KR101261706B1 - Substrate mounting table and method for manufacturing the same, and substrate processing apparatus - Google Patents

Abstract

An object of the present invention is to provide a mounting table capable of effectively preventing the occurrence of etching spots without damaging the substrate. The mounting table 5A includes, for example, a base 7 formed of a conductive material such as aluminum or stainless steel (SUS), and an insulating film 8 provided on the base 7. The upper surface of the insulating film 8 is a substrate mounting surface 50 on which the glass substrate S for FPD is mounted. The substrate mounting surface 50 has a roughening portion 51 having a rough surface having a surface roughness Ra of 2 μm or more and 6 μm or less, and a surface roughness Ra surrounding the periphery of the roughening part 51 of 2 μm. It has the smooth part 53 which is less than.

Description

SUBSTRATE MOUNTING TABLE AND METHOD FOR MANUFACTURING THE SAME, AND SUBSTRATE PROCESSING APPARATUS

The present invention relates to a substrate mounting table for mounting a substrate, a method for manufacturing the same, and a substrate processing apparatus.

In the manufacturing process of a flat-panel display (FPD), a plasma etching process is performed with respect to the board | substrate which is a to-be-processed object. In the plasma etching process, for example, in a processing container in which a pair of parallel plate electrodes (upper and lower electrodes) are disposed, a substrate is mounted on a mounting table that functions as a lower electrode, and high frequency power is applied to at least one of the electrodes. A high frequency electric field is formed between the electrodes. The plasma of the processing gas is formed by this high frequency electric field, and the material film on the substrate is etched by the plasma. When the plasma etching process is repeatedly performed, etching products are generated, which adhere to and accumulate on the mounting surface. In the case where the surface of the mounting table is a smooth surface, a region where an adherend is interposed between the back surface of the substrate and the mounting table is generated, and a difference in thermal conductivity or conductivity occurs between an area where an adherent is not present. As a result, portions with high etching rate and portions with low etching rate are formed in the surface of the substrate, so that etching unevenness occurs. Moreover, a board | substrate may adhere to a mounting table by adhesive matter.

In order to prevent etch stain, the mounting table which provided the embossed shape in the surface is also known. For example, in Patent Literature 1, even if a deposit occurs on the surface of the mounting table, the surface of the mounting table is provided with a plurality of convex portions whose top surface is roughened to maintain the distance between the substrate and the mounting surface. The occurrence of etching stains is prevented. In addition, Patent Document 1 also proposes to improve the heat conduction efficiency of the heat transfer medium when a smooth portion is formed around the mounting table and the mounting table has a function as an electrostatic adsorption electrode.

Further, in Patent Document 2, from the viewpoint of preventing adhesion of the substrate to the mounting table, particle suppression, and process stability, the surface of the mounting table for plasma CVD is shot blasted to form an uneven portion, thereby providing surface roughness ( After Ra) is made 1 micrometer or more and 8 micrometers or less, it has been proposed to remove chemically, electrochemically and / or mechanically to remove sharp projections of the convex portion.

Japanese Unexamined Patent Publication No. 2006-351949 Japanese Unexamined Patent Publication No. 1998-340896

In the mounting table provided with the embossed convex part on the surface, since contact with a board | substrate becomes a point contact, there exists a problem that stress concentrates in a contact site and damages a board | substrate. On the other hand, when the front surface of the mounting table is roughened, when the mounting table functions as an electrostatic adsorption electrode, the supply of the heat transfer medium to the back surface side of the substrate becomes unstable, making it difficult to control the thermal conductivity efficiency, and also etching. Smudges may occur.

This invention is made | formed in view of the said situation, and makes it a subject to provide the mount which can effectively prevent generation | occurrence | production of an etching spot, without damaging a board | substrate.

The substrate mounting table of the present invention includes a substrate and an insulating film covering the substrate, wherein a substrate mounting surface on which the substrate is mounted is formed by the insulating film, and surface roughness Ra is 2 µm or more on the substrate mounting surface. It has a roughening part which is 6 micrometers or less, and the smoothness part whose surface roughness Ra provided around the said roughening part is less than 2 micrometers.

Moreover, the board | substrate mounting table of this invention supports the center part of a board | substrate by the said roughening part, and supports the peripheral part of a board | substrate by the said smoothing part. Moreover, it is preferable that the board | substrate mounting table of this invention is formed with the material which has the hardness at least the said roughening part below the hardness of the said board | substrate.

In addition, the substrate mounting table of the present invention has a first thermal sprayed coating formed by thermal spraying of the insulating film and a second thermal sprayed coating formed by thermal spraying so as to cover at least a portion of the first thermal sprayed coating, wherein the roughening portion is formed of the first spraying film. It is preferable that the said 2nd thermal sprayed coating is laminated | stacked on 1 thermal sprayed coating. In this case, it is preferable that the surface of the said smooth part is formed of the said 1st sprayed film. Moreover, it is preferable that the said 2nd sprayed film is formed of the material which has the hardness below the hardness of the said board | substrate. In this case, the materials of the first thermal sprayed coating and the second thermal sprayed coating may be different, and the second thermal sprayed coating may be formed of a material having a hardness equal to or less than the hardness of the first thermal sprayed coating.

Moreover, it is preferable that the board | substrate mounting table of this invention has a conductive layer embedded in the said insulating film, and has an electrostatic adsorption function.

The substrate processing apparatus of this invention is equipped with any one of said board mounting tables.

The manufacturing method of the board mounting stand of this invention is a manufacturing method of the board mounting stand which mounts a board | substrate at the time of processing to a board | substrate, The surface of the insulating film which covers a base material is polished, and the surface roughness Ra is less than 2 micrometers. The blasting process is performed on the surface of the substrate mounting surface so that the surface of the insulating film after polishing and the surface of the insulating film after polishing are left in the region of the substrate mounting surface so that the smooth surface remains. Ra) is the roughening process of forming the roughening part of 2 micrometers or more and 6 micrometers or less.

Moreover, the manufacturing method of the board mounting stand in another aspect of this invention is a manufacturing method of the board mounting stand which mounts a board | substrate when processing to a board | substrate, The surface of the insulating film which covers a base material is polished, and surface roughness Ra A blasting process for forming a smooth surface having a thickness of less than 2 μm, and a blast treatment in a region serving as the center portion of the substrate mounting surface such that the smooth surface remains in a region serving as the periphery of the substrate mounting surface with respect to the surface of the insulating film after polishing. And a step of reducing the film and forming a thermal sprayed film having a surface roughness Ra of not less than 2 µm and not more than 6 µm by thermal spraying for the region to be the center portion where the thickness is reduced.

In the manufacturing method of the board mounting stand of the present invention, it is preferable that the insulating film is a thermal sprayed film formed by thermal spraying.

The board | substrate mounting board of this invention set it as the structure which has the roughening part whose surface roughness Ra is 2 micrometers or more and 6 micrometers or less on the board | substrate mounting surface, and the smooth part whose surface roughness Ra provided around the roughening part is less than 2 micrometers. In the roughening part, since it can support in multiple points by fine unevenness | corrugation, there is little possibility that a stress will disperse and damage the back surface of a board | substrate. Moreover, since the roughening part which has a fine unevenness | corrugation is hard to be flattened even if a deposit arises, it can suppress the fluctuation | variation of the heat conduction efficiency and electroconductivity from the board | substrate mounting board by a deposit. Therefore, the nonuniformity of processes, such as an etching spot, for example can be improved. In addition, in the smooth portion, the substrate can be held in close contact with the substrate, so that a closed space can be easily formed on the back surface side of the substrate. For example, when a heat transfer medium is introduced into this space to perform temperature control. It is possible to improve the heat transfer efficiency.

1 is a plan view of a mounting table according to a first embodiment of the present invention;
2 is a cross-sectional view taken from the arrow II-II of FIG. 1;
3 is an enlarged cross-sectional view of an essential part showing a structure near the surface of the mounting table of FIG. 2;
4 is a view for explaining a manufacturing step of the mounting table according to the first embodiment;
5 is a view for explaining a process subsequent to FIG. 4;
6 is a sectional view of the mounting table according to the second embodiment of the present invention;
7 is an enlarged sectional view of an essential part showing a structure near the surface of the mounting table of FIG. 6;
8 is a view for explaining a manufacturing step of the mounting table according to the second embodiment;
9 is a view for explaining a process subsequent to FIG. 8;
10 is a diagram showing a state of an insulating film after roughening;
11 is an enlarged cross-sectional view of an essential part showing the structure near the surface of the mounting table after roughening;
12 is a view for explaining a process subsequent to FIG. 10;
13 is a schematic cross-sectional view showing an example of a plasma etching apparatus to which the substrate mounting table of the present invention is applied;
14 is a schematic cross-sectional view showing another example of the plasma etching apparatus to which the substrate mounting table of the present invention is applied.

[First Embodiment]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a plan view of a mounting table 5A as a substrate mounting table according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken from the arrow II-II of FIG. 1. 3 is the sectional drawing of the principal part which expands and shows the structure of the surface vicinity of the mounting table 5A of the part enclosed with the dotted line of FIG.

The mounting table 5A includes a base 7 and an insulating film 8 provided on the base 7. The base material 7 is formed of electroconductive material, such as aluminum and stainless steel (SUS), for example. The upper surface of the insulating film 8 is, for example, a substrate mounting surface 50 on which a glass substrate (hereinafter, simply referred to as a "substrate") S for FPD is mounted. The substrate mounting surface 50 has a roughening portion 51 having a rough surface having a surface roughness Ra of 2 µm or more and 6 µm or less, and a surface roughness Ra surrounding the roughening portion 51 of less than 2 µm. It has the smooth part 53.

The roughening part 51 of the insulating film 8 of the upper surface of the mounting table 5A has fine unevenness | corrugation as shown in FIG. In the roughening part 51, it becomes possible to support the board | substrate S in contact with the board | substrate S in multiple points in the convex part. As a result, damage to the back surface of the substrate S is prevented. In addition, even when the reaction product, the particle, etc. by etching adhere to the roughening part 51, since fine unevenness exists, it is hard to become a flat surface, and etching spots can be suppressed. The surface roughness Ra of the roughening part 51 is 2 micrometers or more and 6 micrometers or less, and 2.5 micrometers or more and 4.5 micrometers or less are preferable. If the surface roughness Ra of the roughening part 51 in the mounting table 5A is a smooth surface of less than 2 micrometers, an etching product will adhere and deposit on the surface of the insulating film 8 by repeating an etching process. By this deposit, heat transfer from the mounting table 5A to the substrate S becomes uneven in the plane of the substrate S, and there is a fear that etching spots may occur. In addition, it is difficult to process the surface roughness Ra of the roughening part 51 to more than 6 micrometers, and when surface roughness Ra is made too large, a contact with a board | substrate will become small, and it will become easy to produce a damage, or an insulating film Sufficient withstand voltage performance of (8) may not be ensured.

Moreover, the surface roughness Ra of the surface 53a of the smooth part 53 is less than 2 micrometers, and 0.4 micrometer or more and 1.5 micrometers or less are preferable. When the surface roughness Ra of the surface 53a of the smooth portion 53 is less than 2 µm, when the substrate S is mounted on the mounting table 5A, the back surface of the peripheral edge of the substrate S is smoothed. It can be in close contact with the surface 53a of the part 53. This makes it possible to form a sealed space between the substrate S and the roughening portion 51 of the insulating film 8, especially in the case where temperature control is performed by supplying the heat transfer gas to the back surface of the substrate S, Since the heat transfer gas can be sealed in the space on the back surface side of the substrate S, the heat transfer efficiency can be improved.

In addition, surface roughness Ra means the arithmetic mean roughness prescribed | regulated to JIS B0601-1994, determines a reference length from the roughness curve in the direction of the average line, and from this average length to the roughness curve measured from the average line The sum of the absolute values of the deviations and the mean value expressed in micrometers (µm).

The relationship between the height of the roughening part 51 and the surface 53a of the smooth part 53 is an average height of the apex of the convex part of an unevenness | corrugation, and the surface 53a of the smooth part 53 rather than the roughening part 51 is an example. For example, 15 micrometers-25 micrometers (preferably 20 micrometers) can be set high.

Although the insulating film 8 may be a single layer or a plurality of insulating films of different materials may be laminated, the outermost layer is the same as the substrate S so as not to damage the substrate S. It is preferable that it is formed with the material of the hardness below it, and it is more preferable that it is formed with the material whose hardness is lower than the board | substrate S. Here, when the substrate S is a glass substrate, since the Vickers hardness HV is about 650, the outermost surface layer of the insulating film 8 is preferably a material having Vickers hardness HV of 650 or less, and the Vickers hardness HV. It is more preferable that the material is 50-400.

As a material of the outermost surface layer of the insulating film 8, ceramics, a metal-ceramic composite, etc. can be used, for example. Examples of the ceramics include alumina (Al ₂ O ₃ ), aluminum nitride (AlN), and the like. Moreover, as a metal-ceramic composite, a mixed material of aluminum / alumina, the mixed material of aluminum / aluminum nitride, etc. are mentioned, for example. When the metal-ceramic composite is an aluminum / alumina mixed material, for example, a thermal spraying method using a thermal spraying material in which an alloy containing metal aluminum or aluminum at least 50% by volume and alumina having an average particle diameter of 3 µm to 20 µm are mixed. The insulating film 8 (or its outermost surface layer) can be formed by this. It is preferable that content of the alumina in the mixed material of aluminum / alumina is 20 volume%-40 volume% from a viewpoint of suppressing Vickers hardness (HV) to 50-400, for example.

Next, the manufacturing method of the mounting table 5A which has the roughening part 51 and the smoothing part 53 on the insulating film 8 is demonstrated, referring FIG. 4 and FIG. First, as shown in FIG. 4, the structure 5a which has the base material 7 and the insulating film 8a which covers this base material 7 is prepared. In addition, the insulating film 8a may be formed by stacking a plurality of insulating films (not to be referred to as thermal sprayed films) having different materials or deposition methods. At least the outermost surface of the insulating film 8a can be formed by, for example, a thermal spraying method for thermally spraying the ceramics or the metal-ceramic composite. The thermal spraying exposes the rough radiation surface to the insulating film 8a. When the insulating film 8a is formed by thermal spraying, pores may be formed, but in this case, it is preferable to perform a hole sealing treatment in order to ensure the withstand voltage performance.

Next, as shown in FIG. 4, the spinning surface is mechanically polished using, for example, the polishing apparatus 200 to be uniformly smoothed. In this polishing step, polishing is performed until the surface roughness Ra of the insulating film 8a is less than 2 µm.

Next, as shown in FIG. 5, the peripheral part of the smoothed insulating film 8a is protected by the mask 201, and the unmasked inner part is blasted using the blast apparatus 202, for example. The blasting method is not particularly limited as long as the surface roughness Ra can form a rough surface having a thickness of 2 µm or more and 6 µm or less. For example, as an abrasive material, alumina (Al ₂ O ₃ ), silicon carbide (SiC), and zirconia (ZrO ₃ ) or the like can be used. By this blasting process, the center part of the insulating film 8a is roughened, and the roughening part 51 whose surface roughness Ra is 2 micrometers or more and 6 micrometers or less is formed. In addition, in FIG. 5, the fine unevenness | corrugation of the surface of the roughening part 51 is emphasized rather than actually, and is typically represented. In the area | region protected by the mask 201 around the roughening part 51, the smooth surface remains and this becomes the smooth part 53. As shown in FIG. Since the polished surface of the smooth portion 53 remains as it is, the surface roughness Ra is less than 2 µm. In this order, the mounting table 5A (see FIGS. 1 to 3) of the present embodiment can be manufactured.

The mounting table 5A of this embodiment manufactured as mentioned above has the roughening part 51 whose surface roughness Ra is 2 micrometers or more and 6 micrometers or less on the board | substrate mounting surface 50, and surface roughness Ra is two. Since it has the smooth part 53 which is less than micrometer, there is little possibility of damaging the board | substrate S, and generation | occurrence | production of an etching spot etc. can be prevented.

In addition, in the above description, only the minimum configuration of the mounting table 5A has been described, but the mounting table 5A does not interfere with having another configuration. For example, the mounting table 5A may be provided with an electrode layer embedded in the insulating film 8 to function as an electrostatic adsorption electrode, and further, to transfer the heat transfer gas from the substrate mounting surface 50 toward the rear surface of the substrate S. FIG. You may be provided with the back cooling mechanism to supply.

[Second Embodiment]

Next, the board | substrate mounting table of 2nd Embodiment of this invention is demonstrated, referring FIGS. 6-12. FIG. 6 is a cross-sectional view of the mounting table 5B of the present embodiment, and FIG. 7 is an enlarged cross-sectional view of an essential part showing the structure near the surface of the mounting table 5B of the portion enclosed by the dotted line in FIG. 6. The mounting table 5B has a base 7 and an insulating film 8 provided on the base 7.

The upper surface of the insulating film 8 has a roughening portion 51 having a rough surface having a surface roughness Ra of 2 µm or more and 6 µm or less, and a surface roughness Ra surrounding the roughening portion 51 of 2 µm. It has the smooth part 53 which is less than. As shown in FIG. 7, the roughening part 51 is the 1st thermal sprayed coating 55 formed by thermal spraying, and the 2nd thermal sprayed coating of the outermost surface layer laminated | stacked by the thermal spraying on this 1st thermal sprayed film 55. As shown in FIG. Has 57 The surface of the 2nd thermal sprayed coating 57 is a radiation surface by thermal spraying. As for the roughening part 51, the 2nd thermal sprayed coating 57 is exposed as an outermost surface layer, and the 1st thermal sprayed coating (preferably in contact with the 2nd thermal sprayed coating 57) below this 2nd thermal sprayed coating 57 55) may be provided and may have another layer (it cannot be called a thermal sprayed coating). The first thermal sprayed coating 55 is exposed on the surface layer of the smooth portion 53.

The relationship between the height of the roughening part 51 and the surface 53a of the smooth part 53 is an average height of the apex of the convex part of an unevenness | corrugation, and the surface 53a of the smooth part 53 rather than the roughening part 51 is an example. For example, 15 micrometers-25 micrometers (preferably 20 micrometers) can be set high.

As a material of the 1st sprayed film 55 and the 2nd sprayed film 57, ceramics, a metal-ceramic composite, etc. can be used, for example. The first thermal sprayed coating 55 and the second thermal sprayed coating 57 may be formed of the same material, but may be formed of different materials. In order not to damage the board | substrate S further, it is preferable to form the 2nd thermal sprayed coating 57 with the material which is the same as the board | substrate S, or it has the hardness below it, and its hardness is harder than the board | substrate S. It is more preferable to form with a low material. Here, when the board | substrate S is a glass substrate, since the Vickers hardness HV is about 650, it is preferable that the 2nd thermal sprayed coating 57 is a material whose Vickers hardness HV is 650 or less, and Vickers hardness HV It is more preferable that the material is 50-400.

As ceramics which can be used for the 1st sprayed film 55 and the 2nd sprayed film 57, an alumina (Al2O3), aluminum nitride (AlN), etc. are mentioned, for example. Moreover, as a metal-ceramic composite which can be used for the 1st sprayed film 55 and the 2nd sprayed film 57, the mixed material of aluminum / alumina, the mixed material of aluminum / aluminum nitride, etc. are mentioned, for example. Since the second thermal sprayed coating 57 supports the substrate S by roughening fine unevenness, the hardness is lower than that of the first thermal sprayed coating 55 which supports the substrate S by the smoothing portion 53. It is desirable to form a low material. From this point of view, for example, ceramics such as alumina and aluminum nitride are used as the first thermal sprayed coating 55, and a mixed material of aluminum / alumina, a mixed material of aluminum / aluminum nitride, etc. as the second thermal sprayed coating 57, respectively. The combination used is preferable. In addition, as a mixed material of aluminum / alumina, the same thing as 1st Embodiment can be used.

The film thickness of the second thermal sprayed coating 57 is preferably 15 µm to 25 µm from the viewpoint of facilitating control of the surface roughness Ra of the roughening portion 51.

The surface roughness Ra of the roughening part 51 of the insulating film 8 is 2 micrometers or more and 6 micrometers or less, and 2.5 micrometers or more and 4.5 micrometers or less are preferable. The reason why the surface roughness Ra of the roughening part 51 was 2 micrometers or more and 6 micrometers or less is the same as that of 1st Embodiment.

Moreover, the surface roughness Ra of the surface 53a of the smooth part 53 is less than 2 micrometers, and 0.4 micrometer or more and 1.5 micrometers or less are preferable. The reason for making surface roughness Ra of the surface 53a of the smooth part 53 into less than 2 micrometers is the same as that of 1st Embodiment.

Next, a method of manufacturing the mounting table 5B having the roughening portion 51 and the smoothing portion 53 on the insulating film 8 will be described with reference to FIGS. 8 to 12. First, as shown in FIG. 8, the structure 5b which has the base material 7 and the insulating film 8b which covers this base material 7 is prepared. Here, the insulating film 8b may be formed by stacking a plurality of insulating films having different materials or film forming methods. At least the outermost surface of the insulating film 8b is, for example, the first thermal sprayed coating 55 formed by the thermal spraying method of thermally spraying the ceramic material. The thermal spraying exposes the rough radiation surface to the first thermal sprayed coating 55. When the insulating film 8b is formed by thermal spraying, pores may be formed, but in this case, it is preferable to carry out hole sealing treatment in order to ensure the withstand voltage performance.

Next, as shown in FIG. 8, the said spinning surface is mechanically polished using the grinding | polishing apparatus 200, for example, and smoothed uniformly. In this polishing step, polishing is performed until the surface roughness Ra of the insulating film 8b is less than 2 µm.

Next, as shown in FIG. 9, the periphery of the smoothed insulating film 8b is protected by the mask 201, and the unmasked inner part is blasted using the blast apparatus 202, for example. By this blasting process, the center part of the insulating film 8b is roughened, and a film | membrane is reduced (namely, the surface is cut | disconnected and a film thickness is made thin). The blasting process can increase the film reduction amount by lengthening the processing time or by increasing the discharge pressure. In addition, in FIG. 9, the fine unevenness | corrugation of the surface of the insulating film 8b is emphasized more than it actually is, and it is typically demonstrated (FIG. 10, 12 is also the same).

FIG. 10 shows the state of the insulating film 8b after roughening, and FIG. 11 shows an enlarged view of the portion surrounded by the dotted lines in FIG. The film reduction part 52 is formed in the center part of the insulating film 8b. In the area | region protected by the mask 201 around the film | membrane reduction part 52, the smooth surface remains and becomes the smooth part 53. As shown in FIG. The surface roughness Ra of the film reduction part 52 is an example, in order to make it easy to control the surface roughness Ra of the roughening part 51, when forming the 2nd thermal sprayed coating 57 in a later process. For example, it is preferable to set it as 2 micrometers or more and 4 micrometers or less. In addition, the film reduction amount of the film reduction part 52 can be 30 micrometers-50 micrometers based on the surface of the smooth part 53, for example. If the amount of film reduction is too small, it is difficult to form the second thermal sprayed coating 57 in a subsequent step. If the amount of film reduction is too large, the insulation by the insulating film 8b may be deteriorated, and the breakdown voltage performance may be impaired.

Next, as shown in FIG. 12, after the surface of the smooth portion 53 is protected using the mask 201, the thermal spraying gun 203 is used to spray the film reduction portion 52 only. The second thermal sprayed coating 57 is formed. Since the 2nd thermal sprayed coating 57 is formed on the roughened 1st thermal sprayed coating 55, it becomes the roughening part 51 whose surface roughness Ra is 2 micrometers or more and 6 micrometers or less (refer FIG. 6). By stacking the second thermal sprayed coating 57 on the surface of the roughened film reduction part 52 in this manner, the surface roughness of the roughened part 51 is easily controlled, and the anchor effect is achieved. By this, the first thermal sprayed coating 55 and the second thermal sprayed coating 57 can be firmly fixed. In the region protected by the mask 201 around the film reduction portion 52, a smooth surface remains, which becomes the smooth portion 53. Since the polished surface of the smooth portion 53 remains as it is, the surface roughness Ra is less than 2 µm.

When changing the material of the 1st sprayed film 55 and the 2nd sprayed film 57, what is necessary is just to select a sprayed raw material in each film-forming process. For example, a case to form a first thermal sprayed 55, as the sprayed material, such as alumina (Al ₂ O _3), selecting a ceramic material such as aluminum nitride (AlN), and the second sprayed coating (57) In the case of forming the thermal spraying material, the first thermal sprayed coating 55 and the second thermal sprayed coating are selected by, for example, selecting a metal-ceramic composite such as a mixed material of aluminum / alumina and a mixed material of aluminum / aluminum as the thermal spray raw material. The hardness of (57) can be made different. In the order as described above, the mounting table 5B according to the present embodiment (see FIG. 6) can be manufactured.

The mounting table 5B of this embodiment manufactured in this way has the surface roughness Ra which has the 2nd thermal sprayed coating 57 formed in the board | substrate mounting surface 50 with the 1st thermal sprayed coating 55 as a base. Has a roughening portion 51 of 2 µm or more and 6 µm or less and a smooth portion 53 having a surface roughness Ra of less than 2 µm, so that the substrate S is less likely to be damaged, and the occurrence of etching spots or the like is prevented. You can prevent it.

The other structure and effect in this embodiment are the same as that of 1st embodiment.

Application Example to Plasma Etching Equipment

Next, an embodiment in which the substrate mounting table of the present invention is applied to a plasma etching apparatus will be described with reference to FIGS. 13 and 14. As shown in FIG. 13, the plasma etching apparatus 100 is comprised as a capacitively coupled parallel plate plasma etching apparatus which performs etching with respect to the board | substrate S for FPD. Examples of the FPD include a liquid crystal monitor (LCD), an electroluminescence (EL) display, a plasma display panel (PDP), and the like.

This plasma etching apparatus 100 has a processing container 1 molded into a square cylinder shape whose surface is made of aluminum subjected to anodization (anodized). The processing container 1 is constituted by the bottom wall 1a and four side walls 1b (only two of the side walls 1b ₁ and 1b ₂ are shown). In addition, the lid 1c is joined to the upper portion of the processing container 1.

The lid 1c is configured to be opened and closed by an opening and closing mechanism (not shown). In the state where the lid 1c is closed, the joined portion between the lid 1c and each side wall 1b is sealed by a seal member 3 such as an O-ring, and the airtightness in the processing container 1 is maintained.

The insulating member 60 and the lower base material 61 provided on this insulating member 60 are arrange | positioned at the bottom part in the processing container 1. On the lower base 61, a mounting table 5 on which the substrate S can be mounted is provided. The mounting table 5, which is also a lower electrode, includes a substrate 7 and an insulating film 8 formed on the substrate 7. The surface of the insulating film 8 is the substrate mounting surface 50 on which the substrate S is mounted. As the mounting table 5, the mounting table 5A of the first embodiment or the mounting table 5B of the second embodiment can be applied. Therefore, although not shown in the following description, on the substrate mounting surface 50 of the insulating film 8, the roughening part 51 whose surface roughness Ra is 2 micrometers or more and 6 micrometers or less, and surface roughness Ra is 2 The smooth part 53 which is less than micrometers is provided.

The heat transfer medium chamber 83 is provided inside the lower base 61. In this heat transfer medium chamber 83, for example, a heat transfer medium such as a fluorine-based liquid is introduced through the heat transfer medium introduction pipe 83a, and is discharged through the heat transfer medium discharge pipe 83b to circulate. The heat of the heat transfer medium (for example, cold heat) is transferred to the substrate S via the lower base 61 and the mounting table 5. Side portions of the mounting table 5, the lower base 61 and the insulating member 60 are surrounded by the insulating member 13. The insulating member 13 ensures insulation of the side surface of the mounting table 5, and prevents abnormal discharge during plasma processing.

Above the mounting table 5, there is provided a shower head 15 that functions as an upper electrode in parallel with and facing the mounting table 5. The showerhead 15 is supported by the lid 1c at the top of the processing container 1. The shower head 15 has a hollow shape, and a gas diffusion space 15a is provided therein. Further, a plurality of gas discharge holes 15b for discharging the processing gas are formed on the lower surface of the shower head 15 (the surface facing the mounting table 5). The shower head 15 is grounded and constitutes a pair of parallel flat electrodes together with the mounting table 5.

In the vicinity of the upper center of the showerhead 15, a gas inlet 17 is provided. The process gas supply pipe 19 is connected to this gas introduction port 17. The process gas supply pipe 19 is connected to a gas supply source 25 that supplies a process gas for etching via two valves 21 and 21 and a mass flow controller (MFC) 23. As the processing gas, for example, a rare gas such as Ar gas can be used in addition to the halogen gas and the O ₂ gas.

At positions close to the four corners in the processing container 1, four exhaust openings 27 as through-holes are formed in the bottom wall 1a (only two are shown). An exhaust pipe 29 is connected to each of the exhaust openings 27. The exhaust pipe 29 has a flange portion 29a at its end, and is fixed with an O-ring (not shown) interposed between the flange portion 29a and the bottom wall 1a. The exhaust pipe 29 is connected to the exhaust device 31. The exhaust device 31 includes, for example, a vacuum pump such as a turbo molecular pump, and is thereby configured to be capable of vacuum suction of the inside of the processing container 1 to a predetermined reduced pressure atmosphere.

In addition, provided with a side wall (1b _1), the substrate feeding opening 33 is as a through-opening of the processing container (1). This board | substrate conveyance opening 33 is opened and closed by the gate valve 35, and the board | substrate S can be conveyed between adjacent conveyance chambers (not shown). Gate valve 35 is fixed to the side wall (1b ₁₎ with a fixing means such as screws in a state in which through the first seal member is an O-ring 37 between the side wall (1b _1).

The feeder line 39 is connected to the lower base material 61. The power supply line 39 is connected to a high frequency power supply 43 via a matching box (M.B.) 41. Thereby, the high frequency electric power of 13.56 MHz, for example, is supplied from the high frequency power supply 43 to the mounting table 5 as a lower electrode via the lower base material 61. In addition, the feed line 39 is introduced into the processing container 1 via an opening 45 for feeding as a through opening formed in the bottom wall 1a.

Next, the process operation in the plasma etching apparatus 100 comprised as mentioned above is demonstrated. First, in the state in which the gate valve 35 is opened, the board | substrate S which is a to-be-processed object is carried in into the process container 1 via the board | substrate conveyance opening 33 by the conveying apparatus fork which is not shown in figure, It is exchanged with the mounting table 5. At this time, the mounting table 5 includes roughening portions 51 having a surface roughness Ra not shown on the substrate mounting surface 50 of 2 µm or more and 6 µm or less, and a smooth portion having surface roughness Ra of less than 2 µm. 53, the roughening part 51 can support the board | substrate S at the multiple point by a fine unevenness | corrugation. As a result, stress is dispersed and there is little possibility that the back surface of the board | substrate S will be damaged. Moreover, in the smooth part 53, since the board | substrate S can be made to adhere and support, it is possible to form a sealed space easily in the back surface side of the board | substrate S. As shown in FIG. Thereafter, the gate valve 35 is closed, and the inside of the processing container 1 is vacuum sucked up to a predetermined vacuum degree by the exhaust device 31.

Next, the valve 21 is opened, and the processing gas is introduced into the gas diffusion space 15a of the shower head 15 from the gas supply source 25 via the processing gas supply pipe 19 and the gas inlet 17. . At this time, the flow rate control of the processing gas is executed by the mass flow controller 23. The processing gas introduced into the gas diffusion space 15a is further uniformly discharged with respect to the substrate S mounted on the mounting table 5 via the plurality of discharge holes 15b, and thus the pressure in the processing container 1. This is kept at a predetermined value.

In this state, high frequency power is applied to the mounting table 5 from the high frequency power supply 43. As a result, a high frequency electric field is generated between the mounting table 5 as the lower electrode and the showerhead 15 as the upper electrode, so that the processing gas is decomposed to form a plasma. By such a plasma, an etching process is performed on the board | substrate S. FIG.

After performing the etching process, the application of the high frequency power from the high frequency power supply 43 is stopped, and gas introduction is stopped, and then the inside of the processing container 1 is reduced to a predetermined pressure. Next, the gate valve 35 is opened, the substrate S is exchanged from the mounting table 5 to a conveying device fork not shown, and the substrate S is opened from the substrate conveyance opening 33 of the processing container 1. Export) By the above operation, the plasma etching process with respect to the board | substrate S is complete | finished. By repeating such a plasma etching process, even if an etching product is produced in the processing container 1 and adheres to the roughening portion 51, the roughening portion 51 having fine concavities and convexities is difficult to be flattened. The fluctuation | variation of the heat conduction efficiency and electroconductivity from (5) to the board | substrate S can be suppressed. Therefore, the nonuniformity of processing, such as an etching spot, can be prevented, for example.

Moreover, the board | substrate mounting table of this invention can also have an electrostatic adsorption function. For example, the plasma etching apparatus 101 shown in FIG. 14 uses a mounting table 5C having an electrostatic adsorption function as the substrate mounting table. Since the other structure of the plasma etching apparatus 101 shown in FIG. 14 is the same as that of the plasma etching apparatus 100 of FIG. 13, the same code | symbol is attached | subjected to the same structure, and description is abbreviate | omitted.

The mounting table 5C, which is a board mounting table, has a substrate 65 made of a conductive material such as aluminum. This base material 65 corresponds to the base material 7 in 1st and 2nd embodiment. On the upper surface of this base material 65, the 1st insulating layer 67, the electrode 69, and the 2nd insulating layer 71 are laminated | stacked in order from the bottom. This second insulating layer 71 corresponds to the insulating film 8 in the substrate mounting tables 5A and 5B of the first and second embodiments. By applying a DC voltage from the DC power supply 73 to the electrode 69 between the first insulating layer 67 and the second insulating layer 71 via the feeder line 75, for example, by a coulomb force, Electrostatic adsorption of (S). On the upper surface of the second insulating layer 71, a substrate mounting surface 50 for adsorption holding of the substrate S is formed. Although not shown, the substrate mounting surface 50 is provided with the roughening part 51 whose surface roughness Ra is 2 micrometers or more and 6 micrometers or less, and the smooth part 53 whose surface roughness Ra is less than 2 micrometers.

A gas passage 77 penetrating the insulating member 60 and the lower base 61 is formed. The heat transfer gas, for example, HE gas or the like, can be supplied to the rear surface of the substrate S via the gas passage 77. That is, the mounting table 5C has a back cooling mechanism for supplying and cooling the heat transfer gas to the rear surface of the substrate S. FIG. The heat transfer gas supplied to the gas passage 77 diffuses in the horizontal direction once through the gas collection portion 79 formed at the boundary between the lower base 61 and the base 65, and then the gas supply communication formed in the base 65. Through the hole 81, it blows off from the surface of 5 C of mounting tables to the back surface side of the board | substrate S. FIG. In this way, cooling heat of 5 C of mounting tables is transmitted to board | substrate S, and board | substrate S is hold | maintained at predetermined temperature.

Since the mounting table 5C of this embodiment which has the above structure is equipped with the electrostatic adsorption mechanism, the board | substrate S is strongly attracted by the board | substrate mounting surface 50, but the fine convex part in the roughening part 51 is carried out. In this case, the stress can be dispersed by contacting the substrate S at multiple points to support the substrate S. FIG. As a result, damage to the back surface of the substrate S is prevented. Moreover, even if the reaction product, particle | grains, etc. by etching adhere to the roughening part 51, since it is a fine unevenness | corrugation, it is hard to become a flat surface. Moreover, since the smooth part 53 can be closely contacted with the back surface of the board | substrate S by the smooth surface, it forms the airtight space between the back surface of the board | substrate S and the roughening part 51, Heat transfer is efficiently performed. Therefore, even if the etching process is repeated, heat transfer from the mounting table 5C to the substrate S can be made uniform in the plane of the substrate S, and generation of etching spots can be prevented.

As mentioned above, although embodiment of this invention was described in detail for the purpose of illustration, this invention is not restrict | limited to the said embodiment. Those skilled in the art can make many modifications without departing from the spirit and scope of the present invention, and they are included in the scope of the present invention. For example, the present invention is not only limited to a plasma processing apparatus for processing a substrate for FPD, but also can be applied to a plasma processing vessel for processing a semiconductor wafer, for example. The present invention can also be applied to a plasma processing apparatus that performs not only the plasma etching apparatus but also other plasma processing such as plasma ashing processing and plasma CVD processing.

1: processing container 1a: bottom wall
1b ₁ , 1b ₂ : side wall 1c: cover
3: seal member 13: insulation member
5: mounting table 7: base material
8 insulating film 15 shower head
15a: gas diffusion space 15b: gas discharge hole
17 gas introduction port 19 process gas supply pipe
21: valve 23: mass flow controller
25 gas supply source 27 exhaust opening
29 exhaust pipe 31 exhaust device
33 substrate opening 35 gate valve
37: O-ring 39: feeder
41: matching box (MB) 43: high frequency power supply
45: opening for power supply 50: substrate mounting surface
51: roughing part 53: smoothing part
100, 101: plasma etching apparatus S: substrate

Claims (13)

The substrate and the insulating film which covers the said base material are provided, The board mounting surface which mounts a board | substrate is formed by the said insulating film, and it is fine so that surface roughness Ra may be 2 micrometer or more and 6 micrometer or less in the said board | substrate mounting surface. The roughening part in which the unevenness | corrugation was formed, and the smoothness of surface roughness Ra provided around the said roughening part is less than 2 micrometers,
The minute unevenness is formed over the entire roughening portion, and the entire roughening portion contacts the substrate and supports the substrate.
Board Mount. The method of claim 1,
The center portion of the substrate is supported by the roughening portion, and the peripheral portion of the substrate is supported by the smoothing portion.
Board Mount. 3. The method according to claim 1 or 2,
At least the roughening portion is formed of a material having a hardness less than or equal to the hardness of the substrate.
Board Mount. 3. The method according to claim 1 or 2,
The insulating film has a first thermal sprayed coating formed by thermal spraying and a second thermal sprayed coating formed by thermal spraying so as to cover at least a portion of the first thermal sprayed coating, and wherein the roughening portion is formed on the first thermal sprayed coating. Stacked desert
Board Mount. The method of claim 4, wherein
The surface of the said smooth part is formed of the said 1st thermal sprayed coating
Board Mount. The method of claim 4, wherein
The second thermal sprayed coating is formed of a material having a hardness less than or equal to the hardness of the substrate.
Board Mount. The method according to claim 6,
Different materials of the first thermal sprayed coating and the second thermal sprayed coating
Board Mount. The method of claim 7, wherein
The second thermal sprayed coating is formed of a material having a hardness less than or equal to the hardness of the first thermal sprayed coating
Board Mount. 3. The method according to claim 1 or 2,
It has a conductive layer embedded in the said insulating film, and has an electrostatic adsorption function.
Board Mount. The board | substrate mounting base of Claim 1 or 2 provided.
/ RTI > In the manufacturing method of the board mounting base which mounts a board | substrate when processing a board | substrate,
A polishing step of polishing the surface of the insulating film covering the substrate to form a smooth surface having a surface roughness Ra of less than 2 μm,
With respect to the surface of the said insulating film after grinding | polishing, a blast process is performed to the area | region used as the center part of the said board | substrate mounting surface so that a smooth surface may remain in the area | region which becomes a peripheral part of a board | substrate mounting surface, and surface roughness Ra is 2 micrometers or more 6 A roughening step of forming a roughening portion in which fine unevenness is formed to be less than or equal to μm,
In the said roughening process, the said roughening part is formed so that the said fine roughness may be formed over the whole said roughening part, and the whole said roughening part contacts a board | substrate and supports a board | substrate.
Method of manufacturing a substrate mount. The method of claim 11,
The roughening process,
Performing a blast treatment on a region that becomes a central portion of the substrate mounting surface to reduce the film;
A step of forming a thermal sprayed film having a surface roughness (Ra) of 2 µm or more and 6 µm or less by thermal spraying with respect to the region to be the center portion where the film is reduced;
Method of manufacturing a substrate mount. 13. The method according to claim 11 or 12,
The insulating film is a thermal sprayed film formed by thermal spraying
Method of manufacturing a substrate mount.

Images