JP5630387B2 - Film forming apparatus and film forming method - Google Patents

Description

  The present invention relates to a film forming apparatus and a film forming method for forming a film on a surface of a granular substrate.

  In order to form a film on the surface of a substrate, a method such as a plasma enhanced chemical vapor deposition (CVD) method is used. Then, in order to form a thin film on the entire surface of the granular substrate such as a spherical shape, a method of forming a film on the surface of the granular substrate while vibrating the granular substrate by vibrating a plate on which the granular substrate is mounted has been proposed. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 9-228027

  However, there are cases where the granular substrate does not roll on the plate and slides sideways. In the film formation process, film formation is performed in a deposition manner from above the granular substrate. Therefore, when the granular substrate slides on the plate, the film is formed only on a certain upper surface of the granular substrate, the region facing the plate, etc. No film is formed. For this reason, there has been a problem that a film is not uniformly formed on the entire surface of the granular substrate.

  In view of the above problems, an object of the present invention is to provide a film forming apparatus and a film forming method capable of forming a film uniformly on the entire surface of a granular substrate.

According to one aspect of the present invention, (a) a plurality of grooves having a main surface on which a granular substrate to be deposited is mounted and extending in parallel with the main surface with a narrower width than the particle size of the granular substrate. The plate formed on the main surface and (b) the granular substrate starts rolling on the main surface when a part of the granular substrate fits into the groove, and on the remaining region of the region where the groove on the main surface is formed (C) A film forming mechanism including a vibration mechanism that vibrates the plate in a direction parallel to the main surface so that the granular substrate rolls , and (c) a thin film forming mechanism that forms a thin film on the exposed surface of the granular substrate on the main surface. An apparatus is provided.

According to another aspect of the present invention, (a) a plurality of grooves having a main surface on which a granular substrate to be deposited is mounted and extending parallel to the main surface with a width narrower than the particle size of the granular substrate. (B) a step of mounting the granular substrate on the main surface of the plate, and (c) a portion of the granular substrate fitted in the groove so that the granular substrate is on the main surface. Oscillating the plate in a direction parallel to the main surface so that the granular substrate rolls on the remaining region of the region where the grooves on the main surface are formed , and (d) the main surface Forming a thin film on the exposed surface of the upper granular substrate, and providing a film forming method in which a thin film forming process including the step of vibrating the plate and the step of forming the thin film is repeated a plurality of times.

  ADVANTAGE OF THE INVENTION According to this invention, the film-forming apparatus and the film-forming method which can form a film | membrane uniformly over the whole surface of a granular substrate can be provided.

It is a schematic diagram which shows the structure of the film-forming apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the example of the state of the granular substrate on the plate of the film-forming apparatus which concerns on embodiment of this invention. FIG. 3A and FIG. 3B are schematic cross-sectional views showing examples of the cross-sectional shape of grooves formed on the main surface of the plate of the film forming apparatus according to the embodiment of the present invention. It is a top view which shows the pattern of the groove | channel formed in the main surface of the plate of the film-forming apparatus which concerns on embodiment of this invention. FIGS. 5A and 5B are plan views showing other patterns of grooves formed on the main surface of the plate of the film forming apparatus according to the embodiment of the present invention. It is a schematic diagram which shows the example which comprised the film-forming apparatus which concerns on embodiment of this invention as a high frequency plasma CVD apparatus. It is a schematic diagram which shows the example of the state of the granular board | substrate on the plate of a comparative example. It is a schematic diagram which shows the film-forming area of the granular substrate formed with the film-forming apparatus of the comparative example. It is a schematic diagram which shows the film-forming area | region of the granular substrate formed with the film-forming apparatus which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic. Further, the embodiment described below exemplifies an apparatus and a method for embodying the technical idea of the present invention, and the embodiment of the present invention has the following structure and arrangement of components. It is not something specific. The embodiment of the present invention can be variously modified within the scope of the claims.

  A film forming apparatus 1 according to an embodiment of the present invention is a film forming apparatus that forms a film on the surface of a granular substrate. As shown in FIG. 1, the film forming apparatus 1 has a main surface 11 on which a granular substrate 50 to be formed is mounted, and a plurality of grooves 110 extending parallel to the main surface 11 are formed on the main surface 11. A plate 10, a vibration mechanism 20 that vibrates the plate 10 in a direction parallel to the main surface 11, and a thin film forming mechanism 30 that forms a thin film on the exposed surface of the granular substrate 50 on the main surface 11.

  The width of the groove formed in the main surface 11 of the plate 10 is set to be narrower than the particle size of the granular substrate 50. The granular substrate 50 is, for example, a silicon (Si) substrate, and the particle size is about 1 to several mm.

  When the vibration mechanism 20 vibrates the plate 10, a part of the granular substrate 50 mounted on the main surface 11 is fitted in the groove 110, so that the granular substrate 50 starts rolling on the main surface 11.

  FIG. 2 shows an example of the granular substrate 50 that is stationary on the main surface 11 of the plate 10. FIG. 2 shows an example in which the shape of the granular substrate 50 is a D-cut shape. The “D-cut shape” is a shape which is a substantially spherical body as a whole but has a flat surface.

  The cross-sectional shape of the groove 110 along the direction perpendicular to the direction in which the groove 110 extends (hereinafter simply referred to as “cross-sectional shape”) is appropriately determined according to the shape of the granular substrate 50. That is, the cross-sectional shape of the groove 110 may be such that when the plate 10 vibrates, a part of the granular substrate 50 is caught by the groove 110 and the granular substrate 50 rolls.

  FIG. 2 shows an example in which the cross-sectional shape of the groove 110 is triangular according to the shape of the granular substrate 50 having a D-cut shape. Thereby, as shown in FIG. 2, the D-cut surface of the granular substrate 50 in a stationary state on the main surface 11 of the plate 10 can be randomly arranged. Further, the groove 110 having a triangular cross-sectional shape is easy to process.

  However, the cross-sectional shape of the groove 110 is not limited to a triangular shape. For example, a square shape as shown in FIG. 3A or a semicircular shape as shown in FIG.

  Needless to say, the granular substrate 50 may be a polyhedron such as a cubic shape or a sphere other than the D-cut shape. For example, as shown in FIG. 3B, when the granular substrate 50 is a sphere, the shape of the groove 110 is changed to a round groove shape that matches the outer shape of the granular substrate 50, so that the granular substrate 50 is formed in the groove 110 without a gap. It can be adhered and stabilized.

  However, the shape of the groove 110 is not uniquely determined with respect to the shape of the granular substrate 50. That is, the optimum shape of the groove 110 is selected according to conditions such as the size of the granular substrate 50 and the arrangement and interval of the grooves 110.

  The width of the opening in the direction perpendicular to the extending direction of the groove 110 is set so that at least a part of the surface of the granular substrate 50 fitted in the groove 110 is above the main surface 11 of the plate 10. For this reason, the width of the opening of the groove 110 is narrower than the particle size of the granular substrate 50 and is wide enough to trigger the rolling of the granular substrate 50. A thin film is formed on the exposed region of the surface of the granular substrate 50.

  Moreover, it is preferable that the space | interval of the groove | channels 110 is set to the same grade or more as the particle size of the granular substrate 50, for example. If the spacing between the stationary granular substrates 50 fitted in the adjacent grooves 110 is narrow, it is difficult to form a film on the side surfaces of the granular substrates 50. On the other hand, a film can be formed on the entire exposed surface of the granular substrate 50 by setting the interval between the grooves 110 to be equal to or larger than the particle diameter of the granular substrate 50.

  In FIG. 4, the figure which looked at the main surface 11 of the plate 10 from upper direction is shown. FIG. 4 shows an example in which the grooves 110 are concentrically arranged on the main surface 11 of the plate 10. By arranging the grooves 110 concentrically, the granular substrate 50 can be uniformly rolled with respect to vibrations in any direction. Further, when the plate 10 is small, the groove 110 can be easily formed by lathe processing or the like.

  For example, as shown in FIG. 5A, the grooves 110 may be arranged in stripes parallel to each other. According to the arrangement of the grooves 110 shown in FIG. 5A, the granular substrate 50 can be effectively rolled when the plate 10 is vibrated in one direction. Further, the processing of the groove 110 is easy. Alternatively, as shown in FIG. 5B, the grooves 110 may be arranged in a lattice shape. Accordingly, when the plate 10 is vibrated in two directions, the granular substrate 50 can be effectively rolled.

  For the plate 10, for example, carbon, stainless steel, aluminum, ceramic or the like can be used.

  FIG. 6 shows an example in which the film forming apparatus 1 is configured as a high-frequency plasma CVD apparatus. In the film forming apparatus 1 shown in FIG. 6, the granular substrate 50 to be processed is mounted on the main surface 11 of the plate 10 in the chamber 31. After the inside of the chamber 31 is decompressed to a predetermined gas pressure by the exhaust device 32, the source gas 300 is introduced into the chamber 31 from the introduction port 33. By supplying high-frequency power from the high-frequency power source 35 between the grounded plate 10 and the electrode 34, the source gas 300 in the chamber 31 is turned into plasma. By exposing the granular substrate 50 to the formed plasma, a film is formed on the exposed surface of the granular substrate 50.

  Other than the high-frequency plasma CVD apparatus, for example, a CVD apparatus that grows a film on the surface of the granular substrate 50 by another method, a sputtering apparatus that deposits a film on the surface of the granular substrate 50, or the like. The film forming apparatus 1 can be configured as an apparatus.

  An example of a method for forming a film on the surface of the granular substrate 50 using the film forming apparatus 1 shown in FIG. 1 will be described below.

  First, the granular substrate 50 to be processed is mounted on the main surface 11 of the plate 10.

  Next, the plate 10 is quickly slid in the direction parallel to the main surface 11 by the vibration mechanism 20. For example, the plate 10 is reciprocated once or several times. Thereby, the granular substrate 50 is caught in the groove 110 formed in the main surface 11, and the granular substrate 50 rolls on the main surface 11. The moving speed of the plate 10 is appropriately set in consideration of the shape and particle size of the granular substrate 50 so that the granular substrate 50 rolls on the main surface 11.

  When the reciprocating motion of the plate 10 is stopped, the granular substrate 50 stands still in various postures on the main surface 11. When a large number of granular substrates 50 are simultaneously rolled on the main surface 11, some of the granular substrates 50 are fitted into the grooves 110 and stopped, and the other granular substrates 50 are stopped between the grooves 110. In this state, a film is formed by the thin film forming mechanism 30 on the exposed surface of the granular substrate 50 by the deposition down method.

  After the film formation for a certain time, the film formation by the thin film formation mechanism 30 is interrupted, and the plate 10 is vibrated again by the vibration mechanism 20. Thereby, the granular substrate 50 having a film formed on at least a part of the surface is rolled on the main surface 11. Thereafter, when the vibration of the plate 10 is stopped, the granular substrate 50 is stationary on the main surface 11 in a posture different from the previous time. In this state, a film is formed on the newly exposed surface of the granular substrate 50.

  By repeating the thin film forming process including the step of vibrating the plate 10 and the step of forming a thin film on the surface of the granular substrate 50, a film is uniformly formed on the entire surface of the granular substrate 50.

  For example, when a desired film thickness of the film to be formed on the surface of the granular substrate 50 is 80 nm and the film of several nm is formed by one thin film forming process, the thin film forming process is performed 20 to 30 times. Repeat about.

  The cross-sectional shape of the groove 110 is preferably a shape in which the granular substrate 50 is stably stationary with a part of the granular substrate 50 fitted in the groove 110. Thereby, a film is stably formed on the surface of the granular substrate 50 in the film forming process.

  In contrast to the film forming method described above, when the main surface 11A of the plate 10A on which the granular substrate 50 is placed is flat as shown in FIG. 7, the granular substrate 50 does not roll on the main surface 11A. For this reason, as shown by a broken line in FIG. 8, only the upper surface of the granular substrate 50 is the film formation target area.

  However, when the film forming apparatus 1 shown in FIG. 1 is used, the granular substrate 50 rolls on the main surface 11 of the plate 10. For this reason, as shown by the broken line in FIG. 9, the entire surface of the granular substrate 50 is the film formation target area.

  As described above, according to the film forming apparatus 1 according to the embodiment of the present invention, the groove 110 is formed in the main surface 11 of the plate 10, so that the granularity is formed on the main surface 11 every time the plate 10 is vibrated. The substrate 50 rolls, and different areas of the surface of the granular substrate 50 are exposed on the main surface 11. For this reason, a film can be uniformly formed on the entire surface of the granular substrate 50 by repeating the process of forming a thin film on the exposed surface of the granular substrate 50 that has been fitted and rolled in the groove 110.

  In the film forming method using the film forming apparatus 1, when the shape of the granular substrate 50 is a shape that hardly rolls on a flat main surface plate on which the grooves 110 are not formed, for example, the granular substrate 50 has a D-cut shape or In the case of a cubic shape, it is particularly effective for forming a film uniformly on the entire surface of the granular substrate 50. In recent years, research on a D-cut Si substrate as a solar cell with high condensing efficiency has been advanced, and the film forming apparatus 1 is promising as a film forming apparatus in this field.

  As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. That is, it goes without saying that the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Film-forming apparatus 10 ... Plate 11 ... Main surface 20 ... Vibration mechanism 30 ... Thin film formation mechanism 31 ... Chamber 32 ... Exhaust device 33 ... Inlet 34 ... Electrode 35 ... High frequency power supply 50 ... Granular substrate 110 ... Groove 300 ... Source gas

Claims (7)

A plate having a main surface on which a granular substrate to be deposited is mounted, and a plurality of grooves extending in parallel to the main surface with a width narrower than the particle size of the granular substrate;
The granular substrate starts rolling on the main surface when a part of the granular substrate fits into the groove , and the granular substrate rolls on the remaining region of the main surface where the groove is formed. as movement, a vibration mechanism for vibrating the plate in the main surface direction parallel
And a thin film forming mechanism for forming a thin film on the exposed surface of the granular substrate on the main surface.   The film forming apparatus according to claim 1, wherein a cross-sectional shape of the groove is a shape in which the granular substrate fitted in the groove is stably stationary.   3. The composition according to claim 1, wherein the thin film formation mechanism forms the thin film on the surface of the granular substrate by converting the raw material gas of the thin film into plasma on the main surface of the plate. Membrane device.   4. The film forming apparatus according to claim 1, wherein a cross-sectional shape of the groove along a direction perpendicular to a direction in which the groove extends is a triangular shape. 5.   The film forming apparatus according to claim 1, wherein the grooves are concentrically arranged on the main surface. A plate having a main surface on which a granular substrate to be deposited is mounted and having a plurality of grooves formed on the main surface and extending in parallel with the main surface with a width smaller than the particle size of the granular substrate is prepared. And steps to
Mounting the granular substrate on the major surface of the plate;
The granular substrate starts rolling on the main surface when a part of the granular substrate fits into the groove , and the granular substrate rolls on the remaining region of the main surface where the groove is formed. Oscillating the plate in a direction parallel to the major surface to move,
Forming a thin film on the exposed surface of the granular substrate on the main surface, and repeating a thin film forming step including vibrating the plate and forming the thin film a plurality of times Film forming method.   The step of forming the thin film forms the thin film on the surface of the granular substrate by converting the raw material gas of the thin film into plasma on the main surface of the plate. Membrane method.

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