JP4087155B2 - Deposition equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a film forming apparatus and a film forming method, and more particularly to a film forming apparatus and a film forming method for forming a film by applying an electric field to excite a film forming material.
[0002]
[Prior art]
One conventional film deposition apparatus is an ion plating apparatus. For example, in an ion plating apparatus that forms a film by applying a high-frequency voltage or a high-frequency voltage and a direct-current voltage, a conductive substrate holder is placed in the chamber as one electrode and filled with a thin film forming material. The evaporated source is arranged to face the substrate holder. And the insulating base material which is film-forming objects, such as an optical glass base material, is attached to the opening part provided in this base material holder.
[0003]
[Problems to be solved by the invention]
When a high-frequency voltage is applied during film formation, self-bias due to plasma generated by the discharge of the high-frequency power is generated in the outer peripheral portion of the substrate that is in direct contact with the substrate holder. The evaporated thin film forming material is excited by this plasma, accelerated by the self-bias, and vigorously collides with the substrate surface. As a result, a dense film is formed, and the refractive index and adhesion of the film are improved (this is called an ion plating effect).
[0004]
On the other hand, in the central part of the base material, since it is not in contact with the base material holder and the base material is insulative, almost no self-bias is generated. For this reason, the thin film forming material cannot be vigorously collided with the substrate surface. Therefore, the adhesiveness to the substrate is lowered, and the denseness of the formed thin film is lowered, so that voids are formed in the film and the refractive index is lowered. In addition, since the moisture in the air is mixed into the gap, the refractive index is likely to change. Thus, the ion plating effect is hardly obtained in the thin film region corresponding to the central portion of the substrate.
[0005]
As described above, since the moment when the thin film forming material collides with the base material is different between the outer peripheral portion and the central portion of the base material, there is partial unevenness in the refractive index, adhesion, etc. of the formed thin film. It will occur and the film quality of the resulting thin film will be non-uniform. In particular, when the film is formed using a base material having a large size or when a multilayer film is formed, such non-uniform film quality is likely to occur. For example, when an optical multilayer filter is formed, the film quality is uneven in each region corresponding to the outer peripheral portion and the central portion of the base material, so that optical characteristics such as transmittance in each region are greatly different. Sometimes.
[0006]
SUMMARY An advantage of some aspects of the invention is to provide a film forming apparatus and a film forming method capable of forming a film having a uniform film quality.
[0007]
[Means for Solving the Problems]
A film forming apparatus according to the present invention includes a chamber for forming a film on a substrate using an electric field therein, a power source for generating the electric field, and a material supply source apparatus for supplying a film forming material. When the disposed in the chamber, a conductive substrate holder which is connected the with a power source electrically to have a opening, mounted in the opening cylindrical conductive substrate supporting member And an auxiliary electrode electrically connected to the base material holder, an insulating base material is fitted inside the base material support member, and the auxiliary electrode includes the base material and includes the base material. The substrate support member is configured to cover from the back surface side opposite to the film formation surface of the substrate (Claim 1).
[0008]
According to such a configuration, by arranging the auxiliary electrode on the surface opposite to the film formation surface of the substrate, sufficient self-bias is applied not only at the outer periphery of the substrate but also at the center of the substrate when an electric field is applied. Can be generated. For this reason, it becomes possible to make the film-forming material collide with the base material with uniform and sufficient momentum at the outer peripheral part and the central part of the base material, and thus it is possible to form a film having a uniform and good film quality. It becomes.
[0009]
Before SL auxiliary electrode may be a mesh-like (claim 2).
[0010]
When the auxiliary electrode has a mesh shape, when the substrate is heated, heat is efficiently transferred to the substrate exposed between the meshes. For this reason, it is possible to efficiently heat the base material while preventing the auxiliary electrode from hindering the temperature rise of the base material.
[0011]
The substrate holder has a plurality of the openings, and the substrate support member and the substrate are respectively attached to the openings, and the plurality of auxiliary electrodes are arranged corresponding to the individual substrates. Well (Claim 3 ), the substrate holder has a plurality of the openings, and the substrate support member and the substrate are respectively mounted in the openings, and the film formation surfaces of the plurality of substrates The common auxiliary electrode that covers the surface opposite to the surface may be arranged (claim 4 ).
[0012]
In the case where auxiliary electrodes common to a plurality of substrates are arranged, it is not necessary to individually arrange auxiliary electrodes on each substrate, so that it is possible to easily arrange auxiliary electrodes and Since the number of parts is reduced, the apparatus cost can be reduced.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. Here, an ion plating apparatus will be described as a film forming apparatus according to the present invention.
(Embodiment 1)
FIG. 1 is a schematic diagram showing the structure of an ion plating apparatus according to Embodiment 1 of the present invention.
[0021]
As shown in FIG. 1, in an ion plating apparatus, a material supply source apparatus for supplying a film forming material, that is, an evaporation source 2 for evaporating a thin film forming material is disposed in a vacuum chamber 1 made of a conductive member. A dome-shaped substrate holder 3 made of a conductive member is disposed so as to face the evaporation source 2. As will be described later, for example, a disk-shaped substrate 4 that is a film formation target is attached to the substrate holder 3. A rotating shaft 5 made of a conductive member is disposed at the center of the back surface of the substrate holder 3 so as to penetrate the wall of the vacuum chamber 1 and extend to the outside. The rotating shaft 5 is rotatably supported by a bearing. A portion (hereinafter referred to as a protruding portion) from the chamber wall portion penetrating portion of the rotating shaft 5 to the tip is connected to a motor 6 serving as a rotation driving portion.
[0022]
A brush (not shown) is provided at a predetermined portion of the protruding portion of the rotating shaft 5 so as to be in direct contact with the rotating shaft 5. The brush is connected to a high frequency power source (RF) 7 and a direct current power source (DC) 8 through a cable. The high-frequency power source 7, the DC power source 8, and the vacuum chamber 1 are grounded.
[0023]
The base material holder 3 is provided with a plurality of circular openings having the same size, and the base material 4 is attached to the openings. The arrangement of the openings is not particularly limited, but here, for example, the openings are arranged at equal intervals on a concentric circle with the rotation axis 5 as the center, and the base material 4 is attached to each of the openings. Such a base material holder 3 is comprised from electroconductive materials, such as aluminum and SUS.
[0024]
FIG. 2 is a schematic cross-sectional view showing a detailed structure of the substrate holder of FIG. 1, and here, one of a plurality of openings is illustrated.
[0025]
As shown in FIG. 2, a base material support member 9 for attaching the base material 4 to the base material holder 3 is fitted into the opening 3 a of the base material holder 3. The substrate support member 9 is made of a conductive material such as aluminum, SUS, or brass, and has the following structure.
[0026]
The main body of the base material supporting member 9 has a cylindrical shape, and has a claw 9A protruding inward at the lower end portion and a flange portion 9B at the upper end portion. The base material support member 9 is supported by the base material holder 3 by the lower surface of the flange portion 9B coming into contact with the peripheral surface of the opening 3a of the base material holder 3, and the base material support member 9 is fitted into the opening. .
[0027]
The base material 4 is fitted and accommodated inside the base material support member 9 attached to the opening 3a so as to be supported by the claws 9A. In the present embodiment, the substrate 4 is made of an insulating material and has a disk shape. In the base material 4 fitted in the base material support member 9, the surface on the inner side of the dome of the base material holder 3 becomes a film formation surface.
[0028]
The surface of the substrate 4 opposite to the film formation surface (hereinafter referred to as the back surface) is completely covered by the auxiliary electrode 10A disposed above. 10 A of auxiliary electrodes are arrange | positioned so that the base-material support member 9 whole including the accommodated base material 4 may be covered from a back surface side, and the peripheral part of the opening part 3a of the base-material holder 3 may be covered. Such an auxiliary electrode 10 </ b> A is electrically connected to the substrate holder 3 by directly contacting the periphery of the opening 3 a of the substrate holder 9. The auxiliary electrode 10A is made of a material that can be used as an electrode material, such as aluminum or SUS. For example, the auxiliary electrode 10A may be formed of aluminum foil.
[0029]
Next, the operation of the ion plating apparatus configured as described above will be described.
[0030]
1 and 2, the base material supporting member 9 on which the base material 4 is arranged is mounted on the opening 3 a of the base material holder 3, and the motor 6 is driven. Then, the rotating shaft 5 and the substrate holder 3 attached to one end thereof rotate. On the other hand, the high frequency power supply 7 and the DC power supply 8 are operated. Then, a high frequency voltage and a direct current voltage are applied to the brush (not shown) via the cable, and further applied to the rotating shaft 5 in contact with the brush. Thereby, a high-frequency voltage and a DC voltage are applied between the substrate holder 3 and the vacuum chamber 1.
[0031]
Next, the thin film forming material filled in the evaporation source 2 is evaporated. Then, the evaporated thin film forming material is excited by the plasma generated by the high frequency voltage, and this excited thin film forming material is accelerated by the self-bias and the direct current electric field, and collides with and adheres to the surface of the substrate 4. Thereby, a thin film is formed on the surface of the substrate 4.
[0032]
At this time, since the auxiliary electrode 10 </ b> A that is electrically connected to the substrate holder 3 is provided on the back surface of the substrate 4, a high-frequency voltage is applied to the auxiliary electrode 10 </ b> A through the substrate holder 3. Since the entire back surface of the base material 4 is covered with the auxiliary electrode 10A, not only the outer peripheral portion in contact with the conductive base material support member 9 but also the center of the base material, even the insulating base material 4 Sufficient self-bias is generated even in the area. Thereby, the momentum when the thin film forming material collides with the surface of the substrate 4 becomes substantially uniform between the outer peripheral portion and the central portion of the substrate 4. For this reason, in the thin film formed on the surface of the base material 4, the film quality such as the refractive index and the adhesiveness is made uniform in the regions corresponding to the outer peripheral portion and the central portion of the base material 4, and the self-bias provides momentum. Since the thin film forming material can be made to collide with the base material 4 well, a dense film is formed, and the film quality such as refractive index and adhesion is improved, that is, sufficient ion plating effect is obtained.
[0033]
The effects in the present embodiment as described above are particularly effective when a film is formed using an optical multilayer filter in which a large number of thin films are laminated or a substrate having a large diameter.
(Embodiment 2)
The ion plating apparatus according to the present embodiment has the same configuration as that of the apparatus of the first embodiment, but differs from the apparatus of the first embodiment in the following points.
[0034]
FIG. 3 is a schematic top view showing the structure of the substrate holder used in the ion plating apparatus of the present embodiment.
[0035]
As shown in FIG. 3, in the present embodiment, the auxiliary electrode 10B has a mesh shape, and the back surface of the substrate 4 is exposed between the meshes. According to such a configuration, when the substrate 4 is heated by the heater at the time of film formation, the heat of the heater can be efficiently transmitted from between the meshes to the back surface of the substrate 4. It can suppress that the temperature rising of the base material 4 is prevented. For this reason, it becomes possible to heat the base material 4 efficiently.
(Embodiment 3)
The ion plating apparatus according to the present embodiment has the same configuration as that of the apparatus of the first embodiment, but differs from the apparatus of the first embodiment in the following points.
[0036]
FIG. 4 is a schematic cross-sectional view showing the structure of the substrate holder used in the ion plating apparatus of the present embodiment. In FIG. 2 of the first embodiment, one of the plurality of openings 3a provided in the base material holder 3 is illustrated. However, in FIG. 4, the plurality of openings and each of the openings attached thereto. The substrate 4 is shown.
[0037]
As shown in FIG. 4, in the present embodiment, the auxiliary electrode 10 </ b> A is not provided for each individual base material 4 arranged in each opening 3 a of the base material holder 3 as in the first embodiment. The auxiliary electrode 10 </ b> C common to the plurality of base materials 4 is provided so as to cover the entire dome outer surface of the base material holder 3. The auxiliary electrode 10C is electrically connected to the substrate holder 3 by a plurality of spacers 11 made of a conductive material. According to such a configuration, it is not necessary to individually arrange the auxiliary electrodes with respect to the plurality of base materials 4, and thus the auxiliary electrodes 10C can be easily arranged. In addition, since the number of parts of the apparatus is reduced, it is possible to reduce the apparatus cost.
(Embodiment 4)
The ion plating apparatus according to the present embodiment has the same configuration as that of the apparatus of the third embodiment, but differs from the apparatus of the third embodiment in that the auxiliary electrode has a mesh shape. According to such a configuration, the same effect as that of the third embodiment can be obtained, and the same effect as that of the second embodiment that enables the base material to be efficiently heated can be obtained.
(Embodiment 5)
The ion plating apparatus according to the present embodiment has the same configuration as that of the apparatus of the first embodiment, but differs from the apparatus of the first embodiment in the following points.
[0038]
FIG. 5 is a schematic cross-sectional view showing the structure of the substrate holder used in the ion plating apparatus of the present embodiment. Here, as in the case of FIG. 2, one of the openings of the substrate holder is illustrated.
[0039]
As shown in FIG. 5, in the present embodiment, the auxiliary electrode 10 </ b> D also functions as the base material support member 9 in the first embodiment. That is, the auxiliary electrode and the substrate support member are integrated. The auxiliary electrode 10D is formed of an electrode body 10a that covers the back surface of the substrate 4 and the periphery of the opening of the substrate holder 3, and nails that extend from the electrode body 10a into the substrate holder 3 and are provided at the ends. 4 and a support portion 10b for supporting the The support portion 10 b is fitted into the opening of the base material holder 3, and the auxiliary electrode 10 </ b> D is supported by the lower surface of the outer periphery of the electrode main body portion 10 a coming into contact with the outer surface of the base material holder 3.
[0040]
According to such a configuration, since the base material supporting member is not necessary, the number of parts of the apparatus can be reduced. Therefore, it is possible to reduce the apparatus cost. In the present embodiment, the auxiliary electrode 10D may completely cover the back surface of the substrate 4 or may have a mesh shape.
[0041]
In the above first to fifth embodiments, the case of using a base material holder having a dome shape and having a plurality of circular openings has been described, but the shape of the base material holder is not limited to this. Further, the number and shape of the openings are not particularly limited.
[0042]
In the first to fifth embodiments, film formation is performed by applying a high-frequency electric field and a direct current electric field. However, the present invention can be applied even when film formation is performed by applying only a high-frequency electric field. .
[0043]
In the above first to fifth embodiments, the case where the present invention is applied to an ion plating apparatus has been described. However, the film forming apparatus according to the present invention is not limited to this, and a high-frequency electric field or a high-frequency electric field is used. And a direct current electric field to form a film, for example, a sputtering film forming apparatus or a CVD (Chemical Vapor Deposition).
[0044]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
(1) By arranging the auxiliary electrode on the back surface of the base material, it becomes possible to generate a sufficient self-bias even in the central part of the base material. The momentum of impact of the thin film forming material becomes substantially uniform. Thereby, in the formed thin film, it is possible to make the film quality uniform in the region corresponding to the peripheral part and the central part of the base material, and to improve the film quality.
(2) Assuming that the auxiliary electrode has a mesh shape, when the substrate is heated, heat is efficiently transferred to the substrate exposed between the meshes. For this reason, it is possible to efficiently heat the base material while preventing the auxiliary electrode from hindering the temperature rise of the base material.
(3) When the base material holder has a plurality of openings and a base material is attached to each of the openings, and a common auxiliary electrode that covers the surface opposite to the film formation surface of the plurality of base materials is disposed, Since it is not necessary to separately arrange auxiliary electrodes on individual substrates, it is possible to easily arrange auxiliary electrodes, and it is possible to reduce the cost of the apparatus because the number of parts of the apparatus is reduced. .
(4) If the base material is attached to the opening of the base material holder via the base material support member, and the auxiliary electrode also serves as the support member, the number of parts can be reduced because there is no need to provide a separate base material support member. Therefore, the apparatus cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the structure of an ion plating apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view schematically showing the structure of the base material holder of FIG.
3 is a schematic top view showing the structure of an auxiliary electrode used in the ion plating apparatus according to Embodiment 2. FIG.
4 is a schematic cross-sectional view showing the structure of an auxiliary electrode used in the ion plating apparatus according to Embodiment 3. FIG.
5 is a schematic cross-sectional view showing the structure of an auxiliary electrode used in the ion plating apparatus according to Embodiment 5. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Evaporation source 3 Base material holder 4 Base material 5 Rotating shaft 6 Motor 7 High frequency power supply 8 DC power supply 9 Base material supporting member 10A-10D Auxiliary electrode 11 Spacer

Claims (4)

A chamber for forming a film on the substrate using an electric field therein;
A power source for generating the electric field;
A material supply source device for supplying a film forming material;
Disposed in said chamber, an electrically conductive substrate holder which possess an opening is connected the with a power source electrically,
A cylindrical conductive base material support member mounted in the opening;
An auxiliary electrode electrically connected to the substrate holder,
An insulating base material is fitted into the base material support member, and the auxiliary electrode covers the base material support member including the base material from the back side opposite to the film formation surface of the base material. The film-forming apparatus comprised in this .   The film forming apparatus according to claim 1, wherein the auxiliary electrode has a mesh shape. The substrate holder has a plurality of openings, and the substrate support member and the substrate are respectively attached to the openings, and the plurality of auxiliary electrodes are arranged corresponding to the respective substrates. Item 2. The film forming apparatus according to Item 1. The substrate holder has a plurality of openings, the substrate support member and the substrate are mounted in the openings, respectively, and the common auxiliary electrode that covers the back side of the plurality of substrates is disposed. The film forming apparatus according to claim 1.

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