WO2022009484A1

WO2022009484A1 - Film forming method

Info

Publication number: WO2022009484A1
Application number: PCT/JP2021/011719
Authority: WO
Inventors: 雄一織井; 宗人箱守; 具和須田; 大 ▲高▼木
Original assignee: 株式会社アルバック
Priority date: 2020-07-08
Filing date: 2021-03-22
Publication date: 2022-01-13
Also published as: TWI821656B; CN114981470A; JP7358647B2; JPWO2022009484A1; KR20220106187A; TW202202644A

Abstract

[Problem] To homogenize film thickness distribution. [Solution] This film forming method involves film forming by sputtering on a substrate using a plurality, at least three, of rotary targets that each have a central shaft and a target surface and are provided, in the interior, with a magnet that is able to rotate about the central shaft. The plurality of rotary targets are arranged so that the central shafts are parallel to one another and are also parallel to the substrate. The film forming by sputtering is performed on the substrate as power is being fed to the plurality of rotary targets and the respective magnets of the plurality of rotary targets are being moved over an arc that has an A-point closest to the substrate about the central shafts. Magnets of at least a pair of rotary targets arranged at two ends, among the plurality of rotary targets, have a shorter duration of film forming in a region that is further apart from the center of the substrate than the A-point on the arc than a duration of film forming in a region closer to the center of the substrate than the A-point.

Description

Film formation method

The present invention relates to a film forming method.

The film formation technology for substrates used in large displays requires high uniformity in film thickness distribution. In particular, when the sputtering method is adopted as the film forming method, it may be difficult to make the film thickness distribution uniform in the substrate surface due to the complicated spatial distribution of the sputtering particles.

Under such circumstances, a plurality of rod-shaped rotary targets provided with magnets inside are arranged side by side facing the substrate, and sputtering particles are incident on the substrate from each rotary target in an attempt to improve the film thickness distribution. There is an example (see, for example, Patent Document 1).

Special Table 2019-519673 Gazette

However, with the recent increase in the size of the substrate, the film thickness at the center of the substrate and the edge of the substrate tends to be more non-uniform. In order to make the film thickness in the substrate surface uniform, it is important how to correct the film thickness in the substrate surface.

In view of the above circumstances, an object of the present invention is to provide a film forming method in which the film thickness distribution in the substrate surface becomes more uniform.

In order to achieve the above object, in the film forming method according to one embodiment of the present invention, at least a plurality of rotary targets having a central axis and a target surface and having a rotatable magnet inside the central axis are provided. Sputtering film formation is performed on the substrate using three or more.
The plurality of rotary targets are arranged so that the central axes are parallel to each other and the central axes are parallel to the substrate.
While applying power to the plurality of rotary targets, the magnets of each of the plurality of rotary targets are moved around the central axis on an arc having the point A closest to the substrate to the substrate. Sputter film formation is performed, and among the plurality of rotary targets, the magnets of the pair of rotary targets arranged at at least both ends form a film on the arc in a region away from the center of the substrate from the point A. The time is shorter than the time for forming a film in the region closer to the center of the substrate than the point A.

With such a film forming method, the movement of the magnets of the pair of rotary targets arranged at both ends is controlled as described above, and the film thickness distribution in the substrate surface becomes more uniform.

In the above-mentioned film forming method, when the angle of the magnet at point A is 0 degree, the counterclockwise direction is a negative angle, and the clockwise direction is a positive angle from 0 degree, the above-mentioned pair of rotary targets The magnet may rotate between a position at any angle in the range of 20 to 90 degrees and a position at any angle in the range of −20 degrees to −90 degrees.

In the above film forming method, one of the pair of rotary targets arranged at both ends started film formation from a region closer to the center of the substrate than the point A on the arc, and was arranged at both ends. The other of the pair of rotary targets may start film formation from a region distant from the center of the substrate from the point A on the arc.

In the above film forming method, in the movement of the magnets of the pair of rotary targets arranged at both ends, the average angular velocity of moving the region away from the center of the substrate from the point A on the arc is the above. It may be faster than the average angular velocity moving in the region closer to the center of the substrate than the point A.

As described above, according to the present invention, there is provided a film forming method in which the film thickness distribution in the substrate surface becomes more uniform.

It is a schematic diagram which shows an example of the film formation method which concerns on this embodiment. It is a figure for demonstrating the definition of the angle of the magnet which rotates around the central axis of a rotary target. It is a graph which shows an example of the moving speed (angular velocity) of a magnet with respect to the angle of a magnet. It is a graph which shows an example of the ratio of the discharge time with respect to the angle of a magnet. FIG. (A) is a graph showing an example of the moving speed (angular velocity) of the magnet with respect to the angle of the magnet. FIG. (B) is a graph showing an example of the ratio of the discharge time to the angle of the magnet. It is a schematic plan view which shows an example of the film forming apparatus of this embodiment. FIG. (A) is a graph showing the film thickness distribution in the substrate surface according to the comparative example. FIG. (B) is a graph showing an example of the film thickness distribution in the substrate surface when the film is formed by the film forming method of the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. XYZ axis coordinates may be introduced in each drawing. Further, the same member or a member having the same function may be designated by the same reference numeral, and the description may be omitted as appropriate after the description of the member. Moreover, the numerical values shown below are examples, and are not limited to this example.

1 (a) and 1 (b) are schematic views showing an example of a film forming method according to the present embodiment. FIG. 1A shows a schematic cross section showing an arrangement relationship between a plurality of rotary targets and a substrate, and FIG. 1B shows a schematic plane showing the arrangement relationship. .. The film forming according to the present embodiment is automatically performed by, for example, the control device 410 of the film forming apparatus 400 shown in FIG.

In the film forming method of the present embodiment, at least three or more of a plurality of rotatable cylindrical rotary targets are used to perform sputtering film formation (magnetron sputtering) on the substrate 10. In FIGS. 1A and 1B, for example, 10 rotary targets 201 to 210 are exemplified. The number of the plurality of rotary targets is not limited to this number, and is appropriately changed according to, for example, the size of the substrate 10.

Each of the plurality of rotary targets 201 to 210 has a central axis 20 and a target surface (sputtering surface) 21. Each of the plurality of rotary targets 201 to 210 is internally provided with a magnet that can rotate around the central axis 20. For example, in the example of FIGS. 1A and 1B, magnets 301 to 310 are arranged in the order of a plurality of rotary targets 201 to 210. Magnets 301-310 are so-called magnet assemblies. The magnets 301 to 310 have a permanent magnet and a magnetic yoke.

The plurality of rotary targets 201 to 210 are arranged so that the central axes 20 are parallel to each other and the central axes 20 are parallel to the substrate 10. For example, the plurality of rotary targets 201 to 210 are arranged side by side so that the target surfaces 21 face each other in the direction intersecting the central axis 20. The direction in which the plurality of rotary targets 201 to 210 are arranged side by side corresponds to the longitudinal direction of the substrate 10. If necessary, the direction in which the plurality of rotary targets 201 to 210 are arranged side by side may be the lateral direction of the substrate 10.

The board 10 is supported by a board holder (not shown). The potential of the substrate holder is, for example, a floating potential, a ground potential, or the like. The plurality of rotary targets 201 to 210 are arranged so that the direction in which the plurality of rotary targets 201 to 210 are arranged is parallel to the longitudinal direction of the substrate 10. The target surface 21 of each of the plurality of rotary targets 201 to 210 faces the film forming surface 11 of the substrate 10.

In FIGS. 1 (a) and 1 (b), the direction in which the plurality of rotary targets 201 to 210 are arranged side by side corresponds to the Y-axis direction, and the direction from the substrate 10 toward the plurality of rotary targets 201 to 210 is the Z axis. Corresponding to, the direction in which each of the plurality of rotary targets 201 to 210 extends corresponds to the X-axis.

Further, in the Y-axis direction, a pair of

rotary targets

201 and 210 are arranged at both ends of a group of a plurality of rotary targets 201 to 210. For example, when the plurality of rotary targets 201 to 210 and the substrate 10 are viewed in the Z-axis direction, the pair of

rotary targets

201 and 210 are arranged so as to protrude from the substrate 10 in the Y-axis direction. For example, a plurality of rotary targets 201 to 210 and a substrate 10 are arranged so that at least a part of each of the pair of

rotary targets

201 and 210 overlaps with the substrate 10.

Specifically, the plurality of rotary targets 201 to 210 and the substrate 10 are arranged so that the central axes 20 of the pair of

rotary targets

201 and 210 and the substrate 10 overlap each other. For example, a plurality of rotary targets 201 to 210 are arranged so that the central axes 20 of the pair of

rotary targets

201 and 210 are located inside the substrate 10.

In the examples of FIGS. 1A and 1B, the central axis 20 of the rotary target 201 and the end portion 12a of the substrate 10 in the Y-axis direction overlap in the Z-axis direction. Further, the central axis 20 of the rotary target 210 and the end portion 12b of the substrate 10 in the Y-axis direction overlap with each other.

By arranging the pair of

rotary targets

201 and 210 and the

ends

12a and 12b of the substrate 10 in this way, the sputtering particles emitted from the

rotary targets

201 and 210 arranged at both ends waste the outside of the substrate 10. It is directed to the vicinity of the

ends

12a and 12b of the substrate 10 without passing through. As a result, the film thickness in the vicinity of the

ends

12a and 12b of the substrate 10 is surely corrected. In the embodiment, among the pair of

rotary targets

201 and 210, the rotary target 201 may be referred to as one rotary target, and the rotary target 210 may be referred to as the other rotary target.

Further, the pitches of the plurality of rotary targets 201 to 210 are set substantially evenly in the Y-axis direction. Further, the relative distance between the plurality of rotary targets 201 to 210 and the substrate 10 during the sputtering film formation is a fixed distance.

The outer diameter of each of the plurality of rotary targets 201 to 210 is 100 mm or more and 200 mm or less. The pitch of the plurality of rotary targets 201 to 210 in the Y-axis direction is 200 mm or more and 300 mm or less. The size of the substrate 10 is 700 mm or more and 4000 mm or less in the Y-axis direction and 700 mm or more and 4000 mm or less in the X-axis direction.

The materials of the plurality of rotary targets 201 to 210 are, for example, a metal such as aluminum, an In—Sn—O system, an In—Ga—Zn—O system oxide, and the like. The material of the substrate 10 is, for example, glass, an organic resin, or the like.

In the present embodiment, discharge power is applied to each of the plurality of rotary targets 201 to 210, and magnets of the plurality of rotary targets 201 to 210 rotate on an arc around the central axis 20 and sputter onto the substrate 10. Film formation is performed.

In particular, in sputtering film formation, the larger the size of the substrate 10, the larger the difference between the thickness of the film formed near the

end portions

12a and 12b of the substrate 10 and the thickness of the film formed in the central portion of the substrate 10. It tends to be. Here, it is assumed that the central portion of the substrate 10 is the region of the substrate 10 on which the rotary targets 202 to 209 face each other.

In the present embodiment, the rotational movement of the magnets of the pair of

rotary targets

201 and 210 arranged at both ends of the group of

rotary targets

201 and 210 and the

rotary targets

202 and 209 arranged between the pair of

rotary targets

201 and 210. By changing the aspect of, the film thickness distribution in the plane of the substrate 10 is controlled more uniformly.

The rotational movement of the magnets of the plurality of rotary targets 201 to 210 may be one rotational movement from the start point to the end point at a rotation angle of 360 degrees or less, or at least one swing at a rotation angle of 360 degrees or less. good. In the swinging operation of the present embodiment, when the magnet is folded back, the magnet does not stop at the folded back position, and the magnet is continuously folded back.

The same power is applied to each of the plurality of rotary targets 201 to 210 in order to substantially equalize the consumption of each rotary target. The input power may be DC power or AC power such as RF band and VHF band. Further, each of the plurality of rotary targets 201 to 210 rotates clockwise or counterclockwise. Each of the plurality of rotary targets 201 to 210 is set to, for example, 5 rpm or more and 30 rpm or less at the same rotation speed.

Hereinafter, specific examples of the rotational operation of the magnets 301 to 310 will be described. First, a specific example of the rotational operation of the

magnets

301 and 310 of the pair of

rotary targets

201 and 210 arranged at both ends of the plurality of rotary targets 201 to 210 will be described.

FIG. 2 is a diagram for explaining the definition of the angle of the magnet that rotates and moves around the central axis of the rotary target. In FIG. 2, as an example, the rotary target 201 is illustrated among the plurality of rotary targets 201 to 210. Regarding the definitions of the magnet angle, the positive angle, the negative angle, and the point A (described later), the same definitions as those for the rotary target 201 are made for the rotary targets 202 to 210 other than the rotary target 201.

In the present embodiment, regarding the angle of the magnet 301, the angle of the magnet 301 when the distance between the center of the magnet 301 and the substrate 10 is the shortest is set to 0 degrees. For example, when a perpendicular line is drawn from the central axis 20 to the film forming surface 11 of the substrate 10, the position where the perpendicular line and the center 30 of the magnet 301 coincide with each other corresponds to an angle of 0 degrees of the magnet 301. When the magnet 301 rotates around the central axis 20, the center 30 draws an arc trajectory. When the angle is 0 degrees, the magnet 310 is closest to the substrate 10, and the point on the arc at this time is defined as the point A. Regarding the positive / negative of the angle of the magnet 301, the clockwise direction is a positive angle (+ θ) and the counterclockwise direction is a negative angle (−θ) from 0 degrees. The position of the magnet 301 is assumed to be the angular position of the center 30 at a certain angle.

By rotating the magnet 301 around the central axis 20 of the rotary target 201, plasma can be concentrated near the target surface 21 on which the magnet 301 faces during magnetron discharge. In other words, the sputtered particles can be preferentially emitted from the target surface 21 on which the magnet 301 faces. Thereby, the direction in which the sputtering particles are emitted from the target surface 21 can be controlled according to the angle of the magnet 301. Further, after the substrate 10 is arranged to face the plurality of rotary targets 201 to 210, the direction of the sputtering particles toward the substrate 10 can be changed ex post facto by changing the range of the moving angle of the magnet 310.

3 (a) and 3 (b) are graphs showing an example of the moving speed (angular velocity) of the magnet with respect to the angle of the magnet. FIG. 3A shows an example of the moving speed of the magnet with respect to the angle of the magnet 301. FIG. 3B shows an example of the moving speed of the magnet with respect to the angle of the magnet 310. Further, it is assumed that the rotational movement of the

magnets

301 and 310 exemplified in FIGS. 3A and 3B is one rotational movement from the start point to the end point. In FIGS. 3A and 3B, as an example, sputtering film formation is performed while rotating the

magnets

301 and 310 in the clockwise direction.

In the present embodiment, when performing a sputtering film formation on the substrate 10, the

magnets

301 and 310 of the pair of

rotary targets

201 and 210 arranged at both ends among the plurality of rotary targets 201 to 210 are as follows. Controls rotational movement.

For example, by changing the angular velocity of the

magnets

301 and 310 on the arc with respect to the

magnets

301 and 310, the time required to form a film in a region farther from the center of the substrate 10 than the point A is longer than that of the point A. Rotate and move so that the time required to form a film is shorter in the region near the center. The rotary target 201 starts film formation from a region closer to the center of the substrate 10 than the point A on the arc, and the rotary target 210 starts film formation from a region farther from the center of the substrate 10 than the point A on the arc. Start.

For example, as shown in FIG. 3A, the magnet 301 rotates and moves in a range of an angle of −60 degrees to +60 degrees. Here, the position at an angle of −60 degrees is the start point of the rotational movement of the magnet 301, and the position at the angle of +60 degrees is the end point of the rotational movement of the magnet 301. When the magnet 301 is located at the starting point, the discharge power is applied to the rotary target 201. The discharge power is also input at the starting point in the other rotary targets 202 to 210. That is, the plasma ignites at the starting point.

In this rotation angle (120 degrees) range, the angular velocity at the starting point position is approximately 0.2 deg. Whereas / sec, the angular velocity at the end point is 120 deg. Set to / sec. For example, the angular velocity in the range from the starting point position to 25 degrees is 0.2 deg. / Sec to 0.2 deg. While it is around / sec, the angular velocity in the range from 25 degrees to the end point position is 120 deg. Set to / sec.

For the magnet 301, in its rotational movement, the average angular velocity of moving in a region farther from the center of the substrate 10 than the point A on the arc is higher than the average angular velocity of moving in a region closer to the center of the substrate 10 than the point A. Rotate and move to make it faster.

For example, as shown in FIG. 3A, in the range in which the magnet 301 rotates and moves from the start point position to the position of point A, the average value of the angular velocities is low, whereas the magnet 301 has the point A. In the range of rotational movement from the position of to the end point position, the average value of the angular velocity is set to high velocity.

Further, as shown in FIG. 3B, the magnet 310 rotates and moves in the range of an angle of -60 degrees to 60 degrees. Here, the position at an angle of −60 degrees is the start point of the rotational movement of the magnet 310, and the position at the angle of +60 degrees is the end point of the rotational movement of the magnet 310. When the magnet 310 is located at the starting point, discharge power is applied to the rotary target 210.

In this rotation angle (120 degrees) range, the angular velocity of the magnet 310 at the starting point position is 120 deg. Whereas / sec, the angular velocity of the magnet 310 at the end point is approximately 0.2 deg. Set to / sec. For example, the angular velocity in the range from the starting point position to -25 degrees is 120 deg. Whereas / sec, the angular velocity in the range from -25 degrees to the end point position is 0.2 deg. / Sec to 0.2 deg. It is set near / sec.

In the magnet 310, in its rotational movement, the average angular velocity of moving in a region farther from the center of the substrate 10 than the point A on the arc is higher than the average angular velocity of moving in a region closer to the center of the substrate 10 than the point A. Rotate and move to make it faster.

For example, in the range in which the magnet 310 rotates from the start point position to the position of point A, the average value of the angular velocities is high, whereas in the range in which the magnet 310 rotates from the position of point A to the end point position. Is set to a low average angular velocity.

In this way, the change in the angular velocity with respect to the angle of the magnet 301 of the rotary target 201 (FIG. 3 (a)) and the change of the angular velocity with respect to the angle of the magnet 310 of the rotary target 210 (FIG. 3 (b)) cause the magnet to rotate and move. The angular velocities of the

magnets

301 and 310 are set so as to be symmetrical in the range (-60 degrees to +60 degrees).

Further, in the pair of

rotary targets

201 and 210, the magnet 301 of the rotary target 201 and the magnet 310 of the rotary target 210 rotate and move in the same rotation direction. The direction of rotation is not limited to this example, and the directions in which the

magnets

301 and 310 rotate and move may be opposite to each other.

4 (a) and 4 (b) are graphs showing an example of the ratio of the discharge time to the angle of the magnet. FIG. 4A shows an example of the ratio of the discharge time to the angle of the magnet 301, and FIG. 4B shows an example of the ratio of the discharge time to the angle of the magnet 310.

Here, the ratio of the discharge time corresponds to the ratio of the residence time of the magnet at the position of a predetermined angle. That is, the higher the ratio of the discharge time, the longer the movement time of the magnet at the angle position. In other words, the ratio of the discharge time corresponds to the ratio of the residence time of the discharge plasma concentrated in the vicinity of the target surface 21 facing the magnet, and the higher the ratio of the discharge time, the more the sputtering particles are emitted from the target surface 21. The amount will increase.

As shown in FIG. 4A, due to the rotational movement of the magnet 301, the discharge time ratio at any position from -60 degrees to +25 degrees is in the range of 3% to 10%, whereas it is +25 degrees. The discharge time ratio at any position from to +60 degrees is controlled to approximately 0%.

As a result, in the vicinity of the target surface 21 of the rotary target 201, the discharge is longer when the magnet 301 is located from -60 degrees to +25 degrees than when the magnet 301 is located from +25 degrees to +60 degrees. Plasma stays. As a result, the sputtering particles emitted from the target surface 21 of the rotary target 201 are preferentially directed to the region from the end portion 12a toward the inside of the substrate 10 rather than the outside of the end portion 12a of the substrate 10.

On the other hand, as shown in FIG. 4 (b), the discharge time ratio at any position from -60 degrees to -25 degrees is approximately 0% due to the rotational movement of the magnet 310, whereas- The discharge time ratio at any position from 25 degrees to +60 degrees is controlled in the range of 3% to 10%.

As a result, in the vicinity of the target surface 21 of the rotary target 210, the time when the magnet 310 is located from -25 degrees to +60 degrees is longer than when the magnet 310 is located from -60 to -25 degrees. The discharge plasma stays. As a result, the sputtering particles emitted from the target surface 21 of the rotary target 210 are preferentially directed to the region from the end portion 12b toward the inside of the substrate 10 rather than the outside of the end portion 12b of the substrate 10.

The examples shown in FIGS. 3 (a) and 3 (b) and FIGS. 4 (a) and 4 (b) are examples, and the rotation angle at which each of the

magnets

301 and 310 rotates is shown in FIG. 3 (a). ), (B) and FIGS. 4 (a) and 4 (b).

For example, the

magnets

301, 310 of a pair of

rotary targets

201, 210 are positioned at any angle in the range 20 to 90 degrees and at any angle in the range -20 to -90 degrees. It may rotate to and from the position of.

For example, the start point of the rotational movement of the magnet 301 of the rotary target 201 is a position at any angle in the range of -20 degrees to -90 degrees, and the end point of the rotational movement is any of the ranges of +20 degrees to +90 degrees. In the case of the position at that angle, the start point of the rotational movement of the magnet 310 of the rotary target 210 is the position at any angle in the range of -20 degrees to -90 degrees, and the end point of the rotational movement is +20. The position may be at any angle in the range from degrees to +90 degrees.

Next, a specific example of the rotational operation of the magnets of the remaining rotary targets 202 to 209 will be described.

FIG. 5A is a graph showing an example of the moving speed (angular velocity) of the magnet with respect to the angle of the magnet. FIG. 5B is a graph showing an example of the ratio of the discharge time to the angle of the magnet. FIG. 5A shows an example of the moving speed of the magnet with respect to the angle of the magnets 302 to 309, and FIG. 5B shows an example of the ratio of the discharge time to the angle of the magnets 302 to 309. There is.

For the magnets 302 to 309, the rotational movement is controlled so that the appearance is different from the rotational movement of the

magnets

301 and 310. In the magnets 302 to 309, the magnets 302 to 309 rotate so that the angular velocity in the middle of the rotational movement becomes the fastest in the range of the rotation angle in which the magnets 302 to 309 rotate.

For example, as shown in FIG. 5A, the angular velocities of the magnets 302 to 309 have the highest angular velocities near the angle of 0 degrees (point A). Here, the position at an angle of −60 degrees is the start point of the rotational movement of the magnets 302 to 309, and the position at the angle of +60 degrees is the end point of the rotational movement of the magnets 302 to 309. Further, the angular velocities at the start and end points of the magnets 302 to 309 are set lower than the angular velocities at the end points of the magnet 301 and the angular velocities at the start point of the magnet 310. When each of the magnets 302 to 309 is located at the starting point, the discharge power is applied to the rotary targets 202 to 209.

That is, in the magnets 302 to 309, the angular velocity is relatively slow near the start point, the angular velocity is relatively high in the middle of the rotational movement range, for example, at 0 degrees (point A), and the angular velocity is relatively slow again near the end point. Is controlled. Each magnet of the rotary targets 202 to 209 rotates and moves in the same rotation direction, for example.

As a result, as shown in FIG. 5B, in the rotary targets 202 to 209, the discharge time ratio near the angle of 0 degrees is close to 0%, while the discharge time near the start point and the end point is near. The ratio is controlled higher than the discharge time ratio near 0 degrees.

As a result, in the vicinity of the target surface 21 of the rotary targets 202 to 209, the discharge plasma is longer when the magnets 302 to 309 are located near the start point and the end point than when the respective angles of the magnets 302 to 309 are located near 0 degrees. Stay. As a result, the sputtering particles emitted from the target surface 21 of the rotary targets 202 to 209 are directed to a wide angle in the range from the start point to the end point.

As a result, the sputtering particles emitted from each of the rotary targets 202 to 209 overlap on the substrate 10, and a film having a substantially uniform thickness is formed in the central portion of the substrate 10 on which the rotary targets 202 to 209 face each other. Will be done.

The example shown in FIGS. 5 (a) and 5 (b) is an example, and the angle of rotation in which each of the magnets 302 to 309 rotates is not limited to the example in FIGS. 5 (a) and 5 (b). ..

For example, toward the center of the group of the plurality of rotary targets 201 to 210 counting from the rotary target 201, and toward the center of the group of the plurality of rotary targets 201 to 210 counting from the rotary target 210. With respect to the magnet of the Nth rotary target, the change in the angular velocity with respect to each angle may be controlled to be symmetrical within the range in which the magnet rotates and moves.

For example, the magnet 302 of the rotary target 202 and the magnet 309 of the rotary target 209 may be controlled so that the change in the angular velocity with respect to each angle is symmetrical within the range in which the magnet rotates and moves. The magnet 303 of the rotary target 203 and the magnet 308 of the rotary target 208 may be controlled so that the change in the angular velocity with respect to each angle is symmetrical within the range in which the magnet rotates and moves. The magnet 304 of the rotary target 204 and the magnet 307 of the rotary target 207 may be controlled so that the change in the angular velocity with respect to each angle is symmetrical within the range in which the magnet rotates and moves. The magnet 305 of the rotary target 205 and the magnet 306 of the rotary target 206 may be controlled so that the change in the angular velocity with respect to each angle is symmetrical within the range in which the magnet rotates and moves.

By performing such symmetrical control, a film having a more uniform thickness is formed in the central portion of the substrate 10.

During sputtering film formation, it is desirable that the magnets do not approach or face each other between adjacent rotary targets in order to ensure the stability of magnetron discharge. Therefore, it is desirable that the magnets of the plurality of rotary targets 201 to 210 rotate and move in the same rotation direction during the film formation.

According to such a method, the thickness of the film formed near the

end portions

12a and 12b of the substrate 10 is corrected, and the thickness of the film formed in the central portion of the substrate 10 and the end portion 12a of the substrate 10 are corrected. The thickness of the film formed in the vicinity of 12b is adjusted to be substantially uniform.

FIG. 6 is a schematic plan view showing an example of the film forming apparatus of the present embodiment. FIG. 6 schematically shows a plan view of the film forming apparatus 400 when viewed from above. At least three or more rotary targets are arranged in the film forming apparatus 400.

As the film forming apparatus 400, a magnetron sputtering film forming apparatus is exemplified. The film forming apparatus 400 includes a vacuum vessel 401, a plurality of rotary targets 201 to 210, a power supply 403, a substrate holder 404, a pressure gauge 405, a gas supply system 406, a gas flow meter 407, and an exhaust system 408. , The control device 410 is provided. The substrate 10 is supported by the substrate holder 404.

The vacuum container 401 maintains a decompressed atmosphere by the exhaust system 408. The vacuum vessel 401 accommodates a plurality of rotary targets 201 to 210, a substrate holder 404, a substrate 10, and the like. A pressure gauge 405 for measuring the pressure inside the vacuum container 401 is attached to the vacuum container 401. Further, a gas supply system 406 for supplying a discharge gas (for example, Ar, oxygen) is attached to the vacuum container 401. The gas flow rate supplied into the vacuum vessel 401 is adjusted by the gas flow meter 407.

The plurality of rotary targets 201 to 210 are film forming sources of the film forming apparatus 400. For example, when a plurality of rotary targets 201 to 210 are sputtered by plasma formed in the vacuum vessel 401, the sputtering particles are emitted from the plurality of rotary targets 201 to 210 toward the substrate 10.

The power supply 403 controls the discharge power applied to each of the plurality of rotary targets 201 to 210. The power supply 403 may be a DC power supply or a high frequency power supply such as RF or VHF. When discharge power is supplied from the power supply 403 to the plurality of rotary targets 201 to 210, plasma is formed in the vicinity of the target surface 21 of the plurality of rotary targets 201 to 210.

The control device 410 controls the electric power output by the power supply 403, the opening degree of the gas flow meter 407, and the like. The pressure measured by the pressure gauge 405 is sent to the control device 410.

The control device 410 controls to perform sputtering film formation on the substrate 10 while rotating and moving the magnets of the plurality of rotary targets 201 to 210 around the central axis 20. For example, the control device 410 controls the rotational movement of the magnets 301 to 310 and controls the power supply to each of the plurality of rotary targets 201 to 210, which are described with reference to FIGS. 1 (a) to 5 (b). do.

FIG. 7A is a graph showing the film thickness distribution in the substrate surface according to the comparative example. FIG. 7B is a graph showing an example of the film thickness distribution in the substrate surface when the film is formed by the film forming method of the present embodiment. The broken line indicates the film thickness distribution when the sputtering particles emitted from the individual rotary targets 201 to 210 are deposited on the substrate 10. The solid line shows the film thickness distribution in which the film thickness distributions formed by the individual rotary targets 201 to 210 are combined. The width direction of the horizontal axis corresponds to the direction in which a plurality of rotary targets 201 to 210 are arranged side by side. The vertical axis is the film thickness.

In the comparative example shown in FIG. 7A, the film thickness distribution when the positions of the magnets 301 to 310 of the individual rotary targets 201 to 210 are fixed at 0 degrees is shown. In this case, the emission angle distribution of the sputtering particles emitted from the individual rotary targets 201 to 210 follows the so-called cosine law. As a result, the film thickness distribution by the individual rotary targets 201 to 210 shows a distribution symmetrical with respect to the center line of the film thickness distribution (broken line). Moreover, the individual film thickness distributions show the same distribution.

It can be seen that in the film thickness distribution (solid line) in which these individual film thickness distributions are overlapped, peaks and valleys appear prominently, and the in-plane distribution of the film thickness varies.

On the other hand, in the present embodiment shown in FIG. 7B, the emission angle distribution of the sputtering particles emitted from the

rotary targets

201 and 210 is closer to the center side of the substrate 10 than in the comparative example, and the emission angle of the sputtering particles is set. Oriented to the center side of the substrate 10. As a result, the film thickness distribution by the

rotary targets

201 and 210 becomes asymmetric with respect to the center line of the film thickness distribution, and the distribution is closer to the center side of the substrate 10. Further, the peak of the film thickness distribution by the

rotary targets

201 and 210 is higher than the peak of the film thickness distribution by the rotary targets 202 to 209.

Furthermore, the emission angle distribution of the sputtering particles emitted from the

rotary targets

201 and 210 is directed to a wider angle than in the comparative example. As a result, the film thickness distribution by the rotary targets 202 to 209 shows an appearance of spreading toward both ends of the substrate 10 as compared with the comparative example.

Therefore, it can be seen that the film thickness distribution (solid line) in which these individual film thickness distributions are overlapped becomes flatter than that in the comparative example, and the in-plane distribution of the film thickness becomes more uniform.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made. Each embodiment is not limited to an independent form, and can be combined as technically as possible.

10 ... Substrate 11 ...

Film formation surface

12a, 12b ... End 20 ... Central axis 21 ... Target surface 201-210 ... Rotary target 301-310 ... Magnet 400 ... Film formation device 401 ... Vacuum container 403 ... Power supply 404 ... Substrate holder 405 ... Pressure gauge 406 ... Gas supply system 407 ... Gas flow meter 408 ... Exhaust system 410 ... Control device

Claims

A film forming method for forming a sputtering film on a substrate by using at least three rotary targets having a central axis and a target surface and having a magnet that can rotate around the central axis inside.
The plurality of rotary targets are arranged so that the central axes are parallel to each other and the central axes are parallel to the substrate.
While applying power to the plurality of rotary targets, the magnets of the plurality of rotary targets are moved around the central axis on an arc having the point A closest to the substrate, and the magnets are moved to the substrate. Sputter film formation,
Among the plurality of rotary targets, the magnets of the pair of rotary targets arranged at least at both ends have a time of forming a film on the arc in a region away from the center of the substrate from the point A from the point A. A film forming method shorter than the time required to form a film in a region close to the center of the substrate.
In the film forming method according to claim 1,
When the angle of the magnet at point A is 0 degree, the counterclockwise direction is a negative angle, and the clockwise direction is a positive angle from the 0 degree.
The magnets of the pair of rotary targets are located between a position at any angle in the range of 20 degrees to 90 degrees and a position at any angle in the range of -20 degrees to -90 degrees. A film formation method that moves in rotation.
In the film forming method according to claim 1 or 2, the film forming method is used.
One of the pair of rotary targets arranged at both ends starts film formation from a region closer to the center of the substrate than the point A on the arc.
A film forming method in which the other of the pair of rotary targets arranged at both ends starts film formation from a region away from the center of the substrate from the point A on the arc.
In the film forming method according to any one of claims 1 to 3, the film forming method is used.
In the movement of the magnets of the pair of rotary targets arranged at both ends, the average angular velocity of moving in a region away from the center of the substrate from the point A on the arc is closer to the center of the substrate than the point A. A film formation method that is faster than the average angular velocity of moving regions.