WO2015130532A1 - Système et procédé de pulvérisation cathodique utilisant une vitesse ou puissance de balayage dépendant de la direction - Google Patents

Système et procédé de pulvérisation cathodique utilisant une vitesse ou puissance de balayage dépendant de la direction Download PDF

Info

Publication number
WO2015130532A1
WO2015130532A1 PCT/US2015/016448 US2015016448W WO2015130532A1 WO 2015130532 A1 WO2015130532 A1 WO 2015130532A1 US 2015016448 W US2015016448 W US 2015016448W WO 2015130532 A1 WO2015130532 A1 WO 2015130532A1
Authority
WO
WIPO (PCT)
Prior art keywords
target
downstream
scan
speed
upstream
Prior art date
Application number
PCT/US2015/016448
Other languages
English (en)
Inventor
Vinay Shah
Alexandru Riposan
Terry Bluck
Vladimir Kudriavtsev
Original Assignee
Intevac, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US14/185,859 external-priority patent/US10106883B2/en
Application filed by Intevac, Inc. filed Critical Intevac, Inc.
Priority to JP2016570910A priority Critical patent/JP2017508892A/ja
Priority to SG11201606930XA priority patent/SG11201606930XA/en
Priority to DE112015000895.0T priority patent/DE112015000895T5/de
Priority to CN201580017462.7A priority patent/CN106414794A/zh
Priority to KR1020167025408A priority patent/KR20160142288A/ko
Publication of WO2015130532A1 publication Critical patent/WO2015130532A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/56—Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks
    • C23C14/568—Transferring the substrates through a series of coating stations
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
    • C23C14/352—Sputtering by application of a magnetic field, e.g. magnetron sputtering using more than one target
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32733—Means for moving the material to be treated
    • H01J37/32752—Means for moving the material to be treated for moving the material across the discharge
    • H01J37/32761—Continuous moving
    • H01J37/32779—Continuous moving of batches of workpieces
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
    • H01J37/3402—Gas-filled discharge tubes operating with cathodic sputtering using supplementary magnetic fields
    • H01J37/3405—Magnetron sputtering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
    • H01J37/3402—Gas-filled discharge tubes operating with cathodic sputtering using supplementary magnetic fields
    • H01J37/3405—Magnetron sputtering
    • H01J37/3408—Planar magnetron sputtering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
    • H01J37/3411—Constructional aspects of the reactor
    • H01J37/3435—Target holders (includes backing plates and endblocks)
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
    • H01J37/3411—Constructional aspects of the reactor
    • H01J37/345—Magnet arrangements in particular for cathodic sputtering apparatus
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
    • H01J37/3411—Constructional aspects of the reactor
    • H01J37/345—Magnet arrangements in particular for cathodic sputtering apparatus
    • H01J37/3455—Movable magnets

Definitions

  • This application relates to sputtering systems, such as sputtering systems used to deposit thin films on substrates during the fabrication of integrated circuits, solar cells, flat panel displays, etc.
  • Sputtering systems are well known in the art.
  • An example of a sputtering system having a linear scan magnetron is disclosed in U.S. patent 5,873,989, in which a magnetron sputtering source for depositing a material onto a substrate includes a target from which the material is sputtered, a magnet assembly disposed in proximity to the target for confining a plasma at the surface of the target and a drive assembly for scanning the magnet assembly relative to the target.
  • the sputtering process relies on the creation of a gaseous plasma and then accelerating the ions from this plasma into the target.
  • the source material of the target is eroded by the arriving ions via energy transfer and is ejected in the form of neutral particles - either individual atoms, clusters of atoms or molecules. As these neutral particles are ejected they will travel in a straight line to impact and coat the surface of the substrate as desired.
  • One of the problems to be resolved in such a system is the uniformity of the film that is formed on the substrate.
  • Another problem to be resolved in such a system is target utilization. Specifically, since the magnets of linear magnetrons scans back and forth, excessive sputtering occurs at both edges of the target, generating two deep grooves along, i.e., parallel to, the scan direction. Consequently, the target has to be replaced, even though the majority of the surface of the target is still usable.
  • Various methods for combating this phenomenon are disclosed in the above cited '989 patent.
  • another target utilization issue that has not been previously addressed is the erosion caused at the edges of the scan cycle. That is, when the magnets reach an end of the target, the scan direction is reversed.
  • the '989 patent suggests to slow the scan speed towards either end of the target.
  • this leads to increased sputtering of the target, leading to excessive erosion at both ends of the target in a direction perpendicular to the scan direction.
  • a sputtering system and method that enhance uniformity of the film formed on the substrate, and also enables high throughput.
  • One embodiment provides a system wherein substrates continually move in front of the sputtering target.
  • the magnetron is linearly scanned back and forth at speed that is at least several times higher than the speed on the substrates' motion.
  • the magnetron is scanned in the direction of substrate travel and then in the reverse direction, repeatedly. During most of its travel, the magnetron is moved at a constant speed. However, as it approaches the end of its travel, is decelerates. Then, when is starts its travel in the opposite direction, it accelerates until it reaches the constant speed.
  • the deceleration/acceleration in one embodiment is 0.5 g and in another it is lg. This enhances utilization of the target.
  • the turning point of the magnetron is changed at successive scans, so as to define a zone of turnaround. This also helps in enhancing target utilization.
  • 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 behinds 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.
  • 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.
  • a system for sputtering material from a target onto a substrate includes a carrier operable to transport the substrate in a downstream direction, and one or more processing chambers, including a first processing chamber, through which the substrate is passed in the downstream direction.
  • the first processing chamber can have a sputtering target, and a magnet operable to scan across the sputtering target in the downstream direction at a downstream scanning speed and in an upstream direction opposite to the downstream direction at an upstream scanning speed that is lower than the downstream scanning speed.
  • a processing chamber includes a sputtering target, and a magnet operable to scan across the sputtering target in the downstream direction at a downstream scanning speed and in an upstream direction opposite to the downstream direction at an upstream scanning speed that is lower than the downstream scanning speed.
  • a sputtering method includes
  • a system for sputtering material from a target onto a substrate includes a carrier operable to transport the substrate in a downstream direction, and one or more processing chambers, including a first processing chamber, through which the substrate is passed in the downstream direction.
  • the first processing chamber can have a sputtering target, and a magnet operable to scan across the sputtering target in the downstream direction at a downstream scanning power level and in an upstream direction opposite to the downstream direction at an upstream scanning power level that is greater than the downstream scanning power level.
  • a processing chamber includes a sputtering target, and a magnet operable to scan across the sputtering target in the downstream direction at a downstream scanning power level and in an upstream direction opposite to the downstream direction at an upstream scanning power level that is greater than the downstream scanning power level.
  • a sputtering method includes transporting a substrate past a sputtering target at a downstream speed, and inducing sputtering of target material onto substrate by scanning a magnet across the sputtering target in the downstream direction at a downstream scanning power level and in an upstream direction opposite to the downstream direction at an upstream scanning power level that is greater than the downstream scanning power level.
  • a sputtering arrangement for a deposition chamber comprising a target having a front surface and a back surface, and having sputtering material provided on its front surface;
  • a movable magnet mechanism having a magnet configured for reciprocally scanning in close proximity to the back surface of the target and a counterweight configured for reciprocally scanning at same speed but opposite direction as the magnet.
  • the movable magnet mechanism includes a motive element which is energize to reciprocally move the target and the counterweight, wherein the magnet and the counterweight are mechanically coupled to the motive element.
  • the motive element may be a deformable tension element, examples of which include belt, a timing belt, a chain, etc.
  • a motor is coupled to the motive element to energize the motive element, and a controller provides signals to activate the motor.
  • method for operating a sputtering system and a controller for operating sputtering system wherein the is controller operable to repeatedly scan the magnetic pole according to: repeatedly scan at upstream direction a distance X, then reverse and scan at downstream a distance Y; when reaching the edge of the target, repeatedly scan at downstream direction a distance X, then reverse and scan at upstream a distance Y; wherein X is longer than Y, and wherein X is shorter than the length of the target.
  • at least one of X and Y is a constant or the distance
  • Figure 1 illustrates part of a system for processing substrate using sputtering magnetron according to one embodiment.
  • Figure 2 illustrates a cross section along lines A- A in Figure 1.
  • Figure 3 illustrates a cross section along lines B-B in Figure 1.
  • Figure 4A illustrates another embodiment, wherein substrates are supported on a conveyor that moves continuously at constant speed
  • Figure 4B illustrates another embodiment wherein a counter-weight is used to balance the motion of the scanning magnetic pole.
  • Figure 5 illustrates an example of a system architecture using a sputtering chamber such as that shown in Figures 4 A and 4B.
  • Figure 6 illustrates an embodiment of a movable magnetic pole, which may be used in any of the disclosed embodiments.
  • Figures 7A-7D are plots of deposition uniformity using constant wafer transport speed and different magnets scan speed.
  • Figure 8A is a plot illustrating that the uniformity drops as the magnet scan speed increases.
  • Figure 8B is another plot illustrating a strange behavior of film deposition uniformity versus magnet scan speed at higher speed than the scan speed.
  • Figure 8C is an enlargement of the portion circled in Figure 8B.
  • Figure 1 illustrates part of a system for processing substrates using sputtering magnetron, according to one embodiment.
  • three chambers, 100, 105 and 110 are shown, but the three dots on each side indicate that any number of chambers may be used.
  • three specific chambers are shown, it is not necessary that the chamber arrangement shown here would be employed. Rather, other chamber arrangements may be used and other type of chambers may be interposed between the chambers as shown.
  • the first chamber, 100 may be a loadlock
  • the second, 105 a sputtering chamber
  • the third, 110 another loadlock.
  • 105 and 110 are sputtering chambers; each evacuated by its own vacuum pump 102, 104, 106.
  • Each of the processing chambers has a transfer section, 122, 124 and 126, and a processing section 132, 134 and 136.
  • Substrate 150 is mounted onto a substrate carrier 120.
  • the substrate 150 is held by its periphery, i.e., without touching any of its surfaces, as both surfaces are fabricated by sputtering target material on both sides of the substrate.
  • the carrier 120 has a set of wheels 121 that ride on tracks (not shown in Figure 1). In one embodiment, the wheels are magnetized so as to provide better traction and stability.
  • the carrier 120 rides on rails provided in the transfer sections so as to position the substrate in the processing section.
  • motive force is provided externally to the carrier 120 using linear motor arrangement (not shown in Figure 1).
  • linear motor arrangement not shown in Figure 1.
  • Figure 2 illustrates a cross section along lines A-A in Figure 1. For simplicity, in
  • substrate 250 is illustrated without its carrier, but it should be appreciated that the substrate 250 remains on the substrate carrier 120 throughout the processing performed in the system of Figure 1, and is continuously transported from chamber to chamber by the substrate carrier, as illustrated by the arrow in Figure 2.
  • the substrate 250 in each chamber, 200, 205 and 210, the substrate 250 is processed on both sides.
  • isolation valves 202, 206 that isolate each chamber during fabrication; however, since in one embodiment the substrates continuously move, the isolation valves can be replaced with simple gates or eliminated.
  • Each chamber includes a movable magnetron 242, 244, 246, mounted onto a linear track 242', 244', 246', such that it scans the plasma over the surface of the target 262, as shown by the double-headed arrows.
  • the magnets are scanned back and forth continuously as the substrates are transported in the chambers on the carriers in a downstream direction. As illustrated with respect to magnets 242, as the magnets reach the leading edge 243 of the target 262, it reverses direction and travels towards the trailing edge 247 of target 262. When it reaches the trailing edge 247, it again reverses direction and is scanned towards the leading edge 243. This scanning process is repeated continuously.
  • downstream direction is aligned parallel to the target 262 from its leading edge 243 to its trailing edge 247.
  • leading edge may also be referred to as the upstream location or region, while the trailing edge may also be referred to the downstream location or region.
  • Upstream and downstream in this respect are therefore defined with reference to the direction of travel of the substrate, which reaches upstream leading edge 243 before it reaches downstream trailing edge 247 in its travel past the target 262.
  • FIG 3 illustrates a cross section along lines B-B in Figure 1.
  • Substrate 350 is shown mounted onto carrier 320.
  • Carrier 320 has wheels 321, which ride on tracks 324.
  • the wheels 321 may be magnetic, in which case the tracks 324 may be made of paramagnetic material.
  • the carrier is moved by linear motor 326, although other motive forces and/or arrangements may be used.
  • the chamber is evacuated and precursor gas, e.g., argon, is supplied into the chamber to maintain plasma. Plasma is ignited and maintained by applying RF bias energy to the movable magnetron 344, situated behind target 364.
  • precursor gas e.g., argon
  • Figure 4 A illustrates another embodiment, wherein substrates 450 are supported on a conveyor 440 that moves continuously for "pass-by" processing, with an arrangement to pass through gates 402 and 406.
  • This arrangement is particularly beneficial when only one side of the substrates needs to be sputtered, such as when fabricating solar cells.
  • several substrates can be positioned abreast such that several are processed simultaneously.
  • the callout in Figure 4A illustrates three substrates abreast, i.e., arranged along a line perpendicular to the direction of motion, as indicated by the arrow.
  • the substrates may be said to be arranged in multiple rows and columns.
  • the dots in the callout indicate that the supply of substrates, in the column direction, may be "endless,” as their number is constantly replenished on the conveyer.
  • the substrates are arranged in an "endless" supply or row direction and in n rows, wherein n in the example of FIG. 4A is 3, although n may be any integer.
  • n in the example of FIG. 4A is 3, although n may be any integer.
  • the target 464 when the target 464 is longer relative to the size of the substrates, then several substrates can be processed simultaneously in columns and rows as the belt continuously moves the substrates under the target 464.
  • the size of the target can be designed so as to enable processing of four substrates in three rows, thus simultaneously processing twelve substrates.
  • the magnetron 444 moves back and forth linearly between the leading and trailing edges of the target, in a direction parallel to the direction of travel of the substrates, as shown by the double-headed arrow.
  • the plasma 403 follows the travel of the magnetron 444 in the opposite side of target 464, to thereby sputter material from target 464 onto the substrates 450.
  • Figure 4B illustrates another embodiment having a scanned magnetic pole 442 and counterweight 446.
  • the magnetic pole 442 is scanned linearly back and forth, as shown by the double-headed arrow. At either end the scanning has to reverse direction. This reverse of direction can cause vibration in the system and may limit the deceleration and acceleration speeds.
  • counterweight 446 is provided as a counter balance, and is scanned in the opposite direction to counter the motion of the magnetic pole. This reduces vibrations in the system and allows for fast deceleration and acceleration of the magnetic pole.
  • the magnetic pole 442 and the counterweight 446 are slidably coupled to a linear track assembly 442, such that the magnetic pole 442 and the counterweight 446 are free to slide on linear track assembly 445.
  • the linear track assembly is seen as a single track, but it may be several tracks arranged to support the magnetic pole 442 and counterweight 446 to freely move linearly back and forth.
  • the magnetic pole 442 is attached to one side of motive element 448, while the counterweight 446 is attached to the other side of the motive element 448.
  • the motive element 448 may be a conveyer such as a chain, a belt, toothed (timing) belt, etc., rotating over wheels 441 and 443.
  • One of the wheels e.g., wheel 443 is energized by motor 449 via coupling mechanism 447, e.g., a toothed belt.
  • the motor 449 is controlled by controller 480, which sends signals to the motor 449 to rotate wheel 443 back and forth, such that the conveyor 448 slides the magnetic pole 442 back and forth on track 442, while sliding the counterweight 446 in the opposite direction. That is, the counterweight moves at the same speed but opposite direction of the magnet.
  • This arrangement drastically reduces the loads on the motor and the system in general. It also reduces vibration and enables high speeds and high accelerations and decelerations.
  • Figure 5 illustrates an example of a system such as that shown in Figure 4A or
  • An atmospheric conveyor 500 continuously brings substrates into the system, and the substrates are then transported on conveyors inside the system so as to traverse a low vacuum loadlock 505, a high vacuum loadlock 510, and, optionally, a transfer chamber 515. Then the substrates, while continuously moving on the conveyor, are processed by one or more successive chambers 520, here two are shown. The substrates then continue on conveyors to an optional transfer chamber 525, then to high vacuum loadlock 530, low vacuum loadlock 535, and then to atmospheric conveyor 540, to exit the system.
  • Figure 6 illustrates an embodiment of the movable magnetron, which may be used in any of the above embodiments.
  • the substrates 650 are moved on the conveyor 640 at constant speed.
  • the target assembly 664 is positioned above the substrates, and movable magnetron 644 oscillates back and forth linearly behind the target assembly, as shown by the double-headed arrow.
  • the plasma 622 follows the magnetron, causing sputtering from different areas of the target.
  • the speed of the magnetron is constant and is at least several times the speed of the substrates. The speed is calculated such that during the time a substrate traverses the sputtering chamber, it is sputtered several times by the moving magnetron.
  • the speed of the magnetron can be five to ten times faster than the speed of the substrate, such that by the time the conveyor moves the substrate past the entire length of the target, the magnets have been scanned back and forth several times behind the target so as to deposit multiple layers on the substrate.
  • each substrate is of length Ls, which is defined in the direction of travel of the conveyor belt.
  • the target has a length Lt, which is defined in the direction of travel of the conveyor, which is parallel with the direction of travel of the magnets.
  • the target's length, Lt is several times longer than the substrate length Ls.
  • offsets E and F are designated at the leading and trailing edges of the target, respectively.
  • the magnetron When the magnetron reaches the offset, it decelerates at a prescribed rate, e.g., 0.5g, lg, etc.
  • the magnetron changes direction and accelerates at the prescribed rate. This is done at both ends of travel of the magnetron, i.e., at the leading and trailing edges of the target.
  • a rotation zone is prescribed, e.g., zones E and F are designated at the leading and trailing edges of the target, respectively.
  • zones E and F are designated at the leading and trailing edges of the target, respectively.
  • the magnetron When the magnetron reaches either of the rotation zones, it changes travel direction at a point within the rotating zone. However, over time the magnetron changes direction at different points within the rotating zone.
  • the callout in Figure 6 As illustrated, at time ti the point of reversing direction is designated as Fi. At time t 2 , the point of reversing direction is designated F 2 , and is further towards the trailing edge of the target as point F ls but is still within the zone designated F.
  • the selection of the points of reversing scan direction can be done using various ways. For example, a random selection can be done at each scan, at each two scans, or after x number of scans. Conversely, a program can be implemented wherein at each scan the point is moved a distance Y in one direction until the end of the zone is reached, and then the points start to move a distance Y towards the opposite end. On the other hand, the movement can be designed to generate an interlaced pattern by moving in one direction a Z amount and then in the next step moving in the reverse direction a -w amount, wherein
  • the magnetron is scanned at constant speed, as it has been found that varying the scan speed adversely affects film uniformity on the substrates. Notably, in configurations where the substrates continuously moves in front of the target, slowing down or speeding up the magnet array over the processing area is inadvisable, even for controlling the film thickness uniformity.
  • moving many substrates on a conveyor can be thought of as a continuous (infinitely long) substrate that is moving at a constant speed.
  • the scan speed must be selected so as to give good uniformity on a substrate moving at a constant speed.
  • special use is made of the start position, the stop position, acceleration, and deceleration to control target utilization. This has the effect of spreading out the deep grooves that occur at the ends when reversing the motion.
  • a pole design is used to reduce the deep grooves at the top and bottom of the plasma track.
  • a thicker target can be used or higher power can be utilized into the targets because the scan is done at a fairly high speed, spreading the power out over the full surface of the substrate. Because each substrate sees multiple target passes of the plasma, the start and stop position can be varied with each pass and the effect of changing the scan length from one pass to the next will not be seen in the film uniformity. That is, while the embodiment of Figure 6 was described such that the rotating zone is designed to be outside of the processing area, this is not necessary when having the substrates continuously move, as described herein. Rather, the rotating zone can be within the processing area.
  • the system is used to fabricate solar cells at a rate of 2400 substrates per hour.
  • the conveyor continuously moves the substrates at a rate of about 35mm/sec.
  • the magnetron is scanned at a speed of at least 250 mm/sec, i.e., more than seven times the speed of the substrate transport.
  • the target and magnetron are designed such that the stroke of the magnetron scan is about 260mm. This provides film uniformity of over 97%.
  • the acceleration/deceleration can be set at 0.5g with a distance of about 6.4mm or lg, for about half that distance.
  • the various calculations and the control of magnetron scan speed, magnetron power, substrate travel speed (e.g., conveyor speed), etc., can be done by one or more controllers 680.
  • Figures 7A-7D are plots of deposition uniformity using constant wafer transport speed and different magnets scan speed.
  • Figure 7A is a plot of uniformity for magnets scan speed that is 5% of the wafer transport speed. For example, for a wafer transport speed of 35mm/s, the magnets were scan at 1.75mm/s. The resulting film uniformity was 90%, which is not adequate for production of devices such as solar cells.
  • the uniformity dropped to 86%, as shown in Figure 7B.
  • the speed was increased to 10% the uniformity dropped to 82%, and when the speed was increased to 12.5% the uniformity dropped even further to 78%.
  • scan speed can be different depending on the direction of magnet travel. For example, when the magnet is scanning the target in the downstream direction (i.e., the same direction as the substrate motion), it can be moved at a constant speed that is faster than when it is scanning the target in the upstream direction (i.e., the opposite direction as the substrate motion). Such speed variation can provide better control of deposition rate, and improved deposition uniformity. In certain embodiments, this speed variation can be used to balance the length of time the magnet spends in the downstream and upstream passes across the substrate. That is, the speed of the magnet scan can be chosen such that the "relative" speed, i.e., the speed of the magnet's travel with respect to the target, is the same in both travel direction.
  • the speed of the substrate is Ss and the relative speed of the magnet is St
  • the magnet travels in the downstream direction it should be scanned at speed St + Ss
  • speed St - Ss when it travels in the upstream direction, it should be scanned at speed St - Ss.
  • the magnetron power can be varied depending on the direction of magnet travel. For example, when the magnet is scanning the target in the downstream direction, less or more power can be applied than when it is scanning the target in the upstream direction. Such power variation can provide better control of deposition rate, and improve deposition uniformity. In certain embodiments, this power variation can be used to balance the amount of power that is applied to the magnet in the downstream and upstream passes across the substrate.
  • variations in both speed and power can be used in combination, as a function of the direction of magnet scan. That is, as explained above, in order to generate constant relative scanning speed, when the magnet travels downstream it scans faster than when it travels upstream. This means that in the downstream direction the magnet spends less time over a given target area than when it travels upstream. Therefore, according to one embodiment the magnetron power is varied during the downstream and/or upstream travel such that the total amount of power delivered to the target during the entire downstream scan equals the total amount of power delivered during the upstream scan.
  • the upstream and the downstream speed of the magnet is constant, or is such that during upstream scan the time that a substrate is exposed to the magnet scan is shorter than during the downstream scan
  • the power difference can be calculated such that the amount of material deposited on the substrate per unit time is the same when the magnet is scanned in either upstream or downstream direction.
  • the power during the upstream and the downstream scanning of the magnet can be adjusted such that while the material sputtered from the target per unit of time is different during upstream and downstream travel of the magnet, the amount of material deposited on the substrate per unit of time is the same.
  • the sputtering power may be increased such that the amount of material sputtered from the target is higher per unit of time than during downstream scan of the magnet, but the amount of material deposited on the substrate per unit of time is the same during upstream and downstream scanning of the magnet.
  • a processing chamber comprising: a sputtering target configured for passage of a substrate therethrough in a downstream direction; and a magnet operable to scan across the sputtering target in the downstream direction at a downstream scanning power level and in an upstream direction opposite to the downstream direction at an upstream scanning power level that is smaller or greater than the downstream scanning power level.
  • the magnet may reverse directions at rotating zones at opposite ends of the target, and wherein successive reversals at each of the rotating zones occur at different locations. The different locations may be selected randomly.
  • the target may be greater in length than the substrate. Multiple substrates may be disposed at a predetermined pitch and are passed through the processing chamber, and the magnet may have a length at least four times the pitch.
  • the scanning reversal can be spread over the entire scanning length, rather than be limited to turning zones.
  • the magnet may be scanned a distance of Xmm, and then be reversed and travel for a distance of -Ymm, wherein
  • the magnet travel is then reversed again and it is scanned for another Xmm and then reversed for another -Ymm.
  • the magnet is advanced Xmm and retracted -Ymm, but since the absolute length of X is loner than the absolute length of Y, the scanning is progressed over the entire length of the target.
  • X and Y are constants, in other embodiments X and Y may be varied, e.g., according to the condition of the target.
  • the target scan distance may be a total of about 240 mm.
  • the pole starts at an initial location, and scans a fraction of this total distance per scan, for example 100 mm, before making a first direction reversal.
  • the pole then returns not exactly to the initial location, but to an offset location from the initial location.
  • the offset in one example may be 40 mm, for a total return distance of 60 mm.
  • This pattern is then repeated 6 times in this example to cover the total 240 mm. Consequently, the scanning reversal point expands over the entire surface of the target and is not bound to a reversal zone.
  • g 9.80665 meters per second squared
  • scan speeds of about 1000 mm/sec, achieving a net speed that is equivalent to a scan speed of 210 mm/sec for a single 240 mm long scan.
  • these values are by way of example and may vary depending on the particular application. This approach allows the start/stop zones to be distributed over a large they migrate in the downstream or upstream direction, enhancing target utilization while maintaining good uniformity of thickness on the substrate.
  • achievement of this approach is realized using a controller that is programmed to set the upstream scan speed, the downstream scan speed, start- stop acceleration/deceleration, upstream power, downstream power, power during acceleration, and power during deceleration.
  • a controller that is programmed to set the upstream scan speed, the downstream scan speed, start- stop acceleration/deceleration, upstream power, downstream power, power during acceleration, and power during deceleration.
  • Each of these parameters may be controlled and varied individually by the controller to achieve the desired effect.
  • the upstream and downstream start and stop locations are at the same distance apart for each successive scan, which is shorter than the total scan distance, so that the start/stop location moves with each successive pass.
  • the distance between Fi and Ei remains constant.
  • the zones Fi and Ei are shown as limited to the edges of the target.
  • the turning points need not be limited to the edges of the target, but may rather be spread over the entire length of the substrate.
  • the upstream and downstream scanning speed may be of same or different magnitude.
  • decelerations may be of same or different magnitude.
  • the upstream and downstream the magnitudes of power applied to the magnetron may be the same or different.
  • the upstream and downstream start and stop location may be the same or different.
  • the upstream and downstream start stop zones locations are the same distance apart, shorter than the total scan distance, so that the start/stop location moves with each successive pass.
  • a sputtering method comprising: transporting a substrate past a sputtering target in a downstream direction; and inducing sputtering of target material onto substrate by scanning a magnet across the sputtering target in the downstream direction at a downstream scanning power level and in an upstream direction opposite to the downstream direction at an upstream scanning power level that is greater than the downstream scanning power level.
  • the magnet may reverse directions at rotating zones at opposite ends of the target, and wherein successive reversals at each of the rotating zones occur at different locations. The different locations may be selected randomly.
  • a system for depositing material from a target onto a plurality of substrates comprising: a conveyor operable to transport the plurality of substrates in a downstream direction; and a processing chamber through which the substrates are passed in the downstream direction, the processing chamber having a target having a length parallel to the downstream direction and longer than a combined length of n substrates; and a magnet operable to reciprocally scan across the target.
  • a downstream scanning power level is applied to the target and during the scanning in the upstream direction opposite to the downstream direction, an upstream scanning power level is applied to the target, and the upstream power may be different from the downstream power level.
  • a counterweight is configured to scan at same speed but opposite direction than the magnet.
  • the conveyor delivers n rows of substrates, wherein n is an integer.
  • the magnet reverses scanning direction at different positions along the length of the target, wherein the reversal direction migrates along the length of the target.
  • the downstream scanning speed and the upstream scanning speed are set so as to maintain a constant speed between the magnet and the substrate in either scanning direction.

Abstract

L'invention porte sur un système de pulvérisation cathodique qui possède une chambre de traitement avec un orifice d'entrée et un orifice de sortie, et une cible de pulvérisation cathodique positionnée sur une paroi de la chambre de traitement. Un agencement d'aimants mobiles est positionné derrière la cible de pulvérisation cathodique et coulisse en va-et-vient derrière la cible. Un transporteur transporte de façon continue des substrats à une vitesse constante devant la cible de pulvérisation cathodique, de telle sorte qu'à tout moment donné, plusieurs substrats font face à la cible entre le bord avant et le bord arrière. L'agencement à aimants mobiles coulisse à une vitesse qui est au moins plusieurs fois supérieure à la vitesse constante du transporteur. Une zone de rotation est définie derrière le bord avant et le bord arrière de la cible, l'agencement à aimants décélérant lorsqu'il entre dans la zone de rotation et accélérant lorsqu'il change de direction de coulissement à l'intérieur de la zone de rotation. La puissance et/ou la vitesse des aimants varie en fonction de la direction de déplacement des aimants.
PCT/US2015/016448 2014-02-20 2015-02-18 Système et procédé de pulvérisation cathodique utilisant une vitesse ou puissance de balayage dépendant de la direction WO2015130532A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP2016570910A JP2017508892A (ja) 2014-02-20 2015-02-18 方向依存性の走査速度又は走査電力を用いるスパッタリングシステムおよびスパッタリング方法
SG11201606930XA SG11201606930XA (en) 2014-02-20 2015-02-18 Sputtering system and method using direction-dependent scan speed or power
DE112015000895.0T DE112015000895T5 (de) 2014-02-20 2015-02-18 Sputtersystem und Verfahren unter Verwendung einer richtungsabhängigen Abtastgeschwindigkeit oder Leistung
CN201580017462.7A CN106414794A (zh) 2014-02-20 2015-02-18 使用依赖于方向的扫描速度或功率的溅射系统及方法
KR1020167025408A KR20160142288A (ko) 2014-02-20 2015-02-18 방향-의존적인 스캔 속도 또는 전력을 이용하는 스퍼터링 시스템 및 방법

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US14/185,859 2014-02-20
US14/185,859 US10106883B2 (en) 2011-11-04 2014-02-20 Sputtering system and method using direction-dependent scan speed or power

Publications (1)

Publication Number Publication Date
WO2015130532A1 true WO2015130532A1 (fr) 2015-09-03

Family

ID=54009516

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2015/016448 WO2015130532A1 (fr) 2014-02-20 2015-02-18 Système et procédé de pulvérisation cathodique utilisant une vitesse ou puissance de balayage dépendant de la direction

Country Status (7)

Country Link
JP (1) JP2017508892A (fr)
KR (1) KR20160142288A (fr)
CN (1) CN106414794A (fr)
DE (1) DE112015000895T5 (fr)
SG (1) SG11201606930XA (fr)
TW (1) TWI519665B (fr)
WO (1) WO2015130532A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10106883B2 (en) 2011-11-04 2018-10-23 Intevac, Inc. Sputtering system and method using direction-dependent scan speed or power

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110055500A (zh) * 2019-04-10 2019-07-26 深圳市华星光电技术有限公司 磁控溅射装置及磁控溅射方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5873989A (en) * 1997-02-06 1999-02-23 Intevac, Inc. Methods and apparatus for linear scan magnetron sputtering
US6306267B1 (en) * 1997-05-14 2001-10-23 Canon Kabushiki Kaisha Method of producing a photovoltaic device using a sputtering method
US20060272935A1 (en) * 2005-06-06 2006-12-07 Applied Materials, Inc. Multiple scanning magnetrons
US20080083610A1 (en) * 2006-10-05 2008-04-10 Applied Materials, Inc. Sputtering Chamber Having Auxiliary Backside Magnet to Improve Etch Uniformity and Magnetron Producing Sustained Self Sputtering of Ruthenium and Tantalum
US7744731B2 (en) * 2007-06-04 2010-06-29 Canon Anelva Corporation Sputtering apparatus of forming thin film
US20130112546A1 (en) * 2011-11-04 2013-05-09 Intevac, Inc. Linear scanning sputtering system and method

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102071403B (zh) * 2011-01-30 2012-09-05 东莞市汇成真空科技有限公司 一种平面磁控溅射靶
US9093252B2 (en) * 2012-02-16 2015-07-28 Taiwan Semiconductor Manufacturing Co., Ltd. Rotation plus vibration magnet for magnetron sputtering apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5873989A (en) * 1997-02-06 1999-02-23 Intevac, Inc. Methods and apparatus for linear scan magnetron sputtering
US6306267B1 (en) * 1997-05-14 2001-10-23 Canon Kabushiki Kaisha Method of producing a photovoltaic device using a sputtering method
US20060272935A1 (en) * 2005-06-06 2006-12-07 Applied Materials, Inc. Multiple scanning magnetrons
US20080083610A1 (en) * 2006-10-05 2008-04-10 Applied Materials, Inc. Sputtering Chamber Having Auxiliary Backside Magnet to Improve Etch Uniformity and Magnetron Producing Sustained Self Sputtering of Ruthenium and Tantalum
US7744731B2 (en) * 2007-06-04 2010-06-29 Canon Anelva Corporation Sputtering apparatus of forming thin film
US20130112546A1 (en) * 2011-11-04 2013-05-09 Intevac, Inc. Linear scanning sputtering system and method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10106883B2 (en) 2011-11-04 2018-10-23 Intevac, Inc. Sputtering system and method using direction-dependent scan speed or power

Also Published As

Publication number Publication date
JP2017508892A (ja) 2017-03-30
SG11201606930XA (en) 2016-09-29
KR20160142288A (ko) 2016-12-12
TWI519665B (zh) 2016-02-01
DE112015000895T5 (de) 2016-11-03
TW201542850A (zh) 2015-11-16
CN106414794A (zh) 2017-02-15

Similar Documents

Publication Publication Date Title
EP2773792B1 (fr) Procédé de pulvérisation cathodique à balayage linéaire
US20160177438A1 (en) Method for sputtering system and using counterweight
EP3108027A1 (fr) Système et procédé de pulvérisation cathodique pour matériaux fortement magnétiques
US10106883B2 (en) Sputtering system and method using direction-dependent scan speed or power
WO2015130532A1 (fr) Système et procédé de pulvérisation cathodique utilisant une vitesse ou puissance de balayage dépendant de la direction
EP3108028B1 (fr) Système de pulvérisation cathodique utilisant un contrepoids
US20090114528A1 (en) Sputter coating device and coating method
WO2009059817A1 (fr) Dispositif de dépôt par pulvérisation et procédé de dépôt
KR20190111745A (ko) 인라인 박막 프로세싱 장치
EP2058836A1 (fr) Dispositif de pulvérisation cathodique et procédé de dépôt

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15755270

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2016570910

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 112015000895

Country of ref document: DE

ENP Entry into the national phase

Ref document number: 20167025408

Country of ref document: KR

Kind code of ref document: A

122 Ep: pct application non-entry in european phase

Ref document number: 15755270

Country of ref document: EP

Kind code of ref document: A1