Electrostatic chuck using a metal shaft

Abstract

An electrostatic chuck (ESC) for a plasma processing chamber and a method of manufacturing the ESC are described. In an example, a substrate support assembly includes a ceramic bottom plate, a ceramic top plate, and a bonding layer between the ceramic top plate and the ceramic bottom plate, where the ceramic top plate is in direct contact with the bonding layer and the bonding layer is in direct contact with the ceramic bottom plate. A metal shaft is bonded to the ceramic bottom plate on a side of the ceramic bottom plate opposite the bonding layer.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Patent Application No. 17 / 672,520, filed on February 15, 2022, which in turn claims the benefit of U.S. Provisional Patent Application No. 63 / 155,964, filed on March 3, 2021, the entire contents of which are hereby incorporated by reference.

[0002] Embodiments of the present disclosure relate to the field of reactors or plasma processing chambers, and more particularly to electrostatic chucks using a metal shaft.

Background Art

[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 by a support for processing. The substrate can be held by 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, from one or more power supplies coupled to the electrodes to the electrodes in the chamber. The excited gas or gas mixture reacts to form a layer of material on the surface of the substrate. The layer can be, for example, a passivation layer, a gate insulator, a buffer layer, and / or an etch stop layer.

[0004] In the semiconductor and other industries, an electrostatic chuck (ESC) is used to hold a workpiece, such as a substrate, on a support during processing of the substrate. 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 electrical 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 by an electrical voltage source with respect to a substrate disposed on the ESC. Opposite electrostatic charges accumulate in the electrodes of the ESC and on the surface of the substrate, and the insulating layer prevents the flow of charge therebetween. The electrostatic force resulting from the accumulation of electrostatic charge holds the substrate to the ESC during processing of the substrate.

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 the ESC.

[0006] In an embodiment, a substrate support assembly includes a ceramic bottom plate, a ceramic top plate, and a bonding layer between the ceramic top plate and the ceramic bottom plate, the ceramic top plate being in direct contact with the bonding layer and the bonding layer being in direct contact with the ceramic bottom plate. A metal shaft is coupled to the ceramic bottom plate on an opposite side of the bonding layer of the ceramic bottom plate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3

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Figure 6

[0008] An electrostatic chuck (ESC) for a plasma processing chamber and a method of manufacturing the ESC are described. In the following description, numerous specific details, such as electrostatic chuck components and material conditions, are set forth in order 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 obscure embodiments of the present disclosure unnecessarily. Additionally, it should be understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.

[0009] One or more embodiments are directed to a vorted axis metal bonded edge purge electrostatic chuck. Embodiments may be implemented to manufacture an ESC using a separate shaft.

[0010] According to one or more embodiments of the present disclosure, an insert is included inside the ceramic portion of an ESC to hold a clamping ring and a shaft. The shaft and the ceramic plate are separate. Embodiments may be implemented to provide a metal shaft with a ceramic plate. Embodiments may be implemented to address cost and / or the need for edge purge. Certain embodiments can include a ceramic (such as a metal oxide or a metal nitride) for use as an ESC on a metal shaft separated by one or more O-rings. The temperature range of the ESC can be adjusted by changing the properties of the upper plate. The upper plate can be configured to hold a clamping ring on the upper plate.

[0011] In an embodiment, the ceramic portion is separated into two parts, then metallurgically bonded to the internal insert, and then attached to the shaft and the clamping ring. In one embodiment, an edge ring is bolted to the insert. In certain embodiments, the use of three locator pins is implemented to accurately maintain the position on the ESC. A ceramic or metal covering can be used on the ESC. In one embodiment, the ring creates a gap so that gas is purged to the back edge of the ESC, is bolted to the insert, and is aligned using three accurate pins.

[0012] As an exemplary manufacturing method, FIG. 1A illustrates a process for manufacturing an electrostatic chuck (ESC) according to an embodiment of the present disclosure.

[0013] Referring to part (a) of FIG. 1A, the manufacture of the substrate support assembly includes joining a ceramic bottom plate 102 (which can be a groove plate and can include a heater) and a ceramic top plate 108 (which can include a heater) using a bonding layer 112. In one embodiment, the bonding layer 112 is a metal layer between the ceramic top plate 108 and the ceramic bottom plate 102, the ceramic top plate 108 is in direct contact with the bonding layer 112, and the bonding layer 112 is in direct contact with the ceramic bottom plate 102. Inserts 152 and 154 can be included within the ceramic bottom plate 102, the ceramic top plate 108, and the bonding layer 112. The ceramic bottom plate 102 can include a facility line 150 bonded to the bottom surface of the ceramic bottom plate 102.

[0014] Referring to part (b) of FIG. 1A, a metal shaft 106 is coupled to an assembly 160 by a ceramic bottom plate 102 at a side of the ceramic bottom plate 102 opposite the bonding layer 112. Also, it should be understood that the ceramic top plate can include other features 162, such as an upper groove (or channel) for accommodating a cooling gas flow that aligns across a passage for gas in the bonding layer and the upper ceramic so that gas is delivered behind the wafer or for edge purge. The metal shaft 106 can include an opening 166 for accommodating an O-ring 164 and a bolt 156. Referring to part (c) of FIG. 1A, an ESC 170 results from the coupling of part (b) of FIG. 1A.

[0015] As an exemplary structure, FIG. 1B illustrates an enlarged view of the components of an electrostatic chuck (ESC) according to an embodiment of the present disclosure.

[0016] Referring to FIG. 1B, the structures of FIG. 1A are shown relative to each other. An enlarged view of inserts 152 and 154 and bolt 156 is depicted. Insert 152 can be a helical coil configured to hold a clamping ring or a covering ring. Insert 154 can be, for example, a helical coil configured to hold shaft 106 to bottom plate 102 by bolt 156.

[0017] As an exemplary manufacturing method, FIG. 2A illustrates a process for manufacturing an electrostatic chuck (ESC) according to an embodiment of the present disclosure.

[0018] Referring to part (a) of FIG. 2A, a clamping ring, a covering ring or an edge ring 172 is provided on the structure 170 of FIG. 1A. Bolt 174 is used to couple the clamping ring, the covering ring or the edge ring 172 to the structure 170 to form an ESC.

[0019] As an exemplary manufacturing method, FIG. 2B illustrates a cross-sectional view of a portion of an electrostatic chuck (ESC) including a covering ring on an upper ceramic plate according to an embodiment of the present disclosure.

[0020] Referring to FIG. 2B, a clamping ring, a covering ring or an edge ring 172 provides a gap 180 between the clamping ring, the covering ring or the edge ring 172 and the ceramic upper plate 108. The gap 180 can enable edge purge of a substrate supported by the electrostatic chuck.

[0021] To further explain, generally, diffusion bonding is a costly process, and heating to such high temperatures affects the thermal and / or electrical properties of the ceramic. State-of-the-art ESCS are typically manufactured using two diffusion bonds, namely, one diffusion bond between the top plate and the bottom plate, and a second diffusion bond between the bonded plates and the shaft. It should be understood that the use of too many diffusion bonds formed at high temperatures can affect the ceramic resistivity. The embodiments described herein can be implemented to eliminate the need for diffusion bonding. The embodiments can be implemented to ensure that the top plate does not change (or only minimally changes) the resistivity during the manufacture of the ESC. The embodiments can be implemented to advantageously reduce the cost of ESC manufacture since at least one high-temperature operation is removed from the manufacturing process. The embodiments can be implemented to maintain or sustain the sintering resistivity of the top ceramic material.

[0022] Advantages of implementing one or more embodiments described herein can include the use of a low-cost metal shaft instead of a high-cost ceramic shaft. The embodiments can enable the manufacture of an ESC with no resistivity change. The advantages can include a reduced manufacturing cost for the ESC. The advantages can include enabling the possibility of manufacturing the ESC to maintain the electrical properties of the components included therein.

[0023] Compared to state-of-the-art techniques that can include two diffusion bonds, according to embodiments of the present disclosure, an aluminum bond is used instead of one of the typical diffusion bonds. For example, an aluminum bond can be used between the top plate and the bottom plate. A metal shaft with an O-ring can be used to replace the ceramic bond between the ceramic shaft and the ceramic bottom plate.

[0024] More generally shown, as an example of a manufactured ESC, FIG. 3 illustrates a cross-sectional view of an electrostatic chuck (ESC) according to embodiments of the present disclosure.

[0025] Referring to FIG. 3, the ESC 300 includes a ceramic bottom plate 302 having a heater coil 304 therein. The heater coil 304 can be coupled to a heater connection 305 (in another embodiment, it should be understood that heater electrodes are screen printed in the case of tape-cast AlN or AlN plate materials used for ESC manufacturing). A metal shaft 306 is coupled to the bottom surface of the ceramic bottom plate 302. An O-ring can be included between the metal shaft 306 and the bottom surface of the ceramic bottom plate 302. The ESC 300 also includes a ceramic top plate 308. The ceramic top plate 308 has an ESC (clamping) electrode 310 or an electrode assembly therein. A metal layer 312 couples the ceramic top plate 308 to the top surface of the ceramic bottom plate 302. A thermocouple 314 extends through openings 315 in the ceramic bottom plate 302 and in the metal layer 312. A high voltage insulation 316 extends through the openings 315 in the ceramic bottom plate 302 and in the metal layer 312 to house an ESC high voltage connection 318. A covering 399, such as that described in connection with FIGS. 2A-2B, can be coupled to the ceramic top plate 308.

[0026] Referring again to FIG. 3, according to an embodiment of the present disclosure, the 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, and the metal layer 312 is in direct contact with the ceramic bottom plate 302.

[0027] In an embodiment, the metal layer 312 provides for the incorporation of a metallic bond instead of a ceramic-ceramic diffusion bond that could otherwise change the resistivity of the upper ceramic during the formation of the diffusion bond. In one embodiment, the metal layer 312 is a metal foil, such as an aluminum foil. In one such embodiment, the metal layer 312 is an aluminum foil impregnated with about 2% to 20% Si (e.g., as atomic % of the total foil composition), with the balance being aluminum or essentially all aluminum (in other words, the aluminum foil contains silicon having an atomic concentration within the range of 2% to 20% of the aluminum foil). In an embodiment, the metal layer 312 is pre-patterned to include an opening 315 and / or additional openings for accommodating, for example, lift pins. In one embodiment, the metal layer 312 is an aluminum foil having a thickness in the range of 50 to 500 microns and can be about 250 microns. In an embodiment, the metal layer 312 is an aluminum foil and is cleaned prior to encapsulation in an ESC manufacturing process, for example, to remove a passivation layer prior to bonding. In an embodiment, the metal layer 312 is an aluminum foil and can withstand a corrosive process, such as a chlorine-based process, without etching or degradation of the metal layer 312 while the ESC is in use. However, when used for a non-chlorine-based process, the metal layer 312 can be composed of a silver-copper alloy, for example, with or without the addition of titanium. In an embodiment, the metal layer 312 is bonded to the upper plate 308 and the bottom plate 302 at a temperature below 600 degrees Celsius, more particularly below 300 degrees Celsius. It should be understood that higher ESC use temperatures, such as 650 degrees Celsius, can be used when the metal bonding is carried out using a high-temperature metal bond, such as a silver-copper or gold-nickel temperature, that is much lower than 1400 degrees Celsius but well above the 650 degrees Celsius use temperature.

[0028] Regarding the ceramic top plate 308 having an ESC (clamping) electrode 310 therein, in an embodiment, the body of the top plate can be formed by sintering a ceramic material such as aluminum nitride (AlN) or aluminum oxide powder or other suitable materials. An RF mesh can be embedded in the body. The RF mesh can have an electrical connection extending through the bottom surface of the body. The RF mesh can include a mesh of molybdenum or another suitable metallic material. In one embodiment, the mesh is a mesh with a diameter of about 125 microns. The materials can be sintered to form a single structure. In one embodiment, the electrode 310 can be made of a metallic material having a coefficient of thermal expansion similar to that of the body, for example, molybdenum. In an embodiment, the ceramic top plate 308 is targeted to withstand temperatures below 350 degrees Celsius, for example, between 150 and 300 degrees Celsius, and can include dopants to optimize operation within such a targeted temperature range.

[0029] 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 the substrate disposed thereon in a fixed position. When the power supplied from the power source is turned off, the charges present in the interface between the electrodes can be maintained over a long time period. To release the substrate held on the electrostatic chuck, a short pulse of power of the opposite polarity can be provided to the electrodes to remove the charges present in the interface.

[0030] The electrode assembly can be formed by a metal bar, sheet, stick, foil and can be preformed, pre-cast, pre-manufactured and disposed on the surface of an insulating base during the manufacture of the electrostatic chuck. Alternatively, a metal deposition process can be implemented to deposit and form the electrode assembly directly on the upper surface of the insulating base. Suitable deposition processes can include PVD, CVD, plating, inkjet printing, rubber stamping, screen printing or aerosol printing processes. Additionally, a metal paste / metal line can be formed on the upper surface of the insulating base. The metal paste / metal line can initially be a liquid, paste or metal gel that is patterned on the surface of an object in a pattern for forming electrode fingers having different configurations or dimensions on the upper surface of the insulating base.

[0031] The ceramic top plate 308 or the ceramic bottom plate 302 can include, but are not limited to, aluminum nitride, glass, silicon carbide, aluminum oxide, yttrium-containing materials, yttrium oxide (Y 2 O 3) may include yttrium aluminum garnet (YAG), titanium oxide (TiO), or titanium nitride (TiN). With respect to the ceramic bottom plate 302, in an embodiment, the ceramic bottom plate 308 is targeted to withstand a temperature of up to 650 degrees Celsius and may include a dopant to optimize operation within such a targeted temperature range. In one embodiment, the ceramic bottom plate 302 has an aluminum nitride composition different from that of 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, titanium, etc. In one embodiment, the heating element 304 is composed of a molybdenum wire. The heating element 304 may be manufactured using a material having thermal properties, such as a coefficient of thermal expansion, that substantially match at least one or both of the aluminum nitride bodies to reduce the stress caused by mismatched thermal expansion.

[0032] In an embodiment, the ceramic top plate 308 is manufactured and then bonded to the ceramic bottom plate by a 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 as the metal layer 312 is bonded to the ceramic bottom plate 302. In another embodiment, first, the metal layer 312 is bonded to the ceramic top plate 308, and then the ceramic top plate / metal layer 312 pairing is bonded to the ceramic bottom plate 302. In another embodiment, first, the metal layer 312 is bonded to the ceramic bottom plate 302, and then the ceramic bottom plate / metal layer 312 pairing is bonded to the ceramic top plate 308. In any case, in a particular embodiment, the ceramic top plate is sintered aluminum nitride (AlN) or aluminum oxide (Al 2 O 3)It is formed from a powder and a metal mesh.

[0033] In an embodiment, bonding the ceramic top plate 308 to the ceramic bottom plate 302 using the metal layer 312 includes heating the ceramic bottom plate 302, the metal layer 312, and the ceramic top plate 308 to a temperature below 600 degrees Celsius. In an embodiment, the metal layer 312 is an aluminum foil, and the method includes cleaning the surface of the aluminum foil to remove the passivation layer of the aluminum foil before bonding the ceramic top plate 308 to the ceramic bottom plate 302 using the metal layer 312.

[0034] 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 within the processing volume 406. The processing volume 406 is accessed through a sealable slit valve opening 408 formed through the sidewall 402, whereby the 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.

[0035] The gas distribution plate 410 is coupled to the cover plate 412 at the outer periphery of the gas distribution plate 410. A gas source 420 is coupled to the cover plate 412 to provide one or more gases through the cover plate 412 into a plurality of gas passages 411 formed in the cover plate 412. The gas flows through the gas passages 411 into the processing volume 406 towards the substrate receiving surface 432.

[0036] The RF power supply 422 is coupled to the cover plate 412 by the RF power supply 424 and / or directly to the gas distribution plate 410 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. The RF return path 425 couples the substrate support assembly 428 to the RF power supply 422 through the sidewall 402. The RF power supply 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 the electrical circuit for the RF energy to prevent the floating plasma from causing RF arcing due to the voltage difference between the substrate support assembly 428 and the sidewall 402. Thereby, the RF return path 425 mitigates arcing that causes process drift, particle contamination, and damage to chamber components.

[0037] 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 facilitate movement of the substrate 405 onto and from the substrate receiving surface 432. An actuator 414 is utilized to extend and retract the lift pins 438. A ring assembly 433 can be disposed across the outer periphery of the substrate 405 during processing. The ring assembly 433 is configured to prevent or reduce unwanted deposition on the surface of the substrate support 430 that is not covered by the substrate 405 during processing.

[0038] 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 below or at less than about 800 degrees Celsius 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 embodiments, the substrate support 430 / substrate support assembly 428 is as described above in connection with FIGS. 1A-1B, FIGS. 2A-2B, and FIG. 3.

[0039] In another aspect, FIG. 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, bottom 504, and showerhead 512 define an internal volume 506. In embodiments, the substrate support assembly 300, such as that described in connection with FIGS. 1A-1B, FIGS. 2A-2B, FIG. 3, is disposed within the internal 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 plasma is present. Advantageously, an RF ground path for maintaining the plasma can be maintained, providing a long life for the substrate support assembly 300.

[0040] In an embodiment, the semiconductor wafer or substrate supported by the substrate support assembly 300 is composed of a material suitable for withstanding the manufacturing process and on which a semiconductor processing layer can be appropriately 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-crystalline silicon substrate. In a particular embodiment, the single-crystalline silicon substrate is doped with impurity atoms. In another embodiment, the semiconductor wafer or substrate is composed of a III-V material.

[0041] Embodiments of the present disclosure may be provided as a computer program product or software that may include a machine-readable medium storing instructions, which may be used to program a computer system (or other electronic device) to perform a process according to embodiments of the present disclosure. In one embodiment, the computer system is coupled with the process chamber 400 and the substrate support assembly 428 described above in connection with FIG. 4, or the processing chamber 500 and the substrate support assembly 300 described in connection with FIG. 5. The machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, the 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 forms of propagated signals (e.g., infrared signals, digital signals, etc.)), and the like.

[0042] FIG. 6 illustrates a diagrammatic representation of a machine in an exemplary form of computer system 600 within which a set of instructions, which when executed cause a machine to perform any one or more of the methodologies described herein, may be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a local area network (LAN), intranet, 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), tablet PC, set-top box (STB), personal digital assistant (PDA), cellular telephone, web appliance, server, network router, switch or bridge, or any machine capable of executing a set (sequential or otherwise) of instructions that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be construed to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein.

[0043] The exemplary computer system 600 includes a processor 602, main memory 604 (e.g., dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), Rambus DRAM (RDRAM), etc., read only memory (ROM), flash memory), static memory 606 (e.g., flash memory, static random access memory (SRAM), etc.), and secondary memory 618 (e.g., data storage device), which communicate with each other via bus 630.

[0044] Processor 602 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, etc. More specifically, processor 602 can 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 can also be one or more dedicated 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.

[0045] 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).

[0046] Secondary memory 618 may include a machine-accessible storage medium (or more specifically, a computer-readable storage medium) 632 in which one or more sets of instructions (e.g., software 622) embodying any one or more of the methodologies or functions described herein are stored. Software 622 may also reside, in whole or at least in part, within main memory 604 and / or within processor 602 during execution of software 622 by computer system 600, and main memory 604 and processor 602 also constitute a machine-readable storage medium. Software 622 may further be transmitted or received over network 620 via network interface device 608.

[0047] The machine-accessible storage medium 632 is shown in an exemplary embodiment as a single medium, but the term "machine-readable storage medium" should be interpreted to include a single medium or a plurality of media (e.g., a centralized or distributed database, and / or associated cache and server) that store one or more sets of instructions. The term "machine-readable storage medium" should also be interpreted to include any medium that is capable of storing or encoding a set of instructions for machine execution and that causes a 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, without limitation, solid state memory, as well as optical and magnetic media.

[0048] As described above, an electrostatic chuck (ESC) for a plasma processing chamber, and a method of manufacturing the ESC have been disclosed.

Claims

**Claim 1**: A substrate support assembly comprising: a ceramic bottom plate including a gas groove in an upper surface thereof; a ceramic upper plate; a bonding layer between the ceramic upper plate and the ceramic bottom plate, wherein the ceramic upper plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate; and a metal shaft bonded to the ceramic bottom plate on a surface of the ceramic bottom plate opposite to the bonding layer. **Claim 2**: A substrate support assembly comprising: a ceramic bottom plate; a ceramic upper plate including a gas groove in a bottom surface thereof; a bonding layer between the ceramic upper plate and the ceramic bottom plate, wherein the ceramic upper plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate; and a metal shaft bonded to the ceramic bottom plate on a surface of the ceramic bottom plate opposite to the bonding layer. **Claim 3**: A substrate support assembly comprising: a ceramic bottom plate; a ceramic upper plate; a bonding layer between the ceramic upper plate and the ceramic bottom plate, wherein the ceramic upper plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate; a metal shaft bonded to the ceramic bottom plate on a surface of the ceramic bottom plate opposite to the bonding layer; and a cover ring on the ceramic upper plate, wherein the cover ring is made of a metal or ceramic material. **Claim 4**: A substrate support assembly comprising: a ceramic bottom plate; a ceramic upper plate; a bonding layer between the ceramic upper plate and the ceramic bottom plate, wherein the ceramic upper plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate, and the bonding layer is an aluminum foil containing silicon having an atomic concentration in the range of 2% to 20% of the aluminum foil; and a metal shaft bonded to the ceramic bottom plate on a surface of the ceramic bottom plate opposite to the bonding layer. ​ ​ A substrate support assembly comprising

5. The substrate support assembly according to any one of claims 1 to 4, wherein the ceramic bottom plate has a heater element therein, and the ceramic top plate has an electrode therein.

6. The substrate support assembly according to any one of claims 1 to 4, wherein the ceramic top plate has a heater element and an electrode therein.

7. An O-ring between the metal shaft and the ceramic bottom plate The substrate support assembly according to any one of claims 1 to 4, further comprising

8. The substrate support assembly according to claim 4, wherein the aluminum foil has a thickness in the range of 50 to 500 microns.

9. A chamber, A plasma source in or coupled to the chamber, An electrostatic chuck in the chamber Comprising, wherein the electrostatic chuck A ceramic bottom plate including a gas groove in the upper surface of the ceramic bottom plate, A ceramic top plate, A bonding layer between the ceramic top plate and the ceramic bottom plate, wherein the ceramic top plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate, A metal shaft coupled to the ceramic bottom plate on the surface of the ceramic bottom plate opposite to the bonding layer A system comprising

10. A chamber, A plasma source in or coupled to the chamber, An electrostatic chuck in the chamber Comprising, wherein the electrostatic chuck A ceramic bottom plate, A ceramic top plate including a gas groove in the bottom surface of the ceramic top plate, A bonding layer between the ceramic top plate and the ceramic bottom plate, wherein the ceramic top plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate, A metal shaft coupled to the ceramic bottom plate on the surface of the ceramic bottom plate opposite to the bonding layer A system comprising

11. A chamber, A plasma source in or coupled to the chamber, An electrostatic chuck in the chamber Comprising, wherein the electrostatic chuck A ceramic bottom plate, A ceramic top plate, A bonding layer between the ceramic upper plate and the ceramic bottom plate, wherein the ceramic upper plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate, the bonding layer; A metal shaft bonded to the ceramic bottom plate on the surface of the ceramic bottom plate on the side opposite to the bonding layer; A system further comprising a covering on the ceramic upper plate, the covering comprising a metal or ceramic material.

12. A chamber; A plasma source inside the chamber or coupled to the chamber; An electrostatic chuck inside the chamber Comprising, the electrostatic chuck being A ceramic bottom plate; A ceramic upper plate; A bonding layer between the ceramic upper plate and the ceramic bottom plate, wherein the ceramic upper plate is in direct contact with the bonding layer, and the bonding layer is in direct contact with the ceramic bottom plate, the bonding layer being an aluminum foil, and the aluminum foil containing silicon having an atomic concentration within the range of 2% to 20% of the aluminum foil, the bonding layer; A metal shaft bonded to the ceramic bottom plate on the surface of the ceramic bottom plate on the side opposite to the bonding layer Comprising, a system.

13. The system according to any one of claims 9 to 12, wherein the ceramic bottom plate of the electrostatic chuck has a heater element therein, and the ceramic upper plate has an electrode therein.

14. The system according to any one of claims 9 to 12, wherein the ceramic upper plate of the electrostatic chuck has a heater element and an electrode therein.

15. The electrostatic chuck being An O-ring between the metal shaft and the ceramic bottom plate Further comprising, the system according to any one of claims 9 to 12.

16. The system according to claim 12, wherein the aluminum foil has a thickness within the range of 50 to 500 microns.

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