JP3416622B2 - Surface treatment device and surface treatment method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment apparatus and a surface treatment method for performing a predetermined treatment on a surface of a substrate by utilizing glow discharge plasma of a discharge gas. The present invention is
In particular, the present invention relates to a surface treatment apparatus and a surface treatment method by reactive plasma that generates plasma by glow discharge of a discharge gas generated by high-frequency power having a frequency of 10 MHz to 300 MHz.

[0002]

2. Description of the Related Art It is known that various types of electronic devices are manufactured by subjecting a surface of a substrate to various treatments using reactive plasma.
It has already been put to practical use in the fields of SI (Large Scale Integrated Circuit), LCD (Liquid Crystal Display), amorphous Si solar cells, thin film polycrystalline Si solar cells, photoconductors for copying machines and various information recording devices.

The technical fields of the surface treatment described above include a wide variety of fields such as thin film formation, etching and surface modification, all of which utilize the chemical action of reactive plasma. Typical examples of the apparatus and method relating to the generation of the reactive plasma are disclosed in Japanese Patent Application Laid-Open No. 8-325759 (Reference 1) and A voltage uni.
formity study in large-area reactors for RF
Plasma deposition: L. Sansonnems, A. Pletze
r, D. Magni, A. A. Howling, Ch. Hollenste
in and J. P. M. Schmitt, Plasma Source Sc
i. Technol. 6 (1997), p. 170-178 (referred to as reference 2).

Hereinafter, three examples, that is, three types of apparatus configurations and methods will be described with reference to FIGS.

(Conventional Example 1) First, as Conventional Example 1, a first device described in Document 1 will be described with reference to FIG. Inside the vacuum vessel 1, a pair of electrodes for generating glow discharge plasma, that is, a non-grounded electrode 2 and a substrate heater 3 are provided.
The ground electrode 4 having a built-in is arranged. The non-grounded electrode 2 is attached to the upper part of the vacuum container 1 via an insulator 5. A matching unit 6 and a high frequency power source 7 for generating a predetermined high frequency power are connected to the non-grounded electrode 2 via a coaxial cable 8, and an output from the high frequency power source 7 is supplied to a power supply point 9 of the non-grounded electrode 2. To be done. The power supply point 9 is located on the surface of the non-grounded electrode 2 on the atmosphere side, that is, the surface not in contact with the space 10 in which plasma is generated. The frequency of the power output from the high frequency power supply 7 is 13.56 MH.
z is commonly used.

A discharge gas introducing pipe 11 is provided in the vacuum container 1.
Is connected to a cylinder (not shown) through the cylinder, and monosilane (SiH ₄ ) is supplied from the cylinder into the vacuum container 1. A vacuum pump 13 is connected to the vacuum container 1 via an exhaust pipe 12, and the gas in the vacuum container 1 is exhausted by the exhaust pipe 12.
Through the vacuum pump 13. The substrate 14 is installed on the ground electrode 4, and is heated to a predetermined temperature by the substrate heater 3 and the substrate heater power supply 15 connected to the substrate heater 3.

Next, the substrate 1 is formed by using the apparatus having such a configuration.
A case where an amorphous Si (a-Si) film is formed on 4 will be described. First, the substrate 14 is set on the ground electrode 4 via a substrate loading / unloading gate (not shown), and the vacuum pump 13 is driven to set the pressure in the vacuum container 1 to 1 × 10 ^−7.
Exhaust to Torr. Further, the temperature of the substrate 14 is set to a predetermined temperature by using the substrate heater 3 and the substrate heater power supply 15. Next, for example, a predetermined amount of monosilane gas is supplied into the vacuum container 1 through the discharge gas introduction pipe 11, the pressure inside the vacuum container 1 is maintained at 0.05 to 0.5 Torr, and the power supply system, that is, the high frequency power supply 7 and the matching device. 6 and coaxial cable 8
Is used to supply power to the pair of non-grounded electrodes 2 and the grounded electrode 4. As a result, glow discharge plasma is generated between the non-grounded electrode 2 and the grounded electrode 4. When monosilane gas is turned into plasma, SiH ₃ and SiH existing in the plasma
₂ , radicals such as SiH are diffused by a diffusion phenomenon, and are adsorbed and deposited on the surface of the substrate 14 to form a-Si.
A film is formed.

By optimizing the mixing ratio of the discharge gas such as the flow rate ratio of SiH ₄ and H ₂ , the pressure, the substrate temperature, and the plasma generation power as film forming conditions, not only a-Si but also minute It is known that crystalline Si and polycrystalline Si can be formed into a film.

Further, it has an etching function as a discharge gas.
Gas, eg SF₆, SiCl _Four, CF_FourAnd NF
_ThreeIf an etching gas such as
It is known that an etching process can be performed.

(Conventional Example 2) Next, as a conventional example 2, FIGS. 23 and 24 will be referred to for the second device described in the document 1. However, the same members as those in FIG. 22 are denoted by the same reference numerals and the description thereof will be omitted. Reference numeral 21 in the figure indicates a gate valve provided on the side wall of the vacuum container. The substrate 14 is taken in and out from the gate valve 21. Inside the insulator 5 located above the vacuum container 1, a non-grounded electrode 2 having a hollow inside is arranged. The lower surface (front surface) 2a of the non-grounded electrode 2, that is, the space 10 in which plasma is generated has a diameter of 0.5 mm.
The number of gas ejection holes 2b is about 10 to 15 mm.
Is formed by. An opening 2c for discharge gas is formed on the upper surface of the non-grounded electrode 2. A discharge gas introduction tube 11b is connected to the opening 2c of the non-grounded electrode 2 via a connecting member 23. For example, monosilane gas (SiH ₄ ) is supplied to the inside of the non-grounded electrode 2 from the discharge gas introduction pipe 11b. On the non-grounded electrode 2,
A power distributor 25 is arranged to branch the output of the high-frequency power supply into a plurality of outputs.

Glow discharge plasma is generated in the vacuum chamber 1 by the non-ground electrode 2 and the ground electrode 4. The non-grounded electrode 2 is a rectangular or square plate-shaped member (thickness 60 mm, about 500 mm × 500 mm to about 1000 mm × 1000 mm), and the material is stainless steel. Required power is supplied to the non-grounded electrode 22 from a power supply system including a high frequency power supply 7, a matching unit 6 and the power distributor 25.

As shown in FIG. 24, the power distributor 25 has a cylindrical connection port 26 arranged in the center, and four strip-shaped branch ports 27 and four radially extending from the connection port 26. Cylindrical members 28a, 28b, 28c,
28d.

Incidentally, reference numerals 9a, 9b, 9c,
9d shows the power supply points, respectively. The gas in the vacuum container 1 is exhausted from the vacuum pump 13 through the exhaust pipe 12. The substrate 14 is installed on the ground electrode 4 with the gate valve 21 opened, and is heated to a predetermined temperature by the substrate heater 3 and the substrate heater power supply 15.

Next, using the apparatus shown in FIG. 21, for example, a-S
The case of forming the i film will be described. First, the gate valve 21 is opened, the substrate 14 is placed on the ground electrode 4, and then the gate valve 21 is closed. Subsequently, the vacuum pump 13 is driven to ^{move the} pressure in the vacuum container 1 to 1 × 10 ⁻⁷ T
Exhaust to about orr. Next, the temperature of the substrate 14 is set to a predetermined temperature by using the substrate heater 3 and the substrate heater power supply 15. Further, the discharge gas introduction tubes 11a, 1
Through 1b, for example, a predetermined amount of monosilane gas is supplied,
The pressure in the vacuum container 1 is kept at 0.05 to 0.5 Torr, and a pair of electrodes, that is, the non-grounded electrodes 2, are connected by using a power supply system.
Power is supplied to the ground electrode 4. As a result, both electrodes 2,
Glow discharge plasma is generated during the period 4.

When the monosilane gas is turned into plasma, the radicals such as SiH ₃ , SiH ₂ and SiH existing therein are diffused by the diffusion phenomenon and are adsorbed and deposited on the surface of the substrate 14 to form a-Si. A film is formed. In addition, as a film forming condition, a mixing ratio of discharge gas, for example, Si
By optimizing the flow rate ratio of H ₄ and H ₂ , the pressure, the substrate temperature, the plasma generation power, etc., not only a-Si,
It is known that microcrystalline Si and polycrystalline Si can be formed into a film. It is known that the surface of the substrate 14 can be subjected to a predetermined etching treatment by using an etching gas such as SF ₆ , SiCl ₄ , CF ₄ and NF ₃ as the discharge gas.

(Conventional Example 3) Next, as Conventional Example 3, an apparatus described in Document 2 will be described with reference to FIGS. 25 and 26. However, the same members as those in FIGS. 22 and 23 are denoted by the same reference numerals, and the description thereof will be omitted.

Reference numeral 31 indicates a high frequency oscillator, which is connected to the matching unit 6 via a high frequency power amplifier 32.
Here, the high frequency oscillator 31 and the high frequency amplifier 32 constitute a high frequency power supply. A vacuum current introduction terminal 33 is provided on the wall surface of the vacuum container 1, and the ungrounded electrode 2 and the matching unit 6 are connected by a coaxial cable 8 passing through the introduction terminal 33. In the vacuum container 1, glow discharge plasma is generated by a pair of electrodes, that is, the wall (bottom surface) 34 on which the non-grounded electrode 2 and the substrate 14 are installed. The high frequency power of the high frequency power supply is supplied to the non-grounded electrode 2 via the vacuum current introduction terminal 33, the coaxial cable 8 and the matching device 6. In this case, the power supply frequency is 70MHz
Is. On the rear surface of the non-grounded electrode 2 (the surface not in contact with the space where plasma is generated), an H-shaped power supply line 35 is formed as shown in FIG. The power supply points 9a, 9b, 9c, 9 are provided at the corners of the power supply line 35, respectively.
d is formed.

With such a device, a size of 350 mm
The following Table 1 is formed on a glass substrate (thickness: 1 mm) of 450 mm.
The a-Si film is formed under the film forming conditions shown in.

[0019]

[Table 1]

As a result, an a-Si film having a film thickness distribution of ± 18% was obtained.

[0021]

By the way, the above-mentioned surface treatment technique, that is, the surface treatment apparatus and the surface treatment method, is used in the LC method.
In all industrial fields such as D, LSI, electronic copiers and solar cells, there is a need for large area and high speed processing such as product cost reduction due to productivity improvement and performance (specification) improvement such as large area wall TV. Is getting stronger year by year.

In recent years, in order to meet the above-mentioned needs, not only in the industrial world but also in academic societies, both plasma CVD (chemical vapor deposition) technology and plasma etching technology are used for high-density plasma using a VHF band (30 MHz to 300 MHz) power source. Research on high-speed film forming technology of CVD and high-speed plasma etching technology has become popular.

However, the conventional technique still has the following problems. 1) First, there is an increase in surface area of plasma (improvement of productivity and performance). As the apparatus and method for plasma surface treatment, the techniques shown in FIGS. 22 to 26 described above are used. According to the study by the present inventors, when a film of an a-Si film is formed by a conventional technique, when the substrate area is about 50 cm × 50 cm, as shown in FIG. 20, the substrate area is 100 cm × 100 cm. In the case of the degree, as shown in FIG. 21, as the power supply frequency increases,
It turned out that there is a problem that the film thickness distribution is extremely poor.

In general, a film thickness distribution of ± 5% in the LCD field and a film thickness distribution of ± 10% in the solar cell field are indexes for practical use. Therefore, in the conventional technique, the substrate area is 0.5 m ×, except for the power supply frequency of 13.56 MHz.
There is a problem that it cannot be practically used in the 0.5 m class to 1 m × 1 m class.

2) Secondly, there is speeding up of surface treatment (improvement of productivity). In order to increase the speed of the surface treatment technology using plasma, it is desired to increase the power supply frequency for plasma generation from 13.56 MHz, which has been practically used in the past, to 50 MHz to 150 MHz, which is about 4 times to about 10 times. ing.

Plasma density increases with increasing frequency,
It increases with the increase. That is, about 4 times to about 10
If it is doubled, the film forming speed will be increased correspondingly to the increase. However, as shown in FIGS. 19A and 19B, when the power supply frequency for plasma generation is increased,
It was found that there is a problem that the film thickness distribution becomes significantly worse.

The reason is that at high frequencies, the wavelength of the wave and the propagation path of the power supply system, that is, the propagation path from the high frequency power source to the electrode and the length of the propagation path on the electrode become approximately equal, Wave interference phenomenon (interference with reflected waves)
It is conceivable that the plasma density is generated and the spatial uniformity of the plasma density cannot be maintained.

As another reason, the conventional 13.56 is used.
Although it also occurs at a frequency of MHz, it is considered that it becomes more remarkable when the skin effect, which is a phenomenon peculiar to high frequency radio waves, becomes 50 MHz to 150 MHz. That is, the skin effect is a phenomenon in which a high-frequency current appears only near the surface of the conductor, and the surface depth δ at which the current flows is δ = (3.14 × f · μ · σ) ^−0.5 where f : Frequency, μ: magnetic permeability, σ: conductivity. For example, if the conductor is copper, its surface depth is 13.5.
About 19 μm at 6 MHz, about 1 at 50 MHz to 60 MHz
It is about 5.8 μm at 0 μm and 150 MHz. Therefore,
In the surface treatment technology using plasma in the VHF band (30 MHz to 300 MHz), the spatial uniformity of the plasma density can be maintained by the impedance increase and the nonuniformity in the power supply propagation path from the high frequency power supply to the electrode. It is thought that it will disappear.

Therefore, it is very difficult and impossible to improve the plasma surface technology by increasing the frequency of the plasma power source for a large area substrate of 1 m × 1 m to 2 m × 2 m class, which is necessary for improving productivity and reducing costs. Has been done. Incidentally, since the plasma density increases almost in proportion to the power supply frequency for plasma generation, such researches have been activated at the related technical field societies, but there has not been a successful example of increasing the area.

The present invention has been made in order to solve the above problems, and has a large frequency even for a substrate whose size is significantly larger than the conventional one, for example, a large area substrate of 1 m × 1 m to 2 m × 2 m class. An object of the present invention is to provide a surface treatment apparatus and a surface treatment method that use a high frequency (VHF) and have high speed and excellent uniformity.

[0031]

Means for Solving the Problems Claims 1 to 13 of the present application
As mentioned above, the inventions listed above are smaller in size than conventional ones.
Substantially large substrates, for example 1m x 1m to 2m x 2m class
Very high frequency (VH) with large frequency even for large area substrates
High-speed and uniform surface treatment device or table using F)
The purpose is to obtain a surface treatment method.

Similarly, in order to achieve the above object, claim 1
In the invention, a vacuum container having an exhaust system in which a substrate is set, a discharge gas introduction system for introducing a discharge gas into the vacuum container, and a substrate in the vacuum container facing the substrate. An electrode arranged, a first ultra-high frequency power source and a second ultra-high frequency power source independent of the ultra-high frequency power source, and high-frequency power is supplied to the electrode to discharge the discharge gas to generate plasma. A surface treatment apparatus for treating a surface of a substrate placed in a vacuum container by using generated plasma, wherein the electrode has a rectangular shape,
A plurality of first power supply terminals connected to the output circuit of the first ultra-high frequency power supply are attached to the first side surface, which is one side surface of the electrode, at equal pitch intervals one by one, and
Ultra-high frequency power having a frequency substantially the same as the frequency of the output of the first ultra-high frequency power supply is generated at an equal pitch interval on the second side surface which is the other side surface facing the first side surface, and the second side surface is generated. It has a configuration in which a plurality of second power supply terminals connected to the output circuit of the ultra high frequency power supply are attached one by one.

In Claim 1 (similarly in other claims), it is meant that the "equal pitch interval" includes not only an exactly equal pitch interval but also a substantially equal pitch interval.

Similarly, in order to achieve the above object, claim 2
Of the present invention, a vacuum container provided with an exhaust system in which a substrate is set, a discharge gas introduction system for introducing a discharge gas into the vacuum container, and an electrode arranged at a predetermined position in the vacuum container. And a high-frequency power supply that changes the phase difference of the two-output and high-frequency power of the two outputs in a sawtooth shape with time, and supplies the high-frequency power to the electrodes to discharge the discharge gas and generate plasma. A surface treatment apparatus for treating the surface of a substrate using generated plasma, the electrode having a rectangular shape, and a first side surface that is one side surface of the electrode. And a plurality of power supply points connected to the output circuit of the high-frequency power source are attached to the second side surface, which is the other side surface opposite to the first side surface, at equal pitch intervals. It has the following configuration.

Similarly, in order to achieve the above object, the following claims
3 of the invention resides in that in Claim 1, has a configuration using a coaxial cable to the power supply to the power supply portion of the electrode by the power supply system.

Similarly, in order to achieve the above object, claim 4
According to the invention of claims 1 and 2 , the frequency of the high frequency power belongs to the HF band to the VHF band of 10 MHz to 300 MHz. Here, the frequency of the high-frequency power is defined as above because the electron temperature is high when the frequency is less than 10 MHz, a high-quality Si-based thin film cannot be obtained, the plasma density is low, and the surface treatment speed is slow. Therefore, the application value is low, and the frequency is 300M.
This is because when the frequency exceeds Hz, the coaxial cable is not used for the power transmission means and the waveguide is required, which is impractical.

Similarly, in order to achieve the above object, claim 5
According to the invention of claim 1 , in the power supply system, at least one high-frequency power source for generating high-frequency power, and at least an output of the high-frequency power source are branched into a number corresponding to the number of the plurality of power supply points. One power distributor, at least one matching device arranged between the high-frequency power source and at least one power distributor via a coaxial cable for high-frequency power transmission, and the power distributor. It is characterized by comprising a plurality of twisted-wire coaxial cables that guide high-frequency power to each of the power supply points.

Similarly, in order to achieve the above object, claim 6
According to the invention of claim 1, in the apparatus according to claims 1 and 2 , any one of an amorphous Si-based thin film, a microcrystalline Si-based thin film, and a polycrystalline Si-based thin film is formed.

[0039] Similarly, in order to achieve the above object, claim 7
The invention of claim 1, in the device of claims 1 and 2 , the electrode has a rectangular shape, and the substrate processed by utilizing plasma is for a solar cell, a liquid crystal display, or a large-scale integrated circuit. It has a structure of being a substrate.

[0040]

Similarly, in order to achieve the above object, the claims
According to the invention of claim 8 , a vacuum container provided with an exhaust system in which a substrate is set, a discharge gas introduction system for introducing a discharge gas into the vacuum container, and a vacuum container arranged at a predetermined position. An electrode and at least two first and second ultra-high frequency power supplies that generate high-frequency power independent of each other, and supply high-frequency power to the electrodes to discharge the discharge gas and generate plasma. A surface treatment method for treating a surface of a substrate using generated plasma by using a surface treatment apparatus including a system, wherein the shape of the electrode is square, and one side surface of the electrode is formed. The first plurality of power supply ends are attached to the side surface at equal pitch intervals, and the second plurality of power supply ends are attached to the second side surface, which is the other side surface facing the first side surface, at equal pitch intervals, Output circuit of the first ultra high frequency power supply The first plurality of power supply terminals are connected one by one with a coaxial cable, and the output circuit of the second ultra-high frequency power supply and the second plurality of power supply terminals are connected one by one with a coaxial cable. It is configured like this.

Similarly, in order to achieve the above object, claim 9
Of the present invention, a vacuum container provided with an exhaust system in which a substrate is set, a discharge gas introduction system for introducing a discharge gas into the vacuum container, and an electrode arranged at a predetermined position in the vacuum container. And a high-frequency power source that changes the phase difference between the two outputs and the high-frequency power of the two outputs in a sawtooth shape with time, and supplies the high-frequency power to the electrodes to discharge the discharge gas to generate plasma. A surface treatment method for treating the surface of a substrate using generated plasma using a surface treatment apparatus having a power supply system for generating, wherein the shape of the electrode is square, and one side surface of the electrode is used. The first plurality of power supply ends are attached to the first side face at equal pitch intervals,
A second plurality of power supply ends at equal pitch intervals on a second side surface, which is the other side surface opposite to the side surface, and the first output circuit and the second output circuit of the ultra-high frequency power source are respectively connected to the second side surface. Each of the first and second power supply terminals is connected by a coaxial cable.

Similarly, in order to achieve the above object, claim 1
0 of invention, in claim 8, 9, an ultra high frequency power supply for supplying required power to oscillate the 10MHz to 300MHz as a high frequency power source, said microwave using at least one of the matching network and a plurality of coaxial cables Power supply 10 MH
The output power of z to 300 MHz is supplied to the power supply location.

Similarly, in order to achieve the above object, claim 1
1st aspect WHEREIN: Amorphous S is used in Claim 8-10 by using at least monosilane gas as discharge gas.
Any one of the i-based thin film, the microcrystalline Si-based thin film and the polycrystalline Si-based thin film is formed.

Similarly, in order to achieve the above object, claim 1
In a second aspect of the present invention, the amorphous S is formed by using at least monosilane gas as the discharge gas in the eighth to eleventh aspects.
Any one of the i-based thin film, the microcrystalline Si-based thin film and the polycrystalline Si-based thin film is formed.

Similarly, in order to achieve the above object, claim 1
According to the third aspect of the invention, a vacuum container having an exhaust system in which a substrate is set, a discharge gas introduction system for introducing a discharge gas into the vacuum container, and a predetermined position in the vacuum container are arranged. An electrode and a high-frequency power source that changes the phase of two-output and high-frequency power of the two outputs in a sawtooth shape with time are provided, and the high-frequency power is supplied to the electrode to discharge the discharge gas to generate plasma. A surface treatment method for treating a surface of a substrate using generated plasma by using a surface treatment apparatus provided with a power supply system for generating, wherein the shape of the electrode is a square, and the four side surfaces of the electrode are One of them is the first aspect
A plurality of power supply points connected to the power supply system are installed on the side surface of the first side surface and the second side surface facing the first side surface, respectively, and are installed on the first side surface and the second side surface. A first output and a second output of the high-frequency power source are connected to power supply points, respectively, and two powers whose phases change from moment to moment are supplied.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have provided a power supply position for supplying power to a non-grounded electrode of a pair of parallel plate electrodes on a side surface of the electrode, that is, a front surface of the non-grounded electrode in contact with a plasma generation space. A method of supplying the electric power was created by installing it on the boundary between the (lower surface) and the rear surface (upper surface) on the back side thereof. In order to verify this, a square electrode was used as a pair of parallel plate electrodes, and a plasma generation experiment and an amorphous silicon film formation experiment using monosilane gas were conducted. As a result, VHF band (30MH
It was possible to generate a plasma having a uniform spatial distribution with a large area plasma capable of supporting a 1 m × 1 m class substrate at z to 300 MHz). Moreover, 1m × 1 which has not been successful in the prior art
An amorphous silicon film having a film thickness distribution of ± 5 to 20% could be formed on a glass substrate having an area of m.

The reason why the conventional problems can be solved by the above new idea is considered as follows. In the prior art,
The high frequency current output from the high frequency power supply is shown in FIG.
As shown in (A) and (B), the non-grounded electrode 2 flowed from the rear surface of the non-grounded electrode 2 through the side surface to the front surface. However, it is considered that the new method realizes a current flow distribution that propagates from the position of the surface of the side surface of the non-grounded electrode near the plasma generation space to the surface of the central portion of the front surface, as shown in FIG. To be Therefore,
The potential distribution in the plasma space in the prior art was as shown in FIG. 14, but it is considered that the new method described above obtained a substantially uniform potential distribution as shown in FIG.

In order to realize the above new method, a coaxial cable having a single core wire is conventionally used as a power supply line for supplying high-frequency power supplied from a high-frequency power source to a non-grounded electrode. However, as shown in FIG. 7, the present inventors have created a stranded coaxial cable having a structure in which an outer conductor 38 is formed outside a stranded core wire 36 via an insulator 37. Then, we obtained a new finding that the impedance is large except for the coaxial cable having the stranded wire type core, Joule heat is generated, and it is impossible to supply electric power. That is, when the coaxial cable has one core wire, the coaxial cable in the vacuum container is heated to a temperature of 400 ° C. or higher due to Joule heat (may be disconnected), but if the number of core wires is increased to 4 or more. The temperature of the coaxial cable became about 100 ° C. or lower.

In order to realize the above new method, a new means as shown in FIGS. 5 and 6 was devised as a method for electrically connecting the coaxial cable and the non-grounded electrode. Details of these configurations will be described in the section of [Example] described later.

That is, in FIG. 5 and FIG. 6, the core wire 3
As a method of connecting the twisted-wire coaxial cable 67a composed of the insulator 37, the outer conductor 38, and the non-grounded electrode 52, a metal cylinder 73 fixed to the non-grounded electrode 52
a and a metal cylinder 73 using a metal bolt 74 and the like.
The core wire 36 of the stranded wire type coaxial cable is pressed against the inner wall 75 of a to form a power supply point.

Furthermore, the inventors of the present invention have made the size of the substrate large, especially 1
In order to cope with the ultra-large size of mx1m to 2mx2m,
As shown in FIG. 3 and FIG. 4, a plurality of first power supply points are arranged at substantially equal pitch intervals on one side surface, that is, the first side surface of the rectangular non-grounded electrode forming the pair of parallel plate electrodes. Is installed, a plurality of second power supply points are installed at substantially equal pitch intervals on the other side surface that is parallel and opposite to the side surface, and two high-frequency power sources, that is, the first high frequency power source and the first high frequency power source, which are independent of each other, are installed. And a second high-frequency power supply, and a VHF class (30M) from the first high-frequency power supply at the first power supply location.
Power of, for example, 70 MHz is supplied from the second high-frequency power source to the second power supply location, and the frequency is approximately the same as that of the first high-frequency power source, for example, 6 MHz.
A new method of generating plasma between the pair of parallel plate electrodes described above was created by supplying electric power of 0 MHz to 80 MHz.

To demonstrate the above new method
Monosilane gas (SiH _Four), 1m ×
Form an amorphous silicon film on a 1m glass substrate
An experiment was conducted. As a result, the first high frequency power source and the
When using the first power supply location, etc., it is shown in Fig. 12 (A).
Film thickness distribution, that is, on the side near the first power supply point
The film thickness is large, and it is in the lateral direction of the ungrounded electrode (X-axis direction in FIG. 4).
It was found that the film thickness becomes thinner as it goes toward the direction.
Also, the second high frequency power source and the second power supply point
, Etc., the film thickness distribution as shown in FIG.
That is, the film thickness on the side close to the second power supply location is large,
It is said that the film thickness becomes thinner in the lateral direction of the ground electrode.
I got the knowledge.

Then, when power is independently supplied to the first and second power supply points from the first and second high frequency power sources, respectively, and amorphous silicon is formed on the 1 m × 1 m glass substrate, It was found that a combined form of FIGS. 12A and 12B, that is, a good film thickness distribution with uniformity can be obtained as shown in FIG. 12C. The reason why the film thickness distribution with good uniformity is formed is that the first and second high-frequency power supplies supply electric powers having an independent relationship to each other to the first and second power supply points. It is considered that no phenomenon or standing wave is generated, and as a result, the potential distribution in the plasma space is kept substantially uniform as a temporal average value, as shown in FIG.

When the first and second high frequency power supplies are not independent, for example, one high frequency power
And power is supplied to the second power supply point, and 1 m × 1 m
It was also found that, when the amorphous silicon film was formed on the glass substrate of No. 2, the film thickness was not uniform as shown in FIG. The reason is that high frequency power is supplied from two different directions, so that the electric fields generated at the electrodes interfere with each other, or a standing wave is generated, and the powers propagated from the two directions are mutually opposite. It is also possible that the reflected wave is fed back to the oscillator constituting the high frequency power supply through the power supply line and the function of the oscillator is significantly deteriorated.

Further, the electrode has a rectangular shape, and one of four side surfaces of the rectangular electrode, that is, a first side surface and a side surface or a second side surface which is parallel to and opposes the first side surface, A high-frequency power supply, in which a plurality of power supply points connected to the power supply system are installed in each, and the high-frequency power supply has two outputs and changes the phase difference between the two outputs of the high-frequency power in a sawtooth shape with time A high-frequency power source for changing the phase difference between the two outputs and the high-frequency power of the two outputs to the power supply locations installed on the first side surface and the second side surface, respectively. The first output and the second output are connected to each other to supply two electric powers whose phases change from moment to moment.

As a result, as shown in FIGS. 18 (A) and 18 (B), the two electric powers supplied from the first and second electric power supply points propagate in the directions in which they collide with each other to form a standing wave. Without any reason, the temporal average value has a substantially uniform spatial distribution. Note that FIG. 18A shows a case where the two-output phase variable high frequency oscillator 42 is connected to the non-grounded electrode 39 via the first high frequency amplifier 43a and the second high frequency amplifier 43b when the phase difference changes from time to time. The general view at the time of making each of the 1st electric power supply location 40a and the 2nd electric power supply location 40b is shown. Further, FIG. 18B is a characteristic diagram showing the relationship between the square of the combined voltage and the distance between the power supply points.

However, if the phase difference of the high frequency powers of the two outputs is fixed at 0 °, for example, a standing wave is formed by mutual interference as shown in FIGS. 19 (A) and 19 (B). Here, in FIG. 19A, when the phase difference is 0 °, the two-output phase variable high frequency oscillator 42 is connected to the first high frequency amplifier 43a and the second high frequency amplifier 43a.
2 is an overall view of the case where the high-frequency amplifier 43b of FIG. 3 is respectively provided to the first power supply location 40a and the second power supply location 40b of the non-grounded electrode 39. In FIG. 19A, the waveform (a) is the voltage W1 of the first power (standing wave).
Shows the waveform (b) of the second power voltage W2 (standing wave)
Indicates. In addition, FIG. 19B is a characteristic diagram showing the relationship between the square of the combined voltage and the distance between the power supply points.

[0059]

EXAMPLES Examples of the present invention will be described below. In the following description, as an example of the surface treatment apparatus and the surface treatment method, an apparatus and a method for producing an amorphous silicon (a-Si) thin film necessary for producing a solar cell are assumed. However, as a matter of course, the object of the invention of the present application is not limited to the apparatus and method of the above specific example.

Example 1 With reference to FIGS.
The apparatus and method of the first embodiment will be described. First of all,
The configuration will be described. Reference numeral 51 in the figure indicates a vacuum container. This
In the vacuum container 51 of the glow discharge, glow discharge plasma
A pair of electrodes for generating a circle, that is, a non-grounded electrode 52
And the ground electrode 54 containing the substrate heater 53 is arranged.
There is. The non-grounded electrode 52 includes insulators 55a, 55b,
It is attached to the upper part of the vacuum container 51 via 55c.
It The lower side of the non-grounded electrode 52, that is, plasma is generated.
The lower surface A that is in contact with the space 56
A large number of gas blowout holes 57 of about 10 mm are provided with a hole interval of 10 to 15
It is formed in mm. On the upper side of the non-grounded electrode 52
A cylinder (Fig.
(Not shown) is attached. Vacuum from this cylinder
For example, monosilane (SiH _Four) Is supplied
It

A first exhaust pipe 59 is provided in the vacuum container 51.
The first vacuum pump 40a is connected via a, and the second vacuum pump 40a is connected via a second exhaust pipe 59b.
b is connected. The gas in the vacuum container 51 passes through the exhaust pipes 59a and 59b, and the vacuum pumps 40a and 4a.
It is discharged by 0b. The substrate 61 is placed on the ground electrode 54, and is heated to a predetermined temperature by the substrate heater 53 and the substrate heater power source 62 connected to the substrate heater 53. The ground electrode 54 is fixed to the support 63. A gate valve 64a for loading and unloading the substrate is provided on a side wall of the vacuum container 51 corresponding to the height of the substrate 61.
64b is provided.

The side surface of the non-grounded electrode 52, that is, one side surface (first side surface) slightly apart from the peripheral portion of the lower surface A of the non-grounded electrode 52 which is in contact with the space 56 is shown in FIGS. 4, a plurality of power supply points 65a,
65b, 65c, 65d, 65e, 65f, 65f, 6
5g and 65h are located. In addition, the second side surface of the non-grounded electrode 52 facing in parallel with the first side surface has a structure shown in FIG.
And as shown in FIG. 4, a plurality of power supply points 65i,
65j, 65k, 65l, 65m, 65n, 65o, 6
5p is located. As shown in FIGS. 1 to 3, a plurality of current introducing terminals 66 are provided on the wall surface of the vacuum container 51.
a, 66b, 66c, 66d, 66e, 66f, 66
g, 66h, and a plurality of current introducing terminals 66
i, 66j, 66k, 66l, 66m, 66n, 66
Groups of o and 66p are provided so as to face each other.

Power supply point 65a of the non-grounded electrode 52
To 65p, a plurality of stranded coaxial cables 67a,
67b, 67c, 67d, 67e, 67f, 67f, 6
7g, 67h, 67i, 67j, 67k, 67l, 67
m, 67n, 67o and 67p are connected to each other. The stranded wire type coaxial cables 67a to 67h include a first power distributor 69a and a first matching unit 70 via the current introducing terminals 66a to 66h and the coaxial cables 68a to 68h, respectively.
a and the first high frequency power source 71a are sequentially electrically connected. Also, the stranded wire type coaxial cables 67i to 67p
Is the current introducing terminals 66i to 66p and the coaxial cable 6
The second power distributor 69b, the second matching unit 70b, and the second high-frequency power source 71b are sequentially electrically connected via 8i to 68p.

The stranded wire type coaxial cables 67a to 67h
The external conductors 38 are provided outside the stranded wire (core wire) 36 made of a plurality of wires through an insulator 37 as shown in FIG.
Is formed. Taking two stranded wire type coaxial cables 67a, 67b as an example, the cables 67a, 67b
67b and the non-grounded electrode 52 are connected as shown in FIGS.

Focusing on the cable 67a, in order to electrically connect the cable 67a and the side surface of the non-grounded electrode 52, a metal cylindrical body sandwiched by an insulator 72 and fixed to the side surface. 73a and the metal bolt 74, the twisted coaxial cable 6 is attached to the inner wall 75 of the metal cylinder 73a.
The stranded wire 36 of 7a is pressure-welded to form a power supply point 65a. The path of the high frequency current from the stranded wire 36 to the non-grounded electrode 52 is defined by the inner wall 75 of the metal cylinder 73a,
It is composed of a threaded portion 76 of the tubular body 73a and a threaded portion 77 provided on the non-grounded electrode 52 for fixing the tubular body 73a. It should be noted that reference numeral 78 in FIG. 5 indicates a bolt, reference numeral 79 in FIG. 6 indicates a screw portion formed on the metal cylinder 73a, and reference numeral 74a indicates a screw portion of the bolt 74.

In FIG. 6, the case of electrical connection between the twisted-wire coaxial cable 67a and the side surface of the non-grounded electrode 52 has been described, but the other twisted-wire coaxial cables 67b to 67p and the side surface of the non-grounded electrode 52 are electrically connected. The same applies when connecting to. Further, metal cylinders 73b to 73p are also provided at the connection points of these cables 67b to 67p with the non-grounded electrode 52, respectively.

Incidentally, the first and second power distributors 69
Although powers a and 69b can be distributed by a circuit in which L, C and resistors are combined, in this embodiment, the power distributor shown in FIG. And the outputs of the first and second matching units 70a and 70b connected to the second high-frequency power sources 71a and 71b, respectively, to the coaxial cables and the T-type connectors 81a, 81b, 82a, 82b, and 82c for coaxial cables, respectively. 82
16 coaxial cables 6 using d, 83a to 83h
A distributor was used that distributed between 8a and 68p.

Next, using the surface treatment apparatus having the structure shown in FIGS. 1 to 7, amorphous silicon (a-S) is used.
i) A method for forming an a-Si film for a solar cell will be described.

First, the pressure inside the vacuum container 51 is kept at atmospheric pressure, and the first and second gate valves 64a for loading and unloading the substrate are provided.
64b is opened, a substrate loading / unloading system (not shown) is used, and the substrate 61, for example, thickness 0.3 cm, 100 cm × 1
A glass substrate of 00 cm is placed on the ground electrode 54. Then, the first and second substrate loading / unloading gate valves 64
a and 64b are closed, and the first and second vacuum pumps 40
a and 40b are operated, and the first and second exhaust pipes 59
The atmosphere in the vacuum container 51 is discharged via a and 59b, and after the pressure reaches about 1 × 10 ⁻⁷ Torr,
The following discharge gas is introduced.

Next, a discharge gas, for example SiH ₄ gas, is supplied from the discharge gas introduction pipe 58 through the gas outlet 57 at a flow rate of about 2,000 to 3,000 sccm,
The pressure is maintained at 0.05 to 0.5 Torr. Further, the temperature of the substrate 61 is kept at, for example, 180 ° C. in the range of 80 ° C. to 350 ° C. by using the relationship between the surface temperature of the substrate 61 and the output (electric power) of the substrate heater power source, which is acquired in advance as data. To do. Next, the frequencies of the first and second high frequency power supplies 71a and 71b are set to 10 MHz to 300 MH.
z, for example, the output frequencies of the first high frequency power source 71a and the second high frequency power source 71b are 60 MHz and 65 MHz,
Both output powers are supplied at 3 kW to 5 kW.

Then, the pair of non-grounded electrodes 52,
A glow discharge plasma of SiH ₄ is generated between the ground electrodes 54. As a result, the Si present in the plasma is
Radicals such as H ₃ , SiH ₂ , SiH, and Si diffuse by a diffusion phenomenon and are adsorbed and deposited on the surface of the substrate 61, thereby forming an a-Si film.

In the above example, the pair of non-ground electrodes 5
2. The size of the ground electrode 54 is 1200 mm × 120, respectively.
The material was 0 mm × 100 mm, the material was stainless steel, and the interval was 50 mm.

Table 2 below shows an example of the film-forming test results of Example 1 above. The substrate size is × 1000 mm × 10
00 mm, the substrate temperature was 180 ° C., and the film thickness distribution was evaluated by measuring the film thickness at 20 points on the diagonal line of the substrate by the double monochromator method and the ellipsometry method.

[0074]

[Table 2]

In the first embodiment, the frequencies of two independent high frequency power supplies, that is, the first and second high frequency power supplies 71a,
The frequencies of 71b are 14 MHz and 16 MHz, respectively.
If (average value 15MHz), 30MHz and 33M
When set to Hz (average value 31.5 MHz), 60 MHz
And 65MHz (average value 62.5MHz), 8
When set to 0 MHz and 90 MHz (average value 85 MHz)
Met. Therefore, the first and second high frequency power sources 71
a, 71b, first and second matching devices 70a, 70b, first and second power distributors 69a, 69b, coaxial cables 68a to 68p, current introducing terminals 66a to 66p, stranded coaxial cables 67a to 67p, etc. Is 90 MHz to 30
Since it is sufficiently applicable to 0 MHz, it can be said that the a-Si film is also sufficiently applicable to the frequency of 90 MHz to 300 MHz.

Now, the above data, that is, Table 2 is shown in FIG.
As shown in (B), it was considered difficult in the conventional example 1
Power supply frequency 15 for ultra large area substrate of mx 1 m
MHz class, 31.5 MHz class, 62.5 MHz class, 85
It is shown that remarkably good results are obtained for both the MHz class.

Further, it is shown that Example 1 of the present invention is extremely effective as a technique for increasing the area of the a-Si film and a technique for increasing the power supply frequency, both in terms of the structure of the surface treatment apparatus and the methodology. ing.

The film forming conditions in Example 1 are as follows.
The discharge gas mixture ratio, for example SiH _FourAnd H_TwoFlow ratio of
Optimize pressure, substrate temperature, plasma generation power, etc.
Therefore, not only a-Si, but also microcrystalline Si and polycrystalline S
It is known that i can be formed into a film.

Further, as discharge gas, SiH ₄ , NH
That a SiN _x film can be formed by using ₃ , N _2, etc.,
Gas having etching action, for example, SF ₆ , SiC
It is also known that the surface of the substrate can be subjected to a predetermined etching treatment by using an etching gas such as l ₄ , CF ₄ and NF ₃ .

(Embodiment 2) Next, FIG. 9, FIG. 10 and FIG.
The apparatus and method of the second embodiment will be described with reference to FIG. First, the configuration of the device will be described. However, the same members as those in FIGS. 1 to 8 are denoted by the same reference numerals and the description thereof will be omitted.

The structure of the surface treatment apparatus shown in FIG. 9 is similar to that of the first and second high frequency power supplies 71a and 71b shown in FIG.
The output oscillates a sine wave signal having a frequency of 10 MHz to 300 MHz, and the phase of the two output signals is 0 ° to 360 °.
2 consisting of a function generator, a phase shifter, and a high-frequency oscillator that can be changed from moment to moment
The output phase variable oscillator 81, the first and second high-frequency signal transmission cables 82a and 82b, and the first and second high-frequency power amplifiers 83a and 83b are used, and all other device constituent elements are the same. Therefore, with respect to device components other than the above, refer to FIG. 1 and will be omitted here.

Next, a method for forming an a-Si film for an amorphous silicon (a-Si) solar cell using the surface treatment apparatus having the structure shown in FIG. 9 will be described. First, the pressure in the vacuum container 51 is kept at atmospheric pressure, and the first and second
The substrate loading / unloading system not shown is used to open the substrate loading / unloading system by opening the substrate loading / unloading gate valves 64a and 64b.
For example, a glass substrate having a thickness of 0.3 cm and 100 cm × 100 cm is installed on the ground electrode 54. Continuing, the first above
And the second substrate loading / unloading gate valves 64a, 64b are closed, the first and second vacuum pumps 60a, 60b are operated, and the vacuum container is operated via the first and second exhaust pipes 59a, 59b. The atmosphere in 51 is discharged, and the pressure is about 1
After reaching × 10 ⁻⁷ Torr, the next discharge gas is introduced.

Next, a discharge gas, such as SiH4 gas, is supplied from the discharge gas introduction pipe 58 through the gas outlet 57 at a flow rate of about 2000 to 3000 sccm, and the pressure is maintained at 0.05 to 0.5 Torr. To do. Here, the surface temperature of the substrate 61 and the output (electric power) of the substrate heater power source, in which the temperature of the substrate 61 is acquired in advance as data.
Using the relationship of, for example, 18 in the range of 80 ℃ ~ 350 ℃
Hold at 0 ° C. Subsequently, the 2-output phase variable oscillator 81
Is transmitted to the first high frequency power amplifier 83a from the first high frequency signal cable 82a, and the second output of the two-output phase variable oscillator 81 is transmitted to the second high frequency signal cable 82b from the second high frequency signal cable 82b. It is transmitted to the power amplifier 83b.

In this case, the 2-output phase variable oscillator 81
The phases of the first and second outputs of are shown in FIGS.
The phase difference θ between the two sine wave signals shown as the phase θ in FIG.
As shown in (A) and (B), the sawtooth wave is changed every moment in the range of ± 45 ° and ± 90 °, for example, in a period of several seconds to several hundredths of a second. In addition,
The vertical axis of FIG. 10 (A) is the first of the two-output phase variable oscillator 81.
10B, and the vertical axis of FIG. 10B shows the first output voltage of the two-output variable phase oscillator 81.

The output frequency of the two-output phase variable oscillator 81 is 10 MHz to 300 MHz, for example 60.
MHz. The power is supplied at 3 kW to 5 kW. Then, the pair of non-grounded electrode 52 and grounded electrode 54
In the meantime, SiH ₄ glow discharge plasma is generated. As a result, SiH ₃ , SiH ₂ , existing in the plasma,
Radicals such as SiH and Si are diffused by a diffusion phenomenon, and are adsorbed and deposited on the surface of the substrate 61, whereby a-Si
A film is formed.

In the above example, the size of the pair of non-grounded electrodes 52 and grounded electrodes 54 is 1200 mm × 1200 mm, respectively.
× 100 mm, the material was stainless steel, and the interval was 50 mm.

Table 3 below shows an example of the film-forming test results of Example 2 above. The substrate size is 1000 mm x 10
00 mm, the substrate temperature was 180 ° C., and the film thickness distribution was evaluated by measuring the film thickness at 20 points on the diagonal line of the substrate by the double monochromator method and the ellipsometry method.

[0088]

[Table 3]

According to the data in Table 3 above, when θ = 0 ° (fixed), a standing wave is generated between the pair of electrodes, and the film thickness distribution is extremely poor, but when θ = ± 180 ° and θ = ± 360 ° It is shown that no standing wave is generated and the film thickness distribution is good particularly under the condition of θ = ± 360 °.

In the second embodiment, the 2-output phase variable oscillator 8
When the output frequency of 1 is 60 MHz and the phase difference θ between the two output signals is fixed at θ = 0 °, θ = ± 180 ° and the time is changed by a sawtooth wave with a period of 1/100 second. In the case of θ = ± 360 °, the time was changed with a sawtooth wave having a period of 1/100 second, but the first and second high frequency power amplifiers 83a and 83b, the first and second high frequency power amplifiers Second
Matchers 70a, 70b, first and second power distributors 6
9a, 69b, coaxial cables 68a to 68p, current introducing terminals 66a to 66p, twisted-wire coaxial cables 67a to 6
Since 7p and the like can be applied to 60 MHz to 300 MHz, the a-Si film can also be applied to 60 MHz to 300 MHz.
It can be said that it is sufficiently applicable at the frequency of.

The above data, that is, Table 3 is shown in FIG.
As shown in (B), it was considered difficult in the conventional example 1
Power supply frequency 60 for ultra-large area substrate of mx 1 m
It shows that very good results are obtained at MHz.

Further, it is shown that the second embodiment of the present invention is extremely effective as a technique for increasing the area of the a-Si film and a technique for increasing the power supply frequency, both in terms of the structure of the surface treatment apparatus and the methodology. ing.

As the film forming conditions in the above Example 2, by optimizing the mixing ratio of the discharge gas, for example, the flow rate ratio of SiH ₄ and H ₂ , the pressure, the substrate temperature, the plasma generation power, etc., only a-Si can be obtained. Of course, microcrystalline Si and polycrystalline Si
It is known that a film can be formed.

SiH was used as the discharge gas._Four, NH
_Three, N_TwoThat the SiNx film can be formed by using
Gas with a etching action, eg SF₆, SiCl_Four，
CF _FourAnd NF_ThreeIf an etching gas is used, the surface of the substrate
It is also known that the surface can be subjected to a predetermined etching treatment.
It

[0095]

As described above, the power supply location is switched on.
If it is installed on the side of the pole, it is possible to make the spatial distribution of the high-density plasma using the VHF band (30 MHz to 300 MHz) power source, which has been difficult to achieve in the past, uniform, and to perform a uniform surface treatment on the substrate, that is, a film formation rate and It has become possible to improve the etching rate and uniformity. This effect is
Not only in the LCD and photoconductor for copying machines industry, but also in the solar cell industry, the contribution to the improvement of productivity is extremely large.

According to the surface treatment apparatus of claim 1 , since a plurality of power supply points are set on the side surfaces of the electrodes, it is possible to target a 1 m × 1 m class super large area substrate, which has been difficult to achieve in the past.
56MHz class and VHF band (30MHz to 300MH
It became possible to make the spatial distribution of the high-density plasma uniform using the power source of z), and to make it possible to perform uniform surface treatment on the ultra-large-area substrate, that is, to improve the film forming rate and etching rate and to improve the uniformity. This effect is especially true for solar cells and LCDs.
The contribution to the reduction of product cost based on the improvement of productivity in the industry is extremely large.

[0097] According to the surface treatment apparatus according to claim 2, the plurality of power supply portions provided on two opposite sides of the non-grounded electrode of the rectangular shape, supplying high frequency power whose phase changes moment by moment with each other Therefore, the spatial distribution of plasma generated in the pair of electrodes can be averaged and made uniform in time and space. This enables uniform surface treatment of a super-large area substrate of 1 m × 1 m class or more, as in the case of the above-mentioned claim 2. Especially, the product cost based on the productivity improvement in the solar cell and LCD industry. The contribution to the reduction of

Claim 3 is highly valuable as a reliable means for realizing Claims 1 and 2 above.

A fourth aspect of the present invention is intended to expand the application range of the apparatus according to the first to third aspects, that is, to improve the film forming rate and the etching rate, and to realize a large substrate area. Remarkably large.

In addition to the effects of claims 1 to 4 , claim 5 is a plurality of high-frequency power supplies, a plurality of matching devices, a plurality of power distributors, and a plurality of coaxial cables. There is an effect that the configuration of the supply system is simple and the cost is significantly reduced.

According to the sixth aspect , the cost performance is remarkably increased because the productivity, quality and performance of the applied product of thin film semiconductor such as LCD, photoconductor for copying machine, solar cell and LSI are improved.

According to claim 7 , the so-called large-area screen, in which the product value increases as the product size increases, creates the effect of being able to create applied products such as LCDs, photoconductors for copying machines, and solar cells. Is extremely valuable.

According to the surface treatment method of claims 8 to 13 ,
The VHF band (30 MHz to 300 MHz, which has been difficult to achieve in the past, is conventionally provided by installing the power supply location, which was installed on the rear surface of the electrode, that is, the surface farthest from the space for generating plasma, in the side surface closest to the plasma generation space. It is possible to make the spatial distribution of the high-density plasma uniform by using the power source (1), and to make it possible to perform uniform surface treatment on the substrate, that is, to improve the film forming rate and the etching rate and to improve the uniformity.

For a 1 m × 1 m class ultra large area substrate, which has been difficult to achieve in the past, 13.56 MHz class and VHF
The spatial distribution of high-density plasma using a band (30 MHz to 300 MHz) power source can be made uniform, and uniform surface treatment, that is, the film forming rate and the etching rate and the uniformity can be improved for an ultra-large area substrate.

Furthermore, high frequency (HF band) and VHF band (3
A plasma phenomenon using a frequency of 0 MHz to 300 MHz, that is, a method of performing a uniform surface treatment can be realized by taking advantage of high density plasma.

The above effects have a very large contribution to the improvement of productivity based on the improvement of productivity especially in the solar cell and LCD industries. Also, in the fields of LSIs, photoconductors for copiers, etc., the degree of contribution to improving productivity is extremely large.

In addition, the productivity and quality / performance of thin film semiconductor application products such as LCDs, photoconductors for copying machines, solar cells, and LSIs can be improved, resulting in a significant increase in cost performance.

The so-called large-area screen method in which the product value increases as the product size increases can be provided for manufacturing applied products such as LCDs, photoconductors for copiers, and solar cells, thus creating a new product. Occurs. Therefore, the industrial value in this field is extremely large.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an entire surface treatment apparatus according to a first embodiment of the present invention.

2 is an explanatory diagram showing a connection state between a coaxial cable and a current introduction terminal and the like around a vacuum container in the surface treatment apparatus of FIG.

FIG. 3 is an explanatory view showing a connection state between a non-grounded electrode and a twisted-wire coaxial cable or the like in the surface treatment apparatus of FIG.

4 is an explanatory view of a non-grounded electrode, which is one configuration of the surface treatment apparatus of FIG. 1, and a twisted-wire coaxial cable connected to the ungrounded electrode.

5 is a first and second configuration of the surface treatment apparatus of FIG.
FIG. 3 is a partially cutaway perspective view for explaining details of a connection state between a core wire and a non-grounded electrode of the stranded wire type coaxial cable of FIG.

6 is a cross-sectional view for illustrating details of a connection state between a core wire and a non-grounded electrode of a first twisted-wire coaxial cable that is one configuration of the surface treatment apparatus of FIG.

FIG. 7 is a perspective view of a first twisted-wire coaxial cable that is one configuration of the surface treatment apparatus of FIG.

FIG. 8 is an explanatory diagram of a power distributor that is a configuration of the surface treatment apparatus of FIG.

FIG. 9 is an explanatory diagram showing an entire surface treatment apparatus according to a second embodiment of the present invention.

10 is a characteristic diagram showing the relationship between the output voltage and the time when the phase difference is 0 in the two-output phase variable oscillator which is one configuration of the surface treatment apparatus of FIG.

11 is a characteristic diagram showing the relationship between output voltage and time when the phase difference changes momentarily in the two-output phase variable oscillator which is one configuration of the surface treatment apparatus of FIG. 9.

FIG. 12 is a film thickness distribution diagram (relative value) of amorphous silicon and a film thickness distribution in a horizontal direction and a vertical direction of an ungrounded electrode in the surface treatment apparatus of the present invention.

FIG. 13 is a diagram for explaining the flow of a high frequency current output from a high frequency power source by a conventional surface treatment apparatus.

FIG. 14 is an explanatory view showing a potential distribution in a plasma space by a conventional surface treatment device.

FIG. 15 is a diagram for explaining the flow of a high frequency current output from a high frequency power source according to the surface treatment apparatus of the present invention.

FIG. 16 is an explanatory view showing a potential distribution in a plasma space by the surface treatment device of the present invention.

FIG. 17 is a diagram for explaining the flow of a high frequency current output from a high frequency power source according to another surface treatment apparatus of the present invention.

FIG. 18 is a schematic diagram showing a surface treatment apparatus of FIG.
Of standing wave when two powers are supplied to non-ground electrode

19 is a diagram showing the surface treatment apparatus of FIG. 9 in which the phase difference between the two-output high-frequency power from the two-output phase-variable high-frequency oscillator is zero.
Explanatory drawing of the standing wave when it is set to °.

FIG. 20: Substrate (area: 50 by conventional surface treatment apparatus
(cm × 50 cm class) characteristic diagram showing the relationship between the film thickness distribution and the power supply frequency.

FIG. 21 shows a substrate (area: 10 by a conventional surface treatment apparatus.
The characteristic view showing the relationship between the film thickness distribution (0 cm × 100 cm class) and the power supply frequency.

FIG. 22 is an explanatory diagram of a conventional surface treatment device.

FIG. 23 is an explanatory view of another conventional surface treatment device.

FIG. 24 is an explanatory diagram of a power distributor that is a configuration of the surface treatment apparatus of FIG. 23.

FIG. 25 is an explanatory view of still another conventional surface treatment apparatus.

26 is an explanatory diagram of a power supply portion formed on a non-grounded electrode in the surface treatment apparatus of FIG. 25.

[Explanation of symbols]

36 ... Stranded wire (core wire), 37, 55a, 55b, 55c ... Insulator, 38 ... outer conductor, 51 ... vacuum container, 52 ... Non-grounded electrode, 53 ... Substrate heater, 54 ... Ground electrode, 56 ... space, 57 ... Gas outlet, 58 ... Discharge gas introduction pipe, 59a, 59b ... Exhaust pipe, 60a, 60b ... Vacuum pump, 62 ... Power supply for substrate heater, 64a, 64b ... Gate valve, 65a-65p ... Power supply points, 66a to 66p ... current introducing terminal, 67a to 67p ... Stranded coaxial cable, 68a-68p ... coaxial cable, 69a, 69b ... Power distributor, 70a, 70b ... Matching device, 71a, 71b ... High frequency power source, 81 ... 2 output phase variable oscillator, 82a, 82b ... high-frequency signal transmission cable, 83a, 83b ... High-frequency power amplifier.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H01L 21/3065 H01L 21/31 C 21/31 H05H 1/46 MH05H 1/46 H01L 21/302 C (72) Inventor Aoi Tatsushi 1-1 1-1 Atsunoura-machi, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (56) Reference JP 6-291045 (JP, A) JP 9-306696 (JP, A) JP 11-354460 (JP, A) JP 2000-3878 (JP, A) JP 8-236294 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 16/00- 16/56 H01L 21/205 H01L 21/3065 H01L 21/31 H05H 1/46

Claims (13)

(57) [Claims] 1. A vacuum container having an exhaust system, in which a substrate is set, an electric discharge gas introduction system for introducing an electric discharge gas into the vacuum container, and a substrate opposed to the substrate in the vacuum container. And the first ultra-high frequency power source and the
It has a second high frequency power supply independent of the high frequency power supply,
High frequency power is supplied to the electrodes to discharge the discharge gas.
And a power supply system for generating plasma.
The surface of the substrate placed in the vacuum vessel is processed using plasma.
The electrode has a rectangular shape, and one side of the electrode is
On the first side surface, the first super high frequency waves are arranged at equal pitch intervals.
A plurality of first power supply terminals connected to the output circuit of the power supply
Mounted one by one and facing the first side surface.
On the second side surface, which is the other side surface, at equal pitch intervals.
Of the same frequency as the output frequency of the first ultra high frequency power supply
Generates ultra high frequency power and outputs the second ultra high frequency power supply
A plurality of second power supply terminals connected to the circuit are taken one by one.
Surface treatment equipment characterized by being attached . 2. A vacuum container having an exhaust system in which a substrate is set, a discharge gas introducing system for introducing a discharge gas into the vacuum container, and a vacuum container arranged at a predetermined position in the vacuum container. The electrode and the two outputs and the phase of the high frequency power of the two outputs
It has a high-frequency power source that changes the difference in a sawtooth shape over time.
High frequency power is supplied to the electrodes to discharge the discharge gas.
And a power supply system for generating plasma.
A surface treatment apparatus for treating a surface of a substrate using plasma , wherein the electrode has a rectangular shape, and one side surface of the electrode is disposed.
One first side surface and the other side facing the first side surface
On the second side, which is a surface, at equal pitch intervals, respectively,
Multiple power supply points connected to the output circuit of the wave power source
A surface treatment device characterized in that they are attached to each other. 3. An electrode power supply unit by the power supply system.
Characterized by using a coaxial cable for power supply to the place
The surface treatment apparatus according to any one of claims 1 and 2 . 4. The high frequency power has a frequency of 10 MHz.
To 300MHz from HF band to VHF band
The surface treatment device according to claim 1, wherein: 5. The high frequency power is generated by the power supply system.
At least one high-frequency power supply to
The power is divided into a number equivalent to the number of power supply points.
From at least one power distributor and the high frequency power supply
At least one power divider is used for high frequency power transmission.
At least one matching device arranged via a shaft cable
And the high frequency power branched by the power distributor
Such as multiple stranded coaxial cables leading to each of the supply points
The surface treatment apparatus according to claim 1, wherein the surface treatment apparatus is configured by: 6. An amorphous Si-based thin film on the substrate surface,
Either microcrystalline Si-based thin film or polycrystalline Si-based thin film
A film is formed from the above.
Placing the surface treatment apparatus. 7. The electrode has a rectangular shape, and a plasma
The substrate to be processed by using is for solar cells or liquid
Substrates for crystal displays or large scale integrated circuits
The surface treatment apparatus according to claim 1, wherein the surface treatment apparatus is a surface treatment apparatus. 8. An exhaust system provided with a substrate set therein.
The vacuum container and a discharge gas for introducing the discharge gas into the vacuum container.
It is installed at a predetermined position in the vacuum container with the electric gas introduction system.
Electrode and independent of each other to generate high frequency power
Both have two first and second high frequency power supplies,
High frequency power is supplied to the electrodes to discharge the discharge gas and
A surface treatment device equipped with a power supply system for generating a Zuma
To process the surface of the substrate using the generated plasma
In the surface treatment method, the shape of the electrode is square and one side surface of the electrode is
A plurality of first power supply terminals on the first side surface at equal pitch intervals
Attached on the other side surface opposite to the first side surface.
The second plurality of power supply terminals are equidistantly spaced on the second side surface.
Attached with the output circuit of the first ultra high frequency power supply and the
Connect the first power supply ends one by one with a coaxial cable
And the output circuit of the second ultra high frequency power supply and
Connect multiple power supply terminals of 2 one by one with a coaxial cable
A surface treatment method characterized by the above. 9. An exhaust system provided with a substrate set therein.
The vacuum container and a discharge gas for introducing the discharge gas into the vacuum container.
And conductive gas introduction system is arranged in a predetermined position in the vacuum chamber
Of the two electrodes and the phase of the high frequency power of the two outputs
It has a high-frequency power source that changes the difference in a sawtooth shape over time.
High-frequency power is supplied to the electrodes to discharge the discharge gas.
Surface treatment with an electric power supply system for generating plasma
The surface of the substrate using the generated plasma using the device
Is a surface treatment method of treating the surface of the electrode with a square shape and one side surface of the electrode.
The first plurality of power supplies at equal pitch intervals on the first side surface
Attach the end and on the other side opposite the first side
A second plurality of power supplies at even pitch intervals on a second side surface
The end is attached, and the first output circuit of the ultra high frequency power source and
The second output circuit is connected to each of the first and second plurality of power sources.
A surface treatment method, characterized in that each of the power supply ends is connected by a coaxial cable . 10. The high frequency power source is 10 MHz to
Ultra high frequency power generator that oscillates 300MHz and supplies the required power
Source, at least one matcher and multiple coaxial cables
10MHz to 300M of the super high frequency power source
The output power of Hz is supplied to the power supply location.
The surface treatment method according to any one of claims 8 and 9, wherein: 11. A discharge gas, at least monosila.
Amorphous Si thin film, microcrystalline Si
To make either thin film or polycrystalline Si thin film
The surface treatment method according to claim 8, wherein the surface treatment method is performed. 12. An area of 50 cm × 50 cm as a substrate
Using a large-area substrate that exceeds 80 ℃
Characterized by surface treatment at temperatures up to 350 ° C
The surface treatment method according to any one of claims 8 to 11 . 13. An exhaust system, in which a substrate is set,
Introduce a discharge gas into the vacuum container equipped with it
Placed in a predetermined position in the vacuum container with the discharge gas introduction system.
Electrodes and the phase of high-frequency power with two outputs and two outputs
It has a high frequency power supply that changes the difference of
High frequency power is supplied to the electrodes to discharge the discharge gas.
Surface treatment with an electric power supply system for generating plasma
The surface of the substrate using the generated plasma using the device
Is a surface treatment method, in which the shape of the electrode is square, and the four side surfaces of the electrode are covered.
A first side surface, which is one side surface, and faces the first side surface
Power supply connected to the power supply system on the second side
A plurality of locations are installed in each of the first side and the second side.
Each of the high-frequency power supplies is installed at the power supply location installed on the side.
Connect the first and second outputs so that the phases are
It is specially designed to supply two powers that change
Surface treatment method for the butterflies.