Method and apparatus for depositing aluminum by physical vapor deposition (PVD) with controlled cooling - Patents.com

Abstract

1. A method and apparatus for performing physical vapor deposition in a reaction chamber to form an aluminum material on a substrate, the method and apparatus comprising: depositing a first aluminum layer on the substrate to form a first aluminum region having a first grain size and a first temperature; and cooling the first aluminum region on the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure relate generally to substrate processing techniques, and more particularly to methods for depositing aluminum during a PVD process. [Background technology]

[0002]

[0002] In semiconductor devices such as integrated circuits, interconnects are used to connect and integrate various components of the device. Typically, devices are composed of many layers of conductive components separated by insulating materials to help minimize signal paths and reduce the size of the device. To establish continuity between the layers, conductive interconnects (contacts or vias) extend between the insulating layers and connect the conductive layers. Thus, interconnects are vertical openings filled with conductive material that are used to connect the components of the various layers of the device to each other and to the semiconductor substrate.

[0003]

[0003] As the integration of semiconductor devices has increased, the size of interconnects has decreased and their aspect ratios (i.e., the ratio of the height to the width of the interconnects) have increased. As a result, methods that were previously sufficient to fill interconnects have proven inadequate for smaller interconnects. Typically, interconnect holes are filled using a metallic material, such as copper, that is deposited inside the hole by chemical vapor deposition (CVD), physical vapor deposition (PVD), electroplating, or a combination thereof.

[0004]

[0004] Interconnects in integrated circuits (ICs) distribute clocks and other signals and provide power / ground to various parts in the circuit. As IC feature sizes continue to shrink, interconnects are becoming a major factor in determining system performance, such as signal propagation delay and power dissipation associated with the line resistance of the interconnects. Over the last two decades, copper (Cu) has been the material of choice for interconnects due to Cu's low resistivity. However, the inventors have observed that copper can interact problematically with silicon at low temperatures or diffuse into the surrounding dielectric. A barrier layer is usually required to prevent diffusion, which detrimentally contributes to the overall resistivity of Cu. The inventors have recognized the need to find an alternative material to copper in IC interconnects.

[0005]

[0005] Furthermore, aluminum has been used to fill and cover features in interconnects using long deposition chambers, but the aluminum coverage of the feature and adjacent fields is insufficient because the deposits of long deposition chambers lack uniform aluminum coverage, which creates problems. The inventors have observed that poor aluminum coverage performance reduces the reliability of interconnects formed therefrom. The inventors have also found that rapid cooling of aluminum deposited on semiconductor substrates is detrimental to the quality of the film, which creates problems: small grain size leads to aluminum line breakage and poor yield; poor reflectivity has detrimental effects on downstream post-deposition processing; silicon precipitation in aluminum-silicon (Al-Si) thin films leads to improper film roughness and precipitation; and increased stress due to AC bias processing leads to high warpage.

[0006]

[0006] Accordingly, the present inventors have provided an improved method for forming an aluminum material on a substrate and a method for improving the aluminum coverage of features such as vias. Summary of the Invention

[0007]

[0007] Provided herein are embodiments for forming an aluminum material on a substrate and increasing the coverage of the aluminum material. In some embodiments, a method of performing physical vapor deposition in a reaction chamber to form an aluminum material on a substrate includes depositing a first aluminum layer on the substrate to form a first aluminum region having a first grain size and a first temperature, and cooling the first aluminum region on the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size.

[0008] In some embodiments, the present disclosure relates to a method of performing physical vapor deposition in a reaction chamber on a substrate disposed on a workpiece support beneath an aluminum sputter target, the method including: maintaining the substrate on the heated workpiece support at a first temperature of 200° C. to 400° C. and a first pressure of less than 10 mTorr; sputtering atoms from the aluminum sputter target by applying a first DC power of about 4 kW to 60 kW and a first AC target bias power of at least 600 W to the aluminum sputter target; maintaining the reaction conditions for a duration sufficient to form a first layer of aluminum having a first grain size; delaying cooling of the substrate for the first duration; and cooling the first layer of aluminum to the second temperature at a rate sufficient to increase the first grain size to a second grain size.

[0009]

[0009] In some embodiments, the present disclosure relates to a physical vapor deposition chamber including a reaction chamber configured to physically vapor deposit a first aluminum layer onto a substrate to form a first aluminum region having a first grain size and a first temperature, and cool the first aluminum region on the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size.

[0010]

[0010] In some embodiments, the present disclosure relates to a computer readable medium having stored thereon instructions that, when executed, cause a physical vapor deposition reaction chamber to perform a method of physical vapor deposition within the reaction chamber to form an aluminum material on a substrate, the method including depositing a first aluminum layer over the substrate to form a first aluminum region having a first grain size and a first temperature, and cooling the first aluminum region over the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size.

[0011]

[0011] Other and further embodiments of the present disclosure are described below.

[0012]

[0012] The embodiments of the present disclosure, briefly summarized above and described in more detail below, can be understood by reference to the exemplary embodiments of the present disclosure illustrated in the accompanying drawings. However, since the present disclosure may admit of other equally effective embodiments, the accompanying drawings depict only typical embodiments of the present disclosure and therefore should not be considered as limiting the scope. [Brief description of the drawings]

[0013] [Figure 1] 1 depicts a flowchart of a method for processing a substrate according to some embodiments of the present disclosure. [Figure 2A]

[0014] 2A-2D depict stages in filling high aspect ratio openings according to some embodiments of the present disclosure. [Figure 2B] 2A-2D depict stages in filling high aspect ratio openings according to some embodiments of the present disclosure. [Figure 2C] 2A-2D depict stages in filling high aspect ratio openings according to some embodiments of the present disclosure. [Figure 2D] 2A-2D depict stages in filling high aspect ratio openings according to some embodiments of the present disclosure. [Diagram 3]

[0015] 1 depicts a schematic cross-sectional view of a physical vapor deposition (PVD) chamber according to some embodiments of the present disclosure. [Figure 4]

[0016] 4 depicts a flowchart of another method for processing a substrate according to some embodiments of the present disclosure. [Diagram 5]

[0017] 1 depicts a schematic cross-sectional view of a physical vapor deposition (PVD) chamber according to some embodiments of the present disclosure. [Figure 6]

[0018] 4 depicts a flowchart of another method for processing a substrate according to some embodiments of the present disclosure. [Figure 7]

[0019] 1 depicts a schematic cross-sectional view of a physical vapor deposition (PVD) chamber according to some embodiments of the present disclosure. [Figure 8]

[0020] 4 depicts a flowchart of another method for processing a substrate according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014]

[0021] For ease of understanding, the same reference numbers have been used, where possible, to designate identical elements that are common to multiple figures. The figures are not to scale and may be simplified for clarity. It is envisioned that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0015]

[0022] Embodiments are provided herein for forming an aluminum material on a substrate. The inventors have improved the use and coverage of aluminum in interconnect structures by including aluminum in IC interconnects and extending aluminum grain growth after deposition. In some embodiments, a first event deposits aluminum having a smaller grain size compared to a later measured grain size of the same material. By delaying and / or controlling the post-deposition cooling of the deposited aluminum, the grain growth period for the aluminum is extended, resulting in a larger aluminum grain size and an improved aluminum film. In some embodiments, a method of performing physical vapor deposition in a reaction chamber to form an aluminum material on a substrate includes depositing a first aluminum layer on the substrate to form a first aluminum region having a first grain size and a first temperature, and cooling the first aluminum region on the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size.

[0016]

[0023] The method embodiments may advantageously provide continuous coverage of the surface of the substrate, e.g., high aspect ratio features with improved coverage and / or low resistivity aluminum material. By starting with a small grain size, the disclosed embodiments advantageously provide continuous coverage of the substrate surface by extending the grain growth period of the deposited aluminum. In some embodiments, by starting with a small grain size and ending with a larger grain size, more grain coalescence events occur during the growth of the aluminum film, improving aluminum mobility, improving aluminum coverage, and preventing line breaks. In some embodiments, downstream post-deposition processes are improved as the reflectivity value of the deposited aluminum film is improved. In some embodiments, film roughness is reduced and silicon precipitation is avoided. In some embodiments, film stress is reduced and warpage is reduced. In some embodiments, the quality of the aluminum film is improved by slowing the rapid cooling of the deposited aluminum. In some embodiments, to resolve aluminum pad anomalies after downstream thermal processing and / or to avoid hillock formation, the grain size may be enlarged during the aluminum deposition process and post-deposition process sequence as described herein.

[0017]

[0024] FIG. 1 depicts a flow chart of a method 100 for forming an aluminum material on a substrate 200 according to some embodiments of the present disclosure. Although the method 100 is described below with respect to filling high aspect ratio features as depicted in FIGS. 2A-2D, the disclosure provided herein may be used to deposit the aluminum material as a sheet or blanket on or over a substrate without features such as high aspect ratio features. Furthermore, the disclosure provided herein may also be used to fill features having other aspect ratios than high aspect ratios. In some embodiments, the aluminum material may be formed as a sheet or blanket on a substrate and may undergo further process flows such as etching, filling, and / or capping. The method 100 may be performed in any suitable PVD process chamber having DC, AC, and / or radio frequency (RF) power sources, such as process chamber 300 described below and depicted in FIG. 3.

[0018]

[0025] 1 begins at 102 by depositing a first aluminum layer over a substrate to form a first aluminum region having a first grain size and a first temperature. In some embodiments, the grain growth period for the aluminum deposition is extended by delaying cooling of the substrate and the first aluminum layer.

[0019]

[0026] Referring to FIG. 2A, a substrate 200 may be provided to a PVD chamber, such as process chamber 300. In some embodiments, the substrate 200 includes a high aspect ratio opening, such as opening 202 formed in a first surface 204 of the substrate 200 and extending into the substrate 200 toward an opposite second surface 206 of the substrate 200. The substrate 200 may be any suitable substrate, including, but not limited to, a substrate having a high aspect ratio opening formed therein. For example, the substrate 200 may include one or more of silicon (Si), (SiO2), (SiN), or other dielectric materials. In some embodiments, the substrate may optionally include a thin metal layer, such as TiN, tantalum nitride (TaN). Additionally, the substrate 200 may optionally include additional layers of material or have one or more completed or partially completed structures formed therein or thereon.

[0020]

[0027] In some embodiments, opening 202 may be any opening having a high aspect ratio, such as those used to form vias, trenches, dual damascene structures, etc. In some embodiments, opening 202 may have a height-to-width aspect ratio (e.g., a high aspect ratio) of at least about 5:1. For example, in some embodiments, the aspect ratio may be about 10:1 or greater, such as about 15:1 or greater. Opening 202 may be formed by etching a substrate using any suitable etching process. Opening 202 includes a bottom surface 208 and sidewalls 210, as shown.

[0021]

[0028] In some embodiments, the bottom surface 208 and sidewalls 210 may be optionally covered with one or more layers prior to depositing aluminum atoms, as described below. For example, as shown by the dotted lines in FIG. 2A, the bottom surface and sidewalls of the opening 202 and the first surface of the substrate 200 may be covered with a dielectric or oxide layer 212, such as silicon oxide (SiO2), (Si), (SiN), or other dielectric material. The oxide layer may be deposited or grown, for example, in a chemical vapor deposition (CVD) chamber or an oxidation chamber, prior to providing the substrate 200 to a PVD chamber. The dielectric or oxide layer 212 may act as an electrical and / or physical barrier between the substrate and an aluminum-containing layer subsequently deposited in the opening, and / or may act as a better surface for adhesion during the deposition process described below than the original surface of the substrate. In some embodiments, materials other than oxides may be used in place of the oxide layer 212.

[0022]

[0029] In some embodiments, a barrier layer 214 may be deposited over the oxide layer 212 (as shown), or over the dielectric layer, or over the bottom and sidewalls of the opening and the first surface of the substrate if no oxide layer is present. The barrier layer 214 may perform a similar function as any of the dielectric or oxide layers 212 described above. In some embodiments, the barrier layer 214 may include at least one of titanium (Ti), titanium nitride (TiN), tantalum (Ta), tantalum nitride (TaN), or the like. The barrier layer 214 may be deposited by any suitable method, such as CVD or PVD, including using the method 100 described below to form a continuous barrier layer in the opening 202.

[0023]

[0030] In some embodiments, the opening 202 may extend completely through the substrate 200, and a surface 216 of a second substrate 218 may form a bottom surface 208 of the opening 202. The second substrate 218 may be disposed adjacent to the second surface 206 of the substrate 200. In embodiments, a device, such as a logic device, or a portion of a device requiring electrical connectivity, such as a gate, contact pad, conductive via, etc., may be disposed in the surface 216 of the second substrate and aligned with the opening 202.

[0024]

[0031] At 102, deposition of an aluminum layer on the substrate 200 may occur in a PVD chamber (FIG. 3). In that case, a first DC power of about 4 kilowatts (kW) to 60 kW may be applied to an aluminum sputter target to generate a plasma from a plasma generating gas, and a first AC target bias power of at least 600 W may be applied to a pedestal that includes, for example, a substrate or workpiece. In some embodiments, the target may be a target 306 that includes or is composed of aluminum. Additionally, the target may include one or more of aluminum alloys, such as pure aluminum with 0.5% copper or pure aluminum with 0.5% silicon, suitable for forming a first aluminum layer 220 on the surface of the opening 202 and the first surface 204 of the substrate 200. Other components, such as metals, such as titanium (Ti), tantalum (Ta), copper (Cu), aluminum (Al), etc., may be present in amounts less than 1% by weight of the total target weight. The plasma generating gas may include an inert gas, such as a noble gas, or other inert gas. For example, non-limiting examples of suitable plasma generating gases may include argon (Ar), helium (He), xenon (Xe), neon (Ne), etc. In some embodiments, the plasma generating gas, such as the process gas, is argon (Ar) having a flow rate of about 50 to 350 sccm. In one embodiment, the plasma generating gas is argon (Ar) having a flow rate of about 70 sccm.

[0025]

[0032] At 102, deposition of a first aluminum layer 220 on a substrate 200 (as shown in FIG. 2B) may be performed in a PVD chamber. RF power may then be applied, optionally at a VHF frequency, to generate a plasma from a plasma generating gas and / or to ionize metal atoms sputtered from a target by the plasma. As used herein, a VHF frequency is a frequency in the range of about 13 MHz to about 100 MHz, e.g., 13.56 MHz. In some embodiments, the applied VHF frequency is about 60 MHz. For example, increasing the VHF frequency may increase the plasma density. In some embodiments, RF power may be applied at 0.5 to 3 kW, such as 1 kW, 1.25 kW, 2.5 kW, or 3 kW.

[0026]

[0033] At 102, deposition of a first aluminum layer on the substrate 200 may occur in a PVD chamber. DC power may then be applied to the target 306 to induce a plasma toward the target 306 from a DC power supply 320 coupled to the target 306, for example, as described below. The DC power may initially range from about 1 to about 60 kilowatts (kW). In some embodiments, the DC power may be about 10-50 kW, or about 20 kW, 30 kW, or 40 kW. The DC power may be adjusted to control the deposition rate of the sputtered aluminum atoms on the substrate 200. In some embodiments, DC power under conditions of the present disclosure may result in the first aluminum layer 220 on the substrate to form a first aluminum region 221 having a first grain size, the grain size may be made smaller in size. By reducing the initial grain size during aluminum deposition, the grain growth period may be extended. In some embodiments, a first aluminum layer 220 is deposited over a substrate 200 to form a first aluminum region 221 having a first grain size and a first temperature, where the first temperature is about 200 to 400 degrees Celsius.

[0027]

[0034] At 102, a first aluminum layer may be deposited on the substrate 200 to form a first aluminum region 221 having a first grain size and a first temperature in a PVD chamber. Aluminum atoms are then sputtered from a target 306 using a plasma while maintaining a first pressure in the PVD chamber. The first pressure may depend on the geometry of the process chamber (size of the substrate, distance between the target and the substrate, etc.) as well as the first AC power and DC power applied. For example, the first pressure may be less than 10 milliTorr (mTorr), or in a range of about 0.2 to about 10 mTorr in a chamber configured with a target. In some embodiments, the chamber may be optionally configured to have a gap between the target and the substrate of about 35 to 90 millimeters (mm). In some embodiments, the first pressure is about 0.5 to about 5 mTorr, or 2 mTorr. The first pressure in the chamber may be maintained by the flow rate of the plasma generating gas and / or the flow rate of an additional gas, such as an inert gas, that may be co-flowed with the plasma generating gas. The first pressure may provide a high density of gas molecules between the target and the substrate with which the sputtered aluminum atoms may collide and be ionized. Pressure may also be utilized to control the amount of aluminum atoms sputtered from the target 306. For example, a low pressure in the gap of the target 306 to the substrate may reduce the grain size of the first aluminum layer 220.

[0028]

[0035] At 102, in one embodiment, depositing a first aluminum layer 220 on a substrate 200 may be performed in a PVD chamber under an Argon (Ar) plasma to form a first aluminum region 221 having a first grain size and a first temperature, where the conditions are an Ar plasma with a flow rate of about 50 to 350 sccm, such as 70 sccm, a process pressure of less than 10 mTorr, and a power such as 1-60 kW DC or about 600 to 1200 W AC, such as RF applied as a bias power to a substrate support pedestal. In some embodiments, the temperature is less than 350 degrees Celsius. At 102, in one embodiment, depositing a first aluminum layer 220 on a substrate 200 may be performed in a PVD chamber under an Ar plasma. The conditions are as follows: Ar plasma has a process pressure of less than 10 mTorr at a temperature of less than 350 degrees Celsius, a DC power of 4-60 kW, and a large AC bias power of 600 W to 1200 W. In some embodiments, the first aluminum layer 220 forms a region defined by the first aluminum layer 220. The grain size is then characterized as small, e.g., 2 microns or less.

[0029]

[0036] In some embodiments, at 102, a first aluminum layer 220 may be deposited in a PVD chamber on a substrate 200 to form a first aluminum region 221 having a first grain size and a first temperature while the substrate is maintained on a heated workpiece support at a first temperature of 200 to 400° C. and a first pressure of less than 10 mTorr while atoms are sputtered from the aluminum sputter target by applying a first DC power of about 4 kW to 60 kW and a first AC target bias power of at least 600 W to the aluminum sputter target.

[0030]

[0037] In some embodiments, the reaction conditions are maintained for a duration sufficient to form a first layer of aluminum having a first grain size and, optionally, a second layer of aluminum having a second grain size larger than the first grain size. With reference to Figure 2C, an optional second aluminum layer 222 is shown adjacent to the first aluminum layer 220 on the first surface 204. In some embodiments, as the deposition of aluminum progresses, the grain size of the aluminum gradually increases through a transition or transition phase.

[0031]

[0038] In some embodiments, at 102, depositing a first aluminum layer 220 on the substrate 200 to form a first aluminum region 221 having a first grain size and a first temperature may be performed in a PVD chamber. Then, as shown in FIG. 2B, a first plurality of aluminum atoms 221 is deposited on the first surface 204 of the substrate 200 and the bottom surface 208 of the opening 202. The first plurality of aluminum atoms 221 may be deposited using the process conditions described above, such as a first temperature, a first pressure, a first AC or RF power, and a DC power to sputter the aluminum atoms 221 generally perpendicular to the substrate 200, as shown in FIG. 2B. In some embodiments, AC power may be applied to the substrate 200 (e.g., an electrode disposed below the substrate 200, such as in a substrate support) during deposition of the first plurality of aluminum atoms 221. The AC power (such as RF bias power) may be applied at a frequency ranging from about 0.5 to about 13.56 MHz and at a power of 1200 W or about 600 W to 1200 W. In some embodiments, the RF bias power may be applied at 0.5 to 3 kW, such as 1 kW, 1.25 kW, 2.5 kW, or 3 kW. In some embodiments, increasing the AC bias power promotes attraction of positive ions impinging on the substrate surface, inhibits coalescence, inhibits aluminum grain growth, and forms smaller Al grains in the first aluminum layer.

[0032]

[0039] In some embodiments, a first RF bias power and a second RF bias power (e.g., RF bias power) may be utilized simultaneously, and the first RF bias power may be used to control the ion energy adjacent to the substrate 200, and the second RF bias power may be used to control the distribution in the ion energy adjacent to the substrate 200.

[0033]

[0040] In some embodiments, at 102, the temperature for depositing the aluminum layer may be between 200 and 400 degrees Celsius, such as between 100 and 250 degrees Celsius. In some embodiments, at 102, a first aluminum layer 220 is formed to a predetermined thickness. In embodiments, the first aluminum layer 220 and first aluminum region 221 have a thickness of about 1-5 micrometers, such as 1 micrometer, or about 1.5 micrometers. In embodiments, after deposition of about 1.5 micrometers of aluminum, grain growth may accelerate.

[0034]

[0041] Referring back to FIG. 1 , in 104, in some embodiments, after forming a first aluminum layer on the substrate to form a first aluminum region 221 having a first grain size, the first aluminum region 221 on the substrate 200 is cooled to a second temperature at a rate sufficient to increase the first grain size to a second grain size. In some embodiments, the cooling includes delaying the cooling for a first duration. For example, after deposition, the process may pause for a duration such as 4 seconds to 120 seconds to cool the substrate and the deposited aluminum. In some embodiments, the first duration is about 5 to 120 seconds. In some embodiments, the cooling is performed at a cooling rate of 10 to 40 degrees Celsius per second, such as about 20 degrees Celsius per second. In some embodiments, the first temperature is 375 to 450 degrees Celsius and the second temperature is less than 100 degrees Celsius. In some embodiments, the cooling is performed by moving the substrate away from the heated surface. In some embodiments, cooling includes delaying transfer of the first aluminum region over the substrate to a rapid cool chamber. In some embodiments, cooling the first aluminum region over the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size further includes increasing a flow of gas adjacent a backside of the substrate to cool the substrate.

[0035]

[0042] In some embodiments, the temperature for cooling is less than the first temperature at 104. In some embodiments, the cooling reduces the temperature of the substrate from about 375 to 450 degrees Celsius to about 100 degrees Celsius.

[0036]

[0043] In some embodiments, following cooling, further aluminum material 250 can be deposited and formed to a predetermined thickness. In some embodiments, the aluminum material 250 (FIG. 2D) has a thickness of about 1-5 micrometers, e.g., 1 micrometer or 3 micrometers. In some embodiments, the further aluminum material is cooled according to the present disclosure. In some embodiments, the further aluminum material is subjected to delayed cooling according to the present disclosure.

[0037]

[0044] In some embodiments, after the aluminum material 250 is formed, the method 100 may end or the substrate 200 may continue to further processing. One example of further processing optionally includes annealing the substrate 200. In some embodiments, the annealing is characterized as ex situ. In some embodiments, the annealing may be performed at a temperature of about 500 to 700 degrees Celsius (e.g., 550 degrees Celsius) for about 10 minutes at a pressure of about 20 bar. In some embodiments, the annealing may be performed, for example, in an annealing chamber.

[0038]

[0045] Referring to FIG. 2D, in some embodiments, a second substrate 218 may be provided prior to performing steps 102-104 above. Thus, as shown in FIG. 2D, the second substrate 218 may be disposed adjacent to the second surface 206 of the substrate 200, with the opening 202 extending completely through the substrate 200, and the surface 216 of the second substrate 218 forming the bottom surface of the opening 202. Additionally, a device or conductive feature 234 may be disposed on the second substrate and exposed at the surface 216, where the device or conductive feature 234 is aligned with the opening 202. The first surface 204 of the substrate 200 may be further processed to remove deposited aluminum atoms. For example, as shown in FIG. 2D, chemical mechanical polishing techniques, etching, etc. may be used to remove deposited aluminum atoms from the first surface 204.

[0039]

[0046] 3 depicts a schematic cross-sectional view of a physical vapor deposition chamber (process chamber 300) according to some embodiments of the present disclosure. An example of a suitable PVD chamber includes the EXECTA™ AL PVD process chamber available from Applied Materials, Inc., Santa Clara, Calif. Other process chambers from Applied Materials, Inc. or other manufacturers may also benefit from the inventive apparatus disclosed herein.

[0040]

[0047] The process chamber 300 includes a substrate support pedestal 302 for receiving a substrate 304, such as a workpiece, thereon, and a sputtering source, such as a target 306. The substrate support pedestal 302 may be positioned within a grounded chamber wall 308. The chamber wall 308 may be a chamber wall (as shown) or a grounded shield (a grounded shield 340 is shown covering at least a portion of the process chamber 300 above the target 306; in some embodiments, the grounded shield 340 may extend below the target to surround the pedestal 302 as well).

[0041]

[0048] In some embodiments, the process chamber includes a power feed structure for coupling RF and DC energy to the target 306. The power feed structure is, for example, an apparatus for coupling RF and DC energy to a target or an assembly including a target, as described herein. A first end of the power feed structure may be coupled to an RF power source 318 and a DC power source 320, which may be utilized to provide RF and DC energy to the target 306, respectively. For example, the DC power source 320 may be utilized to apply a negative voltage or bias to the target 306. In some embodiments, the RF energy optionally provided by the RF power source 318 may be suitable for providing frequencies as described above, or the frequency may range from about 2 MHz to about 60 MHz, or non-limiting frequencies, for example, 2 MHz, 13.56 MHz, 27.12 MHz, or 60 MHz, may be used. In some embodiments, multiple (i.e., two or more) RF power sources may be optionally provided to provide RF energy at multiple of the above-mentioned frequencies. The power supply structure may be fabricated from a conductive material suitable for conducting RF and DC energy from the RF and DC power supplies 318 and 320. In some embodiments, the RF power supply 318 is omitted and the DC power supply 320 is configured to apply a negative voltage, or bias, to the target 306.

[0042]

[0049] In some embodiments, the feed structure may have a suitable length that facilitates a substantially uniform distribution of the respective RF and DC energies around the feed structure. For example, in some embodiments, the feed structure may have a length between about 1 and about 12 inches, or about 4 inches. In some embodiments, the body may have a length to inner diameter ratio of at least about 1:1. Providing a ratio of at least 1:1 or more provides a more uniform RF delivery from the feed structure (i.e., RF energy is more evenly distributed around the feed structure to approximate RF coupling to the true center point of the feed structure). The inner diameter of the feed structure may be as small as possible, for example, about 1 inch to about 6 inches, or about 4 inches in diameter. Reducing the inner diameter facilitates improving the length to inner diameter ratio without increasing the length of the feed structure.

[0043]

[0050] A second end of the feed structure may be coupled to a source distribution plate 322. The source distribution plate includes a hole 324 disposed through the source distribution plate 322 and aligned with the central opening of the feed structure. The source distribution plate 322 may be fabricated from a suitable conductive material to conduct RF and DC energy from the feed structure.

[0044]

[0051] The source distribution plate 322 may be coupled to the target 306 via a conductive member 325. The conductive member 125 may be a tubular member having a first end 326 coupled to a target-facing surface 328 of the source distribution plate 322 near the periphery of the source distribution plate 322. The conductive member 325 further includes a second end 330 coupled to a source distribution plate-facing surface 332 of the target 306 (or to a backing plate 346 of the target 306) near the periphery of the target 306.

[0045]

[0052] A cavity 334 may be defined by the inner facing walls of the conductive member 325, the target-facing surface 328 of the source distribution plate 322, and the source distribution plate-facing surface 332 of the target 306. The cavity 334 is fluidly coupled to the central opening 315 of the body via the holes 324 of the source distribution plate 322. The cavity 334 and the central opening 315 of the body may be utilized to at least partially house one or more portions of a rotatable magnetron assembly 336, as illustrated in FIG. 3 and described further below. In some embodiments, the cavity may be at least partially filled with a cooling fluid, such as water (H2O).

[0046]

[0053] A ground shield 340 may be provided to cover the outer surface of the lid of the process chamber 300. The ground shield 340 may be coupled to ground, for example, via a ground connection in the chamber body. The ground shield 340 has a central opening to allow a power feed structure to pass through the ground shield 340 and be coupled to the source distribution plate 322. The ground shield 340 may comprise any suitable conductive material, such as aluminum or copper. An insulating gap 339 is provided between the ground shield 340 and the outer surface of the source distribution plate 322, the conductive member 325, and the target 306 (and / or the backing plate 346) to prevent RF and DC energy from being routed directly to ground. The insulating gap may be filled with air or some other suitable dielectric material, such as ceramic or plastic.

[0047]

[0054] In some embodiments, a ground collar may be disposed around the body and lower portion of the feed structure. The ground collar is coupled to the ground shield 340 and may be an integral part of the ground shield 340 or may be a separate part coupled to the ground shield to provide grounding of the feed structure. The ground collar may be made of a suitable conductive material such as aluminum or copper. In some embodiments, a gap disposed between the inner diameter of the ground collar and the outer diameter of the body of the feed structure may be kept to a minimum and just sufficient to provide electrical isolation. The gap may be filled with an insulating material such as plastic or ceramic, or may be an air gap. The ground collar prevents crosstalk between the RF feed line (e.g., feed line 205 described below) and the body, thus improving plasma and process uniformity.

[0048]

[0055] An insulating plate 338 may be disposed between the source distribution plate 322 and the ground shield 340 to prevent RF and DC energy from being routed directly to ground. The insulating plate 338 has a central opening to allow a feed structure to pass through the insulating plate 338 and be coupled to the source distribution plate 322. The insulating plate 338 may comprise a suitable dielectric material, such as ceramic or plastic. Alternatively, an air gap may be provided in place of the insulating plate 338. In embodiments where an air gap is provided in place of the insulating plate, the ground shield 340 may have sufficient structural integrity to support any components placed on the ground shield 340.

[0049]

[0056] The target 306 may be supported on a grounded conductive aluminum adapter such as 342 via a dielectric isolator 344. The target 306 comprises a material to be deposited on the substrate 304 during sputtering, such as aluminum or an aluminum alloy. In some embodiments, a backing plate 346 may be coupled to the source distribution plate facing surface 332 of the target 306. The backing plate 346 may comprise a conductive material (such as aluminum) or the same material as the target, such that RF and DC power may be coupled to the target 306 through the backing plate 346. Alternatively, the backing plate 346 may be non-conductive and may include a conductive element (not shown), such as an electrical feedthrough, for coupling the source distribution plate facing surface 332 of the target 306 to the second end 330 of the conductive member 325. The backing plate 346 may be included, for example, to improve the structural stability of the target 306.

[0050]

[0057] The substrate support pedestal 302 has a material receiving surface opposite the major surface of the target 306 and supports a substrate 304 to be sputter coated in a planar position opposite the major surface of the target 306. The substrate support pedestal 302 may support the substrate 304 in a central region 348 of the process chamber 300. The central region 348 is defined as the region above the substrate support pedestal 302 during processing (e.g., between the target 306 and the substrate support pedestal 302 when in the processing position).

[0051]

[0058] In some embodiments, the substrate support pedestal 302 may be vertically movable via a bellows 350 coupled to a bottom chamber wall 352, allowing a substrate 304 to be transferred onto the substrate support pedestal 302 through a load lock valve (not shown) in a lower portion of the process chamber 300 and then lifted to a deposition or processing position. One or more process gases from a gas source 354 may be supplied into the lower portion of the process chamber 300 via a mass flow controller 356. An exhaust port 358 may be provided and coupled to a pump (not shown) via a valve 360 ​​to facilitate evacuating the interior of the process chamber 300 to maintain a desired pressure inside the process chamber 300.

[0052]

[0059] In some embodiments, the substrate pedestal includes an air passage 371 for providing a backside gas to the substrate 304. In some embodiments, the temperature of the substrate 304 is increased by closing the air passage 371 and restricting the flow of backside gas applied to the substrate 304.

[0053]

[0060] In some embodiments, the RF bias power supply 362 may be optionally coupled to the substrate pedestal 302 to induce a negative DC bias on the substrate 304. Additionally, in some embodiments, a negative DC self-bias may be generated on the substrate 304 during processing. For example, the RF power provided by the RF bias power supply 362 may range in frequency from about 2 MHz to about 60 MHz, where non-limiting frequencies such as 2 MHz, 13.56 MHz, or 60 MHz may be used. Additionally, a second RF bias power supply 363 may be coupled to the substrate support pedestal 302 and provide any of the frequencies discussed above for use alone or optionally with the RF bias power supply 362. In some embodiments, a tuning network 399 may be disposed between the RF bias power supply 363 and the substrate support pedestal. In some embodiments, a second tuning network 398 may be disposed between the RF power supply 362 and the substrate pedestal. In some embodiments, the second RF bias power supply 363 is configured to provide AC bias power to lower ion energy. As a result, the aluminum coalesces with a second layer of aluminum having a second grain size to increase the second grain size. In other applications, the substrate support pedestal 302 may be grounded or may be left electrically floating. For example, in applications where RF bias power is not desired, a capacitance adjuster 364 may be coupled to the substrate support pedestal to adjust the voltage on the substrate 304.

[0054]

[0061] The rotatable magnetron assembly 336 may be positioned proximate the backside (e.g., source distribution plate facing surface 332) of the target 306. The rotatable magnetron assembly 336 includes a plurality of magnets 366 supported by a base plate 368. The base plate 368 is connected to a rotation shaft 370 that coincides with the central axis of the process chamber 300 and the substrate 304. A motor 372 may be coupled to the top end of the rotation shaft 370 to drive the rotation of the magnetron assembly 336. The magnets 366 generate a magnetic field within the process chamber 300, generally parallel and proximate to the surface of the target 306, that traps electrons and increases the local plasma density, thereby increasing the sputtering rate. The magnets 366 generate an electromagnetic field around the top of the process chamber 300, and the magnets 366 are rotated to rotate the electromagnetic field that affects the plasma density of the process to more uniformly sputter the target 306. For example, the rotatable shaft 370 may rotate from about 0 to about 150 revolutions per minute.

[0055]

[0062] In some embodiments, the process chamber 300 may further include a process kit shield 374 coupled to a ridge 376 of the adapter 342. The adapter 342, in turn, is sealed and grounded to an aluminum chamber sidewall, such as the chamber wall 308. Generally, the process kit shield 374 extends downward along the wall of the adapter 342 and the chamber wall 308 below the top surface of the substrate support pedestal 302, and then back upward (forming a U-shaped portion 384 at its bottom) until it reaches the top surface of the substrate support pedestal 302. Alternatively, the lowest portion of the process kit shield need not be the U-shaped portion 384, but may have any suitable shape. A cover ring 386 rests on top of the upwardly extending lid 388 of the process kit shield 374 when the substrate support pedestal 302 is in the lower, loading position, but rests on the outer edge of the substrate support pedestal 302 when the substrate support pedestal 302 is in the upper, deposition position to protect the substrate support pedestal 302 from sputtering deposition. An additional deposition ring (not shown) may be used to shield the peripheral edge of the substrate 304 from deposition. Embodiments of the process kit shield are described below in accordance with this disclosure.

[0056]

[0063] In some embodiments, magnets 390 may be disposed about the process chamber 300 to selectively provide a magnetic field between the substrate support pedestal 302 and the target 306. For example, as shown in FIG. 3, the magnets 390 may be disposed about the outside of the chamber wall 308 in the area immediately above the substrate support pedestal 302 when in the processing position. In some embodiments, the magnets 390 may additionally or alternatively be disposed at other locations, such as next to the adapter 342. The magnets 390 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.

[0057]

[0064] A controller 310 may be provided and coupled to the various components of the process chamber 300 to control their operation. The controller 310 includes a central processing unit (CPU) 312, a memory 314, and support circuits 316. The controller 310 may control the process chamber 300 directly or through a computer (or controller) coupled to the specific process chamber and / or support system components. The controller 310 may be one of any form of general-purpose computer processor that may be used in an industrial environment to control various chambers and sub-processors. The memory or computer readable medium 434 of the controller 310 may be one or more of readily available memories such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, optical storage media (e.g., compact disk or digital video disk), flash drive, or any other form of digital storage, local or remote. The support circuits 316 are coupled to the CPU 312 to support the processor in a conventional manner. These circuits include caches, power supplies, clock circuits, input / output circuits and subsystems, etc. The methods of the present invention described herein may be stored in memory 314 as software routines that can be executed or called to control the operation of the process chamber 300 in the manner described herein. The software routines may also be stored and / or executed by a second CPU (not shown) located remotely from the hardware controlled by CPU 312.

[0058]

[0065] In some embodiments, a method is provided herein for depositing aluminum on a high aspect ratio feature formed on a substrate. The method advantageously provides good coverage of the surface of the high aspect ratio feature with aluminum by extending the period of grain growth after the aluminum is deposited. In some embodiments, the present disclosure provides a physical vapor deposition chamber including a reaction chamber configured to physically vapor deposit a first aluminum layer on a substrate to form a first aluminum region having a first grain size and a first temperature, and to cool the first aluminum region on the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size. In some embodiments, the reaction chamber is configured to provide a flow of gas adjacent a backside of the substrate to cool the substrate. In some embodiments, the cooling is performed by moving the substrate away from a heated surface.

[0059]

[0066] In some embodiments, the disclosure provides a computer readable medium having stored thereon instructions that, when executed, cause a physical vapor deposition reaction chamber to perform a method including depositing a first aluminum layer over a substrate to form a first aluminum region having a first grain size and a first temperature, and cooling the first aluminum region over the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size.

[0060]

[0067] 4, a method 400 is shown of performing physical vapor deposition in a reaction chamber on a substrate disposed on a workpiece support beneath an aluminum sputter target. In some embodiments, the method 400 includes, at 402, maintaining the substrate at a first temperature between 200 and 400 degrees Celsius. In some embodiments, at 404, the method 400 includes sputtering atoms from the aluminum sputter target by applying a first DC power of about 4 kW to 60 kW and a first AC target bias power of at least 600 W to the aluminum sputter target. In some embodiments, the AC target bias power is generated from the second RF power source 363.

[0061]

[0068] In some embodiments, the method 400 includes, at 406, maintaining the reaction conditions for a duration sufficient to form a first layer of aluminum having a first grain size. For example, in embodiments, a first region including a small grain size may be formed. In embodiments, the small grain size may average about 1.5 microns.

[0062]

[0069] In some embodiments, the method 400 includes, at 408, delaying cooling of the substrate for a first duration. In some embodiments, the first duration may be about 5 to 120 seconds, e.g., 20 seconds, 30 seconds, 40 seconds, etc. In some embodiments, the delaying includes delaying transferring the substrate including the first layer of aluminum to a rapid cool chamber.

[0063]

[0070] In some embodiments, the method 400 includes, at 410, cooling the first layer of aluminum to a second temperature. In some embodiments, the cooling is performed at a rate sufficient to increase the first grain size to a second grain size. In some embodiments, the cooling includes delaying the transfer of the substrate including the first layer of aluminum to a rapid cooling chamber. In some embodiments, the delaying of the transfer extends the amount of cooling time and / or controls the cooling in accordance with the present disclosure. In some embodiments, the cooling reduces the temperature to about 100 degrees Celsius, such as a temperature of 98 to 102 degrees Celsius. In some embodiments, the cooling in accordance with the present disclosure increases the grain size of the as-deposited aluminum by 3 to 40 percent, e.g., 3 to 25 percent, or 3 to 15 percent. In some embodiments, the second grain size is greater than 2.5 microns on average, or is 2 to 4 microns on average.

[0064]

[0071] In some embodiments, the present disclosure provides a method of performing physical vapor deposition in a reaction chamber to form an aluminum material on a substrate. The method includes depositing a first aluminum layer on a substrate to form a first aluminum region having a first grain size and a first temperature, and cooling the first aluminum region on the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size. In some embodiments, the method further includes delaying the cooling for a first duration. In some embodiments, the first duration is about 5 to 120 seconds. In some embodiments, the cooling is performed at a cooling rate of 10 to 40 degrees Celsius per second. In some embodiments, the first temperature is 375 to 450 degrees Celsius and the second temperature is less than 100 degrees Celsius. In some embodiments, depositing the first aluminum layer on the substrate to form a first aluminum region having a first grain size and a first temperature is performed on a heated surface, and the cooling is performed by moving the substrate away from the heated surface. In some embodiments, cooling the first aluminum region to a second temperature at a rate sufficient to increase the first grain size to a second grain size includes delaying the transfer of the first aluminum region on the substrate to a rapid cooling chamber. In some embodiments, depositing the first aluminum layer is performed at a first DC power amount of 4 kW to 60 kW. In some embodiments, the first aluminum layer is deposited by exposing the substrate to aluminum and argon in a physical vapor deposition process. In some embodiments, the aluminum material is formed using a physical vapor deposition process that includes an aluminum target. In some embodiments, cooling the first aluminum region on the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size further includes increasing a flow of gas adjacent a backside of the substrate to cool the substrate.

[0065]

[0072] In some embodiments, the present disclosure relates to a method of performing physical vapor deposition in a reaction chamber on a substrate disposed on a workpiece support under an aluminum sputter target, the method comprising: maintaining the substrate on a heated workpiece support at a first temperature of 200° C. to 400° C. and a first pressure of less than 10 mTorr; sputtering atoms from the aluminum sputter target by applying a first DC power of about 4 kW to 60 kW and a first AC target bias power of at least 600 W to the aluminum sputter target; maintaining the reaction conditions for a duration sufficient to form a first layer of aluminum having a first grain size; delaying cooling of the substrate for the first duration; and cooling the first layer of aluminum to a second temperature at a rate sufficient to increase the first grain size to a second grain size. In some embodiments, cooling the first layer of aluminum to the second temperature comprises providing a flow of gas adjacent to a backside of the substrate to cool the substrate. In some embodiments, the cooling is performed at a cooling rate of 10 to 40 degrees Celsius per second. In some embodiments, delaying cooling further comprises moving the substrate away from the workpiece support. In some embodiments, delaying further comprises moving the substrate away from the workpiece support by contacting the substrate with one or more lift pins. In some embodiments, delaying cooling further comprises delaying transferring the substrate to a rapid cool chamber.

[0066]

[0073] 5, a schematic cross-sectional view of a physical vapor deposition (PVD) chamber 500 according to some embodiments of the present disclosure is shown. In some embodiments, a wafer or substrate 501 is positioned above a heated surface 505 of an electrostatic chuck 506. In some embodiments, the substrate 501 is cooled by moving one or more lift pins 510 to lift the substrate 501 away from the heated surface 505 of the electrostatic chuck 506. Thermal radiation (indicated by arrow 520) leaving the electrostatic chuck 506 contacts the substrate 501 in a controlled manner and cools the substrate in accordance with the present disclosure. A gap (indicated by arrow 530) is shown between the substrate 501 and the heated surface 505 of the electrostatic chuck 506. Gas can flow behind the substrate 501 or wafer in a controlled manner in accordance with the present disclosure to further cool the substrate 501.

[0067]

[0074] Figure 6 depicts a flow chart of another method 600 for processing a substrate according to some embodiments of the present disclosure. Figure 6 shows a degassing chamber 601, a process chamber for deposition 602, a cool-down chamber 603, a transfer chamber 604, and a FOUP 605 in an order suitable for use in the method of the present disclosure. In some embodiments, the cool-down chamber 603 is moved to a position directly adjacent to the FOUP 605 to facilitate delayed cooling according to the present disclosure. In some embodiments, the method 600 includes delayed cooling of the as-deposited aluminum-containing substrate.

[0068]

[0075] In some embodiments, the method of the present disclosure is applied to a process sequence for deposition of aluminum. In that case, the deposition and post-deposition process sequences each promote aluminum grain growth. For example, cooling according to the present disclosure can be combined with an aluminum deposition process sequence. In that case, the deposition process sequence promotes or forms aluminum with an increased grain size. In one process sequence, the method may include preheating the substrate, such as heating the substrate to a temperature of 200 or 400 degrees Celsius, for example, about 200 degrees Celsius. In some embodiments, preheating the substrate may include using a pedestal heater to warm the substrate to a predetermined temperature near the center of the substrate, along the edge of the substrate, or near the center of the substrate and along the edge of the substrate. Depending on the needs of the process, the center of the substrate and the edge of the substrate may each have a predetermined temperature, which may be the same or different. In some embodiments, the temperature at the edge of the substrate is 20 to 50 degrees warmer than the center of the substrate. In some embodiments, the process sequence may continue by depositing a seed layer of aluminum. In that case, the seed layer includes a grain size that is uniformly distributed across the substrate. For example, in some embodiments, plasma energy is utilized to heat the substrate. In some embodiments, the only heat source is the plasma and no heat sink is provided. The plasma heating transfers heat evenly within the substrate and heats the substrate evenly to a preselected temperature. In some embodiments, plasma heating according to the present disclosure forms an aluminum layer composition with a uniform center / edge grain size. In some embodiments, the seed layer thickness is preselected to grow seed grains at both the center of the substrate and the edge of the substrate to a mature stage. In some embodiments, the process sequence may continue with a high rate growth of aluminum by contacting the substrate with a backside gas and reducing the deposition cooling cycle. In some embodiments, the backside gas is directed toward the center of the substrate to cool the wafer center. In some embodiments, the backside gas cools the wafer while avoiding whisker formation or non-uniform grain growth.In some embodiments, the process sequence continues with the cooling process of the present disclosure as described above. Thus, delaying the aluminum deposition and rapid cooling after deposition may prolong the grain growth of the aluminum. In some embodiments, the grain size or average grain size of the as-deposited aluminum is about 1.5 micrometers, which may be increased to 2-4 micrometers, such as 2.0, 2.4, 2.6, 2.8, 3.0, 3.2, and 3.8 micrometers, using the process of the present disclosure.

[0069]

[0076] 7, a schematic cross-sectional view of a physical vapor deposition (PVD) chamber 700 according to some embodiments of the present disclosure is shown. In some embodiments, a wafer or substrate 701 is placed above a surface 705 of an electrostatic chuck 706. In some embodiments, the substrate 701 is configured to deposit aluminum according to embodiments of the present disclosure. A plasma (indicated by arrow 721) contacts and heats the substrate 701 in a controlled manner according to the present disclosure. A gap (indicated by arrow 730) is shown between the substrate 701 and the surface 705 of the electrostatic chuck 706. Gas can flow behind the substrate 701 or wafer in a controlled manner according to the present disclosure to further cool the substrate 701. In some embodiments, a dual zone heater 750 is provided and configured to heat the substrate to a predetermined temperature for aluminum deposition. In some embodiments, the dual zone heater 750 is configured to heat the outer edge of the substrate to a predetermined temperature that may be the same or different than the predetermined temperature of the center of the substrate.

[0070]

[0077] FIG. 8 depicts a flow chart of a method 800 for processing a substrate according to some embodiments of the present disclosure. FIG. 8 shows a degassing chamber 801, a process chamber for deposition 802, a cooling chamber 803, a transfer chamber 804, a cooling chamber 805, and a FOUP 806 in an order suitable for use in the method of the present disclosure. In some embodiments, the cooling chamber 803 is moved to a position directly adjacent to the FOUP 806 to facilitate delayed cooling according to the present disclosure. In some embodiments, the method 800 includes delayed cooling of the substrate including as-deposited aluminum. In some embodiments, the method 800 is suitable for maximizing the aluminum grain size and enabling grain boundary relaxation to avoid hillock formation.

[0071]

[0078] In some embodiments, the present disclosure relates to a method for performing physical vapor deposition in a reaction chamber on a substrate disposed on a workpiece support under an aluminum sputter target, the method including optionally preheating the substrate to a first temperature, contacting the substrate with a plasma sufficient to maintain the substrate at a first temperature of 200° C. to 400° C., applying a first DC power of about 20 kW to 60 kW to the aluminum sputter target to sputter atoms from the aluminum sputter target to form a first seed layer of aluminum having a uniformly distributed grain size, contacting the substrate with a backside gas to cool the substrate while depositing the aluminum to a predetermined thickness, and cooling the aluminum on the substrate to a second temperature to increase the first grain size to a second grain size. In some embodiments, the method is suitable for avoiding randomized grain orientation and aluminum pad anomalies. In some embodiments, the plasma provides energy for grain growth during deposition, and the cooling or delayed rapid cooling according to the present disclosure enhances grain growth after deposition. In embodiments, after deposition, energy is homogenized across the substrate to reduce center / edge grain size variations and allow grain boundary relaxation, for example by slow cooling.

[0072]

[0079] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof.

Claims

1. 1. A method of forming an aluminum material on a substrate disposed on a workpiece support by performing physical vapor deposition in a reaction chamber, the method comprising: depositing a first aluminum layer over a substrate to form a first aluminum region having a first grain size and a first temperature; cooling the first aluminum region over a substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size.

2. The method of claim 1 , further comprising delaying the cooling for a first duration.

3. The method of claim 2 , wherein the first duration is from about 5 seconds to 120 seconds.

4. The method of claim 1 , wherein the cooling is performed at a cooling rate of 10 to 40 degrees Celsius per second.

5. 2. The method of claim 1, wherein the first temperature is between 375 and 450 degrees Celsius and the second temperature is less than 100 degrees Celsius.

6. 2. The method of claim 1, wherein depositing a first aluminum layer over a substrate to form a first aluminum region having a first grain size and a first temperature is performed over a heated surface, and cooling is performed by moving the substrate away from the heated surface.

7. 2. The method of claim 1 , wherein cooling the first aluminum region to a second temperature at a rate sufficient to increase the first grain size to a second grain size further comprises delaying transport of the first aluminum region over a substrate to a rapid cool chamber.

8. 8. The method of claim 1, wherein depositing the first aluminum layer is performed with a first DC power in an amount of from 4 kW to 60 kW.

9. 8. The method of claim 1, wherein the first aluminum layer is deposited by exposing the substrate to aluminum and argon in a physical vapor deposition process.

10. 8. The method of any one of claims 1 to 7, wherein the aluminum material is formed using a physical vapor deposition process including an aluminum target.

11. 8. The method of claim 1, wherein cooling the first aluminum region over the substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size further comprises increasing a flow of gas adjacent a backside of the substrate to cool the substrate.

12. Depositing the first aluminum layer further comprises: maintaining the substrate on a heated workpiece support at the first temperature of 200° C. to 400° C. and a first pressure of less than 10 mTorr; sputtering atoms from an aluminum sputter target by applying a first DC power of about 4 kW to 60 kW and a first AC target bias power of at least 600 W to the aluminum sputter target; and maintaining the first temperature, the first pressure, the first DC power, and the first AC target bias power for a duration sufficient to form the first aluminum layer having the first grain size; Cooling the first aluminum region includes: cooling the first aluminum layer to the second temperature to increase the first grain size to the second grain size; The method of claim 1 , further comprising delaying cooling the substrate for a first duration.

13. 13. The method of claim 12, wherein cooling the first aluminum layer to the second temperature comprises providing a flow of gas adjacent a backside of the substrate to cool the substrate.

14. 13. The method of claim 12, wherein the cooling is performed at a cooling rate of 10 to 40 degrees Celsius per second.

15. The method of claim 12 , wherein delaying the cooling further comprises moving the substrate away from the workpiece support.

16. The method of claim 15 , wherein delaying the cooling further comprises moving the substrate away from the workpiece support by contacting the substrate with one or more lift pins.

17. 15. The method of claim 12, wherein the substrate is cooled in a rapid cool chamber, and wherein delaying the cooling comprises delaying transfer of the substrate to the rapid cool chamber.

18. 15. A computer readable medium having stored thereon instructions which, when executed by a controller of a reaction chamber, cause a computer to perform a method of performing physical vapor deposition in the reaction chamber to form an aluminum material on a substrate, the method being described in any one of claims 1 to 7 or 12 to 14.

19. 20. The computer-readable medium of claim 18, wherein cooling the first aluminum region over a substrate to a second temperature at a rate sufficient to increase the first grain size to a second grain size further comprises increasing a flow of gas adjacent a backside of the substrate to cool the substrate.

20. The delaying of cooling may further comprise: moving the substrate away from the workpiece support; moving the substrate away from the workpiece support by contacting the substrate with one or more lift pins; or The computer-readable medium of claim 18 , comprising delaying transport of the substrate to a rapid cool chamber.

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