JP2006097072A - Sputtering film deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering film deposition method by which a film thickness distribution in a substrate face can be uniformized. <P>SOLUTION: In the sputtering film deposition method, a plurality of substrates 16 are arranged at the outer circumference of a rotary drum along the direction of the rotary axis of the rotary drum, a target 14 is arranged at the outer part of the rotary drum and also parallel to the rotary axis oppositely to the substrates, and sputtering film deposition is performed while rotating the rotary drum, the substrates 16a, 16b at both the edges among the plurality of substrates 16 are tilted to the target face, and the outward edge parts of the substrates 16a, 16b at both the edge parts 16a, 16b are made closest to the face of the target 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sputtering film forming method, and more particularly to a sputter film forming method using a carousel type sputtering apparatus.

  In a manufacturing process of a liquid crystal display device, an organic EL (Electro Luminescence) display device, or the like, a sputter film forming method is used as a method of forming an optical thin film or a metal thin film on a substrate. In a sputter film forming apparatus used for a sputter film forming method, a target disposed opposite to a substrate is provided in a vacuum chamber. Then, sputtering gas is flowed into the vacuum chamber, and a voltage is applied to the target serving as the cathode to generate plasma between the substrate and the target. Then, ions in the plasma collide with the target surface and the ejected target atoms adhere to the substrate, whereby a desired thin film is formed on the substrate.

  Furthermore, a carousel-type sputter film forming apparatus is used as the sputter film forming apparatus, in which a substrate is attached to a rotating drum and sputter film forming is performed while rotating the rotating drum (for example, see Patent Document 1). This carousel-type sputter film forming apparatus has an advantage of excellent productivity because it can form a film on a plurality of substrates at a time.

Japanese Patent Laid-Open No. 15-27226

Problems with the sputtering film forming method using the conventional carousel type sputtering film forming apparatus will be described with reference to FIG. In a carousel type sputter deposition apparatus, a plurality of substrates 16 are usually attached to a substrate holder 12 of a rotating drum using a substrate fixture 17 along a rotation axis as shown in FIG. Then, the rotating drum is rotated so that the substrate 16 faces the target 14 to perform sputter deposition. At this time, the conventional sputter deposition method has a problem that the film thickness distribution between the upper end substrate 16 and the lower end substrate 16 is deteriorated. That is, as shown in FIG. 5, since the density of the plasma 23 is reduced at both ends of the target 14, the film thickness is reduced above the upper substrate 16 and below the lower substrate 16. Therefore, the film thickness distribution in the substrate surface is deteriorated in the substrates at both ends. Thus, when the film thickness distribution is deteriorated in the substrate surface, there is a problem that display characteristics of a display device manufactured using the substrate deteriorates.
The present invention has been made in view of such problems, and an object of the present invention is to provide a sputter film forming method and a sputter film forming apparatus that can make the film thickness distribution uniform.

  A sputter film forming method according to a first aspect of the present invention is a sputter film forming method for forming a sputter film on a plurality of substrates using a target in a chamber, wherein the plurality of substrates are rotated on an outer periphery of a rotating drum. Sputter deposition is arranged along the direction of the rotation axis of the drum, and the target is arranged outside the rotation drum, facing the substrate and parallel to the rotation axis, and performing sputter deposition while rotating the rotation drum. In the method, among the plurality of substrates, substrates at both ends are inclined with respect to the surface of the target, and outer end portions of the substrates at both ends are closest to the surface of the target. Thereby, the film thickness distribution in the substrate surface of the substrates at both ends can be made uniform.

  The sputter deposition method according to the second aspect of the present invention is the sputter deposition method described above, wherein the outer end portions of the substrates at both ends are brought close to the target surface. Thereby, the setting of the arrangement | positioning position of a board | substrate can be unified and the film thickness dispersion | variation between the board | substrates of both ends can be suppressed.

  A sputter film forming method according to a third aspect of the present invention is the sputter film forming method described above, wherein the plurality of substrates are arranged on an outer periphery of a rotating drum via a substrate holder.

  ADVANTAGE OF THE INVENTION According to this invention, the sputter film-forming apparatus and sputter film-forming method which can make film thickness distribution uniform can be provided.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description is to describe the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description is omitted and simplified as appropriate. Further, those skilled in the art will be able to easily change, add, and convert each element of the following embodiments within the scope of the present invention. In addition, what attached | subjected the same code | symbol in each figure has shown the same element, and abbreviate | omits description suitably.

  A sputter film forming method according to the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing the configuration of a sputter film forming apparatus used in the sputter film forming method according to the present invention. FIG. 1 is a plan view of the sputter deposition apparatus as viewed from above. 10 is a sputter deposition apparatus, 11 is a vacuum chamber, 12 is a substrate holder, 13 is a rotating drum, 14 is a target, 15 is a magnetron section, 16 is a substrate, 18 is a sputtering power supply, and 21 is a rotating shaft of the rotating drum. Yes.

  The sputter film forming apparatus 10 includes a vacuum chamber 11 and a target 14 provided in the vacuum chamber 11. The vacuum chamber 11 has a substantially circular cross section, and a portion for placing the target 14 projects outward. In other words, the vacuum chamber 11 has a circular cross section except for a portion where the target 14 is disposed. This vacuum chamber 11 becomes a reaction chamber for performing sputtering film formation. In the sputter deposition apparatus shown in FIG. 1, two targets 14 are provided at positions facing the vacuum chamber. Of course, the number of targets may be one or three or more. The sputter deposition apparatus 10 includes a vacuum pump (not shown) for exhausting the vacuum chamber 11 and a gas line (not shown) for introducing a sputtering gas such as Ar into the vacuum chamber 11. .

  The sputter film forming apparatus 10 is a carousel type sputter film forming apparatus, and is a batch type apparatus capable of forming a film on a plurality of substrates in a single process. The sputter film forming apparatus 10 includes a cylindrical rotating drum 13 and a substrate holder 12 provided on the outer periphery of the rotating drum 13. The rotary drum 13 is provided so as to be rotatable about a rotary shaft 21 provided at the center of the vacuum chamber 11. The rotating shaft 21 coincides with the center line of the cylindrical rotating drum 13 provided along the vertical direction. For example, a regular decagonal substrate holder 12 is attached to the outside of the rotating drum 13. The center line of the substrate holder 12 coincides with the center line of the rotary drum 13. Further, a substrate 16 is attached to each outer peripheral surface of the substrate holder 12. This board | substrate 16 is attached to the board | substrate holder 12 with the board | substrate fixture mentioned later. When the rotating drum is rotated in the direction of the arrow while the substrate 16 is held by the substrate holder 12, the substrates 16 provided on the outer peripheral surfaces sequentially pass through the front surface of the target 14. The target 14 is a rectangular flat plate, and the surface thereof is arranged in parallel with the rotation shaft 21.

  A magnetron portion 15 is provided on the back side of the target 14. The magnetron unit 15 includes a backing plate and a magnet such as a permanent magnet or an electromagnet. That is, a voltage is applied from the sputtering power source 18 to the target 14 through the backing plate of the magnetron unit 15. Thereby, magnetron discharge occurs in front of the target 14 and plasma can be generated. The sputtering power source 18 may be an AC power source or a DC power source. When the ions in the plasma collide with the target 14 which is a cathode, target atoms are ejected. Thereby, target atoms can be attached to the substrate in the vicinity of the target, and a desired thin film can be formed on the substrate 16. At this time, a voltage is applied to the target 14 while rotating the rotary drum 13 at a constant speed. Thereby, a uniform thin film can be formed on the substrate 16 attached to each outer peripheral surface of the substrate holder 12.

  Next, the rotating drum 13 and the substrate holder 12 attached thereto will be described with reference to FIG. FIG. 2 is a perspective view schematically showing the configuration of the rotating drum 13 to which the substrate holder 12 is attached. FIG. 2 shows a state where the substrate 16 is not held by the substrate holder 12. A regular dodecagonal substrate holder 12 that is slightly larger than the rotating drum is attached to the outside of the cylindrical rotating drum 13. Each outer peripheral surface of the substrate holder 12 has a rectangular shape whose vertical direction is the longitudinal direction. The substrate 16 is disposed such that the film formation surface is substantially parallel to the vertical direction. By rotating the rotary drum 13, the substrate holder 12 rotates.

  The center line of the rotating drum 13 coincides with the center line of the substrate holder 12. The center line becomes the rotary drum 13 and the rotary shaft 21 of the substrate holder 12. Therefore, even if any outer peripheral surface of the substrate holder 12 becomes parallel to the target surface by the rotation of the rotating drum 13, the distance between the parallel outer peripheral surface and the target surface is constant. Therefore, the film thickness of the substrates attached to different outer peripheral surfaces can be made constant. That is, when the distance between the target surface and the substrate 16 (hereinafter referred to as the T / S distance) is long, the number of target atoms attached to the substrate 16 by sputtering decreases and the film formation rate decreases. On the other hand, when the T / S distance is short, the number of target atoms adhering to the substrate 16 by sputtering increases and the film formation rate increases.

  The target 14 is provided so as to face the outer peripheral surface of the substrate holder 12. That is, as shown in FIG. 2, in the case of a vertically long outer peripheral surface, the rectangular target 14 has a vertical direction as a long direction and a horizontal direction as a short direction. In the present invention, a plurality of substrates are attached to each outer peripheral surface of the substrate holder 12. That is, a plurality of substrates are arranged on one outer peripheral surface of the substrate holder 12 along the rotation axis 21. Here, for example, two substrates 16 are attached to each outer peripheral surface. Therefore, 24 substrates 16 can be attached to the regular dodecagonal column substrate holder 12. The two substrates 16 provided on one outer peripheral surface are arranged in a line in the vertical direction.

  In the present invention, the substrate 16 is attached to the substrate holder 12 while being inclined with respect to the surface of the target 14 in order to make the film thickness distribution in the substrate surface of the substrate 16 attached to one outer peripheral surface uniform. The board | substrate 16 attached so that it may incline with respect to this target is demonstrated in detail using FIG. FIG. 3 is a side view schematically showing the configuration of the substrate 16 and the target 14 attached to the substrate holder 12. Here, of the two substrates 16 attached to one outer peripheral surface of the substrate holder 12, the upper substrate is the upper substrate 16a, and the lower substrate is the lower substrate 16b.

  An upper substrate 16 a and a lower substrate 16 b are attached to one outer peripheral surface of the substrate holder 12 by a substrate fixture 17. For example, two substrate fixtures 17 are provided for one substrate 16, and the substrate 16 is attached to the substrate holder 12 so as to hold the upper and lower ends of the substrate 16. At this time, the substrate fixture 17 on the upper side of the upper substrate 16a is higher than the substrate fixture 17 on the lower side of the upper substrate 16a. Therefore, the distance between the upper end of the upper substrate 16a and the target is shorter than the distance between the lower end of the upper substrate 16a and the target. That is, the upper end of the upper substrate 16a is closest to the target surface. Thereby, even if the density of the plasma 23 is thin in the vicinity of the upper end of the target, the film thickness distribution in the substrate surface of the upper substrate 16a can be made uniform.

  Further, the lower substrate fixture 17 on the lower substrate 16b is higher than the upper substrate fixture 17 on the lower substrate 16b. Therefore, the distance between the lower end of the lower substrate 16 b and the target 14 is shorter than the distance between the upper end of the lower substrate 16 b and the target 14. That is, the lower end of the lower substrate 16b is closest to the target surface. Thereby, even if the density of the plasma 23 is reduced in the vicinity of the lower end of the target 14, the film thickness distribution in the substrate surface of the lower substrate 16b can be made uniform.

  In this way, in the substrate 16 at the upper end and the lower end of one outer peripheral surface, the distance between the outer end portion of the substrate 16 and the target surface is made shorter than the distance between the inner end portion of the substrate 16 and the target surface. Thereby, the film-forming rate of an outer side edge part can be improved. Thereby, even when the plasma density of the upper end and the lower end of the target 14 is thin, the film thickness distribution in the substrate surface can be made uniform. That is, the substrate disposed on the outermost side in the carousel-type sputter deposition apparatus tends to have a thin film thickness at the outer edge due to the difference in plasma density. In order to prevent the deterioration of the film thickness distribution due to the difference in plasma density, in the present invention, a difference is provided in the distance from the target surface in one substrate. Thereby, the film thickness distribution of the substrate 16 disposed at the upper end and the lower end of the outer peripheral surface of the substrate holder 12, that is, the substrate 16 disposed at a position corresponding to the upper end and the lower end of the target 14 can be improved.

  In the present invention, the substrate 16 is attached to the substrate holder 12 using two substrate fixtures 17 having different heights. By changing the height of the substrate fixture 17, the film thickness distribution can be easily adjusted. The difference in height of the substrate fixture 17 can be set to 5 mm as shown in FIG. 4, for example. Specifically, the upper substrate 16a is 480 mm × 350 mm, and the long side of the upper substrate 16a is arranged along the rotation axis. Then, the upper end of the upper substrate 16a is pushed out toward the 5 mm target side with respect to the long side of 480 mm and attached to the substrate holder 12. At this time, the inclination angle θ of the upper substrate 16a with respect to the target surface was about 0.6 °. The distance between the target surface at this time and the upper end of the upper substrate 16a was 80 mm. Although FIG. 4 shows the upper substrate 16a, the height of the substrate fixture 17 is similarly changed for the lower substrate 16b. That is, the distance between the upper end of the upper substrate 16a and the target surface is equal to the distance between the lower end of the lower substrate 16b and the target surface. When the substrate was arranged in parallel to the target surface, the film thickness distribution in the longitudinal direction of the target was about ± 10%, but the substrates 16 at both ends were inclined with respect to the target surface as described above. In this case, the film thickness distribution in the longitudinal direction of the target could be improved to ± 5%. In addition, the above-mentioned value is an exemplification, and a suitable inclination angle can be used according to the substrate size, the target size, the T / S distance, and the sputter film formation conditions. The film thickness distribution can be improved by setting the inclination angle θ to 0.3 to 2 °, for example. Thus, in the present invention, the film thickness distribution can be made uniform by adjusting the height of the substrate fixture 17. Therefore, a uniform film thickness distribution can be obtained with a simple configuration. Furthermore, abnormal discharge can be suppressed by generating a gap between the substrate holder 12 and the substrate 16.

  In the above description, an example in which two substrates 16 are attached to one outer peripheral surface has been described, but the present invention is not limited to this. That is, the present invention can also be used for a sputter deposition apparatus that can attach three or more substrates to the substrate holder 12 along the rotation axis. In this case, the upper and lower substrates may be attached to be inclined. Furthermore, you may make it attach the some board | substrate arranged along the direction of a rotating shaft with a different inclination | tilt angle according to the position. Of course, the substrates other than the upper and lower ends may be arranged parallel to the target surface.

  In the above description, a difference is provided in the distance in the substrate surface for the substrates arranged at the upper and lower ends of each outer peripheral surface, but this is not restrictive. For example, when the rotating drum 13 and the substrate holder 12 are arranged in the horizontal direction, the substrates on both the left and right sides are inclined and attached to the substrate holder. That is, when the rotating drum 13 and the substrate holder 12 are arranged in the horizontal direction, the horizontal direction is the direction of the rotation axis. Therefore, a plurality of substrates 16 are arranged along the horizontal direction. Therefore, the left and right substrates may be attached to the substrate holder 12 with an inclination.

  In the above description, the inclination angles of the upper and lower substrates 16 with respect to the target surface are made equal and approach the target surface in the same manner, but different inclination angles may be used depending on the positions of the upper substrate 16a and the lower substrate 16b. . That is, when the distance from the end of the target is different between the upper substrate 16a and the lower substrate 16b, the film thickness distribution can be made uniform on each substrate 16 by setting different inclination angles. Further, when the upper substrate 16a and the lower substrate 16b are arranged symmetrically with respect to the center line of the target 14, it is preferable that the inclination angles are made equal to approach the target surface in the same manner.

  Display characteristics can be improved by manufacturing a display device or a semiconductor device using a substrate having a thin film having a uniform film thickness distribution.

It is sectional drawing which shows typically the structure of the sputter film deposition apparatus concerning this invention. It is a perspective view which shows the structure of the rotating drum used for the sputtering device concerning this invention, and the substrate holder attached to it. It is a side view which shows typically the structure of the board | substrate and target in the sputtering device concerning this invention. It is a side view which shows typically the distance between the board | substrate and target in the sputtering device concerning this invention. It is a side view which shows typically the structure of the board | substrate and target in the conventional sputter deposition apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sputtering device 11 Vacuum chamber 12 Substrate holder 13 Rotating drum 14 Target 15 Magnetron part 16 Substrate 17 Substrate support 21 Rotating shaft 23 Plasma

Claims (3)

A sputter deposition method for sputter deposition on a plurality of substrates using a target in a chamber,
The plurality of substrates are arranged on an outer periphery of a rotating drum along a direction of a rotating shaft of the rotating drum, and the target is arranged on the outer side of the rotating drum so as to face the substrate and be parallel to the rotating shaft. In the sputter film formation method of sputter film formation while rotating the drum,
A sputter deposition method characterized in that, among the plurality of substrates, substrates at both ends are inclined with respect to the surface of the target, and outer end portions of the substrates at both ends are closest to the surface of the target.   The sputter deposition method according to claim 1, wherein outer end portions of the substrates at both ends are brought close to the surface of the target. The sputter deposition method according to claim 1, wherein the plurality of substrates are arranged on an outer periphery of the rotating drum via a substrate holder.

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