Multiple-Radius Magnetron for Physical Vapor Deposition (PVD) and Method of Using the Same

Abstract

In one embodiment, a magnetron assembly for use in a PVD chamber includes: a base plate having a first side, a second side opposite the first side, and a central axis; a magnet plate rotatably coupled to the base plate, the magnet plate rotating about an offset axis relative to the base plate; a magnet assembly coupled to the magnet plate offset from the offset axis and configured to rotate about the central axis and the offset axis; a first motor coupled to the base plate and rotating the magnet assembly about the central axis; and a second motor coupled to the magnet plate and controlling its angular position to position the magnet assembly at each of a plurality of fixed angular positions defining a plurality of different fixed radii.

Description

Technical Field

[0001]

[0001] Embodiments of the present disclosure generally relate to substrate processing equipment.

Background Art

[0002]

[0002] Semiconductor devices are generally fabricated on a substrate as integrated circuits having various conductive layers interconnected to each other to facilitate the propagation of signals within the device. In some examples, the devices are interconnected by vias or electrical connections that provide connections through different layers of the integrated circuit. Vias formed in a silicon material are called through-silicon vias or TSVs. As the complexity of the circuit increases, the size of the semiconductor structure shrinks, and more structures can be obtained for a given area. Also, to increase the density of the integrated circuit, even more layers are incorporated. Due to the high density, the diameter of the TSV has to be reduced, and at the same time, the depth of the TSV has to increase dramatically due to the increase in the number of layers. The inventors have found that in a physical vapor deposition (PVD) chamber, barrier layer materials such as copper or tantalum are not uniformly sputtered on the sidewalls and bottom of the TSV due to the small diameter size and increased depth of the TSV.

[0003]

[0003] Therefore, the inventors have provided an improved PVD chamber for uniformly depositing materials on a high aspect ratio TSV structure.

Summary of the Invention

[0004] A method and apparatus for processing a substrate in a PVD chamber are provided herein. In some embodiments, a magnetron assembly for use in a PVD chamber includes a base plate having a first side, a second side opposite the first side, and a central axis, a magnet plate rotatably coupled to the base plate at the first side of the base plate and rotating about an offset axis with respect to the base plate, a magnet assembly coupled to the magnet plate offset from the offset axis and configured to rotate about the central axis and the offset axis, a first motor coupled to the base plate and configured to rotate the magnet assembly about the central axis, and a second motor coupled to the magnet plate and configured to control its angular position and position the magnet assembly at each of a plurality of fixed angular positions defining a plurality of different fixed radii, wherein the magnet assembly is configured to rotate 360 degrees about the central axis at each of the plurality of fixed radii.

[0005] In some embodiments, a method of depositing a metal film on a substrate includes positioning a magnet assembly at a first fixed radius with respect to a central axis of a target in a physical vapor deposition (PVD) chamber, depositing a metal film on a substrate disposed opposite the target in the PVD chamber while rotating the magnet assembly about the central axis at the first fixed radius for a first period, positioning the magnet assembly at a second fixed radius with respect to the central axis by rotating the magnet assembly about the offset axis, and depositing a metal film on the substrate while rotating the magnet assembly about the central axis at the second fixed radius for a second period.

[0006]

[0006] In some embodiments, a non-transitory computer-readable medium storing computer instructions that, when executed by at least one processor, cause the at least one processor to position a magnet assembly at a first fixed radius relative to a central axis of a target in a physical vapor deposition (PVD) chamber, deposit a metal film on a substrate disposed opposite the target in the PVD chamber while rotating the magnet assembly about the central axis at the first fixed radius for a first period, position the magnet assembly at a second fixed radius relative to the central axis by rotating the magnet assembly about an offset axis, and deposit a metal film on the substrate while rotating the magnet assembly about the central axis at the second fixed radius for a second period.

[0007]

[0007] Other and further embodiments of the present disclosure are described below.

[0008]

[0008] By referring to the exemplary embodiments of the present disclosure shown in the accompanying drawings, the embodiments of the present disclosure summarized above and described in more detail below can be understood. However, the accompanying drawings merely illustrate typical embodiments of the present disclosure and should not be considered as limiting the scope, and the present disclosure may admit other equally effective embodiments.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0016] For ease of understanding, wherever possible, the same reference numbers are used to denote the same elements common to the drawings. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further elaboration.

[0011]

[0017] Methods and apparatuses are provided herein for forming a barrier layer in a through-silicon via (TSV) having a deposition of a high aspect ratio structure with increased step coverage. The apparatuses provided herein include a physical vapor deposition (PVD) chamber including a magnetron assembly having a smaller and more powerful magnet assembly with additional electromagnetic control for enhanced PVD copper coverage on a TSV structure having high film uniformity. The magnet assemblies used with the methods provided herein produce a high ionization rate that advantageously results in better step coverage performance. Process strategies using magnet assemblies positioned at multiple radii from the central axis of the magnetron assembly advantageously improve step coverage and film deposition rate. For example, the process strategy may include a five-radius process strategy. The PVD chamber may also include both lower and upper electromagnets surrounding the chamber body. The additional upper electromagnet induces ions lost typically by the chamber shield towards the substrate, generating more ions on the substrate and helping to improve control of the non-uniformity percentage (NU%).

[0012]

[0018] As classical Moore's law scaling slows down, the semiconductor industry is looking towards new vertical scaling paradigms to drive improvements in power, performance, and cost. TSVs are an essential 3D packaging enabler, and scaling the aspect ratio of TSVs from 5×50um to 3×50um challenges both PVD coverage and the ability of PVD to achieve continuous barrier and seed layers on TSVs. Due to the small diameter and high aspect ratio, a thicker PVD film is required, increasing costs and potentially competing with alternative non-PVD metallization approaches. The PVD chamber of this principle enables cost-effective TSV metallization for next-generation TSVs and enables the expansion of the market adoption scale of 3D packaging.

[0013]

[0019] In some embodiments, the PVD chamber includes a magnetron assembly having an enhanced ground for RF bias current return for more uniform deposition, a deposition ring with enhanced deposition control, and / or a magnet assembly for increasing deposition rate and coverage. In some embodiments, the PVD chamber includes a source having a magnetron assembly with higher DC power for improving coverage and deposition rate, higher RF bias for maintaining a constant high ion energy, and / or central water supply for enabling a stable deposition rate during target erosion.

[0014]

[0020] FIG. 1 is a cross-sectional view of a PVD chamber 100 according to some embodiments. The PVD chamber 100 can be used for the deposition of copper and other materials onto a substrate 110 that can include semiconductor structures such as TSVs. In some embodiments, the PVD chamber 100 can provide a deposition rate of from about 80 angstroms per second to about 135 angstroms per second or more, while achieving a sheet resistivity (Rs) NU% of less than about 5%, using DC power from about 30 kW to about 50 kW and RF bias power from about 1.6 kW to 2.8 kW. The PVD chamber 100 includes a chamber body 102 that includes a processing region 118 disposed therein, and a source 190 that includes a magnetron assembly 104 and a target 112. The substrate 110 is supported by a substrate support assembly 192 that includes an electrostatic chuck (ESC) 108 supported by a substrate support pedestal 106. One or more gases can be supplied from a gas source 184 into the lower portion of the PVD chamber 100. A pump 182 is connected to the PVD chamber 100 to facilitate evacuating the interior of the PVD chamber 100 and maintaining the interior of the PVD chamber 100 at a desired pressure.

[0015]

[0021] Above the processing region 118, there is a target 112 having a backing plate 114. The target 112 includes a sputtering surface 156 facing the substrate 110. In some embodiments, the target 112 may be copper, titanium, tantalum, tungsten, or the like. The DC power supply 128 supplies DC power to the target 112 via the backing plate 114 to sputter the target 112 during processing. The backing plate 114 may include a conductive material such as copper-zinc, copper-chromium, or the same material as the target 112 so as to couple DC power to the target 112 via the backing plate 114. Alternatively, the backing plate 114 may be non-conductive and may include a conductive element (not shown) such as an electrical feedthrough. The backing plate 114 may be disc-shaped, rectangular, square, or any other shape that can be accommodated by the PVD chamber 100. The backing plate 114 is configured to support the target 112 such that the front surface of the target 112 faces the substrate 110 when there is a substrate. The target 112 may be coupled to the backing plate 114 in any suitable manner. For example, in some embodiments, the target 112 may be diffusion-bonded to the backing plate 114.

[0016]

[0022] The magnetron assembly 104 includes a magnet assembly 136 that moves over the target 112 at a plurality of different fixed radii, or fixed positions, about a central axis 154. In some embodiments, the magnet assembly 136 may include a plurality of individual magnets. The support device 134 supports the magnet assembly 136 and enables the magnet assembly 136 to rotate about the central axis 154. In some embodiments, a first motor 174 is coupled to the support device 134 to rotate the magnet assembly 136 about the central axis 154. The magnet assembly 136 is offset from the magnet assembly 136 and rotates about an offset axis 172 that is offset from the central axis 154 to be positioned at each of a plurality of different fixed radii. In some embodiments, a second motor 178 is coupled to the magnet assembly 136 to rotate the magnet assembly 136 about the offset axis 172 to control the radial position of the magnet assembly 136 relative to the central axis 154. In some embodiments, the magnet assembly 136 is configured to rotate at least 180 degrees about the offset axis 172. In some embodiments, the magnet assembly 136 is configured to rotate from a zero-degree position about the offset axis 172 to approximately 180 degrees such that the magnet assembly 136 is positioned at each of a plurality of different fixed radii. The zero-degree position may correspond to when the magnet assembly 136 is at its innermost radial position, or innermost radius. In some embodiments, the second motor 178 is configured to rotate the magnet assembly 136 independently of the first motor 174.

[0017]

[0023] In some embodiments, unlike a typical magnetron assembly configured to rotate the magnet assembly in a planetary motion where the radius, i.e., the distance between the magnet assembly and the central axis, constantly changes, the magnetron assembly 104 is configured to position the magnet assembly 136 at a specific fixed radius (e.g., a first fixed radius) with respect to the central axis, and then rotate the magnet assembly 136 about the central axis 154 at the fixed radius for a predetermined period (e.g., a first period). The magnet assembly 136 is then positioned at a different fixed radius (e.g., a second fixed radius), and then rotated about the central axis 154 at the different fixed radius for a subsequent period (e.g., a second period). The repositioning of the magnet assembly 136 to set different fixed radii and the subsequent rotation of the magnet assembly 136 at the different fixed radii over subsequent periods can be repeated as disclosed herein (e.g., to optionally provide a third fixed radius, a fourth fixed radius, a fifth fixed radius, etc.).

[0018]

[0024] In some embodiments, the magnet assembly 136 is configured to rotate about the central axis 154 of the base plate 202 at five different radii, and the magnet plate 204 is configured to rotate about the offset axis 172 to position the magnet assembly 136 at each of the five different radii. In some embodiments, the first fixed radius can be referred to as the innermost radius in the radial direction (e.g., the smallest possible radius), and the fifth fixed radius can be referred to as the outermost radius (e.g., the largest possible radius). In some embodiments, the first fixed radius is from about 1.5 inches to about 2.6 inches. In some embodiments, the second fixed radius is from about 2.6 inches to about 3.5 inches. In some embodiments, the third fixed radius is from about 3.5 inches to about 4.5 inches. In some embodiments, the fourth fixed radius is from about 4.5 inches to about 5.5 inches. In some embodiments, the fifth fixed radius is from about 5.9 inches to about 7.5 inches.

[0019]

[0025] In some embodiments, the source 190 of the PVD chamber 100 uses a central coolant supply device 132 to maximize the target life by alleviating target cracking and / or warping due to overheating and reducing the deposition rate over the life of the target. In some embodiments, the conventionally supplied coolant supply device structure supplies coolant from the sides of the cavity 194 of the magnetron assembly 104. However, since the coolant flowing to the portion of the target 112 directly below the magnet assembly 136 is blocked by the magnet assembly 136, the portion of the target 112 directly below the magnet assembly 136 does not receive a sufficient amount of coolant. As a result, when the magnetron assembly 104 rotates, the area where the magnet assembly 136 moves upward becomes excessively hot and sometimes reaches up to 400°C. As a result, a temperature gradient is formed between the sufficiently cooled portion and the insufficiently cooled portion of the target 112. This temperature gradient results in cracking and / or warping of the target.

[0020]

[0026] To maintain the target 112 at a temperature below about 200° C., a central coolant supply device 132 supplies coolant to the center of the target 112 (i.e., along the central axis 154). The central coolant supply device 132 extends through the body portion 130 along the central axis 154. The central coolant supply device 132 includes a central channel 158 that extends from the manifold portion 160 through the body portion 130 along the central axis 154. A coolant source 166 is fluidly coupled to the inlet 168 of the manifold portion 160 and supplies coolant into the cavity 194 through the central coolant supply device 132. The central coolant supply device 132 extends through the body portion 130 along the central axis 154 and supplies coolant (indicated by streamline 170) to the cavity 194 at the center of the target 112. As a result, a more uniform coolant flow is advantageously achieved, thereby substantially reducing or eliminating the temperature gradient across the target 112 and reducing cracking and warping of the target. After entering the cavity 194 through the central coolant supply device 132, the coolant then exits the cavity 194 through an opening (not shown) formed in an outlet (not shown) disposed at the top of the cavity. A return line (not shown) is coupled to the outlet to receive the coolant after it has flowed through the cavity 194.

[0021]

[0027] To induce a negative DC bias on the substrate 110, an RF bias power supply 126 can be coupled to the substrate support assembly 192. Further, in some embodiments, a negative DC self-bias can be formed on the substrate 110 during processing. For example, the RF energy supplied by the RF bias power supply 126 can be in a frequency range from about 2 MHz to about 60 MHz, and non-limiting frequencies such as 2 MHz, 2.2 MHz, 13.56 MHz, or 60 MHz can be used. In some embodiments, the RF power can be supplied in a range from about 1.9 kW to about 3.0 kW. In some embodiments, the RF power supplied can vary based on the distance, or radius, at which the magnet assembly 136 is positioned relative to the central axis 154. For example, the RF bias power supplied at the outermost radius may be greater than the RF bias power supplied at the innermost radius in the radial direction. In some embodiments, when the magnet assembly 136 is at a first fixed radius and a second fixed radius, the RF bias power supplied can be about 2.0 MHz. In some embodiments, when the magnet assembly 136 is at a third fixed radius, a fourth fixed radius, and a fifth fixed radius, the RF bias power supplied can be about 2.2 MHz.

[0022]

[0028] In some embodiments, DC power can be supplied from the DC power supply 128 to the target 112 in a range from about 30 kW to about 50 kW. In some embodiments, the DC power supply 128 can supply DC power in a range from about 36 kW to about 40 kW. In other applications, the substrate support assembly 192 can be grounded or can remain electrically floating.

[0023]

[0029] The PVD chamber 100 further includes a process kit shield or shield 152 that surrounds the processing region 118 of the PVD chamber 100 to protect other chamber components from damage and / or contamination due to processing. In some embodiments, the shield 152 can be grounded to the chamber body at the uppermost point 196 to provide an RF ground return path. The shield 152 can include a generally tubular portion that extends downward and has a generally constant diameter that generally surrounds the processing region 118. The shield 152 extends downward along the wall of the chamber body 102 to below the uppermost surface 198 of the ESC 108 and then returns upward until it reaches the cover ring 122 (e.g., forming a U-shaped portion at the bottom of the shield 152). The cover ring 122 rides on top of the upper portion of the inner portion that extends above the shield 152 when the substrate support assembly 192 is in the lower loading position and rides on the outer periphery of the deposition ring 120 when in the upper deposition position to protect the substrate support assembly 192 from sputter deposition. The deposition ring 120 can be used to protect the edge of the substrate support assembly 192, including the substrate support pedestal and / or the ESC 108, from deposition around the edge of the substrate 110. In some embodiments, the deposition ring 120 has a large deposition cavity 186 that allows for more deposition build-up before the deposition ring 120 needs to be replaced.

[0024]

[0030] In some embodiments, a lower magnet assembly 142 may be disposed around the PVD chamber 100 to selectively provide a magnetic field between the ESC 108 and the target 112. For example, the lower magnet assembly 142 may be disposed around the outside of the chamber body 102 in the region directly above the ESC 108 when the substrate support assembly 192 is in the processing position. In some embodiments, an upper magnet assembly 140 may be disposed around and outside of the chamber body 102 closer to the target 112 than to the ESC 108 (above the lower magnet assembly 142 if present). The lower magnet assembly 142 and / or the upper magnet assembly 140 may be electromagnets and may be coupled to a power source (not shown) for controlling the magnitude of the magnetic field generated by the electromagnets. The electromagnets generate a magnetic B field that enables control of the direction and energy of the ions. The addition of the upper magnet assembly 140 allows for control of the ion direction and energy with higher accuracy than in the case of the lower magnet assembly 142 alone. The higher accuracy can improve the step coverage (deposition inside the TSV) of the TSV structure.

[0025]

[0031] The lower magnet assembly 142 and / or the upper magnet assembly 140 may be coupled to a coolant source (not shown) to control the temperature generated by the operation of the electromagnets. In some embodiments, the upper magnet assembly 140 is supplied with a current of from about 6.0 amperes to about 16.0 amperes. In some embodiments, the lower magnet assembly 142 is supplied with a current of from about -18.0 amperes to about 18.0 amperes with respect to the lower inner magnet 142C. In some embodiments, the lower magnet assembly 142 is supplied with from about -18.0 amperes to about 18.0 amperes with respect to the upper inner magnet 142A and the upper outer magnet 142B. In some embodiments, the bottom outer magnet 142D is not used.

[0026]

[0032] A substrate processing system that uses RF-generated plasma requires a return path to return the RF current generated during processing to a source such as an RF power supply that supplied the current. In some cases, the return path may include the current moving through a substrate support (e.g., an ESC) along the floor of the processing system and then finally returning to the source along the walls and / or shields of the processing system. When operating under certain processing conditions, an arc discharge may occur between chamber components, such as between the substrate support assembly 192 (including the ESC 108 and / or the substrate support pedestal 106) and an adjacent chamber component, and / or a stray plasma may be unnecessarily generated, leading to damage to the components and / or the generation of particles that can further unnecessarily contaminate the substrate disposed in the chamber. Inside the processing region 118, the process kit and shield 152 are grounded to the chamber body 102 and provide a main return for the plasma current. In some embodiments, the PVD chamber 100 may include one or more ground loops 124 that electrically connect the substrate support assembly 192 (e.g., the ESC 108 and / or the substrate support pedestal 106) to the shield 152.

[0027]

[0033] The controller 144 can be disposed and coupled to various components of the PVD chamber 100 to control its operation. For example, the controller 144 can be configured to control the rotational speed and position of the magnet assembly 136 during processing, and the flow of current through the lower magnet assembly 142 and / or the upper magnet assembly 140. The controller 144 includes a central processing unit (CPU) 146, a memory 148, and support circuitry 150. The controller 144 can directly control the PVD chamber 100 or control it via a computer (or controller) associated with a specific process chamber and / or support system component. The controller 144 can be one of any form of general-purpose computer processor that can be used in an industrial environment to control various chambers and sub-processors. The memory of the controller 144, or the computer-readable medium 148, can be one or more of readily available memories such as random access memory (RAM), read-only memory (ROM), floppy disks, hard disks, optical storage media (e.g., compact disks or digital video disks), flash drives, or any other form of digital storage, local or remote. The support circuitry 150 is coupled to the CPU 146 to support the processor in a conventional manner. These circuits include caches, power supplies, clock circuits, input / output circuits, and subsystems, etc. The method of controlling the PVD chamber 100 and / or the process can be stored in the memory 148 as software routines that can be executed or initiated to control the operation of the PVD chamber 100 in the manner described herein. The software routines can also be stored and / or executed by a second CPU (not shown) located remotely from the hardware controlled by the CPU 146.

[0028]

[0034] FIG. 2 is a schematic cross-sectional view showing a magnetron assembly 104 at a first fixed angular position having the innermost, e.g., the smallest, fixed radius among a plurality of different fixed radii according to some embodiments of the present disclosure. The first fixed radius R1 is defined as the distance between the central axis 154 and the center of the magnet assembly 136 when the magnet assembly 136 is at the first fixed angular position. In some embodiments, the first fixed radius R1 is from about 1.5 inches to about 2.6 inches.

[0029]

[0035] FIG. 3A is a schematic bottom view showing a magnetron assembly 104 according to some embodiments of the present disclosure. FIG. 3A shows the magnet assembly 136 rotated from the first fixed angular position to the second fixed angular position. For example, in some embodiments, the second fixed angular position can be set by rotating the magnet assembly 136 about 50 to about 70 degrees about the offset axis 172 with respect to the first fixed radius R1 as shown in FIG. 2. The second fixed radius R2 is defined as the distance between the central axis 154 and the center of the magnet assembly 136 when the magnet assembly 136 is at the second fixed angular position. In some embodiments, the second fixed radius R2 is from about 1.5 inches to about 2.6 inches.

[0030]

[0036] FIG. 3B is a schematic bottom view showing a magnetron assembly 104 according to some embodiments of the present disclosure. FIG. 3B shows the magnet assembly 136 rotated from the second fixed angular position to the third fixed angular position. For example, in some embodiments, the third fixed angular position can be set by rotating the magnet assembly 136 about 60 to about 80 degrees about the offset axis 172 with respect to the first fixed radius R1 as shown in FIG. 2. The third fixed radius R3 is defined as the distance between the central axis 154 and the center of the magnet assembly 136 when the magnet assembly 136 is at the third fixed angular position. In some embodiments, the third fixed radius R3 is from about 3.1 inches to about 3.3 inches.

[0031]

[0037] FIG. 3C is a schematic bottom view showing the magnetron assembly 104 according to some embodiments of the present disclosure. FIG. 3C shows the magnet assembly 136 rotated from the third fixed angular position to the fourth fixed angular position. For example, in some embodiments, the fourth fixed angular position can be set by rotating the magnet assembly 136 about 80 to about 90 degrees about the offset axis 172 with respect to the first fixed radius R1 as shown in FIG. 2. The fourth fixed radius R4 is defined as the distance between the central axis 154 and the center of the magnet assembly 136 when the magnet assembly 136 is in the fourth fixed angular position. In some embodiments, the fourth fixed radius R4 is from about 4.5 inches to about 5.5 inches.

[0032]

[0038] FIG. 4 is a view showing the magnet assembly 136 rotated about 180 degrees about the offset axis 172 with respect to the first fixed radius R1 as shown in FIG. 2. FIG. 4 shows the magnet assembly 136 positioned at the fifth fixed radius, or the outermost position in the radial direction, and the fifth fixed radius R5 is from about 5.9 inches to about 7.5 inches. The magnet assembly 136 can be rotated about the offset axis 172 to position the magnet assembly 136 at the second fixed radius, the third fixed radius, and the fourth fixed radius.

[0033]

[0039] Referring back to FIG. 2, in some embodiments, the support device 134 of the magnetron assembly 104 includes a base plate 202 having a first side surface 232 and a second side surface 234 opposite the first side surface. The base plate 202 includes a central axis that coincides with the central axis 154 of the target. In some embodiments, the base plate 202 has a diameter larger than the diameter of the target 116. In some embodiments, the base plate 202 is generally a flat circular plate. In some embodiments, the support device 134 includes a magnet plate 204 rotatably coupled to the base plate 202 at the first side surface 232 of the base plate 202. The offset axis 172 is generally located at the center of the magnet plate 204. In some embodiments, the magnet plate 204 does not extend beyond the central axis 154. In some embodiments, the distance 210 between the central axis 154 and the offset axis 172 is from about 4.0 inches to about 5.0 inches. In some embodiments, the distance 250 between the offset axis 172 and the center of the magnet assembly 136 is from about 2.0 inches to about 3.0 inches.

[0034]

[0040] In some embodiments, the magnetron assembly 104 includes a gearbox 208 for housing one or more gears, shafts, etc. to facilitate rotation of the magnet assembly 136 about the central axis 154 and the offset axis 172. For example, a first motor 174 is coupled to a shaft (not shown) and can rotate the base plate 202 (and the magnet assembly 136 coupled thereto) about the central axis 154. A second motor 178 is coupled to a shaft (not shown) and can rotate the magnet plate 204 (and the magnet assembly 136 coupled thereto) about the offset axis 172. The second motor 178 rotates the magnet plate 204 to control the angular position of the magnet assembly 136 and positions the magnet assembly 136 at each of a plurality of fixed angular positions (e.g., a first fixed angular position, a second fixed angular position, etc.) that define a plurality of different fixed radii. When the magnet assembly 136 is positioned at each of the plurality of fixed angular positions, the second motor 178 stops rotation of the magnet plate 204 and the first motor 174 continues to rotate the base plate 202 about the central axis 154 so that the magnet assembly 136 is configured to rotate 360 degrees about the central axis 154 at each of a plurality of different fixed radii.

[0035]

[0041] In some embodiments, the base plate 202 includes a through hole 218 for a position sensor. To support the position sensor 216, a block 206 may be attached to the second side surface 234 of the base plate 202. In some embodiments, the magnet plate 204 includes a lower plate 220 coupled to an upper plate 224. The lower plate 220 is coupled to the magnet assembly 136, and the upper plate 224 is coupled to the base plate 202. In some embodiments, the upper plate 224 is smaller in size than the lower plate 220 or includes a notch that exposes a flag 226 disposed on or embedded in the upper surface of the lower plate 220. The flag 226 may be any component or material that can trigger the position sensor 216 when there is a line of sight between the position sensor 216 and the flag 226. For example, FIG. 2 shows a magnet plate 204 positioned such that the flag 226 is aligned with the through hole 218 of the base plate 202, triggering the position sensor 216 with respect to the magnet assembly being at one of a plurality of different fixed radii, e.g., a first fixed radius.

[0036]

[0042] In some embodiments, the magnet assembly 136 is disposed at approximately 180 degrees from the position sensor 216 with respect to the offset axis 172 when the magnet assembly is disposed at the first fixed radius. In some embodiments, the magnet assembly 136 is disposed at approximately 0 degrees from the position sensor 216 with respect to the offset axis 172 when the magnet assembly is disposed at the fifth fixed radius.

[0037]

[0043] In some embodiments, a first counterweight 212 is coupled to the base plate 202 on the opposite side of the magnet plate 204 about the central axis 154 to compensate for the weight of the magnet plate 204 and the magnet assembly 136. In some embodiments, a second counterweight 214 is coupled to the magnet plate 204 on the opposite side of the magnet assembly 136 about the offset axis 172 to compensate for the weight of the magnet assembly 136.

[0038]

[0044] FIG. 5 is a flow diagram illustrating a method 500 for depositing a metal film on a substrate (e.g., substrate 110) in a PVD chamber according to some embodiments of the present disclosure. In some embodiments, the metal may include copper, titanium, tantalum, tungsten, etc. In some embodiments, method 500 includes depositing a metal film on a through-silicon via (TSV). A DC power supply (e.g., DC power supply 128) supplies DC power to a target to sputter the target and deposit material on the substrate. In some embodiments, the DC power supply supplies DC power of about 30 kW to about 50 kW. In some embodiments, the DC power supply supplies DC power of about 35 kW to about 40 kW.

[0039]

[0045] At 502, method 500 includes positioning a magnet assembly (e.g., magnet assembly 136) at a first fixed radius with respect to a central axis (e.g., central axis 154) of a target (e.g., target 112) in a PVD chamber (e.g., PVD chamber 100) by rotating the magnet assembly about an offset axis (e.g., offset axis 172). In some embodiments, the first fixed radius is from about 1.5 inches to about 2.6 inches. In some embodiments, the first fixed radius is from about 2.3 inches to about 2.5 inches.

[0040]

[0046] At 504, method 500 includes depositing a metal film on a substrate disposed on the opposite side of the target in the PVD chamber while rotating the magnet assembly at the first fixed radius with respect to the central axis over a first period. In some embodiments, the rate of depositing the metal film on the substrate while rotating the magnet assembly at the first fixed radius is from about 85 to about 105 angstroms per second. In some embodiments, while depositing the metal film at the first fixed radius, RF bias power having a frequency of about 1.9 kW to about 2.1 kW is applied to a substrate support assembly (e.g., substrate support assembly 192) in the PVD chamber.

[0041]

[0047] In some embodiments, while depositing a metal film at a first fixed radius, a current of about 11.0 amperes to about 15.0 amperes is supplied to an upper magnet assembly (e.g., upper magnet assembly 140) disposed around the chamber body of the PVD chamber. In some embodiments, a lower magnet assembly (e.g., lower magnet assembly 142) disposed around the chamber body may include an upper inner magnet (e.g., upper inner magnet A), an upper outer magnet (e.g., upper outer magnet B), and a bottom inner magnet (e.g., bottom inner magnet C). In some embodiments, while depositing a metal film at a first fixed radius, a current of about -7.0 amperes to about -1.0 amperes is supplied to the upper outer magnet and the upper inner magnet. In some embodiments, while depositing a metal film at a first fixed radius, a current of about 7.0 amperes to about 11.0 amperes is supplied to the bottom inner magnet.

[0042]

[0048] In 506, method 500 includes positioning the magnet assembly at a second fixed radius relative to the central axis by rotating the magnet assembly about an offset axis. In some embodiments, the second fixed radius is from about 2.6 inches to about 3.5 inches. In some embodiments, the second fixed radius is from about 3.1 inches to about 3.3 inches.

[0043]

[0049] In 508, method 500 includes depositing a metal film on the substrate while rotating the magnet assembly relative to the central axis at a second fixed radius over a second period. The second period may be the same as or different from the first period. In some embodiments, the rate of depositing the metal film on the substrate while rotating the magnet assembly at the second fixed radius is from about 95 to about 115 angstroms per second. In some embodiments, while depositing the metal film at the second fixed radius, an RF bias power having a frequency of about 1.9 kW to about 2.1 kW is applied to the substrate support assembly of the PVD chamber.

[0044]

[0050] In some embodiments, while depositing the metal film at the second fixed radius, a current of about 13.0 amperes to about 17.0 amperes is supplied to the upper magnet assembly. In some embodiments, while depositing the metal film at the second fixed radius, a current of about -8.0 amperes to about -12.0 amperes is supplied to the upper outer magnet and the upper inner magnet. In some embodiments, while depositing the metal film at the second fixed radius, a current of about 8.0 amperes to about 12.0 amperes is supplied to the bottom inner magnet.

[0045]

[0051] At 510, method 500 includes positioning the magnet assembly at a third fixed radius relative to the central axis by rotating the magnet assembly about an offset axis. In some embodiments, the third fixed radius is from about 3.5 inches to about 4.5 inches. In some embodiments, the third fixed radius is from about 4.1 inches to about 4.3 inches.

[0046]

[0052] At 512, method 500 includes depositing a metal film on the substrate while rotating the magnet assembly at the third fixed radius relative to the central axis over a third period. In some embodiments, the third period is similar to at least one of the first period or the second period. In some embodiments, the third period is different from each of the first period and the second period. In some embodiments, the rate of depositing the metal film on the substrate while rotating the magnet assembly at the third fixed radius is from about 75 to about 95 angstroms per second. In some embodiments, while depositing the metal film at the third fixed radius, an RF bias power having a frequency of about 2.1 kW to about 2.3 kW is applied to the substrate support assembly of the PVD chamber.

[0047]

[0053] In some embodiments, while depositing the metal film at the third fixed radius, a current of about 12.0 amperes to about 16.0 amperes is supplied to the upper magnet assembly. In some embodiments, while depositing the metal film at the third fixed radius, a current of about 14.0 amperes to about 18.0 amperes is supplied to the upper outer magnet and the upper inner magnet. In some embodiments, while depositing the metal film at the third fixed radius, a current of about -14.0 amperes to about -18.0 amperes is supplied to the bottom inner magnet.

[0048]

[0054] 514, method 500 includes positioning the magnet assembly at a fourth fixed radius relative to the central axis by rotating the magnet assembly about the offset axis. In some embodiments, the fourth fixed radius is from about 4.5 inches to about 5.5 inches. In some embodiments, the fourth fixed radius is from about 4.9 inches to about 5.1 inches.

[0049]

[0055] 516, method 500 includes depositing a metal film on the substrate while rotating the magnet assembly at the fourth fixed radius relative to the central axis over a fourth period. In some embodiments, the fourth period is similar to at least one of the first period, the second period, or the third period. In some embodiments, the fourth period is different from each of the first period, the second period, and the third period. In some embodiments, the rate of depositing the metal film on the substrate while rotating the magnet assembly at the fourth fixed radius is from about 115 to about 135 angstroms per second. In some embodiments, while depositing the metal film at the fourth fixed radius, an RF bias power having a frequency of about 2.1 kW to about 2.3 kW is applied to the substrate support assembly of the PVD chamber.

[0050]

[0056] In some embodiments, while depositing the metal film at a fourth fixed radius, a current of about 10.0 amperes to about 14.0 amperes is supplied to the upper magnet assembly. In some embodiments, while depositing the metal film at a fourth fixed radius, a current of about 14.0 amperes to about 18.0 amperes is supplied to the upper outer magnet and the upper inner magnet. In some embodiments, while depositing the metal film at a fourth fixed radius, a current of about -14.0 amperes to about -18.0 amperes is supplied to the bottom inner magnet.

[0051]

[0057] 518, method 500 includes positioning the magnet assembly at a fifth fixed radius relative to the central axis by rotating the magnet assembly about an offset axis. In some embodiments, the fifth fixed radius is from about 5.9 inches to about 7.5 inches. In some embodiments, the fifth fixed radius is from about 6.0 inches to about 6.7 inches.

[0052]

[0058] 520, method 500 includes depositing a metal film on the substrate while rotating the magnet assembly at a fifth fixed radius relative to the central axis over a fifth period. In some embodiments, the fifth period is similar to at least one of the first period, the second period, the third period, or the fourth period. In some embodiments, the fifth period is different from each of the first period, the second period, the third period, and the fourth period. In some embodiments, the rate of depositing the metal film on the substrate while rotating the magnet assembly at the fifth fixed radius is from about 80 to about 100 angstroms per second. In some embodiments, while depositing the metal film at the fifth fixed radius, RF bias power having a frequency of about 2.1 kW to about 2.3 kW is applied to the substrate support assembly of the PVD chamber.

[0053]

[0059] In some embodiments, while depositing the metal film at a fifth fixed radius, a current of about 5.0 amperes to about 9.0 amperes is supplied to the upper magnet assembly. In some embodiments, while depositing the metal film at a fifth fixed radius, a current of about 10.0 amperes to about 14.0 amperes is supplied to the upper outer magnet and the upper inner magnet. In some embodiments, while depositing the metal film at a fifth fixed radius, a current of about -10.0 amperes to about -14.0 amperes is supplied to the bottom inner magnet.

[0054]

[0060] The metal film can be deposited on the substrate at five radii in any order. For example, in some embodiments, the metal film is deposited on the substrate at a first fixed radius, then a second fixed radius, then a third fixed radius, then a fourth fixed radius, and then a fifth fixed radius. In some embodiments, the metal film is deposited on the substrate at a fifth fixed radius, then a fourth fixed radius, then a third fixed radius, then a second fixed radius, and then a first fixed radius. In some embodiments, the rate of depositing the metal film on the substrate is greater when the magnet assembly is at the first fixed radius than when it is at the fifth position.

[0055]

[0061] The foregoing is directed to embodiments of the present disclosure, but other and further embodiments of the present disclosure can be devised without departing from its basic scope.

Claims

1. A magnetron assembly for use in a PVD chamber, comprising: a base plate having a first side, a second side opposite the first side, and a central axis; a magnet plate rotatably coupled to the base plate on the first side of the base plate, the magnet plate rotating about an offset axis with respect to the base plate; a magnet assembly coupled to the magnet plate offset from the offset axis and configured to rotate about the central axis and the offset axis, all magnets of the magnetron assembly being fixedly coupled to the magnet plate; a first motor coupled to the base plate and configured to rotate the magnet assembly about the central axis; a second motor coupled to the magnet plate and configured to control its angular position and position the magnet assembly at each of a plurality of fixed angular positions defining a plurality of different fixed radii, the magnet assembly being configured to rotate 360 degrees about the central axis at each of the plurality of fixed radii. The magnetron assembly further comprises a counterweight coupled to the base plate on the opposite side of the magnet plate from the central axis.

2. The magnetron assembly according to claim 1, wherein the magnet assembly is configured to rotate from a zero-degree position to about 180 degrees about the offset axis to position the magnet assembly at each of the plurality of different fixed radii.

3. The magnetron assembly according to claim 1, further comprising a counterweight coupled to the base plate on the opposite side of the magnet plate from the central axis.

4. The magnetron assembly according to claim 1, further comprising a counterweight coupled to the magnet plate on the opposite side of the magnet assembly from the offset axis.

5. The magnetron assembly according to claim 1, wherein when the magnet assembly is disposed at about 180 degrees from a position sensor with respect to the offset axis, the magnet assembly is disposed at a first fixed radius corresponding to the innermost position in the radial direction of the magnet assembly with respect to the central axis.

6. The plurality of different fixed radii include a first fixed radius of 1.5 inches to 2.6 inches, a second fixed radius of 2.6 inches to 3.5 inches, a third fixed radius of 3.5 inches to 4.5 inches, a fourth fixed radius of 4.5 inches to 5.5 inches, and a fifth fixed radius of 5.9 inches to 7.5 inches, the magnetron assembly according to any one of claims 1 to 5.

7. The distance between the central axis and the offset axis is 4.0 inches to 5.0 inches, the magnetron assembly according to any one of claims 1 to 5.

8. The distance between the offset axis and the center of the magnet assembly is 2.0 inches to 3.0 inches, the magnetron assembly according to any one of claims 1 to 5.

9. A method of depositing a metal film on a substrate, positioning a magnet assembly at a first fixed radius with respect to the central axis of the target in a physical vapor deposition (PVD) chamber; depositing a metal film on the substrate disposed opposite the target in the PVD chamber while rotating the magnet assembly at the first fixed radius with respect to the central axis during a first period; positioning the magnet assembly at a second fixed radius with respect to the central axis by rotating the magnet assembly about an offset axis; depositing a metal film on the substrate while rotating the magnet assembly at the second fixed radius with respect to the central axis during a second period and a method comprising.

10. positioning the magnet assembly at a third fixed radius with respect to the central axis by rotating the magnet assembly about the offset axis; depositing a metal film on the substrate while rotating the magnet assembly at the third fixed radius with respect to the central axis during a third period; positioning the magnet assembly at a fourth fixed radius with respect to the central axis by rotating the magnet assembly about the offset axis; depositing a metal film on the substrate while rotating the magnet assembly at the fourth fixed radius with respect to the central axis during a fourth period; positioning the magnet assembly at a fifth fixed radius with respect to the central axis by rotating the magnet assembly about the offset axis; During the fifth period, depositing a metal film on the substrate while rotating the magnet assembly about the central axis at the fifth fixed radius The method according to claim 9, further comprising.

11. The method according to claim 10, wherein the metal film is deposited on the substrate at the first fixed radius, then at the second fixed radius, then at the third fixed radius, then at the fourth fixed radius, and then at the fifth fixed radius.

12. The method according to claim 10, wherein the first fixed radius is from 1.5 inches to 2.6 inches, the second fixed radius is from 2.6 inches to 3.5 inches, the third fixed radius is from 3.5 inches to 4.5 inches, the fourth fixed radius is from 4.5 inches to 5.5 inches, and the fifth fixed radius is from 5.9 inches to 7.5 inches.

13. The method according to any one of claims 9 to 12, wherein the magnet assembly rotates 360 degrees about the central axis at each of the first fixed radius and the second fixed radius.

14. The method according to any one of claims 9 to 12, further comprising supplying a current of 6.0 amperes to 16.0 amperes to an upper magnet assembly disposed around the chamber body of the PVD chamber while depositing the metal film at the first fixed radius and the second fixed radius.

15. A non-transitory computer-readable medium for storing computer instructions, wherein the computer instructions, when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 9 to 12.

16. The non-transitory computer-readable medium according to claim 15, further comprising applying an RF bias power of 2.0 kW to 2.2 kW to a substrate support assembly of the PVD chamber while depositing the metal film at the first fixed radius.

17. The non-transitory computer-readable medium according to claim 15, further comprising supplying a current of 6.0 amperes to 16.0 amperes to an upper magnet assembly disposed around the chamber body of the PVD chamber while depositing the metal film at the first fixed radius and the second fixed radius.

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