Method and apparatus for processing substrates using improved shielding configurations

Abstract

Provided herein are methods and apparatus for processing substrates using improved shield configurations. For example, a process kit for use in a physical vapor deposition chamber includes a shield including an inner wall having an innermost diameter configured to surround a target when positioned in the physical vapor deposition chamber, the ratio of the surface area of ​​the shield to the planar area of ​​the inner diameter being from about 3 to about 10.

Description

[Technical Field]

[0001] TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate generally to substrate processing methods and apparatus, and more particularly to substrate processing methods and apparatus using improved shielding configurations. [Background technology]

[0002]

[0002] The magnitude of the target self-bias affects the sputtering rate of the target and anode (shield, wafer, etc.) materials. Generally, increasing the negative target self-bias requires increasing the anode area by using an extremely wide chamber body. However, such an approach can increase the footprint of the PVD chamber. Summary of the Invention

[0003]

[0003] Provided herein are methods and apparatus for processing substrates using improved shield configurations. In some embodiments, a process kit for use in a physical vapor deposition chamber includes a shield including an inner wall having an innermost diameter configured to surround a target when positioned in the physical vapor deposition chamber, wherein the ratio of the surface area of ​​the shield to the planar area of ​​the inner diameter is from about 3 to about 10.

[0004]

[0004] According to at least some embodiments, a substrate processing apparatus includes a chamber body having a substrate support disposed therein, a target coupled to the chamber body opposite the substrate support, an RF power source for forming a plasma within the chamber body, and a shield including an inner wall having an innermost diameter configured to surround the target when disposed in a physical vapor deposition chamber, wherein the ratio of the surface area of ​​the shield to the planar area of ​​the inner diameter is from about 3 to about 10.

[0005]

[0005] According to at least some embodiments, a process kit for use in a physical vapor deposition chamber includes a shield including an inner wall having an innermost diameter configured to surround a target when placed in the physical vapor deposition chamber, the inner wall including a plurality of alternating curvatures extending from a top downward, outward, downward, inward, and downward in approximately 90° increments, the plurality of alternating curvatures collectively forming a generally C-shape between the alternating curvatures, and one of a plurality of spaced concentric walls extending upward from a bottom of the shield to define a plurality of vertical wells, wherein the ratio of the surface area of ​​the shield to the planar area of ​​the inner diameter is from about 3 to about 10.

[0006]

[0006] Other further embodiments of the present disclosure are described below.

[0007]

[0007] The embodiments of the present disclosure 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, the accompanying drawings merely illustrate typical embodiments of the present disclosure and therefore should not be considered limiting in scope, as the present disclosure may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a process chamber according to some embodiments of the present disclosure. [Figure 2] 1 is a cross-sectional view of a shield and surrounding structure according to some embodiments of the present disclosure. [Figure 3] 1 is a cross-sectional view of a shield and surrounding structure according to some embodiments of the present disclosure. [Figure 4] FIG. 4 is an enlarged view showing an area of ​​detail of FIG. 3 according to some embodiments of the present disclosure. [Figure 5] 1 is a cross-sectional view of a shield and surrounding structure according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0013] To facilitate understanding, the same reference numerals have been used, wherever possible, to designate identical elements common to the drawings. The drawings are not drawn to scale and may be simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0010]

[0014] Methods and apparatus for improving physical vapor deposition (PVD) processing equipment are provided herein. The PVD process may advantageously be a high-density plasma PVD process, as described below. In at least some embodiments of the present disclosure, the improved methods and apparatus provide a grounded shield for a PVD processing apparatus that advantageously reduces the potential difference to the grounded shield while maintaining target-to-substrate spacing, thereby reducing or eliminating resputtering of the grounded shield to facilitate PVD processing. For example, the shield may include an inner wall having an innermost diameter configured to surround the target when positioned in the PVD chamber. The ratio of the surface area of ​​the shield to the planar area of ​​the inner diameter is from about 3 to about 10.

[0011]

[0015] 1 is a schematic cross-sectional view of a process chamber 100 (e.g., substrate processing apparatus) according to some embodiments of the present disclosure. The particular configuration of the PVD chamber is exemplary, and PVD chambers having other configurations may benefit from modification in accordance with the teachings provided herein. Examples of suitable PVD chambers include any of the lines of PVD processing chambers commercially available from Applied Materials, Inc. of Santa Clara, California. Other processing chambers from Applied Materials, Inc. or other manufacturers may also benefit from the inventive apparatus disclosed herein.

[0012]

[0016] In some embodiments of the present disclosure, a process chamber 100 includes a chamber lid 101 disposed on and removable from a chamber body 104. The chamber lid 101 generally includes a target assembly 102 and a grounding assembly 103. The chamber body 104 includes a substrate support 106 for receiving a substrate 108 thereon. The substrate support 106 is configured to support the substrate such that the center of the substrate is aligned with a central axis 186 of the process chamber 100. The substrate support 106 may be located within a lower grounded enclosure wall 110, which may be a wall of the chamber body 104. The lower grounded enclosure wall 110 may be electrically coupled to the grounding assembly 103 of the chamber lid 101 so that an RF return path is provided to an RF power source 182 disposed above the chamber lid 101. Alternatively, other RF return paths are possible, such as from the substrate support 106 through a process kit shield (e.g., a ground shield (e.g., anode)) and finally back to the ground assembly 103 on the chamber lid 101. The RF power supply 182 may supply RF energy to the target assembly 102, as described below.

[0013]

[0017] The substrate support 106 has a material-receiving surface facing a major surface of the target 114 (e.g., a cathode facing the substrate support) and supports a substrate 108 to be sputter-coated with material ejected from the target 114 in a planar position facing the major surface of the target 114. The substrate support 106 may include a dielectric member 105 having a substrate processing surface 109 for supporting the substrate 108 thereon. In some embodiments, the substrate support 106 may include one or more conductive members 107 disposed below the dielectric member 105. For example, the dielectric member 105 and the one or more conductive members 107 may be part of an electrostatic chuck, RF electrodes, etc. that may be used for chucking or supplying RF power to the substrate support 106.

[0014]

[0018] The substrate support 106 may support the substrate 108 in a first region 120 of the chamber body 104. The first region 120 is a portion of the interior region of the chamber body 104 used for processing the substrate 108 and may be separated from other portions of the interior region (e.g., non-processing regions) during processing of the substrate 108 (e.g., via a shield 138). The first region 120 is defined as the region above the substrate support 106 during processing (e.g., between the target 114 and the substrate support 106 when in the processing position).

[0015]

[0019] In some embodiments, the substrate support 106 may be vertically movable so that the substrate 108 can be transferred onto the substrate support 106 through an opening (e.g., a slit valve, not shown) in the lower portion of the chamber body 104 and then raised to a processing position. A bellows 122 connected to a bottom chamber wall 124 may be provided to maintain separation between the interior region of the chamber body 104 and the atmosphere outside the chamber body 104. One or more gases may be supplied into the lower portion of the chamber body 104 from a gas source 126 through a mass flow controller 128. An exhaust port 130 may be provided and coupled to a pump (not shown) via a valve 132 to facilitate evacuating the interior of the chamber body 104 and maintaining the interior of the chamber body 104 at a desired pressure.

[0016]

[0020] An RF bias power supply 134 may be coupled to the substrate support 106 to induce a negative DC bias on the substrate 108. Additionally, in some embodiments, a negative DC self-bias may be formed on the substrate 108 during processing. In some embodiments, the RF energy supplied by the RF bias power supply 134 may be at a frequency ranging from about 2 MHz to about 60 MHz, with non-limiting frequencies such as 2 MHz, 13.56 MHz, or 60 MHz being used. In other applications, the substrate support 106 may be grounded or may be left electrically floating. Alternatively or additionally, in applications where RF bias power is undesirable, a capacitance adjuster 136 may be coupled to the substrate support 106 to adjust the voltage on the substrate 108.

[0017]

[0021] The shield 138 (e.g., a grounded process kit shield) may be made of at least one of an aluminum alloy and stainless steel and surrounds the processing region, i.e., first region, of the chamber body 104 to protect other chamber components from processing damage and / or contamination. In some embodiments, the shield 138 may be coupled to a ledge 140 of the upper grounded enclosure wall 116 of the chamber body 104. In other embodiments, and as shown in FIG. 1 , the shield 138 may be coupled to the chamber lid 101 via, for example, a retaining ring (not shown).

[0018]

[0022] The shield 138 includes an inner wall 143 disposed between the target 114 and the substrate support 106. In at least some embodiments, the inner wall 143 has an innermost diameter configured to surround the target 114 when disposed in the process chamber 100. In at least some embodiments, the ratio of the surface area of ​​the shield 138 to the planar area of ​​the inner diameter is about 3 to about 10, as described in more detail below. The height of the shield 138 depends on the substrate distance 185 between the target 114 and the substrate 108. The substrate distance 185 between the target 114 and the substrate 108, and the corresponding height of the shield 138, are scaled based on the diameter of the substrate 108. In some embodiments, the ratio of the diameter of the target 114 to the diameter of the substrate is about 1.4. For example, a process chamber for processing 300 mm substrates may have a target 114 with a diameter of about 419 mm, or in some embodiments, a process chamber for processing 450 mm substrates may have a target 114 with a diameter of about 625 mm. In some embodiments, the ratio of the diameter of the target 114 to the height of the shield 138 is about 4.1 to about 4.3, or in some embodiments, about 4.2. For example, in some embodiments of a process chamber for processing 300 mm substrates, the target 114 may have a diameter of about 419 mm and the shield 138 may have a height of about 100 mm, or in some embodiments of a process chamber for processing 450 mm substrates, the target 114 may have a diameter of about 625 mm and the shield 138 may have a height of about 150 mm. Other diameters and heights can be used to achieve the desired ratio. In process chambers having the above ratios, the substrate distance 185 between the target 114 and the substrate 108 is about 50.8 mm to about 152.4 mm for 300 mm substrates or about 101.6 mm to about 203.2 mm for 450 mm substrates. Process chambers having the above configurations are referred to herein as “short throw” process chambers.

[0019]

[0023] Short-focus process chambers advantageously provide enhanced deposition rates over process chambers with longer target-to-substrate distances 185. For example, in some processes, conventional process chambers with longer target-to-substrate distances 185 provide deposition rates of about 1 to about 2 angstroms / second. By comparison, similar processes in short-focus process chambers can achieve deposition rates of about 5 to about 10 angstroms / second while maintaining high ionization levels. In some embodiments, process chambers according to embodiments of the present disclosure can provide deposition rates of about 10 angstroms / second. Such high ionization levels over short intervals can be achieved by providing high pressures, for example, from about 60 mTorr to about 140 mTorr, and very high drive frequencies, for example, from about 27 MHz to about 162 MHz, including readily available frequencies such as 27.12, 40.68, 60, 81.36, 100, 122, or 162.72 MHz.

[0020]

[0024] Furthermore, electrons have higher mobility than ions, and during each half-cycle, both electrodes (e.g., the cathode or power electrode and the anode or ground electrode) rapidly acquire electrons until the electrodes can no longer attract electrons due to repulsion from the accumulated electrons. During the negative half-cycle, both electrodes attract positive ions, but because the ions have lower mobility, the electrodes do not neutralize all of the electrons, achieving a net negative bias for the plasma.

[0021]

[0025] The inventors have found that if the areas of both electrodes (cathode (target) and anode (shield, wafer, deposition ring, cover ring, etc.)) are similar, ions generated in the plasma will be attracted toward both electrodes at equal rates during each negative half-cycle, resulting in equal rates of material being sputtered from both electrodes. However, in RF sputter deposition, it is typically preferable for the target area to be smaller than the anode area (shield, wafer, deposition ring, cover ring, etc.) (e.g., to facilitate more deposition and less etching on the anode side), resulting in a larger magnitude of negative bias and a larger electric field accelerating ions toward the target. Thus, depending on the area of ​​the target (cathode) relative to the shield (anode), deposition from the target (sputter deposition) or etching of the anode (wafer, shield, deposition ring, etc.) (re-sputtering) will occur.

[0022]

[0026] Resputtering of the shield 138 causes undesirable contamination within the process chamber 100. Resputtering of the shield 138 is a result of high voltage on the shield 138. The amount of voltage developed on the target 114 (e.g., cathode or power electrode) and the grounded shield 138 (e.g., anode or ground electrode) depends on the ratio of the surface area of ​​the shield 138 to the surface area of ​​the target 114, with larger voltages developed on smaller electrodes. Sometimes, the surface area of ​​the target 114 may be larger than the surface area of ​​the shield 138, resulting in larger voltages on the shield 138 and thus undesirable resputtering of the shield 138. For example, in some embodiments of a process chamber for processing 300 mm substrates, the target may be approximately 419 mm in diameter and approximately 138 mm in height. 2 and the shield 138 may have a height of about 100 mm and a corresponding surface area of ​​about 132 mm. 2 or in some embodiments for a process chamber for processing a 450 mm substrate, the target may have a diameter of about 625 mm and a corresponding surface area of ​​about 307 mm. 2and the shield 138 may have a height of about 150 mm and a corresponding surface area of ​​about 295 mm. 2 The inventors have observed that in some process chamber embodiments in which the ratio of the surface area of ​​the shield 138 to the surface area of ​​the target 114 is less than 1, a greater voltage is applied to the shield 138, resulting in undesirable resputtering of the shield 138. Therefore, to advantageously minimize or prevent resputtering of the shield 138, the inventors have observed that the surface area of ​​the shield 138 should be greater than the surface area of ​​the target 114. For example, the inventors have observed that a ratio of the surface area of ​​the shield 138 to the surface area of ​​the target 114 of about 3 to about 10 advantageously minimizes or prevents resputtering of the shield 138.

[0023]

[0027] Additionally, the inventors have observed that a ratio of the surface area of ​​the shield 138 to the surface area of ​​the target 114 of about 3 to about 10 advantageously results in a relatively high negative self-bias at the target 114. For example, a relatively high negative self-bias at the target 114 attracts more positive plasma ions (e.g., argon ions) toward the target 114 during operation, resulting in increased sputtering of the target and reduced re-sputtering (e.g., etching) of the shield 138, deposition ring (not shown), substrate 108, or other components.

[0024]

[0028] However, the surface area of ​​the shield 138 cannot be increased by simply increasing the height of the shield 138 due to the desired ratio of the diameter of the target 114 to the height of the shield 138, as described above. The inventors have observed that in some embodiments of a process chamber having the processing conditions described above (e.g., the process pressure and RF frequency used), the ratio of the surface area of ​​the shield 138 to the height of the shield 138 must be about 2 to about 3 to advantageously minimize or prevent resputtering of the shield 138. Furthermore, due to physical constraints in the size of the process chamber, the diameter of the shield 138 cannot be increased sufficiently to increase the surface area of ​​the shield 138 and prevent resputtering of the shield 138. For example, increasing the diameter of the shield 138 by 25.4 mm increases the surface area by only 6%, which is insufficient to prevent resputtering of the shield 138.

[0025]

[0029] Thus, a larger anode area is achieved by providing a shield with a wavy configuration (with or without fins), thus providing a geometry that enables deposition of highly insulating dielectric targets by increasing the negative self-bias on the target. Accordingly, in some embodiments, as shown in FIG. 2 , to achieve a desired ratio of shield surface area to target surface area, a shield 200 configured for use with process chamber 100 includes an inner wall 203 having an innermost diameter D1 configured to surround the target when placed in the physical vapor deposition chamber. For example, the innermost diameter D1 can be larger than the diameter of the target. In at least some embodiments, the ratio of the shield surface area to the inner diameter planar area is from about 3 to about 10 (e.g., anode-to-cathode ratio).

[0026]

[0030] For example, in at least some embodiments, the interior wall 203 includes a plurality of alternating bends 208 extending from a top portion downward, outward, downward, inward, and downward in approximately 90° increments, thus forming a generally C-shape between the alternating bends 208. The alternating bends 208 form vertical square waves with rounded transitions when viewed along a cross section of two consecutive bends. In at least some embodiments, the alternating bends 208 are symmetrical with respect to one another. That is, each of the generally C-shaped portions has the same dimensions. Alternatively, in at least some embodiments, the alternating bends 208 are asymmetrical with respect to one another. That is, each of the generally C-shaped portions has different dimensions; for example, an inward C-shape may extend further inward than an outward C-shape extends outward, or vice versa.

[0027]

[0031] The inner wall 203 includes a bottom region 210. The bottom region 210 may contribute to the overall area of ​​the shield 200. For example, the bottom region 210 may contribute approximately 50 in 2 In at least some embodiments, a plurality of concentric vertical fins 300 are supported on or near the bottom region 210 (FIGS. 3 and 4). The plurality of concentric vertical fins 300 are connected to one another such that successive concentric vertical fins generally form a shape when viewed along a cross section of two successive concentric vertical fins (FIG. 4). The plurality of concentric vertical fins 300 are configured to increase the overall area of ​​the shield 200. In at least some embodiments, the plurality of concentric vertical fins 300 are spaced from one another by about 0.15 inches to about 0.2 inches, and in at least some embodiments, the plurality of concentric vertical fins 300 are spaced from one another by about 0.175 inches.

[0028]

[0032] The multiple concentric vertical fins 300 may have a variety of dimensions, depending on, for example, the desired overall area of ​​the shield. For example, the multiple concentric vertical fins 300 may have a height (e.g., 0.50 inches to about 1.10 inches) that is approximately equal throughout the C-shape between alternating curves, as shown in FIG. 4 . In at least some embodiments, for example, the multiple concentric vertical fins 300 may each have a height of about 0.70 inches to about 1.10 inches. For example, the innermost concentric vertical fin 302 may have a recess 314 (e.g., a portion closer to the substrate processing surface 109) having a height of about 1.05 inches and a protrusion 316 (e.g., a portion further from the substrate processing surface 109) having a height of about 1.00 inches. The height of the recess 314 is slightly greater than the height of the protrusion 316 because the recess 314 defines the outer side of the vertical fin and the protrusion 316 defines the inner side of the vertical fin. The inner portion 316 is positioned opposite the outer portion of the concentric vertical fin 304, which also has a height of approximately 1.00 inches, thus forming a well 318 having a depth of approximately 1.00 inches (e.g., the depth of the well is defined by the recess / protrusion that defines the well). The recess / protrusions of the remaining concentric vertical fins may form similar wells therebetween. For example, the protrusions of the concentric vertical fin 304 may be positioned opposite the recesses of the concentric vertical fin 306, each having a height of approximately 1.00 inches, thereby forming the well 318 having a depth of approximately 1.00 inches.

[0029]

[0033] In embodiments, the wells formed between each of the concentric vertical fins 300 may have the same depth or different depths. For example, in at least some embodiments, the convex portions of the concentric vertical fins 306 disposed opposite the concave outer portions of the concentric vertical fins 308 may each have a height of approximately 0.70 inches, thus forming wells 318 (e.g., intermediate wells) having a depth of approximately 0.70 inches. In the illustrated embodiment, the convex portions of the concentric vertical fins 310 and the concave portions of the concentric vertical fins 308 may form wells similar to the wells formed between the convex portions 316 and the concave portions of the concentric vertical fins 304. Furthermore, the concave portions of the outermost concentric vertical fins 312 may form wells between the convex portions of the concentric vertical fins 310 similar to the wells formed between the convex portions 316 and the concave portions of the concentric vertical fins 304.

[0030]

[0034] Each of the plurality of concentric vertical fins 300 may have a thickness of about 0.04 inches to about 0.06 inches, and each of the plurality of concentric vertical fins 300 may have the same thickness or different thicknesses. For example, in at least some embodiments, the innermost concentric vertical fin 302 and the outermost concentric vertical fin 312 may have a thickness of about 0.04 inches, and the concentric vertical fins 304 to 310 disposed between the innermost concentric vertical fin 302 and the outermost concentric vertical fin 312 may have a thickness of about 0.06 inches.

[0031]

[0035] The plurality of concentric vertical fins 300 may be configured to couple to a side (e.g., a cover ring) that rests on the periphery of the substrate support 106 using one or more suitable coupling devices, such as screws, bolts, nuts, etc. Alternatively or additionally, the plurality of concentric vertical fins 300 may be configured to couple to (or rest on) the bottom region 210 using one or more suitable coupling devices, such as screws, bolts, nuts, etc.

[0032]

[0036] According to at least some embodiments, the anode to cathode ratio may vary based on the configuration of the shield 200 of Figures 2-4. For example, with respect to Figure 2, the shield 200 may be approximately 370 in2 Approximately 470 inches from 2 and the target 114 may have an effective anode area (e.g., planar area) of about 132 in 2 Approximately 135 inches from 2 (e.g., an anode-to-cathode ratio of about 2.74 to about 3.56). For example, in at least some embodiments, the shield 200 may have an effective cathode area (e.g., planar area) of about 370 in 2 Approximately 380 inches from 2 and the target 114 may have an effective anode area of ​​about 132 in 2 Approximately 135 inches from 2 The anode may have an effective anode area of ​​0.15 mm.

[0033]

[0037] Further, with reference to FIGS. 3 and 4, the combination of shield 200 and concentric vertical fins 300 is approximately 800 in. 2 Approximately 1350 inches from 2 , and the target 114 can provide an effective anode area of ​​about 132 in 2 Approximately 135 inches from 2 For example, in at least some embodiments, the shield 200 may have an effective anode area of ​​about 320 in 2 Approximately 420 inches from 2 , for example, a portion of the bottom region 210 of the shield 200 may provide an effective anode area of ​​approximately 480 in 2 Approximately 870 inches from 2 The shield 200 has a slightly smaller effective anode area because it is covered by concentric vertical fins 300 which may have an effective anode area of ​​about 800 in. 2 Approximately 1350 inches from 2 It can increase to.

[0034]

[0038] In at least some embodiments, the shield 500 can include an interior wall including a plurality of spaced-apart concentric walls 502 extending upward from the bottom of the shield 500 to define a plurality of vertical wells 504. In at least some embodiments, the height of each of the plurality of spaced-apart concentric walls 502 gradually decreases from the outermost wall 506 to the innermost wall 508. For example, the outermost wall 506 can have a height of about 3.75 inches to about 4.25 inches, and in at least some embodiments, can have a height of about 4.0 inches. The wall 510 can have a height of about 3.25 inches to about 3.75 inches, and in at least some embodiments, can have a height of about 3.5 inches. The wall 512 can have a height of about 2.75 inches to about 3.25 inches, and in at least some embodiments, can have a height of about 3.0 inches. Wall 514 may have a height of about 2.25 inches to about 2.75 inches, and in at least some embodiments, may have a height of about 2.5 inches. Innermost wall 508 may have a height of about 1.75 inches to about 2.25 inches, and in at least some embodiments, may have a height of about 2.0 inches.

[0035]

[0039] Similarly, outermost wall 506 may have a diameter of about 14.55 inches to about 15.05 inches, and in at least some embodiments, may have a diameter of about 14.80 inches. Wall 510 may have a diameter of about 13.35 inches to about 13.85 inches, and in at least some embodiments, may have a diameter of about 13.60 inches. Wall 512 may have a diameter of about 12.35 inches to about 13.85 inches, and in at least some embodiments, may have a diameter of about 12.60 inches. Wall 514 may have a diameter of about 11.55 inches to about 12.05 inches, and in at least some embodiments, may have a diameter of about 11.80 inches. Innermost wall 508 may have a diameter of about 10.75 inches to about 11.25 inches, and in at least some embodiments, may have a diameter of about 11.00 inches.

[0036]

[0040] Further, with reference to FIG. 5, the shield 500 and spaced apart concentric walls 502 are approximately 1075 in. 2 Approximately 1200 inches from 2 , and the target 114 can provide an effective anode area of ​​approximately 132 in 2 Approximately 135 inches from 2 For example, in at least some embodiments, the shield 500 may have an effective anode area of ​​about 1118 in 2 Approximately 1190 inches from 2 can provide an effective anode area of

[0037]

[0041] 1, the chamber lid 101 rests on a ledge 140 of the upper grounded enclosure wall 116. Similar to the lower grounded enclosure wall 110, the upper grounded enclosure wall 116 may provide a portion of the RF return path between the upper grounded enclosure wall 116 and the ground assembly 103 of the chamber lid 101. However, other RF return paths are possible, such as through the ground shield 138.

[0038]

[0042] As described above, the shield 138 may include one or more side walls that extend downwardly and are configured to surround the first region 120. The shield 138 fits along but is spaced from the walls of the upper ground enclosure wall 116 and the lower ground enclosure wall 110, extending downwardly to below the top surface of the substrate support 106 and then returning upwardly until it reaches the top surface of the substrate support 106 (e.g., forming a U-shaped portion at the bottom of the shield 138).

[0039]

[0043] The first ring 148 (e.g., a cover ring) rests on top of the U-shaped portion (e.g., a first position of the first ring 148) when the substrate support 106 is in its lower load position (not shown), but rests on the outer periphery of the substrate support 106 (e.g., a second position of the first ring 148) when the substrate support 106 is in its upper deposition position (as shown in FIG. 1), thereby protecting the substrate support 106 from sputter deposition.

[0040]

[0044] An additional dielectric ring 111 can be used to shield the periphery of the substrate 108 from deposition. For example, the additional dielectric ring 111 can be positioned around the periphery of the substrate support 106 adjacent the substrate processing surface 109, as shown in FIG.

[0041]

[0045] The first ring 148 may include protrusions extending from a lower surface of the first ring 148 on either side of a U-shaped portion extending upward inside the bottom of the shield 138. The innermost protrusion may be configured to mate with the substrate support 106 to align the first ring 148 with the shield 138 when the first ring 148 moves to a second position as the substrate support moves to a processing position. For example, a surface of the innermost protrusion facing the substrate support may be tapered, notched, etc. to rest within / on a corresponding surface of the substrate support 106 when the first ring 148 is in the second position.

[0042]

[0046] In some embodiments, magnets 152 may be disposed about the chamber body 104 to selectively provide a magnetic field between the substrate support 106 and the target 114. For example, as shown in FIG. 1 , the magnets 152 may be disposed about the outside of the enclosure wall 110 in the region directly above the substrate support 106 when in the processing position. In some embodiments, the magnets 152 may additionally or alternatively be disposed in other locations, such as adjacent the upper grounded enclosure wall 116. The magnets 152 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.

[0043]

[0047] The chamber lid 101 generally includes a ground assembly 103 disposed around the target assembly 102. The ground assembly 103 may include a ground plate 156 having a first surface 157 that may be generally parallel to and facing the back side of the target assembly 102. A ground shield 112 may extend from the first surface 157 of the ground plate 156 and surround the target assembly 102. The ground assembly 103 may include a support member 175 that supports the target assembly 102 within the ground assembly 103.

[0044]

[0048] In some embodiments, the support member 175 may be coupled to a lower end of the grounded shield 112 proximate the outer periphery of the support member 175 and extend radially inward to support a seal ring 181, the target assembly 102, and optionally a dark space shield (not shown, which may be disposed, for example, between the shield 138 and the target assembly 102). The seal ring 181 may be a ring or other annular shape having a desired cross-section to facilitate bonding with the target assembly 102 and the support member 175. The seal ring 181 may be made of a dielectric material, such as ceramic. The seal ring 181 may insulate the target assembly 102 from the grounded assembly 103.

[0045]

[0049] The support member 175 may be a generally planar member having a central opening for receiving the shield 138 and the target 114. In some embodiments, the shape of the support member 175 may be circular or disc-shaped, although the shape can vary depending on the corresponding shape of the chamber lid and / or the shape of the substrate being processed in the process chamber 100. During use, the support member 175 maintains the shield 138 in proper alignment with the target 114 as the chamber lid 101 is opened and closed, thereby minimizing the risk of misalignment due to chamber assembly or opening and closing of the chamber lid 101.

[0046]

[0050] The target assembly 102 may include a source distribution plate 158 facing the backside of the target 114 and electrically coupled to the target 114 along the periphery of the target 114. The target 114 may include a source material 113, such as a metal, metal oxide, metal alloy, magnetic material, etc., to be deposited on a substrate, such as the substrate 108, during sputtering. In some embodiments, the target 114 may include a backing plate 162 to support the source material 113. The backing plate 162 may include a conductive material, such as copper-zinc, copper-chromium, or the same material as the target, such that RF and optionally DC power can be coupled to the source material 113 through the backing plate 162. Alternatively, the backing plate 162 may be non-conductive and may include a conductive element (not shown), such as an electrical feedthrough.

[0047]

[0051] The conductive member 164 may be disposed between the source distribution plate and the backside of the target 114 to propagate RF energy from the source distribution plate to the periphery of the target 114. The conductive member 164 may be cylindrical or tubular and has a first end 166 coupled to the target-facing surface of the source distribution plate 158 proximate the periphery of the source distribution plate 158 and a second end 168 coupled to the source distribution plate-facing surface of the target 114 proximate the periphery of the target 114. In some embodiments, the second end 168 is coupled to the source distribution plate-facing surface of the backing plate 162 proximate the periphery of the backing plate 162.

[0048]

[0052] The target assembly 102 may include a cavity 170 disposed between the backside of the target 114 and the source distribution plate 158. The cavity 170 may at least partially house a magnetron assembly 196. The cavity 170 is defined at least in part by the inner surface of the conductive member 164, the target-facing surface of the source distribution plate 158, and the source distribution plate-facing surface (e.g., backside) of the target 114 (or backing plate 162). In some embodiments, the cavity 170 may be at least partially filled with a cooling fluid, such as water (HO). In some embodiments, a partition (not shown) may be provided to confine the cooling fluid to a desired portion of the cavity 170 (such as the bottom portion shown) and prevent the cooling fluid from reaching components disposed on the other side of the partition.

[0049]

[0053] An insulating gap 180 is provided between the grounded plate 156 and the outer surfaces of the source distribution plate 158, the conductive member 164, and the target 114 (and / or backing plate 162). The insulating gap 180 may be filled with air or other suitable dielectric material, such as ceramic, plastic, etc. The distance between the grounded plate 156 and the source distribution plate 158 depends on the dielectric material between the grounded plate 156 and the source distribution plate 158. When the dielectric material is primarily air, the distance between the grounded plate 156 and the source distribution plate 158 is preferably about 5 to about 40 mm.

[0050]

[0054] The ground assembly 103 and the target assembly 102 may be electrically isolated by a seal ring 181 and by one or more insulators 160 disposed between the first surface 157 of the ground plate 156 and the backside of the target assembly 102, e.g., the side of the source distribution plate 158 that does not face the target.

[0051]

[0055] The target assembly 102 has an RF power supply 182 connected to the electrode 154 (e.g., an RF supply structure). The RF power supply 182 may include an RF generator and a matching circuit, for example, to minimize reflected RF energy that reflects back to the RF generator during operation. For example, the RF energy supplied by the RF power supply 182 may range in frequency from about 13.56 MHz to about 162 MHz or higher. For example, non-limiting frequencies such as 13.56 MHz, 27.12 MHz, 60 MHz, or 162 MHz may be used.

[0052]

[0056] In some embodiments, a second energy source 183 may be coupled to the target assembly 102 to provide additional energy to the target 114 during processing. In some embodiments, the second energy source 183 may be a DC power supply to provide DC energy, for example, to increase the sputtering rate of the target material (and therefore the deposition rate on the substrate). In some embodiments, the second energy source 183 may be a second RF power supply similar to the RF power supply 182 to provide RF energy at a second frequency that is different from the first frequency of the RF energy provided by the RF power supply 182. In embodiments in which the second energy source 183 is a DC power supply, the second energy source may be coupled to the target assembly 102 at any location suitable for electrically coupling DC energy to the target 114, such as the electrode 154 or some other conductive member (e.g., the source distribution plate 158). In embodiments in which the second energy source 183 is a second RF power supply, the second energy source may be coupled to the target assembly 102 via the electrode 154.

[0053]

[0057] The electrode 154 may be cylindrical or otherwise rod-shaped and may be aligned with the central axis 186 of the process chamber 100 (e.g., the electrode 154 may be coupled to the target assembly at a point coincident with the central axis of the target, which coincides with the central axis 186). An electrode 154 aligned with the central axis 186 of the process chamber 100 facilitates asymmetric application of RF energy from the RF power source 182 to the target 114 (e.g., the electrode 154 may couple RF energy to the target at a “single point” aligned with the central axis of the PVD chamber). The central location of the electrode 154 helps eliminate or reduce deposition asymmetry in the substrate deposition process. The electrode 154 may have any suitable diameter, although the smaller the diameter of the electrode 154, the more precisely the RF energy application approaches a single point. For example, in some embodiments, the diameter of the electrode 154 may be from about 0.5 to about 2 inches, although other diameters may be used. The electrode 154 may have any suitable length, generally depending on the configuration of the PVD chamber. In some embodiments, the electrode may have a length of from about 0.5 to about 12 inches. The electrode 154 may be made of any suitable conductive material, such as aluminum, copper, silver, etc.

[0054]

[0058] The electrode 154 may be coupled to the source distribution plate 158 through an opening in the grounded plate 156. The grounded plate 156 may comprise any suitable conductive material, such as aluminum, copper, etc. The open spaces between the one or more insulators 160 allow RF wave propagation along the surface of the source distribution plate 158. In some embodiments, the one or more insulators 160 may be positioned symmetrically with respect to the central axis 186 of the process chamber 100. Such an arrangement may promote symmetric RF wave propagation along the surface of the source distribution plate 158 and, in turn, to the target 114 coupled to the source distribution plate 158. RF energy may be provided in a more symmetric and uniform manner compared to conventional PVD chambers, at least in part due to the central location of the electrode 154.

[0055]

[0059] One or more portions of a magnetron assembly 196 may be disposed at least partially within the cavity 170. The magnetron assembly provides a rotating magnetic field proximate to the target to assist plasma processing within the process chamber 104. In some embodiments, the magnetron assembly 196 may include a motor 176, a motor shaft 174, a gearbox 178, a gearbox shaft 184, and a rotatable magnet (e.g., a plurality of magnets 188 coupled to the magnet support member 172).

[0056]

[0060] The magnetron assembly 196 rotates within the cavity 170. For example, in some embodiments, a motor 176, a motor shaft 174, a gearbox 178, and a gearbox shaft 184 may be provided to rotate the magnet support member 172. In some embodiments (not shown), the magnetron drive shaft may be positioned along the central axis of the chamber, with RF energy being coupled to the target assembly at a different location or in a different manner. As shown in FIG. 1 , in some embodiments, the magnetron motor shaft 174 may be positioned through an off-center opening in the grounded plate 156. The end of the motor shaft 174 protruding from the grounded plate 156 is coupled to the motor 176. The motor shaft 174 is further positioned through a corresponding off-center opening through the source distribution plate 158 (e.g., first opening 146) and coupled to the gearbox 178. In some embodiments, one or more second openings 198 may be disposed through the source distribution plate 158 in a symmetrical relationship to the first openings 146 to advantageously maintain axisymmetric RF distribution along the source distribution plate 158. The one or more second openings 198 may also be used to allow items such as sensors access to the cavity 170.

[0057]

[0061] The gear box 178 may be supported by any suitable means, such as by being coupled to a bottom surface of the source distribution plate 158. The gear box 178 may be insulated from the source distribution plate 158, such as by making at least a top surface of the gear box 178 from a dielectric material or by interposing an insulator layer 190 between the gear box 178 and the source distribution plate 158. The gear box 178 is further coupled to the magnet support member 172 via a gear box shaft 184 to transmit rotational motion provided by the motor 176 to the magnet support member 172 (and thus the plurality of magnets 188). The gear box shaft 184 may advantageously be coincident with a central axis 186 of the process chamber 100.

[0058]

[0062] The magnet support member 172 may be made of any material suitable for providing sufficient mechanical strength to rigidly support the plurality of magnets 188. The plurality of magnets 188 may be configured in any manner that provides a magnetic field having a desired shape and strength to provide more uniform overall erosion of the target, as described herein.

[0059]

[0063] Alternatively, the magnet support member 172 may be rotated by any other means having sufficient torque to overcome the drag force induced on the magnet support member 172 and attached plurality of magnets 188, for example, by the cooling fluid if present in the cavity 170.

[0060]

[0064] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.

Claims

1. 1. A process kit for use in a physical vapor deposition chamber, comprising: a shield including an inner wall having an inner diameter configured to surround a target when positioned in the physical vapor deposition chamber, wherein a ratio of a surface area of ​​the shield to a planar area of ​​the inner diameter is between 3 and 10. Equipped with the inner wall includes a bottom region disposed to engage a first ring, the first ring configured to rest on the bottom region when the first ring is disposed in the physical vapor deposition chamber and a substrate support is in a lower position; a plurality of concentric vertical fins coupled to at least one of a side of the first ring that rests on an outer periphery of the substrate support when the substrate support is in an upper position and the bottom region of the inner wall below the outer periphery of the substrate support.

2. The process kit of claim 1 , wherein the shield is made of at least one of an aluminum alloy and a stainless steel.

3. 10. The process kit of claim 1, wherein the interior wall includes a plurality of alternating curves extending generally 90° downward, outward, downward, inward, and downward from top to bottom, the plurality of alternating curves forming an overall generally C-shape with continuous uninterrupted walls between the alternating curves.

4. 4. The process kit of claim 3, wherein the plurality of alternating bends have inward C-shapes and outward C-shapes that form vertical square waves with rounded transitions when viewed along a cross section of two consecutive bends.

5. The process kit of claim 3 , wherein the plurality of alternating curves are symmetrical with respect to one another.

6. The process kit of claim 3 , wherein the plurality of alternating curvatures are asymmetric with respect to one another.

7. 4. The process kit according to claim 1, wherein an innermost concentric vertical fin of the plurality of concentric vertical fins has a recess that defines an outer side of the innermost concentric vertical fin and a protrusion that defines an inner side of the innermost concentric vertical fin, and the height of the recess is greater than the height of the protrusion.

8. 4. The process kit of claim 1, wherein the plurality of concentric vertical fins are spaced apart from each other by 0.150 inches to 0.2 inches.

9. The process kit of claim 1 , wherein the plurality of concentric vertical fins have an equal height throughout the C-shape between alternating curves.

10. The process kit of claim 1 , wherein the plurality of vertical wells formed between each of the plurality of concentric vertical fins have the same depth.

11. The process kit of claim 1 , wherein the plurality of vertical wells formed between each of the plurality of concentric vertical fins have different depths.

12. A substrate processing apparatus, a chamber body having a substrate support disposed therein; a target coupled to the chamber body opposite the substrate support; an RF power source for forming a plasma within the chamber body; a shield including an inner wall having an inner diameter configured to surround the target when positioned in a physical vapor deposition chamber, wherein a ratio of a surface area of ​​the shield to a planar area of ​​the inner diameter is between 3 and 10; Equipped with the inner wall includes a bottom region disposed to engage a first ring, the first ring configured to rest on the bottom region when the substrate support is in a lower position; a plurality of concentric vertical fins coupled to at least one of a side of the first ring that rests on the outer periphery of the substrate support when the substrate support is in an upper position and the bottom region of the inner wall below the outer periphery of the substrate support; Substrate processing equipment.

13. The substrate processing apparatus of claim 12 , wherein the shield is made of at least one of an aluminum alloy and stainless steel.

14. 14. The substrate processing apparatus of claim 12 or 13, wherein the inner wall includes a plurality of alternating curves extending downward, outward, downward, inward, and downward in approximately 90° increments from top to bottom, the plurality of alternating curves forming an overall generally C-shape with continuous walls between the alternating curves.

15. A substrate processing apparatus as described in claim 14, wherein the multiple alternating curved portions have an inward C-shape and an outward C-shape, and form a vertical rectangular wave with a rounded transition when viewed along a cross section of two consecutive curved portions.

16. The substrate processing apparatus of claim 14 , wherein the plurality of alternating curved portions are symmetrical with respect to one another.

17. The substrate processing apparatus of claim 14 , wherein the plurality of alternating curved portions are asymmetric with respect to one another.

18. 13. The substrate processing apparatus of claim 12, wherein an innermost concentric vertical fin among the plurality of concentric vertical fins has a recess that defines an outer side of the innermost concentric vertical fin and a protrusion that defines an inner side of the innermost concentric vertical fin, and the height of the recess is greater than the height of the protrusion.

19. 19. The substrate processing apparatus of claim 12, 13, or 18, wherein the plurality of concentric vertical fins are spaced apart from each other by 0.150 inches to 0.2 inches.

20. 1. A process kit for use in a physical vapor deposition chamber, comprising:

1. A shield comprising: an inner wall having an innermost diameter configured to surround a target when positioned in the physical vapor deposition chamber comprising a substrate support, the inner wall including a plurality of alternating bends extending downward, outward, downward, inward, and downward in approximately 90° increments from top to bottom, the plurality of alternating bends forming a generally C-shape overall with continuous walls between the alternating bends. Equipped with a ratio of a surface area of ​​the shield to a planar area of ​​the innermost diameter is 3 to 10; the inner wall includes a bottom region having a U-shape; A process kit, wherein a plurality of concentric vertical fins are coupled to at least one of a side surface resting on an outer periphery of the substrate support and the bottom region of the inner wall below the outer periphery of the substrate support.

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