Electrostatic chuck with mesa

Abstract

To provide an electrostatic chuck (ESC) for a plasma processing chamber and a method for manufacturing the ESC.SOLUTION: An ESC 100 includes a ceramic top plate having a top surface 102 with a processing region 107. One or more electrode wires 108 are located within a ceramic top plate. A plurality of mesas 112 are located within the processing region, on the top surface of the ceramic plate, or vertically above an edge of one of the one or more electrode wires. None of the plurality of mesas are located on one or more high topography regions of the top surface of the processing region or above a high voltage electrode edge.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Patent Application No. 17 / 686,324, filed March 3, 2022, which in turn claims the benefit of U.S. Provisional Patent Application No. 63 / 175,218, filed April 15, 2021, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate to the field of reactors or plasma processing chambers, and more particularly to electrostatic chucks with mesas. [Background technology]

[0003] Processing systems, such as reactors or plasma reactors, are used to form devices on substrates, such as semiconductor wafers or transparent substrates. Often, the substrate is held on a support for processing. The substrate may be held on the support by vacuum, gravity, electrostatic force, or other suitable techniques. During processing, a precursor gas or gas mixture in the chamber is energized (e.g., excited) into a plasma by applying power, such as radio frequency (RF) power, to electrodes in the chamber from one or more power sources coupled to the electrodes. The excited gas or gas mixture reacts to form a layer of material on the surface of the substrate. The layer may be, for example, a passivation layer, a gate insulator, a buffer layer, and / or an etch stop layer.

[0004] In semiconductor and other industries, electrostatic chucks (ESCs) are used to hold workpieces, such as substrates, on a support during substrate processing. A typical ESC may include a base, an electrically insulating layer disposed on the base, and one or more electrodes embedded in the electrically insulating layer. The ESC may be provided with an embedded electric heater and may be fluidly coupled to a source of heat transfer gas for controlling the substrate temperature during processing. During use, the ESC is fixed to a support in a process chamber. The electrodes in the ESC are electrically biased with respect to a substrate disposed on the ESC by an electric voltage source. Opposite electrostatic charges accumulate in the electrodes of the ESC and on the surface of the substrate, and an insulating layer prevents charge flow between them. Electrostatic forces resulting from the accumulation of electrostatic charges hold the substrate to the ESC during substrate processing. Summary of the Invention

[0005] Embodiments of the present disclosure include an electrostatic chuck (ESC) for a plasma processing chamber and a method of manufacturing an ESC.

[0006] In an embodiment, the substrate support assembly includes a ceramic top plate having a top surface with a processing region. One or more electrodes are within the ceramic top plate. A plurality of mesas are within the processing region and on the top surface of the ceramic plate or vertically above an edge of one of the one or more electrodes.

[0007] In an embodiment, a substrate support assembly includes a ceramic top plate having a top surface with a processing region, the top surface having one or more high topography regions, and a plurality of mesas within the processing region and on the top surface of the ceramic plate, none of the plurality of mesas overlying the one or more high topography regions on the top surface of the processing region.

[0008] In an embodiment, a substrate support assembly includes a ceramic top plate having a top surface with a processing region. The top surface has one or more high stress regions. A plurality of mesas are located within the processing region and on the top surface of the ceramic plate. None of the plurality of mesas resides on the one or more high stress regions on the top surface of the processing region. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 illustrates a plan view of the top surface of an electrostatic chuck (ESC) and a corresponding enlarged view. [Figure 2A] 1A-1C illustrate cross-sectional views of an electrostatic chuck (ESC) including mesas at various locations in accordance with an embodiment of the present disclosure. [Figure 2B] 10A-10C illustrate cross-sectional views of another electrostatic chuck (ESC) including mesas at various locations in accordance with another embodiment of the present disclosure. [Figure 2C] 10A-10C illustrate cross-sectional views of another electrostatic chuck (ESC) including mesas at various locations in accordance with another embodiment of the present disclosure. [Figure 3] FIG. 1 illustrates a cross-sectional view of an electrostatic chuck (ESC) according to an embodiment of the present disclosure. [Figure 4] 1 is a schematic cross-sectional view of a process chamber including a substrate support assembly according to an embodiment of the present disclosure. [Figure 5] 1 is a partial schematic cross-sectional view of a processing chamber including a substrate support assembly according to an embodiment of the present disclosure. [Figure 6] FIG. 1 illustrates a block diagram of an exemplary computer system, according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] An electrostatic chuck (ESC) for a plasma processing chamber and a method for manufacturing the ESC are described. In the following description, numerous specific details, such as electrostatic chuck components and material conditions, are set forth to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known aspects, such as plasma enhanced chemical vapor deposition (PECVD) or plasma enhanced atomic layer deposition (PEALD) processes, are not described in detail so as not to unnecessarily obscure embodiments of the present disclosure. Furthermore, it should be understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.

[0011] One or more embodiments are directed to reducing surface stress in electrostatic chucks (ESCs) through mesa engineering, profile, and ESC material design. Embodiments can include ESC mesa engineering and top material structure design.

[0012] To provide context, mesas on the surface of the ESC may be used to support the workpiece when it is slightly elevated from the global top surface of the ESC's top plate. In an exemplary embodiment, mesa coverage may be approximately 65% ​​of the total surface area of ​​the process surface, but may be larger or smaller. The mesas may be approximately 15 microns in height, but may be larger or smaller. The mesas may be approximately 1 mm in diameter, but may be larger or smaller. In past and current implementations, mesas are typically placed in many locations, including locations based on high-stress regions on the surface of the ESC. Placement in such high-stress areas may be accompanied by cracking on the top surface of the ESC due to thermal stress in high-stress and / or defect areas.

[0013] According to one or more embodiments of the present disclosure, mesa engineering and profile configuration of the top ESC material and design are implemented for surface stress reduction. Advantages of implementing one or more embodiments described herein can include targeted location of the mesa and improved profile of the top surface of the ESC. The embodiments described herein can be implemented to enable use of the ESC without thermal shock cracking of the top surface at temperatures greater than 500 degrees. The embodiments described herein can be implemented to eliminate or mitigate ESC thermal shock stress cracking.

[0014] The ESC surface can have mesas fabricated on the upper surface, for example, either by grinding or by bead blasting. Such mesas can be described as continuous with the upper surface of the ceramic top plate. The mesas can be formed within the ceramic surface or can be particles, such as diamond particles, added to the ceramic surface. FIG. 1 illustrates a plan view and corresponding close-up 150 of the upper surface of an electrostatic chuck (ESC).

[0015] 1 , the top surface 102 of the ESC 100 includes an outer region 104 surrounding an inner region 106. The top surface 102 can be a ceramic surface, such as an aluminum nitride or aluminum oxide surface. The inner region 106 can include a processing region 107 having electrode wiring 108 therein, such as slightly below the surface of the ceramic. The electrode wiring 108 can be for, for example, an electrostatic electrode of the ESC 100. The processing region 107 can also include a DC braze joint location 110, such as slightly below the surface of the ceramic. A plurality of mesas 112 are fabricated on the surface of the processing region 107.

[0016] 1, and in particular close-up view 150, the plurality of mesas 112 includes not only mesas at numerous locations within the benign region, but also mesas 112A in the region above the region of the DC braze joint location 110. It has been determined that mesas 112A in the region above the region of the DC braze joint location 110 may place mesas 112A in a high stress area.

[0017] FIG. 2A illustrates a cross-sectional view of an electrostatic chuck (ESC) including mesas at various locations, according to an embodiment of the present disclosure.

[0018] 2A , ESC 200 includes a central zone 202, a main zone 204, a DC rod 206, and an ESC mesh 208. DC rod 206 may be in a central location 210 as depicted. ESC 200 also includes mesas, such as mesas 212A, 212B, 212C, and 212D. Mesa 212A is above a high-voltage connection area 210, such as above DC rod 206. Mesa 212B is above an electrode edge. Mesa 212C is in an area without an electrode. Mesa 212D is entirely above an electrode. Mesas 212A, 212B, 212C, and 212D are above ESC mesh 208 at a relatively shallow distance.

[0019] Referring again to FIG. 2A , the ESC surface may include a stress distribution including high-stress and low-stress regions on the top surface based on its manufacturing characteristics. Some high-stress regions are created by the presence of a high-voltage electrode approximately 1 mm below the top surface. For example, high stress may exist (A) at the boundary of the positive or negative electrode edge, (B) above the brazed connection, and / or at the edge of the ESC. According to an embodiment of the present disclosure, a mesa structure is included above the low-stress area but not above the high-stress region. For example, mesas 212A and 212B are in high-stress locations, while mesas 212C and 212D are in low-stress regions. In an embodiment, mesas are included in locations 212C and / or 212D, but not in locations 212A or 212B.

[0020] In another aspect, the as-is ESC surface can have a profile after machining and / or polishing the top surface. The profile can have a bump in the center of the ESC. The size of such a bump in the center can be approximately 10-20 microns, with a 15 micron mesa following the contour, as illustrated in FIG. 2B described below. When a wafer is placed on the ESC, the wafer can have various contact points. The bump in the center can prevent the wafer from contacting the mesa immediately adjacent to the center. According to one or more embodiments of the present disclosure, the vertical amplitude (topographical features) of the surface relative to the horizontal distance for a given mesa height is specified. Heat transfer between the wafer and the ESC, and from the plasma to the wafer via the gas coupled to the ESC, can control the wafer temperature in the area. When only the center bump is polished, the wafer can have a concave contact area across all mesas and heat transfer is uniform. In one embodiment, before the mesas are created, a flatness profile is measured on the surface of the ESC, and the mesas are not formed in locations where the vertical slope (eg, 15 microns / 10 mm) is not met.

[0021] FIG. 2B illustrates a cross-sectional view of another electrostatic chuck (ESC) including mesas at various locations in accordance with another embodiment of the present disclosure.

[0022] 2B , support surface topography 250 can include a mesa profile 254 above ceramic top surface profile 252. Ceramic top surface profile 252 can have a central high point 252A and edge locations 252B. Mesa profile 254 can exhibit grind locations 256A and 256B, with a high central point. Mesa 262 is located on ceramic top surface profile 252. In an embodiment, after determining that the central point is the high point, mesa 262A is not formed at the central location. As a result, wafer profile (dotted line 258) is not formed on the high point of mesa profile 254 that would otherwise include mesa 262A.

[0023] In an embodiment, the uppermost layer of the high-voltage electrode is made thicker than 1 mm but less than 3 mm to strengthen the upper surface and reduce surface stress of the AlN ESC. In an embodiment, the brazed high-voltage connection is 2-4 mm from the upper surface to reduce stress. In an embodiment, the uppermost layer of the electrode is made of high resistivity and high thermal shock resistance. In an embodiment, the microstructure design provides thermal shock resistance of 400 degrees or more.

[0024] 1, 2A, and 2B, according to an embodiment of the present disclosure, a substrate support assembly includes a ceramic top plate having an upper surface with a processing region. One or more DC brazed connections are within 1-2 mm of the surface of the ceramic top plate. A plurality of mesas are located within the processing region and on the upper surface of the ceramic plate. None of the plurality of mesas are vertically above the one or more DC brazed connections.

[0025] 1, 2A, and 2B, according to another embodiment of the present disclosure, a substrate support assembly includes a ceramic top plate having an upper surface with a processing region. The upper surface has one or more high topography regions. A plurality of mesas are located within the processing region and on the upper surface of the ceramic plate. None of the plurality of mesas is located on the one or more high topography regions of the upper surface of the processing region or above a high voltage electrode edge.

[0026] 1, 2A, and 2B, according to another embodiment of the present disclosure, a substrate support assembly includes a ceramic top plate having an upper surface with a processing region. The upper surface has one or more high stress regions. A plurality of mesas are located within the processing region and on the upper surface of the ceramic plate. None of the plurality of mesas resides on the one or more high stress regions on the upper surface of the processing region.

[0027] FIG. 2C illustrates a cross-sectional view of an electrostatic chuck (ESC) including mesas at various locations according to another embodiment of the present disclosure.

[0028] 2C , ESC 270 includes a central zone 272, a main zone 274, a DC rod 276, and an ESC mesh 278. DC rod 276 may be in a central location 280 as depicted. ESC 270 also includes mesas, such as mesas 282A, 282B, 282C, and 282D. Mesa 282A is above a high-voltage connection area 280, such as above DC rod 276. Mesa 282B is above an electrode edge. Mesa 282C is in an area without an electrode. Mesa 282D is entirely above the electrode. Mesas 282A, 282B, 282C, and 282D are above ESC mesh 278 at a relatively shallow distance. In contrast to Figure 2A, in an embodiment, ESC 270 in Figure 2C includes a molybdenum high-voltage electrode mesh 278 connected by metal paste 290 through approximately 0.5 mm vias 292 to brazed nickel rods 276 located a few mm (e.g., 1-4 mm) inside the ceramic. In one such embodiment, the arrangement reduces stress on the top while maintaining electrical connection from the nickel rods to the molybdenum mesh through a fine layer of paste in the horizontal mesh plane and vertically. In one embodiment, mesa 282D is in a relatively lower stress location than mesa 212D in Figure 2A.

[0029] More generally, as an exemplary fabricated ESC, FIG. 3 illustrates a cross-sectional view of an electrostatic chuck (ESC) according to an embodiment of the present disclosure.

[0030] Referring to FIG. 3 , ESC 300 includes a ceramic bottom plate 302 having a heater coil 304 therein. The heater coil 304 may be bonded to a heater connection 305 (it should be appreciated that in another embodiment, the heater electrode is screen printed in the case of tape-cast AlN or AlN plate materials used for ESC fabrication). A shaft 306 is bonded to the bottom surface of the ceramic bottom plate 302. ESC 300 also includes a ceramic top plate 308. The ceramic top plate 308 has an ESC (clamping) electrode 310 or electrode assembly therein. A layer 312, such as a metal layer or a diffusion bond layer, may be used to bond the ceramic top plate 308 to the top surface of the ceramic bottom plate 302. A thermocouple 314 extends through an opening 315 in the ceramic bottom plate 302 and in the metal layer 312. High voltage insulation 316 extends through openings 315 in the ceramic bottom plate 302 and in the metal layer 312 to house ESC high voltage connections 318. The mesa covered surface 399 may be a mesa surface fabricated according to the embodiments described above.

[0031] 3 , according to an embodiment of the present disclosure, a substrate support assembly 300 includes a ceramic bottom plate 302 having a heater element 304 therein. The substrate support assembly 300 also includes a ceramic top plate 308 having an electrode 310 therein. A metal layer 312 is between the ceramic top plate 308 and the ceramic bottom plate 302. The ceramic top plate 308 is in direct contact with the metal layer 312, which in turn is in direct contact with the ceramic bottom plate 302.

[0032] The standard way to make an ESC is by hot pressing plates together and then diffusion bonding them to the shaft. In embodiments without diffusion bonding, metal layer 312 provides a metallurgical bond in place of the ceramic in a ceramic diffusion bond, which could otherwise alter the resistivity of the upper ceramic during diffusion bond formation. In one embodiment, metal layer 312 is a metal foil, such as aluminum foil. In one such embodiment, metal layer 312 is an aluminum foil impregnated with about 2%-20% Si (e.g., as atomic % of the total foil composition), with the remainder being aluminum or essentially all aluminum (in other words, the aluminum foil includes silicon having an atomic concentration within the range of 2%-20% of the aluminum foil). In an embodiment, metal layer 312 is pre-patterned to include openings 315 and / or additional openings, for example, to accommodate lift pins or the like. In one embodiment, metal layer 312 is an aluminum foil having a thickness within the range of 50-500 microns, which may be about 250 microns. In an embodiment, metal layer 312 is aluminum foil and is cleaned prior to encapsulation in the ESC manufacturing process, e.g., to remove a passivation layer prior to bonding. In an embodiment, metal layer 312 is aluminum foil and can withstand corrosive processes, such as chlorine-based processes, without etching or degradation of metal layer 312 when the ESC is in use. However, when used for non-chlorine-based processes, metal layer 312 may be comprised of, for example, a silver-copper alloy with or without the addition of titanium. In an embodiment, metal layer 312 is bonded to top plate 308 and bottom plate 302 at temperatures below 600 degrees Celsius, more particularly below 300 degrees Celsius. It should be appreciated that higher ESC operating temperatures, such as 650 degrees Celsius, may be used if the metal bonding is performed using high-temperature metal bonds, such as silver-copper or gold-nickel, temperatures well below 1400 degrees Celsius but well above the 650 degrees Celsius operating temperature.

[0033] Regarding the ceramic top plate 308 having the ESC (clamping) electrode 310 therein, in embodiments, the body of the top plate may be formed by sintering a ceramic material, such as aluminum nitride (AlN) or aluminum oxide powder, or other suitable material. An RF mesh may be embedded in the body. The RF mesh may have electrical connections extending through the bottom surface of the body. The RF mesh may include a mesh of molybdenum or another suitable metallic material. In one embodiment, the mesh is approximately 125 microns in diameter. The material may be sintered to form a monolithic structure. In one embodiment, the electrode 310 is fabricated from a metallic material, such as molybdenum, that may have a thermal expansion coefficient similar to that of the body. In embodiments, the ceramic top plate 308 is targeted to withstand temperatures below 350 degrees Celsius, for example, between 150 and 300 degrees Celsius, and may include dopants to optimize operation within such a targeted temperature range.

[0034] The clamping electrode 310 can include at least a first electrode and a second electrode. During operation, a negative charge can be applied to the first electrode and a positive charge can be applied to the second electrode, or vice versa, to generate an electrostatic force. During chucking, the electrostatic force generated from the electrodes holds a substrate disposed thereon in a fixed position. When the power supplied from the power supply is turned off, the charge present at the interface between the electrodes can be maintained for an extended period of time. To release a substrate held on the electrostatic chuck, a short pulse of power of the opposite polarity can be provided to the electrodes to remove the charge present at the interface.

[0035] The electrode assembly may be formed from a metal bar, sheet, stick, or foil, and may be pre-formed, pre-cast, pre-fabricated, or placed on the surface of the insulating base during the manufacture of the electrostatic chuck. Alternatively, a metal deposition process may be performed to deposit and form the electrode assembly directly on the upper surface of the insulating base. Suitable deposition processes may include PVD, CVD, plating, inkjet printing, rubber stamping, screen printing, or aerosol printing processes. Additionally, a metal paste / metal line may be formed on the upper surface of the insulating base. The metal paste / metal line may initially be a liquid, paste, or metal gel that can be patterned on the surface of the object in a pattern to form electrode fingers with different configurations or dimensions on the upper surface of the insulating base.

[0036] The ceramic top plate 308 or the ceramic bottom plate 302 may include, but are not limited to, aluminum nitride, glass, silicon carbide, aluminum oxide, yttrium-containing materials, yttrium oxide (YO), yttrium aluminum garnet (YAG), titanium oxide (TiO), or titanium nitride (TiN). With respect to the ceramic bottom plate 302, in embodiments, the ceramic bottom plate 308 is targeted to withstand temperatures up to 650 degrees Celsius and may include dopants to optimize operation within such targeted temperature range. In one embodiment, the ceramic bottom plate 302 has an aluminum nitride composition that is different from the aluminum nitride composition of the ceramic top plate 308. The heating element 304 included in the ceramic bottom plate 302 may use any suitable heating technique, such as resistive heating or inductive heating. The heating element 304 may be composed of a resistive metal, a resistive metal alloy, or a combination of the two. Suitable materials for the heating element may include those with high thermal resistance, such as tungsten, molybdenum, or titanium. In one embodiment, the heating element 304 is constructed from molybdenum wire. The heating element 304 may be fabricated using a material having thermal properties, e.g., a coefficient of thermal expansion, that substantially match at least one or both of the aluminum nitride bodies to reduce stress caused by mismatched thermal expansion.

[0037] In an embodiment, the ceramic top plate 308 is fabricated and then bonded to the ceramic bottom plate by the metal layer 312 (which may already include one or more openings patterned therein). In an embodiment, the metal layer 312 is bonded to the ceramic top plate 308 at the same time that the metal layer 312 is bonded to the ceramic bottom plate 302. In another embodiment, the metal layer 312 is bonded to the ceramic top plate 308 first, and then the ceramic top plate / metal layer 312 pairing is bonded to the ceramic bottom plate 302. In another embodiment, the metal layer 312 is bonded to the ceramic bottom plate 302 first, and then the ceramic bottom plate / metal layer 312 pairing is bonded to the ceramic top plate 308. In either case, in one particular embodiment, the ceramic top plate is formed from sintered aluminum nitride (AlN) or aluminum oxide (AlO) powder and a metal mesh.

[0038] In an embodiment, bonding the ceramic top plate 308 to the ceramic bottom plate 302 with the metal layer 312 includes heating the ceramic bottom plate 302, the metal layer 312, and the ceramic top plate 308 to a temperature less than 600 degrees Celsius. In an embodiment, the metal layer 312 is aluminum foil, and the method includes cleaning a surface of the aluminum foil to remove a passivation layer of the aluminum foil prior to bonding the ceramic top plate 308 to the ceramic bottom plate 302 with the metal layer 312.

[0039] In another aspect, FIG. 4 is a schematic cross-sectional view of a process chamber 400 including a substrate support assembly 428 according to an embodiment of the present disclosure. In the example of FIG. 4, the process chamber 400 is a plasma-enhanced chemical vapor deposition (PECVD) chamber. As shown in FIG. 4, the process chamber 400 includes one or more sidewalls 402, a bottom 404, a gas distribution plate 410, and a cover plate 412. The sidewalls 402, the bottom 404, and the cover plate 412 together define a processing volume 406. The gas distribution plate 410 and the substrate support assembly 428 are disposed in the processing volume 406. The processing volume 406 is accessed through a sealable slit valve opening 408 formed through the sidewall 402, by which a substrate 405 can be transferred into and out of the process chamber 400. A vacuum pump 409 is coupled to the chamber 400 to control the pressure within the processing volume 406.

[0040] The gas distribution plate 410 is coupled to a cover plate 412 at the periphery of the gas distribution plate 410. A gas source 420 is coupled to the cover plate 412 for providing one or more gases through the cover plate 412 to a plurality of gas passages 411 formed in the cover plate 412. The gases flow through the gas passages 411 into the processing volume 406 toward the substrate receiving surface 432.

[0041] An RF power source 422 is coupled to the cover plate 412 and / or directly to the gas distribution plate 410 by an RF power supply 424 to provide RF power to the gas distribution plate 410. Various RF frequencies can be used. For example, the frequency can be between about 0.3 MHz and about 200 MHz, such as about 13.56 MHz. An RF return path 425 couples the substrate support assembly 428 to the RF power source 422 through the sidewall 402. The RF power source 422 generates an electric field between the gas distribution plate 410 and the substrate support assembly 428. The electric field forms a plasma from the gas present between the gas distribution plate 410 and the substrate support assembly 428. The RF return path 425 completes an electrical circuit for the RF energy, preventing stray plasma from causing RF arcing due to a voltage difference between the substrate support assembly 428 and the sidewall 402. The RF return path 425 thereby mitigates arcing, which can cause process drift, particle contamination, and damage to chamber components.

[0042] The substrate support assembly 428 includes a substrate support 430 and a stem 434. The stem 434 is coupled to a lift system 436 adapted to raise and lower the substrate support assembly 428. The substrate support 430 includes a substrate receiving surface 432 for supporting the substrate 405 during processing. Lift pins 438 are movably disposed through the substrate support 430 to move the substrate 405 to and from the substrate receiving surface 432 to facilitate substrate transfer. An actuator 414 is utilized to extend and retract the lift pins 438. A ring assembly 433 may be positioned around the periphery of the substrate 405 during processing. The ring assembly 433 is configured to prevent or reduce unwanted deposition on surfaces of the substrate support 430 that are not covered by the substrate 405 during processing.

[0043] The substrate support 430 may also include heating and / or cooling elements 439 for maintaining the substrate support 430 and the substrate 405 positioned thereon at a desired temperature. In one embodiment, the heating and / or cooling elements 439 may be utilized to maintain the temperature of the substrate support 430 and the substrate 405 disposed thereon at less than about 800 degrees Celsius or less during processing. In one embodiment, the heating and / or cooling elements 439 may be used to control the substrate temperature to less than 650 degrees Celsius, such as between 300 degrees Celsius and about 400 degrees Celsius. In an embodiment, the substrate support 430 / substrate support assembly 428 is as described above.

[0044] 5 is a partial schematic cross-sectional view of a processing chamber 500 including a substrate support assembly 300 according to an embodiment of the present disclosure. The processing chamber 500 has a body 501. The body has sidewalls 502, a bottom 504, and a showerhead 512. The sidewalls 502, the bottom 504, and the showerhead 512 define an interior volume 506. In an embodiment, the substrate support assembly 300, such as that described above, is disposed within the interior volume 506. An RF generator 580 may be coupled to an electrode 582 in the showerhead 512. The RF generator 580 may have an associated RF return path 588 for completing an RF circuit when a plasma is present. Advantageously, an RF ground path for sustaining the plasma is maintained, which can provide a long life for the substrate support assembly 300.

[0045] In an embodiment, the semiconductor wafer or substrate supported by the substrate support assembly 300 is composed of a material suitable for withstanding manufacturing processes and upon which semiconductor processing layers may be suitably disposed. For example, in one embodiment, the semiconductor wafer or substrate is composed of a Group IV-based material, such as, but not limited to, crystalline silicon, germanium, or silicon / germanium. In a particular embodiment, the semiconductor wafer is a single crystal silicon substrate. In a particular embodiment, the single crystal silicon substrate is doped with impurity atoms. In another embodiment, the semiconductor wafer or substrate is composed of a III-V material.

[0046] Embodiments of the present disclosure may be provided as a computer program product or software, which may include a machine-readable medium having instructions stored thereon, which may be used to program a computer system (or other electronic device) to perform processes according to embodiments of the present disclosure. In one embodiment, the computer system is coupled to the process chamber 400 and substrate support assembly 428 described above in connection with FIG. 4 or to the processing chamber 500 and substrate support assembly 300 described above in connection with FIG. 5. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable (e.g., computer-readable) medium includes a machine- (e.g., computer)-readable storage medium (e.g., read-only memory (“ROM”), random-access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine- (e.g., computer)-readable transmission medium (electrical, optical, acoustic, or other form of propagated signal (e.g., infrared signal, digital signal, etc.)), etc.

[0047] 6 illustrates a diagrammatic representation of a machine in an exemplary form, a computer system 600, within which a set of instructions may be executed to cause the machine to perform any one or more of the methodologies described herein. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a local area network (LAN), an intranet, an extranet, or the Internet. The machine may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a cellular phone, a web appliance, a server, a network router, switch, or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by the machine. Furthermore, although only a single machine is illustrated, the term "machine" should also be interpreted to include any collection of machines (e.g., computers) that individually or together execute a set (or sets) of instructions to perform any one or more of the methodologies described herein.

[0048] The exemplary computer system 600 includes a processor 602, a main memory 604 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 606 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory 618 (e.g., a data storage device), which communicate with each other via a bus 630.

[0049] Processor 602 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, etc. More specifically, processor 602 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing a combination of instruction sets. Processor 602 may also be one or more special-purpose processing devices, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), a network processor, etc. Processor 602 is configured to execute processing logic 626 for performing the operations described herein.

[0050] Computer system 600 may further include a network interface device 608. Computer system 600 may also include a video display unit 610 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 612 (e.g., a keyboard), a cursor control device 614 (e.g., a mouse), and a signal generation device 616 (e.g., a speaker).

[0051] The secondary memory 618 may include a machine-accessible storage medium (or more specifically, a computer-readable storage medium) 632 on which is stored one or more sets of instructions (e.g., software 622) that embody any one or more of the methodologies or functions described herein. The software 622 may also reside, completely or at least partially, within the main memory 604 and / or within the processor 602 during execution of the software 622 by the computer system 600, with the main memory 604 and the processor 602 also comprising machine-readable storage media. The software 622 may further be transmitted or received over the network 620 via the network interface device 608.

[0052] While machine-accessible storage medium 632 is shown in the exemplary embodiment to be a single medium, the term "machine-readable storage medium" should be interpreted to include a single medium or multiple media (e.g., centralized or distributed databases and / or associated caches and servers) that store one or more sets of instructions. The term "machine-readable storage medium" should also be interpreted to include any medium capable of storing or encoding a set of instructions for execution by a machine, causing the machine to perform any one or more of the methodologies of the present disclosure. The term "machine-readable storage medium" should therefore be interpreted to include, but not limited to, solid-state memory, and optical and magnetic media.

[0053] Thus, an electrostatic chuck (ESC) for a plasma processing chamber and a method for manufacturing the ESC have been disclosed.

Claims

1. a ceramic top plate having a top surface with a treatment area; one or more DC brazed connections in the ceramic top plate; one or more electrodes in the ceramic top plate; a plurality of mesas within the processing region and on the top surface of the ceramic plate; wherein none of the plurality of mesas is vertically above the one or more DC brazed connections or vertically above an edge of one of the one or more electrodes.

2. The substrate support assembly of claim 1 , wherein the plurality of mesas are contiguous with the top surface of the ceramic top plate.

3. The substrate support assembly of claim 1 , wherein the ceramic top plate comprises aluminum nitride.

4. The substrate support assembly of claim 1 , wherein the ceramic top plate comprises aluminum oxide.

5. The substrate support assembly of claim 1 , wherein the one or more electrodes comprise molybdenum.

6. a ceramic top plate having a top surface with a treatment area; a molybdenum mesh within the ceramic top plate; a nickel rod in the ceramic top plate and bonded to the molybdenum mesh by a metal paste, the nickel rod being at a distance greater than 1 mm from the top surface of the ceramic top plate; a plurality of mesas within the processing region and on the top surface of the ceramic plate; A substrate support assembly comprising:

7. The substrate support assembly of claim 6 , wherein the metal paste comprises tungsten or molybdenum.

8. The substrate support assembly of claim 6 , wherein the nickel rod is approximately 2 mm from the top surface of the ceramic top plate.

9. The substrate support assembly of claim 6 , wherein the ceramic top plate comprises aluminum nitride.

10. The substrate support assembly of claim 6 , wherein the ceramic top plate comprises aluminum oxide.

11. a ceramic top plate having a top surface with a treatment region, the top surface having one or more high topography regions; a plurality of mesas within the processing region and on the top surface of the ceramic plate; wherein none of the plurality of mesas overlies the one or more high topography regions of the top surface of the processing region.

12. The substrate support assembly of claim 11 , wherein the plurality of mesas are contiguous with the top surface of the ceramic top plate.

13. The substrate support assembly of claim 11 , wherein the ceramic top plate comprises aluminum nitride.

14. The substrate support assembly of claim 11 , wherein the ceramic top plate comprises aluminum oxide.

15. The substrate support assembly of claim 11 , further comprising one or more electrodes comprising molybdenum.

16. a ceramic top plate having a top surface with a treated region, the top surface having one or more high stress regions; a plurality of mesas within the processing region and on the top surface of the ceramic plate; wherein none of the plurality of mesas overlies the one or more high stress regions of the top surface of the processing region.

17. The substrate support assembly of claim 16 , wherein the plurality of mesas are contiguous with the top surface of the ceramic top plate.

18. The substrate support assembly of claim 16 , wherein the ceramic top plate comprises aluminum nitride.

19. The substrate support assembly of claim 16 , wherein the ceramic top plate comprises aluminum oxide.

20. The substrate support assembly of claim 16 , further comprising one or more electrodes comprising molybdenum.

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