JP2008306125A - Vacuum thin film processing equipment - Google Patents

Abstract

Particles in an apparatus are satisfactorily captured on a particle adhesion surface from the beginning of thin film processing.
In a vacuum thin film processing apparatus, a particle adhesion surface to which particles generated by thin film processing adhere is subjected to a first blast process and a second blast process in this order. In the second blasting process, irregularities smaller than the irregularities formed on the particle adhesion surface 1 by the first blasting process are formed on the particle adhesion surface 1.
[Selection] Figure 1

Description

  The present invention relates to a vacuum thin film processing apparatus for processing a thin film in a vacuum.

  In a dry etching apparatus which is a kind of vacuum thin film processing apparatus, many reaction products are generated during dry etching. During dry etching, a substance having a high vapor pressure is discharged out of the vacuum system, but a low vapor pressure substance remains in the vacuum system and adheres to the inner wall of the dry etching apparatus or the surface of another structure. 2. Description of the Related Art Conventionally, in order to maintain a state in which the attached substance is attached for a long period of time, the surface of an object to which a substance adheres is subjected to a satin finish to make the surface uneven.

  Blasting is known as one of the satin processing. Blasting means “spraying”, and blasting is a processing method in which a small granular abrasive or similar material is struck against the surface of an object. Specifically, the blasting process is performed by intentionally damaging the surface of the object by hitting small particles (iron particles, abrasive grains, glass particles) against the surface of the object with compressed air.

  Conventionally, the surface of a quartz deposition shield installed in a dry etching apparatus has been textured by this blasting process. Specifically, the alumina shield (No. 120) is used to blast the deposition shield once, and then the deposition shield is washed with hydrofluoric acid to remove particles from the deposition shield. The satin processing of the shield was done.

The above-described conventional technique is disclosed in Patent Document 1.
Japanese Patent Laid-Open No. 62-142758

  FIG. 2 is a graph showing changes in the number of particles with respect to the estimated etching amount after the substrate is etched by the dry etching apparatus. The estimated etching amount is an integration when the etching amount of one substrate is 200 mm. In the case where an adhesion shield that has been satin-finished by a conventional method was installed in a dry etching apparatus, the number of particles increased rapidly from the start of etching. When etching was performed on 30 to 50 dummy substrates, the number of particles was 900, which is the maximum value. The number of particles then gradually decreased as more dummy substrates were subsequently etched. Finally, after etching a total of 100 dummy substrates, the inside of the apparatus is evacuated for several hours, so that 30 particles with a diameter larger than 0.18 μm are obtained. It was possible to achieve the following). This means that it is necessary to etch 100 dummy substrates before performing the actual dry etching process. As a matter of course, a large amount of material generated by etching the dummy substrate before the actual dry etching process adheres to the deposition shield. Therefore, after the actual etching of 100 substrates, film peeling occurred from the deposition shield as soon as possible.

  The present inventors considered the phenomenon described above as follows. In other words, because the roughness of the uneven surface of the initial shield was large, only a part of the reaction product that came in was captured by the uneven surface, and the rest remained in the apparatus. We thought the number increased. When the etching was performed on 30 to 50 dummy substrates, the number of particles reached the maximum value, and thereafter the number of particles decreased. The reason for this was considered that the surface of the deposition shield was changed to an uneven shape in which the reaction product was easily trapped by the reaction product deposited there. The uneven surface on which such reaction products are easily trapped is formed before the number of etched dummy substrates exceeds 100. After that, the deposition shield is the originally intended particle generation prevention function. Is demonstrating.

  As described above, in the prior art, it is necessary to etch about 100 dummy substrates before the particle adhesion surface in the dry etching apparatus such as an adhesion shield exhibits the original particle generation preventing function. Therefore, the labor and cost required for etching the dummy substrate are required. In addition, since the film adhered to the particle adhesion surface may cause film peeling, the number of processed substrates on which the particle adhesion target surface can continue to exhibit the original particle generation prevention function thereafter is limited.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vacuum thin film processing apparatus that can satisfactorily capture particles in the apparatus on the particle adhesion surface from the beginning of thin film processing.

  In order to achieve the above object, the vacuum thin film processing apparatus according to the present invention includes a first blasting process and a first blasting process in which a particle adhesion surface to which particles generated by thin film processing adhere in the vacuum thin film processing apparatus. Thus, a second blasting process is performed in this order to form irregularities smaller than the irregularities formed on the particle adhesion surface on the particle adhesion surface.

  According to the present invention, particles in the vacuum thin film processing apparatus can be favorably captured on the particle adhesion surface from the beginning of thin film processing.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a surface to which particles generated by thin film processing adhere in a vacuum thin film processing apparatus according to an embodiment of the present invention. This particle adhesion surface is the surface of the inner wall of the vacuum thin film processing apparatus, the surface of a component member installed in the vacuum thin film processing apparatus, or the like.

  In the vacuum thin film processing apparatus of the present embodiment, the satin finish is applied to the particle adhesion surface 1 as follows.

  First, the first blasting process is performed on the particle adhesion surface 1 shown in FIG. 1A with alumina particles (No. 120) having a particle size of 75 to 80 μm, and the particle adhesion as shown in FIG. An unevenness of about 1 μm is formed on the surface 1. Next, a second blasting process is performed on the particle-adhered surface on which the first blasting process has been performed using alumina particles (No. 500) having a particle diameter of 30 to 40 μm, as shown in FIG. An unevenness of about 0.1 μm is formed on the surface of the particle adhesion surface 1.

  Thereafter, the particle adhesion surface 1 is etched / washed with 5% hydrofluoric acid to remove microcracks remaining at the tips of the protrusions formed on the surface of the particle adhesion surface 1.

  The particle adhesion surface 1 of the vacuum thin film processing apparatus of the present embodiment is subjected to a satin finish as described above.

  In the particle adhesion surface 1 in this embodiment, after rough irregularities are formed by the first blasting process, finer irregularities are further formed by the second blasting process. For this reason, the surface area of the particle adhesion surface is larger, and the particles are more easily captured. In other words, the particle adhering surface 1 of the present embodiment has a larger surface area than the case where only the blasting with thin particles is performed by performing the second blasting after the first blasting. Yes.

  According to the vacuum thin film processing apparatus of this embodiment, since the particle capturing ability of the particle adhesion surface 1 is enhanced, particles in the apparatus can be captured well from the beginning of the thin film processing. Specifically, the reference value (the number of particles having a diameter larger than 0.18 μm is 30 or less) can be achieved from the start of etching (see FIG. 2). In addition, etching can be performed on the actual substrate from the beginning of thin film processing, and even when etching is continuously performed on 10,000 substrates when the etching amount of one substrate is 200 mm. No film peeling from the particle adhesion surface 1 occurred.

  In addition, the particle adhesion surface provided with the structure demonstrated by this embodiment is applicable to vacuum thin film processing apparatuses, such as a sputtering apparatus and a plasma CVD apparatus, besides an etching apparatus.

It is a figure which shows the surface to which the particle produced by the thin film processing adheres in the vacuum thin film processing apparatus which concerns on one Embodiment of this invention. It is a graph which shows the change of the number of particles with respect to the estimated etching amount after etching a board | substrate with a dry etching apparatus.

Explanation of symbols

1 Particle adhesion surface

Claims (4)

  In the vacuum thin film processing apparatus, the particle adhering surface to which particles generated by thin film processing adhere has a first blasting process and irregularities smaller than the irregularities formed on the particle adhering surface by the first blasting process. A vacuum thin film processing apparatus in which the second blasting process formed on the particle adhesion surface is performed in this order.   The vacuum thin film processing apparatus according to claim 1, wherein the height of the unevenness formed on the particle adhesion surface by the first blasting process is 1 μm.   The vacuum thin film processing apparatus according to claim 1, wherein a height of the unevenness formed on the particle adhesion surface by the second blasting process is 0.1 μm.   4. The vacuum thin film processing apparatus according to claim 1, wherein the particle adhesion surface is cleaned with an acid after the second blast treatment. 5.

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