JP2000345349A - CVD equipment - Google Patents

Abstract

(57) [Problem] To form a silicon oxide film or the like on a large-area substrate by CVD using silane or the like, suppress generation of particles and prevent ions from entering the substrate. SOLUTION: This is a CVD apparatus that generates plasma in a vacuum vessel 12 to generate radicals, and performs a film forming process on a substrate using the radicals and silane. A partition 14 is provided in the vacuum vessel to isolate the interior into two chambers, a plasma generation space 15 and a film formation processing space 16. A plurality of through holes 25 and diffusion holes 26 are formed in the partition. Silane or the like is supplied to the internal space 24, and the silane or the like is introduced into the film formation processing space through the diffusion holes. Radicals generated in the plasma generation space are introduced into the film formation processing space through the through holes. When the gas flow velocity in the hole is u, the length of the substantial hole is L, and the mutual gas diffusion coefficient is D, uL / D>
Condition 1 is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a CVD apparatus,
In particular, CV suitable for film formation on large flat panel substrates
It relates to the D device.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing a large-sized liquid crystal display, a method using a high-temperature polysilicon type TFT (thin film transistor) and a method using a low-temperature polysilicon type TFT are known. High temperature polysilicon type TF
In a manufacturing method using T, a quartz substrate that can withstand a high temperature of 1000 ° C. or higher has been used in order to obtain a high-quality oxide film. On the other hand, in the production of a low-temperature polysilicon type TFT, it is necessary to form a film in a low-temperature environment (for example, 400 ° C.) because a normal TFT glass substrate is used. The method of manufacturing a liquid crystal display using a low-temperature polysilicon type TFT has the advantage that it does not require the use of a special substrate and that the setting of film forming conditions is simple. Is expanding.

[0003] In the production of a liquid crystal display utilizing a low-temperature polysilicon type TFT, when forming a suitable silicon oxide film as a gate insulating film at a low temperature, plasma CVD is used. When a silicon oxide film is formed by plasma CVD, silane, tetraethoxysilane (TEOS), or the like is used as a typical material gas.

When a silicon oxide film is formed by plasma CVD using silane or the like as a material gas, according to a conventional plasma CVD apparatus, a material gas and oxygen are introduced into a space in front of a substrate, and the material gas and oxygen are introduced. Plasma is generated with a mixed gas of oxygen, and the substrate is exposed to the plasma to form a silicon oxide film on the surface of the substrate. As described above, in the conventional plasma CVD apparatus, the material gas is configured to be directly supplied into the plasma generated in the plasma CVD apparatus.
For this reason, according to the configuration of the conventional plasma CVD apparatus,
There has been a problem that high-energy ions are incident on the film-forming surface of the substrate from plasma existing in the space in front of the substrate, damaging the silicon oxide film and deteriorating the film characteristics. Further, since the material gas is directly introduced into the plasma, the material gas and the plasma react violently to generate particles, which causes a problem that the yield is reduced.

Therefore, in order to solve the above problem, a plasma processing apparatus using a remote plasma system has been proposed as an example. In the remote plasma method, the charged particles having a short life are separated from the plasma generation region in the plasma apparatus, and the substrate is arranged in a region where radicals having a relatively long life are predominantly present. It is configured to be supplied near the arrangement area. Radicals generated in the plasma region diffuse in the direction of the region where the substrate is arranged, and are supplied to the front space on the surface of the substrate. Such a remote plasma processing apparatus has the advantages that the intense reaction between the material gas and the plasma is suppressed, the amount of generated particles is reduced, and the incidence of ions on the substrate is also limited.

Conventionally, a plasma CV is disclosed in Japanese Patent Application Laid-Open No. Hei 6-260434 (Japanese Patent No. 2601127).
A D device has been proposed. This plasma CVD apparatus
Has a parallel plate electrode structure, arranges an intermediate electrode between the high-frequency electrode and the substrate holder electrode, partitions the space between the high-frequency electrode and the substrate holder electrode, and supplies high-frequency power only between the high-frequency electrode and the intermediate electrode As a result, a plasma discharge is generated only between the high-frequency electrode and the intermediate electrode, and excited active species and ions generated by the plasma discharge are introduced into the front space of the substrate through through holes formed in the intermediate electrode. The high-frequency electrode is a conventional showerhead type electrode, and a plasma generating gas is introduced into a plasma generating space through each hole of a diffusion plate having a large number of holes. The raw material gas is introduced into the front space of the substrate through a gas introduction pipe, a gas introduction space formed in the intermediate electrode, and a gas ejection port. In this plasma CVD apparatus, the space between the high-frequency electrode and the substrate holder electrode is partitioned by the intermediate electrode, only the space between the high-frequency electrode and the intermediate electrode is formed as a plasma generation space, and the plasma generation region is placed on the substrate. It has a configuration that is remote from the location. This plasma CVD apparatus can be said to be a modified example of a remote plasma type apparatus having a parallel plate electrode structure.

[0007] Conventionally, there is a plasma CVD apparatus disclosed in Japanese Patent Application Laid-Open No. 5-23933. This CVD
The apparatus has a configuration in which a plasma generation chamber and a substrate processing chamber are formed inside a vacuum vessel forming a parallel plate type CVD apparatus, and a mesh plate is disposed at a boundary between the plasma generation chamber and the substrate processing chamber.

Further, in the prior art, Japanese Patent Application Laid-Open No. 8-167596
There is a plasma processing apparatus disclosed in Japanese Unexamined Patent Application Publication No. H11-163,873. In this plasma processing apparatus, a plasma generation chamber and a plasma processing chamber are spatially separated from each other in a vacuum vessel by a metal mesh plate and its supporting member.
According to this plasma processing apparatus, the diameter of the plurality of openings formed in the mesh plate is set to be equal to or less than twice the Debye length of the plasma generated in the plasma generation chamber.
The charged particles in the plasma are shielded, and the object to be processed is irradiated with electrically neutral excited atomic species or the like.

[0009]

In the case of the above-described remote plasma type plasma processing apparatus, the plasma generation region and the substrate disposition region are formed apart from each other via a connection space, and radicals generated at a position away from the substrate are formed. Is supplied to the surface of the substrate by the diffusion action through the connection space, so that there is a problem that the film forming rate is reduced and the distribution of radicals near the surface of the substrate is deteriorated. In particular, there has been a problem that the distribution of radicals in the vicinity of the surface of the substrate is poor, so that the substrate cannot be used for a large-area substrate used for a large-sized liquid crystal display.

JP-A-6-260434 (Patent No. 2)
According to the plasma CVD apparatus disclosed in Japanese Patent Application Laid-Open No. 601127, no material gas is supplied to the plasma generation space between the high-frequency electrode and the intermediate electrode. No accumulation of
Further, the advantage that no generation of particles occurs is claimed. However, when examined strictly, there is no special consideration regarding the size of the through hole formed in the intermediate electrode, and there is a possibility that the material gas may diffuse back into the plasma generation space. Therefore, the material gas may enter the upper side of the intermediate electrode, and a chemical reaction may occur around the high-frequency electrode.

In the case of the plasma CVD apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 5-213393, the size of the through-holes formed in the mesh plate is determined so as not to satisfy the conditions of the present invention. There is a possibility of despreading into space, causing the same problem as described above.

[0012] The plasma processing apparatus disclosed in Japanese Patent Application Laid-Open No. 8-167596 has a structure for preventing the movement of charged particles from the plasma generation chamber to the plasma processing chamber. However, there is no disclosure of a structure that prevents a material gas introduced into a plasma processing chamber from back-diffusing into a plasma generation chamber through a plurality of openings of a mesh plate so as not to touch the plasma. Therefore, the source gas may enter the plasma generation chamber through the mesh plate, and the plasma and the source gas may react.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is intended to manufacture a large-sized liquid crystal display using a low-temperature polysilicon type TFT or the like.
When a silicon oxide film or the like is formed on a large area substrate using a material gas such as silane based on the above, the contact between the plasma and the material gas at the stage before film formation is Eliminates the generation of particles, prevents the incidence of ions on the substrate surface, improves the distribution of radicals near the film formation surface of the substrate, and can be effectively used for film formation on large-area substrates. An object of the present invention is to provide a CVD apparatus.

[0014]

The CVD apparatus according to the present invention is configured as follows to achieve the above object.

The CVD apparatus generates plasma in a vacuum vessel to generate active species (radicals), and performs a film forming process on a substrate using the active species and a material gas. The vacuum vessel is provided with a conductive partition for isolating the inside of the vacuum vessel into two chambers. Of these two chambers, the inside of one chamber is formed as a plasma generation space in which a high-frequency electrode is arranged, and the inside of the other chamber is formed as a film formation processing space in which a substrate holding mechanism for mounting a substrate is arranged. You. Further, a plurality of through-holes are formed in the partition to allow the plasma generation space and the film formation processing space to pass through. The partition further includes an internal space that is isolated from the plasma generation space and communicates with the film formation processing space through a plurality of diffusion holes. A material gas is externally supplied to the internal space, and the material gas supplied to the internal space is introduced into the film forming processing space through a plurality of diffusion holes. The active species generated in the plasma generation space
It is introduced into the film formation processing space through a plurality of through holes formed in the partition. The size (length, diameter, etc.) of the above-mentioned through hole or diffusion hole is designed to satisfy specific conditions as described below.

In the above-described CVD apparatus, the plurality of through holes formed in the partition wall have a gas flow velocity in the hole of u, a substantial hole length of L, a mutual gas diffusion coefficient (two kinds of gas diffusion coefficients on both sides of the hole). Where D is the mutual gas diffusion coefficient of the two gases, uL / D> 1
Satisfies the condition. Further, it is preferable that a plurality of diffusion holes formed in the lower wall of the partition wall are formed so as to satisfy the same conditions as described above.

The above conditions to be satisfied by the through-holes and the like formed in the partition wall portion are as follows. Through these holes, the gas in the plasma generation space becomes a mass transfer flow, and the material gas is diffused.
When it is assumed that they move to the opposite sides, the setting is made such that the amount of movement due to diffusion is limited.

In the above CVD apparatus, preferably,
The partition wall is provided with at least a two-layer diffusion structure for uniformly diffusing the material gas in its internal space.

In the above-described CVD apparatus, in the configuration in which plasma is generated using an oxygen gas and a film is deposited on the surface of the substrate using a material gas such as silane, the inner space of a vacuum vessel as a processing chamber is partitioned. In this case, the space is separated into a space for generating plasma and a film formation processing space, and a processing surface of a substrate disposed in the film formation processing space is not exposed to the plasma. In addition, since the material gas is isolated by the partition, the material gas introduced into the film formation processing space is sufficiently restricted from moving toward the plasma generation space.
Actually, since a plurality of through holes are formed in the partition wall,
The plasma generation space and the film formation processing space on both sides of the partition wall are connected through a through-hole. However, since the size of the through-hole is formed so as to satisfy the above-described conditions, the space was introduced into the film formation processing space. The material gas is prevented from back-diffusing to the plasma generation space side.

In the formation of a substrate, plasma is generated with oxygen gas in a plasma generation space, and radicals (active species of oxygen gas) generated by the plasma and silane or the like, which is a material gas, are generated.
The film is guided to a film formation processing space in which the substrate is arranged, and a film is formed on the surface of the substrate by the action of CVD. An example of the film is a silicon oxide film formed as a gate insulating film at a low temperature in the production of a liquid crystal display using a low-temperature polysilicon type TFT. By providing a partition having a plurality of through-holes and diffusion holes, the internal space of the vacuum vessel is separated into a plasma generation space and a film formation processing space, and utilizing the internal space formed in the partition and the diffusion holes. Silane and the like are introduced directly into the film formation processing space in front of the substrate, avoiding the region where plasma is generated, and radicals generated in the plasma generation space are formed through the above-described through holes formed in the partition wall. Introduced into space. Further, by setting the size of the through hole so as to satisfy the above specific condition, it is possible to prevent the material gas such as silane from diffusing to the plasma generation space side as much as possible, and to prevent the silane etc. from coming into contact with the plasma. I'm preventing. Thus, it is possible to prevent the silane or the like from being directly mixed with the plasma, and to solve the conventional problem.

In the above-described CVD apparatus, the partition is connected to a high-frequency power supply for supplying high-frequency power for cleaning, and supplies high-frequency power to the partition in a timely manner to generate a cleaning plasma in the film formation processing space. Features. In the above-described CVD apparatus, the high-frequency electrode is disposed substantially at the center of the chamber forming the plasma generation space, and the plasma is generated between the high-frequency electrode and the upper surface of the vacuum vessel and between the high-frequency electrode and the partition. It is configured. With this configuration, by using a part of the vacuum vessel and the conductive partition as an electrode, a plasma generation chamber capable of sealing the generated plasma except for the through hole of the partition can be formed. . In the above CVD apparatus, the high-frequency electrode is provided at a position above the plasma generation space,
The plasma discharge may be generated between the high frequency electrode and the partition. This is a modification of the electrode structure, and a closed plasma generation chamber can be formed by using the partition wall except for the through hole of the partition wall.

[0022]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, the CVD according to the present invention will be described.
A first embodiment of the device will be described. 1, in this CVD apparatus, silane is preferably used as a material gas, and a silicon oxide film is formed as a gate insulating film on the upper surface of a normal TFT glass substrate 11. The container 12 of the CVD apparatus is a vacuum container whose inside is maintained in a desired vacuum state by the exhaust mechanism 13 when performing a film forming process.
The exhaust mechanism 13 is an exhaust port 1 formed in the vacuum vessel 12.
2b-1.

Inside the vacuum vessel 12, there is provided a partition 14 made of a conductive member in a horizontal state. The partition 14 having a circular planar shape, for example, is an insulating member whose peripheral edge is annular. It is arranged so as to be pressed against the lower surface of 22 to form a sealed state. The inside of the vacuum vessel 12 is isolated by a partition 14 into two upper and lower chambers. The upper chamber forms a plasma generation space 15, and the lower chamber forms a film formation processing space 16. The partition part 14 has a desired specific thickness, has a flat plate shape as a whole, and has a planar shape similar to the horizontal cross-sectional shape of the vacuum vessel 12.
An internal space 24 is formed in the partition 14.

The glass substrate 11 is placed in a film forming space 16.
It is arranged on the substrate holding mechanism 17 provided in the.
The glass substrate 11 is substantially parallel to the partition 14,
The film forming surface (upper surface) is disposed so as to face the lower surface of the partition wall portion 14. The potential of the substrate holding mechanism 17 is held at the ground potential, which is the same potential as the vacuum vessel 12. Further, a heater 18 is provided inside the substrate holding mechanism 17. The heater 18 keeps the temperature of the glass substrate 11 at a predetermined temperature.

The structure of the vacuum vessel 12 will be described. The vacuum vessel 12 is composed of an upper vessel 12a forming a plasma generation space 15 and a lower vessel 12b forming a film formation processing space 16, from the viewpoint of improving the assemblability. When the upper container 12a and the lower container 12b are combined to form the vacuum container 12, a partition 14 is provided at a position between the two. The isolating portion 14 is arranged so that its peripheral portion contacts the lower insulating member 22 of the annular insulating members 21 and 22 interposed between the upper container 12a and the electrode 20 when the electrode 20 is provided as described later. Attached. Thereby, the partition 14
An isolated plasma generation space 15 and a film formation processing space 16 are formed on the upper side and the lower side. Partition part 14 and upper container 12
a forms a plasma generation space 15. A region where the plasma 19 is generated in the plasma generation space 15 is formed by the above-described partition 14, the upper container 12 a, and a plate-like electrode (high-frequency electrode) 20 arranged at a substantially central position. The electrode 20 has a plurality of holes 20a. The partition 14 and the electrode 20 are formed by two annular insulating members 21 and 2 provided along the inner surface of the side of the upper container 12a.
2 supported and fixed. The annular insulating member 21 is provided with an introduction pipe 23 for introducing oxygen gas into the plasma generation space 15 from the outside. The introduction pipe 23 is connected to an oxygen gas supply source (not shown) via a mass flow controller (not shown) for controlling a flow rate.

The inside of the vacuum vessel 12 is isolated by a partition 14 into a plasma generation space 15 and a film formation processing space 16, and the partition 14 has a plurality of through holes 2 satisfying a predetermined condition.
5 are formed in a dispersed manner so as to penetrate the internal space 24, and the plasma generation space 15 and the film formation processing space 16 are connected only through these through holes 25. The internal space 24 formed in the partition 14 is a space for dispersing the material gas and uniformly supplying the material gas to the film formation processing space 16. Further, a plurality of diffusion holes 26 for supplying a material gas to the film formation processing space 16 are formed on the lower wall of the partition wall 14. The through holes 25 or the diffusion holes 26 are formed so as to satisfy predetermined conditions described later. An introduction pipe 28 for introducing a material gas is connected to the internal space 24. The introduction pipe 28 is arranged so as to be connected from the side. In the internal space 24, a uniform plate 2 having a plurality of holes 27a is provided so that the material gas is uniformly supplied from the diffusion holes 26.
7 are provided substantially horizontally. As shown in FIG. 2, the uniform space 27 allows the internal space 24 of the
Is divided into two space portions 24a and 24b. The material gas introduced into the internal space 24 by the introduction pipe 28 is introduced into the upper space 24a, reaches the lower space 24b through the hole 27a of the uniform plate 27, and further passes through the diffusion hole 26 to form a film. It will be diffused into the space 16. Based on the above structure, it is possible to uniformly supply the material gas over the entire film forming processing space 16.

In FIG. 2, a part of the partition wall portion 14 is shown in an enlarged manner, and essential parts of the through hole 25, the diffusion hole 26, and the uniform plate 27 are shown in an enlarged manner. As an example, the through-hole 25 has a large diameter on the side of the plasma generation space 15, and is narrowed on the side of the film formation processing space 16, and has a small diameter.

A power supply rod 29 connected to the electrode 20 and a power supply rod 30 connected to the partition 14 are provided on the ceiling of the upper container 12a. High-frequency power for discharge is supplied to the electrode 20 by the power supply rod 29. Electrode 2
0 functions as a high-frequency electrode. The outer end of the power supply rod 30 is connected to a cleaning high-frequency power supply 42 or a ground terminal 43 via a changeover switch 41. When the film is formed by plasma, the changeover switch 41 is connected to the ground terminal 43, and the partition 14 is kept at the ground potential.
Further, as will be described later, the changeover switch 41 is connected to the cleaning high-frequency power source 42 at an appropriate timing, and the cleaning high-frequency power is supplied to the partition 14 to perform cleaning. The ground terminal 43 is also connected to the upper container 12a of the vacuum container 12, and the upper container 12a is also kept at the ground potential. The power introduction rods 29 and 30 are covered with insulators 31 and 32, respectively, and are insulated from other metal parts.

A method of forming a film by the CVD apparatus having the above-described configuration will be described. The glass substrate 11 is carried into the vacuum vessel 12 by a transfer robot (not shown), and is placed on the substrate holding mechanism 17. The inside of the vacuum vessel 12 is evacuated by the exhaust mechanism 13, decompressed, and maintained in a predetermined vacuum state. Next, oxygen gas is introduced into the plasma generation space 15 of the vacuum vessel 12 through the introduction pipe 23. At this time, the flow rate of the oxygen gas is controlled by an external mass flow controller. Using equations (1) and (2),
The flow rate (u) of oxygen is determined from the flow rate (Q _O2 ), pressure (P _O2 ), and temperature (T) of the oxygen gas.

[0031]

(Equation 1)

On the other hand, a material gas, for example, silane is introduced into the internal space 24 of the partition 14 through the introduction pipe 28. The silane is first introduced into the upper portion 24a of the interior space 24.
Into the lower part 24b.
, And then introduced directly into the film formation processing space 16 through the diffusion holes 26, that is, without contacting the plasma. Substrate holding mechanism 17 provided in film formation processing space 16
Is maintained at a predetermined temperature in advance because the heater 18 is energized.

In the above state, high-frequency power is supplied to the electrode 20 via the power supply rod 29. A discharge is generated by the high frequency power, and oxygen plasma 19 is generated around the electrode 20 in the plasma generation space 15. By generating the oxygen plasma 19, radicals (excited active species), which are neutral excited species, are generated.

When a film is formed on the surface of the substrate 11, the inner space of the vacuum vessel 12 is filled with a partition 14 made of a conductive material.
In the configuration in which the plasma generation space 15 and the film formation processing space 16 are separated from each other, an oxygen gas is introduced into the plasma generation space 15 and high-frequency power is supplied to the electrode 20 to generate an oxygen plasma 19. In the space 16, silane as a material gas is directly introduced through the internal space 24 and the diffusion holes 26 of the partition wall 14. Plasma generation space 15
Neutral radicals having a long life are introduced into the film forming processing space 16 through the plurality of through-holes 25 of the partition wall portion 14 of the oxygen plasma 19 generated in the above, but most of the charged particles are killed. Silane is applied to the internal space 24 of the partition 14 and the diffusion holes 2.
6 and is directly introduced into the film formation processing space 16. In addition, the silane directly introduced into the film formation processing space 16 is suppressed from back-diffusing into the plasma generation space based on the form of the through-hole 25. As described above, when silane, which is a material gas, is introduced into the film formation processing space 16, the silane does not directly come into contact with the oxygen plasma 19, and violent reaction between the silane and the oxygen plasma is prevented. Thus, a silicon oxide film is formed on the surface of the substrate 11 disposed opposite to the lower surface of the partition 14 in the film formation processing space 16.

In the above structure, the size and the like of the plurality of through-holes 25 of the partition 14 are determined by the plasma generation space 15.
Is assumed to be the mass transfer flow in the through-hole, and the silane in the film forming processing space 16 is assumed to diffuse and move through the through-hole 25 to the space on the opposite side. It is determined to be limited to a range. That is, for example, the mutual gas diffusion coefficient of oxygen gas and silane flowing through the through hole 25 when the temperature of the partition portion 14 is T is D, and the length of the minimum diameter portion of the through hole 25 (the characteristic of the through hole) Target length) is L,
Using the gas flow rate (assuming the gas flow rate u), uL / D>
It is determined that the relationship of 1 is satisfied. The above-described conditions regarding the form of the through hole are preferably applied similarly to the diffusion hole 26 formed in the partition wall portion 14.

The relationship of uL / D> 1 is derived as follows. For example, regarding the relationship between oxygen and silane moving through the through-hole 25, the silane gas density (ρ _SiH4 ) and the diffusion flow rate (u
_The following equation (3) is established using _SiH4 ) and the mutual gas diffusion coefficient ( _DSiH4-O2 ). If the characteristic length of the through hole is L, equation (3) can be approximated to equation (4). As a result of comparing both sides of the equation (4), the diffusion flow rate of silane (u _SiH4 ) is -D
It is represented by _SiH4-O2 / L. Accordingly, when the oxygen flow rate obtained from the above equations (1) and (2) is u and the silane diffusion flow rate is -D _SiH4-O2 / L, the ratio of the absolute values of these two flow rates, that is, | -U / (-D _SiH4-O2 /
L) | = uL / D _SiH4-O2 is the ratio of the oxygen mass transfer rate to the silane diffusion rate, and the ratio uL / D _SiH4-O2 is 1
This means that the convection flow rate is larger than the diffusion flow rate. That is, uL / D
_Setting the value of _SiH4-O2 to 1 or more means that the influence of silane diffusion is small.

Ρ _SiH4 u _SiH4 = −D _SiH4-O2 gradρ _SiH4 (3) ρ _SiH4 u _SiH4 ≒ −D _SiH4-O2 ρ _SiH4 / L (4)

Next, a specific example will be described. The temperature of the partition 14 is 300 ° C., the diameter of the through hole 25 formed in the partition 14 is 0.5 mm, and the length (L) of the portion having a diameter of 0.5 mm.
3 mm, the total number of the through holes 25 is 500, the gas flow rate of the oxygen gas is 500 sccm, and the pressure of the film formation processing space 16 is 100.
Assuming Pa, the value of the above equation is 11. In such a case, the influence of the flow is sufficiently large compared to the diffusion of the silane gas, so that the diffusion of the silane gas into the plasma generation space 15 is reduced.

As described above, the plasma generation space 15 and the film formation processing space 16 are partitioned so as to be closed by the partition wall 14 in which a large number of through holes 25 and diffusion holes 26 having the above characteristics are formed. And the silane directly introduced into the film formation processing space 16 hardly comes into contact with the oxygen plasma. Accordingly, violent reaction between silane and oxygen plasma as in the conventional apparatus is prevented.

Next, the cleaning of the film formation processing space 16 will be described. According to the CVD apparatus of the present embodiment, since the plasma does not sufficiently diffuse into the film formation processing space 16, there is a problem that it is difficult to clean the film formation processing space 16. Therefore, as described above, the power introduction rod 30 is electrically connected to the partition wall portion 14, the changeover switch 41 is connected to the cleaning high-frequency power source 42 side, and high-frequency power is supplied from the cleaning high-frequency power source 42. In the film processing space 16, for example, N
An F ₃ plasma was generated. The inside of the film formation processing space 16 is cleaned with the generated plasma. When the cleaning speed is not a problem, no discharge is performed in the film formation processing space 16 and NF ₃
Cleaning can also be performed by generating plasma and utilizing fluorine radicals diffused into the film formation processing space 16 through the through-hole 25 of the partition 14. At this time, the changeover switch 41 is connected to the ground terminal 43, and the partition 14 is set to the ground potential. The timing for performing such cleaning is performed in a timely manner based on criteria such as every predetermined time or every predetermined number of substrates.

Next, a second embodiment of the CVD apparatus according to the present invention will be described with reference to FIG. 3, elements substantially the same as the elements described in FIG. 1 are denoted by the same reference numerals, and a detailed description thereof will not be repeated. The characteristic configuration of the present embodiment is such that the disk-shaped insulating member 33 is provided inside the ceiling of the upper container 12a, and the electrode 20 is arranged below the insulating member 33. The hole 20a is not formed in the electrode 20 and has the form of a single plate. The electrode 20 and the partition 14 form a plasma generating space 15 having a parallel plate electrode structure. The other configuration is substantially the same as the configuration of the first embodiment. Further, C according to the second embodiment
The operation and effect of the VD device are the same as those of the first embodiment.

In the above-described embodiment, an example of silane as the material gas has been described. However, the present invention is not limited to this, and it is a matter of course that another material gas such as TEOS can be used. Further, the present invention can be applied not only to a silicon oxide film but also to other film formation such as a silicon nitride film. The principle of the present invention can be applied to all processes in which the generation of particles when a material gas comes into contact with plasma and the incidence of ions on a substrate pose a problem, such as film formation, surface treatment, and isotropic etching. Applicable to Further, in the above-described embodiment, the partition portion has a double structure, but it is needless to say that the partition portion can have a multilayer structure as needed.

[0043]

As is apparent from the above description, according to the present invention, when a silicon oxide film or the like is formed on a large area substrate by using a material gas such as silane by plasma CVD, a plurality of silicon oxide films satisfying a predetermined condition can be obtained. The inside of the vacuum vessel is separated into a plasma generation space and a film formation processing space by providing a partition wall in which a through hole or a diffusion hole is formed, and active species generated in the plasma generation space are formed through the through hole in the partition wall. The material gas is introduced into the film processing space, and the material gas is introduced directly into the film formation processing space without touching the plasma through the internal space of the partition wall and the diffusion holes, thereby preventing a violent chemical reaction between the material gas and the plasma. As a result, generation of particles can be suppressed and ion incidence on the substrate can be prevented.

Further, the material gas can be introduced uniformly, and the radicals of oxygen gas can be uniformly supplied to the film formation processing space by the plurality of through holes formed in the partition wall. Etc. to improve the distribution,
Film formation on a large-area substrate can be effectively performed.

In addition, since a cleaning power introduction rod is attached to the partition so that cleaning can be performed by supplying power, a plasma generation space and a film formation processing space separated by the partition are formed in the vacuum vessel. Also, the cleanliness of the film formation processing space can be appropriately maintained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of various holes formed in a partition wall.

FIG. 3 is a longitudinal sectional view showing a configuration of a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Glass substrate 12 Vacuum container 14 Partition part 15 Plasma generation space 16 Film-forming processing space 17 Substrate holding mechanism 20 Electrode 24 Internal space 25 Through-hole 26 Diffusion hole 27 Uniform plate

Continued on the front page F-term (reference) 2H090 HB03X HC03 HC18 4K030 AA06 AA14 BA44 CA06 CA17 DA06 EA05 EA06 FA03 JA01 JA12 KA08 KA17 KA30 LA18 5F045 AA08 AA16 AB32 AB33 AC01 AC02 AC07 AC11 AE19 AF07 BB15 EB18 EB15 EB03

Claims (6)

[Claims] 1. A CVD apparatus that generates plasma in a vacuum vessel to generate active species and forms a film on a substrate using the active species and a material gas. A partition portion is provided in the vacuum chamber, and one of the two chambers is formed as a plasma generation space in which a high-frequency electrode is arranged, and the other chamber is provided with a substrate holding mechanism for mounting the substrate. A plurality of through-holes formed through the plasma generation space and the film-forming processing space are formed in the partition wall, and the through-hole has a gas flow rate in the hole of u. Where L is the substantial pore length and D is the mutual gas diffusion coefficient, uL / D>
The partition part further has an internal space which is isolated from the plasma generation space and communicates with the film formation processing space through a plurality of diffusion holes. The material gas is supplied, the material gas supplied to the internal space is introduced into the film formation processing space through the plurality of diffusion holes, and a high-frequency power is applied to the high-frequency electrode to cause a plasma discharge in the plasma generation space. The CVD apparatus, wherein the activated species generated in the plasma generation space by the generation are introduced into the film formation processing space through the plurality of through holes formed in the partition. 2. The diffusion hole, wherein the gas flow rate in the hole is u,
When the substantial hole length is L and the mutual gas diffusion coefficient is D, the active species is introduced into the film forming space in a state where uL / D> 1 is satisfied. Item 1
The CVD apparatus as described in the above. 3. The CV according to claim 1, wherein the partition has a diffusion structure of at least two layers for uniformly diffusing the material gas in an inner space thereof.
D device. 4. The cleaning device according to claim 1, wherein the partition unit is connected to a high-frequency power supply unit that supplies high-frequency power for cleaning, and supplies high-frequency power to the partition unit in a timely manner to generate a cleaning plasma in the film forming processing space. Claims 1-3
The CVD apparatus according to any one of the above. 5. The high-frequency electrode is disposed at the center of the chamber forming the plasma generation space, and includes the high-frequency electrode, a part of the vacuum vessel as an electrode surrounding the periphery of the high-frequency electrode, and the partition. The CVD apparatus according to any one of claims 1 to 3, wherein a plasma discharge is generated between the steps. 6. The plasma generating apparatus according to claim 1, wherein the high-frequency electrode is provided at an upper position of the plasma generation space, and a plasma discharge is generated between the high-frequency electrode and the partition.
The CVD apparatus according to any one of claims 1 to 3.