Ground return for thin film deposition using plasma

Abstract

A process kit is provided that includes a susceptor having a rectangular body including a perimeter that includes a first major side opposite a second major side and a first minor side opposite a second minor side, each of the minor sides adjacent to and extending between the first and second main sides that meet at a respective corner, and a plurality of grounding devices coupled to the perimeter of the rectangular body outside each corner of the rectangular body, the plurality of grounding devices including four or more side grounding devices coupled to each of the first main side, the second main side, the first minor side, and the second minor side, and eight or more bottom grounding devices on each of the first main side, the second main side, the first minor side, and the second minor side.

Description

[Technical Field]

[0001] Field

[0001] Embodiments described herein generally relate to methods and apparatus for processing large area substrates using plasma. More particularly, embodiments described herein relate to a modulated radio frequency (RF) current return path for a plasma processing chamber. [Background technology]

[0002] background 2. Description of Related Art Plasma-enhanced chemical vapor deposition (PECVD) is commonly used to deposit thin films on substrates, such as semiconductor substrates used in display manufacturing, solar panel substrates, liquid crystal display (LCD) and organic light-emitting diode (OLED) substrates. PECVD is typically accomplished by introducing precursor gases into a vacuum chamber in which a substrate is positioned on a susceptor or substrate support. The precursor gases are typically directed through a gas distribution plate located near the top of the vacuum chamber. The precursor gases in the vacuum chamber are energized (e.g., excited) into a plasma by applying radio frequency (RF) power to the chamber from one or more RF sources coupled to the chamber. The excited gases react to form a thin film of material on the surface of the substrate (or device formed thereon). The gas distribution plate is typically connected to an RF power source, and the susceptor is typically connected to the chamber body, providing a return path for the RF current.

[0003] In the manufacture of OLED devices, PECVD processes are commonly used to form thin films on multiple OLED devices formed on a substrate. The thin films are utilized to encapsulate and / or hermetically seal the devices (known as thin film encapsulation (TFE)). Uniformity is generally desired for these thin films deposited on OLED devices using PECVD processes. If the thin films are not uniform across the substrate area, yields can be reduced. This non-uniformity has been found to be related to the uniformity of the plasma density, which is affected by RF returns.

[0004] Therefore, what is needed is an improved RF return scheme for large area substrates. Summary of the Invention

[0005]

[0005] Embodiments of the present disclosure generally relate to methods and apparatus for plasma processing of substrates. More particularly, embodiments described herein provide a plasma processing chamber having one or more radio frequency (RF) ground or return devices adapted to provide an advantageous RF return path.

[0006] In one embodiment, a process kit is provided. The process kit includes a susceptor having a rectangular body made of a conductive material, the rectangular body including a periphery including a first major side opposite a second major side and a first minor side opposite a second minor side, each minor side adjacent to and extending between the first and second major sides, and the second major sides meeting at respective corners. The susceptor also includes a plurality of grounding devices coupled around the periphery of the rectangular body outside of each corner of the rectangular body, the grounding devices including four or more side grounding devices coupled to each of the first major side, the second main side, the first minor side, and the second minor side, and eight or more bottom grounding devices coupled to each of the first major side, the second main side, the first minor side, and the second minor side. Includes.

[0007] In another embodiment, a process kit is provided. The process kit includes a susceptor having a rectangular body made of an electrically conductive material, the rectangular body including a periphery including a first major side opposite a second major side, and a first minor side opposite a second minor side, each minor side adjacent the first and second major sides at a respective corner and extending between the first and second major sides. The susceptor also includes a bracket coupled to the periphery of the rectangular body, and a plurality of grounding devices coupled to the bracket on each of the first and second major sides and within an electrical ground length of each of the first and second minor sides, the plurality of grounding devices including four or more side grounding devices coupled to each of the first main side, the second main side, the first minor side, and the second minor side, and eight or more bottom grounding devices on each of the first main side, the second main side, the first minor side, and the second minor side. Includes.

[0008] In another embodiment, a plasma processing system is provided. The plasma processing system includes a chamber and a first electrode disposed within the chamber to facilitate generation of plasma within the chamber and movable within the chamber relative to a second electrode. The first electrode has a rectangular body made of a conductive material, the rectangular body including a periphery including a first major side opposite a second major side and a first minor side opposite a second minor side, each minor side adjacent the first and second major sides at a respective corner and extending between the first and second major sides. The first electrode also includes a plurality of grounding devices coupled around the periphery of the rectangular body outside of each corner of the rectangular body, including four or more side grounding devices coupled to each of the first major side, the second main side, the first minor side, and the second minor side, and eight or more bottom grounding devices coupled to each of the first major side, the second main side, the first minor side, and the second minor side.

[0009]

[0009] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description set forth herein briefly summarized above can be made by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure and therefore should not be considered as limiting its scope. [Brief explanation of the drawings]

[0010] [Figure 1A] 1 is a schematic cross-sectional view of one embodiment of a plasma processing system. [Figure 1B]

[0011] 1B is a schematic cross-sectional view of another embodiment of the plasma processing system shown in FIG. 1A. [Figure 2]

[0012] FIG. 1 illustrates an isometric view of one embodiment of a side-grounding device. [Figure 3]

[0013] FIG. 10 is an isometric rear view of a portion of a bracket for coupling a grounding device. [Figure 4]

[0014] FIG. 2 is a schematic cross-sectional top view of the chamber body showing a top view of the susceptor. [Figure 5A]

[0015] 1A-1C are schematic isometric views of various embodiments of grounding devices disposed on brackets around a susceptor. [Figure 5B] 1A-1C are schematic isometric views of various embodiments of grounding devices disposed on brackets around a susceptor. [Figure 5C] 1A-1C are schematic isometric views of various embodiments of grounding devices disposed on brackets around a susceptor. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0016] For ease of understanding, where possible, identical reference numerals have been used to designate identical elements that are common to multiple figures. It is contemplated that elements and / or process steps of one embodiment may be beneficially incorporated in other embodiments without additional description.

[0012]

[0017] FIELD OF THE DISCLOSURE

[0002] Embodiments of the present disclosure generally relate to methods and apparatus for processing substrates using plasma and / or for cleaning components using plasma. A process kit is disclosed that includes a susceptor having various grounding devices connected to enable a radio frequency (RF) return path. The embodiments described herein relate to methods for enhancing plasma formation and depositing material on a substrate by providing an improved grounding or current return path. While the following description describes a plasma-enhanced chemical vapor deposition (PECVD) chamber, it should be understood that the embodiments herein can be similarly implemented in other chambers, including physical vapor deposition (PVD) chambers, etch chambers, semiconductor processing chambers, solar cell processing chambers, and organic light-emitting display (OLED) processing chambers, to name just a few. Suitable chambers that can be used are available from AKT America, Inc., a subsidiary of Applied Materials, Inc., located in Santa Clara, California. It should be understood that the embodiments described herein can also be implemented in chambers available from other manufacturers.

[0013]

[0018] The present disclosure can be utilized to process substrates of any size or shape. However, the present disclosure is not limited to processing substrates of approximately 15,600 cm 2 This provides particular advantages for substrates having a planar surface area of ​​about 90,000 cm 2 These include substrates having planar surface areas of up to 1000 nm (or greater). As the surface area of ​​the substrate increases, it becomes more difficult to provide an adequate ground path, making uniform processing more difficult. The embodiments described herein provide solutions to these challenges during processing of larger substrate sizes.

[0014]

[0019] 1A is a schematic cross-sectional view of one embodiment of a plasma processing system 100. The plasma processing system 100 is configured to process a large-area substrate 101 using a plasma in forming structures and devices on the large-area substrate 101 used in the manufacture of liquid crystal displays (LCDs), flat panel displays, organic light-emitting diode (OLED) devices, or photovoltaic cells for solar cell arrays. The substrate 101 may be a thin sheet of metal, plastic, organic material, silicon, glass, quartz, or polymer, among other suitable materials. The plasma processing system 100 deposits a dielectric material (e.g., SiO2, SiO2) on the large-area substrate 101. X N y , its derivatives or combinations thereof), semiconductor materials (e.g., Si and its dopants), or barrier materials (e.g., SiN x , SiO x N y The plasma processing system 100 may be configured to deposit a variety of materials, including, but not limited to, epitaxial silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, silicon germanium, germanium, silicon dioxide, silicon oxynitride, silicon nitride, dopants thereof (e.g., B, P, or As), derivatives thereof, or combinations thereof, formed or deposited on large-area substrates by the plasma processing system 100. The plasma processing system 100 is also configured to accept gases such as argon, hydrogen, nitrogen, helium, or combinations thereof, for use as purge gases or carrier gases (e.g., Ar, H, N, He, derivatives thereof, or combinations thereof). One example of depositing a silicon thin film on a large-area substrate 101 using the system 100 may be achieved by using silane as a process gas in a hydrogen carrier gas.

[0015]

[0020] As shown in FIG. 1A, the plasma processing system 100 generally includes a chamber body 102 including a bottom 117a and sidewalls 117b that at least partially define a processing region 111. A susceptor 104 is disposed within the processing region 111. The susceptor 104 is adapted to support a substrate 101 on a top surface thereof during processing. The susceptor 104 is coupled to an actuator 138 adapted to move the susceptor at least vertically and / or adjust a distance D between the substrate 101 and the showerhead assembly 103 to facilitate transfer of the substrate 101. One or more lift pins 110a-110d can extend through the susceptor 104. As shown in FIG. 1B, when the susceptor 104 is lowered by the actuator 138 to facilitate transfer of the substrate 101, the lift pins 110a-110d are adapted to contact the bottom 117a of the chamber body 102 and support the substrate 101. In the processing position as shown in FIG. 1A, the lift pins 110a-110d are adapted to lie flush with or slightly below the top surface of the susceptor 104 so that the substrate 101 can lie flat on the susceptor 104.

[0016]

[0021] The substrate 101 and / or susceptor 104 may have a surface area greater than about 5 square meters, for example, greater than about 5.5 square meters. In some embodiments, the substrate 101 and / or susceptor 104 may include dimensions of about 2200 mm (minor side) by about 2500 mm (major side) or greater. The structure formed on the substrate 101 may be a pn junction forming an OLED device, a thin film transistor, or a diode for a solar cell.

[0017]

[0022] The showerhead assembly 103 is configured to supply process gas from a process gas source 122 to the processing region 111. The plasma processing system 100 also includes an exhaust system 118 configured to apply a negative pressure to the processing region 111. The showerhead assembly 103 is typically positioned opposite the susceptor 104 in a substantially parallel relationship.

[0018]

[0023] In one embodiment, the showerhead assembly 103 includes a gas distribution plate 114 and a backing plate 116. The backing plate 116 can function as a blocker plate, allowing for the formation of a gas volume 131 between the gas distribution plate 114 and the backing plate 116. A gas source 122 is connected to the gas distribution plate 114 by a conduit 134. In one embodiment, a remote plasma source 107 is coupled to the conduit 134 to supply a plasma of an activated gas through the gas distribution plate 114 to the processing region 111. The plasma from the remote plasma source 107 can include an activated gas for cleaning chamber components disposed within the processing region 111.

[0019]

[0024] The gas distribution plate 114, the backing plate 116, and the conduits 134 are generally formed from an electrically conductive material and are electrically connected to one another. The chamber body 102 is also formed from an electrically conductive material. The chamber body 102 is generally electrically insulated from the showerhead assembly 103. In one embodiment, the showerhead assembly 103 is attached to the chamber body 102 by an insulator 135.

[0020]

[0025] In one embodiment, the susceptor 104 is also electrically conductive, and the susceptor 104 and showerhead assembly 103 are configured to act as opposing electrodes for generating a plasma 108a between the process gases during processing and / or pre- or post-processing. Additionally, the susceptor 104 and showerhead assembly 103 can be utilized to support a plasma 108b (FIG. 1B) of a cleaning gas during a cleaning process.

[0021]

[0026] Generally, a radio frequency (RF) power source 105 is used to generate a plasma 108a between the showerhead assembly 103 and the susceptor 104 before, during, and after processing, and may also be used to sustain energized species or further excite cleaning gases supplied from a remote plasma source 107. In one embodiment, the RF power source 105 is coupled to the showerhead assembly 103 by a first connection 106a of an impedance matching circuit 121. A second connection 106b of the impedance matching circuit 121 is electrically connected to the chamber body 102.

[0022]

[0027] In one embodiment, the plasma processing system 100 includes a plurality of first RF devices 109 a and a plurality of second RF devices 109 b. Each of the first RF device 109 a and the second RF device 109 b is coupled between the susceptor 104 and a grounded component of the chamber body 102. In one embodiment, the plurality of RF devices 109 a and 109 b are configured to control a return path for returning RF current during processing and / or chamber cleaning procedures.

[0023]

[0028] Each of the first RF devices 109a may be referred to as a side-grounding device 112. Each of the side-grounding devices 112 is configured to selectively contact and / or provide a ground path between a side of the susceptor 104 and the chamber sidewall 117b. Additionally, each of the second RF devices 109b may be referred to as a bottom-grounding device 113. Each of the bottom-grounding devices 113 is configured to provide a return path between the susceptor 104 and the chamber bottom 117a. In some embodiments, each of the side-grounding devices 112 and the bottom-grounding device 113 is coupled to an extension member 119 that is electrically coupled to the susceptor 104. The extension member 119 may be a separate member coupled to the periphery of the susceptor 104 or may be a structure that includes the periphery of the susceptor 104.

[0024]

[0029] Each of the side grounding devices 112 includes a movable conductive member 120 adapted to contact a ledge 124 electrically coupled to the sidewall 117b. Each of the side grounding devices 112 can be selectively actuated to open or close to electrical current. In the closed position (shown in FIG. 1A), each of the side grounding devices 112 is utilized to provide an RF conductive medium for an RF return path between the susceptor 104 and components of the chamber body 102. In the open position (shown in FIG. 1B), each side grounding device 112 is not electrically coupled to chamber components (i.e., components of the chamber body 102 that are electrically connected to the RF power source 105). In one aspect, the opening and closing characteristics of each side grounding device 112 can be controlled by the height of the susceptor 104 relative to the showerhead assembly 103 (i.e., relative to the ledge 124).

[0025]

[0030] One embodiment of RF current paths during substrate processing is shown schematically by arrows in FIG. 1A. RF current generally flows from the first lead 123a of the RF power supply 105 to the first output 106a of the impedance match circuit 121, then along the outer surface of the conduit 134 to the backside of the backing plate 116 and then to the front surface of the gas distribution plate 114. From the front surface of the gas distribution plate 114, the RF current passes through the plasma 108a to the top surface of the substrate 101 or susceptor 104, then through the side grounding device 112 and / or the bottom grounding device 113 to the inner surface 125 of the chamber body 102. From the inner surface 125, the RF current returns from the impedance match circuit 121 to the second lead 123b of the RF power supply 105.

[0026]

[0031] In one embodiment, the return path of the RF current during processing can depend on the spacing between the susceptor 104 and the showerhead assembly 103, which is shown as distance D. The spacing is controlled by the height of the susceptor 104. In one embodiment, distance D is between about 200 mils and about 2000 mils during processing. At this spacing (e.g., the height of the susceptor 104), both the side-grounded device 112 and the bottom-grounded device 113 may remain electrically connected to the RF power supply 105. In this embodiment, the RF return path taken by the RF current can be based on the electrical characteristics and positions of the side-grounded device 112 and the bottom-grounded device 113. The electrical characteristics include the resistance, impedance, and / or conductance of the side-grounded device 112 and the bottom-grounded device 113. For example, because the side grounding device 112 is closer and has a lower impedance for the RF current returning to the second lead 123b of the RF power supply 105, the RF current flows primarily through the side grounding device 112, while little or no RF current flows through the bottom grounding device 113.

[0027]

[0032] 1B is a schematic cross-sectional view of the plasma processing system 100 shown in FIG. 1A. In this figure, the plasma processing system 100 is shown without a substrate to illustrate a chamber cleaning procedure, and arrows are shown to schematically illustrate RF current flow. In this embodiment, energized cleaning gas is flowed from the remote plasma source 107 into the showerhead assembly 103 and processing region 111 to generate a plasma 108b within the processing region 111. During chamber cleaning, the susceptor 104 is moved away from the showerhead assembly 103, and RF power from the RF power source 105 can be applied to the processing region 111 to maintain or further activate the cleaning gas from the remote plasma source 107. In one embodiment, the spacing or distance D of the susceptor 104 relative to the showerhead assembly 103 during chamber cleaning is greater than the spacing or distance D of the susceptor 104 relative to the showerhead assembly 103 during processing. In one embodiment, the distance D between the susceptor 104 and the showerhead assembly 103 during the cleaning process is between about 200 mils and about 5000 mils, or greater.

[0028]

[0033] In one embodiment, the side grounding device 112 may be electrically or physically decoupled from the susceptor 104 so that return RF current flows only through the bottom grounding device 113. In one embodiment, raising the susceptor 104 creates a condition in which RF current is substantially prevented from passing through the side grounding device 112. In one embodiment, when the susceptor 104 is in this lowered position, the side grounding device 112 is detached from the sidewall 117b and the susceptor 104, thereby creating an RF open condition for the side grounding device 112.

[0029]

[0034] 2 is an isometric view of one embodiment of a side grounding device 112 coupled to a perimeter 200 of a susceptor 104. The side grounding device 112 is shown coupled to a bracket 205 (e.g., extension member 119 shown in FIGS. 1A and 1B ). The susceptor 104 includes a body 210 made of a conductive material, such as aluminum. The bracket 205 includes a conductive material, such as aluminum, that is electrically connected to the body 210. In one embodiment, the bracket 205 is configured as a bar coupled to the susceptor 104. The bracket 205 includes extended base members 215 that protrude from the perimeter 200 of the susceptor 104 at selected locations. The extended base members 215 house and / or support the side grounding device 112 at these selected locations.

[0030]

[0035] The side grounding device 112 includes the movable conductive member 120 described in FIGS. 1A and 1B. An extended base member 215 includes an opening 220 adapted to receive a first shaft 222. The first shaft 222 is movably disposed through the opening 220 to provide relative motion between the base member 215 and the first shaft 222. The first shaft 222 is coupled to a second shaft 224 that is received inside a spring shape 226. A collar 228 is coupled to the second shaft 224 and provides a base for the spring shape 226. In one embodiment, the first shaft 222 is movable to any position within a travel distance indicated as 230 in FIG. 2. The travel distance 230 corresponds to a range of distances that the susceptor 104 can move during various processes while maintaining electrical contact or ground potential between the susceptor 104 and the chamber body 102.

[0031]

[0036] The movable conductive member 120 includes at least one resilient portion, shown in this embodiment as spring shape 226 and spring shapes 232A and 232B. The spring shapes 226, 232A, and 232B provide resilience to the movable conductive member 120. The spring shapes 226, 232A, and 232B provide resilience to the movable conductive member 120.

[0032]

[0037] In some embodiments, the spring configuration may be a leaf spring, a coil spring, a compression spring, or other flexible spring device or spring configuration. In one embodiment, spring configurations 232A and 232B comprise a metallic material or a metal alloy, which may be further coated, wrapped, or covered with a conductive material. Examples of metals and metal alloys include nickel, stainless steel, titanium, HAYNES® alloys such as MONEL® material, HASTELLOY® material, HAYNES® 242® material, beryllium copper, or other conductive elastic materials. Examples of conductive materials for coating, wrapping, or cladding include aluminum, anodized aluminum, or other coatings, films, or sheet materials. In one embodiment, each of spring configurations 232A and 232B comprises a nickel or titanium alloy sheet material wrapped or covered with an aluminum material. In another embodiment, spring shape 226 comprises a Ni-Mo-Cr alloy, such as HASTELLOY® material or HAYNES® 242® material. The Ni-Mo-Cr alloy material may be coated, wrapped, or clad with aluminum or a conductive metal sheath or coating. In one embodiment, spring shape 226 comprises MONEL® 400 material, while spring shapes 232A and 232B comprise HAYNES® 242® material wrapped with aluminum foil.

[0033]

[0038] In one embodiment, spring shapes 232A and 232B may be a continuous single sheet of material or a single leaf spring having two ends 234A, 234B. Alternatively, spring shapes 232A and 232B may be two separate, discontinuous pieces of sheet material or two leaf springs joined at their respective ends to a contact pad 236. In either embodiment, spring shapes 232A and 232B are electrically coupled to a contact pad 236 made of a conductive material. When the side grounding device 112 is in the closed position (shown in FIG. 1A ), RF current is conducted from the body 210 through the bracket 205, onto or through spring shapes 232A and / or 232B, and to the chamber body 102 via the contact pad 236, which is in contact with the ledge 124.

[0034]

[0039] The collar 228 may include a nut or may include a threaded portion for a set screw configured to secure to the second shaft 224, thereby capturing the spring shape 226. The second shaft 224 may have a reduced dimension, such as a diameter, so that the spring shape 226 can fit thereover. In this embodiment, the second shaft 224, the spring shape 226, and the collar 228 are disposed or housed within a tubular member 238. As the spring shape 226, the second shaft 224 and the collar 228 are made of a conductive material, and the tubular member 238 is made of a dielectric material to electrically insulate the conductive members therein. In this manner, the possibility of arcing or discharge is reduced.

[0035]

[0040] 3 is an isometric rear view of a portion of the bracket 205. The bracket 205 is shown as viewed from the side that is coupled to the periphery 200 of the susceptor 104 (both shown in FIG. 2). A plurality of extended base members 215 are shown at periodic intervals along the length of the bracket 205. Two or more side grounding devices 112 are shown coupled to the bracket 205 with empty base members 300 between them. Also shown are a plurality of bottom grounding devices 113 (i.e., second RF devices 109b) directly coupled to the bracket 205.

[0036]

[0041] Each of the bottom grounding devices 113 may be a spring shape, strap, wire, or cable (both shown in FIGS. 1A and 1B) adapted to provide an RF conductive medium between the susceptor 104 and the grounded components of the chamber body 102. In one embodiment, the bottom grounding devices 113 are configured as straps made of or coated with a flexible conductive material. The material of the bottom grounding devices 113 may be aluminum or may include one or more of the same material combinations described in connection with the spring shape of the side grounding devices 112.

[0037]

[0042] Each of the bottom grounding devices 113 may be directly coupled to the extended base member 215 and / or the bottom surface 305 of the bracket 205. In one embodiment, at least a portion of the bottom grounding devices 113 is coupled to a recessed region 312 of the bracket 205 between adjacent extended base members 215. The movable conductive members 120 may be staggered between adjacent extended base members 215, while the bottom grounding devices 113 are coupled consecutively to the bracket 205 at a selected spacing. In one example, the side grounding devices 112 include a spacing 310 of about 21 inches to about 25 inches, e.g., about 22 inches to about 24 inches, e.g., 23.5 inches. In contrast, the bottom grounding devices 113 include a spacing 315 of about 9 inches to about 12 inches, such as about 10 inches to about 11 inches. The term "about" in this context means + / - 0.1 inch.

[0038]

[0043] Each of the bottom grounding devices 113 includes a first end 320 and a second end 325. To secure the first end 320 to the bracket 205, the first end 320 is coupled to the bracket 205 using one or more fasteners, such as screws or bolts. The second end 325 includes a fastener interface 330 to facilitate coupling to a surface of the chamber bottom 117a (shown in FIGS. 1A and 1B). The fastener interface 330 may be a slot or slot adapted to receive a fastener, such as a bolt or screw, to fasten the second end 325 to the chamber body.

[0039]

[0044] 4 is a schematic cross-sectional top view of the chamber body 102, showing a top view of the susceptor 104 (with the substrate 101 thereon). FIG. 4 also shows a cross-sectional view of the chamber body 102 (along the plane of the substrate 101) to illustrate one embodiment of the positioning of the side grounding device 112.

[0040]

[0045] The chamber body 102 is shown with the susceptor 104 disposed therein, and the side grounding device 112 is disposed in the space between the inner surface 400 of the chamber body 102 and the bracket 205. The contact pads 236 of the side grounding device 112 are adapted to contact ledges 124 (four shown in phantom) electrically connected to the inner surface 400 of the chamber body 102 to provide an RF return path for the applied RF power. Although not shown, a bottom grounding device 113 is also coupled to the susceptor 104.

[0041]

[0046] In one embodiment, the spacing and concentration of the side-grounded devices 112 and / or bottom-grounded devices 113 are configured to provide symmetry in the RF return path, promoting plasma uniformity and improving deposition uniformity on the substrate 101. In one embodiment, the spacing and concentration of the side-grounded devices 112 and / or bottom-grounded devices 113 are adapted to provide a symmetrical appearance to the applied RF power, accounting for variations in chamber configuration, for example, where the slit valve opening 405 is located on one side of the chamber body 102. The spacing or concentration of the side-grounded devices 112 and / or bottom-grounded devices 113 allows the applied RF power to propagate symmetrically within the processing region even when the chamber is not physically and / or electrically symmetrical.

[0042]

[0047] As shown in FIG. 4 , the susceptor 104 includes a perimeter 200 that includes two long sides 410 and two minor sides 415. The long sides 410 are opposite each other and adjacent to the minor sides 415, which are also opposite each other. The susceptor 104 includes an electrically grounded portion or length 420 on each of the long sides 410 and the minor sides 415. The electrical grounding length 420 is shorter than the length of each of the long sides 410 and the minor sides 415 of the susceptor 104. It is within the electrical grounding length 420 that each of the side grounding devices 112 and / or bottom grounding devices 113 are located. The perimeter 200 also includes corners 425 where each of the long sides 410 and the minor sides 415 intersect. In some embodiments, the side grounding devices 112 and / or bottom grounding devices 113 are not located at the corners 425.

[0043]

[0048] The locations of the side grounding device 112 and bottom grounding device 113 described herein have been extensively tested to determine RF grounding effectiveness for plasma systems such as the plasma processing system 100 described above. Concerns include the possibility of arcing between the susceptor 104 and the grounded portion of the system, which could damage the system and / or the substrate, and even devices formed on the substrate. Therefore, it is not obvious to arbitrarily remove or relocate grounding devices from plasma system components because arcing would damage the plasma system components. In particular, it is not obvious to remove grounding devices from the corners of the susceptor 104, as these areas have a high potential for arcing.

[0044]

[0049] 5A-5C are schematic isometric views (not shown for clarity) of various embodiments of grounding devices located on brackets 205 on the perimeter 200 of susceptor 104. In each of the illustrated embodiments, side grounding devices 112 and bottom grounding devices 113 are not located at corners 425.

[0045]

[0050] 5A, there are eight side grounding devices 112 on the long side 410 of the susceptor 104 and six side grounding devices 112 on the minor side 415 of the susceptor 104. However, there are eight bottom grounding devices 113 on both the long side 410 and the minor side 415 of the susceptor 104. In the embodiment of FIG. 5A, there are two empty base members 300 adjacent to the corners 425.

[0046]

[0051] 5B, there are four side grounding devices 112 on the long side 410 of the susceptor 104 and four side grounding devices 112 on the minor side 415 of the susceptor 104. However, there are eight bottom grounding devices 113 on both the long side 410 and the minor side 415 of the susceptor 104. In the embodiment of FIG. 5B, there are two empty base members 300 on the long side 410 adjacent to the corner 425, while the minor side 415 includes one empty base member 300 adjacent to the corner 425.

[0047]

[0052] In Figure 5C, there are six side grounding devices 112 on the long side 410 of the susceptor 104 and six side grounding devices 112 on the minor side 415 of the susceptor 104. However, as with the other embodiments, there are eight bottom grounding devices 113 on both the long side 410 and the minor side 415 of the susceptor 104. Like the embodiment of Figure 5B, in the embodiment of Figure 5C, there are two empty base members 300 on the long side 410 adjacent to the corner 425, while the minor side 415 includes one empty base member 300 adjacent to the corner 425.

[0048]

[0053] The locations and / or spacing between grounding devices shown in Figures 5A-5C are not exclusive. However, embodiments of the susceptor 104 with grounding devices connected as disclosed herein provide a more uniform RF distribution on the substrate. Testing of the susceptor 104 embodiments described herein has shown improved film uniformity across the substrate. In particular, uniformity at the corners of the substrate is significantly improved compared to conventional susceptor grounding methods. The susceptor 104 embodiments described herein also improved the delta stress of films formed on substrates. For example, using the susceptor 104 embodiments described herein, delta stress was reduced from 136 megapascals (MPa) to approximately 5 MPa (after 250 hours of aging). The susceptor 104 embodiments described herein also improved the moisture barrier performance of films. The stress stability of a film in a high-temperature, high-humidity environment (e.g., approximately 85°C, 85% relative humidity) is an important factor for evaluating the moisture barrier performance of a film formed on a substrate. Testing in this high temperature / high humidity environment showed that using embodiments of the susceptor 104 described herein, the delta stress (after 1000 hours aging) was reduced from 144 MPa to about 13 MPa. Thus, using the susceptor 104 described herein, the film quality at the corners of the substrate is sufficient to protect the film from oxidation even after 1000 hours aging in a high temperature / high humidity environment.

[0049]

[0054] 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, which scope is determined by the claims that follow.

Claims

1. a susceptor having a rectangular body made from an electrically conductive material, the rectangular body including a periphery including a first major side opposite a second major side, and a first minor side opposite a second minor side, each of the minor sides adjacent the first and second major sides at a respective corner and extending between the first and second major sides; a plurality of grounding devices coupled to a periphery of the rectangular body outside each corner of the rectangular body, the plurality of grounding devices including four or more side grounding devices coupled to each of the first major side, the second major side, the first minor side, and the second minor side, and eight or more bottom grounding devices on each of the first major side, the second major side, the first minor side, and the second minor side; Including, the process kit.

2. The process kit of claim 1 , wherein each of the plurality of grounding devices is coupled to a bracket disposed about a periphery of the rectangular body.

3. The process kit of claim 2 , wherein the bracket includes a plurality of base members, each base member adapted to support one of the side grounding devices.

4. The process kit of claim 3 , wherein each of the major sides and each of the minor sides includes at least one blank base member.

5. The process kit of claim 4 , wherein each of the major sides includes four blank base members.

6. The process kit of claim 4 , wherein each of the minor sides includes two blank base members.

7. The process kit of claim 1 , wherein the bottom grounded device is coupled to a bracket disposed around the periphery of the rectangular body.

8. The process kit of claim 7 , wherein the bracket comprises a plurality of base members, at least a portion of each of the plurality of base members comprising one of the side grounding devices.

9. 9. The process kit of claim 8, wherein a portion of the bottom grounded device is coupled to the bracket adjacent one of the base members that includes one of the side grounded devices.

10. 9. The process kit of claim 8, wherein the bracket includes a recessed area between the base members, and the bottom grounding device is coupled to the recessed area.

11. a susceptor having a rectangular body made from an electrically conductive material, the rectangular body including a periphery including a first major side opposite a second major side, and a first minor side opposite a second minor side, each of the minor sides adjacent the first and second major sides at a respective corner and extending between the first and second major sides; a bracket coupled to a periphery of the rectangular body; a plurality of grounding devices coupled to the bracket within an electrical ground length of each of the first and second main sides and each of the first and second minor sides, the plurality of grounding devices including four or more side grounding devices coupled to each of the first main side, the second main side, the first minor side, and the second minor side, and eight or more bottom grounding devices on each of the first main side, the second main side, the first minor side, and the second minor side; Including, the process kit.

12. The process kit of claim 11 , wherein the bracket includes a plurality of base members, each base member adapted to support one of the side grounding devices.

13. The process kit of claim 12 , wherein each of the major sides and each of the minor sides includes at least one blank base member.

14. The process kit of claim 13 , wherein each of the major sides includes four blank base members.

15. The process kit of claim 13 , wherein each of the minor sides includes two blank base members.

16. 12. The process kit of claim 11, wherein each of the bottom grounded devices includes a first end coupled to the bracket and a second end having a slotted hole.

17. 1. A plasma processing system comprising: A chamber; a first electrode disposed within the chamber to facilitate generation of a plasma within the chamber and movable within the chamber relative to a second electrode; a rectangular body made from a conductive material, the rectangular body including a perimeter including a first major side opposite a second major side, and a first minor side opposite a second minor side, each of the minor sides adjacent the first and second major sides at a respective corner and extending between the first and second major sides; a plurality of grounding devices coupled to a periphery of the rectangular body outside of each corner of the rectangular body, the plurality of grounding devices including four or more side grounding devices coupled to each of the first major side, the second major side, the first minor side, and the second minor side, and eight or more bottom grounding devices on each of the first major side, the second major side, the first minor side, and the second minor side. The first electrode includes A process treatment system comprising:

18. 20. The plasma processing system of claim 17, wherein each of the plurality of grounding devices is coupled to a bracket disposed around a periphery of the rectangular body.

19. 20. The plasma processing system of claim 18, wherein the bracket comprises a plurality of base members, each base member adapted to support one of the side grounding devices.

20. 20. The plasma processing system of claim 19, wherein each of the major sides and each of the minor sides includes at least one empty base member adjacent the corners.

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