base material for forming the silicon oxide thin film is not particularly limited as long as the thin film can be formed. For example, polyethylene terephthalate (PET), polycarbonate, acrylic, etc. Resin materials, white plate glass, blue plate glass, glass such as non-alkali glass, quartz, silicon and the like can be suitably used. Further, the material of the base material for forming the titanium oxide thin film is preferably one having heat resistance of 250 ° C. or higher, for example, glass such as white plate glass, blue plate glass, non-alkali glass, quartz, silicon, etc. Can be used.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic explanatory view showing a configuration example of a CVD apparatus for carrying out the method of the present invention, in which 1 is a film forming chamber, 2a is a load lock chamber for introducing a substrate, and 2b is a load for carrying out a substrate. Lock chambers, 3a to 3d are gate valves, 4a to 4d are gas inlets, 5a to 5c are leak ports, 6 is a base material holder, 7 is a base material, 8 is a bearing, 9 is a rotating electrode, 10 is a mount, 11a -11c is a rotating electrode support insulator, 12 is a synthetic quartz glass, 13 is a near-infrared lamp, 14 is a viewing window, 15 is a radiation thermometer, 16 and 19 are high-frequency power supplies, 17 and 20 are matching units, and 18 is a base. A heater 21 incorporated in the material holder indicates glow discharge (plasma generation region).
[0040]
In the apparatus configuration shown in FIG. 1, a substrate introduction load lock chamber 2a and a substrate carry-out load lock chamber 2b are connected to the film forming chamber 1 through gate valves 3b and 3c, respectively. An inert gas such as He is constantly introduced into the load lock chambers 2a and 2b from the gas introduction ports 4a and 4b, respectively (V ₁ , V ₂ Is a flow rate adjusting valve), and the pressure is adjusted by leak ports 5a and 5b provided in the load lock chambers 2a and 2b, respectively (V _Three , V _Four Is a flow rate adjusting valve), and the load lock chambers 2a and 2b are maintained at normal pressure (about 0.1 MPa).
[0041]
In the film forming chamber 1, an inert gas such as He and oxygen (O ₂ ) Is introduced while the flow rate is adjusted via a mass flow (not shown). Further, silicon-based alkoxide or titanium-based alkoxide diluted by bubbling with an inert gas such as He whose flow rate is adjusted through a mass flow (not shown) is introduced from the gas inlet 4d. The pressure in the chamber 1 is performed by adjusting the flow rate from the exhaust port 5c. When forming a titanium oxide thin film, only inert gas such as He is introduced from the gas inlet 4c when oxygen is not required.
[0042]
A base material 7 is placed on the base material holder 6. The base material holder 6 is first transferred and stored in the load lock chamber 2a with the gate valve 3a opened. Thereafter, the gate valve 3a is closed, the gate valve 3b is opened, the base material holder 7 is scanned in the direction of arrow A and stored in the chamber 1, and then the gate valve 3b is closed. It becomes the state of.
[0043]
With the base material holder 6 stored in the chamber 1, a film forming process (this process will be described in detail later) is performed on the surface of the base material 7 placed on the base material holder 6. After the silicon oxide thin film or the titanium oxide thin film is formed on the surface of the base material 7, the gate valve 3c is opened, and the base material holder 7 is stored in the load lock chamber 2b. Subsequently, the gate valve 3c is closed and the gate valve 3d is opened, and the substrate holder 7 and the substrate 7 placed thereon are carried out of the load lock chamber 2b. These series of operations are continuously performed, and the stop and progress of the base material holder 6 can be freely controlled.
[0044]
In order to prevent liquid absorption of silicon-based alkoxide or titanium-based alkoxide, which is a liquid raw material, at the inner wall of the film formation chamber 1 at room temperature, a heater ( It is preferable that each wall surface temperature be as high as about 100 ° C. For the same reason, it is preferable to adjust the temperature of the gantry 10 and the insulators 11a to 11c that support the rotating electrode 9 in the film forming chamber 1 to about 100 ° C. with a built-in heater. Further, the rotating electrode 9 is preferably heated by infrared rays emitted from the near-infrared lamp 13 through the synthetic quartz glass 12 and heated to about 150 ° C. The temperature monitor of the rotating electrode 9 is, for example, BaF ₂ This is done by a radiation thermometer 15 through a viewing window 14 consisting of
[0045]
In the apparatus described above, a silicon oxide thin film or a titanium oxide thin film is formed on the base material 7 by forming plasma by glow discharge 21 in a narrow gap between the rotating electrode 9 and the base material 7. The principle of this film formation will be described. The rotating electrode 9 is made of, for example, aluminum, and its size is, for example, a cylindrical shape having a width of about 120 mm and a diameter of about 100 mm, and its edge portion has a curvature of R5 (mm) to prevent electric field concentration. It is rounded with a radius. In addition, the surface of the rotating electrode 9 is coated with a dielectric to prevent arcing. As the dielectric coating at this time, for example, white alumina is formed by thermal spray coating (thickness: about 150 μm).
[0046]
The surface of the rotating electrode 9 that forms a narrow gap with the base material 7 is polished. The rotating electrode 9 is supported by the bearing 8 and the gantry 10. One shaft end of the rotating electrode 9 is a magnet coupling, which is coupled with a motor end magnet (not shown) arranged outside the film forming chamber 1 so that the rotating electrode 9 is rotated at 0 to 1000 rpm. Can be rotated in range.
[0047]
The gantry 10 is made of, for example, stainless steel, and high frequency power from a high frequency power source 16 can be applied to the gantry 10 via a matching unit 17. When the scanning tip of the substrate holder 6 arrives directly under the rotating electrode 9, the high frequency power is applied, and first the rotating electrode 9 and the substrate holder 6 (that is, the substrate holder 6 corresponds to the counter electrode). The glow discharge 21 is started in the narrow gap. Next, after the base material holder 6 is sequentially scanned and the base material 7 placed on the base material holder 6 arrives immediately below the rotary electrode 9, the narrow gap is between the rotary electrode 9 and the base material 7. .
[0048]
A heater 18 is embedded in the base material holder 6, and the heater 18 is configured so that the temperature of the base material holder 6 can be heated from room temperature to about 300 ° C. The surface of the substrate holder 6 is thermally sprayed with white alumina having a thickness of about 100 μm. Basically, it may be electrically grounded, but as shown in FIG. The high frequency power from the high frequency power supply 19 may be applied via the matching unit 20. In this way, by applying the high frequency power to the substrate holder 6, an increase in plasma density, a plasma containment effect, and the like are exhibited. About the time to apply the power from the high frequency power source 19 to the substrate holder 6, the high frequency power may be applied immediately after the power from the high frequency power source 16 is applied to the rotating electrode 9.
[0049]
The matching unit 17 performs frequency tuning and impedance adjustment to match the high frequency power source 16 side and the load side including the matching unit 17, and maximizes power consumption in the entire load circuit including the matching unit 17. And protecting the high-frequency power supply 16 and the high-frequency oscillation circuit (the relationship between the matching unit 20 and the high-frequency power supply 19 is the same).
[0050]
FIG. 2 is a schematic explanatory view showing another example of a CVD film forming apparatus for carrying out the present invention. The basic structure is similar to the apparatus structure shown in FIG. Duplicate description is avoided by assigning the same reference numerals. In FIG. 2, although not shown in the drawing for convenience of explanation, in this apparatus as well as the apparatus shown in FIG. 1, the substrate introduction load lock chamber 2a, the substrate carry-out load lock chamber 2b, and the accompanying device The member to be arranged is arranged.
[0051]
In the apparatus configuration shown in FIG. 2, an endless belt electrode 22 is provided instead of the cylindrical rotating electrode 9, and the endless belt electrode 22 is made of a conductive member made of, for example, thin steel. It is configured to run around two rollers 23 and 24. Each of the rollers 23 and 24 has a cylindrical outer peripheral surface, and in the plasma generation region P, the surface of the endless belt electrode 22 and the surface of the substrate 7 extending horizontally are parallel to each other, and the narrow gap distance between them is constant. It is arranged to become. The endless belt electrode 22 travels in the same direction as the movement direction of the base material 7 in the plasma generation region P.
[0052]
Of the two rollers 23 and 24, the one located on the right side in FIG. 2 is a metallic drive / feed roller 24. The roller 24 is configured to rotate by rotating the roller 24 with a belt driving motor (not shown). In the film forming chamber 1, the base material 7 placed on the base material holder 6 is moved in the horizontal direction (arrow B direction) by the base material transport mechanism 25.
[0053]
In the plasma CVD apparatus shown in FIG. 2, a silicon-based reaction gas or a titanium-based reaction gas is introduced into the film forming chamber 1 from the gas inlet 4 e and exhausted through the exhaust duct 26. Is maintained at a predetermined atmospheric pressure. Then, the endless belt electrode 22 is caused to travel by the rollers 23 and 24, and a relatively wide line-shaped plasma is generated by glow discharge in a narrow gap between the belt electrode 22 and the base material 7, and the base material 7 is moved. A silicon acid thin film or a titanium oxide thin film is formed on the substrate 7 by a chemical reaction of gas.
[0054]
Next, the working effects of the present invention will be described more specifically by way of examples. However, the following examples are not of a nature that limits the present invention, and any modifications may be made without departing from the spirit of the preceding and following descriptions. Is also included in the technical scope of the present invention.
[0055]
【Example】
(Example 1)
A silicon oxide thin film was formed using the CVD apparatus shown in FIG. At this time, as the substrate holder 6, a substrate having a width of 170 mm and a length (scanning direction length) of 170 mm is used, and the substrate 7 is placed on the substrate holder 6 and stored in the chamber 1. did. Moreover, as the base material 7, the blue glass of width: 100mm, length (scanning direction length): 150mm, and thickness: 2mm was used. And after the front-end | tip of the base-material holder 6 arrived just under the rotating electrode 9, the high frequency electric power (frequency: 13.5 MHz, 300W) was applied to the rotating electrode 9 from the high frequency power supply 16. FIG. Immediately after that, 400 kHz and 3 W of electric power were applied from the high frequency power source 19 to the electrode on the substrate holder 6 side in order to contain the plasma.
[0056]
At this time, the set temperature of the substrate holder 6 was set to 250 ° C., the temperature of the rotating electrode 9 was set to 150 ° C., and the film forming chamber 1 and its members were set to 100 ° C. The rotational speed of the rotating electrode 9 was 500 rpm (peripheral speed: 15000 cm / min), and the narrow gap between the rotating electrode 9 and the substrate 7 was set to 1 mm. At this time, since the scanning speed of the substrate 7 was 3.3 mm / sec, the discharge time between the ends of the substrate 7 in the scanning direction was about 51 sec.
[0057]
The pressure in the film forming chamber 1 was controlled by an auto pressure control (not shown) installed in the exhaust port 5c, and was adjusted to a total pressure of 0.093 MPa in this production example. The reaction gas introduced into the film forming chamber 1 is He, O. ₂ The partial pressure was adjusted by adjusting the flow rate. At this time, the TEOS partial pressure is fixed at 466 Pa (466 Pa / 93000 Pa = 0.5% in terms of partial pressure ratio), and O ₂ The film formation experiment was performed while changing the / TEOS ratio to about 0 to 12.
[0058]
O when a silicon oxide film is formed by the above manufacturing method. ₂ The relationship between the / TEOS ratio and the deposition rate is shown in FIG. First, O ₂ When the / TEOS ratio is in the vicinity of 3.0, the film formation rate becomes saturated. ₂ When the / TEOS ratio exceeded 5.0, it was found that particles were generated on the substrate 7 and were not generated on the lower side. O ₂ A film surface SEM photograph (scanning electron microscope photograph in place of drawing) when the / TEOS ratio is 1.0 is shown in FIG. ₂ Film surface SEM photographs when the / TEOS ratio is 5.5 are shown in FIG.
[0059]
From these facts, in order to efficiently form a silicon oxide thin film without generating particles, O ₂ It has been found that the / TEOS ratio is preferably 5.0 or less. More preferably, O ₂ The / TEOS ratio is preferably 3.0 or less.
[0060]
From this result, it is clear that the film formation speed has an influence on the generation of particles, which could be considered as follows. That is, when the film formation rate is decreased, the TEOS oxidation / crosslinking reaction in the gas phase during film formation proceeds excessively, and the amount that is the precursor of the silicon oxide film in the gas phase before reaching the substrate surface It is considered that particles are generated in the silicon oxide thin film because the molecular weight of the body grows too much.
[0061]
Next, in order to measure the residual amount of organic components in the silicon oxide thin film produced as described above, composition analysis of Si, O, and C was performed by photoelectron spectroscopy (XPS method). . The result is shown in FIG. 6, and as is clear from this, O ₂ When the / TEOS ratio is 1.5 or less, the C content calculated from C1s gradually increases, and O ₂ It can be seen that when the / TEOS ratio is less than 0.5, the C content exceeds 10 atomic%. For these reasons, in order not to leave organic components in the film, O ₂ It was predicted that the / TEOS ratio was preferably 0.5 or more, more preferably 1.0 or more.
[0062]
In order to support the above results, the present inventors evaluated organic components by an Attenuated Total Reflection-Fourier Infrared (ATR-FT-IR method). The result is shown in FIG. 7, which shows a wave number of 1500 to 400 cm. ^-1 A magnified view of the vicinity is also shown (arrow D).
[0063]
In FIG. 7, frequency: 3000-3400 cm ^-1 The peak near the OH group in the film is a frequency: 2800-2900 cm. ^-1 Nearby peaks indicate C-Hx groups (x = 1, 2, 3), respectively. In particular, when a silicon-based alkoxide is used as a silicon source, an alkyl component of OR (R: an alkyl group represented by the general formula CmHn) may be taken into the film, and the C-Hx group is TEOS. C as an alkyl component ₂ H _Five It is estimated that
[0064]
The results shown in FIG. 7 show that the TEOS partial pressure is constant at 466 Pa and O ₂ The partial pressure is changed to 0,46.6,652,1351,5312 (Pa) (that is, O ₂ / TEOS ratio 0, 0.1, 1.4, 2.9, 11.4). And O ₂ Partial pressure is 0 MPa (ie, O ₂ When the / TEOS ratio is 0), -OH groups and CHx groups are recognized, and O ₂ When the partial pressure is 652 Pa, only a few CHx groups are observed. From this result and the result of FIG. 3 (the XPS analysis result), O ₂ It can be seen that when the / TEOS ratio is 1.0 or more, the organic components in the film can be reduced.
[0065]
From these results, O ₂ By setting the / TEOS ratio within the range of 0.5 to 5.0, organic components in the silicon oxide film formed on the substrate can be reduced, and a high-quality silicon oxide film with little change over time can be obtained. I understand.
[0066]
(Example 2)
A silicon oxide thin film was formed using the CVD apparatus shown in FIG. At this time, as the substrate holder 6, a substrate having a width of 170 mm and a length (scanning direction length): 170 mm is used. Stored. Moreover, as the base material 7, the blue glass of width: 100mm, length (scanning direction length): 150mm, and thickness: 2mm was used. And after the front-end | tip of the base-material holder 6 reached right under the rotating electrode 9, the high frequency electric power (frequency: 13.5 MHz, 400W) was applied to the rotating electrode 9 from the high frequency power supply 16. FIG. Thereafter, high-frequency power (frequency: 400 kHz, 4 W) for confining plasma was also applied to the substrate holder 6 (high-frequency power source 19).
[0067]
The set temperature of the substrate holder 6 was set to 250 ° C., the temperature of the rotary electrode 9 was set to 150 ° C., and the film forming chamber 1 and its members were set to 100 ° C. The rotational speed of the rotating electrode 9 was 500 rpm (peripheral speed: 15000 cm / min), and the narrow gap between the rotating electrode 9 and the substrate 7 was set to 1 mm. At this time, since the scanning speed of the substrate 7 was 3.3 mm / sec, the discharge time between the ends of the substrate 7 in the scanning direction was about 51 sec.
[0068]
The pressure in the film forming chamber 1 was controlled by an auto pressure control (not shown) installed in the exhaust port 5c, and was adjusted to a total pressure of 0.093 MPa in this production example. The reaction gas introduced into the film forming chamber 1 is He, O. ₂ The partial pressure was adjusted by adjusting the flow rate. At this time, the TEOS partial pressure was changed from 133 to 4000 Pa [partial pressure ratio conversion (133/93000) × 100 = 0.14 to 4.3%], O ₂ The film formation experiment was conducted with a constant / TEOS ratio of 1.4.
[0069]
FIG. 8 shows the relationship between the TEOS partial pressure (and partial pressure ratio) and the film formation rate when the silicon oxide thin film is formed by the above manufacturing method. As is clear from this result, it is understood that when the TEOS partial pressure is 133 Pa or less (0.14% or less in terms of partial pressure ratio), the deposition rate of the silicon oxide thin film is very small. As is clear from this result, the partial pressure ratio is preferably 0.1% or more, more preferably a partial pressure ratio at which a better forming film speed (0.05 nm · m / sec or more) can be obtained: 0 21% or more is recommended. Further, as apparent from FIG. 8, when the TEOS partial pressure is introduced to 1330 Pa (1.4% in terms of partial pressure ratio) close to the vapor pressure limit of the CVD apparatus (film formation chamber 1) used this time, the film formation rate is obtained. It can be seen that increases to 0.9 nm · m / sec. It has been confirmed that when the TEOS partial pressure exceeds 3000 Pa (3.0% in terms of partial pressure ratio), the plasma becomes unstable and the film formation rate decreases extremely.
[0070]
In Examples 1 and 2 above, blue plate glass having a thickness of 2 mm was used as the base material 7. However, as a base material 7 having the same size, a blue plate glass for building material having a thickness of 4 mm, an FPD (0.7 mm thick). A similar experiment was performed using alkali-free glass ("# 1737" manufactured by Corning) for Flat Panel Display). As a result, the same tendency as the results in Examples 1 and 2 was observed although there was a variation in plasma density in the narrow gap between the rotating electrode and the substrate due to the difference in the dielectric constant of the substrate.
[0071]
From these facts, the partial pressure ratio of TEOS, which is a silicon alkoxide, and O ₂ It was judged that appropriately controlling the / TEOS ratio is extremely effective in forming a silicon oxide thin film by a gas phase reaction.
[0072]
The hardness of the silicon oxide thin film formed in Examples 1 and 2 was evaluated by the nanoindentation method. This nanoindentation method is a method by which the hardness of a thin film can be evaluated without being affected by the adhesion to the substrate. As a result, O in Example 1 ₂ When the / TEOS ratio was 0, it was 0.7 GPa. ₂ When the / TEOS ratio exceeds 0.5, a hardness of 1.0 GPa or more is obtained. ₂ When the / TEOS ratio was in the vicinity of 2 to 4, a value of 2.5 GPa was obtained. From these, O ₂ If the / TEOS ratio is appropriately selected, it can be understood that a dense film having high hardness can be obtained with less organic component remaining in the film and generation of particles during growth.
[0073]
(Example 3)
In Example 2, the TEOS partial pressure was 1351 Pa, O ₂ / TEOS ratio is made constant at 1.4, the remainder of the partial pressure is set to He, and the rotational speed during film formation of the rotating electrode 9 is changed to 0 to 1500 rpm (peripheral speed: 0 to 45000 cm / min or less). A similar film formation experiment was conducted. FIG. 9 shows the relationship between the rotation speed (circumferential speed) and the film formation speed at this time.
[0074]
As is apparent from this result, it can be seen that the film forming speed is greatly improved by increasing the number of rotations of the rotary electrode 9. For example, at a rotational value of 1500 rpm, a high-speed film formation of 1.6 nm · m / sec can be realized. This corresponds to a peripheral speed of 45000 cm / min at the rotating electrode 9 used this time. On the other hand, when the rotational speed is 100 rpm or less (peripheral speed: 3000 cm / min or less), the film forming speed is rapidly decreased to be less than 0.2 nm · m / sec. This is 13% (that is, the yield ratio of the reaction gas is 13%) compared to the film formation speed at the peripheral speed of 45000 cm / min, and it can be seen that the ratio rapidly decreases.
[0075]
These results show that the supply of the reaction gas (raw material gas) to the plasma part and the exhaust of the reaction product are efficiently achieved by increasing the peripheral speed. Such an effect is considered to be obtained by using a rotating electrode or an endless belt electrode. From this result, it can be seen that when the peripheral speed is 3000 cm / min or more, a film forming speed capable of being industrially adequate can be realized.
[0076]
Example 4
Using the CVD apparatus shown in FIG. 1, a silicon thin film was formed on a soda glass substrate in the same manner as in Example 2 except that TMOS was used instead of TEOS. At this time, the TMOS partial pressure is changed from 133 to 665 Pa, and O ₂ The film formation experiment was performed with the / TMOS ratio kept constant at 1.4.
[0077]
As a result, when the TMOS partial pressure was 665 Pa, a high-speed film formation with a film formation speed of 0.52 nm · m / sec could be realized. Since TMOS has a higher vapor pressure than TEOS, it is possible to set a higher partial pressure than TEOS. In addition, when silicon alkoxide-based raw materials are used, the precursor generation by the oxidation / cross-linking reaction of silicon alkoxide with oxygen in the gas phase reaction process in plasma is performed by the same reaction mechanism. In addition to TMOS and TMOS, MTEOS and other silicon alkoxides (for example, triethoxysilane, trimethoxysilane, tetraisopropoxysilane, etc.) were confirmed to have the same effect.
[0078]
(Example 5)
A titanium oxide thin film was formed using the CVD apparatus shown in FIG. At this time, as the substrate holder 6, a substrate having a width of 170 mm and a length (scanning direction length) of 170 mm is used, and the substrate 7 is placed on the substrate holder 6 and stored in the chamber 1. did. Moreover, as the base material 7, the blue glass of width: 100mm, length (scanning direction length): 150mm, and thickness: 2mm was used. And after the front-end | tip of the base-material holder 6 arrived just under the rotating electrode 9, the high frequency electric power (frequency: 13.5 MHz, 300W) was applied to the rotating electrode 9 from the high frequency power supply 16. FIG. Immediately after that, 400 kHz and 3 W of electric power were applied from the high frequency power source 19 to the electrode on the substrate holder 6 side in order to contain the plasma.
[0079]
At this time, the set temperature of the substrate holder 6 was set to 300 ° C., the temperature of the rotating electrode 9 was set to 150 ° C., and the film forming chamber 1 and its members were set to 100 ° C. The rotational speed of the rotating electrode 9 was 500 rpm (peripheral speed: 15000 cm / min), and the narrow gap between the rotating electrode 9 and the substrate 7 was set to 1 mm. At this time, since the scanning speed of the substrate 7 was 3.3 mm / sec, the discharge time between the ends of the substrate 7 in the scanning direction was about 51 sec.
[0080]
The pressure in the film forming chamber 1 was controlled by an auto pressure control (not shown) installed in the exhaust port 5c, and was adjusted to a total pressure of 0.093 MPa in this production example. The reaction gas introduced into the film forming chamber 1 is He, O. ₂ And Ti (t-OC _Four H ₉ ) _Four The partial pressure was adjusted by adjusting the flow rate. At this time, Ti (t-OC _Four H ₉ ) _Four The partial pressure is fixed at 133 Pa (133 Pa / 93,000 Pa = 0.14% in terms of partial pressure ratio). ₂ / Ti (t-OC _Four H ₉ ) _Four Film formation experiments were performed with the ratio varied from about 0 to about 5.
[0081]
O when a titanium oxide film is formed by the above manufacturing method. ₂ / Ti (t-OC _Four H ₉ ) _Four The relationship between the ratio and the deposition rate is shown in FIG. First, O ₂ / Ti (t-OC _Four H ₉ ) _Four As the ratio increases, it decreases monotonously. O ₂ / Ti (t-OC _Four H ₉ ) _Four When the ratio exceeds 2.0, the deposition rate becomes 3 nm · m / min or less, and it is considered that the titanium raw material is consumed as particles in the gas phase reaction and does not reach the substrate.
[0082]
From these facts, in order to efficiently form a titanium oxide thin film without generating particles, O ₂ / Ti (t-OC _Four H ₉ ) _Four It can be seen that the ratio is preferably 2.0 or less. More preferably, O ₂ / Ti (t-OC _Four H ₉ ) _Four The ratio is preferably 1.0 or less.
[0083]
From this result, it is clear that the deposition rate has an influence on the generation of particles, but this is a problem that occurs due to excessive oxidation / crosslinking reaction, as in the formation of silicon oxide film. This is considered to be an essential problem for alkoxide raw materials such as titanium and titanium.
[0084]
FIG. 11 shows O ₂ / Ti (t-OC _Four H ₉ ) _Four The X-ray diffraction pattern of a titanium oxide thin film formed with a ratio of 0 is shown. From the half-value width of the diffraction pattern, it was found to be a good quality anatase type polycrystalline titanium thin film. Similarly, as a result of evaluating the diffraction pattern, O ₂ / Ti (t-OC _Four H ₉ ) _Four A ratio of 0 to 2.0 was found to be anatase type polycrystal. As a result of XPS analysis of the film, it was found that C in the film was 0.1 atomic% or less and contained almost no organic component.
[0085]
It is known that anatase-type polycrystalline titanium oxide thin films have two major effects, that is, a superhydrophilic effect and an organic matter decomposition effect when irradiated with near-ultraviolet light. This time, in order to confirm the photocatalytic effect of the titanium oxide thin film obtained above, irradiation was performed under sunlight for 3 hours, and the water contact angle on the surface of the titanium oxide thin film before and after irradiation was measured. As a result, it was 43 ° before irradiation and 3 ° after irradiation. From this result, it was found that a good photocatalytic superhydrophilic effect was developed.
[0086]
From these results, O ₂ / Ti (t-OC _Four H ₉ ) _Four By setting the ratio within the range of 0 to 2.0 and setting the substrate temperature to 250 ° C. or higher, the organic component in the titanium oxide thin film formed on the substrate can be removed, and high-quality titanium that expresses the photocatalytic effect It can be seen that an oxide thin film is obtained.
[0087]
(Example 6)
A titanium oxide thin film was formed using the CVD apparatus shown in FIG. At this time, as the substrate holder 6, a substrate having a width of 170 mm and a length (scanning direction length): 170 mm is used. Stored. Moreover, as the base material 7, the blue glass of width: 100mm, length (scanning direction length): 150mm, and thickness: 2mm was used. And after the front-end | tip of the base-material holder 6 reached right under the rotating electrode 9, the high frequency electric power (frequency: 13.5 MHz, 400W) was applied to the rotating electrode 9 from the high frequency power supply 16. FIG. Thereafter, high-frequency power (frequency: 400 kHz, 4 W) for confining plasma was also applied to the substrate holder 6 (high-frequency power source 19).
[0088]
The set temperature of the substrate holder 6 was set to 300 ° C., the temperature of the rotary electrode 9 was set to 150 ° C., and the film forming chamber 1 and its members were set to 100 ° C. The rotational speed of the rotating electrode 9 was 500 rpm (peripheral speed: 15000 cm / min), and the narrow gap between the rotating electrode 9 and the substrate 7 was set to 1 mm. At this time, since the scanning speed of the substrate 7 was 3.3 mm / sec, the discharge time between the ends of the substrate 7 in the scanning direction was about 51 sec.
[0089]
The pressure in the film forming chamber 1 was controlled by an auto pressure control (not shown) installed in the exhaust port 5c, and was adjusted to a total pressure of 0.093 MPa in this production example. The reaction gas introduced into the deposition chamber 1 is He and Ti (t-OC). _Four H ₉ ) _Four Mixed gas (O ₂ None) and the partial pressure was adjusted by adjusting the flow rate. At this time, Ti (t-OC _Four H ₉ ) _Four The partial pressure was changed from 13 to 5320 Pa [partial pressure ratio conversion (13/93000) × 100 = 0.014 (%), (5320/93000) × 100 = 5.7 (%)], and a film formation experiment was performed. It was.
[0090]
Ti (t-OC) when a titanium oxide thin film is formed by the above manufacturing method. _Four H ₉ ) _Four FIG. 12 shows the relationship between the partial pressure (and partial pressure ratio) and the film formation rate. As is clear from this result, Ti (t-OC _Four H ₉ ) _Four It can be seen that when the partial pressure is 18.6 Pa or less (0.02% or less in terms of partial pressure ratio), the deposition rate of the titanium oxide thin film is very small. As is apparent from this result, the partial pressure ratio is preferably 0.02% or more, which can provide a film forming speed of 3 nm · m / min or more. Further, as is clear from FIG. 12, Ti (t-OC _Four H ₉ ) _Four When the partial pressure exceeds 5320 Pa (5.7% in terms of partial pressure ratio), Ti (t-OC) is caused by plasma instability or gas phase reaction. _Four H ₉ ) _Four It was confirmed that the film formation speed was reduced.
[0091]
From these, Ti (t-OC) which is titanium alkoxide. _Four H ₉ ) _Four The partial pressure ratio, and O ₂ / Ti (t-OC _Four H ₉ ) _Four It was judged that appropriately controlling the ratio was extremely effective in forming a titanium oxide thin film by a gas phase reaction.
[0092]
(Example 7)
In Example 6 above, Ti (t-OC _Four H ₉ ) _Four Partial pressure is 133 Pa, O ₂ / Ti (t-OC _Four H ₉ ) _Four The film formation experiment was performed in the same manner as described above, with the ratio set to 0, the remainder of the partial pressure set to He, and the rotation speed of the rotating electrode was changed to 0 to 1500 rpm (peripheral speed: 0 to 45000 cm / min). FIG. 13 shows the relationship between the rotational speed and the film formation speed at this time.
[0093]
As is apparent from this result, it can be seen that the film formation rate increases by increasing the number of rotations of the rotary electrode 9.
[0094]
【The invention's effect】
The present invention is configured as described above, and it is possible to form a silicon oxide thin film or a titanium oxide thin film, which has been conventionally performed under a low pressure, even in the vicinity of atmospheric pressure, and appropriately select manufacturing conditions. As a result, these oxide thin films can be formed continuously or at high speed. The obtained silicon oxide thin film is a film that contains almost no organic components, can form a high-quality film with little particle adhesion to the silicon film surface, and has sufficient hardness. The titanium oxide thin film contains almost no organic components, is a high-quality anatase-type polycrystal, and has a photocatalytic effect. The technical application of these oxide thin films is expected to greatly expand.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an example of the configuration of a CVD film forming apparatus for carrying out the method of the present invention.
FIG. 2 is a schematic explanatory view showing another configuration example of a CVD film forming apparatus for carrying out the method of the present invention.
3 shows the film formation rate and O in the silicon oxide thin film obtained in Example 1. FIG. ₂ It is a graph which shows the relationship with / TEOS ratio.
FIG. 4 ₂ 3 is a drawing-substitute scanning electron micrograph showing the film surface when the / TEOS ratio is 1.0.
FIG. 5 ₂ 5 is a drawing-substituting scanning electron micrograph showing the film surface when the / TEOS ratio is 5.5.
6 shows the element content and O in the silicon oxide thin film obtained in Example 1. FIG. ₂ It is a graph which shows the relationship with / TEOS ratio.
7 is a graph showing a reflection spectrum by ATR-FTIR of the silicon oxide thin film obtained in Example 1. FIG.
8 is a graph showing the relationship between the deposition rate and TEOS partial pressure in the silicon oxide thin film obtained in Example 2. FIG.
9 is a graph showing the relationship between the film formation speed and the rotational speed (circumferential speed) of the silicon oxide thin film obtained in Example 3. FIG.
10 shows O in the titanium oxide thin film obtained in Example 5. FIG. ₂ / Ti (t-OC _Four H ₉ ) _Four It is a graph which shows the relationship between ratio and the film-forming speed | rate.
FIG. 11 shows O in Example 5. ₂ / Ti (t-OC _Four H ₉ ) _Four It is an X-ray diffraction pattern of a titanium oxide film formed with a ratio of 0.
12 shows Ti (t-OC) in the titanium oxide thin film obtained in Example 6. FIG. _Four H ₉ ) _Four It is a graph which shows the relationship between a partial pressure and the film-forming speed | rate.
13 is a graph showing the relationship between the film formation speed and the rotational speed (circumferential speed) of the titanium oxide thin film obtained in Example 7. FIG.
[Explanation of symbols]
1 Deposition chamber
2a Load lock chamber for substrate introduction
2b Load lock chamber for substrate removal
3a-3d Gate valve
4a-4d Gas inlet
5a-5c Leakage port
6 Base material holder
7 Base material
9 Rotating electrode
11a to 11c insulator
12 Synthetic quartz glass
13 Near-infrared lamp
14 Viewing window
15 Radiation thermometer
16, 19 High frequency power supply
17, 20 Matching device

Claims (8)

Plasma generated by glow discharge is generated in a narrow gap between the cylindrical rotating electrode or the endless belt electrode and a counter electrode provided to face a part of the electrode under a pressure near atmospheric pressure to generate a silicon-based reactive gas. A CVD apparatus that decomposes and forms a silicon oxide thin film on a substrate placed on the counter electrode is used, and a reactive gas containing an inert gas, oxygen, and a silicon-based alkoxide is used as the silicon-based reactive gas. A method for producing a silicon oxide thin film, characterized in that the silicon oxide alkoxide is operated at a partial pressure ratio of 0.1 to 3.0% in the reaction gas. The manufacturing method according to claim 1, wherein the silicon-based alkoxide is one or more selected from the group consisting of tetraethoxysilane, tetramethoxysilane, and methyltriethoxysilane. The production method according to claim 1 or 2, wherein the volume ratio of oxygen to silicon alkoxide in the reaction gas (oxygen / silicon alkoxide) is 0.5 to 5.0. Plasma generated by glow discharge is generated in a narrow gap between the cylindrical rotating electrode or the endless belt electrode and the counter electrode provided facing a part of the electrode under a pressure near atmospheric pressure to generate titanium-based reaction gas. Using a CVD apparatus that decomposes and forms a titanium oxide thin film on a substrate placed on the counter electrode, and using a reactive gas containing an inert gas and a titanium alkoxide as the titanium-based reactive gas, A method for producing a titanium oxide thin film, wherein the operation is carried out at a partial pressure ratio of titanium-based alkoxide in the reaction gas of 0.02 to 5.0% and a heating temperature of the substrate of 250 ° C or higher. The titanium-based alkoxide is a group consisting of Ti (i-OC ₃ H ₇ ) ₄ , Ti (t-OC ₄ H ₉ ) ₄ , Ti (OC ₂ H ₅ ) ₄ and Ti (n-OC ₄ H ₉ ) _4. The production method according to claim 4, which is at least one selected from the group consisting of: The manufacturing method according to claim 4, wherein the reaction gas further contains oxygen. The production method according to claim 6, wherein the volume ratio of oxygen in the reaction gas to the titanium-based alkoxide (oxygen / titanium-based alkoxide) is 2.0 or less. The manufacturing method according to claim 1, wherein the cylindrical rotating electrode or the endless belt electrode is operated at a peripheral speed of 3000 cm / min or more.

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