JP2001335941A - Gas injection device, and vacuum treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique of improving the reproducibility of the film thickness of a deposited SiO2 film in a plasma-enhanced CVD method. SOLUTION: This film deposition system 1 has a mixing tank 30 for mixing gaseous TEOS(tetraethyl orthosilicate) with gaseous O2 and a shower plate 60 for introducing the gaseous mixture mixed in the mixing tank 30 into a vacuum chamber 2, and an end connection 61 of a gas flow passage 42 of the mixing tank 30 is directly connected to a through hole 50 of an electrode 3. Because, owing to this constitution, practically no pressure loss is brought about between the gas passage 42 of the mixing tank 30 and the through hole 50 of the shower plate 60, for inner pressure of the mixing tank 30 is not increased for pressure loss and the pressure difference between both ends of a mass-flow controller 22 for regulating the flow rate of the gaseous TEOS can be sufficiently secured and the gaseous TEOS can be allowed to flow in a state of stabilized flow rate. Accordingly, the reproducibility of the thickness of the resultant deposited SiO2 thin film can be increased as compared with that of the conventional one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas ejecting apparatus and a vacuum processing apparatus, and more particularly to a plasma CVD method for forming an insulating film on a glass substrate in a process of manufacturing a liquid crystal display device.
The present invention relates to an apparatus and a gas ejection apparatus used in the plasma CVD apparatus.

[0002]

2. Description of the Related Art In recent years, in the technical field of liquid crystal display panels,
In order to improve display speed and display quality, an active matrix driving method using a thin film transistor is often used. In this method, a large number of thin film transistors are formed on a glass substrate.
It is necessary to form a SiO ₂ insulating film having good film quality.

A TEOS (tetraethoxysilane) / O ₂ plasma CVD method has been used as a method of forming an SiO ₂ film having good film quality at a low temperature on a large-area glass substrate. Reference numeral 101 in FIG. 3 denotes a TEOS / O ₂ plasma C
1 shows a film forming apparatus that performs a VD method. This film forming apparatus 101
Has a vacuum chamber 102. The vacuum chamber 102 is connected to a vacuum exhaust system 108, and is configured so that the inside thereof can be evacuated.

[0004] On the ceiling side inside the vacuum chamber 102, a gas ejection device 190 is provided. This gas ejection device 190
Is a shower plate 160 arranged inside the vacuum chamber 102 and a pipe 1 provided outside the vacuum chamber 102.
45 and a mixing tank 130.

The shower plate 160 has an electrode 104 formed in a container shape and a plate 105 arranged so as to cover the electrode 103, and between the plate 105 and the electrode 104. , A gas storage chamber 124 is formed. The electrode 104 is provided with a gas inlet 150 communicating with the gas storage chamber 124, and is connected to one end of a pipe 145.

The other end of the pipe 145 is connected to the mixing tank 1
It is connected to a discharge port 140 provided in 30. The mixing tank 130 has two gas introduction pipes 131 and 132
The gas introduction pipes 131 and 132 are connected to a gas supply source 121 and a gas cylinder 126 via mass flow controllers 122 and 127, respectively.

The gas supply source 121 is configured to be able to discharge TEOS gas.
6 is filled with O ₂ gas, and is supplied with a gas supply source 121.
And the TEOS gas and the O ₂ gas in the gas cylinder 126,
After the flow rate is adjusted by the mass flow controllers 122 and 127, the gas is introduced into the gas introduction pipes 131 and 132, respectively.
After being introduced into the mixing tank 130 and mixed, the gas is introduced from the outlet 140 into the pipe 145, and from the gas inlet 150 into the gas storage chamber 124.

The plate 105 is provided with a number of holes 106, and a mixed gas is supplied from a gas inlet 150 into the gas storage chamber 12.
4, the gas can be ejected from the holes 106 into the vacuum chamber 102.

A plate 105 is provided on the inner bottom surface side of the vacuum chamber 102.
And the lower electrode 103 is arranged in parallel with
The gas ejected from the hole 106 is blown toward the lower electrode 103.

The lower electrode 103 is grounded, and the electrode 104 is connected to a high-frequency power supply 109 provided outside the vacuum chamber 102. When high-frequency power is supplied from the high-frequency power supply 109, the lower electrode 103 is placed between the lower electrode 103 and the electrode 104. It is configured to generate a discharge and generate a plasma.

Using the above-described film forming apparatus 101, TEOS
/ O ₂ plasma CVD method, SiO _{2 on} the surface of the glass substrate
In order to form a film, first, the inside of the vacuum chamber 102 is evacuated to a predetermined degree of vacuum by a vacuum exhaust system 108, and an unprocessed substrate heated to a predetermined temperature in advance with the degree of vacuum maintained. The lower electrode 103 is carried into the vacuum chamber 102.
Place on top.

Next, the gas supply source 121 and the gas cylinder 1
After adjusting the flow rates of the TEOS gas and the O ₂ gas in the MFC 26 by the mass flow controllers 122 and 127, respectively, the mixing tank 13 is set through the respective gas introduction pipes 131 and 132.
When the gas is introduced into the chamber 0, the TEOS gas and the O ₂ gas are mixed in the mixing tank 130, and are introduced from the outlet 140 into the pipe 145. This mixed gas is supplied to gas inlet 1
From 50, the gas is introduced into the gas storage chamber 124, and is sprayed from the hole 106 onto the surface of the substrate 110 placed on the lower electrode 103.

In this state, the electrode 1 is
When high-frequency power is supplied to the electrode 104 to generate a discharge between the electrodes 103 and 104 and generate plasma, the raw material gas is decomposed by the plasma and vapor-phase grows on the surface of the substrate 110, and SiO ₂ is deposited on the surface of the substrate 110. A film is formed.

When a SiO ₂ film having a predetermined thickness is formed on the surface of the substrate 110, the introduction of the source gas and the generation of plasma are stopped, and the substrate 110 is carried out of the vacuum chamber 102. Through the above steps, an SiO ₂ film can be formed on the surface of the substrate 110.

In the above-described film forming apparatus 101, the film quality is good.
Only a TEOS gas is introduced into the mixing tank 130 for forming the SiO ₂ film, and a mixed gas of a TEOS gas and a carrier gas is not used as is generally used.

For this reason, the pressure difference between both ends of the mass flow controller 122 for controlling the flow rate of the TEOS gas, that is, the pressure on the gas supply source 121 side and the mixing tank 130
The pressure difference from the pressure on the side is a predetermined amount (1.33 × 10 ³ Pa (1
0 Torr)) or less, the mass flow controller 122
In addition, the TEOS gas cannot be flowed at a stable flow rate.

Conventionally, the piping 145 connecting the mixing tank 130 and the shower plate 160 is relatively long, and a pressure loss occurs at both ends of the piping 145, so that the pressure in the mixing tank 130 increases by that much. Was.

For this reason, a sufficient pressure difference between both ends of the mass flow controller 122 cannot be ensured, and it becomes impossible to supply the TEOS gas into the gas storage chamber 124 with a stable flow rate. In particular, when the flow rate of the O ₂ gas is relatively large, the TEOS gas does not flow at all. As a result, there have been problems in that the thickness of the formed thin film is not uniform and the reproducibility of the film thickness is low.

[0019]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages of the prior art, and an object of the present invention is to improve the reproducibility of the film thickness when an insulating film is formed on a substrate. It is to provide a technology that will be higher.

[0020]

According to a first aspect of the present invention, there is provided a shower plate container body, wherein a gas storage chamber is provided inside the shower plate container body. A container body, a shower plate in which a hole communicating with the gas storage chamber is formed, and a mixing container body, a mixing chamber is provided inside the mixing container body, and one end is connected to the mixing chamber; A gas flow path having an end provided as an opening provided in the mixing container main body has a mixing tank provided inside the mixing container main body, and the shower plate container main body communicates with the gas storage chamber; A through-hole connected to the opening of the main body is provided, and the gas mixed in the mixing chamber passes through the gas passage from the through-hole to the gas. A gas ejection device configured to be blown out from the hole after being introduced into the storage chamber,
The through hole and the opening of the gas flow path are directly connected. The invention according to claim 2 is the gas ejection device according to claim 1, wherein the length of the gas flow path is 300.
mm or less. The invention according to claim 3 is a vacuum processing apparatus, comprising a vacuum chamber capable of evacuating, wherein the hole in the shower plate faces the inside of the vacuum chamber. A gas ejection device according to claim 2 is provided, and the gas mixed in the mixing chamber is blown out from the hole into the vacuum chamber. The invention according to claim 4 is the vacuum processing apparatus according to claim 3, wherein a mass flow controller is provided outside the mixing tank, and the raw material gas is supplied into the mixing chamber via the mass flow controller. Is configured to be able to be introduced. The invention according to claim 5 is the vacuum processing apparatus according to any one of claims 3 or 4, wherein a voltage can be applied to the shower plate, and a voltage is applied to the shower plate. Discharge occurs, plasma is generated between the substrate disposed in the vacuum chamber and the shower plate by the discharge, and a gas blown out from the hole is decomposed by the plasma to form a thin film on the substrate surface. It is characterized in that it is configured to form a film.

According to the gas ejection device of the present invention, the gas flow path of the mixing tank is directly connected to the through-hole of the shower plate, and there is no piping that conventionally connects the mixing tank and the shower plate. There is almost no pressure loss between the flow path and the through hole of the shower plate.

For this reason, since there is no problem that the internal pressure of the mixing tank rises by the amount of the pressure loss, the TEOS gas and the O ₂ gas are supplied through the mass flow controller to each of the introduction side gas flow paths of the mixing tank. Is connected to the mixing tank and T
A sufficient pressure difference between both ends of the mass flow controller for adjusting the flow rate of the EOS gas can be secured.

Accordingly, the TEOS gas flows through the mass flow controller in a stable state and is supplied to the gas storage chamber, so that the state of the mixed gas of the TEOS gas and the O ₂ gas in the gas storage chamber is higher than in the conventional case. The mixed gas can be ejected in a uniform and uniform state.

Further, according to the vacuum processing apparatus of the present invention, since the gas jetting apparatus of the present invention is provided on one wall surface of the vacuum tank, for example, a mixed gas of TEOS gas and O ₂ gas is supplied in the vacuum tank. When a thin film is formed on a substrate surface by a plasma CVD method using as a source gas, a mixed gas state of TEOS gas and O ₂ gas in a gas storage chamber becomes more uniform than before. Thus, the thickness of the formed thin film becomes more uniform than before, and the reproducibility of the thickness becomes higher than before.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 in FIG. 1 is an example of the vacuum processing apparatus of the present invention, which is a TEOS / O ₂ plasma C.
1 shows a film forming apparatus that performs a VD method.

This film forming apparatus 1 has a vacuum chamber 2. The vacuum chamber 2 is provided with an exhaust port 8 connected to a vacuum exhaust system (not shown), so that the inside can be evacuated.

On the ceiling side inside the vacuum chamber 2, a gas ejection device 90 is provided. The gas ejection device 90 has a shower plate 60 and a mixing tank 30 provided outside the vacuum chamber 2.

A plan view of the mixing tank 30 is shown in FIG.
FIG. 2B is a cross-sectional view taken along the line XX of FIG.
The mixing tank 30 has a mixing vessel main body 85, and one mixing chamber 80, a plurality of introduction-side gas flow paths 51, 52, and gas flow paths 42, 43 inside the mixing vessel main body 85. Are provided. Here, two gas flow paths 51 and 52 and two gas flow paths 42 and 43 are provided.

One end of each of the introduction-side gas flow paths 51 and 52 and each of the gas flow paths 42 and 43 has connection ports 33 and 34 and connection ports 40 and 41 provided on the outer wall surface of the mixing vessel body 85. And the other ends are openings 63 and 6
4, openings 61 and 62, both connecting the inside of the mixing chamber 80 and the outside of the mixing container body 85.

The connection ports 40 and 41 on the gas flow paths 42 and 43 are directly connected to through holes 50 of a shower plate 60 described later. The shower plate 60 is formed in a container shape having an opening, the electrode 3 attached to the ceiling side wall surface of the vacuum tank 2 so that the opening faces vertically downward, and the vacuum tank 2 so as to cover the opening of the electrode 3. And a plate 5 disposed on the inner side of the electrode 5, and a gas storage chamber 24 is formed between the plate 5 and the electrode 3. A plurality of holes 6 are provided in the plate 5, and the inside of the gas storage chamber 24 communicates with the inside of the vacuum chamber 2 through these holes 6.

The electrode 3 constitutes an example of the shower plate container main body of the present invention, and a through hole 50 is provided at an upper portion thereof to communicate with the gas storage chamber 24. , 43 connection ports 40, 4
It is directly connected to 1. Therefore, the opening 6 of the mixing chamber 80
The distance between 1 and 62 and the through hole 50 is equal to the length of the gas flow paths 42 and 43. Here, the length of the gas flow paths 42 and 43 is set to 80 mm. On the other hand, the introduction side gas flow paths 51, 5
The connection ports 33 and 34 on the second side are connected to a gas introduction pipe 31 described later,
32 is connected to one end.

Gas introduction pipes 31 and 3 are provided outside the vacuum chamber 2.
2. Mass flow controllers 22, 27, piping 36, 3
7, a gas supply source 21 and a gas cylinder 26 are provided, and the introduction-side gas flow paths 51 and 52 of the mixing tank 30 are provided.
The connection ports 33, 34 on the side are connected to one ends of gas introduction pipes 31, 32, and the other ends of the gas introduction pipes 31, 32 are connected to one ends of mass flow controllers 22, 27, respectively. The other ends of the mass flow controllers 22 and 27 are connected to one ends of pipes 36 and 37, respectively.
The other ends of 6 and 37 are connected to the gas supply source 21 and the gas cylinder 26, respectively. The gas supply source 21 vaporizes the liquid TEOS inside, and then vaporizes the TEOS.
It is configured such that only gas can be supplied to the outside. On the other hand, the gas cylinder 26 is filled with O ₂ gas.

A lower electrode 3 is arranged on the inner bottom surface side of the vacuum chamber 2 so as to be parallel to the plate 5. The lower electrode 3 is grounded, and the electrode 4 is connected to a high-frequency power supply 9 provided outside the vacuum chamber 2. When high-frequency power is supplied from the high-frequency power supply 9, discharge occurs between the lower electrode 3 and the electrode 4. And generate plasma.

Using the film forming apparatus 1 described above, TEOS / O
_{By two-} system plasma CVD method, SiO 2
_{In order} to form the _two films, first, the inside of the vacuum chamber 2 is evacuated to a predetermined degree of vacuum by a vacuum evacuation system 8, and while maintaining the predetermined degree of vacuum, an unprocessed pre-heated temperature is raised to a predetermined temperature. The substrate 10 is carried into the vacuum chamber 2 and placed on the lower electrode 3.

Valves (not shown) are provided on the pipes 36 and 37 connected to the gas supply source 21 and the gas cylinder 26, respectively, and the valves are set in a state where the substrate 10 is mounted on the lower electrode 3. When opened, the TEOS gas and O ₂ gas in the gas supply source 21 and the gas cylinder 26 are
6 and 37, and the mass flow controllers 22 and 27
While the respective flow rates are adjusted in each gas introduction pipe 31,
32.

The TE supplied to each of the gas introduction pipes 31 and 32
The OS gas and the O ₂ gas are introduced into the mixing chamber 80 from the connection ports 33 and 34 on the introduction gas flow paths 51 and 52 of the mixing tank 30 via the introduction gas flow paths 51 and 52. .

The TEOS gas and the O ₂ gas are mixed in the mixing chamber 80, and the mixed gas is supplied from the openings 61 and 62 to the gas channels 42 and 43, and then supplied to the gas channels 42 and 43.
It is introduced into the through hole 50 via the connection ports 40 and 41 on the third side.

At this time, the through hole 50, the gas flow path 42,
Since the connection ports 40 and 41 on the 43 side are directly connected, the mixed gas has almost no pressure loss during this time.
The gas is introduced from the through hole 50 into the gas storage chamber 24.

The mixed gas of the TEOS gas and the O ₂ gas introduced into the gas storage chamber 24 is jetted out of the hole 6 provided in the plate 5 into the vacuum chamber 2 and is disposed vertically below the plate 5. Is sprayed onto the surface of the substrate 10 placed on the lower electrode 3.

In this state, high-frequency power is supplied from the high-frequency power supply 9 to the electrode 4 while heating the substrate 10 to maintain a predetermined temperature to cause a discharge between the electrodes 3 and 4 to generate plasma. The raw material gas is decomposed by the plasma, and is vapor-phase grown on the surface of the substrate 10 to form an SiO ₂ film on the surface of the substrate 10. This SiO ₂ film has a good film quality because the TEOS gas and the carrier gas are not mixed.

In the film forming apparatus 1 of this embodiment, since the connection ports 40 and 41 on the gas flow paths 42 and 43 and the through-hole 50 of the electrode 4 are directly connected as described above, There is almost no pressure loss between the gas passage 42 and the through hole 50 of the shower plate 60.

Therefore, the internal pressure of the mixing chamber 80 of the mixing tank 30 does not increase by the amount of the pressure loss, so that the pressure difference between both ends of the mass flow controller 22 for adjusting the flow rate of the TEOS gas is set to a sufficiently high level. can do.

Accordingly, the TEOS gas is supplied from the mass flow controller 22 to the gas storage chamber 24 in a state where the flow rate is stable.
Is supplied to the gas storage chamber 24, the state of the mixed gas of the TEOS gas and the O ₂ gas in the gas storage chamber 24 becomes more stable than before, and as a result, the thickness of the formed SiO ₂ film becomes As a result, the film thickness becomes more uniform, and the reproducibility of the film thickness becomes higher than before.

In this embodiment, as the source gas,
Although a mixed gas of TEOS gas and O ₂ gas was used, the present invention is not limited to this, and a TRIES (triethoxysilane) gas may be used instead of TEOS gas, and nitrous oxide may be used instead of O ₂ gas. Gas may be used.

In this embodiment, the gas flow paths 42, 4
Although the length of 3 is set to about 80 mm, the present invention is not limited to this, and may be, for example, in a range of 300 mm or less. Furthermore, in the present embodiment, two introduction-side gas flow paths 51 and 52 and two gas flow paths 42 and 43 are provided, but the present invention is not limited to this, and a plurality of introduction-side gas flow paths are provided. For example, three or more may be provided. On the other hand, only one gas flow path may be provided, or three or more gas flow paths may be provided.

In this embodiment, the film forming apparatus using the TEOS / O ₂ plasma CVD method is described. However, the present invention is not limited to this, and two or more kinds of raw material gases are mixed in the mixing tank 30. After that, it is also possible to carry out a plasma CVD method in which the gas is ejected from the shower plate 60 into the vacuum chamber 2.

Further, in this embodiment, the electrode 4 to which a high-frequency voltage can be applied is used as the shower plate container main body. However, the present invention is not limited to this, and a configuration in which no voltage is applied to the shower plate container main body. It may be. In this embodiment, a plasma CVD apparatus is described as a vacuum processing apparatus, but the vacuum processing apparatus of the present invention is not limited to this.

[0048]

As described above, the variation in the thickness of the thin film is reduced, and the reproducibility of the thickness is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a vacuum processing apparatus according to an embodiment of the present invention.

2A is a plan view illustrating a mixing tank according to an embodiment of the present invention, and FIG. 2B is a cross-sectional view illustrating a mixing tank according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a conventional vacuum processing apparatus.

[Explanation of symbols]

1. Film forming apparatus (vacuum processing apparatus) 2. Vacuum tank 3
…… Electrode (shower plate container body) 6… Hole 2
2, 27: mass flow controller 24: gas storage chamber 42, 43: gas flow path 50: through hole
60 Shower plate 80 Mixing room 8
5: Mixing container body 90: Gas injection device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eisuke Hori 2500 Hagizono, Chigasaki-shi, Kanagawa Japan Nippon Vacuum Engineering Co., Ltd. (72) Inventor Kuniaki Kurokawa 2500 Hagizono, Chigasaki-shi, Kanagawa Nippon Vacuum Engineering Co., Ltd. (72) Katsuhiko Mori 2500 Hagizono, Chigasaki, Kanagawa Prefecture Japan Vacuum Technology Co., Ltd. (72) Inventor Masashi Kikuchi 2500 Hagizono, Chigasaki City, Kanagawa Prefecture Nippon Vacuum Technology Co., Ltd. (72) Inventor Michio Ishikawa 523 Yokota, Yamatake-cho, Yamatake-gun, Chiba F-term (reference) 2H088 EA02 FA20 FA30 HA04 MA20 2H090 HB03X HC03 HC18 4K030 AA06 AA09 AA14 BA44 EA04 FA03 JA01 JA05 KA17 KA41

Claims (5)

[Claims] 1. A shower plate container main body, wherein a gas storage chamber is provided inside the shower plate container main body,
A shower plate in which a hole communicating with the gas storage chamber is formed in the shower plate container main body; and a mixing container main body, a mixing chamber is provided inside the mixing container main body, and one end is connected to the mixing chamber. The other end has a gas flow path serving as an opening provided in the mixing container body has a mixing tank provided inside the mixing container body, the shower plate container body communicates with the gas storage chamber, A through-hole connected to the opening of the mixing container main body is provided, and after the gas mixed in the mixing chamber is introduced into the gas storage chamber from the through-hole through the gas flow path, A gas ejection device configured to be ejected, wherein the through hole is directly connected to an opening of the gas passage. 2. The gas ejection device according to claim 1, wherein the length of the gas flow path is set to be 300 mm or less. 3. A gas discharge device according to claim 1, further comprising a vacuum tank capable of evacuating the gas, wherein the vacuum tank is provided with a gas ejection device according to claim 1 such that a hole of the shower plate faces the inside of the vacuum tank. And a gas mixed in the mixing chamber is blown out from the hole into the vacuum chamber. 4. A vacuum processing apparatus according to claim 3, wherein a mass flow controller is provided outside said mixing tank, and a raw material gas can be introduced into said mixing chamber via said mass flow controller. A vacuum processing apparatus characterized by being configured as described above. 5. The vacuum processing apparatus according to claim 3, wherein a voltage can be applied to the shower plate, and a discharge occurs when the voltage is applied to the shower plate. A plasma is generated between the substrate disposed in the vacuum chamber and the shower plate by the discharge, and a gas blown from the hole is decomposed by the plasma to form a thin film on the surface of the substrate. A vacuum processing apparatus characterized by being configured as described above.