JP2006352033A - Deposition equipment and equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide deposition equipment, through which a flaw is less likely to be generated on a substrate rear surface and reaction products are less likely to come off, after a thinning process. <P>SOLUTION: The deposition equipment has a stage surface 1a for holding an object substrate 2, such that it makes point contacts, the object substrate 2 composed of a material with glass or Vickers hardness of about 5,374 N/mm<SP>2</SP>. The stage surface 1a is formed of stainless steel, whose arithmetic average height Ra in roughness curve is equal to or greater than 0.1 μm and smaller than 0.3 μm, and whose maximum height Ra in roughness curve is equal to or greater than 0.5 μm and smaller than 2.5 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a film forming apparatus for performing a film forming operation in a vacuum or atmospheric pressure. In particular, the present invention relates to a film forming apparatus having a structure in which a glass substrate or a target substrate having the same degree of hardness as that of a glass substrate is held in contact with a stainless steel stage surface to perform a film forming process. Furthermore, it is related with the apparatus generally provided with the stage for mounting a board | substrate.

  As part of a method for manufacturing a screen display device such as a liquid crystal display device or a plasma display device, there is a step of forming a film on one surface of a substrate. The substrate here is, for example, a glass substrate. After the step of forming the film, a process of reducing the thickness of the substrate by removing the substrate material by a certain thickness from the surface opposite to the surface on which the film has been formed by using corrosive chemical etching, that is, a process of reducing the thickness There is.

  When a film is formed on the surface of the substrate, the film is formed by placing the substrate on some stage. When the substrate is placed on the stage, micro scratches (hereinafter referred to as “substrate back micro scratches”) due to unevenness on the stage surface occur on the back surface of the substrate. When this substrate is subjected to the next process, ie, thinning with a corrosive chemical, the substrate back surface micro-scratches are enlarged due to the anisotropic etching effect brought about by the corrosive chemical (hereinafter referred to as “substrate back scratch”). It is said.) Therefore, in order to prevent the occurrence of such scratches on the back surface of the substrate, it is desirable to prevent as little scratches on the back surface of the substrate as possible when the substrate is placed on the stage in the film forming process.

  By reducing the surface roughness of the stage and flattening the surface of the stage, it is possible to suppress the generation of minute scratches on the back surface of the substrate and, as a result, to prevent scratches on the back surface of the substrate. When the surface is reduced and flattened, foreign substances such as reaction products adhering to the stage surface in the course of film formation work are easily peeled off from the stage surface.

In JP-A-8-102443 (Patent Document 1), B is included by setting the surface roughness Ra of a member such as a stage used in the vacuum chamber to a range of 0.2 to 4.0 μm. It has been reported that the reaction product of the amorphous Si film is effective in preventing peeling.
JP-A-8-102443

  It is also conceivable to apply the surface roughness range of the technique of Patent Document 1 to stage surface roughness management for the purpose of preventing scratches on the back surface of the substrate. However, in the definition of the surface roughness using only the Ra value as described above, there may be a case where the Ra value is satisfied even in the stage where the projection is locally provided. Local protrusions cause scratches on the back surface of the substrate, which is insufficient as a provision for managing the surface roughness of the stage.

  In film deposition equipment, when a substrate such as a glass substrate is placed on the stage, minute scratches on the backside of the substrate caused by contact between the substrate and the stage become scratches on the backside of the substrate due to expansion by a corrosive chemical during thinning processing, resulting in poor appearance. As well as a reduction in substrate strength. That is, the durability as a product using this substrate is lowered. Further, in a screen display device such as a liquid crystal display device or a plasma display device, a display defect due to light scattering at a flaw occurrence site becomes a problem.

  By reducing the surface roughness of the stage and smoothing the surface of the stage, the occurrence of scratches on the backside of the substrate can be suppressed to some extent, but in that case, the reaction product attached to the stage surface becomes easy to peel off, A situation occurs in which the peeled reaction product adheres to the substrate. If a foreign substance such as a reaction product adheres to the substrate, a product using the substrate becomes defective.

  In the prior art, a technique for preventing the back surface of the substrate from being scratched and preventing the reaction product from peeling off has not been presented. In view of the above, an object of the present invention is to provide a film forming apparatus in which scratches on the back surface of the substrate after the thinning process are unlikely to occur and the reaction product is unlikely to peel off.

  It is another object of the present invention to prevent the occurrence of minute scratches on the back surface of the substrate in other devices in general.

In order to achieve the above object, a film forming apparatus according to the present invention comprises a stage surface for abutting and holding a target substrate made of glass or a material having a Vickers hardness of about 5374 N / mm ² . The stage surface is made of stainless steel, the arithmetic mean height Ra of the roughness curve is 0.1 μm or more and 0.3 μm or less, and the maximum height Rz of the roughness curve is 0.5 μm or more and 2.5 μm.

  When the present invention is applied to a film forming apparatus, scratches on the back surface of the substrate after the thinning process are less likely to occur, and the reaction product is less likely to be peeled off.

(Embodiment 1)
(Constitution)
With reference to FIG. 1, the film-forming apparatus in Embodiment 1 based on this invention is demonstrated. As shown in FIG. 1, the film forming apparatus includes a vacuum chamber 5 and a stage 1 disposed therein. The stage 1 is for abutting and holding a target substrate made of glass or a material having a Vickers hardness of about 5374 N / mm ² , and has a stage surface 1 a for abutting the target substrate. The fact that the stage 1 which is a part of the film forming apparatus has the stage surface 1a is nothing but that the film forming apparatus includes the stage surface 1a.

  The film forming apparatus further includes a support portion 6 as a mechanism for bringing the target substrate into contact with the stage surface 1a. The stage surface 1a is made of stainless steel, the arithmetic mean height Ra of the roughness curve is 0.1 μm or more and 0.3 μm or less, and the maximum height Rz of the roughness curve is 0.5 μm or more and 2.5 μm. An electrode 3 is disposed at a position facing the stage surface 1 a, and the electrode 3 is electrically connected to a high frequency power source 4 outside the vacuum chamber 5.

(Action / Effect)
In the film forming apparatus according to the present embodiment, the target substrate 2 can be placed so as to abut on the stage surface 1 a as shown in FIG. The target substrate 2 may be a glass substrate. In this state, the inside of the vacuum chamber 5 is evacuated to supply a high frequency from the high frequency power source 4 to the electrode 3, whereby a film forming process can be performed on the surface 2 a of the target substrate 2. At this time, the back surface 2b of the target substrate 2 comes into contact with the stage surface 1a.

  For comparison, several types of surface roughness were prepared as the stage surface 1a, and the glass substrate as the target substrate 2 was formed using each of them. If the substrate back surface scratches occur on the glass substrate, it appears as a substrate back surface scratch after the thinning process, so the back surface was observed after each glass substrate was thinned. FIG. 3 is a graph showing the relationship between the surface roughness of the stage surface 1a and the occurrence rate of scratches on the back surface of the substrate after the thinning process.

As can be seen from FIG. 3, in the stage where the stage surface was finished to Ra = 4.5 μm and Rz = 25.0 μm, the occurrence rate of scratches on the back surface of the substrate was 0.017 / cm ² . In this test, “substrate back surface scratch” refers to a scratch having a diameter of 0.01 mm or more. In the case of using a stage whose stage surface was finished with Ra = 3.0 μm and Rz = 20.0 μm, the occurrence rate of scratches on the back surface of the substrate was 0.004 / cm ² . When the stage surface is finished with Ra = 0.1 μm or more and 0.3 μm or less and Rz = 0.5 μm or more and 2.5 μm or less, the occurrence rate of scratches on the back of the substrate is reduced to 0.001 piece / cm ^2. Was.

  Thus, there is a correlation between the surface roughness of the stage surface used in the film formation process and the occurrence rate of scratches on the back surface of the substrate after the thinning process. In the stage where the stage surface is finished with Ra = 0.1 μm or more and 0.3 μm or less and Rz = 0.5 μm or more and 2.5 μm or less, it can be said that scratches on the back surface of the substrate after the thinning process are extremely difficult to occur.

In order to evaluate the degree of adhesion of the reaction product to the target substrate when using a film forming apparatus equipped with a stage under these conditions, an amorphous silicon film containing P is formed using a chamber pressure of 133 Pa, a substrate temperature of 260 ° C., and a monosilane gas. (SiH ₄ ) 34.8 sccm, hydrogen gas (H ₂ ) 5250 sccm, phosphine gas 0.2 sccm, high-frequency power output of 1000 W, and the number of dust adhering to the substrate during the period until the vacuum chamber cleaning. The transition was investigated in chronological order. The vacuum chamber is cleaned each time the accumulated film thickness from the previous cleaning reaches 80 μm. The results of the survey are shown in FIG. As shown in FIG. 4, no correlation was observed between the accumulated film thickness and the increase in the number of dusts. The fact that the dust adhesion to the substrate can be suppressed in this way without increasing with the integrated film thickness is considered that the reaction product is hardly peeled off on the stage surface of the film forming apparatus.

  As described above, the stage surface 1a finished so that the arithmetic average height Ra of the roughness curve is 0.1 μm to 0.3 μm and the maximum height Rz of the roughness curve is 0.5 μm to 2.5 μm. According to the film forming apparatus provided with the stage having the above structure, it is difficult to cause scratches on the back surface of the substrate after the thinning process and the reaction product is difficult to peel off. The quality of the product can be improved.

In each of the above experiments, a glass substrate was adopted as the target substrate. However, it is considered that the same effect can be obtained even if the target substrate is a substrate made of a material having the same degree of hardness as glass instead of the glass substrate. . That is, the target substrate may be a substrate made of glass or a material having a Vickers hardness of about 5374 N / mm ² .

  In the present embodiment, the film forming apparatus includes the vacuum chamber 5 and has been described on the assumption that the film forming apparatus is used for forming a film on the surface of the target substrate in a vacuum. Not limited to this. The film forming apparatus may be for forming a film on the surface of the target substrate at atmospheric pressure. Even in such a case, it is considered that a similar effect can be obtained by preparing a stage surface that satisfies the above-described conditions.

  Note that the application target of the present invention is not limited to the film forming apparatus. Other apparatuses may be used as long as the surface roughness of the stage for fixing the target substrate is processed within the above-described surface roughness range. In other devices as a whole, it is considered that a fine scratch on the back surface of the substrate is less likely to occur by preparing a stage surface that satisfies the above-described conditions. Regarding this, it is considered that the same effect can be obtained regardless of whether it is in a vacuum or atmospheric pressure.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

It is a conceptual diagram of the film-forming apparatus in Embodiment 1 based on this invention. It is a conceptual diagram of the use condition of the film-forming apparatus in Embodiment 1 based on this invention. It is a graph which shows the relationship between the surface roughness of the stage surface 1a investigated in Embodiment 1 based on this invention, and the generation | occurrence | production rate of the substrate back surface crack after a thickness reduction process. It is a graph which shows change of the number of dust adhering to a substrate investigated in Embodiment 1 based on the present invention in time series.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Stage, 1a Stage surface, 2 Target substrate, 2a (Target substrate) surface, 2b (Target substrate) back surface, 3 Electrode, 4 High frequency power supply, 5 Vacuum chamber, 6 Support part.

Claims (5)

A stage surface for holding a target substrate made of glass or a material having a Vickers hardness of about 5374 N / mm ² in contact therewith,
The stage surface is formed of stainless steel, the arithmetic mean height Ra of the roughness curve is 0.1 μm or more and 0.3 μm or less, and the maximum height Rz of the roughness curve is 0.5 μm or more and 2.5 μm. apparatus.   The film forming apparatus according to claim 1, which is for forming a film on a surface of the target substrate in a vacuum.   The film forming apparatus according to claim 1, which is for forming a film on the surface of the target substrate in an atmospheric pressure. A stage surface for holding a target substrate made of a material having a glass or Vickers hardness of about 5374 N / mm ² in a vacuum is provided.
The stage surface is made of stainless steel, the arithmetic mean height Ra of the roughness curve is 0.1 μm or more and 0.3 μm or less, and the maximum height Rz of the roughness curve is 0.5 μm or more and 2.5 μm. A stage surface for holding a target substrate made of a material having a glass or Vickers hardness of about 5374 N / mm ² and holding it at atmospheric pressure,
The stage surface is made of stainless steel, the arithmetic mean height Ra of the roughness curve is 0.1 μm or more and 0.3 μm or less, and the maximum height Rz of the roughness curve is 0.5 μm or more and 2.5 μm.

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