JP2010174285A - Film forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film forming apparatus capable of forming a film on a substrate with uniform film quality and improving the efficiency of the film. <P>SOLUTION: The film forming apparatus functions in such a manner that plasma 40 is generated by disposing two electrodes 31, 32 opposing to each other in a reaction chamber 21 of a reaction vessel 2 to which a film forming gas 6 is introduced and by supplying high frequency power to the electrodes 31, 32, to decompose the film forming gas 6 and to form a thin film on the surface of a substrate 1 carried between the two electrodes 31, 32. In the apparatus, an electrode plate 31a of one electrode 31 of the two electrodes 31, 32 is provided with a gas blowing section 5 for emitting the film forming gas 6, and the electrode plate 31a is formed larger than the area of the gas blowing section 5. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a film forming apparatus, and more particularly to a reaction gas (film forming gas) exhaust structure in a chemical vapor deposition (CVD) apparatus for forming a thin film for a semiconductor device on the surface of a substrate.

Currently, film forming apparatuses are used in many technical fields to form various thin films (for example, Patent Document 1). Typical examples include thin film solar cells, photosensitive drums, TFT arrays for liquid crystal displays, and the like.
FIG. 4 is a schematic view showing an example of a capacitively coupled parallel plate plasma CVD (Chemical Vapor Deposition) apparatus. This plasma CVD apparatus includes a reaction vessel 2 in which a reaction chamber 21 that can be depressurized is formed. A high frequency power to which high frequency power is supplied from an external high frequency power source (RF power source) 3 is provided in the reaction chamber 21. An electrode (RF electrode) 31 and a ground electrode 32 are disposed at positions facing the high-frequency electrode 31.
A gas introduction path (not shown) is connected to the high-frequency electrode 31, and a film-forming gas (reaction gas) 6 that is a film-forming raw material from the gas introduction path has a number of gas outlets as shower electrodes. From the surface of the substrate toward the substrate 1 in the reaction chamber 21. The ground electrode 32 includes a heater for heating the transported substrate 1. On the other hand, an exhaust port 70 having one end connected to the excluding device 7 is provided on the side wall of the reaction vessel 2.

Next, a procedure for forming a thin film on the surface of the substrate 1 using the plasma CVD apparatus shown in FIG. 4 will be described.
First, the substrate 1 is transported into the reaction chamber 21 of the reaction vessel 2 by a transport mechanism (not shown), placed between the high-frequency electrode 31 and the ground electrode 32 in the decompressed reaction chamber 21, and the substrate 1 The substrate 1 is heated to a desired temperature by the heater.
Next, a film forming gas 6 is introduced into a discharge space between the high-frequency electrode 31 and the substrate 1 from a gas introduction path (not shown), and discharged from the electrode plate 31a on the surface side of the high-frequency electrode 31 toward the substrate 1, When a high frequency voltage is applied to the high frequency electrode 31 by the high frequency power supply 3, plasma 40 is generated in the discharge space. Along with this, the released film forming gas 6 is decomposed in the plasma 40 to be decomposed particles 51, and a film 50 and a residue (flakes) 52 a are generated on the substrate 1 and the high-frequency electrode 31, while the remaining components are formed. The membrane gas 6 is exhausted from the exhaust port 70 to the exclusion device 7.

JP 2008-266711 A

  In the conventional plasma CVD apparatus described above, as shown in FIG. 5A, the length L of the electrode plate 31a of the high-frequency electrode 31 and the generation region of the plasma 40 are substantially the same, and the film forming gas 6 is the plasma 40. As shown in FIG. 5B and FIG. 6, a film 50 as shown in FIG. 5B and FIG. 6 is formed on the substrate 1 at the end of the plasma 40 generation section. And stacked. That is, at this location, the poor-quality inlet film 50a is first formed on the substrate 1, the good-quality central film 50c is then formed on the substrate 1, and finally the poor-quality outlet film. Since the film 50b is formed on the substrate 1, it is inevitable that the film quality deteriorates. Therefore, when the film is formed while the substrate 1 is being transported, the film 50 laminated on the surface of the substrate 1 is partially deteriorated, and there is a problem that a product in which a high-quality film is uniformly formed cannot be obtained. is doing.

  The present invention has been made in view of such a situation, and an object thereof is to provide a film forming apparatus capable of uniformizing the quality of a film formed on a substrate and improving the efficiency of the film. It is in.

  In order to solve the above-described problems of the prior art, the present invention provides two electrodes facing each other in a reaction chamber of a reaction vessel into which a reaction gas is introduced, and supplies high frequency power to the two electrodes. In the film forming apparatus for generating plasma and decomposing the reaction gas to form a thin film on the surface of the substrate transported between the two electrodes, one of the two electrodes The plate is provided with a gas blowing portion for discharging the reaction gas, and the electrode plate is formed wider than the region of the gas blowing portion.

In the present invention, the following configuration is preferable.
(1) A gas exhaust passage for exhausting the reaction gas remaining without being formed on the substrate from the plasma generation unit is provided at an end of the electrode plate.
(2) An insulating member that shields the plasma at the end of the substrate and between the electrode plate and the substrate is installed at the end of the electrode plate.
(3) The film formation on the substrate is performed while the substrate is transported.

As described above, the film formation apparatus according to the present invention generates plasma by arranging two electrodes facing each other in a reaction chamber of a reaction vessel into which a reaction gas is introduced, and supplying high frequency power to the two electrodes. The reaction gas is decomposed to form a thin film on the surface of the substrate conveyed between the two electrodes, and the electrode plate of one of the two electrodes In addition, a gas blowing part that discharges the reaction gas is provided, and the electrode plate is formed wider than a region of the gas blowing part, thus preventing film formation on the substrate at the end of the plasma generation part, The film quality can be improved.
In addition, an insulating member of a mask plate that shields the plasma at the end portion of the substrate and between the electrode plate and the substrate is installed at the end portion of the electrode plate. Film formation on the substrate at the end of the portion can be prevented, and the film quality can be further improved.
As a result, the film quality laminated on the substrate can be made uniform, and even when the film is deposited while the substrate is transported, the film quality laminated on the substrate can be formed without deteriorating, and the film quality can be increased. Efficiency can be improved.

  In the film forming apparatus of the present invention, a gas exhaust channel for exhausting the reaction gas remaining without being formed on the substrate from the plasma generating unit is provided at an end of the electrode plate. Therefore, the reactive gas does not flow to the end portion of the plasma generation portion, and it is possible to reliably prevent the film formation on the substrate at this location. Further, by providing the mask plate, it is possible to suppress the irradiation of the edge plasma to the substrate, and it is possible to reliably prevent the film formation on the substrate at this location.

  And in the film-forming apparatus of this invention, since the film-forming to the said board | substrate is performed while conveying the said board | substrate, a high quality thin film can be formed with the outstanding production efficiency.

It is a plasma CVD apparatus in a film forming apparatus according to an embodiment of the present invention, (a) is a schematic diagram showing the configuration, (b) is a schematic diagram showing the positional relationship between the gas outlet and exhaust outlet and the substrate, (C) is a schematic diagram showing a substrate in plasma. 1 is a plasma CVD apparatus in FIG. 1, in which (a) is a schematic view showing a part of a high-frequency electrode, and (b) is a cross-sectional view taken along line AA in (a). In the plasma CVD apparatus of FIG. 1, (a) is a schematic view for explaining the operation of a film forming gas, and (b) is a schematic view showing a film quality. It is a schematic diagram which shows the structure of the conventional plasma CVD apparatus. In the conventional plasma CVD apparatus, (a) is a schematic diagram for explaining the operation of a film forming gas, and (b) is a schematic diagram showing a film quality. In the conventional plasma CVD apparatus, it is a schematic diagram which shows the film quality formed into a film on the board | substrate of the edge part of a plasma production part in a cross section.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a film forming apparatus according to the present invention will be described in detail based on an embodiment thereof with reference to the drawings. In addition, the same code | symbol is attached | subjected to the site | part same as the prior art example shown in FIG. 4, and description is abbreviate | omitted.

  1 to 3 show a plasma CVD apparatus in a film forming apparatus according to an embodiment of the present invention. FIG. 1 (a) is a schematic diagram of the structure, and FIG. 1 (b) is a gas outlet and an exhaust outlet. FIG. 1C is a schematic diagram of a substrate in plasma, FIG. 2A is a partial schematic diagram of a high-frequency electrode, and FIG. 1B is a cross-sectional view taken along line AA in FIG. FIG. 3 and FIG. 3 are schematic diagrams for explaining the operation of the film forming gas.

The plasma CVD apparatus according to the embodiment of the present invention shown in FIGS. 1 to 3 is configured to form a thin film on the surface of the substrate 1 by the plasma CVD method while transporting the substrate 1 by a roll-to-roll method, for example. ing.
In FIG. 1, in the reaction chamber 21 of the reaction vessel 2 in the plasma CVD apparatus according to the embodiment of the present invention, a number of film forming gases for releasing the film forming gas (reactive gas) 6 to the electrode plate 31a on the surface side. A high-frequency electrode 31 having a blowout port (gas blowout part) 5 is disposed. As shown in FIGS. 1B and 3, the electrode plate 31 a of the high-frequency electrode 31 is longer and wider than the length L of the region of the gas blowing portion provided with the film forming gas blowing port 5. .

  A film forming gas introducing portion 31 b for introducing the film forming gas 6 is provided on the back side of the high frequency electrode 31. The film forming gas introducing portion 31b is connected to the fixing member 31c via the insulating / magnetic sealing material 9. In addition, the film forming gas introduction part 31 b communicates with the reaction chamber 21 through the film forming gas outlet 5. The base end of the film forming gas introduction part 31b is connected to a film forming gas supply source (not shown).

Further, in the electrode plate 31a of the high-frequency electrode 31 according to the present embodiment, the substrate 1 is disposed at both side ends in the transport direction of the substrate 1 as shown in FIGS. 1 (a), 1 (b) and 2 (a). A plurality of exhaust ports 70 are provided for directly exhausting the film forming gas 6 remaining without being formed from the generation unit of the plasma 40, and the exhaust port 70 includes an exhaust duct 8 constituting a gas exhaust passage. One end of each is connected. These exhaust ducts 8 linearly extend from the back side of the high-frequency electrode 31 toward the outside of the reaction vessel 2, and the other end is connected to the exclusion device 7. Therefore, the exhaust port 70 and the exhaust duct 8 are straight pipe gas exhaust passages arranged in a direction perpendicular to the plasma 40 generating portion.
As a result, the gas blowing portion provided with the film forming gas blowing port 5, the exhaust port 70 and the exhaust duct 8 are arranged in the region of the plasma 40 generating portion.

  Further, as shown in FIGS. 1A and 2B, the exhaust duct 8 is provided with an exhaust pipe heater (heating means) 11 that covers the entire periphery of the exhaust duct 8. As a result, the entire circumference of the exhaust duct 8 is heated. Moreover, the exhaust duct 8 is formed on a funnel-shaped inclined surface having an opening with an enlarged end portion profile on the exhaust port 70 side, and is configured to easily collect residues in the plasma 40. The exhaust duct 8 is attached to the wall portion of the reaction vessel 2 through an airtight seal 12.

Next, the operation of the plasma CVD apparatus according to the embodiment of the present invention will be described with reference to FIGS.
The substrate 1 is transported into the reaction chamber 21 of the reaction vessel 2 by a transport mechanism (not shown), and is disposed between the high-frequency electrode 31 and the ground electrode 32, and the substrate 1 is heated by the heater in the ground electrode 32. Then, the film forming gas 6 is introduced into the film forming gas introducing portion 31b of the high frequency electrode 31, and is discharged by being blown out toward the substrate 1 from the film forming gas outlet 5 of the electrode plate 31a. When a high frequency voltage is applied to 31, plasma 40 is generated in the discharge space between the high frequency electrode 31 and the substrate 1. Along with this, the released film forming gas 6 is decomposed (ionized) in the plasma 40 to become decomposed particles 51, which adhere to the substrate 1 and form a film 50.

On the other hand, radicals and ions are present in the deposition gas 6 that remains without being deposited on the substrate 1. In this state, the remaining film-forming gas 6 hardly adheres to the inner wall surface of the reaction chamber 21 or the like, but when it comes out of the generation part of the plasma 40, the fine particles are polymerized to form a powdery residue 52b.
Therefore, in the embodiment of the present invention, the film forming gas 6 that remains without being formed on the substrate 1 is guided directly from the generation part of the plasma 40 to the exhaust port 70 and the exhaust duct 8, and ends of the generation part of the plasma 40. The exhaust device 70 is exhausted through the exhaust port 70 and the exhaust duct 8.
As a second example, the plasma 40 is shielded by installing an insulating member 41 at the end of the electrode plate 31a.
Therefore, as shown in FIG. 3B, the entrance film and the exit film as in the prior art are not formed at the location of the substrate 1 corresponding to the end of the plasma 40 generation unit. Only the central film is formed on the entire surface of the film 1, and the film quality is made uniform.

  As described above, in the plasma CVD apparatus according to the embodiment of the present invention, the electrode plate 31a of the high-frequency electrode 31 is formed longer than the length L of the region of the gas blowing portion where the film forming gas blowout port 5 is provided. An exhaust port 70 and an exhaust duct 8 are provided at the end of the plate 31a, and the film forming gas 6 that remains without being formed on the substrate 1 during film formation is directly discharged from the generation part of the plasma 40 into the exhaust port 70 and the exhaust duct 8. In this case, since the gas is exhausted directly to the excluding device 7 without flowing to the end of the plasma 40 generation section, it is possible to prevent the film from being formed on the substrate 1 corresponding to the end of the plasma 40 generation section. Deterioration of film quality can be prevented. Moreover, since the exhaust duct 8 of this embodiment can heat the whole periphery with the exhaust pipe heater 11 and can make wall surface temperature higher than the temperature of the film-forming gas 6, the powder-like residue 52b is made into a wall surface. It can also be made difficult to adhere. Furthermore, even when the film is formed while the substrate 1 is being transported, it is possible to prevent deterioration of the laminated film and to laminate a uniform film quality.

  While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

  For example, in the above-described embodiment, the electrode plate 31a of the high-frequency electrode 31 is formed to have a large length L in the transport direction of the substrate 1 in the region of the gas blowing portion provided with the film forming gas blowing port 5. However, it is possible to increase the length in the width direction orthogonal to the transport direction of the substrate 1.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Reaction container 3 High frequency power supply 5 Deposition gas outlet (gas outlet)
6 Deposition gas (reaction gas)
7 Exclusion device 8 Exhaust duct (gas exhaust passage)
21 Reaction chamber 31 High frequency electrode 31a Electrode plate 31b Film forming gas introduction part 32 Ground electrode 40 Plasma 41 Insulating member 50 Film 51 Decomposed particles 52a, 52b Residue 70 Exhaust port

Claims (4)

Two electrodes are arranged facing each other in a reaction chamber of a reaction vessel into which a reaction gas is introduced, plasma is generated by supplying high frequency power to the two electrodes, and the reaction gas is decomposed to generate the two electrodes. In a film forming apparatus configured to form a thin film on the surface of a substrate conveyed during
Of the two electrodes, the electrode plate of one of the electrodes is provided with a gas blowing portion for discharging the reaction gas, and the electrode plate is formed wider than the region of the gas blowing portion. A film forming apparatus.   2. The gas exhaust flow path for exhausting the reaction gas remaining without being formed on the substrate from the plasma generation unit is provided at an end of the electrode plate. Film forming equipment.   The insulating member which shields the said plasma in the edge part of the said board between the said electrode board and the said board | substrate and the said board | substrate is installed in the edge part of the said electrode plate. Film forming equipment.   The film forming apparatus according to claim 1, wherein the film formation on the substrate is performed while the substrate is transported.

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