Magnetron design for improved bottom coverage and uniformity

Abstract

A magnet assembly for a magnetron of a processing chamber includes a support member. The support member has a plurality of magnetic tracks attached thereto. Each magnetic track includes a pair of magnetic poles. The support member has a partial magnetic track attached thereto. The partial magnetic track includes a single unpaired magnetic pole. The partial magnetic track is attached near the center of rotation of the support member.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to physical vapor deposition substrate processing systems. [Background technology]

[0002] Two techniques for depositing ionized metal include direct current physical vapor deposition (DC PVD) and radio frequency (RF) PVD. DC PVD processes are characterized by a spacing of approximately 190 to approximately 400 mm between the substrate support surface of a substrate support and an opposing target containing the material to be deposited on the substrate supported by the substrate support, referred to herein as tall spacing. DC PVD processes also use a closed-loop, small, unbalanced magnetron and operate at relatively low pressures and high power. The combination of a small magnetron and high DC power generates a large power density for ionizing the gas medium and sputtering the target. The low pressure and tall spacing provide a "ballistic" transport mechanism, allowing the sputtered material to reach the wafer with few collisions during flight. Due to the cosine distribution and tall spacing, additional neutral metal deposits primarily on the shield.

[0003] However, the inventors of the present invention have recognized that small, powerful magnetrons have a major drawback: localized sputtering. This localized sputtering results in rapid erosion of the target at certain locations due to electron confinement and localized gas ionization. This uneven erosion effect is further accelerated when sputtering magnetic materials such as cobalt (Co) and nickel (Ni) and their alloys. In such cases, very strong magnets are used because a portion of the magnetic flux is diverted into the magnetic material of the target. As the target erodes, the effective magnetic field at the front of the target increases, further accelerating the process. One complex method currently used in DC PVD processes is to use position-controlled magnets that can be moved to more efficiently erode a larger area of ​​the target. However, this still results in inefficiencies in the process, as a result of the high-to-low spacing, since a large portion of the sputtered material is deposited on the shield or, if used, the collimator.

[0004] Uneven target erosion can lead to uneven deposition of target material on the substrate, resulting in inconsistent deposition across successive substrates. Targets that experience uneven erosion have a shorter useful life than targets that experience more uniform erosion, which adversely affects maintenance intervals for the PVD chamber.

[0005] Some RF PVD process chambers also use Torr spacing and drive frequencies of (e.g.) 13.56–27.12 MHz, operating in the (e.g.) 20–60 mTorr pressure regime. The inclusion of RF can open a window for increasing target utilization without sacrificing metal ionization. For example, metal ionization in RF PVD is higher than in DC PVD processes. Electron confinement is enhanced, resulting in gas ionization primarily in the Ez direction due to electron confinement caused by stochastic heating by the oscillating magnetic field. This allows for greater flexibility in the type of magnetron that can be used. For example, unlike DC PVD magnetrons, which require a closed magnetron track, the magnetron track in RF PVD systems does not need to be closed. Additionally, RF PVD magnetrons can be larger than DC PVD magnetrons and still achieve high metal ionization levels at the wafer.

[0006] However, the inventors of the present invention have recognized that in order to achieve good deposition uniformity on the substrate at a spacing of 190 mm, the magnetic field must be generated primarily at the target edge, which causes the target to be eroded primarily at the target edge, resulting in the problem previously mentioned with magnetic materials in that non-uniform erosion of the target is evident.

[0007] Therefore, there is a need for an improved magnetron for use in substrate processing systems. Summary of the Invention

[0008] The present disclosure relates generally to physical vapor deposition substrate processing systems, and more particularly to a magnet assembly suitable for use in a magnetron. In one embodiment, the magnet assembly includes a support member. A plurality of magnetic tracks are coupled to the support member. Each magnetic track includes a first magnetic pole piece coupled to a pair of magnetic poles. The first magnetic pole of each pair of magnetic poles includes a first array of magnets, and the second magnetic pole of each pair of magnetic poles includes a second magnetic pole piece coupled to a second array of magnets. A partial magnetic track is coupled to the support member. The partial magnetic track includes an unpaired magnetic pole including a third magnetic pole piece coupled to a third array of magnets.

[0009] In another embodiment, a magnet assembly includes a support member. A first magnetic track is coupled to the support member. The first magnetic track includes a first magnetic pole including a first array of magnets arranged in a first line forming a first arc. The first magnetic track includes a second magnetic pole including a second array of magnets arranged in a second line forming a second arc. The first magnetic pole and the second magnetic pole are arranged side by side such that a separation distance between the first line and the second line is constant along the length of the second line. A partial magnetic track is coupled to the support member, the partial magnetic track including an unpaired magnetic pole. The unpaired magnetic pole includes a third array of magnets arranged in a third line forming an arc.

[0010] In another embodiment, a substrate processing system includes a process chamber. The process chamber includes an internal volume and a substrate support disposed within the internal volume. A target assembly is disposed within the internal volume, the target assembly facing the substrate support. A magnetron is disposed near the target assembly on a side opposite the substrate support. The magnetron includes a magnet assembly including a support member. A plurality of magnetic tracks are coupled to the support member. Each magnetic track includes a pair of magnetic poles. A first magnetic pole of each pair of magnetic poles includes a first pole piece coupled to a first array of magnets, and a second magnetic pole of each pair of magnetic poles includes a second pole piece coupled to a second array of magnets. A partial magnetic track is coupled to the support member. The partial magnetic track includes an unpaired pole including a third pole piece coupled to a third array of magnets.

[0011] A more particular description of the present disclosure briefly outlined above may be had by reference to embodiments, some of which are illustrated in the accompanying drawings, in a manner that allows the above-listed features of the disclosure to be understood in detail. It should be noted, however, that the accompanying drawings depict only exemplary embodiments and, therefore, should not be considered as limiting the scope of the present disclosure, as the present disclosure may embrace other embodiments that are equally effective. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view of a physical vapor deposition (PVD) process chamber according to some embodiments of the present disclosure. [Figure 2] FIG. 1 is a schematic top isometric view of a magnet assembly for use in a PVD process chamber according to some embodiments of the present disclosure. [Figure 3] FIG. 3 is a schematic bottom isometric view of the magnet assembly of FIG. 2. [Figure 4] FIG. 3 is a schematic top view of the magnet assembly of FIG. 2. [Figure 5] FIG. 3 is a schematic bottom view of the magnet assembly of FIG. 2. [Figure 6]FIG. 6 shows the same view as FIG. 5, highlighting additional aspects. [Figure 7] 3 is a schematic exploded view of an exemplary sensor target assembly for use with the magnet assembly of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0013] For ease of understanding, where possible, identical reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without additional description.

[0014] Described herein are embodiments of magnetrons suitable for extending target lifetime in radio frequency (RF) plasmas. In some embodiments, the present disclosure provides novel apparatus and methods for controlling film uniformity while significantly extending target lifetime in RF plasmas. In some embodiments, the present disclosure may facilitate one or more of significantly higher target utilization (e.g., 300-800% improvement over target utilization in conventional DC PVD process chambers), more uniform metal ionization, and more uniform deposition on the substrate.

[0015] In high-pressure RF PVD, secondary electron confinement is achieved through oscillations of Ez and minimal diffusive losses due to the time-varying nature of the RF period. This provides the primary ionization mechanism at the target "cathode" surface, controlling metal sputtering from the target. Operating at high gas pressures (e.g., 40-400 mTorr) allows two-mechanism collision processes to play a role, enabling high metal ionization at the wafer: "electron bombardment" and "Penning ionization." The latter dominates in this setup. However, RF PVD requires a magnetron to produce uniform deposition of sputtered material. In an exemplary application, magnetic materials may be sputtered using a drive frequency of approximately 40 MHz, which is in the VHF band. As used herein, VHF frequencies are frequencies ranging from approximately 27 MHz to approximately 100 MHz. The chamber geometry may be smaller than typical RF PVD process chambers. In one example, the target diameter may be approximately 1 inch (approximately 25.4 mm) smaller than that of a conventional target, and the target-to-wafer spacing may be half that, approximately 95 mm. In another example, which may be combined with other examples, the target size may be similar to that of a conventional target. In another example, which may be combined with other examples, the target-to-wafer spacing is 95 mm to 190 mm, e.g., 110 mm to 180 mm, 130 mm to 160 mm, 140 mm to 150 mm, or approximately 145 mm. Apparatus according to the present disclosure may provide ionization rates higher than those demonstrated for conventional RF PVD systems. Additionally, the magnetron designs disclosed herein may facilitate very high target utilization, as discussed in more detail below.

[0016] In some embodiments, reducing the target-to-wafer spacing of the chamber, for example by half, allows for increased target utilization (roughly equal to the reciprocal of the spacing) because more sputtered metal reaches the substrate. However, to further maximize target utilization, a magnetron design is provided that can enable more uniform blanket erosion without sacrificing the desired metal ionization or deposition uniformity. While this is not possible in conventional DC PVD or RF PVD process chambers, it has been demonstrated in the exemplary RF PVD process chamber having the magnetron design described herein.

[0017] In some embodiments, which may be combined with other embodiments, use of the magnetron designs described herein allows for increased target-to-wafer spacing while simultaneously realizing the benefits of more uniform metal ionization and erosion from the target.

[0018] This magnetron design consists of multiple distinct magnetic tracks (e.g., four magnetic tracks) that are open loops. These magnetic tracks are spaced from near the center to very close to the edge. One design utilizes four magnetic tracks, where the magnetic tracks have a fixed radius and the length of each track varies as a function of the track's radial position (e.g., shorter magnetic tracks closer to the center and longer magnetic tracks closer to the edge). In some embodiments, each of the four magnetic tracks is equal in terms of track length / radial distance, which advantageously facilitates providing more uniform target erosion. Such track configurations provide full-surface erosion and near-uniform full-surface erosion. This is a significant breakthrough because target utilization is a key customer-specified metric that is becoming even more important with the increased use of rare earth materials.

[0019] Magnetron designs according to embodiments of the present disclosure are described below with respect to the exemplary, but non-limiting, PVD process chamber of FIG. 1 and in more detail in subsequent figures.

[0020] 1 shows a simplified cross-sectional view of an exemplary PVD process chamber 100 having a magnetron assembly according to some embodiments of the present disclosure. This particular configuration of the PVD process chamber is for illustrative purposes only; PVD process chambers having other configurations may benefit from modification according to the teachings described herein. Examples of commercially available PVD process chambers suitable for modification according to the teachings described herein include the ALP® Plus, SIP ENCORE®, and Endura® Cirrus™ PVD processing chambers sold by Applied Materials, Inc. of Santa Clara, California. Other processing chambers from Applied Materials, Inc. or other manufacturers may also benefit from modification according to the inventive apparatus disclosed herein.

[0021] In some embodiments of the present disclosure, a PVD process chamber 100 includes a chamber lid 101 disposed above and removable from a chamber body 104. The chamber lid 101 generally includes a target assembly 102 and a grounding assembly 103. The chamber body 104 includes a substrate support 106 for receiving a substrate 108 thereon. The substrate support 106 is configured to support a substrate such that the center of the substrate is aligned with a central axis 186 of the PVD process chamber 100. The substrate support 106 may be located within a grounded lower enclosure wall 110, which may be a wall of the chamber body 104. In some embodiments, the grounded lower enclosure wall 110 is electrically coupled to the grounding assembly 103 of the chamber lid 101 to provide an RF return path to an RF power source 182 disposed above the chamber lid 101. Alternatively, other RF return paths are contemplated, such as an RF return path extending from the substrate support 106, through a process kit shield (e.g., shield 138, discussed below), and ultimately back to the ground assembly 103 of the chamber lid 101. An RF power supply 182 provides RF energy to the target assembly 102, as discussed below.

[0022] The substrate support 106 has a material-receiving surface facing the major surface of the target 114 and supports a substrate 108 to be sputter-coated with material ejected from the target in a planar position opposite the major surface of the target 114. In some embodiments, the substrate support 106 includes a dielectric member 105 having a substrate processing surface 109 for supporting the substrate 108 thereon. In some embodiments, the substrate support 106 includes one or more conductive members 107 disposed below the dielectric member 105. For example, the dielectric member 105 and the one or more conductive members 107 may be part of an electrostatic chuck, RF electrodes, etc., that may be used to supply chucking power or RF power to the substrate support 106.

[0023] The substrate support 106 provides support for a substrate 108 within a first volume 120 of the chamber body 104. The first volume 120 is a portion of the interior volume of the chamber body 104 that is used to process the substrate 108 and may be separated (e.g., by a shield 138) from the remainder of the interior volume (e.g., a non-processing volume) during processing of the substrate 108. During processing, the first volume 120 is defined as the region above the substrate support 106 (e.g., between the target 114 and the substrate support 106 when in the processing position).

[0024] In some embodiments, the substrate support 106 is vertically movable to allow the substrate 108 to be transferred onto the substrate support 106 through an opening (e.g., a slit valve, not shown) in the lower portion of the chamber body 104 and then raised to a processing position. A bellows 122 connected to a bottom chamber wall 124 may be provided to maintain isolation of the interior volume of the chamber body 104 from the atmosphere outside the chamber body 104. One or more gases are supplied into the lower portion of the chamber body 104 from a gas source 126 through a mass flow controller 128. An exhaust port 130 is provided and is coupled to a pump (not shown) via a valve 132 to evacuate the interior of the chamber body 104 and facilitate maintaining a desired pressure inside the chamber body 104.

[0025] In some embodiments, an RF bias power supply 134 is coupled to the substrate support 106 to induce a negative DC bias on the substrate 108. Additionally, in some embodiments, a negative DC self-bias may be formed on the substrate 108 during processing. In some embodiments, the RF energy provided by the RF bias power supply 134 may be in a frequency range of about 2 MHz to about 60 MHz. Exemplary, non-limiting frequencies such as 2 MHz, 13.56 MHz, 40 MHz, or 60 MHz may be used. In other applications, the substrate support 106 may be grounded or left electrically floating. Alternatively, or in combination, a capacitive tuner 136 may be coupled to the substrate support 106 to adjust the voltage on the substrate 108 for applications where RF bias power is not desired.

[0026] The chamber body 104 further includes a process kit shield (such as shield 138) to enclose the processing or first volume of the chamber body 104 and to protect other chamber components from damage and / or contamination due to processing. In some embodiments, the shield 138 is coupled to a ledge 140 of the grounded upper enclosure wall 116 of the chamber body 104. In other embodiments, the shield 138 may be coupled to the chamber lid 101, for example, via a support member 175, as shown in FIG.

[0027] The chamber lid 101 rests on a ledge 140 of the grounded upper enclosure wall 116. Similar to the grounded lower enclosure wall 110, the grounded upper enclosure wall 116 may provide a portion of an RF return path between the grounded lower enclosure wall 116 and the grounding assembly 103 of the chamber lid 101. However, other RF return paths are also contemplated, such as an RF return path through the grounded shield 138.

[0028] The shield 138 extends downwardly and may include one or more side walls 143 configured to enclose the first volume 120. The shield 138 extends downwardly along and spaced from the walls of the grounded upper and lower enclosure walls 116, 110 to a position below the top surface of the substrate support 106, and returns upwardly toward the top surface of the substrate support 106 (e.g., forming a U-shaped portion at the bottom of the shield 138). The first ring 148 (e.g., cover ring) rests on the top of the U-shaped portion (e.g., a first position of the first ring 148) when the substrate support 106 is in its lower loading position (not shown), but rests on the outer periphery of the substrate support 106 (e.g., a second position of the first ring 148) when the substrate support 106 is in its upper deposition position (shown in FIG. 1) to protect the substrate support 106 from sputter deposition.

[0029] An additional dielectric ring 111 may be used to protect the periphery of the substrate 108 and / or the periphery of the substrate support 106 from deposition. For example, the dielectric ring 111 may be positioned around the periphery of the substrate support 106 adjacent to the substrate processing surface 109, as shown in FIG.

[0030] When the first ring 148 is in the second position (e.g., positioned on the outer periphery of the substrate support 106), a gap may be defined between the first ring 148 and the shield 138. In some embodiments, the gap may be less than about twice the plasma sheath width of a plasma formed at a frequency of about 40 MHz or greater and a pressure of about 140 millitorr or less. In some embodiments, the gap width is less than about 6 millimeters (mm). In some embodiments, the gap has a length-to-width ratio of at least about 4:1. The present inventors have discovered that in some embodiments, a length-to-width ratio of at least about 4:1 can advantageously limit or prevent plasma formed in the first volume 120 from reaching a non-processing volume of the interior volume disposed below the substrate support 106.

[0031] In some embodiments, the first ring 148 may include protrusions extending from an underside of the first ring 148 on either side of an inner U-shaped portion that extends above the bottom of the shield 138. The innermost protrusions may be configured to interface with the substrate support 106 to align the first ring 148 with the shield 138 when the first ring 148 is moved to the second position when the substrate support is moved to the processing position. For example, the substrate support-facing surface of the innermost protrusions may be tapered, notched, etc., to rest in / on a corresponding surface on the substrate support 106 when the first ring 148 is in the second position, such that alignment of the first ring 148 configured as discussed above defines a gap between the first ring 148 and the shield 138.

[0032] In some embodiments, magnets 152 may be disposed about the chamber body 104 to selectively provide a magnetic field between the substrate support 106 and the target 114. For example, as shown in FIG. 1 , the magnets 152 may be disposed around the outside of the enclosure wall 110 in an area slightly higher than the substrate support 106 when in the processing position. In some embodiments, the magnets 152 may additionally or alternatively be disposed in other locations, such as adjacent the grounded upper enclosure wall 116. The magnets 152 may be electromagnets and may be coupled to a power source (not shown) to control the magnitude of the magnetic field generated by the electromagnets.

[0033] The chamber lid 101 generally includes a grounding assembly 103 disposed around the target assembly 102. The grounding assembly 103 includes a ground plate 156 having a first surface 157, which may be generally parallel to or facing the backside of the target assembly 102. A ground shield 112 extends from the first surface 157 of the grounding plate 156 and surrounds the target assembly 102. In some embodiments, the grounding assembly 103 includes a support member 175 to support the target assembly 102 within the grounding assembly 103.

[0034] In some embodiments, a support member 175 is coupled to the lower end of the ground shield 112 proximate the outer periphery of the support member 175 and extends radially inward proximally to support a seal ring 181, the target assembly 102, and optionally a darkspace shield (e.g., not shown, which may be disposed between the shield 138 and the target assembly 102). The seal ring 181 may be ring-shaped or have any other annular shape having a desired cross-section. In some embodiments, the seal ring 181 includes two flat, generally parallel, opposing surfaces to facilitate interfacing with the target assembly 102 (e.g., the backing plate 162) on a first side of the seal ring 181 and with the support member 175 on a second side of the seal ring 181. The seal ring 181 may be made of a dielectric material, such as ceramic. The seal ring 181 insulates the target assembly 102 from the ground assembly 103.

[0035] In some embodiments, the support member 175 is a generally flat member having a central opening for receiving the shield 138 and the target 114. In some embodiments, the support member 175 is circular or disk-like in shape, although this shape may vary depending on the corresponding shape of the chamber lid and / or the shape of the substrate being processed in the PVD process chamber 100. In use, the support member 175 maintains the shield 138 in proper alignment with the target 114 when the chamber lid 101 is open or closed, thereby minimizing the risk of misalignment due to chamber assembly or opening and closing the chamber lid 101.

[0036] The target assembly 102 includes a source distribution plate 158 facing the backside of the target 114, which is electrically coupled to the target 114 along its periphery. The target 114 includes a target source material 113 to be deposited on a substrate, such as the substrate 108, during sputtering. Exemplary target materials 113 include metals, metal oxides, metal alloys, magnetic materials, etc. In some embodiments, the target 114 includes a backing plate 162 for supporting the target source material 113. The target source material 113 is disposed on the side of the backing plate 162 facing the substrate support, as shown in FIG. 1 . In some embodiments, the backing plate 162 includes a conductive material, such as copper-zinc, copper-chromium, or the same material as the target, so that RF power, and optionally DC power, can be coupled to the target source material 113 through the backing plate 162. Alternatively, the backing plate 162 may be non-conductive and may include a conductive element (not shown), such as an electrical feedthrough.

[0037] In some embodiments, a conductive member 164 is disposed between the source distribution plate 158 and the backside of the target 114 to transmit RF energy from the source distribution plate 158 to the periphery of the target 114. The conductive member 164 may be cylindrical or tubular, with a first end 166 coupled to a target-facing surface of the source distribution plate 158 immediately adjacent the periphery of the source distribution plate 158 and a second end 168 coupled to a source-distribution-plate-facing surface of the target 114 immediately adjacent the periphery of the target 114. In some embodiments, the second end 168 is coupled to a source-distribution-plate-facing surface of the backing plate 162 immediately adjacent the periphery of the backing plate 162.

[0038] The target assembly 102 includes a cavity 170 disposed between the backside of the target 114 and the source distribution plate 158. The cavity 170 at least partially houses a magnetron assembly 196, which will be discussed later. The cavity 170 is defined, at least in part, by the inner surface of the conductive member 164, the target-facing surface of the source distribution plate 158, and the surface (e.g., backside) of the target 114 (or backing plate 162) facing the source distribution plate. In some embodiments, the cavity 170 may be at least partially filled with a cooling fluid, such as water (HO). In some embodiments, a divider (not shown) may be provided to contain the cooling fluid to a desired portion (e.g., a lower portion) of the cavity 170 or to prevent the cooling fluid from reaching components disposed on the other side of the divider.

[0039] An insulating gap 180 is provided between the ground plate 156 and the outer surfaces of the source distribution plate 158, the conductive member 164, and the target 114 (and / or backing plate 162). The insulating gap 180 may be at least partially filled with air or some other suitable dielectric material, such as ceramic, plastic, etc. The distance between the ground plate 156 and the source distribution plate 158 depends on the dielectric material between the ground plate 156 and the source distribution plate 158. In some embodiments where the dielectric material is primarily air, the distance between the ground plate 156 and the source distribution plate 158 may be between about 5 mm and about 40 mm.

[0040] In some embodiments, the ground assembly 103 and the target assembly 102 are electrically isolated by a seal ring 181 and by one or more of the insulators 160 disposed between the first surface 157 of the ground plate 156 and the back side of the target assembly 102, e.g., the side of the source distribution plate 158 that does not face the target.

[0041] The target assembly 102 has an RF power supply 182 connected to the electrode 154 (e.g., an RF feed structure). The RF power supply 182 may include an RF generator and a matching circuit, e.g., a matching circuit to minimize reflected RF energy that is reflected back to the RF generator during operation. For example, the frequency of the RF energy supplied by the RF power supply 182 may range from about 13.56 MHz to about 200 MHz or higher. Exemplary, non-limiting frequencies such as 13.56 MHz, 27.12 MHz, 40 MHz, 60 MHz, or 162 MHz may be used.

[0042] In some embodiments, a second energy source 183 may be coupled to the target assembly 102 to supply additional energy to the target 114 during processing. In some embodiments, the second energy source 183 may be DC energy, e.g., a DC power supply for supplying DC energy to enhance the sputtering rate of the target material (and therefore the deposition rate on the substrate). In some embodiments, the second energy source 183 may be RF energy, e.g., a second RF power supply similar to the RF power supply 182 for supplying RF energy at a second frequency different from the first frequency of the RF energy supplied by the RF power supply 182. In embodiments in which the second energy source 183 is a DC power supply, the second energy source may be coupled to the target assembly 102 at any location suitable for electrically coupling DC energy to the target 114, such as the electrode 154 or some other conductive member (e.g., the source distribution plate 158). In embodiments in which the second energy source 183 is a second RF power supply, the second energy source may be coupled to the target assembly 102 by the electrode 154.

[0043] The electrode 154 may be cylindrical or otherwise rod-shaped and may be aligned with the central axis 186 of the PVD process chamber 100 (e.g., the electrode 154 may be coupled to the target assembly 102 at a point coincident with the central axis of the target 114, which is aligned with the central axis 186). Aligning the electrode 154 with the central axis 186 of the PVD process chamber 100 facilitates axisymmetric application of RF energy from the RF power source 182 to the target 114 (e.g., the electrode 154 may couple RF energy to the target at a "single point" aligned with the central axis of the PVD process chamber). This central placement of the electrode 154 helps eliminate or reduce deposition asymmetries in the substrate deposition process. The electrode 154 may have any suitable diameter, although the smaller the diameter of the electrode 154, the closer the application of RF energy will be to a true single point. For example, in some embodiments, the diameter of the electrode 154 may be from about 0.5 inches to about 2 inches, although other diameters may be used. Electrode 154 may generally have any suitable length depending on the configuration of the PVD process chamber. In some embodiments, the electrode may have a length between about 0.5 inches (about 12.7 mm) and about 12 inches (about 304.8 mm). Electrode 154 may be fabricated from any suitable conductive material, such as aluminum, copper, silver, etc.

[0044] The electrode 154 is coupled to the source distribution plate 158 through an opening in the ground plate 156. The ground plate 156 may comprise any suitable conductive material, such as aluminum, copper, or the like. The open space between the one or more insulators 160 allows propagation of RF waves along the surface of the source distribution plate 158. In some embodiments, the one or more insulators 160 may be symmetrically positioned about the central axis 186 of the PVD process chamber 100. Such an arrangement may facilitate symmetric propagation of RF waves along the surface of the source distribution plate 158, ultimately reaching the target 114 coupled to the source distribution plate 158. RF energy may be provided in a more symmetric and uniform manner compared to conventional PVD process chambers, at least in part due to the central positioning of the electrode 154.

[0045] One or more portions of the magnetron assembly 196 are at least partially disposed within the cavity 170. The magnetron assembly 196 provides a rotating magnetic field in close proximity to the target 114 to assist in plasma processing within the process chamber 100. In some embodiments, the magnetron assembly 196 includes a motor 176, a motor shaft 174, a gearbox 178, a gearbox shaft 184, and a rotatable magnet (e.g., a magnet assembly 200 including a plurality of magnets 188 coupled to the magnet support member 172).

[0046] The magnetron assembly 196 rotates within the cavity 170. For example, in some embodiments, a motor 176, a motor shaft 174, a gearbox 178, and a gearbox shaft 184 may be provided to rotate the magnet support member 172. In some embodiments (not shown), the magnetron drive shaft is disposed along the central axis of the chamber, and RF energy may be coupled to the target assembly at a different location or in a different manner. As shown in FIG. 1 , in some embodiments, the motor shaft 174 of the magnetron assembly 196 may be disposed through an off-center opening in the ground plate 156. The end of the motor shaft 174 protruding from the ground plate 156 is coupled to the motor 176. The motor shaft 174 is further disposed through a corresponding off-center opening (e.g., first opening 146) through the source distribution plate 158 and coupled to the gearbox 178. In some embodiments, one or more second openings 198 through the source distribution plate 158 may be positioned symmetrically with the first openings 146 to advantageously maintain an axially symmetric RF distribution along the source distribution plate 158. Additionally, the one or more second openings 198 may be used to allow items such as sensors access to the cavity 170.

[0047] As shown, in some embodiments, which may be combined with other embodiments, one or more of the second openings 198 may be aligned with an access 199 (such as a window or opening) in the ground plate 156. A sensor 155 attached to the chamber lid 101 (e.g., attached to the ground plate 156) aligned with the access 199 and each second opening 198 detects the presence or absence of a characteristic feature on or within the magnet support member 172 while the magnet support member 172 rotates. The characteristic feature may include a sensor target 165. In one example, the sensor target is a reflector, such as a quartz reflector. In such an example, the sensor 155 emits a light beam. The light reflects off the sensor target 165 and returns to the sensor 155. The sensor detects changes in the intensity of the reflected light between (i) instances when the sensor target 165 is aligned with the sensor 155, the access 199, and the respective second openings 198, and (ii) instances when the sensor target 165 is not aligned with the sensor 155, the access 199, and the respective second openings 198. Measurements by the sensor 155 allow the rotational speed of the magnet support member 172 to be monitored separately from inferring the rotational speed via the motor 176.

[0048] The gearbox 178 may be supported in any suitable manner, such as by being coupled to the bottom surface of the source distribution plate 158. The gearbox 178 may be insulated from the source distribution plate 158, such as by fabricating at least the top surface of the gearbox 178 from a dielectric material or by inserting an insulator layer 190 between the gearbox 178 and the source distribution plate 158. The gearbox 178 is further coupled to the magnet support member 172 via a gearbox shaft 184 to transfer the rotational motion provided by the motor 176 to the magnet support member 172 (and thus the plurality of magnets 188). In some embodiments, the gearbox shaft 184 is coincident with the central axis 186 of the PVD process chamber 100. Such an arrangement promotes uniform juxtaposition of the RF energy within the cavity 170 with the magnetic field created by rotating the magnet assembly 200.

[0049] The magnet support member 172 may be constructed from any material suitable for providing sufficient mechanical strength to securely support the plurality of magnets 188. For example, in some embodiments, the magnet support member 172 may be constructed from a non-magnetic metal, such as non-magnetic stainless steel. The magnet support member 172 may have any shape suitable for allowing the plurality of magnets 188 to be coupled to the magnet support member 172 at a desired location. For example, in some embodiments, the magnet support member 172 may comprise a plate, a disc, a crosspiece, or the like. The plurality of magnets 188 may be configured in any manner that provides a magnetic field having a desired shape and strength to provide more uniform overall erosion of the target as described herein.

[0050] In some embodiments, instead of (or in addition to) the illustrated arrangement described above, the magnet support member 172 may be rotated by any other arrangement that provides sufficient torque to overcome the drag forces generated on the magnet support member 172 and the attached plurality of magnets 188. Such drag forces may be caused, for example, by a cooling fluid, if present, within the cavity 170. In one example, in some embodiments (not shown), a separate motor and motor shaft (or motor 176 and motor shaft 174) disposed within the cavity 170 and directly connected to the magnet support member 172 may be used to rotate the magnetron assembly 196 within the cavity 170. Such an example may include a pancake motor arrangement. In such an example, the other motor (or motor 176) must be sized sufficiently to fit snugly within the cavity 170, or the upper portion of the cavity 170 if a partition is present. Motor 176, and any other motors disposed within cavity 170, may be electric motors, pneumatic or hydraulic drives, or any other process compatible mechanism capable of providing the necessary torque.

[0051] 2 and 3 show schematic top and bottom isometric views, respectively, of a magnet assembly 200 (e.g., an arrangement of multiple magnets 188 of a magnetron) for use in a PVD process chamber according to some embodiments of the present disclosure. FIGS. 4-6 show schematic top ( FIG. 4 ) and bottom ( FIGS. 5 and 6 ) views of the magnet assembly 200. As shown in FIGS. 2-6 , the multiple magnets 188 are coupled to a magnet support member 172, which serves as a structural base for the magnet assembly 200. The magnet support member 172 may be fabricated from a material suitable for use as a shunt plate to deflect magnetic fields. The magnet support member 172 may also include a central opening 172A ( FIG. 2 ) and a mounting plate (e.g., a shaft clamp assembly (not shown)) for mounting the magnet support member 172 to a shaft, such as the rotating shaft 184 shown in FIG. 1 , for providing rotation of the magnetron during use. For purposes of clarity, the axis of the rotating shaft 184 is shown parallel to the Z axis as shown in Figure 1. In some embodiments, the central opening 172A may be coincident with the center of rotation 228 of the magnet support member 172.

[0052] The plurality of magnets 188 are arranged into multiple distinct pairs of open-loop magnetic poles coupled to the magnet support member 172, as well as single (“independent,” “unpaired,” or “partially paired”) open-loop magnetic poles. These pairs and partial pairs may be coupled to the magnet support member 172, for example, via multiple mounting holes formed in the magnet support member 172. The embodiment illustrated in FIGS. 2-5 shows three magnetic tracks 208, 210, 212 and one partial magnetic track 214. Each magnetic track 208, 210, 212 includes a pair of open-loop magnetic poles, while partial magnetic track 214 includes a single unpaired open-loop magnetic pole without a corresponding second open-loop magnetic pole. The magnetic tracks 208, 210, 212 and partial magnetic track 214 are spaced from near the center (e.g., center of rotation 228) of the magnet support member 172 to near the radially distal edge 229. By providing a plurality of spaced magnetic tracks on the magnet support member 172 from near the center of the magnet support member 172 to near the radially distal edge 229, a magnetic field may be generated that covers the entire surface of the target 114 or substantially covers the entire surface of the target 114. As shown, in some embodiments that may be combined with other embodiments, one or more of the magnetic tracks 208, 210, 212 or partial magnetic track 214 may be curved. In some embodiments that may be combined with other embodiments, one or more of the magnetic tracks 208, 210, 212 or partial magnetic track 214 may be straight.

[0053] Each of the three magnetic tracks 208, 210, 212 may generally be positioned such that one magnetic track is near the center of the magnet support member 172, such as near the center of rotation 228 (e.g., near the center of the target source material 113), and two magnetic tracks are located at positions corresponding to the outer edges of the target source material 113. In the illustrated example, magnetic track 210 is located near the center of rotation 228, magnetic track 212 is located at the radially distal edge 229 of the magnet support member 172, and magnetic track 208 is located at an intermediate position between the center of rotation 228 and the radially distal edge 229 of the magnet support member 172. In some embodiments, the magnetic track located near the center of the magnet support member 172 may have magnetic poles located on either side of the center of the magnet support member, but no magnetic pole directly above the center. Optional additional magnetic tracks may be located to fill the space between the center of the magnet support member 172 and the radially distal edge 229.

[0054] In some embodiments, the magnetic tracks 208, 210, 212 and partial magnetic track 214 may have lengths that vary as a function of the track's radial position relative to the center of rotation 228. In some embodiments, the ratio of the track length to the track's radial distance from the center of rotation 228 of the magnet support member 172 is substantially equal for each of the magnetic tracks 208, 210, 212 and partial magnetic track 214. This may advantageously provide more uniform erosion of the target 114 compared to conventional arrangements.

[0055] Each pair of open-loop magnetic poles in each magnetic track 208, 210, 212 includes a first open-loop magnetic pole (e.g., 216) and a second open-loop magnetic pole (e.g., 218). As shown, the first and second open-loop magnetic poles 216, 218 are attached to a shunt plate 217. The shunt plate 217 is attached to the magnetic support member 172. In some embodiments, which may be combined with other embodiments, the magnetic support member 172 may be a unitary structure including the shunt plate 217. The first open-loop magnetic pole 216 includes a first pole piece 224, which may be formed in the shape of an arc, with a plurality of magnets 188A disposed between the first pole piece 224 and the shunt plate 217, which is coupled to the magnetic support member 172. The second open-loop magnetic pole 218 includes a second pole piece 226, which may be formed in the shape of an arc. A plurality of magnets 188B are disposed between the second pole piece 226 and the shunt plate 217.

[0056] As shown, the first and second magnetic poles 216, 218 of each magnetic track 208, 210, 212 are parallel to one another. For example, in each magnetic track 208, 210, and 212, the plurality of magnets 188A are arranged as a first line of magnets, and the plurality of magnets 188B are arranged as a second line of magnets, with the first and second lines of magnets parallel to one another. In each magnetic track 208, 210, and 212, the second open-loop magnetic pole 218 is positioned a first distance from the first open-loop magnetic pole 216 in a direction parallel to a first plane parallel to the XY plane of FIGS. 4-6 . Additionally, the first distance is constant throughout the entire length of at least one of the first open-loop magnetic pole 216 or the second open-loop magnetic pole 218.

[0057] In some embodiments, which may be combined with other embodiments, the magnets 188A or 188B may be distributed along the entire length of the respective first or second pole pieces 224, 226 in any one of the magnetic tracks 208, 210, 212. In some embodiments, which may be combined with other embodiments, the magnets 188A or 188B may not be distributed along the entire length of the respective first or second pole pieces 224, 226 in any one of the magnetic tracks 208, 210, 212. For example, the number and / or distribution of the magnets 188A, 188B around the length of the corresponding first or second pole piece 224, 226 may be adjusted to vary the magnetic field strength and / or facilitate improved target life and / or deposition uniformity. In some embodiments in which multiple magnets are not distributed along the entire length of the first or second pole piece, one or more spacers (not shown) may be provided to support the ends of the respective pole pieces 224, 226. However, the total magnetic strength of each of the first and second open-loop magnetic poles 216, 218 may be the same or substantially the same. For example, the balance ratio (i.e., the ratio of the magnetic field strength of an inner magnetic pole, such as the second open-loop magnetic pole 218, to an outer magnetic pole, such as the first open-loop magnetic pole 216) may be between about 0.75 and about 1.25, or in some embodiments, about 1. Providing a more balanced ratio of magnetic field strengths advantageously minimizes magnetic field lines extending in the z-direction (e.g., perpendicular to the magnetic support member 172).

[0058] In some embodiments, the magnetic field provided by the magnetron assembly 196 is relatively weak, meaning that it is just strong enough to provide containment. The magnetic field may be stronger for use with magnetic target materials, and weaker for use with non-magnetic target materials. Similarly, the spacing between the pair of magnetic poles 216, 218 of a given magnetic track (such as magnetic tracks 208, 210, or 212) may be selected based on the total thickness of the target 114 (e.g., the target source material 113 alone, or the target source material 113 and backing plate 162). In some embodiments, which may be combined with other embodiments, the total thickness of the target 114 may be about 1 inch (about 25.4 mm). The spacing may be selected so that the magnetic field extends just to the surface of the target source material 113 facing the substrate 108, or slightly beyond the surface of the target source material 113 into the process volume 120.

[0059] Generally, the first and second pole pieces 224, 226 may be fabricated from a ferromagnetic material, such as, by way of non-limiting example, 400 series stainless steel or other suitable material. The arc length (defined in terms of the angle subtended by the radius) of each of the first and second pole pieces 224, 226 may range from about 45 degrees to about 180 degrees, or from about 80 degrees to about 100 degrees, or may be about 90 degrees. The above description of the pair of magnetic tracks 210 also applies to the remaining pairs of magnetic tracks.

[0060] The polarity orientation, or polarity (e.g., north or south), of each magnet 188A, 188B within a given pole of any pair of open-loop poles is the same (e.g., the magnets within a given open-loop pole have a common polar orientation), but the polarities between pairs of poles 216, 218 of the same magnetic track 208, 210, or 212 are opposite (e.g., north on the inside and south on the outside, or south on the inside and north on the outside). In the illustrated example, each magnet 188A of the first open-loop pole 216 is oriented with its south pole closest to the shunt plate 217, while each magnet 188B of the second open-loop pole 218 is oriented with its north pole closest to the shunt plate 217.

[0061] The partial magnetic track 214 includes a single open-loop magnetic pole 219 arranged similarly to the first open-loop magnetic pole 216. In the illustrated example, each magnet 188 of the single open-loop magnetic pole 219 is oriented with its south pole closer to the shunt plate 217. In other examples (not shown), the polarity orientation of each magnet 188, 188A, 188B may be reversed.

[0062] As shown, the shunt plate 217 of the partial magnetic track 214 includes a provision for accommodating a second open-loop magnetic pole even if the second open-loop magnetic pole is absent. In some embodiments, which may be combined with other embodiments, the shunt plate 217 of the partial magnetic track 214 does not include a provision for accommodating a second open-loop magnetic pole.

[0063] The partial magnetic track 214 is attached to the magnet support member 172 near a center of rotation 228 of the magnet support member 172. Each of the three magnetic tracks 208, 210, 212 is attached to the magnet support member 172 at an incremental distance from the partial magnetic track 214 to a radially distal edge 229 of the magnet support member 172. As shown, at least a portion of the partial magnetic track 214 is attached to the magnet support member 172 between the two magnetic tracks 208, 210. In this embodiment, the partial magnetic track 214 is positioned closer to the second open-loop magnetic pole track 218 of each of the magnetic tracks 208, 210 than to the first loop magnetic pole track 216 of each of the magnetic tracks 208, 210. The polarity orientation of the magnets 188 of the partial track 214 is opposite to the polarity orientation of the magnets 188B of the magnetic tracks 208, 210. As shown, in some embodiments, at least a portion of the second open-loop magnetic pole 218 of magnetic track 208 is adjacent to at least a portion of the open-loop magnetic pole 219 of partial magnetic track 214. As shown, in some embodiments, at least a portion of the second open-loop magnetic pole 218 of magnetic track 210 is adjacent to at least a portion of the open-loop magnetic pole 219 of partial magnetic track 214. In some embodiments, which may be combined with other embodiments, magnetic tracks 208, 210, 212 and partial magnetic track 214 are arranged such that the polarity of magnets 188, 188A, 188B of any one magnetic pole 216, 218, 219 is opposite the polarity of magnets 188, 188A, 188B of the nearest adjacent magnetic pole 216, 218, 219.

[0064] In some embodiments, which may be combined with other embodiments, the magnetic tracks 208, 210, 212 and partial magnetic track 214 are arranged such that the magnet assembly 200 is balanced for rotation about the center of rotation 228. In some of these embodiments, a separate counterbalance may be omitted. In other of these embodiments, a separate counterbalance may be present.

[0065] 6 shows the same view of magnet assembly 200 as FIG. 5, highlighting additional aspects of the embodiment that may be combined with other embodiments. The centerline 214A of magnet 188 (shown in FIG. 3) of open-loop pole 219 of partial magnetic track 214 is arc-shaped. This arc is defined by a radius 214R from center point 214C. Center point 214C is at a different location than center of rotation 228 of magnet support member 172. In other words, center point 214C does not coincide with center of rotation 228 of magnet support member 172.

[0066] The centerline 208A of the magnet 188A (shown in FIG. 3) of the first open-loop pole 216 of the magnetic track 208 is in the shape of an arc. This arc is defined by a radius 208R from a center point 208C. The center point 208C is at a different location than the center of rotation 228 of the magnet support member 172. In other words, the center point 208C does not coincide with the center of rotation 228 of the magnet support member 172. As shown, the center point 208C does not coincide with the center point 214C.

[0067] The centerline 210A of the magnet 188A (shown in FIG. 3) of the first open-loop pole 216 of the magnetic track 210 is in the shape of an arc. This arc is defined by a radius 210R from a center point 210C. The center point 210C is at a different location than the center of rotation 228 of the magnet support member 172. In other words, the center point 210C does not coincide with the center of rotation 228 of the magnet support member 172. As shown, the center point 210C does not coincide with the center point 208C. As shown, the center point 210C does not coincide with the center point 214C.

[0068] The centerline 212A of the magnet 188A (shown in FIG. 3) of the first open-loop pole 216 of the magnetic track 212 is in the shape of an arc. This arc is defined by a radius 212R from a center point 212C. The center point 212C is co-located with the center of rotation 228 of the magnet support member 172. In other words, the center point 212C coincides with the center of rotation 228 of the magnet support member 172. As shown, the center point 212C does not coincide with the center point 208C. As shown, the center point 212C does not coincide with the center point 210C. As shown, the center point 212C does not coincide with the center point 214C.

[0069] As shown, in some embodiments that may be combined with other embodiments, the radius 208R may be a fixed value. For example, the magnitude of the radius 208R from the center point 208C to any position on the center line 208A is a constant value. However, in alternative embodiments that may be combined with other embodiments, the radius 208R may be a variable value. For example, the magnitude of the radius 208R from the center point 208C to each of two different positions on the center line 208A may be different.

[0070] As shown, in some embodiments that may be combined with other embodiments, the radius 210R may be a fixed value. For example, the magnitude of the radius 210R from the center point 210C to any position on the center line 210A is a constant value. However, in alternative embodiments that may be combined with other embodiments, the radius 210R may be a variable value. For example, the magnitude of the radius 210R from the center point 210C to each of two different positions on the center line 210A may be different.

[0071] As shown, in some embodiments that may be combined with other embodiments, the radius 212R may be a fixed value. For example, the magnitude of the radius 212R from the center point 212C to any position on the center line 212A is a constant value. However, in alternative embodiments that may be combined with other embodiments, the radius 212R may be a variable value. For example, the magnitude of the radius 212R from the center point 212C to each of two different positions on the center line 212A may be different.

[0072] As shown, in some embodiments that may be combined with other embodiments, the radius 214R may be a fixed value. For example, the magnitude of the radius 214R from the center point 214C to any position on the center line 214A is a constant value. However, in alternative embodiments that may be combined with other embodiments, the radius 214R may be a variable value. For example, the magnitude of the radius 214R from the center point 214C to each of two different positions on the center line 214A may be different.

[0073] When the magnet assembly 200 is rotated about the center of rotation 228, the arc of the centerline 212A of the magnet 188A of the first open-loop pole 216 of the magnetic track 212 lies on a circle having a radius equal to the radius 212R. Although the magnetic track 212 is open-loop, when the magnet assembly 200 is rotated about the center of rotation 228 at a sufficient speed, such as at least 20 rpm, or even at least 30 rpm, or even at least 60 rpm, the magnetic track 212 behaves like a closed-loop magnetic track.

[0074] In the illustrated embodiment, arc radius 214R of centerline 214A is less than arc radius 210R of centerline 210A. In the illustrated embodiment, arc radius 210R of centerline 210A is less than arc radius 208R of centerline 208A. In the illustrated embodiment, arc radius 208R of centerline 208A is less than arc radius 212R of centerline 212A.

[0075] In the illustrated embodiment, partial magnetic track 214 is located near a center of rotation 228 of magnet support member 172. Magnetic tracks 210 and 208 are located midway between center of rotation 228 and a radially distal edge 229 of magnet support member 172. Magnetic track 210 is closer to center of rotation 228 than magnetic track 208 is to center of rotation 228. Partial magnetic track 214 is closer to center of rotation 228 than magnetic track 210 is to center of rotation 228. Magnetic track 212 is located at the radially distal edge 229 of magnet support member 172. Magnetic track 212 is the farthest from center of rotation 228 of all magnetic tracks 208, 210, 212 and partial magnetic track 214.

[0076] In some embodiments, which may be combined with other embodiments, the magnetic tracks 212 located on the radially distal edge 229 of the magnet support member 172 are magnetically balanced. In some embodiments, which may be combined with other embodiments, the magnetic tracks 212 located on the radially distal edge 229 of the magnet support member 172 are not magnetically balanced.

[0077] In some embodiments, which may be combined with other embodiments, the magnetic tracks 208 located closer to the radially distal edge 229 of the magnet support member 172 than the magnetic tracks 210 are magnetically balanced. In some embodiments, which may be combined with other embodiments, the magnetic tracks 208 located closer to the radially distal edge 229 of the magnet support member 172 than the magnetic tracks 210 are magnetically unbalanced.

[0078] In some embodiments, which may be combined with other embodiments, the magnetic track 210 located closer to the center of rotation 228 of the magnet support member 172 than the magnetic track 208 is magnetically balanced. In some embodiments, which may be combined with other embodiments, the magnetic track 210 located closer to the center of rotation 228 of the magnet support member 172 than the magnetic track 208 is magnetically unbalanced.

[0079] In some embodiments, which may be combined with other embodiments, any one or more of magnetic tracks 208, 210, or 212 may be magnetically balanced. In some embodiments, which may be combined with other embodiments, any one or more of magnetic tracks 208, 210, or 212 may not be magnetically balanced.

[0080] 1 in combination with FIG. 6, in some embodiments, which may be combined with other embodiments, the center of rotation 228 of the magnet support member 172 is aligned with the central axis 186 of the PVD process chamber 100. In addition, the central axis 114C of the target 114 is also aligned with the central axis 186 of the PVD process chamber 100. Furthermore, the outer edge 114E of the target 114 is positioned at a radius 114R from the central axis 114C of the target 114.

[0081] In some of these embodiments, the magnets 188A of the first open-loop pole 216 of the magnetic track 212 are aligned with the edge 114E of the target 114. In some examples, the radius 114R is equal to the radius 212R. In other examples, a portion of each magnet 188A is aligned with the edge 114E of the target 114, but the radius 114R is smaller than the radius 212R. In still other examples, a portion of each magnet 188A is aligned with the edge 114E of the target 114, but the radius 114R is larger than the radius 212R.

[0082] In some embodiments, which may be combined with other embodiments, magnet 188A of first open-loop pole 216 of magnetic track 212 is not aligned with edge 114E of target 114. In some of such embodiments, radius 114R is smaller than radius 212R. In other of such embodiments, radius 114R is larger than radius 212R. In one example, magnet 188B of second open-loop pole 218 of magnetic track 212 may be aligned with edge 114E of target 114.

[0083] As shown in FIGS. 2-4, magnet support member 172 is fitted with a sensor target assembly 250 for use with sensor 155 (FIG. 1). FIG. 7 schematically illustrates an exploded view of an exemplary sensor target assembly 250. In the illustrated embodiment, sensor target 165 is disposed within opening 173 in magnet support member 172. A window 254 (e.g., quartz or sapphire) is disposed over sensor target 165, with seal 252 (e.g., surrounding the periphery of window 254). Window 254 is secured by flange 256, which is coupled to magnet support member 172 by a number of fasteners, such as bolts 258. [Industrial Applicability]

[0084] Embodiments of the present disclosure provide systems and apparatus that achieve improvements in cost, target utilization, and uniformity of films deposited on a substrate compared to conventional systems and apparatus. For example, the open-loop magnetic track 212 located at the radially distal edge 229 of the magnet support member 172 is shorter, lighter, and less expensive to manufacture than an equivalent ring magnet, yet behaves like a ring magnet when rotated, promoting an enhancement of the magnetic field at and around the edge 114E of the target 114. This enhancement of the magnetic field prevents dislodged target material 113 from redepositing on the target 114. This effect reduces the tendency of redeposited target material 113 to cause unwanted arcing.

[0085] Another benefit is that the placement of each of the magnetic tracks 208, 210, 212 and partial magnetic track 214 on the magnet support member can be adjusted to suit the type of target material 113, the size of the target 114, the spacing from the substrate 108 to the target 114, and operating parameters. For example, aligning the magnet 188A of the first open-loop pole 216 of the magnetic track 212 located at the radially distal edge 229 of the magnet support member 172 facilitates shaping the magnetic field to the curvature of the target 114 and preventing dislodged target material 113 from redepositing on the target 114.

[0086] The use of three open-loop magnetic tracks 208, 210, 212 with partial magnetic track 214, combined with the magnetic field enhancement at and around edge 114E of target 114, facilitates magnetic field uniformity across target 114. Such effects promote uniform erosion of target material 113, uniform thickness of target material 113 deposited on substrate 108, and uniform resistivity of target material 113 deposited on substrate 108.

[0087] An additional benefit of uniform erosion of the target material 113 includes greater utilization of the target material 113 than with conventional systems. An additional benefit of tailoring the magnetic field to the curvature of the target 114 includes reduced deposition of the target material 113 on process kits, such as the shield 138, than with conventional systems. These benefits, alone or in combination, provide increased useful life for the target material 113 and process kits, which facilitates processing more substrates between process chamber maintenance shutdowns.

[0088] Additional benefits of embodiments of the present disclosure include an expanded operating parameter range, which facilitates greater operational flexibility for the deposition process. In one example, it was impractical to deposit tungsten at RF frequencies of 40 MHz or greater using conventional RF PVD process chambers and systems. In contrast, embodiments of the present disclosure facilitate the deposition of tungsten at RF frequencies of 40 MHz or greater. In another example, it was impractical to deposit tungsten at pressures of 100 millitorr or greater using conventional RF PVD process chambers and systems. In contrast, embodiments of the present disclosure facilitate the deposition of tungsten at pressures of 100 millitorr or greater.

[0089] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof.

Claims

1. A support member; a plurality of magnetic tracks coupled to the support member, each magnetic track comprising a pair of magnetic poles, the pair of magnetic poles comprising: a first pole piece coupled to the first array of magnets; a second pole piece coupled to the second array of magnets; and a plurality of magnetic tracks, a partial magnetic track coupled to the support member, the partial magnetic track including an unpaired pole with a third pole piece coupled to a third array of magnets; A magnet assembly comprising:

2. The pair of magnetic poles of each magnetic track are: the first array of magnets is arranged as a first line of magnets; the second array of magnets is arranged as a second line of magnets; The first line of magnets and the second line of magnets are parallel to each other. The magnet assembly according to claim 1 , configured as follows:

3. each magnetic track of the plurality of magnetic tracks is configured such that the first and second magnetic poles are coupled to a corresponding first shunt plate of each magnetic track of the plurality of magnetic tracks; Each first shunt plate is connected to the support member; the unpaired magnetic pole is coupled to a second shunt plate connected to the support member; The magnet assembly of claim 1 .

4. The magnet assembly of claim 3 , wherein each shunt plate is coupled to or integral with the support member.

5. each magnet in the first array of magnets is oriented with a south pole closer to the first shunt plate and a north pole farther from the first shunt plate; each magnet in the second array of magnets is oriented with a north pole closer to the first shunt plate and a south pole farther from the first shunt plate; The magnet assembly of claim 3 .

6. 6. The magnet assembly of claim 5, wherein each magnet in the third array of magnets is oriented with a south pole closer to the second shunt plate and a north pole farther from the second shunt plate.

7. The magnet assembly according to claim 6 , wherein at least a portion of the second magnetic pole of one magnetic track of the plurality of magnetic tracks is adjacent to at least a portion of the unpaired magnetic pole of the partial magnetic track.

8. The magnet assembly of claim 1 , wherein the partial magnetic track is coupled to the support member near a center of rotation of the support member.

9. The magnet assembly of claim 8 , wherein at least a first magnetic track of the plurality of magnetic tracks is coupled to the support member between the partial magnetic track and a radially distal edge of the support member.

10. The magnet assembly of claim 9 , wherein at least a second magnetic track of the plurality of magnetic tracks is coupled to the support member at the radially distal edge of the support member.

11. The plurality of magnetic tracks include first and second magnetic tracks, and in each of the first and second magnetic tracks: the first array of magnets having a first polar orientation; the second array of magnets has a second polar orientation opposite to the first orientation; In the partial magnetic track, the third array of magnets assumes the first polar orientation; at least a portion of the partial magnetic track is disposed between the second array of magnets of the first magnetic track and the second array of magnets of the second magnetic track; The magnet assembly of claim 1 .

12. The magnet assembly of claim 1 , wherein the partial magnetic track and the plurality of magnetic tracks are coupled to the support member such that the magnet assembly is rotationally balanced.

13. A support member; a first magnetic track coupled to the support member; a first magnetic pole comprising a first array of magnets arranged in a first line forming a first arc; a second magnetic pole comprising a second array of magnets arranged in a second line forming a second arc; the first magnetic pole and the second magnetic pole are arranged side by side such that a separation distance between the first line and the second line is constant along the length of the second line; a first magnetic track; a partial magnetic track coupled to the support member, the partial magnetic track including unpaired poles with a third array of magnets arranged as a third line forming a third arc; A magnet assembly comprising:

14. the first arc is defined by a first radius from a first center point; the third arc is defined by a second radius from a second center point; The first radius is greater than the second radius. The magnet assembly of claim 13.

15. The magnet assembly of claim 14 , wherein the first center point coincides with a center of rotation of the support member.

16. further comprising a second magnetic track coupled to the support member, the second magnetic track comprising: a fourth magnetic pole comprising a fourth array of magnets arranged in a fourth line forming a fourth arc; a fifth magnetic pole comprising a fifth array of magnets arranged in a fifth line forming a fifth arc; the fourth magnetic pole and the fifth magnetic pole are arranged side by side such that a separation distance between the fourth line and the fifth line is constant along the length of the fifth line; the fourth arc is defined by a third radius from a third center point; the first radius is greater than the third radius; the third radius is greater than the second radius; The magnet assembly of claim 14.

17. further comprising a third magnetic track coupled to the support member, the third magnetic track comprising: a sixth magnetic pole comprising a sixth array of magnets arranged in a sixth line forming a sixth arc; a seventh magnetic pole comprising a seventh array of magnets arranged in a seventh line forming a seventh arc; the sixth magnetic pole and the seventh magnetic pole are arranged side by side such that a separation distance between the sixth line and the seventh line is constant along the length of the seventh line; the sixth arc is defined by a fourth radius from a fourth center point; the first radius is greater than the fourth radius; the fourth radius is greater than the second radius; 17. The magnet assembly of claim 16.

18. The magnet assembly of claim 17 , wherein the first, second, third, and fourth center points are not coincident with one another.

19. a process chamber including an interior volume and a substrate support disposed within the interior volume; a target assembly disposed within the interior volume, the target assembly facing the substrate support; a magnetron positioned opposite the substrate support and near the target assembly, the magnetron including a magnet assembly, the magnet assembly comprising: A support member; a plurality of magnetic tracks coupled to the support member, each magnetic track comprising a pair of magnetic poles, the pair of magnetic poles comprising: a first pole piece coupled to the first array of magnets; a second pole piece coupled to the second array of magnets; and a plurality of magnetic tracks, a partial magnetic track coupled to the support member, the partial magnetic track including an unpaired pole with a third pole piece coupled to a third array of magnets; A substrate processing system comprising:

20. a sensor coupled to the process chamber; a sensor target coupled to the support member; Furthermore, the sensor is configured to emit a light beam toward the sensor target and receive a reflected light beam from the sensor target; 20. The substrate processing system of claim 19.

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