JP2014231633A - Substrate holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a substrate so that a film thickness of a thin film on a substrate surface is not caused to have ununiformity even when the thin film is formed on a substrate holder by sputtering.SOLUTION: A substrate holder 1A includes an opening 1a, holds a substrate 2 such that a substrate surface 2a is exposed to the opening 1a and faces a target 4, and includes an insulation thin film 10 having a film thickness of nm order on a surface of the substrate holder.

Description

  The present invention relates to a substrate holder that holds a substrate when a thin film of the order of nm is formed on the substrate by sputtering.

  A conventional substrate holder will be described with reference to FIG. 6A is a perspective view of the substrate holder, and FIG. 6B is a cross-sectional view taken along line AA in FIG. 6A.

  The conventional substrate holder 1 is made of a conductive material such as aluminum or stainless steel, and has an opening 1a penetrating circularly at the center. In this substrate holder 1, a circularly recessed substrate placement portion 1 b is provided at the periphery on the back surface side of the opening 1 a, and the substrate is placed and held on this substrate placement portion 1 b (Patent Literature). 1).

  FIG. 7 shows a sputtering gun 3 of a sputtering apparatus using the substrate holder 1. In the vacuum chamber, the substrate holder 1 and the sputter gun 3 are disposed to face each other, the substrate 2 is held by the substrate mounting portion 1b of the substrate holder 1, and the target 4 is disposed in the concave portion 3a of the sputter gun 3. 3 is connected to a power source 5.

  During sputtering, a voltage is applied between the substrate holder 1 and the sputter gun 3 by the power source 5, and a magnetic field is formed in a region near the target 4 by a magnetic field generator (not shown).

  When argon gas is introduced into the vacuum chamber in this state, plasma 6 by argon gas is generated in the space between the substrate holder and the sputter gun 3. When the plasma 6 is generated, argon ions in the plasma 6 collide with the target 4, the target 4 is sputtered, sputtered particles jump out from the target 4 toward the surface 2 a of the substrate 2, and sputtered particles are generated on the surface 2 a of the substrate 2. As a result, a thin film is formed on the surface 2 a of the substrate 2.

JP 2001-026866 A

  However, in the sputtering, when sputtering by the sputter gun 3 is repeated, the thin film 7 is formed on the surface 2a of the substrate 2 by the sputter particles as shown in FIG. 8 which is an enlarged view of the main part of FIG. In addition to the film formation, a thin film 8 is also formed on the surface 2a of the substrate holder 1 in the peripheral region 1c of the opening 1a.

  Since the thin film 8 has a non-uniform resistance value, the entire potential including the substrate 2 and the substrate holder 1 when a voltage is applied changes, the surface potential of the substrate 2 becomes non-uniform, and the sputtered particles fly. A distribution occurs in the film thickness of the thin film 7 formed on the surface 2a of the substrate 2, for example, when the track is bent from the required track.

  Therefore, when sputtering is repeated, it is necessary to remove the film 8 from the surface of the substrate holder 1, and this removal requires a number of processes such as polishing, washing, bead blasting, washing, and heating. It takes.

  The present invention has been made in view of the above, and even if a thin film is formed on the substrate holder by sputtering, a substrate holder that can hold the substrate so that the thin film on the surface of the substrate does not have a distribution in the film thickness is provided. It is intended to provide.

  In the substrate holder according to the present invention, a thin film having a film thickness of nm order is formed on the surface of the substrate by sputtered particles from the target while plasma is generated in the space between the target of the sputtering apparatus and the surface of the substrate holder. A conductive substrate holder for holding the substrate when filming, an opening penetrating the front and back surfaces with a smaller penetrating diameter than the substrate, and a surface of the substrate provided on the rear surface side periphery of the opening portion A substrate mounting portion that is exposed on the target, and an insulating thin film is formed in the order of nm on the surface side peripheral region of the opening with a region area at least equal to or larger than the plasma irradiation region. It is provided by the above.

  According to the present invention, since the insulating thin film in the order of nm is provided in the peripheral region of the opening, the sputtering is repeated, so that the thin film is formed not only on the surface of the substrate but also on the insulating thin film. The potential on the substrate surface is not affected by the thin film. As a result, a thin film can be formed on the surface of the substrate without distribution.

  Furthermore, in the present invention, since the thin film on the insulating thin film does not affect the surface potential of the substrate, there is no need to remove the thin film from the substrate holder, thereby reducing the labor, time and cost required for the removal. Can do.

  Further, in the present invention, since the thickness of the insulating thin film is set to the nm order, it is possible to prevent the insulating thin film from being peeled off or cracked due to the difference in thermal expansion coefficient between the substrate holder and the insulating thin film. .

  Preferably, the thickness of the thin film on the surface of the substrate is 50 nm or less, and the thickness of the insulating thin film is 100 nm or less.

  By setting the thickness of the insulating thin film to 100 nm or less, it is possible to more effectively prevent the insulating thin film from being peeled off or cracked due to the difference in coefficient of thermal expansion.

  Preferably, the insulating thin film is also provided on the inner peripheral surface of the opening.

  If the insulating thin film is provided not only on the surface of the substrate holder but also on the inner peripheral surface of the opening, it is not necessary to form a thin film on the inner peripheral surface, and the potential of the entire substrate surface due to the thin film formed on the substrate holder. As a result, the thin film can be formed on the substrate surface with higher accuracy.

  According to the present invention, even if a thin film is formed on the insulating thin film on the surface of the substrate holder by sputtering, the thin film does not change the potential including the substrate and the substrate holder. A thin film can be formed, and an operation for removing the thin film deposited on the surface of the insulating thin film is not required, and labor, time, and cost required for the removal operation can be reduced. Furthermore, according to the present invention, since the thickness of the insulating thin film is on the order of nm, the insulating thin film is peeled off or cracked due to the difference in thermal expansion coefficient between the insulating thin film and the substrate holder. Can be prevented.

It is a perspective view of the substrate holder which concerns on embodiment of this invention. It is sectional drawing of the BB line of FIG. (A) The figure for demonstrating the film-forming state to a board | substrate by sputtering using the substrate holder by embodiment of this invention, (b) is an enlarged view of the principal part of said (a), (c) is conventional. It is an enlarged view corresponding to said (b) at the time of using a substrate holder. (A) is sectional drawing of the substrate holder of other embodiment of this invention, (b) is a top view of said (a). It is sectional drawing of the substrate holder of other embodiment of this invention. (A) is a perspective view of the conventional board | substrate holder, (b) is sectional drawing of the AA line of said (a). It is a figure used for description of sputtering by the conventional substrate holder. It is a principal part enlarged view of FIG.

  Hereinafter, a substrate holder according to an embodiment of the present invention will be described with reference to the accompanying drawings. With reference to FIG. 1 and FIG. 2, the substrate holder which concerns on embodiment of this invention is demonstrated. FIG. 1 is a perspective view of a substrate holder, and FIG. 2 is a cross-sectional view taken along line BB in FIG. In these drawings, parts corresponding to those in FIG. A thin film is formed on the substrate held by the substrate holder with a film thickness on the order of nm.

  The substrate holder 1A is made of a conductive material such as stainless steel, and has an opening 1a that penetrates the front and back surfaces in a circular shape with a smaller penetration diameter than the substrate at the center, and is circularly recessed at the periphery on the back surface side of the opening 1a. A stepped substrate mounting portion 1b is formed.

  In the substrate holder 1A, an insulating thin film 10 made of a metal material such as alumina or titanium nitride is formed on the entire surface 1c. The insulating thin film 10 may be formed by sputtering using a sputtering apparatus, or may be formed by another film forming method, and is not particularly limited.

  In the substrate holder 1A, not only the sputtered particles are deposited on the surface 2a of the substrate 2 but also a thin film is formed on the insulating thin film 10 formed on the surface 1c of the substrate holder 1A.

  However, since the thin film on the insulating thin film 10 is electrically insulated from the substrate holder 1A by the insulating thin film 10, the thin film on the insulating thin film 10 includes the substrate 2 and the substrate holder 1A and affects their surface potential. Will not affect.

  The area of the insulating thin film 10 is provided on the entire back surface of the substrate 2 and is larger than the area of the plasma irradiation area by sputtering. The insulating thin film 10 is formed with a uniform film thickness on the surface 1c of the substrate holder 1A with a film thickness on the order of nm. When the film thickness formed by sputtering on the substrate is 50 nm or less, the film thickness of the insulating thin film 10 is preferably 100 nm or less.

  The film formation on the substrate 2 will be described with reference to FIG. FIG. 3A is a view for explaining a film formation state on the substrate 2 by sputtering using the substrate holder 1A, and FIG. 3B is an enlarged view of the main part of FIG. FIG. 3C is an enlarged view corresponding to FIG. 3B when a conventional substrate holder is used. With reference to FIGS. 3A and 3B, the substrate 2 is placed on the substrate platform 1b. Next, as described with reference to FIG. 8, in sputtering, plasma is irradiated and sputtering is performed by a sputtering gun, and a thin film 7 is formed on the surface 2a of the substrate 2 with sputtered particles from the target. A thin film (not shown) is also formed on the insulating thin film 10 in the peripheral region 1c of the opening 1a on the surface 2a.

  Even if a thin film is formed on the insulating thin film 10 and the resistance value of the thin film is not uniform, the thin film and the substrate holder 1A are insulated from each other by the insulating thin film 10. The entire potential including 1A does not change. As a result, the surface potential of the substrate 2 becomes uniform, and the flight trajectory of the sputtered particles that jump out of the target is not bent from the required trajectory, so that the thin film 20 on the surface 2a of the substrate 2 is formed evenly. In this case, as shown in FIG. 3B, the film thickness of the thin film 20 is uniform even in a narrow region of the outer peripheral edge A of the thin film 20.

  In the conventional substrate holder, since the insulating thin film is not formed on the surface thereof, the resistance value of the thin film formed by sputtering on the surface of the substrate holder is not uniform. As shown in FIG. 3C, the thin film 20A on the surface 2a of the substrate 2 has a non-uniform film thickness at the portion B1, and particularly the outer peripheral edge B2 of the thin film 20a. The film thickness may be non-uniform in a narrow region.

  As described above, when the substrate holder 1A of the present embodiment is used, the thin film 20 can be uniformly formed on the entire substrate 2 by sputtering and simultaneously formed on the insulating thin film 10 by the sputtering. Therefore, the work for removing the thin film is unnecessary, and the labor, time, and cost required for the conventional thin film removal work can be reduced.

  The insulating thin film 10 is formed on the entire surface 1c of the substrate holder 1A. However, the insulating thin film 10 is not necessarily formed on the entire surface 1c. For example, in FIGS. As shown, the insulating thin film 10 may be formed with a region area S2 equal to or larger than the area S1 of the plasma irradiation region by the sputtering apparatus.

  Further, on the surface 1c of the substrate holder 1A, as shown in FIG. 5, the insulating thin film 10 is formed on the inner peripheral surface 1e of the opening 1b in a form continuous with the insulating thin film 10 provided on the surface 1c. It may be formed. The thickness of the insulating thin films 10 and 10a is not particularly limited.

  As described above, according to the present embodiment, since the insulating thin film 10 is provided on the entire surface of the substrate holder 1A, the sputtering is repeated, so that the insulating thin film not only on the surface of the substrate 2 but also on the surface of the substrate holder 1A. Although a thin film having an indefinite resistivity is also formed on the thin film 10, this thin film does not affect the potential of the entire surface including the substrate 2 and the substrate holder 1A. As a result, a thin film necessary for sputtering can be formed on the surface of the substrate 2 with a uniform film thickness.

  In this embodiment, even if the film is formed on the insulating thin film 10 of the substrate holder 1A by repeating sputtering, the film formation does not affect the potential of the entire surface. The operation of removing the thin film is not necessary, and the labor, time, and cost required for the conventional thin film removing operation can be reduced.

  Furthermore, in this embodiment, since the insulating thin film 10 is a thin film having a thickness of 100 nm or less with respect to a thin film thickness of 50 nm formed by sputtering on the surface of the substrate 2, thermal expansion with the substrate holder 1A made of metal is performed. Even if the rates differ greatly, the insulating thin film 10 is peeled off or cracked, and there is no risk of dielectric breakdown, and the substrate 2 can be held stably over a long period of time.

  There is no need to remove the thin film from the substrate holder, and the labor, time, and cost required for the removal work can be reduced.

  When an Al thin film is formed on the substrate as a base film and an Fe thin film is formed on the Al thin film to form a substrate for CNT (carbon nanotube) growth, the substrate holder 1A of the present embodiment is used to Since both the Al thin film and the Fe thin film can be uniformly formed over the whole, it is possible to increase the yield of CNTs having a constant length on a substrate having the same area as compared with the case of using a conventional substrate holder.

1A Substrate holder 1a Opening 1b Substrate mounting portion 1c Surface 10 Insulating thin film

Claims (3)

While the plasma is generated in the space between the target of the sputtering apparatus and the surface of the substrate holder, the substrate is held when a thin film is deposited on the surface of the substrate with a film thickness of the order of nm by the sputtered particles from the target. A conductive substrate holder that comprises:
An opening that penetrates the front and back surfaces with a smaller diameter than the substrate;
A substrate mounting portion that is provided on the rear surface side periphery of the opening and places the substrate such that the surface thereof is exposed to the target side;
Have
A substrate holder, wherein an insulating thin film is provided in a film thickness on the order of nm in the peripheral region on the surface side of the opening with a region area equal to or greater than the plasma irradiation region.   The substrate holder according to claim 1, wherein the thickness of the thin film on the surface of the substrate is 50 nm or less, and the thickness of the insulating thin film is 100 nm or less.   The substrate holder according to claim 1, wherein the insulating thin film is also provided on an inner peripheral surface of the opening.

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