TW201542850A - Sputtering system and method using direction-dependent scan speed or power - Google Patents

Abstract

A sputtering system having a processing chamber with an inlet port and an outlet port, and a sputtering target positioned on a wall of the processing chamber. A movable magnet arrangement is positioned behind the sputtering target and reciprocally slides behind the target. A conveyor continuously transports substrates at a constant speed past the sputtering target, such that at any given time, several substrates face the target between the leading edge and the trailing edge. In certain embodiments, the movable magnet arrangement slides at a speed that is at least several times faster than the constant speed of the conveyor. A rotating zone is defined behind the leading edge and trailing edge of the target, wherein the magnet arrangement decelerates when it enters the rotating zone and accelerates as it reverses direction of sliding within the rotating zone. In certain embodiments, magnet power and/or speed varies as function of direction of magnet travel.

Description

Sputtering system and method using direction-dependent scanning speed or power

The present application claims the priority of U.S. Patent Application Serial No. 14/185,859, filed on Feb. 20, 2014, filed on Jan. Part of the continuation-in-part application, which claims US Provisional Application No. 61/556,154, and the filing date is November 4, 2011. The disclosures of the above are hereby incorporated by reference in its entirety herein.

The present invention relates to techniques for sputtering systems, such as sputtering systems for depositing thin films on substrates during fabrication of integrated circuits, solar cells, flat panel displays, and the like.

Sputter systems are well known in the art. An example of a sputtering system having a linear scanning magnetron is disclosed in U.S. Patent No. 5,873,989. In such a system, a magnetron sputtering source is used to deposit material onto a substrate and includes a target from which the sputtered material is provided. A magnet assembly is disposed proximate the target to regulate a plasma on the surface of the target. There is another drive assembly for driving the magnet assembly to scan relative to the target. The sputtering process begins with the generation of a gaseous plasma that then accelerates ions from the plasma to the target. The source material of the target is eroded by the arriving ions due to the transfer of energy and is ejected in the form of neutral particles, either in the form of individual atoms or as clusters of atoms or molecules. Since these neutral particles are jetted, they travel in a straight line direction and are struck and coated on the surface of the substrate as needed.

One of the technical problems to be solved by the above system lies in the uniformity of the film formed on the substrate. Another technical problem that must be solved is the utilization of targets in such systems. In particular, since the magnets of the linear magnetron are scanned back and forth, excessive sputtering occurs at both side edges of the target, thus creating two deep trenches that extend parallel to the scanning direction. Therefore, even if most of the target surface is still available, the target needs to be replaced. Several methods are disclosed in the '989 patent cited above to address this technical problem.

However, another problem with target utilization is the corrosion caused at the edge of the scan cycle, which has not been solved in the past. That is, when the magnet reaches the end of the target, the scanning direction is reversed. In order to achieve uniformity of the film, the '989 patent suggests reducing the scanning speed when reaching either end of the target. However, this practice results in an increase in the amount of sputtering of the target, resulting in excessive erosion of the target at both ends in the direction perpendicular to the scanning direction.

Therefore, it is necessary in the art to provide a sputtering system to achieve uniform deposition of the film and to improve the utilization of the target.

BRIEF DESCRIPTION OF THE DRAWINGS The following is a brief description of several aspects of the invention and the technical features of the invention. The invention is not to be construed as being limited to the details of the invention. Its sole purpose is to present some of the concepts of the present invention

The present invention discloses a sputtering system and method that can improve the uniformity of a film formed on a substrate and also achieve high yield. One embodiment of the present invention provides a system in which the substrate continues to move in front of the sputter target. The magnetron is scanned linearly back and forth at a speed that is at least several times greater than the speed of movement on the substrate. The magnetron is scanned in the direction in which the substrate travels, and then scanned in the opposite direction, and thus repeated. During most of its travel, the magnetron moves at a constant speed. However, as it approaches the end of its path of travel, it decelerates. Then, when the magnetron is reversed and begins to travel in the opposite direction, the movement is accelerated until the constant speed is reached. In one embodiment the deceleration/acceleration is 0.5 g, and in another embodiment 1 g. In this way, the utilization rate of the target is improved. According to another embodiment of the invention, the magnetron reversal point has a positional change in successive scans, thereby defining an inversion zone. This also helps to increase the utilization of the target.

A sputtering system has a processing chamber having an inlet port and an outlet port. The sputtering system also has a sputter target disposed on the sidewall of the processing chamber. A movable magnet structure is disposed behind the sputter target and reciprocally slides behind the target. A conveyor continuously transports the substrate through the sputter target at a constant speed such that at any given time, the plurality of substrates can face between the leading and trailing edges of the target. In several examples, the movable magnet structure slides at a speed that is at least several times faster than the constant speed of the conveyor. An inversion region is defined behind the leading and trailing edges of the target. Wherein, the magnet structure decelerates when entering the inversion region, and the magnet structure is accelerated after the direction of the reverse rotation in the inversion region.

According to some embodiments of the present invention, there is provided a system for depositing material from a target onto a substrate, comprising a carrier operable to transport the substrate in a downstream direction, and one or more processing chambers, including A first processing chamber allows the substrate to pass in the downstream direction. The first processing chamber can have a sputtering target and a magnet operable to scan the entire sputtering target at a downstream scanning speed in the downstream direction, and in an upstream direction opposite to the downstream direction, The upstream scan speed scans the entire sputter target, wherein the upstream scan speed is lower than the downstream scan speed.

According to some embodiments of the present invention, a processing chamber is provided, including a sputtering target and a magnet operable to scan the entire sputtering target at a downstream scanning speed in the downstream direction, and In the upstream direction of the downstream direction, the entire sputtering target is scanned at an upstream scanning speed, wherein the upstream scanning speed is lower than the downstream scanning speed.

According to some embodiments, the present invention provides a sputtering method comprising: transporting a substrate through a sputtering target at a downstream speed, and including causing a magnet to scan the target at a downstream scanning speed in the downstream direction, The target material is sputtered onto the substrate, and the magnet is scanned in an upstream direction opposite to the downstream direction at an upstream scanning speed for sputtering the target material onto the substrate. Wherein, the upstream scanning speed is lower than the downstream scanning speed.

According to some embodiments of the present invention, there is provided a system for depositing material from a target onto a substrate, comprising a carrier operable to transport the substrate in a downstream direction, and one or more processing chambers a first processing chamber is included to pass the substrate in the downstream direction. The first processing chamber can have a sputtering target and a magnet operable to scan the entire sputtering target at a downstream scanning power level in the downstream direction, and in an upstream direction opposite to the downstream direction, The entire sputter target is scanned at an upstream scan power level, wherein the upstream scan power level is greater than the downstream scan power level.

According to some embodiments of the present invention, there is provided a processing chamber comprising a sputtering target and a magnet operable to scan the entire sputtering target at a downstream scanning power level in the downstream direction, and The entire sputtering target is scanned at an upstream scanning power level opposite to the upstream direction of the downstream direction, wherein the upstream scanning power level is greater than the downstream scanning power level.

According to some embodiments of the present invention, a sputtering method is provided, the method comprising: transporting a substrate through a sputtering target at a downstream speed, and including causing a magnet to have a downstream scanning power level in the downstream direction Scanning the target for sputtering a target material onto the substrate, and causing the magnet to scan the target at an upstream scanning power level in an upstream direction opposite to the downstream direction for using the target Material is sputtered onto the substrate, wherein the upstream scan power level is above the downstream scan power level.

According to a further aspect of the present invention, there is provided a sputtering apparatus for a film forming chamber, the sputtering apparatus comprising: a target having a front surface and a rear surface, and a sputtering material provided on a front surface thereof; a movable magnet mechanism having a magnet configured to reciprocally scan at a rear surface proximate the target; and a counterweight configured to reciprocally scan at the same speed but opposite direction as the magnet . Since the counterweight can move at the same speed but in the opposite direction as the magnet, the vibration and load applied to the system can be reduced, and the magnet can be scanned at a higher speed and can be accelerated at a higher rate. And slow down. The movable magnet mechanism includes a power element that reciprocates the target and the weight after being energized. Wherein the magnet and the weight are mechanically coupled to the power element. The power element can be a deformable tension element, examples of which include belts, timing belts, chains, and the like. An electric motor is coupled to the power element to energize the power element. Another controller provides a signal to activate the motor.

According to another aspect of the present invention, a method for operating a sputtering system and a controller for operating a sputtering system are provided. Wherein the controller is operable to repeatedly scan the magnetic pole by repeating scanning at a distance X in the upstream direction, then inverting and scanning in a downstream direction at a distance Y; and upon reaching the target At the edge, the repeat is first scanned at a distance X in the downstream direction, then reversed and scanned in the upstream direction at a distance Y; where X is greater than Y, and where X is less than the length of the target. In one embodiment, at least one of X and Y is a constant or the distance difference |X | - | Y | remains unchanged.

The above features and orientations can be "mixed and matched" to any designed system to achieve the desired benefits. A particular system may include all of the above features and aspects to achieve maximum benefit, but other types of systems may implement only one or two features. It depends on the specific situation of the system or the application requirements of the system.

Embodiments of the sputtering system of the present invention will now be described with reference to the drawings. In the description, different embodiments will be used to explain the processing methods of different substrates, or ways to achieve different effects, such as productivity, film uniformity, target utilization, and the like. Depending on the results required for the application, the different features disclosed in this disclosure may be used in part or in whole, alone or in combination, to balance the effects and technical limitations to be achieved. Thus, certain advantages are emphasized in different embodiments, but the invention is not limited to the described embodiments.

1 shows a partial schematic view of one embodiment of a substrate processing chamber using a sputter magnetron in accordance with the present invention. Three chambers, 100, 105 and 110 are shown in Figure 1, but three points on either side indicate that the system can use any number of processing chambers. In addition, although three specific chambers are shown in the drawings, it is not necessary to use the configuration shown in the drawings. Other chamber configurations may be used in the application, or other types of chambers may be used, interposed between the chambers as shown. For example, the first chamber 100 can be a loading chamber, the second chamber 105 can be a sputtering chamber, and the third chamber 110 can be another loading chamber.

For purposes of illustration, in the example of FIG. 1, three chambers 100, 105, and 110 are sputter chambers. Each chamber is evacuated by its own vacuum pumps 102, 104, 106, and each processing chamber is provided with a transfer zone 122, 124 and 126, and a processing zone 132, 134 and 136. The substrate 150 is loaded on a substrate carrier 120. In this embodiment, the substrate 150 is supported from the periphery thereof, that is, the surface of the substrate 120 does not contact the substrate, so that both sides of the substrate can be processed during processing to sputter the target material to both surfaces of the substrate. on. The carrier 120 has a set of rollers 121 that run on a track (not shown in Figure 1). In one embodiment, the rollers are magnetized to provide better adsorption and stability. The carrier 120 operates on a track disposed in the transfer zone to position the substrate within the processing zone. In one embodiment, the power is provided to the carrier 120 from the outside using a linear motor configuration (not shown in FIG. 1). When the three chambers 100, 105 and 110 are both sputter chambers, the system is arranged to enter and exit the system via a loading device.

Figure 2 shows a cross-sectional view taken along line A-A of Figure 1. For the sake of simplicity, only the substrate 250 is shown in Figure 2 and its carrier is not shown. It should be understood, however, that throughout the processing in the system of Figure 1, the substrate 250 is held on the substrate carrier 120 and is continuously transported from one chamber to another by the substrate carrier, as in The arrows in Figure 2 are shown. In this illustrative embodiment, in each of the chambers 200, 205 and 210, both sides of the substrate 250 are machined. Also shown in Figure 2 are isolation valves 202, 206 for isolating each chamber during the manufacturing process. However, since in one embodiment the substrate is continuously moved, the isolation valve can be replaced with a simple door or not at all.

Each chamber includes a movable magnetron 242, 244, 246 mounted to the linear track 242', 244', 246' such that the plasma scanned by the magnetron travels back and forth over the surface of the target 262, as shown The double-headed arrows are shown. During the transport of the substrate in the chamber in a downstream direction on the carrier, the magnets are continuously scanned back and forth. The magnet 242 as shown, when the magnet reaches the leading edge 243 of the target 262, reverses the direction of travel and travels toward the trailing edge 247 of the target 262. When the magnet reaches the trailing edge 247 of the target 262, the direction is reversed again and scanned toward the leading edge 243. This scanning process is repeated continuously. It should be noted that in this particular example, the downstream direction is aligned parallel to the line of the target 262 from its leading edge 243 to the trailing edge 247. Additionally, as used herein, the leading edge may also be referred to as an upstream location or an upstream zone, and the trailing edge may also be referred to as a downstream location or a downstream zone. Therefore, in this regard, the upstream and downstream are defined according to the moving direction of the substrate, and when the substrate passes through the target 262, it is first reached to the upstream leading edge 243, and then the downstream trailing edge 247 is reached. .

Fig. 3 shows a longitudinal sectional view taken along line B-B of Fig. 1. The figure shows that the substrate 350 is mounted on the carrier 320. The carrier 320 has a roller 321 and the roller 321 running on the track 324 may be a magnetic roller. In this case, the track 324 may be made of a permanent magnet material. In the present embodiment, the carrier is moved by the linear motor 326. Of course, other power and/or other configurations can also be used. The chamber is evacuated and a pilot gas, such as argon, is supplied to the chamber to maintain the plasma. The RF bias energy is applied to the movable magnetron 344 to ignite the plasma, and the magnetron 344 is located behind the target 364.

4A shows another embodiment of the present invention in which the substrate 450 is transported by a conveyor belt 440 that is continuously moved for "pass-through" processing, that is, through the configuration of the doors 402 and 406. Such a configuration is particularly beneficial when only one side of the substrate requires sputtering, such as when manufacturing a solar cell. In this configuration, for example, a plurality of substrates can be arranged in a row such that a plurality of substrates can be processed simultaneously. In the enlarged view of Fig. 4A, three substrates are shown side by side, i.e., along a line perpendicular to the direction of movement of a substrate (as indicated by the arrows), arranged side by side. This arrangement can also be referred to as arranging the substrates in a plurality of rows and in a plurality of rows. The black dots in the enlarged view indicate that the substrate is continuously supplied in the column direction, and the supply amount may be "continuous supply" because the number of substrates is constantly replenished to the conveyor belt. Thus, the configuration of the substrate is a "continuous" provision in the column direction and is provided in an n-row arrangement, the value of n being 3 in Figure 4A, but the value of n may of course be any integer. Moreover, in such an embodiment, when the target 464 is longer than the size of the substrate, a plurality of columns and a plurality of rows of substrates can be simultaneously processed, at which time the conveyor is continuously moved below the target 464. Substrate. For example, when a three-column configuration is used, that is, when three wafers are side by side, the size of the target can be designed to simultaneously process four columns to form three rows of substrates, so that twelve substrates can be processed simultaneously. As before, the magnetron 444 moves linearly back and forth between the leading and trailing edges of the target, the direction of which is parallel to the direction of travel of the substrate, as indicated by the double-headed arrows in the figure. The plasma 403, on the opposite side of the target 464, follows the movement of the magnetron 444 to sputter material from the target 464 onto the substrate 450.

FIG. 4B shows another embodiment that uses scanning poles 442 and weights 446. Specifically, the magnetic pole 442 is scanned back and forth in a linear manner as indicated by the double-headed arrows in the figure. Reverse the direction when scanning to either end. Vibration in the system can be caused by reversing the direction and may limit the rate of deceleration and acceleration. To reduce this effect, a counterweight 446 is provided as a counterbalance and scanned in the opposite direction to the magnetic pole to counter the movement of the magnetic poles. This approach reduces vibration in the system and increases the rate of acceleration and deceleration of the poles.

In the particular embodiment of FIG. 4B, the magnetic poles 442 and the weight 446 are slidably coupled to the linear track assembly 442 such that the magnetic poles 442 and the weight 446 are free to slide over the linear track assembly 445. As seen from the viewpoint of Fig. 4B, the linear track assembly is shown as a single track, but the linear track assembly can also be arranged in a number of tracks for supporting the magnetic pole 442 and the counterweight 446 so that it can freely move back and forth in a straight line. The pole 442 is attached to one side of the power element 448 and the weight 446 is mounted to the other side of the power element 448. The power element 448 can be a conveyor belt, such as a chain, a belt, a toothed (timing) belt, etc., and rotates on wheels 441 and 443. One of the pulleys, such as roller 443, is powered by motor 449 via a coupling mechanism 447, such as a toothed belt. The motor 449 is controlled by the controller 480, and a signal is sent by the controller 480 to the motor 449 to repeatedly rotate the roller 443, causing the conveyor belt 448 to transfer the magnetic poles 442 back and forth over the track 442, and the counterweight 446 is reversed. Slide in the direction. That is, the counterweight moves at the same speed but in the opposite direction of the magnet. This arrangement substantially reduces the load on the motor and the load on the system. It also reduces vibration and achieves high speed movement and high speed acceleration and deceleration.

Figure 5 shows an example of a system as shown in Figure 4A or 4B. The atmospheric side conveyor 500 continuously supplies the substrate into the system. The substrate is then conveyed to a conveyor inside the system for passage through a low vacuum loading chamber 505, a high vacuum loading chamber 510, and optionally a transfer chamber 515. The substrate is then continuously transferred over the conveyor and processed by one or more successive chambers 520, which show two processing chambers. The substrate is then transferred to an optional transfer chamber 525, then to a high vacuum unload chamber 530, a low vacuum unload chamber 535, and finally to the atmosphere side conveyor 540 to exit the system.

Figure 6 shows an embodiment of the movable magnetic pole that can be used in any embodiment of the present invention. In Figure 6, the speed at which the substrate 650 moves over the conveyor 640 is constant. The target assembly 664 is positioned above the substrate while the movable magnetron 644 moves linearly back and forth along the target assembly, as indicated by the double-headed arrows in the figure. The plasma 622 follows the magnetron movement to eject sputtering from different regions of the target. In the present embodiment, the normal operating speed of the magnetron is a constant speed, and the speed is at least several times the moving speed of the substrate. The speed is set such that during the passage of one substrate through the sputtering chamber, the target can be sputtered multiple times under the control of the moving magnetron. For example, the speed of the magnetron may be 5 to 10 times higher than the speed of the substrate, such that during the period in which the conveyor transports the substrate through the entire length of the target, the magnet has been scanned back and forth multiple times behind the target to A plurality of layers are deposited on the substrate.

As shown in Fig. 6, in the present embodiment, each substrate length is Ls, which is defined as the length along the traveling direction of the conveyor belt. Likewise, the target also has a length Lt defined as the length of the direction of travel of the conveyor belt, which is parallel to the direction of travel of the magnet. In the present embodiment, the length Lt of the target is many times longer than the length Ls of the substrate. For example, the target length can be four times the pitch length. The pitch is defined as the sum of the length of one substrate plus the distance S between the two substrates on the conveyor belt. That is, the pitch P = (L _S + S).

The problem with the linear movement of the magnetron behind the target is that when the magnetron reaches the front or tail end of the target, it stops moving and begins to move in the opposite direction. Therefore, the erosion at the edge portion of the target is more severe than the main surface of the target. When the edge of the target is attacked by an amount specified by the product specification, the target needs to be replaced, even if the central portion of the target is still available. This problem can be solved in the present invention in different embodiments, as described below.

According to one embodiment, the offsets E and F are specified on the leading and trailing edges of the target. When the magnetron reaches the offset, it is decelerated at a specified rate, for example, 0.5 g, 1 g, etc. At the end of the offset the magnetron changes direction and accelerates at a specified rate. This is done at both ends of the magnetron stroke, that is, at the leading and trailing edges of the target.

According to another embodiment, an inversion region is defined, for example, regions E and F are respectively designated at the leading and trailing edges of the target. When the magnetron reaches any of the inversion regions, the direction of travel is changed at a point within the inversion region. However, over time, the magnetron is redirected at different points within the reversal zone. The operation can be seen by referring to the enlarged view in Fig. 6: the point of the reverse direction at time t ₁ is designated as point F ₁ . The point of the reverse direction at time t ₂ is designated as point F ₂ . This point is at the trailing edge of the target, but is still within the designated area F. At time t ₃ , the point of the reverse direction is designated as point F ₃ . This point is located at the trailing edge of the target, but is still within the designated area F. At time t _n , the point of the reverse direction is designated as point F _n . This point returns to a distance from the trailing edge of the target, but in any case, all points F _i are located within the designated area F. In the region E on the other side, that is, at the leading edge of the target, the inversion point and the inversion region are also specified in a similar manner.

The reverse point of the reverse scan direction can be selected in various ways. For example, a random selection can be used to determine the reversal point after each scan, every two scans, or after every x scans. Conversely, it can also be implemented using a program in which after each scan, the reversal point is moved by one distance Y in one direction until the end of the area, and then the reversal point starts to move a distance toward the opposite end. Y. Alternatively, the moving route can be designed in a staggered pattern such that the reversal point is first moved by one z amount in one direction and then moved in the opposite direction by an amount of –w in the next step, where |w | <| z |.

In the previously described embodiment, the magnetron is scanned at a constant speed during the processing, as studies have found that changing the scanning speed will adversely affect film uniformity on the substrate. It is worth noting that in configurations where the substrate is continuously moving in front of the target, it is not desirable to slow or speed up the magnet array within the processing region, even if the purpose is to control the thickness uniformity of the film.

In the disclosed embodiment of the present invention, moving a plurality of substrates on a conveyor can be considered as a continuous (infinite length) substrate moving at a constant speed. The scanning speed must be chosen such that the substrate advancing at a constant speed achieves good uniformity. In these embodiments, the starting position, stopping position, acceleration and deceleration are particularly used to control the utilization of the target. This practice helps to disperse the deep grooves created at the ends when the direction of movement is reversed.

The present invention provides an electrode design for reducing deep trenches created at the top and bottom of the plasma track. A larger thickness target can be used during sputtering, or a higher power can be applied to the target because the scanning is performed at a relatively high speed while dispersing power onto the entire surface of the substrate. Since each substrate faces most of the targets through the plasma, the starting position and the stopping position can be different each time, and the scanning line length of one scanning is changed to the scanning line length of the next scanning, resulting in The effect is not seen from the uniformity of the film. That is, although the description of the embodiment of Fig. 6 describes that the inversion region is set outside the processing region, it is not necessary to use this method as long as the substrate is continuously moved as described herein. In this way, the inversion area can instead be placed in the processing area.

For example, a system in accordance with one embodiment of the present invention is for fabricating a solar cell at a rate of 2,400 substrates per hour. The conveyor belt continuously moves the substrate at a rate of about 35 mm / sec. The magnetron is scanned at a speed of at least 250 mm/sec, that is, at a speed that is 7 times faster than the substrate transport speed. The target and magnetron are designed such that the stroke of the magnetron scan is approximately 260 mm long. This provides more than 97% film uniformity. The acceleration/deceleration can be set at 0.5g, the distance is about 6.4 mm, or 1 g, and the distance is approximately halved. As shown in FIG. 6, various calculations can be performed by one or more controllers 680, and the scanning speed of the magnetron, magnetron power, substrate moving speed (eg, conveyor speed), and the like can be controlled.

Figures 7A through 7D show plots of deposition uniformity produced using fixed wafer transfer speeds and different magnet scan speeds. The graph of Fig. 7A shows the uniformity obtained when the magnet scanning speed is 5% of the wafer transport speed. For example, for a wafer transfer speed of 35 mm/sec, the magnet is scanned at a speed of 1.75 mm/sec. The resulting film uniformity was 90%. This uniformity is not sufficient for producing devices such as solar cells. When the scanning speed of the magnet is increased to 7.5% of the wafer conveying speed, the resulting uniformity is reduced to 86%, as shown in Fig. 7B. In addition, if the speed is increased to 10%, the resulting uniformity is further reduced to 82%, and when the speed is increased to 12.5%, the uniformity is further reduced to 78%. From this point of view, increasing the scanning speed of the magnet results in a corresponding decrease in film uniformity, which indicates that the magnet scanning speed should be a small percentage of the wafer transport speed. This conclusion can be further supported by the graph shown in Figure 8A. In the figure, the uniformity decreases as the scanning speed of the magnet increases.

However, the graph of Figure 8A also shows that the maximum uniformity that can be achieved should be about 90%. As noted above, such uniformity is not sufficient for use in a wide variety of processes. Therefore, the inventors further studied in depth to achieve the results shown in Fig. 8B. Fig. 8B is a graph showing a strange change in film deposition uniformity when the magnet scanning speed is increased above the scanning speed. In fact, if the scanning speed of the magnet is increased, the uniformity of the film is lowered. However, at a certain point, if the scanning speed of the magnet is further increased, the uniformity suddenly starts to improve, so that when the scanning speed of the magnet is about three times the conveying speed of the wafer, a uniformity of about 98% can be achieved. Peak. A brief drop in uniformity can be observed thereafter, but then the uniformity rises when the scanning speed of the magnet is about 5 times the wafer conveying speed, and can be maintained at a high point when the speed is increased. The results are shown in the graph of Figure 8C. Fig. 8C shows an enlarged view of a circled portion in Fig. 8B. As shown in FIG. 8C, when the speed exceeds the wafer transport speed by 5 times, the uniformity is maintained at 97% or more, and when the speed is about 10 times the wafer transport speed, the uniformity is maintained at 98% or more. Higher speeds, from a mechanical load and mechanical design point of view, should not be feasible, and uniformity does not seem to be more improved due to higher speeds. Therefore, from the complexity of the design and potentially higher maintenance costs, the scanning speed can be increased to more than 10 times the wafer conveying speed, which should not be required.

In certain embodiments of the invention, the scanning speed may vary depending on the direction of travel of the magnet. For example, when the magnet scans the target in a downstream direction (ie, in the same direction as the substrate moves), the magnet can move at a speed that is higher than when the magnet scans the target in an upstream direction (ie, in a direction opposite to substrate motion) The speed of movement. This change in speed provides better control over the deposition rate and improves deposition uniformity. In certain embodiments, this change in velocity can be used to balance the length of time that the magnet passes through the substrate in the downstream and upstream directions. That is, the scanning speed of the magnet can be selected such that the "relative" speed, i.e., the speed of travel of the magnet relative to the target, becomes the same in both directions of travel. For example, if the speed of the substrate is Ss and the relative speed of the magnet is St, then when the magnet travels in the downstream direction, it should be scanned at speed St + Ss; and when it travels in the upstream direction, its scanning speed should be St – Ss.

Moreover, in some embodiments, the power of the magnetron may vary depending on the direction in which the magnet moves. For example, when the magnet scans the target in the downstream direction, the power used can be higher or lower than when the magnet scans the target in the upstream direction. This power change provides better control of the deposition rate and improves deposition uniformity. In certain embodiments, such power variations can be used to balance the power applied to the magnet as it passes through the substrate in the downstream and upstream directions.

In certain embodiments of the invention, changes in speed and power can be used in combination as a function of the direction in which the magnet is scanned. That is, as explained above, in order to generate a constant relative scanning speed, when the magnet travels in the downstream direction, its scanning speed is faster than when traveling in the upstream direction. This means that for a given target area, the time required for the magnet to pass through the area in the downstream direction is shorter than the time required to pass in the upstream direction. Thus, according to one embodiment, during the travel of the magnetron in the downstream direction and/or the upstream direction, the power of the magnetron is varied such that the total amount of power delivered to the target during the entire downstream direction scan is equal to the entire upstream direction scan. The total amount of power delivered to the target during the period. Therefore, if the total power transmitted in one scanning direction is Pd, and the time required for scanning in one direction (either direction) is Ts, the power applied to the magnetron in each direction can be calculated as: W = Pd/Ts, where Ts is the product of the target length Lt and the scanning speed St+Ss or St - Ss, depending on the direction of travel.

On the other hand, if, for example, the moving speed of the magnet in the upstream direction and the downstream direction is constant, or when scanning in the upstream direction, the scanning time of one substrate exposed to the magnet is shorter than when scanning in the downstream direction, the upstream direction may be Improve power efficiency during scanning by increasing the power level above the power level during the downstream direction of the scan. That is to say, if the substrate is exposed to the sputtering time from the target and the stroke in the upstream direction of the magnet is short, the sputtering power should be increased in the upstream direction, so that more material per unit time is required. It can be deposited on a substrate. The power difference can also be set such that the amount of material deposited on the substrate per unit time, whether the magnet is scanned in the upstream or downstream direction, is the same. That is, the power of the magnet when scanning in the upstream direction and the downstream direction can be adjusted such that the amount of material sputtered from the target per unit time in the stroke in the upstream direction of the magnet is different from the stroke in the downstream direction of the magnet. However, the amount of material deposited on the substrate per unit time is the same. For example, the sputtering power can be increased in the upstream direction of the magnet so that the amount of material sputtered from the target per unit time is higher than the amount of sputtering in the downstream direction of the magnet, but deposition on the substrate per unit time The amount of material is the same in the scan of the upstream and downstream directions of the magnet.

When the invention described above is used, a processing chamber can be provided, the chamber comprising: a sputtering target configured to pass a substrate in a downstream direction; and a magnet operable to the downstream direction The downstream scanning power level scans the entire sputtering target and scans the entire sputtering target at an upstream scanning power level in an upstream direction opposite to the downstream direction, wherein the upstream scanning power level is greater or less than the Downstream scan power level. The magnet may reverse the direction of the inversion region on the opposite side of the target, and wherein successive inversions occur at different positions in each of the inversion regions. This different location can be chosen at random. The target may be longer than the substrate. A plurality of substrates may be disposed within a predetermined pitch and passed through the processing chamber, and the length of the magnet is at least 4 times the pitch.

The inversion of the scan direction can be distributed over the entire scan length, rather than being limited only to the inversion region. For example, the magnet can be scanned for a distance of X mm and then inverted and travel a distance of – Y mm, where | X |> | – Y |. The direction of travel of the magnet is then reversed, another step of X mm is scanned, and then reversed to travel another path – Y mm. In this way the magnet is advanced by X mm and then back to – Y mm, but since the absolute length of X is greater than the absolute length of Y, the entire length of the target can be scanned. Then, when the magnet reaches the edge of the target, it travels a distance of -X mm, that is, X mm in a direction opposite to the previous travel. The magnet is then reversed and travels a distance of Y mm. This scanning method is repeated such that the inversion position of the magnet scanning is distributed over a large area on the target, and is not limited to the edge portion. In some embodiments, X and Y are both constants, but X and Y in other embodiments may vary, for example, depending on the condition of the target.

In certain embodiments, the target scan distance may be a total of about 240 mm. The electrode begins at an initial position and scans a small portion of the total distance, for example 100 mm, on each scan before the first direction reversal occurs. The pole then returns, but does not fully reach the initial position, but arrives at an offset position away from the initial position. In one example, the offset can be 40 mm, resulting in a total return distance of 60 mm. This method is then repeated 6 times in this example to cover a total distance of 240 mm. As a result, the scan inversion point can be distributed over the entire surface of the target without being limited to an inversion region. In certain embodiments of the invention, this method is applied at high speed acceleration/deceleration (about 4-5G, where G = 9.80665 meters per second) mode, with a scan speed of about 1000 mm/sec, achieving a net speed Equivalent to a scan speed of 210 mm/sec with a single scan length of 240 mm. Of course, the above values are for example only and may vary depending on the particular application. This method allows the start/stop area to be distributed over a large area because the start/stop area migrates in the downstream or upstream direction, which results in improved target utilization while maintaining uniformity of coating thickness on the substrate. good. In some embodiments of the invention, the manner in which such a method is implemented is to use a controller programmed to set: scan speed in the upstream direction, scan speed in the downstream direction, start/stop acceleration/deceleration, Upstream direction power, downstream direction power, acceleration period power, and deceleration power. These parameters can be controlled by the controller or by the controller to achieve the desired effect.

Additionally, in some embodiments, for successive scans, the distance between the start and stop positions of the upstream and downstream directions travels is equal, which is shorter than the total scan distance. Therefore, the start/stop position is moved with each successive scan. Taking the situation in Fig. 6 as an example, the distance between Fi and Ei is kept constant for all points Fi. Meanwhile, in the embodiment of Fig. 6, both the Fi and Ei regions are shown as being defined at the edges of the target. However, as described in the embodiments of the preceding paragraph, the turning points are not necessarily limited to the edges of the target, but may be distributed over the entire length of the substrate.

The present invention has been described in terms of various technical features, and for a particular application, different embodiments may use one or more of the features. In any embodiment, the scanning speeds of the upstream and downstream directions may be the same or different sizes. In any of the embodiments, the acceleration rate and the deceleration rate in the start and stop regions of the upstream direction and the downstream direction may be the same or different sizes. Additionally, the power applied to the magnetron in the upstream and downstream directions in any embodiment may be the same or different sizes. In any embodiment, the start and stop positions of the upstream and downstream directions may be the same or different. In any embodiment, the distance between the start and stop regions of the upstream and downstream directions is the same, the distance being less than the total scan distance, such that the start/stop position moves with each successive travel.

In addition, the present invention also provides a sputtering method, the method comprising: transporting a substrate through a sputtering target at a downstream speed, and including causing a magnet to scan the target at a downstream scanning power level in the downstream direction. The target material is sputtered onto the substrate, and the magnet is scanned in an upstream direction opposite to the downstream direction at an upstream scanning power level for sputtering the target material to the target material. On the substrate, wherein the upstream scanning power level is higher than the downstream scanning power level. The magnet may reverse the direction of travel at the opposite regions of the opposite ends of the target, and wherein the successive reverse directions occur at different locations within each of the reverse regions. This different location can be chosen at random.

Through the above description, the present invention also provides a system for sputtering a material from a target onto a plurality of substrates, comprising: a conveyor belt operable to transport the plurality of substrates in a downstream direction, and a processing chamber to enable The substrate can pass in the downstream direction. The processing chamber has a sputtering target and a magnet having a length parallel to the downstream direction and longer than the total length of the n substrates. The magnet is operable to reciprocally scan the target. In some embodiments, the target is applied at a downstream scan power level during scanning in the downstream direction, and is upstream during scanning in an upstream direction opposite the downstream direction. A scan power level is applied to the target, wherein the upstream scan power level can be different from the downstream scan power level. In other embodiments, the present invention uses a counterweight that is configured to scan at the same speed but in the opposite direction as the magnet. In still other embodiments, the conveyor conveys n rows of substrates, where n is an integer. In a further embodiment, the magnet reverses the position of the scan direction at a different location along the length of the target, wherein the reverse direction migrates along the length of the target. In a further embodiment, the downstream scan speed and the upstream scan speed are set to maintain a relative velocity of the magnet and the substrate in either scan direction at a constant value.

It must be noted that the method steps and techniques disclosed herein are not limited to application to any particular device and can be achieved in any suitable combination of components. In addition, various general-purpose devices are also applicable to the invention. The present invention has been described above with reference to the specific embodiments thereof, and the foregoing description is only intended to illustrate the invention and not to limit the invention. Those having ordinary knowledge and technology in this industry can easily realize the contents of the present invention by extending the other combinations from the above description.

In addition, other methods for carrying out the present invention can be realized by considering the patent specification of the present invention and implementing the content of the present invention. The several aspects and/or components used in the embodiments of the present invention may be used alone or in any manner. The specification and its drawings are intended to be illustrative only, and the true scope and spirit of the invention can be

100,105,110‧‧ ‧ chamber
102,104,106‧‧‧Vacuum pump
120‧‧‧Substrate carrier
121‧‧‧Roller
122,124,126‧‧‧Transfer area
132,134,136‧‧‧Processing area
150‧‧‧Substrate
200, 205, 210‧ ‧ chamber
202,206‧‧‧Isolation valve
242,244,246‧‧‧ movable magnetron
242', 244', 246'‧‧‧ linear orbit
243‧‧‧ leading edge
247‧‧‧ trailing edge
250‧‧‧Substrate
262‧‧‧ Target
320‧‧‧ Vehicles
321‧‧‧Roller
324‧‧‧ Track
326‧‧‧Linear motor
344‧‧‧ movable magnetron
350‧‧‧Substrate
402,406‧‧‧
403‧‧‧ Plasma
440‧‧‧ conveyor belt
441‧‧‧ round
442‧‧‧ magnetic pole
443‧‧‧Roller
444‧‧‧Magnetron
446‧‧‧weight
445‧‧‧linear track assembly
447‧‧‧ coupling mechanism
448‧‧‧Power components
449‧‧‧Motor
450‧‧‧Substrate
464‧‧‧ Target
480‧‧‧ Controller
500‧‧‧Atmospheric side conveyor
505‧‧‧Low vacuum loading chamber
510‧‧‧High vacuum loading chamber
515‧‧‧Transmission chamber
520‧‧‧室
525‧‧‧Transmission chamber
530‧‧‧High vacuum unloading chamber
535‧‧‧Low vacuum unloading chamber
540‧‧‧Atmospheric side conveyor
622‧‧‧ Plasma
640‧‧‧Conveyor
644‧‧‧ movable magnetron
650‧‧‧Substrate
664‧‧‧ Target components

The accompanying drawings are incorporated in and constitute a part of the claims The purpose of the drawings is to exemplify the main features of the embodiments of the present invention in a schematic manner. The drawings are not intended to illustrate all of the features of the actual examples, nor are they used to indicate the relative

1 shows a partial schematic view of one embodiment of a substrate processing chamber using a sputter magnetron in accordance with the present invention. Figure 2 shows a cross-sectional view taken along line A-A of Figure 1. Fig. 3 shows a longitudinal sectional view taken along line B-B of Fig. 1. Figure 4A shows another embodiment of the invention in which the substrate is supported on a conveyor belt that is continuously conveyed at a fixed speed; and Figure 4B shows another embodiment of the invention in which a counterweight is used to balance The movement of the scanning magnetic pole. Figure 5 shows an example of a system architecture using a sputtering chamber, such as the one shown in Figures 4A and 4B. Figure 6 shows an embodiment of a movable magnetic pole that can be used in any embodiment of the present application. Figures 7A through 7D show plots of deposition uniformity produced using fixed wafer transfer speeds and different magnet scan speeds. Fig. 8A is a graph showing that the deposition uniformity is lowered when the scanning speed of the magnet is increased. Fig. 8B is a graph showing a strange change in film deposition uniformity when the magnet scanning speed is increased above the scanning speed. Fig. 8C shows an enlarged view of a circled portion in Fig. 8B.

402,406‧‧‧

403‧‧‧ Plasma

440‧‧‧ conveyor belt

444‧‧‧Magnetron

450‧‧‧Substrate

464‧‧‧ Target

Claims (20)

A system for depositing material from a target onto a substrate, comprising: a carrier operative to transport the substrate in a downstream direction; and one or more processing chambers including a deposition chamber to enable the substrate to Passing in a downstream direction, the deposition chamber includes: a target; a magnet assembly operable to cause a magnetic pole to scan the target at a downstream scanning speed in the downstream direction, and in an upstream direction opposite to the downstream direction, An upstream scan speed scans the target; and a controller operative to control the scan speed as a function of scan direction. The system of claim 1, wherein the upstream scanning speed is lower than the downstream scanning speed. The system of claim 1, wherein the downstream scanning speed is at least 5 times greater than the speed at which the substrate passes through the first processing chamber. The system of claim 1, wherein the downstream scanning speed and the upstream scanning speed are set such that the speed of the magnetic pole relative to the substrate is maintained at a constant value in each scanning direction. The system of claim 1, wherein the controller applies a power level to the target when the magnetic pole is scanned in a downstream direction, and the target is applied when the magnetic pole is scanned in an upstream direction. The power is different. The system of claim 5, wherein the total power delivered to the target over the entire length of the scan in the downstream direction is the same as the total power delivered to the target over the entire length of the scan in the upstream direction. The system of claim 1, wherein the magnetic poles reverse direction in opposite regions of opposite ends of the target, and wherein the successive inversion points occur at different positions in the individual inversion regions. A system as claimed in claim 7, wherein the different locations are selected in a random manner. The system of claim 1, wherein the controller operates to repeatedly scan the magnetic pole in the following manner: repeating scanning a distance X in the upstream direction, then inverting and scanning a distance Y in a downstream direction; Upon reaching the edge of the target, the repeat is first scanned a distance X in the downstream direction, then inverted and scanned in the upstream direction by a distance Y; where X is greater than Y, and wherein X is less than the length of the target. A system of claim 9, wherein at least one of X and Y is a constant. For example, the system of claim 9 wherein the distance difference |X | - | Y | remains unchanged. The system of claim 1, wherein the target length is greater than the length of the substrate. The system of claim 1, wherein the plurality of substrates are arranged at a predetermined pitch and the target length is at least four times greater than the pitch through the processing chamber. The system of claim 1, wherein the deposition chamber further comprises a counterweight operative to scan in a direction opposite to the direction of travel of the magnetic pole. The system of claim 1, wherein the magnet assembly comprises: a linear track assembly, wherein the magnetic pole is coupled to be freely slidable on the linear track assembly. a weight coupled to be slidable on the linear track assembly; a transmitter coupled to the magnetic pole on one side and coupled to the weight on the other side: and a motor coupled to be The signal from the controller energizes the transmitter. A method comprising: transporting a substrate through a sputtering target at a downstream speed; and causing a magnet to repeatedly scan a target in opposite downstream and upstream directions to sputter the target material onto the substrate, wherein The scanning speed is a function of the direction of scanning of the magnet. The method of claim 16, wherein the upstream scanning speed is lower than the downstream scanning speed. The method of claim 16, wherein the downstream scanning speed is at least 5 times greater than the upstream scanning speed. The method of claim 16, further comprising inverting the opposite side of the target, inverting the scanning direction of the magnet, and wherein the direction of the number of connections is reversed in the respective inversion regions, occurring in different positions. The method of claim 19, wherein the different locations are selected in a random manner.