Reducing substrate temperature non-uniformity over target lifetime using pitch compensation

Abstract

Methods and apparatuses for processing a plurality of substrates are provided herein. In some embodiments, a method of processing a plurality of substrates in a physical vapor deposition (PVD) chamber includes performing a series of reflow processes on a corresponding series of substrates during at least a portion of a lifetime of a sputtering target disposed in the PVD chamber, wherein a substrate-to-target distance in the PVD chamber and a support-to-target distance within the PVD chamber are each controlled as a function of the lifetime of the sputtering target.

Description

Use spacing compensation to reduce substrate temperature non-uniformity during the target life. Technical Field

[0001] Embodiments of this disclosure generally relate to substrate processing equipment. Background Technology

[0002] Semiconductor devices such as ICs (integrated circuits) typically have electronic circuit elements, such as transistors, diodes, and resistors, integrated onto a single body of semiconductor material, such as a wafer or substrate. These various circuit elements are connected by conductive connectors to form a complete circuit, which can contain millions of individual circuit elements. Interconnects provide electrical connections between the various electronic components of the integrated circuit and form connections between circuit elements and external contact elements of the device, such as pins, for connecting the integrated circuit to other circuits. Interconnects can be constructed over multiple layers and connected within / between layers via trenches / vias. Reflow processing is commonly used as a method for filling trenches / vias.

[0003] Reflow processing can be performed in a physical vapor deposition (PVD) chamber, which has heating elements to facilitate the reflow process. The PVD chamber includes a target containing material to be sputtered onto a substrate being processed within the PVD chamber. In use, the substrate is placed at a lower deposition position during the deposition process and then raised to a higher reflow position during the reflow process. During the target's lifetime, target material can be sputtered onto the chamber walls and other chamber components, altering the heat distribution within the PVD chamber. However, these changes in heat distribution result in increased temperature non-uniformity across the substrate.

[0004] Therefore, the inventors have provided a method and apparatus for improving temperature uniformity during reflow processing throughout the life of the target material. Summary of the Invention

[0005] Methods and apparatus for processing multiple substrates are provided herein. In some embodiments, the method of processing multiple substrates in a physical vapor deposition (PVD) chamber includes performing a series of reflow processes on a corresponding series of substrates during at least a portion of the lifetime of a sputtering target disposed in the PVD chamber, wherein the substrate-to-target distance in the PVD chamber and the support-to-target distance in the PVD chamber are each controlled as a function of the sputtering target lifetime.

[0006] In some embodiments, a non-transitory computer-readable medium has instructions stored thereon that, when executed by a processor, perform a method of processing multiple substrates in a physical vapor deposition (PVD) chamber. This method includes performing a series of reflow processes on a corresponding series of substrates during at least a portion of the lifetime of a sputtering target disposed in the PVD chamber, wherein the substrate-to-target distance in the PVD chamber and the support-to-target distance within the PVD chamber are each controlled as a function of the sputtering target lifetime.

[0007] In some embodiments, a method of processing multiple substrates in a physical vapor deposition (PVD) chamber includes: performing a reflow process on a first substrate disposed on a substrate support when the sputtering target in the PVD chamber is at a first point in the lifetime of the sputtering target, while the substrate is positioned at a distance from the first substrate to the target in the PVD chamber, and the substrate support is at a distance from the first support to the target; and performing a reflow process on a second substrate when the sputtering target in the PVD chamber is at a subsequent second point in the lifetime of the sputtering target, while the substrate is positioned at a distance from the second substrate to the target in the PVD chamber, the distance from the second substrate to the target being different from the distance from the first substrate to the target, and the substrate support supporting the second substrate at a distance from the second support to the target, the distance from the second support to the target being different from the distance from the first support to the target, wherein the variation between the distance from the first substrate to the target and the distance from the second substrate to the target, and the variation between the distance from the first support to the target and the distance from the second support to the target, are both functions of the lifetime of the sputtering target.

[0008] Other and further implementations of this disclosure will be described later. Attached Figure Description

[0009] The embodiments of this disclosure, briefly summarized above and described in more detail below, can be understood by referring to the exemplary embodiments depicted in the accompanying drawings. However, the drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered as limiting, as other equivalent embodiments are permissible.

[0010] Figure 1 depicts a schematic side view of a processing chamber in a reflow position for a first substrate according to some embodiments of the present disclosure.

[0011] Figure 2 depicts a schematic side view of a processing chamber in a reflow position for a second substrate according to some embodiments of the present disclosure.

[0012] Figure 3 illustrates a method for processing a substrate in a physical vapor deposition (PVD) chamber according to some embodiments of the present disclosure.

[0013] Figure 4 illustrates a method for processing a substrate in a physical vapor deposition (PVD) chamber according to some embodiments of the present disclosure.

[0014] For ease of understanding, common elements in the icons may be designated using the same reference numerals. The illustrations are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be advantageously incorporated into other embodiments without further explanation. Detailed Implementation

[0015] Methods and apparatus for processing multiple substrates are provided herein. The distances from the substrate to the heat source and from the support to the heat source within a physical vapor deposition (PVD) chamber are controlled as a function of the lifetime of the sputtering target. In some embodiments, the heat source is fixed within the PVD chamber. The sputtering target position can be used as a reference point to control the distances from the substrate to the heat source and from the support to the heat source. Therefore, the distances from the substrate to the target within the PVD chamber and from the support to the target within the PVD chamber are each controlled as a function of the lifetime of the sputtering target.

[0016] The methods and apparatus of this disclosure advantageously provide spacing compensation between a series of substrates and the target of a physical vapor deposition (PVD) chamber during the lifetime of the target, to improve substrate temperature uniformity during a series of reflow processes corresponding to this series of substrates. The methods and apparatus of this disclosure advantageously provide spacing compensation between the substrate support of the PVD chamber and the target of the PVD chamber during the lifetime of the target, to improve substrate temperature uniformity during a series of reflow processes corresponding to this series of substrates.

[0017] Figure 1 depicts a schematic side view of a processing chamber in a reflow position for a first substrate, according to some embodiments of the present disclosure. Embodiments of the present disclosure are illustrated herein by way of example with respect to a physical vapor deposition (PVD) chamber. However, the methods and apparatus of this principle can also be used in other processing chambers. Figure 1 depicts a PVD chamber (processing chamber 100), for example, a sputtering processing chamber suitable for sputtering material onto a substrate 101 having a given diameter. In some embodiments, processing chamber 100 further includes a collimator 118 disposed within processing chamber 100. Processing chamber 100 generally includes an upper sidewall 102, a lower sidewall 103, a ground adapter 104, and a cover assembly 111 defining a body 105, which encloses an interior space 106. The interior space 106 includes a central portion having a given diameter approximately equal to that of the substrate to be processed, and a peripheral portion surrounding the central portion. Furthermore, the internal space 106 includes an annular region on the substrate and adjacent to the sputtering target 114, wherein the inner diameter of the annular region is substantially equal to or greater than the diameter of the substrate 101, such that a major portion of the plasma 165 formed in the internal space 106 during processing is disposed on the substrate and in a radially outward position of the substrate.

[0018] An adapter plate 107 may be disposed between an upper sidewall 102 and a lower sidewall 103. A substrate support 108 is disposed within the internal space 106 of the processing chamber 100. The substrate support 108 may include, for example, an electrostatic chuck (ESC) 151 having a disk 161. The substrate support 108 is configured to support a substrate having a given diameter (e.g., 150 mm, 200 mm, 300 mm, 450 mm, or similar length). A substrate transfer port 109 is formed in the lower sidewall 103 for transferring the substrate in and out of the internal space 106. In some embodiments, the processing chamber 100 is configured to deposit, for example, cobalt (Co), copper (Cu), or aluminum (Al), alloys of the foregoing, combinations of the foregoing, or the like, on a substrate such as substrate 101. Non-limiting examples of suitable applications include the deposition of metal gap-filling material in through-holes, trenches, or structures, or similar applications.

[0019] A gas source 110 is coupled to the processing chamber 100 to supply processing gas into the internal space 106. In some embodiments, the processing gas may include inert gases, non-reactive gases, and reactive gases, if necessary. Examples of processing gases that can be supplied by the gas source 110 include, but are not limited to, argon (Ar), helium (He), krypton (Kr), neon (Ne), nitrogen (N2), oxygen (O2), and water (H2O) vapor, etc. A pump device 112 is coupled to the processing chamber 100 in communication with the internal space 106 to control the pressure of the internal space 106. In some embodiments, the pump device 112 may also be used to remove backside gas from the substrate 101 to minimize cooling of the substrate 101. In some embodiments, the pressure level of the processing chamber 100 during deposition may be maintained at approximately 1 mTorr or less. In some embodiments, the pressure level of the processing chamber 100 during deposition may be maintained at approximately 500 mTorr or less. In some embodiments, the pressure level of the processing chamber 100 can be maintained at approximately 0.01 mTorr to approximately 300 mTorr during the deposition process.

[0020] Grounding adapter 104 may support a target, such as sputtering target 114. Sputtering target 114 is made of a material to be deposited on a substrate. In some embodiments, sputtering target 114 may be made of cobalt (Co), copper (Cu), or aluminum (Al), alloys of the foregoing, combinations of the foregoing, or the like. Sputtering target 114 may be coupled to a source assembly including a power supply 117 for sputtering target 114. In some embodiments, power supply 117 may be an RF power supply, which may be coupled to sputtering target 114 via a matching network 116. In some embodiments, power supply 117 may alternatively be a DC power supply, in which case the matching network 116 is omitted. In some embodiments, power supply 117 may include both DC and RF power supplies.

[0021] A magnetron 170 is positioned on a sputtering target 114. The magnetron 170 may include a plurality of magnets 172 supported by a substrate 174 connected to a shaft 176 axially aligned with the central axis of the processing chamber 100 and the substrate 101. The magnets 172 generate a magnetic field within the processing chamber 100 near the front surface of the sputtering target 114 to generate plasma, resulting in a significant ion flux impacting the sputtering target 114 and causing sputtering emission of the target material. The magnets 172 may rotate about the shaft 176 to increase the uniformity of the magnetic field across the surface of the sputtering target 114. Examples of magnetrons include electromagnetic linear magnetrons, serpentine magnetrons, helical magnetrons, double-digitated magnetrons, rectangularized spiral magnetrons, dual-motion magnetrons, and so on. Magnet 172 rotates within an annular region about the central axis of the processing chamber 100, the annular region extending between approximately the outer diameter of the substrate and approximately the outer diameter of the internal space 106. Generally, magnet 172 can be rotated such that the innermost magnet position during the rotation of magnet 172 is positioned above or outside the diameter of the substrate being processed (e.g., the distance from the axis of rotation to the innermost position of magnet 172 is equal to or greater than the diameter of the substrate being processed).

[0022] The processing chamber 100 further includes an upper shield 113 and a lower shield 120. A collimator 118 is positioned within an internal space 106 between the sputtering target 114 and the substrate support 108. In some embodiments, the collimator 118 may be electrically biased to control the ion flux to the substrate and the neutral angular distribution at the substrate, and to increase the deposition rate due to the increased DC bias. Electrically biasing the collimator results in reduced ion loss to the collimator, advantageously providing a larger ion / neutral particle ratio at the substrate. A collimator power supply (not shown) is coupled to the collimator 118 to facilitate the biasing of the collimator 118. In some embodiments, the collimator 118 may be electrically isolated from a grounding chamber component such as a ground adapter 104. For example, as depicted in FIG1, the collimator 118 is coupled to the upper shield 113.

[0023] In some embodiments, a set of magnets 196 may be positioned adjacent to the ground adapter 104 to help generate a magnetic field to guide displaced ions from the sputtering target 114. The magnetic field formed by this set of magnets 196 may alternatively or in combination prevent ions from colliding with the sidewalls of the chamber (or the sidewalls of the upper shield 113) and guide ions vertically through the collimator 118. For example, this set of magnets 196 is configured to form a magnetic field with substantially perpendicular magnetic field lines in the surrounding portion. These substantially perpendicular magnetic field lines advantageously guide ions through the internal space. This set of magnets 196 may include any combination of necessary electromagnets and / or permanent magnets for guiding metal ions along a desired trajectory from the target through the collimator toward the center of the substrate support 108. This set of magnets 196 may be fixed or movable to adjust the position of the set of magnets in a direction parallel to the central axis of the chamber.

[0024] RF power supply 180 can be coupled to processing chamber 100 via substrate support 108 to provide bias power between sputtering target 114 and substrate support 108. In some embodiments, RF power supply 180 may have a frequency between approximately 400 Hz and approximately 200 MHz, such as approximately 13.56 MHz. In some embodiments, RF power supply 180 can provide bias power greater than 0 watts to approximately 1000 watts. In operation, magnet 172 is rotated to form plasma 165 in an annular portion of internal space 106 to sputter sputtering target 114. When collimator 118 is present, plasma 165 may be formed over collimator 118 to sputter sputtering target 114 over collimator 118. In some embodiments, the radius of rotation of magnet 172 may be greater than the radius of substrate 101, such that very little to no sputtered material is directly present on substrate 101.

[0025] In some embodiments, the collimator 118 is positively biased, forcing the sputtered metal material through it. Furthermore, most of the neutral sputtered material traveling toward the central region of the collimator will likely collide with and stick to the collimator wall. Because the orientation of the neutral metal particles is not altered, most of the neutral metal particles advantageously do not deposit on the substrate 101. To ensure that the trajectory of the sputtered metal ions has sufficient space to be modified, the collimator 118 is positioned at a predetermined height above the substrate support 108. In some embodiments, this height is between approximately 400 mm and approximately 800 mm. This height is also chosen to facilitate ion control, using the magnetic field below the collimator 118 to further improve deposition characteristics on the substrate 101. To allow adjustment of the magnetic field above the collimator 118, the collimator 118 may be positioned at a predetermined height below the sputtering target 114. This height may be between approximately 25 mm and approximately 75 mm, for example, approximately 50 mm.

[0026] In some embodiments, the lower shield 120 may be provided adjacent to the collimator 118 and the grounding adapter 104 or the interior of the upper sidewall 102. The collimator 118 includes a plurality of holes to guide the flow of gas and / or material within the interior space 106. The shielding ring 126 may be disposed in the processing chamber 100 adjacent to the lower shield 120 and between the lower shield 120 and the adapter plate 107. The substrate 101 (shown as being supported on the lifting pin 140 in the reflow position) is centered relative to the longitudinal axis of the substrate support 108 by coordinated positioning correction between the substrate support 108 and the robot blade (not shown). Thus, during processing, the substrate 101 may be disposed within the processing chamber, and the shielding ring 126 may be radially centered around the substrate 101. During reflow processing, the substrate 101 may alternatively be disposed on the substrate receiving surface 144.

[0027] In operation, a robotic blade (not shown) having a substrate 101 disposed thereon is extended through a substrate transfer port 109. A substrate support 108 can be lowered to allow the substrate 101 to be transferred to a lifting pin 140 extending from the substrate support 108. The raising and lowering of the substrate support 108 can be controlled by a driver 142 coupled to the substrate support 108. The substrate support 108 can be lowered, while the lifting pin 140 is raised to reach a heating or reflow position. Similarly, by lowering the lifting pin 140 and raising the substrate support 108 to a deposition position, the substrate 101 can be lowered onto the substrate receiving surface 144 of the substrate support 108. Sputtering deposition can be performed on the substrate 101 positioned on the substrate receiving surface 144 of the substrate support 108. The deposition ring 136 can be electrically insulated from the substrate 101 during processing. Therefore, the substrate receiving surface 144 may include a height greater than the height of the portion adjacent to the deposition ring 136 of the substrate 101, so that the substrate 101 avoids contact with the deposition ring 136.

[0028] During the deposition process, material is sputtered from sputtering target 114 and deposited onto the surface of substrate 101. Sputtering target 114 and substrate support 108 are biased relative to each other by power supply 117 or RF power supply 180 to maintain the plasma formed by the process gas supplied by gas source 110. In some embodiments, the DC pulse bias power applied to collimator 118 also helps control the ratio of ions to neutral particles traveling through collimator 118, advantageously improving trench sidewall and bottom fill-up capability. Ions from the plasma are accelerated toward and impact sputtering target 114, causing target material to be removed from sputtering target 114. The removed target material and process gas form a layer with the desired composition on substrate 101. Substrate 101 is then raised to a heating or reflow position and heated by a heat source (such as one or more lamps 150) during the static reflow portion of the process. One or more lamps 150 are then turned off, backside gas is pumped out using pump device 112, and substrate 101 is lowered to the processing or deposition position. Substrate 101 is then heated using RF bias power supplied by RF power supply 180 during the dynamic reflow portion of the processing.

[0029] After sputtering deposition, substrate 101 can be raised to a position spaced apart from substrate support 108 using lifting pin 140. This raised position can be above one or both of shielding ring 126 and reflector ring 148 adjacent to adapter plate 107. Adapter plate 107 includes one or more lamps 150 coupled to the lower surface of reflector ring 148 and at a midpoint of recess 152 of adapter plate 107. The one or more lamps 150 provide optical and / or radiative energy at visible or near-visible wavelengths (such as in the infrared (IR) and / or ultraviolet (UV) spectrum). Energy from the one or more lamps 150 is focused radially inward toward the back side (i.e., lower surface) of substrate 101 to heat substrate 101 and the material deposited on substrate 101. Reflective surfaces on chamber components surrounding substrate 101 are used to focus energy toward the back side of substrate 101 and away from other chamber components where energy would be lost and / or not utilized. After the substrate 101 is brought to a predetermined temperature, the substrate 101 is lowered to a position on the substrate receiving surface 144 of the substrate support 108. The substrate 101 can be removed from the processing chamber 100 through the substrate transfer port 109 for further processing. The substrate 101 can be maintained within a predetermined temperature range, such as, but not limited to, less than 600°C.

[0030] The substrate 101 depicted in FIG. 1 may be a first substrate at a first point in the lifetime of the sputtering target 114, such as at the beginning of the processing lifetime of the sputtering target 114 (e.g., for a new sputtering target but after any burn-in operation). Once the first substrate is removed from the processing chamber 100, subsequent substrates are transferred into the processing chamber 100 through a substrate transfer port. In some embodiments, the distance 182 from the first substrate to the target at a first point in the lifetime of the sputtering target 114 is about 600 mm to about 610 mm. In some embodiments, the distance 190 from the first support to the target at a first point in the lifetime of the sputtering target 114 is about 660 mm to about 680 mm. Over time, deposits from the sputtering target 114 are deposited onto the surfaces of the chamber components exposed to the interior space 106, causing heat from one or more lamps 150 to dissipate or reflect differently during the lifetime of the sputtering target 114. This change in the heat distribution within the internal space 106 results in increased temperature non-uniformity of the substrate 101 at the reflow location. Changing the substrate-to-target distance and the support-to-target distance for subsequent reflow processing of the substrate advantageously alters the substrate-to-heat source distance and the support-to-heat source distance, and improves the temperature uniformity of the subsequent substrate. For example, a temperature non-uniformity (NU) of approximately 15°C or less can be achieved throughout the entire lifespan of the target.

[0031] Figure 2 depicts a schematic side view of a processing chamber in a reflow position for a subsequent substrate 201 (e.g., a second substrate) according to some embodiments of the present disclosure. For the subsequent substrate 201, the substrate-to-target distance 280 differs from the first substrate-to-target distance 182. In some embodiments, for the subsequent substrate 201, the support-to-target distance 290 differs from the first support-to-target distance 190. In some embodiments, the substrate-to-target distance 280 at a point after a first point in the lifetime of the sputtering target 114 is less than the first substrate-to-target distance 182. In some embodiments, the support-to-target distance 290 at a point after a first point in the lifetime of the sputtering target 114 is less than the first support-to-target distance 190. In some embodiments, the substrate-to-target distance 280 at the end of the lifetime of the sputtering target 114 is approximately 597 mm to approximately 602 mm. In some embodiments, the distance 290 between the support and the target at the end of the life of the sputtering target 114 is approximately 662 mm to approximately 666 mm.

[0032] Controller 198 controls the operation of processing chamber 100 using direct control of processing chamber 100 or alternatively by controlling a computer (or controller) associated with processing chamber 100. In operation, controller 198 can collect and provide feedback from processing chamber 100 to optimize its performance. Controller 198 generally includes a central processing unit (CPU) 160, memory 158, and support circuitry 162. CPU 160 can be any type of general-purpose computer processor used in industrial settings. Support circuitry 162 is conventionally coupled to CPU 160 and may include cache, clock circuitry, input / output subsystems, power supply, and the like. Software routines, such as those described later, can be stored in memory 158 and, when executed by CPU 160, transform CPU 160 into a specific target computer (controller 198). Software routines can also be stored and / or executed by a second controller (not shown), located remotely from processing chamber 100.

[0033] Memory 158 is in the form of a computer-readable storage medium containing instructions that, when executed by CPU 160, facilitate semiconductor processing and device operation. The instructions in memory 158 are in the form of a program product, such as a program that performs the methods of this principle. The program code may conform to any of several different programming languages. In one instance, this disclosure may be implemented as a program product stored on a computer-readable medium for use with a computer system. The program of this program product defines the functionality of various aspects, including those described herein. Examples of computer-readable storage media include, but are not limited to: non-writable storage media (e.g., read-only memory devices within a computer, such as CD-ROM discs readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory), on which data is permanently stored; and writable storage media (e.g., floppy disks or hard disk drives within a floppy disk drive or any type of solid-state random access semiconductor memory), on which variable information is stored. Such computer-readable storage media are aspects of this principle when they carry computer-readable instructions directing the functionality of the methods described herein.

[0034] Figure 3 depicts a method 300 for processing multiple substrates in a physical vapor deposition (PVD) chamber. In some embodiments, the processing chamber 100 of Figures 1 and 2 can be used to perform method 300. In operation 302, method 300 includes performing a series of reflow processes on a corresponding series of substrates (i.e., substrates 101) during at least a portion of the lifetime of a sputtering target (i.e., sputtering target 114) disposed in the PVD chamber (i.e., processing chamber 100), wherein the substrate-to-target distance in the PVD chamber and the support-to-target distance in the PVD chamber are each controlled (e.g., via controller 198) as a function of the sputtering target lifetime. In some embodiments, when performing the series of reflow processes, the corresponding series of substrates is raised relative to the substrate support (i.e., substrate support 108). The series of reflow processes on the series of substrates may include reflow processes of cobalt (Co), copper (Cu), or aluminum (Al), alloys of the foregoing, combinations of the foregoing, or the like.

[0035] Figure 4 depicts a method 400 for processing a substrate in a physical vapor deposition (PVD) chamber according to some embodiments of the present disclosure. Method 400 may be an example of method 300. In operation 402, when the sputtering target in the PVD chamber is at a first point in the lifetime of the sputtering target, a series of reflow processes is performed on a first substrate disposed on a substrate support, while the substrate is positioned in the PVD chamber at a first substrate-to-target distance (i.e., first substrate-to-target distance 182), and simultaneously the substrate support is at a first support-to-target distance (i.e., first support-to-target distance 190).

[0036] In operation 404, method 400 includes performing a reflow process on a second substrate when the sputtering target in the PVD chamber is at a subsequent second point in the lifetime of the sputtering target, while the substrate is positioned in the PVD chamber at a second substrate-to-target distance (i.e., second substrate-to-target distance 280), which is different from the first substrate-to-target distance, and simultaneously a substrate support supports the second substrate at a second support-to-target distance (i.e., second support-to-target distance 290), which is different from the first support-to-target distance.

[0037] In some embodiments, reflow processing is performed on the first and second substrates using one or more lamps (i.e., one or more lamps 150) disposed beneath the first and second substrates. In some embodiments, when reflow processing is performed on the first and second substrates, the first and second substrates are raised above a substrate support via lifting pins. In some embodiments, when performing individual reflow processing, the substrates may be rested on the substrate support.

[0038] The variations between the distances from the first substrate to the target and the second substrate to the target, and the variations between the distances from the first support member to the target and the second support member to the target, are both functions of the sputtering target lifetime. In some embodiments, the substrate-to-target distance can vary at a first rate. In some embodiments, the support member-to-target distance can vary at a second rate. In some embodiments, at least one of the substrate-to-target distance and the support member-to-target distance is controlled to vary at a linear rate during the sputtering target lifetime (i.e., at least one of the first rate and the second rate is linear). In some embodiments, at least one of the substrate-to-target distance and the support member-to-target distance is controlled to vary at a non-linear rate during the sputtering target lifetime (i.e., at least one of the first rate and the second rate is non-linear).

[0039] The variation in the substrate-to-target distance (i.e., the first rate) and the variation in the support-to-target distance (i.e., the second rate) during the lifetime of the sputtering target may depend on the target material or the substrate type, or both. In some embodiments, the variation in the substrate-to-target distance during the lifetime of the sputtering target is less than or equal to the variation in the support-to-target distance. In some embodiments, the substrate-to-target distance is controlled to vary from about 0.002 mm to about 0.004 mm per kilowatt-hour of the sputtering target lifetime. In some embodiments, the support-to-target distance is controlled to vary from about 0.002 mm to about 0.006 mm per kilowatt-hour of the sputtering target lifetime. Specific rates of variation of the substrate-to-target distance and the support-to-target distance for different target materials and / or different substrate types may be determined empirically or modeled based on the teachings disclosed herein.

[0040] In some embodiments, the distance from the first substrate to the target at the first point in the lifetime of the sputtering target (i.e., as depicted in FIG. 1) is about 600 mm to about 610 mm. In some embodiments, the distance from the first support to the target at the first point in the lifetime of the sputtering target is about 660 mm to about 680 mm. In some embodiments, the distance from the substrate to the target for about 1000 kWhr of target lifetime after the first point in the lifetime of the sputtering target is about 602 mm to about 606 mm. In some embodiments, the distance from the support to the target for about 1000 kWhr of target lifetime after the first point in the lifetime of the sputtering target is about 668 mm to about 672 mm. In some embodiments, the lifetime of the sputtering target is about 2000 to about 3000 kWhr.

[0041] In some embodiments, multiple substrates are positioned at substrate-to-target distances that remain constant during each substrate reflow process, and substrate supports are positioned at support-to-target distances that remain constant during each substrate reflow process. For example, in any given reflow process, each substrate can be processed with a fixed substrate-to-target distance and a fixed support-to-target distance, but the fixed substrate-to-target distance and the fixed support-to-target distance vary from one substrate to the next during the lifetime of the target (e.g., for different reflow processes), as discussed above. In some embodiments, multiple substrates are positioned at substrate-to-target distances that vary during each reflow process, and substrate supports are positioned at support-to-target distances that vary during each reflow process. For example, variations in the substrate-to-target distance and the support-to-target distance can occur during the processing of individual substrates and between successive substrates.

[0042] While the foregoing describes implementations of this disclosure, other and further implementations of this disclosure may be conceived without departing from the basic scope of this disclosure.

Claims

1. A method for processing a plurality of substrates in a physical vapor deposition chamber, comprising the steps of: performing a series of reflow processes on a corresponding series of substrates during at least a portion of the lifetime of a sputtering target disposed in the physical vapor deposition chamber, wherein the substrate-to-target distance in the physical vapor deposition chamber and the support-to-target distance in the physical vapor deposition chamber are each controlled as a function of the lifetime of the sputtering target.

2. The method of claim 1, wherein at least one of the following is true: the distance from the first substrate to the target at a first point in the lifetime of the sputtering target is 600 mm to 610 mm, or the distance from the first support to the target at a first point in the lifetime of the sputtering target is 660 mm to 680 mm.

3. The method of claim 1, wherein when the series of reflow processes are performed, the substrates of the corresponding series are raised relative to the substrate support.

4. The method of claim 1, wherein the lifetime of the sputtering target is 2000 to 3000 kilowatt-hours (kWhr).

5. The method of claim 1, wherein during the lifetime of the sputtering target, the change in the distance between the substrate and the target is less than or equal to the change in the distance between the support and the target.

6. The method of any one of claims 1 to 5, wherein each substrate of the series of substrates is positioned at a substrate-to-target distance that remains constant during a given reflow process, and wherein the substrate support is positioned at a support-to-target distance that remains constant during the given reflow process.

7. The method of any one of claims 1 to 5, wherein each substrate of the series of substrates is positioned at a substrate-to-target distance that varies during a given reflow process, and wherein a substrate support is positioned at a support-to-target distance that varies during the given reflow process.

8. The method of any one of claims 1 to 5, wherein at least one of the following is true: the distance between the substrate and the target is controlled to vary by 0.002 mm to 0.004 mm per kilowatt-hour (kWhr) of the lifetime of the sputtering target, or the distance between the support and the target is controlled to vary by 0.002 mm to 0.006 mm per kilowatt-hour (kWhr) of the lifetime of the sputtering target.

9. The method of any one of claims 1 to 5, wherein the distance between the substrate and the target and the distance between the support and the target are controlled to vary at a linear rate during the lifetime of the sputtering target.

10. The method of claim 1, wherein the distance between the substrate and the target and the distance between the support and the target are controlled to vary at a non-linear rate during the lifetime of the sputtering target.

11. The method of any one of claims 1 to 5, wherein during at least a portion of the lifetime of the sputtering target disposed in the physical vapor deposition chamber, a series of reflow processes are performed on a corresponding series of substrates comprising the steps of: when the sputtering target in the physical vapor deposition chamber is at a first point in the lifetime of the sputtering target, performing a reflow process on a first substrate disposed on a substrate support, while the first substrate is positioned at a first substrate-to-target distance in the physical vapor deposition chamber, and simultaneously the substrate support is at a first support-to-target distance; and when the sputtering target in the physical vapor deposition chamber is at a first point in the lifetime of the sputtering target, performing a reflow process on a first substrate disposed on a substrate support, while the first substrate is positioned at a first substrate-to-target distance in the physical vapor deposition chamber; and when the sputtering target in the physical vapor deposition chamber is at a first substrate-to-target distance, performing a reflow process on a first substrate disposed on a substrate support, while the first substrate is positioned at a first substrate-to-target distance in the physical vapor deposition chamber; and performing a reflow process on a first substrate disposed on a substrate support, while the first substrate is positioned at a first substrate-to-target distance in the physical vapor deposition chamber; and performing a reflow process on a first substrate disposed on a substrate support, while the first substrate is positioned at a first substrate-to-target distance in the physical vapor deposition chamber; and performing a reflow process on a first substrate-to-target distance in the physical vapor deposition chamber ... At a subsequent second point regarding the lifetime of the sputtering target, a reflow process is performed on the second substrate, while the second substrate is positioned in the physical vapor deposition chamber at a distance between the second substrate and the target that differs from the distance between the first substrate and the target. Simultaneously, the substrate support supporting the second substrate is positioned at a distance between the second support and the target that differs from the distance between the first support and the target, wherein the variation between the first substrate to the target distance and the second substrate to the target distance, and the variation between the first support to the target distance and the second support to the target distance, are both functions of the lifetime of the sputtering target.

12. The method of claim 11, wherein one or more lamps disposed beneath the first substrate and the second substrate are used to perform the reflow process on the first substrate and the reflow process on the second substrate.

13. The method of claim 11, wherein when the reflow process is performed on the first substrate and the second substrate, the first substrate and the second substrate are raised above the substrate support via a plurality of lifting pins.

14. The method of claim 11, wherein the reflow treatment on the first substrate and the reflow treatment on the second substrate comprise a reflow treatment of cobalt, copper, or aluminum, or an alloy thereof.

15. The method of claim 11, wherein the distance from the second substrate to the target is less than the distance from the first substrate to the target, and the distance from the second support member to the target is less than the distance from the first support member to the target.

16. A non-transitory computer-readable medium having a plurality of instructions stored on the non-transitory computer-readable medium, wherein, when executed by a processor, the plurality of instructions perform the method of any one of claims 1 to 5.

17. The non-transitory computer-readable medium of claim 16, wherein each substrate of the series of substrates is positioned at a substrate-to-target distance that remains constant during a given reflow process, and wherein a substrate support is positioned at a support-to-target distance that remains constant during the given reflow process.

18. The non-transitory computer-readable medium of claim 16, wherein each substrate of the series of substrates is positioned at a substrate-to-target distance that varies during a given reflow process, and wherein a substrate support is positioned at a support-to-target distance that varies during the given reflow process.

19. The non-transitory computer-readable medium of claim 16, wherein at least one of the following is true: the distance between the substrate and the target is controlled to vary from 0.002 mm to 0.004 mm per kilowatt-hour (kWhr) of the lifetime of the sputtering target, or the distance between the support and the target is controlled to vary from 0.002 mm to 0.006 mm per kilowatt-hour (kWhr) of the lifetime of the sputtering target.

20. The non-transitory computer-readable medium of any one of claims 16 to 19, wherein the substrate-to-target distance and the support-to-target distance are controlled to vary at a linear rate during the lifetime of the sputtering target.

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