JP2011129618A - Thin film deposition equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide thin film deposition equipment which can deposit a thin film on an uniform substrate while facilitating manufacturing and maintenance, and can prolong a life of a shower plate while reducing manufacturing cost and maintenance cost. <P>SOLUTION: In the thin film deposition equipment including pair electrodes composed of a high frequency electrode 3 and a ground electrode facing each other in a vacuum container where the ground electrode supports a substrate, the vacuum container is filled with gas, and a thin film is deposited on the substrate by applying a high frequency between the pair electrodes, a plurality of planar members 7a and 7b are arranged at the surface 3a side of the high frequency electrode 3 while being superimposed in the thickness direction, the plurality of planar members 7a and 7b are provided with a plurality of pore openings so that gas can be discharged from the surface 3a, diameters of the pore openings in the planar members 7a and 7b are different from each other, and each of the plurality of planar members 7a and 7b is configured to be detachable. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thin film forming apparatus for forming a thin film on a substrate disposed between electrode pairs by introducing a film-forming gas between electrode pairs facing each other in a vacuum and applying a high frequency between the electrode pairs.

  In order to form a microcrystalline silicon thin film, an amorphous silicon thin film, or the like on a substrate, a capacitively coupled plasma CVD method using parallel plate electrodes is often used. In this method, a pair of electrodes for generating plasma in a vacuum vessel are arranged in parallel to each other, a gas for film formation is filled in the vacuum vessel, and a high frequency is applied between the pair of electrodes to generate plasma. To form a thin film on the substrate.

  Here, referring to FIG. 1, a general thin film forming apparatus 1 used in the plasma CVD method is provided with a high-frequency electrode 3 and a ground electrode 4 facing each other in a vacuum vessel 2. The surface 3a and the surface 4a of the ground electrode 4 are arranged to face each other. The high-frequency electrode 3 is configured to be able to supply power from the power source 5, and the ground electrode 4 is grounded to the ground G. Although not shown, the ground electrode 4 is provided with a heater or the like, and a substrate 6 to be formed is held on the ground electrode 4.

  When the film is formed on the substrate 6 having a large surface, the surface 3 a of the high-frequency electrode 3 and the surface 4 a of the ground electrode 4 are formed large so that the gas is widely distributed on the surface of the substrate 6. It is desired to make the in-plane distribution of the thin film formed uniform. In this case, the surface 3a of the high-frequency electrode 3 is configured as a shower plate 7 made of a single plate-like member, or a shower plate 7 made by combining a plurality of plate-like members in the plane direction, and gas is applied to the shower plate 7 In many cases, a plurality of gas introduction holes 8 for introduction are provided. The gas is sent from the gas supply pipe 9 attached to the high frequency electrode 3 to the high frequency electrode 3 and is introduced into the vacuum vessel 2 through the gas introduction hole 8 of the shower plate 7. With such a configuration, a gas is supplied into the vacuum chamber 2 and a high frequency is applied between the high frequency electrode 3 and the ground electrode 4 to generate plasma, thereby forming a thin film on the substrate 6. In the thin film forming apparatus 1, the gas filled in the vacuum container 2 is often exhausted from the gas exhaust pipe 10 attached to the vacuum container 2.

  In order to increase the growth rate of the thin film, it is effective to increase the pressure in the vacuum vessel 2 and shorten the distance between the high-frequency electrode 3 and the ground electrode 4. In this case, in particular, it is possible to reduce the distance between adjacent gas introduction holes 8, to reduce the diameter of the gas introduction holes 8, and to form the gas introduction holes 8 narrowly. It is effective to obtain. For example, in Patent Document 1, the diameter of the gas discharge side portion of the gas introduction hole 8 is formed smaller than the diameter of the gas introduction side portion, and the gas discharge side portion is formed thin. In Patent Document 2, the diameter of the gas introduction side portion of the gas introduction hole 8 is formed smaller than the diameter of the gas discharge side portion, and the gas introduction side portion is formed thin.

JP-A-7-201762 JP 2001-237187 A

  However, when the substrate 6 is formed, a film is also formed on the shower plate 7. If the film is formed repeatedly, the film attached to the shower plate 7 is peeled off. In order to remove this film, cleaning is necessary. If the frequency of maintenance for cleaning becomes high, there is a problem that the maintenance cost increases. Further, since the shower plate 7 is worn by cleaning, if the frequency of cleaning is high, the diameter of the gas introduction hole 8 and the like change in a short period from the start of use of the shower plate 7, and the dimensional accuracy of the shower plate 7 decreases. To do. Therefore, there is a problem that the lifetime of the shower plate 7 is shortened due to factors such as the inability to form a uniform film. Furthermore, when the gas introduction pipe is thinned, the influence of the change is likely to be large, so the life of the shower plate 7 is shortened. Further, when the gas introduction pipe is thinned, the manufacturing cost is also increased, so that the cost of the thin film forming apparatus is further increased.

  Further, in Patent Document 1 and Patent Document 2, a step is formed in the gas introduction hole 8 of the shower plate 7 made of one plate-like member, and the structure of the gas introduction hole 8 is complicated. Therefore, when manufacturing the shower plate 7, it is necessary to cut the gas introduction hole 8 having a complicated structure. Therefore, it becomes difficult to manufacture the thin film forming apparatus 1 and the manufacturing cost further increases. In addition, it is difficult to clean the inside of the gas introduction hole 8 having a complicated structure, and the maintenance of the thin film forming apparatus 1 becomes more difficult, resulting in a further increase in maintenance cost.

  The present invention has been made in view of such a situation, and the object thereof is to enable the formation of a thin film on a uniform substrate, facilitate manufacture and maintenance, extend the life of the shower plate, An object of the present invention is to provide a thin film forming apparatus capable of reducing maintenance costs.

  In order to solve the problems, a thin film forming apparatus of the present invention includes an electrode pair including a high-frequency electrode and a ground electrode facing each other in a vacuum container, holds a substrate by the ground electrode, and supplies a gas into the vacuum container. A thin film forming apparatus that fills and applies a high frequency between the electrode pairs to form a thin film on the substrate, wherein a plurality of plate-like members are thick on the surface side of the high frequency electrode facing the ground electrode. The plurality of plate-like members are provided with a plurality of opening holes so that gas can be released from the surface of the high-frequency electrode, and each of the plate-like members is disposed. The diameters of the opening holes are different from each other, and each of the plurality of plate-like members is configured to be detachable.

  In the thin film forming apparatus of the present invention, the centers of the opening holes in the respective plate-like members are arranged to be aligned with each other, and the diameters of the opening holes in the respective plate-like members are the same as those of the high-frequency electrode that emits gas. It is formed smaller from the surface side toward the gas introduction side.

According to the thin film forming apparatus of the present invention, the following effects can be obtained. The thin film forming apparatus of the present invention includes an electrode pair composed of a high-frequency electrode and a ground electrode facing each other in a vacuum vessel, holds a substrate by the ground electrode, fills the vacuum vessel with a gas, A thin film forming apparatus for forming a thin film on the substrate by applying a high frequency to the substrate, wherein a plurality of plate-like members are arranged in the thickness direction on the surface side of the high frequency electrode facing the ground electrode The plurality of plate-like members are provided with a plurality of opening holes so that gas can be released from the surface of the high-frequency electrode, and the diameters of the opening holes in the respective plate-like members are respectively set. Each of the plurality of plate-like members is configured to be detachable.
Therefore, if the diameter of the opening hole of at least one of the plate-like members is reduced, a part of the gas introduction hole composed of the opening holes of the plurality of plate-like members that are overlapped can be thinned. The gas can be widely distributed on the surface of the substrate, and the in-plane distribution of the thin film can be made uniform.
Further, if each of the opening holes of the plurality of plate-like members is formed in a shape having no step, each of the plurality of plate-like members can be removed separately, and the opening hole without a step can be easily cleaned. Accordingly, maintenance such as cleaning is facilitated, and maintenance cost can be reduced.
Further, when the thin film forming apparatus is manufactured, a shower plate can be formed by forming an opening hole without a step in each plate-like member and then superimposing the plurality of plate-like members on the surface side of the high-frequency electrode. Therefore, it is not necessary to perform complicated processing as in the case of cutting a gas introduction hole with a step in a shower plate made of a single plate-like member. Accordingly, the manufacturing of the thin film forming apparatus can be facilitated and the manufacturing cost can be reduced.

  In the thin film forming apparatus of the present invention, the centers of the opening holes in the respective plate-like members are arranged to be aligned with each other, and the diameter of the opening holes in each of the plate-like members is the surface side of the high-frequency electrode that emits gas Therefore, the plate-like member having a small opening is disposed at a position away from the surface of the high-frequency electrode. Therefore, a film is hardly formed on the plate-like member having the small opening hole, and the maintenance frequency can be reduced. Therefore, for a plate-like member having a small opening that is difficult to manufacture, the progress of wear due to repeated maintenance is slowed, and the life can be extended.

It is sectional drawing which showed the thin film forming apparatus typically. It is the top view which showed an example of the surface of the high frequency electrode in 1st Embodiment of this invention. It is the longitudinal cross-sectional view which showed an example of the high frequency electrode in 1st Embodiment of this invention. It is the A section enlarged view of FIG. It is the longitudinal cross-sectional view which showed an example of the high frequency electrode in 2nd Embodiment of this invention. It is the B section enlarged view of FIG. It is the longitudinal cross-sectional view which showed an example of the high frequency electrode in 3rd Embodiment of this invention. It is the C section enlarged view of FIG. (A) It is the top view which showed a part of 2nd plate-shaped member in 3rd Embodiment of this invention. (B) It is DD sectional drawing of Fig.6 (a).

  A thin film forming apparatus according to an embodiment of the present invention will be described below. In the embodiment of the present invention, the thin film forming apparatus is described as a plasma CVD apparatus, but the thin film forming apparatus may be an etching apparatus. Furthermore, as long as the same effect can be obtained by the same configuration as that of the embodiment of the present invention, the thin film forming apparatus may be other.

[First Embodiment]
The thin film forming apparatus in the first embodiment of the present invention will be described below. The basic configuration of the thin film forming apparatus in the first embodiment is the same as the configuration of FIG. 1 described above. Here, a configuration that is a feature of the first embodiment will be described.

  Referring to FIGS. 2, 3, and 4, the surface 3 a side of the high-frequency electrode 3 is constituted by a shower plate 7. In the high frequency electrode 3, a space 3c surrounded by the shower plate 7 and the high frequency electrode main body 3b is formed. The gas supply pipe 9 is attached to the surface 3d opposite to the surface 3a of the high-frequency electrode 3, and gas is sent from the gas supply pipe 9 to the space 3c.

  The shower plate 7 includes a first plate member 7a and a second plate member 7b. The first plate-like member 7a and the second plate-like member 7b are arranged so as to overlap each other in the thickness direction, the first plate-like member 7a is arranged on the gas introduction side, and the second plate-like member 7b is These are arranged on the gas discharge side so as to constitute the surface 3 a of the high-frequency electrode 3. The first plate member 7a and the second plate member 7b are configured to be detachable. For example, a screw fastening structure is mentioned as an attachment structure of the 1st plate-shaped member 7a and the 2nd plate-shaped member 7b. In this screw fastening structure, a hole penetrating the first plate-like member 7a and the second plate-like member 7b is provided, and a countersunk screw or the like is inserted through the hole, whereby the first plate-like member 7a and the second plate-like member are inserted. The member 7b may be fastened together. In addition, by providing a recess corresponding to the head of the countersunk screw on the surface of the first plate-like member 7a or the second plate-like member 7b, the head of the countersunk screw from the surface of the second plate-like member 7b at the time of screw fastening. It is preferable that a structure that does not protrude is provided. In addition, the structure which makes the 1st plate-shaped member 7a and the 2nd plate-shaped member 7b detachable may be other than a screw fastening structure, if the objective of this invention can be achieved.

  The first plate-like member 7a is provided with a plurality of first opening holes 8a, and the second plate-like member 7b is provided with a plurality of second opening holes 8b. The center of the 1st opening hole 8a and the center of the 2nd opening hole 8b are mutually arrange | positioned, and are arrange | positioned. Therefore, the gas introduction hole 8 is formed by the first opening hole 8a and the second opening hole 8b in a state where the first plate member 7a and the second plate member 7b are overlapped. Regarding the arrangement of the plurality of gas introduction holes 8, the distance between the centers of the adjacent gas introduction holes 8 is equal to or shorter than the distance between the electrodes between the high-frequency electrode 3 and the ground electrode 4. And preferred.

The first opening hole 8a is formed in a cylindrical shape having a thickness circular cross section with a diameter d ₁ throughout the direction of the first plate member 7a. On the other hand, the second opening hole 8b is formed in a cylindrical shape having a circular cross section with a diameter d ₂ over the entire thickness direction of the second plate-shaped member 7b. The diameters d ₁ and d ₂ of the opening holes 8a and 8b in the respective plate-like members 7a and 7b are formed to be smaller from the gas discharge side toward the gas introduction side. Specifically, the relationship between the diameter _{d 2} of the diameter _{d 1} of the first opening hole 8a second opening hole 8b _is a d 1 _{<d 2,} the diameter _{d 1} is a thin film distribution becomes uniform It is good to be formed like this. As an example, the diameter d ₁ is preferably 0.5 mm or less, and the diameter d ₂ is preferably 1 mm or more.

Here, the operation of the thin film forming apparatus 1 in the first embodiment will be described.
In the thin film forming apparatus 1, the gas is sent to the space 3 c in the high frequency electrode 3 through the gas supply pipe 9, and is further passed between the high frequency electrode 3 and the ground electrode 4 from the space 3 c through the gas introduction hole 8. Sent. A substrate 6 attached to the ground electrode 4 is generated by applying high-frequency power between the high-frequency electrode 3 and the ground electrode 4 in a state where gas is filled between the high-frequency electrode 3 and the ground electrode 4. A thin film is formed.

[Second Embodiment]
A thin film forming apparatus according to a second embodiment of the present invention will be described below. The basic configuration of the thin film forming apparatus of the second embodiment is the same as the configuration of the thin film forming apparatus of the first embodiment. Elements similar to those in the first embodiment will be described using the same symbols and names as those in the first embodiment. Here, a configuration different from the first embodiment will be described.

  5 and 6, the first plate member 7a is provided with a plurality of third opening holes 8c, and the second plate member 7b is provided with a plurality of fourth opening holes 8d. The center of the third opening hole 8c and the center of the fourth opening hole 8d are arranged so as to be combined with each other. Therefore, the gas introduction hole 8 is formed by the third opening hole 8c and the fourth opening hole 8d in a state where the first plate-like member 7a and the second plate-like member 7b are overlapped.

The third opening hole 8c is formed so as to penetrate through the entire thickness direction of the first plate-like member 7a. The third opening hole 8c, the gas introduction side has a diameter d _3, the gas discharge side has a diameter d _4. Relationship between the diameter _{d 3} and a diameter _{d 4 has} a _d 3 <d _4. That is, the third opening hole 8c is formed in a substantially conical shape having a diameter that gradually decreases from the gas discharge side to the gas introduction side. The fourth opening hole 8d is formed so as to penetrate through the entire thickness direction of the second plate member 7b. The fourth opening hole 8d, the gas introduction side has a diameter d _4, the gas discharge side has a diameter d _5. Relationship between the diameter _{d 4} and the diameter _{d 5 has} a _d 4 <d _5. That is, the fourth opening hole 8d is formed in a substantially conical shape having a diameter that gradually decreases from the gas discharge side to the gas introduction side. Incidentally, it is equal and the third opening hole 8c diameter d ₄ and a gas introduction side of the diameter d ₄ of the gas discharge side of the fourth opening hole 8d. The gas introduction hole 8 formed by superposing such plate-like members 7a and 7b has the diameters d ₃ , d ₄ and d ₅ of the opening holes 8c and 8d on the side from which the gas is introduced from the side from which the gas is released. Smaller as it goes. As an example, preferably the diameter _{d 3} is 0.5mm or less, preferably a diameter _{d 5} is 1mm or more. The diameter d ₄ is determined by the thickness of the shower plate 7.

  In the state where the first plate-like member 7a and the second plate-like member 7b are overlapped, the gas introduction hole 8 is formed by the third opening hole 8c and the fourth opening hole 8d. At this time, the gas introduction hole 8 is formed in a substantially conical shape whose diameter is gradually reduced from the gas release side toward the gas introduction side.

[Third Embodiment]
A thin film forming apparatus according to a third embodiment of the present invention will be described below. The basic configuration of the thin film forming apparatus of the third embodiment is the same as the configuration of the thin film forming apparatus of the first embodiment. Elements similar to those in the first embodiment will be described using the same symbols and names as those in the first embodiment. Here, a configuration different from the first embodiment will be described.

Referring to FIG. 7, FIG. 8, FIG. 9 (a), and FIG. 9 (b), the surface of the first plate member 7a that contacts the second plate member 7b has the second plate member 7b on the surface. Protrusions 11 that can be fitted into the two opening holes 8b are provided. Specifically, the protrusion 11 is formed in a cylindrical shape consisting of a circular cross section with a diameter d _6, the diameter d ₆ is substantially equal to the diameter d ₂ of the second opening hole 8b. The center of the protrusion 11 is arranged to coincide with the centers of the first opening hole 8a and the second opening hole 8b.

  With such a configuration, in a state where the first plate-like member 7a and the second plate-like member 7b are overlapped, the protrusion 11 of the first plate-like member 7a has the second opening hole 8b of the second plate-like member 7b. And the first plate-like member 7a and the second plate-like member 7b are accurately aligned, and the first opening hole 8a and the second opening hole 8b are accurately aligned. Therefore, the shower plate 7 with high accuracy can be manufactured, and the thin film manufacturing apparatus 1 with high accuracy can be manufactured.

As described above, according to the first to third embodiments of the present invention, the first opening hole is formed in the shower plate 7 composed of the first plate-like member 7a and the second plate-like member 7b that are overlapped. 8a and second openings 8b or the composed gas inlet 8 by a third opening hole 8c and the fourth opening hole 8d, the diameter _{d 3} of diameter _{d 1} and the third opening hole 8c of the first openings 8a, , it is smaller than the diameter d ₄ of the diameter d ₂ and the fourth opening hole 8d of the second opening hole 8b respectively, a portion of the gas introduction hole 8 is formed thin, making it possible to uniformly distribute the gas it can. Therefore, the gas can be widely distributed on the surface of the substrate 6 with a simple structure, and the in-plane distribution of the thin film can be made uniform.
Further, the first opening hole 8a of the first plate member 7a and the second opening hole 8b of the second plate member 7b are formed in a cylindrical shape, or the third opening hole 8c of the first plate member 7a and Since the 4th opening hole 8d of the 2nd plate-shaped member 7b is formed in cone shape, the level | step difference is not formed in each opening hole 8a, 8b, 8c, 8d. Therefore, it is possible to remove each of the first plate-like member 7a and the second plate-like member 7b separately and clean each of the opening holes 8a to 8d having no step. Accordingly, maintenance such as cleaning is facilitated, and maintenance cost can be reduced.
Further, when the thin film forming apparatus 1 is manufactured, the cylindrical first opening 8a or the conical third opening 8c is formed in the first plate member 7a, and the cylindrical first opening 7c is formed in the second plate member 7b. After forming the two opening holes 8b or the fourth opening holes 8d, the first plate member 7a and the second plate member 7b are overlapped on the surface 3a side of the high frequency electrode 3 to form the shower plate 7, There is no need to perform complicated processing as in the case of cutting a gas introduction hole having a complicated step structure on a shower plate made of a single plate-like member. Therefore, the manufacturing of the thin film forming apparatus 1 can be facilitated and the manufacturing cost can be reduced.

According to the first to third embodiments of the present invention, the diameter d ₃ of diameter d ₁ and the third opening hole 8c of the first opening hole 8a of the first plate-shaped member 7a are respectively second plate member It is formed smaller than the diameter _{d 5} of diameter _{d 2} and the fourth opening hole 8d of the second opening hole 8b in 7b. Therefore, the first plate-like member 7 a having the small first opening hole 8 a or the third opening hole 8 c is disposed at a position away from the surface 3 a of the high-frequency electrode 3. Therefore, it is difficult to form a film on the first plate-like member 7a, and the frequency of maintenance can be reduced. Therefore, about the 1st plate-shaped member 7a which has the small 1st opening part 8a or the 3rd opening part 8c which is difficult to manufacture, progress of wear by maintenance becomes slow and can extend a lifetime.

  Although the embodiments of the present invention have been described so far, 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, as a modification of the embodiment of the present invention, the shower plate 7 may have a configuration in which three or more plate-like members are stacked. The same effect as the embodiment of the present invention can be obtained.

[Example 1]
Example 1 of the present invention will be described. The thin film forming apparatus of Example 1 was the same as that of the first embodiment. The diameter of the cross section of the high frequency electrode 3 and the ground electrode 4 was 300 mm, and the distance between the high frequency electrode 3 and the ground electrode 4 was 10 mm. The material of the first plate member 7a and the second plate member 7b constituting the shower plate 7 was aluminum, and the thickness of the shower plate 7 was 1 mm. The diameter _{d 1} of the first opening hole 8a of the first plate member 7a and 0.5 mm, and the diameter _{d 2} of the second opening hole 8b of the second plate-shaped member 7b and 1 mm.

The film formation conditions, 30 sccm silane gas as a gas ^{(5.02 × 10 -2 Pa · m} 3 /s,1sccm=1.69×10 -3 Pa · m 3 / s), 2000sccm hydrogen gas (3. 35 Pa · m ³ / s), the pressure in the vacuum vessel is 6 Torr (799.92 Pa, 1 Torr = 133.32 Pa), and the discharge power applied between the high-frequency electrode 3 and the ground electrode 4 is 300 W. . For cleaning, the first plate-like member 7a was removed, subjected to a sun blast treatment, etched with a mixed solution of hydrofluoric acid and nitric acid, cleaned with pure water, and then dried.

  Regarding the confirmation items, the thickness t of the thin film formed on the substrate was confirmed by repeating the film formation until the first plate-like member 7a needed to be cleaned under the above-described film formation conditions and cleaning. In addition, the number N of times that cleaning can be performed was confirmed before the first plate member 7a had to be replaced. Further, the total thickness T (= t × N), which is the sum of the thicknesses of the thin films formed on the substrate by repeating the film formation, until the replacement of the first plate-like member 7a is required.

  Since the diameter of the second opening hole 8b is larger than that of the first opening hole 8a, the processing of the second plate member 7b is easy, while the diameter of the first opening hole 8a is larger than that of the second opening hole 8b. Since it is small, it is difficult to process the first plate member 7a. Therefore, the lifetime of only the first plate-like member 7a requiring difficult processing is considered.

[Example 2]
A second embodiment of the present invention will be described. The thin film forming apparatus of Example 2 was the same as that of the second embodiment. In Example 2, the basic structural requirements of the thin film forming apparatus 1 in the same manner as in Example 1, a diameter d ₃ and 0.5mm in the third opening hole 8c of the first plate member 7a, the second plate member the diameter _{d 5} of the fourth opening hole 8d of 7b was 1 mm. The diameter d ₄ of the third opening hole 8c and the fourth opening hole 8d is determined by the thickness of the shower plate 7 was 1 mm. The film forming conditions, cleaning, and confirmation items were the same as in Example 1.

[Example 3]
A third embodiment of the present invention will be described. The thin film forming apparatus of Example 3 was the same as that of the third embodiment. In Example 3, the basic configuration requirements of the thin film forming apparatus 1 in the same manner as in Example 1, in this case, the diameter d ₆ of the circular cross section of the protruding portion 11 was set to 1 mm. The film forming conditions, cleaning, and confirmation items were the same as in Example 1.

[Comparative Example 1]
A comparative example 1 of the present invention will be described. The basic structural requirements of the thin film forming apparatus were the same as those in Example 1, and the shower plate was composed of a single plate-like member. The film forming conditions were the same as in Example 1. For cleaning, the same operation as in Example 1 was performed on the entire shower plate. The confirmation items were the same as in Example 1.

[Comparative Example 2]
Comparative Example 2 of the present invention will be described. The basic constituent requirements of the thin film forming apparatus were the same as those in Example 2, and the shower plate was composed of a single plate-like member. The film forming conditions were the same as in Example 1. For cleaning, the same operation as in Example 1 was performed on the entire shower plate. The confirmation items were the same as in Example 1.

  Table 1 shows the results of confirmation of Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2.

  In Example 1 and Example 3, the first plate-like member 7a that affects the growth rate of the thin film needs to be cleaned when the thickness t of the thin film formed on the substrate after repeated film formation becomes 2 mm. became. Further, the number N of times that cleaning can be performed was 20 in the case of Example 1 and 15 in the case of Example 3. Therefore, the total thickness T of the thin film formed on the substrate by repeating the film formation before the replacement of the first plate member 7a is 60 mm in the case of Example 1, and in the case of Example 3. It became 30 mm. Regarding the number N of times that cleaning can be performed, the number of times of Example 3 is less than the number of times of Example 1 because the protrusion 11 is worn and the first plate-like member 7a and the second plate-like member 7b This is due to a decrease in positioning accuracy.

  On the other hand, in Comparative Example 1, the shower plate made of a single plate-shaped member required cleaning when the thickness t of the thin film formed on the substrate after repeated film formation was 0.3 mm. . Further, the number of times N that can be cleaned was 20 times. Therefore, the total thickness T of the thin film formed on the substrate is 6 mm before the shower plate needs to be replaced.

  Therefore, the total thickness T of Example 1 and Example 3 is thicker than the total thickness T of Comparative Example 1, and the first plate-like member 7a of the shower plate 7 in Examples 1 and 3 is used. It was confirmed that the lifetime was longer than the lifetime of the shower plate of Comparative Example 1 having the same shape of gas introduction holes.

  When the diameter of the shower plate opening was constant at 0.5 mm and the distance between the high-frequency electrode and the ground electrode was 10 mm or more, the distribution of the thin film was changed due to the distance between the electrodes. On the other hand, in the structure in which the diameter of the shower plate opening is 0.5 mm on the gas introduction side and the diameter is 1 mm on the gas discharge side, the distance between the high-frequency electrode 3 and the ground electrode 4 is 10 mm. As described above, for example, when the thickness is 12 mm, it has been confirmed that the distribution of the thin film does not change due to the distance between the electrodes.

  In Example 2, it was necessary to clean the first plate-like member 7a when the thickness t of the thin film formed on the substrate after repeated film formation was 3 mm. Further, the number of times N that can be cleaned was 15 times. Therefore, the total thickness T of the thin film formed on the substrate is 45 mm before the first plate member 7a needs to be replaced.

  On the other hand, in Comparative Example 2, it was necessary to clean the shower plate made of a single plate-like member when the thickness t of the thin film formed on the substrate became 0.3 mm. Further, the number of times N that can be cleaned was 15 times. Therefore, the total thickness T of the thin film formed on the substrate is 6 mm before the shower plate needs to be replaced.

  Therefore, the total thickness T of Example 2 is thicker than the total thickness T of Comparative Example 2, and the lifetime of the first plate-like member 7a in Example 2 is a comparative example having gas introduction holes of the same shape. It was confirmed that the lifetime of the shower plate of Example 2 was longer.

DESCRIPTION OF SYMBOLS 1 Thin film forming apparatus 2 Vacuum vessel 3 High frequency electrode 3a Surface 4 Ground electrode 4a Surface 6 Substrate 7 Shower plate 7a First plate member 7b Second plate member 8 Gas introduction hole 8a First opening hole 8b Second opening hole 8c Second 3 opening hole 8d fourth opening hole G ground _{d 1, d 2, d 3} , d 4, d 5, the total thickness N number of thickness T thin film _{d 6} diameter t thin

Claims (2)

An electrode pair comprising a high-frequency electrode and a ground electrode facing each other in a vacuum vessel;
A thin film forming apparatus for holding a substrate with the ground electrode, filling a gas in the vacuum vessel, applying a high frequency between the electrode pair, and forming a thin film on the substrate,
On the surface side of the high-frequency electrode facing the ground electrode, a plurality of plate-like members are arranged so as to overlap in the thickness direction,
Each of the plurality of plate-like members is provided with a plurality of opening holes so that gas can be released from the surface of the high-frequency electrode.
The diameter of the opening hole in each of the plate members is different,
A thin film forming apparatus in which each of the plurality of plate-like members is configured to be detachable. The centers of the opening holes in each of the plate-like members are arranged to be aligned with each other,
2. The thin film forming apparatus according to claim 1, wherein the diameter of the opening hole in each of the plate-like members is formed to be smaller from the surface side of the high-frequency electrode that emits gas toward the gas introduction side.

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