TW202202644A - Film forming method - Google Patents

Abstract

Subject of this invention is to attain uniform of film thickness distribution. In a film forming method according to this invention, sputtering film formation is performed on a substrate using at least three or more of a plurality of rotary targets where each has a central axis and a target surface and internally has a magnet that can rotate around the central axis. These rotary targets are disposed in a manner that the central axes are mutually parallel and the central axes are parallel to the substrate. Each of the magnets of the plurality of rotary targets are moved around the central axis on an arc which has a point A closest to the substrate and sputtering film formation is performed on the substrate while power is applied to the plurality of rotary targets. In the plurality of rotary targets, about the magnets of a pair of rotary targets which disposed at least at both ends, time of forming a film on the arc in a region farther from a center of the substrate than the point A is shorter than time of forming a film on the arc in a region closer to the center of the substrate than the point A.

Description

Film formation method

The present invention relates to a film forming method.

In the film-forming technology for substrates for large-scale displays, high uniformity of film thickness distribution is required. In particular, when a sputtering method is used as a film formation method, it may be difficult to uniformize the film thickness distribution in the substrate surface due to the complicated spatial distribution of sputtered particles.

In such a situation, a plurality of rod-shaped rotary targets with magnets installed inside are arranged in parallel to face the substrate, and sputtering particles are injected from the respective rotary targets to the substrate to try to improve the film. Examples of thickness distribution exist (for example, refer to Patent Document 1). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2019-519673.

[The problem to be solved by the invention]

However, with the further enlargement of recent substrates, the film thickness in the central portion of the substrate and the end portions of the substrate tends to be more uneven. In order to achieve uniformity of the film thickness in the substrate surface, it is important how to perform the film thickness compensation in the substrate surface.

In view of the above-mentioned circumstances, an object of the present invention is to provide a film formation method in which the film thickness distribution in the substrate surface becomes more uniform. [means to solve the problem]

In order to achieve the above object, in the film formation method of one aspect of the present invention, the substrate is sputtered and formed using at least three or more rotating targets having a central axis and a target surface (target surface). surface) and a magnet rotatable around the central axis is provided inside. The plurality of said rotating targets are arranged such that the central axes are parallel to each other and the central axes are parallel to the substrate. While supplying electric power to the plurality of the rotating targets, the magnets of the plurality of the rotating targets are moved around the central axis on an arc having a point A closest to the substrate, while sputtering the substrate to form a film. In the plurality of said rotating targets, at least the magnets of the pair of rotating targets arranged at both ends are formed on the arc in a region farther away from the center of the substrate than the above-mentioned point A. The area where the dot is closer to the center of the above-mentioned substrate has a shorter film formation time.

According to such a film forming method, the movement of the magnets of the pair of rotating 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 the above-mentioned point A is regarded as 0 degree, the counterclockwise direction from the above-mentioned 0 degree is regarded as a negative angle, and the clockwise direction is regarded as a positive angle, The magnets of a pair of the rotating targets can be rotated between a position at any angle within a range from 20 degrees to 90 degrees and a position at any angle within a range from -20 degrees to -90 degrees move.

According to such a film forming method, the movement of the magnets of the pair of rotating 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, one of the pair of rotating targets arranged at both ends can start film formation from a region closer to the center of the substrate than the above-mentioned point A on the arc, and one of the pair of rotating targets arranged at both ends can form a film. The film formation can be started from the area|region farther from the center of the said board|substrate than the said A point on the said circular arc on the other side of the said rotating target.

According to such a film forming method, the movement of the magnets of the pair of rotating 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, in the movement of the magnets of the pair of rotating targets arranged at both ends, the average angular velocity of the movement in the region farther from the center of the substrate than the point A on the arc can be determined. It is faster than the average angular velocity of the movement in a region closer to the center of the above-mentioned substrate than the above-mentioned point A.

According to such a film forming method, the movement of the magnets of the pair of rotating targets arranged at both ends is controlled as described above, and the film thickness distribution in the substrate surface becomes more uniform. [Inventive effect]

As described above, according to the present invention, it is possible to provide a film formation method in which the film thickness distribution in the substrate surface becomes more uniform.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. There are cases where XYZ axis coordinates are imported in each drawing. In addition, there are cases where the same reference numerals are attached to the same members or members having the same functions, and there are cases where the description of the members is appropriately omitted after the description of the members. In addition, the numerical value shown below is an illustration, and it is not limited to this example.

(a), (b) in FIG. 1 is a schematic diagram which shows an example of the film-forming method of this embodiment. (a) in FIG. 1 shows a schematic cross section showing the arrangement relationship between a plurality of rotating targets and the substrate, and (b) in FIG. A schematic plane showing the configuration relationship of . In addition, the film formation of this embodiment is performed automatically by the control apparatus 410 of the film formation apparatus 400 shown in FIG. 6, for example.

In the film formation method of the present embodiment, sputtering film formation (magnetron sputtering) is performed on the substrate 10 using at least three or more of a plurality of rotatable cylindrical rotating targets. In (a) and (b) of FIG. 1, for example, ten rotating targets 201 to 210 are illustrated. The number of the plurality of rotating targets is not limited to this number, and may be appropriately changed, for example, according to the size of the substrate 10 .

Each of the plurality of rotating targets 201 to 210 has a central axis 20 and a target surface (sputtering surface) 21 . Each of the plurality of rotating targets 201 to 210 includes a magnet rotatable around the central axis 20 inside. For example, in the example of (a), (b) in FIG. 1, the magnets 301-310 are arrange|positioned in order of the several rotation target 201-210. The magnets 301 to 310 are so-called magnet assemblies. The magnets 301 to 310 have permanent magnets and magnetic yokes.

The plurality of rotating 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, a plurality of rotating targets 201 to 210 are arranged side by side so that the target surfaces 21 face each other in a direction intersecting with the central axis 20 . The direction in which the plurality of rotating targets 201 to 210 are arranged side by side corresponds to the longitudinal direction of the substrate 10 . In addition, the direction in which the plurality of rotating targets 201 to 210 are arranged side by side can also be set as the short-side direction of the substrate 10 as required.

The substrate 10 is supported by a substrate holder (not shown). The potential of the substrate holder is set to, for example, a floating potential, a ground potential, or the like. The plurality of rotating targets 201 to 210 are arranged such that the direction in which the plurality of rotating targets 201 to 210 are aligned is parallel to the longitudinal direction of the substrate 10 . The respective target surfaces 21 of the plurality of rotating targets 201 to 210 face the film-forming surface 11 of the substrate 10 .

1 (a), (b), the direction in which the plurality of rotating targets 201 to 210 are arranged in parallel corresponds to the Y-axis direction, and the direction from the substrate 10 toward the plurality of rotating targets 201 to 210 corresponds to the Z direction The axes correspond to each other, and the directions in which each of the plurality of rotating targets 201 to 210 extend corresponds to the X axis.

Moreover, in the Y-axis direction, a pair of rotation targets 201 and 210 are arrange|positioned at the both ends of the group of several rotation targets 201-210. For example, when the plurality of rotating targets 201 to 210 and the substrate 10 are viewed in the Z-axis direction, the pair of rotating targets 201 and 210 are arranged to protrude from the substrate 10 in the Y-axis direction. For example, the plurality of rotating targets 201 to 210 and the substrate 10 are arranged such that at least a part of each of the pair of rotating targets 201 and 210 overlaps with the substrate 10 .

Specifically, the plurality of rotating targets 201 to 210 and the substrate 10 are arranged such that the respective central axes 20 of the pair of rotating targets 201 and 210 overlap with the substrate 10 . For example, the plurality of rotating targets 201 to 210 are arranged such that the respective central axes 20 of the pair of rotating targets 201 and 210 are located inside the substrate 10 .

In the example of (a), (b) of FIG. 1, the center axis|shaft 20 of the rotating target 201 and the edge part 12a of the Y-axis direction of the board|substrate 10 overlap in the Z-axis direction. Moreover, the central axis 20 of the rotating target 210 overlaps with the end portion 12b in the Y-axis direction of the substrate 10 .

By arranging the pair of rotating targets 201 and 210 and the ends 12 a and 12 b of the substrate 10 in this way, sputtering particles released from the rotating targets 201 and 210 arranged at both ends are directed to the vicinity of the ends 12 a and 12 b of the substrate 10 . , will not pass through the outside of the substrate 10 needlessly. Thereby, the film thickness of the edge part 12a, 12b vicinity of the board|substrate 10 is compensated reliably. In addition, in the embodiment, among a pair of rotating targets 201 and 210, the rotating target 201 may be called the one rotating target, and the rotating target 210 may be called the other rotating target.

In addition, in the Y-axis direction, the pitches of the plurality of rotating targets 201 to 210 are set to be substantially equal. In addition, the relative distance between the plurality of rotating targets 201 to 210 and the substrate 10 during sputtering film formation is set to be a fixed distance.

Each of the plurality of rotating targets 201 to 210 has an outer diameter of 100 mm or more and 200 mm or less. The pitch of the plurality of rotating targets 201 to 210 in the Y-axis direction is 200 mm or more and 300 mm or less. The dimensions of the substrate 10 are 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 rotating targets 201 to 210 are, for example, metals such as aluminum, In-Sn-O (indium-tin-oxygen)-based oxides, and In-Ga-Zn-O (indium-gallium-zinc-oxygen)-based oxides Wait. The material of the substrate 10 is, for example, glass, organic resin, or the like.

In this embodiment, discharge power is supplied to each of the plurality of rotating targets 201 to 210 and the magnets of each of the plurality of rotating targets 201 to 210 are rotated and moved around the central axis 20 on an arc, while the substrate 10 is subjected to Sputtering to form a film.

In particular, the larger the size of the substrate 10 in sputtering film formation, the greater the difference between the thickness of the film formed in the vicinity of the end portions 12 a and 12 b of the substrate 10 and the thickness of the film formed in the central portion of the substrate 10 tends to be to get bigger. Here, the central portion of the substrate 10 refers to an area of the substrate 10 to which the rotating targets 202 to 209 face.

In the present embodiment, by changing the aspect between the rotational movement of the magnets of the pair of rotating targets 201 and 210 and the magnets of the rotating targets 202 to 209 arranged at both ends of the group of rotating targets 201 to 210, a more uniform The in-plane film thickness distribution of the substrate 10 is controlled, and the rotating targets 202 to 209 are arranged between the pair of rotating targets 201 and 210 .

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

In order to make the consumption of the respective rotating targets approximately equal, the same power is supplied to each of the plurality of rotating targets 201 to 210 . The supply power may be DC power, or AC power in an RF (Radio Frequency) band, a VHF (Very High Frequency) band, or the like. In addition, each of the plurality of rotating targets 201 to 210 rotates clockwise or counterclockwise. The plurality of rotating targets 201 to 210 are each set to, for example, 5 rpm (Revolution Per Minute; revolutions per minute) or more and 30 rpm or less at the same number of revolutions.

Hereinafter, a specific example of the rotation operation of the magnets 301 to 310 will be described. First, among the plurality of rotating targets 201 to 210, a specific example of the rotation operation of the magnets 301 and 310 of the pair of rotating targets 201 and 210 arranged at both ends will be described.

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

In this 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 regarded as 0 degrees. For example, when a vertical line is drawn from the center axis 20 to the film formation surface 11 of the substrate 10 , the position where the vertical line coincides with the center 30 of the magnet 301 corresponds to an angle of 0 degrees of the magnet 301 . When the magnet 301 rotates and moves around the center axis 20, the center 30 draws a circular arc orbit. When the angle is 0 degrees, the magnet 301 is closest to the substrate 10, and the point on the arc at this time is regarded as the point A. In addition, regarding the positive and negative of the angle of the magnet 301, the clockwise direction from 0 degrees is regarded as a positive angle (+θ), and the counterclockwise direction is regarded as a negative angle (-θ). In addition, the position of the magnet 301 refers to the angular position of the center 30 at a certain angle.

By rotating and moving the magnet 301 around the central axis 20 of the rotating target 201 , plasma can be concentrated in the vicinity of the target surface 21 facing the magnet 301 during magnetron discharge. In other words, sputtered particles can be preferentially released from the target surface 21 facing the magnet 301 . Thereby, the orientation of sputtering particles released from the target surface 21 can be controlled according to the angle of the magnet 301 . Further, after the substrate 10 and the plurality of rotating targets 201 to 210 are arranged to face each other, the direction of the sputtering particles toward the substrate 10 can be changed afterwards by changing the range of the moving angle of the magnet 301 .

(a) and (b) of FIG. 3 are graphs showing an example of the moving speed (angular velocity) of the magnet with respect to the angle of the magnet. (a) in FIG. 3 shows an example of the angle of the moving speed of the magnet with respect to the magnet 301 . (b) in FIG. 3 shows an example of the moving speed of the magnet with respect to the angle of the magnet 310 . In addition, the rotational movement of the magnets 301 and 310 illustrated in (a) and (b) of FIG. 3 is regarded as one rotational movement from the start point to the end point. In (a) and (b) of FIG. 3 , as an example, the sputtering film formation is performed while rotating and moving the magnets 301 and 310 in the clockwise direction.

In the present embodiment, when sputtering the substrate 10 into a film, among the plurality of rotating targets 201 to 210, the following operations are performed on the magnets 301 and 310 of the pair of rotating targets 201 and 210 arranged at both ends. Rotational movement control.

For example, by changing the angular velocities of the magnets 301 and 310 on an arc, the magnets 301 and 310 are rotated and moved in such a manner that the time for film formation in a region farther from the center of the substrate 10 than at the point A is longer than that at the point A. A region near the center of the substrate 10 has a shorter film formation time. The rotating target 201 starts film formation from a region closer to the center of the substrate 10 than point A on the arc, and the rotating target 210 starts film formation from a region farther from the center of the substrate 10 than point A on the arc.

For example, as shown in (a) of FIG. 3 , the magnet 301 is rotated and moved within an angle range of -60 degrees to +60 degrees. Here, the position at the angle of −60 degrees is the starting 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, discharge power is supplied to the rotating target 201 . Regarding the supply of discharge power, the other rotating targets 202 to 210 are also supplied at the starting point. That is, the plasma ignites at the starting point.

Within the range of the rotation angle (120 degrees), the angular velocity at the end position is set to be 120 degrees/sec with respect to the angular velocity at the starting point position of approximately 0.2 degrees/sec. For example, the angular velocity in the range from the start position to 25 degrees is set at 0.2 degrees/sec to around 0.2 degrees/sec, and the angular velocity in the range from 25 degrees to the end position is set to 120 degrees/sec.

Regarding the magnet 301, in the rotational movement of the magnet 301, 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 smaller than that in the region moving closer to the center of the substrate 10 than the point A The average angular velocity is faster to make the lodestone 301 rotate and move.

For example, as shown in FIG. 3( a ), the average value of the angular velocity is a low velocity in the range where the magnet 301 rotates from the starting position to the position of the point A, whereas the average value of the angular velocity is The high speed is set in the range from the position of point A to the end point.

Moreover, as shown in FIG.3(b), the magnet 310 rotates and moves in the range of the angle of -60 degrees - 60 degrees. Here, the position at the angle of −60 degrees is the starting 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, the rotating target 210 is supplied with discharge power.

Within the range of the rotation angle (120 degrees), the angular velocity of the magnet 310 at the end position is set to approximately 0.2 degrees/sec with respect to the angular velocity of the magnet 310 at the starting position being 120 degrees/sec. For example, the angular velocity in the range from the start position to -25° is 120°/sec, and the angular velocity in the range from -25° to the end position is set to be around 0.2°/sec to 0.2°/sec.

Regarding the magnet 310, in the rotational movement of the magnet 310, the average angular velocity of moving in a region farther from the center of the substrate 10 than point A on the arc is smaller than that in a region moving closer to the center of the substrate 10 than point A The average angular velocity is a faster way to make the lodestone 310 rotate and move.

For example, the average value of the angular velocities is high in the range where the magnet 310 rotates from the starting position to the position of the point A, whereas the average value of the angular velocities is the average value of the angular velocities until the magnet 310 rotates from the position of the point A to the end position. range is set to low speed.

In this way, the respective angular velocities of the magnets 301 and 310 are set so that the angular velocity is changed with respect to the angle of the magnet 301 of the rotating target 201 within the range (-60 degrees to +60 degrees) of the rotational movement of the magnets (( in FIG. 3 ). a)) is symmetrical with the change of the angular velocity with respect to the angle of the magnet 310 of the rotating target 210 ((b) in FIG. 3 ).

In addition, in the pair of rotating targets 201 and 210, the magnet 301 of the rotating target 201 and the magnet 310 of the rotating target 210 rotate and move in the same rotational direction. The direction of rotation is not limited to this example, and the directions of rotation and movement of the magnets 301 and 310 may be opposite to each other.

(a), (b) in FIG. 4 is a graph which shows an example of the ratio of discharge time with respect to the angle of a magnet. FIG. 4( a ) shows an example of the ratio of the discharge time with respect to the angle of the magnet 301 , and FIG. 4( b ) shows an example of the ratio of the discharge time with respect to the angle of the magnet 310 .

Here, the ratio of the discharge time corresponds to the ratio of the dwell time of the magnet at a predetermined angle. That is to say, the higher the ratio of the discharge time, the longer the moving time of the magnet at the angular position. In other words, the ratio of the so-called 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. many.

As shown in FIG. 4( a ), by the rotational movement of the magnet 301 , the ratio of the discharge time to any position from -60 degrees to +25 degrees is in the range of 3% to 10%, from + The discharge time ratio at any position from 25 degrees to +60 degrees is controlled to be approximately 0%.

Thereby, in the vicinity of the target surface 21 of the rotating target 201, the plasma discharges when the magnet 301 is located at the position from -60 degrees to +25 degrees compared to when the magnet 301 is located at the position from +25 degrees to +60 degrees Stay longer. As a result, the sputtering particles released from the target surface 21 of the rotating target 201 are preferentially directed toward the region from the end portion 12 a toward the inside of the substrate 10 , rather than directed outside the end portion 12 a of the substrate 10 .

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

Thereby, in the vicinity of the target surface 21 of the rotating target 210, the plasma discharges when the magnet 310 is located at a position from -25 degrees to +60 degrees compared to when the magnet 310 is located at a position from -60 degrees to -25 degrees Stay longer. As a result, the sputtering particles released from the target surface 21 of the rotating target 210 are preferentially directed toward the region from the end portion 12 b toward the inside of the substrate 10 , rather than directed outside the end portion 12 b of the substrate 10 .

In addition, the examples shown in (a) and (b) in FIG. 3 and (a) and (b) in FIG. 4 are just examples, and the rotation angles of the respective rotational movements of the magnets 301 and 310 are not limited to those shown in FIG. 3 . Examples of (a), (b) and (a) and (b) in FIG. 4 .

For example, the position of the magnets 301 and 310 of the pair of rotating targets 201 and 210 may be at any angle within the range from 20 degrees to 90 degrees and any one of the positions within the range from -20 degrees to -90 degrees. Rotate and move between positions below the angle.

For example, the starting point of the rotational movement of the magnet 301 of the rotating target 201 is a position at any angle within the range from -20 degrees to -90 degrees, and the end point of the rotational movement is from +20 degrees to +90 degrees. In the case of the position at any angle within the range, it can be set as: the starting point of the rotational movement of the magnet 310 of the rotating target 210 is the position at any angle within the range from -20 degrees to -90 degrees, and the rotation The end point of the movement is the position at any angle within the range from +20 degrees to +90 degrees.

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

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

The magnets 302 to 309 are controlled to have rotational movement in a manner different from the rotational movement of the magnets 301 and 310 . Among the magnets 302 to 309 , the magnets 302 to 309 rotate and move so that the angular velocity during the rotational movement becomes the fastest within the range of the rotation angle of the rotational movement of the magnets 302 to 309 .

For example, as shown in FIG. 5( a ), in terms of the angular velocities of the magnets 302 to 309 , the angular velocities become the fastest when the angle is 0 degrees (point A). Here, the position at the angle of -60 degrees is the starting 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 . Also, the angular velocities at the start and end points of the magnets 302 to 309 are set to be lower than the angular velocities at the end point of the magnet 301 and the angular velocity at the start point of the magnet 310 . When each of the magnets 302 to 309 is located at the starting point, discharge power is supplied to the rotating targets 202 to 209 .

That is, the magnets 302 to 309 are controlled such that the angular velocity is relatively slow in the vicinity of the starting point, the angular velocity is relatively high at 0 degrees (point A) in the middle of the rotational movement range, and the angular velocity is relatively high in the vicinity of the end point The angular velocity is again relatively slow. The respective magnets of the rotating targets 202 to 209 are rotationally moved, for example, in the same rotational direction.

Thereby, as shown in FIG. 5( b ), in the rotating targets 202 to 209 , the discharge time ratio near the starting point and the near end point with respect to the discharge time ratio near the angle of 0 degrees approaches 0%. The time scale is controlled to be higher than the discharge time scale around 0 degrees.

Thereby, the discharge plasma stays longer when the magnets 302 to 309 are located near the target surface 21 of the rotating targets 202 to 209 when the respective angles of the magnets 302 to 309 are near 0 degrees. As a result, the sputtering particles released from the target surfaces 21 of the rotating targets 202 to 209 are directed at a wide angle in the range from the start point to the end point.

As a result, on the substrate 10 , the sputtering particles released from each of the rotating targets 202 to 209 overlap each other, and a substantially uniform thickness is formed on the central portion of the substrate 10 facing the rotating targets 202 to 209 . film.

In addition, the example shown in (a), (b) in FIG. 5 is an example, and the rotation angle of each rotation movement of the magnets 302 to 309 is not limited to the example of (a), (b) in FIG.

For example, regarding the magnet of the N-th rotating target that passes from the rotating target 201 to the center of the group of the plurality of rotating targets 201 to 210, and the number that passes from the rotating target 210 to the center of the group of the plurality of rotating targets 201 to 210 The magnet of the N-th rotating target can be controlled in such a way that the change of the angular velocity with respect to the respective angle is symmetrical within the range of the magnet's rotational movement.

For example, the magnet 302 of the rotating target 202 and the magnet 309 of the rotating target 209 can be controlled so that the change of the angular velocity with respect to each angle becomes symmetrical within the range of the magnet's rotational movement. The magnet 303 of the rotating target 203 and the magnet 308 of the rotating target 208 can be controlled so that the change of the angular velocity with respect to each angle becomes symmetrical within the range of the magnet's rotational movement. The magnet 304 of the rotating target 204 and the magnet 307 of the rotating target 207 can be controlled so that the change of the angular velocity with respect to each angle becomes symmetrical within the range of the magnet's rotational movement. The magnet 305 of the rotating target 205 and the magnet 306 of the rotating target 206 can be controlled so that the change of the angular velocity with respect to each angle becomes symmetrical within the range of the magnet's rotational movement.

By such symmetrical control, a film with a more uniform thickness is formed on the central portion of the substrate 10 .

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

According to this method, the thickness of the film formed in the vicinity of the end portions 12 a and 12 b of the substrate 10 is compensated, and the thickness of the film formed in the central portion of the substrate 10 and the thickness of the film formed in the vicinity of the end portions 12 a and 12 b of the substrate 10 are compensated. is adjusted to be roughly uniform.

FIG. 6 is a schematic plan view showing an example of the film forming apparatus of the present embodiment. In FIG. 6, the top view in the case where the film-forming apparatus 400 is seen from above is schematically drawn. At least three or more rotating targets are arranged in the film forming apparatus 400 .

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

The vacuum vessel 401 is maintained in a reduced-pressure atmosphere by an exhaust system 408 . The vacuum container 401 accommodates the plurality of rotating targets 201 to 210 , the substrate holder 404 , the substrate 10 , and the like. A pressure gauge 405 is installed in the vacuum container 401 to measure the pressure in the vacuum container 401 . In addition, a gas supply system 406 is installed in the vacuum container 401, and a discharge gas (for example, Ar (argon), oxygen) is supplied. The flow rate of the gas supplied into the vacuum container 401 is adjusted by the gas flow meter 407 .

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

The power supply 403 controls the discharge power supplied to each of the plurality of rotating targets 201 to 210 . The power source 403 may be a DC (Direct Current) power source, or may be a high-frequency power source such as RF and VHF. When discharge power is supplied from the power source 403 to the plurality of rotating targets 201 to 210 , plasma is formed near the target surfaces 21 of the plurality of rotating targets 201 to 210 .

The control device 410 controls the electric power output from 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 communicated to the control device 410 .

The control device 410 controls the substrate 10 to sputter film formation while rotating and moving the respective magnets of the plurality of rotating 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 described in FIG. 1( a ) to FIG. 5( b ), and controls the power supply to each of the plurality of rotating targets 201 to 210 .

(a) of FIG. 7 is a graph which shows the film thickness distribution in the board|substrate surface of a comparative example. (b) of FIG. 7 is a graph showing an example of the film thickness distribution in the substrate plane in the case where the film has been formed by the film formation method of the present embodiment. The dotted line shows the film thickness distribution when the sputtering particles discharged from the respective rotating targets 201 to 210 are deposited on the substrate 10 . The solid line shows the film thickness distribution obtained by combining the film thickness distributions formed by the respective rotating targets 201 to 210 . The width direction of the horizontal axis corresponds to the direction in which the plurality of rotating targets 201 to 210 are arranged side by side. The vertical axis is the film thickness.

In the comparative example shown in FIG.7(a), the film thickness distribution in the case where the position of the magnet 301-310 of each rotating target 201-210 is fixed to 0 degree is shown. In this case, the emission angle distribution of the sputtering particles emitted from the respective rotating targets 201 to 210 obeys the so-called cosine law. Thereby, the film thickness distribution by each of the rotating targets 201 to 210 represents a symmetrical distribution (dotted line) based on the center line of the film thickness distribution. In addition, each film thickness distribution system shows the same distribution.

The film thickness distribution (solid line) obtained by superimposing these respective film thickness distributions clearly shows mountains and valleys, and it can be seen that the in-plane distribution of the film thickness is uneven.

On the other hand, in the present embodiment shown in FIG. 7( b ), the sputtering particles released from the rotating targets 201 and 210 have a release angle distribution closer to the center side of the substrate 10 than the comparative example, and sputtering The release angle of the particles is directed to the center side of the substrate 10 . Thereby, the film thickness distribution by the rotating targets 201 and 210 becomes asymmetric with respect to the center line of the film thickness distribution, and the distribution is close to the center side of the substrate 10 . Moreover, the peak (peak) of the film thickness distribution by rotating targets 201 and 210 is higher than the peaks of the film thickness distribution by rotating targets 202-209.

Furthermore, the emission angle distribution of the sputtering particles emitted from the rotating targets 201 and 210 is directed at a wide angle compared to the comparative example. Thereby, the film thickness distribution by the rotating targets 202 to 209 shows the state which expanded toward both ends of the board|substrate 10 compared with a comparative example.

Therefore, the film thickness distribution (solid line) obtained by superimposing these respective film thickness distributions is flatter than that of the comparative example, and it can be seen that the in-plane distribution of the film thickness becomes more uniform.

As mentioned above, although embodiment of this invention was described, this invention is not limited only to the above-mentioned embodiment, Of course, various changes can be added. The respective embodiments are not limited to independent forms, but can be combined as long as the technology permits.

10: Substrate 11: Film-forming surface 12a, 12b: end 20: Center axis 21: Target surface (sputtering surface) 201~210: Rotating target 301~310: Magnet 400: Film forming device 401: Vacuum container 403: Power 404: Substrate holder 405: Manometer 406: Gas Supply System 407: Gas Flow Meter 408: Exhaust system 410: Controls θ: angle

FIG. 1 is a schematic diagram showing an example of the film forming method of the present embodiment. 2] It is a figure for demonstrating the definition of the angle of the magnet which rotates and moves about the center axis|shaft of a rotating target. Fig. 3 is a graph showing an example of the moving speed (angular velocity) of the magnet with respect to the angle of the magnet. Fig. 4 is a graph showing an example of the ratio of the discharge time to the angle of the magnet. (a) in [FIG. 5] is a graph which shows an example of the moving speed (angular velocity) of a magnet with respect to the angle of a magnet. (b) of FIG. 5 is a graph which shows an example of the ratio of discharge time with respect to the angle of a magnet. [ Fig. 6] Fig. 6 is a schematic plan view showing an example of the film forming apparatus of the present embodiment. (a) in [FIG. 7] is a graph which shows the film thickness distribution in the board|substrate surface of a comparative example. (b) of FIG. 7 is a graph showing an example of the film thickness distribution in the substrate plane in the case where the film has been formed by the film formation method of the present embodiment.

10: Substrate

11: Film-forming surface

12a, 12b: end

20: Center axis

21: Target surface (sputtering surface)

201~210: Rotating target

301~310: Magnet

Claims (5)

A film-forming method, comprising using at least three or more rotating targets to sputter a film on a substrate, the plurality of rotating targets having a central axis and a target surface, and a magnet capable of rotating around the central axis inside; A plurality of the rotating targets are arranged such that the central axes are parallel to each other and the central axes are parallel to the substrate; While supplying electric power to the plurality of rotating targets, the magnets of each of the plurality of rotating targets are moved around the central axis on an arc having a point A closest to the substrate, while sputtering and forming a film on the substrate. ; Among the plurality of rotating targets, at least the magnets of the pair of rotating targets arranged at both ends are formed on the arc in a region farther away from the center of the substrate than the point A at a time when the film is formed in a region farther away from the center of the substrate than the point A. A region closer to the center of the aforementioned substrate has a shorter film formation time. The film-forming method according to claim 1, wherein when the angle of the magnet at the point A is regarded as 0 degrees, the counterclockwise direction from the 0 degree is regarded as a negative angle, and the clockwise direction from the 0 degree is regarded as a negative angle. In the case where the clockwise direction is regarded as a positive angle, the position of the magnets of the pair of the rotating targets at any angle within the range from 20 degrees to 90 degrees and the range from -20 degrees to -90 degrees. Rotate and move between positions at any angle. The film-forming method according to claim 1 or 2, wherein one of the pair of rotating targets arranged at both ends starts film-forming from a region closer to the center of the substrate than the point A on the arc; The other of the pair of rotating targets arranged at both ends starts to form a film from a region farther from the center of the substrate than the point A on the arc. The film-forming method according to claim 1 or 2, wherein in the movement of the magnets of the pair of rotating targets arranged at both ends, the area is farther from the center of the substrate than the point A on the arc. The average angular velocity of the movement is faster than the average angular velocity of the movement in a region closer to the center of the substrate than the point A. The film-forming method according to claim 3, wherein in the movement of the magnets of the pair of rotating targets arranged at both ends, the magnets are moved in a region farther from the center of the substrate than the point A on the arc. The average angular velocity is faster than the average angular velocity moving in a region closer to the center of the substrate than the aforementioned point A.

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