Method of cleaning a film deposition apparatus, method of dry etching a film deposition apparatus, and an article production method including a process based on the cleaning or dry etching method

Abstract

A method for performing a cleaning process uses a cleaning gas and high-frequency power upon a film deposition apparatus for depositing a film on a substrate placed in a reactor chamber which can be evacuated to a low pressure. Supplying of high-frequency power is temporarily stopped in the middle of the cleaning process, and the cleaning process is restarted by again supplying high-frequency power. This method is capable of effectively removing by-products from the inside of a reactor chamber and makes it possible to form a high-quality deposition film, in particular, a high-quality electrophotographic photosensitive drum.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to a method of cleaning a film deposition apparatus or a vacuum processing apparatus, a method of dry etching such an apparatus, and an article production method including a process based on the cleaning or dry etching method. More particularly, the present invention relates to a method of cleaning a film deposition apparatus or a vacuum processing apparatus for forming a deposition film on a substrate to produce an electrophotographic photoreceptor or a semiconductor device such as a solar cell, a line sensor for inputting an image, an imaging device, or a TFT, a method of dry etching such an apparatus, and an article production method including a process based on either one of such methods.[0003] 2. Description of the Related Art[0004] Various deposition films have been proposed for use in an electrophotographic photoreceptor and a semiconductor device such as a solar cell, a line sensor for inputting an image, a...

AI Technical Summary

Benefits of technology

[0019] In various aspects of the present invention, the supplying of the cleaning gas and the high-frequency power is temporarily stopped during the cleaning process so that a moderate reaction occurs between the cleaning gas remaining in the film deposition apparatus and the undesired solid substance (such as the undesired deposition film or polysilane), whereby the undesired substance is further removed under reduced pressure without being intentionally subjected to factors or conditions which would enhance the reaction. Thereafter, the cleaning process is restarted. This method allows the cleaning process to occur in an efficient manner and makes it possible to uniformly form a high-quality deposition film, in particular, a high-quality electrophotographic photosensitive drum (electrophotographic photoreceptor) with good repeatability.

[0024] The conditions of supplying the high-frequency power, that is, the frequency and the magnitude of the high-frequency power, may be the same or may be different for the two cleaning steps, i.e., before and after the moderate reaction period. Employing the same conditions is more desirable in that the cleaning process can be performed in a short time using a simple process.

[0025] Furthermore, the type of the cleaning gas (dry etching gas) and the flow rate of the cleaning gas (dry etching gas) may be the same or may be different for the respective two cleaning steps (before and after the moderate reaction period). Employing the same type of gas and the same flow rate is more desirable in that the cleaning process can be performed in a short time using a simple process.

[0030] During the period in which the supplying of the cleaning gas and the high-frequency power is temporarily stopped, a moderate cleaning process is performed by the cleaning gas remaining in the reactor chamber. This moderate cleaning process allows a reduction in the cleaning nonuniformity and also makes it possible to remove, in a short time, particles which would otherwise remain in the reactor chamber.

[0031] It has been found that the cleaning effect can be enhanced by restarting the cleaning process at a different concentration of the cleaning gas. This allows a reduction in the total cleaning time.

[0032] The article production method according to the present invention allows the reactor chamber to be cleaned in a highly efficient manner between adjacent two film deposition cycles, making it possible to produce high-quality articles with good reproducibility at low cost.

Problems solved by technology

Such incorporation of an impurity can cause degradation of the quality of the film.

Polysilane deposited on the substrate can cause the film to have a defect.

As a result, the charging process has become critical, that is, charging is needed to be performed in a shorter time.

This produces a problem that when no voltage is applied to a certain portion of the surface of the photoreceptor, that portion can have a large influence upon the voltage in neighboring portions, and thus an image defect is produced in that portion.

However, in recent more sophisticated copying apparatuses, it is needed to make a high-quality copy of a document including halftone information such as a picture, and an image defect which is not a significant problem in a line copy can result in a significant problem.

In particular, in a certain type of electrophotographic copying machine, an image defect is visually prominent, and thus the electrophotographic photosensitive drum needs to includes a still smaller number of defects.

However, the above-described conventional cleaning techniques for removing the undesired deposition film or polysilane remaining in the reactor chamber after forming the desired deposition film have the following problems to be solved to meet the requirements in terms of the characteristics of the articles such as a photoreceptor (photosensitive drum with a very large size).

That is, in the conventional techniques in which polysilane is removed by reacting polysilane with ClF.sub.3 gas, the cleaning process needs a long time to remove polysilane to a sufficient degree, and thus it is needed to supply a large amount of ClF.sub.3 and a large amount of electric power.

Furthermore, the vacuum pumping means, in particular, the rotary pump, needs to continuously suck ClF.sub.3 gas for a long time, and a large load is imposed upon the vacuum pumping means.

It is known that the remaining particles can fly off during a subsequent film deposition process and can form defects in a deposited film.

This can cause insufficient removal of polysilane and thus can cause the produced electrophotographic photosensitive drum to have a small image defect.

Although the size and the density of defects are sufficiently low for use in conventional applications, the defects cannot be neglected in recent sophisticated apparatuses in which high resolution and high image quality are required.

However, in reality, the cleaning process occurs nonuniformly and the nonuniformity causes residual particles still to remain on the inner wall of the reactor chamber even after the cleaning process.

In order to remove the particles perfectly, it is needed to perform the cleaning for a long time, and thus a large amount of cleaning gas and a large amount of electric power are consumed.

However, it turned out that a simple increase in the concentration resulted in an increase in the amount of residual particles because of reaction between the cleaning gas and the residual deposition film or particles.

That is, a simple increase in the concentration of the cleaning gas resulted in an adverse effect.

When the concentration of the cleaning gas was simply reduced, although a moderate reaction was obtained, a reduction in the cleaning speed occurred also, and thus a simple reduction in the concentration of the cleaning gas is not practical.

Thus, either a simple increase or reduction in the concentration cannot solve the problem of nonuniformity in cleaning.

Conversely, if the concentration is too high, the reaction in the cleaning becomes too rapid and the load upon the components of the apparatus such as the vacuum pump becomes high.

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